• 제목/요약/키워드: Aquisition

검색결과 220건 처리시간 0.022초

비동기식 DS/SS-CSK 통신의 개선된 초기동기 (An Improved Acquisition of the Noncoherent DS/SS-CSK)

  • 김종헌;이한섭;홍대식;강창언
    • 한국통신학회논문지
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    • 제18권12호
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    • pp.1797-1805
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    • 1993
  • 이 논문에서는 DS/SS(Direct Sequence Spread/Spectrum) 시스템에서 초기동기(aquisition)를 위해, 정합 필터의 출력중 부정합된 최대 상관값을 임계값(threshold)으로 결정하는 TDMMC(Threshold Decision from the Maximum Mismatching Correlation value) 알고리듬을 제안한다. PN코드는 주기성과 정합됐을 때의 상관값이 정합되지 않을 때의 상관값보다 크다는 성질을 가지고 있다. 기존의 방식은 위의 2가지 성질 중에서 후자에 기반을 두고 있는 반면, TDMMC는 위의 성질 둘 모두에 기반을 두고 있다. TDMMC의 궁극적인 목적은 수신기에서 신호 검파확률를 1에 가깝게 하는데 있다(Pd$\longrightarrow$1). TDMMC는 임계값 블록(threshold block)을 이용하여 S/N이 변함에 따라 적절한 임계값을 설정할 수 있다. 시뮬레이션 결과, 비동기식 DS/SS-CSK 시스템에 적용된 TDMMC는 기존의 방식에 비해 성능이 향상됨을 보여준다.

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최대 평탄특성을 위한 2-D FIR Circular 필터 설계에 관한 연구 (A Study on Design of Maximally Flat 2-D FIR Circular Filter)

  • 서현수;배상범;김남호
    • 융합신호처리학회 학술대회논문집
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    • 한국신호처리시스템학회 2005년도 추계학술대회 논문집
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    • pp.159-162
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    • 2005
  • Recently, due to rapid developments of wireless communication and digital TV, modern society needs to process of aquisition, storage and transmission of much information. So the importance of signal processing is increasing and various digital filters are used in the two-dimensional signal such as image. And kinds of these digital filters are IIR(infinite impulse response) filter and FIR(finite impulse response) filter. And FIR filter which has the phase linearity, the easiness of creation and stability is applied to many fields. In design of this FIR filter, flatness property is a important factor in pass-band and stop-band. In this paper, we designed a 2-D Circular FIR filter using the Bernstein polynomial, it is presented flatness property in pass-band and stop-band. And we simulated the designed filter with noisy test image and compared the results with existing methods.

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유아의 조기영어교육과 이중언어발달에 영향을 주는 요인 (Children's Early English Education and the Factors on their Bilingual Language Development)

  • 황혜신
    • 한국생활과학회지
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    • 제16권4호
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    • pp.699-710
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    • 2007
  • The study purposes to explore the effects of individual characteristics and home environments of children on their bilingual language aquisition, that is, to examine whether their English language competency is different from their Korean language competency depending on those variables. Thus English or Korean language competency of children who had had early exposure in English learning were studied in terms of child's individual characteristics such as age, gender, exposure period to English, intelligence, and experiences of visiting English-speaking countries, and home environments such as parental age, educational level, income level, their perceived English competency, their perceived significance of English and Korean language, and the frequency of using English at home. 72 children who went to English kindergarten were tested with Peabody Pictures Vocabulary Test-Revised (PPVT-R) in Korean version and in English version respectively. The results show that child's intelligence and experiences of visiting English-speaking countries influence their Korean language competency. Also child's age, exposure period to English and experiences of visiting English-speaking countries influence their English language competency. Moreover their mother's educational background, father's English fluency, mothers' English fluency, and the frequency of using English at home influence child's English language competency, whereas any variables did not influence child's Korean language competency. Accordingly, child's English and Korean language competencies are related to each other.

도로관리통합시스템을 위한 도로영상수집차량개발 (Development of Highway Photologging Vehicle for the Highway Management System)

  • 정동훈;성정곤
    • Spatial Information Research
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    • 제13권3호
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    • pp.211-220
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    • 2005
  • 건설교통부에서는 기존의 도로현황을 더욱 빠르고 정확하게 파악하기 위해 도로관리통합시스템에서 전국의 일반국도에 대해 위치정보를 가진 디지털 영상을 제공하는 방안을 추진 중에 있다. 이를 위해 한국건설기술연구원에서는 도로를 주행하면서 일정거리간격으로 2매의 고해상도의 칼라 CCD영상을 취득할 수 있는 도로영상취득차량을 개발하였다. 본 논문에서는 특히 영상취득 S/W와 동기화장치 개발에 대해 기술하였으며 실험을 통해 차량의 궤적 정확도, 영상취득 S/W, 동기화 장치의 성능을 검토한 결과 도로관리통합시스템에서 필요한 도로영상을 취득하는데 적합한 것으로 판단된다.

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3차원 입체영상에서 양선형 보간법을 이용한 키스톤 왜곡 보정 (A Correction of the Keystone Distortion Using the Bilinear Interpolation Method in 3D Stereoscopic images)

  • 이승우;송영준;김남
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.524-527
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    • 2006
  • 본 논문은 영상에 발생하는 키스톤 왜곡을 효율적으로 제거하는 방법에 대해 논하고 있다. 3차원 영상을 구현하기 위한 2차원 영상 획득 과정에서 발생하는 키스톤 왜곡을 양선형 보간법을 사용하여 최대한 제거시킨다. 보통 2차원 영상에서의 키스톤 왜곡은 광학적인 장비를 사용하여 제거할 수 있으나, 효율성이나 작업의 용이성을 고려했을 때 영상처리 방법을 사용하면 더 큰 효과를 볼 수 있다. 왜곡이 제거된 2차원 영상을 사용하여 3차원 입체영상을 구현하면 더 선명하고 왜곡이 없는 입체영상을 획득한다.

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DEA와 BSC 기법을 이용한 조직 효율성 비교에 대한 연구 (A Combined DEA-BSC methodology for evaluating organizational efficiency)

  • 김범수;장태우;신기태;박진우
    • 산업경영시스템학회지
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    • 제28권2호
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    • pp.18-26
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    • 2005
  • The balanced scorecard(BSC) overcomes the limit of traditional financial statement that focuses on only financial performance. BSC is widely used in government and industry because of the clear representation of the relationship and logic between the key performance indicators(KPI) of 4 perspectives - financial, customer, internal process, and loaming and growth. However, traditional BSC does not consider evaluating the difference between the results measured by BSC. By using relatively small number of inputs and outputs In comparing decision-making units, data envelopment analysis(DEA) can aggregate multiple performance measures. In this research, we propose a methodology named CDB(Combined DEA and BSC) to evaluate the performance of organization considering financial and non-financial perspectives. CDB uses KPI of cause-and-effect relationship on BSC as inputs and outputs of DEA method. In addition, this research proposes a method of converting the KPI of BSC to the input and output variables of DEA, and enhancing discrimination power using the limit number of variables. We illustrate the methodology by giving an example of evaluating aquisition-unit efficiency in a supply chain.

부사관 모집제도 연구 (Study on the NCO Acquisition Pragram of Human Strength)

  • 정재극
    • 융합보안논문지
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    • 제14권3_1호
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    • pp.3-9
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    • 2014
  • 육 해 공군 부사관은 군을 유지 발전시키고 이끌어가는 근간이므로 인력획득업무는 매우 중요하다. 현재 부사관의 모집업무는 각 군이 양성기관별로 중복 운영하면서 지원자의 진로에 대한 궁금증을 효과적으로 해소해 주지 못하고 있는 실정이다. 부사관 선발제도는 군 고유성유지와 획득전문가 활용 및 법령개정 측면에서는 유리하였지만 홍보, 선발효율성, 국민편익증진, 예산절감 등에서 미흡하다고 보여진다. 따라서 각 군별 모집에 대한 일원화를 모병업무 전담기관인 병무청에서 운영한다면 각 군의 노력과 자원을 절감하면서 우수한 간부인력을 획득할 수 있으며, 부사관 지원자들이 적시에 정확한 정보를 제공할 수 있고, 편리한 시설과 시스템을 통한 향상된 서비스를 제공할 수 있을 것으로 기대된다.

고형음식물 위배출시 초기 정체기의 존재에 대한 연구 (Study on Confirmation of Solid-Meal Lag Phase of Gastric Emptying)

  • 이지영;이경수;김창근;정선관;원종진;나용호
    • 대한핵의학회지
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    • 제25권2호
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    • pp.207-210
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    • 1991
  • The purpose of this study was to examine the existence of a lag phase of gastric emptying of solid meals. We studied solid phase gastric emptying in 26 normal subject using continuous data aquisition for 30 minutes. Each ingested a 300 g meal containing $^{99m}Tc-labeled$ scrambled egg (solid 150g, milk 150 ml). Lag phase was determined by 1) inspection of the gastric emptying curve 2) time to a 2% decrease in stomach activity 3) the time of visual appearance of duodenal activity on computer image We concluded that solid meal lag phase exist.

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영국과 우리나라의 수학과 교육과정 비교 분석 연구 -수와 대수영역을 중심으로 (A Study on the Comparison and Analysis of School Mathematics Curriculum in England and Korea, -Focused on the 'Number and Algebra' Domain-)

  • 황혜정;신항균
    • 한국수학교육학회지시리즈A:수학교육
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    • 제41권3호
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    • pp.233-256
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    • 2002
  • This study investigated school mathematics curriculum of England, newly revised in 1998, focused on the 'number and algebra' domain among three major domains of the English curriculum. On the basis of its understanding, this domain was compared and analyzed with school mathematics curriculum of Korea. In doing so, this study explored its plans and procedures and established a frame of comparison for the curriculums between the two countries. The structure of the National Curriculum in England is composed of programmes of study and attainment targets. The former sets out what should be taught in mathematics at key stages 1, 2, 3, and 4 and provides the basis for planning schemes of work, and the latter sets out the knowledge, skills, and understanding that pupils of different abilities and matures are expected to have by the end of each key stage. Attainment targets are composed of eight levels and an additional level of increasing difficulty. According to the results of the present study, Korea focuses on the formal and systematic mathematical knowledge on the basis of sound understanding of certain mathematical terms or concepts. On the other hand, England tends to deal with numbers more flexibly and naturally through the aquisition of mental methods, calculator use methods, etc, and emphasizes that mathematics be realistic and useful in solving a diverse number of problems confronted in everyday life.

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영상처리를 이용한 머리의 움직임 추적 시스템 (Head tracking system using image processing)

  • 박경수;임창주;반영환;장필식
    • 대한인간공학회지
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    • 제16권3호
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    • pp.1-10
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    • 1997
  • This paper is concerned with the development and evaluation of the camera calibration method for a real-time head tracking system. Tracking of head movements is important in the design of an eye-controlled human/computer interface and the area of virtual environment. We proposed a video-based head tracking system. A camera was mounted on the subject's head and it took the front view containing eight 3-dimensional reference points(passive retr0-reflecting markers) fixed at the known position(computer monitor). The reference points were captured by image processing board. These points were used to calculate the position (3-dimensional) and orientation of the camera. A suitable camera calibration method for providing accurate extrinsic camera parameters was proposed. The method has three steps. In the first step, the image center was calibrated using the method of varying focal length. In the second step, the focal length and the scale factor were calibrated from the Direct Linear Transformation (DLT) matrix obtained from the known position and orientation of the camera. In the third step, the position and orientation of the camera was calculated from the DLT matrix, using the calibrated intrinsic camera parameters. Experimental results showed that the average error of camera positions (3- dimensional) is about $0.53^{\circ}C$, the angular errors of camera orientations are less than $0.55^{\circ}C$and the data aquisition rate is about 10Hz. The results of this study can be applied to the tracking of head movements related to the eye-controlled human/computer interface and the virtual environment.

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