• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.95-101
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• 2014

This paper explains effective tracking method for a vehicle cutting in a line on the road automatically. The method employs KLT based on optical flow using play-back image sequence. Main contribution of this paper is play-back image sequence that is in order image frames for rewind direction from a reference point in time. The moment when recognizing camera can read a license plate very well can usually be the reference point in time. The biggest images of object traced can usually be obtained at this moment also. When optic flow is applied, the bigger image of the object traced can be obtained, the more feature points can be obtained. More many feature points bring good result of tracking object. After the recognizing cameras read a license plate on the vehicle suspected of cut-in-line violation, and then the system extracts the play-back image sequence from the tracking cameras for watching wide range. This paper compares using play-back image sequence as normal method for tracking to using play-forward image sequence as suggested method on the results of the experiment and also shows the suggested algorithm has a good performance that can be applied to the unmanned system for watching cut-in-line violation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.391-394
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• 2022

최근 한국을 포함한 여러 국가들에서 프로그래밍 교육이 중요시 되고 있다. 그러나 이런 상황으로 인해 더 많아진 학생들은 미숙함으로 인해 숙련자에 비해 더 많은 오류를 만나지만 이를 해결하기 위한 디버깅 실력은 아직 미숙하다. 따라서 본 논문에서는 프로그래밍 교육 지원을 위한 초보자용 GUI 디버깅 도우미 UDB (Unity-DeBugger)를 제안한다. UDB는 제출한 학생 코드를 분석하여 반응형 추적표와 오류 로그를 생성하고 이를 기반으로 GUI 및 애니메이션으로 만들어 학생과 상호작용한다. 특히 UDB는 반응형 추적표를 통해 프로그램 안에 있는 변수들의 현재 상태를 보여주고 순방향 추적뿐만 아니라 기존 IDE의 디버깅 도구들과는 다르게 역방향 추적이 가능하다는 큰 특징이 있다. 이런 UDB를 예시 코드에 실제로 적용한 결과를 통해 미숙한 학생도 역방향 추적 기능을 사용하여 오류 원인을 쉽게 찾을 수 있음을 보인다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.5
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• pp.397-409
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• 2003

This paper describes an implementation of radix-4 trellis parallel architecture and backward state transition control trace back Viterbi decoder, and presents the application results to high speed wireless LAN. The radix-4 parallelized architecture Vietrbi decoder can not only improve the throughput with simple structure, but also have small processing delay time and overhead circuit compared to M-step trellis architecture one. Based on these features, this paper addresses a novel Viterbi decoder which is composed of branch metric computation, architecture of ACS and trace back decoding by sequential control of backward state transition for the implementation of radix-4 trellis parallelized structure. With the proposed architecture, the decoding of variable code rate due to puncturing the base code can easily be implemented by the unified Viterbi decoder. Moreover, any additional circuit and/or peripheral control logic are not required in the proposed decoder architecture. The trace back decoding scheme with backward state transition control can carry out the sequential decoding according to ACS cycle clock without additional circuit for survivor memory control. In order to evaluate the usefulness, the proposed method is applied to channel CODEC of the IEEE 802.11a high speed wireless LAN, and HDL coding simulation results are presented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.51-62
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• 2003

This paper presents a novel survivor memeory management and decoding techniques with sequential backward state transition control in the trace back Viterbi decoder. The Viterbi algorithm is an maximum likelihood decoding scheme to estimate the likelihood of encoder state for channel error detection and correction. This scheme is applied to a broad range of digital communication such as intersymbol interference removing and channel equalization. In order to achieve the area-efficiency VLSI chip design with high throughput in the Viterbi decoder in which recursive operation is implied, more research is required to obtain a simple systematic parallel ACS architecture and surviver memory management. As a method of solution to the problem, this paper addresses a progressive decoding algorithm with sequential backward state transition control in the trace back Viterbi decoder. Compared to the conventional trace back decoding techniques, the required total memory can be greatly reduced in the proposed method. Furthermore, the proposed method can be implemented with a simple pipelined structure with systolic array type architecture. The implementation of the peripheral logic circuit for the control of memory access is not required, and memory access bandwidth can be reduced Therefore, the proposed method has characteristics of high area-efficiency and low power consumption with high throughput. Finally, the examples of decoding results for the received data with channel noise and application result are provided to evaluate the efficiency of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.8
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• pp.1587-1594
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• 1994

The pitch predictor is one of the most important part for the robust tree coder. The hybrid backward pitch adapation which is a combination of a block adaptation and a recursive adaptation is used for the pitch predictor. In order to improve the error performance and track the pitch period change of the input speech, it is proposed to smooth the input of the pitch predictor. The smoother with three taps can have fixed coefficients or variable coefficients depending on the estimated autocorrelation function of the output of the pitch synthesizer. The inclusion of a variable smoother can track the pitch period change within a block and reduce the effect of channel errors.

• Journal of Advanced Navigation Technology
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• v.1 no.1
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• pp.70-80
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• 1997

In this paper, the performances of two noncoherent code tracking loops, i. e., traditional code tracking loop(TCTL) and modified code tracking loop(MCTL) are analyzed and compared in a CDMA mobile environment. Closed-form formulas for steady-state jitter variance are derived analytically for the two schemes as a function of the pulse shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth. The design issues of the loop filter are also addressed with emphasis on the second-order tracking loop. Finally, the degradation of BER performance due to timing errors is examined in a CDMA reverse link for IMT-2000 designed by ETRI.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.645-655
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• 1997

In this paper, the performance of the noncoherent code tracking loop designed at baseband for CDMA applications is analyzed in detail and is confirmed by computer simulations. Analytical closed-form formula for jitter variance is derived for AWGN channel environments as a function of pulse shaping filter, timing offset, signal-to-interference ratio, and loop filter coefficients. The design issue of the loop filter is also addressed with emphasis on the second-order tracking loop. Finally, the performance of the designed tracking loop is examined by computer simulations for both AWGN and Rayleigh fading channels, when applied to the reverse link of the coherent CDMA system for IMT-2000 designed by ETRI.

• Journal of KIISE
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• v.42 no.3
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• pp.328-340
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• 2015

Software requirements are continuously changed for various reasons, consequently changes of software are inevitable. In the case of changes necessitated by changes in requirements, it is necessary to precisely predict the ripple effects of the changes for efficient management of the changes. This paper proposes the management method of traceability information, which can be applied in object-oriented development. Furthermore, we introduce the guidelines for prediction of the ripple effects of changes based on traceability information among artifacts composing a system. We identify traceability items for the essential artifacts which were composed of the object-oriented system, and define relationships among them. The purpose of the method proposed in this paper is to identify the scope of change precisely through the guidelines. These can then be used for tracing and analyzing the impact of the changes both the forward and backward looking, based on the relationships of traceability items.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.11a
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• pp.161-167
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• 2005

RFID 태그 객체의 위치정보는 시간에 따라 궤적 정보가 누적되는 이동체와 유사한 특성을 가지지만 태그의 위치는 논리적인 리더의 위치로 인식되며 위치보고가 리더의 인식영역 안에서만 이루어지므로 시간축에 평행한 이산적인 시간간격 형태로 나타나는 차이점이 있다. 기존 이동체의 위치 추적 색인에서는 이동체의 위치를 연결된 다중선으로 표현하여 색인에 저장을 하기 때문에 시공간적으로 연결되지 않은 태그의 위치 정보를 저장하면 궤적 검색 비용이 매우 높아지는 문제가 발생한다. 이 논문에서는 이동체와는 다른 태그의 위치 특성을 반영하여 태그의 궤적 검색을 효율적으로 수행하는 색인 기법을 제안한다. 제안된 색인에서는 시간적으로 연결되지 않은 태그의 궤적 정보를 검색하기 위하여 동일 태그의 위치 간의 연결 정보를 유지하는 기법을 제시하고 있다. 또한, 부모 태그와 자식 태그간의 포함관계를 유지하는 기법을 제시함으로써 상품의 역학조사와 같이 물품에 부착된 태그간의 포함관계를 이용한 순방향 및 역방향 궤적 검색을 효율적으로 수행할 수 있도록 하고 있다.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.457-466
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• 1999

원자력 발전소 계측 제어 시스템, 의료 관련 시스템, 항공 관련 시스템 등 실생활과 밀접한 시스템에 소프트웨어의 사용이 점차 증가하고 있다. 이러한 시스템에서 소프트웨어의 오류는 예기치 않는 사고를 유발하여 인명, 재산상의 심각한 타격을 줄 수 있다. 그러므로 고신뢰도 소프트웨어의 개발 시에는 반드시 시스템의 안전성을 보장해 주어야 한다. 역방향 안전성 분석 방법은 시스템의 안전성을 분석하는 한가지 방법으로서 시스템의 위험 상태를 정의하고 그 위험의 원인들을 추적, 분석함으로써 안전성에 대한 효율적인 분석을 수행할 수 있는 장점을 갖는다. 이 논문에서는 소프트웨어 개발 초기 단계에서 안전성을 분석할 수 있는 방법으로 Colored Petri Nets(CPN)에 기반을 둔 역방향 안전성 분석 방법을 제시한다. 또한 CPN 역방향 안전성 분석 도구인 SAC(Safety Analyzer for CPN)의 설계 및 구현에 대해 언급한다. SAC은 기존의 상용 CPN 모델링 도구인 Design/CPN과 연계하여 사용될 수 있으므로 CPN으로 모델링된 시스템의 안전성을 분석할 수 있다는 장점이 있다. 이 논문에서는 예제로 자동 교통 제어 시스템의 일부를 CPN으로 모델링하고 SAC을 이용한 분석 과정을 기술한다.Abstract In safety-critical systems such as nuclear power plants, medical machines, and avionic systems which are closely related with our livings, the usage of software in the controlling part is growing rapidly. Since software errors in safety-critical systems may cause serious accidents leading to financial or human damages, system safety should be ensured during and after development of a system. A backward safety analysis technique defines system hazards and tries to trace their causes by analyzing system states backward. In this paper, we provide a backward safety analysis technique based on Colored Petri Nets(CPN), which is applicable to the early software development phase. Also Safety Analyzer for CPN(SAC), the supporting tool, is designed and implemented. Since SAC is compatible with Design/CPN, a commercial tool for supporting CPN, it can be applicable to analyze safety in practical problems. As an example, we model a part of the traffic light control system using CPN and analyze safety properties of the model using the SAC tool.