• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.258-258
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• 2004

Successful cryopreservation of mammalian oocytes would provide a source of materials for in vitro embryo production. This study was conducted to determine vitrification conditions for bovine immature oocytes using micro-drop method and, to examine maturation, fertilization and development of vitrified bovine immature oocytes. (omitted)

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.197-202
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• 2012

Objective: The aim of this study is to introduce activities for job stress management in shipbuilding industry. Background: Recently, workers are exposed many job stress like workload, interpersonal conflict while management condition of company changes day by day. Particularly, shipbuilding industry has poor environment which aggravating the stress to the workers. So managing job stress may be more important. Method: The method of this study is to investigate preventive actions of job stress in "S" shipbuilding company. Results: This study through case of "S" shipbuilding company introduce activities of prevention of job stress including identification of level of job stress, managing of psychological clinic, training of worker and manager. Conclusion: In order to manage the job stress in the workplace, 1) The total management system based on the concern of the management in the workplace has to be constructed. 2) Computerized system for operation of total management system has to be constructed. 3) New employees need training for Job Stress. Application: Through this case study, I hope to help prevention activities of job stress in the workplace.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.6
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• pp.554-558
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• 2002

In this paper, we propose a robust indirect adaptive fuzzy state feedback regulator based on Takagi-Sugeno fuzzy model. The proposed adaptive fuzzy regulator is less sensitive to singularity than the conventional one based on the feedback linearization method. Furthermore, the proposed control method is applicable to not only plants with a perfect model but also plants with an imperfect model, which causes uncertainties. We verify the global stability of the proposed method by using Lyapunov method. In order to support the achievement, the application of the proposed adaptive fuzzy regulator to the control of a nonlinear system under the external disturbance is presented and the performance was verified by some simulation result.

• Structural Engineering and Mechanics
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• v.54 no.3
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• pp.561-577
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• 2015

The main objective of this paper is to study the dynamic load allowance (DLA) calculation methods for bridges according to the dynamic response curve. A simply-supported concrete bridge with a smooth road surface was taken as an example. A half-vehicle model was employed to calculate the dynamic response of deflection and bending moment in the mid-span section under different vehicle speeds using the vehicle-bridge coupling method. Firstly, DLAs from the conventional methods and code provisions were analyzed and critically evaluated. Then, two improved computing approaches for DLA were proposed. In the first approach, the maximum dynamic response and its corresponding static response or its corresponding minimum response were selected to calculate DLA. The second approach utilized weighted average method to take account of multi-local DLAs. Finally, the DLAs from two approaches were compared with those from other methods. The results show that DLAs obtained from the proposed approaches are greater than those from the conventional methods, which indicate that the current conventional methods underestimate the dynamic response of the structure. The authors recommend that the weighted average method based on experiments be used to compute DLAs because it can reflect the vehicle's whole impact on the bridge.

• Korean Journal of Materials Research
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• v.19 no.6
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• pp.330-336
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• 2009

The size of crystallites in mono-dispersed cubic silver bromide grains was measured by applying a powder X-ray diffraction method and Scherrer's equation to grains that were suspended in swollen gelatin layers. In order to evaluate the existence of defects, the measured crystallite size was compared to those measured by using a scanning electron microscope. In the case of the grains prepared by the controlled double jet method, the size of crystallites was equal to the edge length of the grains that had edge lengths smaller than 400 nm. This result proved the usefulness of the above-stated method for measuring the size of crystallites and also evaluating the presence of any crystal defect in each grain. In the case of the grains, which were precipitated in the presence of a sensitizing dye and potassium iodide, the size of crystallites was smaller than the edge's length, indicating the discontinuities in the grains introduced during the precipitation process.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1995.10a
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• pp.53-59
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• 1995

The accurcy and the application limits of the Three-Curve Method(TCM) and Zonal Cavity Method(ZCM) are evaluated. Average illuminance values are calculated by TCM and ZCM for various lighting conditions using general Diffusing Luminaires and Direct Luminaires. These values are compared with the values from Monte-Carlo Simulation(MCS) for the same lighting conditions. Accuracy of MCS was proved by Moon's Analytical Method.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.611-613
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• 2001

In this paper, the force test of arch-type LIM is treated. The method of direct measurement is used load-cell on 3-component force guage. Indirect method is used search coil on LIM. PC-based data aquistion system include two method and measure the force in driving state. Measured data of direct and indirect method are analyzed and compared.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.180-186
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• 2000

This paper presents a new winding method in the electronic descaling(ED) technology. The ED technology Produces an oscillating electric field via the Faraday's law to Provide necessary molecular agitation to dissolved mineral ions. But present method gives another agitation force to mineral ions, which is Lorentz's force. Experiments were peformed at various Renolds number. A series of tests was conducted, measuring pressure drop across test section and the overall heat transfer coefficient as a function of time. In order to accelerate the rate of fouling, artificial hard water of 1000ppm $CaCO_3$ was used throughout the tests. The results show that the new method accelerates collision of mineral ions and improvs efficiency of system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.161-165
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• 1969

Since Guha and Maheshwari's works on the induction of haploid plant from the cultured anther of Datura innoxia an her culture has become a big topic among geneticists and breeders. Presen paper is the summarized report on the anther culture method based on the author's recent researches.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.11 s.116
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• pp.1158-1164
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• 2006

For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.