• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.340-342
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• 2003

본 연구의 목표는 난연화를 위한 기존 공법의 단점 보완과 환경 친화적인 난연제를 사용한 비 난연 XLPE 케이블의 난연화 방법과 최적의 난연 코팅액 배합에 있다. 전력용, 통신용 등과 같이 고난연성이 요구되는 경우 기존 컴파운드 방법으로는 난연제를 다량으로 첨가하여 사용하며, base polymer와의 혼합성, 기계적인 물성에도 영향을 끼쳐서는 안되는 등 여러 가지 요구 조건을 만족시켜야 하는 문제점을 가지고 있다. 각 난연 코팅액에 따른 코팅 표면을 고찰한 결과 모든 코팅의 표면은 깨끗하였으며, 코팅층의 두께는 약 10～20 ㎛로 일정하게 코팅이 되었다. Mg(OH)₂/Zinc Borate의 경우는 무게비(wt％)가 1 : 0.5, 1: 0.6에서 난연 효과를 보였으나. 1 : 0.7이상에서는 유연성이 떨어져 코팅층의 균일이 발생하여 연소 테스트시 난연 효과가 떨어지는 현상을 볼 수 있었다. Mg(OH)₂/AF100 S/Zinc Borate의 경우는 AF100 S의 첨가량이 증가할수록 탄화막 형성되어 난연성이 향상되었다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.2
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• pp.89-96
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• 2012

Based on the hydroelastic theory and the matched eigenfunction expansion method(MEEM), the dynamic behavior of the porous flexible net sheet and wave forces have been investigated in monochromatic waves. The net sheet is installed vertically with the submergence depth. Top end of a net sheet is fixed and its lower end is attached by a clump weight. It is assumed that the initial tension is sufficiently large so that the effects of dynamictension variation can be neglected. The boundary condition on the porous flexible net sheet is derived based on Darcy's fine-pore model and body boundary condition. The developed analytic model can be extended to the impermeable/permeable vertical plate and the impermeable flexible membrane. The analytical model was used to study the influence of design parameters(wave characteristics, porosity, submergence depth, initial tension) on the response characteristics and wave load of the net sheet.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.157-166
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• 2020

Firms perform various actions that affect management performance measurement by managing the volatility and capital cost of reported income through income smoothing. This study attempted to analyze with a focus on the relationship between managerial competence and income smoothing. Therefore, this study attempted to analyze and focus on the relationship between managerial competency and profit softening using a measure of managerial competency presented in Demerjian et al. (2012). The results of the analysis are as follows. It was confirmed that there was a significant positive relationship between manager ability and income smoothing at the 1% level. When managers make income, it can be interpreted that managers with superior ability can make profits better by accurately predicting the future. It is the same result as the expectation of this study that managers with excellent ability have high incentives to soften profits by reducing profit volatility through more accurate forecasting. Therefore, this study empirically analyzed that managers with excellent abilities are more effective in implementing income smoothing strategies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.21-29
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• 1987

In this paper the liquid sloshing effects in vertical storage tanks under earthquake loadings are studied. The study focuses on the investigation of the effect of the flexibility of the tank wall on the hydrodynamic forces exerted on it. The tank structure is modelled using finite elements. The motion of the liquid is expressed by the Laplace equation. The equation of motion of the fluid shell system is formulated including the coupling effect between the shell motion and the sloshing motion. A procedure is developed to obtain the natural frequencies and the mode shapes of the sloshing motion as well as the shell vibration. Dynamic analyses have been carried out for several tanks with different dynamic characteristics utilizing the time history method as well as the response spectra method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2406-2414
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• 2013

The data-driven IT project model has been improved by adding processes such as analysis/design of data structure and channels of data collection/distribution, application of data standard and securing the flexibility in IT convergence devices data configuration on existing informatization project procedure driven by HW and SW function. This model focused on the evaluation of improvement effect which warrants data flexibility of IT convergence device. IT convergence device was divided into sensor and reactor and a situation when new information system is additionally linked to these devices was assumed. The system improvement complexity and index on network environment were estimated and they were compared to existing method.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1345-1353
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• 2021

The purpose of this study was to investigate the effects of 6 weeks hip joint strengthen on muscle strength, dynamic posture control and low extremity injury criterion. Twenty athletics were divided into two groups, the exercise group was conducted for three times a week, 60 minutes, and six weeks. The dependent variables of this study were flexibility, muscular strength, dynamic posture control, and lower body injury criterion. The results of this study showed that the flexibility was not significant, but muscle strength was significant difference. The dynamic posture control was significantly effective in the left posterolateral and posteromedial. In addition, total score was significantly exercise effect, and there was no difference between left and right leg length. In conclusion, hip joint strengthen increased muscle strength and dynamic posture control, and decreased the concern of low extremity injury criterion.

• Journal of radiological science and technology
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• v.34 no.2
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• pp.141-147
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• 2011

We developed an alternative radiation shielding material which is economical and has high protection efficiency. We validated the material in the form of sheet to make an apron. We increased the rate of barium and mixed tourmaline into silicon to improve the flexibility and protection rate of the sheet. The results showed that the shielding effect at low radiation energy is good enough with both 5 mm and 7 mm thickness. In the future, we will perform a quantitative evaluation of the reproducibility, volumetric efficiency, and porosity in mixing the ingredients.

• 대한공업교육학회지
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• v.31 no.2
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• pp.364-380
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• 2006

This paper presents a procedure for designing command to maneuver flexible structure with very little residual vibration, even in the presence of modeling errors. For the open loop maneuver, the various shaped profiles using multiple step inputs delayed in time are considered for robustness and compared with the responses of rigid body and flexible body in virtue of simulations and experiments. Input shaping generates vibration-reducing shaped commands through convolution of an impulse sequence with the desired command. A flexible model with a cylindrical hub and four symmetric appendages is considered to examine the responses to real plant, and to illustrate the effectiveness of the proposed shapers. The appendages are long and flexible, leading to low frequency vibration under any control action. It is shown by a series of simulation that a properly designed feedback controller with input shaper performs well, as compared with open loop controller with input shaper. The control objective is to achieve a fast settling time of residual vibration to flexible structure and robustness (insensitivity)to plant uncertainty, to eliminate residual vibration.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.88-88
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• 2011

최근 소비자의 생활수준이 향상되면서 섬유제품에 대한 기술적인 요구가 증가하고 있는데 그 중에서도 기모제품을 응용한 원단에 대한 요구가 급격히 증가하고 있다. 특히 기모원단은 기모공정 후 원단에 존재하는 기모유연제를 처리하기 위해 정련공정을 거쳐야 하는데 대부분의 염색공장에서는 이를 무시한 채 염색을 하고 있다. 이 때문에 잔존하는 기모유연제에 의해 염색 불량을 발생하게 된다. 기모원단에서 정련공정을 생략할 수 있다면, 공정의 단축으로 인한 Cost 절감 효과뿐만 아니라 폐수 부하량도 감소하는 등 시장 및 환경적인 측면에서 동시에 경쟁력을 가질 수 있게 된다. 본 연구에서는 (주)한송인더스트리에서 생분해성을 가지는 환경친화형 기모유연제를 개발하여 이를 염색공정 중 함께 처리함으로써 전체 공정을 단축하고, 개발한 친환경 기모유연제가 염색성에 영향을 미치지 않는 것을 확인하였다. 또한 기존 유연제와 개발된 유연제를 염색공정에서 동일한 조건으로 처리 하였을 때, 기존 유연제 처리 시료는 표면의 불순물과 Oil의 잔존으로 흡습성이 떨어져 균염성 떨어졌고, 염색된 원단에서도 염색불량을 확인할 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1082-1089
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• 2004

In this paper, miniaturization of an elliptic-response open-loop resonator filter and design flexibility using similarity transformation of the coupling matrix are proposed. Moreover, the filter with wider fractional bandwidth is designed by the proposed method. In order to verify the proposed method, three 4th-order elliptic-response open-loop resonator filters with a relative bandwidth of 4 % at the center frequency of 2.0 GHz are designed. One is realized with constant-width microstrip line resonator and the others are implemented with different-width microstrip line resonator. Compared with the former one, the latter have shown the size reduction of 13 % and 25 %, respectively. Since it may not be possible to implement the resonators with very narrow spacing for the required coupling coefficient filters with two different configurations representing same response characteristic through similarity transformation of the coupling matrix are proposed. From this design flexibility, a filter with a relative bandwidth of 8 % at the center frequency of 2.0 GHz is designed with realizable design parameters.