• 한국통신학회논문지
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• 제16권11호
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• pp.1095-1102
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• 1991

본 논문에서는 2-h CPM의 차동 복조 방식을 제안하고 이에 따른 오율 성능을 분석한다. 차동 복조에 적합한 변조지수 집합을 도출하고 이로부터 얻어진 변조지수에 따른 전력 스펙트럼을 구하여 기존의 MSK와 OPSK등과 비교,분석하였다. 또한 제안된 차동 검파기에 의한 오율 성능과 2-h CPM의 차동 복조식 비터비검파기를 적용시켜 얻은 오율 성능 등을 비교, 분석하였다.

• Toxicological Research
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• 제7권1호
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• pp.21-27
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• 1991

We developed a simple method to determine benzodiazepines in biological samples using electron capature detectors and nitrogen-phosphorous detectors. The extraction of 13 benezodiazepines in urine at pH 9.5 with toluene and its analysis in GC/NPD showed the peaks in 9-16 min. In this retention time range, the biological backaground was fairly low and the drugs could be identified in low concentrations. The benzodiazepines in urine samples were screened by the fluorescence polarization immunoassay and positive samples were confirmed by the GC/NPD method.

• Journal of Communications and Networks
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• 제9권1호
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• pp.28-33
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• 2007

Estimated channel information, especially multipath length and multipath channel of the desired user, is necessary for most previously reported linear blind multiuser detectors in code division multiple access (CDMA) systems. This paper presents a new blind intersymbol decorrelating detector in asynchronous CDMA systems, which uses the cross correlation matrix of the consecutive symbols. The proposed detector is attractive for its simplicity because no channel estimation is required except the synchronization of the desired user. Compared with other reported multiuser detectors, simulation results show that the proposed detector provides a good performance when the active users have significant intersymbol interference and the multipath length is short.

• 대한조선학회논문집
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• 제41권5호
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• pp.63-69
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• 2004

This study contains the CFD analysis to predict the flow in engine room and utilize the results as a reference for arranging smoke detectors. FLUENT, a commercial CFD code is adopted because of its good application experience in DSME(Daewoo Shipbuilding & Marine Engineering Co.. Ltd.). The target is the engine room of VLCC. which was delivered in 2002. The model for analysis includes main structure elements, ventilation ducts, main engine and other big size equipment. From the analysis results, the internal flow pattern can be observed and some guidelines for the position of smoke detectors cane be presented.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.141-147
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• 2017

Mechanical shim is an advanced technology for reactor power and axial offset control with control rod assemblies. To address the adverse accuracy impact on the ex-core power range neutron flux measurements-based axial offset control resulting from the variable positions of control rod assemblies, the lead-lag-compensated in-core self-powered vanadium detector signals are utilized. The prompt ${\gamma}$ current of self-powered detector is ignored normally due to its weakness compared with the delayed ${\beta}$ current, although it promptly reflects the flux change of the core. Based on the features of the prompt ${\gamma}$ current, a method for configuration of the lead-lag dynamic compensator is proposed. The simulations indicate that the method can improve dynamic response significantly with negligible adverse effects on the steady response. The robustness of the design implies that the method is of great value for engineering applications.

• 반도체디스플레이기술학회지
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• 제19권2호
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• pp.11-15
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• 2020

In a typical initial setup of a PCB component inspection system, operators should manually input various information such as category, position, and inspection area for each component to be inspected, thus causing much inconvenience and longer setup time. Although there are many deep learning based object detectors, RetinaNet is regarded as one of best object detectors currently available. In this paper, a method using an extended RetinaNet is proposed that automatically detects its component category and position for each component mounted on PCBs from a high-resolution color input image. We extended the basic RetinaNet feature pyramid network by adding a feature pyramid layer having higher spatial resolution to the basic feature pyramid. It was demonstrated by experiments that the extended RetinaNet can detect successfully very small components that could be missed by the basic RetinaNet. Using the proposed method could enable automatic generation of inspection areas, thus considerably reducing the setup time of PCB component inspection systems.

• 한국통신학회논문지
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• 제23권8호
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• pp.2072-2079
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• 1998

본 논문에서는 비동기 CDMA 채널을 위한 의사 역행렬 형태의 역상관 검출기를 제안한다. 본 논문에서는 먼저 동기 CDMA 채널에서 역상관 검출기의 동작이 확산 수열로 구성된 행렬의 의사 역행렬 처리와 동일함을 보이고, 이 사실을 이용하여 역상관 검출기가 다중접속 간섭신호를 완전히 제거하는 선형 검출기들 중 최대의 신호대 잡음비를 가짐을 보인다. 그 후, 의사 역행렬 형태를 비동기 채널로 확장하여 새로운 역상관 검출기를 제안하고, QR-분해를 이용한 구현 방법에 대해 논의한다. 제안 방법은 각 사용자별로 분산적인 형태를 가지기 때문에 사용자 수 변화에 대한 검출기 계수의 갱신을 효율적으로 수행할 수 있다. 본 논문에서는 마지막으로 제안된 역상관 검출기의 성능을 비트오류율의 관점에서 분석한 후, 컴퓨터 모의 실험을 통해 기존의 정합 필터링 방법에 대한 성능 향상 정도를 확인한다.

• 한국ITS학회 논문지
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• 제19권5호
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• pp.97-105
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• 2020

최근 스마트시티 구축을 위하여 지능형 도로인프라를 이용한 차량의 교통정보를 취득하고, 이를 효율적으로 관리하기 위한 기술의 개발이 요구되고 있다. 그동안 도로의 교통정보를 분석하기 위해서는 루프 검지기, 초음파 검지기, 영상식 검지기 등의 다양한 기술들이 활용되고 있었다. 그런데, 이러한 종래의 기술들은 도로내에서 이동하는 차량을 대상으로 교통정보 DB 구축을 위해 필요한 교통 밀도, 대기행렬의 길이등 다양한 교통 DB의 수집에 어려움이 있었다. 따라서, 본 논문에서는 도로위에 지능형 CCTV등 카메라 인프라를 기본으로 구축되는 스마트 시티를 가정하여 도로의 CCTV카메라를 이용하여 도로 CCTV의 Vision Tracking을 이용한 주행차량의 교통DB산출하는 솔루션을 제시하고, 이에 대한 모의실험과 기초성능 검증을 행하였다. 본 논문에서 제시한 솔루션은 일반론으로 발전시켜야할 숙제는 여전히 남아있지만, 가변하는 스마트시티 도로환경속에서 도로부착형 CCTV카메라 이동차량 환경을 반영한 새로운 지능형 교통DB산출솔루션으로 관련 분야에서 유용하게 활용될수 있을것으로 기대된다.

• 약학회지
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• 제30권5호
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• pp.214-219
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• 1986

A gas chromatographic procedure is described for the quantitative analysis of ephedrine hydrochloride, pseudoephediiiie hydrochloride and norephedrine hydrochloride in pharmaceutical preparations. The procedure was based upon the determination of thioureas formed from amines and phenylisothiocyanate. The recoveries of ephedrine, pseudoephedrine and norephedrine from pharmaceutical preparations were 100.7(S.E. 0.9), 99.5(0.8), 99.1(0.8) and 99.1%(O.9), respectively. The high accuracy and precision of this assay were inherent in the flame photometric detectors normally used in gas chromatography.

• 전기의세계
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• 제15권4호
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• pp.18-21
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• 1966

A transistorized counting-rate meter was designed by substituting one of diodes in the ordinary diode pumping circuit by the Darling's constant current source. Its circuit is so simple and stable that it is proper to use as a part of portable radiation detectors. Maximum readable counting rate is well above 100 kc/s and the linearity is very good. Output deviations due to the variations of embient temperatures are less than 5% in the temperatures from 20.deg. C to 40.deg. C.