506 research outputs found

    Structural, vibrational and thermal properties of densified silicates : insights from Molecular Dynamics

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    Structural, vibrational and thermal properties of densified sodium silicate (NS2) are investigated with classical molecular dynamics simulations of the glass and the liquid state. A systematic investigation of the glass structure with respect to density was performed. We observe a repolymerization of the network manifested by a transition from a tetrahedral to an octahedral silicon environment, the decrease of the amount of non-bridging oxygen atoms and the appearance of three-fold coordinated oxygen atoms (triclusters). Anomalous changes in the medium range order are observed, the first sharp diffraction peak showing a minimum of its full-width at half maximum according to density. The previously reported vibrational trends in densified glasses are observed, such as the shift of the Boson peak intensity to higher frequencies and the decrease of its intensity. Finally, we show that the thermal behavior of the liquid can be reproduced by the Birch-Murnaghan equation of states, thus allowing us to compute the isothermal compressibility

    Information architecture for effective Workload Control: an insight from a successful implementation

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    The implementation of Workload Control (WLC), a Production Planning and Control concept uniquely designed for Make-To-Order companies, has been a constant challenge. Scholars argued that WLC is largely developed through simulations of well-defined environments while much more complex circumstances (e.g. information availability) have emerged in field research. A recent trend of WLC research is to improve the practical applicability of the concept, where empirical evidence is essential. However, success in WLC implementation remains impeded. The availability of data has been a significant area that frustrates the implementation process. While there is a tendency to simplify data requirements in recent WLC theory development, it is important to understand and maintain the information that is essential for the concept to be effective. For the first time in the field, this paper details the information architecture for WLC. Key informational entities of relevance to the input/output control functions in WLC as well as performance measurement are discussed based on evidence from a successful implementation. The paper not only sheds light for practitioners on how to construct an information system that facilitates successful WLC implementation but also has implications for future development of WLC mechanisms coping with information uncertainties in practice

    Static and Dynamic Properties of a Viscous Silica Melt Molecular Dynamics Computer Simulations

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    We present the results of a large scale molecular dynamics computer simulation in which we investigated the static and dynamic properties of a silica melt in the temperature range in which the viscosity of the system changes from O(10^-2) Poise to O(10^2) Poise. We show that even at temperatures as high as 4000 K the structure of this system is very similar to the random tetrahedral network found in silica at lower temperatures. The temperature dependence of the concentration of the defects in this network shows an Arrhenius law. From the partial structure factors we calculate the neutron scattering function and find that it agrees very well with experimental neutron scattering data. At low temperatures the temperature dependence of the diffusion constants DD shows an Arrhenius law with activation energies which are in very good agreement with the experimental values. With increasing temperature we find that this dependence shows a cross-over to one which can be described well by a power-law, D\propto (T-T_c)^gamma. The critical temperature T_c is 3330 K and the exponent gamma is close to 2.1. Since we find a similar cross-over in the viscosity we have evidence that the relaxation dynamics of the system changes from a flow-like motion of the particles, as described by the ideal version of mode-coupling theory, to a hopping like motion. We show that such a change of the transport mechanism is also observed in the product of the diffusion constant and the life time of a Si-O bond, or the space and time dependence of the van Hove correlation functions.Comment: 30 pages of Latex, 14 figure

    Co-creation workshops for work life oriented ICT education

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    ICT Companies in Finland today are facing problems in recruiting the right skilled workforce to meet their needs [1]. There is particular shortage of application developers, application designers, web professionals and coders in the South Ostrobothnia area of Finland [2]. Typical degree courses offered by universities would not work because there is a mismatch between the university degrees offered and the needs of these companies. There is a need to develop a new approach to address this shortage. In response to this, local University of Applied Sciences has developed a new ICT education programme using co-creation methods. The new approach is based on the concepts of co-creation of value from service science. This paper discusses the importance of this new approach in education and how it can be implemented. Empirical data is gathered through observation of and reflection on the development of the ICT programme which follows the principles of co-creation

    On identity: Contemporary music research in the Asia-Pacific region. Introduction

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    Anthropology, as the study of human societies, has always been inclusive of music in some form or another, whether simply referencing a culture’s music through evocative book titles or delving in detail into musical forms and performances themselves. Music is acknowledged as a gateway to understanding a people’s experience*in particular song, which gives voice to human expression not always possible in everyday language. From another angle, music research has increasingly engaged with anthropology and this has occurred most notably in the development of the discipline of ethnomusicology, which grew from comparative musicology, and the publication of one of its key texts, Alan Merriam’s The Anthropology of Music(1964). This issue of The Asia Pacific Journal of Anthropology(TAPJA) contributes with a special focus on contemporary music research in the Asia Pacific region

    "...because I am something special" or "I think I will be something like a guinea pig": information and assent of legal minors in clinical trials – assessment of understanding, appreciation and reasoning

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study is to assess and evaluate the capacities for understanding, appreciation and reasoning of legal minors with psychiatric disorders and their parents and their competence to consent or assent to participation in clinical trials. The beliefs, fears, motivation and influencing factors for decision-making of legal minors and parents were also examined.</p> <p>Methods</p> <p>Using the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR), an instrument developed for adults whose capacities to consent are unclear, we provided information about clinical trials and assessed understanding, appreciation and reasoning. We adapted this tool for legal minors and examined 19 children and adolescents between the ages of 7 and 15 with attention deficit/hyperactivity disorder (ADHD) or ADHD combined with oppositional defiant disorder (DSM-IV 314.00/314.01/312.8) enrolled in clinical trials. Parents were also examined using the MacCAT-CR.</p> <p>Results</p> <p>Facts such as the procedures involved in trials or their duration were well understood by legal minors, but more abstract issues like the primary purpose of the trial were not understood by children and adolescents or by many parents. Legal minors also had difficulties understanding the nature of placebo and the probability of receiving placebo. Children's and adolescents' decisions were influenced by fears about their disorder worsening and by problems in their relationship with their parents. Parents wanted the best therapy for their children in order to minimize problems in school.</p> <p>Conclusion</p> <p>Legal minors and parents need to be informed more precisely about specific issues like placebo and the primary purpose of trials. In general, the reasoning of children and adolescents was influenced by their experience with their disorder and decision making was based on reasonable arguments. Their fears were based on everyday experiences such as school performance or family relationships.</p

    Natural gaits of the non-pathological flat foot and high-arched foot

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    There has been a controversy as to whether or not the non-pathological flat foot and high-arched foot have an effect on human walking activities. The 3D foot scanning system was employed to obtain static footprints from subjects adopting a half-weight-bearing stance. Based upon their footprints, the subjects were divided into two groups: the flat-footed and the high-arched. The plantar pressure measurement system was used to measure and record the subjects' successive natural gaits. Two indices were proposed: distribution of vertical ground reaction force (VGRF) of plantar and the rate of the footprint areas. Using these two indices to compare the natural gaits of the two subject groups, we found that (1) in stance phase, there is a significant difference (p<0.01) in the distributions of VGRF of plantar; (2) in a stride cycle, there is also a significant difference (p<0.01) in the rates of the footprint areas. Our analysis suggests that when walking, the VGRF of the plantar brings greater muscle tension to the flat-footed while a smaller rate of the footprint areas brings greater stability to the high-arched.Comment: 8 pages, 4 figure

    A conceptual model for action and design research

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    Organizational research has a pattern of special characteristics which make a clear distinction from other research paradigms. When using these approaches – based on Action and Design – the Interpretivist, Constructivist, and Participatory perspectives dominate. They have already proven to have strong foundations, which turn these paradigmatic approaches into effective ways for getting knowledge, doing things, and promoting change within organizational settings. It combines the traditional scientific, engineering, and organization development approaches, depicting how an organization can, simultaneously, solve multidimensional problems and produce actionable knowledge, effective change and useful artifacts. It has been developed using a Design Science Research approach, tested in a major organizational change program (Henriques, 2015; Henriques & ONeill, 2014), and successfully used to teach research methods essentials to Master and DBA students.info:eu-repo/semantics/publishedVersio

    Lucy's Flat Feet: The Relationship between the Ankle and Rearfoot Arching in Early Hominins

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    BACKGROUND. In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved. METHODOLOGY/PRINCIPAL FINDINGS. Here, we present evidence from radiographs of modern humans (n=261) that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8%) have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and "Lucy" (A.L. 288-1), a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles. CONCLUSIONS/SIGNIFICANCE. This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis "Lucy" has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch development in Plio-Pleistocene hominins.Leakey Foundatio
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