• 전자공학회논문지A
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• 제32A권4호
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• pp.1-14
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• 1995

A new stochastic Petri nets model, called Stochastic Petri Nets Reward Model(SPNRM) is used for modeling and evaluating the performance of telecommunication protocols. We have developed a SPNRM of the TDX-10 Internal protocol, which has a packet data exchange facility between DCEs, Especially a timer and retransmission handling model is presented for error control of the data transmission phase. The stochastic Petri nets package(SPNP), a software package for SPNRM used in this paper, has been used to generate numerical results by analytical-numerical method rather than simulation. From the steady state solution of the net, it is possible to calculate automatically the performance measure of the protocol medeled with both end-to-end and link-by-link method, which are the mean response times and the throughputs.

• International Journal of Quality Innovation
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• 제1권1호
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• pp.64-74
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• 2000

This paper investigates the issue of performance testing on web browsing environments. Among the typical non-functional characteristics, index of link validity will be deeply explored. A framework to certify link correctness in web site is proposed. All possible navigation paths are first formulated to represent a usage model with the Markov chain property, which is then used to generate test script file statistically. With collecting any existing failure information followed by tracing these testing browsed paths, certification analysis may be performed by applying Markov chain theory. The certification result will yield some significant information such as: test coverage, reliability measure, confidence interval, etc. The proposed mechanism may provide not only completed but also systemic methodologies to find any linking errors and other web technologies errors. Besides, an actual practice of the proposed approach to a web-based system will be demonstrated quantitatively through a certification tool.

• International Journal of Advanced Culture Technology
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• 제7권2호
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• pp.42-51
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• 2019

This study tests the applicability of concepts of integrated leadership-in-government and follower happiness in South Korea and then comes up with implication and limitations on the applicability based on the study of Mathias et al. (2018). The study adopts eight leaderships: accountability, rule-following, political loyalty, network governance, task-oriented, relations-oriented, change-oriented and diversity-oriented leadership that Mathias et al. (2018) employ from Fernandez et al. (2010) and Tummers and Knies (2016). We also select job satisfaction and self-perceived performance to measure follower happiness depending on Mathias et al. (2018). According to the analytical results, it shows that accountability leadership, network governance leadership, task-oriented leadership, relations-oriented leadership, and change-oriented leadership have positive influences on follower happiness measured. Based on the analytical results, this study suggests implication and limitation on the applicability of the link between integrated leadership and follower happiness in comparison to the results from Mathias et al. (2018).

• 통상정보연구
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• 제8권4호
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• pp.209-227
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• 2006

This paper analyse current interpretation of the "causal link" that in particular, focuses principally on the so-called "non-attribution" requirement of Article 4.2(b) of the Safeguards Agreement. The safeguard measures are justified as a temporary economic adjustment to harm that is caused by an increase in imports. The problem with this justification is that there are other kinds of economic forces that may injure domestic industries, such as changes in consumer tastes, government spending or a lack thereof, and economic downturns. These problems do not justify government-imposed remedies. When factors therefore other than increased imports are causing injury to the domestic industry at the same time, such injury shall not be attributed to increased imports. The Appellate Body stressed that a contribution of third-party imports to the existence of serious injury must be sufficiently clear as to establish the existence of the causal link required, it found that Article 4.2(b) does not suggest that increased imports be the sole cause of the serious injury, or that other factors causing injury must be excluded from the determination of serious injury. The interest in separation is to ensure that a measure is not applied to remedy harm not caused by imports, but this basic point assumes that the harm is distinguishable in the first place. It also assumes that the safeguard is designed to respond to harm caused by imports. In fact safeguards were never intended to respond to this kind of unfair trade, but rather to provide whatever emergency relief might assist an ailing domestic industry if imports happened to be a part of that injury. The Appellate Body's insistence in breaking cause and effect down to minutia in the non-attribution analysis seems to be so overly intricate that it conflicts with it's broader focus on evaluating factors that effect harm on the industry as a whole.

• 융합정보논문지
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• 제10권5호
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• pp.1-7
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• 2020

본 논문은 수중 IoT 네트워크에서 센서의 전력 소비를 줄이고 네트워크의 처리량을 향상하는 수중 링크적응 방법을 제안한다. 링크 적응 방법의 하나인 AMC(Adaptive Modulation and Coding) 기술은 SNR(Signal Noise Rate)과 BER(Bit Error Rate)의 강한 상관관계를 이용하지만, 수중에 바로 적용하는 것은 어렵다. 따라서 수중 환경에 적합한 머신러닝 기반의 AMC 기술을 제안한다. 제안하는 MCS(Modulation Coding and Scheme) 예측 모델은 수중 채널 환경에서 목표 BER 값을 달성하기 위한 통신 방법을 예측한다. 예측된 통신 방법을 실제 수중 무선 통신에서 적용하는 것은 현실적으로 어렵기 때문에 본 논문에서는 높은 정확도의 BER 예측 모델을 사용해 MCS 예측 모델의 성능을 확인한다. 결과적으로 제안하는 AMC 기술은 통신 성공 확률을 올림으로써 머신러닝의 적용 가능성을 확인시켰다.

• 한국ITS학회 논문지
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• 제16권3호
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• pp.59-72
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• 2017

기존 실시간 신호제어시스템의 루프검지기 기반 수집체계의 한계를 극복하기 위해 실시간 택시 GPS 데이터를 신호제어에 활용할 수 있는 방안에 대한 연구의 일환으로, 본 논문은 2016년 발표한 링크평균통행시간과 대기차량길이의 추정 모형과 교통상황 판단 알고리즘에 대해 평과와 개선을 수행하였다. 링크평균통행시간은 연동그룹과 비연동그룹을 고려하여 평균통행시간을 고도화하였고, 대기차량길이는 교통상황을 고려하여 추정모형을 고도화 하였다. 링크평균통행시간의 정확도는 약 95%, 대기차량길이의 정확도는 약 85%로 분석되었다. 교통상황판단 알고리즘은 정확도가 향상된 통행속도와 대기차량길이를 반영하였다. 반영된 지표들의 변동을 줄이고 교통상황의 추세를 판단하기 위해 평활화를 수행하였으며, 과포화 상황 판단 기준에 통과주기를 반영하여 알고리즘을 고도화하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제2권2호
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• pp.111-123
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• 1998

Performance index is a measure of telecommunications network integrating reliability and capacity simultaneously. This paper suggests a computerized algorithm evaluating a performance index for telecommunications network and compares this computerized algorithm with the algorithm[1] by experimenting on several benchmarks. A computerized algorithm proposed by this paper is superior to the algorithm[1] with respect to the computation time for most of the benchmarks.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.205-206
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• 2012

A general method to measure the inverter DC bus capacitor current is described. It is an indirect estimated method. By measuring the input and out voltage and current can calculate DC bus capacitor current. This paper will develope the theory that describes the indirect method. It will discuss and verify the feasibility of this approach through the use of the PSIM. Using SPWM control method will be simulated and compared.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.200-205
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• 1989

The performance of conventional robot arms is inhibited by trade-off between speed and accuracy. Because these systems measure only joint angles, in spite of slow speed, they must rely on a stiff structure in order to attain positioning accuracy. Lightweight links would allow faster motion, but their flexibility would also produce positioning errors. This research is involved with the development and evaluation of an End-point Control System whose major goal is to compensate for link deflections and thus mitigate the speed versus accuracy conflict in conventional manipulator.

• The Journal of the Acoustical Society of Korea
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• 제17권4E호
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• pp.41-47
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• 1998

Microphone is the first link in the speech recognition system. Depending on its type and mounting position, the microphone can significantly distort the spectrum and affect the performance of the speech recognition system. In this paper, characteristics of the speech signal for different microphones and microphone distances are investigated both in time and frequency domains. In the time domain analysis, the average signal-to-noise ration is measure ration is measured for the database we collected depending on the microphones and microphone distances. Mel-frequency spectral coefficients and mel-frequency cepstrum are computed to examine the spectral characteristics. Analysis results are discussed with our findings, and the result of recognition experiments is given.