• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.2
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• pp.27-35
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• 2006

Al used in automobiles is mostly material, and according to the innovation of technique is in rapid development. Al die casting is an important field as today's trend of lightweight on automobiles. Valve housing in steering system improves driver's controling. The valve housing which is widely reliable to the most automobiles are developed this moment in our automobile industry. Therefore, they are produced by casting method which cost three times or even more expensive in production. If valve housing which is a part of steering system is produced by gravity casting, the space for manufacturing equipment will be increased, and more time and workers would be brought into service. For such reason, die casting would replace gravity casting in order to minimize cost of time, manpower, and working space. This study is the forming analysis of the 2 cavity die casting for automobile valve housing.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.47-54
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• 2002

A barrel cam is used as a very important part of an index drive unit. The index drive unit must have an intermittent-rotational motion. The barrel typed cam and roller gear mechanism has the advantages of high reliability to perform a prescribed motion of a follower. This paper proposes a new method for the shape design of the barrel cam and also a CAD program is developed by using the proposed method. As defined in this paper, the relative velocity method for the shape design calculates the relative velocity of the follower versus cam at a center of roller, and then determines a contact point by using the geometric relationships and the kinematic constraints, where the direction of the relative velocity must be parallel to a common tangential line at the contact point of two independent bodies, i.e. the cam and the follower Then, the shape of the cam is defined by the coordinate transformation of the trace of the contact points. This paper presents two examples for the shape design of the barrel cam in order to prove the accuracy of the proposed methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.73-80
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• 2005

Biped robot requires that an energy source and a control part should be installed on the body to realize active system. So, we choose the DC motor having high torque in compact size in this study. In the DC motor serve system, we choose power amplifier with analog configuration, developed the module combined the controller and the driver. We applied this module to robot actuator and studied the response characteristics in an action and a return. Main controller with serve system, loading PIC micro controller, can be load on the robot with light weight.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6090-6097
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• 2013

A pneumatically-driven driving simulator that provides a realistic representation of the driving environment was developed. The motion platform for the driving simulator is a mechatronic device that gives a driver the realistic feeling of an actual vehicle. The cost of the motion platform comprises the largest part of the expenses in developing a driving simulator. In this project, to develop a low-cost motion platform, the self-built motion platform based on the Stewart platform configuration that is constructed by six pneumatic cylinders was used as its actuator. The Stewart platform that moves in response to the operating signals of the joystick showed satisfactory tracking performance. We confirmed the possibility of the driving simulator using rFactor that is a commercially available racing game software.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.6
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• pp.299-306
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• 2000

The primary cause of air pollution by vehicles is imperfect combustion of fuel. One of the most usual causes of this imperfect combustion is the misfire in IC(Intenal Combustion) engine. Recently it is obligated for an ECU to monitor the emission level and warn the driver in case of exceeding specified emission standards. Therefore, in order to comply with this OBD-II regulations, car makers are investing a considerable amount into technology which would enable the detection of misfire and the particular cylinder in which misfire is taking place. So far, it has been able to detect misfire using engine speed, which can be obtained crank angle. However, such a method posed a problem in analyzing at high speed and in recognizing the misfire from the load impact at bumpy road. In this paper, misfire detection is made possible by simple arithmetic using WDFT, especially at high engine speed. In addition, the moving window method of a Walsh function is applied to determine the cylinders under misfire in case of multiple misfires. An actual experiment was conducted to prove that WDFT is applicable to effective in computation speed and to same result in misfire detection and cylinder determination at idle, part load and bumpy road conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.687-690
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• 2000

Lately, many studies have been progressed for the protection human's lives and property as holding in check accidents happened by human's carelessness or mistakes. One part of these is the development of an autonomouse vehicle. General control method of vision-based autonomous vehicle system is to determine the navigation direction by analyzing lane images from a camera, and to navigate using proper control algorithm. In this paper, characteristic points are abstracted from lane images using lane recognition algorithm with sobel operator. And then the vehicle is controlled using two proposed auto-steering algorithms. Two steering control algorithms are introduced in this paper. First method is to use the geometric relation of a camera. After transforming from an image coordinate to a vehicle coordinate, a steering angle is calculated using Ackermann angle. Second one is using a neural network algorithm. It doesn't need to use the geometric relation of a camera and is easy to apply a steering algorithm. In addition, It is a nearest algorithm for the driving style of human driver. Proposed controller is a multilayer neural network using Levenberg-Marquardt backpropagation learning algorithm which was estimated much better than other methods, i.e. Conjugate Gradient or Gradient Decent ones.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.59
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• pp.113-135
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• 2013

Piracy has been an ongoing and serious problem in international shipping industry. Somalia is often in the news these days. Somalia has been in a state of unrest for more than two centuries. In recent times, the situation has remained unstable. The persistent unrest is the major driver behind the piracy epidemic in Somalia waters. By the MIA 1906, s.78(1), the expenses in order to be recoverable must have been "properly incurred". The underwriter is also liable in certain circumstances for expenses incurred by the assured in an attempt to avert or diminish loss covered by the policy, under provisions. This class of expenditure is commonly referred to as sue and labour expenses, or suing and labouring expenses; less commonly, as particular charges. The standard marine policy(the S.G.Form) contained what was invariably called the sue and labour clause, which has been replaced in the current Institute Clauses by the "Duty of Assured(Sue and Labour)" Clause in the Hull Clauses, and the "Duty of Assured" Clause, headed "Minimizing losses", in the Cargo Clauses. Sue and labour charges are not confined to expenditure on the part of the assured and his agents, but can include quantified loss consequent upon a sacrifice properly and reasonably made to avert or minimize an insured loss.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1274-1278
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• 2009

Fracture characteristics for plate and dome shapes of glass filled ceramics using shock tube were carried out. Glass filled ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role as separated membrane between combustion and external air, and needs the frangible characteristics that the particles of fractured glass filled ceramics should not affect the internal components of combustion. The objectives of this study are to evaluate the fracture pressures for various thicknesses and diameters of shock impact area. Also fracture phenomena of separated membrane using a shock tube compare with analytical method. The experimental apparatus consists of a driver, a driven section and a dump tank. The used material is glass filled ceramic made from Corning company. Specimens have the thickness of 3, 4.5 and 6mm. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

• Journal of the Ergonomics Society of Korea
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• v.22 no.2
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• pp.15-28
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• 2003

The one of the most important factors is the platoon design on developing AH3(Advanced Highway System), as it is related to traffic efficiency and drivers' safety. This study was evaluated that how much speed is comfortable for drivers and how long distance is appropriate for vehicular gap of platoon by measuring drivers' physiology signal and sensibility. A fixed-based AHS simulator was developed by using a real vehicle cockpit and the restructured part of Korean highway for human factors evaluation. The EEG(electroencephalogram), ECG (electrocardiogram) and GSR(Galvanic Skin Response) were measured for obtaining drivers' physiology signal according to the change of speed and gap. The brain wave(${\alpha},\;{\beta},\;{\delta},\;{\theta}$) by EEG, the response of the autonomic nervous system. the sympathetic and parasympathetic nervous system, by ECG, and relax-arousal situation by GSR were analyzed. The SD(Semantic Differential) method was also applied to evaluate drivers' sensibility by 5-grade evaluation scale with 96 adjectives. SSQ(Simulator Sickness Questionnaire) was used to measure the simulator sickness of pre and post driving, two times. As the results, drivers were comfortable with 120km/h speed of platoon and lam to 15m vehicular distance. The results of this study may differ from the adaption of the reality because of many parameters. However, the purpose of this study is show to significant results of the drivers' safety and the acceptability of human factors evaluation.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.707-710
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• 2002

A 120kV/70A high voltage switch has been installed at Korea Atomic Energy Research Institute in Taejon to supply power with Korea Superconducting Tokamak Advanced Research (KSTAR) Neutral Beam Injection (NBI) system. NBI system requires fast cutoff of the power supply voltage for protection of the grid when arc detected and fast turn-on the voltage for sustaining the beam current. Therefore the high voltage switch and arc current detection circuit are important part of the NBI power supply and there are much need for high voltage solid state switches in NBI system and a broad area of applications. This switch consisted of 100 series connected MOSFETs and adopted the proposed simple and reliable gate drive circuit without bias supply, Various results taken during the commissioning phase with a 100kW resistive load and NBI source are shown. This paper presents the detailed design of 120kV/70A high voltage MOSFETs switch and simple gate drive circuit. Problems with the high voltage switch and gate driver and solutions are also presented.