• 한국조경학회지
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• 제31권5호
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• pp.20-30
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• 2003

This study is aimed at establishing the categories and items for ecological assessment and evaluation of the environmental friendliness of golf courses in the capital region of Korea. The categories and items for the assessment have been derived based on the existing literature and interviews with golf experts. This study covers 32 golf courses in the capital region of Korea that are available in terms of data and on-site surveys. In order to conduct a comprehensive assessment of the environmental friendliness of the golf courses, the assessment area was divided into 4 categories that include a total of 14 sub-categories. The 4 categories encompass 1) location, 2) topography, 3) vegetation, and 4) construction. As its sub-categories, the location category includes current land use and zoning in the National Land Use Management Law. Topography has 2 sub-categories in the damage ratio of existing topography, gradient, cut area, and slope height. The assessment of vegetation is largely based on site surveys in the categories of preservation of the existing vegetation, the use of natural resources and existing trees, the component ratio of native tree species, the multi-layered structure of vegetation, and the utilization of water purification plants. In the aspect of construction, afforestation on tile slopes and the utilization of existing surface soil were evaluated. The examination of comparative analysis among the 10 items as a ratio measure showed that the scores were low in the sub-categories of current land we, the use of existing trees, and the multi-layered structure of vegetation. However, the rating results were satisfactory in the 2 sub-categories including cut area, and the utilization of native tree species. Those proved to be contributing factors in the ecological health of the golf courses. According to correlation analysis of the 10 items to the overall ecological rating of each golf course, the sizes of the 32 golf courses were mainly affected by the damage ratio of existing topography, gradient, preservation of vegetation and slope height. This study has the initiative to conduct an ecological assessment of golf courses in the country based on site surveys. The study results revealed that location factors such as current land use, damage ratio of topography and gradient and topographical factors were the main factors affecting the environmental friendliness of golf courses. This indicates indicating the significance of these factors in the future construction practices of golf courses. Furthermore, this study raises the need for follow-up studies to establish more detailed assessment criteria and to develop assessment techniques for areas such as slope afforestation and water purification plants that need a qualitative approach.

• 한국구조물진단유지관리공학회 논문집
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• 제19권1호
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• pp.100-108
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• 2015

본 연구의 목적은 아라미드섬유의 표면개질에 의한 시멘트 복합재료의 강도특성 및 내충격성능의 향상효과를 평가하는 것이다. 단섬유 형태의 아라미드섬유를 섬유길이와 섬유의 표면유제처리율을 달리하여 시멘트 복합재료에 혼입하였다. 아라미드섬유보강 시멘트 복합재료의 강도특성은 섬유의 혼입율, 섬유의 표면유제처리율, 섬유의 길이에 따라 다르게 나타났으며, 특히, 동일한 섬유혼입율 및 섬유길이에 대한 인장강도 및 휨강도는 섬유의 표면유제처리율을 증가시킨 시험체가 향상되는 경향을 확인하였다. 이러한 정적 강도특성 결과는 고속비상체의 충돌에 의한 내충격성능에도 영향을 미쳤으며, 아라미드섬유의 표면유제처리율이 증가함에 따라 배면박리가 억제되는 것을 알 수 있었다. 하지만, 아라미드섬유를 섬유보강 시멘트 복합재료용 보강재로 활용하기 위해서는 섬유와 시멘트 복합재료간의 분산능력 및 부착효율을 향상시켜야 할 것으로 판단된다. 이는 아라미드섬유의 표면특성을 소수성으로 개질하는 것에 의해 가능할 것으로 사료되며, 1.2 %이상의 표면유제처리율 및 성능개선에 대해서는 추가적인 검토가 필요할 것으로 판단된다. 또한, 아라미드섬유와 후크형 강섬유를 하이브리드 한 시험체의 경우, 강도특성 및 내충격성능의 향상효과는 강섬유의 기여도가 높은 것으로 나타났다.

• 한국산학기술학회논문지
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• 제17권10호
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• pp.520-526
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• 2016

본 연구는 서울지역 특1급 호텔을 대상으로 2015년도 재무비율을 변수로 활용하여 표준재무비율을 산출하며, 다변량 판별분석에 의한 부실예측모형 개발 및 부실예측력 평가에 목적이 있다. 서울소재 19개 특1급 호텔의 14개 재무비율을 분석대상으로 선정하여 실증분석을 실시하였으며 분석결과는 다음과 같다. 첫째, 분석결과 우수기업과 부실기업을 판별하는 7개 재무비율은 유동비율, 차입금의존도, 영업이익대비 이자보상비율, 매출액영업이익율, 자기자본순이익율, 영업현금흐름비율, 총자산회전율로 나타났다. 둘째, 7개 재무비율을 활용하여 우수기업과 부실기업을 판별하는 판별함수를 다변량판별분석에 의해 추정하였으며, 추정된 판별함수를 실제 소속집단과 예측집단으로 분류가 가능한가의 예측력 검정 결과, 예측 판별력의 정확도는 87.9%로 분석되었다. 셋째, 추정된 판별함수의 예측 판별력의 정확도 검증결과 판별분석에 의한 부실예측모형의 예측력은 78.95%로 분석되었다. 이러한 분석결과, 호텔 경영진은 호텔기업의 부실기업집단을 판별하는 7개 재무비율을 중점적으로 관리해야 함을 시사하고 있다. 또한 호텔기업이 타 산업과는 뚜렷한 재무구조의 차이와 부실예측 지표가 상이하며, 이에 호텔기업 대상의 신용평가시스템 구축 시 호텔기업의 재무적 특성을 반영한 시스템 구축이 필요함을 시사하고 있다.

• 수산해양교육연구
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• 제27권2호
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• pp.363-370
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• 2015

넙치종묘 방류가 자연집단의 성비에 어떠한 영향을 미치는지 5 개 지역에서 어획된 넙치집단에 대한 성비를 조사하였다. 조사된 지역에서 방류넙치와 자연넙치가 혼획 되어 어획된 집단의 암컷 비율의 범위는 7.9~64.6%로 나타났으며, 고흥집단에서의 수컷의 비율이 92.1%로 가장 높게 나타났다. 방류어의 암수비율을 보면 완도집단에서 56.3%와 43.7%로 암컷의 비율이 다소 높게 나타났으나 고흥집단은 8.3%와 91.7%였고, 추자집단에서 26.4%와 73.6%로 수컷의 비율이 높게 나타났다. 방류넙치의 혼획률이 높은 고흥집단과 완도집단에서는 방류 넙치의 암수비율이 자연 집단의 성비에 영향을 미치는 것으로 나타났다.

• 한국환경과학회지
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• 제24권2호
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• pp.229-236
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• 2015

In this study, the fish-migration ratios of rivers were analyzed, with the aim of proposing objective materials to help South Koreans to establish fish migration systems efficiently in the future. A total of 34,012 weirs have been built in the five major basins, with 5,081 fish-ways observed. Consequently, the fish migration ratio was considered low (14.9 %). According to the findings of the study analyzing the 5,081 fish-ways, standard-type fish-ways took up 68 % of the total while the non-standard types accounted for 32 %. The five major basins were observed to have a total fish-migration ratio of 21.4 %. Regarding tributaries, Tributary 1 accounted for 27.5 % of the fish-migration ratio, while Tributary 2 and 3 accounted for 19.8 % and 16.3 %, respectively. In conclusion, the study argues that any relevant field in the fishing industry of South Korea needs to improve their understanding of the fish-migration ratio. This would be expected, eventually, to help them maximize the efficiency of a minimum number of fish-ways. In addition, the study supports the need for those in relevant fields to study carefully the ecological needs of each fish species, before establishing priority standards for the building of fish-ways.

• 상하수도학회지
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• 제22권1호
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• pp.105-112
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• 2008

Disinfection is a basic and effective microorganism inactivation method and historically contributed a decrease in waterborne diseases. To guarantee the disinfection ability, improving T in CT value is important. Many indexes are used to estimate the hydraulic efficiency, however, these are black-box analysis. Therefore it is need to develope new estimation method. In this study, internal short-circuiting estimation method (ISEM) is developed using CFD and we inquire into the factor which causes increase of $T_{10}/T$ value as LW ratio increases. And the effect of shape on the relation of LW ratio and $T_{10}/T$ is analyzed. As LW ratio increases, internal short-circuiting index (ISI) of influent and effluent zone is rapidly reduced and recirculation and dead zone are reduced in channel zone. Therefore, as the $T_{10}/T$ value converges maximum value, ISI curve is changed from "V" shape to "U" shape and hydraulic efficiency is improved especially in downstream portion of clearwell. The less the shape ratio(width/length of clearwell) is the less the $T_{10}/T$ value is at a same LW ratio because the portion of turning zone increases as shape ration decreases, therefore more boundary separation is generated.

• 한국연소학회지
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• 제15권3호
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• pp.8-14
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• 2010

Fuel processing systems which convert fuel into rich gas (such as stream reforming, partial oxidation, autothermal reforming) need high temperature environment ($600{\sim}1,000^{\circ}$). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1~5 kW fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas, mixture of natural gas & anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural gas & anode off gas as reformer fuel in the porous ceramic burner. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity. In particular, the blue surface flame is found to be very stable at a very lean equivalence ratio at heat capacity and different fuels. The exhausted NOx and CO measurement shows that the blue surface flame represents the lowest NOx and CO emissions since it remains very stable at a lean equivalence ratio.

• 한국습지학회지
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• 제18권3호
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• pp.267-274
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• 2016

농촌 지역 하수도 보급은 하천, 호소 및 습지와 같은 수계 수질 보호를 위해서 반드시 필요하다. 또한 안정적인 소규모 하수처리장 운영을 위해서는 유입 유량과 농도의 변화가 큰 소규모 하수도 특성을 고려해야 한다. 본 연구에서는 봉화군 18개의 소규모 하수처리장 운전 결과를 통해 유입유량비 (유입 유량 / 설계 유량) 특성, 소규모 하수처리장 처리 효율에 미치는 영향과 적정 유입유량비 산정에 관한 연구를 수행하였다. 분석 결과 유입유량비는 여름철에 가장 높은 것으로 나타난 반면, 유입 하수 농도는 가을철과 겨울철에 높은 것으로 나타났다. 유입유량비가 증가할수록 처리 효율이 증가하는 경향을 보였으며, 영양염류 처리 효율이 유기물과 부유물질 처리 효율에 비해 민감한 영향을 받는 것으로 나타났다. 안정적인 소규모 하수처리장 처리 효율을 위해서는 유입유량비 0.8 이상을 유지해야 할 것으로 판단된다.

• KIEAE Journal
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• 제13권3호
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• pp.71-78
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• 2013

A need for building energy efficiency is on the issue since energy demand in the building stock in Korea represents about 24% of the final energy consumption. As a way of improving the thermal performance of buildings for reducing maintenance costs and environmental conservation, a lot of effort is shown to improve the building energy efficiency by applying improvement of envelope insulation performance for buildings whose energy efficiency is low relatively through the remodeling. The windows of building envelopes are areas that lead to the biggest heat loss in the building. So windows are considered to be the primary target of energy efficiency in remodeling and various studies for windows have been done. Currently, however, only U-factor and airtightness of windows performance are regulated. Window wall ratio(WWR) and solar heat gain coefficient(SHGC) of windows are not considered when conducting the remodeling. In this study appropriate performance of windows(U-factor and SHGC) for existing residential is proposed according to the window wall ratio by using EnergyPlus. As the results of this study, the U-factor of windows representing the maximum energy savings is $1.0W/m^2K$ but in case of SHGC, the values that indicate the maximum energy savings are different depending on the window wall ratio. Therefore, when conducting the remodeling of windows, to determine energy efficiency by considering only the U-factor is inadequate so it is necessary that appropriate windows are applied to buildings by considering window wall ratio and windows properties(U-factor and SHGC).

• Structural Engineering and Mechanics
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• 제7권5호
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• pp.473-484
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• 1999

In the present study, the thermal buckling analysis of thick anisotropic laminated composite plates is carried out using the finite strip method based on the higher-order shear deformation theory. This theory accounts for the parabolic distribution of the transverse shear strains through the thickness of the plate and for zero transverse shear stresses on the plate surfaces. Therefore, this theory yields improved results over the Mindlin plate theory and eliminates the need for shear correction factors in calculating the transverse shear stiffness. The critical temperatures of simply supported rectangular cross-ply and angle-ply composite laminates are calculated. The effects of several parameters, such as the aspect ratio, the length-to-thickness ratio, the number of plies, fibre orientation and stacking sequence, are investigated.