Design and Code Optimization for Systems with Next-generation Racetrack Memories

With the rise of computationally expensive application domains such as machine learning, genomics, and fluids simulation, the quest for performance and energy-efficient computing has gained unprecedented momentum. The significant increase in computing and memory devices in modern systems has resulted in an unsustainable surge in energy consumption, a substantial portion of which is attributed to the memory system. The scaling of conventional memory technologies and their suitability for the next-generation system is also questionable. This has led to the emergence and rise of nonvolatile memory ( NVM ) technologies. Today, in different development stages, several NVM technologies are competing for their rapid access to the market. Racetrack memory ( RTM ) is one such nonvolatile memory technology that promises SRAM -comparable latency, reduced energy consumption, and unprecedented density compared to other technologies. However, racetrack memory ( RTM ) is sequential in nature, i.e., data in an RTM cell needs to be shifted to an access port before it can be accessed. These shift operations incur performance and energy penalties. An ideal RTM , requiring at most one shift per access, can easily outperform SRAM . However, in the worst-cast shifting scenario, RTM can be an order of magnitude slower than SRAM . This thesis presents an overview of the RTM device physics, its evolution, strengths and challenges, and its application in the memory subsystem. We develop tools that allow the programmability and modeling of RTM -based systems. For shifts minimization, we propose a set of techniques including optimal, near-optimal, and evolutionary algorithms for efficient scalar and instruction placement in RTMs . For array accesses, we explore schedule and layout transformations that eliminate the longer overhead shifts in RTMs . We present an automatic compilation framework that analyzes static control flow programs and transforms the loop traversal order and memory layout to maximize accesses to consecutive RTM locations and minimize shifts. We develop a simulation framework called RTSim that models various RTM parameters and enables accurate architectural level simulation. Finally, to demonstrate the RTM potential in non-Von-Neumann in-memory computing paradigms, we exploit its device attributes to implement logic and arithmetic operations. As a concrete use-case, we implement an entire hyperdimensional computing framework in RTM to accelerate the language recognition problem. Our evaluation shows considerable performance and energy improvements compared to conventional Von-Neumann models and state-of-the-art accelerators

The Use of Autoethnography in Educational Research: Locating Who We Are in What We Do

Autoethnography is a research method that engages the individual in cultural analysis and interpretation (Chang, 2008). The resultant self-analysis can have purposeful implications for the preparation of teachers and schools leaders. The process of self-exploration and interrogation aids individuals in locating themselves within their own history and culture allowing them to broaden their understanding of their own values in relation to others. In this paper, the methodological implications of autoethnography as well as its value as a research method is discussed in the context of understanding the self/other dialectic. Further, the relationship between autoethnography and the philosophical and practical implications relating to identity within education is examined

The West Virginia Autism Training Center @ Marshall University Magazine, Fall 2012

https://mds.marshall.edu/ac_magazine/1001/thumbnail.jp

Bit-Flip Aware Data Structures for Phase Change Memory

Big, non-volatile, byte-addressable, low-cost, and fast non-volatile memories like Phase Change Memory are appearing in the marketplace. They have the capability to unify both memory and storage and allow us to rethink the present memory hierarchy. An important draw-back to Phase Change Memory is limited write-endurance. In addition, Phase Change Memory shares with other Non-Volatile Random Access Memories an asym- metry in the energy costs of writes and reads. Best use of Non-Volatile Random Access Memories limits the number of times a Non-Volatile Random Access Memory cell changes contents, called a bit-flip. While the future of main memory is still unknown, we should already start to create data structures for them in order to shape the future era. This thesis investigates the creation of bit-flip aware data structures.The thesis first considers general ways in which a data structure can save bit- flips by smart overwrites and by using the exclusive-or of pointers. It then shows how a simple content dependent encoding can reduce bit-flips for web corpora. It then shows how to build hash based dictionary structures for Linear Hashing and Spiral Storage. Finally, the thesis presents Gray counters, close to bit-flip optimal counters that even enable age- based wear leveling with counters managed by the Non-Volatile Random Access Memories themselves instead of by the Operating Systems

Maternal diet affects juvenile Carpetan rock lizard performance and personality

Differences in both stable and labile state variables are known to affect the emergence and maintenance of consistent inter-individual behavioural variation (animal personality or behavioural syndrome), especially when experienced early in life. Variation in environmental conditions experienced by gestating mothers (viz. non-genetic maternal effects) are known to have significant impact on offspring condition and behaviour, yet, their effect on behavioural consistency is not clear. Here, by applying an orthogonal experimental design, we aimed to study if increased vitamin D3 content in maternal diet during gestation (vitamin-supplemented vs. vitamin control treatments) combined with corticosterone treatment (corticosterone-treated vs. corticosterone control treatments) applied on freshly hatched juveniles had an effect on individual state and behavioural consistency of juvenile Carpetan rock lizards (Iberolacerta cyreni). We tested the effect of our treatments on (i) climbing speed and the following levels of behavioural variation: (ii) strength of animal personality (behavioural repeatability), (iii) behavioural type (individual mean behaviour) and (iv) behavioural predictability (within-individual behavioural variation unrelated to environmental change). We found higher locomotor performance of juveniles from the vitamin-supplemented group (42.4% increase), irrespective of corticosterone treatment. While activity personality was present in all treatments, shelter use personality was present only in the vitamin-supplemented × corticosterone-treated treatment and risk-taking personality was present in corticosterone control treatments. Contrary to our expectations, behavioural type was not affected by our treatments, indicating that individual quality can affect behavioural strategies without affecting group-level mean behaviour. Behavioural predictability decreased in individuals with low climbing speed, which could be interpreted as a form of anti-predator strategy. Our results clearly demonstrate that maternal diet and corticosterone treatment have the potential to induce or hamper between-individual variation in different components of boldness, often in interactions

The Impact of Gaming on Rural Heritage Communities: A Case Study of Elora, Ontario

Since the early 1990s, rural decline has led many communities to begin social and economic restructuring. Several locales are seeking alternative approaches to the primary sector to support their declining industrial base (Markey et al, 2008). The tourism industry is an alternative to traditional rural livelihoods. Rural amenities and scenic landscapes have encouraged stakeholders to develop heritage tourism. The commodification of heritage has a profound impact on the place identity of rural landscapes. This is illustrated in the Model of Creative Destruction. In an earlier paper, Mitchell (1998) described the process of creative destruction through 5 stages being early commodification, advanced commodification, early destruction, advanced destruction and post destruction. In later papers, Mitchell and Vanderwerf (2010) describe the model as one that predicts that rural landscapes may evolve through three identities; rural town-scape, heritage-scape (or heritage village) and leisure-scape. Communities will remain as heritage-scapes if the desire to preserve is a dominant motivation. In contrast, if stakeholders are motivated more by a desire to profit or promote economic growth, then investments in non-conforming venues may result. This ultimately will shift the identity from one of heritage-scape to leisure-scape of mass consumption. Such investments may jeopardize a tourist’s heritage-seeking experience, and their perception of the community as a heritage village. Gaming recently has been introduced as a form of rural economic development in communities that commodify heritage (i.e. heritage-scapes). The introduction of slot machine parlours at racetracks (racinos) has helped combat the decline in the horse racing industry (Thalheimer and Ali, 2008). Furthermore, the positive economic impacts of these facilities are numerous. Negative implications, however, also accompany this type of tourism development. To date, little research has been conducted on the impacts that racino gaming developments have on communities, and, more specifically, on heritage-scapes. This thesis seeks to address this deficiency in a case study of Elora, Ontario and the Grand River Raceway. The purpose of this study was i) to determine the impact of the Grand River Raceway on Elora’s identity as a heritage village; ii) to identify the positive and negative socio-economic benefits that the facility has on the community and iii) to provide recommendations to communities who are considering similar development. To meet these objectives, data were collected through business and tourist surveys, unstructured interviews and a content analysis of secondary sources. Results suggest that the Grand River Raceway has not compromised Elora’s identity as a heritage-scape, in the eyes of business owners and tourists. Although the presence of the Grand River Raceway suggests that Elora is at the stage of early destruction or is on the way to becoming a leisure-scape, its presence has not detracted from visitor experience, as predicted by the model. This situation is attributed to marketing, location and uniformity with the existing landscape. Furthermore, the Grand River Raceway has had both positive and negative socio-economic impacts on Elora. Some of the benefits include employment, tax revenues, sponsorships and financial contributions to the municipality. At the same time, however, the Grand River Raceway has created a divided community, generated several legal issues and resulted in an uneven distribution of economic benefits. It is recommended that public consultation and resident involvement in decision making will help to minimize these negative impacts

Re-Imagining Local Governance: The Landscape of Local in Toronto

In 1997, the Province of Ontario formed the City of Toronto, amalgamating one regional and six small municipalities into a single city government. This action altered the formal institutions of local governance, replacing what was once regional with a City Council meant to represent city-wide issues, and without providing a clear model for local or smaller-than-city decision-making. The purpose of this dissertation is to conceptualize the meaning of local governance within the City of Toronto as a result of the overlap of wards (as represented by councillors), community councils, business improvement areas and neighbourhood associations, each of which claim geographical boundaries as justification for the representation of locally-based populations, and claim to be open to participation to some degree. This research asks whether the overlap of these bodies has unrecognized consequences, in particular, the effect on historically marginalized residents. This dissertation offers a theoretical conceptualization of local governance grounded in legal pluralism and legal geography that presents the city as a set of uneven and overlapping local legal spaces operating on multiple scales. Using a mixed methods approach that includes doctrinal review, case studies, and semi-structured interviews, the dissertation finds that wards dominate the law and practice of local decision-making, and do not represent an inclusive local governance model in Toronto. BIAs and neighbourhood associations are unevenly distributed across and the city, exist mainly in the socio-economically privileged areas and have grown in number and broadened their mandates since Torontos 1997 amalgamation. Torontos community councils, which were initially conceived by the province as a means to provide local access to municipal decision-making, have failed to achieve their legislative potential. The dissertation concludes that reimagined community councils, grounded within a normative understanding of the urban commons, serve as a means to create a more inclusive and participatory local governance model in Toronto

Re-Imagining Local Governance: The Landscape of "Local" in Toronto

In 1997, the Province of Ontario formed the City of Toronto, amalgamating one regional and six small municipalities into a single city government. This action altered the formal institutions of local governance, replacing what was once regional with a City Council meant to represent city-wide issues, and without providing a clear model for local or smaller-than-city decision-making. The purpose of this dissertation is to conceptualize the meaning of local governance within the City of Toronto as a result of the overlap of wards (as represented by councillors), community councils, business improvement areas and neighbourhood associations, each of which claim geographical boundaries as justification for the representation of locally-based populations, and claim to be open to participation to some degree. This research asks whether the overlap of these bodies has unrecognized consequences, in particular, the effect on historically marginalized residents. This dissertation offers a theoretical conceptualization of local governance grounded in legal pluralism and legal geography that presents the city as a set of uneven and overlapping local legal spaces operating on multiple scales. Using a mixed methods approach that includes doctrinal review, case studies, and semi-structured interviews, the dissertation finds that wards dominate the law and practice of local decision-making, and do not represent an inclusive local governance model in Toronto. BIAs and neighbourhood associations are unevenly distributed across and the city, exist mainly in the socio-economically privileged areas and have grown in number and broadened their mandates since Torontos 1997 amalgamation. Torontos community councils, which were initially conceived by the province as a means to provide local access to municipal decision-making, have failed to achieve their legislative potential. The dissertation concludes that reimagined community councils, grounded within a normative understanding of the urban commons, serve as a means to create a more inclusive and participatory local governance model in Toronto