• 한국해안·해양공학회논문집
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• 제25권6호
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• pp.405-411
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• 2013

점착성 표사의 유동 특성을 다루기 위하여 점착력을 고려한 표사유동 수치계산 모델이 제안되었다. 제안된 계산 모델에서는, 각각의 모래 입자는 점토의 얇은 층으로 둘러싸여 있는 상태를 가정했다. 모래 입자에 작용하는 점착력을 적용하기 위해 한계 Shields수와 소류사량을 결정하는 항이 수정되었다. 제안된 표사모델은 3차원 유체 구조 지형변화 연성 수치계산 모델에 적용하여, 인공여울의 지형변화특성을 파악하였다. 수치계산 결과, 각각의 점토 함유율, 단위면적당 작용하는 점착 저항력, 함수비의 증가는 한계 Shields수를 증가 시키고, 반대로 소류사량을 감소시킴으로써 지형변화 경향에는 영향을 미치지 않은 채 여울의 지형변화를 억제하는 것으로 나타났다. 점토를 모래 입자와 혼합함으로써 여울의 지형변화를 감소시킬 수 있는 것을 암시한다.

• 대한후두음성언어의학회지
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• 제19권2호
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• pp.142-145
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• 2008

Background and Object: The aim of this study is to evaluate the change of patient's subjective voice handicap index (VHI) and acoustic parameters before and after laryngeal microsurgery for benign vocal cord disease. Materials and Method: We analyzed 78 patients who received laryngeal microsurgery for benign vocal cord disease from January 2004 to February 2007 retrospectively. There were 28 vocal polyp, 40 vocal nodule, 5 intracordal cyst and 5 Reinke's edema. Jitter, shimmer, harmony to noise ratio (HNR) were analyzed before surgery and 2-3months after surgery using the Doctor's speech science program. The voice handicap index introduced by the Pittsburgh Voice Center was used to examine patient's subjective change of voice quality. Results: Acoustic parameters of jitter, shimmer and HNR were improved in patients with vocal polyp and vocal nodule after surgery. The acoustic parameters were not improved in patients with Reinke's edema, statistically. Only jitter was improved significantly in patients with intracordal cyst (p<0.05). The VHI was significantly improved after surgery. The change of jitter and shimmer was significantly correlated with the change of VHI after surgery. Conclusion: The acoustic parameters and VHI were significantly improved in patients with benign vocal disease after laryngeal microsurgery.

• 지능정보연구
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• 제12권4호
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• pp.51-60
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• 2006

정성적 추론은 자연 세계에 대한 정성적, 직관적인 지식을 밝혀내어 코드화하는 목표를 갖고 연구되어 왔다. 정성적 추론은 전자, 기계 등의 도메인에서 성공적으로 사용되어 그 실효성을 입증할 수 있었으나, 대부분의 추론은 시뮬레이션에 집중되어 왔다. 본 연구에서는 주어진 상황에서 변화가 발생했을 때, 이 변화가 어떻게 영향을 미치며 파급되는지를 예측할 수 있는 정성적 비교분석 기법을 소개하고자 한다. 본 연구에서는 파라미터의 상대적인 변화의 파급만을 예측한 기존의 연구에 상대적 변화의 증가율 변화에 대한 추론을 추가하여 확장하였다. 상대적인 주어진 상황에 대한 인과모델이 정성적 분야 모델로부터 형성되고, 여기에 비교분석 추론 기법을 적용하여 변화의 연쇄적인 인과 관계를 추적하게 된다. 이러한 기법은 변화의 예측 뿐 아니라, 이런 변화를 이끌어낸 인과 관계를 설명하는 기능을 제공하게 되어, 디자인, 진단, 지능형 교육 시스템, 환경 영향평가 등에 이용되리라 기대된다.

• 대한안전경영과학회지
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• 제10권2호
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• pp.225-235
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• 2008

It is expected that the change of industrial structure of Knowledge based economy, and service based economy would affect on economic life of physically-challenged person with no exceptions. There have been some former studies which have been misunderstood the employment of disabled due to the declining employment of the disabled and prejudice to the disabled based on biased perspective and public opinion. This study have analyzed the employment conditions of the ordinary workers and disabled workers out of those prejudices and biased opinions. Wage, economic activity ratio, age, educational background and industry those 5 parameters are brought for analyzing the two comparison group. Each parameter have compared based on the statistical data of ordinary workers and disabled workers for past 7 years. Weight between each parameter have been drawn by collecting the experts' opinion using AHP(Analytic Hierarchy Process), and utility of employment of two comparison groups have been estimated through progress inclination of each parameter. Through the estimated outcome, present condition and controversial issues and way of improvement of domestic employment of ordinary workers and the disabled is mentioned.

• 대한토목학회논문집
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• 제14권1호
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• pp.195-202
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• 1994

본 연구에서는 모래의 전단파괴 포락선의 곡률특성을 구명하고 전단강도와 Been과 Jefferies가 제시한 상태정수간의 매개변수관계를 밝히기 위하여 많은 압밀배수삼축시험의 결과를 분석하였다. 통상적인 삼축시험에서 시료의 단면적 변화와 멤브레인의 영향에 대한 수정은 특히 한계상태를 결정하는데 중요하다고 할 수 있다. 실험결과로부터 전단강도를 밀도와 응력수준의 함수로 표현하는 모델을 제시하였고 모래의 전단파괴포락선의 곡률특성과 상태정수와 전단강도정수간의 관계를 밝혔다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.180.2-180.2
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• 2010

The purpose of this research is to analyze the sensitivity of WindSIM in complex terrain. As the flat areas for wind turbine installation become scarce globally, it becomes inevitable to install wind turbines in complex terrain. In order to predict annual energy production (AEP) in a more precise manner in complex terrain, it is of great importance to conduct such research. Three parameters: reference velocity, roughness and resolution have been chosen to see to which parameter WindSIM was the most sensitive in terms of annual energy production in complex terrain. By fixing two parameters and setting one parameter as a variable, it could be easily found that how annual energy production was effected by the change in each parameter.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권1호
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• pp.11-16
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• 2005

This paper considers a robust observer-based H/sub ∞/ controller design method for singular systems with parameter uncertainties using an LMI condition. The sufficient condition for the existence of controller and the controller design method are presented by a perfect LMI condition in terms of all variables using singular value decomposition, Schur complement, and change of variables. Therefore, one of the main advantages is that a robust observer-based H/sub ∞/ controller can be established by solving one LMI condition compared with existing results. Numerical example is given to illustrate the effectiveness of the proposed controller design method.

• 산업경영시스템학회지
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• 제20권41호
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• pp.15-23
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• 1997

Because of various request of consummer and rapidly chang, a product change and new-production come out variously. To satisfy the condition, companies must develop the product of rapidity and good quality. But, a product design difficults to consider many parameters and increase the level of each parameter. In order to solve this problem, this paper studies out algorithms taken into account more parameters and increased the level of parameters using the Genetic Algorithms. Because this algorithm can search detailed and wide for the level of parameter, in case of new-product development, we can use it for designing parameters of new-product.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1919-1924
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• 2006

In this study, the run-up of water waves on slopes of s-berm breakwaters was investigated by performing a series of hydraulic experiments. The run-up height was analyzed in detail by using the effects of wave steepness and surf similarity parameter. In general, the run-up heights were decreased as the height and the width of berm were increased. However, the variation of run-up height was small for change of wave steepness and surf similarity parameter.

• 전기학회논문지
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• 제57권1호
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• pp.20-24
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• 2008

A bid-based pool(BBP) model is representative of energy market structure in a number of restructured electricity markets. Supply function equilibrium(SFE) models of interaction better match what is explicitly required in the bid formats of typical BBP markets. Many of the results in the SFE literature involve restrictive parametrization of the bid cost functions. In the SFE models, two parameters, intercept and slope, are available for strategic bidding. This paper addresses the realistic competition format that players can choose both parameters arbitrarily. In a fixed demand function, equilibrium conditions for generation company's profit maximization have a degree of freedom, which induces multi-equilibrium. So it is hard to choose a convergent equilibrium. However, consideration of stochastic demand function makes the equilibrium conditions independent each other based on the amount of variance of stochastic demand function. This variance provides the bidding players with incentives to change the slope parameter from an equilibrium for a fixed demand function until the slope parameter equilibrium.