• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.179-183
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• 1989

This study presents a methodology to choose the optimal parameter of controller by using the performance index sensitivity. The pro-posed method is to select the controller parameter to have the minimum sensitivity. It is shown that the optimal parameter proves the effectiveness in the dynamic stability of power system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.534-534
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• 2000

This paper proposes a dynamic compensation scheme for input-constrained feedback linearizable nonlinear systems to cope with the windup phenomenon. Given a feedback linearizing controller for such a nonlinear system designed without considering its input constraint, an additional dynamic compensator is proposed to account for the constraint. This dynamic anti-windup is based on the minimization of a reasonable performance index, and some stability properties of the resulting closed-loop are presented.

• 제어로봇시스템학회논문지
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• 제6권8호
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• pp.672-681
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• 2000

Based on the dynamic anti-windup strategy a novel control methodology for state constrained control systems is presented. First a linear controller is designed for an open-loop stable plant to show a desirable nominal performance by ignoring state constraints. And then an additional dynamic compensator is introduced to preserve the nominal performance as closely as possible int he face of state constraints. This paper focuses on the second step under the assumption that a linear controller has already been designed appropriately by using an effective controller design method. By minimizing a reasonable performance index the dynamic compensator is derived explicitly which is expressed int he plant and controller parameters. the proposed method not only guarantees the total stability of the overall resulting systems but also provides desirable output performance because it solves the state-positioning problem completely.

• 한국화재소방학회논문지
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• 제17권1호
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• pp.33-39
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• 2003

본 논문에서는 벽지의 방염성능 및 열 안정성을 평가하고 연소가스인 CO, $CO_2$, HCN, HCl의 독성지수를 정량적으로 독성평가를 하여 벽지의 종합적 화재 위험성을 평가하였다. 방염성능은 방염성능기준인 45。 연소실험방법으로 열 안정성은 DSC분석과 TGA분석으로 평가하였다. 그리고 독성평가는 CO, $CO_2$, HCN, HCl 연소가스의 농도를 NIST N-GAS Model에 적용하여 독성지수로서 평가하였다. 위의 평가로 얻은 연구결과는 다음과 같다. 첫째, 방염성능 평가결과 방염한 종이벽지, 콜크벽지, PVC벽지는 방염성능 기준에 적합한 것으로 나타났다. 둘째, 열 안정성 평가인 DSC분석 결과 미방염한 종이벽지, 콜크벽지, PVC벽지가 방염한 것보다 상대적으로 저온부에서 발열개시가 되었으며, 더 많은 발열량을 내었으므로 열적으로 더 위험하였다. 그리고 TGA분석 결과 미방염한 종이벽지, 콜크벽지, PVC벽지의 분해속도가 방염한 것보다 휠씬 빨랐으므로 열 분해 위험성이 더 크다고 판단된다. 셋째, 연소가스 독성평가 결과는 방염한 종이벽지, 콜크벽지, PVC벽지가 미방염한 것보다 독성지수가 더 높게 나타났다. 또한 종이벽지와 콜크벽지보다 PVC벽지가 상대적으로 독성지수가 더 높음을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2471-2474
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• 2003

This paper focuses on the stability and operability of a man-machine system considering a human operator. Some papers' main interest has been the stability only, but the operability such as fatigue is also the other main interest. In a man-machine system, feelings such as motional, visual, and kinesthetic are important since those enable operators to work easily or fatigue operators. A model of a man-machine system has been developed. Motional, visual, and kinesthetic feelings may be considered as feedbacked sensor signals. We also have quantified the degree of fatigue with respect to reference operation. This is a performance index to be optimized. Several methods are presented to optimize the degree of fatigue and the stability of the integrated system. Examples are presented to show that the usefulness of the proposed modeling method and fatigue mitigating algorithm.

• PNF and Movement
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• 제12권4호
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• pp.249-258
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• 2014

Purpose: This study examines deficits in upper-extremity function and trunk control ability on the osmotic demyelination syndrome of a patient with Hyponatremia and Hypokalemia. Using a proprioceptive neuromuscular facilitation program, this case report aims to describe the effects of trunk stability exercises on trunk control ability, hand function, and daily living activities as well as its effects on the osmotic demyelination syndrome of a patient with Hyponatremia and Hypokalemia. Methods: The patient is a 47-year-old woman with osmotic demyelination syndrome as well as trunk and upper extremity impairment. She participated in this training intervention for four weeks. Results: The patient demonstrated improvements in trunk control ability, hand function, and performance of ADL. The following outcomes were measured before and after the training program: trunk impairment scale, hand power, Jebsen-Taylor hand function test, the Chedoke arm and hand inventory, and the modified Barthel index. Conclusion: The results suggest that trunk stability exercises in the form of a proprioceptive neuromuscular facilitation program in Hyponatremia and Hypokalemia patients may increase trunk control ability, increase hand function, and improve ADL.

• 유통과학연구
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• 제15권12호
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• pp.95-102
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• 2017

Purpose - This study aims to develop diagnostic indices for managerial performance of agro-food distribution corporations. In particular, weights of diagnostic indices were estimated using the AHP method. Management diagnosis on agro-food distribution corporations is expected to increase their competitiveness in the domestic market as well as in international markets. Research design, data, and methodology - It develops weights or importance of the diagnostic indices based upon the survey of 21 experts in food distribution management. The survey was carried out using e-mail. Management diagnostic indices were developed based upon four BSC(Balanced Scorecard) perspectives of finance, learning/growth/leadership, customer, and internal process/technology. Results - Diagnostic indices on financial perspective consist on profitability, productivity, growth, stability and activity. Learning and leadership perspective indices consist of management will, CEO leadership, level of learning, innovation, and level of management information system. Customer perspective indices are branding, customer and channel management and internal process/technology indices consist of fourteen sub-indices representing technologies, efficiency, and dynamics. It was estimated that the weight of financial perspective index was 0.3, internal process/technology perspective index 0.248, customer category index 0.247, and learning, growth and leadership perspective index 0.205. This study also estimates weights of sub-indices for managerial diagnosis by four different perspectives. Estimated weight of profitability (0.085) is the greatest among financial perspective indices, followed by stability (0.072), growth (0.053), productivity (0.051), and activity (0.038). While estimated weights of leadership, capability, and information indices are 0.100, 0.061, and 0.044 respectively, weights of marketing, customer management, and quality and service indices are 0.104, 0.093, and 0.051, respectively. Among internal process/technology perspective, estimated weights of efficiency, technology, and innovation indices are 0.106, 0.088, and 0.054, respectively. Conclusions - The diagnostic indices for managerial performance of agro-food distribution corporations would be utilized by agro-food distribution corporations themselves, extension service institutions, and consultants. It is also expected that central and local governments use diagnostic indices developed in this study for the purpose of evaluating the effects of governmental support programs for agro-food distribution corporations. Futhermore researchers and consultants would modify diagnostic indices developed in this study, reflecting characteristics and situation of types of agro-food distribution corporations.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.49-49
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• 2009

Phosphors with oxide host material, YAG:$Ce^{3+}$ and $(Ca,Sr,Ba)_2SiO_4:Eu^{2+}$ yellow phosphor, has been used for LED applications. The WLEDs using these phosphors are widely used for LCD backlighting, automobile, and general lighting applications since they have high conversion efficiency and good thermal and chemical stability which can meet necessary life time of LED products up to now. With advances of LED chip technology, the external quantum efficiency and driving current in chip get higher so that the phosphors for high power chip are required to maintain high conversion efficiency and stability at high temperature due to the heat dissipated from LED chips. In addition, higher color rendering index of LED lighting and color reproducibility of LCD than those of LEDs with single yellow phosphors are required. In order to overcome these technical issues rising from evolution of LED technology, new phosphors are in demand and nitride phosphors, one of the promising new candidate materials, will be discussed here.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.421-428
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• 1998

Sensitivity analysis of suspension elements of an articulated bogie for light railway vehicles is presented. The ride, stability and safety are used as dynamic performance index. Suspension elements of 10 and a conicity of wheel are used as design variables, To analyze sensitivity of design variables, the railway vehicle dynamics analysis program AGEM is used. The results shows that the secondary suspension elements have a strong effect on ride and the primary suspension elements have a moderate effect on ride. Conicity of wheel has a strong effect on the stability, The safety is not effected by all the design variables.

• 항공우주시스템공학회지
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• 제15권2호
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• pp.16-25
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• 2021

Reliability of fatigue strength on Aircraft Composites(GFRP) Structures was assessed in this paper. Fatigue strength of GFRP was used through the existing fatigue test data with Monte Carlo method. The S_a-N_f curve of composites fatigue strength was assumed as normal distribution and reliability was analyzed using SSIT model. Fatigue stress was designed IAW ASTM F3114-15 with special safety factor of S_sf=1.2~2.0. Reliability was calculated by analytic method and FORM. Sensitivity for the effect of mean and standard deviation of fatigue strength as well as fatigue stability was evaluated. This result can be usefully applied to reliability and fatigue design for composite structures of light weight aircraft.