• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.612-617
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• 2006

As the on-board electric devices determine the performances of vehicles, production of reliable devices is important. To keep the reliability of devices constant, management of performance evaluation of the on-board devices is crucial. Because temperature has a serious effect on failures of the components of the devices, its measurement is the first step for good management. In this study, we described performance characteristics of domestic auxiliary block developed through G7 project. We measured the performances of auxiliary block during test running by the developed on-line measurement system. After we save the input real-time data from each signal of Korean High Speed Train through the network line, we can acquire necessary information through post-processing program. We verify the motor block characteristics of Korean High Speed Train by this system.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.274-276
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• 1995

The non-ideal elements inherent in all categories of AC drives have a significant influence on the performance of speed control. For the high performance of speed control, these non-ideal elements must be considered. This paper discusses the side effects of non-ideal elements such as the offset current of A/D converter, asymmetry of motor and so on and proposes simple compensation methods which are also applicable to any kinds of the motor drive systems. In the experimental results, it is observed that the proposed compensation methods improve the performance of speed control.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.4
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• pp.289-292
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• 2002

In the design of high speed fishing vessel, it's hull form has to be decided from a view point of resistance and propulsion performance without neglection of seakeeping characteristics. In spite of many efforts, the performance improvement by hull form itself has it's limitations, specially for high speed craft. In this paper, a study on the improvement of performance for high speed planing hull type fishing vessel has been introduced.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.338-348
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• 1998

The study was carried out about the design and the performance study of brake system for Korean High Speed Train of maximum operating speed of 350km/h. The brake system was studied to two parts the function of brake system and the performance of brake system base on Korean-TGV. According to the simulation of brake system, the train should be provided the eddy current brake system for maximum operating speed of 350km/h. The eddy current brake system take charge of about 31% on normal condition and about 22% on emergency by condition. The performance study of brake system would be continued for definition of adhesion factor un friction factor assumed to analysis and simulation.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.533-539
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• 1998

Described in this paper are the dynamic model and the dynamic performance of catenary-pantograph system for TGV-K(maximum operating speed of 300km/hr). Dynamic simulations showed that the system satisfies the performance criteria such as contact loss ratio, contact force and lift-off of the contact wire. It is also shown by the simulations that the dynamic behavior and contact performance of the system at the operating speed of 350km/hr are found unacceptable. Design parameters of the catenary-pantograph system should be optimized for the speed-up of the TGV-K.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.437-445
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• 2000

The reuse partitioning system in microcellular networks are dropped performance of system because of increase hand-off of high-speed terminal. In this paper, we propose hand-off algorithm to improve the performance of reuse partitioning system using microcell according to the ratio of traffic distribution between innercell and outercell from resource management of high-speed and slowspeed terminal. Also, we compare to RPS and evaluate the teletraffic performance analysis of high-speed and slow-speed terminal through computer simulations that we derive the hand-off probability, call dropping probability.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.34-37
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• 2001

In this paper the comparison of conventional PI control and nonlinear sliding mode control is presented for Switched Reluctance Motor(SRM). SRM drives require a nonlinear controller for high dynamic Performance but the high nonlinearity makes a poor performance in conventional PI control. However SRMs with sliding mode control achieve a robust performance for speed control. In this paper nonlinear sliding mode controller is suggested for high performance speed. State equation and modeling are proposed. And we present the speed comparison of PI control and SLMC.

• Journal of Power System Engineering
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• v.6 no.4
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• pp.16-22
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• 2002

This study was conducted to find performance evaluation method for automobile air conditioner. Experimental facilities were constructed to simulate wide range of operating condition for the automobile air conditioner. Compressor speed was controled by variable speed electric motor and the power was measured through torque transducer and tachometer was used to measure compressor speed. Parametric studies were conducted in this study, to figure out effect of environment variables on the performance of the automobile air conditioner. The environmental variables are inlet air temperature, relative humidity and air flow rate for the evaporator and inlet air temperature and air flow rate for the condenser. Compressor speed is also changed. The results of this study shows that air flow rate of the evaporator is more sensitive to the performance of the automobile air conditioner than the other variables. However relative humidity of the inlet air of the evaporator strongly affects capacity rather that COP.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.2
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• pp.54-60
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• 2007

In this paper, we suggest the high efficient control method based on general PI control law for a variable speed refrigeration system. In the variable speed refrigeration system, the capacity and the superheat are mainly controlled by an inverter and an electronic expansion valve, respectively, for saving energy and improving coefficient of performance. Thus, we proposed a decoupling model to eliminate the interfering loop between the capacity and superheat at first. Next, we designed PI controller to control the capacity and superheat independently and simultaneously. Finally, the control performance was investigated through some experiments. The experimental results showed that the proposed PI controller based on the decoupling model can obtain good control performance under the various control references and thermal load.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.3
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• pp.269-276
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• 2020

Sea trial tests are necessary to verify speed-power performance, and are an import contract between ship owners and shipyards. The International Organization for Standardization (ISO) published ISO 15016:2015, which specifies the correlation method between model and full-scale ships. The results of sea trials have been questioned because of the uncertainty of speed and power measurements, especially when sea conditions differ from ideal calm water conditions. In this paper, such uncertainties were investigated by utilizing the standard speed-power trial analysis procedure defined in ISO 15016:2015 through Monte Carlo simulations. It was found that the expanded uncertainty of the delivered power (P_Did) at 95 % confidence interval (k = 2) was ±1.5 % under 75 % MCR conditions.