• Monthly Korean Chicken
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• v.1 no.4 s.4
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• pp.2-4
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• 1995

북한 닭고기 생산량 남한의 $\frac{1}{10}$수준 - 농산물유통마진 최고 $71.7{\%}$ - 국내칼로리 섭취증가율 아시아에서 1위 - 닭고기 장기보관방법 - 국제 곡물가격 폭등세 - 농축수산물 원산지 표시제 통합실시 - 육계 ${\cdot}$ 근육 골격이상 질병발생율 높아

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.88-92
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• 2009

Total pressure recovery ratio in intake is crucial factor to the operational characteristics of supersonic propulsion system because it does not compress inlet air mechanically by compressor, but does compress inlet air by ram compression. As the result of that the dynamic characteristic analysis of engine was performed before the controller was designed, it could be ascertained when the AoA of flight vehicle increases, the buzz margin decreases so that the shock wave produced outside intake in the specified area according to flight operation's characteristics. Therefore the PID control algorithm was designed to be controlled buzz margin that the characteristic of shock wave could meet the requirement of performance in intake. The PID controller was designed that the buzz margin value is being positive number using the control variables; fuel flow and nozzle throat area.

• The Korean Journal of Financial Management
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• v.15 no.2
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• pp.235-254
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• 1998

본 연구의 목적은 1993년에 미국에서 도입된 변동요율제도(risk-based deposit insurance system)의 도입으로 인한 미국은행들의 위험.이윤추구행동의 변화와 이러한 변화에 대한 주식시장 투자가들의 평가에 대한 실증적분석에 있다. 1989-1995년간 82개 미국 상장은행들을 대상으로 한 분석 결과 변동요율제도의 도입이후에 고(高)위험수준 은행, 즉 비싼 보험료를 부과받게 될 은행들의 위험추구는 저(低)위험수준 은행, 즉 낮은 보험료를 부과받게 될 은행들의 위험추구에 비하여 유의적으로 낮아졌음을 발견하였으며 이러한 결과는 은행산업의 안정을 도모하기 위하여 도입된 변동요율제도의 유효성을 뒷받침하여 주는 결과라고 할 수 있을것이다. 한편 변동요율제도하에서 고(高)위험.고(高)보험료로 인하여 위험추구가 많이 감소된 은행들은 위험추구의 감소로 인한 기대이윤(expected profit)의 감소를 이자율마진의 유리한 조정을 통해 은행고객 즉 예금자와 대출자들에게 집합적으로 전가함으로써 다소 만회할 수 있었다. 그러나 이러한 이자율마진의 유리한 조정은 위험추구의 감소로 인한 기대이윤의 감소를 완전히 상쇄하지는 못하였으며 따라서 주식시장 투자가들의 일반적인 평가는 변동요율제도하에서 위험추구가 많이 감소된 은행 즉 고(高)위험.고(高)보험료 은행의 주가수익율이 저(低)위험 저(低)보험료 은행의 주가수익을 보다 대체로 많이 하락하는 것으로 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.233-236
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• 2005

본 논문에서는 중첩되는 두 개 이상의 PAN의 무선영역이 간섭을 일으키는 경우와 다수의 무선기기가 동시에 접속하는 경우에 대비하여 간섭마진 정보를 이용한 가변 전송율을 갖는 UWB 통신 시스템을 제안한다. 또한, 가변 전송율 UWB 통신 시스템을 불완전 다중접속 간섭 환경에서 고정 전송율을 갖는 UWB 통신 시스템과의 성능을 비교 분석하고 전송효율을 평가하였다.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.221-237
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• 2005

This paper presents and analyzes field test results of Equalization Digital On-Channel Repeater (EDOCR) using ATSC(Advanced Television Systems Committee) terrestrial digital TV broadcasting system. In the field test, according to EDOCR On/Off, types of antennas and receivers we measured reception possibility, C/N(Carrier to Noise Ratio), reception power, noise and input margin at each test point. By the field test results, the reception rate of the receiver manufactured in 2004 was $33\%$ when EDOCR is off and directional antenna is used. However, the reception rate was $100\%$ when EDOCR is on. In addition, the noise margin, which determines reception quality was increased at least 6 dB, so that it is capable of constructing SFN(Single Frequency Network) using the EDOCR.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.341-350
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• 2007

In this paper, the derivation of protection ratio is newly proposed for the detailed planning of frequency coordination in microwave relay networks, and computed results for protection ratio of co-channel and adjacent channel are illustrated over the actual system and its frequency. It is shown that the suggested method based upon availability prediction can be expressed in terms of composite fade margin, interference-to-noise ratio(I/N), net filter discrimination, and system parameters. According to results, for 6.7 GHz, 60 km, 64-QAM, and I/N= -6 dB at BER $10^{-6}$, composite fade margin and co-channel protection ratio provide 25.5 and 50.7 dB, respectively. Also, net filter discrimination and adjacent channel protection ratio are obtained as 26.3 and 24.4 dB, respectively, at the first adjacent channel of 40 MHz. The proposed method provides some merits in computing protection ratio for microwave relay networks in view of an easy extension and practical applications considering more detailed and various system parameters.

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.272-273
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• 2001

Normalized gain difference for index-coupled and quarter wavelength shifted DFB lasers for various facet reflectivities are calculated as a function of facet phases.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.28-28
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• 2002

가스터빈 엔진을 운용하는 데 있어서 가/감속율을 크게 하면 엔진성능 천이 시간은 짧으나 압축기에서의 서지나 터빈 입구온도의 급격한 상승이 발생할 수 있으며 가/감속율을 작게 하면 엔진은 안정적이나 천이시간이 길어지게 되어 결과적으로 엔진의 동적 응답성이 나빠지게 된다. 또한 압축기에서 발생할 수 있는 서지를 방지하기 위하여 압축기 서지 마진이 l0%∼20%인 서지 한계선(조정선)을 설정하여 엔진이 서지 한계선을 넘지 않도록 제어한다.

• Progress in Medical Physics
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• v.23 no.2
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• pp.81-90
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• 2012

The effect of setup uncertainties on CTV dose and the correlation between setup uncertainties and setup margin were evaluated by Monte Carlo based numerical simulation. Patient specific information of IMRT treatment plan for rectal cancer designed on the VARIAN Eclipse planning system was utilized for the Monte Carlo simulation program including the planned dose distribution and tumor volume information of a rectal cancer patient. The simulation program was developed for the purpose of the study on Linux environment using open source packages, GNU C++ and ROOT data analysis framework. All misalignments of patient setup were assumed to follow the central limit theorem. Thus systematic and random errors were generated according to the gaussian statistics with a given standard deviation as simulation input parameter. After the setup error simulations, the change of dose in CTV volume was analyzed with the simulation result. In order to verify the conventional margin recipe, the correlation between setup error and setup margin was compared with the margin formula developed on three dimensional conformal radiation therapy. The simulation was performed total 2,000 times for each simulation input of systematic and random errors independently. The size of standard deviation for generating patient setup errors was changed from 1 mm to 10 mm with 1 mm step. In case for the systematic error the minimum dose on CTV $D_{min}^{stat{\cdot}}$ was decreased from 100.4 to 72.50% and the mean dose $\bar{D}_{syst{\cdot}}$ was decreased from 100.45% to 97.88%. However the standard deviation of dose distribution in CTV volume was increased from 0.02% to 3.33%. The effect of random error gave the same result of a reduction of mean and minimum dose to CTV volume. It was found that the minimum dose on CTV volume $D_{min}^{rand{\cdot}}$ was reduced from 100.45% to 94.80% and the mean dose to CTV $\bar{D}_{rand{\cdot}}$ was decreased from 100.46% to 97.87%. Like systematic error, the standard deviation of CTV dose ${\Delta}D_{rand}$ was increased from 0.01% to 0.63%. After calculating a size of margin for each systematic and random error the "population ratio" was introduced and applied to verify margin recipe. It was found that the conventional margin formula satisfy margin object on IMRT treatment for rectal cancer. It is considered that the developed Monte-carlo based simulation program might be useful to study for patient setup error and dose coverage in CTV volume due to variations of margin size and setup error.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1667-1671
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• 2015

Multi-level holographic data storage is a candidate for the next generation data storage system, since it can store more than one bit per pixel. It is possible to increase the number of codewords if the number of levels is increased, and the code with an appropriate selection of codewords can also increase the minimum distance. In this paper, we propose three multi-level modulation codes of the code rate 1 bit/pixel and compare the performance according to the minimum distance. The result shows that the code with small number of levels is better than that of large number of levels because it is hard to detect threshold value.