• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.489-493
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• 2012

Automatic tool changers(ATCs) store tools used in a machining center to its magazine and changes the tools automatically. Tools of machine centers are changed and then precisely equipped to spindle system by the ATC. Therefore, the stability and reliability of the ATC is very important. But, there is lack of development and evaluation on basic performance and vibration of the ATCs. So, in this study, a BT40 ATC test bench was developed to verify stability and reliability of BT40 ATCs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.163-174
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• 1997

Development of control model and system for AMS (Automated Manufacturing Systems) has long been interested by researchers. Presented in the paper is a systematic approach to constructing a Petri-nets(PNs) model of AMS and method for design a graphical model of a AMS by using a new modeling tool which is called PNs. So, the procedure of modeling in the AMS is the same as current practice of AMS design and is based on the IOM (Integrated Object-oriented Modeling) paradigm. An AMS, which consists of various machine groups, can produce machine parts in different physical dimensions and lot size. To model such a system, the method which utilizes Sub-PNs are proposed. This enables the models according to part routings. The machine group which causes bottleneck is obtained and modified to relieve the problem. By iterating these steps which consist of modelling, simulation, and performance evaluation, an AMS can e obtained which satisfies the required manufacturing conditions. Finally, the implementation issues of PN modeling are addressed. The approach is the IOM from PN modeling by Sub-PNs and the other is a development of IOM tool for the performance evaluation of AMS.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.97-103
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• 2006

This paper described the design and performance evaluation of fiber optic gyro using digital closed-loop processing. For the feedback to null the gyro input rate, digital serrodyne modulation was employed, and for scale factor stabilization, the control circuits of modulation amplitude and optical power are implemented. Performance tests show that prototype fiber optic gyro has bias stability of 0.34 deg/hr, scale factor non-lineality of about 100ppm, and maximum measurement range of ${\pm}500$ deg/sec.

• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.37-41
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• 2012

High-efficiency and low-noise axial flow fan is developed by combining the FanDAS, a computerized axial fan design/performance analysis system, and CFD software(CFX). Based on fan design requirements, FanDAS conducts 3-D blade geometry design, quasi-3D flow/ performance analyses and noise evaluation by using through-flow analysis method and noise models for discrete frequency and broadband noise sources. Through the parametric studies of fan design variables using FandDAS, preliminary and baseline design is achieved for high efficiency and low noise fan, and then can be coupled with a CFD technique such as the CFX code for constructing final and optimized fan design. The FanDAS-CFX coupled system and its design procedure are applied to actual fan development practice. The FanDAS provides an optimized 3-D fan blade geometry, and its predictions on the performance and the noise level of designed fan are well agreed with actual test results.

• Nuclear Engineering and Technology
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• v.35 no.6
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• pp.566-580
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• 2003

To resolve the concern of the SWR possibility in LMR and improve the economic feature of LMR, relative performance of various SG designs using a double tube bundle configuration is evaluated and a new SG design concept is proposed. The new steam generator design houses two tube bundles that are functionally different and its tube bundle region is radially divided into two. It prevents the occurrence of sodium water reaction while sodium is still used as the coolant for the primary heat transport system. The feasibility of the SG with a double tube bundle for actual use in an LMR plant is evaluated by setting up the skeleton of the NSSS for various possible configurations of the SG tube bundles. The evaluation revealed the relative advantages and disadvantages of the configurations and the new SG design concept performs good and can be actually used in an LMR plant.

• IE interfaces
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• v.17 no.spc
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• pp.152-159
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• 2004

The Purpose of this paper is to propose performance evaluation schemes of flexible manufacturing cell using a generalized stochastic Petri net. In the competitive and global manufacturing environment, to evaluate the feasibility and manufacturability of a product in the product design stage is highly required. Through this process, all the possible problems which may occur in the manufacturing stage can be fixed in early stage. The scheme of generalized stochastic Petri net utilizing both immediate and exponential distributed transitions are applied to model a manufacturing cell with flexible machines, material handler, transporter and buffers. Performance analyses are performed based on behavioral, structural and quantitative properties. A flexible manufacturing cell is evaluated using a Petri net simulator.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.4
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• pp.197-204
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• 2017

This paper aims to analyze the economic feasibility and investigate the possibility of elastic seismic design of wind-designed highrise concentrically braced frames considering change of mechanical properties of Korean steel under the strong wind and the low seismicity in Korea. To this end, first, highrise concentrically braced frames were designed considering strong wind load. And then, analyses of the economics of them were performed. The seismic performance evaluation of wind-designed highrise buildings was conducted using the response spectrum analysis procedure. Analysis results show that it is possible to save up to approximately 90% of the amount of steel on the 10% increase in steel strength without serviceability. However, with serviceability, the design sectional area of the steel with relatively high strength tends to increment considerably because of the lateral stiffness due to reduction of the inertia moment and so on. This point might apply to limitation of the steel with high tensile yield strength.

• KIEAE Journal
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• v.15 no.4
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• pp.85-90
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• 2015

Purpose: In design and planning Building Integrated Photovoltaic(BIPV) system can reduce cost by replacing building facade as construction material such as roofs, outer walls and windows as well as generating electricity. BIPV system should be applied at the early stage of architectural design. However, it is hard to decide whether using BIPV system or not for architects and builders who are not professional at BIPV system because performance of system is considerably influenced by types of module, installation position, installation methods and so on. It is also hard for experts because commercialized analytical program of photovoltaic systems is too complicated to use and domestic meteorological data is limited to partial areas. Therefore, we need evaluation program of BIPV system which can easily but accurately interpret generating performance and evaluate validity of BIPV system at the early stage of architectural design even for inexpert. Method: In this study, we collected meteorological data of domestic major region and analyzed generation characteristic of BIPV system by using PVsyst(commercialized software) in accordance with regions, types of solar module, place and methods of installation and so on. Based on this data, we developed performance evaluation program of BIPV system named BIPV-Pro, through multiple regression analysis and evaluated its validity. Result: When comparing predictive value of annual average PR and annual electricity production of BIPV-Pro an that of PVsyst, each of root mean square error was 0.01897 and 123.9.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.91-99
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• 2020

A liquid rocket engine goes through many tests to prove its performance before liftoff. It means the tests for setting ignition and start-up conditions or a test on design condition, which verifies the design performance. However, the development process requires verification of performance under off-design conditions through tests involving different operating conditions, which affects the duration of engine development. The off-design performance test is performed by altering the conditions of the propellant supplied to the engine in conjunction with the engine performance test that varies the opening of the control valves in the engine. This paper is based on the results of the engine tests performed at the KSLV-II engine test facilities in the Naro Space Center and describes the operations of the test facility for off-design condition test that changes the inlet conditions of the turbo-pump due to changes in the pressure and temperature of the propellant supplied to the test engines.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.337-348
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• 2015

Touch input method is unintended difficulties regarding touch and input have increased with touch input methods when compared to using a mouse for input in previously existing menus. This study attempted to analyze usability evaluations according to form and size changes of minimal button forms in button menus. This attempted to verify possibilities through more effective applications of the quantitative performance prediction evaluation model through comparative analysis of Fitts' Law, the representative model of the regression model formula and the interface human performance evaluation method, so that applications can be made in interface designs of touch input methods. Therefore it was significant in that it made reflections on design with consideration given to use user times according to button forms and size changes that can be applied to touch screens.