Showing papers by "University of Windsor published in 2012"

Complexity in engineering design and manufacturing

Abstract: This paper reviews the breadth of complexity of the design process, products, manufacturing, and business. Manufacturing is facing unprecedented challenges due to increased variety, market volatility and distributed global manufacturing. A fundamental residue of globalization and market uncertainty is the increasing complexity of manufacturing, technological and economic systems. The nature and sources of complexity in these areas are reviewed and complexity modeling and management approaches are discussed. Enterprises that can mitigate the negative aspects of complexity while managing its positives should thrive on the continuous change and increasing complexity. To reap these benefits in the future, manufacturing companies need to not only adopt flexible technical solutions but must also effectively innovate and manage complex socio-technical systems.

Habitat complexity: approaches and future directions

Abstract: Habitat complexity is one of the most important factors structuring biotic assemblages, yet we still lack basic understanding of the underlying mechanisms. Although it is one of the primary targets in conservation management, no methods are available for comparing complexity across ecosystems, and system-specific qualitative assessment predominates. Despite its overwhelming importance for faunal diversity and abundance, there has been surprisingly little interest in examining its effects on other community and ecosystem attributes. We discuss possibilities of such effects, outlining potentially fruitful areas for future research, and argue that complexity may be implicated in community persistence and ecosystem stability by acting as a decoupling mechanism in predator–prey interactions. We provide a brief overview of methods used to quantify complexity in different ecosystems, highlighting contributions of the current issue of Hydrobiologia, and discuss potential application of these approaches for cross-ecosystem comparisons. Better understanding of the role of habitat complexity resulting from such comparisons is critically important for preservation of biodiversity and ecosystem function in an era of unprecedented habitat loss.

The Harm of Symbolic Actions and Green-Washing: Corporate Actions and Communications on Environmental Performance and Their Financial Implications

Abstract: We examine over 100 top performing Canadian firms in visibly polluting industries as we seek to answer four research questions: What specific environmental issues are firms addressing? How do these issues differ between industries? Are both symbolic and substantive actions financially beneficial? Does green-washing, measured as the difference between symbolic and substantive action, and/or green-highlighting, measured as the combined effect of symbolic and substantive actions, pay? We find that substantive actions of environmental issues (green walk) neither harm nor benefit firms financially, but symbolic actions (green talk) are negatively related to financial performance. We also find that green-washing (discrepancy between green talk and green walk) has a negative effect on financial performance and green-highlighting (concentrated efforts of the talk and walk) has no effect on financial performance. In this article, we provide explanations of our findings and put forth future research directions.

Hydrothermal Mobilisation of the Rare Earth Elements – a Tale of “Ceria” and “Yttria”

Abstract: Although the rare earth elements have been thought by many to be immobile in hydrothermal fluids, we have known since the first attempts to separate them in the early nineteenth century that they are soluble in aqueous solutions. Driven by a need to isolate individual REEs for industrial applications, and more recently to explore for them, we have started to develop an understanding of their solubility and speciation in hydrothermal fluids. This knowledge is allowing us to understand the processes that promote their transport in the Earth's crust, their concentration, and their fractionation.

An integrated model for closed-loop supply chain configuration and supplier selection: Multi-objective approach

Abstract: Reverse logistics consists of all operations related to the reuse of products. External suppliers are one of the important members of reverse logistics and closed loop supply chain (CLSC) networks. However in CLSC network configuration models, suppliers are assessed based on purchasing cost and other factors such as on-time delivery are ignored. In this research, a general closed loop supply chain network is examined that includes manufacturer, disassembly, refurbishing, and disposal sites. Meanwhile, it is managed by the manufacturer. We propose an integrated model which has two phases. In the first phase, a framework for supplier selection criteria in RL is proposed. Besides, a fuzzy method is designed to evaluate suppliers based on qualitative criteria. The output of this stage is the weight of each supplier according to each part. In the second phase, we propose a multi objective mixed-integer linear programming model to determine which suppliers and refurbishing sites should be selected (strategic decisions), and find out the optimal number of parts and products in CLSC network (tactical decisions). The objective functions maximize profit and weights of suppliers, and one of them minimizes defect rates. To our knowledge, this model is the first effort to consider supplier selection, order allocation, and CLSC network configuration, simultaneously. The mathematical programming model is validated through numerical analysis.

A Review on the Challenges for Increased Production of Castor

Abstract: Castor (Ricinus communis L.) is one of the oldest cultivated crops, but currently it represents only 0.15% of the vegetable oil produced in the world. Castor oil is of continuing importance to the global specialty chemical industry because it is the only commercial source of a hydroxylated fatty acid. Castor also has tremendous future potential as an industrial oilseed crop because of its high seed oil con- tent (more than 480 g kg -1 ), unique fatty acid composition (900 g kg -1 of ricinoleic acid), potentially high oil yields (1250-2500 L ha -1 ), and ability to be grown under drought and saline conditions. Th e scientifi c literature on castor has been generated by a relatively small global community of researchers over the past century. Much of this work was published in dozens of languages in journals that are not easily accessible to the scientifi c community. Th is review was conducted to provide a compilation of the most relevant historic research information and defi ne the tremendous future potential of castor. Th e article was prepared by a group of 22 scientists from 16 institutions and eight countries. Topics discussed in this review include: (i) germplasm, genetics, breeding, biotic stresses, genome sequencing, and biotechnology; (ii) agronomic production practices, diseases, and abiotic stresses; (iii) management and reduction of toxins for the use of castor meal as both an animal feed and an organic fertilizer; (iv) future industrial uses of castor including renew- able fuels; (v) world production, consumption, and prices; and (vi) potential and challenges for increased castor production.

Metal-organic frameworks with dynamic interlocked components.

Abstract: The dynamics of mechanically interlocked molecules such as catenanes and rotaxanes have been studied in solution as examples of rudimentary molecular switches and machines. A metal–organic framework with a [2]rotaxane as a building block demonstrates that such dynamic processes can also operate inside a solid-state material.

Stable isotopes and elasmobranchs: tissue types, methods, applications and assumptions.

Abstract: Stable-isotope analysis (SIA) can act as a powerful ecological tracer with which to examine diet, trophic position and movement, as well as more complex questions pertaining to community dynamics and feeding strategies or behaviour among aquatic organisms. With major advances in the understanding of the methodological approaches and assumptions of SIA through dedicated experimental work in the broader literature coupled with the inherent difficulty of studying typically large, highly mobile marine predators, SIA is increasingly being used to investigate the ecology of elasmobranchs (sharks, skates and rays). Here, the current state of SIA in elasmobranchs is reviewed, focusing on available tissues for analysis, methodological issues relating to the effects of lipid extraction and urea, the experimental dynamics of isotopic incorporation, diet-tissue discrimination factors, estimating trophic position, diet and mixing models and individual specialization and niche-width analyses. These areas are discussed in terms of assumptions made when applying SIA to the study of elasmobranch ecology and the requirement that investigators standardize analytical approaches. Recommendations are made for future SIA experimental work that would improve understanding of stable-isotope dynamics and advance their application in the study of sharks, skates and rays.

Coordination polymers containing rotaxane linkers

Abstract: A class of coordination polymers in which the linking ligands are mechanically interlocked rotaxane molecules is reviewed. To date, four different, axle – wheel templating motifs have been used to create the [2]pseudorotaxane linkers for these unique solid-state materials; (1) protonated diaminoalkane axles with cucurbit[6]uril wheels, (2) 1,2-bis(4,4′-bipyridinio)ethane axles with dibenzo[24]crown-8 wheels, (3) 2,6-naphthalene dicarboxylate axles with tetra-imidazolium macrocycle wheels and (4) a Cu(I) complex of a 1,10-phenanthroline containing dicarboxylate axle with a 1,10-phenanthroline containing crown ether wheel. The synthesis and solid state structure of each coordination polymer is described. The future directions of this area of research and some designs for the next generation of these compounds are discussed.

Qualitative Research With Small Connected Communities Generating New Knowledge While Upholding Research Ethics

Abstract: Qualitative researchers have a dual mission: to generate knowledge through rigorous research and to uphold ethical standards and principles. Qualitative researchers often conduct studies with small connected communities in which relationships exist among community members. When engaging such communities, researchers might face ethical issues in upholding confidentiality standards while they work to achieve their dual mandate. Qualitative scholars have paid little attention to the ethical challenges that might arise in this context. Drawing on our experiences conducting studies with such communities, we expand the dialogue concerning qualitative research ethics by making explicit conceptual and practical tensions that emerge at various stages of the research process; articulating our respective reflective processes; and exploring issues associated with strategies for upholding confidentiality. We conclude with lessons learned to guide researchers who might face similar challenges.

The Possibility and Actuality of Visual Arguments

Abstract: The chapter investigates the extension of argument into the realm of visual expression. Although images can be influential in affecting attitudes and beliefs it does not follow that such images are arguments. So we should at the outset investigate whether there can be visual arguments. To do so, we need to know what a visual argument would look like if we encountered one. How, if at all, are visual and verbal arguments related? An account of a concept of visual argument serves to establish the possibility that they exist. If they are possible in a non-metaphorical way, are there any visual arguments? Examples show that they do exist: in paintings and sculpture, in print advertisements, in TV commercials and in political cartoons. But visual arguments are not distinct in essence from verbal arguments. The argument is always a propositional entity, merely expressed differently in the two cases. And the effectiveness in much visual persuasion is not due to any arguments conveyed.

Laser-induced breakdown spectroscopy (LIBS): an overview of recent progress and future potential for biomedical applications.

Abstract: The recent progress made in developing laser-induced breakdown spectroscopy (LIBS) has transformed LIBS from an elemental analysis technique to one that can be applied for the reagentless analysis of molecularly complex biological materials or clinical specimens. Rapid advances in the LIBS technology have spawned a growing number of recently published articles in peer-reviewed journals which have consistently demonstrated the capability of LIBS to rapidly detect, biochemically characterize and analyse, and/or accurately identify various biological, biomedical or clinical samples. These analyses are inherently real-time, require no sample preparation, and offer high sensitivity and specificity. This overview of the biomedical applications of LIBS is meant to summarize the research that has been performed to date, as well as to suggest to health care providers several possible specific future applications which, if successfully implemented, would be significantly beneficial to humankind.

Field test of an affordable, portable, wireless microphone array for spatial monitoring of animal ecology and behaviour

Abstract: Summary 1. Using arrays of microphones, biologists can monitor the position of free-living animals based on the sounds they produce. Microphone array technology exploits differences in sound arrival times at each microphone to calculate an animal’s position. This technology provides new opportunities for studying animal ecology and behaviour and has many advantages over tracking technologies that require capturing animals and fitting them with external devices, or technologies that focus on one individual in isolation of the activities of nearby animals. 2. The efficacy of microphone arrays for triangulating the position of wild animals has been established through previous studies. Yet widespread use of microphone array technology has been limited by many factors: arrays are expensive, custom manufactured, and cumbersome. Consequently, microphone arrays are used infrequently, in spite of their transformative potential for studying animal ecology and behaviour. 3. We conducted a field test of a new wireless microphone array system that has multiple advantages over previous systems: it is relatively inexpensive, commercially available, includes an integrated global positioning system (GPS) for time-synchronizing microphones, and it is small enough to fit in a backpack. We set up an array of four stereo recorders (each with a pair of stereo microphones) at 12 sites and tested the system’s accuracy for estimating the location of loudspeakers broadcasting 25 types of bird, mammal and frog sounds. 4. We found that this system produced accurate location estimates based on multi-channel recordings of many types of acoustic signals. The average location accuracy was 1·87 ± 0·13 m, on par with cable-based microphone array systems. Location accuracy was significantly higher when the recorders were closer together and when sounds were broadcast inside the area bounded by the microphones. Accuracy tended to be higher in field vs. forest habitats. 5. We discuss how this system may be used to enhance studies of animal ecology and behaviour across a wide range of contexts. As with previous arrays, this system will allow researchers to monitor animals that produce distinctive acoustic signals. In contrast to previous microphone arrays, this system is affordable, portable and commercially available. Consequently, this system stands to dramatically enhance research on wild, free-living animals.

The Rhetoric of Visual Arguments

Abstract: The chapter is about visual arguments. I address the relationships among these three: rhetoric, argument, and the visual. How can there be visual arguments when arguments as we usually know them are verbal? And if there can be visual arguments, what is their rhetorical aspect? Since arguments are supposed to be tools of persuasion and rhetoric is often thought of as including (but not exhausted by) the study and use of the instruments of persuasion, I first explore the relationships among rhetoric, argument and persuasion. Then I turn to the difficulties and opportunities that present themselves when considering visual argument in particular. The chapter ends by taking up the question: What does being visual add to arguments? It adds drama and force of a much greater order. Beyond that it can use such devices as references to cultural icons and other kinds of symbolism, dramatization and narrative to make a powerfully compelling case for its conclusion. The visual has an immediacy, a verisimilitude, and a concreteness that help influence acceptance and that are not available to the verbal. When argument is visual, it is, above all, visual rhetoric.

A history of AI and Law in 50 papers: 25 years of the international conference on AI and Law

Abstract: We provide a retrospective of 25 years of the International Conference on AI and Law, which was first held in 1987. Fifty papers have been selected from the thirteen conferences and each of them is described in a short subsection individually written by one of the 24 authors. These subsections attempt to place the paper discussed in the context of the development of AI and Law, while often offering some personal reactions and reflections. As a whole, the subsections build into a history of the last quarter century of the field, and provide some insights into where it has come from, where it is now, and where it might go.

Lost in the Moment? An Investigation of Procrastination, Mindfulness, and Well-being

Abstract: In this study, we extend previous work documenting links between procrastination, stress, and physical health by examining the potential role of mindfulness in explaining the high stress and poor health reported by procrastinators. A sample of 339 students (81% female) completed an on-line survey that included measures of trait procrastination, mindfulness, perceived stress, and perceived health. Univariate analyses revealed that procrastination was associated with low mindfulness, high stress, and poor perceived health. Structural equation modelling was used to test the role of mindfulness in explaining the links between procrastination and stress, and between procrastination and perceived health. The overall measurement model indicated a good fit to the data. Tests of the nested mediation models revealed that the effects of procrastination on stress and health were mediated by mindfulness, and bootstrapping analyses confirmed the significance of these effects. Our findings are consistent with previous research and theory on the salutatory effects of mindfulness for health and well-being and indicate that for procrastinators, low mindfulness may be a risk factor for poor emotional and physical well-being.

Stretchable light-emitting electrochemical cells using an elastomeric emissive material.

Abstract: Remarkable progress in stretchable electronics over the past few years has produced some amazing devices: Devices that can be laminated onto skin, [ 1 ] hemispherical arrays of photodetectors that mimic the human retina, [ 2 ] and arrays of light-emitting devices for use in fldisplays [ 3 ] are just a few examples. The methodology used to impart stretchability connects rigid circuit elements with stretchable conductive interconnects that absorb applied strain. [ 4 ] A different approach to stretchability is now emerging, in which the devices themselves are fabricated to be intrinsically stretchable. Here, we describe the use of a stretchable electroluminescent material to produce a light-emitting device that exhibits intrinsic stretchability at room temperature. These devices are well-suited to new applications in stretchable and conformable lighting that require uniform, diffuse light emission over large areas. We demonstrate devices with large emission areas ( ∼ 20‐175 mm 2 ) that tolerate linear strains up to 27% and repetitive cycles of 15% strain with minimal performance degradation relative to devices fabricated using a conventional electroluminescent material. There are few examples of intrinsically stretchable devices‐ that is, systems in which the device itself operates under tensile strain. The two strategies that have been used to impart stretchability to these devices are identical to those used to fabricate stretchable device interconnects: Device materials can be either dispersed into an elastomeric matrix or deposited onto a prestretched elastomeric substrate. Kaltenbrunner et al. used the fi rst strategy to produce a stretchable battery of gel materials encased in an elastomer that can withstand uniaxial strains up

Relative Humidity Effects on the Life History of Hermetia illucens (Diptera: Stratiomyidae)

Abstract: Black soldier flies, Hermetia illucens (L.) (Diptera: Stratiomyidae) are of particular interest for their application in waste management such as reducing manure accumulations in confined feeding operations. Determining black soldier fly development time as a result of climatic variations will allow for optimizing their utilization as a waste management agent at landfill sites and confined animal feeding operations. To implement a black soldier fly waste management program in Canada, where seasonal variability does not support H. illucens development on a year round basis, determining maximum and minimum abiotic thresholds to sustain larval development is important. In Canadian winters, maintaining greenhouse temperatures necessary for black soldier fly development results in low relative humidity that could impact their development. The objective of this study was to determine relative humidity thresholds on egg eclosion and adult emergence. Egg eclosion success was measured at 25, 40, 50, 60, and 70% relative humidities and adult emergence success was measured at 25, 40, and 70% RH. Egg eclosion and adult emergence success increased with increasing relative humidities, while development time decreased with rising relative humidities.

Growth of Archean continental crust in oceanic island arcs

Abstract: Understanding the origin of the continental crust is one of the key objectives of earth sciences because as a land species we owe our existence to continents. In addition, change in the volume of the continental crust and distribution of continents on Earth's surface have profound effects on major

Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case–control study

Abstract: Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further characterize possible links between breast cancer risk and occupation, particularly in farming and manufacturing, as well as to examine the impacts of early agricultural exposures, and exposure effects that are specific to the endocrine receptor status of tumours. 1005 breast cancer cases referred by a regional cancer center and 1146 randomly-selected community controls provided detailed data including occupational and reproductive histories. All reported jobs wereindustry- and occupation-coded for the construction of cumulative exposure metrics representing likely exposure to carcinogens and endocrine disruptors. In a frequency-matched case–control design, exposure effects were estimated using conditional logistic regression. Across all sectors, women in jobs with potentially high exposures to carcinogens and endocrine disruptors had elevated breast cancer risk (OR = 1.42; 95% CI, 1.18-1.73, for 10 years exposure duration). Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82); bars-gambling (OR = 2.28; 95% CI, 0.94-5.53); automotive plastics manufacturing (OR = 2.68; 95% CI, 1.47-4.88), food canning (OR = 2.35; 95% CI, 1.00-5.53), and metalworking (OR = 1.73; 95% CI, 1.02-2.92). Estrogen receptor status of tumors with elevated risk differed by occupational grouping. Premenopausal breast cancer risk was highest for automotive plastics (OR = 4.76; 95% CI, 1.58-14.4) and food canning (OR = 5.70; 95% CI, 1.03-31.5). These observations support hypotheses linking breast cancer risk and exposures likely to include carcinogens and endocrine disruptors, and demonstrate the value of detailed work histories in environmental and occupational epidemiology.

Biology of the Greenland shark Somniosus microcephalus.

Abstract: Greenland shark Somniosus microcephalus is a potentially important yet poorly studied cold-water species inhabiting the North Atlantic and Arctic Oceans. Broad-scale changes in the Arctic ecosystem as a consequence of climate change have led to increased attention on trophic dynamics and the role of potential apex predators such as S. microcephalus in the structure of Arctic marine food webs. Although Nordic and Inuit populations have caught S. microcephalus for centuries, the species is of limited commercial interest among modern industrial fisheries. Here, the limited historical information available on S. microcephalus occurrence and ecology is reviewed and new catch, biological and life-history information from the Arctic and North Atlantic Ocean region is provided. Given the considerable by-catch rates in high North Atlantic Ocean latitudes it is suggested that S. microcephalus is an abundant predator that plays an important, yet unrecognized, role in Arctic marine ecosystems. Slow growth and large pup sizes, however, may make S. microcephalus vulnerable to increased fishing pressure in a warming Arctic environment.

Robust Student's-t Mixture Model With Spatial Constraints and Its Application in Medical Image Segmentation

Abstract: Finite mixture model based on the Student's-t distribution, which is heavily tailed and more robust than Gaussian, has recently received great attention for image segmentation. A new finite Student's-t mixture model (SMM) is proposed in this paper. Existing models do not explicitly incorporate the spatial relationships between pixels. First, our model exploits Dirichlet distribution and Dirichlet law to incorporate the local spatial constrains in an image. Secondly, we directly deal with the Student's-t distribution in order to estimate the model parameters, whereas, the Student's-t distributions in previous models are represented as an infinite mixture of scaled Gaussians that lead to an increase in complexity. Finally, instead of using expectation maximization (EM) algorithm, the proposed method adopts the gradient method to minimize the higher bound on the data negative log-likelihood and to optimize the parameters. The proposed model is successfully compared to the state-of-the-art finite mixture models. Numerical experiments are presented where the proposed model is tested on various simulated and real medical images.

A Survey of Applications of Identity-Based Cryptography in Mobile Ad-Hoc Networks

Abstract: Security in mobile ad-hoc networks (MANETs) continues to attract attention after years of research. Recent advances in identity-based cryptography (IBC) sheds light on this problem and has become popular as a solution base. We present a comprehensive picture and capture the state of the art of IBC security applications in MANETs based on a survey of publications on this topic since the emergence of IBC in 2001. In this paper, we also share insights into open research problems and point out interesting future directions in this area.