• Steel and Composite Structures
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• v.15 no.5
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• pp.507-518
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• 2013

The seismic performance of six types of weak-axis steel moment connections was investigated through cyclic testing of six full-scale specimens. These weak-axis moment connections were the column-tree type, WUF-B type, FF-W type, WFP type, BFP-B type and DST type weak-axis connections. The testing results showed that each of these weak-axis connection types achieved excellent seismic performance, except the WFP and the WUF-B types. The WFP and WUF-B connections displayed poor seismic performance because a fracture appeared prematurely at the weld joint due to stress concentrations. The column-tree type connection showed the best seismic behavior such that the story drift ratio could reach 5%.

• ETRI Journal
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• v.25 no.5
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• pp.321-327
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• 2003

Testing time and power consumption during the testing of SoCs are becoming increasingly important with an increasing volume of test data in intellectual property cores in SoCs. This paper presents a new algorithm to reduce the scan-in power and test data volume using a modified scan latch reordering algorithm. We apply a scan latch reordering technique to minimize the column hamming distance in scan vectors. During scan latch reordering, the don't-care inputs in the scan vectors are assigned for low power and high compression. Experimental results for ISCAS 89 benchmark circuits show that reduced test data and low power scan testing can be achieved in all cases.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1393-1405
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• 2017

It is well known that duty-cycling control by dynamically adjusting the polling interval according to the traffic loads can effectively achieve power saving in wireless sensor networks. Thus, there has been a significant research effort in developing polling interval adaptation schemes. Especially, Dynamic Low Power Listening (DLPL) scheme is one of the most widely adopted open-looping polling interval adaptation techniques in wireless sensor networks. In DLPL scheme, if consecutive idle (busy) samplings reach a given fixed threshold, the polling interval is increased (decreased). However, due to the trial-and-error based approach, it may significantly deteriorate the system performance depending on given threshold parameters. In this paper, we propose a novel DLPL scheme, called SDL (Sequential hypothesis testing based Dynamic LPL), which employs sequential hypothesis testing to decide whether to change the polling interval conforming to various traffic conditions. Simulation results show that SDL achieves substantial power saving over state-of-the-art DLPL schemes.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.5-6
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• 2008

차단기, 개폐기, 배전반과 같은 전력기기에 대한 성능시험시, 전압과 전류, 제어신호를 측정하고, 필요한 경우 고속카메라를 이용해 시험장면을 촬영한 다음, 이들을 종합적으로 분석하여 시험결과를 판정한다. 이때, 대부분 개별 시스템으로 전압-전류 시험파형과 시험영상을 측정하고 분석하기 때문에, 시간 동기화가 불가능하여 시험현상이나 시료동작특성 분석에 많은 어려움이 있다. 따라서 개별 시스템으로 측정한 신호를 동기 시켜 동시에 분석할 수 있는 프로그램이 있다면, 시험결과 판정뿐만 아니라 시험 중에 발생하는 전기적 과도현상이나 시료의 동작특성분석에 많은 도움이 될 것이다. 이러한 목적을 위해, PT&T에서는 측정시스템과 고속카메라를 이용하여 측정한 전압-전류 시험파형과 시험영상을 동기 시켜 동시에 분석할 수 있는 프로그램인 Dual Viewer를 개발하였다. 본 논문에서는 Dual Viewer에 대한 기능과 특징에 대해 소개하고자 한다.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.206-211
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• 2000

The accelerated testing technique using the equivalent load condition plays an important part in development process. However, in the industrial field, the theoretical background and advantages of this accelerated testing technique have been lack of understanding. Because the environmental durability condition forms the foundation of the accelerated testing technique, it is important to analyze the loading components and damage in service environment. In this work, we present the theoretical background and process for accelerated testing, and introduce our accelerated equivalent load analysis program. We developed the GUI program, and the user can easily obtain the result by selecting the program module.

• Journal of the Korean Institute of Navigation
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• v.19 no.4
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• pp.63-82
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• 1995

This paper is a study on standard testing method for type approval of DSC which is the main structure of the terrestrial communication. As authority inspecting offices and producers have no experience for type approval of relative equipments as adapting GMDSS. In this paper, it is to be improved the understanding for type approval ; a system, standard of technic and testing methods, etc and make better quality of relative equipments. Additionally it could help quality and quantity improvement in all radiocommunication parts. Of course, the regulation for type approval had made but most makers didn't know it correctly, so the method of solution have been studied. By result of this study, with comparision and analysis of structure and a condition of efficiency with adapting GMDSS is could help some problems slove in the field and gave testing method of machinery and tools, electrical conditions, came out measurement and did ways standard efficiency.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.3
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• pp.270-279
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• 2003

Parametric studies have been conducted into the variability of the factors affecting the ultrasonic testing applied to weldments. The influence of ultrasonic equipment, transducer parameters, test technique, job parameters, defect type and characteristics on reliability far defect detection and sizing was investigated by experimentation. The investigation was able to build up substantial bank of information on the reliability of manual ultrasonic method for testing weldments. The major findings of the study separate into two parts, one dealing with correlation between ultrasonic techniques, equipment and defect parameters and inspection performance effectiveness and other with human factors. Defect detection abilities are dependent on the training, experience and proficiency of the UT operators, the equipment used, the effectiveness of procedures and techniques.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.154-159
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• 1987

In the previously reported Part I, the behavior of the flank wear for carbide tool was studied as a preceeding step to present a simple method for Quick Tool-Life Testing, and the following general equation was obtained $W_{f}$ =(a+bt) $V^{m}$ . In this study the following step-cutting formula for the constants a, b and m in the above general model is derived by using step-cutting data [a numerical formula] To check the validity of the above formula, the comparison is made between the tool-life equation inferred in this method and that inferred in the conventional tool-life testing method, when the wear criterion is 0.3mm. The equation obtained in the present method is V(T')$^{0.57}$=1763 whereas the equation obtained in the conventional tool-life testing method is V(T)$^{0.56}$=1605 The results of the above two formula are satisfactory and also verify the validity of the present research.earch.

• The Korean Journal of Applied Statistics
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• v.23 no.2
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• pp.219-234
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• 2010

In index investing according to KOSPI, we estimate Value at Risk(VaR) from the extreme losses of the daily returns which are obtained from KOSPI. To this end, we apply Block Maxima(BM) model which is one of the useful models in the extreme value theory. We also estimate the extremal index to consider the dependency in the occurrence of extreme losses. From the back-testing based on the failure rate method, we can see that the model is adaptable for the VaR estimation. We also compare this model with the GARCH model which is commonly used for the VaR estimation. Back-testing says that there is no meaningful difference between the two models if we assume that the conditional returns follow the t-distribution. However, the estimated VaR based on GARCH model is sensitive to the extreme losses occurred near the epoch of estimation, while that on BM model is not. Thus, estimating the VaR based on GARCH model is preferred for the short-term prediction. However, for the long-term prediction, BM model is better.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.787-796
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• 2019

In this paper, we propose the design and test measure of Ringer injection IoT system for controling the ringer injection status and notifying the server system of the collected status informations such as the completion of injection, the remaining liquid, the injection status, and the emergency alarming of the urgent patients. We design the circuit diagrams composed of linger injection sensors, switches, status indicators, wireless communication functionalities, and propose the controlling and monitoring algorithms for sensing the linger injection status and notifying the collected status informations to a server system. Furthermore, we derive the testing criteria, such as linger liquid sensing time, sensing distance, operating temperature, input power, power consumption, and wireless communication speed, and analyze the test results.