• Proceedings of the Korea Association of Information Systems Conference
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• 2004.11a
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• pp.431-443
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• 2004

Many e-Learning companies are incorporated for the last five years, but most of them are failed or merged by the other company. The main reasons are the absence of competitive strategies and recognition of critical success factors. There are many researches on the critical success factors of Information System (IS) and Electronic Commerce (EC) . We derived e-Learning success factors from the previous IS and EC researches. We classified the success factors into five dimensions, (1) contents management, (2) learner management, (3) business strategy, (4) organizational support and ability, (5) learning management system (LMS), and each dimension has 9 or more success factors measurement items. We surveyed the perceived importance of the success factors from the manager of South Korea e-Learning firms. The paper categorized the items into two or more factors for each dimension by the exploratory factor analysis. Finally, we conducted one-way ANOVA for each success factors by the business model. As a result, there is different importance level for each success factors by the business model. We concluded that each e-Learning company needs different strategies to their business model.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.2
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• pp.42-53
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• 1983

In Korea, the demand for water is increasing greatly due to Korea's raqid economic progress which is similar to Japan's. A correct estimation of the runoff factors is the question that must be settled first to establish the appropritae plans for water use and water resources. of these plans the estimation of catchment evapotranspiration for every river basin is the subject of the most importance. It is impossible theoretically to measure evapotranspiration directly, because it is an at mospheric translatory phenomenon. Many approaches have been devised to estimate evapotranspiration, but each of these methods estimates from information taken from a specified point, and these methods are considered incomplete for estimating catchment evapotranspiration. In this paper, the seasonal evapotranspiration estimating method that was proposed by Linsly and was applied in the Kamigamo exprimental basin (subjected to Kyoto Univ.) by Takase et al, was used for the Geum river which is the main river in Korea. Conclusion of experiment. 1) The average annual Ec in this river basin from 1966 to 1972 was 470mm. That is considered appropriate since the average value for the six other large river basin in korea was 485mm. 2) The Ec/Ep and Ec/Epm ratios were 0.43 and 0.52, respectively (Ec : estimated evapotranspiration by water balance method, Ep : average pan evaporation, Epm : evaporation by Penman method). The seasonal Ec/Ep ratios were : 0.4 in spring, 0.6 in summer, 0.4 in autumn and 0.2 in winter. These are rather small when compared to Japan's or England's. 3) The reason for this was that the precipitational difference in wet and dry seasons were greater, an there was not sufficient soil moisture harmonize with the evapotranspiration capacity in the dry season, and that evapotranspiration was small due to the numerous barren mountains.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.47-59
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• 2023

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4⁺ and CD8⁺ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4⁺ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8⁺ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4⁺ T-cell early priming.

• Proceedings of the CALSEC Conference
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• 1999.07a
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• pp.193-205
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• 1999

Nowadays, public domain software CALS/EC projects give their attention to the importance of test and evaluation (T＆E). This article proposed a survey on T＆E procedures of the international standards ISO 9000-3, ISO/IEC 9126 and ISO 14598, and of the U.S. Army pamphlet as well as that of MIL-STD-498. And features of testing tools such as their characteristics were reviewed for a reference in selecting appropriate one. Large-scale software projects often encounter with problems during T＆E, when they become close to the end of development cycle. The problems generally act as a bottleneck of a project, leading to slippage of the entire schedule. This article tried a close look at the problems and solution alternatives of the T＆E policy, management, and technical issues, and proposed a T＆E model to support a variety of software development environment.

• Journal of Animal Environmental Science
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• v.7 no.2
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• pp.83-102
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• 2001

Phytic acid (myo-inositol hexaphosphate or IP6) is the major storage form of phosphorus in cereals and legumes, representing 18 to 88% of the total phosphorus. Phytate form of phosphorus is not readily utilized by monogastric animals and this result causes pollution problem by phosporus released in areas of intensive livestock production. The interaction between phytic acid and essential dietary minerals, protein, or vitamins is considered to be one of the primary factors limiting the nutritional values of cereals and legunes in monogastric animals. Attempts have been made to hydrolyze dietary phytic acid by phytases to improve the feed quality and to decrease the amount of phosphorus excreted by animals. Phytase(myo-inositol hexakisphosphate phosphohydrolase) hydrolyzes phytic acid to myo-inositol and phosphoric acid. Two types of phytases are known: 3-phytase (EC 3.1.3.8) and 6-phytase (EC 3.1.3.26), indicating the intial attack to the susceptable phosphoester bond. Because of its great industrial importance, there is ongoing interest in isolating new bacterial strains producing novel and efficient phytases.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6789-6794
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• 2015

Background: To analyze the expression of estrogen receptors (ER), progesterone receptors (PR), C-erbB-2 and Ki-67 in endometrial carcinoma (EC) and their relationships with the clinicopathological features. Materials and Methods: Sixty-seven EC samples, 53 normal endometrial samples and 53 atypical hyperplasia endometrial samples were all selected in Shaanxi Provincial People's Hospital from Jun., 2012 to Jun., 2014. The expression of ER, PR, C-erbB-2 and Ki-67 in EC tissue, normal endometrial tissue and atypical hyperplasia endometrial tissue was respectively detected using immunohistochemical SP method. The relationships between the expression of ER, PR, C-erbB-2 and Ki-67 and the patients' clinicopathological features as well as their correlations in EC tissue were also analyzed. Results: The positive expression rates of ER and PR in EC tissue were 44.8% and 41.8%, respectively, dramatically lower than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). The positive expression rates of C-erbB-2 and Ki-67 in EC tissue were 80.6% and 64.2%, respectively, significantly higher than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). In EC tissue, the expression of ER and PR was closely associated with the differentiated degrees and depth of myometrial invasion (P<0.05), while that of C-erbB-2 and Ki-67 with the clinical staging, differentiated degrees, depth of myometrial invasion and presence or absence of lymph node metastasis (P<0.05). Spearman correlation analysis further displayed that the expression of ER was positively correlated with PR (r=0.393, P=0.001), but negatively with C-erbB-2 and Ki-67 (r=-0.469, P=0.000; r=-0.329, P=0.007); The expression of PR was negatively correlated with C-erbB-2 and Ki-67 (r=-0.273, P=0.025; r=-0.251, P=0.041), but that of C-erbB-2 positively with Ki-67 (r=0.342, P=0.005). Conclusions: Abnormal expression of ER, PR, C-erbB2 and Ki-67 might play an important role in endometrial malignant transformation and cell differentiation, so their joint detection is likely to be a comprehensive combination of immune factors, which is of great importance for EC prognosis.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.31-34
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• 2001

The customer unsatisfaction in the new products exists, though the most of enterprises using QFD. It is mainly caused by the failure of corrective determination of technical importance rating(TIR). To derive the technical importance rating, the impact of the fulfillment of design requirements on the satisfaction of customer requirements must first be quantified. This has been accomplished through the use of a 1-3-9 or a 1-5-9 scale and ignored the peak of the house of quality(HOQ). In this paper we suggested the methodology reflecting effectiveness among engineering characteristics and adjusting the relationship strength between customer attribute(CA) and engineering characteristic (EC), by using limit probability and PCMR(pairwise comparison and median rank). With using this method, the determination of TIR would be more suitable for the voice of customers objectively. Here negative correlation is ignored.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1811-1817
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• 2008

According to development of electronic commerce, the university's curriculums related electronic commerce should be renewed and added some chapters. I researched on university curriculums of electronic commerce, which has required by enterprise. In particular, the electronic commerce consist of two parts; IT technology and business management. Therefore it is regarded as a convergence subject. I did a correlation analysis between management's performance of enterprise and importance of university curriculum on electronic commerce. The questionnaire includes demands of enterprise and e-business model on electronic commerce. The result of this research indicates a necessary of changing by correlation ratio. Based on this research result, I suggest extended curriculums for electronic commerce.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.

• Corrosion Science and Technology
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• v.16 no.1
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• pp.1-7
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• 2017

When aiming for an increased and more sustainable use of metals a thorough knowledge of the corrosion phenomenon as function of the local metal microstructure is of crucial importance. In this work, we summarize the information presented in our previous publications[1-3] and present an overview of the different local (electrochemical) techniques that have been proven to be effective in studying the relation between different microstructural variables and their different electrochemical behavior. Atomic force microscopy (AFM)[1], scanning electrochemical microscopy (SECM)[2], and electrochemical scanning tunneling microscopy (EC-STM)[3] were used in combination with electron backscatter diffraction (EBSD). Consequently, correlations could be identified between the grain orientation and grain boundary characteristics, on the one hand, and the electrochemical behavior on the other hand. The grain orientation itself has an influence on the corrosion, and the orientation of the neighboring grains also seems to play a decisive role in the dissolution rate. With respect to intergranular corrosion, only coherent twin boundaries seem to be resistant.