• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.1-10
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• 2012

Recently, we have witnessed the definitely negative impacts of large-scale accidents happened in such areas as atomic power plants and high-speed train systems, which result in increased fear for the potential danger. The problems appear to arise due to the deficiency in the design of large-scale complex systems. One of the causes can be attributed to the design process that does not fully reflect the safety requirements in the early stage of the system development because of the substantially increased complexity. In this paper, to enhance the systems safety an integrated process is studied, which considers simultaneously both the system design process and system safety process from the beginning of the system development. In the conceptual system design phase an integrated process model is constructed by analyzing the activities of both the system design and safety processes. As a case study example, an inner city train system is described with the application of the developed process. The computer simulation of the example case is followed by the result discussed. The results obtained in the paper are expected to be the basis for the future study where a detailed process and its associated activities can be developed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1993.10a
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• pp.51-54
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• 1993

In this paper, it is proposed the the SCADA(Supervisory control and Data Acquisition) system in Apartment complex. The proposed SCADA system make use of the computer CRT(Cathod RAy Tube), which automatically observe the Electrical Facility, Elvator Facility, Fire Alarm Facility and process in the real-time data. In order to improve the hardware performance and the information process, the SCADA system composed of master-slave topology and decentralized the supervisory Facility. This system is expected the retrenchment of construction expenditure and the level-up of supervisory execution.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.79-85
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• 1993

An integrated structural design system can define and process complex design information that occurs in each of the design stages for flexible cooperation. It can also reduce human error on sequential design steps: preliminary design, analysis and detailed design. Therefore, it's very important to have consistent semantic expression and procedure for structural design information that has complex relationships. In this study, we introduce the object-oriented concepts and object-oriented database thechnique that provides high level semantic expression in order to develop an integrated structural design system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1109-1113
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• 1993

A refuse incineration plant is a complex process, whose multi-variable control problems can not be solved conventionally by deriving an exact mathematical model of the process. The usage of advanced fuzzy technologies within the suitable development methodology is demonstrated by a controller implemented for the refuse incineration plant in Hamburg-Stapelfeld, Germany.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.760-767
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• 2010

For complex channel blind equalization, this study presents the performance and characteristics of two complex blind information theoretic learning algorithms (ITL) which are based on minimization of Euclidian distance (ED) between probability density functions compared to constant modulus algorithm which is based on mean squared error (MSE) criterion. The complex-valued ED algorithm employing constant modulus error and the complex-valued ED algorithm using a self-generated symbol set are analyzed to have the fact that the cost function of the latter forces the output signal to have correct symbol values and compensate amplitude and phase distortion simultaneously without any phase compensation process. Simulation results through MSE convergence and constellation comparison for severely distorted complex channels show significantly enhanced performance of symbol-point concentration with no phase rotation.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.2
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• pp.113-124
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• 2010

Since the 1970s the increased economy allowed population to concentrate on larger cities which facilitated the lack of apartment complex in the cities. In order to have the solution to the problem, apartment complex were expected to consider the efficiency of using its land. Therefore, The purpose of this study is to clarify the change of the Apartment Complex especially in the Forms and Compositions of outdoor planning of Apartment complex. As a result, the analysis of this researching process of them has shown us the following important characteristics in the change of the Apartment Complex.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.653-659
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• 2017

In this study, the complex forging process of an outer support ring was developed and the prototype was manufactured. The current process, hot forging and MCT machining, has a disadvantage of excessive material removal rates and longer machining hours. To overcome this disadvantage, a general shape is given through hot forging and the precision is achieved through cold forging. The complex forging process was developed with the minimal machining process. Forging analysis was carried out to design a forging process using the commercial program, Deform-3D. The hot and cold forging processes were set up based on the analyzed result. The mold and prototype were manufactured. Hardness, surface roughness, internal defect, the grain low line of the prototype were evaluated. The results showed no particular problems, and there were no problems in mass production. Using complex forging, the material was reduced by approximately 27 % compared to the process using hot forging and MCT machining. In addition, the production speed was improved 2.15 fold compared to that of hot forging and MCT machining. Through this study, a cost-effective process and mold design technology were established, which is expected to have positive effects on other related automotive parts production.

• Transactions of Materials Processing
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• v.28 no.6
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• pp.321-327
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• 2019

In this study, a hot and cold forging process was investigated to produce a complex-shaped hub of dual clutch transmission with low material loss and high productivity. The process was designed by the commercial finite element (FE) analysis program, DEFORM-2D (hot forging) and 3D (cold forging). And, the material flow and ductile fracture characteristics were studied to check the surface crack initiation of the specimen. The simulation results indicated that the proposed process could manufacture the complex-shaped hub with no surface crack and high-efficiency compared to the conventional machining process. For verification the numerical results, the hub of the SCM440 was fabricated by the proposed process and the mechanical properties and microstructure evolution were studied. It was demonstrated that the suggested hot and cold forging process might be useful in producing the key components of the automobile industry as a high-efficiency and environmentally friendly process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.464-467
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• 2005

Among several polishing techniques for micro structures, polishing process using magnetorheological(MR) fluid has advantages in the finishing process of 3-D micro structures because abrasives in the fluid can reach surfaces with complex feature and play their role. Although many researchers have been trying to reveal its polishing mechanism of the MR polishing, it has not been successful because in-situ measurement of state variables is difficult and process parameters are complex. In fact, one of the key factors for applying process control methodologies, such as Run-to-Run control, is the measuring and monitoring of slurry quality because the process strongly depends on the fluid property. Therefore, it is necessary to maintain consistent slurry quality to guarantee the process repeatability. The proposed equipment achieves the longer life cycle of MR fluid and reduces the variability of products. A new method to measure the material removal rate in MRF polishing process is also proposed and discussed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.371-374
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• 2009

Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D. Samples of metal parts were subsequently fabricated by using hydraulic press machinery.