identifier: Triassi, Elizabeth  (2018) Shifting School’s Climate to Enhance Emotional Intelligence for 21st Century Learners. -Case-Study #WeCare.  Masters thesis, Concordia University.

abstract: In the present case study, a SEL initiative entitled the #WeCare approach was designed and implemented over a two-year time span within EM Elementary School. Through the support of school administration, the #WeCare approach provided staff training, curriculum modifications, construction of a multisensory environment room, as well as online interactive digital support tools to help teachers and support staff integrate SEL skills within their classrooms. A total of 23 teachers and support staff participated in initial training sessions, while 11 participants completed online surveys reporting on the results, including 3 participants who agreed to be interviewed in depth about their experiences. Results of surveys and interviews were analyzed and coded into four main themes including: the need for a proactive school climate, pedagogy using the RULER approach (Recognizing, Understanding, Labeling, Expressing and Regulating emotions), Behaviour Management for the Digital Child, and Self-Regulation Strategies using the Harmony Room. Findings state that there was a positive climate change, where teachers created a safe and supportive environment for students. There need for further training was discussed by participants and that the teachers were motivated to implement the changes recommended. Potential limitations of the present study are discussed, and avenues for future research are highlighted with the focus of parental involvement in the #WeCare approach.


identifier: Devaux, Camille  (2018) Knit Two Together and Repeat: Breaking with Tradition through Yarnbombing by the Cercles de Fermières du Québec.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: In 2015, Quebec celebrated the 100th anniversary of the Cercles de Fermières. For this celebration, the current members chose to yarnbomb their communities, a type of street art in which knitted and crocheted elements are created to cover up the urban landscape. As their general reputation is for being ‘traditional,’ setting their craft practices as distant from the contemporary practice of knitted graffiti used in this anniversary celebration, this thesis will explore the historical and present perception of the organisation, in order to better understand and argue against this dichotomy. Interviews done with local practitioners of yarnbombing, and current members of the Cercles de Fermières help prove the importance of oral history in deconstructing the narrative constructed around the Cercle de Fermières and yarnbombing. At the moment of this celebration, their engagement with this contemporary street art was understood as an attempt to mobilize and enliven their ‘traditional’ skills for newer craft practices and aims, and thus actively participate in present-day craft discourse in Quebec. By comparing their practice to that of local and international yarnbombers, and discussing it in light of current discourse around the street art, I argue that while the impact of this activity on the image of the organisation was small, exploring the impact of this activity on the Cercles de Fermières in the years following it has shown that they regained some of the popularity and relevance they had lost over time.


identifier: Kourkchi, Hossein  (2018) MAP Joint Source-Channel Arithmetic Decoding for Compressed Video.  PhD thesis, Concordia University.

abstract:
In order to have robust video transmission over error prone telecommunication channels several mechanisms are introduced. These mechanisms try to detect, correct or conceal the errors in the received video stream.
In this thesis, the performance of the video codec is improved in terms of error rates without increasing overhead in terms of data bit rate. This is done by exploiting the residual syntactic/semantic redundancy inside compressed video along with optimizing the configuration of the state-of-the art entropy coding, i.e., binary arithmetic coding, and optimizing the quantization of the channel output. The thesis is divided into four phases.
In the first phase, a breadth-first suboptimal sequential maximum a posteriori (MAP) decoder is employed for joint source-channel arithmetic decoding of H.264 symbols. The proposed decoder uses not only the intentional redundancy inserted via a forbidden symbol (FS) but also exploits residual redundancy by a syntax checker. In contrast to previous methods this is done as each channel bit is decoded. Simulations using intra prediction modes show improvements in error rates, e.g., syntax element error rate reduction by an order of magnitude for channel SNR of 7.33dB. The cost of this improvement is more computational complexity spent on the syntax checking.
In the second phase, the configuration of the FS in the symbol set is studied. The delay probability function, i.e., the probability of the number of bits required to detect an error, is calculated for various FS configurations. The probability of missed error detection is calculated as a figure of merit for optimizing the FS configuration. The simulation results show the effectiveness of the proposed figure of merit, and support the FS configuration in which the FS lies entirely between the other information carrying symbols to be the best.
In the third phase, a new method for estimating the a priori probability of particular syntax elements is proposed. This estimation is based on the interdependency among the syntax elements that were previously decoded. This estimation is categorized as either reliable or unreliable. The decoder uses this prior information when they are reliable, otherwise the MAP decoder considers that the syntax elements are equiprobable and in turn uses maximum likelihood (ML) decoding. The reliability detection is carried out using a threshold on the local entropy of syntax elements in the neighboring macroblocks.
In the last phase, a new measure to assess performance of the channel quantizer is proposed. This measure is based on the statistics of the rank of true candidate among the sorted list of candidates in the MAP decoder. Simulation results shows that a quantizer designed based on the proposed measure is superior to the quantizers designed based on maximum mutual information and minimum mean square error.


identifier: Lucas, Simone  (2018) An Imperfect Shelter: Interpreting Female Friendship Through Video Art and Critical Theory.  Masters thesis, Concordia University.

format: text video

abstract:
Representations of female friendships in film are often overly romantic, wrought with conflict, or overshadowed by heterosexual romance. In order to investigate and trouble these tropes, I undertook a research-creation project in which I made a prototype for an experimental video about female friendship entitled So You Know I Think About You Every Day. In this video, my friend Tilda* and I read our email correspondences as voice-overs. These voice-over readings are accompanied by images of an abandoned construction site. Within this site, two young women interpret our emails through dance. The dancers watch and perform for each other, but rarely manage to touch. In their dance, they strive towards an ideal friendship of reciprocity and closeness, but never quite reach it. The current document is a complement to this creative endeavor. I discuss the process of making video art and conduct a textual analysis of the finished piece. I approach the making of the video through the lens of interpretive autobiography. The autobiographical genre defies stable notions of subjects, memory and truth. Using my personal archive of emails as source material, I took inspiration from music videos and dance films to create an impressionistic, visual narrative. This narrative conveyed my interpretation of my email exchange and friendship with Tilda. I also borrowed from conventions of narrative storytelling and documentary editing in order to distil the broad reality of a relationship into a single concept and a single story. I analyze my video as a text in a theoretical chapter. First, I use Chantal Akerman’s film News from Home (1991) as a counterpoint to consider email correspondence and the construction of female intimacies through communication technologies. I then discuss the formal elements of So You Know I Think About you Every Day, in particular the use of movement, framing and space. I conclude with a discussion on embracing loss as an integral, though not a final, element of friendship as well as the possibility of play in both friendship and creation.
*Fictional name.

An Imperfect Shelter: Interpreting Female Friendship Through Video Art and Critical Theory


identifier: Colburn, Michael  (2018) Short-lived signatures.  Masters thesis, Concordia University.

title: Short-lived signatures

abstract: A short-lived signature is a digital signature with one distinguishing feature: with the passage of time, the validity of the signature dissipates to the point where valid signatures are no longer distinguishable from simulated forgeries (but the signing key remains secure and reusable). This dissipation happens "naturally" after signing a message and does not require further involvement from the signer, verifi�er, or a third party. This thesis introduces several constructions built from sigma protocols and proof of work algorithms and a framework by which to evaluate future constructions. We also describe some applications of short-lived signatures and proofs in the domains of secure messaging and voting.


identifier: Hernández, Stefania  (2018) Regaining the Shore Agency of Maracaibo. Coastal Waste Narratives.  Masters thesis, Concordia University.

abstract:
Maracaibo has lived from its territory, particularly the Maracaibo Lake. Throughout the years the lake has been exploited for its oil, resulting in a clear degradation. If design can serve as a narrative by interpreting the traces of the space, how can we read this broken space from the perception of its inhabitants? Understanding the notion of the area’s vulnerability, how can we acknowledge and have preferable measures for recognition and respectful use of the shore? The research is based on the concepts of spatial justice, community participation and empowerment to accomplish the regaining of this coastal space.

It was observed through a historical and geographical analysis that the city has had little concern in integrating the coast to its planning, causing a fragmented space, and looks on the reasons and consequences this has had. This research develops a proposal through the selection of a case study community, Lago y Sol. This is made recollecting the community’s insight and narratives through participation methods like workshops and interviews. The data compiled served as a base to develop the design that aims to create a place for them to enjoy while addressing the issue of coastal waste. The intent is to present an example of how the natural and the built environment can bridge for a better urban development based on the imaginary of its direct users. Responding to the necessity for a better development, especially because of its rich potential for social encounter, in a country where much reconciliation is needed.


identifier: Eccles, Stephanie Mary Rose  (2018) The Precarity of Pitbull-type Dog Life: A Case Study of Contested Companionship in Montréal, Quebec.  Masters thesis, Concordia University.

abstract: In June 2016, Christiane Vadnais was killed by her neighbour’s neglected dog, Lucifer. Immediately following the incident the City of Montréal ushered in Breed Specific Legislation (BSL) that enlivened an already conflicted debate surrounding pitbull-type dogs. In this thesis I track BSL as a discourse – that is, as it stems from and shapes broader, shifting discursive constructions of pitbull-type dogs – and as it unfolds on-the-ground in Montréal, with profound effects for the lives of those dogs and their guardians. My theoretical approach draws from critical animal geography, legal geography, and extinction studies to approach BSL as an example of how humans discursively construct and materially affect nonhuman animals through processes of domination. My methodological approach is informed by multispecies ethnography and intimate feminist geographies; as such, it is mutually committed to including nonhuman animals as participants and to pushing the boundaries of conventional methodologies, such as by including personal experience. The thesis is broken into two contextual and two analytical chapters. First, I contribute to the ongoing development of multispecies ethnography by detailing my methodological approach and practices. Following this, I situate BSL in the historiography of pitbull-type dogs. In chapters 3 and 4 I explore both the effects and affects of BSL by tracing the law’s performativity. First, I argue BSL is an example of spatial injustice as it denies pitbull-type dogs – and, if applicable, their guardians – access to space. Second, I suggest BSL is a dealer of death through three modes: the physical death (killing), the death of future generations (sterilization), and the death of a relationship (contested companionship) for pitbull-type dogs. The underlying goal of this research project is to re-story pitbull-type dogs as worthy of adoration, love and life.


identifier: D'Cunha, Tracey  (2018) The Neural Mechanisms Mediating the Augmentation of Heroin Seeking Induced by Chronic Food Restriction.  PhD thesis, Concordia University.

abstract:
Addiction can be defined as a chronic relapsing disorder that is characterized by a loss of control over drug consumption. One of the major obstacles in the treatment of drug addiction is relapse, with the majority of individuals relapsing within the first year of drug abstinence. In humans, restricted food intake can modulate the main triggers of relapse thereby increasing drug craving and relapse. In animal models of relapse, caloric restriction will also increase drug seeking. The experiments presented in this thesis investigated the neuronal mechanisms that mediate the augmentation of heroin seeking induced by chronic food restriction in the rat. The mesolimbic dopamine pathway is heavily implicated in reward and motivation. Therefore, the experiments presented in Chapter 3 explored the role of dopamine in the mesolimbic pathway, specifically the nucleus accumbens, in the augmentation of heroin seeking induced by chronic food restriction. Extracellular dopamine in the nucleus accumbens core and shell subregions was differentially altered during the heroin-seeking test in chronically food restricted rats. Blockade of dopamine D1-like receptors in the nucleus accumbens shell decreased heroin seeking, whereas blockade of D1-like receptors in the nucleus accumbens core selectively reduced heroin seeking in the food restricted rats.
	Hormones involved in energy balance and food intake, such as leptin and ghrelin are implicated in drug-related behaviors. Thus, the experiments in Chapter 4 investigated the role of leptin and ghrelin in heroin seeking induced by chronic food restriction. As expected, chronic food restriction decreased plasma levels of leptin and increased plasma levels of ghrelin. Furthermore, administration of leptin or a ghrelin receptor antagonist into the ventral tegmental area exclusively decreased heroin seeking in the food restricted rats. These results suggest that leptin and ghrelin may modulate drug seeking by acting upstream from the mesolimbic dopamine pathway.
	Finally, in addition to the dense innervations from dopamine projections, the nucleus accumbens also receives a multitude of glutamatergic innervations from a variety of brain regions. Hence, in Chapter 5 we investigated the role of glutamate in the nucleus accumbens on the augmentation of heroin seeking induced by chronic food restriction. Contrary to our predictions, there were no changes in extracellular glutamate in the nucleus accumbens during ongoing heroin seeking. Moreover, administration of a glutamate receptor antagonist had no effect on heroin seeking induced by chronic food restriction. Taken together, these findings demonstrate that the augmentation of heroin seeking induced by chronic food restriction is mediated by dopamine transmission in the nucleus accumbens and can be modulated by hormones involved in metabolic processes, such as leptin and ghrelin.


identifier: Samaei, Ali  (2018) Conformation-activated metal binding and oxidation in native anoxygenic photosystems.  Masters thesis, Concordia University.

abstract:
In green plants oxygenic photosynthesis uses a manganese cluster to catalyze the oxidation of water molecule to molecular oxygen and protons. It is assumed that oxygenic photosynthetic organisms evolutionarily developed from their more ancient anoxygenic relatives. Until recently, the binding and utilization of manganese as a secondary electron donor in anoxygenic photosynthesis from Rhodobacter sphaeroides has only been achieved in genetically modified strains.
In our current work we revealed that the binding is facilitated by light-induced conformational changes. The conformationally-activated electron transfer from manganese to the oxidized bacteriochlorophyll dimer was found to be 50 % faster than that of detected in the dark-adapted conformation.
In order to characterize the accessibility of the binding site, the local dielectric constant was altered by incorporating hydrophobic molecules, such as detergents to the vicinity metal binding site. Tuning the dielectric properties of the binding site by incorporating detergent molecules diminished the observed differences between the electron transfers in the dark- and light-adapted conformations.
The EPR spectra of Cu-BTP complex at various BTP concentration and pH values were recorded. As the concentration of BTP increased, new spectral features emerged in Cu2+ spectra, indicating that the water molecules coordinating Cu2+ in the hexa-aquo complex are replaced by BTP molecules, forming a Cu-BTP structure. The pH dependency of Cu-BTP complex was studied by monitoring the EPR spectra of the complex from pH values of 4.0 to 9.5, and the effect of deprotonation of amine groups of BTP on coordination of copper ions was observed.


identifier: Mallik, Biva Arani  (2018) Revisiting the Environmental Kuznet's Curve in the Presence of Trade.  PhD thesis, Concordia University.

abstract:
In my research I have investigated the impact of trade on the Environmental Kuznets Curve (EKC). I investigate the impact on the level and curvature of the EKC by varying the degree of export and import.
In my first paper, I have revisited the Andreoni and Levinson (2001) model in the presence of trade. In their original work, they conclude that the desired relationship between pollution and income can be traced only when there exists increasing returns to abatement technology. I have built upon the model by introducing trade and heterogeneity in abatement technology. I conclude when pollution sources from production and countries engage in trade, increasing returns to abatement technology no longer remains a necessary condition for a country to experience the EKC. When countries experience CRS or DRS, engaging in trade with countries with IRS enables them to attain the EKC. This however is possible only in the case of transboundary pollutants.
 For my second paper, I look at the impact of trade on the multi-country framework of EKC developed by Diamantoudi and Filippiadis (2010). Introducing trade shows that pollution dependence among countries can exist even when the nature of pollutants is local in addition to the case of global pollutants. Results show that the impact of trade is more favorable for local pollutants both for the shape of the EKC and the scope for pollution substitution.
My third paper is an extension of my second paper where I investigate the impact of trade on the multi-country framework when technology is heterogeneous. When countries of different levels of technology engage in trade with each other, it is found that the relative level of technology has an impact on the scope of pollution substitution as well as the EKC. Results of this paper reveal that when the level of technology of the foreign country is better, engaging in imports, and when the level of technology of the home country is better, engaging in exports helps the scope of pollution substitution as well as the shape of EKC.


identifier: deidouss, john  (2018) Fighting Reasons: Motivations for Combat Sports Participation.  Masters thesis, Concordia University.

abstract: Combat sports has been emerging with the rise in popularity of Mixed Martial Arts (MMA) bringing forward various martial arts styles with it. Why are people deciding to participate in combat sports? And why do they decide to compete in combat sports? These are the questions I will be answering in my research, focusing on the role of embodied emotions and identity in the decision to compete in combat sports. Theories of emotions and identity are discussed in relation to the social roles individuals play to demonstrate the influence they have on the decision to compete in combat sports.


identifier: Moradi Dezfouli, Kaveh  (2018) Essays in Corporate Governance and Environmental Risks.  PhD thesis, Concordia University.

abstract:
This thesis consists of two essays focusing on long-term perspective in management.
The first essay (chapter 2) studies how family firms’ valuations are affected by the presence of free cash flow and anti-takeover provisions. Both free cash flow and anti-takeover provisions are believed to increase the severity of agency conflicts. However, we found that in family firms, the existence of free cash flow and anti-takeover provisions are not perceived as damaging. Our findings indicate that higher levels of free cash flow and higher levels of anti-takeover provisions in family firms are associated with higher valuations as measured by the firms’ Tobin’s Q. Moreover, we find that an increase in strength of anti-takeover provisions or level of free cash flow in family firms positively affects family firms’ valuation.
The second essay (chapter 3) uses a unique data set of natural disasters that occurred around the world during the period 1970 to 2015 and study their impact on the price and price volatility of globally traded agricultural commodities. Our results show that natural disasters affect most of the commodities examined in this study by causing an increase in their price volatility whereas prices are only marginally affected. In addition to this, we find that the total damage caused by a natural disaster affects the magnitude of price and price volatility changes of a given commodity. Finally, natural disasters affecting countries with a higher share of the global production of a commodity have a more significant impact on the price and price volatility of that commodity.


identifier: Frasinescu, Iulian  (2018) Understanding Inquiry, an Inquiry into Understanding: a conception of Inquiry Based Learning in Mathematics.  Masters thesis, Concordia University.

abstract: IBL (Inquiry Based Learning) is a group of educational approaches centered on the student and aiming at developing higher-level thinking, as well as an adequate set of Knowledge, Skills, and Attitudes (KSA). IBL is at the center of recent educational research and practice, and is expanding quickly outside of schools: in this research we propose such forms of instruction as Guided Self-Study, Guided Problem Solving, Inquiry Based Homeschooling, IB e-learning, and particularly a mixed (Inquiry-Expository) form of lecturing, named IBLecturing. The research comprises a thorough review of previous research in IBL; it clarifies what is and what is not Inquiry Based Learning, and the distinctions between its various forms: Inquiry Learning, Discovery Learning, Case Study, Problem Based Learning, Project Based Learning, Experiential Learning, etc. There is a continuum between Pure Inquiry and Pure Expository approaches, and the extreme forms are very infrequently encountered. A new cognitive taxonomy adapted to the needs of higher-level thinking and its promotion in the study of mathematics is also presented. This research comprises an illustration of the modeling by an expert (teacher, trainer, etc.) of the heuristics and of the cognitive and metacognitive strategies employed by mathematicians for solving problems and building proofs. A challenging problem has been administered to a group of gifted students from secondary school, in order to get more information about the possibility of implementing Guided Problem Solving. Various opportunities for further research are indicated, for example applying the recent advances of cognitive psychology on the role of Working Memory (WM) in higher-level thinking.


identifier: Corbeil, Sonia ORCID: https://orcid.org/0000-0002-6728-4453 <https://orcid.org/0000-0002-6728-4453>  (2018) Traduire Exploring Translation Theories, par Anthony Pym : une expérience dialogique.  Masters thesis, Concordia University.

abstract: Ce mémoire, combinant pratique et théorie, porte sur la traduction d’un texte en sciences sociales. Plus précisément, c’est la traduction commentée d’un chapitre de l’ouvrage Exploring Translation Theories, par Anthony Pym, brossant un portrait des principaux paradigmes de la traductologie des années 1950 à aujourd’hui. Le bien-fondé de deux choses est ressorti de mes recherches : 1) lorsqu’on traduit un ouvrage sur la théorie de la traduction, il est nécessaire de refléter l’idéologie traductionnelle de l’auteur; 2) le dialogue entre le traducteur et l’auteur (lorsque c’est possible) bénéficie aux deux parties. En effet, on ne peut traduire un traductologue contre lui-même, c’est ce que je tenterai de vous démontrer à l’aide d’arguments et de citations d’experts de la traduction. Grâce à la communication traducteur-auteur, le traducteur comprend mieux le texte et les intentions de l’auteur, ce qui augmente les chances d’obtenir une bonne traduction; et l’auteur peut, par la lecture intimiste du traducteur et ses commentaires, corriger des erreurs ou améliorer son texte. Dans le cas de Pym, j’ai adopté une stratégie de traduction fondée sur la discussion franche. J’ai osé lui poser des questions directes sur ses intentions, son ton, son oralité, ses erreurs, au risque de le déranger, ou pire, de le choquer. Pym est demeuré collaboratif et enthousiaste, me fournissant des réponses ouvertes et détaillées. Nous avons échangé une quarantaine de courriels, et les avantages de cette discussion sont manifestes. J’ai été inspirée par son approche préconisant la gestion de risques en traduction, et ma façon de traduire a changé. Dans les pages qui suivent, vous serez témoins de cette évolution. Ce qui en résulte est une traduction qui prend des « risques », et une oralité qui unit l’ouvrage et son lecteur.


identifier: Cartile, Andrea  (2018) Process mapping approaches for high-value safety-critical aircraft modification design and development: A case study.  Masters thesis, Concordia University.

abstract:
The aircraft modification sector of the aerospace industry involves the design, build, test, and certification of complex, safety-critical systems for existing aircraft. The high product diversity and low-volume high-value production of this sector results in many unique process challenges. Small-to-medium sized aircraft modification enterprises have adopted product lifecycle management (PLM) methodologies to manage these complex product development processes.

This thesis studies the current-state processes of a typical aircraft modification case study company in Canada, using the research methodology of process mapping. The current-state processes are captured in process maps, which are then assessed to find areas of opportunity for process improvement. The current-state processes are mapped at three different levels of detail: a Tier 1 Phase level, a Tier 2 Milestone level, and a Tier 3 Activity level.

Results of the Tier 1 Phase level analysis illustrate some of the challenges related to simultaneously using multiple PLM methodologies across the product development lifecycle. This finding also affects process communication at the Tier 2 Milestone and Tier 3 Activity levels. Tier 2 Milestone level findings also demonstrate the impact of product diversity on milestone traceability. Tier 3 Activity level findings include the level of detail for effective Tier 3 process mapping, the importance of workflow traceability through documentation, and the challenges of change management.


identifier: Pour Iliaei, Sadaf  (2018) The Effects of Bilingualism and Vocabulary Size on Infants’ Cognitive Control.  Masters thesis, Concordia University.

abstract:
The Effects of Bilingualism and Vocabulary Size on Infants’ Cognitive Control

Sadaf Pour Iliaei
There is increasing evidence that bilingualism may lead to cognitive advantages, and some evidence suggests that these may emerge as early as infancy. The present study examined if such advantages could be found in preverbal bilingual infants (7-month-olds), and older bilingual infants who have an emerging vocabulary (20-month-olds). We compared monolinguals and bilinguals in an anticipatory eye movement paradigm. During the training phase, infants learned to use a visual and auditory cue to anticipate a visual reward on one side of a screen. During the test phase, the reward would appear on the opposite side of the screen, necessitating infants to inhibit the previously-learned rule. Results suggest that both 7-month-old and 20-month-old bilingual infants were better able to inhibit their previously learned response than monolinguals. This effect was most apparent in the middle block of test trials. At 20 months, infants with lower vocabulary size were more engaged in the task, showing more total anticipations (both correct and incorrect) than those with higher vocabulary size. Overall, this research provides some evidence that bilingualism may lead to improvements in cognitive control for preverbal and older infants.
Keywords: infancy, bilingualism, cognitive control, inhibitory control, eye-tracking


identifier: Palermo, Melissa  (2018) Visualizing Support Through Speculative Digital Spaces.  Masters thesis, Concordia University.

abstract:
Rape culture permeates all facets of society. It is a culture wherein sexual violence, especially sexual violence against women, is treated as a normal and acceptable part of our daily lives. While we know that rape culture impacts many people, over the past few years we have seen and heard first hand accounts of the impact of rape culture in an unprecedented way. Social media has become an important space for those impacted by rape culture to share stories of sexual violence and harassment with viral hashtags from #YesAllWomen to #MeToo. While these stories have provided insight into the ways in which rape culture permeates society, wholistic spaces of support have not manifested themselves in online spaces in the same way. Through my work I will demonstrate how the visualization of affective, qualitative data can be used to consider what wholistic spaces of support can look like in a digital context.

I will discuss the development of my research-creation project What Do You Need? as an example of how non-traditional data visualization can be used to explore the diversity of ways that people imagine supportive and empowering environments. What Do You Need? is a visualization of imaginative spaces of support that uses participant submitted visual data to make computer generated collages. Through participatory design methods and a combination of collage and computation I explore how multidisciplinary approaches to qualitative data visualization can be used to gain insight into complex issues.


identifier: Wang, Tian  (2018) Phase equilibria and permanent magnets in the Ce-Fe-Co-B system.  PhD thesis, Concordia University.

abstract:
Ce-Fe-Co-B is a promising system for permanent magnets. A high-throughput screening method combining diffusion couples, key alloys, Scanning Electron Microscope/ Wavelength Dispersive X-ray Spectroscope (SEM/WDS), and Magnetic Force Microscope (MFM) is used in this research to understand the phase equilibria and to explore promising magnetic phases in this system. Three magnetic phases are detected and their homogeneity ranges are determined at 900°C, which are presented by the formulae: Ce2Fe14-xCoxB (0≤x≤4.76), CeCo4-xFexB (0≤x≤3.18) and Ce3Co11-xFexB4 (0≤x≤6.66). The phase relations among the magnetic phases in this system have been studied. Ce2(Fe, Co)14B appears to have stronger magnetization than Ce(Co, Fe)4B and Ce3(Co, Fe)11B4 based on MFM analysis when comparing the magnetic interactions of selected key alloys. Two non-magnetic compounds have been detected in this system, a Co-rich with CeCo12-xFexB6 (0≤x≤8.74) formula; and a B-rich with Ce13FexCoyB45 (32≤x≤39, 3≤y≤10) formula. The crystal structure of this B-rich phase could not be found in the literature and its XRD pattern is extracted in the current study. Moreover, ternary solid solutions ε1 (Ce2Fe17-xCox (0≤x≤12.35)) and ε2 (Ce2Co17-xFex (0≤x≤3.57)) are found to form between Ce2Fe17 and Ce2Co17 in the Ce-Fe-Co ternary system at 900°C.
The intrinsic magnetic properties of Ce2Fe14-xCoxB (0≤x≤4.76) are studied at 25°C using key alloys annealed at 900°C for 25 days. The saturation magnetization (Ms) and the Curie temperature (Tc) of Ce2Fe14-xCoxB increase with Co content. However, the anisotropy field (Ha) of Ce2Fe14-xCoxB diminishes precipitously with Co content. The process of crystal structure refinement indicates that the saturation magnetization of Ce2Fe14-xCoxB is related to the site occupancy of Co atoms at different Fe atomic sites. Co atoms prefer to occupy 8j2 site, followed by 16k2, 4e and 16k1 sites sequentially. Moreover, Co atoms occupying 8j2 site are more effective leading to an increase in the Ms. The individual effects of Ni or Cu on the intrinsic magnetic properties of Ce2Fe12.98-xCo1.02NixB and Ce2Fe12.98-yCo1.02CuyB are evaluated. The maximum solid solubilities of Ni and Cu in Ce2Fe12.98Co1.02B at 900ºC are found to be 8 at.% and 0.8 at.%, respectively. Ni or Cu enhances Tc, but decreases both Ms and Ha of Ce2Fe12.98Co1.02B. This work also discussed the combined effects of Ni and Cu on the intrinsic magnetic properties of Ce2Fe12.98Co1.02B. The Ms of Ce2Fe12.98-x-yCo1.02NixCuyB (0≤x≤0.41, y≈0.119) increases after doping with both Ni and Cu, reaching around 155 emu/g. Meanwhile, the Ha and the Tc are measured to be near 24 kOe and 280°C, respectively.
The domain width and domain wall energy of the Ce2Fe14-xCoxB solid solution are studied for the first time in this work. The influence of Co content on these properties has been analyzed with the aid of magnetic force microscopy using diffusion couple and key alloys. The domain widths of Ce2Fe14-xCoxB decrease with increasing Co content at about 0.02 μm per 1 at.% Co. In Ce2Fe14-xCoxB, phase shift, domain width and saturation magnetization are related in a way that lower average domain width is associated with higher phase shift and higher saturation magnetization. The highest domain wall energy of Ce2Fe14-xCoxB is measured as 31.7 erg/cm2 after dissolving 14 at.% Co (x=2.38). The effects of Ni and Cu on the domain width and domain wall energy of Ce2Fe14-xCoxB (x=1.02) are also studied and reported using response surfaces. The domain width and domain wall energy of this solid solution increase after doping with 1 at.% Ni at constant Co content of 6 at.%, measuring 1.39 μm for domain width and 33.4 erg/cm2 for domain wall energy. Both properties are determined as 0.71 μm and 18.6 erg/cm2, respectively, after doping with 0.8 at.% Cu, while keeping Co content constant at 6 at.%. When Ce2Fe14-xCoxB (x=1.02) is doped with both Ni (1 at.%) and Cu (0.8 at.%), the domain width and domain wall energy measured 0.99 μm and 33.8 erg/cm2, respectively.


identifier: Borquez Schwarzbeck, Marcela  (2018) Investigating the Relationship between Materiality and Meaning in Art Education Settings.  Masters thesis, Concordia University.

abstract: This thesis explores ways in which the new materialist idea of the entanglement of materiality and meaning can be investigated in art education encounters. For this study, I developed a workshop with the methodology of Design Based Research that was implemented in two iterations in the Art Education graduate studio in Concordia University and in the Montreal Museum of Fine Arts respectively. Five students enrolled in the BFA specialization in Art Education in Concordia University volunteered to participate. Their experience as students, art makers and teachers was key for pointing towards procedures and theory that could be applied to future educational encounters. Throughout the workshops it was possible to observe that our understandings of materiality and its relationship to meaning are deeply rooted in and performed by the way we position ourselves in the world and thus our learning and teaching. An important achievement of the exercises was providing opportunities to witness that things make sense together with and without us. Added to that, the research pointed towards the potentialities of a pedagogy of diffraction for articulating the relationship between materiality and meaning in art education settings. That is, it the exercises allowed for unexpected and unconventional approaches to materiality as a way to produce difference, rather than replicating sameness, and to give way for things to take shape and meaning in relations.


identifier: Parmar, Vinodbhai  (2018) Computational Investigation of the Structure, Dynamics, and Functions of Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) Relevant to Its Reactions with Nitric Oxide Donors.  PhD thesis, Concordia University.

abstract:
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a well-known glycolytic enzyme, exhibits moonlighting functions, including catalysis of glyceryl trinitrate (GTN) to release vasoactive nitrite (NO2–) or nitric oxide (NO). GTN catalysis generates a thionitrate (E-Cys-NO2) intermediate at the catalytic thiol of GAPDH. Thus, we investigated decomposition of CH3SNO2, a model compound for E-Cys-NO2, using state-of-the-art quantum mechanics techniques. We showed that the well-studied homolysis pathway, which releases NO, is energetically unfavorable. Instead, hydrolysis and thiolysis pathways that release NO2– are energetically favorable. The release of NO2– upon the attack of anionic nucleophiles (e.g. OH– or CH3S–) along the S–N bond is barrierless which could explain the instability of thionitrates in aqueous solutions. We also looked at the effect of protonation on the stability of the S–N bond of CH3SNO2 to mimic the effect of proton donation from the protein. We found that O- and S-protonation stabilize and destabilize the S–N bond, respectively. We evaluated the electronic structures of the protonated isoforms of CH3SNO2 to elucidate the observed stability/instability of the S–N bond. Further investigation of nitrite release by hydrolysis of E-Cys-NO2 in the active site of GAPDH using quantum mechanics / molecular mechanics (QM/MM) techniques revealed similar activation barriers as shown by the QM methods.
Each subunit of the GAPDH homotetramer binds the cofactor nicotinamide adenine dinucleotide (NAD+). The tetramer binds NAD+ with negative cooperativity. We carried out normal mode analysis and molecular dynamics (MD) simulations of GAPDH-NAD+ to probe the mechanism of negative cooperativity and define the subunit interactions that contribute to this phenomenon. We compared the dynamics of GAPDH-NAD+, GAPDH-NADH, and apo-GAPDH and observed concerted motions between subunits of GAPDH-NAD+ and GAPDH-NADH. These motions are lost in apo-GAPDH, indicating that NAD+ binding induces these dominant and functionally relevant motions of GAPDH. We also indicated the changes in the NAD binding-site residues and active-site residues that are observed in the crystal structure of apo- vs. holo-GAPDH.
Many moonlighting functions of GAPDH depend on its oligomeric state. MD simulations are thus carried out for the three oligomeric states, tetramer, dimer or monomer. Our study shows that the dimer and monomer are less stable than the tetramer and functionally important motions are centered on the NBDs in tetramer and dimer, but they are centered on the S-loop in the monomer. The importance of the dynamics of the S-loop are highlighted. This disordered loop in the dimer and particularly monomer could promote binding of the GAPDH dimer and monomer with multiple protein partners to affect different functions.
We modeled GAPDH and the seven in absentia homolog 1 (Siah1) protein-protein interactions. By investigating complex formation between the different oligomeric states of each protein, we show that the GAPDH monomer binds more tightly to Siah1 than the GAPDH tetramer. Thus, GAPDH monomer could stabilize Siah1 and the complex could be translocated to the nucleus to initiate apoptosis.
Overall, our study provides molecular-level insights into novel functions of GAPDH. We have highlighted the importance of the dynamics of its various structural domains, which contribute to the different functions of GAPDH.


identifier: Bruce, Halina  (2018) Involvement of Cognitive Resources in Sensory and Sensorimotor Functioning with Age.  PhD thesis, Concordia University.

abstract:
Epidemiological research indicates a link between hearing loss and poor mobility (Lin & Ferrucci, 2012; Viljanen et al., 2009). One explanation for this association is cognitive compensation, wherein older adults compensate for hearing loss and declines in mobility by recruiting higher-level cognitive resources. A growing body of research using various approaches demonstrates that cognitive resources are involved in both hearing and mobility with age. Our work complements these studies by using experimental, intervention and modeling techniques to investigate how these domains relate in an aging population.
Using an experimental approach, older adults and older adults with hearing loss completed a cognitive-motor dual-task protocol, in which they performed an auditory working memory task and a balance recovery task singly or concurrently. Older adults with mild hearing loss showed disproportionately greater dual-task costs on the auditory working memory task, particularly when auditory challenge was added. Given the involvement of cognitive resources in challenging dual-task conditions and particularly among a hearing loss population, the second study took a cognitive enhancement approach. Specifically, older adults with and without hearing loss were given either simultaneous or sequential cognitive-physical training formats. While sequential training appeared to benefit performance on the auditory working memory task, older adults with hearing loss appeared to improve on this same task regardless of format. To complement these group-wise effects we took a structural equation modeling approach using data pooled from the two previous studies to examine individual differences in hearing and cognition which might influence mobility. An additional consideration was the impact of self-efficacy. It was found that the association between greater hearing loss and reduced mobility was mediated by cognitive status, and that self-efficacy in the hearing domain may be an important contributor to balance confidence.
Taken together, the current work points to the importance of cognitive resources in both sensory and motor aging, particularly among older adults with age-related hearing loss. As such, the work suggests that cognitive remediation may be a useful complement to traditional hearing and mobility rehabilitation. Moreover, self-efficacy appears to be an important contributor in understanding the relation between hearing loss and mobility.


identifier: Yetman, Heidi  (2018) A Movement in Three Parts: Artist, Educator and Activist.  Masters thesis, Concordia University.

abstract: This thesis is the product of a heuristic methodology using creation as research. Walking back through the studio door, Yetman immerses herself in art making in the hopes of discovering the relationship between three identities: artist, educator, and activist. A series of work using the body and gestures become the catalyst to personal and professional growth. Gestures in drawing become the metaphor of action (movement) and the result is unexpected: a greater involvement in the politics of education and unionism. In the end, new knowledge was presented through a creative presentation, a live art performance.


identifier: Lapierre, Cynthia  (2018) The role of first language influence in the learning of second language grammar: The case of his/her in English.  Masters thesis, Concordia University.

abstract: The present study addresses the potential role of crosslinguistic influence (e.g., Luk & Shirai, 2009) on the development of second language (L2) grammar acquisition (e.g., Goldschneider & DeKeyser, 2001). White (1998) developed an 8-stage framework for the acquisition of possessive determiners (PDs) his and her in English (Spada & Lightbown, 1999; White et al., 2007), which captured common stages of development as learners progressed towards mastery of this feature. To date, however, studies have involved Romance speakers only, for whom difficulties may result from incongruencies in the gender agreement rule for PDs between their first language (L1) and L2 English. In French, for example, the PD is determined by the grammatical gender of the possessed (e.g., Il [masc.] parle à sa mère [fem.]/son père [masc.]) rather than that of the possessor, as in English (e.g., He [masc.] speaks to his [masc.] mother/father). We investigated whether White’s (1998) framework similarly captures development for L1 Taiwanese Mandarin (TM), a language which does not have 1) PDs, or 2) grammatical gender. Fifty-seven participants (aged 8 to 12) completed: (1) a grammaticality judgment task, (2) an oral picture-description task, and (3) a stimulated recall of (1). Results of a cross-sectional analysis suggest that L1 TM follow the broad three-category progression of White’s framework, including the phase during which learners struggle with using the correct PD in kin-different contexts (e.g., a father and his daughter), although this was more evident in production than comprehension (see also, Pozzan & Antón-Méndez, 2017). However, participants did not appear to require the full set of sub-stages of the framework. In particular, L1-influenced forms were used in lieu of his/her (e.g., she/she’s father). Overall, our findings suggest that there are both universal as well as L1-particular factors influencing learners on their path to acquisition of a grammatical feature in the L2.


identifier: Salama, Tarek  (2018) Optimized Planning and Scheduling for Modular and Offsite Construction.  PhD thesis, Concordia University.

abstract:
Offsite construction has gained momentum in recent years due to its improved performance in projects‘ schedule, quality, safety, and environmental impact without increasing cost. Several research studies have introduced planning and scheduling techniques for modular and offsite construction using Building Information Modeling (BIM) and simulation tools. In this research, a questionnaire survey was carried out in collaboration with the modular building institute (MBI), Niagara Relocatable Buildings Inc. (NRB Inc.), and the School of Building Science and Engineering at the University of Alberta. The questionnaire focused on two issues: (1) modular and offsite construction industry characteristics, and (2) barriers to increased market share in this industry. For the latter issue, effort was made to address five factors that emanated from the workshop on ―challenges and opportunities for modular construction in Canada,‖ held in October 2015, Montreal to analyze barriers to modular construction growth in Canada. Key findings of this questionnaire include requests for the use of a separate modular construction design code, innovative financing and insurance solutions, standards that consider procurement regulations, and lending institutions that partner with financial houses to create special lending programs for modular construction. Findings of this questionnaire were published on the official MBI website.
This research presents an alternative BIM-based integrated framework for modeling, planning, and scheduling of modular and offsite construction projects. BIM Vertex BD software was used in the proposed framework for automating data exchange between projects‘ BIM model and the proposed scheduling method. The proposed method integrated linear scheduling method (LSM), critical chain project management (CCPM), and the last planner system (LPS) into a comprehensive BIM-based framework for scheduling, monitoring, tracking, and controlling of projects while considering uncertainty associated with activity durations. A procedure for integrating offsite and onsite construction was introduced based on the proposed scheduling methodology. Then, a new multi-objective optimization model was developed using genetic algorithm (GA) to optimize the integration between the LSM and CCPM. This optimization model minimizes time, cost, and work interruptions simultaneously while considering uncertainty in productivity rates, quantities, and availability of resources. The developed model was based on the integration of six modules: 1) uncertainty and defuzzification module, 2) schedule calculations module, 3) cost calculations module, 4) optimization module, 5) module for identifying multiple critical sequences and schedule buffers, and 6) reporting module. Schedule buffers were assigned whether or not the optimized schedule allows for interruptions. This method considers delay and work interruption penalties and bonus payments. The developed integrated scheduling model for offsite and onsite construction was automated in newly developed software named ―Mod-Scheduler‖ using the ASP.NET system coded in C# programming language. A number of case studies were presented and analyzed to demonstrate the developed methodologies‘ features and capabilities.
This research also introduces a novel modular suitability index (MSI), which utilizes five indices; 1) connections index (CI), 2) transportation dimensions index (TDI), 3) transportation shipping distance index (TSDI), 4) crane cost penalty index (CCPI), and 5) concrete volume index (CVI). Calculating the MSI provided a unified indicator to assist in selecting near optimum module configurations for efficient planning of modular residential construction.
This research identifies the main factors affecting the configuration of modules in hybrid construction projects to introduce a new configuration model that is expected to assist hybrid construction stakeholders in identifying the most suitable configuration for each type of modules (i.e. panels) in their projects. A hybrid construction case study was selected to demonstrate the applicability of proposed model and to highlight its capabilities in selecting the most suitable configuration of panelized projects.


identifier: Gauthier, Emilie  (2018) Tintin and the Adventures of Translation: Les Bijoux de la Castafiore.  Masters thesis, Concordia University.

abstract:
Abstract
Although the fields of children’s literature and comics in translation studies have attracted attention in recent years, there has been less investigation of the translation of comics for children, specifically. The main aim of this dissertation is to demonstrate how the losses and gains of expressive language can be attributed to the complexity of transferring meaning for a young audience. In assessing specific translation challenges found in Les Bijoux de la Castafiore we can attempt to understand the translators’ decision-making processes and determine the different methods and strategies used when translating for children. We propose to examine how various forms of expressive language have been translated into English, and to identify the dilemmas posed by linguistic and cultural differences.

Translation for children is frequently associated with a reader-oriented approach. Therefore, the applicability of functionalism as well as the theories of Riitta Oittinen and Göte Klingberg, prominent scholars in the translation of children’s literature, will be discussed. In this case study, we believe the translators adapted the album for a British target audience and cultural setting in order to guarantee positive reception. When viewed from an adult perspective, it becomes clear that there are many factors of the translation process and specific issues regarding children’s comics translation which must be taken into consideration. Consequently, no single strategy can be applied to all contexts, and translation challenges must instead be approached on a case-by-case basis.

Résumé
Bien que la littérature jeunesse et les bandes dessinées aient fait l’objet d’études en traductologie dans les dernières années, les bandes dessinées destinées aux enfants ont, quant à elles, reçu peu d’attention. L’objectif principal de ce mémoire est de montrer que les pertes et les gains du langage expressif peuvent être attribués à la complexité de l’exercice de traduction du sens pour un jeune public. En examinant les défis de traduction spécifiques de Les Bijoux de la Castafiore, nous pouvons tenter de cerner les processus de prise de décision des traducteurs et déterminer les différentes méthodes et stratégies utilisées lors de la traduction pour enfants.  Nous proposons d’évaluer comment les diverses manifestations du langage expressif ont été traduites en anglais et d’identifier les dilemmes posés par les différences linguistiques et culturelles.
La traduction pour les enfants est souvent liée à une approche orientée vers le lecteur. Ainsi, l’applicabilité du fonctionnalisme et les théories de Riitta Oittinen et Göte Klingberg, deux chercheurs en traduction de littérature jeunesse, seront étudiés dans le présent ouvrage. Dans cette étude de cas, nous pensons que les traducteurs ont adapté l’album à un public cible britannique et à un contexte culturel afin de garantir une réception positive. Du point de vue des adultes, il devient évident que de nombreux facteurs entrent en jeu dans le processus de traduction et que des défis spécifiques à la traduction de bandes dessinées pour enfants doivent être pris en compte. Par conséquent, il n’existe aucune stratégie qui puisse être appliquée à tous les contextes. Les défis de la traduction doivent plutôt être abordés au cas par cas.


identifier: Sedki, Firas  (2018) A Hormonal, Neuronal, And Behavioural Approach To The Augmentation Of Heroin Seeking In Chronically Food-Restricted Rats Under Withdrawal.  PhD thesis, Concordia University.

type: Thesis PeerReviewed

abstract:
Why can’t we stop? Despite one’s greatest efforts to remain abstinent, re-exposure to drug- associated cues can elicit drug-craving and promote relapse after withdrawal. Interestingly, hunger can increase the vulnerability to relapse. In chronically food-restricted, compared to sated rats, we demonstrated augmented heroin seeking under withdrawal. However, the mechanisms responsible for this susceptibility remain unclear. Here, we evaluated the hormonal, neuronal, and behavioural processes that may contribute to the enhanced vulnerability to drug seeking in calorically-restricted rats.
Estradiol (E2) may facilitate, while progesterone may attenuate drug seeking; however, we are the first to assess these hormones’ role in calorically-restricted, heroin-seeking rats. Removal of the ovaries and subsequent progesterone replacement yielded no effects. However, E2 replacement attenuated the augmented heroin seeking observed in food-restricted rats, providing a therapeutic target for drug-addiction treatment in females.
Next, we investigated the role of the glutamate GluA1 and phosphorylated GluA1 (p-Ser845- GluA1) subunits, which contribute to the long-term relapse vulnerability of abused drugs. Re- exposure to heroin cues, compared to heroin-trained rats not re-exposed to the cues, increased p-Ser845-GluA1 protein levels in the nucleus accumbens (NAc) shell. Reduced NAc shell GluA1 and p-Ser845-GluA1 protein levels were also observed in heroin-trained compared to drug- naïve rats. No changes were observed due to dietary restriction. As we did not dissociate membrane-bound and cytoplasmic receptors, our findings may be a limitation of the
iii
procedure employed. Further work is needed to clarify the role of the GluA1 receptor in chronically food-restricted, heroin-seeking rats.
Lastly, we investigated whether augmented heroin seeking in our food-restricted rats was a function of the cues’ association with the drug, or the inherent value of light cues alone. While some light-cue-specific effects were observed, we concluded that caloric restriction contributes to the motivational properties of light cues as a result of their heroin association.
Collectively, we demonstrate the value of a multi-dimensional approach to the understanding a novel behavioural procedure. While we have answered some questions on the hormonal, neuronal, and behavioural mechanisms underlying the enhanced vulnerability to drug abuse in calorically-restricted rats, we have importantly presented many questions to drive future research.


identifier: Xu, Bowen  (2018) Laboratory measurements and computer simulations of highly curved flow after sluice gate.  Masters thesis, Concordia University.

abstract:
Sluice-gates are widely used for such purposes as the control of discharges and water levels in hydraulic engineering systems. It is important to understand the features of turbulent flow passing underneath a sluice-gate. Previously, a great deal of research attention has centred on such flow features as the head-discharge relationship and the pressure distribution over the gate surfaces, leading to impressive progress in those aspects of the turbulent flow problem. However, little attention has been paid to the curvature of flow profiles immediately downstream of the gate. This is in spite of its relevance to the optimal design and safe operations of sluice-gates.
The purpose of this research work is to characterise the highly curved turbulent flow through laboratory flume experiments and to extend the experimental results by computer simulations. The experiments covered the conditions that the gate opening ranged from one to two inches and the ratio of the upstream depth to the gate opening ranged from four to 16. The computer simulations produced finite volume solutions to the Reynolds-averaged Navier-Stokes equations. Under the same conditions as the flume experiments, the computed flow profiles as well as pressure distributions from the simulations compare well with the experimental data. Much of the success in computations is attributable to the implementation of rigorous procedures to validate mesh convergence, the independence of numerical results on time step and initial conditions used, and the suitability of turbulence closure schemes. The shear stress transport k-ω model is shown to be a suitable model for turbulence closure. It is shown that the volume of fluid method works well for tracking the highly curved free water surface.
This thesis reports further computational results of the flow and pressure fields for large gate openings up to 16 inches, which are close to field scales or prototype scales, and which are difficult and expensive to set up in laboratories. Using the new experimental and computational results, reliable relationships for flow curvature parameters, including the radius of the circle of curvature, the centre of the circle, and the angle of a tangent to the free surface with the channel-bottom, have been developed. The introduction of these new relationships to the permanent literature about sluice-gate flows represents a significant contribution from this research work. This thesis also provides an update of the contraction distance and coefficient, the results being consistent with the literature values. Moreover, corrections to some existing formulations of the sluice-gate flow problem are proposed.


identifier: Yang, Tianlin  (2018) An Accurate FEA of Turning Simulation and Parameters Optimization for Slender Shaft Turning.  Masters thesis, Concordia University.

abstract: There is a high demand to conduct high performance machining in industry to produce high quality parts with high efficiency. Thus, physical machining simulation is a must. Many researches have been conducted on machining simulation with the finite element analysis method.  However, the prior machining simulation method is not completed, and the results are not reliable. In this thesis, a completed and accurate method of machining simulation is proposed. First, the cutting tool and the workpiece 3-D solid models are accurately built. These are often ignored in the prior methods. Second, the tool and the workpiece models are set up in the Thirdwave System machining simulation software according to the actual tool location and orientation in machining. Third, the adaptive meshing method is employed, and the mesh size is adapted for high accuracy and efficiency.  Then, this approach is applied to a slender shaft turning. A detailed discussion on the constitutive equation for simulation is provided for more accurate results. The experiment results are used as a reference for the simulation model to improve the precision. Finally, the parameters for turning the slender shaft are optimized according to the simulated cutting temperatures and forces. The approach can be directly used in industry for high performance machining.


identifier: Taylor, Leslie  (2018) Large eddy simulation of oscillating and deforming airfoils.  Masters thesis, Concordia University.

abstract:
This study examines the aerodynamic features of oscillating and deforming airfoils with vertical axis wind turbine applications. An in-house large eddy simulation (LES) computational fluid dynamic code with the wall-adapting local eddy viscosity sub-grid scale model is used to perform simulations, first to replicate the results of a water tunnel experiment studying an oscillating airfoil, and second to analyze the effects of airfoil deformation on aerodynamic properties.

The main features shown in the water tunnel experiments at a Reynolds number of 10,000 are present in the results of the simulations, including separation bubbles and laminar to turbulent transition, showing the effectiveness of using LES to simulate dynamic stall.

The deformation of the airfoil's trailing edge is implemented using a spring-based mesh deformation method, showing the effects of this movement on the airfoil's pressure coefficient.


identifier: Ghiasi, Leila  (2018) Effect of Early versus Late Lipid Overload on Cellular Programming of Preadipocytes and Adipocytes in Regional Tissue Depots: A Preliminary Study.  Masters thesis, Concordia University.

abstract:
Current research reveals that obesity and adipose tissue growth leads to lipotoxicity resulting in several health perturbations in the human body. Little is known about how the age at which lipid overload starts affects cellular programing in different regions of adipose tissue. In this preliminary study, we hypothesized that the age at which lipotoxicity occurs (age of lipid overload) affects cellular senescence, adipocyte size and number, and preadipocyte proliferation in regional adipose tissue.
          We recruited 7 participants with early lipid overload and 13 participants with late lipid overload. Dual x-ray absorptiometry (DXA) and computed tomography (CT) scans were performed to measure body composition. Adipose tissue was collected via biopsy from the abdominal and femoral subcutaneous depots. Adipose tissue was then digested with collagenase. Adipocyte size was determined by digital pictomicrographs. Primary preadipocytes were isolated and cultured from the stromal vascular fraction (SVF) of adipose tissue. Proliferative capacity of cloned preadipocytes was evaluated via DNA quantification using CyQuant dye (Molecular Probes, Inc.) after 5 and 10 passages, while cellular senescence was assessed by β-galactosidase staining.
          Regardless of the age of obesity onset, femoral preadipocytes are significantly (p<0.001) more capable of proliferation than abdominal cells at the earlier passages (P5). Moreover, after 5 passages preadipocytes from the femoral depot had greater DNA concentration than they had after 10 passages (p<0.001), whereas DNA concentration in preadipocytes from the abdominal depot did not change across passages. There were no differences in adipocyte size and number between groups, though in general, the abdominal depot had more adipocytes than the femoral subcutaneous adipose tissue depot (p <0.05). There were no differences in cellular senescence between depots or groups.
Taken together, our findings suggest that younger preadipocytes in the femoral depot have better capacity to replicate, create mature adipocytes, support the expansion of SAT and maintain healthy adipose dynamics. The future inclusion of more participants will allow us to draw more solid conclusions as to whether the age at which lipid overload develops affects cellular programming of regional adipose tissue.


identifier: Aldoum, Murad  (2018) Wind Loads on Low-slope Roofs of Low-rise and Mid-rise Buildings with Large Plan Dimensions.  Masters thesis, Concordia University.

abstract:
The present study examines wind loads on low-slope roofs of low-rise and mid-rise buildings with large plan dimensions (118 m) to investigate the suitability of wind provisions of the North American codes and standards to such buildings. Examination of such buildings is necessary since the wind provisions of the North American codes and standards were established based on wind tunnel studies involved in the determination of wind loads on buildings with common plan dimensions, i.e. less than 60 m.
The size of roof pressure zones and the magnitude of pressure coefficients on low-sloped roofs of low-rise and mid-rise buildings with large spans have been examined experimentally in the wind tunnel of Concordia University. Three building models were constructed at a length scale of 1:400 with identical plan dimensions (118 m x 118 m) and different heights (5 m, 10 m, and 20 m). The models were tested in simulated open country and suburban exposures for 7 wind directions: 0°, 15°, 30°, 45°, 60°, 75° and 90°. The pressure measurements have been presented in terms of contours of enveloped pressure coefficients, local pressure coefficients, and area-averaged pressure coefficients. The results of the current study have been compared with previous studies, full-scale data and the wind provisions of the North American codes.
It was found that the magnitude of external peak pressure coefficients recommended by ASCE 7-16 for low-slope roofs of low-rise buildings are much higher than the experimental findings and using those recommended by ASCE 7-10 is safe and more economical for large low-rise buildings. Also, for buildings of 8 m height or more, the corner zone should be sized according to ASCE 7-10 and NBCC 2015; and shaped based on ASCE 7-16.
Moreover, for large low-rise building with low heights, say 5 m, it was found that wind loads on the roof corner are approximately equal to those on the edge zone. Exceptions for low-rise buildings with large configurations and low-slope roofs are proposed for ASCE 7 and NBBC regarding roof pressure zones and the magnitude of cladding and components external peak pressure coefficients.


identifier: Kratsios, Anastasis  (2018) Arbitrage-free regularization, geometric learning, and non-Euclidean filtering in finance.  PhD thesis, Concordia University.

abstract:
This thesis brings together elements of differential geometry, machine learning, and pathwise stochastic analysis to answer problems in mathematical finance. The overarching theme is the development of new stochastic machine learning algorithms which incorporate arbitrage-free and geometric features into their estimation procedures in order to give more accurate forecasts and preserve the geometric and financial structure in the data.

This thesis is divided into three part. The first part introduces the non-Euclidean upgrading (NEU) meta-algorithm which builds the universal reconfiguration and universal approximation properties into any objective learning algorithm. These properties state that a procedure can reproduce any dataset exactly and approximate any function to arbitrary precision, respectively. This is done through an unsupervised learning procedure which identifies a geometry optimizing the relationship between a dataset and the objective learning algorithm used to explain it. The effectiveness of this procedure is supported both theoretically and numerically. The numerical implementations find that NEU-ordinary least squares outperforms leading regularized regression algorithms and that NEU-PCA explains more variance with one NEU-principal component than PCA does with four classical principal components.

The second part of the thesis introduces a computationally efficient characterization of intrinsic conditional expectation for Cartan-Hadamard manifolds. This alternative characterization provides an explicit way of computing non-Euclidean conditional expectation by using geometric transformations of specific Euclidean conditional expectations. This reduces many non-convex intrinsic estimation problems to transformations of well studied Euclidean conditional expectations. As a consequence, computationally tractable non-Euclidean filtering equations are derived and used to successfully forecast efficient portfolios by exploiting their geometry.

The third and final part of this thesis introduces a flexible modeling framework and a stochastic learning methodology for incorporating arbitrage-free features into many asset price models. The procedure works by minimally deforming the structure of a model until the objective measure acts as a martingale measure for that model. Reformulations of classical no-arbitrage results such as NFLVR, the minimal martingale measure, and the arbitrage-free Nelson-Siegel correction of the Nelson-Siegel model are all derived as solutions to specific arbitrage-free regularization problems. The flexibility and generality of this framework allows classical no-arbitrage pricing theory to be extended to models that admit arbitrage opportunities but are deformable into arbitrage-free models. Numerical implications are investigated in each of the three parts making up this thesis.


identifier: Larocque, Kevin  (2018) Characterization of a New Anti-Cancer Compound Using Multi-Cellular Tumour Spheroids.  Masters thesis, Concordia University.

abstract: We synthesized a thieonoisoquinoline scaffold amenable to modifications and found that several derivatives selectively kill cancer cells in the nanomolar range. Further characterization of one of these molecules, C75, revealed that it uniquely targets spindle poles. This phenotype is due to specific functional groups and not the scaffold because another derivative, C87, has no effect on cells. To demonstrate C75’s potential for use in vivo, we found that C75 successfully regresses or inhibits the growth of multi-cellular tumour spheroids grown from HeLa (cervical cancer), A549 (lung cancer) and HCT-116 (colorectal cancer) cells. Since C75 is a small molecule, we also determined if controlling its delivery and release would improve its efficacy in spheroids. As a proof-of-concept, we tested the release of Doxorubicin (Dox) from novel polymer-based nanoparticles with dual-controlled release in HeLa and A549 spheroids. Dox levels from nanoparticles increased sooner, and to a greater extent within the core of spheroids vs. free Dox. Encapsulating C75 in similar nanoparticles increased its efficacy in HeLa and A549 spheroids compared to free compound. Lastly, we also explored the potential to use C75 in combination therapies with paclitaxel (TaxolTM), which is an anti-cancer drug that patients often develop resistance to and/or causes severe side-effects. We found that C75 and paclitaxel have different mechanisms of action at a cellular level, and cause regression of HCT 116 spheroids when used in combination at subthreshold doses. Thus, our results show that C75 has the potential to be explored for its use as an anti-cancer drug.


identifier: Hakimitoroghi, Navid  (2018) A Study on Vibration Sensors with Application in Structural Health Monitoring (SHM).  Masters thesis, Concordia University.

abstract:
With the prolific usage of vibration analysis to extract information about different structures (buildings and bridges etc.), vibration sensors have become an important device in Structural Health Monitoring (SHM). In this study, we tried to modify the previous generation of vibration sensors in the analog front end and build a new porotype for a vibration sensor with applications in SHM.
A vibration sensor system includes different modules. Each module has its own functionality. In a vibration sensor system, all these modules have to work together deliberately to form a sensor system. Among the modules that form a sensor system, analog sub-system is responsible to prepare the output signal of the seismic sensor for the analog-digital converter. Mass-spring velocity meter (geophone) which is one of the mostly used sensor in SHM is the main seismic sensor in our sensor prototype. In each geophone, vibrations below a certain frequency which is called corner frequency, is hard to detect because of geophone frequency response. Several techniques have been proposed in this study to modify the lower frequency response of the geophone.
We have verified the compensation techniques in two different situations. First, using a shake table, we excited the geophone with different frequencies and evaluated the compensated frequency response. For the final verification in a real test environment, we tested qualification of the geophone in detecting the vibration of a real building at low frequencies.


identifier: Chen, Jueji  (2018) Agency, Stewardship and Corporate Acquisition Decisions.  Masters thesis, Concordia University.

abstract: We test whether companies with better ESG performance make poorer merger and acquisition deals because they may limit their choices for targets with similar ESG performance or need to invest more into improving targets’ ESG performance, compared to acquirers with poor ESG performance. We also test whether companies with better ESG performance are more likely to pay CEOs lower percentage of equity-based compensation, and are more likely to adopt CEO duality since CEOs tend to be driven by stewardship in companies with better ESG performance.  We find that acquiring companies with above-average ESG performance underperform those with below-average ESG performance and the finding is robust to controlling for bidder, target, and deal characteristics; acquiring companies with below-average ESG performance outperform those with above-average ESG performance in the long-term post-acquisition period as well; companies with better ESG performance pay CEOs higher percentage of equity-based compensation and the relation between CEO duality and companies’ ESG performance is insignificant and neither is the relation between CEO duality and M&A performance. Overall, our results show that firms with better ESG performance underperform firms with poorer ESG performance during and after M&A events. They also show that CEOs who work for high-ESG companies are not driven by stewardship. Our results imply that firms with good ESG performance do not make value-maximizing merger and acquisition deals nor have CEOs driven by stewardship.


identifier: Jekanowski, Rachel  (2018) A Nation of Fur, Fish, and Fuel: Documenting Resource Extraction in Canada.  PhD thesis, Concordia University.

abstract:
As concerns about the environmental and uneven social impacts of human industry mount, humanities scholarship has sought to re-examine assemblages of energy cultures, Western epistemologies of the nature-culture divide, colonialism, and ecology. Against these considerations, this thesis seeks to historicize natural resource extraction as a localized, national, and imperial phenomenon within twentieth-century capitalism. The project focuses on Canadian moving image production in relation to the country’s historical resource economy and cultural attachment to landscape. Examining a range of private- and public-sector nontheatrical and documentary films released between 1920 and 1985, the thesis theorizes these productions as examples of “resource cinema,” given their entanglements with industrial-scale resource extraction on the level of production, narrative, and discourse. The notion of “entanglement” emerges as a framing concept for the project, expressing the shifting yet intimate relations between cultural production, economy, and environments. This term derives from Anna Tsing’s theorization of environmental-economic entanglements within late capitalism.

Each chapter of this comparative study concentrates on films from a different historical period to trace the changing depictions of the geographies, infrastructures, and social practices entwined with natural resource extraction. These include sponsored films about the Northern fur trade (Chapter 2); petroleum, geology, and mining films in Western Canada (Chapter 3); and films interrogating community, sustainability, and energy futures in the Atlantic offshore oil and fishing industries (Chapter 4). The thesis is also invested in contributing to broader interdisciplinary conversations about media and environments. Each chapter theorizes the ways in which these cinematic histories help constitute geo-biological materials as “natural” resource commodities, as a microcosm of capitalism’s wider engagements with nature. The thesis also argues that fur, petroleum, and fish function concomitantly as fuels, in that they power not only the movement of human and nonhuman bodies, but also cinematic imaginaries and the emergence of social, political, and infrastructural practices. In demonstrating how cinema was used as a communication technology and documentary practice, as well as a resource in itself, the project contributes to the emergent fields of energy and environmental humanities, Canadian cultural studies, and Canadian and settler colonial cinemas.


identifier: Zoroddu, Giovanni  (2018) Large deviations for the local time of a jump diffusion with two sided reflections.  Masters thesis, Concordia University.

abstract:
Let X be a jump diffusion, then its reflection at the boundaries 0 and b > 0 forms the process V . The amount by which V must reflect to stay within its boundaries is added to a process called the local time. This thesis establishes a large deviation principle for the local time of a reflected jump diffusion. Upon generalizing the notion of the local time to an additive functional, we establish the desired result through a Markov process argument. By applying Ito’s formula to a suitably chosen process M and in proving that M is a martingale, we find its associated integro-differential equation. M can then be used to find the limiting behavior of the cumulant generating function which allows the large deviation principle to be established by means of the Gartner-Ellis theorem. These theoretical results are then illustrated with two specific examples. We first find analytical results for these
examples and then test them in a Monte Carlo simulation study and by numerically solving the integro-differential equation.


identifier: Lakoff, Aaron  (2018) Changing On The Fly: Radical Sports Journalism and Social Justice in Hockey.  Masters thesis, Concordia University.

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abstract: This research-creation M.A. thesis involves engaging with an important emerging media trend that I call “radical sports journalism”. Radical sports journalism investigates how political power is manifested and contested both through and around sports. The last year has witnessed widespread protests in sports to various forms of oppression, yet why have such protests not permeated the hockey world in North America? As a media practitioner, researcher, and hockey enthusiast, I am very interested in how sports journalism and broadcasting can be mobilized to create circumstances for a better world. However, very little radical sports journalism has touched on hockey in Canada. This research involves interviews with athletes, sports scholars, and hockey commentators whose work looks at gender, sexuality, race and nationalism in hockey. I examine how Canadian nationalist ideologies are deployed, reinforced and contested through hockey. The final product of this research-creation project is a podcast series showcasing my interviews.


identifier: Patalas, Iola  (2018) Assessing the Meaning of Metaphors in Real-Time: A Cross-Modal Investigation.  Masters thesis, Concordia University.

abstract: Natural language is replete with figurative expressions such as "my lawyer is a shark," and listeners are expected to intuitively understand the intended, rather than the literal meaning of such expressions. But what are the cognitive resources involved in attaining meaning for such sentences? According to proponents of the pragmatic model of metaphor comprehension, metaphors are first interpreted literally, and then, upon realizing they cannot be true, listeners search for implicatures that could convey the speaker’s intended meaning (Searle, 1979; Grice, 1989). In contrast, direct-access models of metaphor processing have posited that metaphors can be understood directly, circumventing higher-order cognitive processes (e.g. Glucksberg & Keysar, 1990). The present thesis investigated these theories using a cross-modal lexical decision paradigm (Swinney, 1979) with a novel brief masked target presentation at two probe points, in order to assess the moment-by-moment on-line processes involved in metaphor comprehension. We predicted that, following the pragmatic model, literally related target words would yield greater priming effects at the vehicle (e.g., shark) recognition point (a), compared to figurative targets, in both metaphor and simile conditions. At the later probe point (b), 500 ms after the vehicle’s recognition point, we expected that figurative targets would yield greater priming effects during metaphor comprehension as literal meanings were discarded. Results obtained from a preliminary sample demonstrated priming of related target words across conditions, but no significant differences between conditions. We discuss how these results may best be interpreted as supporting the dual-processing account of metaphor interpretation put forth by Carston (2010), which suggests that metaphors are held in the mind as literally true even as fast ad-hoc concepts are simultaneously created to interpret intended speaker meaning.


identifier: Jnaid, Aid  (2017) Design, Modelling, and Seismic Performance of Outrigger Braced Frame Steel Buildings Subjected to Crustal and Subduction Earthquakes.  PhD thesis, Concordia University.

abstract:
Concentrically braced frames (CBFs) are widely used in North America. The CBFs possess high stiffness and moderate ductility, while braces are designed to buckle in compression and yield in tension. However, after a brace experiences buckling, its compression strength diminishes and the system undergoes asymmetrical response, while the distribution of internal forces and deformations is influenced by the frequency content of ground motions. Despite the system’s stiffness, CBFs are prone to concentrate damage within a floor which leads to the formation of storey mechanism. To preserve the stability of the system during the nonlinear seismic response, the National Building Code of Canada (NBCC) imposes limits on a building’s height which depends on the selected ductility-related force modification factor, Rd. Thus, the height limit for buildings with moderately ductile concentrically braced frames, MD-CBFs, is 40 m and for limited ductility concentrically braced frames, LD-CBFs, is 60 m.
To safely increase the height limit of ductile braced frame buildings, a system labelled Outrigger Braced Frame, OBF, is proposed and developed in this study. According to the Council on Tall Buildings and Urban Habitat (CTBUH), a building with more than 14 stories or more than 50 meters in height may be considered a high-rise building. The aim of this research is to develop, design, model, and study the seismic performance of mid-rise (e.g. tweleve-storey) and high-rise (e.g., sixteen-storey) OBF buildings subjected to dynamic loads. It is noted that the outrigger system functions by tying together a core system and a perimeter system. Herein, the core system is made of MD-CBFs and the perimeter system is made of gravity columns. Furthermore, only the core braces are designed to dissipate energy, while the outrigger’s diagonals are designed to respond in the elastic range. The performance of OBF system is controlled by the amount of added stiffness and optimum location of outriggers across the building’s height, the number of levels with outriggers and the intensity of seismic zone.  All multi-storey buildings are located in high-risk seismic zone of Victoria, B.C. Canada, on Site Class C. The selection of ground motions was made to capture the seismic characteristics at buildings location. Herein, two sets of crustal and subduction ground motions were considered such as California records and the mega-thrust magnitude 9 Tohoku records, respectively. The nonlinear time-history dynamic analyses were conducted using the OpenSees software.
The main objectives of this thesis are three-fold: i) to identify the effect of subduction versus crustal ground motions on the seismic response of low-rise, mid-rise and high-rise MD-CBF buildings and to study their seismic performance from yielding to failure, ii) to provide design method and optimum location for outriggers of OBF steel buildings, iii) to assess the collapse safety of the proposed mid-rise and high-rise OBF steel buildings using FEMA P695 procedure and to compare their seismic performance against that resulted for MD-CBF buildings.
It is concluded that the OBF buildings are slightly stiffer than the corresponding MD-CBF buildings, and they experienced lower interstorey drift and residual interstorey drift than the MD-CBF buildings. In all case studies considered here, the collapse margin ratio (CMR) is greater for buildings subjected to crustal ground motions than subduction ground motions. Evaluation of seismic performance of sample 12-storey and 16-storey OBF buildings shows that these buildings are able to pass the collapse safety acceptance criteria, ACMR ≥ ACMR10%, when subjected to both sets of ground motions. On the other hand, the corresponding MD-CBF buildings are not able to pass the collapse safety acceptance criteria when subjected to subduction records set. Hence, special attention should be given when designing buildings in seismic regions which are prone to both types of earthquakes.


identifier: Dera, Abdulrahman  (2018) The Effect of Childhood - versus Adult -Onset Obesity on Cardiorespiratory Fitness, Handgrip Strength, Resting Metabolic Rate and Substrate Oxidation in Adults.  Masters thesis, Concordia University.

abstract: BACKGROUND: Obesity is associated with a variety of cardiovascular, pulmonary, and skeletal muscle aberrations that negatively affect physical fitness and other metabolic parameters. However, it is unclear whether these impairments are exacerbated in lifelong obesity. OBJECTIVE: We aimed to examine how age of obesity onset (childhood versus adult) affects cardiorespiratory fitness (CRF), handgrip strength, resting metabolic rate (RMR), and substrate oxidation in adults. METHODS: We recruited 31 adults (BMI 29.5 to 39.4 kg/m2) who had either developed obesity before puberty (childhood-onset [CO]; n=13) or after the age of 18 (adult-onset [AO]; n=18). CRF was measured using the YMCA submaximal bike test and handgrip strength was measured using handgrip dynamometry. RMR and substrate oxidation was measured using indirect calorimetry. RESULTS: Mean handgrip strength (±SD) was lower in adults with childhood- versus adult-onset obesity (CO: 56 ± 10 vs. AO: 72 ± 20 kg; p = 0.01). Fat oxidation was also lower in the childhood-onset group (CO: 51.07 ± 18.39 vs. AO: 67.55 ± 23.83 mg/min; p = 0.04), while CRF, RMR and carbohydrate oxidation were not different between groups (p > 0.05). These results persisted when adjusting for age, sex, and body composition. CONCLUSION: Our results show that persistent obesity since childhood impairs muscle strength and fat oxidation, but not RMR and CRF, compared to adult-onset obesity. These results suggest that maintaining a healthy body weight early in life may delay the loss of muscle strength and impairment in fat oxidation in later life and help prevent future disease.


identifier: Faraji, Keyhan  (2018) Seismic performance of a semi-active MR damper improved by fuzzy control system.  Masters thesis, Concordia University.

abstract:
Abstract
Control systems play a crucial role in the operation of airplanes, robots and the new generation of smart automobiles to improve their performance, safety and robustness. Considering the ability of control systems to optimize the functionality of damping devices, such controllable devices can effectively dissipate the seismic vibrations of structures in which they are installed. Although dampers are utilized in many structures, the main issue is that most of such devices function in passive mode without control systems. In some cases, such passive damping systems may perform inefficiently and cause detrimental effects which may endanger the safety of the structures. Magnetorheological (MR) damper is a type of semi-active damper that produces variable resistant force according to the intensity of the magnetic field which is induced by a direct electricity current (DC). Since direct current can be supplied by batteries, this type of damper is functional and serviceable in harsh conditions in which the power supply may be interrupted. Therefore, the capability of variable force production demanding less energy is the major advantage of MR dampers. In this research, seismic response of a 2D single-story structure which is equipped with an adaptive MR damper is investigated and a fuzzy control system is added to the damper to smartly control and adjust its performance in real time. The fuzzy controlled system adjusts the applied electric current to the damper according to the displacement response of the structure caused by an earthquake. Therefore, it makes the resisting damper force proportional and adaptive to the magnitude of the earthquake forces. The analytical results illustrate that such controllable damping system can effectively dissipate the seismic vibration of the structure subjected to two sets of far-field and near-field (pulse- like) earthquake records. In this way the average of the maximum seismic demands in the dynamic model including wave energy, acceleration, velocity and displacement decrease by 38%,40%,36% and 83% for far-field records and by 40%,43%,40% and 82% for near-field (pulse-like) records respectively.

Keywords:    MR damper, fuzzy logic, mamdani system, seismic loads, energy dissipation


identifier: mellah, hakim  (2018) Design of LP01 to LPlm Mode Converters for Mode Division Multiplexing.  PhD thesis, Concordia University.

abstract:
Mode division multiplexing (MDM) over few mode fiber (FMF) has been proposed as an alternative solution to tackle the capacity limitations of optical networks based on standard single mode fiber (SMF). These limitations are caused by the fiber nonlinear effects. MDM is realized through excitation of different fiber spatial modes, each mode being an independent transmission channel. Therefore, MDM over FMF requires mode conversion (basically from fundamental mode to higher order modes and vice versa) as well as mode multiplexing and demultiplexing.
Mode conversion, multiplexing and demultiplexing can be realized through different techniques. It can be achieved using free-space optics based on matching the profile of an input mode to the profile of an output mode using phase mask or spatial light modulator. Mode conversion and (de)multiplexing can also be achieved using waveguide structures. These mode converters and (de)multiplexers are mainly based on optical fiber and planar waveguide, which include fiber grating, tapering, lanterns, planar lightwave circuit (PLC), photonic crystal fiber (PCF), mode selective coupler (MSC) and Y-junction. It is worth mentioning that more than one technique may be applied to realize a specific converter/ (de)multiplexer for a specific mode.
In general, Mode converters and (de)multiplexers based on free space optics are polarization insensitive and wavelength independent, but they result in high insertion loss and are bulky. On the other hand, all-waveguide mode converters and (de)multiplexers have high mode conversion efficiency (less insertion loss and high extinction ratio) and are compact, but they are wavelength dependent.
Recently, many research works demonstrate the design, analysis and fabrication of several types of mode converters and (de)multiplexers. However, almost all the proposed devices are specific to a certain number of modes, therefore, they result in mode-specific designs.

The explosive growth of traffic over telecommunication networks, especially in the access networks mandates that more and more modes would be (de)multiplexed to respond to the high traffic demands. As a result, proposing a universal mode converter and (de)multiplexer, that can convert and (de)multiplex any required number of modes is needed.
In this thesis, mode converters and (de)multiplexers are thoroughly investigated. A universal LP01 to LPlm mode converter and (de)multiplexer is proposed. The mode converter is based on tapered circular waveguides and the (de)multiplexer is based on symmetric directional couplers.
An LP01 to LP02 is first introduced. It consists of a tapered circular waveguide followed by a non-tapered circular waveguide. Inside the second waveguide, a circular tapered element is inserted. The initial tapered waveguide allows excitation of LP02 mode as well as other LP0m modes (m > 2). The second waveguide (comprising the circular section and the inner tapered element) is used to make conversion to be mainly from LP01 to LP02. Simulation shows that conversion efficiency of almost 100% at the central wavelength of O- S- and C-band, and above 98% over the S- and C-band is achieved. Moreover, suppression of non-desired higher order modes is more than 10 dB over the whole O-, S- and C-band. In particular, suppression is more than 19 dB over the entire C-band. The analysis also shows that the performance of the mode converter is not sensitive to slight variations of the converter’s parameters. In addition, the same converter can be used for converting LP02 back to LP01. Further, a (de)multiplexer for an LP02 and an LP01 mode is designed using the mode converter combined with a symmetric directional coupler. The multiplexer is broadband and has insertion loss less than 0.5 dB over the C-band.
The proposed design is fabricated by inscribing it in the bulk of a borosilicate glass using a femtosecond laser. The converter has an insertion loss of less than 1 dB for the entire C-band and a total length of 2.22mm. this fabricated prototype validates the proposed mode converter design.
The LP01 to LP02 mode converter structure can also be used to convert to other LP0m mode by proper tuning its parameters. After extensive simulations and optimizations, an LP01 to LP0m mode converter is proposed. The proposed converter structures are designed not only to provide high performances (low insertion losses and high extinction ratios), but also to be able to be fabricated by respecting the fabrication requirements (in terms of lengths and refractive indices). As a case study, six mode converters, converting LP01 to LP0m, with m = 2 to 7 are reported. The structures have insertion losses ranging from 0.1 dB to 2.5 dB. These performance results outperform all reported similar mode converters.
To (de)multiplex the resulting LP0m modes, a (de)multiplexer based on symmetric directional couplers is proposed. This kind of devices are easy to design and fabricate and provide low insertion loss and cross talk. As an example, the first five modes (LP01 to LP05) are (de)multiplexed with an insertion loss less than 2.5 dB and cross talk less than -15 dB at the design wavelength. These results outperform the reported results for similar devices.
The LP01 to LP0m mode converter structure is modified by inserting more inner elements to be able to convert to any LPlm mode. Therefore, a universal LP mode converter structure is proposed. The number and parameters of these inner elements depend on the desired LPlm mode. For instance, structures to convert LP01 to LP11, LP21 and LP31 are provided. These modes require between 5 to 6 inner elements with different radii and lengths. The simulation results for these three structures shows that an insertion loss less than 1.9 dB and an extinction ratio higher than 10 dB are achieved for the three modes at the design wavelength of 1550nm.
Furthermore, the three modes (LP11, LP21 and LP31) are (d)multiplexed using a symmetric directional coupler with an insertion loss less than 0.9 dB and a cross talk below -17 dB for the three modes at the design wavelength.
All the parameters of the presented mode converters and (de)multiplexers are designed to allow them to be fabricated using 3D femtosecond laser inscription technique.