• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.639-650
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• 2008

Electricity price forecasting has become an integral part of power system operation and control. In this paper, a wavelet transform (WT) based neural network (NN) model to forecast price profile in a deregulated electricity market has been presented. The historical price data has been decomposed into wavelet domain constitutive sub series using WT and then combined with the other time domain variables to form the set of input variables for the proposed forecasting model. The behavior of the wavelet domain constitutive series has been studied based on statistical analysis. It has been observed that forecasting accuracy can be improved by the use of WT in a forecasting model. Multi-scale analysis from one to seven levels of decomposition has been performed and the empirical evidence suggests that accuracy improvement is highest at third level of decomposition. Forecasting performance of the proposed model has been compared with (i) a heuristic technique, (ii) a simulation model used by Ontario's Independent Electricity System Operator (IESO), (iii) a Multiple Linear Regression (MLR) model, (iv) NN model, (v) Auto Regressive Integrated Moving Average (ARIMA) model, (vi) Dynamic Regression (DR) model, and (vii) Transfer Function (TF) model. Forecasting results show that the performance of the proposed WT based NN model is satisfactory and it can be used by the participants to respond properly as it predicts price before closing of window for submission of initial bids.

• Journal of Information Technology Services
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• v.6 no.2
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• pp.63-80
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• 2007

In this paper, the function factors contributing to ITA/EA functions in their organizations, are suggested. Also the reasons to the construction of IT governance system and their effects on the their organizations are discussed and the relationships are verified by empirical model. From the survey, the data of the 227 respondents were collected and regression analysis was performed for validating the research model. ITA/EA functions consist of the IT infrastructure systemization, ITA/EA business process support, IT investment efficiency factors. And the factors of IT resource and performance management, IT process management, IT service management are included to IT governance. The main analysis results described significantly are shows as follows. At first, IT resource and performance management factor is effected by the ITA/EA business process support factor and IT investment efficiency factor. In similarly, IT service management factor is also affected by the factors such as ITA/EA business process support, IT investment efficiency, and IT infrastructure systemization. In additional analysis, IT investment efficiency factor in official sectors, ITA/EA business process support factor in private sectors respectively are described as the significant factors on the IT governance.

• Korean Journal of Social Welfare
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• v.49
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• pp.343-378
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• 2002

This study examines the organizational performance of human service organizations from the quality output perspective. Using the 2001 evaluation data about 89 community welfare centers in Seoul, this study attempts to identify the levels of the performance of human service organizations in Korea. This study also attempts to identify the factors that predict performance of human service organizations measured in terms of client satisfaction and experts' evaluation about the functioning of each center. Results are as follows: (1) when pooling 866 clients' satisfaction level into satisfaction score about each center, the average of client satisfaction about the centers is 3.42 at 4 points scale. (2) 41.6% of the community welfare centers is evaluated as "highly qualified" in its overall operation and functioning by the professional evaluation team, (3) the employee reward system(+), practice based on the program guideline manual(+), the portion of the government support grant in its budget(-), the overall employee salary level(-), the level of acquirement of program grants from external sources (-) are the predictors in explaining clients' satisfaction level, and (4) the level of professional expertise of the executive director(+), the level of professional supervision of middle managers(+), the employee reward system(+), the program need assessment(+), the level of client information system(+), the portion of government support grant(-), the overall employee salary level(-) are the predictors for "being highly qualified" in its overall operation and function of each center. Through the empirical analysis, this study provides valuable knowledge about organizational performance of community welfare centers from the quality output perspective. Finally, this study discusses implications for more effective and efficient organizational performance of community welfare centers in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.4
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• pp.308-315
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• 2012

Hebei Spirit Oil Spill that happened in 2007 had prompted the need of revisiting the coastal safety. In response to this, Korea had made an effort to implement VTS in every coastline in the country. There are a lot of theoretical studies on VTS function nowadays, but coastal VTS are less frequently studied. In this paper, performance analysis results and accident prevention activities of Jindo Coastal VTS center were summarized and the Coastal VTS function are investigated. Jindo Coastal VTS covers relatively wide area and various places with various maritime traffic characteristics are the major navigation vessels, which means that it is important to control these vessels. Since the probability of accidents due to human error is relatively high in coastal area due to negligence tendency of crews during coastal area navigation, coastal VTS has to provide sufficient assistance to navigating vessels. Like most harbour VTS, Coastal VTS provides not only main information service, navigational assistance and traffic organization services but also various services related with advanced search-and-rescue assistance, marine national security, maritime crime prevention, oil spill response, traffic services for non-service vessel, and safety supervision for water leisure boats.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.182-190
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• 2018

Many pharmaceutical companies operate the SFA system to support salespeople. The SFA system is used for various behaviors of salespeople. However, there is a lack of empirical analysis on the performance of SFA in Korea. The purpose of this study is to investigate the utilization of SFA system and the non - financial performance of SFA system. The subjects of the survey were 347 pharmaceutical community members who consisted of pharmaceutical salespeople and surveyed online for 18 days from March 13, 2018 to April 30, 2018. and the effective response rate was 23.1% (80/347). The analysis shows that the higher the level of SFA system utilization, the higher the non - financial performance. By type of company, the utilization level of multinational companies was higher than that of domestic companies. Among the SFA utilization level items, 1.47 points (3.65, 2.18) were higher than the domestic companies in terms of the support service items. Among the SFA performance items, foreign companies were 1.47 points (3.16, 1.69) Respectively. This suggests that the SFA development and operation method of the domestic company focuses on the management service rather than the support service for the salesperson and the customer satisfaction. Through this study, it is considered that domestic companies should strengthen sales person support and customer satisfaction information providing function when operating SFA system.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.122-131
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• 2002

Recently, performance assessment that makes growing use of free response items in a large scale assessment has been emphasized. This study is an empirical examination of the effectiveness of free response items in comparison with multiple choice items. Using the information function in Item Response Theory (IRT) framework, item information of free response items and multiple-choice items from the Third International Mathematics and Science Study-Repeat (TlMSS-R) were obtained. Test information of the whole science area as well as each area of science contents was computed. On average, free response items yielded more information than multiple choice items, especially in earth science, physics, chemistry, and life science. This study also showed that free response items were appropriate for students in high science ability. Also, free response items estimated students' science ability more accurately than multiple choice items with smaller number of free response items.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.55-62
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• 2015

Cracking is an inevitable fact of asphalt concrete pavements and plays a major role in pavement deterioration. Pavement cracking is one of the main factors determining the frequency and method of repair. Cracks can be treated with a number of preventative maintenance actions, including overlay surface treatments such as slurry sealing, crack sealing, or crack filling. Pavement cracks can show up as one or all of the following types: transverse, longitudinal, fatigue, block, reflective, edge, and slippage. Crack sealing is a frequently used pavement maintenance treatment because it significantly extends the pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Because current test methods are mostly empirical and only provide a qualitative measure of the bond strength, they cannot accurately predict the adhesive failure of the sealant. This study introduces a laboratory test aimed at assessing the bonding of hot-poured crack sealant to the walls of pavement cracks. A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the bonding strength of the hot-poured crack sealant as a function of the curing time and temperature. Based on a limited number of test results, the hot-poured crack sealants have very different bonding performances. Therefore, this test method can be proposed as part of a newly developed performance-based standard specification for hot-poured crack sealants for use in the future. PURPOSES : The purpose of this study was to evaluate both the adhesion and failure performance of a crack sealant as a function of its curing time and curing temperature. METHODS: A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the adhesion performance of a crack sealant as a function of the curing time and curing temperature. RESULTS: With changes in the curing time, curing temperature, and sealant type, the bond strengths were found to be significantly different. Also, higher bond strengths were measured at lower temperatures. Different sealant types produced completely different bond strengths and failure behaviors. CONCLUSIONS: The bonding strength of an evaluated crack sealant was shown to differ depending on various factors. Two sealant types, which were composed of different raw materials, were shown to perform differently. The newly proposed test offers the possibility of evaluating and differentiating between different crack sealants. Based on alimited number of test results, this test method can be proposed as part of a newly developed performance-based standard specification for crack sealants or as part of a guideline for the selection of hot-poured crack sealant in the future.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.324-331
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• 2014

In the design of a combat vehicle, various performances such as firepower, mobility and survivability, etc., should be considered. Furthermore, since these performances relate to each other, design framework which can treat an integrated system should be employed to design the combat vehicle. In this paper, we use empirical interior ballistic and 3D combat vehicle analyses for predicting firepower and mobility performances which are developed in previous study (1) integrated performance modeling. In firepower performance, pitch and roll angle by sequential firing are considered. In mobility performance, vertical acceleration after passing through a bump is regarded. However, since there are many design variables such as mass of vehicle, mass of suspension, spring and damping coefficient of suspension and tire, geometric variables of vehicle, etc., for firepower and mobility performance, we utilize analysis of variance and quality function deployment to reduce the number of design variables. Finally, integrated design optimization is carried out for integrated performance such as firepower and mobility.

• Journal of Korea Technology Innovation Society
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• v.16 no.1
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• pp.279-302
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• 2013

This paper empirically examines the effect of government R&D support on the performance of the firm in Korea. In particular, we examine to what extent the government R&D support affected the firm's exploratative performance. Using a novel dataset combining patent information with national government R&D funding data and firm performance indicators from 2005-2008, we construct and run an empirical model where a firm's exploratative activity, measured by a firm patenting in a different field, is a function of the government R&D support a firm receives. The empirical results show that the government R&D support has a positive effect on the firm's exploratative activity. Especially, this effect is stronger for the small and medium size firms, while large firms are relatively relying on their own R&D funding for exploration. This result indicates that the government needs to focus more on R&D funding for small and medium size firms, if it wants more exploratative outcomes to enhance potential resources for economic development.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.357-368
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• 2013

This research explores the efficiency of social welfare expenditure in Korea by analyzing marginal productivity, scale economies, and elasticity of substitution that could be obtainable from a production function. By virtue of VES production function, such productive indicators are easily identified. If once the efficiency is revealed in the production process, it brings to a positive impact to increase the level of income. Empirical evidences are shown that the public expenditure is operated systematically in comparing with the private one. This is mainly due to the fact that the system of the public sector is well-established. It implies that an operational system for the private sector ought to be built up in a short period of time. Otherwise, increasing in expenditure by a private sector would not be helpful to improve efficiency in the production side. Accordingly, level of income.