• Title/Summary/Keyword: Ordering scheme

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Optimal Respiratory Ordering Scheme (OROS) for Correcting Blurring Artifacts in Abdominal Magnetic Resonance Imaging (복부 핵자기공명 영상에서 영상번짐의 교정을 위한 최적 호흡 정렬법)

  • Jung, Kwan-Jin;Ahn, Woo-Youn;Cho, Zang-Hee
    • Proceedings of the KOSOMBE Conference
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    • v.1990 no.11
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    • pp.15-18
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    • 1990
  • In abdominal NMR imaging the respiratory ordering techniques have been successfully used to remove the ghosting artifacts arising from the respiratory motion. In the existing respiratory ordering schemes, however, it is generally accepted that blurring of the moving parts still remains as in the signal averaging technique. A new optimal respiratory ordering scheme which can correct the blurring as well as the ghosting artifacts is theoretically derived through the analysis of the phase encoding directional motion effects in Fourier imaging. The performance of the optimal respiratory ordering scheme is experimentally confirmed together with a suboptimal ordering scheme which is suggested as a compromise for the practicality.

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Enhanced Ordering Scheme for Lossless Grayscale Image Compression (그레이스케일 이미지에서의 무손실 압축을 위한 강인한 Ordering 기법)

  • Kim, Nam-Yee;Jang, Se-Young;Seo, Duck-Won;You, Kang-Soo;Kwak, Hoon-Sung
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.6-8
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    • 2006
  • Using enhanced ordering scheme of graylevel in an image, we can apply it to lossless image compression in this paper. The proposed method is ordering scheme to replace an original grayscale image with a particular ordered image without additional information. From the simulation, it is verified that the proposed method reduces the bit rates than plain ordering scheme. And it can be applied in various fields of lossless compression, water marking and edge detection.

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Partial Go back N Scheme for Occupancy Control of Reordering Buffer in 3GPP ARQ (3GPP ARQ에서 재정렬 버퍼의 점유량 조절을 위한 부분 Go back N 방식)

  • Shin, Woo-Cheol;Park, Jin-Kyung;Ha, Jun;Choi, Cheon-Won
    • Proceedings of the IEEK Conference
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    • 2003.11c
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    • pp.302-305
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    • 2003
  • 3GPP RLC protocol specification adopted an error control scheme based on selective repeat ARQ. In the 3GPP ARQ, distinctive windows are provided at transmitting and receiving stations so that those stations are prohibited to send or receive data PDU's out of window. An increase in window size enhances delay performance. Such an increase, however, raises the occupancy at re-ordering buffer, which results in a long re-ordering time. Aiming at suppressing the occupancy at re-ordering buffer, we propose partial go back N scheme in this paper In the partial go back N scheme, the receiving station regards all data PDU's between the first (lowest sequence numbered) error-detected PDU and last (highest sequence numbered) error-detected PDU. By the employment of the partial go back N scheme, the occupancy at the re-ordering buffer is apparently reduced, while the delay and throughput performance may be degraded due to the remaining properties of go back N. We thus consider peak occupancy of re-ordering buffer, mean sojourn time at re-ordering buffer, mean delay time, and maximum throughput as measures to evaluate tile proposed scheme and investigate such performance by using a simulation method. From numerical examples, we observe a trade-off among performance measures and conclude that the partial go back N scheme is able to effectively reduce the occupancy of re-ordering buffer.

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The Broad System of Ordering as a switching language (스위칭언어로서의 BSO(Broad System of Ordering))

  • 이경호
    • Journal of Korean Library and Information Science Society
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    • v.14
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    • pp.149-179
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    • 1987
  • The concept of a "switching language " between different indexing languages and information retrieval systems has been discussed since the mid-1960s. Some preliminary investigates into the feasibility of switching between mediating tool yielded positive results. The Broad system of ordering(BSO) , a general classification scheme for information exchange and switching, has been under development as a joint FID/UNESCO project since 1973. The purpose of this study is to find out the origin, development, definition, and principle of BSO. The results of the study can be summarized as follows: (1) BSO is a switching language for the purpose of interconnection of information system which is located different regions, or using different indexing languages. (2) BSO is in effect, fully faceted and broad classification system. (3) BSO is not only a subject code but also an ordering system. (4) BSO can be used information retrieval system because the notation of composite subjects is formed by combining notation. (5) BSO has to some extent sacrificed brevity by leaving large unused notational gap for future use. (6) The structure of the scheme is in no way dependent upon the notation. notation.

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A Certification Protocol based on Broadcast Invalidation Approach (브로드케스트 무효화 기법을 이용한 인증 프로토콜)

  • Sung-Ho Cho;Min-Goo Kang
    • Journal of Internet Computing and Services
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    • v.3 no.6
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    • pp.79-89
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    • 2002
  • The performance of OCC is very sensitive to the transaction abort rate, Even if the abort probability can be reduced by re-ordering, most of re-ordering schemes have space overhead in maintaining a graph or histories, In this paper, we proposed an efficient re-ordering scheme based on a broadcast invalidation mechanism. Our scheme, called CBI, can reduce the abort probability without space overhead in maintaining a graph or histories, By simulation studies, we showed that CBI reduced the abort rate and unnecessary operations, Additionally, we showed that CBI outperforms not only BTS but also TSH with low space overhead.

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A Minimum Degree Ordering Algorithm using the Lower and Upper Bounds of Degrees

  • Park, Chan-Kyoo;Doh, Seungyong;Park, Soondal;Kim, Woo-Je
    • Management Science and Financial Engineering
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    • v.8 no.1
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    • pp.1-19
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    • 2002
  • Ordering is used to reduce the amount of fill-ins in the Cholesky factor of a symmetric positive definite matrix. One of the most efficient ordering methods is the minimum degree ordering algorithm(MDO). In this paper, we provide a few techniques that improve the performance of MDO implemented with the clique storage scheme. First, the absorption of nodes in the cliques is developed which reduces the number of cliques and the amount of storage space required for MDO. Second, we present a modified minimum degree ordering algorithm of which the number of degree updates can be reduced by introducing the lower bounds of degrees. Third, using both the lower and upper bounds of degrees, we develop an approximate minimum degree ordering algorithm. Experimental results show that the proposed algorithm is competitive with the minimum degree ordering algorithm that uses quotient graphs from the points of the ordering time and the nonzeros in the Cholesky factor.

Development of a Bandwidth Reduction Algorithm by Combining the Two-Step Approach and the Frontal Ordering Scheme (이단계 번호 부여 방법과 선단집합 이용방법을 결합한 밴드폭 감소 알고리즘 개발)

  • 이병채;구본웅
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.19-27
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    • 1991
  • A new bandwidth reduction algorithm is developed by combining the two-step approach and the frontal ordering scheme. In the two-step approach, finite elements are numbered first, followed by nodal numbering based on the graph theory. The concept of wave front is incorporated into it to control the cardinality of the set of adjacent nodes and the bandwidth to be achieved. They are controlled systematically by rational selection of next candidates with the purpose of getting the smaller bandwidth efficiently. Eighteen meshes are renumbered and the results are compared with those of well-known algorithms. The results demonstrate the efficiency and the reliability of the proposed algorithm.

H.264/AVC Video Quality Improvement by Improved Interference Cancellation Ordering in Multiple Antenna Systems (다중안테나 시스템의 향상된 간섭제거 순서화를 통한 H.264/AVC 비디오 품질향상)

  • Bak, SangHyun;Kim, Jaekwon
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.3 no.2
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    • pp.50-57
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    • 2010
  • In this paper, we address H.264/AVC video transmission using multiple antennaed phycical layer. When multiple antennas are used, the signals from the other antennas are interferences from the perspective of a target antenna, resulting in lowered video quality. In an effort to improve the video quality, in this paper, we propose a novel detection ordering scheme. We conduct computer simulations to show the efficacy of the proposed scheme.

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Reversible Data Hiding Algorithm Based on Pixel Value Ordering and Edge Detection Mechanism

  • Nguyen, Thai-Son;Tram, Hoang-Nam;Vo, Phuoc-Hung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.10
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    • pp.3406-3418
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    • 2022
  • Reversible data hiding is an algorithm that has ability to extract the secret data and to restore the marked image to its original version after data extracting. However, some previous schemes offered the low image quality of marked images. To solve this shortcoming, a new reversible data hiding scheme based on pixel value ordering and edge detection mechanism is proposed. In our proposed scheme, the edge image is constructed to divide all pixels into the smooth regions and rough regions. Then, the pixels in the smooth regions are separated into non overlapping blocks. Then, by taking advantages of the high correlation of current pixels and their adjacent pixels in the smooth regions, PVO algorithm is applied for embedding secret data to maintain the minimum distortion. The experimental results showed that our proposed scheme obtained the larger embedding capacity. Moreover, the greater image quality of marked images are achieved by the proposed scheme than that other previous schemes while the high EC is embedded.

A Study of Deferred Commitment for Transaction Management in Multidatabase Systems (멀티 데이터베이스 시스템에서 트랜잭션 관리를 위한 지연완료 기법 연구)

  • Lee Sang-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.5 s.37
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    • pp.41-48
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    • 2005
  • In this thesis, we propose a concurrency control scheme which schedules global transactions in multidatabase systems Unlike other scheme which commit global transactions as soon as they have finished their execution, this scheme has attempted to delay them if their exist another global transactions that should be proceeded. Owing to the deferred commitment, the number of global restarts could be greatly reduced. This scheme's performance gain increased through simulations in case more than one LDBS employ timestamp ordering(TO) as a local concurrency control scheme.

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