• 제목/요약/키워드: evaluation materials

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한국산업표준(KS)에 따른 로크웰 경도 시험기의 불확도 산정에 관한 연구 (A Study on the Evaluation of Uncertainty of Rockwell Hardness C Scale According to the Korean Industrial Standards(KS))

  • 방건웅;탁내형
    • 열처리공학회지
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    • 제13권3호
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    • pp.163-169
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    • 2000
  • Recently, uncertainty of hardeness became a major concem for the people working on the laboratory evaluation and accreditation. It is required to indicate uncertainty of hardness tester on the report after calibration. In addition to this, uncertainty of certified hardness reference block is also required to indicate on the certification sheet. Method on the evaluation of uncertainty in hardness measurement is agreed only recently for Rockwell hardness C scale. In this paper, a preliminary calculation of uncertainty based on type B evaluation has been made for hardness testers which satisfies the requirements of Korean Standards. It was found that the tolerance limit of mean value specified in KS should be increased to be compatible with the calculated uncertainty.

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인테리어 내장재의 고급감에 관한 시각 및 촉각변수의 수량화 모형 개발 (Development of Quantification Models on Visual and Tactile Design Characteristics for the Luxuriousness of Interior Covering Materials)

  • 반상우;윤명환
    • 대한산업공학회지
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    • 제33권4호
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    • pp.393-401
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    • 2007
  • Affective aspects of design attributes such as color, Pattern, and texture are important to the overall impression and the success of interior products. Among all the interior materials, wallpapers and flooring materials take up largest construction area and they are main components in creating affective impression for customers. This study aims to investigate the relationship between luxuriousness and related affective variables and design elements of wallpapers and flooring materials. The approach consists of 3 steps: (1) selecting related affective features and product design attributes through a literature survey, opinion of expert panel, and focus group interview, (2) conducting evaluation experiments, and (3) developing Kansei models using multivariate statistical analysis and analyzing critical attributes. Evaluation experiment was conducted using a questionnaire made up of 7-point scale and 100-point scale and 30 housewives and 20 interior designers participated in the evaluation experiment. The result of evaluation was analyzed through principal component regression and quantification I analysis. As a result of analyzing the survey data, the relationship between luxuriousness and related affective features and product design attributes was identified, moreover a optimal combination of the design component was identified. Consequently, it is expected that the results of the study would be a basis of the concept of emotion-based design by giving insights about how customers perceive the luxuriousness and suggesting the optimal combination, and providing specific quantitative design guidelines.

Thermomechanical Properties of Thermal-Stress Relief Type of Functionally Gradient Materials

  • Watanabe, Ryuzo
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 1993년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
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    • pp.2-2
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    • 1993
  • The present status of the thennomechanica1 evaluation of functionally gradient materials(FGMs) for space plane application was reviewed, in which research activities and the cooperation of the national project team organized to study FGM science were demonstrated. The project team was divided into three working groups; de singing, processing and evaluation, each of which had their own tasks in the project cooperation. The testings details of the various thennomechanical tests for the FGM samples fabricated by the processing groups were described, along with their corresponding heating conditions of the real environments in the space plane application. For small-sized samples, laser beam heating test and burner heating test were well applied to study the heat shielding and heat resisting properties. Arc-heated wind tunnel test and high temperature!high velocity gas flow test were used for large-sized panel assemblies having cooling structures. The criteria for the evaluation of the heat shielding and heat resisting properties of the FGMs, as well as a crack activation mechanism in their differential temperature heating, were proposed on the basis of the observation in the burner heating test.

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HVDC 케이블용 XLPE 절연 재료에 대한 DC/Impulse 중첩실험 시스템 구축 (Build-up of DC/Impulse Superposition Testing System for XLPE materials in HVDC cables)

  • 김정태;김동욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1608-1609
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    • 2011
  • In this study, in order to develop the evaluation method for XLPE materials for HVDC cables, DC/Impulse superposition testing system was builded up. Throughout the P-spice simulation, optimal values of the protection resistor for the DC generation system and the blocking capacitor for the Impulse generator were calculated. DC/Impulse superposition system showed good result maintaining their proper wave shapes and amplitudes. This system would be planned to apply to the evaluation of XLPE materials for HVDC cables.

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구체적 조작물을 활용한 교수-학습과 평가자료 개발에 관한 연구 (A Study of Teaching-Learning Method Using Real Objects and Development of Materials for Student Evaluation - Focused on 1st Grade Middle School Students -)

  • 고혜정;김승동
    • 한국학교수학회논문집
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    • 제5권2호
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    • pp.1-15
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    • 2002
  • The purpose of this study came to start to be helpful in that the teachers in field produced evaluation subject about the mathematics and applied by analyzing the performance capacity for the students about the subject developed through the application of subject about the teaching-learning model that can utilize the learners' learning experience and the development of items that can evaluate it by utilizing various and concrete operational materials as an object of the first year at the middle schools. The concrete purpose of realizing it is as follows. 1. This study is to develop the teaching-learning model centered on activities adequate to utilize various and concrete operational materials. 2. This study is to develop evaluation data for utilizing the concrete operational materials by making construction through the application of developed teaching-learning model as possible. 3. This study is to present standards initiative for reliable and fair marking about the evaluation data and to analyze the students' practice capacity by using it effectively. For accomplishing the purpose of this research, this study is the work-oriented teaching and learning model using learning data that can be easily found around the surroundings and 8 evaluation programs in order that the experience-oriented learning based on circumstances learning among the learning models of constructivism. Also, it is to examine the result after applying that on a basis of 25 students, consisted of only on class in a year, in the first year at the small size of agricultural middle schools. The result of this study from this research is as follows. First, as a result of frequency survey, of response about the developed evaluation data it showed positive response more than 80% of all the items. The atmosphere of self-directed learning was produced because the developed evaluation data could induce activity-based learning naturally by stimulating the students' curiosity and promoting interest. Second, this study executed t-test for the result of questionnaire about the mathematics propensity, and there were significant differences in 19 items among 25 items. It presented that the application of data about the teaching-learning and evaluation directly using concrete operational materials to the constructional learning by level might have desirable affect on the students' mathematical propensity. It came to be a motive that could increase value recognition and interest on the subject of mathematics by investigating a mathematical principle rule and confirming it through activity learning using the concrete operational materials.

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대사증후군 교육 인쇄물의 이독성과 적합성 평가 (Evaluation of the Readability and Suitability of Printed Educational Materials on Metabolic Syndrome)

  • 김정은;양숙자
    • 한국보건간호학회지
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    • 제30권1호
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    • pp.149-163
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    • 2016
  • Purpose: The aim of this study was to assess the readability and suitability of printed educational materials related to metabolic syndrome in South Korea. Methods: Data were collected on 15 educational materials on metabolic syndrome from public health centers in Seoul. The 9 Graded Korean Vocabulary Classification and Korean version of SAM (Suitability Assessment of Materials) were used for the readability evaluation and the suitability evaluation respectively. Results: Overall average of the readability was 3.0th grade level. The percentage of 1st to 4th grade words was 79.4%. The printed educational materials on metabolic syndrome were written according to recommended reading levels. In suitability assessment, 2 out of 15 materials(13.3%) were scored as superior, 12 materials(80.0%) were scored as adequate and only 1 (6.7%) was scored as inadequate. The total average score of suitability was adequate. However, there are limitations in "summary and review" and "context is given first" due to limited writing pages. Conclusion: Readability and suitability of educational materials for metabolic syndrome were evaluated as adequate level. However, future health educational materials should be evaluated for readability via different factors including length of sentences, numbers of sentences, and structure of sentences. In addition, for easier understanding and motivation of readers, materials should use summary & review, context and proper interaction.

폴리머 애자 신뢰성평가 기준 제정 방향 및 평가설비 구축 (The criterion of reliability evaluation and the evaluation facility for composite insulator)

  • 김익수;김민규;김익균;강동필;박효열;한동희;신영준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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    • pp.147-148
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    • 2001
  • The construction of reliability evaluation according to their fields was promoted under the supervision of Agency for Technology and Standards for establishing the relevant institution & infrastructure that can fundamentally solve the reliability problems, the biggest obstruction when the developed electric components & materials come into the market. This paper describes the criterion of reliability evaluation and the evaluation facilities for the purpose of heightening the reliability of composite insulator estimated as the new material among the electric components & materials. We will understand the criterion of reliability evaluation with two parts as the performance evaluation based on various kinds of standards (especially IEC) and as the long-term reliability evaluation utilizing the accelerated aging & flashover test methods. Therefore we aim for constructing the criterion of reliability evaluation as the foundation for evaluation so as to support the industrial group based on KERI facilities.

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Homologous 산화물 ZnkIn2O3+k(k=1∼9)의 열전 특성 (Thermoelectric Properties of ZnkIn2O3+k(k=1∼9) Homologous Oxides)

  • 남윤선;최정규;홍정오;이영호;이명현;서원선
    • 한국재료학회지
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    • 제13권8호
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    • pp.543-549
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    • 2003
  • In order to investigate the thermoelectric properties of $Zn_{k}$ $In_2$$O_{ 3+k}$ homologous compounds, the samples of $Zn_{k}$ /$In_2$$O_{3+k}$ / (k = integer between 1 and 9) were prepared by calcining the mixed powders of ZnO and $In_2$$O_3$fellowed by sintering at 1823 K for 2 hours in air, and their electrical conductivities and Seebeck coefficients were measured as a function of temperature in the range of 500 K to 1150 K. X-ray diffraction analysis of the sintered samples clarified that single-phase specimens were obtained for $Zn_{k} /$In_2$$O_{3+k}$ with k = 3, 4, 5, 7, 8, 9. Electrical conductivity of the $Zn_{k}$ $In_2$$O_{3+k}$ / decreased with increasing temperature, and decreased with increasing k for k $\geq$ 3. The Seebeck coefficient was negative at all the temperatures for all compositions, confirming that $Zn_{k}$ $In_2$$O_{3+k}$ / is an n-type semiconductor. Absolute values of the Seebeck coefficient increased linearly with increasing temperature and increased with increasing k for k $\geq$ 3. The temperature dependence of the Seebeck coefficient indicated that Z $n_{k}$I $n_2$ $O_{3+k}$ could be treated as an extrinsic degenerate semiconductor. Figure-of-merits of Z $n_{k}$I $n_2$ $O_{3+k}$ were evaluated from the measured electrical conductivity and Seebeck coefficient, and the reported thermal conductivity. Z $n_{7}$ I $n_2$ $O_{10}$ has the largest figure-of-merit over all the temperatures, and its highest value was $1.5{\times}$10$^{-4}$ $K^{-1}$ at 1145 K.5 K.

열간 등압 성형된 니켈기 초내열 합금 IN 713C 분말 소결체의 특성 평가 (Characterization of Hot Isostatically Pressed Ni-Based Superalloy IN 713C)

  • 김영무;김은표;정성택;이성;노준웅;이성호;권영삼
    • 한국분말재료학회지
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    • 제20권4호
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    • pp.264-268
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    • 2013
  • Nickel-based superalloy IN 713C powders have been consolidated by hot isostatic pressing (HIPing). The microstructure and mechanical properties of the superalloys were investigated at the HIPing temperature ranging from $1030^{\circ}C$ to $1230^{\circ}C$. When the IN 713C powder was heated above ${\gamma}^{\prime}$ solvus temperature (about $1180^{\circ}C$), the microstructure was composed of the austenitic FCC matrix phase ${\gamma}$ plus a variety of secondary phases, such as ${\gamma}^{\prime}$ precipitates in ${\gamma}$ matrix and MC carbides at grain boundaries. The yield and tensile strengths of HIPed specimens at room temperature were decreased while the elongation and reduction of area were increased as the processing temperature increased. At $700^{\circ}C$, the strength was similar regardless of HIPing temperature; however, the ductility was drastically increased with increasing the temperature. It is considered that these properties compared to those of cast products are originated from the homogeneity of microstructure obtained from a PM process.

Effects of the Loading Rate and Humidity in the Fracture Toughness Testing of Alumina

  • Cho, Seong-Jai;Kim, Jai-Chun;Yoon, Kyung-Jin;Chu, Min-Cheol;Lee, Yoon-Cheol;Quinn George;Lee, Hong-Lim
    • 한국세라믹학회지
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    • 제43권1호
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    • pp.4-9
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    • 2006
  • To test the fracture toughness of alumina; a Surface-Crack-in-Flexure (SCF) method, a Single-Edge-Precracked-Beam (SEPB) method and a Single-Edge-V-Notched-Beam (SEVNB) method were used at crosshead rates ranging from 0.005 mm/min to 2 mm/ min and relative humidity ranging from $15\%\;to\;80\%$. The results show that the fracture toughness tested by the SCF method increases with either an increasing loading rate or decreasing relative humidity; in contrast, the toughness by the SEPB method and the SEVNB method does not depend on the loading rate or the relative humidity. Theoretical analysis of the way slow crack growth affects the apparent fracture toughness indicates that the three testing methods have different effects with respect to the loading rate and the relative humidity; moreover, these differences are attributable to differences in the size of the cracks or notches.