• Tunnel and Underground Space
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• v.19 no.6
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• pp.534-544
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• 2009

The collapse of the underground cavity can cause the abrupt local subsidence of the ground surface. It can be hazardous to the stability of road and building for human activity. Therefore it is necessary to develop reinforcement methods for the filling of the underground cavity. This study was executed to improve the material quality and systems to fill the calcium-aluminate mineral $(C_{12}A_7)$ environmentally, and minimize the loss of filling materials for the steep underground cavity. Filling material which was developed in this study is composed of rapid hardening material and additives. The developed material had rapid hardening and non-separation ability in the water cavity condition, so it made the effective underground dam in the cavity with prevention of material loss when it was poured in the water cavity. Results of heavy metal leaching test for environmental assessment showed that it was environmentally suiTable material for the filling in the mine cavity.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.215-224
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• 2012

The purpose of this study is to investigate the external collaboration factors that affect the performance of Korean venture businesses. We use 1,567 firm data (from Venture Business Survey by Small & Medium Business Administration) and analyze the effect of the external collaborations with large business, research institutions, other small business, and foreign companies, on their sales increase between 2008 and 2009. Our analysis shows that Korean venture business' collaborations with research institutions or foreign companies increase their sales statistically significantly, while their collaborations with large business decrease their sales significantly. In the mean time, their collaborations with other small businesses show no significant result. Additional analysis on the collaboration categories between venture businesses and large businesses shows that collaborative R&D, employee training and collaborative marketing help venture business to increase their sales significantly, while financial collaborations have a significant negative effect on sales increase. Technology transfers and profit-sharing mechanism have no significant effect. The result shows that venture business' collaborations for the increase in the fundamental capability of innovations and for searching new markets rather than simple transfer of technology or financial collaborations, have significant positive effects on the increase in sales.

• Tunnel and Underground Space
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• v.12 no.3
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• pp.171-178
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• 2002

A dynamic analysis of a horseshoe_shaped tunnel near to cavity was performed to study the effect of the cavity on the dynamic behavior of the tunnel. In order to obtain the dynamic response of the tunnel embedded in a semi-infinite domain, a hybrid numerical technique was primarily developed. A dynamic fundamental solution in frequency domain for multi-layered half planes was derived and subsequently incorporated in the boundary element method. Coupling of the boundary element method for the far field with the finite element method for the near field is made by imposing compatibility condition of a displacement at the interface. The boundary element method is then coupled with the finite element method, which is utilized to model the near field including the tunnel and the cavity. In order to demonstrate the validity of the proposed technique, dynamic responses of single and multiply-layered semi-infinite structural systems are obtained by using the Kicker waveform and investigated in the limestone layer to find how the being and the location of the cavity affect the dynamic characteristics of the system.

• Journal of the Korean Geotechnical Society
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• v.21 no.9
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• pp.35-44
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• 2005

Recently, underground cavities such as limestone cavity and abandoned mine give rise to a lot of damage in SOC facilities. But there are many difficult problems such as delay of the working terms and enormous economic losses in finding a new method and changing construction design. In this study, a new filling material for underground cavities was developed using the stone-dust classified as industry waste polluting environment. As a result of test, filling material properties was that a compressive strength was $34{\~}60\;kgf/cm^2$, a change ratio in length was $0.268{\~}0.776\%$ and water absorption was $34.3{\~}46.9\%$. Also as a result of suspended mass test and pH test, it was confirmed that the developed filling material has a characteristic of non-separating in water and it was an environmentally friendly material.

• Journal of the KSME
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• v.53 no.1
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• pp.47-50
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• 2013

장비산업은 다품종 소량 생산 및 수주 개발의 특성으로 인하여 제품의 경쟁력을 개발 초기에 확보하기 위한 디지털 개발 프로세스의 도입이 필수적이며 이를 위해서는 형상 설계, 구조/유동해석, 제어 설계 등 구성 요소의 기능만큼이나 기능간의 연계가 중요하다. 디지털 개발의 확산을 위해서는 단위 요소의 개발과 더불어 이종 SW 개발자 간의 공동 개발을 통해 실 사용자의 요구를 반영한 통합 솔류션의 제공이 필요하다.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.101-109
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• 2011

As climate change is becoming the main issue, various efforts are focused on saving building energy consumption both at home and abroad. In particular, it is very important to save energy by maintenance, repair and rehabilitation of existing multi-family housing complex, because energy consumption in residential buildings is not only forming a great part of gross energy consumption in Korea but the number of deteriorated complexes is also sharply increasing. However, energy saving is not considered as a main factor in decision making on rehabilitation project. Also, any supporting tool is not appropriately prepared in existing process. As the first step for development of decision support system on rehabilitation, this paper developed a breakdown structure, which makes clusters of multi-family housing complexes. Decision tree, one of data mining methods, was used to make clusters based on the characteristics and energy consumption data of multi-family housing complexes. Energy saving and CO2 reduction will be maximized by considering energy consumption during rehabilitation process of multi-family housing complex, based on these results and following research.

• Journal of Korea Spatial Information System Society
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• v.7 no.2 s.14
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• pp.29-38
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• 2005

Even though underground conduits have became important city-infra structures which should be exhaustively and efficiently managed, there is few systems which supports the well-defined facility management standards. Due to the lack of the supporting systems, experts must visit underground conduits scattered several cities over the country to see and check the status of the underground conduits including built-in facilities. This type of management gives us a little bit delayed status information at the end of so much time and money costs. In this paper, to solve this problem and manage the conduit synthetically, we developed a web-based facility management system for underground conduits by using information technologies. The developed management system has a simplified map drawing interface to depict the overall architectures and locations of underground conduits and their built-in facilities into sketch maps. And, the system uses the 3D panorama image technology with zooming functions in addition to still images and video images to give the feeling of a spot inspection. Moreover, since the system accumulates the data of repair/reinforcement, occasional inspections and safety diagnosis, conduit managers can synthetically and effectively manage the facilities within underground conduits and themselves.

• Korea Petroleum Association Journal
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• no.6 s.160
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• pp.54-58
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• 1994

이 자료들은 지난 4월27일 한국종합전시관 소회의실에서 열린 해외석유개발협회ㆍ한국자원경제학회 공동주회의 석유개발정책세미나에서 발표된 논문들을 옮긴 것이다.<편집자 주>

• Proceedings of the KAIS Fall Conference
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• 2002.11a
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• pp.185-188
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• 2002

컴퓨터 망을 이용하는 분산 환경에서 다양한 역할의 작업자간의 컨덴츠를 효율적으로 관리 할 수 있는 공동 저작용 협업 시스템을 구현한다. 공동저작을 위한 협업 시스템의 기반기술인 메시징 엔진 개발과 자료 공유를 위한 컨텐츠 네트워크 관리, 참석자간의 편리한 의사교환 기능을 지원하는 프로그램 소프트웨어를 구현하였다.

• Defense and Technology
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• no.12 s.154
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• pp.56-59
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• 1991

현재 한국 방위산업은 R&D 투자확대, 기존장비 대폭개선, 첨단무기체계 개발촉진 등과 같은 과제에 직면하고 있습니다. 미국정부와 방산업체들은 마케팅활동과 기술이전에 대해 보다 유연한 자세를 갖고, 보다 적극적으로 응해야 할것입니다. 한국은 생산기술과 품질관리면에서 국제경쟁력을 갖춘 국가로 성장했습니다. 한국을 제3국시장으로의 공동진출을 위한 동남아 수출 전진기지로 활용할 것을 제의합니다