• Journal of the Korea Institute of Information and Communication Engineering
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• 제12권1호
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• pp.115-121
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• 2008

This paper presents a new sustain driver employing energy recovery function to minimize power losses transpired during the operation of plasma display panel. The proposed circuit uses the resonance between the equivalent capacitance of panel and an external inductor to provide/recover energy to/from the panel. The proposed circuit can save the system cost compared with the conventional one, and has high-performance in energy recovery. To verify the validity of the proposed circuit, we implemented experiments based on 7.5 inch AC-PDP.

• Korean Journal of Labor Studies
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• 제17권1호
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• pp.243-267
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• 2011

This paper explores the impact of the external workers on employment performance in Korea, using Workplace Panel Survey (WPS). I find the use of external workers, e.g., temporary agency workers, in-subcontract workers, and contract workers, is mainly negatively related with employment performance. Especially the use of in-subcontract workers and contract workers is negatively related with the job creation rate of standard workers and the net growth rate of internal workers. The results show the existence of a substitute effect between the use of internal and external workers.

• Journal of the Korea Concrete Institute
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• 제14권4호
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• pp.483-491
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• 2002

This paper summarizes the results of experimental studies concerning the flexural strengthening of reinforced concrete beams by the external bonding of the new reinforcement material, which is composite panel with an advanced fiber sheet bonded on light concrete precast panel. The structural behaviors of strengthened beams are compared with codes in terms of yield load and ultimate load, deflection, flexural stiffness, ductility. Thirty nine large-scale beams were tested experimentally to evaluate the strength enhancement provided by the composite panel. According to the results, it is shown that beams strengthened with composite panel are structurally efficient and that the strength of the strengthened beams are improved comparing with beams strengthened with fiber sheet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.685-688
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• 2005

An efficient sustain driver and a useful reset circuit composition technique are proposed for plasma display panel drive. The proposed sustain driver uses a series resonance between an external inductor and a panel to recover the energy dissipated by a capacitive displacement current of PDP. It consists of four switching devices, an inductor, and external capacitors, which supply sustain voltage sources. Although the amplitude of an input voltage source is twice as high as that of conventional sustain drivers, average voltage stress imposed on power switching devices is nearly same in their values. Moreover, the input voltage source can be directly applied for the use of a reset voltage source. Owing to this scheme, the proposed sustain driver and the embedded reset circuit have a simple configuration. The operational principle and design example are given with theoretical analyses. The validity of the proposed drive system is verified through experiments using a prototype equipped with a 7.5-inch-diagonal AC plasma display panel.

• Human Ecology Research
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• 제60권4호
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• pp.497-505
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• 2022

This study aims to examine the mediating role of peer attachment between affective school environments and the problematic behaviors of children using data from the Panel Study on Korean Children 10th wave (2017). Descriptive statistics, reliability analysis, correlation analysis, multiple regression analysis, Sobel test, and bootstrapping versification were performed using SPSS 28.0 and Process Macro 28.0. The results indicate that controlled and rigid school environments were negatively associated with peer attachment and positively associated with both internal and external behavior problems. Furthermore, peer attachment was negatively associated with both internal and external behavioral problems. Peer attachment completely mediated the link between affective school environments and internal behavioral problems, and partially mediated the link between affective school environments and external behavioral problems. These results show the important role of supportive and democratic school environments regarding peer attachment.

• Advances in concrete construction
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• 제9권5호
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• pp.459-467
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• 2020

Mechanical and thermal properties of composite sandwich wall panels are affected by changes in their external environment. Humidity and temperature changes induce stress on wall panels and their core connectors. Under the action of ambient temperature, temperature on the outer layer of the wall panel changes greatly, while that on the inner layer only changes slightly. As a result, stress concentration exists at the intersection of the connector and the wall blade. In this paper, temperature field and stress field distribution of UHPC-RW-RC (Ultra-High Performance Concrete - Rock Wool - Reinforced Concrete) wall panel under high temperature-sprinkling and heating-freezing conditions were investigated by using the general finite element software ABAQUS. Additionally, design of the connection between the wall panel and the main structure is proposed. Findings may serve as a scientific reference for design of high performance composite sandwich wall panels.

• Journal of the Society of Naval Architects of Korea
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• 제29권2호
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• pp.115-122
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• 1992

A sandwich element is a special Hybrid structural form of the composite construction, which is consisted of three main parts : thin, stiff and relatively high density faces separated by a thick, light, and weaker core material. In a sandwich construction, the shear deformation of the faces. Therefore, in the calculation of the bending stiffness, the shear effect should be included. In this paper, the minimum weight is selected as an object function, as the weight critical structures are usually composed of these kind of construction. To obtain the minimum weight of sandwich panel, the principle of minimum potential energy is used and as for the design constraints, the allowable bending stress of face material, the allowable shear stress of core material, the allowable value of panel deflection and the wrinkling stress of faces are adopted, as well as the different boundary conditions. For the engineering purpose of sandwich panel design, the results are tabulated, which are calculated by using the nonlinear optimization technique SUMT.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.250-253
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• 2008

A touch screen panel embedded 12.1-inch TFT LCD employing a standard a-Si:H TFT process has been successfully developed. Compared with conventional external touch screen panels, the new internal TSP exhibits a clearer image and improved touch feeling. Our new internal proposed TSP can be fabricated with low cost.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.85-89
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• 1999

FDE panel was successfully fabricated through the integration of a 0.7" diagonal Si-based Mo-tip FEA with 25${\times}$25 pixels, Y2O3:Eu or ZnO:Zn phosphor screen, and vacuum sealing through an exhausting glass tube, including a getter. The panel system was driven by an external driver circuit having pulse width modulation(PWM) driving scheme. Before character imaging, it was stabilized through tip aging by slowly increasing a pulse-mode emission current and phosphor aging by a coulombic charging process. After aging, luminescent characteristics such as emission uniformity, charging and arcing phenomena were shown to be improved significantly.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1515-1516
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• 2006

The low luminous efficacy is one of the major demerits of plasma display panel (PDP). In this work we propose the new driving method for high efficiency AC-PDP and analyze its discharge characteristics. The suggested method can control the effective capacitance of panel by external circuit. As a result of the new suggested method, the current becomes less and the discharge time becomes long, because of voltage distribution between panel and auxiliary capacitor. So this method can decrease the power consumption much more than that of the conventional driving method.