3,668 research outputs found

    The Immanent Contingency of Physical Laws in Leibniz’s Dynamics

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    This paper focuses on Leibniz’s conception of modality and its application to the issue of natural laws. The core of Leibniz’s investigation of the modality of natural laws lays in the distinction between necessary, geometrical laws on the one hand, and contingent, physical laws of nature on the other. For Leibniz, the contingency of physical laws entailed the assumption of the existence of an additional form of causality beyond mechanical or efficient ones. While geometrical truths, being necessary, do not require the use of the principle of sufficient reason, physical laws are not strictly determined by geometry and therefore are logically distinct from geometrical laws. As a consequence, the set of laws that regulate the physical laws could have been created otherwise by God. However, in addition to this, the contingency of natural laws does not consist only in the fact that God has chosen them over other possible ones. On the contrary, Leibniz understood the status of natural laws as arising from the action internal to physical substances. Hence the actuality of physical laws results from a causal power that is inherent to substances rather than being the mere consequence of the way God arranged the relations between physical objects. Focusing on three instances of Leibniz’s treatment of contingency in physics, this paper argues that, in order to account for the contingency of physical laws, Leibniz maintained that final causes, in addition to efficient and mechanical ones, must operate in physical processes and operations

    Virtual Reality Games for Motor Rehabilitation

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    This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

    Understanding Experiences Of Gratitude In Elementary Teachers: Implications For School Leaders

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    The science of gratitude is a fairly recent phenomenon, emerging out of positive psychology. The basic premise of the field is that cultivating a positive perspective and focusing on what one can be grateful for has positive outcomes in life. The benefits discovered include increases in subjective well-being and life satisfaction, better interpersonal relationships, and increases in pro-social behavior. In the school setting, research has found that developing gratitude can increase adolescents’ level of satisfaction with school experience and academic attainment. The purpose of this phenomenological study is develop a deeper understanding of how elementary teachers experience gratitude. By learning more about how elementary teachers experience gratitude and construct meaning around those experiences, school leaders may be able to positively influence the culture of the school and build collaborative approaches to change through strengthening relationships. A constructivist-developmental framework served as the primary lens through which to study teachers’ experiences of gratitude. Seven elementary teachers participated in a gratitude journaling exercise followed by individual interviews and a focus group. Three major themes emerged from the data: gratitude in contrast to negativity, perspective and choice, and making a difference/feeling valued. The results indicate that elementary teachers experience gratitude in their school settings through a sense of positivity, through being involved in student success, and in experiences of feeling valued for their work. The data also indicated that teachers’ perspectives on events or the amount of attention paid to daily occurrences with students and colleagues plays a role in the way that teachers experience gratitude. The participating teachers described a contrast between experiences of gratitude and attitudes of negativity. It is recommended that school leaders actively engage in promoting the value and meaning of teachers’ work on a routine basis and seek methods to heighten teachers’ awareness of gratitude in their school experiences. Data from the study and reviewed literature also support the use of gratitude interventions as a means to increase both awareness of gratitude and the effects of gratitude on individual’s lives

    Correlation function of spin noise due to atomic diffusion

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    We use paramagnetic Faraday rotation to study spin noise spectrum from unpolarized Rb vapor in a tightly focused probe beam in the presence of N2_2 buffer gas. We derive an analytical form for the diffusion component of the spin noise time-correlation function in a Gaussian probe beam. We also obtain analytical forms for the frequency spectrum of the spin noise in the limit of a tightly focused or a collimated Gaussian beam in the presence of diffusion. In particular, we find that in a tightly focused probe beam the spectral lineshape can be independent of the buffer gas pressure. Experimentally, we find good agreement between the calculated and measured spin noise spectra for N2_2 gas pressures ranging from 56 to 820 torr.Comment: 6 pages, 4 figure

    NASTRAN general purpose interface requirements document

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    This NASTRAN (NASA STRuctural ANalysis) General Purpose Interface Requirements Document (IRD) defines standards for deliverables required of New Capability Contractors (NCCs) and relates these deliverables to the software development cycle. It also defines standards to be followed by NCCs for adding to and modifying the code in the NASTRAN software system and for adding to and modifying the four official NASTRAN manuals: The NASTRAN Theoretical Manual, the NASTRAN User's Manual, The NASTRAN Programmer's Manual, and The NASTRAN Demonstration Problem Manual. It is intended that this General Purpose IRD shall be incorporated by reference in all contracts for a new NASTRAN capability

    Electrochemistry in silver catalysed ferric sulfate leaching of chalcopyrite

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    Journal ArticlePrevious investigations have demonstrated the catalytic effect of silver additions in the ferric sulfate leaching of chalcopyrite. CuFeS2 + 4Fe+3 > Cu++ + 5Fe++ + 2S° The enhanced rate of leaching was found to be due to the formation of an intermediate Ag2S film which forms on the CuFeS2 surface by an exchange reaction. Under these conditions, unlike the uncatalysed ferric sulfate leach, the elemental sulfur forms a nonprotective reaction product on the Ag2S crystallites. As a result, the rate appears to become limited by an intermediate electrochemical reaction in the Ag2S film rather than by transport through the elemental sulfur reaction product

    Teleology and Realism in Leibniz's Philosophy of Science

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    This paper argues for an interpretation of Leibniz’s claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibniz’s fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibniz’s thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibniz’s use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibniz’s use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz
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