• Title/Summary/Keyword: Quantitative investigation

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Investigation on the Description Method of Extrusion Die Surface using B-Spline Surface Scheme (B-스플라인 곡면기법을 이용한 압출금형 곡면의 표현방법에 관한 연구)

  • 유동진;임종훈
    • Transactions of Materials Processing
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    • v.12 no.2
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    • pp.142-150
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    • 2003
  • To construct the extrusion die surface, a B-Spline surface scheme based on the cubic B-Spline curve interpolation method is proposed in the present work. The inlet and outlet profiles are described with B-Spline curves by using the centripetal method for uniform parameterization. The interior control points of surface are generated using the derivative characteristics of B-Spline curve. A complete B-Spline surface is constructed by using appropriate coordinate transformation and knot deletion. In the present study, a quantitative measure for the control of surface is suggested by introducing the tangential vector and inclination angles at the inlet and outlet sections. To verify the validity of the proposed method, automatic surface generation is carried out for the various types of extrusion die surface.

A Case Study of Jet fire Estimation Model on the High Pressurized Pipeline of Natural Gas (고압가스배관의 제트화재 예측모델에 관한 사례연구)

  • Lee, Sang-Gon;Kim, Dong-Sung;Hwang, Cheol-Seung;Cho, Won-Cheol;Lee, Tae-Shik
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.371-375
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    • 2007
  • Due to the benefit of QRA(Quantitative Risk Analysis) method, we can evaluate the risk, and it helps us to make our safe. We also depend to some of correlation equations to assess the jet fire at high pressurized transmission line. However, we can evaluate the risk within limitations. After comparing the current model to investigation report of natural gas transmission line accident at EL-Paso in U.S., this study concludes that more research and study are required because currently developed model cannot expect factors of the fire risk such as flame configuration.

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An experimental study on mechanism for the disintegration of liquid film surface waves by a parallel air flow (평행공기류에 의한 액막류 표면파의 분열기구에 관한 실험적 연구)

  • 이규영;양옥용
    • Journal of the korean Society of Automotive Engineers
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    • v.14 no.6
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    • pp.81-90
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    • 1992
  • This paper deals with an experimental study on the initial condition of liquid film surface waves disintegration and investigation on the behavior of liquid film surface waves formed by the high speed air flow on the solid plane surface. The authors conducted the qualitative and quantitative study to in vestigate the liquid film flow phenomena, the liquid film disintegration mechanism, and droplet formation process with breaking the liquid film surface wave. The newly devised transparent rectangular test section which has semi-two-dimensional flow at the center of the bottom was introduced to perform the experimental study, and it can generate the uniform thickness liquid film at the bottom. The strobo streak camera was used to obtain the instantaneously transformed photographs. The electronic measuring device was also used to measure the liquid film thickness variation in order to perform the easy and effective analysis of complex flow phenomena in the air-water cocurrent flow.

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Gas-liquid Chromatographic Analysis of Some Tropane Alkaloids

  • Paik, Nam-Ho;Im, Yong-Bin;Park, Man-Ki
    • YAKHAK HOEJI
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    • v.20 no.3
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    • pp.125-129
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    • 1976
  • The aim of this investigation was to develop a quantitative gas-liquid chromatographic method of analysis forhyosyamine and scopolamine, and to apply this method to the analysis of preparations. The trimethylsily(TMS) derivatives of the alkaloids were found to be far superior to the nonsilylating compounds in charomatagrams. Bis(trimethylsilyl) acetamide(BSA) was evaluated and found to be a good reagent for silyation of the alkaloids. The optimum derivatization conditions were heating the alkaloids in a closed tube at $70^{\circ)$ for 30 min with a 150 molar excess of BSA to the alkaloids were found to be alkaloids. Calibration curves for the two alkaloids were alkaloid. The standard deviations were 1.1% for hyoscyamine and 1.5% for scopolamine. The minimum detectable amount using the hydrogen flame ionization edtector was determined to be 2$\times$10$^{-11}$ moles of each alkaloid injected.

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Numerical Simulation of Flows Past Two spheres aligned in the streamwise direction (유동 방향으로 놓여진 2개의 구를 지나는 유동에 대한 수치 해석적 연구)

  • Yoon, Dong-Hyeog;Yang, Kyung-Soo
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1418-1423
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    • 2004
  • A parametric study on the interactions of two spheres aligned in the streamwise direction is carried out using an immersed boundary method. The numerical results for the case of single sphere for the range of Re ${\leq}$ 300 are in good agreement with other authors' experimental and numerical results currently available. Then, our main investigation is focused on identifying the change of the vortical structures in the presence of a nearby sphere aligned in the streamwise direction for the range Re ${\leq}$ 220. It turns out that significant changes in physical characteristics are noticed depending on how close the two spheres are. In this paper, not only quantitative changes in the key physical parameters such as the force coefficients, but also qualitative changes in vortex structures are reported and analyzed.

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Identifying Satisfiers and Dissatisfiers in the Service Encounter

  • Bo, Edvardsson;Lars, Nilsson-Witell
    • International Journal of Quality Innovation
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    • v.6 no.1
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    • pp.8-23
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    • 2005
  • Service attributes are important for customer perceptions of service quality. However, in spite of huge amount of research, the role of service attributes as satisfiers and dissatisfiers in service encounters is not understood well enough. An empirical investigation is conducted concerning a problem resolution service in the telecommunication industry. We use both qualitative and quantitative service performance data to describe and analyze how critical incidents can be used to identify and understand which service attributes are perceived as satisfiers and dissatisfiers. Our study reveals that there is a subset of critical incidents, so called critically critical incidents, which are perceived differently and are different in content compared to critical incidents. These incidents are extremely rich of information and have the possibility to reveal the real satisfiers and dissatisfiers in a service encounter.

Bayesian Hierarchical Model with Skewed Elliptical Distribution

  • Chung Younshik
    • Proceedings of the Korean Statistical Society Conference
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    • 2000.11a
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    • pp.5-12
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    • 2000
  • Meta-analysis refers to quantitative methods for combining results from independent studies in order to draw overall conclusions. We consider hierarchical models including selection models under a skewed heavy tailed error distribution and it is shown to be useful in such Bayesian meta-analysis. A general class of skewed elliptical distribution is reviewed and developed. These rich class of models combine the information of independent studies, allowing investigation of variability both between and within studies, and weight function. Here we investigate sensitivity of results to unobserved studies by considering a hierarchical selection model and use Markov chain Monte Carlo methods to develop inference for the parameters of interest.

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Quantitative Determination of Barbiturates by Column Chromatographic Method (Column Chromatography에 의한 바르비탈류 분리 정량법에 관한 연구)

  • Chung, I.M.;Shim, S.I.;Choi, K.S.;Chun, S.W.;Ko, M.H.;Bu, I.H.
    • Journal of Pharmaceutical Investigation
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    • v.9 no.4
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    • pp.1-7
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    • 1979
  • The analytical method of phenobarbital and mephobarbital in the pharmaceutical preparation were investigated by the partition chromatographic method. The influence of 13 kinds of excipients and various kinds of ingredients such as 8 kinds of antipyretics and 5 kinds of antacids on the partition chromatographic analysis of phenobarbital and mephobarbital in the preparation were investigated. The results were not affected by materials with the exception of caffeine, aspirin and sulpyrin.

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Liposome Immunoassay for Bioactive Substances (리포좀을 이용한 생리활성물질의 면역학적 분석법)

  • Kim, Chong-Kook;Park, Kyung-Mi
    • Journal of Pharmaceutical Investigation
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    • v.24 no.4
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    • pp.201-215
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    • 1994
  • Recent development in the immunochemical technique has resulted in a new ultrasensitive analytical method known as liposome immunoassay (LIA). Liposome is a key element in performing liposome immunoassays, specifically designed to participate in immune reactions. A variety of markers can be encapsulated in liposomes and used as quantitative indicators of reactions. Liposome immunoassay based on agglutination, complement-mediated Iysis, cytolysin-mediated Iysis, detergent-mediated Iysis or destabilization of the liposomal membrane have been reviewed. The quantity of markers released from liposomes should be proportional to the concentration of the analytes. Therefore, liposomal agglutination and Iysis which are essential to liposomal Iysis are critically reviewed to provide a better understanding of liposome immunoassay. Based on the literature review of recent advances in liposome immunoassay for bioactive substances, this assay method may provide a convenient, specific and highly sensitive method for detecting and measuring trace amount of clinically relevant substances in the future.

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Effect of Welding Heat Input on Mechanical Properties of Underwater Welded Joints of KR Grade A-1 Steel Plates (국산 선급 A-1 강판의 수중용접 입열량이 기계적 특성에 미치는 영향에 관한 연구)

  • 오세규;이종석;한상덕
    • Journal of Ocean Engineering and Technology
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    • v.1 no.1
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    • pp.120-126
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    • 1987
  • In this paper, the optimizing investigation of characteristics of underwater welding by a gravity type arc welding process is experimentally carried out by using the .phi. 4mm ilmenite type of domestic coated welding electrodes for welding the domestic marine structural steel plates of 8mm thickness in order to develop the underwater welding techniques in practical use, resulting in the quantitative analysis possibility for the relationship between the mechanical propernical properties of underwater welded joint HAZ and the welding heat input.

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