• Journal of Electrical Engineering and Technology
• /
• v.12 no.5
• /
• pp.1729-1742
• /
• 2017

In designing System Protection Schemes (SPSs) in power systems, protecting transmission network against extreme undesired conditions becomes a significant challenge in mitigating the transmission line overloading. This paper presents an intelligent Special Protection and Control Scheme (SPCS) using of Differential Evolution with Adaptive Mutation (DEAM) approach to obtain the optimum generation rescheduling to solve the transmission line overloading problem in system contingency conditions. DEAM algorithm employs the attraction-repulsion idea that is applied in the electromagnetism-like algorithm to support the mutation process of the conventional Differential Evolution (DE) algorithm. Different N-1 contingency conditions under base and increase load demand are considered in this paper. Simulation results have been compared with those acquired from Genetic Algorithm (GA) application. Minimum severity index has been considered as the objective function. The final results show that the presented DEAM method offers better performance than GA in terms of faster convergence and less generation fuel cost. IEEE 30-bus test system has been used to prove the effectiveness and robustness of the proposed algorithm.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.7
• /
• pp.349-361
• /
• 2002

Occasionally, equipment in a distribution system fails due to damage from weather, vandalism, or other causes. Failures and unexpected events do not always occur as and where expected. Therefore, a good contingency plan, multi-zone or otherwise, provides flexibility by locating switches at various strategic locations so that parts of a feeder can be picked up in the event of line outages at various places. It is possible to create feeder system layout that achieve remarkable contingency support economics, even as their normal peak loading levels approach thermal capacity, by utilizing six, seven, or even nine switchable zones per feeder. But many switchable zones per feeder are of questionable practicality and effectiveness, because of the complexity and time required for the switching operation. In practice, a zonal scheme with between three and four zones will usually provide complete contingency backup for all feeders. Line switches have both capital and maintenance costs, the planning for multi-zonal schemes is considerably more difficult than or loop or single-zone systems, and the required switching operations required during contingencies take more time. But multi-zonal schemes are used because these costs come to far less than the cost of additional capacity required for loop or single-zone. In this paper, we present the optimal number of switchable zones per feeder in Kora distribution system.

• Journal of Information Technology Applications and Management
• /
• v.16 no.2
• /
• pp.1-21
• /
• 2009

The balanced scorecard(BSC) framework is a tool for strategic decision making and task support that aims for efficiency in performance management and strategy execution. BSC evolved from an old performance management practice, which tended to be limited to a finance-only perspective, to a new system of corporate management looking at corporate tasks from a multi-dimensional, future-inclined value perspective. This form of BSC amounts to a framework capable of driving management innovation and renewing the ways in which companies conceive their strategy and perform their operations. Since BSC draws integrally on user participation, it can be expected that users' satisfaction with BSC systems is an important factor in systems' success or failure. However, previous studies of the BSC system have not yet considered it as a theoretical model, specifically examining BSC system and task characteristics. To date, only a few studies have put forward plans for the implementation and use of BSC systems, and these studies have the common limitation of failing to consider the circumstances or theoretical structure of the companies for which a BSC system is being proposed. This paper then begins to fill some of this gap by characterizing the BSC system from the perspective of contingency theories. Contingency theories can be particularly useful in the Korean context in exploring how different companies use the BSC system in ways determined by their unique environmental characteristics, which may also determine the performance factors behind the application of a company's particular BSC system. In order to provide concrete suggestions for implanting and using the BSC system from a contingency theory perspective, this study sets out to determine the relationships between the contingency variables affecting BSC system performance and BSC system property variables(in given cases) through an empirical analysis. The study takes into account the perspective from which contingency theory is to be applied in individual cases, sets contingency and BSC property variables with reference to the BSC system user's environment and BSC system's character, and frames initial hypotheses concerning corporate structure and environmental variables and BSC system performance variables with reference to previous studies. A survey was then conducted on users in Korean companies that have implemented the BSC system in order to verify the research model and understand results.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.5
• /
• pp.125-136
• /
• 2019

This study investigated checked risk level before bid, actual risk level after award, contingency, and cost growth rate in the 124 international construction projects executed by Korean major companies. This study conducted comparative analysis by product type using rank analysis, ANOVA and correlation analysis. As a result, plant and civil projects have worse risk level than architecture projects not only in before bid but also in after award. Especially, country risk is the worst risk in both plant and civil projects, followed by project risk and capability risk. Also, although plant and civil projects reflect more contingency than architecture projects, contingency is not correlated with the checked risk level before bid. Lastly, the cost growth rate is correlated with the actual risk level in all product types. This study is expected to support in planning better practical risk management for international construction projects.

• Journal of the Korean Data and Information Science Society
• /
• v.19 no.3
• /
• pp.925-936
• /
• 2008

An association rule mining finds the relation among each items in massive volume database. In generating association rules, the researcher specifies the measurements randomly such as support, confidence and lift, and produces the rules. The rule is not produced if it is not suitable to the one any condition which is given value. For example, in case of a little small one than the value which a confidence value is specified but a support and lift's value is very high, this rule is meaningful rule. But association rule mining can not produce the meaningful rules in this case because it is not suitable to a given condition. Consequently, we creat insignificant error which is not selected to the meaningful rules. In this paper, we suggest clustering technique to association rule measures for finding effective association rules using measure of association.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.557-560
• /
• 2005

The Korea Multi-Purpose SATellite-2 (KOMPSAT -2) will be launched into a circular sun synchronous orbit in Dec. 2005. For the mission operation of the KOMPSAT-2 satellite, KARl Ground Station (KGS) consists of the Mission Control Elements (MCE), Image Reception & Processing Elements (IRPE) and the overseas stations. For the oversea stations, the Kongsberg Satellite Services (KSAT) is the prime supplier of support service. KSAT has the capability to provide Tracking Telemetry and Commanding (TT&C) nominal, contingency and anomaly support for every single orbit for most polar orbiting satellites. Also KSAT provides nodal service through the network management functionality for all oversea ground stations. This paper describes the oversea stations and the support for Launch and nominal TT&C services for KOMPSAT-2 and the operation plan for KOMPSAT-2.

• Journal of Information Processing Systems
• /
• v.4 no.1
• /
• pp.27-32
• /
• 2008

Minimum support and confidence have been used as criteria for generating association rules in all association rule mining algorithms. These criteria have their natural appeals, such as simplicity; few researchers have suspected the quality of generated rules. In this paper, we examine the rules from a more rigorous point of view by conducting statistical tests. Specifically, we use contingency tables and chi-square test to analyze the data. Experimental results show that one third of the association rules derived based on the support and confidence criteria are not significant, that is, the antecedent and consequent of the rules are not correlated. It indicates that minimum support and minimum confidence do not provide adequate discovery of meaningful associations. The chi-square test can be considered as an enhancement or an alternative solution.

• The Journal of the Korea Contents Association
• /
• v.7 no.7
• /
• pp.133-143
• /
• 2007

The object of this study is to empirically analyze the effects of information support quality and service quality on service satisfaction of department store. To investigate the purpose of this study, literature review and survey were conducted. for statistical analysis, factor analysis, analysis of variance(ANOVA), and regression in order by the contingency grouping method were used. In conclusion of this study are as follows First, The regression analysis had effects on information support quality and service satisfaction. Second, The Analysis of variance(ANOVA) and regression had effects on information support quality and service satisfaction as service quality factors. Result, The information support accuracy and service quality had additional effect about customer relation.

• Asia pacific journal of information systems
• /
• v.15 no.1
• /
• pp.135-152
• /
• 2005

In order to explore a relationship among KM context, KM effects, and sustainability of competitive advantage of organizations, a contingency model of KM, which is based on resource-based as well as knowledge-based theory, is developed from the information systems and strategic management literature. To put it concretely, our motivation for this paper was to answer the following questions: (1) What factors affect the degree to which an organization achieves KM effects? (2) Is there a positive relationship between KM effects and organizational performance achieved by linking KM to competitive advantage? A detailed exploratory analysis of survey responses from 79 Korean companies provides the following significant findings: (1) This study found support for the proposed research model. (2) The organization's degree of process and organizational outcomes of KM effects is determined by technical and social resources and its capabilities. Furthermore, the influence of technical and social resources of KM context on process and organizational outcomes of KM effects is controlled by different types of organizational perspectives on KM. (3) There is a relationship between process and organizational outcomes of KM effects and organizational performance enhanced by linking KM to competitive advantage.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.10
• /
• pp.1035-1046
• /
• 2020

This study aims to find empirical evidence of causal relationship between strategy type, market orientation, strategic management accounting (SMA) strategic costing technique, and financial sector performance of private universities in Indonesia. The research object in this study are private universities in Yogyakarta, Indonesia. Yogyakarta is chosen because universities there are one of the barometers of higher education in Indonesia, and the city has quite a number of universities. The respondents in this study are the leader (manager) of private universities in Yogyakarta, Indonesia. The data analysis is done using SEM-PLS with WarpPLS 3.0 software. The results of this study show that market orientation has significant influence on the development and implementation of SMA strategic costing technique, while strategy type does not have significant influence on the development and implementation of SMA strategic costing technique. This study also finds that the implementation of SMA strategic costing technique significantly influences the financial sector performance of private universities in Yogyakarta, Indonesia. This study provides theoretical implication regarding SMA development in universities that consider that contingency factors (market orientation) can encourage increased organizational performance. It indicates support for contingency theory that states there are no general principles that apply to all situations.