• Title/Summary/Keyword: Concept of Physical Change

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Simulation of material failure behavior under different loading rates using molecular dynamics

  • Kim, Kunhwi;Lim, Jihoon;Kim, Juwhan;Lim, Yun Mook
    • Structural Engineering and Mechanics
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    • v.30 no.2
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    • pp.177-190
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    • 2008
  • Material failure behavior is generally dependent on loading rate. Especially in brittle and quasi-brittle materials, rate dependent material behavior can be significant. Empirical formulations are often used to predict the rate dependency, but such methods depend on extensive experimental works and are limited by practical constraints of physical testing. Numerical simulation can be an effective means for extracting knowledge about rate dependent behavior and for complementing the results obtained by testing. In this paper, the failure behavior of a brittle material under different loading rates is simulated by molecular dynamics analysis. A notched specimen is modeled by sub-million particles with a normalization scheme. Lennard-Jones potential is used to describe the interparticle force. Numerical simulations are performed with six different loading rates in a direct tensile test, where the loading velocity is normalized to the ratio of the pseudo-sonic speed. As a consequence, dynamic features are achieved from the numerical experiments. Remarkable failure characteristics, such as crack surface interaction/crack arrest, branching, and void nucleation, vary in case of the six loading cases. These characteristics are interpreted by the energy concept approach. This study provides insight into the change in dynamic failure mechanism under different loading rates.

Overview of Human Adaptive Mechatronics and Assist-control to Enhance Human's Proficiency

  • Suzuki, Satoshi;Furuta, Katsuhisa;Harashima, Fumio
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1759-1764
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    • 2005
  • Human Adaptive Mechatronics(HAM) is a new concept which was proposed in our university's research project sponsored by Japanese Ministry of Education, Sports, Culture, Science and Technology(MEXT), and is defined as "intelligent mechanical systems that adapt themselves to the user's skill under various environments, assist to improve the user's skill, and assist the human-machine system to achieve best performance". In this paper, the concept and key-items of HAM are mentioned. And the control strategy to realize a HAM human-machine system is explained in the case of physical-interface system, i.e. haptic system. The proposed assist-control of a force-feedback type haptic system includes online estimation of a operator's control characteristics, and a `force assist' function implemented as a change in the support ratio according to the identified skill level. We developed a HAM-haptic device test system, executed evaluation experiments with this apparatus, and analyzed the measured data. It was confirmed that the operator's skill could be estimated and that operator's performance was enhanced by the assist-control.

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Concept Development of Resilience (회복력 (Resilience) 개념 개발)

  • 김혜성
    • Journal of Korean Academy of Nursing
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    • v.28 no.2
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    • pp.403-413
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    • 1998
  • The Resilience is described as the personal capacity which brings psychosocial comeback. The role of nursing is to do its best to rehabilitate patients and to explore the individual in order to promote patients psychosocial change. However, as the current nursing is heavily physical nursing oriented, the identity of the nursing would be lost. Therefore this researcher reviewed if the concept of resilience can be applied to the nursing after examing the concept of resilience by Documents and Fieldwork. The methodology of this research is Hybrid Model developed by Schwartz-Barcott and Kim for the concept development and analysis. The process and procedure consist of The Theoretical Phase, The Fieldwork Phase and The Final Analytical Phase in accodance with the Hybrid Model. The followings the summary of the Research. 1. The Concept of Resilience Finally Analyzed by Documents and Fieldwork (1) The Redefinition of Resilience The resilience is the latent psychosocial capacity which minimize the negative emotion and promote the adaptation under adversity. Resilience appears as cognitive, emotional and behavioral response in the course of changing from negative response to positive response through the interaction of the individual and the enviroments in a given time. Resilience changes and decreases according to time and situation and it can be nurtured. Resilience is the higher concept including hardiness, sense of coherence and self-strength which maintain the health under stress. (2) The Attribute of Resilience The attribute of resilience was devided into psychological and social dimension. In psychological attributes, there are admittion of reality of situation, denial of negative emotion, desire to live, responsibility, confidence, courage, hope, pursuit of positive meaning, identification and pursuit of goal, self-esteem, reception, spontaneity, planning, positiveness, will power, flexibility and creativity. In social attributes, there are a sense of belonging, perception of social support and active social relations. (3) The Process of Resilience There are 4 resilience phases which were the process minimizing the possibility of the negative chain reactions under adversity, the process minimizing the negative emotion under adversity, the process gaining the desire to live and the process exposing the active social relations. 2. The Application Possibility of Resilience Concept to Nursing The resilience concept is the psychosocial capacity with which an individual manages adversity. As many nursing scientists have developed nursing theory based on this capacity and the identification of nursing has been established in this field, resilience is not the new conception in nursing. However, since resilience appears in the attributes related with the resilience process concretely, it would help a lot when nurses execute psychosocial nursing.

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The Effect of Self-Growth Program on the Self-Concept and Peer-Relationship of Elementary School Student (자기성장 프로그램이 초등학생의 자아개념과 또래관계에 미치는 효과)

  • Gim, Tae-Hui
    • The Korean Journal of Elementary Counseling
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    • v.4 no.1
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    • pp.215-236
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    • 2005
  • The Purpose of this study is that self-growth program searches effect self-concept and peer-relationship with elementary school student, and advance following assumption to achieve this purpose and achieved study. First, self-concept point of experiment group students who execute self-growth program will be improved is meaning than self-concept point of control group students. Second, peer-relationship point of experiment group students who execute self-growth program will be improved is meaning than peer-relationship point of control group students. Third, effect that self-growth program gets to self-concept may be meaning difference according to sex. Fourth, difference that impact that self-growth program gets in peer- relationship is meaning according to sex may join. Chose fifth-year student 2 class 68 people (experiment group n=34, control group n=34) in I primary school locating to Jeonrabuk-do Iksan-si to verify above construction for study target. Disposal about experiment group executed over 10th for 60-80 minute 2 times in a week because investigator uses reconstructing self-growth program with virtue research paper such as learning program for own growth of Lee-Hyeong-Deuk (1998). In order to verify the effect after experiment, 1 collected materials for estimation by providing the subject children with questionaires about self-concept and peer-relationship before and after the experiment, and then analyzed the average differences in number of marks between the experiment group and the control group before and after the experiment through and by using One-Way ANOVA, and SPSS 11.0 program. The following is the result what I obtained from the above study. First, there was significant difference is between average difference before and after of experiment group and control group which execute self-growth program in self-concept elevation ($F_{(1,66)} =28.734$, p <.001). From the sub-variable, there was significant difference in academic self ($F_{(1,66)}=6.423$, p<.05), Social Self ($F_{(1,66)}=48.331$, p<.001), Physical Self ($F_{(1,66)}=11.074$, p <.01), sentimental self ($F_{(1,66)}=9.402$, p <.01) Second, there was significant difference is average difference before and after of experiment group and control group which execute self-growth program in peer-relationship promotion ($F_{(1,66)}=24.109$, p <.001). From the sub-variable there W3S Significant difference in trust ($F_{(1,66)}=14.507$, p<.001), respect ($F_{(1,66)}=15.271$, p <.001). Third, there was expose that significant difference does not exist in average self-concept before and after by sex of experiment group which executes self-growth program, and was not shown significant difference in sub-vairable. Fourth, there was expose that significant difference of whole peer- relationship and in respect of sub-variable in average peer-relationship before-after by sex of experiment group which execute self-growth program, but significant difference did not appear in trust. Could get conclusion that self-growth program is effect in elementary school student self-concept elevation and peer-relationship promotion according to these study finding, and confirmed possibility that self-growth program may contribute to change emotional special quality of children positively in education spot.

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The Proxy Variables Selection of Vulnerability Assessment for Agricultural Infrastructure According to Climate Change (논문 - 기후변화에 따른 농업생산기반 재해 취약성 평가를 위한 대리변수 선정)

  • Kim, Sung-Jae;Park, Tae-Yang;Kim, Sung-Min;Kim, Sang-Min
    • KCID journal
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    • v.18 no.2
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    • pp.33-42
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    • 2011
  • Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.

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A Study on the Concept of Operations and Improvement of the Design Methodology for the Physical Protection System of the National Infrastructure - Focused on Nuclear Power Plants - (국가기반시설 물리적 방호체계 운영개념 및 설계방법 개선방안 연구: 원자력발전소를 중심으로)

  • Na, Seog-Jong;Sung, Ha-Yan;Choi, Sun-Hee
    • Korean Security Journal
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    • no.61
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    • pp.9-38
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    • 2019
  • As the scales & density of the Korean national infrastructures have been increased, they will be identified as rich and attractive potential targets for intensified North Korea's attack in the rear region and terrorism attack. In addition, due to changes in security environment such as drone threats and lack of security forces under the 52-hour workweek law, I think that it is the proper time point to reevaluate the effectiveness and appropriateness of the current physical protection system and its shift to a new system. In this study, the direction and improvement of the perimeter physical protection systems of the national infrastructures are to be studied from the viewpoints of its concepts of operations and design methodology, focusing on the nuclear power plant. The reason why we focus on nuclear power plants is because they cause wide-range and long-term damages caused by radioactive materials disperal and pollution, along with short-term damage caused by the interruption of electricity generation in the event of damage to nuclear power plants. With the aim of extracting improvement directions, as we will comprehensively review domestic research trends and domestic·overseas related laws, and consider Korea's specificity, we try to reframe the concept of operation - systematization, mobilization and flexibility -, and establish criteria on system change. In order to improve the technical performance of the new perimeter physical protection system, we study on high-fidelity·multi-methodology based integrated design methodology, breaking from individual silo-type design methods, and I suggest improvement of government procurement, its expansion to export business and other national infrastructure.

Lesson for New Urbanism from the Traditional Space in East Asia

  • Lee, Jawon
    • International Journal of Advanced Culture Technology
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    • v.6 no.4
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    • pp.143-151
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    • 2018
  • Industrialization has accelerated the expansion of mobility to the urban areas, land use for function of residence and consumption. With the urbanization, the management and distribution of the physical space of the city and rational design have also become major issues. Rapid and widespread urbanization has consistently accumulated problems of natural, physical, environmental, and psychological circumstances, and most of urban areas have begun to focus on restoring an efficient, safe and healthy urban environment to improve of the quality of life since the latter half of the 20th century, New-Urbanism is a new urban development paradigm that resembles the practical implications of a shared economy for social, economic and environmental cost reduction.. The geographical significance of the sharing city's concept of the alleys is to revitalize sustainable cities while restoring the attractive elements of the city. This study examines the lessons of New-Urbanism in those traditional urban space comparing with each East Asia's cities such as golmok (alley or backlane) in Seoul, Huton in Beijing, Lilong in Shanghai, and Roji in Japan. This study diagnoses whether main principals of New-Urbanism such as development of good community and walkable pedestrian route, restoration of regional identity and sense of the place, and mitigation of climate change strategy can be practiced in the community of alley as well.

Negotiations in Space and Time: Changing Gender Relations in Thai Tourist-oriented Encounters

  • King, Victor T.;Rotheray, J.
    • SUVANNABHUMI
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    • v.11 no.2
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    • pp.25-57
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    • 2019
  • The paper addresses Erik Cohen's pioneering work on tourism in Thailand, specifically his publications on the relations between Thai women and foreign (farang) men in tourist-oriented encounters. Of sociological-anthropological interest is his conceptualization of these relations as "open-ended prostitution as a skilful game of luck" based on his study of a Bangkok soi (lane) in 1981-1984, and his exploration of Thai culture in terms of ambiguity and contradiction. On the basis of recent ethnographic research in the northern Thai tourist hub of Chiang Mai and wide-ranging observations on tourism development in Thailand, we examine continuity and change in these male-female engagements since Cohen's research, especially in the context of the increasing availability of such electronic agencies as social media, messaging, video chat, and internet dating. Whereas Cohen's concept of ambiguity and illusion has tended to disappear from physical spaces, it seems to have resurfaced in virtual space. The complexities of host-guest relations, and particularly the interactions both within the variegated category of "guests" themselves and then between their "hostesses" are explored in terms of sites of tourism-oriented encounters in both physical and virtual space so as to deconstruct these oppositional categories which have been formative in studies of tourism.

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A study of basic developmental model for experiential farm - Case study on the farm of Sucheong Village located in Gyeonggi Province - (농촌체험농장 개발모형 연구 - 수청마을농장을 중심으로 -)

  • Bark, JS;Kwon, Y.H
    • Journal of Practical Agriculture & Fisheries Research
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    • v.11 no.1
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    • pp.21-33
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    • 2009
  • The agricultural tourism is something that urban people can have an experience of the traditional culture and knowledge of the agriculture, so that it result the improvement of the agricultural profit and keep the special agricultural system. Recently, the demand of the agricultural tourism was increasing, but it was not really enough today that the practice of the tourism for essential farm experience or physical plan. The experiments were practiced by a land in Sucheong-li, Namjong-myun, Gwangju-si, Gyeonggi-do which provides the program for the basic plan and management of the experiential farm, so it shows a developmental model of that typical farm. The basic design of developmental model was formed by the analysis of the natural, civilized and visual environments. The site plan for the experiential farm was composed of a parking lot, public facilities, resting place, experiential site, sports facilities and pedestrian space. There was an examination that the activation of experiential farm should change the concept of the big production or labor-focused farm from a tourism-focused form.

An Analysis of Research on Postpartum Weight Retention (산후체증정체(Postpartum Weight Retention)관련 국외 연구논문 분석)

  • Lee, Seoung-Eun;Yoo, Eun-Kwang
    • Women's Health Nursing
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    • v.9 no.3
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    • pp.287-298
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    • 2003
  • Purpose: To explain the concept of postpartum weight retention and to analyze factor effect on it. Method: A total of 20 studies related postpartum weight retention were selected in the year of 1988-2001 and analysis was done. Result: A demographic factor like parity, age, social and economic level and life style such as exercise, diet, breast feeding are influential factor on postpartum retention weight. But parts of them don't agree the same results. Meanwhile, in some studies, psychological factor like women's self esteem related to postpartum retention weight, body image change, depressing is found to be very related. As a result, postpartum overweight gain could be a bad factor of physical and mental health. In Korea, we have few studies related to them. Conclusion: It is required to do many-sided and deep studies about aspects of postpartum retention weight and the factor that effect on it. Postpartum retention weight should be approached by controling weight from the period of pregnancy. And it would rather be researched through individual approach considered women's various demographic, social-cultural and physical level than be required standardized level of weight gain.

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