An evaluation of location management procedures

This paper gives a comparative description of two scenarios for location management in a mobile telecommunications system. The first scenario uses fixed location and paging areas. Mobiles perform a location update as they enter a new location area. The second scenario uses a time-out based location updating scheme. Mobiles start their timer as they leave the paging area they are currently registered in. As the timer elapses, the mobile performs a location update. Both scenarios also differ in the way paging is performed. In the first scenario it is only necessary to page in the location area the mobile is currently registered in. In order to do this efficiently, the paging is done in a 2-step fashion: mobiles are paged first in the paging area in which they were registered in, and next in the entire location area they are registered in. In the second scenario the mobile is paged in multiple steps: first in the paging area it is registered in, next in a circle of paging areas surrounding that area, and so on, until the mobile is found, or the number of steps has reached a certain upper limit. Results comprise a quantitative and qualitative comparison of these scenarios, and guidelines for optimal applicatio

Epistemic Contrastivism

Contrastivism about knowledge is the view that one does not just know some proposition. It is more adequate to say that one knows something rather than something else: I know that I am looking at a tree rather than a bush but I do not know that I am looking at a tree rather than a cleverly done tree imitation. Knowledge is a three-place relation between a subject, a proposition and a contrast set of propositions. There are several advantages of a contrastivist view but also certain problems with it

Brains In Vats? Don\u27t Bother!

Contemporary discussions of epistemological skepticism – the view that we do not and cannot know anything about the world around us – focus very much on a certain kind of skeptical argument involving a skeptical scenario (a situation familiar from Descartes\u27 First Meditation). According to the argument, knowing some ordinary proposition about the world (one we usually take ourselves to know) requires knowing we are not in some such skeptical scenario SK; however, since we cannot know that we are not in SK we also cannot know any ordinary proposition. One of the most prominent skeptical scenarios is the brain-in-the-vat-scenario: An evil scientist has operated on an unsuspecting subject, removed the subject\u27s brain and put it in a vat where it is kept functioning and is connected to some computer which feeds the brain the illusion that everything is “normal”. This paper looks at one aspect of this scenario after another – envatment, disembodiment, weird cognitive processes, lack of the right kind of epistemic standing, and systematic deception. The conclusion is that none of these aspects (in isolation or in combination) is of any relevance for a would-be skeptical argument; the brain-in-the-vat-scenario is irrelevant to and useless for skeptical purposes. Given that related scenarios (e.g., involving evil demons) share the defects of the brain-in-the-vat-scenario, the skeptic should not put any hopes on Cartesian topoi

Auditory-induced negative emotions increase recognition accuracy for visual scenes under conditions of high visual interference

The effect of emotion on memory is powerful and complex. While there seems to be agreement that emotional arousal generally increases the likelihood that events are remembered, it is somewhat disputed whether also the valence of emotions influences memory. Specifically, several experiments by Kensinger and colleagues have provided evidence for the hypotheses that negative valanced emotions facilitate the encoding of perceptual details. On the other hand, Mather and colleagues have suggested that these results could be explained by confounding relationships of valence and arousal, i.e., that items that generate negative emotions are typically also more arousing. In this study, we provide a conceptual replication of Kensinger's findings. We employed a novel experimental design, in which the effects of standardized emotional arousing sounds on recognition accuracy for neutral visual scenes was measured. We indirectly manipulated the amount of visual detail that was encoded, by requiring participants to memorize either single exemplars (low interference) or multiple exemplars (high interference) of visual scene categories. With increasing visual overlap in the high interference condition, participants were required to encode a high degree of visual detail to successfully remember the exemplars. The results obtained from 60 healthy human participants confirmed Kensinger's hypothesis by showing that under conditions of high visual interference, negative valanced emotions led to higher levels of recognition accuracy compared to neutral and positive emotions. Furthermore, based on the normative arousal ratings of the stimulus set, our results suggest that the differential recognition effect cannot be explained by differing levels of arousal

Measurements of the electron-positron continuum in ALICE

The status of the analysis of electron-positron pairs measured by ALICE in pp collisions at $\sqrt{s} = 7$ TeV and central Pb-Pb collisions at $\sqrt{s_\mathrm{NN}}=2.76$ TeV is presented. Key questions and the main challenges of the analysis are discussed on the basis of first raw invariant mass spectra for both collision systems.Comment: 6 pages, 7 figure

Introduction

Introduction to and overview over my book "Epistemic Contextualism. A Defense" (OUP 2016

Brains in Vats? Don't Bother!

Contemporary discussions of epistemological skepticism - the view that we do not and cannot know anything about the world around us - focus very much on a certain kind of skeptical argument involving a skeptical scenario (a situation familiar from Descartes’ First Meditation). According to the argument, knowing some ordinary proposition about the world (one we usually take ourselves to know) requires knowing we are not in some such skeptical scenario SK; however, since we cannot know that we are not in SK we also cannot know any ordinary proposition. One of the most prominent skeptical scenarios is the brain-in-the-vat-scenario: An evil scientist has operated on an unsuspecting subject, removed the subject’s brain and put it in a vat where it is kept functioning and is connected to some computer which feeds the brain the illusion that everything is “normal”. This paper looks at one aspect of this scenario after another – envatment, disembodiment, weird cognitive processes, lack of the right kind of epistemic standing, and systematic deception. The conclusion is that none of these aspects (in isolation or in combination) is of any relevance for a would-be skeptical argument; the brain-in-the-vat-scenario is irrelevant to and useless for skeptical purposes. Given that related scenarios (e.g., involving evil demons) share the defects of the brain-in-the-vat-scenario, the skeptic should not put any hopes on Cartesian topoi

Nearly Solving the Problem of Nearly Convergent Knowledge

This is a reply to Chris Tweed's recent attempt to solve the problem of "nearly convergent knowledge" and thus defend a binary account of knowledge against a contrastivist alternative. Ingenuous as his proposal is, it still does not solve the problem

Reliabilism: Modal, Probabilistic Or Contextualist

This paper discusses two versions of reliabilism: modal and probabilistic reliabilism. Modal reliabilism faces the problem of the missing closeness metric for possible worlds while probalistic reliabilism faces the problem of the relevant reference class. Despite the severity of these problems, reliabilism is still very plausible (also for independent reasons). I propose to stick with reliabilism, propose a contextualist (or, alternatively, harmlessly relativist) solution to the above problems and suggest that probabilistic reliabilism has the advantage over modal reliabilism