• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.417-426
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• 2014

Plant management have a greatest influence on the corporate variety of tasks such as production, quality, environment. So, various performance indices for plant management are operating. But plant management tasks can be carried out effectively, so that all of how to organize and efficiently manage indicators is lacking real condition In this paper, improved profitability, cost savings by applying the concept for the performance assessment, plant management services, such as the key indices for performance according to the objectives of the firm. Dashboard for plant management work using me to develop a system that manage.

• Journal of Korean Physical Therapy Science
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• v.4 no.4
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• pp.511-518
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• 1997

For the perfect cure of rheumatoid arthritis, the ultimate hope of patients and therapist, it is necessary to find a patient early and treat him properly and to teach him what rheumatoid arthritis is. 1. Although rheumatoid arthritis is a chronic disease and its cause is uncertain matke the patient understand that there are many ways to reduce symptoms and to prevent deformation. 2. Explain the peculiarity and the procedure of rheumatoid arthritis to the patient and encourage him. 3. Teach the patient how to protect his arthrosises by showing him concrete movement. 4. Teach the patient or his family the ways to relieve rheumatoid arthritis easily in his house for continuous remedy. In order to make that remedy most effective for the patient, a complex and balanced treatment, considering medication, surgical teatment and rehabilitative treatment, has to be applied, which needs team work. Team work occurs when doctors, physiotherapists, nurses, nutritionists, clinical psychologists, prosthesis manufacturers, social workers, employment agents and the family of the patient work together. The members of the tern have to onderstand the procedure of the treatment of rheumatoid arthritis and apply proper remedies according to the condition of the patient.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.61-68
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• 2012

This paper deals with a fault diagnosis algorithm for open faults in the switching devices of PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive. The proposed diagnostic algorithm is realized in the controller using the informations of three-phase currents or reference line-to-line voltages, without requiring additional equipments for fault detection. Under switch open fault conditions, the conventional dq model used to control an AC motor cannot directly be applied for the analysis of drive system, since three-phase balanced condition does not hold. To overcome this limitation, a fault model based on the line-to-line voltages is employed for the simulation studies. For comparative performance evaluation through the experiments, the entire control system is implemented using digital signal processor (DSP) TMS320F28335. Simulations and experimental results are presented to verify the validity of the proposed diagnosis algorithm.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.1
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• pp.36-40
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• 2008

Most of the low-voltage feeder are designed with approximately balanced and connected at the three phase four wire systems. However, Most of the power distribution systems' load which is composed of single or three phase are unbalanced by generating load unbalance. Unbalanced current will draw a highly unbalanced voltage. The power factor of an induction motor at rated operation is between 25 and 90%, depending on the size and speed of the motor. However, many induction motors operate below the nominal rating, resulting in poor power factor. This condition needs power factor improvement. Addition of power capacitor at the motor terminal may draw to stress due to voltage unbalance. This paper presents operation characteristics on steady states of a three-phase induction motor under unbalanced voltages with power capacitor. The existence of voltage unbalance have an effect on stress of power capacitor.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.259-266
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• 2003

This paper introduces a relation to determine the span ratio between exterior and interior spans, which is strongly required in the preliminary design stage of bridges constructed by Free Cantilever Method (FCM). A relation for the initial tendon force is derived on the basis of an assumption that no vertical deflection occurs at the far end of a cantilever beam due to the balanced condition between the self-weight and the cantilever tendons. In advance, the span ratio can be determined by using an assumption that the negative maximum moment must be the same with the positive maximum moment along the entire spans to be a rational bridge design. Finally, many rigorous lime-dependent analyses are conducted to establish the validity of the introduced relations. The obtained numerical results show that the rational design of FCM bridges may be achieved when the span length ratio of the exterior span to the interior span ranges about 0.75 to 0.8.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.753-762
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• 2004

Conceptual studies of a combined-cycle engine have been conducted. Herein, the results are presented. The engine is composed of ejector-jet, ramjet, scramjet and rocket modes, and will be mounted on the Single-Stage-to-Orbit aerospace plane. Propellants are hydrogen and oxygen. Calculated engine thrust performances and cooling requirement of the engine are presented. Pitching moment of the plane with the engine will be balanced even in the vacuum condition. The experimental results of the inlet and the ejector-jet, ramjet and scramjet modes are presented. The effect of the airframe configuration on the engine performance and the thermal environment in the in-side of the plane are also presented. Through the investigations, possibilities of the combined-cycle engine and the aerospace plane are being made clear now.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.177-180
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• 2006

Experimental study has been performed in order to evaluate the effects of steel reinforcement ratio on the flexural behavior of RC beams strengthened with CFRP sheets. The steel reinforcement ratio of $0.78%({\rho}_s/{\rho}_b=24%)$ is selected to have balance failure when control RC beams were strengthened with 1 ply CFRP sheet. Total 6 half-scale specimens were manufactured including each unstrengthened specimens, which have 3 different reinforcement ratios. The specimens strengthened with CFRP sheet consist of under- or over-reinforced beams for the balanced failure condition. Moreover, the behavior of un strengthened or strengthened beams were compared to evaluate flexural performance. The results of this study show that the over-reinforced specimens were failed by concrete crushing prior to CFRP sheet failure by debonding or rupture. On the contrary, the under-reinforced specimen were failed by rupture of CFRP sheet.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.3
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• pp.173-181
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• 1989

A split-phase induction motor with asymmetrical magnetizing reactance axes develops starting torque and its efficiency can be high under certain conditions. In this paper, one method of producing the asymmetry of magnetizing reactance axes is described. The grain-oriented silicon steel core is used to produce the asymmetric axes instead of non-oriented silicon steel core which is used in general motors. The optimum design method for the motor is suggested and analyzed. To verify this suggestion, the permanent capacitor run type induction motors are designed to be driven at balanced condition by its asymmetrical effect, and then the oscillating torque due to the asymmetry of motor structures are analyzed. Tests of the sample motor have shown good performance comparable to ordinary types. This motor structure can be used where high effciency and reliability are required, and also the amount of core materials can be reduced due to its high permeability.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.347-348
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• 2017

This paper presents a new current balancing operation for LED using double-step-down dc-dc converter. The two output currents of the proposed converter can be balanced by charge balance condition although the two output resistances are different. In addition, voltage stresses of the switches of the proposed converter are lower than those of interleaved buck converter. To verify the operation of the proposed converter, simulation program is used.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.2
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• pp.58-64
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• 2004

Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, in the user power distribution systems, most of the loads are single & three phase and unbalanced, generating voltage unbalance. Voltage unbalance is a condition in a polyphase system in which the rms values of the line-to-line voltages or the phase angles between consecutive line-to-line voltages, are not all equal. Slight voltage unbalance generates a disproportionately high current unbalance at the motor stator winding. This paper presents a scheme on operation states of a three-phase induction motor under unbalanced voltages. The three-phase voltages applied to the stator winding of the studied induction motor are controlled by respectively adjusting the magnitude and phase angle of each phase. The voltage unbalanced factor(VUF) of the three-phase source voltages can then be varied to examine the different values of VUF on machine's operation characteristics.