• 제목/요약/키워드: Update

검색결과 3,134건 처리시간 0.033초

함정전투체계 표적 색인을 위한 TPR-Tree 상향식 갱신 기법 (A Study on Bottom-Up Update of TPR-Tree for Target Indexing in Naval Combat Systems)

  • 고영근
    • 한국군사과학기술학회지
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    • 제22권2호
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    • pp.266-277
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    • 2019
  • In modern warfare, securing time for preemptive response is recognized as an important factor of victory. The naval combat system, the core of naval forces, also strives to increase the effectiveness of engagement by improving its real-time information processing capabilities. As part of that, it is considered to use the TPR-tree in the naval combat system's target indexing because spatio-temporal searches can be performed quickly even as the number of target information increases. However, because the TPR-tree is slow to process updates, there is a limitation to handling frequent updates. In this paper, we present a method for improving the update performance of TPR-tree by applying the bottom-up update scheme, previously proposed for R-tree, to the TPR-tree. In particular, we analyze the causes of overlaps occurring when applying the bottom-up updates and propose ways to limit the MBR expansion to solve it. Our experimental results show that the proposed technique improves the update performance of TPR-tree from 3.5 times to 12 times while maintaining search performance.

SDINS의 영속도 보정 칼만필터 설계 (Design and performance analysis of a zero-velocity update Kalman filter for SDINS)

  • 박흥원;정태호;박찬빈;이장규
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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    • pp.633-638
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    • 1988
  • In this paper, a zero-velocity update technique to improve navigation accuracy of a SDINS(Strapdown Inertial Navigation System) has been studied. An indirect feedback Kalman filter which includes SDINS error equations based on a quaternion between body-fixed frame and local level navigation frame is employed for processing zero-velocity updates in an on-board navigation filter. Simulation results for land-mobile vehicle show that the zerovelocity update technique make a significant contribution to improving SDINS performance without any external aids.

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MODIFIED MULTIPLICATIVE UPDATE ALGORITHMS FOR COMPUTING THE NEAREST CORRELATION MATRIX

  • Yin, Jun-Feng;Huang, Yumei
    • Journal of applied mathematics & informatics
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    • 제30권1_2호
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    • pp.201-210
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    • 2012
  • A modified multiplicative update algorithms is presented for computing the nearest correlation matrix. The convergence property is analyzed in details and a sufficient condition is given to guarantee that the proposed approach will not breakdown. A number of numerical experiments show that the modified multiplicative updating algorithm is efficient, and comparable with the existing algorithms.

Multirate 무선랜 환경에서 Fragment Burst의 전송을 위한 개선된 NAV Update 방법 (The Improved NAV Update method for Transmit of Fragmented Burst in Multirate WLAN environment)

  • 김태환;송경희;박동선
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.53-56
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    • 2003
  • In order to enhance the system capacity of multi rate IEEE 802.11 WLAN, we propose the transmission rate select method using the control frame in this paper. The transmission rate is selected dynamically based on the RSSI(Received Signal Strength Indicator) of received control frame. And we also propose the Enhanced NAV Update method for Fragmented MPDU burst transmission in multirate WLAN environment. This method can improve the system capacity by support the burst transmission of fragmented MPDU.

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Optimal Time-Interval for Time-based Location Update in Mobile Communications

  • Lee, Yong;Lee, Goo-Yeon
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.169-173
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    • 2003
  • In this paper, we analyze a time-based update method in location management and calculate the optimal time-interval. We obtain the probability that an MT is j rings away from the center cell. And using these values, an exact analysis is made for the time-based location management cost. From the result, when the time-based method is applied to location update, we can get the optimal time-interval which minimizes the location management cost.

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단체법에서 여러가지 상하 분해요소 수정방법들의 비교 (A comparative study between various LU update methods in the simplex method)

  • 임성묵;김기태;박순달
    • 한국국방경영분석학회지
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    • 제29권1호
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    • pp.28-42
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    • 2003
  • The simplex method requires basis update in each iteration, which is the most time consuming process. Several methods have been developed for the update of basis which is represented in LU factorized form, such as Bartels-Golub's method, Forrest-Tomlin's method, Reid's method, Saunders's method, etc. In this research, we compare between the updating methods in terms of sparsity, data structure and computing time issues. The analysis is mainly based on the computational experience.

민감도 분석을 통한 프리스트레스 콘크리트 거더의 유한요소모델 개선 (FE-model Update for System Identification of PSC Girde)

  • ;이소영;김정태
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2009년도 정기 학술대회
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    • pp.425-428
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    • 2009
  • This paper presents a sensitivity-based finite element (FE)-model update procedure for prestressed concrete (PSC) girder bridge model using vibration test results. Firstly, the stiffness parameters of the structure such as flexural rigidity of concrete and flexural rigidity of tendon are chosen as updating parameters. Next, the numerical frequencies of first two bending modes are calculated using a three-dimensional FE model which is established for the PSC girder. Then, the corresponding experimental frequencies which are obtained from forced vibration tests are selected. In order to perform the model update, the eigensensitivity-based method is employed. Finally, the effect of prestress-loss on the stiffness parameters is evaluated.

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유효갱신기간에 기반한 가변 데드레코닝 알고리즘 (An Adaptive Dead Reckoning Algorithm using Update Lifetime)

  • 유석종;정혜원;최윤철
    • 한국멀티미디어학회:학술대회논문집
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    • 한국멀티미디어학회 2000년도 춘계학술발표논문집
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    • pp.449-452
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    • 2000
  • This paper proposes a new, adaptive Dead Reckoning model, called Dynamic Dead Reckoning , for Distributed Interactive Simulation and humanoid avatar systems. The proposed model can overcome the weak points of traditional Dead Reckoning caused by a fixed threshold and strong dependency on rotation event. This paper introduces new criteria for update message filtering , named as Update lifetime. The Dynamic Dead Reckoning keeps the balance between extrapolation fidelity and filtering performance by two component models, Variable Threshold Mechanism and Rotation Event model. The experimental results show that the proposed model can lower the increment rate of update traffic to the increase of rotation frequency without any significant loss of accuracy.

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NEW COMPLEXITY ANALYSIS OF PRIMAL-DUAL IMPS FOR P* LAPS BASED ON LARGE UPDATES

  • Cho, Gyeong-Mi;Kim, Min-Kyung
    • 대한수학회보
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    • 제46권3호
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    • pp.521-534
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    • 2009
  • In this paper we present new large-update primal-dual interior point algorithms for $P_*$ linear complementarity problems(LAPS) based on a class of kernel functions, ${\psi}(t)={\frac{t^{p+1}-1}{p+1}}+{\frac{1}{\sigma}}(e^{{\sigma}(1-t)}-1)$, p $\in$ [0, 1], ${\sigma}{\geq}1$. It is the first to use this class of kernel functions in the complexity analysis of interior point method(IPM) for $P_*$ LAPS. We showed that if a strictly feasible starting point is available, then new large-update primal-dual interior point algorithms for $P_*$ LAPS have $O((1+2+\kappa)n^{{\frac{1}{p+1}}}lognlog{\frac{n}{\varepsilon}})$ complexity bound. When p = 1, we have $O((1+2\kappa)\sqrt{n}lognlog\frac{n}{\varepsilon})$ complexity which is so far the best known complexity for large-update methods.

모바일 셀룰러 네트워크에서 차별화 된 사용자 이동 패턴을 이용한 동적인 Location Update 기법 (Dynamic Location Update Scheme using Differentiated Moving Pattern in Mobile Cellular Networks)

  • 박송화;임성렬;정기동
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (A)
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    • pp.478-480
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    • 2005
  • 본 논문에서는 모바일 셀룰러 네트워크상에서 다양한 이동 단말 이동성을 이용한 동적인 Location Update 기법을 제안한다. 동적인 Location Update 기법에서는 다양한 이동 단말들의 이동 패턴을 고려하기 위해서 Differentiated-Walk Model을 이용하고 그 모델에서 제공하는 핸드오프 확률과 이동성 등급을 이용하여 LA(Location Area)를 형성한다. LA는 사용자의 이동 패턴을 고려하여 동적으로 형성되며 본 논문에서는 이러한 LA를 기반으로 제공되는 페이징 기법을 제안한다.

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