• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.295-306
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• 2008

The Intersection is inner traffic facilities and the space where the roads are intersected and connected. And also, the Intersection is the decision-making section for drivers to select the route according to the geometric structure and operation method. However decision-making section cause to raise car accidents rate because it imposes a heavy burden on drivers. In that reason, many countries such as Europe use the Roundabouts to reduce the numbers of decision making and collision. In Korea, the kinds of method are just introduced and it is using now but there are no exact standards. Hence, this study suggests the process to evaluate and determine the types of Intersection which are based on the traffic flow (congestion) and traffic safety (accidents). Firstly, this study presents the number of accident at each Intersection which is depended on the traffic volume. Secondly, this study calculates and analysis the accident at signalized Intersection, non-signalized Intersection and Roundabout by TSIS-NETSIM program. Thirdly, this study concludes the best suitable Intersection type through the materials which are mentioned before.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.948-952
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• 2006

인구의 증가와 경제의 발전으로 인해 한정된 수자원에 대한 수요가 급증하였고 향후 고도의 복지사회 구현과 지방 자치화에 따른 각종 용수 수요에 대한 심각한 물 배분 문제가 대두되고 있다. 특히 심각하게 물 배분 문제가 야기될 때 각 수요지점별로 필요한 용수를 공급하기 위해서 단지 상류에서 하류 단으로 물을 배분한다면 수리권의 공정성 문제가 제기되며 물 관리 원칙의 결여에 따른 곤란한 상황이 발생할 수 있다. 이렇게 갈수 및 가뭄 시와 같이 물 배분 문제가 생길시 에는 우선 하천유역 전체의 가용수량을 파악한 후 각 용수 사용별로 중요성을 감안하여 용수공급 우선순위를 설정하여 전 하천 유역을 통하여 일관된 배분을 실시할 수 있는 수자원 최적화 배분 시스템을 개발 할 필요성이 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 한국수자원공사 수자원연구원과 콜로라도주립대학에서 공동 개발한 유역 네트워크 유량 모델(River Basin Network Flow Model)인 K-MODSIM을 이용하여 유역통합 실시간 일 저수지 운영 모델을 개발하였다. 개발된 유역통합 실시간 일운영 모델은 금강유역에 적용하였으며, 금강유역을 12개의 소유역으로 구분하고, 용담댐과 대청댐을 포함하며, 유역관리는 용수공급, 치수대책, 발전수력 및 하천 유지용수의 공급등의 유역내 수자원 관리 상황을 포함하였다. 이처럼 유역의 매우 자세한 세부사항을 고려함으로서 기존에 개발된 모델이 가지고 있던 단순화의 단점을 보완하고 유역의 특성을 최대한 반영하도록 하였다. 또한 유역통합 실시간 일운영 모델의 장기적인 저수지 운영 문제를 해결하기 위해 암시적 추계학적 동적계획법을 사용하여 도출된 월운영룰을 일운영모델에 적용할 수 있는 방법을 제시 하였다.기능으로 구성되어 있으며, 각 기능을 선택하면 해당 화면으로 GUI가 전환된다. 따라서 다량의 측정자료의 신뢰성을 유지하고 이를 모형의 입력자료로 활용하는 일련의 과정을 시스템화하기 때문에 자료의 이상적 유지 관리가 이루어지며 복잡한 2차원 수질해석 모형을 수월하게 운영할 수 있는 시스템으로 개발하였다.제외하면, 부자측정 방법에 의한 유량산정시 가장 큰 오차원인은 홍수시 측정된 유속측선의 위치와 홍수 전후로 측정된 횡단면상의 위치가 일치하지 않는 점과, 대부분 두 측정 구간의 평균값을 대푯값으로 사용한다는 점이다. 본 연구는 다년간의 유량 측정 및 검증 경험과 자료를 토대로 현장에서 부자를 이용하여 측정된 측정성과를 정확도 높은 유량자료로 산정하는데 있어서의 문제점을 도출하고, 이로 인해 발생하는 오차를 추정하여 그 개선방안을 제시해 보고자한다. 더불어 보다 정확한 유량 산정을 위한 기준과 범주를 제시하고자 한다.리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을

• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.685-692
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• 2016

This study aimed to develop the indicator-based approach to assess water use vulnerability in watersheds and applied to the unit watershed within the Han River watershed. Vulnerability indices were comprised of three sub-components (exposure, sensitivity, adaptive capacity) with respect to water use. The indicators were made up of 16 water use indicators. Then we estimated vulnerability indices using the Technique for Order of Preference by Similarity to Ideal Solution approach (TOPSIS). We collected environmental and socio-economic data from national statistics database, and used them for simulated results by the Soil and Water Assessment Tool (SWAT) model. For estimating the weighted values for each indicator, expert surveys for subjective weight and data-based Shannon's entropy method for objective weight were utilized. With comparing the vulnerability ranks and analyzing rank correlation between two methods, we evaluated the vulnerabilities for the Han River watershed. For water use, vulnerable watersheds showed high water use and the water leakage ratio. The indices from both weighting methods showed similar spatial distribution in general. Such results suggests that the approach to consider different weighting methods would be important for reliably assessing the water use vulnerability in watersheds.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.3-11
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• 2013

Recently according to increasement of the single family and dual-earner couples, the number of infants and young children stays on a long time to the childcare facilities. this is increasing the importance to improve the physical environment. However, the operating and maintenance costs of the national-public childcare facilities have taken effect of the unfair support issues of municipality's financial situation. Especially, because of the lack of the operating and maintenance costs of the facility and the shortage of facilities equipment maintenance repair costs, nursery operations and Maintenance items are needed to distribute appropriately. Therefore, this study is to estimate the importance to facility operations and maintenance items based on "Kindergarten and Childcare Facilities"presented at the Child Care Policy Study. we are expected to allocate appropriately of operation and maintenance cost of a limited budget. In particular, those can be considered for operation and maintenance cost about the National-Public Childcare Facilities and be determined to a safe and pleasant environment to kindergartens through the appropriate operations and maintenance support.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.1-15
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• 2020

This study explores reasonable alternatives to internet interconnection policy. Due to the development of information and communication technology, patterns of the Internet usage are changing rapidly, including increase of video streaming services. For this reason, there is a lively discussion of the Internet interconnection policy, which integrates various Internet service operators into one ecosystem. We conducted an Analytic Hierarchy Process(AHP) analysis with 16 experts in government/public, and academic sectors, and alternative selection criteria and their corresponding alternatives and detailed tasks were evaluated. According to the results, the most important alternative selection criteria was a "fair charge against foreign service operators", and the most desirable alternative was "partial revise". Moreover, the experts responded that "reassessment of the principle of the charge" is the most urgent task to improve the Internet interconnection policy.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.555-563
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• 2016

Line capacity of railways is a core criterion to decide maximum trips in accordance with traffic demand and a priority in railway investment to improve transportation capability. Particularly, because two operators will start revenue services in the HSR from mid-2016, the line capacity should be carefully calculated and controlled to avoid conflicts between the maximum number of KTXs, and the number needed to guarantee the effective competition of the operators. Meanwhile, there have been many arguments about calculating the line capacity, because this number is affected by the number of trips by train types, stopping pattern and dwell time in each station, journey time, crossing or passing, safety headway between trains, etc. To deal successfully with these kinds of problems, this study proposes a simulation method to calculate the line capacity that considers train operation according to the operator's service policies.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.1-11
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• 2009

This study was intended to set development priorities for five undeveloped neighborhood parks scattered throughout the downtown area of Cheongju City using a PDPI(Park Development Pressure Index). In order to calculate the PDPI, this study employed an additive integration method. The PDPI was graded from 1 to 5, based on the evaluation scores in accordance with nine indicators selected through literature reviews and interviews with public officials. The indicators have been classified into three categories: physical environment, utilization possibility, and facility distribution. The indicators are as follows: 1) 'altitude and inclination' and 'NDVI' as physical environment indicators; 2) 'ratio of residential area', 'forecasted utility population', 'undeveloped period', 'redevelopment near parks', 'ratio of area divided by main streets', reflecting utilization possibility; and 3) 'Distance between Neighborhood Parks' and 'Distribution of alternative facilities' as facility distribution. The following results were found: 1) three neighborhood parks including 'Sagic 2', 'Sachen', and 'Dangsan' were ranked in the first grade of PDPI; and, 2) one neighborhood park 'Samsungdang' was ranked in the fifth grade of PDPI. The above results mean that among undeveloped neighborhood parks, three have been exposed to extremely strong park development pressure, and that while two neighborhood parks have had strong exposure to park development pressure due to potential users according to their close location to Sagic Ro, an east-west main axis of Cheongju City, one neighborhood park has had weak exposure to development pressure because of the close location to 'Chuungbuk National University' and a lack of residential areas, showing a low possibility for development.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.5
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• pp.455-463
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• 2020

Road facilities with a service life of more than 30 years are expected to triple in the next ten years. The seismic performance of road facilities should be reviewed with consideration of the "Common Application of Seismic Design Standards" issued by Korea's Ministry of Public Administration and Security in 2017. These standards should be applied to all existing road facilities, including retrofitted or seismic-designed facilities, for evaluating seismic performance. In order to manage seismic performance for a large number of facilities, decision-support technology that can provide economic and reliable results is needed. However, the indices method currently used in Korea is a deterministic method, and the seismic performance of individual facilities is evaluated based on qualitative indices so that only retrofitting among road facilities is prioritized. In turn, with the indices method, it is difficult to support decisions other than the decision to prioritize retrofitting. Therefore, it is necessary to use the seismic risk assessment method to overcome such shortcomings and provide useful information such as direct loss, indirect socio-economic loss, and benefit of the investment.

• Clean Technology
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• v.27 no.4
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• pp.297-305
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• 2021

In the domestic aluminum industry, the extrusion process is a major process accounting for more than 40% of the total production. However, most domestic aluminum extrusion companies produce aluminum using old equipment that is more than 30 years old. Extrusion press is when the equipment is not replaced before the wear and breakage of major parts occur, reducing productivity and increasing the defect rate compared to new equipment. The old extrusion press often loses part drawings, so it is difficult to repair them properly on-site and to remanufacture them due to the lack of technical skills for maintenance. Therefore, a systematic remanufacturing plan must be designed from dismantling the equipment. In this study, remanufacturing FMEA was devised to remanufacture old extrusion press. The risk priority was analyzed by considering the degree of damage to the recycled parts, the cycle due to breakage/damage during the extrusion process, and the value of recycling resources due to remanufacturing. To standardize the remanufacturing process, remanufactured FMEA was performed through part analysis according to the structural analysis of the extrusion press. In addition, remanufacturing priorities were selected for each part, while remanufacturing itself was studied for efficiency of resource circulation and product quality stabilization.

• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.291-297
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• 2020

In recent years, an increase in deaths and injuries of port cargo handling workers, has raised the need for more effective accident management. The purpose of this study was to evaluate the accident risk for port cargo handling workers and assess ports with high accident risk within the Korean alternative ports using the Entropy & GRA (Grey Relational Analysis). To achieve this purpose, first, 11 Korean ports were selected and the evaluative factors for their outranking evaluation by brainstorming were extracted. Second, the Grey Relational Coefficient of 11 alternative ports was calculated using the GRA. This paper, finally, determined the priority orders of accident risk through calculation of the Grey Relational Grade as the link Grey Relational Coefficient method and the weights of the evaluative factors were calculated by using the Entropy method. In the proposed model, eight criteria such as cargo worker, old cargo worker, work hours, facilities environment, steel cargo volumes, cargo volumes, injury numbers, and death numbers were collected. Busan port was identified as highest accident risk port, and so it should be a top priority to develop a plan to mitigate the risk.