• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.11a
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• pp.503-519
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• 1997

정보SYSTEM을 구축함에 있어서 많은 시간과 노력이 필요하다. 이에 반해 기대되는 효과는 예측하기 힘들거나 명확하지 않은 경우가 많다. S/W개발자의 약점이 개발에는 능하나 업무자체에는 둔감한 것이다. 이를 보완하기 위한 방법으로 업무를 진행하는 사람이 주가 되어 진행하는 개발방법론으로 CIM기법이 대두되었다. 이 기법을 이용하여 통합 정보SYSTEM을 구축하고 효과분석을 실시하였다.

• 전기의세계
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• v.51 no.12
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• pp.22-25
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• 2002

많은 연구를 통해 음성 인식은 잡음이 존재하지 않는 환경에서는 매우 높은 인식률을 보이고 있으며 실제로 여러 분야에서 응용되고 있다 하지만 여러 잡음이 존재하는 환경에서는 그 성능이 급격하게 저하되어 잡음 에 둔감한 인식기와 잡음 제거가 필수적이다. 본 내용에서는 독립 요소 기법에 기반 한 잡음 제거 기법을 소개하고 이를 칩으로 구현하고 그 결과를 고찰해 보겠다.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.718-724
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• 2014

Insensitive Munition(IM) reduces the explosive weakness of munitions, at the same time, maintains its performances in the moment of discharge, which improves safety of soldiers and minimizes unexpected accidents and casualties from being shot in case of transportation, storage and military operation. Development of IM has been focused as the global trend, which was required to satisfy the demand of army that is to minimize the loss of non-battle forces and to retain the competitiveness in export abroad. In this study, we categorize all the munitions used by ROK Army, then determine the priority of IM by deploying AHP(Analytic Hierarchy Process) method. In conclusion, we suggest the priority of IM which is suitable to the affairs of ROK Army.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1A
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• pp.84-92
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• 2004

Eigenstructure-based adaptive beamfoming has advantages of fast convergence and the insentivity to errors in the arrival angle of the desired signal. Eigen-decomposing the sample matrix to extract a basis for the Sl (signal plus interference) subspace, however, is very computationally expensive. In this paper, we present a simple subspace based beamforming which utilizes off-diagonal elements of the sample matrix to estimate the Sl subspace. The outputs of overlapped subarrays are combined to produce the final adaptive output, which improves SINR (signal-to-interference-plus-noise ratio) comapred to exploiting a single subarray. The proposed adaptive beamformer, which employs an efficient angle estimation is very roubust to errors in both the arrival angles and the number of the incident signals, while the eigenstructure-based beamforer suffers from severe performance degradation.

• New & Renewable Energy
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• v.3 no.3
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• pp.36-44
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• 2007

Most airfoils for wind turbines commercially available have been developed for aircrafts, which are operated at high Reynolds numbers. However, Reynolds numbers of wind turbines are very low compared to those of aircrafts. In other to improve wind turbine performances, airfoils for the use of wind turbine shall be designed such as S-series airfoils developed by NREL in America. The authors have designed new airfoils for wind turbines considering designated operation conditions of wind turbines and even local wind resources in Korea. The designed airfoils are characterized by improved roughness insensitivities compared to other airfoils such as S814 and S820. The developed KWA005-240 and KWA009-127 are for root and tip sections of a wind turbine blade, respectively. Although the results show much improved performances against NACA airfoils, performance data of post-stall regulation loses some accuracies due to the characteristics of the simulation tool of XFOIL. Therefore, wind tunnel experiments are required for more accurate evaluation of the designed airfoils. Currently, the experiments has been completed and the data analysis works are going on now. The final results obtained from the experiments will be published soon.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.4
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• pp.96-106
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• 2017

In pressable polymer bonded explosives (PBXs), densification occurs due to rearrangement and deformation of explosive particles during pressing. If brittle explosives are compressed till particle fraction become higher than theoretical random close packing fraction (RCPF), bigger particles should be fractured to fill the void. In this study, multi-modal particle system was introduced for the decrease in possibility of particle fracture during compression expecting decrease in shock sensitivity of highly filled pressable PBX. The experimental results showed the trimodal particle system had low sensitivity with high density, compared to bimodal particle system.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.396-400
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• 2006

We present a weather-insensitive optical free-space communication method supporting optical packet channels. It operates optical fiber amplifiers in gain-saturation regions. When the propagation loss gets too high, it decreases the average packet rate, or the average packet length, or both, to increase the optical power level launched into the free-space. As a demonstration, we transmit $8{\times}10$ Gigabit Ethernet channels over a terrestrial distance of 2.4 km. One gain-saturated free-space optical repeater is used at the halfway point.

• Journal of IKEEE
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• v.24 no.4
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• pp.942-949
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• 2020

In this paper, we propose an improved algorithmic ADC for CMOS Image Sensor that is suitable for a column-parallel readout circuit. The algorithm of the conventional algorithmic ADC is modified so that it can operate as a single amplifier while being independent of the capacitor ratio and insensitive to the gain of the op-amp, and it has a high conversion efficiency by using an adaptive biasing amplifier. The proposed ADC is designed with 0.18-um Magnachip CMOS process, Spectre simulation shows that the power consumption per conversion speed is reduced by 37% compared with the conventional algorithmic ADC.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.1-9
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• 2008

This paper suggests the triple-mode CMOS DC-DC converter that has temperature/voltage variation compensation techniques. The proposed triple-mode CMOS DC-DC converter is used to generate constant or variable voltages of 0.6-2.2V within battery source range of 3.3-5.5V. Also, it supports triple modes, which include Pulse Width Modulator (PWM) mode, Pulse Frequency Modulator (PFM) mode and Low Drop-Out (LDO) mode. Moreover, it uses 1MHz low-power CMOS ring oscillator that will compensate malfunction of chip in temperature/voltage variation condition. The proposed triple-mode CMOS DC-DC converter, which generates output voltages of 0.6-2.2V with an input voltage sources of 3.3-5.5V, exhibits the maximum output ripple voltage of below 10mV at PWM mode, 15mV at PFM mode and 4mV at LDO mode. And the proposed converter has maximum efficiency of 93% at PWM mode. Even at $-25{\sim}80^{\circ}C$ temperature variations, it has kept the output voltage level within 0.8% at PWM/PFM/LDO modes. For the verification of proposed triple-mode CMOS DC-DC converter, the simulations are carried out with $0.35{\mu}m$ CMOS technology and chip test is carried out.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.59-65
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• 1980

An attempt was made to survey soybean cultivars that were nonsensitive to the photoperiod for selection as possible breeding materials for wide area adaptable varieties. Fifty-five cultivars were subjected to different day length conditions. The number of days from sowing until flowering was shortened under short day length conditions, and late varieties tended to be more sensitive to day length than early varieties. The response to day length of the tested cultivars might be divided into three groups; low, intermediate and high degree, by their accelerated rate of flowering. Especially four varieties in the low responding group, Gembokin, Wirth, Wayne and Pi.54613 were identified to be nonsensitive to day lengths, that is, neutral varieties. They also showed little variation in morphological characteristics under different day length conditions.