• Title/Summary/Keyword: FSA system

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Optimal Frame Size Allocation Scheme for RFID Systems

  • Lim, In-Taek
    • Journal of information and communication convergence engineering
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    • v.6 no.1
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    • pp.24-28
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    • 2008
  • In RFID System, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred to anti-collision algorithm. Among the existing anti-collision algorithms, static framed slot allocation algorithm is very simple. But when the number of tags is variable, its performance degrades because of the fixed frame size. This paper proposes an optimal frame size allocation scheme that determines the frame size. The proposed scheme is based on the number of collision slots at every frame. According to the simulation results, the tag identification time is faster that of SFSA.

Fast Motion Estimation Algorithm for Efficient MPEG-2 Video Transcoding with Scan Format Conversion (스캔 포맷 변환이 있는 효율적인 MPEG-2 동영상 트랜스코딩을 위한 고속 움직임 추정 기법)

  • 송병철;천강욱
    • Journal of Broadcast Engineering
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    • v.8 no.3
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    • pp.288-296
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    • 2003
  • ATSC (Advanced Television System Committee) has specified 18 video formats for DTV (Digital Television), e.g., scan format, size format, and frame rate format conversion. Effective MPEG-2 video transcoders should support any conversion between the above-mentioned formats. Scan format conversion Is hard to Implement because it may often induce frame rate and size format conversion together. Especially. because of picture type conversion caused by scan format conversion, the computational burden of motion estimation (ME) in transcoding becomes serious. This paper proposes a fast ME algorithm for MPEG-2 video transcoding supporting scan format conversion. Firstly, we extract and compose a set of candidate motion vectors (MVs) from the input bit-stream to comply with the re-encoding format. Secondly, the best MV is chosen among several candidate MVs by using a weighted median selector. Simulation results show that the proposed ME algorithm provides outstanding PSNR performance close to full search ME, while reducing the transcoding complexity significantly.

Classifier Selection using Feature Space Attributes in Local Region (국부적 영역에서의 특징 공간 속성을 이용한 다중 인식기 선택)

  • Shin Dong-Kuk;Song Hye-Jeong;Kim Baeksop
    • Journal of KIISE:Software and Applications
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    • v.31 no.12
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    • pp.1684-1690
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    • 2004
  • This paper presents a method for classifier selection that uses distribution information of the training samples in a small region surrounding a sample. The conventional DCS-LA(Dynamic Classifier Selection - Local Accuracy) selects a classifier dynamically by comparing the local accuracy of each classifier at the test time, which inevitably requires long classification time. On the other hand, in the proposed approach, the best classifier in a local region is stored in the FSA(Feature Space Attribute) table during the training time, and the test is done by just referring to the table. Therefore, this approach enables fast classification because classification is not needed during test. Two feature space attributes are used entropy and density of k training samples around each sample. Each sample in the feature space is mapped into a point in the attribute space made by two attributes. The attribute space is divided into regular rectangular cells in which the local accuracy of each classifier is appended. The cells with associated local accuracy comprise the FSA table. During test, when a test sample is applied, the cell to which the test sample belongs is determined first by calculating the two attributes, and then, the most accurate classifier is chosen from the FSA table. To show the effectiveness of the proposed algorithm, it is compared with the conventional DCS -LA using the Elena database. The experiments show that the accuracy of the proposed algorithm is almost same as DCS-LA, but the classification time is about four times faster than that.

Effect of Bupleurum falcatum on the immune system (시호 추출물이 면역계 세포의 활성에 미치는 영향)

  • Cho, Jeong-gon;Kim, Jong-myeon
    • Korean Journal of Veterinary Research
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    • v.34 no.4
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    • pp.769-779
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    • 1994
  • The root of Bupleurum falcatum L.(BF) has been widely used in oriental medicine as a major camponent in many prescriptions for chronic hepatitis, renal disease, tuberculosis and some other infectious diseases. Many attempts have done to investigate the therapeutic effects of these principles. However, any kinds of screenig on immune regulatory- and antitumor- effects of BF has not been reported. The present study, therefore, was undertaken to investigate the BF-effects on cellular- and humoral-immune responses, phagocytic activities of macrophages, lymphokine- and Immunoglobulin(Ig)-production of lymphocytes, tumorigenesis of implanted sarcoma 180 cells and B16 melanoma cells, and proliferations of some tumor cell lines(Fsa II, 3LL and EL4). BF increased phagocytic activities of mouse peritoneal macrophages in a dose- and time-dependent fashion. Arthus reaction and antibody responses to SRBC were slightly enhanced but delayed hypersensitivity was depresed when BF was injected before- and after-SRBC sensitization. BF inhibited the proliferative responses of human tonsillar lymphocytes to PHA- and Con A-stimulation but slightly augmented the response of these cells to Staphylococcus aureus Cowan 1(SAC)-activation. Ig secretion of human mononuclear cells activated with SAC was slightly increased by BF. BF significantly augmented the SAC-induced IL 6 production of human mononuclear cells but not influenced Con Ainduced IL 2 secretion. NK cell activities of mouse splenocytes were somewhat increased when BF was pretreated and this responses were due to the increment of binding affinities of effector cells to target cells and of lytic activities of effector cells against target cells. In vitro BF significantly inhibited the proliferations of cancer cells such as Fsa II, 3LL and EL4 strains. BF decreased not only the frequency of tumor induction but also the tumor size per sarcoma 180 or B16 cell-implanted mouse. Taken together, these results indicate that BF is one of the potential immunomodulator, and suggest its possibility to be used as a desirable antitumor agent.

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LH-FAS v2: Head Pose Estimation-Based Lightweight Face Anti-Spoofing (LH-FAS v2: 머리 자세 추정 기반 경량 얼굴 위조 방지 기술)

  • Hyeon-Beom Heo;Hye-Ri Yang;Sung-Uk Jung;Kyung-Jae Lee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.309-316
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    • 2024
  • Facial recognition technology is widely used in various fields but faces challenges due to its vulnerability to fraudulent activities such as photo spoofing. Extensive research has been conducted to overcome this challenge. Most of them, however, require the use of specialized equipment like multi-modal cameras or operation in high-performance environments. In this paper, we introduce LH-FAS v2 (: Lightweight Head-pose-based Face Anti-Spoofing v2), a system designed to operate on a commercial webcam without any specialized equipment, to address the issue of facial recognition spoofing. LH-FAS v2 utilizes FSA-Net for head pose estimation and ArcFace for facial recognition, effectively assessing changes in head pose and verifying facial identity. We developed the VD4PS dataset, incorporating photo spoofing scenarios to evaluate the model's performance. The experimental results show the model's balanced accuracy and speed, indicating that head pose estimation-based facial anti-spoofing technology can be effectively used to counteract photo spoofing.

Optimal Parameter Selection of Q-Algorithm in EPC global Gen-2 RFID System

  • Lim, In-Taek
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.469-474
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    • 2009
  • Q-algorithm is proposed at EPC global Class-1 Generation-2 RFID systems to determine the frame size of next query round. In Q-algorithm, the reader calculates the frame size without estimating the number of tags. But, it uses only the slot conditions: empty, success, or collision. Therefore, it wastes less computational cost and is simpler than other algorithms. However, the constant parameter C value, which is used for calculating the next frame size, is not optimized. In this paper, we propose the optimized C values of Q-algorithm according to the number of tags within the identification range of reader through a lot of computer simulations.

Influence of a weak superposed centripetal flow in a rotor-stator system for several pre-swirl ratios

  • Nour, Fadi Abdel;Rinaldi, Andrea;Debuchy, Roger;Bois, Gerard
    • International Journal of Fluid Machinery and Systems
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    • v.5 no.2
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    • pp.49-59
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    • 2012
  • The present study is devoted to the influence of a superposed radial inflow in a rotor-stator cavity with a peripheral opening. The flow regime is turbulent, the two boundary layers being separated by a core region. An original theoretical solution is obtained for the core region, explaining the reason why a weak radial inflow has no major influence near the periphery of the cavity but strongly affects the flow behavior near the axis. The validity of the theory is tested with the help of a new set of experimental data including the radial and tangential mean velocity components, as well as three components of the Reynolds stress tensor measured by hot-wire anemometry. The theoretical results are also in good agreement with numerical results obtained with the Fluent code and experimental data from the literature.

Higher-order soilton puliton pulse generation and compression in dispersion decreasing fiber for optical time division multiplexing system source applications (분산감소광섬유에서의 고차 솔리통 펄스 생성 및 압축을 통한 광시간분할다중시스템 광원의 제작에 대한 연구)

  • 이덕기;김나영;박남규
    • Korean Journal of Optics and Photonics
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    • v.11 no.2
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    • pp.102-107
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    • 2000
  • We propose a new scheme for generating a pedestal-free, femtosecond soliton pulse train by utilizing quasI-adiabatic high order soliton pulse evolution in dispersion decreasing fiber in conjunction with the intermediate pedestal suppression stage. Compression factor over 280 was achieved from lOGHz sinusoidal input, to 176 is soliton pulse train. train.

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Application of Formal Safety Assessment Methodology to Marine Structural Design (공식안전평가기법의 선박해양구조설계에의 적용)

  • Lee, Joo-Sung
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.133-138
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    • 2001
  • Formal safety assessment (FSA) is defined as a structured and systematic methodology aimed at enhancing maritime safety including protection of life, health, and the marine environment and property, by using risk and cost/benefit assessment or, more specifically, it is a process of identifying hazard, evaluating risk and deciding on course of action to control those risks. Emphasis is placed on the structural aspect of the failure of cargo hold. This study is expected to illustrate how a new methodology, i.e. the Formal Safety Assessment, can be applied to specific ship safety problems.

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Performance Analysis of FSA Algorithm for Tag Identification in RFID Systems (RFID 시스템에서 태그 식별을 위한 SFSA 알고리즘의 성능 분석)

  • Lim, In-Taek;Choi, Jin-Oh;Choi, Jin-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.563-566
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    • 2008
  • In RFID system. when a variety of tags are present in the interrogation zone of a single reader at the same time, the system requires a multiple tag identification scheme that allows the reader to read data from the individual tags. Anti-collision algorithms required for the multiple tag identification are essential for the implementation of RFID system. This paper analyzed the performance of SFSA algorithm, which is easy to implement. According to the analytical results, the algorithm's performances are closely related with the number of tags and the frame size.

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