• 한국경제지리학회지
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• 제13권3호
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• pp.487-497
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• 2010

본 연구의 목적은 도시의 소득 및 지출함수를 이용하여 우리나라 7대 광역시의 인구규모가 적정 수준에 있는 지를 분석하는 것이다. 효용극대화 가계와 이윤극대화 생산자 문제의 균형인구를 완전경쟁조건으로부터 도출한 결과, 최적인구 규모는 도시의 기술수준 및 공공서비스 수준에 의해 결정된다. 이러한 측면에서 각 도시의 인구규모 수준을 살펴보면 서울, 부산, 대구, 인천 등은 과밀한 것으로 광주, 대전, 울산 등은 과소한 것으로 나타났다.

• 신재생에너지
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• 제19권3호
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• pp.1-12
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• 2023

This study aims to evaluate the optimal size of the hydrogen facility to be installed in a zero-energy district in terms of load matching and facility efficiency. A mismatch between energy generation and consumption is a common occurrence in zero-energy districts. This mismatch adversely effects the energy grid. However, using an energy carrier such as hydrogen can solve this problem. To determine the optimal size of hydrogen fuel cells to be used on-site, simulation of hydrogen installation is required at both district-and building- levels. Each case had four operating schedules. Therefore, we evaluated eight scenarios in terms of load matching, heat loss, and facility operational efficiency. The results indicate that district-level installation of hydrogen facilities enables more efficient energy use. Additionally, based on the proposed model, we can calculate the optimal size of the hydrogen facility.

• 교통기술과정책
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• 제9권1호
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• pp.23-33
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• 2012

• 한국환경복원기술학회지
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• 제18권3호
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• pp.39-50
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• 2015

This research selected Daegu Metropolitan City representing a combination of natural space and urban space for this case study. To achieve this, a prerequisite was to set up an optimal block size to evaluate landscape diversity of the research site by using a RPR-Area Curve. Further, landscape diversity evaluation was conducted based on land cover map by using FRAGSTATS to analyze spatio-temporal changes. Notably, this research regarded it as the most significant to set forth criteria in order to apply landscape diversity to the development plans of the newtown and outskirt of a city under high pressure development. Results derived from this research are summarized as follows. According to the results derived from establishing the optimal block size, a size about $2km^2$ was analyzed to measure landscape diversity of the research site. Also, according to the results derived from land diversity evaluation based on land cover map, land diversity was highly measured around urban stream such as Nakdong River and Geumho River, and in particular, the value of landscape diversity was measured considerably high around the urban parks. Results derived from analysis on spatio-temporal changes of land diversity demonstrated that a certain level of urban development exerted a positive effect on an increase in land diversity, but consistent urban development lowered a value of landscape diversity. Results derived from regression analysis to set forth the optimal urban space showed that an urban area of a space about $2km^2$ exerted a positive effect at a rate of about 0~43.3% and a negative effect at a rate about 43.3~100%. In conclusion, the results of this research are considered to provide important basic data for future urban and landscape planning. Nonetheless, as only the layout on the 2D plane was analyzed in this research, further research in future is required to complexly consider diverse factors such as height of structure and change in visible real area arising from geographical features.

• 도시과학
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• 제6권2호
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• pp.35-47
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• 2017

Tax evasion is increasing, but efficiency of tax administration is evaluated as improving. This is because the taxation cost, which is a measure to judge the efficiency of the tax administration, does not consider the tax evasion effect at all. This method of estimating the cost of taxation is a dispute that neglects the role of taxation authorities in tax evasion. The existing study focuses on the development of a tax evasion model focused on maximizing the utility through the tax evasion of the taxpayer as the tax evasion approaches the individual 's deviant problem. However, this has the aspect of making the role of the tax authorities in tax evasion negative. This study empirically derived the optimal size of tax administration in Korea by using tax collection cost and tax cooperation cost. Also, it is meaningful to consider the role of the taxation authorities in tax evasion and to derive the optimal taxation cost model by estimating the decrease in tax evasion due to the taxation expenditure of the tax authorities. In order to derive the optimal size of tax administration in Korea, taxation cost and tax cooperation cost are derived by classifying tax officials. The optimal taxation cost model was derived by estimating the taxation expenditure related to tax evasion. This study is meaningful to make it possible to emphasize the role of tax authorities in studying future tax evasion by studying the effect of taxation expenditure on tax evasion.

• 지역연구
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• 제31권1호
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• pp.21-42
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• 2015

본 연구는 도시규모 확장에 따른 최적인구규모를 추정하고 지역간 통행량 분포를 통해 도시규모의 변화를 1기 신도시 건설의 사례를 통해 검증하고자 한다. 이를 위해 수도권 지역의 소득 및 지출함수, 그리고 적정인구수준의 분석과 거리별 통행량 증감에 따른 도시규모 확장과 지역경제 활성화의 가능 여부를 계측하였다. 연구 결과로서 도시규모 확장과 지역경제 활성화는 기종점에 관계없이 통행목적의 기점과 통행량은 반비례 관계에 있음을 추정할 수 있다. 약 20~40km 지점을 전후로 한 지역을 중심으로 통행량이 증가하는 경향이 있는 것으로 도출되었다. 따라서 이 구역을 중심으로 신도시를 건설하는 것이 지리적, 기능적으로 효과적이라고 평가할 수 있다.

• 한국전자통신학회논문지
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• 제9권10호
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• pp.1153-1159
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• 2014

본 논문은 항만 개발에서 일부분의 주민참여가 아닌 대부분의 주민들이 참여가 가능한 ICT(Information Communication Technology)과 소셜 네트워크 기술을 적용하여 동해시의 묵호항 재개발 사업 친수 시설 규모 산정방안에 대한 새로운 방법을 제시한다. 이를 위해 항만 재개발 과정에서 효과적인 주민참여를 위한 방법으로 기존의 단순한 설문조사 방식과 더불어 다양한 SNS(Social Network System)을 적용하여 주민들의 의견 최대화한 도시 마케팅 방안을 분석한다. 또한 이를 위해서 주민 참여에 대한 비율을 최적 선정을 수행하고 최적 건설비 산정과 도시 마케팅 방안을 제시한다.

• 한국분말재료학회지
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• 제30권5호
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• pp.436-441
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• 2023

Molybdenum-tungsten (Mo-W) alloy sputtering targets are widely utilized in fields like electronics, nanotechnology, sensors, and as gate electrodes for TFT-LCDs, owing to their superior properties such as high-temperature stability, low thermal expansion coefficient, electrical conductivity, and corrosion resistance. To achieve optimal performance in application, these targets' purity, relative density, and grain size of these targets must becarefully controlled. We utilized nanopowders, prepared via the Pechini method, to obtain uniform and fine powders, then carried out spark plasma sintering (SPS) to densify these powders. Our studies revealed that the sintered compacts made from these nanopowders exhibited outstanding features, such as a high relative density of more than 99%, consistent grain size of 3.43 ㎛, and shape, absence of preferred orientation.

• 기술사
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• 제43권6호
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• pp.31-34
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• 2010

Recently, due to localized heavy rain and flash floods in urban areas is becoming more frequent flood damage. To prevent flood inundation damage, to formulate the diverse directions in connection with the drainage system of buildings, roads, sewerage, pump stations, detention (retention) pond, and streams is very important. In addition, it is important for the uniform design criteria, the consistent of hydrologic and hydraulic analysis method, and a flood disaster mitigation systems connected with structural and nonstructural measures. To accomplish this, the method such as installation of storage facilities, infiltration facilities, and underground water tank, the optimal size of the design gutter and grate of the road, ensure the capacity of pumping stations, and the installation of a flood control channel into the deep underground requires comprehensive measures dimension in urban areas.

• 한국환경보건학회지
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• 제30권3호
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• pp.253-258
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• 2004

Synthetic organic polyelectrolytes can be used to condition sludges to enhance their dewaterability. Intermittent aerobic digestion is an useful digestion technology and has many advantages like neutral pH, low installation cost and easiness to operation. The objectives of this study were to investigate the dewaterability of intemittent aerobic digestion sludge and to find the relationship between dewaterability and particle size distribution change under the conditioning of intermittent aerobic digestion sludge by cationic polyelectrolyte. Digested sludge from intermittent aerobic digestion was used and cationic polyacrylamide polymer was added as a conditioner. CST(capillary suction time), TTF(time-to-filtration) were tested as a dewaterability index and the number of particle distribution was analyzed using particle size analyzer. The results indicate that cationic polyelectrolytes is useful to enhance dewaterability of intermittent aerobic digestion sludge. Mean particle diameter was increased as polymer dosage increased and its value was reached up to 100 mm on the condition of optimal cationic polymer dosage. CST and TTF are well correlated with mean particle diameter when the weighting order is 1.7. By the optimal conditioning with cationic polymer, particles in the filtrate are also reduced significantly and this means that conditioning is helpful to main stream by reducing SS loading from return flow.