• Title/Summary/Keyword: acquisition time

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IS-95역방향 링크에서 단일 적분 및 이중 적분 검색 방식의 성능 분석 (Performance evaluation of the single-dwell and double-dwell detection schemes in the IS-95 reverse link)

  • 강법주;박형래;손정영;강창언
    • 한국통신학회논문지
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    • 제21권2호
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    • pp.383-393
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    • 1996
  • This paper considers the evaluation of the ecquistion performance for an accesschannel preamble based on a random access procedure of direct sequence code division multiple access(DS/CDMA) reverse link. The parallel acquistion technique that employs the single-well detection scheme and the multiple-dwell(double-dwell) detection scheme is mentioned. The acquisition performance for two detection schemes is compared in therms of the acquisition probability and the acquisition time. The parallel acquisition is done by a bank of N parallel I/Q noncoherent correlators. Expressions on the detection, false alarm, and miss probabilities of the single-dwell and multiple-dwell(double-well) detection schemes are derived for multiple H$_{1}$ cells and multipath Rayleight fading channel. comparing the single-dwell detection scheme with the multiple-dwell(double-dwell) detection scheme in the case of employing the parallel acquisition technique in the reverse link,the numerical results show that the single-dwell detection scheme deomonstrates a better performance.

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무기체계 신뢰도 향상방안 연구 (A Study on the Improvement for RAM for Weapon Systems)

  • 최석철;손문국
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제8권1호
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    • pp.39-59
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    • 2008
  • The performance of weapon system, based on the acceleration of advanced scientific technology, has been reinforced to the state of precision, complexion and multi-function. People have given great interest for a long time on its development, acquisition cost and enormous expense of operation/support. Under this environmental situation, this research paper proposes two kinds of implementation that can improve the RAM(Reliability, Availability, Maintainability) on weapon system. The first section is to understand all of the actual states on its reliability, in the acquisition process and to make the improvement for RAM at the milestones on the acquisition steps. The next section is to establish a defense RAM center, which will be closely cooperated with acquisition organization such as Ministry of Defense, DAPA(Defense Acquisition Program Administration), DTaQ(Defense agency for Technology and Quality) and ADD(Agency for Defense Development), etc. and to conclusively improve the RAM of weapon system in South Korea.

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망막 두께 측정을 위한 32채널 영상획득장치 개발 (Development of 32-Channel Image Acquisition System for Thickness Measurement of Retina)

  • 양근호;유병국
    • 융합신호처리학회 학술대회논문집
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    • 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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    • pp.110-113
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    • 2003
  • In this paper, the multi-channel high speed data acquisition system is implemented. This high speed signal processing system for 3-D image display is applicable to the manipulation of a medical image processing, multimedia data and various fields of digital image processing. In order to convert the analog signal into digital one, A/D conversion circuit is designed. PCI interface method is designed and implemented, which is capable of transmission a large amount of data to computer. In order to, especially, channel extendibility of images acquisition, bus communication method is selected. By using this bus method, we can interface each module effectively. In this paper, 32-channel A/D conversion and PCI interface system for 3-dimensional and real-time display of the retina image is developed. The 32-channel image acquisition system and high speed data transmission system developed in this paper is applicable to not only medical image processing as 3-D representation of retina image but also various fields of industrial image processing in which the multi-point realtime image acquisition system is needed.

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위상에러를 고려한 DS/CDMA시스템의 PN 부호 획득에 관한 연구 (A Study on the PN code Acquisition for DS/CDMA System over Phas-Error)

  • 정남모
    • 한국컴퓨터정보학회논문지
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    • 제7권3호
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    • pp.128-134
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    • 2002
  • 본 논문에서는 나카가미-m 확률밀도함수를 이용하여 페이딩 환경을 고려한 DS/CDMA시스템의 PN 부호 획득(acquisition)에 대한 성능을 분석하였다. 성능 분석은 PN 부호 획득 시간에 영향을 미치는 검출확률(detection Probability) $P_D$와 오경보확률(false alarm probability) $P_{FA}$에 대한 식을 유도하여 시뮬레이션으로 입증하였다. 그 결과 위상 에러를 보정하기 위하여 PLL의 이득을 높이고 레이크 수신기를 동시에 적용할 경우 PN 부호의 검출확률 $P_D$는 개선되었고, 오경보확률 $P_{FA}$는 감소하여 PN 부호의 동기 획득 성능을 개선시킬 수 있음을 입증하였다.

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임부의 위험상태에 따른 모성역할 획득의 예측인자들 (Predictors of Maternal Role Acquisition by Risk Status)

  • 이선아
    • 대한간호학회지
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    • 제29권4호
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    • pp.940-950
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    • 1999
  • One hundred two high-risk women(HRW) and 115 low-risk women(LRW) were studied at post-partal hospitalization and at 1, 4, and 8 months after giving birth to determine whether they would differ in the achievement of perceived maternal acquisition and whether predictors of maternal acquisition would differ for the two groups over time. The subjects were 102 HRW and 115 LRW, all in the above 27 weeks, admitted to two hospitals and to two clinic in the Kyoungnam area between July 1, 1998 and May 4, 1999. The data were analyzed by a SPSS program and the results are as follows ; 1) Predictors of Maternal role acquisition in the HRW were fetal attachment, maternal attachment, state anxiety, relationships of partner, social support in the early postpartum, maternal attachment, relationships of partner, depression, infant's health status in the postpartal 1 month, relationships of partner, self-esteem, educational degree in the postpartal 4 month, and maternal attachment, social supports in the postpartal 8 month. 2) Predictors of Maternal role acquisition in the LRW were fetal attachment, social supports, perceived experience about labor and delivery in the early postpartum, maternal attachment, sense of mastery in the postpartal 1 month, sense of mastery, experience with infants, relationships of partner in the postpartal 4 month and maternal attachment, experience with infants, social supports in the postpartal 8 month. 3) The hypothesis that HRW would score significantly lower on maternal competency than LRW was rejected. 4) The hypothesis that maternal acquisition would be significantly related to maternal attachment was accepted.

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가변구조를 갖는 순차 예측 방법을 이용한 m 계열 신호의 고속 포착 (Rapid Acquisition of m-sequence Signals by Sequential Estimation with Flexible Structure)

  • 현광민;박상규
    • 한국통신학회논문지
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    • 제27권7B호
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    • pp.664-672
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    • 2002
  • 본 논문은 고속으로 m 계열 신호를 포착하기 위하여 가변 구조를 갖는 순차 예측 포착 시스템을 제안하고 그 성능을 분석한 것이다. 고속 포착을 위해 예측기 내부 레지스터들의 초기값으로 저장되는 수신 PN 칩(chip)들 중에 1개의 오류를 가진 경우 다수의 국부 PN 부호 발생기를 이용하여 이 오류를 정정하고 부호 포착 성능을 개선한다. 제안된 시스템에서 예측 재생된 각각의 국부 PN 부호들과 수신된 PN 부호간의 해밍 거리는 설정된 경계값과 비교되어 바른 경로일 가능성이 높은 경로 선택과 부호 포착 선언에 사용된다. 시스템의 성능을 확인하기 위해 신호 흐름도 기법을 적용하여 검출 확률과 오 경보 확률에 의해 결정되는 평균 포착 시간을 계산한다. 본 논문에서 제안한 포착 시스템은 PN 부호 포착 시스템에 일반적으로 널리 사용되는 정합 필터를 가변 구조로 변형하여 사용함으로써 효율적이고 고속으로 부호 포착을 수행할 수 있음을 보였다.

PLM 기반 함정획득을 위한 프레임워크 개발 방법론 (Framework for an Advanced Naval Ships Acquisition based on PLM)

  • 신종계;오대균
    • 대한조선학회논문집
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    • 제46권2호
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    • pp.189-202
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    • 2009
  • As naval ships become more complex with the reduced cost and time for their development, modeling and simulation are increasingly used. The US navy has being applied the concept of a simulation-based acquisition(SBA) to their acquisition process. However, there have been few studies on a simulation-based acquisition for naval ships (SBA-NS) in the Korean naval shipbuilding. In this paper, we discuss a framework to establish collaborative environment(CE) for an advanced naval ships acquisition based on PLM. For this, we propose architectures and a naval ship information model for design the framework of the SBA-NS. To design the framework, we develop the methodology that is composed of three major processes that are the requirement analysis process, the SBA-NS architectures design process and the design process of a reference model of a naval ship product information. Applying the methodology, the framework suitable for the Korean Navy context is developed.

GPS L2C 소프트웨어 수신기의 빠른 신호 획득 기법 (Fast Acquisition Method for GPS L2C Software Receiver)

  • 권금철;심덕선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1754-1755
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    • 2011
  • GPS modernization program offers a new civil signal on L2 band and there are currently 9 GPS satellites transmitting L2C signal. The acquisition of L2C takes much time comparing with that of L1 signal. This paper suggests a fast acquisition method for the L2C GPS signals for software receivers.

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CDMA 환경하에서 최적화된 유사임의 코드 획득에 대한 연구 : 선형 공간적인 접근방법 (On Optimal PN Code Acquisition in CDMA Communications Environment : A Vector Space Approach)

  • 장승용;장우진;김운경
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 추계종합학술대회 논문집
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    • pp.13-16
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    • 1999
  • Many of the currently used PN code acquisition algorithms detect the phase of the incoming PN signal on the basis of ML estimation principle and utilize statistics grounded in taking inner products. As an extension of PN code acquisition algorithm using one auxiliary code introduced by Salih in 1996, we propose a more and optimal (hardware / time / space complexity wise) algorithm by using a vector space approach. We outline some important differences between our algorithm and that introduced by Salih and in the process point out some advantages of our algorithm.

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Active vision을 이용한 곡면의 형상정보 획득 및 NC가공 시스템

  • 손영태;최영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1992년도 춘계학술대회 논문집
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    • pp.256-261
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    • 1992
  • Acquisition of 3D points is an essential process for modelling of physical 3D objects. Although Coordinate Measuring Machine(CMM) is most accurate for this purpose, it is very time consuming. To enhance the data aquisition speed for scuptured surfaces, active vision with reflecctometric method was used for our system. A fter the data acquisition, the system automatically generates cutting tool path for the 3-axis milling of the object. The fullyintegrated system from the data acquisition to the NC-code generation was implemented with IBN-PC/386 and necessary hardwears.