• Smart Structures and Systems
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• v.18 no.4
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• pp.663-682
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• 2016

Continuum manipulators as a kind of mechanical arms are useful tools in special robotic applications. In medical applications, like colonoscopy, a maneuverable thin and flexible manipulator is required. This research is focused on developing a basic module for such an application using shape memory alloys (SMA). In the structure of the module three wires of SMA are uniformly distributed and attached to the circumference of a flexible tube. By activating wires, individually or together, different rotation regimes are provided. SMA model is used based on Brinson work. The SMA model is combined to model of flexible tube to provide a composite model of the module. Simulating the model in Matlab provided a platform to be used to develop controller. Complex and nonlinear behavior of SMA make the control problem hard especially when a few SMA actuators are active simultaneously. In this paper, position control of the two degree of freedom module is under focus. An experimental control strategy is developed to regulate a desired position in the module. The simulation results present a reasonable performance of the controller. Moreover, the results are verified through experiments and show that the continuum module of this paper would be used in real modular manipulators.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.2
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• pp.61-69
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• 2020

Due to its flexibility of the composite propeller blade, it is necessary to design a shape capable of generating a desired load at a design point in consideration of the shape change of the propeller. In order to design it, we need to evaluate not only the hydrodynamic force around it, but also its structural response of flexible propeller according to its deformation. So, it is necessary to develop a design tool to predict the hydroelastic performance of a flexible propeller with deformation considering fluid-structure interaction and special operating conditions. Finally a design optimization tool for flexible propellermade of CFRP is required. In this study, a design methodology of the specific flexible composite propeller is suggested, considering fluid-structural interaction analysis of the specific flexible propeller.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2720-2728
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• 2012

Recently flexible mobile terminals which can freely change the shape of their device are coming out with the development of the flexible display, high capacity memory and system integration technology. The display and the antenna configuration of the future terminals will be altered according to the QoS (quality of service) and the communication environment of users. In particular, we present the new emergence of a multimedia language for human and system to communicate over subjective concepts, intention of users. The intension of users is expressed by changing the shape of their mobile terminal. In addition, antenna configuration is also related to shape of terminal and QoS of users. Therefore, we set up a specific usage scenarios for future mobile terminals and propose an adaptive MIMO (multiple-input multiple-output) schemes that can maximize channel capacity and fit to QoS of users simultaneously.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.163-168
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• 2018

In this paper presents comparison of performance of flexible solar cells construction applied to curtain walls. The proposed paper compares power generation for curtain walls of various shapes using flexible PV. Through the comparison of performance, the power generation was compared by installing various types of flexible PV on the air layer of double windows. By comparing the measured power generation, it is possible to find an optimal flexible PV shape that can be applied to a curtain wall. Flexible PV installation was divided into diagonal, S and W shapes. As a result of comparison, the amount of power generation when there was no flexure of flexible PV was large. Also, as the angle with the light source increased, the power generation decreased. Therefore, it is necessary to study the structure which can fix the PV more than the flexible PV and to be able to direct the sun without distortion.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.321-332
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• 2021

Though development of reinforced earth wall is on the rise recently, safety verification for various methods remains behind which has caused the problems including collapse after installation. This study aims to evaluate the field applicability of the shape of flexible strip reinforcement according to pullout resistance test and field damage test. The test specimens were 3 shape of reinforcement, the typical flexible band reinforcement, developed luged band reinforcement, and band type reinforcement made by cutting geogrid. It was found that reinforcement of type have strengths and weaknesses, respectively. The best type of flexible strip reinforcements can be selected, if the conditions are considered with the installation conditions of the reinforcing earth retaining wall and the particle size of the backfill materials.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.3
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• pp.27-33
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• 2017

In this paper presents the MPPT tracking algorithm using angle control of flexible PV in BIPV. The proposed algorithm is based on MPPT tracking algorithm for curtain wall using flexible PV. It is an algorithm to find optimal power generation condition by controlling the angle of flexible PV using the air layer of window. The angle of flexible PV tests the power generation by separating the center of flexible PV into the interior angle in the interior direction and the external angle in the center of flexible PV. When the angle of flexible PV was used as interior angle, the generation amount was increased by 15.79% and increased by 8.45% compared with the external angle. MPPT tracking is performed on the generation amount of the interior angle which has the most power after comparing the generation amount according to the bending shape of the flexible PV. This algorithm can be the most efficient method for the curtain wall using flexible PV because the bending pattern with the greatest amount of power generation may be different because the environment of the building applying the curtain wall is different.

• Journal of computational fluids engineering
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• v.11 no.1 s.32
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• pp.21-28
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• 2006

Reliability Based Design Optimization(RBDO) is one of the optimization methods that minimize the product failure due to small changes of operating conditions or process errors. It searches the optimum that satisfies the safety margin of each constraint, and it gives stable and reliable designs. However, RBDO requires many times oj computational efforts compared with the conventional deterministic optimization(DO) to evaluate the probability of failure about each constraint, therefore it is hard to apply directly to large-scaled problems such as a flexible wing shape design optimization. For the efficient reliability analysis, the approximate reliability analysis method with the two-point approximation(TPA) is proposed In this study, the lift-to-drag ratio maximization designs are performed with 3-dimensional Navier-Stokes analysis and NASTRAN structural analysis, and the optimization results about the deterministic, FORM and SORM are compared.

• Journal of Computing Science and Engineering
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• v.11 no.3
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• pp.79-91
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• 2017

In this paper, the abdominal-deformation measurement scheme is conducted on a shape-flexible mannequin using the DIC technique in a stereo-vision system. Firstly, during the integer-pixel displacement search, a novel fractal dimension based on an adaptive-ellipse subset area is developed to track an integer pixel between the reference and deformed images. Secondly, at the subpixel registration, a new mutual-learning adaptive particle swarm optimization (MLADPSO) algorithm is employed to locate the subpixel precisely. Dynamic adjustments of the particle flight velocities that are according to the deformation extent of each interest point are utilized for enhancing the accuracy of the subpixel registration. A test is performed on the abdominal-deformation measurement of the shape-flexible mannequin. The experiment results indicate that under the guarantee of its measurement accuracy without the cause of any loss, the time-consumption of the proposed scheme is significantly more efficient than that of the conventional method, particularly in the case of a large number of interest points.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1842-1847
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• 2007

In this study, we are to analyze the life and the main failure mode of flexible tubes fitting for pneumatic that are usually applied in the factory automation line. Flexible tubes fitting for pneumatic have complicated failure cause because they are organized as a complex of various elements. Therefore, in this paper, we analyzed the main failure mode of flexible tubes fitting for pneumatic, and then performed life test and performance test according to the international standards. On the basis of these processes, we estimate shape parameter that is the main factor for the calculation of test time for the reliability of flexible tubes fitting for pneumatic and their data analysis of life distribution.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.5
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• pp.437-443
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• 2008

In this paper, analysis and control of the flexible multibody system using MATLAB is presented. The equations of motion of a flexible body are derived in terms of the modal coordinate. The rigid-flexible multibody dynamic solver is developed. Finite element information required to analyze motion of flexible bodies is imported from ANSYS. The modified finite element data, such as modal mass matrix, modal stiffness matrix and constraint mode shapes, is calculated in the solver. Since the solver is developed using MATLAB, it is very easy to connect with SIMULINK which is widely used to control motion of the multibody system. Several simulations are implemented to verify the developed solver. A control example is carried out and the usefulness of the developed solver is demonstrated.