• Geomechanics and Engineering
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• 제20권4호
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• pp.313-322
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• 2020

This study focuses on a prediction approach of compaction compensation grouting efficiency in sandy soil. Based on Darcy's law, assuming that the grouting volume is equal to the volume of the compressed soil, a two-dimensional calculation model of the compaction compensation grouting efficiency was improved to three-dimensional, which established a dynamic relationship between the radius of the grout body and the grouting time. The effectiveness of this approach was verified by finite element analysis. The calculation results show that the grouting efficiency decreases with time and tends to be stable. Meanwhile, it also indicates that the decrease of grouting efficiency mainly occurs in the process of grouting and will continue to decline in a short time after the completion of grouting. The prediction three-dimensional model proposed in this paper effectively complements the dynamic relationship between grouting compaction radius and grouting time, which can more accurately evaluate the grouting efficiency. It is practically significant to ensure construction safety, control grouting process, and reduce the settlement induced by tunnel excavation.

• International Journal of Railway
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• 제6권2호
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• 품질경영학회지
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• 제50권4호
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• pp.811-830
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• 2022

Purpose: In this paper, we will discuss 1) prioritizing databases to be integrated; 2) which data elements should be emphasized in federated database integration; and 3) the degree of efficiency in the integration. This paper aims to lay the groundwork for building data governance by presenting guidelines for database integration using metrics to identify and evaluate the capabilities of the UK's air quality databases. Methods: This paper intends to perform relative efficiency analysis using Data Envelope Analysis among the multi-criteria decision-making methods. In federated database integration, it is important to identify databases with high integration efficiency when prioritizing databases to be integrated. Results: The outcome of this paper aims not to present performance indicators for the implementation and evaluation of data governance, but rather to discuss what criteria should be used when performing 'federated integration'. Using Data Envelope Analysis in the process of implementing intelligent data governance, authors will establish and present practical strategies to discover databases with high integration efficiency. Conclusion: Through this study, it was possible to establish internal guidelines from an integrated point of view of data governance. The flexiblity of the federated database integration under the practice of the data governance, makes it possible to integrate databases quickly, easily, and effectively. By utilizing the guidelines presented in this study, authors anticipate that the process of integrating multiple databases, including the air quality databases, will evolve into the intelligent data governance based on the federated database integration when establishing the data governance practice in the railway industry.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.152-160
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• 1998

Korea Railway aims to be the most important public transportation for nationwide basic industries in 21st century. It is urgently necessary for us to construct economical railway network and to strengthen(strengthen) its competitive power in advance. In this paper the economical construction of railway network in Germany will be introduced. They lay emphasis on train speed and higher efficiency of railroad track.

• 산업기술연구
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• 제31권B호
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• pp.17-21
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• 2011

Since the railway passenger services have been recognized as important factor for success in railway, electrical energy consumption in railway station for high quality service has greatly increased. Furthermore, the number of the private railway station has gradually increased. Therefore, the operation conditions for railway power distribution system is dramatically changed in comparison with the past. So, this paper proposes the optimal construction method for railway power distribution system considering economical efficiency and the reliability of power supply to establish the railway power distribution system standard for the future railway industry.

• International Journal of Railway
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• 제1권2호
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• pp.45-58
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• 2008

The concept of lean production originated and was applied mainly to manufacture industries Even proven successful with such companies as Toyota, lean production has to be combined railway transportation production in order to bring its function into full play. The paper analyzes for applicability of lean production in railway transportation production organization, puts forward implementation methods such as transportation resource integration, station-zone organization, dispatch command optimization, railway performance evaluation index system, etc., and makes an exemplification study of lean production of Urumqi Railway Bureau in China, which testifies the applicability and efficiency of railway lean production.

• 한국철도학회논문집
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• 제15권6호
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• pp.638-644
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• 2012

본 연구에서 일반철도의 선로이용율의 범위인 60%를 검토하여, 이용가능한 시간과 이용 불가능한 시간을 수치화 하였다. 또한 선로이용율을 변화시키는 요소인 선로유지보수시간에 대한 계산과 적정한 추정시간을 분석하였다. 적절한 철도운영계획과 원활한 시설유지보수를 통한 열차의 안전을 보장하여야 한다. 동시에 매일 연속되는 열차Dia의 원상회복력도 운영계획에 반영되어야 한다. 이런 사항들을 고려하여 보유 중인 기계장비와 국가철도망에 대한 자료를 활용하여 유지보수작업시간 산출방법을 개선하고, 열차지연에 대비한 여유시간을 확보하도록 검토하였다. 결론적으로 일반철도의 선로이용율과 선로유지보수시간 구성요소를 함께 수량화하여, 선로이용율은 60% 내외가 타당함을 증명하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.319-326
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• 2001

Railway signaling safety system organizes equipments and facilities of railway, increases transport efficiency and assures safe operation of railway. In the early days of signaling system railway managers made sure of safety by using relay logic technology based on fail-safe concept. But the development result of computer and science having been introduced to railway industry, railway signaling equipments begin to be operated through micro electronic control system. Accordingly high speed and high density operation of train became possible. Software reliability and safety technology that controls important systems of railway was highlighted. In the middle of 1990s the standard or guideline of railway reliability and safety were studied and established, and are being reviewing in Europe, Japan etc. Our reliability and safety technology have depended largely on foreign countries. In this study we performed a basic study about the reliability of software that controls the railway signaling system.

• Structural Engineering and Mechanics
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• 제46권4호
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• pp.571-594
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• 2013

Railway truss bridges are amongst the essential structures in railway transportation. Minimization of the construction and maintenance costs of these trusses can effectively reduce investments in railway industries. In case of railway bridges, due to high ratio of the live load to the dead load, the moving load has considerable influence on the bridge dynamics. In this paper, optimization of the railway truss bridges under moving load is taken into consideration. The appropriate algorithm namely Hyper-sphere algorithm is used for this multifaceted problem. Through optimization the efficiency of the method successfully raised about 5 percent, compared with similar algorithms. The proposed optimization carried out on several typical railway trusses. The influences of buckling, deformation constraints, and the optimum height of each type of truss, assessed using a simple approximation method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.784-791
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• 2007

Most operational organization and railway authority which conduct scheduled maintenance(SM) have carried out the preventive maintenance(PM) based on the information provided from supplier and manufacturer of railway system. However these activities are far away from reality and low the efficiency, it is because an appropriate methods for system selection didn't take into account for improving maintenance efficiency. Therefore, the current SM tasks and maintenance activities lead to lots of spend on the cost and time. To solve the above problem, this thesis presents new approach methodology. This proposes the criteria for reliability centered maintenance(RCM) system selection through level of quantification of each parameter, i.e, frequency, severity and maintenance cost, etc. To do this, the field operation data and information of maintenance cost are essential. As applying this methodology, we can look forward to improving efficiency of PM/SM, and reducing cost.