• 전기의세계
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• v.31 no.2
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• pp.126-131
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• 1982

Induction motors are known to cause voltage dip, oscillating torque and inrush current on the dynamic period. To compensate for these undesirable effects, the prediction of dynamic performances is required. The dynamic performances are determinated by circuit time constants. From this point of view, in this paper, the dynamic equivalent circuit included only three time-constant parameters are presented. To predict more simply dynamic performances, the new characteristics time constant parameters are analyzed, and now these parameters are described as the function of circuit time constants. This paper reviews and analyzes the use of series capacitance compensations, and the use of this analysis can make simply a prediction about oscillating conditions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.304-307
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• 2000

This paper presents a numerical simulation study for remote parallel pseudo-dynamic testings using Internet. In this testing method, experimental facilities located at different places can be parallelly used for testing a large-scale structure with many components subjected to severe nonlinear behavior. Example analysis is carried out on a base- isolated bridge for earthquake loading. The results indicate that the time required for data communication between two facilities located 250km apart through Internet for t 000 time steps is about 20 minutes, which is fairly equivalent to the time required for pseudo-dynamic testing. This testing method can be more powerful, as the data transmitting technique through Internet improves.

• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.997-1006
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• 2015

In industrial quality control, when engineers use VSI control procedure they should consider both required time to signal and switching behaviors together in the case of production process changed. Up to the present, many researchers have studied fixed sampling interval (FSI) chart and variable sampling interval (VSI) chart in the points of average number of samples to signal (ANSS) and average time to signal (ATS). However, ANSS and ATS do not provide any switching information between different sampling intervals of VSI schemes. In this study, performances of two sampling intervals VSI chart and three sampling intervals VSI chart are evaluated and compared. The numerical results show that ANSS and ATS values of two sampling intervals VSI chart and three sampling interval VSI chart are similar regardless the amount of shifts. However, the values of switching behaviors including ANSW are less efficient in three sampling intervals VSI charts than in two sampling intervals VSI chart.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.139-144
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• 2006

Forest fire is due to difficulty in approaching the forest fire at the time of forest fire and quite a long of time required for post-fire investigation, accurate analysis of damages to the forest area caused by forest fire is difficult to obtain. Recently, In attempt to overcome such difficulty, many researches are using satellite images. Nevertheless, it is not easy for everyone to obtain the satellite image data, and additional researches in order to verify accuracy of such data are also required. Therefore, in this study for satellite image to about damages to the forest areas caused by forest fire using tile selected two data of spectral reflectance of the vegetation, gained by using a spectrometer. That is we wished to search about mistake that is apt to happen by one time eyesight observation by analyzing two datas that is used spectral radiometer 3 months and 6 months later and gets.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.123-134
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• 2003

Fire Sequencing Problem (FSP) is to find a sequence of targets, where there exist a number of targets with different time units required to fire. Because of the weapon's specifications and the size of the targets, several weapons may fire on the same targets, and the time units required on firing for each weapon may be different from each other. The objective is to minimize the completion time of firing for given number of targets. Mathematical formulation is given, and the heuristic algorithm based on the paring of targets in advance is suggested. Performance of the heuristic is evaluated by comparison of heuristic appeared in the literature through the computational experiments.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.3
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• pp.113-119
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• 2002

A target adaptive guidance(TAG) algorithm is proposed employing the near-zone signal that can be measured from an infrared seeker. The guidance order is composed of a conventional PNG command and an additional command to be calculable from an additional LOS rate between a hot point of target and a required intercept point. The characteristic of the near-zone signal is similar to that of LOS rate that is inversely proportional to the square of time-to-go. Hence the proposed scheme can be applied to real systems with no estimator for time-to-go. From analysis results on the miss distance with perfect missile and perfect seeker, it follows that the proposed TAG algorithm guarantees missile to be ideally guided to the required intercept point. And it is less affected by the TAG start time and a proportional navigation ratio than other TAG schemes using a LOS rate such as a step bias or a ramp bias.

• Journal of the Korean Society of Combustion
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• v.8 no.2
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• pp.50-55
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• 2003

Synthesis of carbon nanofibers on a metal substrate by an ethylene fueled inverse diffusion flame was observed. Stainless steel plates were used for the catalytic metal substrate. The effects of radial distance and residence time of the substrate were investigated. The role of hydrocarbon composition in the fuel was also viewed. Nanofibers with a diameter range of 30-70nm were found on the substrate. The carbon nanofibers were formed and grown in the region from 4 to 5.5mm from the central axis of a flame outside of the visible flame front in the radial direction. The minimum residence time required for the formation of carbon nanofibers were about 20 seconds, and over 60 seconds were required for the full-scale growth. The characteristic time of the formation of carbon nanofibers was much shorter than that of the substrate temperature growth. In this study, the variation in hydrocarbon composition had no significant effect on the formation and growth of the carbon nanofibers.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1187-1190
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• 2005

The ramp reset driving method proposed in [1] has been widely adopted because of its stability and high contrast ratio. However, when the conventional ramp reset method is used in PDPs of higher resolution, the long required time for reset often becomes a problem. In this paper, a new driving method that requires much less reset time and that significantly improves the contrast ratio is introduced. Using this new driving method, the required time for reset could be reduced to 150us from 350us of the conventional ramp reset method, and the contrast ratio is almost infinite because the luminance of the off-cell is almost zero.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.118.5-118
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• 2001

This paper describes an image processing method for inspecting the surface outlook of high speed moving plates. Noise free image and a new real time processing methods are required to inspect the surface outlook of the high speed moving plates in real time. It is difficult to get a noise free image due to a signal noise, a light noise and background image in typical industrial factory. Thus, pre-processing techniques should be required to get a good image and produce so many time steps to proceed the image data. The objective of this research is to get image on the surface of the moving plates with a speed of 1m/sec and to detect some defaults on the surface image. So, the pre-processing techniques ...

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.610-614
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• 1996

In machining muliple components fixed on the same pallet of a NC machine, it is very important to minimize the total time required to finish the machining by carefully determining the component layout on the pallet, and the tool path of NC machine, and the sequence of tools to be used. In this paper, a linear integer programming model is presented to obtain an efficient layout; and a two-phased heuristic algorithm is proposed to minimize the total time for machining multiple components. Numerical examples are given for the case of identical components and nonidentical components, respectively. The result of either case shows significant reduction of 7.2~15.0% in the total time required to finish the machining.