• Title/Summary/Keyword: Transition Detection

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The Low Probability of Intercept RADAR Waveform Based on Random Phase and Code Rate Transition for Doppler Tolerance Improvement (도플러 특성 개선을 위한 랜덤 위상 및 부호율 천이 기반 저피탐 레이다 파형)

  • Lee, Ki-Woong;Lee, Woo-Kyung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.11
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    • pp.999-1011
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    • 2015
  • In modern electronic warfare, RADAR is under constant threat of ECM(Electronic Counter Measures) signals from nearby jammers. The conventional linear frequency modulated(Linear-FM) waveform is easy to be intercepted to estimate its signal parameters due to its periodical phase transition. Recently, APCN(Advanced Pulse Compression Noise) waveform using random amplitude and phase transition was proposed for LPI(Low probability of Intercept). But random phase code signals such as APCN waveform tend to be sensitive to Doppler frequency shift and result in performance degradation during moving target detection. In this paper, random phase and code rate transition based radar waveform(RPCR) is proposed for Doppler tolerance improvement. Time frequency analysis is carried out through ambiguity analysis to validate the improved Doppler tolerance of RPCR waveform. As a means to measure the vulnerability of the proposed RPCR waveform against LPI, WHT(Wigner-Hough Transform) is adopted to analyze and estimate signal parameters for ECCM(Electronic Counter Counter Measures) application.

Transition-based Data Decoding for Optical Camera Communications Using a Rolling Shutter Camera

  • Kim, Byung Wook;Lee, Ji-Hwan;Jung, Sung-Yoon
    • Current Optics and Photonics
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    • v.2 no.5
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    • pp.422-430
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    • 2018
  • Rolling shutter operation of CMOS cameras can be utilized in optical camera communications in order to transmit data from an LED to mobile devices such as smart-phones. From temporally modulated light, a spatial flicker pattern is obtained in the captured image, and this is used for signal recovery. Due to the degradation of rolling shutter images caused by light smear, motion blur, and focus blur, the conventional decoding schemes for rolling shutter cameras based on the pattern width for 'OFF' and 'ON' cannot guarantee robust communications performance for practical uses. Aside from conventional techniques, such as polynomial fitting, histogram equalization can be used for blurry light mitigation, but it requires additional computation abilities resulting in burdens on mobile devices. This paper proposes a transition-based decoding scheme for rolling shutter cameras in order to offer simple and robust data decoding in the presence of image degradation. Based on the designed synchronization pulse and modulated data symbols according to the LED dimming level, the decoding process is conducted by observing the transition patterns of two sequential symbol pulses. For this, the extended symbol pulse caused by consecutive symbol pulses with the same level determines whether the second pulse should be included for the next bit decoding or not. The proposed method simply identifies the transition patterns of sequential symbol pulses other than the pattern width of 'OFF' and 'ON' for data decoding, and thus, it is simpler and more accurate. Experimental results ensured that the transition-based decoding scheme is robust even in the presence of blurry lights in the captured image at various dimming levels

Detection of Conflict Transition Scene Using Character Regions (인물 면적을 이용한 갈등 전환 장면 검출)

  • Park, Seung-Bo;Lee, Chang-Hyun
    • Journal of Broadcast Engineering
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    • v.26 no.5
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    • pp.543-552
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    • 2021
  • The story is formed by the flow of the development and resolution of the conflict between the characters. Namely, the story consists of conflict setting, development, and resolution. Character region is an important expression technique to describe the emotions or states of characters and the relationship between characters and the environment. The purpose of this paper is to propose a method for detecting the transition of conflict from the graph of character region's change. To this end, we present a method of generating a change graph of a character region in a movie by calculating the character region and a method of detecting a conflict transition scene from a graph of character region's change. To verify the performance of the proposed method, an experiment was conducted to extract conflict transition scenes for 7 movies, and performance evaluation results of 73.57% accuracy and 77.26% recall were obtained. This proves that it is possible to extract conflict transition scenes based on the character region.

Synthesis and Characterization of Polymer and Polymer Complex with Some Transition Metal Ions (몇 개의 전이금속 이온과 고분자와 고분자 Complex의 합성과 특성연구)

  • Badr, S.K.;Mohamed, T.Y.
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.43-48
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    • 2010
  • Polyamide derived from azo compound of o-amino phenol coupled with acetyl acetone, maleic anhydride acid and p-phenylene diamine were prepared. The prepared polyamide (PA) was refluxed with metal salts of transition metal ions include, $Co^{+2},\;Cr^{+2},\;Ni^{+2},\;Cu^{+2},\;Zn^{+2},\;Cd^{+2}$ and $Fe^{+3}$ in dimethyl formamide (DMF) in different molar ratios. These complexes were characterized and identified by elemental and thermal analysis, IR, 1H NMR spectra. The data showed that PA ligand coordinates with metal ions in abidentate manner through donating N=N and O-H groups. The metal ions are surrounded by coordinated water molecules and anions to establish the geometrical structure of the complexes. The thermal analysis degradation at different temperatures explained the weight loss of hydrated water and the decompositions of complexes until a constant weight loss of metal oxides is obtained.

The Relay Circuits Translation to EMFGs (릴레이 회로의 확장된 마크흐름선도 변환)

  • 여정모;백형구
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.11
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    • pp.952-957
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    • 2003
  • We propose how to translate relay circuits to the EMFGs(Extended Mark Flow Graphs) formally and analyze the original one by using the mark flow of it. Firstly, the concepts of the output condition, the output-on condition and the output-off condition are introduced in the relay circuits. These can be used to find the structure and the operation of respective relay outputs but the sequential operations of them cannot be obtained from these. Secondly, a relay circuit is translated to the corresponding EMFG as the all output-on conditions and all output-off conditions of it are translated to EMFGs. For the adequate translation, the condition arc and the concepts of the generation transition and the degeneration transition are introduced, and the duality for the simplification of the result. Thirdly, we analyze the operation of the original circuit by analyzing the mark flow of the resulting EMFG. We can achieve easy and fast analysis based on the EMFG's operation algorithm. Finally, we apply these to the relay circuit for an electric furnace and analyze its operation with the mark flow of the resulting EMFG. The formal translation from relay circuits to EMFGs makes the analysis easy so that these results can be used to design, modelling, the fault detection and the maintenance.

Measurement of the Biological Active Point using the Bio-electrical impedance analysis based on the Adaptive Frequency Tracking Filter (적응주파수추적필터기반의 생체임피던스분석을 통한 생물학적활성점측정에 관한 연구)

  • Park, Hodong;Lee, Kyoungjoung;Yeom, Hojun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.109-114
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    • 2013
  • The biological active points (BAP) are known as low resistance spots or good electro-permeable points. In this paper, a new method for BAP detection using the bio-impedance measurement system based on the adaptive frequency tracking filter (AFTF) and the transition event detector is presented. Also, the microcontroller process continuous time demodulation of the modulated signal by multi frequency components using the AFTF. The transition event detector based on the phase space method is applied about each frequency using the BAP equivalent model which is proposed.

Design and Implementation of High-Speed Pattern Matcher in Network Intrusion Detection System (네트워크 침입 탐지 시스템에서 고속 패턴 매칭기의 설계 및 구현)

  • Yoon, Yeo-Chan;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11B
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    • pp.1020-1029
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    • 2008
  • This paper proposes an high speed pattern matching algorithm and its implementation. The pattern matcher is used to check patterns from realtime input packet. The proposed algorithm can find exact string, range of string values, and combination of string values from input packet at high speed. Given string and rule set are modelled as a state transition graph which can find overlapped strings simultaneously, and the state transition graph is partitioned according to input implicants to reduce implementation complexity. The pattern matcher scheme uses the transformed state transition graph and input packet as an input. The pattern matcher was modelled and implemented in VHDL language. Experimental results show the proprieties of the proposed approach.

Preventive Medicine in Times of a Rapid Epidemiologic Transition in Korea (예방의학의 발전 방향)

  • Park, Jung-Han
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.1
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    • pp.2-6
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    • 2006
  • Ever since the foundation of the Korean Society for Preventive Medicine in 1947, members of the Society had made remarkable contributions to the public health development and national health promotion. They had played key roles in establishing national health system, improving environmental hygiene, controlling infectious and chronic diseases, promoting family planning, improving industrial and environmental health, and developing health service management. However, the Society had less actively responded to the changes in health service needs of the population that were caused by a rapid epidemiologic transition in last a few decades. Early detection and treatment of chronic diseases including cancer and cardiovascular diseases and risk reduction by the life style modification are major approaches to the contemporary national health problems and they are the core contents of preventive medicine. The author proposed to develop the clinical preventive medicine specialist who will have additional training in clinical medicine for health screening and life style modification to the current preventive medicine training program and thus will be able to provide comprehensive preventive medical services. Another area that the Society may take the initiative is training preventive medicine specialist in the disaster, including bioterrorism, preparedness and management. The Society should be more active in proposing health policy and health service program and also participate collectively in a large scale health research project of the government. These approaches may not only contribute more effectively to the national health promotion but also improve the identity of the Society.

Shot Transition Detection based on Improved Fuzzy Association Memory (개선된 퍼지연상기억장치에 기반한 장면전환 검출)

  • Lee, Dong-Ha;Go, Il-Ju;Kim, Gye-Yeong;Choe, Hyeong-Il
    • Journal of KIISE:Software and Applications
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    • v.29 no.8
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    • pp.565-572
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    • 2002
  • 학습과 추론을 위하여 유용한 방법으로 퍼지연상기억장치가 있다. 본 논문에서는 보다 효과적으로 추론결과를 유도하기 위하여 퍼지연상기억장치를 학습하는 단계에서 오류 역전파를 통하여 노드들 사이의 연결가중치를 재조정하는 방법과 퍼지규칙들을 간결화하는 방법을 제안한다. 제안된 방법은 비디오 데이타의 장면전환을 검출하는 분야에 적용하여 성능평가를 수행한다.

Cut and Fade Detection of Scene Change Using Wavelet transform (웨이블렛 변환을 적용한 장면전환의 cut과 fade검출)

  • 이명은;박종현;박순영;방만원;조완현
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.207-210
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    • 2000
  • 본 논문에서는 신호를 해석하는데 유용한 웨이블렛 변환을 적용하여 장면전환 요소 중 cut과 fade를 검출하는 알고리즘을 제안한다. 제안된 방법은 웨이블렛 저대역 부밴드로부터 각 프레임의 히스토그램을 구한 후 이전 프레임과 현재 프레임사이의 히스토그램 차를 구하여 이 값이 임계값 이상이면 급격한 장면전환(abrut shot transition)인 cut으로 분류한다. 다음으로 페이드인(fade in)이나 페이드 아웃(fade out)등 컷의 지점이 불분명한 점진적 장면전환(gradual scene transition)을 검출하기 위하여 고대역 부밴드에서 추출한 에지성분에 모멘트를 계산하여 인접한 프레임 사이의 변동율을 분석하여 값이 증가하면 페이드 인을 검출하고 반면에 감소하면 페이드 아웃을 검출하게된다. 성능평가를 위하여 실제의 비디오 분할에 적용한 결과 웨이블렛 적용 방법론이 매우 높은 Precision을 갖는다는 것을 알 수 있으며 윤곽정보에 모멘트 정보를 더함으로써 기존의 방법보다 정확한 페이드(fade) 구간을 검출할 수 있었다.

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