• Title/Summary/Keyword: s diagram

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Effect of Cyclodextrins on the Solubility and Stability of Aspalatone in Aqueous Solutions (수용액중 시클로덱스트린류가 아스팔라톤의 용해성과 안정성에 미치는 영향)

  • Gwak, Hye-Sun;Chun, In-Koo
    • Journal of Pharmaceutical Investigation
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    • v.30 no.4
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    • pp.267-271
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    • 2000
  • The effect of cyclodextrins on the solubility and stability of aspalatone (acetylsalicylic acid maltol ester, AM, CAS 147249-33-0), which has been recently found to have an antithrombotic effect, was investigated. The addition of ${\beta}-cyclodextrin\;({\beta}-CD),\;dimethyl-{\beta}-cyclodextrin\;(DMCD)\;or\;2-hydroxypropyl-{\beta}-cyclodextrin\;(HPCD)$ to the aqueous solution increased the solubility of AM concentration-dependently. From the phase solubility diagram, stability constants for $AM-{\beta}-CD$, -DMCD or -HPCD complexes were calculated to be 43.1, 78.3 and $53.0\;M^{-1}$. The addition of ${\beta}-CD$, DMCD or HPCD to AM solution retarded the degradation rate of AM in the acidic region. However, ${\beta}-CD$ and HPCD rather acted as an accelerator of degradation in the neutral and alkaline regions. DMCD had a stabilizing effect at all pHs studied.

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A Study on Complementary Usage of System Dynamics and Theory of Constraints Approaches for Solving a Dilemma (갈등문제 해결을 위한 시스템다이내믹스와 제약이론 방법론의 상호 보완적 적용에 관한 연구)

  • Yee, Soung-Ryong
    • Korean System Dynamics Review
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    • v.12 no.4
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    • pp.63-92
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    • 2011
  • The purpose of this paper is to investigate a possibility of applying multimethodological approach for solving a dilemma. The motivation of this attempt is that the two different approaches, the system dynamics and the theory of constraints, resemble each other in having mental models for describing the target system and using graphic tools for representing those mental models. After a brief discussion on the comparison of the two approaches, a combined method applying to the problem of dilemma is suggested. For an experimental example, the proposed approach is applied to the sales and finance conflict on an inventory issue. The study shows that the suggested approach is able to complement each other's drawbacks. Especially constructing a stock-and-flow model and implementing a computer simulation would be very useful for quantifying the system's behavior which is hardly tracked down when applying the theory of constraints alone.

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Salt-Induced Protein Precipitation in Aqueous Solution: Single and Binary Protein Systems

  • Kim, Sang-Gon;Bae, Young-Chan
    • Macromolecular Research
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    • v.11 no.1
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    • pp.53-61
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    • 2003
  • A molecular-thermodynamic model is developed for the salt-induced protein precipitation. The protein molecules interact through four intermolecular potentials. An equation of state is derived based on the statistical mechanical perturbation theory with the modified Chiew's equation for the fluid phase, Young's equation for the solid phase as the reference system and a perturbation based on the protein-protein effective two body potential. The equation of state provides an expression for the chemical potential of the protein. In a single protein system, the phase separation is represented by fluid-fluid equilibria. The precipitation behaviors are simulated with the partition coefficient at various salt concentrations and degree of pre-aggregation effect for the protein particles. In a binary protein system, we regard the system as a fluid-solid phase equilibrium. At equilibrium, we compute the reduced osmotic pressure-composition diagram in the diverse protein size difference and salt concentrations.

Experimental and Analytical Researches on Mechanical Properties Related to Formability of AZ31B Alloy Sheet (AZ31B 합금판재 성형관련 기초물성 시험 및 해석 연구)

  • Kim, S.H.;Park, K.D.;Jang, J.H.;Kim, K.T.;Lee, H.W.;Lee, G.A.;Choi, S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.366-369
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    • 2008
  • In this paper, tension tests and formability tests are performed to construct a database related to mechanical properties and the formability of the AZ31B Mg alloy sheet. A forming test with a hemi-spherical punch is conducted at varying temperatures to establish a forming limit diagram. In order to verify the applicability of the analysis using the conventional flow hardening model, a finite element analysis is performed on the hemi-spherical punch forming process and the results are compared with experimental ones. The study investigates problems involving a computational analysis that does not consider flow softening of the magnesium alloy at elevated temperatures.

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Thin Sheet Metal Forming Process Analysis and Formability Evaluation using Electromagnetic Force (전자기력을 이용한 박판 성형 공정 해석 및 성형성 평가)

  • Seo, Y.H.;Heo, S.C.;Ku, T.W.;Song, W.J.;Kim, J.;Kang, B.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.387-390
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    • 2008
  • Electromagnetic forming (EMF) technology, which is one of the high speed forming methods, has been used for the forming process in various industry fields. Numerical approach by finite element simulation of the EMF process is presented in this study. The implicit code is used to obtain the numerical model of the time-varying currents that are discharged through the coil in order to obtain the transient magnetic forces. In addition, the body forces generated in the workpiece are used as the loading condition to analyze deformation of thin sheet metal workpiece using explicit code. Numerical approach for a dimpled shape by EMF process is carried out and the simulated results of the dimpled shape by EMF are reviewed in view of the deformed shape and formability evaluation.

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Application of a CNT Surface Heating Element to the Ship Equipment (탄소나노튜브 면상발열체의 선박 기자재 적용 연구)

  • Bae, Sang-Eun;Lee, Woon-Seek
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.673-680
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    • 2019
  • This study investigates the validity of applying new carbon nanotube (CNT, Carbon Nano Tube) surface heaters, which are applied in combination with various products, to the vessel's materials, and proposes the commercializable products accordingly. In order to actually apply a CNT surface heating system technology to the ship's equipment for the first time in Korea, we carried out the interview of experts in the technology field and the due diligence of the shipyard, and presented the technology road map for the selected three items. Finally, for "Heating System of Ship Fuel Tank" with the highest commercialization potential, we proposed a conceptual diagram to enable the final development of the product through the product analysis.

An Interpretation of Verses Related to Lobes of Liver(肝葉) in the 『Yixuerumen(醫學入門)』 (『의학입문』 간엽(肝葉) 관련 문장의 새 해석)

  • Jo, Hak-jun
    • Journal of Korean Medical classics
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    • v.34 no.1
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    • pp.27-36
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    • 2021
  • Objectives : This paper aims to solve difficulties surrounding the verses related to lobes of liver in the 『Yixuerumen』. Methods : First, relevant verses were selected from the 『Yixuerumen』, then compared to texts from which they had originated. The differences and contrarieties between the texts were resolved through the perspective of plant taxonomy. Results : Wangbing's 'buye(布葉)' was taken as the seed leaf of the dicotyledonous plant and corrected to 'daye(大葉)' by Li Chan. The expression 'Yixiaoye(一小葉)' was understood as describing the many main leaves that look like one big leaf, which grow in between the seed leaves. 『Nanjing』's interpretation of there being three leaves on the left, and four on the right describes the leaf pattern that grows in alternation. Conclusions : Through analysis of the verses related to lobes of liver in the 『Yixuerumen』, we can presume that Li Chan had the knowledge and understanding required in plant taxonomy such as characteristics of a dicotyledonous plant and phyllotaxis.

PHOTOMETRY STUDY OF NGC288 ON UVBY BANDPASS

  • CHEN ROSIE CHANG-HUI;Lu PHILLIP K.;TSAY WEAN-SHUN
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.135-136
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    • 1996
  • We present a new photometric study of the globular cluster NGC288 in Stromgren u, v, b, y, and H$\beta$ system. This cluster is known to have an intermediate metallicity but its color-magnitude diagram has a pure blue horizontal branch, which is a signature of metal poor stellar population. We compare our dataset with Bergbusch's (1993) in both field size and CMD to see whether different photometry system would determine the same physical parameters of a cluster. Demarque and Yi's isochrones (1996, private communication) were applied to Bergbusch's dataset, and we obtained distance modulus of (m - M) = 14.9 $\pm$ 0.2, color excess of E(B - V) = 0.03, and age of 1.5$\pm$3 Gyr. Vandenberg's (1985) isochrones for Stromgren system were also applied to Bergbusch's and our data. We find that the isochrone fits to different photometric systems give rather in consist ant solutions. The source of this discrepancy may become clear when the Demarque and Yi's isochrones for Johnson system are converted to those of Stromgren system. We note that Kurucz model atmospheres provide a useful ground for this conversion work as well as theoretical study of Stromgren characteristics of globular cluster stars.

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A Framework For Web Service Evolution using UML and OWL-S (UML과 OWL-S를 사용한 웹 서비스 진화 프레임워크)

  • Kim, Jin-Han;Lee, Chang-Ho;Lee, Jae-Jeong;Lee, Byung-Jeong
    • Journal of Digital Contents Society
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    • v.8 no.3
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    • pp.269-277
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    • 2007
  • Web service is an important technology to develop business to business e-commerce application. From a business perspective of time to market, dynamic evolution offers flexibility that software can adapt to unforeseen and fluctuating business requirements. OWL-S, based on OWL, is a service ontology language. The semantics provided by OWL support automation of service discovery, invocation, and service composition. In this paper we propose a framework to support dynamic evolution of service-oriented applications. We extend use-case analysis method to derive service description by defining requirements concept and mapping from requirement concept to activity diagram. A prototype is provided to show the validity of this framework.

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A Study on the Driver's Preferences of Prividing Direction Information in Road Signs (방향표지 정보제공 방법에 대한 운전자 선호도 연구)

  • Chong, Kyusoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.6
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    • pp.69-76
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    • 2015
  • Although traffic information has been actively analyzed using big data, it has not been used as much with the consideration of driver characteristics. Among the various types of information, road signs can directly affect the driver. Road signs must provide the optimal information that enables drivers to reach their destinations with ease as well as information suitable for navigation systems. However, present road sign rules provide standardized information, regardless of the road type or size. This study suggests a method for providing road information that will help drivers determine their behavior. First, the minimum character size that can be used on a road sign for each design speed was obtained with respect to the visibility and decipherability of a road sign. Instead of conventional diagram-based direction guidance, a scenario using split-based direction guidance was created. To verify the effectiveness of the provided information, a three-dimensional simulated road environment was constructed, and a driving simulator was used for the test. At a simple plane intersection, the driver was not greatly influenced by directional guidance, but at a complex, three-dimensional intersection, the driver preferred summary-based directional guidance, which is instinctive guidance, over diagram-based guidance. On the basis of the test results, a secondary verification test that applied split-based guidance at a three-dimensional intersection confirmed that the driver had no problems in making decisions.