• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.4
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• pp.48-54
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• 2000

자성재료에 자기장을 걸어주변 가열되고 자기장을 제거하면 냉각되는 성질이 있는데, 이를 자기열량효과(magnetocaloric effect)라고 하며, 이것을 이용해서 저온을 생성시키는 방법을 자기냉동(magnetic refrigeration)이라고 한다. 큐리 온도(Curie temperature) 부근의 강자성체에 자 기장이 가해지면 전자례도내에서 쌍을 이루지 않은 전자들의 자기모벤트들이 자기장에 평행 하게 배열되는데, 이로 인해 열역학적 무질서의 척도인 엔트로피는 낮아지고 이러한 손실을 보상하기 위해 재료의 온도가 올라가게 된다.반대로 자기장이 제거되면 자기모벤트가 본래의 무질서한 상태로 돌아오며, 엔트로피가 증가하 고 재료의 온도는 떨어지게 되는 것이다. 역사적으로 보면 1881년에 Warburg가 큐리온도 부근의 철에서 자기열량효과를 처음 발견하였으며. 1926년과 1927년에 Debye와 Giauque가 각각 단열소자볍 (adiabatic demagnetization)을 제안함으로써 실용화되기 시작하여 주로 극저온을 얻는 방법으로 이용되어 왔다. 1950년도 이전의 연구는 절대온도 영도(OK)에 도달하고 자 하는 순수과학적인 노력으로서 개방사이클(open cycle)을 이용한 단열냉각 방식을 추구하 였으나, 1950년 이후부터는 공학적인 응용을 목적으로 밀폐사이클(closed cycle)을 형성하는 자기냉동기에 관한 연구가 진행되었다. 1976년에 Brown은 희토류(rare earth) 금속인 가돌리늄(Gd)을 사용하여 유체(물 80%와 에틸 알코올 20%)를 재생시킴으로써 상온에서 작동 하는 자기냉동기를 보고한 바 있다. 그는 7 T의 큰 자장을 이용하였으며, 고온부와 저온부의 온도는 각각 $46^{\circ}C와\;-1^{\circ}C로서\;47^{\circ}C$의 온도간격을 얻었다. 자기냉동에 있어서의 또 하나의 중요한 진전은 1978년과 1982년에 Steyert와 Barclay에 의해서 능동자기재생기(active magnetic r regenerator)의 개념이 소개되고 개발된 것으로, 이는 자성재료가 냉매로서 뿐만 아니라 열전달 유체의 재생기로도 사용되는 방식이다. 이상과 같은 자기냉동기술의 발달에 이어서 1997년에 미국의 Astronautics사(Wisconsin주 Madison시 소재)와 Ames 연구소(Iowa주 Ames 시 소재)의 공동연구팀이 발표한 두 가지의 새로운 진전으로 인해 공기조화 및 냉동분야에 적용할 수 있는 자기냉동기의 실용화 가능성이 한층 높아졌다. 이들의 연구결과는 (1) 자기냉동이 실온에서도 실현 가능한 기술이며 증기압 축식 냉동에 필적할 만하다는 것을 보인 것과 (2) 이미 알려져 있던 자기냉동재료보다 자기 열량효과가 훨씬 큰 새로운 재료를 발견한 것이다. 이로써 자기냉동에 대한 관심과 기대가 한결 커지고 있다. 본 원고에서는 자기냉동의 원리가 되는 자기열량효과와 이를 이용한 자기냉동의 방법 그리고 최근에 이루어진 새로운 진전에 대해 소개하고 공기조화 및 냉동분야에의 적용 가능성을 전망해 보고자 한다.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.815-824
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• 2003

Many organizations operate security systems and manage them using the intergrated secutity management (ISM) dechnology to secyre their network environment effectively. But current ISM is passive and behaves post-event manner. To reduce cost and resource for managing security and to remove possbility of succeeding in attacks by intruder, the perventive security management technology is required. In this paper, we propose PRISM model that performs preventative security management with evaluating the security level of host or network and the sensitivity level of information asset from potential risks before security incidents occur. The PRISM can give concrete and effective security management in managing the current complex networks.

• Journal of Science and Technology Studies
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• v.15 no.2
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• pp.163-189
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• 2015

While Science tries to be far from Society, it actually does yearn for the trust from Society, on the other side. Its efforts getting back the trust has been witnessed with its fast evolution, consistent distrust from Society and Scientists' accountability with investment of public fund. Furthermore, many scholars have argued that there is the need to integrate science and society. In this regards, this paper explores how to integrate both spheres by participatory evaluation. To identify how the participatory evaluation works and should be, three main issues are mentioned. One is about evaluation methods; Objective-oriented and Behaviour aspects. Second is about prerequisite factors; sharing scientific language and changed recognition between civil society and scientists. Third is about challenge to be tackled; epistemological gap among evaluators and complex index. Under these issues, this paper sets out that the participatory evaluation should adopt the appropriate evaluation methodology. Last but not least, self-recognition and motivation by evaluators themselves are important factors, along with societal system which can take participatory evaluation.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.4
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• pp.1-9
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• 2013

An active anti-ship missile decoy system was designed conceptually to analyze propulsion system requirements and feasibility to use a liquid bi-propellant rocket engine. Overall mass, size, and shape were assumed referring to specifications of Nulka which was developed by US and Australia in 1990s. The propulsion system was assumed to be a 1,000 N-class $H_2O_2$/kerosene rocket engine with a pressurized feed system. A three-degree-of-freedom optimal trajectory was calculated based on the assumptions, and mass budget was designed from the calculation results. It was found that the requirements for the propulsion system is that it shall be operated more than 100 sec; it shall be re-ignitable; it shall have a throttle capability of a range from 35% to 100% when the maximum thrust at sea level is 1,000 N.

• Journal of Christian Education in Korea
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• v.66
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• pp.11-48
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• 2021

This paper is a thesis that explored the necessity and possibility of spiritual teaching that forms the inner side of human beings in the age of AI where objective knowledge is prevalent, focusing on "contemplative pedagogy". For this it first examined the characteristics of objective epistemology of AI and the direction of school education in the AI and explored the necessity and character of spirituality and spiritual teaching as a request for the AI era, and also explores the possibility of realization of spiritual teaching in general school setting through contemplative pedagogy, which actually puts this into practice. As a result of the study, it found that spiritual teaching is not exclusive to a specific area such as religious studies or theology, but is a teaching that should be embodied in all schools and educational fields in today's era where third person knowledge is widespread. It also found that in addition to contemplative teaching, various spiritual teaching models need to be developed and put into practice for this purpose.

• 한국사회정책
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• v.25 no.3
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• pp.247-278
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• 2018

Anti-oppressive practice (AOP) is a form of social work practice that has developed in the UK. In South Korea, Anti-oppressive social work has not been widely studied / explored unlike in other countries in the world. Its main principles, social justice and human rights, have become commonplace. AOP includes transformational practice because its orientation emphasizes social change through celebrating diverse identities and rejecting hierarchies of oppression and prestige. Recently, a growing body of literature on social work with foreign workers has resulted in an increased understanding of its population and its needs. It needs a theoretical and practical framework for foreign workers necessary to inform effective models of service delivery, reflecting cultural competence, and changing oppressive social structure. In this paper, we will introduce the main principles of AOP, analyse written texts reflected by foreign workers and social work practitioners' opinion, and suggest the implications on possibilities and constraints of applicability to foreign workers in South Korea.

• 한국사회정책
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• v.25 no.2
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• pp.31-55
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• 2018

The economic penalty of care and gender inequality reinforce each other. Unequal distribution and treatment of care are at the basis of gender inequality. Care creates economic penalty that deepen gender inequality. Those who perform care work tend to take the position of the vulnerable in socio-economic power relations. Due to their weak position, it is difficult for them to voice out a fair treatment and reward for their work. As a result, care workers both at home and in the public sector suffering from lower economic value of care are positioned in unequal gender relations with more vulnerable socioeconomic status. The basic income system may have the potential to mitigate multifaceted gender inequalities in our society. For the introduction of basic income to help realize the real freedom for women, it is necessary to understand unique natures of care work and tackle economic penalties of care work. This paper examines the relationships between care penalties and basic income, focusing on the debate on the introduction of the basic income system. We argue that if the economic penalties caused by unique natures of care work are not eased or resolved, the introduction of the basic income may not contributes to alleviating gender inequalities.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.495-506
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• 2019

The purpose of this study was to provide the customized-service program for the family of dementia patients as an family-function reinforcement program. This study was designed to develop the therapeutic recreation program for the family supporting senior with dementia. The therapeutic program consisted of assessment, planning, implementation, evaluation. This study found the followings. First, this study shows the possibility of implication of the therapeutic recreation for the family supporting senior with dementia. Second, the therapeutic recreation program has a strong theoretical background. Third, the therapeutic recreation program has the clear goal, performing activity, intervention strategy. The therapeutic recreation program for the family supporting senior with dementia that this study provides would be valuable basic data for future studies.

• The Southeast Asian review
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• v.27 no.2
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• pp.155-184
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• 2017

ASEAN marking its 50th anniversary in 2017 draws hopes and concerns. There is hope for the full realization of the vision of ASEAN Community since 2015 while there are increasing concerns about the changing internal and external environments. This article reviews the process of ASEAN's community building and its external relations. First, after reviewing institutionalization and functional cooperation in 2016, it argues that there is increasing pressure for the modification of the 'ASEAN Way' mainly due to the recent political changes in some ASEAN member states. Second, this article considers the nature of ASEAN's external relation focusing on continuity rather than change. The tendency of external relations of ASEAN appears to be 'avoiding conflict' and 'status quo' while it concentrates on development cooperation. We argue that such attitude contributes to the unity of ASEAN as it is useful in searching for regional resilience which is a common goal of ASEAN power elites.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.270-281
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• 2021

With the development of information technology, the size of insurance fraud is increasing rapidly every year, and the method is being organized and advanced in conspiracy. Although various forms of prediction models are being studied to predict and detect this, insurance-related information is highly sensitive, which poses a high risk of sharing and access and has many legal or technical constraints. In this paper, we propose a machine learning insurance fraud prediction model based on blockchain, one of the most popular technologies with the recent advent of the Fourth Industrial Revolution. We utilize blockchain technology to realize a safe and trusted insurance information sharing system, apply the theory of social relationship analysis for more efficient and accurate fraud prediction, and propose machine learning fraud prediction patterns in four stages. Claims with high probability of fraud have the effect of being detected at a higher prediction rate at an earlier stage, and claims with low probability are applied differentially for post-reference management. The core mechanism of the proposed model has been verified by constructing an Ethereum local network, requiring more sophisticated performance evaluations in the future.