• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.387-390
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• 1997

Grinding process takes a long time that grinding machine is setted properly. It is difficult for user to judge correctly the abnormal states generated in grinding process. Air grinding has to be reduced for the improvement of productivity. In addition, it is important to monitor the dressing and the grinding process so that the grinding working maintains optimal grinding conditions. In this study, the monitoring system using the acoustic emission is developed to monitor these processes continuously. This system was able to reduce the preparation as well as the machine setting time in grinding operation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.4
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• pp.303-311
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• 1981

Machine tool dynamics is investigated under actual working conditions. Experimental evaluation of cutting dynamics in a lathe is made with cutting conditions and cutting positions varied. The thrust force and the toolpost and tailstock accelerations during turning process are modelled and analyzed by employing Dynamic Data System methodology. It is found that two acceleration signals are good enough to replace the thrust force, when used for machine tool identification under cutting process and for chatter detection.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.527-535
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• 2020

This study analyzed main causes of claims in EPC/Turnkey projects. For this purpose, this study referred to the FIDIC silver book, which lists the international standard contract conditions for EPC/Turnkey projects. The most frequent cause of claim was delay. A process was then proposed to determine whether the owner or contractor was the responsible party when the delay claim occurred. The proposed process was for damages for delay which is the conditions of contract for indemnities against delay claim. The process was based on conditions of the contract of two previous EPC/Turnkey projects that were constructed in 2010, the FIDIC silver book, as well as the obligations of owner and contactors. The proposed process is applicable depending on the conditions of the contract and the owner's meaning. Furthermore, by identifying the responsible party, this study will contribute in identifying the possible claim types before concluding a contract and writing the specific contract.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.557-575
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• 1999

As the Internet has been used widely in modern firms for gaining competitive advantage in the market, EC (Electronic Commerce) emerged as one of strong alternatives for this purpose. Many researchers and practitioners have proposed a wide variety of EC frameworks that can consider only the structured conditions, but there exists no EC mechanism in which engaged entities can take into account the various unstructured conditions. With the conventional EC framework, the structured EC conditions such as price, quantity, delivery date, etc. can be fully negotiated during the EC process. However, no studies have been conducted on the issue of incorporating those unstructured conditions which are difficult to represent in an explicit form and therefore hard to consider explicitly during the EC process. They are characterized by causal properties. This means that we should have a new EC mechanism which is capable of dealing with causal knowledge. In this sense, we propose a FCM (Fuzzy Cognitive Map)-based simulation framework for EC to resolve the problem of considering the unstructured conditions during the EC process. We experimented our prototype with several illustrative examples and proved that our approach is robust and meaningful.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.537-555
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• 1999

As the Internet has been used widely in modern firms for gaining competitive advantage in the market, EC (Electronic Commerce) emerged as one of strong alternatives for this purpose. Many researchers and practitioners have proposed a wide variety of EC frameworks that can consider only the structured conditions, but there exists no EC mechanism in which engaged entities can take into account the various unstructured conditions. With the conventional EC framework, the structured EC conditions such as price, quantity, delivery date, etc. can be fully negotiated during the EC process. However, no studies have been conducted on the issue of incorporating those unstructured conditions which are difficult to represent in an explicit form and therefore hard to consider explicitly during the EC Process. They are characterized by causal properties. This means that we should have a new EC mechanism which is capable of dealing with causal knowledge. In this sense, we propose a FCM (Fuzzy Cognitive Map)-based simulation framework for EC to resolve the problem of considering the unstructured conditions during the EC process. We experimented our prototype with several illustrative examples and proved that our approach is robust and meaningful.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.431-439
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• 1996

New design principles nad necessary conditions for a mechanical system have been suggested to be kept in the design process using a washing machine transmission as a model. The necessary conditions are funcitnal requirement condition and spatial arrangement condition. The design principles to satisfy the necessary conditions are the principle of sequence and the principle of expansion. Decision sequence for state variables and design varibles of various mechanicla elements have been formulated. New automatic design program for washing machine transmission has been developed observing the necessary conditions and design principles investigated in this study. It was verified to be very effective to follow the design conditions, principles nad formulated decision sequence in mechanical system design process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.10a
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• pp.30-36
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• 1995

This paper proposed on the effective cutting conditions of cage motor rotor by turning. If you want to introduce automatic manufacturing system into the cutting process of cage motor rotor, the selections of effective cutting conditions are necessary. The cutting process of cage motor rotor requires the precision and the out of roundness of cage motor rotor. The surface roughness of cutting face. it is very important factor with effect on the magnetic flux density of cage motor rotor. The purpose of this study is to find out the effects of cutting condition. upon adapting this results, we will improve the production rate in the cutting process of cage motor rotor. As a result, the selection of cutting conditions are important factors to production rate. And these are chosen by the investigations of cutting characters and surface roughness. The experimental result, showed that the increase of cutting speed caused the decrease of cutting force and the high surface integrity. The increase of feed rate and increase of depth of cut caused the increase of cutting force and surface roughness. Thus, the effective cutting conditions of cage motor rotor by turing are cutting speed 291m/min, feed rate 0.10mm/rev, depth of cut 0.05mm.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.378-380
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• 2009

$MgF_2$ is a current material for the optical applications in the UV and deep UV range. Process variables for manufacturing the $MgF_2$ thin film were established in order to clarify optimum conditions for growth of the thin film depending upon process conditions, and then by changing a number of vapor deposition conditions and substrate temperature, Annealing conditions variously, structural and Optical characteristics were measured. Thereby, optimum process variables were derived. Nevertheless, modern applications still require improvement of the optical and structural quality of the deposited layers. In the present work, the composition and microstructure of $MgF_2$ single layers grown on slide glass substrate by Electro beam Evaporator(KV-660) processes, were analyzed and compared. The surface Substrate temperature having an effect on the quality of the thin film was changed from $200[^{\circ}C]$ to $350[^{\circ}C]$ at intervals of $50[^{\circ}C]$. and annealing temperature an effect on the thin film was changed from $200[^{\circ}C]$ to $400[^{\circ}C]$ at intervals of $50[^{\circ}C]$. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM.

• Transactions on Electrical and Electronic Materials
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• v.11 no.1
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• pp.33-36
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• 2010

$MgF_2$ is a current material used for optical applications in the ultraviolet and deep ultraviolet range. Process variables for manufacturing $MgF_2$ thin film were established in order to clarify the optimum conditions for the growth of the thin film, dependant upon the process conditions, and then by changing a number of the vapor deposition conditions, substrate temperatures, and heat treatment conditions, the structural and optical characteristics were measured. Then, optimum process variables were thus derived. Nevertheless, modern applications still require improvement in the optical and structural quality of the deposited layers. In the present work, in order to understand the composition and microstructure of $MgF_2$, single layers grown on a slide glass substrate using an Electron beam Evaporator (KV-660), were analyzed and compared. The surface substrate temperature, having an effect on the quality of the thin film, was changed from $200^{\circ}C$ to $350^{\circ}C$ at intervals of $50^{\circ}C$. The heat treatment temperature, which also has an effect on the thin film, was changed from $200^{\circ}C$ to $400^{\circ}C$ at intervals of $50^{\circ}C$. The physical properties of the thin film were investigated at various fabrication conditions, such as the substrate temperature, the heat treatment temperature, and the heat treatment time, by X-ray diffraction, and field emission-scanning electron microscopy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.10-16
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• 2021

Drilling is a crucial process that takes up a significant amount of weight during machining operations. In addition, drill tip-type tools and related operations have been developed for manufacturing industries to achieve economic efficiency. In this study, SM45C carbon steel, widely used for machine structures, was utilized as the working material after quenching and tempering. Insert-tip types of carbide tools, such as TiN and TiAlN, were used as tool materials. Drilling conditions such as the spindle revolution, feed rate, step of cut, and tool diameter were used to measure roughness, roundness, and straightness using the orthogonal array table statistical method. The surface roughness, roundness, and straightness characteristics based on the conditions were analyzed using ANOVA. The results showed that the spindle speed and feed rate were the main factors influencing carbide insert-tip drilling under the same conditions as the experimental conditions.