• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.677-682
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• 2006

Statement of problem. Various double crown systems have been used with removable partial dentures in the clinical field. Although retentive force between inner and outer crown are affected by several factors, differences between the retentive forces of different double crown system types are expected. Purpose. The purpose of this study was to evaluate the initial retentive force of outer crowns fabricated by the conventional casting technique in conus and hybrid double crowns. Material and methods. Ten double crowns were fabricated. The groups were as follows. Group 1, double crowns of hybrid inner and outer crowns using the conventional casting method; Group 2, double crowns of conus inner and outer crowns using the conventional casting method. Tensile strengths of double crowns when the inner and outer crowns were separated on a universal testing machine were measured. These values of retentive force were then statistically analyzed using the Kruskal-Wallis test. Results. Retentive force in group 2 was significantly higher than that in group 1(p<.05). Conclusion. The initial retentive forces of double crowns were affected by the types of the double crown system.

• Journal of Korean Association for Spatial Structures
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• v.4 no.2 s.12
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• pp.99-105
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• 2004

The structure systems with non-rigid member were classified by the composition type of line and surface members. As a result of the classification, there are 1-way cable structure, cable net and radial cable net structure in the line member system. And there are pneumatic structure and suspension membrane structure in surface member system. In addition, when the line and surface members are composed together, there is the hybrid membrane system which are divided into hanging type and supported type. In this paper, the Korean terms of structure systems with non-rigid member are recommended through this classification.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.602-608
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• 2005

In the virtual environment, force feedback to the human operator makes virtual experiences more realistic. To ensure the safe operation and enhance the haptic feeling, stability should be guaranteed. Both motors and brakes are commonly used for haptic devices. Motors can generate a torque in any direction, but they can make the system active during operation, thus leading to instability. Brakes can generate a torque only against their rotation, but they dissipate energy during operation, which makes the system intrinsically stable. Consequently, motors and brakes are complementing each other. In this research, a two degree-of-freedom (DOF) haptic device equipped with motors and brakes has been developed to provide better haptic effects. Each DOF is actuated by a pair of motor and brake. Modeling of the environment and the control method are needed to utilize both actuators. Among various haptic effects, contact with the virtual wall, representation of friction and representation of plastic deformation have been investigated extensively in this paper. It is shown that the hybrid haptic device is more suited to some applications than the motor-based haptic device.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.8
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• pp.735-743
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• 2010

A new Fuzzy sliding mode controller is proposed to improve the cornering performance of the four wheel hybrid vehicles. The Fuzzy sliding mode control is applied for the control of rear motor and EHB (Electro-Hydraulic Brake) to improve the cornering performance. The modeling of the automobile is simplified that each of the two wheels is modeled as two degrees of freedom object and the friction coefficient between the wheel and the ground is assumed to be constant. The output of the Fuzzy sliding mode algorithm is the direct yaw moment for the rear wheels, which compensates for the slip angle. Through the simulations using ADAMS and MATLAB Simulink, the cornering performance of the proposed algorithm is compared to the conventional PID to show the superiority of the proposed algorithm. In the simulation experiments, the J-Turn and single lane change are used for each of the Fuzzy sliding mode algorithm and PID controller with the optimal gains which are tuned empirically.

• 전자공학회논문지 IE
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• v.43 no.2
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• pp.75-79
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• 2006

Blind techniques without the help of training sequences are able to detect the information signal which has the minimal information of desired user. In this paper, we proposed the blind multiuser detector using the hybrid cost function to cancel the multiple user interference in direct sequence code division multiple access systems. The cost function of proposed blind multiuser detector is the hybrid type which joints both least mean square(LMS) algorithm and least mean fourth(LMF) algorithm. We evaluate the bit error rate(BER) performance of proposed blind multiuser detector under additive white Gaussian noise channel. Simulation results show that the proposed blind detector has an about 3dB of signal to noise ratio more than blind minimum output energy(MOE) multiuser detector under existing active user 20.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.3
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• pp.51-57
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• 2012

Pacman is known as the terminator of the loved classic game in the world. In this paper, classic pacman game without using a keyboard or a mouse we should be able to play the game with simple hand gestures. In other words, It use motion game to be a substitute for the hand direction key using the center coordinates. Also, movements of the monster is to be replaced depending on your hand movements by extracting a pointer of hand taking pictures in the MFC dialog using Cam. In this paper, YCbCbr image is convert to RGB images to extract skin color, and multiplication operations and hybrid median filtering was used in order to obtain better images. And it is used to obtain movement of the hand area based on obtain the center of gravity of the hand region.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.04a
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• pp.29-33
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• 2000

MEMS, Micro Electro-Mechanical Systems, present one of the greatest advanced packaging challenges of the next decade. Historically hybrid technology, generally thick film, provided sensors and actuators while integrated circuit technologies provided the microelectronics for interpretation and control of the sensor input and actuator output. Brought together in MEMS these technical fields create new opportunities for miniaturization and performance. Integrated circuit processing technologies combined with hybrid design systems yield innovative sensors and actuators for a variety of applications from single crystal silicon wafers. MEMS packages, far more simple in principle than today's electronic packages, provide only physical protection to the devices they house. However, they cannot interfere with the function of the devices and often must actually facilitate the performance of the device. For example, a pressure transducer may need to be open to atmospheric pressure on one side of the detector yet protected from contamination and blockage. Similarly, an optical device requires protection from contamination without optical attenuation or distortion being introduced. Despite impediments such as package standardization and complexity, MEMS markets expect to double by 2003 to more than ＄9 billion, largely driven by micro-fluidic applications in the medical arena. Like the semiconductor industry before it. MEMS present many diverse demands on the advanced packaging engineering community. With focused effort, particularly on standards and packaging process efficiency. MEMS may offer the greatest opportunity for technical advancement as well as profitability in advanced packaging in the first decade of the 21st century! This paper explores MEMS packaging opportunities and reviews specific technical challenges to be met.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.3
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• pp.256-263
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• 2014

Torque ripple is a very essential index for evaluating the effectiveness of a switched reluctance motor (SRM). Many common design strategies for reducing torque ripples of a SRM are changing the excitation trigger angle of stator windings, delaying the cut-off time of winding excitation, adjusting the ratio of arc angle between stator and rotor, and changing the geometric shape of rotor. However, the output torque or the efficiency of the SRM may drop as the above design strategies are solely adopted. In this paper, a hybrid design model which is obtained by the Taguchi Method for optimally designing a SRM with lower torque ripple and higher efficiency is presented. A 12S/8P motor is taken as a study case, and the 3D finite element method (FEM) is applied to analyze the characteristics of the motor and optimize the design process. The results have shown that the proposed method can achieve the design goal of obtaining a high-performance SRM for light electric vehicle applications.

• The Journal of Information Systems
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• v.14 no.1
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• pp.41-65
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• 2005

The credit ration is a significant area of financial management which is of major interest to practitioners, financial and credit analysts. The components of credit rating are identified decision models are developed to assess credit rating an the corresponding creditworthiness of firms an accurately ad possble. Although many early studies demonstrate a priori which of these techniques will be most effective to solve a specific classification problem. Recently, a number of studies have demonstrate that a hybrid model integration artificial intelligence approaches with other feature selection algorthms can be alternative methodologies for business classification problems. In this article, we propose a hybrid approach using rough set theory as an alternative methodology to select appropriate attributes for case-based reasoning. This model uses rough specific interest lies in lthe stable combining of both rough set theory to extract knowledge that can guide dffective retrevals of useful cases. Our specific interest lies in the stable combining of both rough set theory and case-based reasoning in the problem of corporate credit rating. In addition, we summarize backgrounds of applying integrated model in the field of corporate credit rating with a brief description of various credit rating methodologies.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.303-306
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• 2003

In radar tracking, since the sensor measures range, azimuth and elevation angle of a target, the measurement equation is nonlinear and the extended Kalman filter (EKF) is applied to nonlinear estimation. The conventional EKF has been widely used as a nonlinear filter for radar tracking, but the considerably large measurement error due to the linearization of nonlinear function in highly nonlinear situations may deteriorate the performance of the EKF To solve this problem, a fuzzy-model-based Kalman filter (FMBKF) is proposed for radar tracking. The FMBKF uses a local model approximation based on a TS fuzzy model instead of a Jacobian matrix to linearize nonlinear measurement equation. The hybrid GA and RLS method is used to identify the premise and the consequent parameters and the rule numbers of this TS fuzzy model. In two-dimensional radar tracking problem, the proposed method is compared with the conventional EKF.