• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.67-69
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• 2002

This paper present increasing of Power density of slotless PMLSM by inserting core between phase winding. PM width is changed and PM is divided into two part to reduce and eliminate high order space harmonics affecting torque ripple. Flux density, back EMF, inductance, thrust, normal and detent force are computed by 2D FEM, and analysis values are compared with each other.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.855-857
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• 2003

A slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its low thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force and maxize thrust, this paper applies the neural network to inserted core type of slotless PMLSM.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.727-730
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• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed far each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Virtual Engineering of the separator inserting machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.

• Clinical Endoscopy
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• v.51 no.6
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• pp.552-557
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• 2018

Although colonoscopy was originally a diagnostic imaging procedure, it has now expanded to include an increasing range of therapeutic interventions. These procedures require precise maneuvers of instruments, execution of force, efficient transmission of force from the operator to the point of application, and sufficient dexterity in the mobilization of endoscopic surgical instruments. The conventional endoscope is not designed to support technically demanding endoscopic procedures. In case of colonoscopy, the tortuous anatomy of the colon makes inserting, moving, and orientating the endoscope difficult. Exerting excessive pressure can cause looping of the endoscope, pain to the patient, and even perforation of the colon. To mitigate the technical constraints, numerous technically enhanced systems have been developed to enable better control of instruments and precise delivery of force in the execution of surgical tasks such as apposing, grasping, traction, counter-traction, and cutting of tissues. Among the recent developments are highly dexterous robotic master and slave systems, computer-assisted or robotically enhanced conventional endoscopes, and autonomously driven locomotion devices that can effortlessly traverse the colon. Developments in endoscopic instrumentations have overcome technical barriers and opened new horizons for further advancements in therapeutic interventions. This review describes examples of some of these systems in the context of their applications to advanced therapeutic colonoscopy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.4
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• pp.310-318
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• 2008

This paper presents a parallel typed walking robot to improve walking space and stability region. The robot is designed by inserting an intermediate mechanism between upper leg mechanism and lower leg mechanism. The leg mechanism is composed of three legs and base, which form a parallel mechanism with ground. Seven different types of walking robot are invented by combining the leg mechanisms and an intermediate mechanism. Topology is applied to design the leg mechanism. A motor vector is adopted to determine Jacobian and a wrench vector is used to analyze dynamics of the robot. We explore the stability region of the robot from the reaction force of legs and compute ZMP including the holding force to contact the foot to a wall. This investigates a walking stability when the robot walks on the ground as well as on the wall. We examine the walking space generated by support legs and by swing legs. The robot has both a large positional walking space and a large orientational walking space so that it can climb from a floor up to a wall.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.111-117
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• 2020

Centrifugal casting is suitable for producing hollow-products using centrifugal force. Bush type metal bearings are the key parts that facilitate the rotational movement of various machinery. Metal bearings produced by conventional centrifugal casting machines show rotational imbalance. Therefore, after injecting a large amount of material, the product's precision is secured in the secondary processing. Rotational imbalance is caused by the force acting on the rotary disc plate. In order to minimize rotational imbalance, NASTRAN was used for the optimal design and structural analysis. It was concluded that the rotating plate of the conventional centrifugal casting machine should be prevented from tilting. For this purpose, the location & thickness of the stiffeners were obtained through the optimum design. In the conventional centrifugal casting machine, both ends of the product are lower in temperature than the center part, so internal stress occurs. This solves this problem by inserting a heating coil into the rotating plate.

• Korean Journal of Acupuncture
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• v.35 no.3
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• pp.149-158
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• 2018

Objectives : In this study, we quantitatively evaluated the needle forces using needle insertion-measurement system and compared the needle sensation of each acupuncture practical model. Methods : After inserting acupuncture with a sensor to six models, a lifting-thrusting motion was implemented using the needle insertion-measurement system. The needle force was measured repeatedly, and the measurement was analyzed based on the modified Karnopp friction model for a comparison of friction coefficients. After the insertion, practitioners did lifting-thrusting manipulations. They quantified the similarity of needle sensation with VAS (Visual Analogue Scale). Results : When friction force and coefficients of friction in five different models were compared with a porcine shank model, all five models were significantly different from a porcine shank model, cotton and apple showing the closest frictional values to that of a porcine shank model. In the Cp and Cn values of cotton and in the Cp values of IM injection pad, there was no statistically significant difference. The similarity of the needle sensation between the porcine shank and five models was the highest in the apple, and overlapping papers was the lowest. Conclusions : This study quantitatively compared the physical forces in the practical model when implementing lifting-thrusting manipulations, using a needle insertion-measurement system. We suggest that a reproducible exercise model that reflects the characteristics of various human tissues, such as viscoelasticity or strength, needs to be further developed. This will contribute to establishing standardized acupuncture practice training.

• KSBB Journal
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• v.26 no.4
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• pp.277-282
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• 2011

The penetration of outside material into skin is not easy. It is since the skin, which is a very hard barrier, protects the body against outside chemical and physical stimulation. Microneedle system which can help improve drug penetration into skin is advancing variously in transdermal drug delivery system (TDDS) in the field of skin care. After inserting microneedle into skin by using electrical or artificial forces, it makes microhole and drug penetration easily and induces natural skin rejuvenation. Diffusion and penetration of drug by optical and electrical force of microneedle is better for fast and effective TDDS. This is more developed than the traditional method such as the manual stamp, roller, and meso gun. The drug absorbed into dermal layer by microneedle helps revive and repair damaged skin. In the future, utilization of microneedle for skin care will progress constantly because of its human-friendly biodegradable materials and the development of the no pain microneedle.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1275-1280
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• 2004

This paper presents the construction of an active suspension system of a one-wheel car model by using fuzzy reasoning. The car model is approximately described by a nonlinear two degrees freedom system subject to excitation from a road profile, and the active control force is constructed by actuating a pneumatic actuator, and the degradation of the performance due to the delay of the pneumatic actuator is improved by inserting a compensator. The fuzzy control is obtained by single input rule modules fuzzy reasoning, and the excitation from the road profile is estimated by using a disturbance observer. The experimental result shows that the proposed active suspension system much improves the performance in the vibration suppression of the car model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.633-638
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• 2000

This paper reports an example of flow-induced vibration in a very large plant and the whole procedure of reducing the vibration. During the operation of flue gas desurfurization unit of the thermal power plant, serious vibration occurred at all around the unit. The worst vibration was recorded on the heat exchanger surface, which weighed 180 tones, as 17.8 m/$s^2$ in vibration amplitude at 34Hz. To identify the vibration, frequency analysis on the response vibration, the expected excitation force and the system resonance was executed. This investigation revealed that the cause of the vibration was vortex shedding from the circular pipes in the heat exchanger. Vortices from the pipes excited acoustic resonance in the heat exchanger room, which, in turn, made the structure vibrate. Through inserting the baffles between the pipes, which had an effect of cutting the acoustic wave at resonance frequency, the vibration was eliminated dramatically.