• Title/Summary/Keyword: Search Range

Search Result 825, Processing Time 0.025 seconds

Frame-rate Up-conversion using Hierarchical Adaptive Search and Bi-directional Motion Estimation (계층적 적응적 탐색과 양방향 움직임 예측을 이용한 프레임율 증가 방법)

  • Min, Kyung-Yeon;Park, Sea-Nae;Sim, Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.46 no.3
    • /
    • pp.28-36
    • /
    • 2009
  • In this paper, we propose a frame-rate up-conversion method for temporal quality enhancement. The proposed method adaptively changes search range during hierarchical motion estimation and reconstructs hole regions using the proposed bi-direction prediction and linear interpolation. In order to alleviate errors due to inaccurate motion vector estimation, search range is adaptively changed based on reliability and for more accurate, motion estimation is performed in descending order of block variance. After segmentation of background and object regions, for filling hole regions, the pixel values of background regions are reconstructed using linear interpolation and those of object regions are compensated based on the proposed hi-directional prediction. The proposed algorithm is evaluated in terms of PSNR with original uncompressed sequences. Experimental results show that the proposed algorithm is better than conventional methods by around 2dB, and blocky artifacts and blur artifacts are significantly diminished.

An Efficient Range Search and Nearest Neighbor Search Algorithm for Action Parts of Active Systems in Sparse Area (능동 시스템에서 위치관련 액션 수행을 위한 희소공간 공간객체의 효율적인 영역질의와 최근접질의)

  • Kim, Jung-Il;Hong, Dong-Kweon
    • The KIPS Transactions:PartD
    • /
    • v.8D no.2
    • /
    • pp.125-131
    • /
    • 2001
  • Various kind of disasters happens in our society. Most of them require immediate treatment to save life or to protect valuable products. When an accident happens in a place, it is reported to the headquarter of emergency measures system. According to the nature of accident several treatments orders are transmitted to the related authorities. In this paper, we introduce an intelligent emergency measures system that uses trigger mechanism of active databases. The system responds to various events spontaneously without intervention of mankind by triggering proper rules. The most important part of an action in the system is the capability of searching places to apply adequate treatments quickly. We have developed a new method for range queries and nearest neighbor queries which utilize the z-ordering technique to get fast responses. Those new methods are further extended to handle more realistic actual distance of road among positions.

  • PDF

Optimal Acoustic Search Path Planning Based on Genetic Algorithm in Discrete Path System (이산 경로 시스템에서 유전알고리듬을 이용한 최적음향탐색경로 전략)

  • CHO JUNG-HONG;KIM JUNG-HAE;KIM JEA-SOO;LIM JUN-SEOK;KIM SEONG-IL;KIM YOUNG-SUN
    • Journal of Ocean Engineering and Technology
    • /
    • v.20 no.1 s.68
    • /
    • pp.69-76
    • /
    • 2006
  • The design of efficient search path to maximize the Cumulative Detection Probability(CDP) is mainly dependent on experience and intuition when searcher detect the target using SONAR in the ocean. Recently with the advance of modeling and simulation method, it has been possible to access the optimization problems more systematically. In this paper, a method for the optimal search path calculation is developed based on the combination of the genetic algorithm and the calculation algorithm for detection range. We consider the discrete system for search path, space, and time, and use the movement direction of the SONAR for the gene of the genetic algorithm. The developed algorithm, OASPP(Optimal Acoustic Search Path Planning), is shown to be effective, via a simulation, finding the optimal search path for the case when the intuitive solution exists. Also, OASPP is compared with other algorithms for the measure of efficiency to maximize CDP.

A Study on Terrain Surface Modeling and Polygon-Searching Algorithms (지표면 모델링 및 폴리건 검색기법에 관한 연구)

  • 공지영;강현주;윤석준
    • Proceedings of the Korea Society for Simulation Conference
    • /
    • 2002.11a
    • /
    • pp.163-170
    • /
    • 2002
  • Terrain surfaces have to be modeled in very detail and wheel-surface contacting geometry must be well defined in order to obtain proper ground-reaction and friction forces for realistic simulation of off-road vehicles. Delaunay triangulation is one of the most widely used methods in modeling 3-dimensional terrain surfaces, and T-search is a relevant algorithm for searching resulting triangular polygons. The T-search method searches polygons in successive order and may not allow real-time computation of off-road vehicle dynamics if the terrain is modeled with many polygons, depending on the computer performance used in the simulation. In order to accelerate the searching speed of T-search, a terrain database of triangular polygons is modeled in multi-levels by adopting the LOD (Level of Detail) method used in realtime computer graphics. Simulation results show that the new LOD search is effective in shortening the required computing time. The LOD search can be even further accelerated by introducing an NN (Neural Network) algorithm, in the cases where a appropriate range of moving paths can be predicted by cultual information of the simulated terrain, such as lakes, houses, etc.. Numerical tests show that LOD-NN search almost double the speed of the original T-search.

  • PDF

Subset selection in multiple linear regression: An improved Tabu search

  • Bae, Jaegug;Kim, Jung-Tae;Kim, Jae-Hwan
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.40 no.2
    • /
    • pp.138-145
    • /
    • 2016
  • This paper proposes an improved tabu search method for subset selection in multiple linear regression models. Variable selection is a vital combinatorial optimization problem in multivariate statistics. The selection of the optimal subset of variables is necessary in order to reliably construct a multiple linear regression model. Its applications widely range from machine learning, timeseries prediction, and multi-class classification to noise detection. Since this problem has NP-complete nature, it becomes more difficult to find the optimal solution as the number of variables increases. Two typical metaheuristic methods have been developed to tackle the problem: the tabu search algorithm and hybrid genetic and simulated annealing algorithm. However, these two methods have shortcomings. The tabu search method requires a large amount of computing time, and the hybrid algorithm produces a less accurate solution. To overcome the shortcomings of these methods, we propose an improved tabu search algorithm to reduce moves of the neighborhood and to adopt an effective move search strategy. To evaluate the performance of the proposed method, comparative studies are performed on small literature data sets and on large simulation data sets. Computational results show that the proposed method outperforms two metaheuristic methods in terms of the computing time and solution quality.

Direction-Oriented Fast Full Search Algorithm at the Divided Search Range (세분화된 탐색 범위에서의 방향 지향적 전영역 고속 탐색 알고리즘)

  • Lim, Dong-Young;Park, Sang-Jun;Jeong, Je-Chang
    • Journal of Broadcast Engineering
    • /
    • v.12 no.3
    • /
    • pp.278-288
    • /
    • 2007
  • We propose the fast full search algorithm that reduces the computational load of the block matching algorithm which is used for a motion estimation in the video coding. Since the conventional spiral search method starts searching at the center of the search window and then moves search point to estimate the motion vector pixel by pixel, it is good for the slow motion picture. However we proposed the efficient motion estimation method which is good for the fast and slow motion picture. Firstly, when finding the initial threshold value, we use the expanded predictor that can approximately calculate minimum threshold value. The proposed algorithm estimates the motion in the new search order after partitioning the search window and adapt the directional search order in the re-divided search window. At the result, we can check that the proposed algorithm reduces the computational load 94% in average compared to the conventional spiral full search algorithm without any loss of image quality.

Microwave Oscillator Stabilized by Phase-locked Loop (위상고정 Loop를 사용한 안정 징파발진기)

  • 나정웅;김종진
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.12 no.3
    • /
    • pp.20-25
    • /
    • 1975
  • A microwave oscillator stabilized by a phase-locked loop (PLL) is developed. The PLL system is chosen 'compared with the cavity stabilized oscillator in view of the domestic manufacturing, because special machining and materials are needed for the latter. A sampler with a low pass filter is shown to be used as a phase detector in the PLL, and the sampler capable of sampling up to 4GHz is developed for this use. Frequency stability of about 10-6 is obtained from the developed microwave oscillator, operating at 2.16 GHz with more than 120 milliwatts output power, Ivhereby a crystal oscillator operating at about 110MHz is used as a reference source in the PLL. The capturing range of this oscillator is extended up to its lock-in-range of about 10MHz by employing a search oscillator in the system.

  • PDF

A $CST^+$ Tree Index Structure for Range Search (범위 검색을 위한 $CST^+$ 트리 인덱스 구조)

  • Lee, Jae-Won;Kang, Dae-Hee;Lee, Sang-Goo
    • Journal of KIISE:Databases
    • /
    • v.35 no.1
    • /
    • pp.17-28
    • /
    • 2008
  • Recently, main memory access is a performance bottleneck for many computer applications. Cache memory is introduced in order to reduce memory access latency. However, it is possible for cache memory to reduce memory access latency, when desired data are located on cache. EST tree is proposed to solve this problem by improving T tree. However, when doing a range search, EST tree has to search unnecessary nodes. Therefore, this paper proposes $CST^+$ tree which has the merit of CST tree and is possible to do a range search by linking data nodes with linked lists. By experiments, we show that $CST^+$ is $4{\sim}10$ times as fast as CST and $CSB^+$. In addition, rebuilding an index Is an essential step for the database recovery from system failure. In this paper, we propose a fast tree index rebuilding algorithm called MaxPL. MaxPL has no node-split overhead and employs a parallelism for reading the data records and inserting the keys into the index. We show that MaxPL is $2{\sim}11$ times as fast as sequential insert and batch insert.

A Fast Fractal Image Compression Using The Normalized Variance (정규화된 분산을 이용한 프랙탈 압축방법)

  • Kim, Jong-Koo;Hamn, Do-Yong;Wee, Young-Cheul;Kimn, Ha-Jine
    • The KIPS Transactions:PartA
    • /
    • v.8A no.4
    • /
    • pp.499-502
    • /
    • 2001
  • Fractal image coding suffers from the long search time of domain pool although it provides many properties including the high compression ratio. We find that the normalized variance of a block is independent of contrast, brightness. Using this observation, we introduce a self similar block searching method employing the d-dimensional nearest neighbor searching. This method takes Ο(log/N) time for searching the self similar domain blocks for each range block where N is the number of domain blocks. PSNR (Peak Signal Noise Ratio) of this method is similar to that of the full search method that requires Ο(N) time for each range block. Moreover, the image quality of this method is independent of the number of edges in the image.

  • PDF

Enhancing Retrieval Performance for Hierarchical Compact Binary Tree (계층형 집약 이진 트리의 검색 성능 개선)

  • Kim, Sung Wan
    • Journal of Creative Information Culture
    • /
    • v.5 no.3
    • /
    • pp.345-353
    • /
    • 2019
  • Several studies have been proposed to improve storage space efficiency by expressing binary trie data structure as a linear binary bit string. Compact binary tree approach generated using one binary trie increases the key search time significantly as the binary bit string becomes very long as the size of the input key set increases. In order to reduce the key search range, a hierarchical compact binary tree technique that hierarchically expresses several small binary compact trees has been proposed. The search time increases proportionally with the number and length of binary bit streams. In this paper, we generate several binary compact trees represented by full binary tries hierarchically. The search performance is improved by allowing a path for the binary bit string corresponding to the search range to be determined through simple numeric conversion. Through the performance evaluation using the worst time and space complexity calculation, the proposed method showed the highest performance for retrieval and key insertion or deletion. In terms of space usage, the proposed method requires about 67% ~ 68% of space compared to the existing methods, showing the best space efficiency.