CP-nets and Nash equilibria

We relate here two formalisms that are used for different purposes in reasoning about multi-agent systems. One of them are strategic games that are used to capture the idea that agents interact with each other while pursuing their own interest. The other are CP-nets that were introduced to express qualitative and conditional preferences of the users and which aim at facilitating the process of preference elicitation. To relate these two formalisms we introduce a natural, qualitative, extension of the notion of a strategic game. We show then that the optimal outcomes of a CP-net are exactly the Nash equilibria of an appropriately defined strategic game in the above sense. This allows us to use the techniques of game theory to search for optimal outcomes of CP-nets and vice-versa, to use techniques developed for CP-nets to search for Nash equilibria of the considered games.Comment: 6 pages. in: roc. of the Third International Conference on Computational Intelligence, Robotics and Autonomous Systems (CIRAS '05). To appea

Editor’s Introduction to a Debate on Proper Use of Partial Least Squares (PLS) Analysis in Information Systems

This debate addresses an issue that has divided the Information Systems research community for years. Partial Least Squared (PLS) has both strong advocates and strong critics. In this debate, two prominent PLS critics (Jöerg Evermann and Mikko Rönkkö) make a set of 14 evidence-based recommendations for how and when PLS may be appropriately used. Six different responses were received, some supportive, some critical, and some making further suggestions. Significantly, even those critical responses did not make arguments against the recommendations. As such, these recommendations should serve as current recommendations for best practice for quantitative researchers as well as reviewers and editors of work making use of PLS

A Preliminary Evaluation of Mounds to Divert Wayward Vehicles Away from Rigid Obstructions

In the summer of 1965, the first fatality report involving an interstate median bridge pier in Kentucky caused concern among state and national officials for the safety of motorists who perchance or otherwise enter upon a collision course toward an unprotected bridge pier. A consensus of opinion seemed to indicate that some form of attenuation or deflection device was necessary. Early innovations employed various short guardrail configurations to deflect wayward vehicles from the piers. The use of small, short sections has since evolved until present methods include surrounding the bridge pier with several hundred feet of guardrail, including ramped-end treatment (see Figure 1). The use of guardrail has not been questioned from the standpoint of safety design, yet some effort has been applied by Kentucky and other states to finding an alternative approach. From these efforts, the use of mounds to decelerate and deflect vehicles originated. It was thought that this design concept was consistent with current safety developments as well as being an economical treatment of the problem, since most of the work involved in constructing the mound can be done during grade and drain construction using natural materials available on location. These mounds have since been constructed on certain interstate projects and on all bridge locations of the Jackson Purchase (51.4 miles) and Pennyrile (56.6 miles) Parkways in Kentucky. Having found no records of accidents involving these mounds in the interim, there has been no substantial means of evaluating the effectiveness of this innovation in preventing or reducing the severity of collisions with bridge piers. Consequently, it was decided that low speed excursions over a mound might provide a basis for evaluation. The Division of Research made a series of driver-controlled traverses at low speeds on a typical site constructed on a 60-foot median. The purpose of this report is to summarize the results obtained from these initial, low-speed tests and, in so doing, attempt to make some determination of the reliability of this particular type of earthwork. It is anticipated that these low-speed tests will be supplemented eventually by testing at higher speeds, using some form of remote guidance system in place of the human driver. Also, it must be emphasized that conclusions drawn from this report apply only to low-speed encroachments. Additional effects which may be encountered during high-speed testing can only be hypothesized at this time

Reconstructing a water balance for north Crestone Creek: streamflow variability and extremes in a snowmelt dominated internal drainage basin

May 2013.Includes bibliographical references.The San Luis Valley in Colorado is a semi-arid region that relies on streamflow from the surrounding mountain ranges for agricultural productivity and to recharge the important aquifer systems of the basin. The (North) Crestone Creek watershed is characteristic of the many small watersheds that drain the Sangre de Cristo Mountains on the eastern side of the valley providing water for local water users, wildlife, and augmentation of Rio Grande flows through the Closed Basin Project reclamation efforts. This study investigates the range of hydrologic variability and extremes in this area over the last 426 years using readily available historic hydrologic and paleo-climatic data derived from tree-rings and other sources. Streamflow and precipitation reconstructions were generated and compared to the historic period of observation. Water balance modeling was performed using historic and paleo-derived model inputs. The results of this study show that the drought conditions experienced in the San Luis Valley over the last decade are not unusual in the context of streamflow and precipitation reconstructions spanning hundreds of years. Past droughts were at least as intense as those in 1950 and 2002 and several droughts in the paleo-record were of much longer duration than any recorded in the instrumented period. These results are similar to those demonstrated in other paleo-hydrologic research from the western part of the San Luis Valley in Colorado and throughout the western United States. The water balance modeling provided a means to examine monthly changes to runoff and other hydrologic and state variables output by the model under differing past climate conditions. Together, the climate reconstructions and water balance model provide insight into regional water use sustainability and future development issues for a highly variable natural system

Gender differences in skin and core body temperature during exercise in a hot, humid environment.

Background. It is universally accepted that men and women regulate heat differently during exercise in hot, humid environments. Despite this common knowledge, little empirical data is available to explain how gender differences effect core/skin temperature changes. Further, the data that is available includes only limited measurement sites and/or time points. Methods. The purpose of this study was to measure the heat regulatory patterns for both men and women during 60-min of exercise in a hot, humid environment. Twenty aerobically fit subjects (10 men; 10 women) completed an acclimation session followed by a 60-min exercise protocol in an environmental chamber set at 39.9 ± 1.1 °C and 46.4 ± 4% relative humidity. Each exercise protocol consisted of four intervals of an 8-min walk (mean ± SD; men: 4.0 ± 0.3, women: 3.0 ± 0.2 mph) and 7-min light jog (men: 5.4 ± 0.5, women: 5.0 ± 0.3 mph). Subjects were confirmed to be euhydrated (urine specific gravity) prior to exercise and were encouraged to drink water to maintain hydration during exercise. Pre- and Post-exercise body weights did not differ, thus it appears hydration was maintained during exercise. Skin temperatures (iButton wireless loggers) were recorded every minute at seventeen sites (right and left: upper chest, mid-chest, abdomen, upper back, mid-back, lower back, upper arm, and lower arm, and back of the neck). In addition, core body temperature (rectal), rating of perceived exertion (RPE), and heart rate (wireless telemetry) were also recorded at the end of each interval of the protocol. Statistical analysis was carried out using a 2 (gender) x 60 (time) repeated measures ANOVA. Other variables were analyzed using a 2 (gender) x 8 (time) ANOVA with repeated measures on the 2nd factor. Any non-normally distributed data was log transformed. Significance was set at p\u3c0.05 and location of effects will be determined using individual t-tests with a Bonferroni correction for multiple comparisons. Results. Analysis revealed significantly higher skin temperatures in four locations on men compared to women: right upper back (p=0.048), right mid-back (p=0.001), right lower back (p=0.001), and left upper back (p\u3c0.001). Additionally, these changes were seen despite no significant differences between genders in core body temperature, RPE, and heart rate. This latter finding supports the conclusion that a similar degree of exercise, heat stress was applied to both men and women. Conclusions. We found gender differences at four different skin temperature locations. These changes might suggest that men retain more metabolic heat in various locations on the back when exercising in a hot, humid environment compared to women. Further research is needed to understand how these changes may affect post-exercise recovery return to baseline skin and core temperature values

Comparing Three Methods of Measuring Skin Temperature during Exercise in a Hot, Humid Environment

Exercise in a hot, humid environment substantially increases the physiological stress of exercise. Most of the techniques that are currently used to monitor changes in skin temperature have been in use for more than 20 years with little innovation. The purpose of the present study was two-fold: 1) to compare three techniques for measuring skin temperature (wired skin electrode, wireless temperature data logger, and thermal imaging) and 2) to compare and contrast these measures in men and women completing 45-min of cycling in a hot (39±2°C), humid (45±5% RH) environment. The CPHS committee approved all procedures described in this report and subjects gave written consent to participate. Men (N=14) and women (N=18) completed all study requirements out of 45 subjects that were enrolled. Following a baseline screening session that included a measurement of body composition (whole body DXA scan) and an aerobic fitness test (VO2peak), subjects were scheduled for an experimental exercise trial between 0500 and 0800. Subjects arrived to the laboratory and were tested for hydration using urine specific gravity and if dehydrated, they were provided water to drink before starting the exercise trial. Exercise consisted of 50-min of cycling. After 50-min, subjects were asked to continue cycling until their rectal core body temperature exceeded 39.3°C. The time they were able to exercise beyond 50-min was recorded and compared between individuals. Wired skin temperature was monitored using YSI400 banjo probes, wireless skin temperature was monitored using a data logging system (iButton), and thermal skin temperature was measured from images taken with a thermal camera (RAZR Max-IR). These skin measurements were made on the bicep and abdomen. All body temperatures were recorded at rest, every 10-min during exercise, and immediately following the end of exercise. Data was statistically analyzed using a 2 (gender: men & women) x sensor method (wired, wireless, and thermal) x time (0, 10, 20, 30, 40, 50, end) ANOVA with repeated measures on the 2nd and 3rd factors. Significance was set a

The Behavior of Coupled Automata

We study the nature of statistical correlations that develop between systems of interacting self-organized critical automata (sandpiles). Numerical and analytical findings are presented describing the emergence of “synchronization” between sandpiles and the dependency of this synchronization on factors such as variations in coupling strength, toppling rule probabilities, symmetric versus asymmetric coupling rules, and numbers of sandpiles

On Implementing Ethical Principles in Design Science Research

Technological innovations raise axiological questions such as what is right or wrong, good and bad, and so on (i.e., ethical considerations). These considerations have particular importance in design science research (DSR) projects since the developed artifacts often actively intervene into human affairs and, thus, cannot be free from value. To account for this fact, Myers and Venable (2014) proposed six ethical principles for DSR in order to support researchers to conduct ethical DSR. However, ethical principles per se—and the ethical DSR principles that Myers and Venable propose— have an abstract nature so that they can apply to a broad range of contexts. As a consequence, they do not necessarily apply to specific research projects, which means researchers need to contextualize them for each specific DSR project. Because doing so involves much challenge, we explore how contemporary DSR publications have dealt with this contextualization task and how they implemented the six ethical principles for DSR. Our results reveal that DSR publications have not discussed ethical principles in sufficient depth. To further promote ethical considerations in DSR, we argue that both DSR researchers and reviewers should be supported in implementing ethical principles. Therefore, we outline two pathways toward ethical DSR. First, we propose that researchers need to articulate the next generation of ethical principles for DSR using prescriptive knowledge structures from DSR. Second, we propose extending established DSR conceptualizations with an ethical dimension and specifically introduce the concept of ethical DSR process models. With this work, we contribute to the IS literature by reviewing ethical principles and their implementation in DSR, identifying potential challenges hindering efforts to implement ethics in DSR, and providing two pathways towards ethical DSR

Developing a Theory of Knowledge Identification Effectiveness in Knowledge Management

This paper reports on research conducted to explore the problems that organisations have with respect to a key first step in effective Knowledge Management: Knowledge Identification. The paper reports on the results from an exploratory, interpretive investigation on the problems organisations have with respect to identifying what knowledge exists within their boundaries. The research conducted 17 interviews of Knowledge Management practitioners, the data from which were analysed using domain analysis and cognitive mapping. The research identified 25 lower-level problems with Knowledge Identification and 4 higher-level factors that potentially explain Knowledge Identification Effectiveness: Knowledge Needs Identification, Knowledge Recording, KI Methods Effectiveness and KI Operationalisation. The paper explains the four factors and formulates them into a nascent (untested) theory that explains Knowledge Identification Effectiveness, which is further hypothesised to influence Knowledge Management Effectiveness