• 제목/요약/키워드: effective diffusion

검색결과 844건 처리시간 0.028초

아동의 공격성과 분노조절전략, 분노조절정도간 관련성 (Analysis of the Relationships between Children's Aggression, Anger Regulation Strategies and Anger Regulation Degree)

  • 이혜련;김경연
    • 대한가정학회지
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    • 제46권8호
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    • pp.27-36
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    • 2008
  • The purpose of the present study was to investigate the relationship between children's aggression, their anger regulation strategy and anger regulation degree. Using an aggression scale, a total of 428 elementary school children in grades 5 and 6 were examined and partitioned into two groups; -the high aggression group (n = 107) and low aggression group (n = 109). They rated the degree to which they felt anger in anger events. They selected one strategy used to regulate anger. Then they rated the degree to which they felt anger after using the selected regulation strategy. The results of this study showed that the high aggression group responded by high degree of anger, low degree of anger regulation and used more affect diffusion strategy. Regardless of children's aggression source, support pursuit strategy was confirmed to be the most effective remedial method while children regulated anger in anger events.

헴트 소자의 해석적 직류 모델 (AN ANALYTICAL DC MODEL FOR HEMTS)

  • 김영민
    • ETRI Journal
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    • 제11권2호
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    • pp.109-119
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    • 1989
  • Based on the 2-dimensional charge-control simulation[4], a purely analytical model for MODFET's is proposed. In this model, proper treatment of the diffusion effect in the 2-DEG transport due to the gradual channel opening along the 2-DEG channel was made to explain the enhanced mobility and increased thershold voltage. The channel thickness and gate capacitance are experssed as functions of gate vlotage including subthreshold characteristics of the MODFET's analytically. By introducing the finite channel opening and an effective channel-length modulation, the slope of the saturation region of the I-V curves was modeled. The smooth transition of the I-V curves from linear-to-saturation region of the I-V curves was possible using the continuous Troffimenkoff-type of field-dependent mobility. Furthermore, a correction factor f was introduced to account for the finite transtition section forming between the GCA and the saturated section. This factor removes the large discrepanicies in the saturation region fo the I-V curves presicted by existing 1-dimensional models. The fitting parameters chosen in our model were found to be predictable and vary over relatively small range of values.

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Technology Transfer and Entrepreneurial Development through University Business Incubation Process in Thailand

  • Wonglimpiyarat, Jarunee
    • World Technopolis Review
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    • 제3권2호
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    • pp.78-88
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    • 2014
  • This study is concerned with the process of technology transfer and commercialization. It is focused on the entrepreneurial development through the university business incubation process of Thailand. The study analyzes the leading university business incubators (UBIs) as well as major science and technology incubators to understand the strategies for commercialization of technology. The analyses of results, based on the Triple Helix model, have shown that the incubation program is one of the major policy mechanisms to support innovation and suggested that UBIs should act as an intermediary between the spheres of university and industry to provide interactive linkages and promote effective utilization of university research. The empirical study provides theoretical and managerial implications on the government policies to support the entrepreneurial development, innovation development and diffusion.

공간적 멀티스케일 모델의 동적 해석 (Dynamic Analysis of Spatial Multiscale Models)

  • 김성엽;박종연;조영삼;전석기;임세영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.547-550
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    • 2004
  • We present a multiscale scheme which describes the dynamic pictures of atoms in the multiple length-scale systems. Large-scale atomic systems are reduced to coarse grained system by the quasicontinuum, of which the dynamic pathways are rendered by the action-derived molecular dynamics proved effective for multiple time-scale problems such as rare events. Adatom diffusions on the metal (001) surface are selected for our numerical examples. The energy barriers of the diffusions and the real dynamic trajectories of the adatoms are calculated.

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중수로 압력관의 크리프 처짐 해석 기법 및 프로그램 개발 (Development of Creep Deflection Analysis Method and Program for CANDU Pressure Tube)

  • 심도준;허남수;박보규;장윤석;김윤재;김영진;정현규
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.66-71
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    • 2004
  • Estimation of the CANDU pressure tube deflection is important since the deflection may cause significant structural failure due to hydrogen diffusion and blister. However, there is no appropriate engineering model to estimate it exactly. The purpose of this paper is to propose a new analysis method and program to resolve this issue. For development of proper analysis method, a series of finite element analyses has been carried under elastic-creep condition. In addition, for effective estimation of the creep deflection, an analysis program named PC-DAS was developed based on the proposed method. Comparison of simple case study results with corresponding reference ones showed good agreement. Therefore, the proposed method and program can be utilized as one of valuable toolkit for integrity assessment of CANDU pressure tube.

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반응표면기법에 의한 고분자전해질형 연료전지 시스템의 최적화 (Optimization of PEM Fuel Cell System Using a RSM)

  • 현동길;김진완;남양해;닝천;김영배
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.3140-3141
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    • 2008
  • The output power efficiency of the fuel cell system depends on the demanded current, stack temperature, air excess ratio, hydrogen excess ratio and inlet air humidity. Thus, it is necessary to determine the optimal operation condition for maximum power efficiency. In this paper, we developed a dynamic model of fuel cell system which contains mass flow model, diffusivity gas layer model, membrane hydration and electrochemistry model. In order to determine the maximum output power and minimum use of hydrogen in a certain power condition, response surface methodology (RSM) optimization based on the proposed PEMFC stack model is presented. The results provide an effective method to optimize the operation condition under varied situations.

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어촌 소멸위험의 영향 요인 분석 (The Analysis about Factors Affecting of Extinction Risk in Fishing Village)

  • 이서구;김정태
    • 수산경영론집
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    • 제51권1호
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    • pp.67-79
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    • 2020
  • The purpose of this study is to propose a policy improvement plan by analysis of the extinction risk factors reflecting the specificity of fishing villages, fishing village support policies, and settlement conditions of fishing villages as one of the solutions to the immediate problem of fishing village extinction. The results of the study show the higher the level of number of fishing ports, number of returning rural population, and housing diffusion rate, the dependent variable extinction risk index was a positive effect while vacant house ratio and aged house ratio was analyzed to be in was a negative (-) relationship with the dependent variable.The policy implications through this study were to prepare an effective policy to reduce the risk of extinction, to improve urgent settlement conditions, and to prepare a condition to convert returning rural population into fishery population.

Monte Carlo방법을 이용한 Germanium 기판의 결공형 클러스터링 형성에 대한 연구 (A Study of Germanium Substrate Vacancy Clustering Formation using Monte Carlo Method)

  • 이준하
    • 반도체디스플레이기술학회지
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    • 제10권2호
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    • pp.45-48
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    • 2011
  • In this paper, vacancy clustering formation and diffusion of germanium substrate was studied. The analysis method was adopted Monte Carlo method. At temperatures higher than melting point, fewer clusters formed, but there was less variation in the number of clusters than at lower temperatures, as the time increased. Equilibrium diffusivities in the clustering region were $10^2$ lower than those of free vacancies in the initial stage of kinetic lattice Monte Carlo simulations. They were expressed according to three temperature regimes: at temperatures above 1,100 K, at temperatures of 1,100-900 K, and at temperatures below 900 K. The effective mean migration energy, 1.1 eV, closely coincided with that of the 1.0-1.2 eV in experiments.

In Vitro Effects of Essential Oils from Ostericum koreanum against Antibiotic-Resistant Salmonella spp

  • Shin, Seung-Won
    • Archives of Pharmacal Research
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    • 제28권7호
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    • pp.765-769
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    • 2005
  • The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

AA 2014 알루미늄 합금의 고상율에 따른 미세조직 및 반응고 변형 거동 (Microstructures and Deformation Behavior of AA 2014 Aluminum Alloys in the Semi-Solid State)

  • 한도석
    • 한국주조공학회지
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    • 제37권5호
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    • pp.157-163
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    • 2017
  • In the present study, the microstructural evolution and deformation behavior of AA 2014 aluminum alloys with different microstructures in a semi-solid state were investigated. For a given alloy, applied load and deformation time, the measured strain was higher at a higher temperature, indicative of a lower solid fraction. When a large proportion of the liquid was present as intragranular droplets, the alloy would not as easily deform because the effective liquid fraction between the solid grains had decreased. Greater deformation was achieved with higher grain boundary misorientations due to the enhanced wetting of the grain boundaries with liquid. A semi-empirical constitutive model is proposed for semi-solid deformation under the conditions in the present study. The mechanism of semi-solid deformation incorporates the initial flow of the liquid in the early stages of deformation, followed by a more gradual increase in the strain due to deformation by grain sliding accompanied by self-diffusion in the solid grains.