• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.41-42
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• 2014

현대 산업에서 철은 매우 중요한 재료이다. 다양한 산업적 요구에 맞게 제철산업에서도 다양한 성질의 강을 개발하고 생산하고 있다. 강의 주요 물성으로는 인장강도, 항복강도, 연신율 등이 있으며 이러한 물성들을 향상시키거나 변경하는데 다양한 첨가원소와 제조 공법들이 적용되어진다. 본 연구에서는 그 중 합금 원소를 첨가하여 강도를 높이는 초고강 강에 대해서 화성처리 특성을 연구하고 그에 영향을 미치는 인자에 대해서 분석하였다. 그리고 화성처리 공정을 개발하여 초고강도강의 인산염특성을 향상 시켰다.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.90-98
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• 2008

The technical improvement of high-rise building construction is getting better as the demands of the skyscrapers is increasing. The interior construction has become the essential factor which directly affects the whole project because of skyscraperization. This study has proposed the site image-based space model as the tool for supporting decision-making for preparation and execution of the interior construction. It is expected to make the space model which is suitable for the project characteristics and work packages.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.42-50
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• 2008

There are many plans of the high-rise buildings these days in domestic and will be constructed from now on. It is required to develop energy saving techniques immediately because the high-rise buildings consume a lot of energy. The most effective energy savings method is the application of the efficient lighting designs and fixtures. The purpose of this study is to analyze a trend of lighting design, fixture and control system between overseas and domestic. It can be used the guide line for the high-rise buildings in domestic application.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.77-80
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• 2014

멀티미디어 기술의 보급 확산 및 급속한 발전으로 새로운 영상 압축 기술인 HEVC(High Efficiency Video Coding) 고화질 영상 압축 표준을 탄생시켰으며, 사용자 또한 대형 화면에 대한 선호도가 높아지고 있다. 그 결과 기존의 HD급 영상보다 4배 이상, 16배까지 선명한 초고화질 UHD(Ultra High Definition) 영상 서비스가 차세대 방송기술로 새롭게 주목받고 있다. 또한 JPEG 2000 압축도 기존 처리된 $4096{\times}4096$ 픽셀 이미지를 넘어 초고화질 해상도 이미지(8K : $7680{\times}4320$ 혹은 $8192{\times}4320$ 픽셀)를 처리 지원을 하고 있다. 따라서 초고화질 이미지의 획득 및 저장을 위해서는 고속의 처리 기술이 필요하다. 이에 본 논문은 초고화질 해상도 이미지의 고속 처리를 위한 병렬처리 기술에 대해 단계적 연구를 실행하며, 이를 위하여 1차적으로. JPEG 2000의 처리 과정을 살펴보고 전처리 단계인 색공간 변환 알고리즘 적용을 위하여 사용자 정의의 쓰레드 기반 고속처리를 수행하였다. 실험 결과 기존의 처리보다 사용자 정의 기반 쓰레드 고속처리가 초고화질 해상도 이미지(UHD 8K : $7680{\times}4320$)를 기준으로 최대 15배의 성능 향상의 결과를 보여주었다.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.411-416
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• 2007

This study was performed to investigate the reduction of toxicity and improvement of anticancer activities from R. sachalinensis by ultra high pressure extracts process. The cytotoxicity on human kidney cell (HEK293) and human lung cell (HEL299) was showed below 20.4% and 21.6% as compare to normal extracts in adding 1.0 $mg/m{\ell}$ concentration. This showed that toxic materials through ultra high pressure processing is broken or degraded. Because bond such as hydrogen bond, electrostatic bond, Van der waals bond, the hydrophobic bond, can be broken by high pressure. The anticancer activity was also increased in over 7% by high pressure processing in A549, AGS, MCF-7 and Hep3B cells. The result showed that extraction by high pressure have low cytotoxicity and high anticancer activity. So, the high pressure extraction technology can play an important role in eruption of new material with high biological activity.

• Transactions of the KSME C: Technology and Education
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• v.3 no.4
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• pp.299-305
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• 2015

Nuclear hydrogen production technology is being developed for the future energy supply system. The sulfur-iodine thermo-chemical hydrogen production process directly splits water by using of the heat generated from very high temperature gas-cooled reactor, a typical Generation IV nuclear system. Nuclear hydrogen key technologies are composed of VHTR simulation technology at elevated temperature, computational tools, TRISO fuel, and sulfur iodine hydrogen production technology. Key technology for nuclear hydrogen production system were developed and demonstrated in a laboratory scale test facility. Technical challenges for the commercial hydrogen production system were discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.277-287
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• 2009

Recently, the high-strength steel of 400~600MPa tensile strength is producing in the country. Use of high-strength steel member in the design of high-rise buildings is expected to increase the efficiency of structural design in the aspect of structure material weight and cost, however it has been used only a narrow extent. No efficient design method to use high-strength steel in the design of high-rise buildings has been developed. Therefore, in this study structural cost optimization technique that can minimize the structural material cost of high-rise buildings using high-strength steels is developed. The efficiency of the technique is evaluated by comparing the experience-based design for 6 high-rise building examples. As a result, the proposed techniques can save 7~21% of structural material cost compared with experienced-based design. And also, the rough guideline for effective use of high-strength steels in the structural design of high-rise buildings is introduced on the basis of results.

• Journal of KIISE
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• v.41 no.11
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• pp.974-981
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• 2014

These days, use of multimedia streaming service and demand of QoS (Quality of Service) improvement have been increased because of development of network. QoS of streaming service is influenced by a jitter, delay, throughput, and loss rate. For guaranteeing these factors which are influencing QoS, the role of transport layer is very important. But existing TCP which is a typical transport layer protocol increases the size of congestion window slowly and decreases the size of a congestion window drastically. These TCP characteristic have a problem which cannot guarantee the QoS of UHD multimedia streaming service. In this paper, we propose a router buffer based congestion control method for improving the QoS of UHD streaming services. Our proposed scheme applies congestion window growth rate differentially according to a degree of congestion for preventing an excess of available bandwidth and maintaining a high bandwidth occupied. Also, our proposed scheme can control the size of congestion window according to a change of delay. After comparing with other congestion control protocols in the jitter, throughput, and loss rate, we found that our proposed scheme can offer a service which is suitable for the UDH streaming service.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.211-217
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• 2020

There is an increasing demands of more efficient and economical ways of mold making according to the spreading trend of small quantity batch production system. Therefore, this study aims to examine the applicability of ultra high strength concrete, which has a compressive strength over 80MPa, as a mold material. The ultra high strength concrete has several advantages such as lower cost, lighter weight and convenience of shape making compared to the traditional mold materials. Although the strength of the ultra high strength concrete is lower than that of the tool steel, it was considered to be useful for small batch processes with relatively low pressure. Therefore, in this study, a prototype mold for reaction injection molding of polyurethane was developed using ultra high strength concrete and it was examined that the possibility and characteristics of concrete as a mold material.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.553-562
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• 2006

Lateral loading due to wind or earthquake is a major factor that affects the design of high-rise buildings. This paper highlights the problems associated with the seismic design of high-rise buildings in regions of strong wind and moderate seismicity. Seismic response analysis and performance evaluation were conducted for wind-designed concentrically braced steel high-rise buildings in order to check the feasibility of designing them per elastic seismic design criterion (or strength and stiffness solution) in such regions. Review of wind design and pushover analysis results indicated that wind-designed high-rise buildings possess significantly increased elastic seismic capacity due to the overstrength resulting from the wind serviceability criterion. The strength demand-to-capacity study showed that, due to the wind design overstrength, high-rise buildings with a slenderness ratio of larger than four or five can elastically withstand even the maximum considered earthquake (MCE) with the seismic performance level of immediate occupancy under the limited conditions of this study. A step-by-step seismic design procedure per the elastic criterion that is directly usable for practicing design engineers is also recommended.