• 한국인구학
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• 제27권1호
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• pp.147-169
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• 2004

이 연구는 울릉도 주민의 이주와 정착에 관한 것이다. 본 논문에서는 역사적인 문헌 자료와 현지조사 자료를 통해 오늘날 울릉도에 거주하고 있는 사람들의 이주와 정착과정을 울릉도의 사회ㆍ문화ㆍ정치적 현상들과 연관지어 분석하였다. 이를 통해 울릉도 초기 개척령 당시의 주민들은 어떤 경로를 통해 울릉도로 들어왔으며, 어떤 과정을 거쳐 정착하였는지, 인구의 증가와 감소 현상이 단순한 것이었는지, 아니면 당시 울릉도나 본토의 정치, 경제, 문화적 상황과 어떠한 연관성을 맺고 있는지를 밝혀 보고자 한 것이다. 연구의 결과 울릉도민의 이주동기는 혼란한 육지의 사회ㆍ정치적 상황을 피해 울릉도로 이주한 사회ㆍ정치적 동기와 경제적인 안정을 찾아 이주한 경제적 동기 그리고 범죄 행위에 대한 도피처로 울릉도를 선택한 범죄적 동기 등 크게 3가지로 나누어진다. 이러한 정착과정을 거치면서 울릉도는 하나의 독특한 사회로 발전하였다.

• Corrosion Science and Technology
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• 제6권2호
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• pp.50-55
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• 2007

The smaller size and higher integration of advanced electronic package systems result in severe electrochemical reliability issues in microelectronic packaging due to higher electric field under high temperature and humidity conditions. Under these harsh conditions, electronic components respond to applied voltages by electrochemical ionization of metal and the formation of a filament, which leads to short-circuit failure of an electronic component, which is termed electrochemical migration. This work aims to evaluate electrochemical migration susceptibility of the pure Sn, Sn-3.5Ag, Sn-3.0Ag-0.5Cu solder alloys in $Na_{2}SO_{4}$. The water drop test was performed to understand the failure mechanism in a pad patterned solder alloy. The polarization test and anodic dissolution test were performed, and ionic species and concentration were analyzed. Ag and Cu additions increased the time to failure of Pb-free solder in 0.001 wt% $Na_{2}SO_{4}$ solution at room temperature and the dendrite was mainly composed of Sn regardless of the solders. In the case of SnAg solders, when Ag and Cu added to the solders, Ag and Cu improved the passivation behavior and pitting corrosion resistance and formed inert intermetallic compounds and thus the dissolution of Ag and Cu was suppressed; only Sn was dissolved. If ionic species is mainly Sn ion, dissolution content than cathodic deposition efficiency will affect the composition of the dendrite. Therefore, Ag and Cu additions improve the electrochemical migration resistance of SnAg and SnAgCu solders.

• 한국융합학회논문지
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• 제12권2호
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• pp.221-231
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• 2021

본 논문은 인구이동의 이론에 따라 혁신도시 이전기관 종사자 구성세대의 이동 요인을 추출하고 요인들의 상대적 영향을 설명하고자 하였다. 개인 및 가구변수와 거리와 인구의 중력모델, 네트워크변수, 지방재정·지역경제·교육·문화·주택 등 전입지와 전출지의 상대적 유용성판단의 지역변수를 선정하였다. 종속변수의 이산성과 데이터의 구조를 감안하여 다층로짓모형 구축하였고 최종모형은 확률절편모델을 선택하였다. 실증분석 결과 개인·가구변수에서는 남성보다 여성이, 30대 미만보다는 30-40대가, 대졸이하보다는 박사학위취득자가, 취업한 배우자보다는 미취업배우자의 이전종사자가 주민등록을 더하였다. 지역변수에서는 중력모델과 관련하여 기관까지 거리가 멀수록 주민등록을 더 한 반면, 이전 시기(t-1)의 일반 유입이 클수록 주민등록 이전을 덜 하였다. 지역간 상대적 유용성과 관련하여 전입지의 지역경제, 교육환경, 주거환경이 클수록 이전을 더하였고 지방재정의 경우는 반대였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권6호
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• pp.1892-1912
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• 2022

With the massive demand and growth of cloud computing, virtualization plays an important role in providing services to end-users efficiently. However, with the increase in services over Cloud Computing, it is becoming more challenging to manage and run multiple Virtual Machines (VMs) in Cloud Computing because of excessive power consumption. It is thus important to overcome these challenges by adopting an efficient technique to manage and monitor the status of VMs in a cloud environment. Reduction of power/energy consumption can be done by managing VMs more effectively in the datacenters of the cloud environment by switching between the active and inactive states of a VM. As a result, energy consumption reduces carbon emissions, leading to green cloud computing. The proposed Efficient Dynamic VM Scheduling approach minimizes Service Level Agreement (SLA) violations and manages VM migration by lowering the energy consumption effectively along with the balanced load. In the proposed work, VM Scheduling for Efficient Dynamically Migrated VM (VMS-EDMVM) approach first detects the over-utilized host using the Modified Weighted Linear Regression (MWLR) algorithm and along with the dynamic utilization model for an underutilized host. Maximum Power Reduction and Reduced Time (MPRRT) approach has been developed for the VM selection followed by a two-phase Best-Fit CPU, BW (BFCB) VM Scheduling mechanism which is simulated in CloudSim based on the adaptive utilization threshold base. The proposed work achieved a Power consumption of 108.45 kWh, and the total SLA violation was 0.1%. The VM migration count was reduced to 2,202 times, revealing better performance as compared to other methods mentioned in this paper.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.110-115
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• 1999

The surface gloss of an injection molded part is one of the most significant point for evaluating the quality of products appearance. The effects of process condition on the gloss of ABS(Acrylonitrile-Butadiene-Styrene) molded part were investigated in this work. The measurements of gloss and morphology on the surface of molded part were carried out with different melt temperature, mold temperature, mold surface roughness, injection pressure and holding pressure. Gloss had a maximum value with melt temperature in the range of 210 to 220 ${^\circ}C$ and with mold temperature 40 to 50${^\circ}C$ and with injection pressure 80~90 MPa, respectively. Melt temperature was shown to have the largest effect on gloss in our work. Gloss was not improved in the region of melt temperature 240${^\circ}C$ above and of mold temperature 60${^\circ}C$ above. It was concluded that the variation of gloss was mainly caused by rubber particles migration under shear stress not by their aggregation or necklace.

• 농촌계획
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• 제12권2호
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• pp.37-47
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• 2006

Recently, due to the growing concern of the public in rural amenities and hobby farming works, much more urbanites, especially near-retirees, have been interested in rural life style than before. However, in spite of popular preference to ruralities, little has been known about their demand on retired rural life. Therefore, this study examined urbanites' attitude to preparatory works for out-migration, preferred residential site conditions and life style in the countryside. For this purpose, data were collected from a survey with the sample of 386 urban residents aged 40 to 65 rho hoped moving into the countryside after retirement, through structured questionnaires. Descriptive statistical works were performed using SPSS/PC windows program. The major findings of this study were as follows; (1) Host of urbanites, who answered in this study, planned to prepare ex-urban movement in their fifties and to put into practice in their sixties. (2) Key factors of location decision on movement were proximity/accessibility to centre city, medical service level, and distance to their family or friends. And about a half of respondents wanted second home in the countryside. (3) Most favoured rural life styles were nature-friendly well-being and hobby/healthy firming. Generally, the respondents of this survey had the positive attitude to do works in their later life, especially preferred to farming and volunteering in their communities.

• 인터넷정보학회논문지
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• 제24권2호
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• pp.1-10
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• 2023

The Multi-access Edge Computing (MEC) paradigm equips network edge telecommunication infrastructure with cloud computing resources. It seeks to transform the edge into an IT services platform for hosting resource-intensive and delay-stringent services for mobile users, thereby significantly enhancing perceived service quality of experience. However, erratic user mobility impedes seamless service continuity as well as satisfying delay-stringent service requirements, especially as users roam farther away from the serving MEC resource, which deteriorates quality of experience. This work proposes a deep reinforcement learning based service mobility management approach for ensuring seamless migration of service instances along user mobility. The proposed approach focuses on the problem of selecting the optimal MEC resource to host services for high mobility users, thereby reducing service migration rejection rate and enhancing service availability. Efficacy of the proposed approach is confirmed through simulation experiments, where results show that on average, the proposed scheme reduces service delay by 8%, task computing time by 36%, and migration rejection rate by more than 90%, when comparing to a baseline scheme.

• 농촌지도와개발
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• 제19권1호
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• pp.29-48
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• 2012

Many of the urban people wish to move to rural area to avoid urban problems like pollution, crowdedness, crime and after their retirement. The purpose of this study was to analyse of adaptation of inmigration in rural community. For this purpose, data were collected from 239 migrations to rural area. The major findings of this study are as follows: 1) 32.0% of respondents wished to move to rural area that they were expected for countryside life, 2) 68.1% of respondents had experience to visit farmer's house 3) 49.5% of respondents agreed to rural community person is good 4) many person of migration to rural area(74.5%) have the idea that they should be active participation for community volunteer work 5) migration people was wanted to take care of them by natives in rural community on the lonely time.

• 마이크로전자및패키징학회지
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• 제13권3호
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• pp.1-8
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• 2006

인쇄회로기판이나 플라스틱 패키지 등 다양한 전자소자 부품내 배선간 간격이 갈수록 좁아짐에 따라 최근 많이 발생하고 있는 electrochemical migration(ECM) 현상은 양극에서 이온화된 금속에 의한 conductive anodic filament(CAF) 및 덴드라이트와 같은 전도성 필라멘트의 성장으로 인해 전자부품의 절연파괴를 일으키고 있다. 본 연구에서는 공정조성 Sn-37Pb솔더 합금의 ECM 거동과 부식특성 사이의 연관성 평가를 통해 ECM 우세원소를 파악하기 위해 D.I Water 및 NaCl 용액에서 Water Drop Test(WDT)와 분극실험을 실시하여 서로 비교하였다. WDT 실시 결과 공정조성 Sn-37Pb 솔더 합금에서 Pb-rich 상이 Sn-rich 상보다 우선적으로 양극 패드에서 녹아나서 상대적으로 ECM 저항성이 낮았으며, 음극패드에서 자라난 덴드라이트에도 Pb가 훨씬 많이 존재하였다. NaCl에서의 분극실험 결과 전기화학적으로 부동태 피막을 형성하는 Sn에 비해 Pb의 부식속도가 크게 나타났으며, WDT의 결과와 같은 경향을 보였다. 따라서 공정조성 SnPb 솔더 합금의 부식저항성과 ECM 저항성 사이에는 좋은 상관관계가 존재한다.

• 한국아동복지학
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• 제58호
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• pp.231-262
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• 2017

다문화 사회로의 진입을 목전에 두고 있는 한국사회에서, 이주배경 청소년들의 총체적 이주경험은 그간 실천적 학문적으로 충분히 논의되지 못해 왔다. 국외 실증연구들의 결과와 이론적 논의에 의하면 이주와 연관되어 출생지에서 경험하는 유수기간 및 유수기간 내 동거인의 차이와 이주 이후의 거주기간, 가족과 또래의 지지 등 정주지 사회에서의 경험은 이주경험이라는 큰 틀에서 설명될 수 있는 것이며, 이는 이주배경 청소년들의 정신건강에 적지 않은 영향을 미치는 요인이다. 이에 본 연구는 탐색적 시론적인 연구로서, 이주배경 청소년들의 이주이전 경험과 이주이후 경험 그리고 우울, 불안, 자살생각 등의 부정적 정신건강문제 간의 관계를 살펴보았다. 연구결과, 이주이전의 유수기간과 유수기간 내 주 양육자 이외 친척, 형제, 친구와의 동거여부는 이주이후 또래와 가족의 지지 및 한국문화적응 수준과 마찬가지로 현재의 부정적 정신건강문제들과 연관성을 나타냈다. 본 연구는 이와 같은 결과를 바탕으로 정책적 실천적 함의 등을 논의하였다.