• Journal of Labour Economics
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• v.43 no.4
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• pp.117-141
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• 2020

The paper focuses on the question of whether and how the labor underutilization indicator supplements the unemployment rate. The research is based on the differences in the labor market behavior among three groups of the not-employed; the unemployed, potential labor force and the rest of outside the labor force. The annual transition rate among the labor market states shows that the potential labor force has the explicit unmet need for employment different from the rest of the outside the labor force. The multinomial logit regression controlling the effects of individual characteristics rejects the hypothesis that the potential labor forces are behaviorally identical to the unemployed. The evidence shows that the two indices should be interpreted distinctively.

• Journal of Aerospace System Engineering
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• v.11 no.3
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• pp.16-21
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• 2017

In this paper, we propose a new folding method (the blossom method) to increase storage efficiency of drag-sail. To resolve the issue caused by increase in the thickness of the sail, we allowed margin space (offset) along the folding line and made holes at the intersection of offset lines to prevent distortion of film. In addition, to verify applicability of the blossom method, we fabricated quarter of the sail by using Mylar film and conducted a deployment experiment. If the blossom method is applied, storage ratio (storage volume: deployed area) is 1: 68.64, that is approximately 1.88 times more than the z-fold method of folding sailing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1499-1505
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• 2010

In general, magnetic abrasive polishing can be used to effectively produce a mirror-like surface; however, industrial applications of this process involve some unsolved problems. For example, the polishing efficiency is low, and the used abrasives have to be treated. In this study, which is aimed at solving these problems, a novel medium of silicone gel, consisting of ferromagnetic particles and abrasives, is developed, and the effect of this medium is assessed on the basis of Taguchi's experimental method. The workpiece is a tungsten carbide steel and the surface roughness after magnetic abrasive polishing using the silicone gel is evaluated.

• Journal of Korea Multimedia Society
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• v.7 no.3
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• pp.357-367
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• 2004

In VOD systems the number of channels available to a video server is limited since the number of channels, the video server can support, is determined by the communication bandwidth of the video server. Multicast techniques such as batching, patching and batch-patching have been proposed to reduce I/O demand on the video server by sharing multicast data. In this paper, we propose a channel reservation batch-patching technique that first applies the batching technique to hot video requests and then applies the patching technique to the batches of the hot video requests. And the proposed technique reserves a part of the channel capacity of the video server for many hot video requests, so that the hot video requests can be served without defection. The performance of the proposed technique is compared with those of Patching and Batch-Patching techniques in terms of average service latency, defection rate, fairness and frame reduction rate by simulations.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.367-370
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• 2012

본 연구는 하나의 장치 내에서 "싸이클론-관성충돌-여과포 집진"이라는 다단 제진 단계가 동시에 이루어져 입경 분포별로 순차적인 제진이 가능한 멀티 집진기의 처리가스 제어 효율을 극대화시킬 수 있는 기류 흐름을 얻기 위한 최적화 설계 조건을 검토하는 것이다. 우선 1단계 제진 과정인 원심력을 이용하여 조대입자의 유선 이탈을 촉진시킬 수 있는 사이클론 유동을 최적화시키기 위한 집진기 입구 형상 설계 검토를 위해 수치 해석적 연구를 수행하였다. 그 결과, 멀티집진기 입구 형상을 일반적인 설계 방식인 접선 유입식으로만 설계한 것에 비해 선회류를 한번 더 가속화시킬 수 있는 가이드 베인을 추가로 설계한 경우 선회류의 pitch가 짧고 강하게 형성되어 사이클론부에서 조대입자의 유선 이탈을 촉진시키는데 매우 효과적인 것으로 예측되었다. 단, 사이클론부 하단 벤츄리 형상으로 인해 약 4~5 m/s의 강한 하향 흐름이 호퍼 하단까지 형성되고 있어 탈리 분진의 재비산 문제가 발생할 가능성이 크므로 벤츄리 형상 설치 유무에 대한 영향도 추가적으로 연구가 필요할 것으로 판단된다.

• Communications for Statistical Applications and Methods
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• v.18 no.6
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• pp.687-696
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• 2011

Customer Lifetime or Customer Lifetime Value is a essential metric of differentiated CRM marketing and differentiated marketing strategy as a company core competency. However, customer lifetime used in companies is easily obtained from a confined simple customer attrition rate at some specific time point regardless of customer characteristics. In this study, in order to overcome the constraints of previous simple methods and to make practical use of it in industries, we suggest a method that estimates a customer lifetime using a customer segment based survival analysis with the censored data of customers; in addition, we apply this method to A mobile telecom company data. A method using customer segment based survival analysis is suggested in this study 1) includes all customers having different subscription dates, 2) reduces individual error, 3) can reflect trends after the observed time point and is more realistic.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.223-235
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• 2006

Textile industry of Korea has been assumed advanced textile industry nation's aspects with production system and equipment. But has been descended in the sector of design, brand, recognition comparing with Italy, Japan, England. And products of middle and low price do not have competitiveness against China, South East Asia. The world's textile industry nation has been confronted with Free Trade, and Regional Trade Blocks. New market has been opened with free Trade, but Trade Blocks(NAFTA, EU, APEC etc.) which encourage regional member country's profit maximize made textile export driven nation to consider strategies to cope with. Advanced textile industry nation divided the work among themselves and composed linking system among them which highly valuable products are manufactured at advanced nation and low price products are manufactured by global outsourcing. The purpose of this study is to analyze impact of process which requires to secure international competitiveness into business performance experimentally.

• Land and Housing Review
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• v.13 no.1
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• pp.39-54
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• 2022

Using the 1st to 13th rounds of occupational history data of the Korea Employment Information Service's Youth Panel (YP2007), this study explores the trends and characteristics of the youth labor market in Seoul. We further empirically investigated the job duration and wage determinants of youth employed in Seoul. The results confirm that workers who have a higher income and a higher consistency with their majors are less likely to leave. In addition, we find that workers in full-time, householders, or labor unions have a higher income if they are men and work in large companies. In particular, compared to the reference group (appropriate academic background, appropriate skill), mismatches in the lack of education and skill showed a wage increase effect of 4.9% and 5.5%, respectively. For the major consistency, the wage of the matched major group is 3.8% higher than the non-matched major group.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.204-206
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• 2016

대한민국은 우수한 기술력을 바탕으로 한 각종 플랜트 산업이 주력업종인 강국이다. 이러한 특성에 맞게 각 산업단지에서는 고중량 대형화물에 대한 운송수요가 꾸준히 발생하고 있는 추세이다. 대형화물의 운송량이 증가할수록 고정결박 불량에 의한 화물 낙하, 이탈로 인한 차량파손, 도로파손 등의 사고가 지속적으로 발생하고 있으며, 이러한 사고의 발생 가능성은 항상 내재하고 있다. 하지만 현행 도로교통법에는 화물적재 및 고정에 대한 구체적 규정이 전무하여 화물운전자가 책임을 부담하고 있는 실정이다. 본 연구에서는 기존 화물적재 규정을 살펴보고 적합한 고정결박 지침을 제정하고 관리하는 절차의 지정을 제안하였다.

• Electronics and Telecommunications Trends
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• v.23 no.2 s.110
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• pp.46-55
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• 2008

융합환경 하에서 새로운 기술과 서비스의 제공이 가능해지고 차세대 네트워크의 투자가 확대되면서 미래 통신시장에서 유선부문 지배적 사업자의 시장지배력이 전이될 가능성이 높아지고 있다. 이러한 통신시장의 환경변화에 대응하여 영국, 이탈리아, 스웨덴, 아일랜드 등 유럽의 많은 국가가 구조분리를 추진하였거나 진행중에 있다. 또한 EU는 2007년 11월 통신법 개정안을 통해 EU 27개 회원국 규제기관에 영국식 기능분리 권고안을 제안하였고, 개별 회원국의 찬성을 전제로 2009년 구조분리가 현실화 될 예정이다. 특히 EU의 통신법 개정안은 기존 병목설비에 적용되던 필수성과 독점성의 원칙을 상당히 탄력적이고 포괄적으로 해석하고 있다. 또한 유선시장의 경쟁 상황이 점차 개선되고 있음에도 구조분리를 강력하게 추진하고 있다. 이처럼 컨버전스 환경에 대비한 EU 및 유럽 각국의 강력한 구조분리 추진현황은 유선시장의 경쟁이 활발하지 않고, 구조분리 논의가 필수설비의 필수성과 독점성의 원칙에서 진전되지 못하고 있는 우리나라의 유선시장에 많은 시사점을 제시하고 있다.