• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.10a
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• pp.281-289
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• 1999

The objective of this paper is to propose a brand new interface mechanism to provide more intelligent decision making support for EC problems. Its main virtue is based on a numerical process mechanism by using an Extended AND-OR Graph (EAOG)-based logic algebra. Using this mechanism, decision makers engaged in electronic commerce (EC) can effectively deal with complicated decision making problems. In the field of traditional expert systems research, AND-OR Graph approach has been suggested as a useful tool for representing the logic flowchart of the forward and/or backward chaining inference methods. However, the AND-OR Graph approach cannot be effectively used in the EC problems in which real-time problem-solving property should be highly required. In this sense, we propose the EAOG inference mechanism for EC problem-solving in which heurisric knowledge necessary for intelligent EC problem-solving can be represented in a form of matrix. Finally, we have proved the validity of our approach with several propositions and an illustrative EC example

• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.242-250
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• 1999

The objective of this paper is to propose an Extended AND-OR Graph (EAOG)-driven inferential simulation mechanism with which decision makers engaged in electronic commerce (EC) can effectively deal with complicated decision making problem. In the field of traditional expect systems research, AND-OR Graph approach cannot be effectively used in the EC problems in which real-time problem-solving property should be highly required. In this sense, we propose the EAOG inference mechanism for EC problem-solving in which heurisric knowledge necessary for intelligent EC problem-solving can be represented in a form of matrix. The EAOG method possesses the following three characteristics. 1. Realtime inference: The EAOG inference mechanism is suitable for the real-time inference because its computational mechanism is based on matrix computation.2. Matrix operation: All the subjective knowledge is delineated in a matrix form, so that inference process can proceed based on the matrix operation which is computationally efficient.3. Bi-directional inference: Traditional inference method of expert systems is based on either forward chaining or based on either and computational efficiency. However, the proposed EAOG inference mechanism is generically bi-directional without loss of both speed and efficiency.We have proved the validity of our approach with several propositions and an illustrative EC example.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.557-575
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• 1999

As the Internet has been used widely in modern firms for gaining competitive advantage in the market, EC (Electronic Commerce) emerged as one of strong alternatives for this purpose. Many researchers and practitioners have proposed a wide variety of EC frameworks that can consider only the structured conditions, but there exists no EC mechanism in which engaged entities can take into account the various unstructured conditions. With the conventional EC framework, the structured EC conditions such as price, quantity, delivery date, etc. can be fully negotiated during the EC process. However, no studies have been conducted on the issue of incorporating those unstructured conditions which are difficult to represent in an explicit form and therefore hard to consider explicitly during the EC process. They are characterized by causal properties. This means that we should have a new EC mechanism which is capable of dealing with causal knowledge. In this sense, we propose a FCM (Fuzzy Cognitive Map)-based simulation framework for EC to resolve the problem of considering the unstructured conditions during the EC process. We experimented our prototype with several illustrative examples and proved that our approach is robust and meaningful.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.537-555
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• 1999

As the Internet has been used widely in modern firms for gaining competitive advantage in the market, EC (Electronic Commerce) emerged as one of strong alternatives for this purpose. Many researchers and practitioners have proposed a wide variety of EC frameworks that can consider only the structured conditions, but there exists no EC mechanism in which engaged entities can take into account the various unstructured conditions. With the conventional EC framework, the structured EC conditions such as price, quantity, delivery date, etc. can be fully negotiated during the EC process. However, no studies have been conducted on the issue of incorporating those unstructured conditions which are difficult to represent in an explicit form and therefore hard to consider explicitly during the EC Process. They are characterized by causal properties. This means that we should have a new EC mechanism which is capable of dealing with causal knowledge. In this sense, we propose a FCM (Fuzzy Cognitive Map)-based simulation framework for EC to resolve the problem of considering the unstructured conditions during the EC process. We experimented our prototype with several illustrative examples and proved that our approach is robust and meaningful.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.6
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• pp.485-491
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• 2015

This study was aimed to investigate the relaxation effects of Eucomiae Cortex (EC) extract in isolated rabbit corpus cavernosum smooth muscle and its mechanism. To evaluate the relaxation of EC extract in rabbit corpus cavernosum, EC extract was treated in corporal strips which were precontracted with phenylephrine(PE). To study its mechanism, Nω-nitro-L-arginine (L-NNA) was pretreated after infuse of EC extract and compared with non-treated. In calcium chloride (Ca²⁺) -free krebs solution, EC extract and Ca²⁺ 1 mM were infused by turns after Ca²⁺ 1 mM was treated into corporal strips contracted by PE. Cell ability, nitric oxide (NO) and epithelial nitric oxide synthase (eNOS) on human umbilical vein endothelial cell (HUVEC) were measured by MTT assay, Griess reagent system and histochemical, immunohistochemical methods. EC extract showed a significant relaxation effects on the corporal strips, this effects were inhibited by pretreatment of L-NNA. EC extract inhibited the increase of contraction by Ca²⁺ influx in Ca²⁺-free krebs solution, and eNOS positive reaction in corpus cavernosum, NO production in HUVEC increased by treatment of EC extract. These result suggest that the relaxation effects of EC extract in isolated corpus cavernosum smooth muscle are involved in increase of eNOS and NO production, blocking of extracellular Ca²⁺ influx.

• Journal of Pharmacopuncture
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• v.19 no.4
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• pp.329-335
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• 2016

Objectives: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. Methods: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using $10^{-6}-M$ phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME ($10^{-6}M$) or indomethacin ($10^{-5}M$), each for 20 minutes. Results: Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME ($EC_{50}=0.29$ vs. $EC_{50}=0.43$) or with indomethacin ($EC_{50}=0.29$ vs. $EC_{50}=0.35$), where $EC_{50}$ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal. Conclusion: This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium-independent mechanism.

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.165-171
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• 1991

The electrochemical reduction of carbon-6-dibromo groups on 6,6-dibromo penicillanic acid 1,1-oxide(DBPA) was investigated by direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The irreversible two electrons transfer on the reductive debromination of each bromo group proceeded by EC,EC mechanism at the two electrode reduction steps(-0.48, -1.62 volts). The 6-bromo-PA and 6,6-dihydro-PA was synthesized by controlled potential electrolysis. Upon the basis of results on the products analysis and interpretation of polarograms obtained at various pH, electrochemical reaction mechanism was suggested.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.1-20
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• 2006

This paper presents the interior penalty discontinuous Galerkin finite element methods (DGFEM) for solving the rotating disk electrode problems in electrochemistry. We present results for the simple E reaction mechanism (convection-diffusion equations), the EC' reaction mechanism (reaction-convection-diffusion equation) and the ECE and $EC_2E$ reaction mechanisms (linear and nonlinear systems of reaction-convection-diffusion equations, respectively). All problems will be in one dimension.

• Journal of the Korean Society for Library and Information Science
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• v.23
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• pp.1-31
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• 1992

The present study aims at a systematic access to EC information. EC information is the outcome of the complex organizations, the continuous changes in functions and the subsequent changes in policies. An attempt for an effective approach to the information requires the examination of the organizational structures and changes, the processes involved in formulating and implmenting the information policies, and the infrastucture for information. Information activities of the major organizations of EC have been examined with a special reference to the Commission of European Communities. The Commission is the EC institution from which the majority of the EC's documentation originates. The information functions of the Commission have been studied in such categories as information production and distribution, authorizing services, and information services to the public.

• Journal of Surface Science and Engineering
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• v.30 no.4
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• pp.223-230
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• 1997

Tungsten oxide and nickel oxide thin films were deposited onto ITO(Indium Tin Oxide) transparent glass by the E-beam evaporation and were used as a cathode and an anode for the EC(Electrochromic) smart window, respectively. Stoichiometric structures of the deposited films were investigated by the implementation of XPS(X-ray Photoelectron Spectroscopy) analysis and the results were $WO_{2.42}$ and $NiO_{0.44}$. This oxygen deficincy might affect affect the transparency of the thin films. The electrolyte for the EC smart windows was PAN-$LiCIO_4$ conducting polymer. EC(Ethylene Carbonate)and PC(Propylene Carbonate) were added as plasticizer to enhance ion conductivity. When the weight ratio of the EC : PC was 3 : 1, transmission difference and cycle life performance were tested. Polymer EC windows showed 40% $\Delta$T at 1.5V operating volage for 3,200 cycles. Structural degradation was observed by the SIMS(Secondary Ion Mass Spectroscopy) analysis and it was confirmed that structural degradation of polymer caused by the solvent evaporation was the main cause to degrade EC smart windows.