General Relativistic MHD Simulations of the Gravitational Collapse of a Rotating Star with Magnetic Field as a Model of Gamma-Ray Bursts

We have performed 2.5-dimensional general relativistic magnetohydrodynamic (MHD) simulations of the gravitational collapse of a magnetized rotating massive star as a model of gamma ray bursts (GRBs). This simulation showed the formation of a disk-like structure and the generation of a jet-like outflow inside the shock wave launched at the core bounce. We have found the jet is accelerated by the magnetic pressure and the centrifugal force and is collimated by the pinching force of the toroidal magnetic field amplified by the rotation and the effect of geometry of the poloidal magnetic field. The maximum velocity of the jet is mildly relativistic ($\sim$ 0.3 c).Comment: 4 pages, 1 figure, aipTEX, contribution to the 2003 GRB Conference, held at Santa Fe, N

Variation in human water turnover associated with environmental and lifestyle factors

Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking ( 2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors. </p

Modeling Reliance on XAI Indicating Its Purpose and Attention

This study used XAI, which shows its purposes and attention as explanations of its process, and investigated how these explanations affect human trust in and use of AI. In this study, we generated heat maps indicating AI attention, conducted Experiment 1 to confirm the validity of the interpretability of the heat maps, and conducted Experiment 2 to investigate the effects of the purpose and heat maps in terms of reliance (depending on AI) and compliance (accepting answers of AI). The results of structural equation modeling (SEM) analyses showed that (1) displaying the purpose of AI positively and negatively influenced trust depending on the types of AI usage, reliance or compliance, and task difficulty, (2) just displaying the heat maps negatively influenced trust in a more difficult task, and (3) the heat maps positively influenced trust according to their interpretability in a more difficult task

A preliminary study of a cloth guiding mechanism for automatic sewing system

Purpose - In the trend from mass production to mass customization, more flexible production systems are required. In the clothing field, many studies about automatization of sewing processes have been done into producing small amounts of various kinds of products. The purpose of this paper is to propose a versatile guiding mechanism of a cloth for an automatic sewing system. Design/methodology/approach - Real sewing processes were referenced for the mechanism, and curved stitch is formed holding a point on a cloth. This mechanism consists of a solenoid for holding a cloth and a roller to prevent deformation of the cloth. When a cloth is sewn with the mechanism, the trajectory of the stitch is unstable because of anisotropy of a cloth. A precise trajectory was obtained by adding a device to control the pressure of the roller for holding a cloth and keeping a tension properly applied to a cloth. Findings - It was found out that shearing property is the most related to the stability of sewing trajectory: lithe tension for guidance applied to a cloth is constant, deformation of the cloth was observed and it was the cause of unstableness of sewing trajectory. By controlling the tension for guidance applied to a cloth properly according to the direction of the cloth, precise sewing trajectory was obtained. Originality/value - There have been some studies in which sewing conditions were dynamically controlled according to the mechanical properties of a cloth. To these studies, here it was proposed that sewing conditions were kept constant by controlling the guidance of a cloth according to its mechanical properties.ArticleINTERNATIONAL JOURNAL OF CLOTHING SCIENCE AND TECHNOLOGY. 24(1):6-14 (2012)journal articl

Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals &gt;4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.</p

Numerical Calculations in Phase Equilibrium by Equation of State v3

A practical method for phase equilibrium calculations using the equation of state for a perfect solid and a perfect liquid is shown along with examples of Excel worksheets. The molecular systems of a perfect solid and a perfect liquid are assumed to be composed of single-type spherical molecules. The molecular interaction is expressed by a Lennard-Jones potential function. The pressure and internal energy of the system are expressed as functions of temperature and volume. Other thermodynamic functions such as entropy are also given as functions of temperature and volume. A thermodynamic constancy test is performed.完全固体・完全液体の状態方程式 v3に基づいて、相転移を計算する方法を示した。エクセルのワークシートを使って、ギブズエネルギーやその他の熱力学量を温度と体積の関数として得ることができる。VBAプログラムの例も添付した。熱力学的な恒等式を用いて、数値計算に大きな矛盾がないことを確かめた

Phase Equilibrium Calculations by Equation of State v2

Practical methods for phase equilibrium calculations by the equation of state for a perfect solid and liquid (v2) are described using examples of worksheets. Using the Microsoft Excel worksheets, the pressure, Gibbs energy and other thermodynamic quantities of a molecular system are obtained as functions of temperature and volume. Some examples of VBA (Visual Basic for Applications) programs are given to obtain volume and other thermodynamic properties as a function of temperature under a given pressure. The thermodynamic consistency test is performed as a function of temperature at a given pressure, where the difference between the heat capacity under a constant pressure and that under a constant volume should equal to an expression consisting of the thermal expansion coefficient, temperature, volume and isothermal compressibility.完全固体・完全液体の状態方程式に基づいて、相転移を計算する方法を示した。エクセルのワークシートを使って、ギブズエネルギーやその他の熱力学量を温度と体積の関数として得ることができる。VBAプログラムの例も添付した。熱力学的な恒等式を用いて、数値計算に大きな矛盾がないことを確かめた

UTILIZATION OF METADATA FOR QUALITY ASSURANCE IN THE INTERNATIONAL SHARING AND REUSE OF OPEN EDUCATIONAL RESOURCES

In order to sustain the development and utilization of learning content under the limited financial and human resources, the sharing and reuse of open educational resources (OERs) have been promoted in various school levels and disciplines. In many countries, central organization(s) collect both learning content and its metadata, and provide them to learners and teachers with distinctive value‐added services from their portals. Collaborations among the national portals have also emerged beyond borders.Global Learning Object Brokered Exchange (GLOBE) is an international consortium of the hub organizations, which manage a federated repository and/or a meta‐referatory in each country and region. GLOBE was established in September 2004 by five founding members, and now twelve organizations in the world participate in. By adopting IEEE LOM version 1.0 for the metadata standards, SQI for the query language, and OAI‐PMH for harvesting, GLOBE realized a global search and delivery infrastructure for lifelong learning (LLL). At present, while the repositories all over the world store huge number of learning content and metadata, the variance of the quality becomes much bigger. In addition, because the effectiveness of learning content is relative and dependent on contextual factors, both optimizations specialized in learner characteristics and localizations to each language/culture are indispensable. The users need some supports on the quality and pedagogical guidance when they find their right content. GLOBE, based on multilingualism, multiculturalism and pluralism, collaborates to build up standardized services on the quality assurance of the content utilizing the “Educational” items of LOM. In AAOU framework also, the organizations can promote “openness”, and share the quality learning content and educational information by using a standardized content search and delivery infrastructure

Perfect Solid and Liquid

A 3-phase equilibrium in argon is obtained by the thermodynamics of the perfect solid and liquid. The equation of state (EOS) for a perfect solid is obtained for a pure substance of spherical molecules that undergo molecular interaction of the Lennard-Jones form. The primitive internal energy EOS for a perfect solid (referred to as v0 EOS) is the sum of the thermally averaged kinetic energy and the potential energy of the nearest neighbors in a face-centered cubic (FCC) solid at 0 K. The extended internal energy EOS for a perfect solid (v1) includes a long-range effect in the low density region as the internal energy in the van der Waals EOS. The pressure EOS is written as the volume derivative of the potential energy at 0 K to satisfy the EOS with respect to thermodynamics. The temperature effect in the virial term is included in the extended pressure EOS. The EOS for a perfect liquid is the van der Waals EOS with empirical coefficients to explain the 3-phase equilibrium. The change in entropy for a reversible process is calculated by the standard method. The thermodynamic quantities of each phase are written as functions of volume and temperature. In this way, the Gibbs energy per molecule is plotted as a function of pressure for both solid and liquid phases, and the crossing point in the plot is the phase transition point. The p-V-T relations on the equilibrium lines are comparable with the experimental and molecular simulation results. The calculated average potential energy and entropy on the phase boundaries are consistent with the simulations. The thermodynamic quantities under a low pressure are compared with the molecular dynamic simulations. The quantities examined are volume, internal energy, enthalpy, entropy, Helmholtz energy, Gibbs energy, expansion coefficient, isothermal compressibility and heat capacity under a constant pressure.固体についてレナードージョーンズ相互作用と面心立方格子を仮定して、簡単化した状態方程式を示した。これを完全固体の状態方程式と呼ぶ。液体と気体については実験値の解析から得られたファンデルワールス状態方程式を仮定した。これを完全液体の状態方程式と呼ぶ。これらを用いて球形分子系の３相平衡をギブズエネルギーの計算から導いた。その結果をアルゴン系についての実験結果および、モンテカルロ法・分子動力学法シミュレーションと比較して、全体的に良い対応関係を得た