• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.36-40
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• 2010

In this paper, the well-known LOB-based emitter localization using linear LSE algorithm is numerically implemented and the heuristic guidelines for the parameter values to achieve 1% RMS error are presented. In the simulation, we changed the total observation durations for LOB measurements, time interval between successive LOB measurements and sensor trajectories. The effects of the time interval of LOB measurements, the time duration of the LOB measurements and the angle of flight path arc on the performance are illustrated. The dependence of the performance on the various parameters is investigated and rule-of-thumbs for the parameter values corresponding to 1% RMS error are presented for each simulation condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.9
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• pp.2494-2504
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• 1996

This paper describes about the spread specturm radio wave propagation characteristics in urban microcells. The experiments are carried out with respect to the mean excess delay, the RMS delay spread, and the received maximum peak power in the two kinds of geogrphical areas, LOS area and N-LOS area, especially whose variations are observed while varying the transmission distance and tilting the transmitting antenna. The typical results obtained in pariticular urban sites in Seoul are 300-600 nsec of mean excess delay and about 75 nsec of averaged RMS delay spread for LOS area, and 270-280 nsec of mean excess delay and about 100 nsec for N-LOS area. With the transmitting antenna gilted, obsered in the experiments are increase in RMS delay spread as expected, but increase of the received power at N-LOS areas in particular.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.341-351
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• 1996

The values for the average and rms currents in a three-level PWM inverter are required in order to select the various components such as power semiconductor devices, capacitors and reactors of inverter circuit. And those are very useful for the designing of the heat sink. In this paper, therefore, the simple current equations are proposed for a three-level PWM inverter. Analysis of inverter current waveforms indicate that the average and rms inverter currents are dependent on the load power factor and PWM modulation index (Ma). Error analysis and experiment results verify the effectiveness of the proposed current equations. (author). refs., figs., tabs.

• Structural Engineering and Mechanics
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• v.12 no.4
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• pp.409-428
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• 2001

The characteristics of dynamic wheel loads of heavy vehicles running on bridge and rigid surface are investigated by using three-dimensional analytical model. The simulated dynamic wheel loads of vehicles are compared with the experimental results carried out by Road-Vehicles Research Institute of Netherlands Organization for Applied Scientific Research (TNO) to verify the validity of the analytical model. Also another comparison of the analytical result with the experimental one for Umeda Entrance Bridge of Hanshin Expressway in Osaka, Japan, is presented in this study. The agreement between the analytical and experimental results is satisfactory and encouraging the use of the analytical model in practice. Parametric study shows that the dynamic increment factor (DIF) of the bridge and RMS values of dynamic wheel loads are fluctuated according to vehicle speeds and vehicle types as well as roadway roughness conditions. Moreover, there exist strong dominant frequency resemblance between bounce motion of vehicle and bridge response as well as those relations between RMS values of dynamic wheel loads and dynamic increment factor (DIF) of bridges.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1848-1853
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• 2003

Stuff threshold modulation(STM) technique is analyzed as method for reducing pointer adjustment jitter. The method for jitter reduction is described, and simulation results are presented to illustrate rms jitter performance. The results show that rms jitter value decrease to less than 50％ as compared to a conventional pointer adjustment system.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.469-471
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• 2003

TWBP 도매전력시장의 개설과 더불어 도입되는 PPS&RMS 하의 계약 제도는 전력시장가격 안정화 및 발전사업자의 수익 보장 등 여러 가지 목적이 있지만 그 중에서도 시장점유율이 높은 한수원의 시장지배력 완화 역시 도입 목적 가운데 하나이다. 한수원은 설비용량 기준 30%, 공급량 기준 40%의 거대 발전사업자이므로 시장지배력 행사에 대한 잠재적 가능성이 존재하기 때문에 시장초기에 PPS&RMS를 도입하여 공급 물량의 95%를 계약으로 묶게 된다. 본 논문에서는 이러한 환경적 요인을 반영하여 현재 우리나라의 전력시장 현황을 분석한 다음, 2004년 베스팅 계약이 적용되었을 경우 한수원의 시장지배력 가능성에 대해서 분석해 본다.

• 연구논문집
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• s.31
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• pp.77-88
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• 2001

In this paper, the critical vibration limits of a spindle unit for a high speed ball pen tip processing machine are studied. The vibration of the spindle is measured by FFT, and the influence of the vibration amplitude due to unbalance, bearing deflect, bite, and timing belts tension is analyzed. The critical vibration limits of the spindle is determined by the X, and Z directional vibrations of the spindle. Both FET and RMS values can be used to analyze the vibration characteristics of the spindle. From experimental results the limit line can be drawn for the spindle. The RMS value for the vibration limit is 3 G.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.176-188
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• 2002

This paper presents results of continuous wave and swept frequency response measurements over the frequency range of UNII lower and middle bands from 5.15GHz to 5.35GHz in indoor environments. From the continuous wave measurements at 5.2GHz, the excess path loss, and the statistical characteristics of the temporal and spatial fading were found. By sweeping the frequency over the band, envelope correlation as a function of frequency was found and the coherence bandwidth (CBW) was determined from the envelope correlation. Using a channel model, the CBW was used to evaluate RMS delay spread. The dependence of CBW on the antenna polarization was simulated and compared with the measurement results. The influence of room size and separation of transmitter and receiver for LOS paths on RMS delay spread was discussed.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.82-88
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• 2003

The nondestructive internal quality evaluation of agricultural products has been strongly required from the needs for individual inspection. Recently, the ultrasonic wave has been considered as a solution fur this problem, and an ultrasonic system was constructed for the ultrasonic NDE of fruits and vegetables in our previous work. In this paper, the practical applicability of our ultrasonic system is tested fur the inspection of internal defects (central cavity) in Atlantic potato. Sound speed and RMS of transmitted ultrasonic wave signal were measured and classification algorithm using 2 dimensional stochastic analysis. was presented. Experimental results showed greater value of sound speed and RMS (root mean square) of transmitted signal in normal samples than in abnormal samples with cavity. Also a stochastic method to distinguish normal and abnormal showed fault detection rate less than 5%.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.1
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• pp.74-83
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• 1991

A study on the Correlation of Orthogonal Cutting Parameter (Cutting speed, Depth of cut, Feed Rate) and Acoustic Emission Signal. It is well known that acoustic emission (AE) is the emission of elastic wave resulting from the deformation and fracture of materials. This study estabished correlation of orthogonal cutting parameter and AE signal, and researched into in-process monitoring of tool wear and failure. The results are as follow; 1. AE RMS was under the influence of cutting speed but hardly influenced by depth of cut and feed rate. 2. AE RMS was under the influence of flank wear. 3. AE count rate increased by increased cutting speed. 4. AE RMS value was rapidly increased in 130 m flank wear.