• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.375-376
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• 2005

본 연구에서는 폐전선 피복플라스틱의 재활용을 위해 마찰하전형 정전선별법을 이용하여 PVC와 rubber의 재질분리 실험을 수행하였다. 하전물질의 종류에 따른 실험결과 PVC와 Rubber의 중간 일함수 값을 갖고 있는 PP 재질이 가장 효과적이었으며, 단일 시료보다PVC와 Rubber의 혼합조건에서 더 높은 하전 값을 나타내었다. 하전특성 실험결과 공기량은 10.28wt/s 이상 그리고 상대습도는 40% 이하의 조건에서 입자의 높은 하전량을 얻을 수 있음을 확인하였다. 분리특성 실험결과 전압세기가 25kv 이상 그리고 분리대의 위치는 전기장의 중앙(0)으로부터 Negative 전극으로 -lcm 이동한 지점으로, 이때 PVC의 품위와 회수율을 각각 99.5%와 95%인 결과를 얻었다.

• Journal of Korean Society for Quality Management
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• v.29 no.4
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• pp.1-17
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• 2001

The characteristics of Telecommunication Industry encompass not only hardware and software but also the service aspect of them. One way to improve the industry up to the international level in terms of hardware and software as well as service aspect is to comply with tile TL 9000 standard, which was established by QUEST Forum, the group consisted of U.S. communication industry, based on the ISO 9000 Quality Management System. In this study, design, establishment, implementation, maintenance and improvement of quality system for domestic telecommunication industry are thoroughly investigated based on TL 9000 standard, with its LCM(Life Cycle Model) model and measurements. Also, Process Approach is suggested to help the industry realize the system to meet its specific needs. In addition, specific examples with the successful certification to TL 9000 standard are presented.

• Korea-Australia Rheology Journal
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• v.20 no.1
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• pp.7-14
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• 2008

The objective of this work is to propose a procedure to simulate the flow in the LCM (Liquid Composites Molding) processes by finite difference discretization in a curvilinear coordinate system adapted to the shape of the saturated zone. The numerical results obtained are compared with experimental results obtained by an experimental device elaborated at our laboratory. It allows to realize linear and radial injections for different porosities and to observe the flow front kinetics. Numerical and experimental results are then compared with those of the literatures and excellent agreements are noticed. Finally, we suggest a concept of the capillary number to explain the variations of the permeability obtained for pressure values lower than 0.25 Bar.

• Korea-Australia Rheology Journal
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• v.18 no.4
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• pp.217-224
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• 2006

Rapid flow advancement without void formation is essential in the liquid composite molding (LCM) such as resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM). A highly permeable layer in multi-layered preform has an important role in improvement of the flow advancement. In this study, a multi-layered preform which consists of three layers is employed. Radial flow experiment is carried out for the multi-layered preform. A new analytic model for advancement of flow front is proposed and effective permeability is defined. The effective permeability for the multi-layered preform is obtained analytically and compared with experimental results. Compaction test is performed to determine the exact fiber volume traction of each layer in the multi-layered preform. Transverse permeability employed in modeling is measured experimentally unlike the previous studies. Accurate prediction of flow advancement is of great use for saving the processing time and enhancing product properties of the final part.

• Korea-Australia Rheology Journal
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• v.19 no.1
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• pp.17-25
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• 2007

In liquid composite molding (LCM), composites are produced by impregnation of a dry preform with liquid resin. The resin flow through the preform is usually described by Darcy's law and the permeability tensor must be obtained for filling analysis. While the resin flow in the thickness direction can be neglected for thin parts, the resin flow in the transverse direction is important for thicker parts. However, the transverse permeability of the preform has not been investigated frequently. In this study, the transverse permeability was measured experimentally for five different fiber preforms. In order to verify the experimental results, the measured transverse permeability was compared with numerical results. Five different fiber mats were used in this study: glass fiber woven fabric, aramid fiber woven fabric, glass fiber random mat, glass fiber braided preform, and glass/aramid hybrid braided preform. The anisotropic braided preforms were manufactured by using a three dimensional braiding machine. The pressure was measured at the inlet and outlet positions with pressure transducers.

• Convergence Security Journal
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• v.5 no.2
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• pp.37-42
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• 2005

Development of Information Technology and knowledge information society transfer brought huge change of education training field. According as Ubiquitous society approaches, e-Learning will be evolving by u-Learning. This presages in other form with present that professor-learner environment may change. This study proposes and embodied administration method of various studying contents by development of Learning environment, And through operation platform analysis, proposed LMS that can do practical use of contents efficiently.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.89-98
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• 2001

There have been a lot of studies about repair & strengthening of the concrete structure. But there has almost not been my study on section damage effect due to holes drilled out for installing additional facilities or equipment, such as rack on the wall of building or underground culvert system, plumbing system through the column or wall of it, after being occupied. This study is to find out how much the section loss due to holes will give loss of section strength. We cm determine if we repair or reinforce it completely or not, using strength loss from the hole. Hole size of diameter 3cm, 2cm, lcm, depth of 3cm, 5cm, 10cm, and position of each hole has been considered as variables of this study. It is concluded that section loss 30% results in 53% of strength damage.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.729-732
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• 2004

최근 e-Learning에 대한 관심이 많아지고 있는 가운데, 기존의 e-Learning은 웹에서의 설계방식이 주류를 이루었다. 이러한 웹 기반에서 사용되는 LCMS(Learning Contents Management System)는 LMS(learning Management System)와 CMS(Contents Management System)를 통합할 수 있고, 다양한 학습 콘텐츠를 부분적으로 업그레이드하고 재구성할 수 있는 환경으로 확대되고 있다. 하지만, 웹 기반의 e-Learning 설계는 유비쿼터스 환경에는 적합하지 않다. 기존 웹 기반의 LCMS은 다양한 학습기기를 사용할 수 없으며, 적시성(Just-in-time)이 이루어지지 않아, 학습시 불편함이 발생된다. 이에 본 논문에서는 다양한 학습기기와 적시성에 대한 문제를 해결할 수 있도록 유비쿼터스 환경에 적용될 수 있는 LCMS 기반의 e-Learning 설계 방법을 제시 하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.954-957
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• 2015

본 연구는 컴퓨터시스템을 이용한 맞춤형 정음기반 한국어 학습 지원시스템의 효율적인 모델에 관한 연구 논문으로서, IMS/AICC 국제규격을 준수하는 LCMS와 SCORM 기반의 정음 정보처리로 한국어 교육이 가능한 학습지원시스템에 구축 시스템의 세부 모음들을 정의하였다. 주 내용은 학습자의 학습결과와 학습 습관을 분석 평가하여 자가 주도 식으로 학습할 수 있는 기능을 제공한 것이다. 본 연구는 효율적인 PMS 세부모듈 시스템은 물론, 표준 역량모델관리시스템, 학습자 개별 역량 관리시스템, 역량저장 및 저장소, 커뮤니티를 활용한 역량 모델기반의 지식관리시스템, 교육 수요분석용 e-Survey시스템, 모바일 학습지원서비스 시스템 등이다. 앞으로 클라우드컴퓨팅 기술을 적용한 외국인을 위한 정음기반 한국어 학습지원시스템 구축 표준 모델을 제시하였다.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.124-138
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• 2018

This research was conducted to examine the availability of spatial data for assessing absorption rates of $CO_2$ in the forest of Ansan-si and evaluate the validity of methods that analyze $CO_2$ absorption. To statistically assess the $CO_2$ absorption rates per year, the 1:5,000 Digital Forest-Map (Lim5000) and Standard Carbon Removal of Major Forest Species (SCRMF) methods were employed. Furthermore, Land Cover Map (LCM) was also used to verify $CO_2$ absorption rate availability per year. Great variations in $CO_2$ absorption rates occurred before and after the year 2010. This was due to improvement in precision and accuracy of the Forest Basic Statistics (FBS) in 2010, which resulted in rapid increase in growing stock. Thus, calibration of data prior to 2010 is necessary, based on recent FBS standards. Previous studies that employed Lim5000 and FBS (2015, 2010) did not take into account the $CO_2$ absorption rates of different tree species, and the combination of SCRMF and Lim5000 resulted in $CO_2$ absorption of 42,369 ton. In contrast to the combination of SCRMF and Lim5000, LCM and SCRMF resulted in $CO_2$ absorption of 40,696 ton. Homoscedasticity tests for Lim5000 and LCM resulted in p-value <0.01, with a difference in $CO_2$ absorption of 1,673 ton. Given that $CO_2$ absorption in forests is an important factor that reduces greenhouse gas emissions, the findings of this study should provide fundamental information for supporting a wide range of decision-making processes for land use and management.