• 한국가스학회지
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• 제17권6호
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• pp.52-57
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• 2013

본 연구에서는 안전모 쉘 구조물의 정상부에 돌출부를 설치한 경우와 설치하지 않은 경우에 대해, 안전모의 두께와 하중면적을 변수로 변형률 에너지 밀도, 응력, 변위거동을 유한요소법으로 해석하였다. 변형률 에너지 밀도는 안전모로 전달되는 충격에너지 전달을 흡수하는 성능을 나타내는 변수로 안전모의 안전성을 고찰하는 중요한 요소 중의 하나이다. 유한요소 해석 결과에 의하면, 4,540N의 충격력이 안전모의 정상부 표면에 가해질 때 충격하중을 받는 하중면적이 증가할수록 최대응력은 선형적으로 줄어든다. 그러나, 최대 변형률 에너지 밀도는 하중면적이 증가할수록 커지는 것으로 나타났다. 변형률 에너지 밀도가 줄어들면, 안전모 착용자의 머리와 목 부분으로 전달되는 충격력은 줄어드는 것으로 나타났으며, 이것은 안전모의 충격에너지 흡수 안전성을 약화시키는 요인이 될 수 있다. 따라서, 안전모의 안전한 설계를 위해서는 정상부에 돌출 구조물을 설치하는 것이 좋지만, 이러한 수정 안전모는 충격에너지 흡수성능 측면에서는 불리함을 알 수 있다.

• 환경영향평가
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• 제7권1호
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• pp.49-61
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• 1998

Zoning areas within national parks in Korea are classified into Natural Preservation Zone(NPZ). Natural Environment Zone(NEZ), Settlement Zone(SZ) and Mass Facility Zone(MFZ) based on the Natural Park Act Large-scale development which might cause permanent destruction of natural resources are being done in NEZ which covers 90% of the total natural park area. Thus it is necessary to examine National Park Act which refers the authorized criteria and development activities of NEZ. However, the current environmental impact statement(EIS) does not cover the full impact of the development inside the national park area. Based on these concepts, the study examines the appropriate resources to distinguish the NPZ and NEZ in Mt. Teogyu National Park, then compare the distribution of resource characteristics between two area by using GIS. Through this study, the conclusions are as follows; (1) In terms of scenic resource analysis, the current NPZ does not meet the criteria on the National Park Act Rather, most of the resources which should be located within the NPZ are located within the NEZ. (2) In terms of elevation analysis, Mt. Teogyu National Park, most of NPZ are located on high altitude which is more than l,200m above the mean sea level. Therefore, it shows the elevation is the only criteria for distinguishing NPZ and NEZ. (3) In terms of Degree of Green Naturality(DGN), the second forest areas, the eighth grade of DGN in Mt. Teogyu National Park are distributed much more in the NEZ than NPZ. (4) After examining five factors - scenic resources, elevation, slope and DGN, vegetation- it was found out that zoning of Mt. Teogyu National Park is not adequatly designated. Zoning of national parks should be accomplished based on the precise inventory of the current resources.

• 한국습지학회지
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• 제21권4호
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• pp.290-297
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• 2019

하구는 하천이 개방해역과 연결되어 있어 담수와 염수가 만나는 전이지대로 생물다양성이 매우 높고 독특한 생태계를 구성하고 있다. 그러나 하구의 생태적 가치를 인식하기 전부터 다양한 훼손 및 교란이 이루어져 왔으며, 이를 위한 대책이 필요한 실정이다. 하구를 구성하는 하천의 하천기본계획은 지속적인 교란요소로 작용하고 있으나, 수재해로부터 인명피해를 최소화하고 하천의 기능을 강화시켜 국가 수자원을 관리하기 위한 공익적 목적이 있다. 따라서 개발과 생태계 보호라는 대립적 관계가 공존할 수 있는 방안에 대한 연구가 필요하다. 본 연구에서는 이를 위해서 환경창이라는 개념을 이용해 하구 생태계가 개발의 부정적인 영향으로부터 교란이 최소화되는 기간인 저영향 개발 기간을 산정하였다. 본 연구에서 제시한 저영향 개발 기간 산정방법은 향후 이루어질 개발사업이나 교란·훼손 행위 등으로부터 생태계를 보호하기 위한 근거 및 기초자료로 활용될 수 있을 것으로 판단된다.

• 환경영향평가
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• 제3권1호
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• pp.9-30
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• 1994

Environmental Impact Assessment System, ever since its enactment in Korea fourteen years ago, has been steadily improved by introduction and implementation of new concepts and methodologies which include Environmental Impact Statement(EIS) preparation technique, selection of environmental factors, and the like. However, current guideline requires that every EIS, regardless of the specifics of the project type or characteristics of the site, must evaluate and study for all twenty-two environmental factors as set forth in the regulation. The situation causes many undesirable problems like; lack of site specific evaluation in most EISs, over-sized EIS drafts, consuming too much time and costs for EIS preparation, and so on. The objectives of this study are: - To establish a set of criteria to classify the types of the projects in terms of features of the project content and the characteristics of the site area. - To establish a guideline for selecting major environmental factors of the project type criteria, and - To provide basic materials for the preparation of complets draft EIS of the Amendment of Environmental Impact Assessment Act.

• 한국정밀공학회지
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• 제22권2호
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• pp.164-171
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• 2005

This study aims to examine an effect of stacking sequence and curvature on the penetration characteristic of a composite laminated shell. For the purpose, we manufactured specimens with different stacking sequences and curvatures, and conducted a penetration test using an air-gun. To examine an influence according to stacking sequence, as flat plate and curvature specimen had more plies, their critical penetration energy was higher, Critical penetration energies of specimen A and C with less interfaces somewhat higher than those of B and D with more interfaces. The reason that with less interfaces, critical penetration energy was higher is pre-impact bending stiffness of composite laminated shell with less interfaces was lower than that of laminated shell with more interfaces, but bending stiffness after impact was higher. And it is because interface, the weakest part of the composite laminated shell, was influenced by transverse impact. As curvature increases, critical penetration energy increases linearly. It is because as curvature increases, resistance to in-plane deformation as well as bending deformation increases, which need higher critical penetration energy. Patterns of cracks caused by penetration of composite laminated shells include interlaminar crack, intralaminar crack, and laminar fracture. A 0$^{\circ}$ply laminar had a matrix crack, a 90$^{\circ}$ply laminar had intralaminar crack and laminar fracture, and interface between 0$^{\circ}$and 90$^{\circ}$laminar had a interlaminar crack. We examined crack length and delamination area through a penetration test. For the specimen A and C with 2 interface, the longest circumferential direction crack length and largest delamination area were observed on the first interface from the impact point. For the specimen B and D with 4 interface, the longest crack length and largest delamination area were observed on the third interface from the impact point.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.431-442
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• 2021

The purpose of this study is to identify the effect of seasonality on the tourism and hospitality industry in ArugamBay after the civil unrest across the different firms in tourism. This study uses both quantitative and qualitative analyses using primary data. Fifty questionnaires give valid responses that were used for analysis. Out of 80 questionnaires, the average response rate was 62.5%. An exploratory study, descriptive analysis, and an Independent Sample Test were used to identify the potentials of tourism, the overall impact of seasonality, and the impact of seasonality across different travel and tourism sector of the study area. According to the results, 83%, 75%, 68%, and 59.9% of firms agreed on the impact of seasonality on environment, workers, supply, and quality of services, respectively in ArugamBay. It also concluded that the impact of seasonality on workers, supply, and quality of services is not the same among all the categories of firms except environment. The variation in seasonality in the travel and tourism sector is because of the lack of regional planning considering the types of firms in the tourism sector. Also, insufficient resources and lack of consistent capacity between various firms in the sectors are also course variations because of the effect of seasonality.

• 환경영향평가
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• 제21권6호
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• pp.941-949
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• 2012

The various plants including power plants have been increased near downtown in accordance with the policy objective of rising the power feed rate and development projects. As a result of these various plants near residential area, noise damage complaints has been raised very often. The power plant is included with the range of environmental impact assessment project. Nevertheless, environmental noise issues regarding construction of these power plants have arisen. Accordingly it is time to consider the environmental and social issues of plants noise in accordance with the government's policy objectives of increased power production. In this study, we reviewed the current noise impact assessment and we also sought solutions to these issues. In order to minimize the problem of noise impact on neighborhood and residents, we intended to propose alternative method of 3D simulation in dealing with these issues.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.382-399
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• 2011

Impact factor of concrete and ballast track which has been used in Korea railway was applied to equation (1+0.513V/100) from AREA. As the use of this equation, overcapacity of track design might be occurred. Therefore, this study compared impact of ballast track (well, bad) and concrete track (sleeper embeded system, rail floating and sleeper floating) by field test to analyzing dynamic effect of track structure's characteristic and wheel load on service line. In addition, it suggested a method to generate reasonable track impact factor on each track type.

• 대한기계학회논문집
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• 제18권3호
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• pp.573-583
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• 1994

In this study, the shock characteristics for high velocity impact phenomena during the initial shock state by the long rod penetrator are calculated. From these results we re-analyze the one-dimensional hydrodynamic penetration theory by introducing the effective area ratio calculated from the mushroomed strain which is dependent on impact velocity. Calculated penetration depth and mushroomed strain show good agreement with high velocity impact experimental data. In addition we visualize the shock wave propagation in a transparent acryle block.

• 환경영향평가
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• 제20권1호
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• pp.79-87
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• 2011

In this study, we investigated the effect of carbon sequestration and sink on the environmental impact assessment of a housing redevelopment project. Through the case study, we found that the amount of carbon sequestration and sink increased with the increase of the area of park and green space and, furthermore, the amount of carbon emission decreased slightly with implementation of district heating and renewable energy. Therefore, it is necessary for its land use plan to be established to minimize the amount of net carbon emission, taking account of both the amount of present carbon emission and the amount of the future carbon sink, sequestration, and emission.