• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.47-48
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• 2002

LNG보일러는 과거 기름을 주요 연료로 하던 보일러와는 달리 황산화물이나 매연이 거의 배출되지 않는다. LNG연소는 상대적으로 다른 연료에 비하여 오염물질 배출이 적지만 질소산화물을 비롯한 일부오염물질은 배출될 수밖에 없다 본 연구의 목적은 LNG보일러 시설에서 발생되는 주요 대기오염물질에 대한 국내 실정에 맞는 배출계수를 개발하고 배출되는 오염물질의 특성을 파악하여 정확한 대기오염 배출량 산출에 관한 기초를 마련하고자 함에 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.183-184
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• 2002

도시와 산업의 발달 및 인구의 도시 집중화로 다양한 종류의 오염물질이 다량으로 대기 중으로 배출되는 통 환경오염이 날로 심각해지고 상황에서, 특히 악취(odor)와 VOCs(Volatile Organic Compounds) 물질이 사회의 중요한 환경오염 문제고 부각되고 있다 광화학스모그의 선구물질인 VOC의 주요 배출원은 도로차량, 비도로차량, 용제사용과 유류저장으로 파악되고 있으며 그중 용제사용 부문에는 세정, 인쇄, 세탁, 도장, 농약살포, 소비용품, 도로포장 통에서 대부분 배출되는 것으로 알려져 있다 또한 환경기초시설인 하폐수처리장, 폐기물 소각장 및 매립장 등에서도 다량의 VOC/악취 물질들이 배출되고 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1026-1031
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• 2003

A vibration isolation system fur a large reverberation chamber (1,228㎥, 1,000ton) has been installed. The reverberation chamber generates loud noise and induces high level of vibration to perform spacecraft acoustic environmental tests. The isolation system prevents vibration transfer from the chamber to enclosure buildings. This paper describes logical design process and commissioning experiments of the system. Design criteria have been induced from rigid body model of the chamber. Finite element model has been employed to select the characteristics of rubber pads. A total of 21 rubber pads have been installed between the chamber and supporting pedestals. A sand bag of 800kg was dropped on the chamber floor to measure the natural frequency of the isolation system. Absolute transmissibility has been measured while generating 145㏈ in the chamber. The natural frequency of the chamber is 10.5㎐, which is 80% of estimated value. Overall transmissibility at working frequency range (25㎐-10,000㎐) is less than -6㏈.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.862-866
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• 2002

High intensity vibro-acoustic testing is the appropriate method for flight qualification testing of space flight vehicle which must ensure the acoustic environment of launch. To qualify vibro-acoustic environment during its flight, High Intensity Acoustic Test was performed for KOMPSAT-2(Korea Multi-Purpose SATellite) STM(Structural Thermal Model). This paper presents the detailed description on the high intensity acoustic test for KOMPSAT-2. Additionally the test results was compared with the analysis ones, which were estimated with 3-D SEA(Statistical Energy Analysis) model.

• Education of Primary School Mathematics
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• v.2 no.1
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• pp.27-35
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• 1998

The purpose of this research is to analyze the problem of mathematic education of Korean Kindergarten, to search for the solution of the problem in korean Kindergarten. In particular, materials are mostly made and used by the teachers themselves, consuming too much time. Mathematics education materials available in Kindergartens were found to be insufficient. The reasons were the lack of effort by teachers to develop new materials as well as the lack of marketed materials.

• School Mathematics
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• v.2 no.2
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• pp.509-543
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• 2000

The purpose of this paper is to study the present situation of the performance assessment having been introduced for recent years as a new system to measure students' mathematical power as well as their achievement in mathematics by analyzing math teachers' recognition about the assessment. The specific research questions are as follows: (1) what is the difficulty in the administrative process of the assessment\ulcorner (2) what is mathematics teachers' recognition about the assessment with respect to its nature and purpose\ulcorner (3) what is the situation of the in-service program for the newly introduced assessment\ulcorner (4) what is the administrative procedure of the assessement\ulcorner (5) what is mathematics teachers' recognition about the effectiveness of the assessemtn\ulcorner (6) What support is requried to improve the assessemt?

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.141-143
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• 2007

Increasing demand of using low weight materials in recent automotive trends has been the challenge to develop a sound welding of aluminum alloys. A heat treatable AA6082-T6 and a non-heat treatable AA5083-0 aluminum alloys were joined in this study. Investigations revealed that about 60 UTS will be reduced due to welding process. Fracture happened in the interface between fusion zone and base metal of top specimen where penetration is shallow. Therefore, lower welding torch angle produced the better strength which allows deeper penetration to the top specimen. PWHT at $560^{\circ}C$ for 2 hours can be used to return the original UTS of the specimens.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.3
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• pp.35-41
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• 1998

Cost estimate system Will be changed from the prime. cost calculation to the historical cost data because the present system has some problems. In this situation, each owner should prepare his own cost estimate system based on the historical cost data. In this study, the standard work items were classified and the criteria of their work amount computation were established for rural improvement projects. And also the historical cost data were collected in all range of rural improvement projects, and the database system, "HICOMS" (HIstorical COst data Management System) was built. In order to test the applicability of the HICOMS, standard work cost and contractor cost were compared. The results by HICOMS showed high significance and it was concluded that the HICOMS could be applicable for the cost estimate of the rural improvement projects. projects.

• Economic and Environmental Geology
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• v.16 no.4
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• pp.257-268
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• 1983

The Cretaceous sandstone and felsite distributed in north-western border part of Taegu city were studied in the viewpoint of engineering geology with an emphasis of their discontinuities. The probability of continuity of sandstone is 0.69 and that of felsite is 0.56. The correlation coefficients of sandstone are 0.52 and 0.54. Those of felsite are 0.47 and 0.48. These values reflect that the rocks have been strongly jointed. $K_0$ value of the sandstone is close to its $K_a$ value and the test suggests that the sandstone has been in active state. On the other hand, $K_0$ value of the felsite is close to its $K_p$ value, which reflects that the felsite has been in passive state, in order to maintain the stability of the sandstone. $\delta$ value should be changed to be less than 13.2.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.48-50
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• 2005

본 연구에서는 차량 충돌 시험시 결과에 관하여 측정하는 방법 중 인체 상해 기준에 따른 평가를 지원해주기 위한 시스템에 관한 것이다. 차량 충돌시험의 가장 큰 분류인 정면 충돌과 측면충돌 2가지에 대찬 내용을 기준으로 인체 모형 각 부분의 결과 값에 따른 기준과 계산 방법 및 법규 규정을 제시하여 준다. 이러한 시스템은 인체 모형의 구성과 차량 충돌 시험시 중요시하는 인체 부분에 대한 이해를 돕는다 실제 인간의 대신한 인체 모형의 이해는 실제 인간이 승차하고 있는 차량의 안전도의 이해를 돕는다. 본 연구에서는 차량 충돌 시험 평가와 인체 상해 기준에 대해 차량충돌 안전부문 관련자들에게 온라인으로 이용할 수 있는 정보지원시스템에 대하여 기술하였다.