1,792 research outputs found
Another analytic view about quantifying social forces
Montroll had considered a Verhulst evolution approach for introducing a
notion he called "social force", to describe a jump in some economic output
when a new technology or product outcompetes a previous one. In fact,
Montroll's adaptation of Verhulst equation is more like an economic field
description than a "social force". The empirical Verhulst logistic function and
the Gompertz double exponential law are used here in order to present an
alternative view, within a similar mechanistic physics framework. As an
example, a "social force" modifying the rate in the number of temples
constructed by a religious movement, the Antoinist community, between 1910 and
1940 in Belgium is found and quantified. Practically, two temple inauguration
regimes are seen to exist over different time spans, separated by a gap
attributed to a specific "constraint", a taxation system, but allowing for a
different, smooth, evolution rather than a jump. The impulse force duration is
also emphasized as being better taken into account within the Gompertz
framework. Moreover, a "social force" can be as here, attributed to a change in
the limited need/capacity of some population, coupled to some external field,
in either Verhulst or Gompertz equation, rather than resulting from already
existing but competing goods as imagined by Montroll.Comment: 4 figures, 29 refs., 15 pages; prepared for Advances in Complex
System
Virtual Reality Techniques for 3D Data-Warehouse Exploration
This paper focuses on the evaluation of virtual reality (VR) interaction techniques for exploration of data warehouse (DW). The experimental DW involves hierarchical levels and contains information about customers profiles and related purchase items. A user study has been carried out to compare two navigation and selection techniques. Sixteen volunteers were instructed to explore the DW and look for information using the interaction techniques, involving either a single WiimoteTM (monomanual) or both WiimoteTM and NunchuckTM (bimanual). Results indicated that the bimanual interaction technique is more efficient in terms of speed and error rate. Moreover, most of the participants preferred the bimanual interaction technique and found it more appropriate for the exploration task. We also observed that males were faster and made less errors than females for both interaction techniques
3D Interaction Techniques for Virtual Shopping : design and preliminary study
Virtual Reality is now recognized as a powerful tool for the assessment and rehabilitation of both motor and cognitive impairments. In this context, effective Virtual Environments (VEs) that simulate everyday tasks must be proposed. We have developed a virtual supermarket (VS) in which the user can explore and collect various items using a shopping cart. Four interaction techniques have been designed and compared in terms of usability, performance and workload with healthy volunteer participants. These techniques go beyond the desktop paradigm by offering a more immersive and intuitive way of interaction. Results showed that participants were more efficient in terms of performance (completion time and travelled distance) using the game-pad rather than using full body gestures. However, they had more fun performing the task under these conditions
Extended twin study of alcohol use in Virginia and Australia
Drinking alcohol is a normal behavior in many societies, and prior studies have demonstrated it has both genetic and environmental sources of variation. Using two very large samples of twins and their first-degree relatives (Australia ≈ 20,000 individuals from 8,019 families; Virginia ≈ 23,000 from 6,042 families), we examine whether there are differences: (1) in the genetic and environmental factors that influence four interrelated drinking behaviors (quantity, frequency, age of initiation, and number of drinks in the last week), (2) between the twin-only design and the extended twin design, and (3) the Australian and Virginia samples. We find that while drinking behaviors are interrelated, there are substantial differences in the genetic and environmental architectures across phenotypes. Specifically, drinking quantity, frequency, and number of drinks in the past week have large broad genetic variance components, and smaller but significant environmental variance components, while age of onset is driven exclusively by environmental factors. Further, the twin-only design and the extended twin design come to similar conclusions regarding broad-sense heritability and environmental transmission, but the extended twin models provide a more nuanced perspective. Finally, we find a high level of similarity between the Australian and Virginian samples, especially for the genetic factors. The observed differences, when present, tend to be at the environmental level. Implications for the extended twin model and future directions are discussed
Visualizing the logistic map with a microcontroller
The logistic map is one of the simplest nonlinear dynamical systems that
clearly exhibit the route to chaos. In this paper, we explored the evolution of
the logistic map using an open-source microcontroller connected to an array of
light emitting diodes (LEDs). We divided the one-dimensional interval
into ten equal parts, and associated and LED to each segment. Every time an
iteration took place a corresponding LED turned on indicating the value
returned by the logistic map. By changing some initial conditions of the
system, we observed the transition from order to chaos exhibited by the map.Comment: LaTeX, 6 pages, 3 figures, 1 listin
A New 2D Interaction-based Method for the Behavioral Analysis of Instrumental Activities of Daily Living
In neuropsychology, many computerized solutions have been proposed in order to assess patients’ functioning in activities of daily living, via realistic interactive simulation. In this context, most developed systems are based on simple devices, real time 2D interaction, and monoscopic 3D computer graphics environment. Behavioral analysis has drawn the interest of many domains, such as neuropsychology, ergonomics, web design, or virtual reality. However, advances on this topic remains fragmented in their respective areas. Thus, in computerized solutions applied to neuropsychology, the behavioral analysis does not take into account the data from interaction. The potential interest of computerized solutions is hence underexploited. In this paper, we propose a transdisciplinary solution, based on a finer analysis of 2D interaction data, such as stop duration. This method could reveal interesting aspects of users’ behaviors
Entanglement of a microcanonical ensemble
We replace time-averaged entanglement by ensemble-averaged entanglement and
derive a simple expression for the latter. We show how to calculate the
ensemble average for a two-spin system and for the Jaynes-Cummings model. In
both cases the time-dependent entanglement is known as well so that one can
verify that the time average coincides with the ensemble average.Comment: 10 page
Modelling OpenComRTOS tasks interaction
The model of tasks interaction in Open Communication Real Time Operation System (OpenComRTOS) is developed and discussed in the paper. The main feature of the proposed approach is the using the intermediate hub entity for decoupling interacting tasks. Different temporal semantics (waiting, non waiting and waiting timeout) of tasks synchronization mechanism is introduced. Emerging the effects (i.e. synchronisation or the absence of it) in the case when the tasks actions have different temporal semantics is analysed. The different approaches for expanding the hub model with using TLA and Hoare triplets are proposed.У статті розроблюється й обговорюється модель взаємодії задач в операційній системі реального часу OpenComRTOS. Головна особливість запропонованого підходу – використання сутності синхронізації Hub як проміжної ланки в механізмі взаємодії задач. Проаналізована різна часова семантика процесу синхронізації задач (очікування, неочікування, очікування протягом періоду часу). Розглянуто виникнення ефекту синхронізації у випадку, коли дії задач мають різну часову семантику. Запропоновані різні підходи для розширення моделі Hub з використанням TLA (Temporal Logic of Actions) і трійок Hoare (Hoare triplets).В статье разрабатывается и обсуждается модель взаимодействия задач в операционной системе реального времени OpenComRTOS. Главная особенность предложенного подхода – использование сущности синхронизации Hub как промежуточного звена в механизме взаимодействия задач. Проанализирована различная временная семантика процесса синхронизации задач (ожидание, неожидание, ожидание в течение периода времени). Рассмотрено возникновение эффекта синхронизации в случае, когда действия задач имеют различную временную семантику. Предложены различные подходы для расширения модели Hub с использованием TLA (Temporal Logic of Actions) и троек Hoare (Hoare triplets)
Extracellular Nucleotides Regulate Arterial Calcification by Activating Both Independent and Dependent Purinergic Receptor Signaling Pathways
Arterial calcification, the deposition of calcium-phosphate crystals in the extracellular matrix, resembles physiological bone mineralization. It is well-known that extracellular nucleotides regulate bone homeostasis raising an emerging interest in the role of these molecules on arterial calcification. The purinergic independent pathway involves the enzymes ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), 5′-nucleotidase and alkaline phosphatase. These regulate the production and breakdown of the calcification inhibitor—pyrophosphate and the calcification stimulator—inorganic phosphate, from extracellular nucleotides. Maintaining ecto-nucleotidase activities in a well-defined range is indispensable as enzymatic hyper- and hypo-expression has been linked to arterial calcification. The purinergic signaling dependent pathway focusses on the activation of purinergic receptors (P1, P2X and P2Y) by extracellular nucleotides. These receptors influence arterial calcification by interfering with the key molecular mechanisms underlying this pathology, including the osteogenic switch and apoptosis of vascular cells and possibly, by favoring the phenotypic switch of vascular cells towards an adipogenic phenotype, a recent, novel hypothesis explaining the systemic prevention of arterial calcification. Selective compounds influencing the activity of ecto-nucleotidases and purinergic receptors, have recently been developed to treat arterial calcification. However, adverse side-effects on bone mineralization are possible as these compounds reasonably could interfere with physiological bone mineralization
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