• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.107-112
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• 2006

The previous acquisition method of GPS receiver for reference station adopts not only the coherent integration method but also the non-coherent integration method in order to enhance sensitivity under noisy environment. However, under noisy environment, the previous GPS signal acquisition method causes the non-coherent integration loss which is a major factor among losses that can be caused during GPS signal acquisition. The non-coherent integration loss also increases with the strength of the received noise. This paper has intention of analyzing the performance of the GPS signal acquisition method proposed to effectively enhance sensitivity of DGPS reference receiver under noisy environment. This paper presents that the proposed GPS signal acquisition method suppresses the non-coherent integration loss through post-processing simulation. Furthermore, with regard to the mean acquisition time, it is shown that the number of search cells of the proposed GPS signal acquisition method is much fewer than that of the previous GPS signal acquisition method.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.96-102
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• 2004

For sensitivity enhancement, the general assisted-GPS acquisition method adopts not only the coherent accumulation technique but also the non-coherent accumulation technique since the long coherent accumulation period increases the number of frequency search cells. But the non-coherent accumulation technique causes tile squaring loss, which is a dominant factor among the acquisition losses of assisted GPS dealing with weak GPS signals. This paper derives the squaring loss of the previous assisted-GPS acquisition method and proposes an assisted-GPS acquisition method for solving the problem of squaring loss in weak signal environment. In this paper, it is explained that the proposed assisted-GPS acquisition method prevents the squaring loss using a coupled coherent accumulation technique and the number of search cells of the proposed assisted-GPS acquisition method is much smaller than that of the previous assisted-GPS acquisition method. Finally, through the simulation by the GPS simulator, the acquisition success rate of the proposed assisted-GPS acquisition method is compared with that of the previous assisted-GPS acquisition method and the acquisition improvements are shown in weak signal environment.

• 전자공학회논문지S
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• 제34S권8호
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• pp.10-19
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• 1997

In this paper, perfodrmance of matched-filter (MF) acquisition scheme is analyzed for a direct-sequence/code-division-multiple-access (DS/CDMA) system in a microcellular environment. Mean acquistion time is used as a performance measure. It is demonstrated that acquisition performance is enhanced using interference suppression filter in a Rician fading channel. To apply for multiuser environments, multiple access interference is considered in the performance analysis. From the numerical results, it is shown that mean acquistion time decreases with the increasing SNR/chip, and acquisition performance is improved as the number of taps of interference suppression filter. It is also shown that mean acquisition time increases with the number of users in the system, and acquistion performance is degraded as the icrease of narrowband interference bandwidth. The analysis in this paper can be applied to a DS/CDMA overlay environment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.185-188
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• 2000

In this paper, performance of a PN code acquisition scheme is analyzed and simulated for a DS/CDMA overlay system where a CDMA user and a narrowband user coexist in the same frequency band. To suppress the NBI, an interference suppression filter is employed at the receiver front-end. From the simulation results, it is shown that the interference suppression filter is very effective for suppression of the NBI and rapid PN code acquisition in a DS/CDMA overlay environment. It is also shown that the one-sided tap number of 5 fur interference suppression filter is sufficient to suppress the NBI.

• 한국국방경영분석학회지
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• 제28권1호
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• pp.67-82
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• 2002

In this paper, we consider a rule of application of PRICE(Parametric Review of Information for Costing and Evaluation) model to the environment of Korean defense industry. The PRICE model which is a computer model to estimate the cost of an acquisition program, was developed for the regulation of defense acquisition program in the United States. Therefore, it is essential for us to figure out how we can adopt it under our defense acquisition regulations. We will give an alternative method to apply the PRICE model to the mapping problem between two regulations.

• 한국국방경영분석학회지
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• 제36권2호
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• pp.71-84
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• 2010

본 연구는 복합시스템 환경에서의 능력기반 획득프로세스에 대해 기술하며, 인식 패러다임을 기반으로 쓰여진 정성적인 논문이다. 미래 전장은 단일전구 내에서 다양한 센서와 슈터가 각각의 그리드를 형성하고, 네트워크기반 전장관리체계에 의해 임무와 기능을 수행하는 복합시스템 개념으로 변화되고 있다. 복합시스템은 특정 능력을 충족시키기 위해 개별 시스템들을 보다 큰 시스템으로 통합한 시스템의 묶음 또는 배열이다. 따라서, 획득프로세스도 기존의 단일시스템 요구사항 중심에서 복합시스템 환경하의 능력기반 획득으로 변화되고 있다. 이러한 관점에서 본 논문은 능력기반 획득프로세스의 핵심 요소인 JCIDS, DAS 그리고 CEP에 대해 기능측면에서 분석하였다. 그리고, 이러한 종합적 분석결과로 부터 한국적 획득환경에 적합한 능력기반 획득적용방안을 제시하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.77-80
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• 2000

Adaptive filter based code acquisition scheme offers a fast acquisition with a low error probability. However, it has been studied only under a coherent environment. In this paper, the noncoherent adaptive code acquisition scheme employing a differential detection technique is proposed. For the proposed scheme, system probabilities and the mean acquisition time are analyzed numerically. Simulation results show that the proposed system outperforms over the conventional matched filter by 2-4 ㏈ under AWGN channel for 16 taps.

• 한국군사과학기술학회지
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• 제17권4호
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• pp.492-500
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• 2014

The defense industry export of Korea has been steadily risen since 2006. It is attained $340million, the highest export amounts ever, in 2013. As the defense industry export increase, Defense Acquisition Program Administration (DAPA) built defense industry export and import management system to assist export and to protect defense technologies. In this paper, we study factors to activate the defense industry export and import management system using Technology Acceptance Model(TAM) in compulsive usage environment. The significance of this study is as follows: First, we prove the reliability and feasibility of measurement variables in defense industry of compulsive usage environment. Second, we suggest factors to activate the defense industry export and import management system. Third, we present methodology to find factors in computation systems of public institute using TAM.

• 한국통신학회논문지
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• 제31권4C호
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• pp.371-380
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• 2006

수신안테나 다양성을 쓰는 직접수열 부호분할 다중접속 시스템에서 의사잡음 부호를 획득할 때 평균값, 큰값, 그리고 작은값 일정 오경보 확률 처리기의 성능 특성을 균질 잡음 환경에서 얻고 견주어 본다. 균질 잡음 환경에서는 평균값 일정 오경보 확률 방법이 성능이 가장 좋고 큰값 일정 오경보 확률 방법은 평균값 일정 오경보 확률 방법과 성능이 거의 같다는 것을 모의실험으로 보인다. 이 논문의 2부에서는 비균질 잡음 환경에서 부호획득에 알맞게 평균값, 큰값, 그리고 작은값 일정 오경보 확률 처리기를 다룬다.

• 한국해안해양공학회지
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• 제9권4호
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• pp.176-181
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• 1997

토목환경공학분야의 응용을 위하여 실용적이고 사용이 간편한 자료수집기를 개발하였다. 이 기기는 PC의 병렬포트를 이용하여 자료를 획득·전송하고 비전문가라 하더라도 실내 및 현장실험에 손쉽게 응용할 수 있도록 설계되었다. 통상의 자료수집기는 저장용량이 작아 불편한 점을 감안하여 컴퓨터의 저장장치를 그대로 이용하여 문제를 해결하였다. 또한 PC의 고급 프로그래밍 언어를 직접 이용하여 복잡한 자료수집계획을 손쉽게 수행할 수 있도록 하였다. 방화대교 건설현장에서 각종 센서와 GPS를 이용하여 행한 실제 현장시험을 통하여 개발된기기의 실용성을 입증하였다.