identifier: Chen, Xing  (2014) An empirical examination of White Knight Corporate Takeovers: Performances and Motivations.  Masters thesis, Concordia University.

type: Thesis PeerReviewed

abstract: While many studies research on the bidding contest, several studies have assessed the impact of the white knight's bid on common stock returns. However, these studies focus on the reaction of the market to a single decision. In this paper, we are interested in both the short-run effect of management's decision to make a white-knight bid and the long-term cumulative effect made by management. As the first paper to research on the motivation of the white knight and on the factors that affect its market reaction, we place the white knight's decision to enter the control contest in a broad context. Our hypothesis is that poor governance mechanisms and ownership structure may lead to both poor management and thus a decision to join the bidding contest with an overpaid price. We employ a unique hand-collected dataset on firm characteristics, governance mechanisms and ownership structure for the bidding pairs with white knights. Our results show that board size, tenure average, the ownership held by directors and executives as a group and institutional ownership have an important effect on abnormal returns. However, we find no significant effect of financial strength and ownership structure on the likelihood of a white knight takeover attempt. Instead, we find that striving for the market power in its industry is an important motivation for a white knight attempt.


identifier: Semerdjiev, Boyan  (2014) Alternative Approaches to Significant Zero Crossings (SiZer) Method for Feature Detection in Non-Parametric Univariate Kernel Density Estimation.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: This work presents several methods for feature detection in density estimation of univariate data. Two versions of the original Significant Zero Crossings for Derivatives (SiZer) method and two other SiZer approaches for signal detection with Euler and Hadwiger characteristics are explored. The latter are based on approximating level-crossing probabilities by expected number of upcrossings. In addition, a method for two-sample density comparison is proposed, based on the discussed SiZer methodologies. Estimating a single best bandwidth parameter value is difficult. Therefore, all signal detection and comparison approaches utilize the concept of scale-space and color maps, allowing consideration of curve smoothing at multiple bandwidth levels simultaneously. Finally, the proposed methodologies do not compete and are therefore not compared. Instead, they complement each other and combining the observations from all of them together allows for better statistical inference of the data set.


identifier: Ibrahim, Rasha  (2014) Three Dimensional Finite Element Optimization Using the Partial p-Adaptive Method for Stress Analysis of Underground Excavations with Prismatic Cross-sections.  Masters thesis, Concordia University.

abstract: As the complexity and challenges in the field of geomechanics rise, reducing computational costs has become a major theme to be investigated. This thesis evaluates the p-adaptive mesh optimization method’s performance for problems in the 3D finite element stress analysis of underground excavations with prismatic cross-sections. The p-adaptivity changes the element formulation within the finite element mesh, based on the concept of excavation disturbed zone. The changes in element formulation require the use of transition elements to connect linear hexahedral finite elements with quadratic ones. The forthcoming research was conducted using sim|FEM (Zsaki 2010), a research computer code intended for excavation design, which solves 2D plane strain and 3D problems. It was written in C++ and its key feature is its capability to test models with transition elements, which is not found in other analysis software. The research project started with an overview of 3D element formulations, both normal and transitional, which were implemented in the code then simple, yet practical models were tested and the results were analyzed. For some models, the results were compared to commercial software to prove that a correct behavior of the elements tested was obtained. Finally, the p-adaptive method was developed for this class of excavations and it was applied to a linear elastic medium with two circular excavations in a triaxial stress field representing a practical scenario of perhaps a transportation tunnel with a service tunnel running beside it excavated in intact rock. Mesh optimized and non-optimized models were compared and the results showed that optimization results in a reduction of the global stiffness matrix size on average by 82 percent and a reduction of solution times by about 82 percent for optimized models tested using 12-node and 16-node transitional elements, respectively, as compared to non-optimized models.


identifier: Huang, Kang  (2014) Minimum Number of Accelerograms for Time-History Analysis of Typical Highway Bridges.  Masters thesis, Concordia University.

abstract: Time-history analysis is the most reliable method for the assessment of the behaviour of bridges subjected to seismic loads. It has been widely used in recent years on the evaluation of the seismic vulnerability of bridges. The selection of seismic motions is one of the most important issues for the time-history analysis. This thesis discusses four different methods for obtaining spectrum-compatible acceleration time histories (i.e., accelerograms) of seismic motions. Based on these methods, four sets of accelerograms compatible with the design spectrum for Montreal were selected for this study. These included (i) scaled real accelerograms, (ii) modified real accelerograms, (iii) simulated accelerograms, and (iv) artificial accelerograms. The selected sets were used as excitation motions in the nonlinear analysis of two existing bridges in Montreal. The bridges included a three-span continuous concrete slab bridge and a three-span continuous slab-girder type bridge. These two bridges are considered to be representative of typical highway bridges in Quebec. A number of response parameters, such as, the deck displacement, bearing displacement, column curvature ductility, and base shear were used for the evaluation of the effects of the selected sets on the response of the bridges. Based on the results from the analysis, simulated accelerograms are recommended for use in the time-history analysis of the bridges. Furthermore, a study was conducted on the investigation of the minimum number of accelerograms required for both linear and nonlinear time-history analyses. Two different scaling methods, i.e., partial area under the spectrum and the spectral acceleration at the fundamental period of the bridge, were used to obtain the bridge responses. It was found that 5 accelerograms are sufficient for the linear time-history analysis and 10 accelerograms are required for the nonlinear time-history analysis based on the results from the two bridges considered in this study.


identifier: Burstein, Michelle T.  (2014) Lithocholic Acid Extends Yeast Chronological Lifespan, Drives the Evolution of Longevity Regulation Mechanisms in Ecosystems and Suppresses Mitochondrial Deficiency Causing a Neurological Disorder in Humans.  PhD thesis, Concordia University.

abstract: This thesis describes studies in which the budding yeast Saccharomyces cerevisiae was used as a model organism for uncovering mechanisms underlying aging of eukaryotic cells. We identified lithocholic acid (LCA), a bile acid, as a natural compound that increases the chronological lifespan of yeast cultured under longevity-extending caloric restriction (CR) conditions by targeting lipid metabolism. Our findings revealed mechanisms by which LCA extends yeast chronological lifespan, drives the evolution of longevity regulation within ecosystems, and suppresses mitochondrial deficiency known to cause a neurological disorder in humans. We demonstrated that the age-dependent dynamics of the mitochondrial tubular network regulates longevity of chronologically aging yeast by modulating age-related apoptosis. This mitochondria-controlled form of programmed apoptotic death is elicited by the efflux of the pro-apoptotic proteins cytochrome c, Aif1p and Nuc1p from mitochondria in reproductively mature yeast cells that enter stationary growth phase; furthermore, this form of age-related apoptotic death depends on the metacaspase Yca1p. We provided evidence that the CR diet delays the fragmentation of the mitochondrial tubular network during early stationary phase. This, in turn, slows down the age-related exit of pro-apoptotic proteins from mitochondria, attenuates apoptotic cell death, and ultimately prolongs lifespan. Our findings also revealed that LCA further increases the chronological lifespan of CR yeast by preventing mitochondrial fragmentation during late stationary phase, thus averting the age-related exit of pro-apoptotic proteins from mitochondria and inhibiting programmed apoptotic cell death. Moreover, findings reported in this thesis imply that LCA extends longevity of chronologically aging yeast only if added at certain critical periods of their lifespan. Based on these findings, we propose a hypothesis of a biomolecular longevity network undergoing a stepwise progression through a series of checkpoints in chronologically aging yeast. In this thesis we also propose a hypothesis in which LCA - as well as other interspecies chemical signals released into the environment - create xenohormetic, hormetic and cytostatic selective forces driving the ecosystemic evolution of longevity regulation mechanisms. Moreover, findings described in this thesis suggest a previously unknown mechanism by which LCA suppresses mitochondrial deficiency causing the late-onset Leigh syndrome, a severe neurological disorder in humans.


identifier: Cools, Valérie  (2014) Motifs, textures and folds: Japanese popular visual culture as transcultural and phenomenological flow.  PhD thesis, Concordia University.

abstract: Since the 1980s, Japanese popular visual culture has known great popularity in Western Europe and North America, most strikingly in the form of manga, anime and Japanese video games. However, one is struck by how fragmented this cultural flow is: not only is it composed of three different media, but it also contains works that are wildly different from one another. Can something be said to connect these works together, other than their Japanese provenance? This dissertation proposes two avenues for answering this question and establishing a certain cohesiveness within the fabric of Japanese popular visual culture as it has been exported: on the one hand, this thesis explores recurrent content and themes (motifs) within a purposefully varied corpus of manga, anime and games; on the other, it establishes phenomenological consistencies (textures and folds) across the corpus, demonstrating that these works provide medium-based experiences that are similar in significant respects. Parallel to this demonstration, this dissertation examines the effects of this cohesion on the Western reception of these works. The author argues that, while cultural motifs evoking “Japaneseness” play an initial part in gathering these works into a perceived flow, it is their common phenomenology that cements their perceived cohesion and facilitates their integration into non-Japanese imaginaries. By analysing the transcultural travels of Japanese popular visual culture, this thesis examines a case where differentiated imaginaries meet and merge, and thereby develops a theory of the imaginary as phenomenological and processual space, as a fabric that surrounds us and which we collectively and continually weave and unravel. Ultimately, the author determines that this particular imaginary is regulated by two key notions: on the one hand, a dynamic of flux and stasis, and on the other, a series of interconnected and intermingled folds.


identifier: Freire Carneiro Leao, Tiago  (2014) Characterization of the Spatial Distribution of the Electric Field Strength in Indoor Propagation at 2.45 GHz.  PhD thesis, Concordia University.

abstract:
Small-scale spatial variations of the electric field strength or “fast fading” are encountered in indoor environments, and are of particular concern for indoor wireless communication applications as well as for electromagnetic compatibility assessment. This thesis is motivated by the problem of electromagnetic interference with a critical-care medical equipment caused by fields radiated by portable electronic devices such as cell phones and tablet computers. Measurement and computer simulation of the electric field strength, in both controlled and real-world scenarios, are explored to estimate parameter values of statistical models for the fast fading in a region of interest inside a building.

First, a method for measuring the dielectric constant of wall construction materials is developed for two reasons: little information available on electrical properties of such materials in the frequency range of interest, 2.4 GHz ISM band, and variations in material properties caused by different manufacturing processes employed by different manufacturers. The proposed technique, referred to as the parallel-path method, falls into the category of free-space methods and is shown to be more sensitive to the dielectric constant than free-space methods based on normal incidence only.

Having determined the dielectric constant of gyproc slabs and of a wooden door, a controlled multipath environment is built inside an anechoic chamber. Two line-of-sight and a non-line-of-sight scenarios, each with about 4000 measurement points, are studied. We apply the Friedman’s goodness-of-fit test at 5% significance level to show that a ray-tracing technique based only on 3D geometrical optics is suitable for estimating the fast fading of the electromagnetic field at 2.45 GHz in a very controlled situation. Then the Anderson-Darling goodness-of-fit test, also at 5% significance level, is applied to show that in the vicinity of a transmitter the Ricean, Normal, Nakagami, and Weibull distributions can be equivalently used to represent the spatial fast fading for both line and non-line-of-sight scenarios. Furthermore, the effects of metal studs are shown to worsen not only point-by-point agreement between measurement and GO simulation, but also the agreement on the statistics of the fast fading in a 65 by 65 cm region.

Another aspect of this thesis is the development of a new method for estimating the parameters of the Ricean probability density function. This new method is compared to the maximum-likelihood method, and is shown to provide accurate estimates with samples containing as few as 36 data points for regions within 2 m from a transmitter, and as few as 9 data points for regions farther away. This is a considerable improvement in term of computation time when compared to estimates based on approximately 4000 points, or even 200 data points. Together with GO simulations, this method reduces the initial and elaborated measurement approach to only a few simulated points and a statistical model.

Finally, this methodology is extended and applied to real-world scenarios such as a long hallway and a conventional laboratory room. The agreement between measurement and GO simulation is not as good as that of the experiment conducted in a shielded anechoic chamber, but it is still reasonable, especially because the interior structures of walls such as metal studs are not modeled by the GO code. As for the statistical models used to describe the electric field strength variation in a region, it is shown that the Ricean, Normal, Nakagami, and the Weibull distributions can be employed. However, for the data collected in this work, the Normal distribution is the one that results in the worst fit to measured data for most of the cases. It is demonstrated that, even though diffracted rays are not taken into account, GO simulation allows for an accurate estimation of the parameters of a statistical model for the fast fading, for both controlled and most real-world scenarios, provided that the site geometry and electrical properties of walls, floor, and ceiling are known.


identifier: Asgariazad, Maryam  (2014) Game theory and network security: Economic incentives and barriers.  Masters thesis, Concordia University.

abstract:
Nowadays, the Internet and computer networks play an increasing role in our modern society. However, we also witness new types of security and privacy incidents such as the propagation of malware, the growth of botnets, and denial-of-service (DoS) attacks against business and governments’ websites. Therefore, experts must investigate security solutions to defend against these well-organized and sophisticated adversaries. Instead of designing a defence against a specific attack, game theory attempts to design a quantitative decision framework to determine the possibility of adversaries’ attacks, and suggest defence strategies for the defenders. This thesis illustrates some examples for the potential usefulness of game theory in information systems security.
First, we present a game theoretic scenario to study the strategic behavior of two Internet Service Providers (ISPs) who have to decide whether to invest in deploying security technologies that detect and prevent malicious cyber-attacks. In particular, we consider the case where the ISPs can determine malware-infected machines among their subscribers, and their action (i.e., quarantining these infected machines) may well mitigate cyber security incidents. By analyzing the financial incentive for the ISPs to deploy security policy among their subscribers, we find the best action of the ISPs considering their customers’ security awareness and their market shares. We also identify the need for government regulations and incentives in order to better guide the role of ISPs in enhancing the global security of the Internet.
Then, we present a game theoretic model for analyzing the dynamic interaction between  attackers and  defenders as a two-player game with uncertainty while considering multi-level of detection for defence devices configurable by the defender and multi-level of severity for attacks chosen by the attacker. By assuming that higher levels of defence and high level of attack severity are associated with higher levels of investments by the defender and the attacker, respectively, we compute mixed strategy Nash Equilibria for both the attacker and defender considering the cases when the players’ valuation follows a uniform distribution and the case where it follows a truncated normal distribution. We then formulate an n-player game to capture competition among n attackers who aim to successfully attack the same target and analyze the mixed strategy Nash Equilibria in both models.
Finally, we consider networks in which the worm propagator and the defender can dynamically decide their optimal propagation rate for the warm and security patches, respectively, considering their associated cost. We combine the propagation process with a game theoretic model as a two-player non-zero sum differential game. Then we formulate the decision problem as a continuous-time optimal control problem and solve it using the Pontryagin’s maximum principle. The obtained result leads to a better understanding of the worm propagator behavior and can be utilized to inhibit the scale of loss resulting from Internet worms.


identifier: Zhang, Min  (2014) Using Six Sigma to Achieve Sustainable Manufacturing: A Case Study in Aviation Company.  Masters thesis, Concordia University.

abstract: Sustainability has been widely discussed from different points of view. Manufacturing is contributing a critical part of incompliance to environment and human rights in our modern society. While a lot of companies are seeking strategies to either promote corporation image or stimulate employees’ work passion, most of research and guidelines are focusing on how to measure the sustainability based on the cases from big firms. Most of manufacturing firms are medium and small sized, they are searching for a comprehensive and systematical way to implement sustainability practice step by step without using very experienced professionals. This thesis research is supplying a systematic framework for firms to achieve sustainability in manufacturing environment with the widely used problem solving tool Six Sigma. Inexperienced professionals will be able to implement the sustainability practice from defining problems to achieving leadership in sustainability. It has also supplied a case study where it illustrates how to customize the framework content based on individual needs.


title:
Using Six Sigma to Achieve Sustainable Manufacturing:
A Case Study in Aviation Company


identifier: Khundker, Nafisa  (2014) Preventing confidential information leakage in supply chains through trust-based heuristic supplier selection.  Masters thesis, Concordia University.

abstract: In today's global economy, outsourcing has become increasingly popular in design and production. Manufacturers need to share massive information with their suppliers during an outsourcing activity. In the meantime, the manufacturers need to protect confidential information related to the product for the purpose of intellectual property (IP) protection. In such a context, secure collaboration has become an emerging research topic in global supply chain management.  A number of methods were proposed to select secure and eligible suppliers among all potential suppliers involved in a supply chain system to satisfy security requirements and to minimize the cost at the same time. The selection can be performed by assessing suppliers' ability, risk assessment of information leakage, and cost analysis. However, depending on given security requirements, a valid selection of suppliers to meet such requirements may not always be possible to obtain. Moreover, such a selection process is usually very expensive with existing risk assessment algorithms.   This thesis addresses both issues by proposing a method which is both secure and efficient for generating optimal selections of suppliers for a supply chain system. First, we introduce a multi-level trust model of suppliers to address the cases where existing approaches based on a flat trust model will fail to generate any valid supplier selection. To our best knowledge this is the first work on formally modeling the level of trust in suppliers. Second, we propose efficient heuristic algorithms for eliminating insecure selections of suppliers as early as possible in the process such that the need for expensive risk assessment on such selections is avoided. The effectiveness and efficiency of proposed approaches were analyzed and validated through a case study.


identifier: Elboushi, Ayman  (2014) ANALYSIS AND DESIGN OF ANTENNA PROBES FOR DETECTION / IMAGING APPLICATIONS.  PhD thesis, Concordia University.

abstract:
Analysis and Design of Antenna Probes for Detection / Imaging Applications
Ayman Elboushi, Ph.D.
Concordia University.

As a result of increasing international terrorist threats, the need for an efficient inspecting tool has become urgent. Not only for seeing through wall applications, but also to be employed as a safe human body scanner at public places such as airports and borders. The usage of microwave and millimeter wave antennas and systems for detection / imaging applications is currently of increasing research interest targeting the enhancement of different security systems. There are many challenges facing researchers in order to develop such systems. One of the challenges is the proper design of a low cost, reduced size and efficient antenna probe to work as a scanning sensor.
In this thesis, two different technology choices of antenna probes for the feasibility of constructing detection / imaging systems are investigated. The first one covers the Ultra Wide Band (UWB) range (3.1 GHz to 10.6 GHz), while the second operates over the Millimeter-Wave (MMW) range.  In addition to the development of several antenna probes, two detection / imaging systems are demonstrated and showed reasonably accurate detection results.
Three different UWB monopole antenna prototypes, with different radiator shapes (circular, crescent and elliptical) have been introduced. These antennas are designed using a standard printed circuit board (PCB) process to work as probing sensors in a proposed UWB detection / imaging system. In order to enhance the resolution and the detection accuracy of the probe, 4-element Balanced Antipodal Vivaldi Antenna (BAVA) array fed by 1-to-4 UWB modified Wilkinson power divider has been developed.  Some successful experiments have been conducted using the proposed UWB detection / imaging system combined with the fabricated antenna probes to detect the presence of a gap between two walls made of different material types, to evaluate the gap width and to estimate the size and exact location of a hidden target between the walls.
The second research theme of this thesis is to develop small-sized, light-weight and high gain MMW scanning antenna probes. For the realization of such probes, several gain enhancement techniques have been adopted, including hybridization and a multi-element array principle. Several high-gain hybrid antennas have been designed, fabricated and tested.  For demonstration purposes, experiments have been carried out for detecting and imaging a small metallic coin under the jeans layer of a three-layer target emulating a human body’s covering layers. A performance comparison between a standard metallic MMW horn and hybrid microstrip patch/conical horn antenna has been made. The proposed reduced size antenna sensor shows increased efficiency compared with the bulky horn antenna.
Resolution enhancement of the reconstructed image of the hidden target is implemented using a new triple-antenna MMW sensor. The triple-antenna sensor consists of three adjacent microstrip patch / conical horn antennas separated by 1.5 wavelengths at the center frequency for coupling reduction between these elements. The middle element of the sensor is used for monitoring the time domain back-reflected signal from the target under inspection, while the side elements are used for monitoring the scattered signals. By the aid of a special signal processing algorithm, an enhanced image of the concealed object can be obtained by combining the three readings of each point in the area under study. The proposed system shows a great ability for detecting a hidden target and enhances the reconstructed image resolution.


identifier: Fornea, Michele  (2014) Comparison of big Heegner points at intersections of Hida families.  Masters thesis, Concordia University.

abstract: Given a Hida family $\cal{F}$ of tame level $W$, for a quadratic imaginary field $K$ that satisfies the Heegner hypothesis for $W$, one can construct some classes in the Galois cohomology of a self-dual twist of Hida's big Galois representation associated to $\cal{F}$, which are called big Heegner points. When two families intersect, a natural question is to compare the big Heegner points at the intersection. We show that the specializations at intersections agree up to multiplication by some Euler factor that arise from the difference in the tame levels.


identifier: Eglal, Mahmoud  (2014) Nanofer Zero-Valent Iron Nanoparticles: Surface Morphology, Structure and Reactivity with Contaminants.  PhD thesis, Concordia University.

abstract:
ABSTRACT
Nanofer Zero-Valent Iron Nanoparticles: Surface Morphology, Structure and Reactivity with Contaminants
Mahmoud M. Eglal
Nanoscale zero valent iron is emerging as a new option to treat contaminated groundwater. Despite its high potential for environmental application, there is only a limited knowledge about the fundamental properties of nZVI, particularly, its structure, surface composition and the change in these characteristics in an aqueous media, as nanoparticles interact with aqueous contaminants. Nanofer zero valent iron (nanofer ZVI) is a new and innovative nanomaterial capable of removing organic as well as inorganic contaminants in water. It displays a decrease in agglomeration, when it is coated with Tetraethyl orthosilicate (TEOS). TEOS imparts an increase in reactivity and stability to nanofer ZVI. The present study investigates the structure and surface chemistry of nanofer ZVI to understand the mechanism of reactivity towards organic and inorganic contaminants in water. The characteristics of nanofer ZVI were determined using scanning electron microscope/electron dispersive spectroscope (SEM/EDS), transmission electron microscope (TEM) and X-ray diffraction (XRD). The nanoparticle size varied from 20 to100 nm and its surface area was in the range of 25-30 m2 g-1. The thickness of the oxidizing layer had a range of 2 to 4 nm.
The adsorption and the oxidation behavior of nanofer ZVI used for the removal of Cu (II), Pb (II), Cd (II) ions and TCE from aqueous solutions was investigated. The optimal pHs for Pb (II), Cu (II), Cd (II) and TCE removal were found to be 4.5, 4.8, 5.0 and 6.5 respectively. Test data were used to form the Langmuir and the Freundlich model isotherms. The maximum loading capacity was estimated as 270, 170, 110, 130 mg per gram of nanofer ZVI for Cu (II), Pb (II), Cd (II) and TCE respectively. The adsorption of metal ions were compared with their hydrated ionic radii and their electronegativity. TCE oxidation followed the dechlorination pathway resulting in nonhazardous byproducts. Kinetic experiments indicated that the adsorption of heavy metals [Pb (II), Cd (II), and Cu (II)] and TCE was very rapid during the initial step of 50 minutes, which was followed by a much slower second step that was related to the solid state diffusion rate and the available surface area. Removal rates of 99.7% for Pb (II), 99.2% for Cd (II), 99.9% for Cu (II), and 99.9 % for TCE were achieved in less than 180 minutes.
iv
The Lagergren model (LM) and the single diffusion model (SDM) were used to understand the removal mechanism associated with nanofer ZVI. The time interval for particles to agglomerate and settle was between 4-6 hrs. SEM/EDS images showed that the particle size increased from 50 nm to 2 μm due to the particle agglomeration.
The competitive adsorption and displacement of mixed metals are complicated processes that are influenced by several factors. The occurrence of more than one possible adsorption mechanism, on nanofer ZVI contributes to the multi-faceted nature of these interactions. The binding of metal ions is thought to depend on the hydrated ionic radii and the electronegativity of metals. The mechanisms for binary and multi adsorption involved are influenced by time, pH and initial adsorbent concentration as well as the presence and properties of competing metal ions in the solution. In the isotherm and kinetic studies performed for binary and multi metal adsorption experiments, compared to Pb II and Cd II, Cu II achieved the higher adsorption capacity during the initial 5 min. However, after 120 min, all metals achieved removal efficiency in the range of 95 to 99%. Comparing the results of single and competitive adsorption kinetic tests for all the three metals during the initial 5 min, the presence of other metals slightly reduced the removal efficiency.
A part of the studies was devoted to the removal of mixed organic and inorganic contaminants. To this end, the removal of TCE by nanofer ZVI in the presences of Cu II at different environmental conditions was investigated. The kinetics of TCE degradation by nanofer ZVI was observed. At a dosage of 25 mg of nanofer ZVI, only 45% TCE was removed. However, when 0.01M Cu II and 0.15 TCE were present, 80 % degradation of TCE was achieved due to the presence of Cu II. SEM/EDS images indicated that Cu II is reduced to form Cu0 and Cu2O. These formations are considered to be responsible for enhancing TCE degradation. Direct TCE degradation in presence of Cu II involves hydrogenolysis and β-elimination, while indirect reduction involves atomic hydrogen and no direct electron transfer from the metal to reactants. Most of the iron present in nanofer ZVI could get dissolved causing the generation of localized positive charge regions and form metal chlorides to maintain electro neutrality in the system. Local accumulation of hydrochloric acid inside the pits regenerates new reactive surfaces to serve as sources of continuous electron generation. However, no significant effect of TCE was noticed for either increasing or decreasing Cu II sequestering on the surface of nanofer ZVI.


identifier: Yaghootkar, Bahareh  (2014) A Study of Novel Fabrication Techniques for Development of 3-D Silicon Nano-structure Array.  PhD thesis, Concordia University.

abstract:
The large surface area and high aspect ratio of nano-structures make them promising candidates as a fundamental building block for manufacturing various devices. The potential applications of silicon nano-structure array include, but are not limited to, electron emitters, sensors, solar cells, rechargeable batteries, and hydrogen storage devices. With advances in nanotechnology, various techniques have been reported for synthesis and fabrication of nano-structures. However, these techniques like chemical vapor deposition and vapor liquid solid suffer from the need of very sophisticated and high cost equipment. Furthermore, the need of high operating temperature, high vacuum, and catalyst material such as gold are major challenges of these techniques. On the other hand some fabrication techniques such as top-down approaches involve complicated fabrication steps that ultimately increase the cost of the device.
Therefore, a rising impetus has been devoted to development of less complicated and low-cost fabrication techniques of silicon nano-structure.
The goal of this thesis was to introduce novel and cost-effective fabrication methods which also maintain the benefits of CMOS compatibility. Two non-lithography top-down approaches were introduced for fabrication of silicon nano-structures array with capability of controlling the structure characteristics.
The first fabrication approach consists of three steps: 1) patterning of silicon surface in TMAH using anisotropic etching technique, 2) formation of porous layer on patterned silicon surface using electrochemical anodic etching, and 3) treatment of porous silicon layer using an alkaline etching to reveal the silicon nano-structure array.
The second fabrication approach consisted of two steps, namely: Anisotropic etching followed by electrochemical etching. The main idea behind this approach was that unlike the first approach the electrochemical etching is performed in transition regime not porous silicon formation regime.
These techniques allowed for the controlling the characteristics and morphology of   silicon nano-structures.
Completely different morphologies of nanostructures were achieved as a result of transforming the electrochemical process from porous silicon formation to transition regime.
A study on effect of type of dopant, p- and n-type, on over-mentioned fabrication methods was also investigated.


identifier: Wu, Shikui  (2014) Three Studies on Multi-attribute Market Mechanisms in E-procurement.  PhD thesis, Concordia University.

abstract:
Successful e-procurement depends on selecting the appropriate mechanisms that comprise rules governing and facilitating transaction process. Existing mechanisms have theoretical or practical limitations such as limited number of attributes, disclosure of buyer’s preferences and costly processes. The present research addresses these issues through three studies. Study 1 presents two feasible mechanisms for multi-attribute multi-supplier transactions. They allow buyers to control preference representation and information revelation, assuring that suppliers obtain sufficient information in making effective proposals while protecting confidential information. Following the design-science approach, the mechanisms are implemented to support multi-attribute reverse auctions and multi-bilateral negotiations. Study 2 examines the revelation of information in multi-attribute reverse auctions. Three revelation rules are formulated with admissible bids, winning bids and all bidders’ bids. Their effects on the process, outcomes and bidders’ assessment are tested in two experiments. The results show significant improvement in process efficiency when more information is revealed. The suppliers reached better outcomes with either admissible bids only or all bidders’ bids, while the buyers gained more when revealing the winning bids only. Bidders were more satisfied with the outcomes and system when more information was provided. Study 3 compares multi-attribute reverse auctions and multi-bilateral negotiations in both laboratory and online experiments. The results show that auctions are more efficient than negotiations in terms of the process. Auctions led to greater gains for the buyers, whereas more balanced contracts were reached in negotiations. Suppliers’ assessment was affected by their outcomes, and the winning suppliers were more satisfied with the process, outcomes and system. The buyer’s role was also examined. Different types of information conveyed from buyer influence suppliers’ behavior in making bids/offers and concessions, which in turn affected buyer’s gains.
This research provides implications to future studies and practices in e-procurement, in particular, the formulation of a procedure of two multi-attribute mechanisms and the formulation of general guidelines for strategic use of different mechanisms in various e-procurement contexts.


identifier: Saberi, Soroush  (2014) Numerical Model and Analysis on Performance of a Straight-Through Swirl Tube Cyclone (Inertial Gas-Solid Separator).  Masters thesis, Concordia University.

abstract:
ABSTRACT
Numerical Model and analysis on performance of a straight-through swirl tube cyclone
Soroush Saberi
A numerical simulation for the rotational flow inside a special configuration of inertial gas-solid separators is performed. The inertial gas-solid separator of the present work can be fit in category of straight-through swirl tube cyclones. Using the results of parametric studies a modified geometry configuration for the inertial gas-solid separator is achieved which shows considerable performance improvement in comparison with the original model. In this approach, the CAD model for the original geometry of the dust separator was generated and the turbulent flow field was solved using time-independent solver and Reynolds stress turbulence model. The solution approach demonstrates consistency with the a
vailable experimental data proving the accuracy of the solution method. The highly rotational flow pattern and its features are described by analyzing the different flow variables. The main contributors of the pressure loss production in the flow field are identified and the most effective geometry parameters are recognized in order to perform the parametric analysis. The modifications are implemented on the original geometry and flow simulation is performed for each new configuration with the same solution method as used for the original model. The flow field changes are evaluated by comparing the contours of flow variables and the generated pressure loss for each case are compared with original configuration. Considering the results of parametric studies, a final model was made and solved numerically. The results show that the final modifications will result in considerable improvements in the amount of pressure loss while preserves the same dust collection efficiency.


identifier: Yu, Qing  (2014) Activation of Temoporfin Using Upconverting LiYF4: Tm3+/Yb3+ Nanoparticles.  Masters thesis, Concordia University.

abstract:
A novel and facile approach has been developed to functionalize lithium yttrium fluoride (LiYF4:Tm3+/Yb3+) upconverting nanoparticles with the second generation photosensitizer 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (m-THPC, Temoporfin, Foscan®) for photodynamic therapy.  The synthesized nanoconstruct was capable of generating singlet oxygen under near-infrared excitation.
The upconverting nanoparticles LiYF4:Tm3+/Yb3+ were prepared via the thermal decomposition method. A post-synthesis treatment with HCl was applied to render the nanoparticles monodispersible in aqueous solution, as well as leaving positive charges on the nanoparticle’s surface for conjugating potential ligands with negative charges via electrostatic interaction.
m-THPC has been modified using a bio-compatible linker 4-(bromomethyl)benzoic acid (BMBA), which not only facilitated the grafting of the m-THPC onto the nanoparticle’s surface but also induced a bathochromic shift of the most intense blue absorption peak (Soret band) of m-THPC which resulted in an overlap with the blue emission peak(s) from LiYF4:Tm3+/Yb3+. The overlap is of paramount importance for the fluorescence resonance energy transfer from the nanoparticle to the photosensitizer. The bathochromic shift of the Soret band has been studied using computational chemistry by stimulating the electronic and optical properties of m-THPC and m-THPC-MBA.
In vitro cell viability test was carried out and the results showed the nanoconstruct was capable of causing cell death up to 70% under 980 nm irradiation for a period of 1 hour. The irradiation with near-infrared light gives a deep tissue penetration and the approach to synthesize this nanoconstruct is very general and could be applied to prepare other photosensitizers in photodynamic therapy.


identifier: Oad, Gul Bahar  (2014) Diameter and Broadcast Time of the Knödel graph.  Masters thesis, Concordia University.

abstract:
Efficient dissemination of information remains a central challenge for all types of networks. There are two ways to handle this issue. One way is to compress the amount of data being transferred and the second way is to minimize the delay of information distribution. Well-received approaches used in the second way either design efficient algorithms or implement reliable network architectures with optimal dissemination time. Among the well-known network architectures, the Knödel graph can be considered a suitable candidate for the problem of information dissemination. The Knödel graph W_(d, n) is a regular graph, of an even order n and degree d, 1 ≤ d ≤ floor(log n). The Knödel graph was introduced by W. Knödel almost four decades ago as network architecture with good properties in terms of broadcasting and gossiping in interconnected networks. Although the Knödel graph has a highly symmetric structure, its diameter is only known for W_(d, 2^d). Recently, the general upper and lower bounds on diameter and broadcast time of the Knödel graph have been presented.
In this thesis, our motivation is to find the diameter, the number of vertices at a particular distance and the broadcast time of the Knödel graph. Theoretically, we succeed to prove the diameter and the broadcast time of the Knödel graph W_(3, n). We also claim that the Knödel graph W_(3, n) for n = 4 mod 4 and n > 16,  is a diametral broadcast graph. We present that W_(3, 22) is a broadcast graph. Experimentally, however, we obtain the following results; (a) the diameter of some specific Knödel graphs, and (b) the propositions on the number of vertices at a particular distance. We also construct a new graph, denoted as HW_(d,2^d), by connecting Knödel graph W_(d-1,2^(d-1)) to hypercube H_(d-1) and experimentally show that HW_(d,2^d) has even a smaller diameter than Knödel graph W_(d,2^d).


identifier: Khan, Zafar Ullah  (2014) Community Driven Framework for Sustainable Municipal Asset Management.  PhD thesis, Concordia University.

abstract: Best practices for municipal asset management require municipalities and communities to clearly define their expectations and to express that in terms of achievable goals for levels of service. The challenge lies in the fact that asset performance from a community perspective may be quite different from a municipality perspective. The real problem is to inter-relate these two perspectives and to determine the optimum quantity of improvement required in the condition of municipal assets to meet community expectations.  The literature reveals the need for development of such methods and management tools to support solutions for sustainable municipal assets that take the above into consideration. To address these issues, a community driven level of service based methodology is developed for municipal corridor management that integrates technical and financial plans of a municipality. The concept of municipal corridor is augmented for the purpose of determining integrated repair/ rehabilitation interventions for pavement, water distribution and sewer collection assets and is termed here as municipal corridor rehabilitation. The developed methodology comprises of three phases. In the first phase, performance modelling and mapping the targeted levels of service to condition rating is developed to quantify asset condition improvement. This is achieved via three models; (1) Analytical Hierarchy model to relate Level of Service with required performance, (2) Fuzzy weighted average model to assess the capacity to deliver targeted performance and (3) Fuzzy Alpha Cut model to map the asset improvement requirement and asset capability. The output of this phase is fed into the second phase, where prioritization of corridors’ intervention plans is established, using an Artificial Neural Network model. In the last phase, the outputs of the preceding two phases are utilized as input to develop a Goal Programming based optimization model which generates optimised intervention plans of municipal corridors.  The developed methodology was applied to a case study in the City of Riyadh in KSA to demonstrate its use and to illustrate its capabilities. The results obtained were found acceptable by management of that city. The case demonstrated the flexibility and utility of the developed methodology and its models in support of integrated optimized intervention plans for water, sewer and municipal roads.


identifier: Shalmani, Tayebeh  (2014) Exploring Pre-service ESL Teachers' Interpretation of Second Language Motivation.  Masters thesis, Concordia University.

abstract: Although many second language (L2) teachers identify motivating their students as an important challenge, few education programs focus on raising pre-service teachers’ awareness of the role that motivation plays in L2 learning. There is little consideration of the beliefs and assumptions that most teachers hold about why learners demonstrate varying degrees of involvement in classroom activities and what factors could account for this variation. This exploratory study investigated how six pre-service teachers in an initial pedagogy course in a Canadian university perceived L2 motivation and how they interpreted L2 learners' participation/non-participation. The participants wrote five journal entries over the ten weeks of a practicum during which they facilitated ESL lessons for adult learners. The first journal entry acted as a narrative since it required the participants to reflect on their previous L2 learning experiences. The other writing prompts were designed to elicit their interpretation of L2 motivation. Additional data were collected through interviews and stimulated recall sessions during which the participants watched video-recordings of their ESL lessons and reflected on their students’ participation/non-participation, as well as on classroom events and task types that might affect the learners' willingness to participate. Lastly, during a group meeting, the participants discussed topics and stimulus materials relevant to the notion of motivation. The findings that emerged from the data suggest that the multi-faceted and complex construct of L2 motivation was mainly ambiguous and under-recognized by the participants. This calls for raising critical awareness of such sensitive notions through teacher education programs.


identifier: Pharaon, Joe  (2014) Set-Valued Maps and Their Applications.  Masters thesis, Concordia University.

title: Set-Valued Maps and Their Applications

abstract: The serious investigation of set-valued maps began only in the mid 1900s when mathematicians realized that their uses go far beyond a mere generalization of single-valued maps. We explore their fundamental properties and emphasize their continuity. We present extensions of fixed point theorems to the set-valued case and we conclude with an application to Game Theory.


identifier: Harvey, Brenda  (2014) Predicting Autonomy-Supportive Parenting and Associated Socio-Emotional Outcomes in Children: A High-Risk Longitudinal Study.  Masters thesis, Concordia University.

abstract:
The present study was designed to examine the psychosocial antecedents (maternal childhood histories of risk, SES and psychosocial risk (comprised of maternal mental health, social support and parental stress)) of autonomy-supportive parenting during preschool and the associated socio-emotional outcomes in childhood (e.g. behavioural problems, social competence), in an at-risk community sample. At Time 1, participants were 100 mothers with their preschool aged children (1-6 years). At Time 2, 78 of the same mothers and children participated when the children were school aged (6-11 years).  All participants were drawn from families who participated in the Concordia Longitudinal Risk Project (a longitudinal, intergenerational study of disadvantaged children screened on measures of aggression and social withdrawal). Autonomy support was coded in two contexts: 1) free play and 2) interference (i.e., mother completes a questionnaire while her child plays alone).
Results revealed that maternal childhood histories of both aggression and social withdrawal, low SES and high psychosocial risk predicted the use of less autonomy support, thus more control; however, only when in a challenging interference context. Conversely, within the free play context, only high SES was predictive of autonomy support. Furthermore, autonomy support during the challenging interference context at Time 1, predicted less problem behaviour, as well as more social competence at Time 2. Taken together, results indicate the importance of parenting behaviours at an early age for children’s later socio-emotional outcomes. Ultimately, results have implications for the design of preventive interventions addressing vulnerability, and fostering healthy relationships through informing parenting practices.


identifier: Karimi, Behnam  (2014) An automatic system for classification of breast cancer lesions in ultrasound images.  PhD thesis, Concordia University.

abstract:
Breast cancer is the most common of all cancers and second most deadly cancer in women in the developed countries. Mammography and ultrasound imaging are the standard techniques used in cancer screening. Mammography is widely used as the primary tool for cancer screening, however it is invasive technique due to radiation used.

Ultrasound seems to be good at picking up many cancers missed by mammography. In addition, ultrasound is non-invasive as no radiation is used, portable and versatile. However, ultrasound images have usually poor quality because of multiplicative speckle noise that results in artifacts. Because of noise segmentation of suspected areas in ultrasound images is a challenging task that remains an open problem despite many years of research.

In this research, a new method for automatic detection of suspected breast cancer lesions using ultrasound is proposed. In this fully automated method, new de-noising and segmentation techniques are introduced and high accuracy classifier using combination of morphological and textural features  is used.

We use a combination of fuzzy logic and compounding to denoise ultrasound images and reduce shadows. We introduced a new method to identify the seed points and then use region growing method to perform segmentation. For preliminary classification we use three classifiers (ANN, AdaBoost, FSVM) and then we use a majority voting to get the final result. We demonstrate that our automated system performs better than the other state-of-the-art systems. On our database containing ultrasound images for 80 patients we reached accuracy of 98.75% versus ABUS method with 88.75% accuracy and Hybrid Filtering method with 92.50% accuracy.

Future work would involve a larger dataset of ultrasound images and we will extend our system to handle colour ultrasound images. We will also study the impact of larger number of texture and morphological features as well as weighting scheme on performance of our classifier. We will also develop an automated method to identify the "wall thickness" of a mass in breast ultrasound images. Presently the wall thickness is extracted manually with the help of a physician.


identifier: Malla, Veera Nagasiva Tejeswi  (2014) Design and Validation of Receiver Access Control in the Automatic Multicast Tunneling Environment.  Masters thesis, Concordia University.

abstract:
Standard IP multicast offers scalable point-to-multipoint delivery, but no control over
who may send and who may receive the data stream. Participant Access Control has
been developed by Islam and Atwood, but only for multicast-enabled network regions.
Automatic Multicast Tunneling has been developed by the Internet Engineering Task
Force. It extends the range of multicast data distribution to unicast-only network
regions, but provides no Participant Access Control.
We have designed the additional features that AMT must have, so that AMT has
the necessary Participant Access Control at the receiver's end in the AMT environment. In addition, we have validated our design model using the AVISPA formal
modeling tool, which confirms that the proposed design is secure.


identifier: Weiner, Oren  (2014) Psychometrics of Pediatric Heart Rate Variability: Reliability and Stability.  Masters thesis, Concordia University.

abstract: Measures of heart rate variability (HRV) are commonly used in longitudinal studies among infants, children, and adolescents as an indicator of autonomic cardiovascular control. However, the psychometric properties of pediatric HRV measures have yet to be established. This thesis examined the psychometrics of time- and frequency-domain HRV measures among infants and youth through two complementary studies. The first study was a systematic review and meta-analysis of 46 studies that evaluated how study methodology (study protocol, sample characteristics, ECG signal acquisition and pre-processing, HRV analyses) affects HRV test-retest reliability. HRV displayed moderate reliability overall across infant/toddler (Mage <5 yrs; Fisher’s Z = 0.42) and child/adolescent groups (Mage 5–18 yrs; Z = 0.64); reliability among infant/toddler studies was relatively more sensitive to examined a priori moderator variables. The second study examined temporal stability of HRV measures obtained from children (Mage 9 yrs) participating in a large, longitudinal cohort study (N = 632) within Quebec. Results indicated that HRV is a moderately stable individual difference in children (ICCrange = 0.74–0.85; rrange = 0.67–0.75), and stability was robust to initial differences in, and developmental changes among demographic (age, puberty), cardiovascular (blood pressure), anthropometric (height, adiposity indices), and physical activity (e.g., weekday/end screen time) covariates. However, stability of HRV measures reflecting parasympathetic (rMSSD, pNN50, HF) activity was augmented following statistical control of time-varying heart rate measures. Together, this thesis contributes original knowledge regarding the psychometrics of pediatric HRV measures. Pertinent methodological and intra-individual factors recommended for consideration by future researchers are discussed.


identifier: Hoang, Hai Anh  (2014) Scalable Column Generation Models and Algorithms for Optical Network Planning Problems.  PhD thesis, Concordia University.

abstract:
Column Generation Method has been proved to be a powerful tool to model and solve large scale optimization problems in various practical domains such as operation management, logistics and computer design. Such a decomposition approach has been also applied in telecommunication for several classes of classical network design and planning problems with a great success.

In this thesis, we confirm that Column Generation Methodology is also a powerful tool in solving several contemporary network design problems that come from a rising worldwide demand of heavy traffic (100Gbps, 400Gbps, and 1Tbps) with emphasis on cost-effective and resilient networks. Such problems are very challenging in terms of complexity as well as solution quality. Research in this thesis attacks four challenging design problems in optical networks: design of p-cycles subject to wavelength continuity, design of dependent and independent p-cycles against multiple failures, design of survivable virtual topologies against multiple failures, design of a multirate optical network architecture. For each design problem, we develop a new mathematical models based on Column Generation Decomposition scheme.

Numerical results show that Column Generation methodology is the right choice to deal with hard network design problems since it allows us to efficiently solve large scale network instances which have been puzzles for the current state of art. Additionally, the thesis reveals the great flexibility of Column Generation in formulating design problems that have quite different natures as well as requirements.

Obtained results in this thesis show that, firstly, the design of p-cycles should be under a wavelength continuity assumption in order to save the converter cost since the difference between the capacity requirement under wavelength conversion vs. under wavelength continuity is insignificant. Secondly, such results which come from our new general design model for failure dependent p-cycles prove the fact that failure dependent p-cycles save significantly spare capacity than failure independent p-cycles. Thirdly, large instances can be quasi-optimally solved in case of survivable topology designs thanks to our new path-formulation model with online generation of augmenting paths. Lastly, the importance of high capacity devices such as 100Gbps transceiver and the impact of the restriction on number of regeneration sites to the provisioning cost of multirate WDM networks are revealed through our new hierarchical Column Generation model.


identifier: Watson, Andrew  (2014) Preference for appraisal format: How individual differences shape perceptions of ratings and comments.  Masters thesis, Concordia University.

abstract:
ABSTRACT
Preference for Appraisal Format: How Individual Differences
Shape Perceptions of Ratings and Comments
Andrew Watson
The current study explores the differences between the two most commonly used appraisal formats, ratings and comments. Lending both from literature on performance appraisals, and individual differences, this study looks at an appraisee’s perceptions of how useful each performance appraisal format is dependent on the appraisee’s individual differences (Goal orientation, Tenure). A total of 188 university professors took part in this study. Participants completed an online questionnaire that dealt with perceptions of their past teacher evaluations, and their individual characteristics. Regression analysis was used to explore the relationship between different individual differences and the perceptions the participants had of how useful ratings and comments were. The findings conclude that overall university professors find both comment and ratings as useful, with comments being more useful than ratings. It was also found that as tenure increases, comments will decrease in perceived usefulness faster than ratings. Practical implications and future research avenues are discussed.


identifier: Berthold, Florence  (2014) INTEGRATION OF PLUG-IN HYBRID ELECTRIC VEHICLE WITH THE GRID USING VEHICLE-TO-HOME AND HOME-TO-VEHICLE CAPABILITIES.  PhD thesis, Concordia University.

format: text text

abstract:
The challenge for the next few years is to reduce CO2 emissions, which are the cause of global climate warming. CO2 emissions are mainly due to thermal engines used in transportation. To decrease this emission, a viable solution lies in using non-polluting electric vehicles recharged by low CO2 emission energy sources.
New transportation penetration has effected on energy production. Energy production has already reached peaks. At the same time, load demand has drastically increased. Hence, it has become imperative to increase daily energy production. It is well-known that world energy production is mainly produced thermal pollutant power plants, except in Québec, where energy is produced by hydro power plants.
The more recent electricity utility trend is that electric, and plug-in hybrid electric vehicles (EV, PHEV) could allow storage and/or production of energy. EV/PHEV batteries can supply the electric motor of the vehicle, and act as an energy storage that assists the grid to supply household loads. This power ﬂow is called vehicle-to-grid, V2G. In this dissertation, the V2G power ﬂow is speciﬁcally called vehicle-to-home, V2H. That is battery is used during peak. Moreover, the EV battery is charged during the night, when energy production is low and cheap. This important aspect of Vehicle-to-Home (V2H) is that the vehicle battery is not connected to the grid, but is a part of a house micro-grid.
This dissertation presents an ofﬂine optimization technique, which includes different energy ﬂows, between the home, EV/PHEV, and a renewable energy source (such as photovoltaic - PV and/or wind) which forms the micro-grid.
This optimization has been realized through the dynamic programming algorithm. The optimization objective is to minimize energy cost, including fuel cost, electricity cost, and renewable energy cost.
Two fuzzy logic controllers, one located in the vehicle and the second one in the house, have been designed, tested by simulation (online simulation) and validated by experiments.
The research analyses two seasonal case studies: one in winter and the other one in summer. In the winter case, a cost reduction of 40 % for the ofﬂine simulation, 27 % for the online simulation and 29 % for the experiment is realized whereas in the summer case a cost reduction of 62 % for the ofﬂine simulation, 60 % for the online simulation and 64 % for the experiment is presented.


identifier: Carabet, Lavinia Arielle  (2014) Theoretical Study of the Nitric Oxide Dioxygenase Reaction of the Truncated Hemoglobin N from Mycobacterium tuberculosis.  Masters thesis, Concordia University.

abstract: Tuberculosis (TB) is one of the oldest human afflictions and is still declared a major threat worldwide. The contemporary resurgence of the TB epidemic is due to multidrug-resistant strains of Mycobacterium tuberculosis (Mtb). The success of Mtb as a human lung pathogen is attributed to its capacity to survive in the alveolar macrophages of the host immune system by entering, for a prolonged time, a state of latency where it can resist oxidative and nitrosative species (e.g. O2•- and •NO), and then reactivates to cause TB. •NO plays an important role in the host defense against the pathogen by inhibiting key biological processes. For instance, •NO and its highly reactive derivatives (OONO- and •NO2) inhibit respiration and effect nitration that can lead to cell death. The truncated hemoglobin N (trHbN) of Mtb protects the aerobic respiration of the bacillus from •NO inhibition and prevents its own irreversible nitration, by actively metabolizing •NO to innocuous NO3-, through the rapid nitric oxide dioxygenase reaction (NOD). The NOD reaction is central to the defense system of Mtb, for coping with the toxic effects of •NO under hypoxia. The mechanism of the NOD reaction includes the formation of the OONO- intermediate and its isomerization to a nitrato-complex, followed by the release of the NO3- anion. Discrepancies exist in the literature with respect to the isomerization mechanism and the role of the active site residues in assisting the reaction. These aspects of the NOD reaction have been investigated here using state-of-the-art computational approaches. The results suggest a sequential mechanism with very short-lived intermediates. Distal Gln58, Tyr33, Leu54, Phe46, Phe32 and Val94 residues facilitate and cage the highly reactive FeIV=O2- and •NO2 intermediates that result from OONO- homolysis. Tyr33 is involved in a dynamic H-bonding network with Gln58 and Leu54 backbone. Tyr33 changes conformations and transiently stabilizes the •NO2 radical. Gln58 stabilizes the O-atom of oxo-ferryl species and assists •NO2 rebinding via H-bonding. Phe46 stabilizes the bound product. The H-bonding network between Tyr33, Gln58 and Leu54 prevents the oxidation and nitration of Tyr33 by keeping the hydroxyl and phenyl groups at safe distance and orientation with respect to FeIV=O2- and •NO2. Similar dynamics of the distal site residues have been observed for NO3- release. Tyr33, Gln58, Phe46 and Phe32 stabilize NO3- via H-bonding, and promote the breaking of the FeIII-O bond of the bound NO3-, its dissociation and release.


identifier: Zhang, Xuehua  (2014) Relaying Strategies for Cooperative Systems.  PhD thesis, Concordia University.

abstract:
In this thesis, we investigate several relaying strategies for cooperative networks with the aim of finding techniques to improve the performance of such networks. The objective here is to increase the spectral efficiency while achieving full diversity. Therefore, we focus on two-way
relaying and relay assignment since they are both efficient ways in improving the spectral efficiency of cooperative networks. Specifically,we propose efficient relay strategies to cope with the asymmetric data rates in two-way relay channels and address practical issues in relay assignment.

In the first part of the thesis, we consider two decode-and-forward (DF) relaying schemes for two-way relaying channels where the two sources may have different rate requirements.
One scheme combines hierarchical zero padding and network coding (HZPNC) at the relay. The novelty of this scheme lies in the way the two signals (that have different lengths) are network-coded at the relay. The other scheme is referred to as opportunistic user selection (OUS) where the user with a better end-to-end channel quality is given priority for transmission. We analyze both schemes where we derive closed form expressions for the end-to-end(E2E) bit error rate (BER). Since the two schemes offer a trade-off between performance and throughput, we analyze and compare both schemes in terms of channel access probability and average throughput. We show that HZPNC offers better throughput and fairness for both users, whereas OUS offers better performance. We also compare the performance of HZPNC with existing schemes including the original zero padding, nesting constellation modulation and superposition modulation. We demonstrate through examples the superiority of the proposed HZPNC scheme in terms of performance and/or reduced complexity.

In the second part of the thesis, we consider a hybrid relaying scheme for two-way relay channels. As per the proposed scheme, if the E2E signal-to-noise ratio (SNR) of both users is above a specified threshold, both sources transmit over orthogonal channels and the relay node uses hierarchical modulation and network coding to relay the combined signals to both sources in the third time slot. Otherwise, the user with the better E2E SNR transmits, while the other user remains silent. The advantage of the proposed scheme is that it compromises between throughput and reliability. That is, when both users transmit,
the throughput improves. Whereas when the better user transmits, multiuser diversity is achieved. Assuming asymmetric channels, we derive exact closed-form expressions for the E2E BER, access probability and throughput for this scheme and compare its performance to that of existing schemes. We also investigate the asymptotic performance of the proposed scheme at high SNRs where we derive the achievable diversity order of both users. We show
through analytically and simulation results that the proposed scheme improves 1) the overall
system throughput, 2) fairness between the two users, and 3) the transmission reliability. This all comes while achieving diversity two for both users, which is the maximal diversity.

In the third part of the thesis, we study relay assignment with limited feedback. In networks with many multiple source-destination pairs, it is normally diffcult for destinations to acquire the channel state information (CSI) of the entire network without feedback. To this end, we design a practical limited feedback strategy in conjunction with two relay assignment schemes, i.e., fullset selection and subset selection, which are based on maximizing
the minimum E2E SNR among all pairs. In this strategy, each destination acquires its SNR,quantizes it, and feeds it back to the relays. The relays then construct the E2E SNR table
and select the relay assignment permutation from all possible relay assignment permutations or only a subset of these permutations. We analyze the performance of these schemes over independent Rayleigh fading channels in terms of the worst E2E SNR. We derive closed-form
expressions for the E2E BER and investigate the asymptotic performance at high SNR. We show that relay assignment with quantized CSI can achieve the same first-order diversity as
that of the full CSI case, but there is a second-order diversity loss. We also demonstrate that increasing the quantization levels yields performance that is close to that of having full knowledge of the CSI.


identifier: Roumanis, Melissa  (2014) The Relationship between Movement and Pain Related Fear, Function, and Depression in Chronic Pain Patients.  Masters thesis, Concordia University.

abstract: Chronic pain affects multiple facets of a person’s life. Interdisciplinary programs are effective in treating chronic pain, but approaches used to improve function are different between programs. It is unclear which aspect of rehabilitation is responsible for improving function. In these programs, patients’ allocation to groups and post program assessments are based on subjective and self-report evaluations from the patients. The purpose of this study was to objectively evaluate chronic pain patients’ day and night movement to see the relationship between movement to baseline and final outcomes in pain related fear, function, depression, and pain. Twenty-four patients were diagnosed with chronic pain and wait listed for a chronic pain rehabilitation program (age=48.1±11.8years, weight=76.2±21.2kg, height=164.6±7.3cm). There were two groups at this rehabilitation center, specialized (S) and super-specialized (SP), 12 patients in each group. Patients’ pain related fear, function, depression, and pain was assessed prior to the starting the program and at the completion of the 9-week program. Day movement and night movement were monitored for 7 days prior to starting the program using actigraphy. All pain related fear, function, depression, and pain variables significantly improved upon completion of the program. Movement during the day was significantly related to self-reported function, but not to the 6-minute walk test. Moreover, movement during the day was correlated with depression and pain. In conclusion, day and night movement cannot be used to predict successful completion of the program. Clinicians should use self-reported and objective function measurements to accurately reflect patient ability.


identifier: Price, David William  (2014) Case Studies of Implementing Writing Courses Online in Higher Education.  Masters thesis, Concordia University.

abstract: Reports of online writing courses at universities provide isolated experiences rather than multiple-case comparisons. This study uses activity theory to explore the nature of successful developments of four online writing courses in higher education. Universities desire online learning to meet strategic and accessibility needs. Faculty may lack skills and resources but administrators can provide supportive environments. Online learning risks higher dropouts and simplistic pedagogies, but effective design encourages productive interactions and ongoing course improvements. Six reported cases described online writing courses that either preserved classroom writing pedagogies, or addressed systemic dysfunctions in classroom courses. This qualitative study uses a convenience sample of four case studies recruited from online university courses in technical or professional writing in the United States and Canada. Information was collected through interviews with instructors and available personnel, course walkthroughs and artifacts. Cases were analyzed using activity theory. Cases consisted of undergraduate and graduate courses in technical or educational writing, legislative drafting, and proposal writing. The courses were ongoing activity systems constrained by professor experience and source materials, but subject to structural tensions that resulted in expanded motivations for access, achievability, and community integration. Stakeholders can recognize the impact on design from the reason the course was requested, professor independence, existing course materials, and ongoing measurement. The small sample was suitable for generating theory but not statistical generalization. Future research can explore courses in other countries and languages, writing disciplines, and institutions.


identifier: Eid, Pedro Maroun  (2014) A Knowledge-based Approach for Creating Detailed Landscape Representations by Fusing GIS Data Collections with Associated Uncertainty.  PhD thesis, Concordia University.

abstract:
Geographic Information Systems (GIS) data for a region is of different types and collected from different sources, such as aerial digitized color imagery, elevation data consisting of terrain height at different points in that region, and feature data consisting of geometric information and properties about entities above/below the ground in that region. Merging GIS data and understanding the real world information present explicitly or implicitly in that data is a challenging task. This is often done manually by domain experts because of their superior capability to efficiently recognize patterns, combine, reason, and relate information. When a detailed digital representation of the region is to be created, domain experts are required to make best-guess decisions about each object. For example, a human would create representations of entities by collectively looking at the data layers, noting even elements that are not visible, like a covered overpass or underwater tunnel of a certain width and length. Such detailed representations are needed for use by processes like visualization or 3D modeling in applications used by military, simulation, earth sciences and gaming communities. Many of these applications are increasingly using digitally synthesized visuals and require detailed digital 3D representations to be generated quickly after acquiring the necessary initial data.

Our main thesis, and a significant research contribution of this work, is that this task of creating detailed representations can be automated to a very large extent using a methodology which first fuses all Geographic Information System (GIS) data sources available into knowledge base (KB) assertions (instances) representing real world objects using a subprocess called GIS2KB. Then using reasoning, implicit information is inferred to define detailed 3D entity representations using a geometry definition engine called KB2Scene. Semantic Web is used as the semantic inferencing system and is extended with a data extraction framework. This framework enables the extraction of implicit property information using data and image analysis techniques. The data extraction framework supports extraction of spatial relationship values and attribution of uncertainties to inferred details. Uncertainty is recorded per property and used under Zadeh fuzzy semantics to compute a resulting uncertainty for inferred assertional axioms. This is achieved by another major contribution of our research, a unique extension of the KB ABox Realization service using KB explanation services.

Previous semantics based research in this domain has concentrated more on improving represented details through the addition of artifacts like lights, signage, crosswalks, etc. Previous attempts regarding uncertainty in assertions use a modified reasoner expressivity and calculus. Our work differs in that separating formal knowledge from data processing allows fusion of different heterogeneous data sources which share the same context. Imprecision is modeled through uncertainty on assertions without defining a new expressivity as long as KB explanation services are available for the used expressivity. We also believe that in our use case, this simplifies uncertainty calculations. The uncertainties are then available for user-decision at output. We show that the process of creating 3D visuals from GIS data sources can be more automated, modular, verifiable, and the knowledge base instances available for other applications to use as part of a common knowledge base. We define our method’s components, discuss advantages and limitations, and show sample results for the transportation domain.


identifier: Eshita, Israt Jahan  (2014) Analysis of New Multi Cellular Vortex Model.  Masters thesis, Concordia University.

abstract:
A complete theoretical description of multi-celled vortices is complex. Nevertheless, a simplified approach like the one presented in this thesis can provide the most fundamental characteristics satisfactorily.
In this model all velocity distributions are bounded. The solution is obtained using MATLAB and Maple 14 code. The main goal is to develop a numerical technique that will provide good fits to a variety of actual vortices of different types.
The simulated results correlate well actual data of some naturally and experimentally occurring vortices. Two-celled vortices developed in the intakes of gas turbine engines operating near the ground, wing-tips, tornadoes and vortices generated under a liquid-air interfacial wave by wind action are examined here.
The correlations provided in this thesis are biased towards two-cell vortices because a fair number of actual data for the velocity are readily available in the scientific literature. In addition, a simulated four-cell vortex model also described.


identifier: Chiche-Lapierre, Valentine  (2014) Van Der Corput's Lemma in Number Theory and Analysis and its Applications to Abelian Varieties with Prescribed Groups.  Masters thesis, Concordia University.

abstract:
Let A be an Abelian variety over a finite field Fq. We are interested in knowing the distribution of the groups A(Fq) of rational points on A as we run over all varieties defined over Fq. In particular, we want to show that they are in general not too "split". For the case of dimension 1 (elliptic curves) and dimension 2 (Abelian surfaces), there are some theoretical results due to David and her collaborators, but the general case is open.

We are interested in Abelian Varieties of dimension 3. We use Rybakov's criterion, which relates the existence of a given abstract group as the group of points of some Abelian variety to properties of the characteristic polynomial of the variety. We can use it to derive precise properties and then we use the fact that some sequence of monomials of five variables is uniformly distributed modulo one to obtain stronger results that will hold with probability one.

By Weyl's criterion, equidistribution follows by bounding exponential sums, and in order to do so, we will use a combination of different methods. We are particularly interested in Van Der Corput's lemma. It has a continuous version that exhibits the decay of oscillatory integrals and a discrete version that gives a bound for exponential sums. We will see the relation between these two versions and how they apply to the original problem of Abelian varieties.


identifier: Wang, Mianbo  (2014) A Comparative Study on the Performance of Gamma Kernels for Nonparametric Imputation.  Masters thesis, Concordia University.

abstract:
The problems with using the symmetric kernels for nonparametric density and regression
estimators for nonnegative data have been widely discussed. The use of asymmetric
kernels for nonparametric regression, focusing on gamma kernels, have been recently proposed
based on two different angles: one by Chaubey et al. (2010) and the other one by
Shi and Song (2013). These estimators are based on the density estimators proposed by
Chaubey et al. (2012) and Chen (2000). In the present thesis, we explore the performance
of these estimators in the context of nonparametric imputation method under strongly
missing at random assumption that has not been investigated yet in the literature. It is
found that under certain assumption on the regression function, the estimator of Chaubey
et al. (2010) may have a slight advantage over Shi and Song (2013) estimator whereas in
other cases the comparison is not conclusive and further investigation may be needed.


identifier: Paradis-Hautcoeur, Adeline  (2014) L’espace comme récepteur de la personnalité artistique : Une analyse comparative des portraits d’artistes de Sam Tata et Gabor Szilasi.  Masters thesis, Concordia University.

abstract: Les représentations d’artistes ont produit une image mythique dans laquelle la vie et l’œuvre sont intrinsèquement liées. Cette idéalisation de l’artiste s’applique-t-elle au contexte canadien? Ce mémoire se base sur une comparaison entre deux séries réalisées par Sam Tata (1911-2005) et Gabor Szilasi (né en 1928). Les photographes, qui ont fait de Montréal leur ville d’adoption, ont respectivement produit A Certain Identity – 50 Portraits by Sam Tata, diffusés sous la forme d’une publication (1983), et Portraits/Intérieurs, présentée en 1979 au Musée d’art contemporain de Montréal. Ces séries se  composent de portraits d’artistes canadiens réalisés dans leur résidence privée. Les photographes ont dû utiliser l’espace afin de signifier le statut particulier de leurs sujets, mais comment y sont-ils pris? Les deux photographes ont représenté le milieu environnement de manières complètement différentes, ce qui permet d’interpréter leurs photographies comme des approches divergentes à la figure de l’artiste. Gabor Szilasi présente une vision plus matérialiste de la créativité alors que Tata reprend les codes de l’artiste romantique. Des initiatives contemporaines témoignent de la fascination toujours vivante du public pour la vie privée des artistes de renom. Conséquemment, une étude des cas de figure précédents la tendance actuelle permet de donner un point de vue plus local sur un phénomène mondial.


identifier: Gallant, Stephanie  (2014) Neurodevelopmental animal models of schizophrenia-like behaviours: Behavioural and neurochemical consequences of maternal immune challenge and prenatal NMDA receptor blockade.  Masters thesis, Concordia University.

abstract: Schizophrenia is a severe psychiatric illness characterized by positive, negative, and cognitive symptoms.  The observation that the onset of clinical symptoms is often in early adulthood has led to the neurodevelopmental hypothesis which posits that schizophrenia results from altered developmental processes beginning long before onset of clinical symptoms.  The present thesis aimed to evaluate two neurodevelopmental animal models of schizophrenia-like behaviours.  Chapter one explored the epidemiological association between maternal infection and schizophrenia by using a well-validated animal model of maternal viral infection.  Pregnant Wistar rats were injected with the viral mimic polyriboinosinic-polyribocytidilic acid (poly I:C) and juvenile and adult offspring were assessed for altered novel object preference (NOP), sensitivity to the locomotor-activating effects of amphetamine, and deficits in preattentive sensorimotor gating mechanisms.  Our findings suggest that prenatal poly I:C did not result in the expected behavioural deficits in adulthood.  Our findings challenge the robustness of the poly I:C model.  In chapter two, we examined behavioural and neurochemical consequences of prenatal blockade of the glutamate receptor, N-methyl-D-aspartate (NMDA), in juvenile and adult offspring.  Pregnant Long-Evans rats received daily injections of saline or the NMDA receptor antagonist, MK-801.  Offspring were exposed to a battery of behavioural tasks.  The most dramatic of our findings were the altered NOP, hyposensitivity to MK-801 challenges, and deficits in cognitive flexibility observed in the adult male offspring.  Although sometimes contrary to our hypotheses, the overall pattern of our results suggest that prenatal NMDA receptor blockade disrupted normal brain development and induced important behavioural deficits in adulthood.


identifier: Cunningham, Alexander  (2014) Development of reduction-responsive degradable polylactide-based amphiphilic block copolymers for drug-delivery applications.  Masters thesis, Concordia University.

abstract:
Ubiquitous in nature as a result of their versatility both in their structure and properties, smart polymers have been the subject of intensive research in the design of synthetic materials in the field of biomedicine. Of notable consideration, these polymers as drug delivery vehicles offer the potential to increase the bioavailability of therapeutic molecules while reducing the side effects customarily associated with small molecule delivery.
Amphiphilic block copolymers (ABPs) bear a hydrophobic block comprising the hydrophobic core of the nanostructure, and a hydrophilic block providing colloidal stability. The ABP-based micellar carriers are endowed with great advantages that include, but are not limited to, the use of biocompatible material in their synthesis, thereby avoiding adverse side effects from the use of noxious materials. Moreover, the material can be synthesized using facile synthetic methods that allow a narrow size distribution and versatility in their physicochemical properties. Furthermore, their chemical flexibility in their design allows for the incorporation of targeting ligands at the hydrophilic corona promoting active targeting into specific cells. Another point to consider is the incorporation of dynamic chemical bonds in the architecture of the delivery vehicle to promote spatio-temporal release of the encapsulated cargo. Known as stimuli-responsive degradation (SRD), this concept has been exercised to take advantage of endogenous cellular triggers such as gradients in redox potential, pH or temperature that exists among different sub-cellular organelles as well as in different cell types/states; e.g. healthy vs. cancerous cells. One such promising stimuli-responsive platform is the disulfide-thiol chemistry.
In addition, polylactide, a hydroxyalkanoic acid-based hydrophobic polyester, is a promising material in the synthesis of ABPs for biomedical applications. Indeed, it is biocompatible, biodegradable, FDA-approved, and has tunable mechanical properties. However, two challenges remain to be resolved before a successful polylactide-based drug delivery system can be developed: 1) its inherent hydrophobicity; 2) its slow degradation. In this thesis, potential solutions are examined.
	This research is based on the development of monocleavable thiol-responsive degradable polylactide-based amphiphilic block copolymers for drug delivery applications. Different synthetic strategies for the preparation of disulfide-labeled ABPs are presented using either a methacrylate-based or an ethylene oxide-based hydrophilic block. These ABPs are synthesized by a combination of ring-opening polymerization with either atom-transfer radical polymerization or a facile coupling reaction. They are amphiphilic and thus self-assemble to form colloidaly stable micellar aggregates in aqueous solutions above their critical micellar concentration (CMC). These drug loaded ABPs were tested for drug delivery by studying the extent of drug loading and release through analytical methods. Results suggest the disulfide-labeled ABPs respond to the presence of a reducing agent by releasing the encapsulated drug providing support for their potential as delivery vehicles for the targeted release of loaded drugs in both time and space.


identifier: Deschênes, Sonya S.  (2014) The Role of Anger in Symptoms and Processes of Generalized Anxiety Disorder.  PhD thesis, Concordia University.

abstract: Research investigating the associations between anger and symptoms of generalized anxiety disorder (GAD) is limited. The goals of the current program of research were to examine the various forms of anger associated with GAD as well as the cross-over effects of worry and anger on cognitive mechanisms characteristic of GAD and high trait anger. In Study 1, participants (N = 381) completed a series of questionnaires assessing various aspects of anger and GAD diagnostic criteria via self-report. Our results indicated that GAD analogues reported higher levels of trait anger, anger suppression, and hostility than less anxious participants. In Study 2, the effects of laboratory-induced anger on negative style, negative beliefs about uncertainty, and worry were examined. Participants were randomized to an anger induction condition (n = 43) or a control condition (n = 34). An interpretation bias task, questionnaire items assessing beliefs about uncertainty, and a structured worry task were administered following the manipulation. Participants in the anger condition reported greater increases in negative interpretive style and in the belief that uncertainty is unfair and spoils everything than participants in the control condition; however no group differences were found with worry. In Study 3, the effects of anger and worry on interpretive style and hostile attributions were examined. Participants were randomized to a worry induction (n = 51), anger induction (n = 50), or control condition (n = 49). We also examined whether GAD analogues reported greater hostile interpretations of ambiguous intent than less anxious participants, and whether GAD analogue status interacted with the worry and anger experimental conditions in predicting increased hostile and threatening interpretations of ambiguous information. Although we found no effects of condition or interactions between GAD and condition on interpretive style or hostile attributions, we found that GAD symptoms were associated with greater negative interpretive style and greater hostile attributions. Together, findings from these studies suggest that elevated levels of multiple dimensions of anger, as well as hostile attributions, characterize individuals who meet diagnostic criteria for GAD and provide some, albeit limited, support for the notion that elevated anger contributes to cognitive vulnerabilities underlying GAD.


identifier: Elhalwi, Alexandre  (2014) Comparison of Immune Reactivity to Respiratory Challenges in Asthmatics with and without Panic Disorder.  Masters thesis, Concordia University.

abstract:
Objective
Asthma and panic disorder (PD) are highly comorbid conditions. The objective of this study was to examine if PD altered immune reactivity in asthmatics to two acute respiratory stress challenges. We hypothesized that asthmatics with PD would have increased proportions of sputum eosinophils compared to asthmatics without PD in reaction to both challenges.

Methods
Eleven participants (7 PD, 4 non-PD) inhaled methacholine (which produces an asthma attack) on a first day, and on a second, two gases in randomized order: compressed air and a 35% carbon dioxide (CO2) solution (the latter produces a ‘simulated’ panic attack). Following each challenge, we induced sputum to assess immune cell profiles.

Results
ANCOVA-like GLMs demonstrated that the PD group had a significantly lower proportion of sputum lymphocytes (β=-0.75, 95% CIs = -1.30–0.20) than the non-PD group in response to methacholine. A trend also emerged for the PD group reacting with more eosinophils (β=5.03, 95% CIs = -0.73–10.79). The presence of PD conferred no effect on neutrophils (β=-11.72, 95% CIs = -34.64–11.18) or macrophages (β=0.10, 95% CIs = -22.63–22.82). Analyses did not reveal a significant effect of PD on immune reactivity to CO2.

Conclusions
PD appears to influence immunological responses in asthmatics by decreasing the proportion of sputum lymphocytes following a methacholine challenge, but does not seem to alter the immunological responses to CO2 inhalation. Additional studies are indicated to characterize the immunological interrelations between these conditions; these discoveries could allow clinicians to select more targeted treatments for this population.


identifier: Harutyunyan, Louisa  (2014) Efficient Data Dissemination in Wireless Ad Hoc Networks.  PhD thesis, Concordia University.

abstract:
In this thesis, we study the problem of efficient data dissemination in wireless sensor and mobile ad hoc networks. In wireless sensor networks we study two problems: (1) construction of virtual backbones and clustering hierarchies to achieve efficient routing, and (2) placement of multiple sinks, where each sensor is at a bounded distance to several sinks, to analyze and process data before sending it to a central unit. Often connected dominating sets have been used for such purposes. However, a connected dominating set is often vulnerable due to frequent node failures in wireless sensor networks. Hence, to provide a degree of fault-tolerance we consider in problem (1) a 2-connected (k,r)-dominating set, denoted D(2,k,r), to act as a virtual backbone or a clustering hierarchy, and in problem (2) a total (k,r)-dominating set to act as sinks in wireless sensor networks.

Ideally, the backbone or the number of sinks in the network should constitute the smallest percentage of nodes in the network. We model the wireless sensor network as a graph. The total (k,r)-dominating set and the 2-connected (k,r)-dominating set have not been studied in the literature. Thus, we propose two centralized approximation algorithms to construct a D(2,k,r) in unit disk graphs and in general graphs. We also derive upper bounds on the total (k,r)-domination number in graphs of girth at least 2k+1 as well as in random graphs with non-fixed probability p.

In mobile ad hoc networks we propose a hexagonal based beacon-less flooding algorithm, HBLF, to efficiently flood the network. We give sufficient condition that even in the presence of holes in the network, HBLF achieves full delivery. Lower and upper bounds are given on the number of forwarding nodes returned by HBLF in a network with or without holes. When there are no holes in the network, we show that the ratio of the shortest path returned by HBLF to the shortest path in the network is constant. We also present upper bounds on the broadcast time of HBLF in a network with or without holes.


identifier: wang, pei  (2014) ceo age and firm performance post acquisitions.  Masters thesis, Concordia University.

abstract: I examine if firm performance following acquisitions is affected by CEO age. Younger CEOs have larger career concerns compared to CEOs closer to retirement which should better align their incentives with shareholders. Older CEOs closer to retirement are more likely to manipulate firms and make acquisitions that only benefit themselves. On the other hand, younger CEOs have less experience compared to older CEOs. Using a large sample of 1062 acquiring firms and a subsample of 480 public targets, I investigate the post-acquisition firm performance of acquiring firms over the CEOs’ aging process. The empirical results show that the firms operated by younger CEOs (less than 50 years old) perform worse than the firms managed by older CEOs after the acquisitions, both in the short-term and long-term. Although younger CEOs are faced with less agency and horizon problem, and they have more career concerns, these factors do not contribute to better performance. An examination of target characteristics shows that younger CEOs acquire high growth targets. Cross-sectional tests show that the poor performance is related to CEO overconfidence and riskier targets acquired by younger CEOs.


identifier: De Cicco, Michael  (2014) Exploring the role of agrin in skeletal muscle growth.  Masters thesis, Concordia University.

abstract: Skeletal muscle growth is important for organism development. It also occurs during adult life for exercise and to recover from injuries and diseases. Defects in the genetic programming underlying these processes give rise to myopathies. The molecular mechanisms underlying muscle growth are not fully elucidated, but it is known to be triggered by the initial contact between neuron and muscle fiber. This interaction promotes secretion of agrin by the motor neuron to initiate development of neuromuscular junctions. However, recent studies suggest that agrin may play a more prominent role in skeletal muscle growth and development. In this thesis, I characterized this new role for agrin by studying model myoblasts (cultured C2C12 cells) using fluorescence microscopy, immunoblot analysis and qPCR analysis. First, I examined effects of agrin on muscle cell proliferation and differentiation by treating C2C12 cells with recombinant neural agrin for the duration of their differentiation into myotubes. Agrin-treated cells show greater levels of MEF2c and myogenin, markers indicative of differentiation, which correlates with an observed increase in myotube number and area. I then determined that agrin did not use the calcineurin pathway to achieve these phenotypes. Rather, agrin was able to restore growth of calcineurin-inhibited cells, suggesting it targets a different second messenger system. As the Akt/mTOR pathway is critical for muscle growth, I tested whether agrin utilizes this signaling pathway through the use of an mTOR inhibitor, rapamycin. Although the Akt/mTOR pathway was found to be upregulated with agrin treatment, this did not fully account for the effects of agrin on growth and differentiation, suggesting that perhaps another second messenger pathway may be responsible. Although there is much more to explore, this data uncovers a new role for agrin in the development of the early stages of skeletal muscle growth. These new findings allow a better understanding of muscle physiology, and serve as a novel potential target in the treatment of sarcopenia and cachexia.