• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.17-23
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• 2019

The diesel engine generate many pollutants such as PM(Particulate matter) and NOx(Nitrogen oxide). So the SCR(Selective catalytic reduction) must be required to meet the emission standard. The SCR catalyst market is growing rapidly, and the automobile markets using alternative energy sources are growing rapidly. This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and accept to be safety, But we cannot trade off anything in terms of safety. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion(%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. the CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces. Our tests are our stability guarantee and efficient together with operation.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.399-407
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• 2021

Stock movement is difficult to predict because it has dynamic characteristics and is influenced by many factors. Even so, there are some approaches to predict stock price movements, namely technical analysis, fundamental analysis, and sentiment analysis. Many researches have tried to predict stock price movement by utilizing these analysis techniques. However, the results obtained are varied and inconsistent depending on the variables and object used. This is because stock price movement is influenced by a variety of factors, and it is likely that those studies did not cover all of them. One of which is that no research considers the use of fundamental analysis in terms of currency exchange rates and the use of foreign stock price index movement related to the technical analysis. This research aims to predict stock price movements in Indonesia based on sentiment analysis, technical analysis, and fundamental analysis using Support Vector Machine. The result obtained has a prediction accuracy rate of 65,33% on an average. The inclusion of currency exchange rate and foreign stock price index movement as a predictor in this research which can increase average prediction accuracy rate by 11.78% compared to the prediction without using these two variables which only results in average prediction accuracy rate of 53.55%.

• The Journal of Economics, Marketing and Management
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• v.7 no.4
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• pp.20-32
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• 2019

Purpose - There have been many studies regarding the preceding factors required for success of start-up. The purpose of this study is to verify one of the paths by which the individual characteristics of founders and governmental support lead to enhanced start-up performance, via entrepreneurship and network building. Research design, data, methodology - Data for this study was collected from surveys of 332 founders throughout South Korea, and statistical analyses of this data were performed using SPSS 22.0 and Smart PLS 2.0. To verify our hypothesis, path analysis was performed using a structural equation model. Results -The variables, entrepreneurial self-esteem and experience were found to have positive effects on the entrepreneurship and networks. Secondly, governmental support did not have significant positive effect on entrepreneurship, but it did have positive effect on networking. Thirdly, entrepreneurship and networking were confirmed to have positive effects on both the utilization of opportunities and financial performance, which are variables indicating start-up performance. Conclusion - Although founder's characteristics are important for success of start-up, it is also critically important to actively utilize governmental support. Notably, many founders suffer from inadequate networks. They would be able to enhance their start-up performance by utilizing various governmental support programs to reinforce their network capabilities.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.669-683
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• 2012

The water supply pipes are buried across wide range of areas, so it is hard to spot them using excavation and takes a large amount of expense. Thus, there is a high risk for direct research and application, accompanying many difficulties in implementation of them. Therefore, it is more economical and convenient to use indirect evaluation variables than direct evaluation of the buried pipes in assessing the degree of pipe deterioration. To assess the degree of pipe deterioration using the indirect evaluation variables, it should be done first to identify how and to what extent they affect the degree of deterioration. This study measured the evaluation variables for pipe deterioration using the pipe endoscope and analyzed the measurement results and the degree of impact on the pipes. In addition, this study attempted to evaluate the adequateness of the pipe deterioration evaluation using the indirect variables based on the analysis results. The evaluation variables measured through the pipe endoscope were the thickness of sediments, size of scale, degree of desquamation and condition of connections. For the indirect evaluation variables, the data such as the property data from GIS pipe network map as well as the material, diameter, age and pipe lining material of the pipe, road type, leakage frequency, average water velocity and water pressure using the leakage repair records was collected. Using the collected data, this study comparatively analyzed the indirect evaluation variables for the degree of pipe deterioration and the results from the pipe endoscope to choose appropriate variables for pipe deterioration evaluation and calculated the weights of the indirect variables on the degree of deterioration. The results showed that the order of the impact of indirect variables on deterioration was pipe age > pipe lining material > road type > leakage frequency > average water velocity with their weights of 0.45, 0.20, 0.15, 0.10, and 0.10, respectively. Conclusively, the results suggest that the measures of sediment thickness, scale size, degree of desquamation and condition of connections are appropriate for the evaluation of pipe deterioration and sufficient for the analysis of the impact of the indirect variables on deterioration.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.674-683
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• 1999

The purpose of this study was to compare the ideas of pupils with that of the scientists about controlling and identifying of variables, in the two cases: open or guided inquiry. The subjects were the 7th grade boys and girls in a school, in Seoul, Korea. For the guided inquiry, the problems were given by the experiments of pupils' text. Pupils were asked to identify the variables in the experiments. For the open inquiry, pupils set their own inquiry problem. The pupils whose marks are within upper one-third of three classes were chosen. Pupils' ideas on variables were investigated in the design of experiment for their problems. In that, questionnaire developed by researchers was used. In the former, many of the pupils identify just only one variable despite of the fact there were two independent or dependent variables in the experiments. In the latter, the number of independent variables increased two or three. However, pupils do not control independent variables: they vary two independent variables simultaneously in the design of experiment. From these, we compared the pupils' ideas on variables with the scientists'

• Korean Business Review
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• v.12
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• pp.161-187
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• 1999

Organ(1988) has suggested that OCB should be considered an important component of job performance because citizenship behaviors are part of the spontaneous and innovative behaviors. Also it has been suggested that organizational characteristics may potentially explain many organizational behavior outcome variables(Hackman & Oldham, 1980). In recent years there has been a resurgence of interest in the validity of personality measures as a moderator between many variables and organizational outcome variables. This is largely due to the facts that first personality is difficult to control for promoting many organizational outcomes and next many researchers have found the moderating effects of personality(Brief & Aldag, 1975; Wanous, 1974). The purpose of this research is to test the moderating effects of tenure and growth needs on the relationships between organizational characteristics and OCB. To assess the moderating effects, the hierarchical regression procedures outlined by Cohen and Cohen(1983) were followed. On the basis of data from 698 teachers in Wonju province, results indicated that job variety has more impacts than any other independent variable on OCB like other studies. It is found that job variety and job identity have more impacts on courtesy and altruism in lower growth needs group than in higher growth needs group. Also it is resulted that job importance and autonomy have more impacts on sportsmanship in higher growth needs group than in lower growth needs group.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.77-86
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• 2001

An operational strategy for inventory control on finished goods in the distribution system has been given attention to many enterprises and many studies regarding this field have been done and is also on-going currently. Many of these studies represented a large scale distribution network with a unified formulation by using defined symbols. These methods have provided the systematic approach of the distribution network but they are impossible to applying the reality system due to not considering the service rate of demand and treating the shortage of inventory. In order to overcome these unrealistic problems, the novel safety stock policy of responding to customers' inventory distribution network is suggested. this paper explores the transportation between Central Distribution Center(CDC) and Regional Distribution Center(RDC). Especially, the relation of transportation cost between CDC and RDC and cost of inventory control according to safety inventory with service level are emphasized. We could obtain the good results of this study by determining the optimal safety stock considering the various variables and constraints.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.183-190
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• 2001

Topology optimization. has been evolved into a very efficient conceptual design tool and has been utilized into design engineering processes in many industrial parts. In recent years, topology optimization has become the focus of structural optimization design and has been researched and widely applied both in academy and industry. Traditional topology optimization has been using homogenization method and optimality criteria method. Homogenization method provides relationship equation between structure which includes many holes and stiffness matrix in FEM. Optimality criteria method is used to update design variables while maintaining that volume fraction is uniform. Traditional topology optimization has advantage of good convergence but has disadvantage of too much convergency time and additive checkerboard prevention algorithm is needed. In one way to solve this problem, element remove method is presented. Then, it is applied to many examples. From the results, it is verified that the time of convergence is very improved and optimal designed results is obtained very similar to the results of traditional topology using 8 nodes per element.

• Advances in Computational Design
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• v.6 no.1
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• pp.43-53
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• 2021

Multi-stage pumps are the most popular pumps among various kinds of centrifugal pumps. Athorough review of different kinds of literature has led to the conclusion that there is a desperate need to increase the performance of the multi-stage centrifugal pump. Many investigators have put their efforts to increase the pump performance and also the work is being projected on various aspects of pump performance variables. To improve the multistage centrifugal pump performance by investigation, modification, and analysis many works of literature are available. For analysis, many researchers used the Navier-Stokes solver to create the three-dimensional unsteady turbulent flow numerical model with the standard k-ε turbulent equation. This paper mainly focuses on research related to the multi-stage centrifugal pump.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.142-153
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• 2009

As many companies have adopted and used ERP systems, concerns about ERP performance also have increased. The purpose of this research is to examine the relationships between qualitative variables and quantitative variables measuring ERP performances. Qualitative research, widely used in MIS research, typically examines perceived usefulness of ERP, such as information quality, system quality, system satisfaction. Quantitative research, often done in accounting research, usually examines ERP performance based on financial statements. An empirical study led to the following conclusions: 1) There were significant correlations among the qualitative variables measuring perceived usefulness of ERP; 2) Significant correlations were also observed among the quantitative variables based on financial statements; 3) However, no significant correlations was found between the qualitative variables and quantitative variables measuring ERP performance.