• Journal of Korea Society of Industrial Information Systems
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• v.19 no.4
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• pp.41-52
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• 2014

In this paper, O-ring size measurement algorithm based on a small machine vision inspection equipment which can replace a expensive and large machine vision inspection equipment is presented. The small machine vision inspection equipment acquires a image from a CCD camera shooting a measurement plane which located on a back light and the proposed size measurement algorithm is apply to the image. For improvement of size measurement accuracy, camera lens distortion correction and perspective distortion correction are conducted by software technique. Consider O-ring's shape, ellipse fitting model is applied. In order to increase the reliability of ellipse fitting, RANSAC algorithm is applied.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.5
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• pp.391-395
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• 2008

KEPCO 80MVA UPFC has been operated in Gangjin Substation since May 2003. This UPFC is composed of 40MVA shunt inverter and 40MVA series inverter, and developed in technical cooperation between Hyosung and Siemens. KEPCO has tried to localize UPFC control technique after its installation and developed GTO Thyristor Valve Test Equipment for annual maintenance test. The development of this equipment make it possible to process GTO Thyristor module test automatically and manage historic data systematically, which could improve UPFC reliability.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.432-438
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• 2010

In this paper, we propose a system which can perceive status of semiconductor equipment and evaluate its performance. The proposed system acquires the information such acceleration, pressure, temperature and gas sensors in the surrounding semiconductor equipment. After acquiring information, it is sent to server through multi hop transmission. The transmitted data generates 3 steps alarm using context-aware algorithm of unit or multiple event. From the experiment's result of the proposed system, we confirm that the reliability and efficiency of information is more improved about 80% than a system that doesn't use context-aware algorithm. Moreover, this system can be effective status monitoring of semiconductor equipment because lots of client nodes acquire surrounding information.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.173-179
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• 2013

This paper describes a testbed that was designed and implemented for the development of KSLV-II onboard equipment simulator. It used the CPCI-based industrial hardware system for scalability and the QNX real-time operating system for reliability and real-time simulation. In addition, a real-time application under QNX for function simulations of the KSLV-I PDU was developed and it was verified through interface experiments with KSLV-I upper-stage test equipment. The implemented simulator testbed will be used to verify the development feasibility in the design and development phase of a real KSLV-II onboard equipment simulator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.5
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• pp.451-457
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• 2008

Flat Panel Display(FPD) is widely used a video display terminals to consumer products of LCD and PDP. The contamination and damage were affected by using the previous contact conveyor's method. In this paper, it analyzes the FPD deflection to develop the non-contact FPD transfer process using lift force. Each conveyor's equipment is called a horizontal conveyor, vertical conveyor and robot pick-up equipment. As result of an analysis of FPD panel's deflection, a robot pick-up equipment has performed according to under the present conditions like panel's weight and loaded glass to move FPD panel from one place to other places properly. Results of the analysis showed 0.474 mm, 0.424 mm and 1.237 mm. Those values are lower than a predicted optimum values : 2 mm for both horizontal and vertical conveyers; 5 mm for robot pick-up equipment. Therefore, those results verify each equipment have safety and reliability.

• Plant Journal
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• v.9 no.4
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• pp.37-42
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• 2013

Power plants have many components and equipment. It is difficult for operators to know the each equipment fails or what equipment fails. It is important to prevent failure in advance. Recently, outlook of maintenance tasks is changing from time based maintenance to condition based maintenance. In this study, we selected RCM-based maintenance intervals for coal handling equipment at coal power plant. For RCM analysis, we have made great progress in a maintenance task and interval. If we apply RCM analysis to the whole plant system, we can expect qualitative improvement and efficient operation of power plant system.

• Journal of Drive and Control
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• v.11 no.4
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• pp.61-67
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• 2014

When a manual transmission equipped car stops on an incline where the nose of the car is higher than the rear, hill-start control or hill-holder could prevent the vehicle from rolling backward as the car moves forward. The easy-hill assist valve consists of a check valve and a needle type ON/OFF solenoid valve connected in parallel; it is a hydraulic actuator that can maintain brake pressure using an electrical signal from the ECU. As the EHA valve is a safety-related component of the brake system, high reliability as well as superior dynamic performance is required for it to be applied in commercial vehicles. This paper presents the design of the EHA valve as a piece of equipment that can simulate the brake actuation pressure with a pressurizing piston. Following specific test standards, the experimental results validate the implemented functions of the test equipment, proving the test stand to be effective for the performance and endurance of the EHA valve.

• Journal of Power Electronics
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• v.9 no.4
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• pp.544-552
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• 2009

This paper presents a novel spring pressure contact interconnect technique for medium power integrated power electronics modules (IPEMs). The key technology of this interconnection is a spring which is made from Be-Cu alloy. By means of the string pressure contact, sufficient press-contact force and good electrical interconnection can be achieved. Another important advantage is that the spring exhibits excellent performance in enduring thermo-mechanical stress. In terms of manufacture procedure, it is also comparatively simple. A 4 kW half-bridge power inverter module is fabricated to demonstrate the performance of the proposed pressure contact technique. Electrical, thermal and mechanical test results of the packaged device are reported. The results of both the simulation and experiment have proven that a good performance can be achieved by the proposed pressure contact technique for the medium power IPEMs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.49-55
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• 2008

This paper presents a novel evaluation method of life expectancy of power system equipment. The life expectancy means expected remaining lifetime; it can be usefully utilized to maintenance planning, equipment replacement planning, and reliability assessment. The proposed method is composed of three steps. Firstly, a cumulative probability for future years is evaluated for targeted age year. Secondly, the cumulative probability is modeled by well-blown cumulative distribution function(CDF) such as Weibull distribution. Lastly, life expectancy is evaluated as the mean value of the model. Since the model CDF is established in the proposed method, it can also evaluate the probability of equipment retirement within specific years. The developed method is applied to examples of generators of combined cycle power plants to show its effectiveness.

• Journal of Korean Institute of Industrial Engineers
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• v.38 no.1
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• pp.46-56
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• 2012

The purpose of virtual metrology (VM) in semiconductor manufacturing is to predict every wafer's metrological values based on its process equipment data without an actual metrology. In this paper, we propose novelty detection-based reliability estimation models for VM in order to support flexible utilization of VM results. Because the proposed model can not only estimate the reliability of VM, but also identify suspicious process variables lowering the reliability, quality control actions can be taken selectively based on the reliance level and its causes. Based on the preliminary experimental results with actual semiconductor manufacturing process data, our models can successfully give a high reliance level to the wafers with small prediction errors and a low reliance level to the wafers with large prediction errors. In addition, our proposed model can give more detailed information by identifying the critical process variables and their relative impacts on the low reliability.