• Proceedings of the KSR Conference
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• 2005.05a
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• pp.979-984
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• 2005

2005, National railway was converted from government enterprise form to public corporation form. Korail is facing in necessity to equip new manpower operating system to achieve public enterprise's part and two purposes called profit creation according to conversion to construction system. Accordingly, railway construction work began services for formation diagnostic and job analysis to construct management formation of new paradigm, personnel management course manpower operation system of the job value priority. This dissertation is research for direction establishment of human resource management(HRM) of railway construction work. Examined problem of current personnel management system with trend of HRM paradigm for this. And presented various strategy to construct greeting executive system of job putting first in person putting first and strengthens formation capacity.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.153-168
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• 1998

In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished Products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be backordered. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, the proportion of backordered demands, the average number of backordered demands and the mean waiting time of a backordered demand. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A matrix geometric method is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the approximate method provides fairly good results.

• Journal of the Korean Society for Library and Information Science
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• v.25
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• pp.233-264
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• 1993

The authorized form is called the heading must be unique and consistent. Without both uniqueness and cosistency, retrieval from the bibliographic database will not be optimal and in some cases may even be impossible. But the authority control is extremely expensive, because it is labour-intensive and dependent on professional investigation and judgement. In fact, it is by far the most expensive function in all of bibliographic control. The processes used to determine the form of access points. maintain. use. and evaluate very accurate authority records reduce the efficiency to generate or merge bibliographic items without modification from any national level bibliographic utilities as well as individual library. In this paper non-authority control system was suggested to solve the disadvantages of authority work. The apparent advantages of the non-authority control system are it is easy to determine the heading, input the bibliographic data. integrate the access points into an existing file, and generate and merge bibliographic data without modification. In addition, non-authority control system can be transmitted into online information retrieval system conducted with a mixture of controlled vocabularies and natural language.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.9
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• pp.414-421
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• 2001

If a machine has some faults, we can detect them using vibration or noise signals. However some maintenance engineers who don\`t have export knowledge, need the help of vibration experts for diagnosing the machine. In this paper a case based reasoning (CBR) system is developed which is able to manipulate the past experiences of vibration diagnosis experts. In the CBR system, the maintenance engineers can retrieve the information form previous cases which are most similar to new problem s that they can solve new problem using solutions form the previous cases. In this paper, a new case retrieval method of CBR system using Petri net is proposed and also applied to diagnosis for electric motors as a practical problem.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1034-1036
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• 2006

In this paper, I used microprocessor and sensor and designed to improve the efficiency of the photovoltaic system the photovoltaic position tracker device, and compared the normal photovoltaic system of fixed form with the photovoltaic system of solar position tracked form. Moreover, compared the catalogue of solar cell module and the simulation through a mathematics modelling with the solar cell's characteristic interpreting and, composed an power conversion system with boost converter and voltage source inverter. Used the constant voltage control method for maximum power point tracking in boost converter control and, used the SPWM(Sinusoidal Pulse Width Modulation) control method in inverter control.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.516-528
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• 2009

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.18-25
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• 1999

Western coastal ports of Korea experience severe tidal range with up to 9.7 meter between high and low tides. The significant water level variation implicates many operational difficulties during loading and un-loading from cargo ships. To overcome problems due to tide and to secure the continuous loading operation, a new loading system for container cargo called "container pallet system" is developed and introduced in the paper. Three types of structure forms, offshore structural deck, double bottom structural form and the mixed form, are inverstigated with MSC/NASTRAN software. The results prove that the mixed type structure with truss enforcement is found to be the most appropriate for the region.

• IE interfaces
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• v.9 no.1
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• pp.1-10
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• 1996

In this study, expert system for the selection of the optimal cutting speed and feed rate was developed using NEXPERT system shell. The NC system has been usually used inefficiently because the input command, which contains cutting speed, feed-rate and the depth of cut, is fixed value which depends on principally operator's experience and machining handbooks providing a guideline for applicable ranges. On the other hand, the optimal cutting conditions vary with time, and depend on tool and machine characteristics, work materials, and cost factor and so on. In this study, if cutting factors, such as, cutting method, material type, cutting depth, and tool nose radius are specified, our expert system gets the information about the standard cutting speed form the cutting speed database, and provides optimum feed rate for these cutting conditions. This cutting speed database can be updated by inputting valid cutting speed which is obtained form the practices.

• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.206-211
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• 2005

The LC filter design procedure of the inverter output filter is described. The transfer function of the filter output voltage to the load current is described with the capacitor value and the system time constant considering the system controller. By using the closed form of the relation between the filter capacitor value and the system time constant, the capacitor value can be calculated with the given system time constant and vice versa. It is more practical for the implementation of power and control circuit of inverter. And as the effect of the load current to the voltage distortion can be calculated from the closed form, it is possible to analyze the system how much the voltage waveform is distorted in case of the nonlinear load. All the proposed design procedure is verified with the simulation and experimental results.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.9
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• pp.76-84
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• 1992

The DSP silicon compiler consists of language compiler, module generator, placement tool, router, layout generation tools, and simulator. In this paper, The language compiler, the module generator, placement tool, and simulator were developed and provided for the system designer. The language compiler translates the designer's system description language into the intermediate form file. The intermediate form file expresses the interconnections and specifications of the cells in the cell library. The simulator was developed and provided for the behavioral verification of the DSP system. For its implementation, the event-driven technique and the C$^{++}$ task library was used. The module generator was developed for the layout of the verified DSP system, and generates the functional block to be used in the DSP chip. And then the placement tool determines the appropriate positions of the cells in the DSP chip. In this paper, the placement tool was implemented by Min-Cut and Simulated Annealing algorithm. The placement process can be controlled by the several conditions input by the system designer.