• Proceedings of the KSR Conference
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• 2008.11b
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• pp.673-678
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• 2008

In crushed service areas of Metro railway lines, there are problems such as the buildup discontent, the irregular operation time and rotation of rolling stocks, caused by frequently occurred train delay. Train delay is affected by operation conditions or infrastructure capacities such as train schedule, line capacity, car rotation plan, shunting movements at origin and destination, and also by transport demand characteristics. Furthermore, a delay produce another delays and spread over the following trains. So it is not easy to build up a protection and recovery plan. In this research, we conduct experimental analysis study based on the real metro data, and as a result, present the relation between the traffic demand and the dwell time. And finally, propose future research themes for improving the operation efficiency of metro railways.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.658-668
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• 2009

Earth-moving operation has a great impact on the overall budget and schedule of any heavy civil projects. More often than not, the operational decisions are made largely based on field personnel's experience and judgment. In particular, decisions on earth moving operations by scraper-dozer fleets have been heavily influenced by the following belief: "The longer a dozer pushes a scraper for loading, the better earth-moving productivity is gained by the fleet." Even though there is some truth to this notion, scraper-dozer earth moving operations involve a much complex process that requires a systematic analysis for predicting the maximum production. To this end, this paper presents a spreadsheet-based scraper-dozer fleet operation model for its production optimization. Various optimization techniques, including a genetic-algorithm method, are presented for comparison and each technique's pros and cons are discussed.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.655-656
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• 2015

In this paper, diagnosis for 85 high voltage induction motors which have operated for more than 20 years in 18 wide area water supply offices were applied and the results of diagnosis were analysed. Furthermore, main factors that would be affecting rotor defects were selected and correlations between dependent variables which was magnitude for sideband frequency on current during operation and independent variables such as starting characteristic, operating time, number of operation, load factor, maker, rotation speed, capacity were analysed. It was clear that factors including starting characteristic, number of operation, maker, rotation speed caused break by correlation analysis. From this, regression equation was deduced through regression analysis. Based on suggested regression equation, it is applied usefully that we can estimate the condition of rotor without onsite diagnosis and plan the schedule of diagnosis.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1241-1245
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• 2011

High RAM performance and efficient operation plan and maintenance equipment and policies are needed for improving the system availability performance such as punctuality and schedule adherence while reducing life cycle cost. Because railway systems are repairable, complex and have multi-echelon maintenance support structure, it is much complicated to set RAM performance targets and operation and maintenance plan. It is not easy to solve these problem by mathematical method and simulation can be consider for them. This article suggests the conceptual simulation model for analysing availability of railway system which has complex system structure and operation/maintenance environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.167-172
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• 2022

Currently, ship control, tug, and pilot work in import/export ports including Gwangyang Port are operated according to factors such as the order of arrival and departure regardless of the shipping company. Also, even this is done very inefficiently by hand. Therefore, there is an urgent need to develop a system to increase the efficiency of port and ship operation through standardization and digitalization of tasks related to Berthing and unberthing of ships. In this study, we propose a method to increase the efficiency of port and vessel operation by designing a smart port operation system based on big data such as vessel location information, pilotage and tug schedule, arrival/departure operation information, and weather information.

• Korean Management Science Review
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• v.10 no.2
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• pp.61-77
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• 1993

This paper involves a study of developing the production scheduling system in a general job shop type mechanical factory. We consider realistic situations in the job-shop environments, such as alternative machines for operation, the new kinds of processes, the machining center with the plural pallet, the operational situation of each machine during the scheduling period, occurings of urgent orders and machine breakdowns. We also propose the methodology of re-schedule. It is very fast and acceptable for real time production control system. These all functions are implemented on IBM PC and program source is written in PASCAL language.

• 연구논문집
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• s.30
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• pp.5-13
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• 2000

The computation scheme of simulating gas turbine transient behavior was developed. The basic principles of this scheme and main input data required are described. Calculation results are presented in terms of whole operating regime of the cycle. The influence of main initial parameters such as starting engine power, moment of inertia of the rotor, fuel supplying schedule etc. on performance characteristics of has turbine during transient operation is studied In addition, bleeding air influence on transient behavior was also considered For validation of the developed code, comparison of present calculation with that of measurement data of the experimental data for the range of operating period studied.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.92-97
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• 1988

The path planning is done at the joint level. Cubic spline functions are used for constructing joint trajectories for industrial robots. For N-joint robot, Cartesian knots are transformed into N sets of joint displacements, with one set for each joint. For industrial application the speed of operation affects the productivity. An algorithm is developed to schedule the time intervals between each pair of adjacent knots such that the total traveling time is minimized subject to the physical constraints on joint velocties acceleration and jerks.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.145-152
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• 2021

Environmental change due to construction of large offshore wind farm has been a debate for a long time in Korea. There are various data acquired on hydrodynamics around this area before and during construction of offshore wind farm but no data during operation could be made due to delayed schedule. In this study, environmental change such as bathymetry change and scouring was forecasted using MIKE, numerical hydrodynamics model, and its results were validated using the observation data before and during construction.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.221-228
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• 2009

For a stable supply of electric power, periodical inspection of the electric facilities and repair of the distribution lines are required. In case of any unexpected accidents, looped operation among distribution lines may be necessary in order to supply electricity through the sound lines, separating the faulted lines. As a result of this study, it was found that normal looped operation became impossible when phase difference of the looped distribution lines is more than 3 degrees compared with the voltage supply of the distribution lines. Therefore, for a stable supply of electric power to Chuncheon, it is judged to be desirable that looped operation of the distribution lines coming from the same substation M. Tr Bank shall be performed in principle and in case of looped operation with the substation of different system, looped operation among the lines shall be performed after voltage regulation of the substation M. Tr Bank, maintaining similar voltages and load supply volume in order to avoid phase difference through checking the operation conditions of each substation M. Tr Banks. And when looped operation among the distribution lines is scheduled, voltage regulation schedule has been established so far by calculating maximum supply volume through the transformer of the substation and the maximum load volume through the distribution lines but in the future, looped operation of the distribution lines shall be carried out by removing voltage difference with regulating tap or load of the surrounding transformers, with giving prior notice to the substation operators.