• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.2
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• pp.29-34
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• 1983

A simulated inductance, with a phase parameter control circuit containing only two resistors and one operational amplifier, is realized as a two terminal network. Analytical results of the proposed circuit avow that we can realize a simulated inductance for constant inductance value, and experimental results confirm the theoretical predictions. Error of maximum 4%, between theoretical and experimental results of equivalent inductance, has been observed over a wide range of frequencies up to about 100 KHz.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.51-53
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• 2013

A MIMO antenna using the resonance of ground planes is proposed for 4G mobile application. A resonant mode is generated when the double ground planes (upper and lower) in the mobile terminal are excited as the radiator. By combining the resonant modes contributed from both the antenna element and the ground planes, the proposed MIMO antenna realizes a wideband property over LTE band 13. In addition, an inductive coil is employed to reduce the antenna volume. These approaches not only simplify antenna design but also effectively improve bandwidth and efficiency. The proposed MIMO antenna has an excellent ECC value of below 0.1 because of the nearly orthogonal radiation patterns of the two radiators. Moreover, an additional antenna is adopted to cover WiMAX, WLAN, and Bluetooth services simultaneously in frequency range from 2 GHz to 2.7 GHz.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.269-272
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• 2007

In order to expand cell coverage, increase system capacity, and offer various multimedia service with high throughput in indoor environment, WiBro Access Point(AP) is developed. Home AP is IFA/Omni type and has stack-up structure of channel card and RF board. SOHO AP is designed to support up to 2FA and has remote RF(RRF) structure using UTP method. Inter-operational test with mobile terminal were completed for 3 terminals using web browsing service simultaneously. The performance test results of WiBro AP are as follows: RCE(EVM) value is -34.431 dB for 64-QAM and throughput is up to 6.79 Mbps(DL) and 1.1 Mbps(UL) with 2.5m Line-of-Sight(LOS) condition.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.358-361
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• 2003

As the information and communication technology has been developed, demand for internet and multimedia is increased and customer's needs becomes diverse. Therefore, the convergence of fixed and mobile networks has emerged. Fixed - Mobile Convergence (FMC) service means that it provides users with one type of services from network access to billing regardless of networks and terminal. FMC service is expected to provide an advanced value with both networks providers and users. Wireless local area network (WLAN) and 2.3㎓ HPi are promising services that will generate enormous demands among FMC services. For that reason, this paper investigates the trend of WLAN and HPi in Korea and abroad and suggests future deployment based on reviewing the literature.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.46-48
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• 2007

This paper presents research about improvement of fault detection algorithm in FRTU on the feeder of distribution system. FRTU(Feeder Remote Terminal Unit) is applied to fault detection schemes for phase fault, ground fault, and cold load pickup and Inrush restraint functions distinguish the fault current and the normal load current. FRTU is occurred FI(Fault Indicator) when current is over pick-up value also inrush current is occurred FRTU indicate FI. Discrete wavelet transform(DWT) analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate inrush current from the fault status by a gradient descent method. In this paper, fault detection is improved using voltage monitoring system with DWT and neural network. These data were measured in actual 22.9kV distribution system.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.227-228
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• 1990

The cooking properties of waxy rice, Olchal (Japonica type) and Hangang-chalbyeo $(J{\times}\;Indica\;type)$, were studied. The values of cooking rate constant of Hanganchalbyeo were higher than those of Olchal. However, the activation energies were essentially the same. The activation energy for cooking at $80-100^{\circ}C$ was about 1.6 times greater than at $100-120^{\circ}C$. The Z-value and $Q_{10}$ calculated from the terminal point of cooking were also similar between waxy rices.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.245-248
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• 1996

This paper suggests a new concept for missile guidance control, called linearized common curvature guidance law that enhances the probability to kill a target. The proposed guidance system is composed of two switching modes; one for the midcourse guidance and the other for the terminal guidance, which is switched by a specified critical value (.epsilon.). And the system and the commands are formulated and its simulations are provided in comparison with the conventional commanded line of sight guidance algorithm. Miss distance and angle of attack are denoted as performance of parameters. This new concept, common curvature guidance algorithm, revises the navigation guidance and accompanies, various considerations.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.489-492
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• 2010

This paper proposes the planar-type modified monopole antennas of loop structure. This antenna has an opened center of a conventional closed loop structure with an inside-folded terminal of the loop microstrip line. The size of the proposed antenna was minimized by folding the end of the loop. Also, the reactance value has been minimized by increasing capacitances between the coupled microstrip line. Therefore the proposed antenna has been compacted to about 20% from a conventional loop antenna and has increased its efficiency. The proposed antennas have an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6~3.56 GHz) with VSWR$\leq$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9%. These properties could satisfy the S-DMB band.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.10
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• pp.1349-1355
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• 1999

A power distribution facility map is drawn on cadastral map. Besides, grid lines are added on the map for sectionalization. For automatic recognition of the map, we first extract recognizing regions. In this paper, we propose an extraction method of recognizing regions by partially extending thinned image. The proposed method is consist of three phases, binarization phase, thinning phase and partial extending phase. The first phase generate a binary image using threshold value which is obtained by histogram analysis. The binary image contains many part of recognizing regions, but not all. The second phase generate thinned image which is generated by appling thinning operator to the binary image. And the third phase extends thinned image from terminal point until satisfying termination condition. The proposed method is tested on several power distribution facility maps, and the results are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.104.2-104
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• 2001

In the intelligent integrated systems, the delay time must be reduced using highly parallel processors, as well as high throughput performance. In this paper, we propose a new concept for building 3D highly parallel processors using multi-layer printed wiring boards with built-in soldering heater (BISH-PWB). The proposed BISH is realized with the long and narrow cupper wiring pattern on the internal layer in the terminal pattern area. Based on the linearity of the cupper resistance vs. temperature, we can measure the BISH, temperature and its calorific value from the heater voltage and current measurements. If we provide the BISH temperature control systems for each BISH, selective multi-point soldering can be realized with same ...