• Proceedings of the KSR Conference
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• 2001.05a
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• pp.443-450
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• 2001

This paper shows the reduction effect of tile earthquake-induced liquefaction potential of soils that improved by Vibro-Replacement Stone Columns. The Vibro-Replacement Stone Columns method transforms soft cohesive soils into a composite mass of compacted granular or crushed stone columns by using vibrating equipment and water jets. This study investigated and analyzed the behavior of the stone columns and composite ground using the results of in situ test and measurement at the job-site. This paper shows the evaluation of the earthquake-induced liquefaction potential of soils using in situ test. There are different types of in situ test used in the evaluation the liquefaction potential. In the particular study the Standard penetration test, and Cone penetration test were used. The N value of Standard Penetration test has been used all over for a very long time. The evaluation of the liquefaction of soil was performed using the worldwide renewed Cone penetration test

• Agribusiness and Information Management
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• v.9 no.1
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• pp.18-22
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• 2017

It takes lots of time and labor if a worker have to measure the water quality at a certain but designated time every day in an un-automated aqua farm. In addition, if the equipment is soaked in the sea water consistently, it will be contaminated by diverse floating matters and barnacles, and it often becomes mal-functional within 2~3 months. Therefore, we need to develop a system with which the sensed data could be checked in real time and operated automatically, while preventing the contamination of the sensor, a crucial component for water quality measuring equipment, as much as possible, and increasing the replacement cycle. We have developed a non-cleaning water quality measuring equipment and its software which are used in the fishery household of offshore aqua farms. By providing the workers with a mobile application which has a function of monitoring the water quality in real time, they can check the situation directly without going to the fishery household.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.143-145
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• 2007

The development of excitation control system (ECS) for emergency diesel generator in nuclear power plant is the replacement project of existing control system to resolve the maintenance problems caused by aging and obsolescence, The excitation control system is classified as a safety-related system. To guarantee the performance of developing excitation control system is equal to or higher than that of other systems, establishing the quality assurance scheme, doing software verification and validation activities, and planning equipment qualification. In this paper, we'd like to introduce the equipment qualification of excitation control system.

• Geomechanics and Engineering
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• v.23 no.4
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• pp.381-392
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• 2020

The difficulties, challenges and limitations faced in standard pressuremeter testing in the measurement of low soil deformations led a number of researchers to think about the possible modification of the equipment, and especially the replacement of the volumeter by a Hall Effect sensor. This article is a major contribution in this direction. It makes an attempt to detail the design, manufacture and operation of the new equipment. The calibration of the various components was carried out according to the rules presently in force. This proposal was applied, on an exploratory basis, to the data of a real site located in France. The authors present the preliminary results of some cyclic pressuremeter tests, previously carried out in the laboratory, on a sandy material, and they then provide a basic interpretation of these results. The findings indicated that the proposed apparatus is capable of providing high-quality information about constraints and deformations. Although these tests were performed within the laboratory, it was possible to analyze the power, quality, performance and insufficiencies of the proposed equipment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.87-92
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• 2018

One of the problems with the base station equipment is that there is a large difference between the replacement time of the hardware equipment such as the base station equipment and the radio access equipment, and the evolution period of the communication standard. Therefore, the base station communication platform must be flexible enough to handle the evolving communication standards after purchase. Recent research on reconfigurable communications platforms has focused on the efficient architecture of the communications platform to meet these requirements through software downloads while still using existing hardware. This paper presents a prototype of a base station communications platform based on the ETSI standard reconfigurable architecture. The communication platform presented in this paper is implemented as an ETSI standard reconfigurable architecture using a general-purpose DSP (Digital Signal Processor). In the implemented prototype, we verify the real-time feasibility of communication protocol updates through software reconfiguration.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2152-2153
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• 2011

According to a sharp increase in demand for electricity supply secure, and $CO_2$ regulation in accordance with global environmental problems and to solve problems, etc. These factor less pollution, higher energy conversion hyoyulin way that the new electrical equipment, nano-composites The rapid degeneration of the unit study utilizing the power that is required is Free. Accordingly, cables, transformers and switchgear (GIS)-capacity of power equipment, such as, high-voltage high-density along with the miniaturization of equipment have made angry the reliability of these devices is becoming a very important issue. Insulation materials used in electrical equipment for high voltage withstand, power equipment, power equipment due to aging and overloading caused by a weakening of the insulation failure and replacement in accordance with the age due to increased costs because of the reliability of electrical equipment should be secured should. Therefore, improved performance and longevity of insulation material is recognized as an important challenge. In this study, power isolation and degeneration of the unit for use in various parts of the molding epoxy resin to improve the insulation performance of the epoxy resin by varying the added amount of nano-SiO2 nanocomposites made epoxy/SiO2 analysis and breakdown properties of the experiment want to improve the electrical properties through the geometry.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.61-83
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• 1991

There has been a great deal of research dealing with the optimal replacement of stochastically deteriorating equipment and research in queueing systems with a finite calling population. However. there has been a lack of research which combines these two areas to deal with optimal replacement for a fixed number of machines and a limited number of repairmen. In this research, an optimal control policy for replacement involving two machines and one repairman is developed by investigating a class of age replacement policies in the context of controlling a G/M/1 queueing system with a finite calling population. The control policy to be imposed on this problem is an age-dependent control policy, described by the control limit $t^{\ast}$. The control limit is operational only when the repairman is idle; that is. if both machines are working, as soon as a machine reaches the age $t^{\ast}$ it is taken out of service for replacememt. We obtain the ${\epsilon}$-optimal control age which will minimize the long-run average system cost. An algorithm is developed that is applicable to general failure time distributions and cost functions. The algorithm does not require the condition of unimodality for implementation.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.48-50
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• 2005

New environment change of electric power system focused in consumer's energy supply and demand. But electric power reliability preservation and reliability improvement countermeasure also need for long-term. It is need that change equipments that is composing electric power system in well-timed time and by maintaining, prevent breakdown beforehand and prevent consumer's power interruption by equipment fail. However, as only quantitative estimation is available by reliability estimation method that is presented in existing, it is no to use in dictionary fault prevention. Therefore, applied optimum reliability preservation through existent equipment fault data analysis of electric power system in equipment replace side, and this when maintain equipment replace of electric power system for reliability preservation using responsiveness analysis to base ordering evaluate. In existing about main equipment plain that this paper is power system the valued failure rate use this by score and precedence of electric power system equipment for replace of system considered expense.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2015-2020
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• 2011

Key set the current non-urban rail power failure of equipment to operate the railway will generate a lot of problems. I know in advance the ideal of power equipment to prevent the failure to derive an efficient replacement cycle for the power equipment monitoring and diagnosis of the condition can become necessary to develop a system. In order to determine the status of the power plant during operation and behavior of the partial discharge current state data, regular monitoring and inspection requirements also stamp the basic current, voltage, temperature and humidity should be identified.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.139-143
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• 2007

The need for technological developments of lithography equipment is urgent for the stable production in response to the rapid growth of the recent display industry. As an example, the products currently in the market face alteration problems resulting from excessive weight of the mask holder part. This is one of obstacle for the automation of the equipment. In response, the mask holder part problem has been minimized through FEM and design of experiments in order to optimize the situation with minimized Deflection and reduced mass for satisfactory replacement of the mask holder part.