• 한국정밀공학회지
• /
• 제20권2호
• /
• pp.168-175
• /
• 2003

In this research, a bridge-type flexure hinge mechanism is developed and optimized to amplify the displacement of a multilayer piezostack. Developed hinge mechanism has three-dimensional structure to reduce link size, so it have high amplification ratio with respect to small size. A flexure hinge is assumed to be 6 degree-of-freedom spring elements and matrix methods are used to model a hinge mechanism. To verify derived matrix model, a displacement and frequency experiments are performed. The analysis result shows that the displacemental error between matrix model and experiments is below 10 percents and the deformation of hinge in parasitic direction should be considered In hinge modeling. Using developed matrix model, an optimal design is performed to maximize the performance of hinge mechanism.

• 대한기계학회논문집A
• /
• 제29권11호
• /
• pp.1509-1517
• /
• 2005

This paper presents the two degree-of-freedom(DOF) planar parallel mechanism called 2R$\underline{P}$R-RP manipulator, whose degree-of freedom is dependent on a passive constraining leg connecting the base and the platform. First, the kinematic analysis of the mechanism is performed analytically: the inverse and forward kinematic problems are solved in the closed font the practical workspace is systematically derived, and all of the singular configurations are examined. Then, in order to determine the geometric parameters and the operating limits of the actuators, the optimization of the mechanism is performed considering its dexterity and stiffness. Finally, the kinematic performances of the optimized mechanism are evaluated through comparing to the 5-bar parallel manipulator.

• 제어로봇시스템학회논문지
• /
• 제11권2호
• /
• pp.127-136
• /
• 2005

In this paper, a new architecture and comprehensive design methodology of genetically optimized Rule-based Fuzzy Polynomial Neural Networks(gRFPNN) are introduced and a series of numeric experiments are carried out. The architecture of the resulting gRFPNN results from asynergistic usage of the hybrid system generated by combining rule-based Fuzzy Neural Networks(FNN) with polynomial neural networks (PNN). FNN contributes to the formation of the premise part of the overall rule-based structure of the gRFPNN. The consequence part of the gRFPNN is designed using PNNs. At the premise part of the gRFPNN, FNN exploits fuzzy set based approach designed by using space partitioning in terms of individual variables and comes in two fuzzy inference forms: simplified and linear. As the consequence part of the gRFPNN, the development of the genetically optimized PNN dwells on two general optimization mechanism: the structural optimization is realized via GAs whereas in case of the parametric optimization we proceed with a standard least square method-based learning. To evaluate the performance of the gRFPNN, the models are experimented with the use of several representative numerical examples. A comparative analysis shows that the proposed gRFPNN are models with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.

• 로봇학회논문지
• /
• 제12권2호
• /
• pp.107-115
• /
• 2017

In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.

• Earthquakes and Structures
• /
• 제15권2호
• /
• pp.215-225
• /
• 2018

To reach a better foundation treatment project, an optimized analysis of composite foundation was studied in the field of hydraulic engineering. Its unique characteristics in hydraulic engineering were concluded. And, the overall and detailed analysis of the composite foundation model established was carried out. The index parameters of the vertical reinforced rigid pile composite foundation were formulated. Further, considering the unique role of cushion in hydraulic engineering, its penetration and regularity were analyzed. Then, comparative and optimized analyses of cushion multistage physical dimensions and multistage material characteristics were established. The parameters of the piles distance were optimized and the multilevel scientific and reasonable parameters information was obtained. Based on the information of these parameters, the practical application was verified. It effectively supported the effective application of vertical reinforcement rigid pile composite foundation in hydraulic engineering. The service mechanism of composite foundation was fully analyzed.

• 정보저장시스템학회논문집
• /
• 제2권4호
• /
• pp.230-235
• /
• 2006

The machine locking system is an important device for the safety of persons using the machine. In this study, a locking system using electromagnetic fields is proposed to decrease the defects and the cost for repairing and maintenance of the existing locking system using structural mechanism. We analyze the electromagnetic locking system and calculate the generated force considering direction by the finite element method. Also, we set up two design domains for the topology optimization; first domain is optimized to reduce the volume and the other is optimized to maximize the generated force keeping the volume, especially. The optimal design is obtained by integration of the two optimized results. An improved design is obtained by the optimal topology and it is confirmed by comparison with the initial locking system.

• EDISON SW 활용 경진대회 논문집
• /
• 제5회(2016년)
• /
• pp.222-227
• /
• 2016

In this paper, the optimized design for bow structure was investigated by using EDISON software. Considering the mechanism of the bow, non-linear FEM analysis was essential. The factors of the design are height, width, number of holes and taper value. High performance of the internal energy and lowest mass were main issues. The limit of the von-mises stress was yield strength for the material. Material was chosen by considering typical bow material, Aluminum. Using Taguchi method($L_9$), 9 models were selected and contribution rate was calculated for each factors. Following the contribution rate, 3 factors were fixed and optimized model was predicted. After making optimized model for FEM analysis, the value of internal-energy, mass for FEM model were compared with predicted value, calculated the percentage error and figure out the reliability of Taguchi method.

• 한국정보과학회논문지:정보통신
• /
• 제37권3호
• /
• pp.198-203
• /
• 2010

본 논문에서는 자신의 이익만을 극대화하도록 이기적인 행동을 하는 애드혹 네트워크의 노드들을 관리하는 새로운 라우팅 프로토콜을 제안한다. 제안된 라우팅 기법에서는 무선 노드간의 거리와 남은 에너지를 고려하여 노드 간의 전송 비용을 계산하고 이를 통해 에너지 효율적인 경로를 설정한다. 또한, 해당 경로상의 노드들에게 협조적인 행동을 유도하기 위해 메커니즘 디자인의 일종인 VCG 메커니즘을 이용하여 각 중계 노드에게 인센티브를 제공하고 이를 기반으로 대역폭 예약을 수행해 실시간 데이터에 대한 서비스 품질을 보장하도록 하였다.

• 한국군사과학기술학회지
• /
• 제11권3호
• /
• pp.161-168
• /
• 2008

The deployable space structure is necessary to minimize the satellite volume and launch cost. For the deployment, passive deployment mechanism has widely been used to attenuate a latch shock induced when the structure is just fully deployed. To reduce the latch shock, viscous damper is applied to the passive deployment mechanism and it can control the deployment speed of the structure. In this paper, dynamic analysis of the deployable space structure using the passive deployment mechanism with the viscous damper has been performed. The viscous damping values have been optimized through numerical simulation. The satellite's attitude influenced by pyro activation for the release of the structure has also been investigated.

• 한국생산제조학회지
• /
• 제18권4호
• /
• pp.375-380
• /
• 2009

In this paper, it has been proposed an automatic vegetable bundling mechanism that makes use of heat melt sticking. The proposed mechanism is consisted of three modules for the rationality of manufacture. Design specification has been determined by the bundling mechanism that was optimized mechanically. And, it has been manufactured the prototype of the automatic bundling machine. It has been carried out directly the field test for verification of performance in farmhouse which produces vegetable. In field test, this bundling machine showed efficiency of about 3.6 times than the manual working by manpower, and other performance it got satisfied result. This automatic vegetable-bundling machine was already registered as the agricultural machine. and This machine will be commercialized soon.