• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1098-1103
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• 2014

This study deals with the development of an electrofusion welding machine that is capable of joining plastic pipes using a recently developed electrofusion fitting. This fitting has built-in conductive plastics that are used to weld the joint together as a heating element. In order to explain the mechanism of the new machine, 1) the resistance characteristics of the heating element were explained, 2) the method of electric welding that uses the electrofusion fitting was described, and 3) the method of power supply based on controlling the firing angle was explained. A control system for an intelligent electrofusion welding machine was proposed. This system has the ability to recognize the diameter of an electrofusion fitting using a lookup-table based on the difference of resistance curves according to fitting types, and it is able to weld the fittings regardless of the ambient temperature. A new algorithm was developed to control the power of electric welding through the recognition of feature points from the resistance curve of the heating element. In order to evaluate the performance of the developed welding machine, tests involving the welding of 16 mm- and 20 mm-type fittings were carried out. Examining the welding results, we concluded that the proposed welding machine will offer high productivity and reliability in the field of electrofusion welding.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.691-717
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• 2008

The Kyoto Mechanisms allows a supplementary means for compliance, CDM(Clean Development Mechanism) and JI(Joint Implementation) projects. The investment in CDM projects is increasing rapidly as the first implementation period began in 2008. This paper seeks to determine factors affecting the price of primary CER using UNFCCC CDM Project Development Document(PDD) data. This study employs the Cluster analysis and the GLS(Generalized Least Squares) method.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2171-2172
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• 2006

Magnetic nerve stimulation treatment is much backward real condition than other field. Specially, successful medical treatment introduction of magnetic field (MF) can was refered long ago in Avicenna's work, and is thought as age of medicine magnetology development recently. These development is achieved through biologist and biophysicist and clinician's joint effort, but, new mountings and relationship air tassel are developed steadily. Magnetic nerve stimulation treatment field designs treatment system by each function during long wave high-amplitude (traditional magneto therapy of greatly great that strong that) short time that CMF, VMF, PMF field etc. are representative but are HPMT technology in this research and manufacture and special quality did comparative analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.267-278
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• 2010

To improve the grout penetration characteristics, vibration method was adopted in this study. The grout material perturbed by cyclic vibration is injected into the ground. By applying the vibrating flow system, cement particles will become less adhesive and the clogging tendency will be decreased. A series of pilot-scale chamber tests were performed to verify the enhancement of the groutability by applying the vibratory grout injection; assessment on change of the lumped parameter $\theta$ which represents a barometer of clogging phenomenon was made. Moreover, the effect of vibratory grout injection through the joint was also investigated using artificially made rock joints. Experimental results as well as analytical results show that the grout penetration depth can be substantially improved by vibration grouting. Moreover, it was found that enhancement of the permeation grouting due to vibratory injection is more dominant at low grouting pressure of less than 400kPa.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.325-332
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• 2009

This study is aimed to investigate the application of DITA(Defense Information Technical stAndard) on the weapon information systems and defense management information systems in order not only to update the current DITA version 4.0, but also to develop SoS(System of systems) interoperability policy in the armed forces of Korea. For this study, 18 information systems were considered, their development products(System/Sub-system Specification, Technical architecture View, System Interoperability Test and Evaluation products) were reviewed and analysed. As a result of the investigation and analysis, it was found that the 44% of the DITA standard profiles were used for the development of the defense information systems. We conclude that DITA should be updated to be a minimal set so that all the defense information systems should be DITA-compliant. And it should be reviewed periodically to reflect the new information technology.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.81-88
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• 2005

In soft grounds with deep bearing stratum, the PHC piles are generally joined by welding or prefabricated method. However, the existing joining methods have some problems in a side view of workability, quality and cost etc. In this study, a new joining method of PHC piles, which removes the problems of the existing methods, is developed. Static and dynamic load tests in fields as well as laboratory tests such as tensile and bending tests are conducted to investigate the workability and structural safety of PHC piles joined by the new method. The test results show that tensile and bending resistances of the joint part are higher than those of PHC pile itself. PHC piles with 400mm diameter are joined by the new method within 4 minutes while 25 minutes for welding method. Bearing capacities of the PHC piles joined by the new method are nearly the same as those of jointed PHC piles by welding method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.93-100
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• 1993

With increasing technology, requirement to car noise and related dynamics are getting competitive keypoint. Unfortunately, vibro - acoustic behavior of a car is nowadays only possible after development of prototypes. But, obviously, in the Area of Research, many of Industrials, Universities and research centers try to codevelop the design tools to predict the vibro-acoustic behaviors. At this stage, it is more realistic to represent the existing technologies in order for the engineer to get their own know-how to design and to Integrate existing techniques, to setup their test facility, and to develope some tools with which they can successfully predict noise levels of car in the design phase. Moreover, most of the theories which will be represented in this paper can be used in the design phase. At any way, finding the cause of trouble shooting is more urgent than the design of a car to the test engineer. In this paper, transfer path analysis, noise source identification, and the key test method of modal analysis is introduced. Later, if I get the opportunity to present in KSNVE, the approach method of modal analysis is introduced. Later, if I get the opportunity to present in KSNVE, the approach method of finding characteristics of joint and welding part will be introduced. Most parts of this paper was quoted from the papers of LMS.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.385-394
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• 2013

Short-term agricultural machinery rental system has been operated by agricultural extension organization of local government (agricultural technology center) and sponsored by Ministry of Agriculture, Food, and Rural Affairs, to improve utilization efficiency and save agricultural production cost through joint utilization of agricultural machinery. This study was conducted to analyze current status of the rental system operation and provide recommendations for future direction. Question survey was conducted for officers in charge of the rental system in the technology center, and strategic improvement was suggested through importance performance analysis (IPA). Survey results showed that 11 issues should be reformed or improved by 2015, which is not practically feasible. IPA analysis resulted that administration and manpower support, cooperation between federal and local organizations, and cooperation with other organizations should be focused for successful operation of the rental system. Issues that seem to happen after 2015 need to be handled as future research.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1430-1436
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• 2010

Tubular member is hollow and is an excellent source of structural member with great buckling resistance and tortional resistance. With its development and simplicity in structure, steel tubular truss has the ability to be structured in long span bridges, without a stiffener. Recently, it has been used in many countries in Europe, Canada, Japan, and the US with the help of international committees such as CIDECT(International Committee for the Development and Study of Tubular Structures and International Institute of Welding). The most important problem when using the tubular member is the fact that it is difficult to test the fatigue stress determined by nominal stress, since geometrical stress concentration occurs due to the welded joint's nod of complexity. The purpose of this study is to compare and examine current theories and widely applied Hot Spot stress determinations through finite element analysis, which is about welded joints of steel tubular truss. We would like to suggest a way of design practice which involves a bridge plan with rarely domestically used steel tubular truss` basic research data as well as considering the future of tubular member.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.263-270
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• 2006

Magnetic nerve stimulation treatment is much backward real condition than other field. Specially, successful medical treatment introduction of magnetic field (MF) can was refered long ago in Avicenna's work, and is thought as age of medicine magnetology development recently. These development is achieved through biologist and biophysicist and clinician's joint effort, but, new mountings and relationship air tassel are developed steadily. Magnetic nerve stimulation treatment field designs treatment system by each function during long wave high-amplitude (traditional magneto therapy of greatly great that strong that) short time that CMF, VMF, PMF field etc. are representative but are HPMT technology in this research and manufacture and special quality did comparative analysis.