• Korean Journal of Optics and Photonics
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• v.4 no.4
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• pp.493-495
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• 1993

The frequency of the 633 nm internal mirror He-Ne laser has been stabilized by using the beat frequency and the intensity difference between two Zeeman split components in a transverse magnetic field. The frequency stability and the frequency temperature coefficient for the beat frequency method was $7.0{\times}10^{-11}$ and $170 kHz/^{\circ}C$, respectively, and those for the intensity difference was $1.1{\times}10^{-9}$ and $1.8 MHz/^{\circ}C$, respectively.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.209-210
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• 2012

철원군은 군사문화유적지와 더불어 과거 태봉국의 도읍지로서 한 시대를 풍미했던 역사문화유산이 살아 숨 쉬고 있는 우리역사의 장이다. 또한 청정지역의 이미지는 생태 관광지로서의 가능성을 보여주고 있다. 이에 따라 본 고에서는 에코뮤지엄(ecomuseum)의 개념을 토대로 철원군의 지역문화자원을 활용하는 방안을 제시하려고 한다. 연구의 이론적 바탕이 될 에코뮤지엄은 기존의 박물관처럼 한정된 공간 내에 수집품을 모아놓고 관람객을 끌어들이는 것이 아니라 지역 전체를 하나의 박물관으로 구성하는 새로운 형태의 박물관이다. 따라서 지역의 문화유산, 생태 환경, 관광자원을 포함한 포괄적인 유,무형의 자원이 모두 에코뮤지엄의 요소가 될 수 있으며, 관람객은 주변 환경과 일체가 되어 직, 간접적인 체험을 공유한다. 지역 주민은 적극적인 역할을 수행함으로써 지속적으로 지역의 개발과 보존에 주체적으로 참여하게 된다. 이러한 관점에서, 지역의 다양한 문화자원을 바탕으로 한 에코뮤지엄은 철원군의 지속가능한 경제 활성화에도 기여하게 될 것이다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.161-169
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• 2000

Recycled aggregates were generated when concrete structures were dismembered. However, in concrete structures, because of durability, strength and toughness, recycled aggregates don't use generally. This study was done to use recycled aggregate in concrete structures. Problems of durability, strength, and toughness were caused troubles, when recycled aggregates were used, were solved as steel fibers and additives were added. Of course, steel fiber length, steel fiber contents, additive substitution, and recycled aggregate substitution were variables of this study. After flexural specimens($15{\times}15{\times}70cm$) with notch(45mm) were fabricated, basic strength tests were done and toughness was estimated using fracture mechanics parameters. The results suggest that JIC is a promising fracture criterion for all of these, while KIC(or GIC) almost certainly are not.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.205-213
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• 1997

The production activity by human is accompanied by various accidents which resulted in human and property loss. If information on these industrial accidents can be collected and analyzed for the purpose of preventing industrial accidents, we sill be able to get ride of inductrial accidents. The accidents which involved absence from work at least 4 days in small manufacturing factories were considered in this study. 84 accidents which occurred in 1996 were investigated. These accidents were analyzed in terms of employment sector, work period, cause of accident and form of acciednt. The accidents of small manufacturing factories are numerous and are often serious and worthy of greater attention than they have received. Successful strategies for accident prevention depend on effective analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.120-125
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• 1992

The fatigue tests were performed on the high strength concrete beams with single edged notch which was reinforced steel fiber. The steel fibers were used 1.0 percent by volume fraction. These were tested consists of constant amplitude tests for different levels of loading. The test program included endurance limit with repect to flexural fatigue and relation of load-CMOD(crack mouth opening displacement). The results of test, it is found from S-N curve that the fatigue strength for a life of 2 million cycles of load was approximately 70percent with respect to the static ultimate strength .

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.259-264
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• 2002

In this study the shear strengths of a poorly grad ed rock material(d/sub max/≤50.8mm, C/sub u/=1.86) were determined by large direct shear test and large triaxial test. The obtained stress-strain curves by the above large shear tests for the rock materials are similar to the loose sand's or normally consolidated clay's curve, in which the peak strength does not appear obviously. And for the uniformly graded rock material the shear strength by large direct shear test may be overestimated around 1.54∼1.70 times that of large triaxial test.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.49-55
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• 2010

Many electric poles in the softground have been collapsed due to external load. In this study, 10 types of tests were performed with variation of location, numbers and depths of anchor blocks as well as depth of poles to find stresses acting on concrete electric poles. The stresses of concrete poles are relaxed at 600~700[kg] of tensile load, and stresses are concentrated at top of pole, and spread to lower part of pole. In the concrete pole collapse test, tensile load at failure was approximately 1,400[kg], which is twice of design load. As passive zone in the soil increases, the stresses acting on concrete pole are concentrated at lower part of pole based on moment arm earth pressure distribution.

• Information and Communications Magazine
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• v.24 no.10
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• pp.7-14
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• 2007

미래의 전장환경은 기존의 플랫폼 중심전(PCW: Platform Centric Warfare)에서 센서로부터 들어온 디지털 정보를 타격체계에 곧바로 전달하는 Sensor-to-Shooter 개념의 네트워크 중심전 (NCW: Network Centric Warfare)으로 기본 패러다임이 급속히 바뀌고 있으며 네트워크 중심전 수행 능력의 기반이 되는 전술데이터링크의 중요성이 크게 부각되고 있다. 전술데이터링크는 1960년대부터 개발되기 시작하였으며 정보통신의 발전과 함께 무기체계의 디지털화 및 작전개념의 발전 등으로 다양한 전술데이터링크가 개발되고 있다. 현재 미군은 최신의 전술데이터 링크인 LINK-16을 다양한 무기체계에 탑재하고 있으며 연합작전 및 합동작전을 위한 전술데이터링크를 구축하고 있는 반면 아직 우리군은 각 무기체계별로 일부 선진국의 전술데이터링크를 도입하여 적용하고 있을 뿐 모든 무기체계에 적용 할 수 있는 표준 전술데이터링크 및 한국군 단독으로 작전을 수행하기 위한 전술데이터링크가 학보 되지 않아 미래 네트워크 중심전 수행이 미흡한 실정이다. 본고에서는 네트워크 중심전의 핵심인 전술데이터링크에 대한 전반적인 개념과 선진국의 주요 전술데이터링크에 대해서 알아보고 현재 한국군의 전술데이터링크 구축 현황 및 미래 한국군 전장환경에서 적용할 수 있는 한국형 전술데이터링크에 대해서 알아본다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.21-26
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• 1999

In this study, to assess chip breaking characteristics of cold-drawn free machining steels, a newly developed non-dimensional parameter, chip breaking index, C/sub B/ has been adopted. And for comparison with free machining steels, chip breaking characteristics of conventional carbon steels were investigated. Properly controlled chips were produced with the C/sub B/ value of 0.05∼0.2, regardless of steel types. In case of cold-drawn free machining steels, however, cycle times of chip breaking are relatively shorter than those of conventional steels. And properly controlled chips were obtained from wider range of feed rate.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.448-453
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• 2005

Tunnel excavation is an inevitable process for railroad construction in Korea and it being a one of the major issues of its environmental impact assessment. Ground water flow by tunnel excavation is an important parameter to determine environmental effects. The current method to determine the ground water flow is used a unit number induced a highway construction site. But it does not consider any site characteristics; ground water level, soil properties and others. The purpose of this study is to suggest the determination way of ground water flow considering site characteristics in tunnel construction.