• Title/Summary/Keyword: Design Test Evaluation

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A study of the improvement of the national technical qualification practical evaluation method on National Competency Standards in the field of floral design

  • Hyun-Ho, Jang;Taek-Keun, Oh;Jwakyung, Sung
    • Korean Journal of Agricultural Science
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    • v.48 no.4
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    • pp.865-873
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    • 2021
  • The purpose of this study is to suggest an improvement plan for the practical evaluation method used to determine the national technical qualification in field of flower design to improve its development. First, an advisory committee was formed, after which comparisons, an analyses and matching were conducted of the currently used national technical qualifications and competency units and the competency unit elements of the National Competency Standards in an effort to strength practical skills and industrial field abilities in the field of flower design. Second, we visited an industrial site to understand the practical and technical aspects as well as the facilities and equipment used in the flower design field. The status of workers in the industrial field in the field of flower design was then analyzed. Through this process, practical examination questions were developed for improve the evaluation method. In addition, to ensure a properly configured result, a pilot test was conducted involving those majoring in the field of flower design. To investigate the feasibility of the developed exam, a survey focusing on targets related to flower design was conducted. Based on the results, by suggesting an improvement plan for the practical evaluation method of national technical qualifications in the field of flower design, it is possible to improve knowledge, technical aspects, and literacy, allowing us to train outstanding technical professionals. In the end, this study can be expected to contribute to the improvement of the flower design industry.

Useful Lifetime Evaluation of Rubber Component for Elevator Cabin (승강기용 방진고무부품 특성 및 사용수명 평가)

  • Woo, Chang-Su;Park, Hyun-Sung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.576-580
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    • 2008
  • Rubber material properties and useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the evaluation of characteristics and useful life prediction of rubber component for elevator cabin were experimentally investigated. The material test and accelerated heat-aging test were carried. Rubber material constants were obtained by curve fittings of simple tension, pure shear and bi-axial tension test data. Heat aging test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the rubber material and component test several useful life prediction equations for rubber component were proposed. Predicted useful life of rubber component for elevator cabin agreed fairly with the experimental lives.

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A Comparative Study on Connection Strength Evaluation Methods of Wall Facing-Geosynthetics using the Design Case (설계사례를 이용한 전면 벽체/보강재의 연결강도 평가방법에 관한 비교 연구)

  • Han, Jung-Geun;Hong, Ki-Kwon;Shin, Ju-Oek;Cho, Sam-Deok;Lee, Kwang-Wu
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.2
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    • pp.21-29
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    • 2009
  • The connection strength between wall facing and geosynthetics should be evaluated by experimental method in the design of reinforced earth wall. However, the evaluation result of connection strength using the typical design method, FHWA(1996) and NCMA(1997), is excessively because of a safety factors. Therefore, this study is conducted in connection strength test between wall facing and geosynthetics, then the test result is applied to the design case by NCMA, FHWA and Soong & Koener(1997). The results confirmed that the evaluation method by Soong & Koener, which is used ultimate connection strength by connection strength test in allowable connection strength, is satisfied with stable in design.

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Design Improvement of Front-End Loader for Tractor to Reduce Stress Concentration and Evaluation of Impact Safety (응력집중 저감을 위한 트랙터용 프론트 로더의 설계개선 및 충격 안전성 평가)

  • Lee, Boo-Youn
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.3
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    • pp.109-119
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    • 2018
  • The purpose of this study is to evaluate the structural safety of the front-end loader for the 90 kW class of agricultural tractors in impact test conditions. Deformation and stress on the loader under the impact test conditions are analyzed using the commercial finite element analysis software ANSYS. In previous research dealing with the initial design of the loader, the maximum stress occurred in the mount and exceeded the yield strength of the material. In this paper, an improved design of the mount of the loader was proposed to reduce the stress concentration in the initial design. The safety of the improved design was verified by performing rigid-body dynamics analysis, transient structural analysis, and static structural analysis under three impact test conditions: a drop and catch test, a corner pull test, a corner push test. It was found that the local stress concentration in the mount that appeared in the initial design was greatly reduced in the improved design, and that the maximum stresses occurred in the three impact test conditions are smaller than the yield strength. It is expected that the design improvement of the mount proposed in this study and the method of analysis may be effectively used to enhance structural safety in the development of new model front loaders in the future.

A Study on the Statistical Model Validation using Response-adaptive Experimental Design (반응적응 시험설계법을 이용하는 통계적 해석모델 검증 기법 연구)

  • Jung, Byung Chang;Huh, Young-Chul;Moon, Seok-Jun;Kim, Young Joong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.347-349
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    • 2014
  • Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

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Cost-effectiveness Analysis for Clothing Design Improvement Using Ergonomic Methods: Evaluation of Flame-proof Clothing and Design Optimization (의복 개선 설계의 비용 대비 인간공학적 효과 분석: 방연복의 평가 및 최적 설계 도출)

  • Cho, Ja-Young;Jeong, Jung-Rim;Yeon, Soo-Min;Chang, Joon-Ho;You, Hee-Cheon;Kim, Hee-Eun
    • Journal of the Ergonomics Society of Korea
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    • v.27 no.4
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    • pp.45-58
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    • 2008
  • Ergonomic techniques have been required to analyze the effectiveness of functional clothing design improvement in a systematic and analytic manner. The goals of the present study are to: (1) comprehensively and analytically examine the effectiveness of clothing improvement by using the relationship analysis between clothing design components (D) and ergonomic evaluation measures (E) and (2) prove the usefulness of cost-effectiveness analysis for clothing design optimization. The cost effectiveness analysis is comprised of the preliminary evaluation based on expertise and the in-depth evaluation where the D-E relationship analysis is applied. As a result of the cost effectiveness analysis applied to flame-proof clothing, an optimal design was identified by analyzing costs and qualitative/quantitative effects. In the preliminary evaluation, the expected effectiveness of each design alternative on wear efficiency and wear comfort was estimated. In the in-depth evaluation, however, the effectiveness of each design alternative was analyzed by quantitative evaluation in a wearing test using a questionnaire prepared based on the D-E relationship analysis. It was concluded that the D-E relationship analysis and the cost-effectiveness analysis are useful for comprehensive evaluation and optimization of functional clothing design.

The Comparison of Subjective Evaluation of Band between On-line and Off-line by Structure and Sensibilities of Fabric (직물의 구조와 감각특성에 따른 온라인과 오프라인에서의 주관적 태평가 비교)

  • Kim, Hee-Sook;Cho, Shin-Hyun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.1 s.160
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    • pp.1-10
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    • 2007
  • This research was designed to compare the subjective evaluation of Hand between on- and off-line by structure and sensible characteristics of fabric. 113 subjects who have a fashion design major evaluated the subjective evaluation of Hand of various 16 kinds of specimens on- and off-line. T-test and pearson correlation coefficient were used for statistical analysis by SPSS WIN 11.0. The results of this study were as follows: The results of correlation analysis of the evaluation score indicated that Crash and Satin show high correlation between two kinds of evaluation score. But, fabrics which have distinct characteristics such as Plush, Dobby, Seersucker represented low correlation coefficient. The results of t-test fer the difference of the evaluation score showed that thin fabrics like Organdy represent a large difference between on- and off-line evaluation. On the other hand, twill weaved fabrics like Drill, Tweed, Saxony did not show many differences. Analysing each item in terms of correlation of evaluation of hand between on- and off-line gave results that the shininess was most deliverable through on-line and density and the dryness was not so deliverable through on-line. Comparison of evaluation score between on- and off-line items showed that the estimation to real fabric is more negative than that of on-line. The results of most preferable hand between on-and off-line showed exact opposite preference between shinny, smooth and soft Satin and rough, woolen Tweed. Organdy showed the most different subjective evaluation of hand in real ones compared with that of on-line.

The Study of Optimal Performance Improvement Method for Aircraft of Various Variants within the Same Type (다양한 형상의 동일 기종 항공기에 대한 성능개량 최적 구현 방안 연구)

  • Kim, Youngil;Ahn, Seungbeom;Choi, Myeongseok
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.3
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    • pp.311-320
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    • 2022
  • In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.

Reliability Evaluation of a Slurry Pump (슬러리 펌프의 신뢰성 향상)

  • Jung, Dong Soo
    • Journal of Applied Reliability
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    • v.16 no.4
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    • pp.263-271
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    • 2016
  • Purpose: A slurry pump for flue gas desulfurization system performs a role that discharges the slurry of a plaster shape in a thermal power plant. Since a slurry pump transfers the slurry by the centrifugal force, it has the friction wear in the impeller and liner because of the slurry. Methods: In this study, failure analysis and test evaluation on the slurry pump have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement design has been presented. Results: Reliability improvement is established by analysis of the test results of before and after acceleration test. Conclusion: This study can be provided to improve the product reliability through failure analysis of a slurry pump.

Fatigue Test and Evaluation of Landing Gear (착륙장치 피로 시험평가)

  • Lee, Sang-Wook;Lee, Seung-Gyu;Shin, Jeong-Woo;Kim, Tae-Uk;Kim, Sung-Chan;Hwang, In-Hee;Lee, Je-Dong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.10
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    • pp.1181-1187
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    • 2012
  • For the fatigue design of aircraft landing gear, the safe-life approach is applied. Structural defects such as cracks or detrimental deformations should not occur under the fatigue load spectrum depicting the entire lifetime usage of the aircraft. In the design phase, the fatigue life of the landing gear is estimated analytically by adopting the stress-based approach because the fatigue of aircraft landing gear is generally high-cycle fatigue. This utilizes S-N curves that are factored to produce design curves that account for the scatter and surface finish of the material. In the test and evaluation phases, a fatigue test should be conducted for full-scale landing gear to substantiate the fatigue design requirement in the end. In this study, the procedure for the fatigue test and evaluation of aircraft landing gear is presented with real application cases.