• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.201-208
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• 2000

In this study, the behavior of saturated sandy soils under dynamic loads - pore water pressure and effective stress - was investigated using Disturbed State Concept(DSC) model. The model parameters are evaluated from laboratory test data. During the process of loading and reverse loading, DSC model is utilized to trace strain-hardening and cyclic softening behavior. The procedure of back prediction proposed in this study are verified by comparing with laboratory test results. From the back prediction of pore water pressure and effective mean pressure under cyclic loading, excess pore water pressure increases up to initial effective confining pressure and effective mean pressure decrease close to zero in good greement with laboratory test results. Those results represent the liquefaction of saturated sandy soils under dynamic loads. The number of cycles at initial liquefaction using the model prediction is in good agreement with laboratory test results. Therefore, the results of this study state that the liquefaction of saturated sandy soils can be explained by the effective tress analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.697-698
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• 2008

This paper deals with finite element characteristic analysis of brushless DC motor according to magnetic property measurement methods. Magnetic property data for non-oriented (NO) electrical steel for electric motors are measured by the Epstein test which is considered as the international standards. Data from Epstein test may result in discrepancy from motor characteristic tests due to innate anisotropic property of NO electrical steel. Finite element analysis were performed for a BLDC motor by various measurement methods such as Epstein test, Ring test and single sheet test (SST), and calculated results were compared with considering anisotropic property conditions.

• Computers and Concrete
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• 제31권3호
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• pp.241-252
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• 2023

Corrosion of rebar is one of the major deteriorating mechanisms that affect the durability of reinforced concrete (RC) structures. The increase in CO₂ concentration in the atmosphere leads to early carbonation and deterioration due to corrosion in RC structures. In the present study, an attempt has been made to modify the existing carbonation depth prediction empirical model. The modified empirical model is verified from the carbonation data collected from selected RC structures of CSIR-SERC campus, Chennai and carbonation data available from the reported literature on in-situ RC structures. Attempt also made to study the carbonation depth in the laboratory specimens using oxygen permeability index (OPI) test. The carbonation depth measured from RC structures and laboratory specimens are compared with estimated carbonation depth obtained from OPI test data. The modified empirical model shows good correlation with measured carbonation depth from the identified RC structures and the reported RC structures from the literature. The carbonation depth estimated from OPI values for both in-situ and laboratory specimens show lesser percentage of error compared to measured carbonation depth. From the present investigation it can be said that the OPI test is the suitable test method for both new and existing RC structures and laboratory RC specimens.

• 한국정보전자통신기술학회논문지
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• 제14권2호
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• pp.161-167
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• 2021

실험실정보관리시스템(LIMS, Laboratory Information Management System)은 실험실 데이터를 저장, 가공, 검색 그리고 분석하기 위한 중앙화된 데이터베이스로서 검사, 분석, 시험 업무를 수행하는 실험실을 위해 특별히 고안된 컴퓨터 시스템 또는 시스템을 의미한다. 특히 LIMS는 실험실의 운영을 지원하는 기능을 갖추고 있으며, 워크플로우 관리나 데이터 추적지원 등이 필요하다. 본 논문에서는 실험실의 운영을 위하여 빅데이터 자동화 수집 기술의 하나인 크롤링 기술을 활용하여 웹사이트 및 다양한 채널에 존재하는 데이터를 수집한다. 수집된 시험 방법 및 내용 중 시험자가 활용할 수 있는 유용한 시험 방법 및 내용을 추천한다. 그리고 이에 대한 피드백을 관리하여 수집 채널의 검증이 가능한 상호보완적인 LIMS 플랫폼을 구현한다.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.238-249
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• 2012

Flight test of flapping micro air vehicles (FMAVs) is carried out using an instrumented measurement system to obtain various engineering parameters and hence to assess the flight performance of the vehicles through the data investigation. An indoor flight test facility equipped with a motion capture system and tracking cameras is used for the work presented in this paper. Maneuvers including straight-level flight, ground flapping, takeoff and landing are tested. Spatial position and orientation data are obtained from the retro-reflective tracking markers attached to the vehicles. Subsequent test analysis is carried out by generating performance parameters from raw data and then assessing the flight performance by comparison of the vehicles. The main findings of this work confirm that the test method and procedures presented here enable the systematic numerical data measurement and assessment of the flying performances of these vehicles, and show the applicability for the test and evaluation of general flapping MAVs.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권4호
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• pp.463-469
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• 2016

This paper presents a compression-friendly low power test scheme in EDT environment. The proposed approach exploits scan slices reusing to reduce the switching activity during shifting for test scheme based on linear decompressor. To avoid the impact on encoding efficiency from resulting control data, a counter is utilized to generate control signals. Experimental results obtained for some larger ISCAS'89 and ITC'99 benchmark circuits illustrate that the proposed test application scheme can improve significantly the encoding efficiency of linear decompressor.

• 한국물환경학회지
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• 제21권3호
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• pp.274-276
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• 2005

To investigate bioassay for toxic level evaluation of wastewater, toxic levels were checked influents and effluents of 6 wastewater discharge facilities with Daphnia magna and Vibrio fischeri. In view of test duration, D. magna is preferred at 48 hours. And it was judged to efficient that one of the two was choosen for toxicity test method (Daphnia test and Vibrio test). Analysis data for wastewater is average toxic level for influent more higher than effluent. And effluent toxic level is sharp decrease than effluents.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권4호
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• pp.299-307
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• 2013

The value of blood sugar is measured by a personal blood glucose meter which consists of two parts: a glucose strip and a blood glucose meter. A personal blood glucose meter makes use of electric media which are composed of glucose oxidase and electron. This study is to propose a method of reliability demonstration test derived from field data analysis and FMEA(Failure Mode and Effect Analysis). Detailed Conditions for reliability demonstration test are selected from the comparison of various failure mechanisms. The most dominant failure mechanism is wear-out which is caused by strip insertion/extraction. The testing device that can reproduce the failure mechanism of strip insertion/extraction is made to conduct reliability demonstration test. Using the testing device, it is confirmed that target lifetime of selected devices is more than 2 years.

• 대한임상검사과학회지
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• 제45권2호
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• pp.60-65
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• 2013

Data from repeated measurements are accomplished through repeatedly processing the same subject under different conditions and different points of view. The power of testing enhances the choice of pertinent analysis methods that agrees with the characteristics of data concerned and the situation involved. Along with the clinical example, this paper compares the analysis of the variance on ex-post tests, gain score analysis, analysis by mixed design and analysis of covariance employable for repeating measure. Comparing the analysis of variance on ex post test, and gain score analysis on correlations, leads to the fact that the latter enhances the power of the test and diminishes the variance of error terms. The concluded probability, identified that the gain score analysis and the mixed design on interaction between "between subjects factor" and "within subjects factor", are identical. The analysis of covariance, demonstrated better power of the test and smaller error terms than the gain score analysis. Research on four analysis method found that the analysis of covariance is the most appropriate in clinical data than two repeated test with high correlation and ex ante affects ex post.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권2호
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• pp.93-96
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• 2014

RFID (Radio Frequency IDentification) system is recognition technology which can maintain various object's information. Reliability of RFID tags is the most important factor in RFID system. In this paper, we proposed ALT (Accelerated Life Test) method for UHF RFID tags. Temperature and humidity were adopted as stress factors and the accelerated life tests were conducted in three different conditions. We performed failure analysis for identifying failure mechanism and statistical analysis of test data. In the statistical analysis, we employed Inverse Power law for relationship between tag's life and stress. Through the statistical analysis, we proposed acceleration factor for several levels of temperature-humidity. The reliability qualification test plans were also designed for the tag's target reliability.