• Title/Summary/Keyword: Test&Evaluation

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Study on safety performance evaluation of stationary SOFC stack (건물용 고체산화물연료전지 스택 안전성능평가 연구)

  • Park, Tae Seong;Lee, Eun Kyung;Lee, Seung Kuk
    • Journal of Energy Engineering
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    • v.27 no.4
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    • pp.1-12
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    • 2018
  • The code and standards related to fuel cells were analyzed to derive the SOFC(Solid Oxide Fuel Cell) stack safety performance evaluation items and evaluation methode. Safety performance evluation of the SOFC stack was tested by quoting derived test items. The stack used in the test is an anode-supported type 2 Cell stack (Active surface area : 220cm) manufactured by MICO Inc, and SOFC stack safety performance evaluation system used for the test is self-manufactured. We conducted a leakage test, current voltage characteristic test, rated output test, and power response characteristics test. In the safety performance evaluation test, the stack showed no gas leakage, the maximum output and rated output was recorded to 65.6 W(1.41 V, 46.5 A, $422mA/cm^2$), 62.3 W(1.57 V, 40 A, $363mA/cm^2$). In the power response characteristics test verified that the output is kept stable within two seconds. At the maximum load (40 A) and the minimum load (8 A), the output was recorded 62 W and 16W in $750^{\circ}C$. This study will contribute to the universalization and to provide much safe environment of operating the solid oxide fuel cell system.

The Structuring Process of Multi‐Centered Usability Evaluation Method (다자 중심적 사용성 평가 방법의 구조화 과정)

  • Kim, Jung-Yong;Lee, Ha-Yeun;Choi, Young-Cheol
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.2
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    • pp.25-33
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    • 2005
  • In order to minimize a biased view of evaluators in usability test, a multiple evaluation method so called Multi-Centered Usability Evaluation Method(MCUEM) was suggested and structured in this study. To use MCUEM, the existing evaluation methods were re-categorized into 'developer and evaluator-centered', 'evaluator-centered', 'user-centered', 'evaluator and user-centered', and the 'developer, evaluator, and user-centered methods. Furthermore, in order to verify the relevance of MCUEM, the usability of mobile phone was tested in this study. In results, it was found that different evaluation methods generated greatly different results, that showed the risk of using a particular usability method due to different perspectives of evaluators. At the same time, it was found that MCUEM could greatly minimize such biases. Therefore, it was concluded that using MCUEM could help the usability engineer design a test protocol with a minimal risk of bias due to different perspective of evaluators.

The Visibility Evaluation of the Wheel Loader by Comparing Prototype and Computer Simulation (휠로더의 시계성 평가: 프로토타입과 컴퓨터 시뮬레이션을 이용한 방법)

  • Jung, Doo-Ho
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.2
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    • pp.249-255
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    • 2010
  • The visibility evaluation is significant for the development of construction equipment. The visibility evaluation follows the standards of ISO 5006, ISO 14401-1, and ISO 14401-2. The evaluation contains the operator's visibility and the visibility of rear-view mirrors. The operator's visibility includes the visibility test which requires the recognition of the rectangular line surrounding the machine by one meter and the circle with a 12 meter radius. This study describes the two evaluation processes for the development of the wheel loader. The first process is the light bulb shadow test by using a prototype wheel loader. The second process is based on computer simulation in virtual space. The advantages and disadvantages of computer simulation process are investigated.

University Students' Perceptual Lecture Evaluation of Online Lectures During the COVID-19 Situation

  • Nam, Sangzo;Cho, Soohyun
    • International Journal of Contents
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    • v.18 no.1
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    • pp.85-97
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    • 2022
  • Students' perceptions of generosity and fairness in lecture evaluation and grades, communication with professors, and self-fidelity and satisfaction during the COVID-19 situation were statistically analyzed by surveying students at M university in Daejeon. These data were analyzed in the context of parameters that might impact online class lecture evaluations, namely gender and school year. Descriptive analysis shows students' perceptions of online lectures are significantly high. As for differences by gender and school year, the t-test results indicate female students generally have better perceptions of online classes than male students. However, there is no statistical difference between male and female students regarding the generosity of lecture evaluation. Also, ANOVA test results show that as the school year increases, the general perceptions for online classes become negative. However, there is no statistical difference by school year regarding the generosity of lecture evaluation. Regression analysis shows that the "perceptual generosity of grades" most significantly influenced the "perceptual generosity of lecture evaluation."

Proposal for Using Sine with Dwell for the Evaluation of ESC for Medium Commercial Vehicles (중형 상용차량 ESC 평가를 위한 Sine with Dwell Test 제안)

  • Kwon, Baeksoon;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.7 no.2
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    • pp.32-38
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    • 2015
  • A sine with dwell test is well known as a test scenario for evaluation of performance of electronic stability control(ESC) on passenger vehicles and heavy commercial vehicles. However, when it comes to ESC for medium commercial vehicles, the test scenario has not been established yet. In this paper, the sine with dwell test was modified considering characteristics of medium commercial vehicles. The three main modifications of the original test scenario are the steering angle level, steering frequency, and loading condition of the vehicle. These modifications are derived from simulation study for different medium commercial vehicles. From simulation study, it was shown that the ESC system for medium commercial vehicle is objectively evaluated by the proposed test scenario. A clear improvement on vehicle stability was seen in the results when ESC system was used.

A Case Study on Implementing Graded English Class (수준별 영어강좌 운영에 대한 사례연구)

  • Lee, ChangHoon
    • Journal of Engineering Education Research
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    • v.16 no.4
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    • pp.15-20
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    • 2013
  • The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.