• Title/Summary/Keyword: 확산 이론

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Molecular Theory of Superplastic Deformation (초소성변형의 분자론)

  • Chang Hong Kim;Taikyue Lee
    • Journal of the Korean Chemical Society
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    • v.23 no.4
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    • pp.217-236
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    • 1979
  • The author's theory for plastic deformation was applied to superplastic alloys (Zn-Al eutectoid, Al-Cu, Pb-Sn, Sn-Bi, Mg-Al eutectics). The plastic deformation of the superplastic alloys could be described by two Maxwell models connected in parallel which represent two grain boundary flow units. The flow units are characterized by the two parameters $X_{gj}/{\alpha}_{gj}\;and\;{\beta}_{gj}$ (j=l or 2, g signifies the grain boundary) the values of which were obtained by applying our flow equation [Eq. (5)] to experiment. We confirmed that our flow equation describes the superplasticity very well. The curve of strain rate sensitivity m (=${\partial}\;In\;f/{\partial}\;In\;\dot{s})\;vs.\;-In\dot{s}$, where f and s are stress and strain rate, respectively, showed two peaks corresponding to flow unit gl and g2, the separation of the two peaks is determined by the difference between ${\beta}_{g1}\;and\;{\beta}_{g2}$. The condition of superplasticity is also determined by ${\beta}_{gj}$, which satisfies $\dot{s}_{mj}{\leqslant}1.53}{\beta}_{gj}$ [Eq.(13)], where $\dot{s}_{mj}$ is the s of the jth unit at the peak. The grain size dependence of ${\beta}_{gj}$ is described by $ln({\beta}_{gj})^{-1}$=alnx+b [Eq. (16)], where x is the grain size, and a and b are constants. The activation enthalpy for each flow unit, ${\Delta}H_{gj}^{\neq}$ was also determined from the temperature dependence of ${\beta}_{gj}$ which is proportional to the relaxation time of the j th unit. Since the superplasticity is determined by Eq. (13), and since ${\beta}_{gj}$ and ${\Delta}H_{gj}^{\neq}$ are related, we obtained the conclusion that superplasticity occurs in the system having small ${\Delta}H_{gj}^{\neq}$ values. The Aej values were equal to the activation enthalpies of grain boundary self-diffusion of the component atoms of the alloys, this accords with our proposed flow mechanism. The ${\Delta}H_{gj}^{\neq}$ value increases with grain size as expected from Eq. (16).

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Case Study on Organization Entrepreneurship for preliminary Entrepreneurs (조직기업가정신이 예비창업자에게 주는 시사점)

  • Seon, Seung Won;Jang, Ae Sung;Han, Jung Hee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.2
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    • pp.221-232
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    • 2014
  • Many preliminary entrepreneurs are ready to start a business in every year. However, starting and preparing business have a lot of difficulties. Entrepreneurship is the most important factor for overcoming these difficulties. But, it is not easy to understand entrepreneurship to founders despite many research scholars. In this paper, we are focused on easy understanding of entrepreneurs. Instead of vague theories, we analyzed selected two companies in Korea. From the beginning until now, these companies have founders entrepreneurship and organization entrepreneurship. we studied these entrepreneurship factors with other Various causes. Analysis of two cases is summarized into three type. First, both companies had well-founded internal network system. Trained employees in internal network were flexible to meet the market conditions. Also, network effect made that employees can offer their idea and make discussions. Second, The company quickly recognized for organizational culture despite of most other companies recent awareness. This factor was the basic driving force for solving human resource management problem of small size companies. final factor is innovation capacity of these companies. Financial difficulties experienced of establishment is common to every company. However, two companies has continued to invest research and development despite of this financial problem. As a result, intellectual property management was accepted, as well as technology development. Clearly, these three factors are consistently applied since established and led to the company's continued growth and success.

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South Korean Universal Service and Korean Reunification: A Policy Analysis (한국의 보편적 서비스정책과 남북한 통일: 정책분석)

  • Jeong Bun-Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.39 no.1
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    • pp.147-166
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    • 2005
  • The purpose of this study is to redefine the concept and scope of universal service and to develop universal service policy of South Korea for Korean reunification. The basic assumption of this study is that well developed universal service may contribute to the eventual reunification by ensuring equal access to information resources for the two peoples. The theoretical foundation of this study includes social capital and diffusion of innovations theory. This study uses policy analysis as both data collection and data analysis, more specifically qualitative policy analysis with triangulation for improving credibility. Data for the analysis were collected through legislation, other policy documents, and major agreements between North and South Korea related to informatization and unification. This study, identified the major characteristics of universal service and explored the current universal service in South Korea by analyzing major poicy instruments of South Korea. In addition, this study presented a great possibility of cooperating in telecommunication policy and telecommunication infrastructure. Consequently, this study proposed policy recommendations in five areas: 1) redefining the scope of universal service, 2) developing a unified telecommunication infrastructure, 3) developing policy instruments, 4) restructuring government organizations, and 5) creating a participatory universal service model for Korean reunification.

A Survey on a Status of Sensory Integration Therapy in Korea (국내 감각통합치료 실태조사)

  • Kim, In-Sun
    • The Journal of Korean Academy of Sensory Integration
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    • v.13 no.2
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    • pp.1-19
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    • 2015
  • Objective : To provide a foundation to develop clinical training program based on a status of sensory integration therapy in Korea identified through the study. Methods : A questionnaire has been developed that is investigating such as environment of therapy, level of knowledge of therapist, and etc. The questionnaire was distributed from June 1st,2014 June 1 to August 31st,2014. The total questionnaire result collected and analyzed are 232 responses. Results : In terms of ratio of therapist who are administrating sensory integration, occupational therapist takes biggest percentage. In most case, it is equipped enough to do treatment in terms of space and tools. Generally, therapists are performing evaluation and documentation earnestly, and willingly participating to continued education and clinical training coursework. However, it is found that some cases are implementing treatment without through evaluation and/or without professional training. Conclusion : This study propose that sensory integration therapists need to train their clinical knowledge and skills through professional training education based on the Ayres Sensory Integration (ASI) theory. Most of professional trainings are administered in capital area currently. The educational opportunities need to be extend to outside of capital region so the level of clinical competence and the quality of the therapy service can be improved.

A Study on Jeju Music Education Direction through Philosophies of Music Education (음악 교육 철학적 접근을 통한 제주 음악 교육 방향 고찰)

  • Ko, Hye-young;Hwang, Kyung-Soo;Yang, Jeong-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.597-607
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    • 2019
  • In this study, we suggest a policy for setting the direction of Jeju Music Education with implications from the process of arranging philosophical theories related to music education and analyzing advanced cases. The philosophical theories of music education were examined by Schiller, Steiner, Dewey, Bourdieu, Reimer, and Elliotts. In addition, this study checked the lessons in music education programs in Germany, Venezuela, and Finland, and we make policy suggestions in four contexts to set the direction of music education in the Jeju community based on interviews with 10 experts. Suggestions for improving social awareness of music education, suggestions for music education in the elementary and secondary public school sectors, in the proposals for music education in the lifelong education sector, and the suggestions for institutional policy all included music education professionals recruited from among the culture and art sectors within the Jeju Special Self-Governing Province's Cultural Policy Division. Music advisors were also recruited from the music and sector music councils within the Jeju Special Self-Governing Province Council.

Study of the Curing Reaction Rate of a Glass Fiber Reinforced Bisphenol-A (BPA) Epoxy Prepreg by Differential Scanning Calorimetry (DSC) (Differential Scanning Calorimetry (DSC)를 이용한 유리섬유 Bisphenol-A(BPA)계 에폭시 프리프레그의 경화 반응 속도 연구)

  • Kwon, Hyeon-Jin;Park, Hee-Jung;Lee, Eun-Ju;Ku, Sang-Min;Kim, Seon-Hong;Lee, Kee-Yoon
    • Composites Research
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    • v.31 no.1
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    • pp.30-36
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    • 2018
  • The curing behavior of glass fiber reinforced epoxy prepregs based on Bisphenol-A (BPA) was studied by differential scanning calorimetry (DSC). The total heat of reaction(${\Delta}H_{total}=280.3J/g$) was determined based on the results of the dynamic heating scanning experiments. Isothermal experiments were carried out at $110{\sim}130^{\circ}C$, and it was observed that the maximum conversion and the maximum reaction rate were increased as temperature increased. Also Kamal equation was applied to analyze autocatalytic reaction of epoxy prepregs. The higher temperatures, the greater reaction rate constants ($k_1$, $k_2$). Theoretical values were calculated by these reaction rate constants and compared with experimental values. And it was confirmed that they were in reasonable agreement. At the beginning of the reaction, the experimental data and theoretical prediction were shown the same tendency, but at the end of reaction, the experimental data were smaller than theoretical predicted values due to reaction rates controlled by diffusion.

The Froude Scaling Study on the Ventilation of Non-isothermal Concentrated Fume from the Semi-closed Space (반밀폐형 공간에서 비등온 고농도 연무의 배연산출량 산정을 위한 Froude 상사연구)

  • Chang, Hyuk-Sang;Choi, Byung-Il;Park, Jae-Cheul;Kim, Myung-Bae
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.8
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    • pp.877-885
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    • 2005
  • The Froude scaling between the prototype and the model was tried to estimate the necessary ventilation rate for non-isothermal concentrated fume from the semi-closed inner space. Based on the non-dimensional similitude equations derived from the Zukoski plume rise analysis, the scaling experiments were done to verify the relationship of the non-dimensional energy release rate and the non-dimensional mass flow rate by using two different scaled volume models, model A ($1\;m{\times}1\;m{\times}1\;m$) and model B ($0.5\;m{\times}0.5\;m{\times}0.5\;m$). The experimental results showed that the theoretical similitude between the models is acceptable for the prediction of ventilation rate of the concentrated fume. The maximum energy release rate used for the experiments was $20\;kW/m^3$. In the experimental range, the similitude between the energy release rate and the ventilation mass flow rate was well defined and the necessary ventilation rates were 20-30% higher than the stoichiometric ventilation mass flow rate. Based on results of current study, the design of the local air ventilation system can be improved by correcting the effects of buoyancy and diffusion of the non-isothermal concentrated fume.

Study on the Academic Discussion about Animation Authorship (애니메이션 작가주의에 대한 학술담론 연구)

  • Jeon, Gyongran
    • Cartoon and Animation Studies
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    • s.43
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    • pp.123-150
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    • 2016
  • There has been discussed very little about animation authorship studies, especially the themes of authors and their original animation texts since 1990s. This study is to explore the academic discourse of animation authorship studies understanding the media aesthetics of animation and the scholarly approach of animation studies about authorship. This article examines 55 articles via meta analysis about animation authorship studies drawn from the 1,516 articles on the general animation studies. The results were as follows. First, the domestic animation studies on the authorship were made about animators of Japan, US, and european countries. Second, It was dominant that scholarly interest on the screen direction and visual expression of animation texts. This shows the authorship approaches were mainly about visual aspects of animations. The domestic animation authorship studies did not trace the authorship issues on author's world view and visual style revealed in the corpus of texts. Instead, they discussed authorship issues on the characteristics of individual animation text. It has been evident that animation studies were not enthusiastic about building the independent theory on animation. Therefore, animation studies have tried theorizing the animation issues borrowing the literature and film theories. This study can contribute to increase phase of animation studies by drawing the intensive discussion of animation authors and their authorship.

A Study on the Factors Influencing SMEs' internet marketing Adoption (중소기업 인터넷마케팅 도입 영향요인에 관한 연구)

  • Won, Dongjun;Jo, Hyungrae
    • Journal of Digital Contents Society
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    • v.15 no.6
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    • pp.683-699
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    • 2014
  • This study examines the key factors which influence the strategic consideration and intention of adoption of internet marketing of small-and-medium sized companies, based on theoretical consideration of innovation diffusion theory and previous studies related. The result of analysis shows that the degree of market competitiveness, customer dependency, the level of internet marketing knowledge and experience have significant effects on both of strategic consideration and adoption intention for internet marketing. Also, learning commitment has negative influence on strategic consideration only, while environmental dynamism does on adoption intention. Comprehensively, the findings implies that firms consider selection of internet marketing to reduce the severity of competitiveness and that firms which has more knowledge or experience about internet marketing seems to consider selection of internet marketing through the perception of the effects of internet marketing or possible access to internet marketing. Based on the findings that the level of internet marketing knowledge and experience have much significant effects on both of strategic consideration.

사이버 시대의 윤리 교육 : 청소년을 중심으로

  • 류나정;고석하
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.417-424
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    • 2002
  • 컴퓨터는 인간의 모든 꿈과 희망을 실현시켜 줄 수 있는 마법상자는 아니다. 정보화 시대라고 일컫는 현재, 정보의 가치를 더해주는 컴퓨터의 중요성은 날로 커지고 있는 반면 인간의 존엄성은 경시되고 있다. 많은 사람들은 요즘 사회가 커다란 도덕적 위기에 빠졌다고 걱정하지만 컴퓨터 사용과 관련된 윤리적 문제에 대해서는 심각하게 느끼지 못하고 있는 것 같다. 정보통신 기술의 발달에 따라 새로운 교육의 필요성이 대두되고 있다. 기존의 전통적인 교육방식에서 사이버 윤리 교육은 교과서 중심의 단편적인 교육이었기 때문에 학습자의 흥미를 유발하지 못하였으며, 교육자와 학습자의 상호작용이 부족하여 사이버 윤리 교육의 효과가 미흡하였다. 정보통신 기술의 발달에 따라 새로운 교육의 필요성이 대두되고 있다. 기존의 전통적인 교육방식에서 사이버 윤리 교육은 교과서 중심의 단편적인 교육이었기 때문에 학습자의 흥미를 유발하지 못하였으며, 교육자와 학습자의 상호작용이 부족하여 사이버 윤리 교육의 효과가 미흡하였다. 이런 관점에서 본 논문은 정보통신 시대가 수반하고 있는 사회적 영향력과 윤리적 이슈들에 대하여 좀더 교육적인 측면으로 접근해 윤리교육의 현황과 문제점, 그리고 체계적인 확산방안에 대해 살펴보았다. 본 논문에서는 사이버공간에서 윤리 교육을 받는 청소년들을 중심으로 그들에게 새로운 윤리교육의 한 형태인 사이버공간에서 관련된 문제들을 교육적인 측면으로 해결할 수 있는 방안을 제시하고자 한다. 그러나, 무엇보다 우리가 명심해야 할 것은 인간의 존엄성은 그 어떤 이유를 막론하고 존중되어야 한다는 사실이다. 검증되지 않은 스토리 보드에 의한 저작 단계로 바로 돌입하고 있는 것이 한국의 실정이라 하겠다. 따라서 본 프로젝트에 의해 개발 된 교수 설계 도구는 교육/학습 컨텐츠의 품질 보증을 위한 방법론인 교육 공학의 체제적 교수 설계 이론 Model (Instructional System Design Model), 특히 그 중에서도 이 분야의 사실상의 표준 이론(de facto standard)인 Dick & Carey 교수와 Gagne 교수의 인지주의 ISD Model을 기반으로 정교한 교수 설계와 코스 맵 설계를 가능하게 함으로써 학습 컨텐츠의 품질 보증 활동을 지원 할 수 있는 도구로 개발하였다. 특히 Linux 기반에서 PHP로 개발 함으로써 Platform에 구애받지 않은 사용 환경을 구현 하였으며 향후 많은 e-Learning Platform에 교수 설계 모듈로 장착 함으로써 기존의 e-Learning Platform들의 가치를 높일 수 있는 계기가 될 것으로 생각한다.실징후를 파악하는데 그치지 않고 부실의 원인을 파악하고 이에 대한 대응 전략을 수립하며 그 결과를 측정하는데 활용될 수도 있다. 따라서 본 연구에서는 기업의 부도예측 정보 중 현금흐름정보를 통하여 '인터넷기업의 미래 현금흐름측정, 부도예측신호효과, 부실원인파악, 비즈니스 모델의 성격규정 등을 할 수 있는가'를 검증하려고 한다. 협력체계 확립, ${\circled}3$ 전문인력 확보 및 인력구성 조정, 그리고 ${\circled}4$ 방문보건사업의 강화 등이다., 대사(代謝)와 관계(

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