• 대한기계학회논문집A
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• 제21권9호
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• pp.1432-1440
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• 1997

The flexibility as well as the stiffness is required to perform mechanical function of a structure such as compliant mechanisms, which can be applied to MEMS(Micro-Electro-Mechanical Systems), flexible manufacturing devices, and design for no assembly. In this paper, the optimal design problem to achieve both structural flexibility and stiffness is formulated using multi-objective function, and the optimization problem is resolved by using Finite Element Method(FEM) and Sequential Linear Programming(SLP). Design examples of compliant mechanisms are presented to validate the design method.

• 대한안전경영과학회지
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• 제6권4호
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• pp.1-10
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• 2004

As for the purpose of this study, education facilities must be considered by a change of an education facilities equipment acid education system and aromatic character of an educational policy with a means to support to efficiently proceed education by study about a plan of the school education facilities which considered safety. That is, education facilities must become maintenance on design construction according to education action character and goal. This is not for a function of education to be decided according to education facilities, and education facilities must be decided so that adjustment can do an education function. The student center, a student are convenient, and an actor must do a plan of education facilities with an usable physical space contrariety, future directivity. As for the plan of school education facilities, facilities must be designed on functionality, an economy, flexibility, aesthetic appreciation anger, a foundation of stability for this so that objective of education realization is easy.

• 한국해양공학회지
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• 제17권6호
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• pp.47-52
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• 2003

To determine the effect of transverse open crack on the dynamic behavior of simply-supported Euler-Bernoulli beam with the moving masses, an iterative modal analysis approach is developed. The influence of depth and position of the crack in the beam, on the dynamic behavior of the simply supported beam system, have been studied by numerical method. The cracked section is represented by a local flexibility matrix, connecting two undamaged beam segments that is, the crack is modeled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section, and is derived by applying a fundamental fracture mechanics theory. As the depth of the crack is increased, the mid-span deflection of the simply-supported beam, with the moving mass, is increased. The crack is positioned in the middle point of the pipe, and the mid-span defection of the simply-supported pipe represents maximum deflection.

• 한국경영과학회지
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• 제31권2호
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• pp.129-140
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• 2006

Quantity Flexibility contract coordinates individually motivated supplier and buyer to the systemwide optimal outcome by effectively allocating the costs of market demand uncertainty. The main feature of the contract is to couple the buyer's commitment to purchase no less than a certain percentage below the forecast with the supplier's guarantee to deliver up to a certain percentage above. In this paper we refine the previous models by adding some realistic features including the upper and lower limits of the purchase. We also incorporate purchase and canceling costs in a cost function to reflect the real world contracting process more accurately. To obtain the solution of the model, we derive a condition for extreme points using the Leibniz's rule and construct an algorithm for finding the optimal solution of the model. Several examples illustrating the algorithm show that the approach is valid and efficient.

• 국제물리치료학회지
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• 제9권1호
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• pp.1387-1392
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• 2018

The purpose of this study was to investigate the effect of fall injuries on the balancing abilities and ankle flexibility. Fifteen of the voluntary participants had no experience of falling in the last two years (none falling group, NFG) and 15 others experienced at least one (falling group, FG). Static balance (sway length, sway area), dynamic balance (timed up and go (TUG), and functional to reach test (FRT) were measured in each group. In comparison of static balance, sway length was not significantly different between NFG and FG in both eyes open and eyes close, however the sway area of the FG was significantly wider than that of the NFG (p<.05). In dynamic balance comparisons, TUG of FG was significantly longer than that of NFG (p <.05), however FRT and STS were no significant difference between groups. Ankle flexibility was significantly higher in NFG than in FG. This study suggests that the fall prevention program should include methods for improving ankle stability and lower extremity function.

• 대한건축학회논문집:구조계
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• 제34권1호
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• pp.27-32
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• 2018

This work provides the analytical methods to represent the updated form of stiffness or flexibility matrices using the measurements of the first few natural frequencies and the corresponding mode shapes. This study derives the mathematical forms on the variance of stiffness or flexibility matrices to minimize the performance index in the satisfaction of the eigen-function including the residual force depending on the measured data. The proposed methods can be utilized in detecting damage and updating the parameter matrices deviated from the analytical parameter matrices. The validity of the proposed methods is investigated in a numerical experiment of truss structure and the numerical results of stiffness-based and flexibility-based methods are compared. The sensitivity to the external noise is also examined for applying to the practical work.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.555-561
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• 2019

본 연구의 목적은 제주도 하우스감귤의 출하구조를 순별, 월별로 구분하여 분석하는 것이다. 이를 위해 제주도 하우스감귤의 가격신축성함수를 추정, 분석함으로써 어떻게 출하조절을 하는 것이 하우스감귤농가의 소득을 안정 증대시킬 수 있는지를 모색하고, 정책적 시사점을 도출하는 것이다. 제주도 하우스감귤의 순별 가격신축성은 시기에 따라 상이하게 나타나고 있는데, 6월 상순에서 7월 하순까지의 하락폭이 큰 것으로 나타나 이 시기의 출하조절의 필요성이 크다. 품질이 떨어지는 해를 나타내는 더미변수인 DUM_Q의 부호는 음(-)이고, 통계적으로 유의미한 결과를 보여주고 있다. 추석이 10월에 들어있는 해를 나타내는 더미변수인 DUM_SUK의 10월 중순부터 하순까지의 부호가 음(-)을 보이고 있다. 하우스감귤의 출하물량 1% 증대에 따른 월별 가격신축성은 상이하게 나타나고 있는데, 6월에서 7월과 9월에서의 하락폭이 큰 것으로 나타나 이 시기의 출하조절의 필요성이 요구된다. 월별 가격신축성함수의 더미변수인 DUM_Q 및 DUM_SUK의 부호는 음(-)이고, 통계적으로 유의미한 결과를 보여주고 있다. 따라서 순별 및 월별 가격신축성함수의 더미변수인 DOM_Q와 DUM_SUK의 부호가 음(-)을 보인다는 것은, 품질이 좋은 해보다 품질이 나쁜 경우에, 그리고 추석이 9월에 있는 경우보다 10월에 있는 경우에 출하조절의 필요성이 더 중요함을 의미한다.

• Journal of the Korean Statistical Society
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• 제36권1호
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• pp.93-109
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• 2007

Gamma distributions are some of the most popular models for hydrological processes. In this paper, a very flexible family which contains the gamma distribution as a particular case is introduced. Evidence of flexibility is shown by examining the shape of its pdf and the associated hazard rate function. A comprehensive treatment of the mathematical properties is provided by deriving expressions for the nth moment, moment generating function, characteristic function, Renyi entropy and the asymptotic distribution of the extreme order statistics. Estimation and simulation issues are also considered. Finally, a detailed application to drought data from the State of Nebraska is illustrated.

• 융합정보논문지
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• 제9권10호
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• pp.133-143
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• 2019

본 연구의 목적은 조기영어학습 경험의 유형에 따른 실행기능의 차이를 분석하는 것이다. 연구대상은 어학원에서 몰입식 영어교육 경험을 가진 23명의 유아, 어린이집에서 방과후 영어학습 경험을 가진 52명의 유아, 총 75명을 대상으로 삼았다. 연구도구는 주의통제의 경우 스트룹 과제, 인지적 융통성의 경우 카드분류과제와 숫자 따라 외우기 소검사, 정보처리의 경우 도안 유창성, 목표설정의 경우 미로 소검사를 사용하여 측정하였다. 자료분석은 전체지능지수를 공변인으로 한 공분산분석을 적용하였다. 연구결과 첫째, 주의통제와 인지적 융통성은 조기영어학습의 유형에 따라 유의한 차이를 보였다. 둘째, 정보처리와 목표설정은 조기영어학습의 유형에 따라 어떠한 차이를 보이지 않았다. 본 연구는 전일제 조기영어학습의 경험이 주의통제와 인지적 융통성에는 긍정적인 영향을 미치는 반면, 정보처리와 목표설정에는 어떠한 영향도 미치지 않음을 시사한다.

• Wind and Structures
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• 제16권1호
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• pp.61-91
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• 2013

An analytical model of internal pressure response of a leaky and quasi-statically flexible building with a dominant opening is provided by including the effect of the envelope external pressure fluctuations on the roof, in addition to the fluctuating external pressure at the dominant opening. Wind tunnel experiments involving a flexible roof and different building porosities were carried out to validate the analytical predictions. While the effect of envelope flexibility is shown to lower the Helmholtz frequency of the building volume-opening combination, the lowering of the resonant peak in the internal and net roof pressure coefficient spectra is attributed to the increased damping in the system due to inherent background leakage and envelope flexibility. The extent of the damping effects of "skin" flexibility and background leakage in moderating the internal and net pressure response under high wind conditions is quantified using the linearized admittance functions developed. Analytical examples provided for different combinations of background leakage and envelope flexibility show that alleviation of internal and net pressure fluctuations due to these factors by as much as 40 and 15% respectively is possible compared to that for a nominally sealed rigid building of the same internal volume and opening size.