• Title/Summary/Keyword: quantitative evaluation method

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Quantitative Evaluation of Dislocation Density in Epitaxial GaAs Layer on Si Using Transmission Electron Microscopy

  • Kim, Kangsik;Lee, Jongyoung;Kim, Hyojin;Lee, Zonghoon
    • Applied Microscopy
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    • v.44 no.2
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    • pp.74-78
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    • 2014
  • Dislocation density and distribution in epitaxial GaAs layer on Si are evaluated quantitatively and effectively using image processing of transmission electron microscopy image. In order to evaluate dislocation density and distribution, three methods are introduced based on line-intercept, line-length measurement and our coding with line-scanning method. Our coding method based on line-scanning is used to detect the dislocations line-by-line effectively by sweeping a thin line with the width of one pixel. The proposed method has advances in the evaluation of dislocation density and distribution. Dislocations can be detected automatically and continuously by a sweeping line in the code. Variation of dislocation density in epitaxial GaAs films can be precisely analyzed along the growth direction on the film.

Evaluation of Residual Stresses of Hardened Surface by Magnetoelastic Method (Magnetoelastic Method를 이용한 표면 경화층의 잔류응력 평가)

  • Nam, O.B.;Lee, I.W.;Kim, S.W.;Kim, M.I.
    • Journal of the Korean Society for Heat Treatment
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    • v.5 no.3
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    • pp.157-164
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    • 1992
  • Barkhausen noise (BN) is created by the abrupt changes in the magnetization of materials under applied AC magnetizing field. These changes are known to be sensitive to residual and applied stresses. In this study, BN theory was reviewed and it was examined how BN intensity was affected by simultaneous stress, hardness and microstructural changes. Also, magnetoelastic effect was used to evaluate residual stresses through carrying out the cantilever beam test. An increase in BN intensity was observed when applied and residual stress changes from compression into tension. Microstructural softening by tempering also increased the amount of BN. Therefore, the quantitative evaluation of residual stress and microstructural changes will be possible, provided BN method is more studied about various materials through comparing with different stress measuring techniques.

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A Study on the Reinforcement Corrosion Evaluation of Repair Material and Method for Reinforced Concrete Structure by Long Term Exposure Experiment (장기폭로실험에 의한 철근콘크리트구조물 보수재료$\cdot$공법의 철근부식특성 평가)

  • Kim Young Sun;Lee Eui-Bae;Kim Young Duck;Cho Bong Suk;Kim Jae Hwan;Kim Moo Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.197-200
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    • 2005
  • In this study, for the establishment of the performance evaluation methods and the quality control standards of durability recovery method, the quantitative exposure data by long term exposure test under the coast is accumulated and analyzed Investigating and evaluating the result of exposure test at 30 month of exposure age under the coastal environment, carbonation and salt damage are not happened at all but the difference in electric potential are found. Therefore, it is considered that the reinforcement corrosion at replacement with repair material are caused by active-passive corrosion macrocells.

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A Study on the Application to PSM (Process Safety Management) Policy in the Construction (건설현장의 PSM(Process Safety Management) 제도 적용에 관한 연구)

  • 양광모;전현정
    • Journal of the Korea Safety Management & Science
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    • v.5 no.4
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    • pp.21-30
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    • 2003
  • In this paper, we select evaluation criteria by construction progress, classify into several categories, and regard potential danger which often occurs, as a evaluation criterion. Further step is to allow workers or collaborated companies to express their expert opinions or experiences and to encourage quality and process control and autonomous safety control by applying PSM method. The reason why PSM method should be quantitative and substantial progress is because it contributes Korean constructing companies to enhancing their safety control ability and to taking an equal stance just like developed countries,' thereby strengthening there competitive edges. Boost of safety control system by PSM method will make an enormous contribution to preventing construction accidents on the site by establishing and securing an autonomous safety control system.

A Study of the Priority Order Valuation for Multi-Intermodal Transfer Center (복합환승센터 투자우선순위 평가기법 연구 - 경제성분석과 AHP 분석기법을 중심으로 -)

  • Kim, Hwang Bae;Chang, Kyung Uk;Choi, Jin Hee;Kim, Dong Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6D
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    • pp.561-567
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    • 2010
  • Recently, several number of Multi-Intermodal Transfer Center are nominated to improve convenience of public transportation user. Due to budget constraints, it should be defined which is the first consideration among the discussed many works. In this circumstance, there are some absurdities in the evaluation of validity of existing methods. Therefore, we suggested the Priority Order Valuation for Multi-Intermodal Transfer Centerer. The evaluation method, we suggested, is considered quantitative analysis and qualitative analysis. In this study, we find out that B/C ratio and construction costs are strongly related to the quantitative analysis so that Multi-Intermodal Transfer Centers in metropolitan area are evaluated the positive results. Therefore, both quantitative analysis and qualitative analysis are applied to the Priority Order, metropolitan area and other area are fairly evaluated the results for the Priority Order.

REAL-TIME QUALITY EVALUATION OF FRICTION WELDING OF MACHINE COMPONENTS BY ACOUSTIC EMISSION (음향방출법(AE)에 의한 기계요소재의 마찰용접 품질 실시간 평가)

  • SAE-KYOO OH
    • Proceedings of the KWS Conference
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    • 1995.10a
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    • pp.3-20
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    • 1995
  • Development of Real-Time Quality Evaluation of Friction Welding by Acousitc Emission : Report 1 ABSTRACT : According as the friction welding has been increasingly applied in manufacturing various machine components because of its significant economic and technical advantages, one of the important concerns is the reliable quality monitoring method for a good weld quality with both joint strength and toughness in the process of its production. However no reliable nondestructive test method is available at present to determine the weld quality particularly in process of production. So this paper presents an experimental examination and quantitative analysis for the real-time evaluation of friction weld quality by acoustic emission, as a new approach which attempts finally to develop an on-line quality monitoring system design for friction welds using AE techniques. As one of the important results, it was confirmed, through this study, that AE techniques can be reliably applied to evaluating the friction weld qualify with 100% joint strength, as the cumulative AE counts occurring during welding period were quantitatively correlated with reliability at 95% confidence level to the joint strength of welds. Real-Time Evaluation of Automatic Production Quality Control for Friction Welding Machine : Report 2 Abstract : Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.

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Use Studies of Library Collections (장서평가에 관한 소고 -특히 이용조사를 중심으로-)

  • Yoo Chae-Ock
    • Journal of the Korean Society for Library and Information Science
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    • v.15
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    • pp.175-195
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    • 1988
  • Use studies of library collections have been conducted as a method of evaluating collections in a library. The main purpose of use studies is to evaluate the quality of a library collection in terms of extent and mode of its use. In addition to use studies, both quantitative and qualitative methods could be utilized in order to evaluate a library collection. However, the quantitative and qualitative collection evaluation methods are more concerned with the collection itself than with its use. Use studies have been conducted in large academic libraries for the following specific purposes: 1) They attempt to identify little used portion of collections that can be retired less accessible and less expensive storage area. 2) They try to identify core collections to satisfy some degree of circulation demands in the near future. 3) They try to identify use patterns of selected subject areas or type of books that can be used to adjusting collection development practices or fund allocations. 4) They try to assess the document delivery capability of a library to improve their availability. A number of methodologies employed for these specific purposes fall into four major categories; 1) circulation analysis method, 2) last circulation method, 3) relative use method, and 4) document delivery test. Each method is briefly reviewed with its limitations.

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Multi-class, Multi-residue Analysis of 59 Veterinary Drugs in Livestock Products for Screening and Quantification Using Liquid Chromatography-tandem Mass Spectrometry

  • Yu Ra Kim;Sun Young Park;Tae Ho Lee;Ji Young Kim;Jang-Duck Choi;Guiim Moon
    • Korean Journal of Environmental Agriculture
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    • v.41 no.4
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    • pp.288-309
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    • 2022
  • BACKGROUND: The objective of this study was to develop a comprehensive and simple method for the simultaneous determination of 59 veterinary drug residues in livestock products for safety management. METHODS AND RESULTS: For sample preparation, we used a modified liquid extraction method, according to which the sample was extracted with 80% acetonitrile followed by incubation at -20℃ for 30 min. After centrifugation, an aliquot of the extract was evaporated to dryness at 40℃ and analyzed using liquid chromatography combined with tandem mass spectrometry. The method was validated at three concentration levels for beef, pork, chicken, egg, and milk in accordance with the Codex Alimentarius Commission/Guidelines 71-2009. Quantitative analysis was performed using a matrix-matched calibration. As a results, at least 52 (77.6%) out of 66 compounds showed the proper method validation results in terms of both recovery of the target compound and coefficient of variation required by Codex guidelines in livestock products. The limit of quantitation of the method ranged from 0.2 to 1119.6 ng g-1 for all matrices. CONCLUSION(S): This method was accurate, effective, and comprehensive for 59 veterinary drugs determination in livestock products, and can be used to investigate veterinary drugs from different chemical families for safety management in livestock products.

- A Study on Improving Reliability for Multiple Criteria Decision Making Using Taguchi Method - (다구찌 기법을 적용한 다기준 의사결정 모형의 신뢰성 향상에 관한 연구)

  • Heo Jun Young;Park Myeong Kyu
    • Journal of the Korea Safety Management & Science
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    • v.6 no.3
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    • pp.249-273
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    • 2004
  • Finding an optimal solution in MADN[(Multi-Attribute Decision-Making) problems is difficult, when the number of alternatives, or that of attributes is relatively large Most of the existing mathematical approaches arrive at a final solution on the basis of many unrealistic assumptions, without reflecting the decision-maker's preference structure exactly. In this paper we suggest a model that helps us find a group consensus without assessing these parameters in specific cardinal values. Therefore, This research provides a comprehensive Decision Making of the theory and methods applicable to the analysis of decisions that involve risk and multiple criteria attributes. after, The emphasis of the procedure will be on developments from the fields of decisions analysis and utility theory of Taguchi Method. This theoretical development will be illustrated through the discussion of several real-world application and a case study. When the multiple number of decision makers are involved in the decision making procedure, the problem of uncertainties invariably occurs, because of the different views between them. In this paper, New decision making model using Taguchi Method is applied to effectively model the multi-attribute-decision making(MADM) procedure in the uncertainties dominated two area(quantitative and qualitative factors), Quantitative factors evaluation is used Loss Function of Taguchi, qualitative factors evaluation is used 50 ratio by each specialist. thus it can be used for aiding of preferable alternative. as a result, We will be proved efficiency about New decision making model of applied Taguchi Method with Analytical presentation of all the expecting outcomes when a specific strategy or an alternative plan is selected under expecting future environment.

Quantitative Analytical Method for Eighteen Marker Compounds in Ongyeong-tang, a Traditional Herbal Formula, Using High-Performance Liquid Chromatography for Quality Assessment

  • Kim, Jung-Hoon;Shin, Hyeun-Kyoo;Seo, Chang-Seob
    • The Korea Journal of Herbology
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    • v.30 no.4
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    • pp.11-20
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    • 2015
  • Objectives : Ongyeong-tang (OGT) is a traditional herbal formula used to cure gynaecological disorders. OGT consists of 12 herbal medicines containing various bioactive components. Therefore, the development of suitable analytical method for the marker compounds is necessary for the quality control of OGT. Methods : Determination of the 18 marker compounds in OGT preparations was quantitatively performed by high-performance liquid chromatography-photodiode array detection analysis. The marker compounds were separated on a reversed-phase C 18 column and the analytical method was successfully validated, which was applied to compare OGT extracts from laboratory preparation and commercial OGT granules. Results : Limit of detection and limit of quantification values were in the ranges of $0.001-0.016{\mu}g/mL$ and $0.003-0.047{\mu}g/mL$, respectively. Precision was 0.03-3.71 % within a day and 0.03-3.81 % over four consecutive days. Recovery of marker compounds ranged from 90.63-108.26 %, with relative standard deviation (RSD) values < 4.0 %. Reproducibility was < 2.5 % of the RSD value. The 18 marker compounds were stable within 16 h at $10^{\circ}C$, with the RSD value < 3.5 %. Quantitative analysis results showed that the quantities of the 18 marker compounds varied among OGT samples. Pearson coefficient evaluation and principal component analysis demonstrated that an OGT water extract produced by a laboratory method clearly differed from commercial OGT granules. Conclusions : The developed analytical method was simple, precise, and reliable. Therefore, it can be used for the quality assessment of OGT preparations.