• Smart Structures and Systems
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• 제13권1호
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• pp.137-154
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• 2014

Servohydraulic shaking tables are being increasingly used in the field of earthquake engineering. They play a critical role in the advancement of the research state and remain one of the valuable tools for seismic testing. Recently, the National Earthquake Engineering Research Center, CGS, has acquired a 6.1m x 6.1 m shaking table system which has a six degree-of-freedom testing capability. The maximum specimen mass that can be tested on the shaking table is 60 t. This facility is designed specially for testing a complete civil engineering structures, substructures and structural elements up to collapse or ultimate limit states. It can also be used for qualification testing of industrial equipments. The current paper presents the main findings of the experimental shake-down characterization testing of the CGS shaking table. The test program carried out in this study included random white noise and harmonic tests. These tests were performed along each of the six degrees of freedom, three translations and three rotations. This investigation provides fundamental parameters that are required and essential while elaborating a realistic model of the CGS shaking table. Also presented in this paper, is the numerical model of the shaking table that was established and validated.

• 한국인터넷방송통신학회논문지
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• 제16권5호
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• pp.151-156
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• 2016

IoT 기술이 발전하면서 주변 환경 정보 수집을 위해 사용 가능한 센서는 종류와 수가 급격히 증가하고 있다. 센서의 종류가 늘어나면서 IoT 제품 및 서비스를 개발하기 위해 적합한 센서 노드를 선정하고 테스트하기 위한 효율적인 시스템의 필요성이 증가하고 있다. 본 연구에서는 IoT 서비스 및 제품 개발 기간 단축을 위한 센서 시험 운용 시스템을 제안한다. 제안하는 시스템은 IoT 센서 노드의 성능 및 기능 범위를 시험하여 제품 및 서비스의 빠른 프로토타이핑에 활용된다. 이를 위해 IoT 센서 시험 운용 시스템의 요구사항을 분석하고, 기능 요소별 설계를 기반으로 시스템을 설계한다. 마지막으로 시험 어플리케이션을 구현하여 설계한 시스템의 기능 요소를 테스트한다.

• 융합보안논문지
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• 제13권4호
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• pp.33-39
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• 2013

소프트웨어 개발을 성공적으로 수행하기 위하여서 유닛 테스팅은 아주 필수 불가결한 요소이다. Python, Java, C# 등의 현대 컴퓨터 개발 언어에서는 유닛 테스팅을 용이하게 하기 위하여 다양한 기능을 제공하고 있다. 하지만, C++ 언어에 있어서는 워낙 많은 프레임워크를 제공하고 있는 관계로, 유닛 테스팅을 위한 프레임워크 선택이 결코 용이하지 않다. 이 논문에서는 C++ 언어에서의 유닛 테스팅을 위한 프레임워크를 집약된 test runner와 분리된 test runner의 두 그룹으로 나눠서 고찰하였다.

• 한국과학교육학회지
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• 제37권5호
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• pp.891-909
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• 2017

이 연구는 과학 교육 현장에서 인지적 정의적 평가를 중심으로 한 양적 자료와 질적 자료에서 나타나는 몇 가지 불일치 사례를 분석했다. 308명의 고등학교 2학년 학생을 대상으로 학업 성취도와 정의적 성취도를 양적 자료로 수집했고, 그 중 33명의 학생을 면담한 질적자료를 분석했다. 주로 검사 도구의 측면에서 불일치 사례의 원인과 유형을 고찰했다. 연구 결과 양적 자료인 인지적 성취와 정의적 성취 영역 각각에서 과목별, 구인별 차이가 크게 나타나는 학생들이 상당수 있었고, 특히 두 영역 간 성취도 경향이 일치하지 않는 학생들도 20% 이상 분석되었다. 선택한 진로와 진학을 위해 의도적으로 과학 학습을 조절한 사례, 학교 과학과 과학에 대한 인식 차이에 따라 다른 반응 등의 사례가 면담을 통해 발견되었다. 도구로 측정한 양적 자료와 학생들의 면담 내용인 질적 자료를 비교한 결과 스스로 반응한 양적 자료와 다르게 자신을 평가하는 학생들이 대부분이었다. 이는 다양한 특성을 지닌 학생들이 검사 도구와 상호작용하는 과정에서 비롯된다. 검사 도구와 관련된 불일치 유형은 '문항 개발자가 의도한 개념과 학생들이 이해하는 개념 간 차이'와 '표현된 반응과 속마음 간의 차이'로 나타났다. 검사 도구에서 사용한 용어가 학생들에게 모호하게 인식될 때 자의적이거나 일관성 없이 반응하는 경우가 전자에, 사회적 바람직성이나 자아 방어 기제에 의한 반응 왜곡은 후자에 해당한다. 이상 연구 결과를 바탕으로 자기보고식 검사 도구가 학생들의 실제 인식을 잘 반영하고 있는지 검토하고 정교화하려는 노력, 학습 경험을 획일적으로 고정시키는 평가 개선 등이 필요하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.305-311
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• 1993

In recent years, it has been variously developed for testing the accuracy of circular motion of NC machine tools, for example Telescoping Ball Bar Method by Bryan,Circular Test Method by Knapp and r $_{- \theta}$ Mathod by Tsutsumi etc., but it is not yet settled in the code of measuring methods of motion errors of NC machine tools, because of errors of measuring units and sensors, and also especially the difficulties of centering of measuring units. In this paper, in use of magnetic type linear scale with resolution of 0.5 .mu. m and tick pulses come out from computer, it has become possible for detecting of linear displacement of radial errors and measuring of revolution angle of circular motion of NC machine tools.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.435-439
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• 2002

In view of reliability assessment, the failure mode analysis by performance tests for machine tools is researched in this study. First, the error analysis with circular movement test data is studied. The various errors and their origins are analyzed by the error equations and then related parts and failure modes are investigated. Second, This paper deals with analysis of vibration testing for machine tools spindle. The various frequency components are classified by fourier transform and order analysis. The simple measuring devices and web-based analysis programs for each test are also developed.

• International Journal of Knowledge Content Development & Technology
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• 제10권3호
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• pp.21-31
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• 2020

The study examined information retrieval tools as predictors for information resources utilization, four research questions, and four hypotheses were made to guide the study. A descriptive survey was adopted for the study. Random sampling technique was used to select sample of 393 from a population of 557 academic staff registered in the University of Port Harcourt library. The questionnaire was adopted as a data collection instrument titled Information retrieval as predictors for information resources utilization (IRPIRUQ). Data were analyzed using both simple and multiple regression while analysis of variance (ANOVA) associate with regression was used for testing the hypotheses at 0.05 alpha level. The study revealed that information resources are under utilized as the OPAC and Online Databases are not easily accessed. Further findings showed that the academic staff made use of internet search engines more often than the OPAC and online databases. It was recommended among others that a new library software be installed in place of KOHA for wider connectivity and adequate distribution of software that will aid usage of the online databases and OPAC.

• 한국정밀공학회지
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• 제12권2호
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• pp.37-47
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• 1995

In recent years, it has been variously developed for testing the accuracy of circular motion of NC machine tools, for example Telescoping Ball Bar Method by Bryan, Circular test Method by Knapp and $r^{-{\theta} }$ Method by Tsutsumi etc., but these methods are all 2-dimentional measuring methods on plane. These simple methods of circular motion accuracy test of NC machine tools have been studied by many reserchers as above, but it is not yet settled in the code of measuring methods of motion errors of NC machine tools, because of errors of measuring units and sensors, and also especially the difficulties of centering of measuring units and the spindle of machining center. In this paper, in use of 2 rotary encoders and 1 magnetic type linear scale with resolution of 0.5 .mu. m, it has become possible for measuring of 3 dimentional space motion accuracy.

• Journal of Korean Medical Science
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• 제33권46호
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• pp.304.1-304.7
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• 2018

Background: The Republic of Korea has a very low prevalence of human immunodeficiency virus (HIV) infection, but the number of new HIV diagnoses has steadily risen, strongly indicating a large number of undetected HIV infections. Thus, it is important for Korean public health authorities to adopt and encourage cost-effective HIV detection tools, such as rapid HIV screening tests. In this study, we aimed to evaluate the cost-effectiveness of enzyme-linked immunosorbent assays (ELISA) and rapid tests in a public health center (PHC) setting. Methods: We developed a decision analytic model to assess the per-examinee cost and the cost-effectiveness of identifying HIV patients in a PHC setting using two HIV testing strategies: conventional HIV screening by ELISA versus rapid HIV testing. Analysis was performed in two scenarios: HIV testing in an average-risk population and in a high-risk population. Results: Compared to the ELISA, the rapid test was cost-saving and cost-effective. The per-examinee cost was USD 1.61 with rapid testing versus USD 3.38 with ELISA in an average-risk population, and USD 4.77 with rapid testing versus USD 7.62 with ELISA in a high-risk population. The cost of identifying a previously undiagnosed HIV case was USD 26,974 with rapid testing versus USD 42,237 with ELISA in an average-risk population, and USD 153 with rapid testing versus USD 183 with ELISA in a high-risk population. Conclusion: Rapid testing would be more cost-effective than using conventional ELISA testing for identifying previously undiagnosed HIV-infected cases in Korea, a country with extremely low HIV prevalence.

• 대한임베디드공학회논문지
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• 제9권6호
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• pp.307-314
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• 2014

Recently, software reliability and safety issues are seriously considered since failures of embedded systems may cause the damages of human lifes. For verifying and testing embedded software, execution environment including sensors and actuators should be prepared in the actual plants or virtual forms on PC. In this paper, we provide the virtual prototype based code simulation techniques and testing framework on PC. Virtual prototypes are generated by combining the Adobe's Flash SWF images corresponding to the state machine of HW or environment components. Code simulation on PC is possible by replacing the device drivers into virtual drivers which connect to virtual prototypes. Also, testing is performed by controlling the states of virtual prototype and simulators. By using these tools, embedded software can be executed in the earlier development phase and the efficiency and SW quality can be enhanced.