• Korean Journal of Social Welfare Studies
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• v.41 no.3
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• pp.135-162
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• 2010

The Purpose of this study is to get basic material about voluntary association in local community and its utilization. In order to achieve the purpose of this study, it was considered that trust of social capital plays a leading part in voluntary association to maintain or strengthen its role and activities. For this reason we attempt to find the process of trust building in voluntary association. The revised ground theory that is complementary weaknesses of ground theory is used in this study and in 11months, four times researches have investigated. As a result, it was analyzed that the structure of building trust can be categorized into three structure, building up relationship, dynamic interaction and structural stabilization in voluntary association. In the space that is structured spatially and temporal, role, activity, accomplishment, attitude, conflict and environment acted as basic attributes. These attributes can be found in every building process of trust and influence on continuance and growth of voluntary association. The fact that this study offers in-depth understanding of voluntary association and empirical directivity regarding the community welfare services is of great significant.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1100-1105
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• 2020

We investigated the driving force and the required charges for spontaneous reduction of metal nanoparticles (NPs) on a scotch tape induced by mechanochemical activation. The charges were analyzed based on anodic stripping voltammetry (ASV) of silver, which is proportional to the number of charge identities on the tape. The results supported that the driving force is mechanochemical radicals rather than ions in the light of the high charge density on the tape.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.103-108
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• 2023

In this study, basic research was conducted to secure microbial resources applicable to autonomous crack healing concrete. To this end, in this experiment, biomineral-forming microorganisms were separated from natural sources, and the ability of survival in cement and calcium carbonate precipitation were compared to secure suitable microbial resources. Bacillus-type bacteria forming endospores were isolated from the sample, and the amount of calcium carbonate produced by the six microorganisms identified by 16S rRNA sequencing was compared. Two types of microorganisms, Bacillus velezensis and Bacillus subtilis, with the highest calcium carbonate precipitation were selected, and the survival of the microorganisms was confirmed through phase contrast microscopy after being cured after being added to the mortar. In addition, it was confirmed that the autonomous crack healing capability by the crack healing material produced by microorganisms was confirmed by artificially generating cracks in the mortar.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.685-690
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• 1998

The wetting behavior and the characteristic of spontaneous infiltration of pure Al and Al-(Si)-Mg alloys on {{{{ { {Al }_{ 2} O}_{3 } }} in vacuum argon and nitrogen atmosphere were investigated to find out the spontaneous in-filtration mechanism. The wetting of molten Al and Al alloys on {{{{ { {Al }_{ 2} O}_{3 } }} was only possible in cacuum at-mosphere but the sponataneous infiltration of molten Al-(Si)-Mg alloys was successfully made on {{{{ { {Al }_{ 2} O}_{3 } }} pre-form in nitrogen atmoshpere. The difference of wettability and spontaneous infiltration of molten Al and Al alloys on {{{{ { {Al }_{ 2} O}_{3 } }} were found to be related to formation of the Mg-N compound coated layer on {{{{ { {Al }_{ 2} O}_{3 } }} particles which was believd to increase wettability of molten Al alloys on {{{{ { {Al }_{ 2} O}_{3 }.

• Proceedings of the KGS Conference
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• 2004.05a
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• pp.90-90
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• 2004

한인 13가구가 최초로 러시아로 이주한 1863년 이후 그 수는 기하급수적으로 증가하였다. 초기에는 국경지대를 중심으로 한인촌을 형성하였으나 점차 연해주는 물론 동시베리아 지역으로까지 확산되었다. 블라디보스토크에서도 도시의 건설 및 성장과 함께 한인 집단 거주지가 형성되었고, 두 차례 에 걸친 강제 이주와 한 번의 자발적 이주로 위치가 이동하였다. (중략)

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.82-87
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• 2011

The pulp infection of primary tooth is often caused by dental caries or trauma. But, if it is not managed properly, it can be produce the periapical lesion. The periapical lesion can cause some complications such as enamel hypoplasia, displacement, root dilaceration and impaction. Treatment options of displaced permanent successor are clinical and radiological follow-up after extraction of primary teeth, surgical opening, orthodontic traction, transplantation and extraction. In these cases, the premolars with abnormal eruption path caused by periapical lesion of the primary tooth have shown successful spontaneous eruption just as a result of extraction of infected primary tooth and space maintenance.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.329-334
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• 2007

The infection of primary teeth occurs by caries or trauma. But, if it is not treated on time, the complication may occur such as enamel hypoplasia, discoloration, impaction, displacement and dilaceration of permanent successors. The periapical lesion on primary tooth could displace the permanent successors in any direction. Treatment options of displaced tooth are observation after extracting the primary teeth, surgical exposure orthodontic traction, transplantation and extraction. In these cases, displacement of permanent central incisor caused by the periapical lesion of primary teeth was observed. The spontaneous eruption after extraction of primary teeth was expected considering degree of displacement, development of root and direction of eruption. This case report shows spontaneous eruption of displaced permanent tooth germ was achieved with periodic examination after extraction of primary teeth.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.119-133
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• 2014

This study examines the effects of social network support types on the subjective satisfaction of life for elderly people focused on the impact of voluntary and present oriented social network type represented by hobby club vs. non voluntary and past oriented social network type for example alumni association in Korean society respectively. According to the advanced studies figured out by preceding researchers, most of social networks had a good and positive effects on the elderly people's subjective satisfaction of life. However, this study tried to classify the social networks by type such as starting time to make relationship among members and voluntary or non voluntary for participation to the networks. As a result of this study, voluntary and present oriented social network represented by hobby club has a very positive relationship with Korean elderly people's subjective satisfaction of life while non voluntary and past oriented social network as alumni association has no relationship with elderly people's subjective satisfaction of life. Therefore, government policies and budget should be concentrated on encouraging or supporting voluntary and present oriented social networks such as hobby club, voluntary agency etc. rather than non voluntary and past oriented social networks so as to maximize the effect for increasing Korean elderly people's subjective satisfaction of life.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.235-238
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• 1998

파이프의 양 끝단에 심한 온도구배가 형성될 때 음향이 발생한다는 사실은 이미 알려진 사실이다. 본 연구는 열구동식 열음향냉동기를 구현하기 위해서 1단계로 열원에 의한 음향발생을 달성하고자 했다. 이를 위해 1/4 파장의 열음향 발생장치를 설계 및 제작하여 실험에 사용하였다. 열음향 발생기는 직경 3cm, 길이 16cm의 공명관에 가열부, 박판집적체, 고온부 및 저온부의 열교환기로 구성되며 발생음의 기본주파수는 520Hz로 설계하였다. 고온부를 38$0^{\circ}C$로 가열한 결과 열음향발생기의 개구부로부터 1m 떨어진 곳에서 최초 음압측정값이 약 112dB, 음향출력으로 약 1와트에 해당하는 값을 얻었다. 박판집적체에 급격한 온도구배가 형성되면서 주변의 기체가 자발적인 진동을 하여 형성된 음향동력중 일부는 공명관 벽에 흡수되고 일부는 열교환기에서 점성에 의해 소산된다. 따라서 실제로 음향으로 변하는 부분은 이들을 감한 부분인데 실험결과 약 53%의 음향 생성효율을 달성했으며 이는 스위프트 등이 얻었던 결과보다 우수하다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.241.2-241.2
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• 2011

다공 소재는 큰 비표면적과 규칙적으로 정렬된 구조의 특성으로 인해 자성메모리 소자용 재료, 나노 와이어 제작용 템플릿, 마이크로 반응기, 메타물질용 소재 등으로 각광을 받고 있다. 자기조립 수직배열 다공구조 재료를 제작하는 방법으로 흔히 알루미늄의 양극산화 방법과 이원공정계의 상분리 방법이 등이 있다. 본 연구에서는 상변태를 비롯한 패턴형성과 계면 운동을 가장 정확하게 다루는 이론적 모델로 알려진 상장모델(Phase Field model)을 이용하여 이원공정계의 박막성장과정 동안의 자발적 상분리에 의한 수직배열 자기조립 다공구조 형성을 시뮬레이션 한다. 상장모델을 기초로 하여 상분리 메커니즘에 의해 발현된 미세조직을 해석하고 다양한 공정변수가 미세조직 발현에 미치는 영향에 대해 연구한다. 또한 상장모델을 통해 얻은 결과는 기존에 발표된 연구들의 결과와 비교를 통해 유효성을 입증한다.