• Fire Science and Engineering
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• v.31 no.4
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• pp.86-94
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• 2017

In the present study, a Cook Book method and a Static System Analysis method were compared with each other on the basis of a seismic design criteria of fire-fighting facilities and analyzed. The Cook Book method is analyzed by dividing a pipeline in each same section. In this method, a stress analysis is not possible except for the section analyzed in such a way that a brace is designed according to the weight of pipe, water and pipe fitting. To the contrary, in case of the Static System Analysis method, the stress analysis for the whole pipeline can be performed because the whole pipeline is regarded as a single structure. For the fatal stress values locally generated, it is necessary to actively perform a pipeline analysis by installing a device capable of locally relieving the stress of the pipeline. In Korea, only the Cook Book method is provided as the seismic design criteria of fire-fighting facilities, which causes many problems with diversification of seismic design. Thus, it is necessary to apply the seismic design method of the pipeline by using various kinds of engineered Static System Analysis methods.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.59-63
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• 2007

We propose a controller design analysis for a cross-coupling control system, which is essential for achieving high contouring accuracy in multi-axis CNC systems. The proposed analysis combines three axial controllers for each individual feed drive system together with a cross-coupling controller at the beginning of the design stage in an integrated manner. These two types of controllers used to be separately designed and analyzed since they have different control objectives. The proposed scheme is based on a mathematical formulation of a three-dimensional contour error model and includes a stability analysis for the overall control system and a performance analysis in terms of contouring and tracking accuracy at steady state. A computer simulation was used to demonstrate the validity of the proposed methodology. The performance variation was investigated under different operating conditions and controller gains, and a design range was elicited that met the given performance specifications. The results provide basic guidelines in systematic and comprehensive controller designs for multi-axis CNC systems. A cross-coupling control system was also implemented on a PC-based three-axis CNC testbed, and the experimental results confirmed the usefulness of the proposed control system in terms of contouring accuracy.

• Korean Journal of Computational Design and Engineering
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• v.15 no.4
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• pp.261-270
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• 2010

These days, architectural projects are becoming larger and more complex. And lots of information occurs through each phases and areas. For these reason, it is emphasized that collaboration with other parts. Therefore we need more effective architectural design process. However, it is difficult to collaborate in early stage with existing design process and it causes unnecessary spending of time and cost because of 2D-based working system. For solving these problem, we should introduce BIM-based Integrated Design Process which makes it possible to collaborate with other parts from early stage. Now the AEC industry in Korea has been trying to introduce BIM, and promoting variety of related business. However, for actual application of this system, it is unfortunately necessary to change various system throughout the construction industry. And this will cause lots of effort and expense. It is essential that scientific analysis and evaluation of efficiency and validity about this investment, because estimation of the investment and accompanying effects will provide reasonable standard of judgment for investment decision. Thus, this research conducted Cost-Benefit Analysis about BIM-based Integrated Design Process compared to existing design process. It is expected that this paper can be used for preliminary data in the future BIM market.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.393-400
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• 2010

Korea Astronomy and Space Science Institute has been developing one mobile satellite laser ranging system named as accurate ranging system for geodetic observation-mobile (ARGO-M). Preliminary design of ARGO-M operation system (AOS) which is one of the ARGO-M subsystems was completed in 2009. Preliminary design results are applied to the following development phase by performing detailed design with analysis of pre-defined requirements and analysis of the derived specifications. This paper addresses the preliminary design of the whole AOS. The design results in operation and control part which is a key part in the operation system are described in detail. Analysis results of the interface between operation-supporting hardware and the control computer are summarized, which is necessary in defining the requirements for the operation-supporting hardware. Results of this study are expected to be used in the critical design phase to finalize the design process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.355-360
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• 2000

There are many changed while a design is completed. Therefore, if the impact of the design changes is estimated, it may result in the improvement of design efficiency. But, the design changes have various types and affect other parts of the design system. Hence, it is difficult to deal with design changes directly. The purpose of this research is to develop a systematic change propagation tracing algorithm and a method of change impact analysis and then, to implement a change impact analysis system. Process based design is set up for the field of this research. Also the design, composed of design parameters and constraints, is set up for the subject of the research. Change propagation tracing algorithm traces change propagation based on the following concept : If the design parameters are changed, other parameters within the constrains including them may be changed. Using the result of change propagation tracing algorithm, changeable parameters, constraints and tasks can be found. The method of change impact analysis, to calculate change impact value from this changeable tasks, is developed. Change propagation tracing algorithm and the method of change impact analysis are implemented into change impact analysis system and it is applied to the redesign of 2 stage gear drives. It can support different kinds of design activities systematically. especially, at the redesign step, where many design change alternatives exist, change impact value of each alternative exist, change impact value of each alternative is calculated and design change is performed toward direction to minimize the impact of design change. Consequently, it is expected to improve the efficiency of the whole design.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.3
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• pp.140-151
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• 2004

This paper presents the HVDC system modelling for analysis of subsynchronous oscillation and the design of the subsynchronous oscillation damping controller in HVDC system with the aid of novel eigenvalue analysis program. The HVDC system models include both the steady-state model for power flow calculation and the dynamic model for constructing the state matrix. The design procedures of the subsynchronous oscillation damping controller (SODC), which is integrated with PI controller at rectifier, consist of three steps:1) to identify the dominant torsional oscillation mode in the AC/DC system;2) to determine the parameters of the SODC for compensating the phase lagging due to the rectifier controller;3) to validate the control parameters and to determine the appropriate gain using a time-domain simulation program. The proposed design method has been tested against two AC/DC systems for validation.

• Korean Journal of Computational Design and Engineering
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• v.15 no.2
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• pp.157-165
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• 2010

In the manufacturing industries, CAE analysis results are frequently required during the product development process for design verification. CAE data which include all related information of an analysis is, however, not efficiently shared among engineers because CAE data size is in general very large to deal with. At first, we represent a proposed lightweight format which is capable to include all the types of CAE analysis results and to support hierarchical data structure. Since each CAE system has different data structures of its own, a translator which translates to the proposed format is also represented. Unlike the design environment with CAD system, many CAE systems are used in a manufacturing company because many sorts of analysis are performed usually for a product design. Thus, lots of CAE results are generated and occupy huge size within storage, and they make it harder to manage or share many CAE results efficiently. A multi-CAE management system which is able to share many types of CAE data simultaneously using lightweight format is proposed in this paper. Finally, an implementation of the system for this will be introduced.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.155-158
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• 1997

In design of current transformer, equivalent circuit parameters is obtained by electromagnetic analysis and used circuit simulation. Precise core secton area and turns of coil can be determined by circuit analysis. Therefore exact design of current transformer is possible by field and circuit analysis.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.5
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• pp.630-639
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• 1998

The present research aimed at development of a computer code for the optimal design of ventilation system based on one-dimensional analysis of the air flow. Model experiment and three-dimensional flow analysis have been implemented to determine loss coefficients that were needed for the optimization technique. A research on optimum shape of ventilation shaft has been also carried out through the three-dimensional analysis of the flow.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.633-636
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• 2005

An electro-optical camera system consists of many subsystems such as the optics, the detector, and the electronics and so on. They may create variations in the processed image that were not present original scene. The performance analysis of the electro-optical camera system is a mathematical construct that provides an optimum design through appropriate trade off analysis. The SNR(Signal to Noise Ratio) is one of the most important performance for the electro-optical camera system. The SNR analysis shown in this paper is performed based on the practical high resolution satellite camera design. For the purpose of the practical camera design, the analysis assumes that the defined radiance, which is calculated for the Korean peninsula, reached directly to the telescope entrance. In addition, the actual operation concept such as integration time and the normal operation altitude is assumed. This paper compares the SNR analysis results according to the various camera characteristics such as the optics, the detector, and the camera electronics. In detail, the optical characteristics can be split into the focal length, F#, transmittance, and so on. And the system responsivity, the quantum efficiency, the TDI stages, the quantization noise and the analogue noise can be used for the detector and the camera electronics characteristics. Finally this paper suggests the optimum design to apply the practical electro-optical system.