• ETRI Journal
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• v.37 no.2
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• pp.273-282
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• 2015

Vehicle-to-grid presents a mechanism to meet the key requirements of an electric power system, using electric vehicles (EVs) when they are parked. The most economic ancillary service is that of frequency regulation, which imposes some constraints regarding the period and duration of time the vehicles have to be connected to the grid. The majority of research explores the profitability of the aggregator, while the perspective of the EV fleet owner, in terms of their need for usage of their fleet, remains neglected. In this paper, the optimal allocation of available vehicles on a day-ahead basis using queuing theory and fuzzy multi-criteria methodology has been determined. The proposed methodology is illustrated on the daily scheduling of EVs in an electricity distribution company.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1283-1286
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• 2003

Human can update the memory with new information not forgetting acquired information in the memory. ART(Adaptive Resonance Theory) does not need to change all information. The methodology of ART is followed. The ART updates the memory with the new information that is unknown if it is similar with the memorized information. On the other hand, if it is unknown information the ART adds it to the memory not updating the memory with the new one. This paper shows that ART is able to classify sensory information of a certain object. When ART receives new information of the object as an input, it searches for the nearest thing among the acquired information in the memory. If it is revealed that new information of the object has similarity with the acquired object, the model is updated to reflect new information to the memory. When new object does not have similarity with the acquired object, the model register the object into new memory

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.81-86
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• 2001

The concrete bridge decks are in need of replacement and rehabilitation due to decreasing load carrying capacity. In this study, to propose a strengthening technique that improves usability and structural performance of the bridge deck and to propose an efficient strengthening design technique which satisfies both the strength End serviceability of the bridge deck, this paper shows the failure characteristics of the strengthened bridge decks and proposes an empirical yield criterion. Therefore, strengthening efficiency was proposed based on the experiment and yield line analysis result. The yield line theory which adopts the modified criteria of Johansen is considered to predict the ultimate strength about all strengthening material(Carbon Fiber Sheet, Carbon Fiber Rod, Grid Type Carbon Fiber).

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.296-301
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• 1998

The Rough Set theory suggested by Pawlak in 1982 has been useful in AI, machine learning, knowledge acquisition, knowledge discovery from databases, expert system, inductive reasoning. etc. The main advantages of rough set are that it does not need any preliminary or additional information about data and reduce the superfluous informations. but it is a significant disadvantage in the real application that the inference result form is not the real control value but the divided disjoint interval attribute. In order to overcome this difficulty, we will propose approach in which Rough set theory and Neuro-fuzzy fusion are combined to obtain the optimal rule base from lots of input/output datum. These results are applied to the rule construction for infering the temperatures of refrigerator's specified points.

• Archives of design research
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• v.11 no.2
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• pp.167-176
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• 1998

The modern contains many problems that cannot be solved by the reductionism based on western natual science. Up until now, it has been formed determinism over the basis of empiricism or rationalism, this can be called a mechanical view of the world. In the field of natural science since 20C, however, raised the standard of revolt in traditional determinism, plural theory headed up. Consequently, in the name of post modernity, western reason became to deconstruct, further, new theory came to need. This new paradigm also affected design, and was studied to overcome the limitation of modern design.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.466-471
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• 2004

Efficient numerical finite element analysis of creeping concrete structures requires the use Kelvin or Maxwell chain model, which is most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with aging was previously worked out by Bazant and Xi, but only for the case of a continuous retardation spectrum based on Kelvin chain. The present paper is motivated by the need to incorporate concrete creep into the recently published microplane model M4 for nonlinear triaxial behavior of concrete, including tensile fracturing and behavior under compression. In that context. the Maxwell chain is more effective than Kelvin chain. because of the kinematic constraint of the microplanes used in M4. Determination of the continuous relaxation spectrum for Maxwell chain. based on the solidification theory, is outlined and numerical examples are presented.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.228-231
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• 2000

When the vector control which does not need a speed signal from a mechanical speed sensor it is possible to reduce the cost of the control equipment and to improve the control performance in many industrial application. In this paper describes a rotor speed estimate method of induction motor based on the theory of counter EMF MRAS. This method eliminated the pure integrator. and we can be expected to rapid responsibility of the speed identification, Therefore we improve the initial condition of the integrator and drift problem. The stability of speed estimator is proved on the basis of hyperstability theory. In order to confirm the performance of the proposed system Simulation and experiment is performed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.145-150
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• 2004

This paper suggests an evaluation of risk level for damage of marine accidents in SRRs. Qualitative analyses in words is sometimes priorior to quantative analyses in numeric symbols. This paper intoduces a concept of fuzzy theory with the plenty of related literature riview and AHP in the Korean SRRs of RCC and RSC. The methodology of this paper is maxㆍmin composition of fuzzy extensive principle, defuzzifiation is centroid of gravity methods. At the result, the evaluation of risk level is especially over Serous for smarine accident of Taean, Gunsan, Mokpo, Yosu, Tongyoung, Busan SRR. This paper recommends that many Resale Vessels and Equipments need to the reduction of risk level about those.

• Perspectives in Nursing Science
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• v.3 no.1
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• pp.1-15
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• 2006

With accumulated nursing research results from older adults, refined middle range nursing theories are evolving in gerontological nursing area. Three middle range nursing theories and framework were reviewed and described. Life transition framework for older adults were developed through research related to relocation and other transitions taken place in later life. Self-efficacy exercise model was developed by extensive research related to rehabilitation of older adults based on self efficacy expectations and outcome expectations concept from social cognition theory. Need-Driven dementia-compromised Behavior (NDB) model was developed by a group of nursing scholars studying dysfunctional behaviors of demented older adults. All of these theories are approaching to practice theory by developing interventions and nursing therapeutics. There are more needs to develop theories for specific gerontological nursing phenomena such as delirium, end of life and self integrity.

• Korea Journal of Hospital Management
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• v.21 no.3
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• pp.53-64
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• 2016

The study empirically examines the classic hypothesis on resource-based view(RBV) theory, which is the possible relationship between competitive advantage and performance. For the study, we have surveyed 198 hospital administrators in Korea. By testing the hypotheses at conceptual level, a more robust approach, we found that (1) if a hospital possesses and exploits resources and capabilities that are both valuable and rare, it will attain a competitive advantage, and (2) the attaintment of such advantage will enable the hospital to improve its performance. The results may be interest to both academics and practitioners. From an academic standpoint, the study more accurately captures the dynamics of the theory by pairing resources-capabilities as opposed to individual resources or capabilities. From a practitioner perspective, it is suggested that hospital managers need no necessarily seek out novel resources and capabilities, but rather develop novel ways in which to combine those resources and capabilities to which they do have access.