• 한국터널지하공간학회 논문집
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• 제19권6호
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• pp.959-972
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• 2017

발파진동 안정성 평가는 일반적으로 발파 진동추정식을 통해 최대진동속도(PPV)를 산정하고 추정된 속도 값과 법규 혹은 기준에 제시된 허용 기준 값을 비교하여 안정성 여부를 판단한다. 현장 고유의 발파 진동추정식은 시험 발파의 횟수, 대상지반의 지질학적 구조와 발파 조건에 따라 달라지기 때문에 이 식을 통해 정확한 응답 값을 예측하는 것은 한계가 있다. 또한 최대진동속도는 지반에 예상되는 응답 값으로 구조물에 대한 직접적인 평가는 불가능하다. 이와 같은 한계점으로 인해 발파 진동에 대한 구조물의 정밀한 안정성을 평가할 경우 엔지니어들은 상용화된 수치해석 프로그램을 이용한다. 하지만 폭발로 인해 발생하는 발파공 주변 암반의 복합적인 상태변화(파쇄, 분쇄, 균열, 소성변형)를 기존 수치해석 프로그램으로 정확히 모델링 하기가 쉽지 않다. 만약 이러한 일련의 과정을 모사할 경우 절점 수의 제한으로 인해 모델링이 가능한 범위가 한정적이고 긴 연산시간이 소요된다. 따라서, 본 연구에서는 폭발로 발생하는 암반의 복합적 상태변화 과정을 모사하지 않고 파쇄영역 이후 탄성에너지 전파만을 모사하는 해석 방법에 대한 연구를 수행하였으며, 이때 파쇄영역의 형상 및 크기에 따른 속도의 응답특성을 분석하였다. 그 결과 폭원 주변에서는 설정되는 파쇄영역에 따라 계산된 속도의 크기 및 감쇠에 차이를 보였다. 전파되는 진동은 폭원으로부터 멀어질수록 구형으로 확산되는 것으로 나타났다.

• 지역연구
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• 제8권1호
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• pp.31-50
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• 1992

The aim of this paper is to define major factors influencing land development of each of major uses (residential, commercial, industrial) in the process of rapid urban expansion. The main hypothesis of this study is that land use changing patterns are directed by supply side of land managed to public policies rather than demand side. The graphic analysis is applied to relationships between urban growth and land development process of each use and between land development project managed to public policies and land development process. Public and land development projects and zonning protection seem to be major roles of land supply and main determinants of urban spatial structure. Location factors for land development of each uses are selected in 23 variables. Factor analysis is applied to test correlation between variables in 1971 and 1981. Factor structure between two years is similar, but progressive processing of functional separation is derived such as intensive land use is grouped, different location between residential and industrial use is deep. Dependent variables are standardized to logarithm of land development of each use per unit vacant land in two periods, between 1971 and 1980 year and between 1981 year. Correlation analysis between 6 dependent variables and 23 location factors in each years are applied. Major factors of each use are selected in criteria such as high correlation with dependent variables, low correlation between independent variables and common application in two periods. As the result, major factors for residential land development are Land Readjustment Project (LRP), percent of total zoned area in residential zone, residential floor space density per available area, percent of total area in industrial use; for commercial development is distance to CBD, percent of total area in commercial use, residential floor space density per available area in each year, and volumn rate of industrial use; for industrial use is percent of total area of industrial use is percent of total area of industrial use, Industrial Estate Project (IES), LRP, and distance from CBD. Land development pattern of each use between two periods are slightly different. So 6 equation is derived from appling backward method of regession. Adjusted multiple R squares of all is more than 0.5 and those equation is statistically significant and valuable to assist urban land use forecasting.

• 산학경영연구
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• 제15권
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• pp.59-78
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• 2002

전자산업과 정보기술(Information Technology)산업의 발달은 산업 및 경제구조를 크게 변화시키고 전자상거래는 새로운 방법이 도래하였다. 전자상거래는 시간적 공간적 제약을 극복하고 국경을 뛰어넘는 경제활동을 수행하면서 경제 사회 패러다임에 큰 변화를 가져오고 지난 수 천년 동안 인류가 행하여 왔던 상거래방식인 중간유통단계인 상점을 매개수단으로 하는 방법에서 벗어나 기업은 소비자에게 제품을 직접 판매할 수 있고 소비자들은 자신이 원하는 상품을 자신의 집에서 선택할 수 있어 비용절감 효율성 증대 시장확대 등의 효과를 가져올 수 있다. 전자상거래의 발달로 조세분야에서도 OECD, 미국등 선진국에서는 통일된 과세원칙을 정립하기 위하여 많은 관심을 보이고 있다. 우리 나라에서도 최근 전자상거래에 따른 조세정책 및 조세행정의 문제 등 과세문제에 대한 논의가 활발하나 아직 구체적인 방안이 마련되지 않고 있다. 따라서 본 연구에서는 국내외 논의 동향을 중심으로 우리 나라 전자상거래의 조세제도에 대한 문제점에 대한 개선방안을 제시하고자 한다.

• 한국농촌건축학회논문집
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• 제12권1호
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• pp.25-32
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• 2010

The aim of this thesis is to present why the business district of old downtown in Jejusi collapsed and what sort of problems caused by that as collecting objective data, which help us to comprehend how the commercial zone has been decaying, on the physical state of the specific area near 'Sinheungro' and 'Chilsungro', which are main commercial sites in the downtown, and analysing it. Firstly It was revealed that most land investigated was property in which structure was able to built or poor land within $60m^2$. This was caused by increasing in land value and high density in space use so that the area did not develop. Secondly, In addition to be low density, most of buildings in 'Sinheungro' and 'Chilsungro' were so old and inefficient - the old buildings were abandoned without improving due to expensive rent and complicated property rights. Thirdly, According to the survey accomplished, major commercial facilities in the area have struggled with the continuous recession in their business. It was the inevitable result of not having an effective alliance with surrounding retail shops and a lack of a strategic action for satisfying consumers desire or adapting to new shopping patterns. Fourthly, Infrastructure in the site was ruining the beauty of the urban landscape as well as bringing on bad access to the inner city as not having improved enough. Furthermore, many administration departments which were in charge of each infrastructure existed. This was resulted from not considering unification between each infrastructure and regional characteristics of the local community.

• 한국재료학회지
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• 제14권1호
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• pp.1-8
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• 2004

Laser weldability of aluminized steels for deep drawing application has been investigated. Test coupons for Nd:YAG laser welding and $CO_2$ laser welding were prepared trom the commercial steels. According to the test results, total penetration and back bead width of aluminized steels were sensitive to the welding conditions. Bead width at the half thickness of the overlap joint, however, was rather constant. Laser weldability of aluminized steels was superior to that of zinc coated steel. Weld microstructure revealed that overlap zone adjacent to the fusion line was filled with coated materials, which was thought to be desirable to protect weld from crevice corrosion. The aluminum coated materials was also found in the weld metal. Practically no spattering was observed in the laser welding of aluminized steels even when the welding was performed without joint gap. In the welding of zinc coated steel, however, spattering was so severe that it was difficult to get the acceptable weld. Bead quality of aluminized steel laser weld was smooth and stable.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.191.2-191.2
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• 2010

The conventional method to assess turbine performance is its model testing which becomes costly and time consuming for several design alternatives in design optimization. Computational fluid dynamics (CFD) has become a cost effective tool for predicting detailed flow information in turbine space to enable the selection of best design. In the present paper, Francis turbine of commercial small hydropower plants which is under 70kw is investigated. Solutions are investigated with respect to the hydraulic characteristics against an outward angle of guide vane, the number of guide vane and head (inlet velocity). By suitable modification of the runner shape, low pressure zone on the leading edge can be reduced. If the entire runner is to be optimized in this manner, flow simulation tests have to be carried out on a series of different geometrical shape.

• 한국주거학회논문집
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• 제14권3호
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• pp.137-146
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• 2003

The Primary Purpose of this study is to evaluate transportation conditions (including parking space shortage problem) of the old single house district and to derive some policy implications for living environment improvement policy. For these purposes, data were collected from field survey and questionaire survey. The main findings are follows. Residents are discontent about building structure, old house, high risk of traffic accident in the housing district and parking space shortage. The living environment of the old single house district is further degraded by mix of commercial and business functions in the residential area. Based on these findings, we suggest that the introduction of resident-first parking zones, restriction of use of facilities with more detail division of use than current zoning system for improvement of living environment.

• 한국주거학회논문집
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• 제14권2호
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• pp.9-18
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• 2003

The vitality of a main street is essential to get the urbanity of the urban residential estates. The purpose of this study is to analyze the relationship between the vitality of a main street and street land uses in the residential estate. The outcomes of this study are as follows: first, the street land uses have influence on the vitality of a main street; the main streets with the small commercial and business facilities are more vitalized than those with the boundary wall of the residential building or the buffer zone. Second, the number of shops in street has positive influence on the vitality of a main street. Third, the vitality of a main street is effected by the entrance of apartment site.

• 대한교통학회지
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• 제11권2호
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• pp.27-44
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• 1993

The purpose of this study is to classify the regional structure of Pusan based on socio-economic phenomena in 1979 and 1991, and to analyze correlations between the regional structure change and traffic demend. To formalize the land-use by each zone, the Principal Component Analysis were performed by using 15 socio-sconomic variables. As a result of the analysis, five land-use factors(i.e., official, residential, commercial, manufactural, and other functions) in 1979 and four factors(i. e., residential, 3rd industrial, manufactural, and other functions) in 1991 were extracted as main regional structure components. It was proved that there is strong correlations between the regional structure change and traffic demand by using Quantification Theory II and also by testing correlation coefficient.

• 한국주조공학회지
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• 제26권3호
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• pp.129-132
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• 2006

In the present study the new method was proposed by using the real-time X-ray observation and metal die in order to evaluate fluidity and viscosity of the molten metal during pouring into the mold. The special mold for the present experiment was introduced since X-ray could not transmit thick mold wall and scatter the image of the molten metal during pouring. The present study also discussed for evaluation of viscosities by using the flow data from radioscopy images, and the viscosities of six commercial aluminum alloys were evaluated and compared.