• Journal of Applied Reliability
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• v.5 no.2
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• pp.273-287
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• 2005

Accelerated life test models and procedure are developed to assess the reliability of Refrigerator door switch. The main function of door switch is to operate bulb lamp and fan motor in the refrigerating room. The accelerated life test method and test equipments are developed using the relationship between stresses and life characteristics of the products. Using the developed accelerated life test method, the parameters of the ALT model and life time distribution are estimated and the reliability of the Door S/W at use condition if assessed. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test time and costs of the tests remarkably.

• KIEAE Journal
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• v.16 no.6
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• pp.129-134
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• 2016

Today, natural ventilation systems are widely applied in multi-family housing. However, studies using the wind data trend line of the blower door test are insufficient. Purpose: Through this study, we will propose a computational method about ventilation performance of natural ventilation systems by conducting blower door test. Method: First, we sealed the gaps between the main systems including the natural ventilation system and conducted the blower door test. Next, the natural ventilation system was opened, the blower door test was conducted, and the difference in air flow rate between when closed and when opened was checked. Blower door test was carried out with a pressure difference of 50 Pa. Result: Therefore, the ventilation performance of the natural ventilation system was checked by drawing a trend line using the data to calculate the air flow rate at 2 Pa of the natural ventilation equipment standard pressure difference.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.159-162
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• 2014

Recently, from 2008 to 2012, there are many of elevator safety patents from patent office survey. In this paper, we analyzed the elevator safety patent from 2009 to 2013, found out safety factor is safety control, emergency stop equipment and door opening equipment. Through reliability statistics, we defined the most important things for safety elevator factor is this three things, studied the reason about many patents. Finally, we propose the Kinect Scada elevator system for prevention safety accident.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.119-125
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• 2008

The traditional way for convergence of smart appliances was software integrations on middleware. It is possible advantage to integrate easily and quickly with this way. But basically the middleware approach is slowly executed as it is huge the size of software. To solve this problem, we suggest a modeling tool for convergence. As we can execute and generate the automatic source code at the design phase with our modeling tool, it is possible to do software integration without the middleware. We use one example of U-Home environment to show the convergence for TV and the door lock system. With our approach, we will be able quickly to develop the convergent products what the customers desire with inexpensiveness, that is, the convergence of smart appliances without the middleware.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.6
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• pp.520-524
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• 2011

A 27-year-old female presented to our hospital with a slow growing, hard and soft palate mass on the right that had been present for the several months. Physical examination showed a 2 cm, firm, well-circumscribed, painless mass on the right side of the palate. PNS computer tomographic imaging showed a $1.5{\times}1.3{\times}2$ cm well-defined cystic mass on the right side of both the hard and soft palate without any underlying bone change. The lesion was completely excised under general anesthesia. In order to preserve the palatal mucosa, trapdoor approach for removal of the pleomorphic adenoma was done. This technique provided more comfortable healing of the operative site. Three years after surgery, there was no evidence of recurrence. If pleomorphic adenoma without bony and mucosal destruction exists, we suggest consideration of the trapdoor approach to protect the palatal mucosa. In view of the potential for tumour recurrence, long-term follow-up and careful examination are necessary.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.887-895
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• 2017

This paper presents a study on the accelerated life tests of parts that operate during the opening and closing of door frames, particularly door hinges. Hinge theoretical verification and validation of the test equipment in the present study and the different structures and fault mode, depending on the purpose of usage analysis, failure mode for one of the hinges of the switchgear components used for electromagnetic shielding facilities and on-site operating conditions. The accelerated life test was designed for the characteristic lifetime prediction of the components, by estimating the shape parameter and the acceleration factor.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.216-221
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• 2011

An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1027-1036
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• 2007

Since the opening of the Seoul Metro in 1974, the electric railway passengers have been increased rapidly and as the advanced equipments(OC,PSD) were introduced, additional power facilities were built in a limited area for the comfortable transportation environment. Present grounding system were built according to old Electric equipment standards and all the electric signal, communication and electronic equipments were built only for the purposes of protecting building structure, people and electronic equipments. Grounding system which was additionally built in the limited area caused problems with the building structure and it caused secondary damages when earth fault happens. One of the problems is grounding system of the building structure; grounding system does not work properly since grounding equipments are not separated from each other. So, existing grounding system needs to be improved and unified grounding system in the building should be established. The purposed of this study is to analyze all the grounding systems that had been built in different year and to establish unified grounding system of Seoul Metro.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.134-141
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• 2006

Surface deflections have a great effect on the external appearance of automobiles. Usually, they are occurred on large flat panels containing sudden shape changes and of very small size about $\pm$30$\sim$300$\mu$m. Since the current numerical method is not sufficient for predicting these defects, the correction of these defects still depends on trial and error, which requires a great deal of time and expense. Consequently, developing the numerical method to predict and prevent these defects is very important far improving cosmetic surface qualities. In this study, an evaluation system that can analyze surface deflections using numerical simulation and a visualization system are reported. To calculate the surface deflections numerically, robust algorithms and simulation methodologies are suggested and to visualize them quantitatively, the curvature variation algorithm is proposed. To verify the developed systems, the experimental die of the handle portion of exterior door is analyzed. The results showed that the experimental and simulational visualization are in good agreement. Compensation methods to correct the surface deflections are also tested. The evaluation system proposed in this paper could be used to predict and minimize the occurrence of surface deflections in die manufacturing.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.164-173
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• 2015

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.