identifier: Chow, Virginia  (2004) Infants' attribution of agent and recipient roles to animate and inanimate objects in a causal event.  Masters thesis, Concordia University.

abstract: Research on the perception of causality suggests that infants' ability to perceive causal events develops during the first year of life (Oakes, 2003). However, few studies have investigated whether infants associate the role of an agent with animate beings and the role of a recipient with inanimate objects in a causal event. Using an infant-controlled habituation procedure, the aims of the present two experiments were to examine whether (a) infants are able to detect a role-reversal in a causal event featuring animals and furniture items and (b) infants are able to detect an incongruent role-reversal in which an inanimate object plays the role of an agent. Results of Experiment 1 revealed that 16-month-old infants who had habituated to causal events involving animal agents and furniture recipients looked longer at the test trial, in which the roles were reversed relative to the habituation events, than at the test trial, in which the roles were maintained. Results from Experiment 2 revealed that when infants were habituated to category-congruent causal events, 19-, but not 13-, month-old infants looked longer at the test event featuring an incongruent role-reversal than at the test event featuring a congruent role-reversal. Overall, these results indicate that infants are able to perceive a role-reversal between animals and furniture, and that by 19 months of age, infants are able to associate agent-recipient roles with the appropriate category. These results shed light on infants' developing knowledge of causal events as well as their conceptualization of animates and inanimates.


identifier: Qu, Zhenqian  (2004) Noise statistics in optically pre-amplified DPSK receivers with optical Mach-Zehnder interferometer demodulation.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: A comprehensive theoretical analysis of noise statistics in optically pre-amplified DPSK receivers with optical Mach-Zehnder interferometer demodulation is presented for the first time. For such a receiver, there are three dominant noise sources which degrade the performance of DPSK systems: signal-ASE beat noise, ASE-ASE beat noise, and nonlinear phase noise. The first two noise sources are added to the signal, and thus they can be referred to as linearly additive noise. The detailed derivations of the exact noise statistics considering both the linearly additive noise and nonlinear phase noise are given in this thesis. Due to simplicity, the Gaussian approximation has been widely used in the case of optical systems with intensity modulation and direct detection (IM/DD). Therefore, the Gaussian approximation of noise statistics is also given and compared with the exact noise statistics in DPSK receivers. Numerical calculations show that the exact noise statistics are quite different from the Gaussian approximation, particularly for DPSK receivers with balanced detection. The numerical results of probability density functions and bit error rate with the exact noise statistics are in good agreement with the published experimental results. A comparative study of noise statistics in both DPSK and IM/DD receivers is also given.


identifier: Cormack, Gregory  (2004) An EST-based genomics project in potato : solanum tuberosum.  Masters thesis, Concordia University.

abstract: Expressed sequence tags (ESTs) are partial DNA sequences generated from either the 5 ' or the 3 ' end of cDNA clones. Many large scale cDNA sequencing projects generating thousands of ESTs have been performed. Such EST collections can reflect a substantial proportion of the expressed genes of a species under a given set of conditions. Two potato cDNA libraries derived from pathogen challenged tissue were enriched by virtual subtraction and single pass sequencing of selected clones resulted in 4,795 EST sequences. 4,184 unigenes (3,305 singletons + 879 contigs) were discovered from grouping the ESTs into clusters and contigs. The virtual subtraction enrichment before sequencing of the cDNA libraries was found to be highly effective at reducing EST redundancy and enriching for ESTs of genes expressed at low levels, namely transcription factor genes. As much as 30 fold decreases in the numbers of ESTs representing certain highly expressed genes were observed while some transcription factor ESTs were up to 10 times more abundant than in public EST sets developed from randomly selected clones. In addition, the EST collection was analyzed for percent full length cDNA composition corresponding to genes of different lengths. A potato microarray was constructed from the enriched set of cDNA clones. The B2 gene of potato, a gene believed to be involved in its disease response, was cloned into the gene overexpression vector pRD526 and into the RNAi gene silencing vector pDARTHVECTOR. The constructs were each transformed into Agrobacterium tumefaciens . Future studies conducted using transgenic plants made from these constructs and the microarray will enable the elucidation of the function of B2 through the discovery of interactions between B2 and other disease response genes.


identifier: Jiang, Tao  (2004) Nonlinear fault diagnosis and recovery for satellites using parameter estimation techniques.  Masters thesis, Concordia University.

abstract: This thesis focus is emphasized on the nonlinear fault diagnosis and recovery problems for both the satellite's orbital model and the satellite's attitude model through construction of residual generators that are based on least-squares parameter estimation techniques. By viewing system anomaly caused by faults and/or malfunctions as changes of certain parameters in the system, our goal is to detect, isolate and recover from the faults through estimating these parameters and adaptively redesigning the controllers. Given that the system with the triggered recovery procedure will be different from the system without it, two different fault detection and isolation subsystems are considered and applied to the different cases. The convergence properties of these two subsystems are shown analytically. Furthermore, the robustness properties of these residual generators are investigated, and subsequently, the corresponding decision logic and thresholds for the fault diagnosis are properly selected and specified. (Abstract shortened by UMI.)


identifier: Shi, Ying  (2004) Modulation of renal autoregulation by nitric oxide - cellular mechanism.  Masters thesis, Concordia University.

abstract: Normal renal function requires stable renal blood flow. It is achieved by autoregulation. Nitric oxide contributes to the regulation of multiple pathways that are relevant to myogenic autoregulation. We examined the signal transduction mechanism of nitric oxide on myogenic autoregulation in the present thesis.  Because some paracrine factors contribute to the renal autoregulation, we first isolate the effects of nitric oxide from other paracrine factors. The pressor and renal vasoconstrictor responses to nitric oxide synthase inhibition are independent of angiotensin II. There is an interaction between nitric oxide and endothelin, mediated by endothelin B receptors, that affects renal blood flow and renal autoregulation.  Y-27632, Rho-kinase inhibitor reverses completely the enhanced myogenic autoregulation by L-NAME, and L-NAME does not affect the myogenic autoregulation pre-treated by Y27632.  In conclusion, the effect of Rho-kinase with consequent inhibition of myosin light chain phosphatase may be an essential component of the modulation of myogenic autoregulation by nitric oxide. Therefore, the signal transudation of nitric oxide on renal autoregulation passes through Rho-kinase pathway.


identifier: Martinuk, Matthew J. M  (2004) Eriugena and the re-enchantment of nature.  Masters thesis, Concordia University.

abstract: This work is an attempt to show the similarities between the concept of nature held by Eriugena and Heidegger. This similarity provides the basis for both a criticism of the view of nature held by recent epistemology and a criticism of recent epistemology's view of medieval thought. These criticisms open the way for a modern understanding of nature in terms of the Good, that is, a re-enchantment of nature. This re-enchantment centers upon the development of the modern sciences, both natural and historical, and the effect that these have had upon metaphysics. The re-enchantment of nature discussed in this work is not an attempt to dismiss modern science in favour of medieval science. Instead, it is an attempt to re-capture the notion that human nature or the self can only be understood in relation to the Good and, in so far as human nature is a part of nature itself, an understanding of the self in terms of the Good is also an understanding of nature in terms of the Good.


identifier: Wang, Shan  (2004) Localization of the cell division proteins in filaments resulting from a lack of S-adenosylmethionine in Escherichia coli K-12.  Masters thesis, Concordia University.

abstract: The metK gene of Escherichia coli encodes S-adenosylmethionine synthetase, which catalyzes the biosynthesis of S-adenosylmethionine (SAM), the primary methyl group donor. A partial defect in metK expression caused by a point mutant in its promoter leads to a decrease in the cellular SAM concentration, resulting in a block in cell division. Thus metK mutants form filaments with regularly distributed nucleoids.  This thesis aims to find out the division step at which cell division process stops. Herein I examine localization of 8 division proteins in metK84 filaments. The results show that early division proteins, FtsZ, FtsA and ZipA, are able to establish themselves in the septum, while the late proteins, FtsQ, FtsW, FtsI and FtsN, fail to localize. FtsK localizes to the septum at some extent, but the result is uncertain. Further study of FtsK localization in metK84 filaments is required. This localization study suggests that metK84 filamentation is caused by the failure of FtsQ or FtsK to localize to the septum during the cell division process.


identifier: Fu, Chunyan  (2004) Signaling for multiparty sessions in peer-to-peer ad hoc networks.  Masters thesis, Concordia University.

abstract: Multiparty sessions are the basis of several important applications. Audio/video conferencing, distance learning and gaming are some of the examples. So far, very little attention has been devoted to the applications for ad hoc networks. In contrast to conventional networks, ad hoc networks are formed by a set of devices that communicate without using a pre-existing network infrastructure. Multiparty session control faces new challenges in ad hoc networks: peer-to-peer communication, limited resources and transient network connectivity. This thesis addresses the most critical component of multiparty sessions in peer-to-peer ad hoc networks: signaling. Signaling requirements are derived and existing signaling protocols such as SIP, H.323 and ICEBERG signaling are analyzed. By discussing and comparing alternative signaling architectures, we propose a novel signaling scheme based on clustering architecture. The signaling scheme is implemented as an extension to SIP. A prototype is built to evaluate the feasibility and performance of the signaling scheme.


identifier: Podder, Chandra Nath  (2004) Approximation of absolutely continuous invariant measures for Markov compositions of maps of an interval.  Masters thesis, Concordia University.

abstract: We study the approximation of absolutely continuous invariant measures of systems defined by random compositions of piecewise monotonic transformation (Lasota-Yorke maps). We discuss a generalization of Ulam's finite approximation conjecture to the situation where a family of piecewise monotonic transformations are composed according to a Markov law, and study an analogous convergence result. Also, we present bounds for the L 1 error of the Ulam's approximation.


identifier: Carter, David  (2004) Interactions between canine plasminogen and ANS : structural insight into the binding determinants of a fluorescent probe.  Masters thesis, Concordia University.

abstract: The canine variant of the serum protein, plasminogen (DPgn) binds the fluorescent molecule, 8-anilino-l-naphthalene sulfonate (ANS). Binding is pronounced at low pH, as witnessed by steady-state fluorescence, native PAGE and isothermal titration calorimetry. At pH 6.3 ANS binding occurs, but with a largely diminished magnitude. Binding occurs at multiple sites. A strong site binds ANS with a K a of 3.3 {604} 10 4 M -1 . Two weaker sites were observed with K a 's of 6.2 {604} 10 3 M -1 and 360 M -1 respectively. ANS binds equally well to both the closed and opened conformations of DPgn at pH 3.0. Enhanced binding at low pH is accompanied with changes in protein flexibility as monitored by sedimentation velocity analysis. Changes in frictional ratios were observed indicating an increased flexibility for both conformations of DPgn at pH 3.0 compared to pH 6.3. This finding was confirmed from the observation of altered near UV circular dichroism spectra of the protein at low pH. Taken together, the data indicate that ANS may be binding to a pH induced molten globule state of DPgn. Binding sites for ANS were localized within kringle domains as well as the proteolytic domain. However, it is unlikely that binding occurs within the lysine binding sites of each respective kringle.


identifier: Boju, Lorena  (2004) Expression, purification, crystallization and preliminary X-ray analysis of PR-AMP cyclohydrolase : a zinc binding enzyme from methanobacterium thermoautotrophicum.  Masters thesis, Concordia University.

abstract: Histidine is an essential amino acid since humans and other higher eukaryotes lack the cellular biosynthetic machinery for its manufacture. Phosphoribosyl-AMP cyclohydrolase (PRA-CH, EC 3.5.4.19) is the third enzyme in the histidine biosynthetic pathway. PRA-CH catalyzes the hydrolysis of the N1-C6 bond of the purine substrate N1-(5 ' -phosphoribosyl)adenosine 5 ' -monophosphate (PR-AMP). The enzyme from Methanobacterium thermoautotrophicum , overexpressed in E. coli , was selected for crystallization trials as steps towards obtaining its three dimensional structure by X-ray diffraction.  Initial attempts of purifying the recombinant hexa histidine tag protein were not successful. A new construct encoding for PRA-CH without the His-tag was made, overexpressed in E. coli and purified to homogeneity using heat treatment followed by one chromatographic step. Yields of 50-60 mg were obtained per liter of culture. The enzyme was shown by Dynamic Light Scattering studies to form a homodimer of 31 500 Da.  Crystals of the protein were formed at an unusually low concentration of 2.1 mg/ml by the vapour-diffusion method using sodium acetate as precipitant. The presence of 50 mM Cd(SO 4 ) 2 in the reservoir solution was essential for the crystallization of the protein. Crystals appeared within two weeks at room temperature. They belong to the orthorhombic system, space group P2 1 2 1 2 1 , with cell dimensions a = 39.7Å, b = 54.3Å, c = 117.3Å, [Special characters omitted.] = [up down arrow] = [white square] = 90{493}. These crystals diffracted to 1.76Å at the synchrotron beamline. Several attempts to determine the 3-D structure of PR-AMP cyclohydrolase by multiwavelength anomalous dispersion were unsuccessful. Following completion of the thesis, however, the structure was eventually solved by single wavelength anomalous dispersion.


identifier: Kanade, Sudhan  (2004) A novel approach for generating test suites for component-based safety critical systems.  Masters thesis, Concordia University.

abstract: Safety-critical system is a class of systems whose failure may cause severe consequences as such systems have absolute demands regarding correctness of functional as well as timing behavior of the system. Our proposed CAGILY framework introduces a formal framework for identifying a set of test cases from a well-specified system to validate critical functionalities of the system. This framework incorporates the concept of component identification and specification, and defines contracts/morphisms by adapting the theories of constraint cross-product in category theory to generate sets of comprehensive test suites. The formalization of the system is provided by specifying the system composition using the specification and verification tool called Specware. Further, we have developed and implemented Sampuma tool, which generates a set of test cases depending on the constraints imposed on the system. We illustrate the effectiveness of our proposed approach by applying it to a case study of mine pump problem. The important feature of our approach is that, we have been able to decompose the system depending upon their functional requirements and then testing the system for its critical functionality. (Abstract shortened by UMI.)


identifier: Anzellotti, Dominique  (2004) Biochemical and molecular characterization of a novel dioxygenase, flavonol 6- hydroxylase, involved in flavonol biosynthesis from chrysosplenium americanum.  PhD thesis, Concordia University.

abstract: Plants synthesize a vast array of natural products, collectively known as secondary metabolites, of which flavonoids constitute an important group. Flavonoid compounds are ubiquitous in Nature and play important roles in plant physiology, development and the plant's interaction with its environment. They contribute to flower color, ultraviolet protection, cell signalling and defence against plant pathogen attack, in addition to their potential benefits to mammalian organisms. In most cases, structure-activity relationships have been observed and, therefore, modification of the substitution pattern of certain compounds may enhance the quality and/or performance of plants through metabolic engineering.  Chrysosplenium americanum , a semi-aquatic weed, elaborates a variety of highly methylated flavonoids that are synthesized by regio-specific enzymes, and are believed to protect the plant against microbial attack. Several of the substitution reactions involved in the proposed pathway of their biosynthesis previously have been elucidated. One of the enzymes involved at the branchpoint of this pathway, the flavonol 6-hydroxylase (F6H) has been the primary focus of this research. The novelty of this enzyme lies in the fact that it is the only reported {460}-ketoglutarate-dependent dioxygenase that introduces a phenolic hydroxyl group on the flavonoid ring; more specifically at position 6 of trimethylquercetin, which is subsequently methylated. The dioxygenase nature of the enzyme has been established and the hydroxylation reaction has been characterized at the biochemical level, including its physicochemical properties and kinetic mechanism. The F6H protein was purified to near homogeneity in its functional state, through an original strategy involving conventional chromatography and affinity columns, and partial amino acid sequences of the purified protein were obtained.  The microsequence information obtained was used as a guide in primer design for the cloning of the F6H cDNA from a C. americanum library that was screened using a PCR-based strategy. A cDNA fragment was subsequently isolated and cloned and its gene product was characterized at the biochemical and molecular levels. The protein predicted from the F6H cDNA clone contains the conserved motifs for this class of enzymes, as well as the microsequences obtained from the purified plant protein. In addition, the clone exhibits F6H activity when expressed in both prokaryotic and eukaryotic expression systems. At the molecular level, F6H is present as a single copy in the C. americanum genome, and contains two introns of approximate length and position comparable to a particular class of dioxygenases, suggesting an evolutionary relationship. (Abstract shortened by UMI.)


identifier: Jha, Anshuman  (2004) Dynamic testing of structures using scale models.  Masters thesis, Concordia University.

abstract: Dynamic testing is very useful in the design and development of products and systems. Although designers employ most powerful analysis tools, using the most elaborate electronic computers, actual testing is required in order to ensure the proper functioning of the designed system. For the structures that are extremely small such as the Micro Electromechanical Systems (MEMS) or that are very large such as civil and aerospace structures complex dynamic tests can be carried out on a replica of the system, called the model , made to larger or smaller scale, respectively, for reasons of economy, convenience and saving in time.  Similitude theory is employed to develop the necessary similarity conditions (scaling laws) for dynamic testing of scaled structures. Scaling laws provide relationship between a full-scale structure and its small scale model, and can be used to predict the response of the prototype by performing dynamic testing on inexpensive model conveniently. Such scaled models have been extensively used in wind tunnel testing of large structures such as automobiles, buildings and aircrafts structures. The difficulty of making completely similar small scale models often leads to certain types of relaxations and distortions from exact duplication of the prototype (partial similarity). Both complete and partial similarities are discussed. These scaling laws are then validated both by carrying out finite element analysis using ANSYS 7.1, and by performing experiments in the laboratory for a simple structures.  The above methodology has also been applied to the design validation of a shipboard monitor console. The console is required to isolate the monitor from the shock and vibration inputs and ensure its proper functioning. The shipboard console and its scale model have been investigated for their dynamic response subjected to sinusoidal and shock loads and a good correlation has been found between the prototype and the model.


identifier: Li, Yu  (2004) Reactive tuple space for a mobile agent platform.  Masters thesis, Concordia University.

abstract: An agent programming model can simply specify agent behaviors as proactive behaviors and reactive behaviors. Typically a multi-agents system is based on message passing, which usually is space and time coupled. This thesis aims at developing a multiple reactive tuple space coordination media that provides space and time decoupling for agent dynamic interaction. It provides three categories of primitives: (i) synchronous primitives, (ii) asynchronous primitives, and (iii) reactive primitives. The synchronous and asynchronous primitives are intended to support agent proactive behaviors. The reactive primitives are for supporting agent reactive behaviors. The formal specification of the reactive tuple space is also described based on the state machine model. In order to enhance system efficiency, a replication protocol is designed to accommodate both locality and concurrency of tuple accesses. The reactive tuple space has been fully implemented and integrated with the JADE mobile agent platform. Comparing with ACL message passing in JADE, experiments are conducted to show that the reactive tuple space can provide competitive performance in terms of interaction latency and bandwidth for tuple spaces of reasonable size.


identifier: Zhang, Yu  (2004) A tuple space based agent programming framework.  Masters thesis, Concordia University.

abstract: Software agent has become a research focus in distributed systems in recent years. This thesis aims at developing a methodology that facilitates the design and implementation of distributed agent applications. We propose an agent programming model called TSAM, which is a development framework for building distributed agent systems. TSAM provides an agent architecture that distinguishes three types of agent behaviors as (i) sensory behaviors, (ii) reactive behaviors, and (iii) proactive behaviors. Role models are used to design different proactive behaviors assigned to an agent. TSAM supports agent couplings with both message passing and distributed tuple spaces. A tuple space facilitates dynamic coordination among a group of agents that work together towards a common goal. We apply TSAM to an example of an e-market system to validate its usefulness, simplicity and support for dynamic couplings among application agents. Performance testing is conducted on the implemented system to demonstrate that the flexibility of tuple space based coordination does not incur significant runtime overhead when compared with message passing.


identifier: Ali, A. N. M. Asad  (2004) Six sigma design through process optimization using robust design method.  Masters thesis, Concordia University.

abstract: Six Sigma or high level of process output is very common interest of world class industry. Six Sigma methodology not only ensures the quality of products but also ensures the quality of each element associated with that product, from conception to the end of the product life cycle. Because of such ensuring, Six Sigma qualities made an evolution in industry in 1990's. Now Six Sigma is almost a proven methodology for industry to produce high level quality of products. To achieve Six Sigma quality, industries need to optimize the process; there are many mathematical, engineering and statistical methods that are being used for optimizing the process. However, these methods do not always deal with a combined consideration of the effects of mean and variability of quality characteristics of the product.  One of the major steps to achieve a high level of quality is to optimize the process. It is well known that processes have many inputs, and inputs are key element to the quality of process output. Therefore, optimization of the process contributes a vital impact for Six Sigma. The proposed Taguchi robust method optimization will take both effects such as mean and variation of product quality characteristics into consideration.  In view of Dr. Taguchi's very popular phrase "loss to society", in this research we applied Taguchi method to optimize the process for Six Sigma design. We showed that a positive gradient relationship exists between S/N ratio and process sigma. The robust design method ensures minimum variation of quality characteristics of the product or to produce almost "defects free" products. Due to such minimal variation in product, it will ensure minimum use of resources for manufacturing of product. Therefore unit cost of production will become lower and as well as it satisfies customer's implied and stated need. These are the main objectives of Six Sigma design and this research contributes to formulate a generalized and easier method to optimize the process for Six Sigma design in an industry.


identifier: Xiangnian Zeng  (2004) Concatenated channel coding and orthogonal space-time block coding for MIMO systems : antenna selection and performance bounds.  Masters thesis, Concordia University.


identifier: Wu, Hua  (2004) Simulations of blind and non-blind channel estimation techniques for bluetooth systems.  Masters thesis, Concordia University.

abstract: Only few years after Bluetooth technology emerged as a new wireless technology, it has grasped the focus of top manufacturers in the world and got widespread use. Indeed, it is an excellent solution to replace cumbersome cables, which used to carry information between devices. Like other wireless technologies, fading and time-varying channels greatly degrade the performance of Bluetooth communications. In the first part of this thesis, Bluetooth specifications are introduced. This is followed by channel estimation techniques applicable to Bluetooth systems. Bluetooth adopts slow frequency hopping modulation. Hence, it is possible to implement channel estimation at the hop beginning, and then compensate for the impairment during the later header and payload parts of data packets. Classical channel estimation techniques are discussed and compared in the Bluetooth case, such as LMS, LS, MMSE, and blind channel estimation algorithms. We derive the specific channel estimation equations for each channel estimation technique. In the last chapter, the simulation results of these channel estimation techniques are presented in various fading cases, i.e. slow and fast fading.


identifier: Varma, Nikhil Kumar  (2004) Formal analysis of fault tolerant real time multiprocessor allocation and scheduling protocols.  Masters thesis, Concordia University.

abstract: Dependable real-time distributed systems rely on allocation and scheduling protocols to satisfy stringent resource and timing constraints. As these protocols have both dependability and real-time attributes, verification of such composite services warrants a rigorous and formal levels of assurance for their correctness.  The wide acceptance of formal techniques in the design and development of dependable real-time systems is limited because, most of these formal theories for real-time scheduling have been developed without much regard for their further reuse. This makes the formal specifications and their proof constructs in general difficult to reuse, and to verify or analyze similar or related protocols.  To expand the utility of formal techniques, this thesis explores the possibility of effectively defining and then reusing formal theories in order to simplify verification and analysis for a wide spectrum of dependable real-time protocols.  We present a modular formal analysis of a fault-tolerant version of a real-time task allocation and scheduling policies. The main aim is to develop a library of formal theories for the identified modules for real-time and dependable services which could be systematically, and if required, repeatedly used to develop different and new composite dependable multiprocessor real-time allocation and scheduling protocols.  We demonstrate a rigorous and tool-assisted formal analysis of three multiprocessor real time fault tolerant allocation and scheduling protocols for both periodic and aperiodic task models using the concept of reuasability of previously defined theories. We show the reduced effort in the analysis and verification process by reusing the previously formalized theories. Formal analyses of these protocols have been performed using a mechanized theorem proving environment, called PVS from SRI labs.


identifier: Qin, Xiang Hua  (2004) An object-oriented framework for constructing availability management services : system architecture and application development.  Masters thesis, Concordia University.

abstract: We describe an object-oriented framework for designing and implementing availability management services. We present a library of object-oriented implementation of a suite of dependable distributed protocols, and show how these protocols can be composed together to build an application that provides highly available services to users. Specifically, we introduce our proposed system architecture called JAMS (Java-based Availability Management System) which integrates the availability management service and the online FDIR (Fault diagnosis, isolation and reconfiguration) service on a distributed heterogeneous platform. The JAMS architecture is described in a way that reflects the design and development phases, spanning from requirement analysis to module implementation. A case study of a banking service is presented to illustrate how JAMS can be used to build a dependable distributed application in a modular manner ensuring that the application service remains continuously available to the user despite the presence of failures, maintenance and growth. (Abstract shortened by UMI.)


identifier: Frassetto, Juliana Cristina  (2004) Performance of micropiles.  Masters thesis, Concordia University.

title: Performance of micropiles

abstract: Micropiles are known to be small in diameter (maximum 300 mm), replacement piles, drilled, composed of placed or injected grout under pressure.  This study presents a critical review of the existing design methods and examines the parameters governing the design of these piles. Furthermore, a design procedure is proposed to take into account the geometry of the micropiles, the interaction with the soil and to incorporate the parameters, which seemed to be ignored in the previous methods. The proposed designed procedure was validated against field tests, where good agreement could be found.  Numerical models were developed using the finite element technique to provide solutions for the case stated. The first model was to simulate the installation techniques of the micropiles and to perform a parametric study. The second numerical model was to simulate the cavity expansion caused by grouting pressure and to develop the relationships of pressure versus expansion of the pile diameter, length of expansion and soil properties. (Abstract shortened by UMI.)


identifier: Zhang, Rui  (2004) A new three-parameter lifetime distribution with bathtub shape or increasing failure rate function and a flood data application.  Masters thesis, Concordia University.

abstract: In this thesis, a new three-parameter lifetime distribution with bathtub shaped or increasing failure rate function is given by adding a shape parameter in the distribution which is suggested by Chen (2000). It can be used for modeling lifetime data from reliability, survival analysis and various extreme value data. The detailed analysis of this distribution includes density shapes, tail classification and character, hazard function shapes and the extremes and extreme spacings distributions. The confidence intervals for the parameters are discussed by using bootstrap method. Its application in modeling extreme value data is illustrated by the floods data of the Floyd River at James, Iowa.


identifier: Zohari, Parissa  (2004) Language acquisition and the argument from the poverty of the stimulus.  Masters thesis, Concordia University.

abstract: This thesis represents an attempt to illustrate the significance of two fundamental concepts related to first language acquisition (FLA): (1) The primary linguistic data (the PLD), and, (2) The argument from the poverty of the stimulus (POS). The central claim is that the notion of the PLD and the POS argument, which have traditionally been presented as distinct, are intimately related. The PLD is viewed as the external basis for FLA as well as the POS Argument. This thesis proposes a new, tri-level definition for the (linguistic data: (a) The available linguistic data (ALD), (b) The received [by the acquirer's brain] linguistic data (RLD), and, (c) The perceived linguistic data (PLD). In addition, three issues related to the POS concept are discussed: Innateness, Negative Evidence, and the POS argument. Chomsky proposed the POS concept as evidence that FLA cannot occur in the absence of innate language universals. The idea was that people attain knowledge of their language despite the impoverished linguistic data. This thesis explores Geoffrey Pullum and Barbara Scholz's (2002) recent challenges to the POS argument which attempt to undermine the nativist view of FLA. Two POS exemplars studied and rejected by Pullum and Scholz are reexamined here. This thesis concludes that the claims made by Pullum and Scholz lack scientific evidence and, hence, the POS Argument still remains unchallenged. This thesis also suggests that the next crucial step in language acquisition research is to explore second language acquisition (SLA) and its relation to language universals.


identifier: Hosseini-Zadeh, Mehrdad  (2004) Stability of haptic rendering for deformable objects.  Masters thesis, Concordia University.

abstract: Stable and robust point-based haptic rendering interaction and sliding with and on various types of deformable elastic objects, ranging from low-stiffness (soft) to high-stiffness (rigid), is one of the main technical challenges in the field of virtual environments and force feedback haptic displays. The methods proposed in this work offer a high-fidelity 3D force reflecting haptic model to guarantee a stable interaction and sliding of deformable objects. Consequently, one is able to maintain a continuous force feedback field over the surface of polygonal-based deformable bodies with different normal stiffnesses in each polygonal mesh. Several control strategies are developed and investigated for maintaining and improving on the stability margins and achievable performances for haptic rendering intended for interacting with virtual deformable objects. Two specific classes of control strategies are investigated in this thesis. The first is a Lead-Lag compensator design based on classical control theory and the second scheme is a Linear-Quadratic-Gaussian (LQG) controller designed according to modern control theory. A detailed comparative evaluation of the proposed control strategies are presented to illustrate the performance of the resulting controlled haptic display when applied to deformable objects.


identifier: Fan, Yu  (2004) Characterization of fiber Bragg Grating sensor array embedded in composite structures.  Masters thesis, Concordia University.

abstract: FBG (fiber Bragg Grating) sensor becomes a hotspot in recent researches, based on its numerous advantages, especially it can be easily multiplexed to realize sensor network. A number of networking scenarios have been proposed [1] [2], "orthogonal array" is one of the most convincing solutions, in which wavelength division multiplexed FBG sensors are patterned along a single optical fiber and analogical fibers are orthogonally deployed, so that any randomly oriented ambient change can be analytically monitored along two orthogonal sensors of local intersection. Further, by means of various addressing mechanisms [3], stimulus is positioned. However, detailed characterization of a single orthogonal unit is the essence to model entire network.  This work reports a set of experiments on an orthogonal FBG array unit embedded in specific Graphite/Epoxy composite structure. First of all, photoelastic behaviour of identical bare FBG fiber was observed, which is to profile an "ideal" FBG strain gage. Then optimization process was carried out to determine the optimal layout for FBG array embedment, which induces minimum perturbation to both sensors and host structure. After optimized specimens were fabricated, tensile loads were applied to specimens. Recurring to surface mounted resistance strain gages, embedded FBG strain gages are recalibrated and their sensing alterabilities are evaluated. Finally, suspended concerns are discussed and conclusions are drawn upon experimental data. (Abstract shortened by UMI.)


identifier: Collishaw, Mary Ann  (2004) Emotional labour, client perceptions and client responses in leisure services.  Masters thesis, Concordia University.

abstract: Employers in the leisure service industry ask their employees to be enthusiastic and display appropriate emotions, even if they are not feeling them. This concept of managing emotions by amplifying or suppressing emotions, in the work context, has been termed emotional labour. Employers assume that, even if employee's displayed emotions are not genuine, appropriate employee emotional displays will encourage client satisfaction and loyalty. The effects of emotional labour on employees have been studied by a number of researchers, however, studies on the effects of emotional labour on client responses are rarer. Through questionnaires distributed to instructors and their clients in group fitness classes, this study demonstrates that some indicators of emotional labour are related to client perceptions of instructor vitality as well as to client responses to the service. It was also found that client perceptions of vitality had significant relationships with client responses to the service. This study attempts to spark thought in practitioners and academics alike for the need to question the relationship that emotional labour has on client responses.


identifier: Giguère, Marie-Paule  (2004) High-growth strategies of entrepreneurial firms in technology industries.  Masters thesis, Concordia University.

abstract: The purpose of this research was to enhance our understanding of strategies used by rapid growth firms. This study has attempted to answer the following question: "Which new venture strategies are associated with higher growth?"  More specifically the purpose of this research was to examine the next two arguments: (1) HGEFs employ multiple strategic emphases; (2) Growth strategy evolves across time.  On one hand, results of this study support the argument that HGEFs use multiple strategic emphases as the largest group identified in this study follow a multi-faceted strategy pattern. Firms tend to employ a minimum of three competitive strategic actions at the same time. Fast-growing firms simultaneously control costs, improve product quality and product offerings. These findings support those of other new venture researchers in that no single strategy appears to always work best (McDougall 1987/Ostgaard & Birley 1994).  On the other hand, the present study supports the argument that strategy evolves across time. Younger firms tend to be more niche-oriented and innovative. Older and larger firms, on the other hand, tend to have a broad customer and market segmentation basis. In addition, some tendencies seem to characterize all HGEFs. Those strategies emphasize are international focus, innovation, corporate partnerships with large firms, low cost and productivity.  As an exploratory step, this study is useful in illustrating the complexity of strategy patterns and providing good insights for venture capitalists and entrepreneurs to understand what are the different high-growth tactics to use across time.


identifier: Jeddi, Mohamed Ali  (2004) The impact of new issue of equity warrants on the Toronto Stock Exchange listed stocks.  Masters thesis, Concordia University.

abstract: This study empirically examines the impact of equity warrant introduction on the underlying stock on the Toronto Stock exchange. We investigate both the announcement and issuance price effect using an event study methodology with a 21 day event window. Taking into account outliers, it is shown that the introduction of equity warrants leads to a negative and permanent effect around both the announcement and issuance date. To test for the effect of warrant introduction on the volatility, we calculate the before and after, unadjusted and adjusted volatility to obtain the respective unadjusted and adjusted volatility ratios of the underlying stock. We find that no significant impact occurs on the volatility of the underlying stock neither at the announcement nor at the issuance event date.


identifier: Lin, Hui Ling Ellen  (2004) An international look at the lawsuit avoidance hypothesis of IPO underpricing.  Masters thesis, Concordia University.

abstract: One potential explanation for the underpricing of initial public offerings is the lawsuit avoidance hypothesis of Tiniç (1998). In this study, we empirically test the insurance effect of the lawsuit avoidance hypothesis which states that firms that are subject to higher litigation risk underprice their issues more to reduce the likelihood of being sued in connection with their IPO. In addition, by underpricing their issues, firms can limit the amount of damages plaintiffs can claim in a lawsuit.  We examine the relationship between IPO underpricing and litigation risk in an international setting using a sample of 6,326 firms that went public across 34 countries between January 1995 and December 2002. We control for known determinants of IPO underpricing and test whether IPOs in countries with higher levels of litigation risk are more underpriced.  While the majority of single-country studies do not find support for the lawsuit avoidance hypothesis, we find a significant positive relationship between litigation risk and underpricing in a cross-country framework. Contrary to all single-country legal liability studies outside the US and consistent with the US studies of Tiniç (1988) and Lowry and Shu (2002), our empirical results support the insurance effect of the lawsuit avoidance hypothesis in an international context. Our findings imply that the degree of litigation risk in a given country affects the level of underpricing for firms that go public in that country. We conclude that differences in legal risk factors can partially explain differences in underpricing across countries.


identifier: Lin, Yi  (2004) Dynamic relationships and technological innovation in hot and cold issue markets.  Masters thesis, Concordia University.

abstract: The puzzle of hot and cold issue markets has attracted substantial interest in the academic community. The behavior of IPO volume and initial returns over time is well documented respectively (see, Ibbotson and Jaffe (1975), Ritter (1984), Rock (1986), McGuinness (1992), Lee, Taylor, and Walter (1999) and Lowry (2003)). Few studies, however, investigate the dynamic interrelationship between IPO volume and initial returns. This paper uses a simultaneous equations approach to study the endogenous interrelationship between IPO volume and initial return. We find that higher IPO volume causes higher initial returns, but not vice versa. Furthermore, lagged IPO volume is significantly negatively related to initial returns. In other words, the underpricing of a new issue is affected by not only the concurrent number of new issues at the mean time but also by the numbers of new issues in prior periods.  Another purpose of our study is to test the hypothesis that technological innovation is the main driver behind hot issue markets. Welch (1989) and Hoffmann-Burchardi (2001) suggest that the clustering of new issues is caused by IPO volume spikes in industries that have recently experienced technological innovations or favorable productivity shocks. Through analysis of the industry correlation matrix of new issue activity and a fixed-effects model based on industry level data, we find evidence against the technological innovation hypothesis.


identifier: Manovas, Mantas  (2004) Investigating the relationship between knowledge management capability and knowledge transfer success.  Masters thesis, Concordia University.

abstract: To gain a competitive advantage, a company must have the ability to effectively manage its chief asset, knowledge. Out of various types of knowledge that firms possess, its ability to satisfy customer requirements plays a crucial role in its ability to provide a quality product/service. More specifically, in information technology (IT) projects, customer requirements need to be effectively and efficiently transferred to the IT department. In return, the IT department must efficiently and effectively meet these needs.  This thesis examined the relationship between knowledge management capabilities and knowledge transfer success in IT departments in Canadian companies. An online survey collected empirical data from 54 IT managers. This data was analyzed using the partial least square (PLS) structural equation modeling method.  The findings show that for knowledge transfer to be successful in an IT project, the IT department must have both a solid knowledge infrastructure and a knowledge process capability. Within these capabilities, key infrastructure factors and knowledge processes were identified. Application and Acquisition proved to be significant in ensuring a solid process infrastructure, while Culture of Learning, Culture of Sharing, Collaboration Technology, Opportunity Generation Technology, Structure that supports Collaboration and System of Rewards were found to be important infrastructure elements. Furthermore, the findings reveal that knowledge processes are key to ensuring knowledge transfer efficiency, but not necessarily effectiveness; while knowledge infrastructure determines knowledge transfer effectiveness, but not necessarily efficiency.


identifier: Miao, Zhibin  (2004) A generic and intelligent approach of feed rate determination for CNC profile milling.  Masters thesis, Concordia University.

abstract: Determination of optimal machining parameters--spindle rate, feed rate, and depth of cut--has been a research topic for decades. Since the parameters of CNC machining significantly influence part machining time, part surface quality, and tool life, techniques of determining optimal machining parameters are in high demand in manufacturing industry. Usually the depth of cut and spindle rate are determined according to machinist manuals before machining; and the feed rate is determined subjectively either by CNC machine operators or programmers. As a result, the feed rate is not optimal in terms of the machining condition at every cutter location, and it is fixed at a conservative value causing longer machining time or shorter tool life. In this work, a generic and intelligent approach of feed rate determination for CNC profile milling is proposed. First a two-dimension chip load model is introduced and an example database of machining parameters is presented. Second a fuzzy rule-based system is established to predict the cutting force based on the radial and axial depths of cut, and the assumed feed rate. The next step is to identify the geometric features of the part, calculate the engagement angles of the geometric features, and find proper feed rates for them. Finally the approach is applied on an example part for profile milling, and the results are simulated with CATIA CAD/CAM system to demonstrate the advantages of this approach.


identifier: Tandon, Abhishek  (2004) Low-complexity adaptive filtering algorithms based on the minimum L [infinity]-norm method.  Masters thesis, Concordia University.

abstract: The complexity of an adaptive filtering algorithm is proportional to the tap length of the filter and hence, may become computationally prohibitive for applications requiring a long filter tap. In this thesis, we provide a framework for developing low-complexity adaptive filter algorithms by utilizing the concept of partial-updating along with the technique of finding the gradient vector in the hyperplane based on the L {592} -norm criterion. The resulting algorithm should have low-complexity not only because of the updating of only a subset of the filter coefficients at each time step, but also from the fact that updating a filter coefficient using the algorithm based on L {592} -norm requires less number of operations compared to the L 2 -norm algorithm. Two specific coefficient selection techniques, namely the sequential and M -Max coefficient selection techniques, are considered in this thesis. Statistical analyses of these two algorithms are carried out to derive the evolution equations for the mean and mean-square of the filter coefficient misalignment as well as to obtain stability bounds on the step-size of the two algorithms. Further, these analyses are used to show that the algorithm employing the M -Max coefficient selection technique can achieve a convergence rate that is closest to the full update algorithm. As a consequence, even though there are various ways of selecting a subset of the filter coefficients, the study of the other techniques becomes redundant. Simulations are carried out to validate the results obtained from the statistical analyses of the algorithms. The concept of developing algorithms based on the partial-updating and L {592} -norm is extended to proportionate adaptive filtering. Finally, the performance of the proposed adaptive filtering algorithms as well as that of the existing ones is studied in echo cancellation.


identifier: Tang, Zhigang  (2004) Application of network transposition in the design of OTA-C filters and oscillators.  Masters thesis, Concordia University.

abstract: Recent advances in analog integrated circuit and signal processing have shown that the current-mode approach is superior to the voltage-mode in terms of its wide bandwidth, high speed, low voltage and power. As a wide range of voltage-mode analogue circuits already exist, a straightforward method of converting these voltage-mode circuits to current-mode circuits would be very useful. The network transposition, introduced by Bhattacharyya and Swamy as early as in 1971, provides a perfect solution to this question of conversion from voltage-mode to current-mode circuits.  A vast body of literature already exists concerning voltage-mode OTA-C filter structures. At the same time, many current-mode OTA-C filter structures are being reported in the literature. These two apparently independent areas of research and development could be unified by the application of the principle of network transposition. For this reason, an intensive investigation on the OTA-C structures is conducted. The result of this investigation shows that transposition relationship could be used to advantage in deriving current-mode filter structures from the voltage-mode filter structures and vice versa. The principle of transposition has been extended to oscillator circuits to derive new OTA-C oscillator structures from known ones. The concept of transposition has been extended to differential input dual-output (DIDO) structures, since such structures can increase the common-mode rejection ratio, eliminate the even-order harmonic distortion components and reduce the effects of power supply noise. The theoretical work presented in the thesis is verified by simulation results as well as by practical circuits using discrete resistors, capacitors and OTA devices. In addition, an oscillator is fabricated in a 0.18 om CMOS process to further verify the validity of network transposition. The measurement result shows good agreement with the theoretical analysis.


identifier: Tooher, Patrick  (2004) Space-time layered block codes : bridging the gap between maximum rate and full diversity.  Masters thesis, Concordia University.

abstract: Impairments found in the wireless channel, such as destructive multipath fading, cannot be fully addressed by using coding alone, despite its recent advances. Recent results show that gains in capacity can be obtained by using multiple antenna elements at the transmitter and the receiver. Instead of mitigating the effects of the multipath fading, multiple-input multiple-output (MIMO) systems use the rich scattering channel to increase the capacity at no bandwidth cost. Methods include BLAST, which maximizes the rate, and space-time coding, which maximizes the diversity.  In this thesis, the fundamental trade-off between rate and diversity is derived for binary codes. Simple codes that can perform at any realizable rate/diversity are designed. These codes are referred to as Space-Time Layered Block Codes (STLBC), since they are in effect a 1-dimensional code layered into a space-time code. By selecting speck 1-D codes, the required diversity can be achieved at the maximal allowable rate.  In order to detect the new STLBC codes, an iterative MMSE detector is used jointly with a soft input soft-output decoder. This detector/decoder uses a principle similar to Turbo decoding. STLBC codes introduce the concept of coding between layers, which requires a detector capable of dealing with possibly dependent layers. The classical multiuser detector is modified to allow for dependence.  Lastly, techniques to improve the performance of STLBC are presented. These are based on a new design criterion that ensures codebooks of high average rank, as well as making certain the information is spread out over the two available dimensions.


identifier: Zhang, Jian  (2004) Edge detection in a pixel array circuit.  Masters thesis, Concordia University.

title: Edge detection in a pixel array circuit

abstract: Edge detection is commonly used to extract important features of an image, while providing a compression of image data, and thus it is one of the most important operations in image processing systems. Such a detection is usually implemented in a system of data processor(s) with its input image signals provided by a camera. However, in many applications, in which the constraints of speed, power and size of the hard-ware are critical, it will be favorable to implement the edge detection in a smart sensor, i.e. a pixel array circuit, in which each pixel operates in parallel with other to perform signal acquisition and processing.  In this thesis, the design of a CMOS pixel array for edge detection is presented. The work of this thesis is in the two aspects, detection algorithms and circuit implementations. A new version of the algorithm for edge detection has been proposed, aiming at facilitating its implementation in an integrated circuit with simple inter-pixel connections and processing units in the pixels. It has been demonstrated that the proposed algorithm can result in a quality of the detection as good as the most commonly used detection algorithms. To implement this algorithm, a pixel array circuit has been designed with simple current-mode modules and logic gates in each pixel. The research effect in the circuit aspect is on solving the problems of the transistor mismatch, which makes identically-designed units behave non-uniformly, and charge injection in the current-mode circuits. With special compensation schemes implemented in the pixel circuit, the uniformity of the processing units integrated in the pixel array increased more than ten times, which improves significantly the quality of the operations in the process of the detection in the circuits. The pixel array circuit can be easily implemented with a standard CMOS technology


identifier: Dhar, Joydeep  (2004) A hybrid approach to differentiated services multicast.  Masters thesis, Concordia University.

abstract: Internet, the largest network of networks has evolved from a research-oriented network to one with a myriad number of commercial applications. Over the last several years, there has been an explosion in the introduction of new Internet technologies with high-end workstations being engaged in real-time and multimedia communications like video conferencing, IP telephony, streaming video broadcast, online gaming etc. Supporting both the legacy services like email, file transfer and real-time multimedia like video conferencing requires service differentiation of Internet traffic. Moreover, multipoint communication requires implementation of multicast services. Two of the emerging technologies for service differentiation in multipoint communication are Differentiated Services (DiffServ) and multicasting. Although the two technologies share complementary goals, the integration of the two technologies is a non-trivial issue due to three fundamental problems. The problems are the scalability of per-group state information, sender- versus receiver-driven QoS, and resource management.  The issues surrounding how to solve these problems provide the basis for this thesis. Edge Based Multicast (EdgeCast)--has been proposed here to satisfy the requirements for scalable DiffServ multicasting architectures. In addition it also presents a new join/leave protocol to support the EdgeCast architecture. Performance simulation has been done and compared with some already developed techniques. Finally, the whole work has been summarized and comments have been made on future applications of the architecture and several potential areas for future research.


identifier: Barua, Amitabh  (2004) A fault-tree approach for identifying causes of actuator failure in attitude control subsystem of space vehicles.  Masters thesis, Concordia University.

abstract: In this thesis, we have proposed a novel approach which strengthens existing efficient fault-detection mechanisms with an additional ability to classify different types of faults to effectively determine potential causes of failure in a subsystem. This extra capability ensures a quick and efficient recovery/reconfiguration from disruptions. Our developed diagnosis/analysis procedure exploits a widely used qualitative technique called fault-tree analysis for failure analysis in the Attitude Control Subsystem (ACS) of a spacecraft. The proposed fault-tree synthesis algorithm utilizes machine-learning techniques to classify and rank primitive events in terms of their severity for a particular system failure. The effectiveness of the fault-tree synthesis algorithm presented in this thesis has been demonstrated under different simulated ACS failure scenarios. Constructed fault-trees have been able to represent combinations of events leading to different failures resulting due to artificially injected faults in a Simulink model of ACS. It is important to emphasize that proposed technique has potentials for being integrated in an on-board spacecraft health monitoring and diagnosis tool. (Abstract shortened by UMI.)


identifier: Wu, Xinyu  (2004) Second law analysis of residential heating systems.  Masters thesis, Concordia University.

abstract: Effective analysis methods/tools and assessment indicators appear to be essential in the design process, in order to improve the energy performance of buildings. With respect to HVAC system, which contributes to a major fraction of the building energy use and CO 2 emissions, the second law analysis is an appropriate tool to evaluate its performance.  This thesis presents the second law analysis of 20 design alternatives of the HVAC-DHW system of a house located in Montreal. The following design alternatives were considered: (1) heating system: (a) electric or hot water baseboard heaters, (b) forced air system, and (c) radiant heating floor; (2) heating equipment: (a) electric or gas-fired boiler, (b) ground-source-heat-pump, and (c) air-to-air heat pump; (3) heat recovery: (a) air-to-air heat exchanger, (b) earth-tube heat exchanger, and (c) boiler economizer.  Engineering Equation Solver (EES) program was used to perform the second law analysis for both peak design conditions and annual operating conditions. The results show that the HVAC-DHW system using electric baseboard heater and separate electric air ventilation heater has the lowest exergy efficiencies of 7.4% and 4.1%, respectively, under the above two conditions, while its energy efficiencies are 64.2% and 61.6% respectively under the same conditions. The HVAC-DHW system with the highest exergy efficiency of 23.2% (at peak design conditions) and 10.9% (at annual operating conditions) is composed of: radiant floor heating system; ground source heat pump; air-to-air heat exchanger; earth tube heat exchanger; gas-fired DHW heater.


identifier: Zhang, Xiao Jun  (2004) Automatic generation of SDL specifications from timed MSCs.  Masters thesis, Concordia University.

abstract: The integration of Formal Description Techniques (FDTs) in the software process enables formal validation, translation, synthesis and code generation. Message Sequence Charts (MSC) and Specification and Description Language (SDL) are two formal languages, widely used in the telecommunication industry. Generally MSC is used for the behavioral requirement specification, while SDL is used for the detailed design specification. The transition from the requirement specification to the design specification is usually performed manually; and the design has to be validated against the requirement specification.  In a previous research work, researchers from the telesoft group at Concordia University devised an approach for generating SDL specifications from MSC specifications with a given target architecture. It guarantees correctness of the design, and consistency between the SDL specification and the MSC specification. The need for validation has been eliminated.  Time concepts have been introduced in MSC-2000, which enables real-time requirements to be specified in MSC. Building on the existing framework, this thesis presents a new approach for translating MSCs with real-time requirements into SDL specifications. We analyzed and classified different types of time constraints and measurements. New algorithms for analyzing MSC specifications and generating SDL code were devised. We also built the tool and experimented with case studies to prove the feasibility of our approach.


identifier: Li, Jian  (2004) Design and development of a piezoelectric linear actuator for smart structures.  Masters thesis, Concordia University.

abstract: The objective of this research is to present a proof-of-concept design of an inchworm-type piezoelectric actuator with output of maximum displacement and force (or power) for shape control and vibration control of adaptive truss structures. The proposed inchworm actuator adopts "pusher" type with frictional clamping mechanisms and similar to most inchworm-type actuators it consists of three main components: two clamping or braking devices and expanding device. The central expanding device consists of a longitudinal PZT stack and a thin wall tube to provide extension-contraction motion and output force. The clamping device consists of the same tubular type PZT stack, a compliant mechanism to amplify the displacement of PZT stack, and a pre-load mechanism. The compliant mechanism consists of three flexure clamps with flexible hinges, two support rings with adjustable screws and two cover wafers, which integrate all three flexure clamps into a compliant frame. (Abstract shortened by UMI.)


identifier: Singh, Harpiyar  (2004) Design, finite element and experimental analysis of piezoelectric tactile sensors for endoscopic graspers.  Masters thesis, Concordia University.

abstract: This dissertation reports on the design, experimentation and the finite element analysis of a prototype PVDF endoscopic tooth-like tactile sensor capable of measuring the compliance of a contact tissue/sensed object. Present day endoscopic graspers are designed tooth-like in order to grasp slippery tissues, but do not measure tissue tactile properties like force and softness. The main objective of this study is to design and model a sensor capable of measuring the total applied force on the sensed object as well as compliance of the tissue/sensed object. The sensor consists of a rigid and compliant cylindrical element. Determination of the compliance of sensed objects is based on the relative deformation of contact object/tissue on the compliant and rigid elements of the sensor. A PVDF film is sandwiched between rigid cylinder and plate, which measures the force applied on the rigid element. Another PVDF film is sandwiched between the two base plates to measure the total force applied on the sensor.  Using 2D finite element analysis, the tissue has been modeled as an elastic beam on rigid and elastic foundations and the results are compared with 3D ANSYS model. (Abstract shortened by UMI.)


identifier: Xu, Haipeng  (2004) Smooth estimation of survival and MRL functions under mean residual life order.  Masters thesis, Concordia University.

abstract: Let X and Y be two random variables denoting life times having finite means. Let, S 1 , S 2 and M 1 , M 2 denote their survival and MRL functions, respectively. X is said to be smaller than Y in mean residual life order, if and only if [Special characters omitted.] In this thesis smooth estimators for the survival and MRL functions under the above ordering are studied. Nonparametric method given by Hu et al. (2002) has shown good properties, but it is not smooth enough, when the true function is continuous.  Chaubey and Sen (1996) have proposed a new approach to smooth survival and density function in stead of the popular kernel method. Following their approach, we introduce two methods for smooth estimation of a survival function based on the two criteria of mean residual life ordering. The strong uniform consistency of the estimators has also been shown here. Numerical studies based on simulation indicate both smooth estimators to be superior to the estimator due to Hu et al. (2002) in terms of bias and MSE in majority of cases.


identifier: Miguel, Marco  (2004) Web and paper questionnaires : an experimental comparison.  Masters thesis, Concordia University.

abstract: The objective of this study is to investigate and model the acceptance of Web and paper-and-pencil questionnaires applied within a company. The study population consists of employees of United Nations agencies at any level with a corporate e-mail account and easy access to an Internet browser. This study uses a crossover design to avoid confounds such as order effects and variability between participants. Acceptance is assessed through the behavioral intention to respond (future) questionnaires, in a model where perceived ease of use, perceived enjoyment, portability value and computer anxiety are proposed as determinant variables. The results of this research do not indicate a difference in the reported behavioral intention to respond to future questionnaires between the two media. Nevertheless, response rates were higher for paper questionnaires.


identifier: Tang, Ya  (2004) Acquisition stock performance : do ownership and outside directors matter?  Masters thesis, Concordia University.

abstract: In this study, we examine how corporate internal control mechanisms, including the percentage ownership by executive officers and directors and the proportion of outside directors on the board of directors, affect the market's perception of corporate acquisition decisions. The evidence suggests that in the period around acquisition announcements, the use of insider ownership and outside directors disciplines managers to make decisions that the market perceives as better reflecting the interests of shareholders. The combination of stock ownership and outside director monitoring is perceived as providing a better control system for top management than the sole use of either of these two external governance mechanisms. Compared to firms with low insider ownership interest, acquirers with high ratios of officer and director ownership pay less for targets that have higher growth opportunities. With regard to the longer post-acquisition period, ex post market performance is consistent with outside directors (but not insider ownership) acting in shareholders interests.


identifier: Yucui, Bai  (2004) A multiobjective mixed integer programming application on the design of a material supply system.  Masters thesis, Concordia University.

abstract: This thesis presents the development of a multi-objective mixed linear programming model to design a material supply system for an ethanol manufacturing company. China has proposed a cassava development program to encourage cassava processing enterprises, mainly ethanol enterprises. These companies will build raw material production bases in mountain areas of Guang'xi province to help increase the revenues of local impoverished farmers. A cassava supply system responsible for raw material transportation from the farmers to the ethanol manufacturing plant is one of the essential strategies to ensure smooth operations of the company. The model is built to aid decision makers in selecting farmers for cassava supply and locating processing centers to serve farmers in order to construct the supply system. The locations of farmers and processing centers are determined to achieve the maximum poverty reduction and the minimum operation cost under the condition that cassava from all selected farmers meets the demand of the manufacturing plant. The maximum poverty reduction is accomplished by the largest poverty coverage and highest average income increase rate. The constraint method is applied to solve the model. The mathematical modeling formulation is coded in LINGO served by Excel data sheet. Trade-off solutions are presented to provide ample choices to decision makers on farmer selections and the processing center locations. The decision makers may choose to enlarge population coverage of the poor or increase their income increase rate, the cost will rise accordingly; or they may choose to reduce the cost with fewer covered poor farmers or with lower income increase rate.


identifier: Khor, Susan Lay Choo  (2004) A genetic algorithm test generator.  Masters thesis, Concordia University.

title: A genetic algorithm test generator

abstract: Use of a genetic algorithm and formal concept analysis to generate test data for branch coverage is explored in a prototype automatic test generator (ATG) called genet . genet is unique in the sense that it requires minimal source code instrumentation and analysis, and is programming language independent. Besides the novelty of using formal concept analysis within a genetic algorithm, genet extends the opportunism of another evolutionary ATG. Experiments were designed to evaluate the effectiveness of genet and the importance of selection in the evolution of test data. The results of the experiments indicate genet is most effective when selection plays a significant role. This is the case when test solutions for a program are necessarily organized. When it is not necessary for test solutions to resemble each other, adaptation appears to be the more dominant factor and the identification of suitable genetic operators becomes more important. Nevertheless, even in the latter situation, the presence of genet accelerated the evolutionary process for our test programs. Notwithstanding equal adaptation instructions, genetics mattered.


identifier: Li, Qiu Wen  (2004) Reengineering an object-oriented framework for extensible query optimization.  Masters thesis, Concordia University.

abstract: In this thesis, we describe a third-generation extensible query optimization framework that has evolved from the OPT++ framework of Navin Kabra for relational databases. Our framework does not change the infrastructure of the OPT++ architecture, which consists of three components: a Search Strategy component, a Search Space component and an Algebra component. However, we address the problems encountered while building two query optimizers in the framework: a simple bottom-up optimizer and an instance of the PostgreSQL query optimizer and enhance the modularity and the collaboration of the three components of the framework at detailed level, which in turn leads to a more flexible, easier to extend and cleaner implementation. The framework has been validated by implementing the two query optimizers. While both these cases were for the relational data model, we believe the design does cover the optimization process for other data models.


identifier: Zheng, Zhi Hong  (2004) On efficient fixpoint computation of deductive databases with uncertainty.  Masters thesis, Concordia University.

abstract: Uncertainty management has been identified as an important challenge in AI and database research. Many frameworks of logic programming have been proposed to manage uncertain information in deductive databases and expert systems. These proposals address fundamental issues of modeling, semantics, query processing and optimization. However, there have been fewer reports on efficient implementation of such frameworks. In this research, we study this issue in the context of a fragment of the parametric framework [19] over the certainty domain of [0, 1]. It has been shown that the standard Semi-Naive fixpoint evaluation method does not have a counterpart when uncertainty is present [32]. We have refined a Semi-Naive method, originally proposed in [32], and developed a Semi-Naive evaluation engine that takes into account the multiplicity of derivations of the same atom. We also introduced a refinement of this evaluation, called Semi-Naive with Partition, which further improves the efficiency of the Semi-Naive method with uncertainty. Finally, we adopt "stratification" from Datalog, which is shown to make a significance efficiency for certain input programs with uncertainty. We have conducted numerous experiments to assess the benefits of the collection of optimizations proposed in this research. Our experiments and benchmarks indicate that the proposed techniques and tricks yield a useful, efficient evaluation engine for deductive databases with uncertainty.


identifier: Xu, Duosheng  (2004) Buckling analysis of tri-axial woven fabric composite structures.  PhD thesis, Concordia University.

abstract: The buckling of a structure may have an adverse effect on the structural performance and may cause instability of the structure or even failure of a structure, especially in structures with thin elements. Single layered tri-axial woven fabric composite structures belong to this type of thin structures. The load at which buckling will occur has to be determined. It is the purpose of the present dissertation to perform this task. The study of the dissertation covers the following aspects: (1) The buckling analyses of several simple tri-axial composite structures, such as straight composite beam and curved composite beam subjected to different boundary conditions, simply-supported composite structure with two intersected curved tows and simply-supported tri-axial woven composite structure with three intersected curved tows, that are a part of tri-axial woven fabric composite tow structures are performed. (2) The buckling behavior of more complicated tri-axial woven fabric composite structures is studied. These more complicated structures include basic tri-axial structure, modified basic tri-axial structure and enlarged basic tri-axial structure where additional weavings are added to make the sample longer and wider. The basic tri-axial structure is subjected to uni-directional or bi-directional loading. The sensitivity of the buckling behavior of the basic tri-axial structure to the change in the boundary conditions and to the imperfection due to initial configuration is investigated. The sensitivity analysis of buckling behavior to the in-plane aspect ratio of the structure is also conducted. Their numerical results and corresponding physical explanations are given. In order to gain some insight into the buckling behavior of more complicated tri-axial woven fabric composite structures, the buckling analysis of the modified and enlarged basic tri-axial composite structures subjected to uni-directional loading is also conducted. (3) The value of the buckling load is normalized. Extension to the buckling of real life large tri-axial structures is discussed. Buckling load of a real life large tri-axial structure can be obtained approximately by subtracting from the value of the approximate analytical solution by 8%. Thus determined value of buckling load for a real life larger sized tri-axial structure is on the safe side. (Abstract shortened by UMI.)


identifier: Raja, Usman  (2004) The relationship of the big five personality dimensions to personal and organizational outcomes : answering the questions who? and when?  PhD thesis, Concordia University.

abstract: Despite the enormous growth of research on personality due to the development of the Big Five model, there is still much to be learned about the relation of personality to personal and organizational outcomes. An area requiring attention is the incorporation of situational variables into empirical models to enhance the predictive capacity of personality in explaining outcomes. This study fills this gap by exploring the joint effects of the Big Five personality dimensions and contextual factors (job scope, social aspects of job, and justice perceptions) on a variety of personal and organizational outcomes. The results support many hypotheses suggesting the moderating role of job scope in personality-outcomes relationships. Job scope moderated the relationship between various Big Five traits and job satisfaction, job stress, job performance, and creativity. Similarly, distributive justice and voice had joint effects with personality on citizenship behaviors.


identifier: Bergeron, Jasmin  (2004) Antecedents and consequences of salesperson listening effectiveness in buyer-seller relationships.  PhD thesis, Concordia University.

abstract: To advance the claim that effective listening is a skill of paramount importance for sales representatives may appear prima-facie to belabour an obvious assumption. Yet, a consensus seems to exist in the literature that the average salesperson exhibits, at best, poor listening skills. This claim provides the impetus for the development of listening studies in the buyer-seller paradigm, which historically have been underpresented within the overall domain of sales research. The goals of the present dissertation were fourfold: (a) to define what it means to "listen" in the selling context, (b) to test the multidimensional structure of the listening construct, (c) to examine several key antecedents and (d) major consequences of salesperson listening effectiveness. First, a content analysis of key words in more than 50 conceptualizations of listening lead us to define listening as: "the selective act of physically sensing, mentally processing, and responding to verbal and/or nonverbal messages." To attain the three next objectives, a survey was distributed to more than 600 buyer-seller dyads in the banking industry. In order to collect relevant data, numerous strategies were employed, such as survey pre-notification, response incentives, sponsorship, and follow-ups. Nearly 1200 respondents, representing more than 10 financial institutions, completed our questionnaires. A battery of statistical tests indicated that listening in personal selling encompasses three dimensions: physical sensing, mental processing, and responding. Out of 12 variables hypothesized to influence effective listening, the following seven salesperson-related factors were identified as significant precursors: customer orientation, motivation to listen, customer knowledge, empathy, memory, past listening training, and internal buyer-seller similarity. Our empirical results also indicated that listening effectiveness is positively (and strongly) associated with service quality, trust, satisfaction, word-of-mouth propensity, purchase intentions, and sales performance (whether measured by perceptions or quantitative data). Several interesting conclusions were distilled from the findings and numerous theoretical and practical recommendations were suggested. It is our hope that this dissertation will (a) entice organizations to emphasize salespeople listening skills as a competitive advantage and (b) be used as a spring board by sales researchers to accrue research efforts and continued theory development in understanding the truly rich role of listening.


identifier: Uddin, Mohammed Taj  (2004) Cure rate estimation based on uncensored and censored data.  Masters thesis, Concordia University.

abstract: This thesis deals with the analysis of cure model under uncensored and censored data. First we provide related concepts and second, we develop the cure rate model. Thirdly, we study the non-parametric maximum likelihood method to estimate the parameter of cure model. We consider both uncensored and censored data as well as Type 1 and Type 2 censoring to estimate the parameter of the model. Finally, we develop some parametric and non-parametric estimating equations to estimate the parameter of the cure rate model.


identifier: Karp, Jennifer  (2004) Comparing maternal and observer ratings of child temperament in the prediction of concurrent functioning and later school adjustment.  PhD thesis, Concordia University.

abstract: The goal of this research was to compare a new observational temperament measure with an existing temperament questionnaire in the prediction of concurrent child and parent functioning and later school adjustment. In Study 1, mothers of infants and preschoolers, who were drawn from an at-risk sample, were asked to complete the EAS Temperament Survey along with various indices of child behaviour during the course of two home visits. They were also asked to participate in videotaped mother-child interactions, which were subsequently coded for child temperament using an observational rating system. Correspondence between the measures was evaluated along with the incremental validity of the observational technique. In Study 2, longitudinal data were used to assess the predictive validity of the maternal and observer ratings in relation to children's early school adjustment. A secondary purpose of this study was to determine the longitudinal stability of temperament ratings. The findings suggested modest congruence between observational and maternally rated temperament. Interestingly, the observational and maternal ratings showed a differential predictive pattern. Specifically, maternal ratings predicted internalizing and externalizing behaviours, whereas the observational ratings predicted cognitive functioning and adaptive behaviour during the cognitive assessment. Importantly, observational ratings showed unique incremental value in the prediction of parenting stress. In the longitudinal study, however, maternal ratings provided a more reliable prediction of later school adjustment relative to the observational system. Temperament was found to be moderately stable over time. The findings suggest that observational ratings of temperament offer distinct and useful information in comparison with maternal ratings, although this interpretation is somewhat limited to contemporaneous measurement. This investigation also provides validation for the role of maternal ratings in predicting children's concurrent and longitudinal functioning. Taken together, this research highlights the importance of adopting a multi-method approach to the study of child temperament.


identifier: Houpert, Carol Beer  (2004) Female body and identity : a critical reflection into the art of mid-life.  Masters thesis, Concordia University.

abstract: This thesis articulates how my own artwork/artistic process is part of a lifelong narrative about my female body and identity, which has unfolded within a patriarchal society and its language. This project of articulation is supported by two related activities. First, I compare my current artwork and life narrative, which are focused on mid-life and menopause, with those of artist Pauline Aitken. Second, by using selected literature from feminist art scholarship, I interpret and contextualise key themes of my own and Aitken's artworks and life narratives.  I show how gender influences the woman artist's intent and process: her choice of subject matter and materials, and the resulting narrative. I examine how other women artists and I create a visual vocabulary that is true to our female identities, a vocabulary that can withstand the language of our patriarchal society. This thesis concludes with critical reflections on my own art learning experiences.


identifier: Fligel, Sasha  (2004) Journeying through a housecoat.  Masters thesis, Concordia University.

title: Journeying through a housecoat

abstract: This thesis consists of personal research involving reflections into particular threads of my life which have sewn change into the fabric of my artwork. Through an autobiographical approach I have investigated the path of this change and documented how the change occurred. In doing so, I have recognized my need for broader research methods and acknowledged a very different community of artists with which I can identify. The conclusions I make for my own personal journey and my role as an art educator are poststructuralist in nature. I recognize the value of multiplicity and individual experience in the processes of making, thinking about and discussing art.


identifier: Walker, Kate and Scott, Susan  (2004) Observations and reflections of learning and teaching in a university studio art class : interview with Susan G. Scott.  Masters thesis, Concordia University.

creator:
Walker, Kate
Scott, Susan

abstract: As a teacher of art I am constantly reflecting on effective teaching in studio art classes and the qualities that define good teaching in order to inform my own practice. The question I am investigating in this study is "What organizational and personal qualities of a teacher, as exemplified by an active artist and studio teacher at Concordia University, lead to the success of a studio art class at the University level and contribute to the essence of good teaching?"  In order to answer this question I returned to Susan G. Scott's 460 level painting course, Materials and Methods of the Artist because it was as a student of hers in this course that my model of 'good teaching' began to form. Through reflective practice I re-evaluated my own learning experience in this course. Using the methods of participant observation and interview I uncovered and examined the organization of the course, the content and the pedagogical qualities of Susan G. Scott that contributed to the success of the course. The information that emerged from this study enabled me to define the essence of good teaching for me and to develop a base from which to construct my philosophy of education


identifier: Bolton, Stephanie  (2004) An analysis of the task force on museums and first peoples : the changing representation of aboriginal histories in museums.  Masters thesis, Concordia University.

abstract: Debate erupted in the Canadian museum world of the mid-1980s in response to a contentious exhibition of Aboriginal art and artefacts, The Spirit Sings: Artistic Traditions of Canada's First Peoples (1988), presented by the Glenbow Museum in Calgary. In order to address some of the issues circulating around the representation of Aboriginal peoples within museums in Canada, the Canadian Museums Association and the Assembly of First Nations jointly organized the Task Force on Museums and First Peoples. The Task Force consisted of arts professionals and scholars, Native and non-Native, along with concerned community members and elders. The group published a report, Turning the Page: Forging New Partnerships Between Museums and First Peoples (1992), which provided guidelines for better understanding between museums and Aboriginal Canadians.  This thesis examines the history and development of the Task Force on Museums and First Peoples, as well as an in-depth look at its report and recommendations. I consider the McCord Museum of Canadian History in Montreal as a case study for the implementation of the Task Force recommendations. It is my premise throughout this thesis that the Task Force report has influenced museum practices across Canada and that, more than a decade after the appearance of the report, museums, scholars, and Aboriginal communities are continually striving to cooperate and compromise to develop an acceptable framework for the presentation of Aboriginal arts, cultures, and histories in Canadian museums.


identifier: Diner, Robyn  (2004) Bodies of irony : irony, the unruly body, feminist performance.  PhD thesis, Concordia University.

abstract: Bodies of Irony begins at the crossroads where theories of irony, configurations of the unruly female body and particular performance pieces meet, greet and get off on one another. As I re-present spectacular scenes featuring Karen Finley, Courtney Love, Princess Superstar, Spiderwoman, Coco Fusco and Guillermo Gómez-Peña among others, I show how irony can give familiar feminist and/or postcolonial sentiments a fresh, funky edge; how it may highlight hypocritical states of affairs and how it enables one to adopt a sensibility that juggles the seemingly irreconcilable. Irony also becomes embodied. I demonstrate how a variety of figures associated with the unruly female grotesque--the madwoman, the slut, the hysteric and the noble savage--are re-done with irony as they rage, smirk and laugh their way across specific stages, spaces and streets. In turn, conversations emerge around: postmodernism feminism, political activity and claims to identity; postcolonial inquiry into concepts like hybridity, authenticity, memory and Otherness as exotic spectacle; critiques of the good girl/bad girl binary and the norms that ground and surround appropriate femininity. As I elaborate on responses to the performances re-staged throughout this project, the risks and dangers linked to irony and the unruly body are fleshed out. Many of the performers that I focus on have been trivialized, dismissed, detested, arrested and/or recuperated. Often their words and deeds seem to perpetuate what they seek to critique. However, although I suggest that ironic and unruly endeavors can backfire, I also stress that such serious play can prove pleasurably, provocatively and politically promising.


identifier: Man, Jun  (2004) Proteomic analysis of phenol degradation in soil yeast Trichosporon cutaneum.  Masters thesis, Concordia University.

abstract: Trichosporon cutaneum is a soil yeast that utilizes a variety of aromatic compounds as sole carbon and energy sources. T. cutaneum is perhaps the best-characterized aromatic-degrading fungus from which further information about biodegradation can be obtained. In this thesis, the global effects on the T. cutaneum proteome associated with growth on phenol have been examined. In order to identify all the enzymes involved in the phenol degradation pathway and to find other proteins associated with the degradation process that are not part of the catabolic pathway, proteomic analysis combine high-resolution two-dimensional gel electrophoresis (2-DE) and mass spectrometry. The optimized sample preparation methods and experimental conditions provide a great advantage in quantitative analysis and potential high-throughout applications. Three mass spectrometry methods, matrix-assisted laser desorption/ionization quadrupole time-of-flight mass spectrometry (MALDI-QTOF-MS), nano-electrospray mass spectrometry (nanoESI-MS/MS) and capillary liquid chromatography mass spectrometry (CapLC-MS/MS), have been successfully applied to studying proteins of T. cutaneum strain ATCC 58094 differentially expressed in response to growth on phenol. Cross-species identification provides a powerful tool in protein identification with an unknown genome and was applied to the mass spectral data obtained. Except for phenol hydroxylase and cis, cis -muconate cyclase, the other identified 24 proteins were not previously known to be associated with phenol degradation in T. cutaneum


identifier: Ciortea, Mihai  (2004) Catalytic role of copper in nitric oxide transfer from S-nitrosothiols to low-molecular-weight thiols.  Masters thesis, Concordia University.

abstract: In recent years, much attention has been focused on the chemistry and biology of nitric oxide due to the discovery that it plays a key role in a wide variety of physiological processes. It has been suggested that S-nitrosothiols may be directly involved in many of the biological functions of nitric oxide and that they play a role in nitric oxide storage, transport and delivery. The mechanism of nitric oxide transfer from an S-nitrosothiol to a low-molecular-weight thiol or to a protein-based thiol is still unknown. In this work, evidence for a mechanism in which traces of copper play a role in nitric oxide transfer between thiols is presented. A new synthesis for dansyl homocysteine is described and this fluorescent thiol is used as a direct and sensitive nitric oxide-transfer probe. The results demonstrate that redox turnover of copper is required for efficient nitric oxide transfer between low-molecular-weight thiols.


identifier: Ali, Md. Eaqub  (2004) Modification of local and global conformational stability of hemoglobin by the allosteric effectors BPG and IHP.  Masters thesis, Concordia University.

abstract: FTIR studies of the effects of BPG and IHP binding on the p(SH) stretching vibrations of human deoxyhemoglobin A (deoxyHbA) between 25 and 75{493}C reveal that the effectors stabilize the p(SH) peak of Cysβ93 at 2576 cm -1 at high temperatures (55{493}C or above). In the presence of the effectors, the p(SH) peak of Cys{460}104 at 2558 cm -1 is broadened, and the p(SH) shoulder of Cys{460}112 at 2564 cm -1 fluctuates in intensity with increasing temperature, indicating that the effectors destabilize the {460} 1 β 1 interface of the deoxyHbA tetramer (2{460}2β).  At 25{493}C, the Soret CD bands of 0.5 mM effector-bound deoxyHbA are observed at 418 and 432 nm with ellipticities of -2.4 and +28 M -1 cm -1 , respectively. These signals are intensified by 2-5 units at 55{493}C. In contrast, effector-free deoxyHbA loses {598}50% of its Soret CD absorption and {598}10% of its unpolarized Soret absorption on heating to 55{493}C. Effector binding also stabilizes the 287-nm negative CD band and the three-valley CD absorption between 250-270-nm, which reflect changes at the {460} 1 β 1 interface.  FTIR-monitored thermal unfolding of 3.0 mM deoxyHbA reveals that loss of the {460}-helical absorption at 1653 cm -1 occurs in three phases. These may be associated with tetramer [arrow right] dimer, dimer [arrow right] monomer and monomer [arrow right] denatured-monomer transitions. In the presence of BPG and IHP, the FTIR denaturation curves are shifted by {598}5{493}C to lower temperature, indicating that effector binding destabilizes the secondary structure of deoxyHbA.


identifier: Gunasekara, Nirosha  (2004) Phylogenetic and molecular dating analyses of the tropical tree family Dipterocarpaceae based on chloroplast matK nucleotide sequence data.  Masters thesis, Concordia University.

abstract: The theories that explain the origin and evolution of the pantropical tree family Dipterocarpaceae have long been controversial, with two alternative hypotheses of Gondwanic origin and vicariance or Eurasian origin and dispersal. To test these two hypotheses, I have inferred the divergence dates of major clades through molecular phylogenetic and dating analyses using the nucleotide sequences of the chloroplast matK gene and fossil data of 49 dipterocarp species. Phylogenetic analyses produced highly consistent, well-resolved tree topologies with molecular clocklike evolution up to the level of the genera and sections. Independent calibration points based on dipterocarp fossil data were used to calibrate the molecular clock. The results revealed the early Cretaceous Gondwanic origin of the family and the radiation of the Pakaraimoideae (121-117 Mya), mid to late Cretaceous radiation of the Monotoideae (117-88 Mya) and the late Cretaceous to early Eocene origin and diversification of the Dipterocarpoideae (88-54 Mya). The rate of nucleotide substitution of the matK gene in dipterocarps is 2.5 {604} 10 -10 per synonymous site per year. The absolute age estimates showed a gradual pattern of speciation in agreement with the "museum hypothesis" up to the level of genera and sections. The results were highly congruent with the paleogeographical and paleoclimatic events, morphological and ecological evidence. This study supports the view that ancestral stocks of dipterocarpoids dispersed from the African to Deccan plate and subsequently dispersed to the Eurasian plate and diversified in Southeast Asia giving rise to the present day species richness in the far eastern rain forests.