• 한국인터넷방송통신학회논문지
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• 제8권2호
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• pp.49-55
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• 2008

To address the convergence issue of power control algorithms, a number of algorithms have been developed hat shape the dynamics of up-link power control for cellular network. Power algorithms based on fixed point iterations can be accelerated by the use of various methods, one of the simplest being the use of Newton iterations, however, this method has the disadvantage which not only needs derivatives of the cost function but also may be weak to noisy environment. we showed performance of the power control schemes to solve the fixed point problem under static or stationary channel. They proved goof performance to solve the fixed point problem due to their predictor based optimal control and quadratic convergence rate. Here, we apply the proposed power control schemes to the problem of the dynamic channel or to dynamic time varying link gains. The rigorous simulation results demonstrated the validity of our approach.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.196-201
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• 2001

Very Large Floating Structures have been planned for effective utilization of ocean space in recent years. The VLFS usually has a control tower to guide airplane securely. This paper present an effective method for calculating the wave induced hydroelastic responses of VLFS considering the effect of control tower-shapes. The source and dipole distribution method is used to calculate the hydrodynamic loads and equation of motion is derived by considering the static and dynamic coupling effects from different segments of the plate. The rigidity matrix for VLFS is formulated by finite element method using a plate theory. The calculated results for VLFS with a control tower are compared with those for VLFS without a control tower.

• 한국공작기계학회논문집
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• 제10권1호
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• pp.51-58
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• 2001

The use of tailor welded blanks (TWB) in automotive applications is increasing due to the potential of weight and cost saving. The object of this study is development of the front side member by static analysis and crash simulations. Accord-ing to the results , energy absorption and barrier force is very important parameter to control passenger safety and deforma-tion shape. A energy absorbability point of view, tailor welded blanks is most effective to absorb energy than non-twb. Non-TWB front side member and TWB applied front side member were simulated. It shows reduce stmping parts weight reduction and cost down.

• 대한전기학회논문지:전력기술부문A
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• 제51권10호
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• pp.483-494
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• 2002

In this thesis an optimal design technique of fuzzy logic controller using the real variable elitist genetic algorithm(RVEGA) as a supplementary control to Static Var Compensator(SVC) in order to damp oscillation in an AC-DC Dower system was proposed. Fuzzy logic controller is designed self-tuning shape of fuzzy rule and fuzzy variable using genetic algorithm based on natural selection and natural genetics. To verify the robustness of the proposed method, considered dynamic response of system by applying a load fluctuation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.891-893
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• 2000

Because of linear operation by direct drive and compact system, and the free accumulation of position error, LPM is suitable for proportional control valves actuator. In this study, to develop electromagnetic proportional valves actuator we designed tooth shape of double sides LPM and suggested the driving principle based upon the excitation method, It's the magnetic structure is so complex by the cubic effect configuration that finite element analysis is required. By the 3D finite element analysis, we got the magnetic distribution of LPM and analyzed static thrust force characteristics. By this analyzation, we obtained basic data required for the practical use of driving system for the proportional control valves. Thus, considering electrical and mechanical constants we could design and manufacture double sides LPM for the proportional control valves.

• 동의생리학회지
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• 제14권2호통권20호
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• pp.11-21
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• 1999

In this paper the nine orifices were analyzed horizontally and vertically and the relationship between the upper seven orifices and lower two orifices was looked into specifically. The following results were obtained : l. Horizontal is the shenji (神機) which comes in and out, and it symbolizes animality based on heaven. so it is dynamic. Vertical is the qiji (氣機) which goes up and down. and it symbolizes vegetability based on earth. so it is static. 2. The shape of the eyes and lips is horizontal, so the shape of the liver and spleen which are related to the eyes and lips respectively is also horizontal. Thus the eyes and lips can move and the action of these are mainly concerned with the coming in and out of energy. 3. The shape of the nose and ears is vertical. so the shape of the lungs and kidneys which are related to the nose and ears respectively is also vertical. Thus the nose and ears remain still and the action of these are mainly concerned with going up and down of energy. 4. One means yang(陽) and two means yin(陰). so the nose and mouth which have one are yang. the eyes and ears which have two are yin. 5. The urethra consists of yangming(陽明) and taiyin(太陰) which control the front so it draws out urine which is yang(陽). The anus controls the back. so it draws out feces which is yin(陰). 6. The upper seven orifices are related to the five viscera which control immaterial spirit. The lower two orifices are related to the six bowels which control material movement.

• 대한기계학회논문집A
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• 제32권10호
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• pp.882-889
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• 2008

A humanoid is a robot with its overall appearance based on that of the human body. When the humanoid moves or walks, dynamic forces act on the body structure. Although the humanoid keeps the balance by using a precise control, the dynamic forces generate unexpected deformation or vibration and cause difficulties on the control. Generally, the structure of the humanoid is designed by the designer's experience and intuition. Then the structure can be excessively heavy or fragile. A humanoid design scenario for a systematic design is proposed to reduce the weight of the structure while sufficient strength is kept. Lower parts of the humanoid are selected to apply the proposed design scenario. Multi-body dynamics is employed to calculate the external dynamic forces on the parts and structural optimization is carried out to design the lower parts. Because structural optimization using dynamic forces directly is fairly difficult, linear dynamic response structural optimization using equivalent static loads is utilized. Topology and shape optimizations are adopted for two steps of initial and detailed designs, respectively. Various commercial software systems are used for analysis and optimization. Improved designs are obtained and the design results are discussed.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1484-1493
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• 2004

In this study, it induced to a conclusion below by experiment consideration to regarding an effective supercooling ends method of the flow cooling water in a tube of continuous ice making method and the static cooling water in a tube of continuous ice making method which used magneticfluid in a dynamic type ice storage system. Continuous ice making in a tube of the flow cooling water was shortened about 12 minutes until supercooling ends that case which gave vertical eccentricity rotation magnetic field 120rpm than did not provide magnetic field by experimental result that was tested to supercooling ends effect from shape control of magneticfluid. Continuous ice making method in a tube of the static cooling water compared with and reviewed the case that was not provided with the magnetic field and exposed cooling surface instantaneously by magnetic field. It confirmed that supercooling degree $\Delta$ $T_{c}$, $\Delta$ $T_{s}$, and $\Delta$ $T_{w}$ became lower because of heat transfering increasing by the occurrence of natural convection between after cooling starting progress time 1∼3 minutes if it did not give a magnetic field, and peformed the supercooling ends when natural convection occurred confirmed that refrigerating capacity was better. That relation $\Delta$ $T_{c}$, and $t_{e}$/($\Delta$ $T_{c}$-$\Delta$ $T_{s}$) after convection occurred, was not depended on $T_{b}$ and initial temperature if the depth of water and thickness of magneticfluid were regular and it was possible to verify conjecture of tp from $\Delta$ $T_{s}$ and $\Delta$ $T_{c}$.lar and it was possible to verify conjecture of tp from $\Delta$ $T_{s}$ and $\Delta$ $T_{c}$.c}$.>.

• International Journal of Control, Automation, and Systems
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• 제4권4호
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• pp.466-479
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• 2006

This paper addresses a formation navigation issue for a group of mobile robots passing through an environment with either static or moving obstacles meanwhile keeping a fixed formation shape. Based on Lyapunov function and graph theory, a NN formation control is proposed, which guarantees to maintain a formation if the formation pattern is $C^k,\;k\geq1$. In the process of navigation, the leader can generate a proper trajectory to lead formation and avoid moving obstacles according to the obtained information. An evolutionary computational technique using particle swarm optimization (PSO) is proposed for motion planning so that the formation is kept as $C^1$ function. The simulation results demonstrate that this algorithm is effective and the experimental studies validate the formation ability of the multiple mobile robots system.

• 한국전산유체공학회지
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• 제21권2호
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• pp.99-105
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• 2016

The present study has been carried out to analyze the flow characteristics with geometric shape and control conditions in subsea by-pass valve. The function of by-pass valve is to prevent reverse flow. In this study, the static analysis has been perform for analyzing fluid flow in open state. In order to consider the turbulent effect, the standard ${\kappa}-{\varepsilon}$ model was used. A variety of parametric studies, such as by-pass valve type or size, volume flow rate, leakage hole size, leakage hole position, block type, block shape, were performed. The pressure difference across the valve in the model broadened the flow channel cross-sectional area was greater than the base model for the same operating conditions. As the pipe diameter in the block decreases the pressure difference is greatly increased. The pressure difference according to block shape such as edge type and round was almost negligible. For the same Reynolds number the pressure difference was little changed according to the size of the valve.