• 제목/요약/키워드: Comparison Test

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Comparison of Antenna Parameters of R-/S-Band Standard Gain Horn Antennas

  • Kang, Jin-Seob;Kim, Jeong-Hwan;Park, Jeong-Il
    • Journal of electromagnetic engineering and science
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    • 제15권4호
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    • pp.224-231
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    • 2015
  • A comparison of the antenna parameters for R-band (1.7-2.6 GHz) and S-band (2.6-3.95 GHz) standard gain horn antennas has been performed by the Korea Research Institute of Standards and Science (KRISS), together with seven domestic participants from private companies and public institutions. Its purpose, as a proficiency test program of the 'Antenna Measurement Club' of KRISS, was to check equivalences in antenna parameter measurements between KRISS and the participants, particularly in the R-/S-band, to support antenna manufacturers and end users in Korea. The measurement parameters of this comparison are the power gain, radiation pattern, and reflection coefficient of the traveling standards for R-/S-band pyramidal standard gain horn antennas. The comparison used a gain comparison method and an extrapolation method to measure the power gain of the two traveling standards; the radiation patterns were measured in the far-field region of the transmitting and receiving antennas.

가격비교사이트 평가기준의 중요도와 만족도 분석 (Perceived Importance and Satisfaction of Evaluation Criteria of the Price Comparison Website)

  • 차경욱
    • 가족자원경영과 정책
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    • 제11권4호
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    • pp.1-20
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    • 2007
  • The purpose of this study was to identify the criteria of evaluating a price-comparison website, and to investigate the consumers' perceived importance and satisfaction of each criterion. Also, it compared both the importance and satisfaction levels based on consumers' socio-economic and Internet-usage characteristics. Data for this study came from a questionnaire completed by consumers (n=417), who had used the price-comparison website, and were analyzed through factor analysis, t-test, and ANOVA. The findings of the study were as follows: First, the evaluation criteria of the price-comparison website were categorized into five variety of information, accuracy, convenience, credibility, and the website system. Second, convenience of searching information was seen by consumers as both the most important and most satisfactory criterion. Variety of information was also considered important. For most of the evaluation criteria, the level of consumers' satisfaction was significantly lower than the level of consumers' recognized importance. Third, consumers in their 20s, students, and housewives were less likely to be satisfied by the price-comparison website overall. Older people were less likely to be satisfied with the convenience of the website, and the higher-income group was less likely to be satisfied with the variety of information on hand.

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휠 차량의 내구 시험장 조성을 위한 매개변수 연구 (A Parametric Study for the Construction of Durability Test Track of a Wheel Type Vehicle)

  • 송세철;김형근;박태건;김동준
    • 한국자동차공학회논문집
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    • 제6권1호
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    • pp.73-79
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    • 1998
  • For the design and development of the wheel type excavator, the dynamic effects of travelling on the performance of the equipment should be first analyzed and conside- red in the initial design stage. In order to test the durability of the equipment in a short period, th travelling test should be performed over accelerated durability test tracks. which is more severe than general field roads such as city road, paved road, unpaved road and rough road. In this paper, a parametric study is performed in order to determine important design parameters of durability test track of a wheel type excavator. A rigid body model is developed using DADS and dynamic analysis is performed for the equipment travelling over several test roads with different severity. A comparison of test and analysis results is also presented.

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Fall Cone Test의 일점법을 이용한 액성한계 추정 (Estimation of Liquid Limit by a Single-point Method of Fall Cone Test)

  • 손영환;장병욱;원정윤;김성필
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.203-206
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    • 2003
  • The liquid limit(LL) test is universally used as a standard test for determining one of the index properties of a clay. There are two methods of determining the LL, Casagrande method and cone penetration method that is fall cone test. The interpretation of the Casagrande method of obtaining the LL is not obvious, but it has been suggested that the fall cone test is essentially a strength test and that the LL test simply ascertains the moisture content at which a clay has a certain standard undrained shear strength. This paper presents a determination of the LL by a single-point method. Results obtained from fall cone that is general method and a single-point method are analyzed by comparison.

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우세측에 따른 상지와 하지의 기능 비교 (Comparison of Upper and Lower Limb Functional Ability Depends on Dominants)

  • 이선명
    • 한국임상보건과학회지
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    • 제4권3호
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    • pp.622-633
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    • 2016
  • Purpose. The purpose of this study was compared of left dominant and the right dominant hands about coordination. Methods. The participants were 30 occupational therapy students in M university in Changwon, from April 28th 2015 to May 1. The test tools were Jebson-Taylor Hand Function Test, Hand Strength & Pinch, Grooved Pegboard Test, Box & Block and Balance Test. Results. Right dominant hand was higher than left dominant in hand grip and dexterity, hand manipulation skills. And one leg standing and toe standing were higher left foot than right foot dominant. Conclusion. Most of all evaluation items showed a better result right dominant hand than left dominant. But shows that there is no functional difference between left-hand dominant than right-hand. So left-hand dominant coordination was evaluated by a better than right-handed.

시험방법에 따른 신ㆍ구 콘크리트의 부착강도 특성 (Characteristics of Bond Strength with Measuring Methods of Concrete)

  • 장흥균;김성환;홍창우;윤경구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.597-600
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    • 2003
  • The development and maintenance of a sound bond are an essential requirements of concrete repair and replacement. The bond property of a bonded overlay to its substrate concrete during the lifetime is one of the most important performance requirements which should be quantified. A standard or a verified bond strength measurement method is required at field for screening, selecting materials and quality control for overlay or repair materials. This study compares the nipple pipe direct tensile test, flexural adhesion test, and core pull-off test with their test results. Substantial differences in the failure stresses of three test methods were attributed to their different geometries and loading conditions. From these comparison and investigation, core pull-off test was relatively good because the coefficient of variation values were about 2%. It would be suitable for use in-situ because of its simplicity and accuracy.

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Random Permutation Test for Comparison of Two Survival Curves

  • Kim, Mi-Kyung;Lee, Jae-Won;Lee, Myung-Hoe
    • Communications for Statistical Applications and Methods
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    • 제8권1호
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    • pp.137-145
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    • 2001
  • There are many situations in which the well-known tests such as log-rank test and Gehan-Wilcoxon test fail to detect the survival differences. Assuming large samples, these tests are developed asymptotically normal properties. Thus, they shall be called asymptotic tests in this paper, Several asymptotic tests sensitive to some specific types of survival differences have been recently proposed. This paper compares by simulations the test levels and the powers of the conventional asymptotic tests and their random permutation versions. Simulation studies show that the random permutation tests possess competitive powers compared to the corresponding asymptotic tests, keeping exact test levels even in the small sample case. It also provides the guidelines for choosing the valid and most powerful test under the given situation.

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직경 2m급 축소로터 시험장치 개조 및 보완 (Modification of Dia. 2m-Small-scaled Rotor Test Facility)

  • 송근웅;이재하;김승호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 추계학술대회 논문집
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    • pp.190-195
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    • 2012
  • Small-scaled Rotor Test facility(GSRTS, General Small-scaled Rotor Test Facility) in KARI could not use the test because facility aging and parts discontinued. Also in order to perform a joint international research, GSRTS modifications should be needed. So requirements of GSRTS modifications were established and according to the requirements, GSRTS modifications were conducted. Facility operation test, 6-component fixed balance calibration, Small-scaled OLS rotor performance test were performed to verify the results of GSRTS modifications. Reasonable results were obtained in comparison to calculation results. Then GSRTS ready was completed to conduct international collaborative research and wind tunnel test.

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횐깨엿강정 만드는 법에 관한 연구 (A Study on the Standardization of the Preparation Method for Whiteseed Sesame Yut Kang Jung)

  • 조재홍;조신호;이효지
    • 한국식품조리과학회지
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    • 제9권2호
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    • pp.78-81
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    • 1993
  • "Yut Kang Jung" is a kind of Korean traditional cookie. The purpose of this study is to examine the effects of various kinds of syrups and cooking methods of Yut Kang Jung. The quality of Yut Kang Jung was evaluated by sensory and Instron machine test. The results is as follows; 1. The Recipe of the best Yut Kang Jung is this: White sesame 120g, sugar syrup 40g, and crude maltose watery 50g are used. Mixing sugar syrup crude maltose watery boiling for 4 min, in temperature $105^{\circ}C$. The sugar density after boiling was 86%. 2. Yut Kang Jung made by sugar syrup and crude watery maltose got the best result in sensory best. 3. Yut Kang Jung made by crude watery maltose got the best result in mechanical test. 4. The comparison between the sensory test & mechanical test were as follow; The hardness in the mechanical test was comparable with hardness & fracturability in the sensory test, and the chewiness in the mechanical test was comparable with flavor, adhesiveness, fractur ability in sensory test.

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가속열화시험에 의한 폴리머애자의 신뢰성 평가 (Reliability Assessment of Polymer Insulators by Accelerated Aging Test)

  • 한채홍;이병성;정종욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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    • pp.10-14
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    • 2001
  • In order to assess the long-tenn reliability of polymer insulators for distribution power systems, we have developed the accelerated aging test method which can simulate the operation conditions. In this study, 3000 hours aging test for 4 kinds of polymer insulators has been completed by the developed accelerated aging test. After 3000 hours aging test, visual inspection and electrical tests were carried for identifying a change of characteristics. Some specimens showed the surface erosion and the manufacturing defect. In the electrical tests, the wet flashover voltage was significant1y decreased by the accelerated aging test. In comparison with the field-aged polymer insulators, it can be concluded that the developed test method can evaluate the long-tenn reliability within short time and screen the manufacturing defect.

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