• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.215-220
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• 2012

Miniature ultrasonic and tactile sensors on Si substrate have been proposed, fabricated and characterized to detect objects for a dexterous robot. The ultrasonic sensor consists of piezoelectric PZT thin film on a Pt/Ti/$SiO_2$ and/or Si diaphragm fabricated using a micromachining technique; the ultrasonic sensor detects the piezoelectric voltage as an ultrasonic wave. The sensitivity has been enhanced by improving the device structure, and the resonant frequency in the array sensor has been equalized. Position detection has been carried out by using a sensor array with high sensitivity and uniform resonant frequency. The tactile sensor consists of four or three warped cantilevers which have NiCr or $Si:B^+$ piezoresistive layer for stress detection. Normal and shear stresses can be estimated by calculation using resistance changes of the piezoresitive layers on the cantilevers. Gripping state has been identified by using the tactile sensor which is installed on finger of a robot hand, and friction of objects has been measured by slipping the sensor.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.3
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• pp.201-206
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• 1998

We reviewed 240 patients with facial bone fractures treated at the department of oral and maxillofacial surgery between Jan. 1. 1997 to Dec. 31. 1997. These results were obtained as follows : 1. The ratio of men to women was 3.5 : 1 2. The age frequency was highest for people in their 20's 34.2%, in their 10's 21.63%, and in their 30's 20.41%. 3. The fractures were at the highest incidence in September at 13.3%, followed by in May at 11.25%. 4. The frequent causes were traffic accidents 47.9%, fisticuffs 20%, accidents caused by falling or slipping 16.25%, working traumas 8.75%, and sports 7.1%. 5. The most common location of facial bone fractures was the mandible 67.2%. The frequent fracture sites of the mandible were symphysis, angle, condyle, and body in the order. 6. The associated injuries of facial bone fractures were neurosurgry, orthopedic surgery, cardiothoracic surgery, ophthalmic surgery and general surgery. 7. In respect of treatment, open reduction used 84.3% of the time. 8. Post operation complicatins were as follows : neurological problem 2.08%, malunion 1.67%, facial asymetry 0.83%, malocclusion 0.83%, and infection 0.41%.

• Journal of the Korea Furniture Society
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• v.25 no.4
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• pp.353-363
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• 2014

Design of the container was designed to be able to have a sense of security by emphasizing the points and easy to use sophisticated in order to match the image of the company in an environmentally friendly form of the whole. The design of the natural detergent container, because the container itself is to prevent related bar closely with water, a slip, with an emphasis on the form of fish swim, looks the handle of the oval for the harmony of the entire container I was used to the point. The image extraction in the ordinary, you can design by applying the curve of streamlined feet of thin in order to emphasize the image of honest companies, oval fuselage top, easily without slipping and harmony of the image of the entire container in view of the functional aspects can grab to, which is designed to enter the interior. The design of the natural environment detergent container industry, it was incorporated as much as possible to the vessel and corporate image and sense of stability and the proportion of the overall shape, the basic concepts, the form on the productivity and functionality in the field of design, through the change and simplicity, with an emphasis on merchantability.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.183-190
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• 2016

Engine torque is transferred to the transmission where drag torque is minimized improving fuel efficiency. This is particularly true in a wet clutch pack. This study measures slip friction when the wet clutch pack in a DCT (Dual-Clutch Transmission) is disengaged, and the friction pads are slipping. Shudder engagement velocity, and applied forces can be measured under various working conditions through these torque transfer experiments. Test results demonstrate that the design parameters, and engagement conditions of wet clutch packs can be optimized to reduce shudder and frictional vibration during engagement in a dual clutch transmission.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.103-112
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• 2009

A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobe with elliptical and involute shapes, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• Journal of the Korean Dietetic Association
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• v.16 no.4
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• pp.318-331
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• 2010

The objectives of this study were to investigate the status of accidents and to assess hazards in institutional foodservices in the Changwon and Masan areas. A survey was conducted from February 1 to March 31, 2009 using questionnaires, and 142 dietitians participated. The dietitians' perception of accident risks in workplace averaged 3.11 points. Forty-five percent of the respondents responded that accidents had occurred more than once between 2006 and 2008. In addition, 28.2% of the respondents experienced employee absences or turnover due to accidents during Year 2008. 'Musculoskelectal injuries or disorders (65.5%)', 'slips or falls (64.8%)', 'burns (57.7%)', and 'cuts and punctures (48.6%)' were the predominant accidents in foodservice. 'Knives (76 points)', 'steam kettles (41 points)', 'vegetable cutters (34 points)' and 'turn kettles (26 points)' were the equipment with severe accidents, such as burns or cut injuries. Among foodservice processes, 'carpal tunnel syndrome while washing (2.83 points)', 'burned by frying oil (2.64 points)', 'cut by sharp tools (2.55 points)', 'musculoskelectal injury by moving heavy weight food materials (2.41 points)', and 'injury by slipping on wet workplace floors and trenches (2.19 points)' were the most frequently occurring accidents at foodservice sites. To prevent safety accidents, dietitians' perceptions of safety supervision should be improved, and therefore, it is necessary they receive safety education.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.440-445
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• 2011

This paper presents a new regenerative brake system of electric vehicles that employs a continuous variable transmission(CVT) and a flywheel. The developed device has advantages over existing regenerative brakes from a standpoint of reliability and versatility in actual driving conditions. The system consists of a CVT, two wheels, a flywheel, a coupling and auxiliary powertrain components. The CVT is designed as a combination of two cones and a roller, which causes the velocity difference between the wheel and the flywheel. The power flow of the flywheel system is controlled by the CVT roller and the coupling through step motors. A prototype has been developed and then its performance has been investigated for various operating conditions. Results show that the storage efficiency of the flywheel is much affected by the vehicle's velocity and it is reduced below 20% for high speed, as compared to the 25% efficiency for an ideal condition. The CVT is a primary factor for lowering the flywheel efficiencies due to large friction and slipping between the cone and the roller.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.211-218
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• 2012

Two experiment are planed to identify driver's safe driving behaviour by curve radius, road surface condition in curve section. At four-lane and two-lane road, conducted experiments are check on driver's feeling of safety that 30 subjects do not feel discomfort. And using the data from these experiments, this study compare physical speed (not slipping, fall our of the road) with safety driving speed(drivers felt a comfortable and safe speed) each curve radius and fiver road surface condition(drying, wet, rain, snow and ice). As a result, safe driving behaviour factors that are derived to curve radius of 100m units, five road surface conditions enable to represent quantitative analysis of driver's discomfort. This study will develop road design method and evaluation reflected ergonomic aspects.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.91-92
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• 2018

As we begin to develop into an aging society, a lot of safety issues are emerging recently. Also, laws and products related to the safety and welfare of the elderly are being released. Therefore, this paper investigated the safety of the elderly. In this paper, we propose a system that can detect motion such as falling or slipping of elderly people by using gyro sensor and accelerometer to solve these factors.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1146-1154
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• 2008

This paper presents a method for the acceleration analysis of multi-legged walking robots in consideration of the frictional ground contact. This method is based on both unified dynamic equation for finding the acceleration of a robot's body and constraint equation for satisfying no-slip condition. After the dynamic equation representing relationship between actuator torques and body acceleration, is derived from the force and acceleration relationship between foot and body's gravity center, the constraint equation is formulated to reconfigure the maximum torque boundaries satisfying no-slip condition from given original actuator torque boundaries. From application of the reconfigured torques to the dynamic equation, interested acceleration boundaries are obtained. The approach based on above two equations, is adapted to the changes of degree-of-freedoms of legs as well as friction of ground. And the method provides the maximum translational and rotational acceleration boundaries of body's center that are achievable in every direction without occurring slipping at the contact points or saturating all actuators. Given the torque limits in infinite normsense, the resultant accelerations are derived as a polytope. From the proposed method, we obtained achievable acceleration boundaries of 4-legged and 6-legged walking robot system successfully.