• Journal of Welding and Joining
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• v.17 no.2
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• pp.25-28
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• 1999

국내에 건설되어 거의 20∼30년 가동되고 있는 발전설비, 석유화학 플랜트 등 거대설비 기기의 건전성(integrity) 및 신뢰성 확보와 잔존수명 예측을 위해서는 구조물 내부 또는 표층부에 존재하는 결 함의 특성을 아는 것과 함께 그 재료의 특정 부위에 어느정도의 응력이나 변형이 있는가를 아는 것이 매우 중요하다. 일반적으로 강 용접부의 비파괴적 결함검출에는 주로 SV파(vertically shear wave)와 SH파(horizontally shear wave)라 불리는 횡파를 이용한 초음파사각탐상법이 실용화되어 이용되고 있다. 그러나 비파괴적인 방법에 의한 실험적인 잔류응력 측정, 변형해석법에는 전기 저항 및 자기 스트레인 게이지법, X선회절법, 광탄성법(photoelasticity), 모아레(Mohr's)법, 레이저스펙클(Laser speackle)법, 응 력도료법, Barkhausen Nosise법, Caustics법 등이 제시되어 있으나 그 유용성 면에서는 아직 해결되야할 문제가 많이 남아 있는 실정이다. 응력이나 변형을 해석하는 방법으로 이론적 방법, 계산적 방법 실험적 방법이 잇다. 이론적 방법에는 재료 역학적으로 취급하는 방법, 탄성론 등이 있고, 계산적인 방법에는 유한요소법이 있지만, 이론적 방법이나 계산적 방법만으로는 해석이 불가능한 경우가 많기 때문에 실험 적 방법이 필요하게 된다. 이 글에서는 파괴 시험 또는 다른 비파괴평가기술에 비해 간편한 측정, 높은 측정정도, 시험결과 도출의 신속성, 검사비용의 절감 등 많은 장점을 가지고 있고 실험적으로 유용성이 일부 검증되고 있는 음탄성법(Acoustoelasticity)에 의한 잔류응력 측정법에 관해 소개하고자 한다.TEX> mg/L(평균 49 mg/L)로 비교적 안정적인 처리효율을 보여주었다. 본 연구결과 HVC 공정은 화학약품 사용량의 절감 및 이에 따른 화학슬러지 발생량의 감소를 기대 할 수 있는 친환경기술로 유지관리비를 최소화할 수 있는 장점이 있었다. 않은 사람들 중 미래의 검진실행의지에 건강소식지가 영향을 미친 경우는 48.7%였다. 보건교육을 받은 후 유방암 자가검진 실천율은 사업군에서 53.9%로 받기 전의 27.3%보다 증가하였으나 대조군의 경우는 별 차이가 없었다. 연령별로는 60대가 가장 높았고 사업군에서 검진율의 증가분은 30대가 가장 컸다. 교육수준별로는 사업군은 고졸이, 대조군은 전문대졸이 가장 높았고 사업군에서 검진율의 증가분은 고졸에서 가장 컸다. 보건교육 후 유방암과 관련된 건강지식의 정도는 사업군이 3.7점으로 대조군보다 유의하게 높았으며, 유방암 자가검진법을 실천하는 사람들의 동기는 ‘일반 대중매체의 영향’이 가장 많았으며 건강소식지가 동기인 경우도 20.4%였다. 사업군에서 건강소식지가 유방암 자가검진법 실천에 영향을 미친 경우가 79.6%였으며 유방암 자가검진법에 관한 보건교육을 받고 실천하지 않은 사람들 중 미래의 실천의지에 건강소식지가 영향을 미친 경우는 43.6%였다. 이상의 소견에서 지역주민을 대상으로 인쇄매체를 통한 보건교육은 인쇄물만으로도 쉽게 실천 할 수 있는 유방암 자가검진법이 가장 효과적이었으며, 자궁암검진에 관해서도 검진을 받을 수 있도록 지역사회의 보건의료의 하부구조를 정비하여 제도적 장치를 마련하고 정보를 제공한다면 자궁암검진 실천율도 증가할 것이다.고 12.9% 의 발달율을 보여 유의적인 차이를 보이지 않았다. 이상의 결과로 보아 핵이식 수정란을 효율적으로 생산하기 위하여

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.460-468
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• 2021

This study investigated the enhanced combustion efficiency of an "air-cooled combustion system" with single F.D. fan, and performed a numerical analysis for the operation and design conditions to increase the combustion efficiency. The combustion efficiency in an actual combustor was compared before and after the structure modification. Numerical analysis for application of a single fan revealed the difficulty of forming a turbulence for circular combustion conditions. This is because the supply ratio of combustion air supplied into 2 flow paths becomes irregular in the combustion furnace due to a change in friction force and pressure in each flow path. Subsequently, two methods of supplying air into the combustion furnace were analyzed numerically to obtain the optimal combustion conditions of an air-cooled combustion system. The first method involved injecting the preheated combustion air after a 180~360 degree rotation from the outer wall, whereas in the second method, the combustion air was injected into the combustion furnace in a tangential direction after primary heat exchange outside the combustion furnace, by applying a rotatable vane structure in the combustion furnace. Results reveal that application of a single F.D. fan to the air injection into a rotatable combustion furnace is desirable for optimization of the combustion conditions for applying a duct structure having a dual cooling wall for the cooling of the outer wall of the combustion furnace, and for maintaining perfect mixing in the combustion furnace. We therefore confirmed enhanced combustion efficiency by comparing the actual combustion efficiency before and after structure modification.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.101-113
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• 2022

This study is planned with the aim of developing a systematic construction process based on the scientific and engineering theory of the water-sealing grouting construction applied to the tunnel excavation process during the construction of the downtown underground traffic network, so that the construction quality of the relatively backward domestic tunnel water-sealing grouting construction is improved and continuously maintained no matter who constructs it. The main contents of the improved tunnel water-sealing grouting can be largely examined in the classification of tunnel water-sealing grouting application and the definition of grouting materials, the correlation analysis of groundwater pressure conditions with groundwater inflow, the study of the characteristic factors of bedrock, and the element technologies and injection management techniques required for grouting construction. Looking at the trends in global research, research in the field of theoretical-based science and engineering grouting is actively progressing in Nordic countries (Sweden, Finland, Norway, etc.), Japan, Germany, and the United States. Therefore, in this study, the algorithm is established through theoretical analysis of the elements of tunnel water-sealing grouting construction techniques to provide an integrated solution including a construction process that can effectively construct tunnel water-sealing grouting construction.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.817-838
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• 2005

In this paper, the resource adequacy as well as the optimum fuel mix is obtained by the following procedures. First, the regulation body, the government agency, determine the reliability index as well as the optimum portfolio of the fuel mix during the planning horizon. Here, the resources with the characteristics of public goods such as demand-side management, renewable resources are assigned in advance. Also, the optimum portfolio is determined by reflecting the economics, environmental characteristics, public acceptance, regional supply and demand, etc. Second, the government announces the required amount of each fuel-type new resources during the planning horizon and the market participants bid to the government based on their own estimated fixed cost. Here, the government announces the winners of the each auction by plant type and the guaranteed fixed cost is determined by the marginal auction price by plant type. Third, the energy market is run and the surplus of each plant except their cost (guaranteed fixed cost and operating cost) is withdrew by the regulatory body. Here, to induce the generators to reduce their operating cost some incentives for each generator is given based on their performance. The performance is determined by the mechanism of the performance-based regulation (PBR). Here the free-riding performance should be subtracted to guarantee the transparent competition. Although the suggested mechanism looks like very regulated one, it provides two mechanism of the competition. That is, one is in the resource construction auction and the other is in the energy spot market. Also the advantages of the proposed method are it guarantee the proper resource adequacy as well as the desired fuel mix. However, this mechanism should be sustained during the transient period of the deregulation only. Therefore, generation resource planning procedure and market mechanisms are suggested to minimize possible stranded costs.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.1
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• pp.13-28
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• 2023

This study examines the process of project promotion in Busan, which introduced the private participation-type consultative body for the first time in the country in the promotion stage of the private-initiated park development project, and introduced flexible application of the system and differentiated policy elements in the implementation process, and examines the operational characteristics and we tried to analyze performance, etc. As a result of the analysis, first, the preferred bidder was selected by introducing a mixed method in the project method, which is an independent project method that cannot be seen in other local governments. Second, by specifying guidelines considering the characteristics of each park and detailed guidelines such as the location, area, and maximum height of non-park facilities, criteria for establishing a rational development plan utilizing regional identity and the basis of evaluation standards were laid. Third, in the project process, transparency was secured through the delegation-type roundtable, in which the private sector performs the functions and roles of key actors, thereby preventing disputes such as suspicion of preferential treatment. Fourth, in order to improve the quality of park facilities to be donated and to secure design adequacy, after approval of the implementation plan, a general planner was introduced and construction project management (design stage) services were performed to promote efficient implementation and specialization of luxury parks in the region. As a result, the city of Busan carried out the project efficiently by conserving 5 parks from sunset, a park area of 2.25km², and reducing land compensation and park construction costs by KRW 740 billion. Reinforcement of the public nature of the private-initiated park development project was suggested. However, due to the application of these systems and verification procedures, the project period is prolonged, and park services are delayed along with the financial burden on private operators.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.1
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• pp.9-43
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• 2005

The Korean government established her first "National Space Program" in 1996, and revised it in 2000 and 2005. As embedded in the National Space Program, Korea aims to become one of the world's top countries in space technology by 2010. All of 13 satellites are planned to be put into orbit as schematized, which include 7 multi-purpose satellites, 4 science satellites and 2 geostationary orbit satellites. The Space Center in Korea is to be built at Woinara-Do, Bongrae-Myon, Koheung-Goon, Junlanam Province on the southern coast of the Korean peninsular. The first phase of the construction of the space center will be finished by 2007 for launch of KSLV-l. This will make Korea be the 13th advanced country in space development having a launching site in the world. The "Space Center" will serve as the infrastructure for the development of space technology and related technology, and plan to launch a low earth orbit satellite in 2007. A second science satellite made in Korea will be launched from the space center by 2007. From 2010, the center will be operated on a commercial basis operating launch facilities for low-to mid-altitude orbit satellites. Since the 'Aircraft Industry Promotion Act' was replaced by the 'Aerospace Industry Development Promotion Acf of 1987, this Act had been amended seven times from 1991 year to 2004. Most of developed countries has been enacted the space law including the public or private items such as an (1)DSA, (2)Russia, (3)the United Kingdom, (4)Germany, (5)France, (6)Canada, (7)Japan, (8)Sweden, (9)Australia, (10)Brazil, (11)Norway, (12)South Africa, (13)Argentina, (14)Chile, (15)Ukrainian etc. As the new Space Exploration Promotion Act was passed by the resolution of the Korean Congress on May 3, 2005, so the Korean government has made the public proclamation the abovementioned Act on May 31, this year. This Act takes effect on December 1, 2005 after elapsing six months from the date of promulgation. The main contents of Space Exploration Promotion Act of 2005 is as the following (1)establishing a basic plan for promoting space exploration, (2)establishment and function of national space committee, (3)procedure and management of domestic and international registration of space objects, (4)licensing of launch by space launch vehicles, (5)lability for damages caused by space accidents and liability insurance, (6) organizing and composition of the space accident investigation committee, (7)Support of non-governmental space exploration project, (8)Requesting Support and Cooperation of Space Exploration, (9)Rescue of Astronauts and Restitution of Space Objects, etc.. In oder to carry out successfully the medium and long basic plan for promoting space exploration and to develope space industry in Korea, I think that it is necessary for us to enlarge and to reorganize the function and manpower of the Space Technology Development Division of the Ministry of Science & Technology and the Korea Aerospace Research Institute. Korea has been carrying out its space program step by step according to the National Space Program. Korea also will continually strengthen the exchange and cooperation with all the countries in the world under the principle of equality, friendship relations and mutual benefits. Together with all other peoples around the globe, Korea will make due contribution towards the peaceful utilization of space resources and promotion of human progress and prosperity.