• 제목/요약/키워드: Pointing

검색결과 668건 처리시간 0.02초

자기토커 배치와 반작용휠 모멘텀 덤핑 성능 관계 (Relationship between Magnetic Torquer Arrangement and Reaction Wheel Momentum Dumping Performance)

  • 손준원
    • 한국항공우주학회지
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    • 제46권9호
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    • pp.760-766
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    • 2018
  • 위성에 작용하는 외란으로 인해서 반작용휠에 원치 않는 모멘텀이 쌓인다. 이를 해소하기 위해서 위성의 축방향으로 설치한 세 개의 자기토커를 이용한다. 자기토커는 지구 자기장과 상호 작용하여 간접적으로 토크를 생성한다. 따라서 모멘텀 덤핑시 자기토커와 자기토커 주위에 형성되는 지구 자기장을 동시에 고려해야 한다. 높은 경사각을 가지는 저궤도 위성이 지구지향을 할 때 위성체의 피치축으로는 매우 약한 지구자기장이 형성된다. 이 경우 하나의 자기토커에 과부하가 걸려서 모멘텀 덤핑 성능이 떨어진다. 본 연구에서는 자기토커의 배치를 변경하여 지구지향자세에서 모멘텀 덤핑 성능을 향상시키는 방법에 대해서 살펴본다.

직교 시퀀스를 이용한 양자통신에서의 효율적인 신호 검출 기법 (Efficient Signal Detection Technique Using Orthogonal Sequence for Quantum Communication)

  • 김윤현;김진영
    • 한국위성정보통신학회논문지
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    • 제7권1호
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    • pp.21-26
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    • 2012
  • 우리나라는 지난 20여 년 디지털 정보기술 강국을 지향해 왔지만 선진국에서 이미 투자를 시작한 양자 정보 과학 분야에 대한 연구 및 투자는 거의 이루어지지 않았으며, 양자 정보 통신 기술의 수준 또한 개발 선진국들에 비해 턱없이 부족한 상황이다. 최근, 양자역학에 기반을 두고 있는 양자 정보 처리 및 통신에 대한 연구가 세계적으로 활발히 진행 중이다. 90년대부터 본격화된 양자정보이론의 연구는 양자 컴퓨팅, 양자 통신, 양자 정보이론 등의 분야에서 발전해오고 있으며, 90년대 말에 이르러 양자 암호 통신 및 양자 알고리즘 등의 분야에서 큰 연구 성과를 나타내기 시작하였다. 본 논문에서는, 양자 통신 시스템에서 효율적인 양자 신호 전송 및 검출을 위해 직교 시퀀스를 이용한 효율적인 양자 신호 검출 방안에 대해 논하고자 한다.

컴퓨터 작업에서 마우스 종류에 따른 상완 부하 평가 (Assessment of the Upper Limb Work Load according to the Mouse Size in VDT Tasks)

  • 송영웅;김경아
    • 대한산업공학회지
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    • 제37권3호
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    • pp.209-215
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    • 2011
  • The objective of this study was to determine whether there are differences in hand muscle activities (APB : abductor pollicis brevis, ED : extensor digitorum, ECU : extensor carpi ulnaris, and EI : extensor indicis) and subjective discomfort according to the three mouse sizes (small, medium, large) and two task types (pointing and scrolling). The mouse size and task type showed significant interaction effects on the total NEMG (p = 0.004) and on the NEMG of the abductor pollicis brevis muscle (p = 0.001). The total NEMG and the NEMG of APB showed the highest value in the 'scrolling' task using the 'small' mouse. However, the NEMG of the EI was different according to the mouse size, and the 'small' mouse showed the lowest value. The subjective discomfort was the lowest in the 'medium' mouse, and all nine subjects preferred the 'medium' size. The hand-size related anthropometric variables showed different correlations according to the task type and mouse size with the NEMGs and subjective discomfort. The results of this study could be used as a basic information for the determination of the proper mouse size according to the hand size.

CdS센서 배열을 이용한 비접촉 입력장치에 관한 연구 (A study on the Non-Contact Human Interface using by CdS Sensor Array)

  • 차성복;황대석;이영우
    • 한국정보통신학회논문지
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    • 제10권11호
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    • pp.2045-2048
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    • 2006
  • 본 연구에서는 키보드나 마우스와 같은 기존의 입력 방식이 아닌 CdS센서 배열을 이용하여 비접촉 방식의 입력방식을 제안하였다. 여기에 측정 하고자 하는 위치에 빛을 조사하였다. 이 때 CdS 센서에서 측정된 값을 A/D 변환하였고 주변 CdS 센서와의 비를 구해 좌표 값을 획득하였다. 획득된 좌표값은 RS-232통신으로 PC에 전송하여 LabVIEW를 이용해 모니 터 화면에 나타내었다. 구현된 장치를 이용하여 측정한 결과로 CdS 센서간 거리를 100등 분 했을 때 위치 값을 정확히 표시함을 확인할 수 있었다.

교차참조점에 기반한 정지영상의 워터마크 생성 및 유사성 삽입 기법 (A Technique of Watermark Generation and Similarity Embedding for Still Images Based on Cross Reference Points)

  • 이항찬
    • 전기학회논문지
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    • 제56권8호
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    • pp.1484-1490
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    • 2007
  • The Cross Reference Point(CRP) is a robust method for finding salient points in watermarking systems because it is based on the geometrical structure of a normalized image in order to avoid pointing error caused by digital attacks. After normalization of an image, the 100 CRPs are calculated. Next, the 100 blocks centered by CRPS are formed. These 100 blocks are arranged using a secrete key. Each boundary of 50 out of 100 blocks is surrounded by 8 blocks which are selected by the ordered number of a preceding block. This number is a seed of random number generator for selecting 8 out of 50 blocks. The search area of a center block is formed by a secrete key. The pixels of a center block are quantized to 10 levels by predefined thresholds. The watermarks are generated by the 50 quantized center blocks. These watermarks are embedded directly in the remaining 50 blocks. In other words, 50 out of 100 blocks are utilized to generate watermarks and the remaining 50 blocks are used to watermark embedding. Because the watermarks are generated in the given images, we can successfully detect watermarks after several digital attacks. The reason is that the blocks for the generation and detection of watermarks are equally affected by digital attacks except for the case of local distortion such as cropping.

Design of Antenna Tracking Software for MSC(Multi-Spectral Camera) Antenna Control

  • Kim, Young-Sun;Yong, Sang-Soon;Kong, Jong-Pil;Heo, Haeng-Pal;Park, Jong-Euk;Paik, Hong-Yul
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.235-240
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    • 2002
  • This paper shows the desist concept of an ATS(Antenna Tracking Software) to control the movement of the MSC(Multi-Spectral Camera) antenna. The MSC has a two-axes directional X-band antenna for image transmission to KGS(KOMSAT2 Ground Station). The main objective of the ATS is to drive the APM(Antenna Pointing Mechanism) to the required elevation and the azimuth position according to an appropriate TPF(Tracking Parameter File). The ATS is implemented as one task of the SBC(Single Board Computer) software, which uses VxWorks as a real time OS. The ATS has several operational modes such as STANDBY mode, First EL mode, First AZ mode, Normal Operation mode, and so on. The ATS uses two PI controllers fur the velocity and the position loop respectively, to satisfy the requirements specification. In order to show the feasibility of the described design concept, the various simulations and the experiments are performed under specific test configuration.

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Effect of the Signal-to-Noise Power Spectra Ratio On MTF compensated EOC images

  • Kang, Chi-Ho;Choi, Hae-Jin
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.202-207
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    • 2002
  • EOC (Electro-Optical Camera) of KOMPSAT-1 (Korea Multi-Purpose SATellite) has been producing land imageries of the world since January 2000. After image data are acquired by EOC, they are transmitted from satellite to ground via X-band RF signal. Then, EOC image data are generated and pass through radiometric and geometric corrections to generate standard products of EOC images. After radiometric correction on EOC image data, Modulation Transfer Function (MTF) compensation is applicable on EOC images with user's request for better image quality. MTF compensation is concerned with filtering EOC images to minimize the effect of degradations. For Image Receiving and Processing System (IRPE) at KOMPSAT Ground Station (KGS), Wiener filter is used in MTF compensation for EOC images. If the Pointing Spread Function (PSF) of EOC system is known, signal-to-noise power spectra ratio is the only factor in the determination of Wiener filter. In this paper, MTF compensation in IRPE at KGS is introduced and MTF compensated EOC 1R images are generated using Wiener filters with various signal-to-noise power spectra ratios. MTF compensated EOC 1R images are correlated with EOC 1R images for observing linearities between them. As a result, the effect of signal-to-noise power spectra ratio is shown on MTF compensated EOC 1R images.

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Strategies for activation of the domestic chocolate culture and development of new chocolate market: Activation of chocolate market through fusion with Herbal Bio-industry

  • Kwon, Hyo-Jeong;Lee, Seing-Heon;Jung, Ji-Wook
    • Journal of Evidence-Based Herbal Medicine
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    • 제3권1호
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    • pp.25-33
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    • 2010
  • The aims of this study recognize the limitations of the domestic chocolate market compared to domestic and foreign chocolate market and investigate the strategies for activation of the domestic chocolate culture and development of new chocolate market throughout pointing out the various problems. We analyzed the trends for the food market and confectionery market, main market for chocolate, and also compared domestic and foreign cases for market of chocolate as food or non-food. We sought for solutions and implications for diversification of domestic chocolate market through prospects for the future. Domestic chocolate market is not enough to be competitive compared with overseas market, yet. However, we speculated that domestic chocolate market would gradually develop through fusion with herbal bio-industry as rapid economic development. Besides, we demonstrated a few ways which derive larger development through combination of chocolate market and herbal bio-industry. For these sakes, we suggest that at first, if paradigm which is considered oriental medicinal characters and back innovative and differentiated ideas should be present, the activation of markets of chocolate and herbal bio-industry as well as the diversities of market may be obtained.

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Distinct Repressive Properties of the Mammalian and Fish Orphan Nuclear Receptors SHP and DAX-1

  • Park, Yun-Yong;Teyssier, Catherine;Vanacker, Jean-Marc;Choi, Hueng-Sik
    • Molecules and Cells
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    • 제23권3호
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    • pp.331-339
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    • 2007
  • It has been suggested that the structure and function of nuclear receptors are evolutionally conserved. Here, we compare the molecular functions of the nile tilapia (Oreochromis niloticus) small heterodimer partner (nSHP/NR0B2) and the Dosage-sensitive sex reversal AHC critical region on X chromosome gene 1 (nDAX-1/NR0B1) with those of human SHP and DAX-1 (hSHP and hDAX-1, respectively). We found that, upon transient cotransfection of human cells, nDAX-1 repressed the activity of tilapia SF-1 (nSF-1) but not that of human SF-1, although the physical interaction with human SF-1 was retained. Similarly, nSHP repressed the activity of nSF-1, whereas hSHP did not, pointing to divergent evolution of SHP/SF-1 in fish and human. We thus propose that the repressive functions of SHP and DAX-1 have been conserved in fish and mammals although with different transcriptional targets and mechanisms. These differences provide new insights into the physiological diversification of atypical orphan nuclear receptors during vertebrate evolution.

A Qualitative Study on Customer Management and Response of Apparel Shop Masters

  • Jang, Eun Young
    • 패션비즈니스
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    • 제12권3호
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    • pp.167-174
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    • 2008
  • The purpose of this study was to categorize customers types in accordance with current shop masters' perception of difficult customers and to identify their responding techniques and know-hows in dealing with those customers in detail, a qualitative study is carried out by conducting thorough interviews with the shop masters. The interview contained questions on occupational hold-ups of shop masters, types of hard-to-handle customers, techniques in handling difficult customers, their know-hows in customer managements and what they perceived as the qualities of a shop master. T The results were as follows: 1) Customers who are perceived as difficult by shop masters are categorized into six types, making unreasonable demands, pointing out product defects, disregarding salespersons, making no purchase after testing products, having no personality and having no response. 2) Responding techniques for difficult customers were categorized into three types, 'active response', 'standby' and 'polite refusal'. 3)The result from the question on know-hows of shop masters in customer management can be divided into 4 groups, providing special treatment or information, building one-to-one relationship with the customer, suggesting garments in accordance with the customer's taste and providing friendly customer service. 4) For the question on perceived qualities as a shop master, individual quality, customer management capacity, work experience and occupational knowledge were answered.