• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.860-869
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• 2011

It is very important that reduce the maintenance cost and extend life time of the urban transit EMU through effective maintenance method research. The maintenance cost of the urban transit EMU shares 60%~70% of it's life cycle cost. It means that the maintenance cost is bigger than the introduction cost of the urban transit EMU. In this study, I introduces a quality control technique to improve the urban transit vehicle reliability. I suggest the control chart using quality control technique. And the control charts apply to the Static Inverter of EMU.

• 대한교통학회지
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• 제25권4호
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• pp.123-133
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• 2007

본 연구에서는 위계구조를 갖는 대중교통 노선망이 효율적인지, 효율적이라면 과연 어떤 조건 하에서 효율적인지에 대한 해석적 검토를 수행하였다. 대중교통 노선망을 구성하는 총 비용을 모형화하고 구축된 모형을 통해 위계구조를 갖는 대중교통 노선망과 단일 위계로 구성된 노선망의 총 비용을 비교하여 위계구조를 갖는 대중교통 노선망의 효율적 조건을 제시하였다. 위계구조 노선망의 효율성 조건은 상위 노선이 도입됨에 따라 절감되는 통행비용 절감이 상위 노선이 도입됨에 따라 추가적으로 발생하는 접근비용, 대기비용, 그리고 운영비용의 합인 비통행비용의 증가보다 클 경우에 해당한다. 이는 일반적인 상식과 부합하며 경제성평가의 비용/편익 분석의 개념과도 일치하는 결과이다. 상위 노선으로 구분된 단위 공간 내부의 통행은 하위 노선만을 이용하여 통행하고 단위 공간 외부의 통행은 하위 노선과 상위 노선을 모두 이용하여 통행하는 것으로 수요조건을 가정하였을 경우에는 상위 노선을 이용하는 통행수요가 노선간격 감소에 제곱하여 증가하게 되는데 이는 상위 노선의 간격이 줄어들어 상위 노선망이 연계체계를 이룰수록 적은양의 수요증가로도 상위 노선망의 효율성이 보장됨을 의미한다. 이는 대중교통 노선망에 있어서 규모의 경제를 의미하는 것으로, 대도시의 대중교통 노선망이 확장되어 효율적인 연계체계가 구축될수록 대중교통 통행수요가 급격하게 증가하는 현상과 일맥상통하는 결과로 해석된다. 본 연구는 대중교통 노선망에서의 위계구조를 해석적으로 풀이한 최초의 연구이며 대중교통 노선설계에 관한 수리적 연구의 기반이 될 것이다. 그러나 본 연구는 해석적 연구로써 현실적인 네트워크를 고려하는데 있어서 한계를 갖기 때문에 수리적 연구의 보완이 필요하다.시 인접교차로와의 관계를 고려하여 유출연결로의 위치를 결정하는 설계기준에 반영할 수 있을 것이고, 이로 인해 향후 인터체인지 주변의 교차로 운영과 고속도로 본선 교통류의 효율적 관리에 기여할 것으로 기대된다.22.97 %로 quercetin의 함량이 가장 큰 것으로 나타났다. 루이보스 추출물의 ethylacetate 분획의 TLC 크로마토그램은 7개의 띠로 분리되었고, HPLE 크로마토그램은 9개의 피이크를 보여주었다. TLC와 HPLC의 띠와 피이크를 확인한 결과, HPLC의 9개의 피이크는 용리순서로 peak 1 (조성비 14.71 %)은 isoorientin, peak 2 (28.84 %)는 orientin peak 3 (5.63 %)은 vitexin, peak 4 (12.73 %)는 rutin과 isovitexin, peak 5 (9.24 %)는 hyperoside, peak 6 (5.40%)은 isoquercitrin, peak 7 (1.48 %)은 luteolin, peak 8 (17.61 %)은 quercetin 및 peak 9 (4.59 %)는 kaempferol로 확인되었다. Aglycone 분획은 elastase 저해활성($IC_{50}$)이 $9.08\;{\mu}g/mL$로 매우 큰 활성을 나타내었다. 이상의 결과들은 루이보스 추출물이 $^1O_2$ 혹은 다른 ROS를 소광시키거나 소거함으로써 그리고 ROS에 대항하여 세포막을 보호함으로써 생체계, 특히 태양 자외선에 노출된 피부에서 항산화제로서 작용할 수 있음을 가리키며, 루이보스 성분에 대한 분석과 ethylacetate 분획의 당 제거 실험 후 얻어진 aglycone 분획의

• 시스템엔지니어링학술지
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• 제8권1호
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• pp.1-7
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• 2012

This research aims to propose a model to estimate the appropriate SE Cost rate to the total project cost when systems engineering applied to light rail transit project. In this research an investment cost estimation model is proposed with reference to COSYSMO (Constructive System Engineering Cost Model). This model includes four input factors such as requirement numbers, interface numbers, algorithm numbers, and scenario numbers. When 2600 requirement numbers are considered on a proposal document with 350 pages in a light rail transit specification of 500 billion~trillion won scale, COSYSMO demo version estimates 42.5 billion won of SE cost (about 5% of total project cost or about 10% of E&M cost).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1902-1907
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• 2007

This paper suggests improvements in travel cost function of transit assignment model by analysing existing model. Two types of travel cost function are widely used for congested public networks. The one is used for strictly restricting public transport capacity. Another is non-decreasing function such as BPR function. In this paper, we analyse two types of travel cost function in case of intercity rail. The characteristics of intercity rail are different from those of public transit in urban area. Therefore travel cost function must be differently applied in each case.

• 산업공학
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• 제18권4호
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• pp.477-484
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• 2005

This paper is concerned with the life-cycle cost(LCC) of the urban transit system which was developed by KRRI and is now under test in Gyeongsan, Korea. Its reliability, availability and maintainability(RAM) were analyzed. LCC is the core part of analyzing the total cost of acquisition and ownership of a system. LCC analysis of a system is the most effective when it is applied in the it's early design phase. In this paper, we present IEC 60300-3-3(Life Cycle Costing) in detail and propose how to apply LCC in assessing the urban transit system according to RAM process. This case study demonstrates that reliability management system is very effective in reducing the operating cost of subway corporations in Korea.

• 대한교통학회지
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• 제14권3호
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• pp.27-44
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• 1996

The purpose of the thesis is providing a new formulation for the transit assignment problem. The existing models dealing with the transit assignment problem don't consider the congestion effects due to the insufficient capacity of transit vehicles. Besides, these models don't provide solutions satisfying the Wardrop's user equilibrium conditions. The congestion effects are considered to be concentrated at the transit stops. For the transit lines, the waiting times at the transit stops are dependent on the passenger flows. The new model suggests the route section cost function analogous to the link performance function of the auto assignment to reflect the congestion effects in congested transit network. With the asymmetric cost function, the variational inequality programming is used to obtain the solutions satisfying Wardrop's condition. The diagonalization algorithm is introduced to solve this model. Finally, the results are compared with those of EMME/2.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.30-40
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• 2007

The demand for light-rail construction projects has recently been increasing, and they are mostly supervised by private construction companies. Therefore, a private construction company that aim to raise gains from the operation of the facilities during the contract period greater than what they invested should b able to accurately calculate the costs from the aspect of Life Cycle Cost (LCC). In particular, a light-rail transit bridge that has a heavier portion from the aspect of the cost of light-rail transit construction requires a more accurate calculation method than the conventional LCC calculation method. For this, an LCC analysis model was developed and a cost breakdown structure was suggested based on literature review. The construction costs by shape of the upper part of a light-rail transit were calculated based on the cost breakdown system presented in this paper, and the cost generation cycle and cost unit price were collected and analyzed based on records on maintenance costs, rehabilitation and replacement. In addition, after forming some hypotheses in order to perform the LCC analysis, economic evaluation was conducted from the aspect of the LCC by using performance data by item.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.619-627
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• 2009

장기간 수명주기(Life Cycle)을 갖는 도시절도차량은 조기 도입비용보다 유지보수비용이 많은 비중(70%$\sim$80%)을 점유하고 있으므로 효율적인 유지년수 연구를 통하여 유지보수 비용의 절감과 대형시스템의 수명 연장을 주구하는 일이 무엇보다 시급하다. 이를 위해 본 연구에서는 신뢰성기반의 유지보수체계에 대해 여러 산업분야의 국내 외 사례 조사 분석을 수행하였으며, 이를 통하여 도시절도차량의 가용도/신뢰도 관리시스템 관련 시스템 개발방랑을 제시하였다.

• 한국철도학회논문집
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• 제9권1호
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• pp.23-28
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• 2006

Many services have been served by the exiting subway systems since they have opened in 1975. But its efficiency and competition were going down because of the high construction cost and difficult connection with other transportations, etc. Otherwise, the light rail transit system is much lower construction cost than the subway and the high way building. Also those systems are good at the inexpensive operation cost, the fixed time and safety, the easy access. Recently, the several provinces are planning or advancing the light rail transit system because of these many benefits. Consequently, those system's economical feasibility analysis is required rapidly to show the resonable construction's cause and to get the private investment. This paper offers the system's economical feasibility through the several benefit analysis after the light rail transit system's construction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2297-2302
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• 2010

The status and effectiveness of Bi-modal Tram is analyzed through the comparison of the transport effectiveness and operation cost between the public transportation systems (bus, light rail transit) considering the vehicle and operation characteristic of new transit system Bi-modal Tram. The standard operation schedule is established in consideration of the vehicle specification and operation characteristic of main public transportation modes, and then the annual average operation cost is estimated depending on the volume, speed, analysis length for respective public transportation mode. Through analyzing the operation cost and distribution characteristic of public transportation modes depending on the transport volume and travel speed, the operational efficiency suitable for the city is derived. It is concluded that the operational efficiency of Bi-modal Tram is superior to that of the bus and light rail transit on the aspect of travel volume and operation speed.