• Steel and Composite Structures
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• 제42권4호
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• pp.477-487
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• 2022

The shear stiffness of headed-stud shear connectors has no unified definition due to the nonlinear characteristics of its load-slip relationship. A unified framework was firstly adopted to develop a general expression of shear load-slip equation for headed-stud shear connectors varying in a large parameter range based on both force and energy balance. The pre- and post-yield shear stiffness were then determined through bilinear idealization of proposed shear load-slip equation. An updated and carefully selected push-out test database of 157 stud shear connectors, conducting on studs 13~30mm in diameter and on concretes 30~180 MPa in cubic compressive strength, was used for model regression and sensitivity analysis of shear stiffness. An empirical calculation model was also established for the stud shear stiffness. Compared with the previous models through statistical analysis, the proposed model demonstrates a better performance to predict the shear load-slip response and stiffness of the stud shear connectors.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1074-1081
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• 2010

Today, the research related to the robot is achieved in various part. With the high interest in means of transport, various researches about autonomous mobile robot and next generation transport is continuing. The unicycle robot among these needs much control technique like balance control model and driving model. For autonomous driving of this unicycle robot, from the basic balance control to direction switching control and velocity control are needed. But the environment elements like a gradient and frictional force or unbalanced elements from the structural feature. The unicycle needs the real time balance control so more complex, harder to control. And when functional addition is made, the problem that fall entire reaction velocity or accuracy would be happen. This paper introduces entire dynamics modeling of the unicycle robot and reduced model. And propose the new balance control algorithm using fuzzy controller. Also the evaluation about performance would be made through the test.

• 로봇학회논문지
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• 제11권3호
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• pp.183-192
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• 2016

Generating motion of center of mass for biped robots is a challenging issue since biped robots can easily lose balance due to limited contact area between foot and ground. In this paper, we propose force control method to generate high-speed motion of the center of mass for horizontal direction without losing balancing condition. Contact consistent multi-body dynamics of the robot is used to calculate force for horizontal direction of the center of mass considering balance. The calculated force is applied for acceleration or deceleration of the center of mass to generate high speed motion. The linear inverted pendulum model is used to estimate motion of the center of mass and the estimated motion is used to select either maximum or minimum force to stop at goal position. The proposed method is verified by experiments using 12-DOF torque controlled human sized legged robot.

• 대한조선학회논문집
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• 제47권4호
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• pp.477-486
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• 2010

During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For predicting sail force, a model test was carried out according to running attitude. Through the model test, drag and side force of the real ship was predicted. A purpose of this study is to find sail force to C.E from changed attitude during running direction. By balance of hull and sail, a heeling force of designed sail is predicted. Also through heeling force and driving force, total sail force and direction from C.E are considered with changed mast including leeway and heeling.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1564-1568
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• 2004

The requirements of internal balance were studied that should be considered on performing force & moment transonic wind tunnel testing to develop combat aircraft. In many insecure factors of test condition, uncertainty analysis was conducted to verify one drag count measurements. The analysis result was applied to T-50 aircraft model and compared for data verifaction. In conclusion, the aerodynamicist should estimate the validation and accuracy of test data by having an overall grasp of system components including internal balance. It will help him get high productivity of testing and effective validated data at tunnel.

• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.249-260
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• 2020

This study aims to explore the role of Khan's engagement dimension previous study in mediating the relationship between work-life balance and in-role and extra-role performance of salesforce. To measure the data, a quantitative approach conducted through a survey of the sales force in the financial services industry sector in Makassar City, Indonesia. We determine the sample by using purposive sampling technique, and a total of 188 salesforce respondents. SEM-PLS with the second-order model was applied to test the measurement model and the mediator role of the engagement. The results show that the engagement dimension fully mediates the effect of work-life balance on both in-role and extra-role performance direct or indirect effect. the findings in this study also address the great concern of both individuals and organizations that the antecedents of the work-life balance variable are fundamental reasons for improving performance. The results of this study indicate that the work-life balance program positively influences engagement. Overall, we can conclude that commitment not only serves as a means for employees to fulfill formal job requirements. This can also encourage them to take action that goes beyond the precise requirements of their work by presenting them physically, emotionally, and cognitively in the work environment.

• 한국수소및신에너지학회논문집
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• 제26권6호
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• pp.659-665
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• 2015

In this study, an experimental investigation is performed for evaluation of a liquid pool spreading model with continuous release. The model considered in this study was developed based on a concept which means that the liquid pool spreading is governed by a balance between an inertia force from gravity and a frictional force from friction with the ground under the whole base of the liquid pool. For evaluation of the model, experimental study is performed. Experimental apparatus is setup for measuring release rate, spreading velocity, and evaporation rate from a liquid pool. The experimental results are compared with results from the model. By applying release and evaporation rates obtained from experiments to solving the model, liquid pool radius variation according to time can be obtained. For evaluation of an effect of friction force in the spreading model, results obtained from the models with and without the friction force are compared with those obtained from the experiments. As a result, it is shown that there exists a large deviation between the results obtained from the model without the friction force and the experimental results. On the other hand, the tendency of liquid pool radius variation according to time is similar between the results obtained from the model without the friction force and the experimental results.

• 한국군사과학기술학회지
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• 제3권2호
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• pp.81-87
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• 2000

This paper presents an application of forced oscillation technique to measure pitch dynamic stability derivatives of a missile model in the low speed wind tunnel. The missile model is oscillated by D.C. electric servomotor with constant amplitudes and frequencies. Phase shift is determined as the difference of peak values between input and output signals from the dynamic stability balance installed at the center of gravity of the model. Stability derivatives were calculated by using phase shifts, amplitudes, forcing moments and input frequencies. Test results show the proper usage of the force oscillation technique with good damping effects.

• Wind and Structures
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• 제18권4호
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• pp.323-345
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• 2014

Less than 30 years ago a new method was introduced in wind-tunnel testing of tall buildings, known variously as the High-Frequency Base Balance or High-Frequency Force Balance, which revolutionized the determination of design wind loads using model studies. The method is reviewed in hindsight, in the perspective of the present, and with a crystal ball to speculate on future developments. These viewpoints focus on various technical issues that have been solved, are being solved, and need to be solved. The intent is to assist the uninitiated develop appreciation for the technology involved, to identify various pitfalls awaiting those who embark in the method, and to identify areas of need so that practicing design engineers-the users of such studies-can appreciate the limitations and collaborate on future advances while promoting improved communication between executor and user.

• 대한기계학회논문집
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• 제10권5호
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• pp.653-660
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• 1986

본 논문에서는 단일 노치가 있는 봉의 소성굽힘, 밀폐형단조, 4각형블록의 압 축, 2차원 절삭가공 및 평면변형 후방추출 등 평면변형 성형문제에 대해서 공구와 소 재사이에 일정한 마찰응역이 작용한다는 가정하에 운동학적 가용속도장으로 구한 상 계해와 동일한 변형모델을 사용하여 힘평형법으로 구한 상계해를 비교.검토하여 2가지 접근법으로 구한 상계해가 동일함을 입증하였다.