• JSTS:Journal of Semiconductor Technology and Science
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• 제13권1호
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• pp.71-78
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• 2013

In highly reliable and durable systems, failures due to aging might result in catastrophes. Aging monitoring techniques to prevent catastrophes by predicting such a failure are required. Aging can be monitored by performing a delay test at faster clocks than functional clock in field and checking the current delay state from the test clock frequencies at which the delay test is passed or failed. In this paper, we focus on test clock control scheme for a system-on-chip (SoC) with multiple clock domains. We describe limitations of existing at-speed test clock control methods and present an on-chip faster-than-at-speed test clock control scheme for intra/inter-clock domain test. Experimental results show our simulation results and area analysis. With a simple control scheme, with low area overhead, and without any modification of scan architecture, the proposed method enables faster-than-at-speed test of SoCs with multiple clock domains.

• 대한전기학회논문지:전력기술부문A
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• 제48권9호
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• pp.1161-1166
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• 1999

Delay testing has become highlighted in the field of digital circuits as the speed and the density of the circuits improve greatly. However, delay faults in sequential circuits cannot be detected easily due to the existence of state registers. To overcome this difficulty a new scan filp-flop is devised which can be used for both stuck-at testing and delay testing. In addition, the new scan flip-flop can be applied to both the existing functional justification method and the newly-developed reverse functional justification method which uses scan flip-flops as storing the second test patterns rather than the first test patterns. Experimental results on ISCAS 89 benchmark circuits show that the number of testable paths can be increased by about 10% on the average.

• ETRI Journal
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• 제25권3호
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• pp.187-194
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• 2003

Delay testing has become an area of focus in the field of digital circuits as the speed and density of circuits have greatly improved. This paper proposes a new scan flip-flop and test algorithm to overcome some of the problems in delay testing. In the proposed test algorithm, the second test pattern is generated by scan justification, and the first test pattern is processed by functional justification. In the conventional functional justification, it is hard to generate the proper second test pattern because it uses a combinational circuit for the pattern. The proposed scan justification has the advantage of easily generating the second test pattern by direct justification from the scan. To implement our scheme, we devised a new scan in which the slave latch is bypassed by an additional latch to allow the slave to hold its state while a new pattern is scanned in. Experimental results on ISCAS'89 benchmark circuits show that the number of testable paths can be increased by about 45 % over the conventional functional justification.

• 대한교통학회지
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• 제27권5호
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• pp.179-187
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• 2009

본 연구에서는 구간통행시간을 기반으로 하는 실시간 교통신호제어 알고리즘을 개발하였으며, 알고리즘의 현장 실험 및 평가를 수행하였다. 구간통행시간 기반 실시간 신호제어 알고리즘은 전체 접근로의 지체 균등화를 목적함수로 하며, 주요 과정으로는 개별차량 지체와 차량관측 시간을 이용한 대기행렬 해소시간의 산정과 이를 기반으로 교차로 지체를 산정하는 과정이다. 이후 이동류별 주기단위 지체변화량을 산정하고, 주기 결정 및 현시 배분 등의 과정이 이루어진다. 이동류별 지체의 산정과정에서는 연동교차로의 특성을 고려하여 HCM의 연동계수를 이용한 독립교차로에서의 지체로 환산하는 과정을 수행하며, 이때 누적주기의 프르브 차량 정보를 이용함으로써 보다 안정적 신호제어를 도모하였다. 통행시간 기반 신호제어 알고리즘의 현장실험 및 평가를 통해 TOD 제어와의 비교평가를 수행하였으며, 실험대상 가로축은 약 400m의 평균 교차로 간격을 가지는 일련의 4개 교차로로 구성되어 있다. 현장실험 및 평가 결과 TOD 제어 대비 지체 감소 효과와 더불어 이동류별 지체의 표준편차 감소를 통해 지체의 균등화 효과를 확인하였다. 본 연구를 통해 교통정보수집을 위한 범용의 검지체계에서 산출되는 개별차량의 구간통행시간 정보를 기반으로 하는 실시간 신호제어 알고리즘의 개발 및 평가를 수행하였으며, 이는 유비쿼터스 환경의 급속한 확산이라는 교통환경의 변화에 부응하기 위한 신호제어 방법론의 근본적인 변화에 궁극적인 목표를 두고 있다.

• 한국도로학회논문집
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• 제19권3호
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• pp.1-10
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• 2017

PURPOSES : This paper focuses on strength development according to the mix design with cement type and mineral admixture from laboratory and field tests in cool weather. METHODS : Two methods evaluated the mix design of concrete pavement in cool weather. Firstly, laboratory tests including slump, air contents, setting time, strength, maturity, and freezing-thawing test were conducted. Three alternatives were selected based on the tests. Secondly, a field test was conducted and the optimum mix design in cool weather was suggested. RESULTS : It is an evident from the laboratory test that a mix with type III cement showed better performance than the one with type I cement. There was a delay in strength development of a mix with mineral admixture compared to mix design without any mineral admixture. In the field test, type III cement+flyash 20% mix design proved the best performance. CONCLUSIONS : For concrete pavement in cool weather, mix design using type III cement could overcome the strength delay due to mineral admixture. Moreover, it is possible to make sure of durability of pavement. Therefore, strength and durability problems due to cool weather would decrease.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(3)
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• pp.189-192
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• 2000

This paper presents a new DR(Dead Reckoning) algorithm in client-server-based networked virtual environment using network delay estimation. In the algorithm, a new update packet is sent to server (or client) whenever the difference of current real value and tracking value after network delay is larger than threshold. To confirm the proposed algorithm, a test network game was implemented. Through iterative field tests, we knew that this algorithm provides fair service and stability.

• 한국초전도ㆍ저온공학회논문지
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• 제22권3호
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• pp.13-19
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• 2020

This study presents the experiment and simulation results on the magnetic field response and electrical stability behaviors of no-insulation (NI) and metal insulation with stainless steel tape (MI-SS) which wound in form of racetrack type coils. First of all, the structural design of the racetrack type bobbin was shown along with its parameters. Then, the current-voltage tests were carried out to measure the critical current of both test coils. Also, the sudden discharging and charging tests were performed in the steady state to estimate the decay field time and magnetic field response, respectively. Finally, the overcurrent tests were conducted in the transient state to investigate the electrical stability of these test coils. Based on the experimental results, the contact surface resistances were calculated and applied to the field coils (FCs) of 10-MW-class second generation high temperature superconducting generator (2G HTSG) used in wind offshore environment. The charging delay time and electrical stability for NI and MI-SS HTS FCs of 10-MW-class 2G HTSG are analyzed by the equivalent circuit model and the key parameters which were obtained from the electromagnetic finite element analysis results.

• ETRI Journal
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• 제19권3호
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• pp.259-280
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• 1997

This paper briefly explains the configuration of CDMA Mobile System (CMS) test bed. The measured fading and delay results of CDMA signal in Taejon area are shown. In comparison to other cellular systems, there are more parameters in the CDMA systems that affect system performance and capacity. We performed the optimization test of the selected parameters and present the effect of each parameter on the performance. This paper presents the capacity and performance test results of CMS. The capacity test was performed on ETRI site of three sectors in Taejon area. The performance tests include call completion rate, busy hour call attempt, and the delay characteristics of voice.

• 품질경영학회지
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• 제40권3호
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• pp.270-277
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• 2012

Purpose: In this paper, storage lifetime of delay system in the fuse of 81MM illuminating projectile is estimated. Methods: Accelerated degradation testings of tungsten delay system using both temperature and humidity stresses were performed, and then delay time increase of the systems were analyzed as degradation data based on distribution-based degradation processes. Results: The estimated storage lifetime of detonator is between 11.8 years and 17.6 years with each stress-life relationship. Conclusion: Comparing with field data, storage lifetime of 90% reliability is about 12 years.

• 한국전자파학회논문지
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• 제11권5호
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• pp.830-838
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• 2000

약 2에 걸쳐서 대전지역을 대상으로 DTV 현장측정을 실시하였다. 총 33개의 측정지점을 선정하였고 각 지점에서 수신전력, 잡음전력, SER, RMS 지연확산 및 등화기의 성능을 측정하였다. 전체 측정지점 중의 약 50%가 영상과 음성의 질이 만족할 만한 수준이었고, 등화기는 고스트신호에 대하여 보상능력이 있었으며 13.7dB의 S/N개선을 얻었다. 이 결과로부터 DTV를 위한 측정결과를 확립할 수 있을 것이다.