Bus bunching is ostensibly regarded as a detrimental phenomenon in bus systems. We study a bus loop with two bus stops, one regular bus stop and one spike bus stop, where bunched buses can outperform staggered buses. The spike bus stop models a bus stop connected to a train or metro service, where passengers arrive in groups at periodic intervals. We introduce the configuration of synchronised bunched buses, where bunched buses wait for the spike in demand. For a wide range (...) of parameters, synchronised bunched buses outperform perfectly staggered buses in terms of minimising the waiting time of commuters. We present an analytical formulation of the average waiting time in the case of bunched buses, synchronised bunched buses, and perfectly staggered buses with the consideration of different passenger demands, number of buses, and bus capacity. We demonstrate the validity of our analytical results through an agent-based simulation of the bus loop system. (shrink)

In this paper, we propose an empirically based Monte Carlo bus-network model as a test bed to simulate intervention strategies to overcome the inefficiencies of bus bunching. The EMB model is an agent-based model which utilizes the positional and temporal data of the buses obtained from the Global Positioning System to constitute a set of empirical velocity distributions of the buses and a set of exponential distributions of interarrival time of passengers at the bus stops. Monte Carlo sampling is then (...) performed on these two derived probability distributions to yield the stochastic dynamics of both the buses’ motion and passengers’ arrival. Our EMB model is generic and can be applied to any real-world bus network system. In particular, we have validated the model against the Nanyang Technological University’s Shuttle Bus System by demonstrating its accuracy in capturing the bunching dynamics of the shuttle buses. Furthermore, we have analyzed the efficacy of three intervention strategies: holding, no-boarding, and centralized-pulsing, against bus bunching by incorporating the rule set of these strategies into the model. Under the scenario where the buses have the same velocity, we found that all three strategies improve both the waiting and travelling times of the commuters. However, when the buses have different velocities, only the centralized-pulsing scheme consistently outperforms the control scenario where the buses periodically bunch together. (shrink)

The vertebrate retina is said to be inverted because the photoreceptors are oriented in the posterior direction and are thus unable to maximize photodetection under conditions of low illumination. The tapetum lucidum is a photoreflective structure located posterior to the photoreceptors in the eyes of some fish and terrestrial animals. The tapetum reflects light forward, giving incident photons a “second chance” to collide with a photoreceptor, substantially enhancing retinal photosensitivity in dim light. Across vertebrates (and arthropods), there are a wide (...) variety of tapeta that vary in structure, chemical composition, and even tissue architecture, indicating repeated convergent evolution. To date, the tapetum has not been observed in any cephalopod, however, which also possess a camera‐like eye, but with the retinal photoreceptors oriented in the anterior direction. We therefore hypothesize that the tapetum lucidum is a compensatory adaptation for the suboptimal design of the inverted retina of vertebrates. (shrink)

Ockham’s Razor advises us to not multiply entities without necessity. Recently, Jonathan Schaffer and Karen Bennett have argued that we ought to replace Ockham’s Razor with the Laser, the principle that only advises us to not multiply fundamental entities without necessity. In this paper, I argue that Ockham’s Razor is preferable to the Laser. I begin by contending that the arguments offered for the Laser by Schaffer and Bennett are unpersuasive. Then I offer two cases of theory assessment that I (...) believe the Razor handles better than the Laser. Finally, I argue that accepting the Laser gives rise to a difficult explanatory challenge: It is difficult to explain why fundamental entities and non-fundamental entities ought to be treated differently in ontological parsimony assessments. A recurring secondary theme of the paper is that the most tempting ways of responding to my arguments frequently result in the Laser losing much of its significance for debates about ontology. Thus, not only is it difficult to defend a preference for the Laser over the Razor, but it is especially difficult to do so while maintaining the Laser’s dialectical significance. (shrink)

Although the doctrine of divine simplicity has faced substantial criticism in recent years, Jeffrey Brower has recently offered a novel defense of the view by appealing to contemporary truthmaker theory. In this paper, I will argue that Brower’s defense of divine simplicity requires an implausible account of how truthmaking works for essential intrinsic predications. I will first argue that, unless Brower is willing to make an ad hoc exception for how truthmaking works in God’s case, he is committed to saying (...) that essential intrinsic predications about any object are made true by that object alone, not by its having essential properties. I will then argue that reflecting on cases where distinct essential intrinsic predications about an object have different causal explanations behind them shows that this general view of truthmaking is implausible. (shrink)

Some philosophers accept what I call minimalist views about composition. They either deny that composition ever occurs, or they only allow that composition occurs when some things are taken up into a life. While minimalists often take their views to be somewhat revisionary, they usually want to distinguish their views from truly radical views such as the view that there is no external world at all. They often do this by noting that, although they don’t believe that there are tables, (...) chairs, or planets, they do believe that there are mereological simples arranged tablewise, chairwise, and planetwise. In this paper, I appeal to the nature of perceptual experience to present a problem for this move. I contend that, given some plausible assumptions, compositional minimalists cannot consistently maintain that they are justified in their minimalism and justified in believing propositions about the arrangements of mereological simples. I will argue that this commits such minimalists to external world skepticism. (shrink)

Smart argues that saw ("british journal of aesthetics", Vol. I, 2) has given an account of the subject-Matter of aesthetics which is too general. It allows that the playing and watching of some games are aesthetic phenomena. Saw admits that there are aesthetic elements involved in these cases, But she claims that in enjoying these aspects of games one is not enjoying the game as such. (staff).

Cross-sectional studies indicate that normal aging is accompanied by decreases in brain structure. Longitudinal studies, however, are relatively rare and inconsistent regarding their outcomes. Particularly the heterogeneity of methods, sample characteristics and the high inter-individual variability in older adults prevent the deduction of general trends. Therefore, the current study aimed to compare longitudinal age-related changes in brain structure in two large independent samples of healthy older adults ; the Longitudinal Healthy Aging Brain database project at the University of Zurich, Switzerland, (...) and 1000BRAINS at the Research Center Juelich, Germany. Annual percentage changes in the two samples revealed stable to slight decreases in cortical thickness over time. After correction for major covariates, i.e., baseline age, sex, education, and image quality, sample differences were only marginally present. Results suggest that general trends across time might be generalizable over independent samples, assuming the same methodology is used, and similar sample characteristics are present. (shrink)

This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be (...) preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

Substantial evidence indicates that cognitive training can be efficacious for older adults, but findings regarding training-related brain plasticity have been mixed and vary depending on the imaging modality. Recent years have seen a growth in recognition of the importance of large-scale brain networks on cognition. In particular, task-induced deactivation within the default mode network is thought to facilitate externally directed cognition, while aging-related decrements in this neural process are related to reduced cognitive performance. It is not yet clear whether task-induced (...) deactivation within the DMN can be enhanced by cognitive training in the elderly. We previously reported durable cognitive improvements in a sample of healthy older adults who completed 6 weeks of process-based object-location memory training compared to an active control training group. The primary aim of the current study is to evaluate whether these cognitive gains are accompanied by training-related changes in task-related DMN deactivation. Given the evidence for heterogeneity of the DMN, we examine task-related activation/deactivation within two separate DMN branches, a ventral branch related to episodic memory and a dorsal branch more closely resembling the canonical DMN. Participants underwent functional magnetic resonance imaging while performing an untrained object-location memory task at four time points before, during, and after the training period. Task-induced activation values were extracted for the ventral and dorsal DMN branches at each time point. Relative to visual fixation baseline: the dorsal DMN was deactivated during the scanner task, while the ventral DMN was activated; the object-location memory training group exhibited an increase in dorsal DMN deactivation relative to the active control group over the course of training and follow-up; changes in dorsal DMN deactivation did not correlate with task improvement. These results indicate a training-related enhancement of task-induced deactivation of the dorsal DMN, although the specificity of this improvement to the cognitive task performed in the scanner is not clear. (shrink)

Ruth Saw; I—The Presidential Address: The Logic of the Particular Case, Proceedings of the Aristotelian Society, Volume 66, Issue 1, 1 June 1966, Pages 1–14, ht.

Any rational discipline has as its proper and primary task to present itself as an internally interconnected and coherent system. If it is important to human beings that it should be true, its practitioners cannot be content with premisses from which it follows as a hypothetical system, but must either show them as indubitable by their own nature or as grounded in fact. If they are grounded in fact then we must continually appeal to experimentally verified hypotheses which will further (...) anchor the science to our actual world. Mathematics is in the peculiar position of having no possible empirical verification of its theorems, but of being continually verified by application. Mathematics ‘works’ when applied to the building of bridges and skyscrapers, the knitting of pullovers and the designing of engines. It also appeals to rational beings as intellectually satisfying in itself. Metaphysics is like mathematics in presenting itself as intellectually satisfying to those willing to submit themselves to its discipline; it is unlike mathematics in that it has, in the ordinary sense of the word, no application. Nevertheless, Spinoza makes a determined attempt to exhibit metaphysics as satisfying on all counts. It is an internally coherent system, it justifies itself by its effect on its practitioners, and it could not be effective in this way if it were not at the same time true. (shrink)

This examination of the concept “work of art” has been prompted by the desire to find a starting point for aesthetic inquiry which, to begin with at any rate, will arouse no dispute. A claim for general agreement such as Clive Bell's: “The starting point for all systems of aesthetics must be the personal experience of a pecular emotion”, is countered by I. A. Richards's “the phantom aesthetic state”, and any attempt to claim “beauty” as the central concept is straightway (...) confused by the varied contexts in which “beauty” and “beautiful” may function. We hear much more often of a beautiful stroke in cricket than in painting, and many of our moral judgments have an aesthetic flavour. An action may be bold, dashing, mean, underhanded, unimaginative, cringing, fine, as well as right or wrong. Aesthetic adjectives and adverbs may occur in any context, and part of our job is to separate out the various uses and establish their inter-relationships. (shrink)

Spinoza's avowed aim is to discover and present the essential stages in achieving the life of human blessedness. The most important element in this progression is knowledge, of one's own nature as man, and of one's place in the universe. Utility as opposed to truth of belief will not serve Spinoza's purpose. Spinoza assumes the unity of the human individual without question, and it is doubtful whether this assumption is justified on his own principles. The concept of the human individual (...) is examined first as a system of modifications of substance under the attributes of extension and thought, then as enduring and finally as an agent. The conclusion is reached that unity and self?identity are illusions, but the question then arises: Who or what could be under such illusions ? The possibility of false claims to self?identity is examined and found to be difficult to accept. Nevertheless, if Spinoza is taken as speaking suitably at varying levels of discourse, he has enlightening things to say about the human person, even though from one point of view his enterprise may be seen as self?stultifying. (shrink)