• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.229-234
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• 2006

Acquisition is to detect the presence of the GPS signal. Once the signal is detected, the estimated frequency and code phase are passed to a tracking loop to demodulate the navigation data. In order to detect the weak signal, multiple length of data integration is always needed. In this paper, we present five different acquisition approaches based on circular correlation and Fast Fourier Transform (FFT), using coherent as well as non-coherent integration techniques for the multiple length of collected GPS satellite signal. Moreover a general approach of determining the acquisition threshold is introduced based on noise distribution which has been proved effective, and independent of the hardware. In the end of this paper, the processing speed and acquisition gain of each method are illustrated, compared, and analyzed. The results show that coherent approach is much more time consuming compared to noncoherent approaches, and in the case of multiple length of data integration from 2ms to 8ms, the processing times consumed by the fastest non-coherent acquisition method are only 25.87% to 1.52% in a single search, and 34.76% to 1.06% in a global search of those in the coherent acquisition. However, coherent acquisition also demonstrates its better performance in the acquisition gain, and in the case of 8ms of data integration it is 4.23 to 4.41 dB higher than that in the non-coherent approaches. Finally, an applicable scheme of combining coherent and non-coherent acquisition approaches in the development of a real-time Software GPS receiver in the University of Tokyo is provided.

• 국제지역연구
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• 제14권3호
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• pp.339-362
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• 2010

본 연구는 1986년부터 2008년까지 해외기업을 인수한 284개 한국의 상장기업들을 대상으로 인수기업의 피인수기업에 대한 통제수준이 국제 인수합병(M&A) 성과에 미치는 영향에 대하여 실증 분석하였다. 본 연구의 분석결과, 인수기업의 피인수기업에 대한 통제수준이 국제 인수합병 성과와 음(-)의 관계가 있음을 보여주었다. 또한 피인수기업에 대한 통제수준과 문화적 거리의 상호작용은 국제 인수합병 성과와 음(-)의 관계가 있으며, 피인수기업에 대한 통제수준과 관련형 인수의 상호작용도 국제 인수합병 성과와 음(-)의 관계가 있는 것으로 나타났다. 즉, 본 연구는 문화적 거리가 클수록 또는 관련형 인수일수록 피인수기업에 대한 통제수준은 국제 인수합병 성과에 더욱 부정적인 영향을 주는 것을 보여주었다. 이러한 결과는 국제 인수합병 성과의 결정요인으로서 피인수기업에 대한 통제수준의 역할에 대한 이해를 높이는 것은 물론, 문화적 거리 및 관련형 인수와 국제 인수합병 성과간의 관계에 대한 설명에 있어서도 피인수기업에 대한 통제수준을 고려함으로써 기존 연구들을 보완해 주고 있다.

• 아동학회지
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• 제31권6호
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• pp.153-166
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• 2010

The purpose of this study was to examine Korean young children's acquisition of honorific expressions. The participants of the present study were 297 young children (ages 3-5 years) from Kyunggi province. The results of the study showed that young children acquire honorific markers in the order of hearer-honorific expressions, subject-honorific expressions, and then object-honorific expressions. Five-year old children acquired at least 75% of the hearer-honorific expressions. The result can be explained by the fact that most of them were used in greetings. Even though more than 90% of five-year old children acquired the subject-honorific marker si, the acquisition rates of subjecthonorific nouns and subject-honorific verbs were less than 10%. Finally, the acquisition rates of objecthonorific expressions were less than 20%, with the exception of the object-honorific noun ce. The results of the study suggest that educational programs should be developed in order to facilitate the acquisition of honorific markers in young children.

• 한국신뢰성학회지:신뢰성응용연구
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• 제7권2호
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• pp.73-87
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• 2007

In this paper, based on the American weapon acquisition management framework in DoD Instruction 5000.2 "Operation of the Defence Acquisition System" and the contents of "DoD Guide for Achieving Reliability, Availability, and Maintainability" published by Defense Acquisition University, the kinds and roles of technical reviews are introduced and the identification of RAM related tasks which are performed at levels of technical reviews during acquisition process are considered. And the task allocations for developers, development managers, and users are proposed. Finally the relationships of acquisition management framework, technical reviews and RAM tasks are tabulated.

• 유통과학연구
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• 제12권5호
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• pp.15-26
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• 2014

Purpose - This study addresses an acquisition's impact on a firm's strategic relationship based on findings of existing academic studies and theoretical assertions. Through examining existing research results and theoretical grounds for an acquisition's impact on various stakeholders, this study indirectly approaches the impact on stakeholders including alliance partners. Research design, data, and methodology - This research identified a variety of related theoretical foundations and empirical studies. Research objectives of prior studies mainly focused on merging firms and direct participants of acquisition activity. In addition, academic attention on the impact on rival firms has recently been growing. However, little research on alliance partners was found. Prior studies simultaneously employed event study methodology and cross-sectional analysis to make further theoretical contributions. Results and Conclusions - Based on the findings of prior studies, this research proposed a complementary research model for future academic inquiry into the impact of an acquisition on an alliance partner's return and for predicting an acquisition announcement's effect on alliance partners.

• ETRI Journal
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• 제29권1호
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• pp.1-7
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• 2007

In this paper, we analyze the performance of double-dwell hybrid initial acquisition in a direct sequence ultra-wideband (DS-UWB) system via detection, miss, false alarm probabilities, and mean acquisition time. In the analysis, we consider the effect of the acquisition sequence as well as the deployment scenario of the abundant multipath components over small coverage of the piconet in the DS-UWB system. Based on the simulation, we obtain various performance measures for the mean acquisition time by varying parameters such as the total number of hypotheses to be searched, subgroup size, and dwell time. We thereupon suggest the optimum parameter set for the initial acquisition in the DS-UWB system.

• 아동학회지
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• 제13권1호
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• pp.125-138
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• 1992

The purpose of the present study was to examine the development of embedding through relative clause formation in the first language acquisition of Korean. Results are reported from the study of the spantaneous natural speech of 36 young Korean children ranging from 16 months to 45 months in age acquiring Korean as their first language in Chinju, Korea. The results revealed a developmental order in the first language acquisition of Korean relative clause structures. Namely, a free or headless relative clause appears to be acquired first, before lexically headed restrictive relative construction. This order is consistent with one evidenced in English (and also Chinese) first language acquisition, 'free' relatives appear to provide a developmentally early stage in the acquisition of restrictive relative clauses. The Korean data provided additional evidence for an intermediary stage with an overt complementizer as well as an overt lexical head. Implications for the results are disscused with regard to a continuous theory of universal grammar in the first language acquisition.

• 한국전자파학회논문지
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• 제11권5호
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• pp.723-730
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• 2000

이 논문은 Rayleigh 페이딩 채널환경에서 가산 백색 가우시안 잡음 제거 필터를 적용한 직렬 탐색 동기 획득 방식에 대한 성능을 분석하고, 임계치를 페이딩 정도에 따라 변화시킬 수 있도록 참조 필터를 추가하여 페이딩 환경에서 강인하게 동기 획득이 이루어지도록 하였다. 성능 분석을 위해 사용된 채널 모델은 JAKE 모델이며 성능분석 결과, 제안된 동기 획득 방식이 기존의 직렬 탐색동기 획득 방식과 수신된 신호에 대한 칩별 연속 평균을 구해 페이딩에 의한 감쇄요소를 보상하는 가산 백색 가우시안 잡음 제거 필터만을 적용한 동기 획득 방식보다 낮은 신호대잡음비에서 평균 동기 획득 시간이 줄어듬을 알 수 있었다.

• 정보처리학회논문지D
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• 제9D권1호
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• pp.161-166
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• 2002

PN 코드 포착 과정에서 기존의 방식은 한 시점에서 PN 코드를 검색하므로 PN 코드 포착시간에서 문제가 있다. 본 논문에서는 서로 다른 2개의 코드시점에서 PN 코드를 검색하므로 PN 코드 포착시간을 줄일 수 있는 알고리즘을 제안한다. 본 논문에서는 새롭게 제안한 알고리즘으로 ASIC 칩을 설계하였다. 제안한 알고리즘을 이용하여 설계한 ASIC 칩은 기존의 PN 코드 포착과정보다 면적(게이트의 수)은 약간 늘어났지만 PN 코드포착의 성능은 기존의 방법보다 더 좋음을 확인했다.

• 한국통신학회논문지
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• 제31권7A호
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• pp.696-701
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• 2006

In this paper, we analyze the performance of double-dwell hybrid initial acquisition in DS-UWB system via detection, miss, false alarm probabilities and mean acquisition time. In the analysis, we consider the effect of the acquisition sequence, and deployment scenario of the abundant multipath components over the small coverage of the piconet in DS-UWB system. Based on the simulation, we obtain various performance on the mean acquisition time by varying the parameters, such as the total number of hypotheses to be searched, subgroup size, and dwell time. Then, we suggest the optimum parameter set for the initial acquisition in DS-UWB system.