• Steel and Composite Structures
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• v.20 no.2
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• pp.295-316
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• 2016

This paper presents the results of experimental investigation, numerical calculation and theoretical analysis on axial compression ratio limit values for steel reinforced concrete (SRC) special shaped columns. 17 specimens were firstly intensively carried out to investigate the hysteretic behavior of SRC special shaped columns subjected to a constant axial load and cyclic reversed loads. Two theories were used to calculate the limits of axial compression ratio for all the specimens, including the balanced failure theory and superposition theory. It was found that the results of balanced failure theory by numerical integration method cannot conform the reality of test results, while the calculation results by employing the superposition theory can agree well with the test results. On the basis of superposition theory, the design limit values of axial compression ratio under different seismic grades were proposed for SRC special shaped columns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.75-81
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• 2014

It has been widely accepted that open phase may separate one of the power lines from power supply which is mainly caused by fuse melting, malfunction for source circuit breaker, contact failure, and disconnection under normal operating conditions, and is considered a kind of failure mode during disconnection of neutral wires as well. When open phase occurs, unequal voltage between phase might happen in the unbalanced load connected each phase, and further, depending on conditions of load, malfunction by providing low voltage. Moreover, load could be burned or overheated with overvoltage, which, in turn, can be a contributor to starting fires. Accordingly, in order to clearly overcome these problems, the current study aims to introduce the theory of uninterruptible power open phase compensation device, meaning that unbalanced power automatically restores balanced power and provides continuously the power supply without blackout, and verify it through simulation and experiments.

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