A Technical and Economic Feasibility Study of Implementing a Microgrid at Georgia Southern University

The performance and benefits of microgrids were considered, and the feasibility of implementing a microgrid for a portion of the Georgia Southern University campus assessed. The existing power delivery system was described and characterized to ascertain whether conversion to a microgrid would be both feasible and beneficial. Different types of distributed generation were considered for their appropriateness for use on campus. A detailed economic analysis of potential microgrid configurations was then performed using HOMER, and the results were presented in the form of recommended action and alternatives

Asymmetric distances for approximate differential privacy

Differential privacy is a widely studied notion of privacy for various models of computation, based on measuring differences between probability distributions. We consider (epsilon,delta)-differential privacy in the setting of labelled Markov chains. For a given epsilon, the parameter delta can be captured by a variant of the total variation distance, which we call lv_{alpha} (where alpha = e^{epsilon}). First we study lv_{alpha} directly, showing that it cannot be computed exactly. However, the associated approximation problem turns out to be in PSPACE and #P-hard. Next we introduce a new bisimilarity distance for bounding lv_{alpha} from above, which provides a tighter bound than previously known distances while remaining computable with the same complexity (polynomial time with an NP oracle). We also propose an alternative bound that can be computed in polynomial time. Finally, we illustrate the distances on case studies

Judging the morality of utilitarian actions: How poor utilitarian accessibility makes judges irrational.

Is it acceptable and moral to sacrifice a few people's lives to save many others? Research on moral dilemmas in psychology, experimental philosophy, and neuropsychology has shown that respondents judge utilitarian personal moral actions (footbridge dilemma) as less appropriate than equivalent utilitarian impersonal moral actions (trolley dilemma). Accordingly, theorists (e.g., Greene et al., 2001) have argued that judgments of appropriateness in personal moral dilemmas are more emotionally salient and cognitively demanding (taking more time to be rational) than impersonal moral dilemmas. Our novel findings show an effect of psychological accessibility (driven by partial contextual information; Kahneman, 2003) on utilitarian moral behavior and response time for rational choices. Enhanced accessibility of utilitarian outcomes through comprehensive information about moral actions and consequences boosted utility maximization in moral choices, with rational choices taking less time. Moreover, our result suggests that previous results indicating emotional interference, with rational choices taking more time to make, may have been artifacts of presenting partial information

The big-O problem for labelled markov chains and weighted automata

Given two weighted automata, we consider the problem of whether one is big-O of the other, i.e., if the weight of every finite word in the first is not greater than some constant multiple of the weight in the second. We show that the problem is undecidable, even for the instantiation of weighted automata as labelled Markov chains. Moreover, even when it is known that one weighted automaton is big-O of another, the problem of finding or approximating the associated constant is also undecidable. Our positive results show that the big-O problem is polynomial-time solvable for unambiguous automata, coNP-complete for unlabelled weighted automata (i.e., when the alphabet is a single character) and decidable, subject to Schanuel’s conjecture, when the language is bounded (i.e., a subset of w_1^* … w_m^* for some finite words w_1,… ,w_m). On labelled Markov chains, the problem can be restated as a ratio total variation distance, which, instead of finding the maximum difference between the probabilities of any two events, finds the maximum ratio between the probabilities of any two events. The problem is related to ε-differential privacy, for which the optimal constant of the big-O notation is exactly exp(ε)

Rapid recovery following short-term acoustic disturbance in two fish species

ArticleNoise from human activities is known to impact organisms in a variety of taxa, but most experimental studies on the behavioural effects of noise have focused on examining responses associated with the period of actual exposure. Unlike most pollutants, acoustic noise is generally short-lived, usually dissipating quickly after the source is turned off or leaves the area. In a series of experiments, we use established experimental paradigms to examine how fish behaviour and physiology are affected, both during short-term (2 min) exposure to playback of recordings of anthropogenic noise sources and in the immediate aftermath of noise exposure. We considered the anti-predator response and ventilation rate of juvenile European eels (Anguilla anguilla), and ventilation rate of juvenile European seabass (Dicentrarchus labrax). As previously found, additional-noise exposure decreased eel anti-predator responses, increased startle latency and increased ventilation rate relative to ambient-noise-exposed controls. Our results show for the first time that those effects quickly dissipated; eels showed rapid recovery of startle responses and startle latency, and rapid albeit incomplete recovery of ventilation rate in the 2 min after noise cessation. Seabass in both laboratory and open-water conditions showed an increased ventilation rate during playback of additional noise compared to ambient conditions. However, within 2 min of noise cessation, ventilation rate showed complete recovery to levels equivalent to ambient-exposed control individuals. Care should be taken in generalizing these rapid-recovery results, as individuals might have accrued other costs during noise exposure and other species might show different recovery times. Nonetheless, our results from two different fish species provide tentative cause for optimism concerning recovery following short-duration noise exposure, and suggest that considering periods following noise exposures could be important for mitigation and management decisions.DefraNER

Organising a multidisciplinary postgraduate colloquium

The Warwick Postgraduate Colloquium in Computer Science (WPCCS) is an annual event for research students in the Department of Computer Science at the University of Warwick. The aims of the colloquium are to provide: (i) an experience of a conference setting for students, (ii) a place to practise presentation skills, (iii) a place to receive feedback and suggestions on their research, and (iv) an opportunity to learn about research being performed by other attendees. WPCCS has been held annually since 2003, but since 2016 many changes have been made to the event; in particular the introduction of networking aids (such as conference guides and lanyards), a new venue, the introduction of guest speakers and various efforts to encourage attendance. Meanwhile the number of submissions has increased, placing strain on the colloquium’s schedule and budget. In this paper the organising committees from 2016, 2017, and 2018 reflect critically on the experience WPCCS delivers to the attendees. We present an examination of what worked well, what did not work, and what we would like to try in the future, with the aim that these experiences are useful to the organisers of similar events