• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.950-953
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• 2003

In this paper, sigma-delta A/D converter for ADSL modems using oversampling technique is designed. Conventionally, the oversampling A/D converter is consist of opamps, switched capacitors, quantizers, infernal D/A converters, and decimation filters. 3-bit flash A/D converter, 3-bit thermometer-based D/A converters, and sub-blocks are used for high speed operation. HSPICE simulator and CADENCE tool are used for verification and layout of the designed modulator. The internal A/D converter and D/A converters are operated at 130 MHz. In design of decimation filter Matlab is used for calculating coefficients and ModelSim and VHDL are used for design.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.2
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• pp.76-90
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• 1986

This paper discusses the analysis of flexible manufacturing systmes design using computer simulation method. The simulation language employed is SIMAN which is a powerful tool to model flexible manufacturing systems. The important characteristics of FMS, its design and operational problems, and structures based on the number of NC machine tools and their layout are discussed for the appli- cations of FMS to manufacturing. A new algorithm for forming part families and machine groups has been proposed and its software is also developed. Simulation procedure using SIMAN for analysis of FMS designs is discussed and two design problems are analyzed and evaluated to illustrate systemstic procedure for analysis of FMS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.972-975
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• 2004

In order to reduce the noise of BLDC motor, a systematic optimization procedure for rotor structure is presented. The noise index is defined as the sum of volume velocity of FE-model that are calculated at the dominant frequencies during dehydration process, which is based on the principle of radiation simple volume source. Then, the five design variables are selected to represent the shape and layout or rotor structure. This discrete design optimization problem for minimizing the noise index is solved by 3-level orthogonal array based effect analysis. Finally, the response surface method (RSM) combined optimization approach is employed for more refining the approximate optimum.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.455-461
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• 2000

A multichannel signal processing algorithm for generating real time virtual sound field was proposed. Evaluation of the system performance was done by an objective function that minimizes the difference between the real and generated signals at each control point. Since impulse responses at the surface of a rigid sphere show characteristics similar to those of real HRTF, a rigid sphere model was adequate to simulate the multichannel sound system. A two-channel system and two four-channel systems were studied with various combinations of source locations and speaker positions. The results show that a two-channel system has its best configuration when the angle spanned by the loudspeakers is less than $60^{\circ}$. In the case of four-channel systems, the overall performance was highly improved with one pair of speakers fixed at an optimal position. Left/right symmetry was a reasonable choice, but the additional front/back symmetry degraded the performance of system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.2
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• pp.1-9
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• 2019

In this study, we constructed a system to operating and manage the resources of the Smart Library Reading Room automatically using the Internet of things. The persistent problem of smart library or unattended library is electric energy waste and efficient seat management. The electricity and seat layout management method of the existing library reading room is being treated as concentrated management in the central system. However, this approach results in wasting electricity and seats do not provide a fair opportunity for each user. In this study, IoT sensor was used to turn off electricity and empty seat for about 20 minutes, so that it could be marked as vacant and managed efficiently, so that opportunities for seats were evenly maintained. In the future, we will improve this and construct a model in the reading room of actual village library or school library, and analyze and reflect the result.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.171-179
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• 1994

For successful implementation of robotic painting system, a structured design and analysis procedure is necessary. In designing robotic system, both functional and economical feasibility should be investigated. As the robotization is complicated task involving implemen- tation details (such as robot selection, accessory design, and spatial layout) together with operation details, the computer aided design and analysis method should be sought. However, conventional robotic design systems and off-line programming systems cannot accommodate these inquiries in a unified fashion. In this research, we develop an interactive design support system for robotization of a cycle painting line. With the developed system called SPRPL (Simulation Package for Robotic Painting Line) users can design the painting objects (via FRAME module), select robot model (ROBOT), design the part hanger (FEEDER), and arrange the workcell. After motion programming (MOTION), the design is evaluated in terms of: a) workpace analysis, b) coating thickness analysis, and c) cycle time (ANALYSIS).

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.19.1-24
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• 1998

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don't have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, and etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of a refrigerator. EMG measurement was used to evaluate the load of user's lumbar muscle. Based upon the experimental EMG data, we developed a model to predict the relative load according to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R style, were compared with the model. A three-dimenaional motion analysis method was used to evaluate the user's motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the user's arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we made several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of a refrigerator.

• International Journal of Contents
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• v.16 no.2
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• pp.92-101
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• 2020

Industrial integration is the innovative embodiment of regional economic theory. The promotion of industrial integration is conducive to improving the scale effect and spillover effect of the industry. Also, it has the power to radiate, drive, and lead the innovation and development of the whole industrial cluster. The purpose of this paper was to identify the most suitable development pattern of the ice-snow sports tourism industry in Zhangjiakou, one of the host cities of the 2022 Winter Olympics. This study combs the characteristics of the development of the ice-snow sports industry, and analyzes the current situation of the industry in Zhangjiakou based on the SWOT-AHP method. This paper argues that the integrated industry is the most suitable development pattern for the promotion of the ice-snow culture industry in Zhangjiakou. The following content will present effective countermeasures to accelerate the development of the ice-snow culture industry integration in Zhangjiakou from three aspects: industrial resource integration, industrial chain layout, and scientific and technological innovation. The IT live simulation technique facilitates identifying some vital elements during the data collection.

• Structural Engineering and Mechanics
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• v.43 no.6
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• pp.711-724
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• 2012

The goal of this study is to conceptually orientate optimized layouts of outrigger belt trusses which are in widespread use today in the design of tall buildings by strut-and-tie truss models utilizing a topology optimization method. In this study unknown strut-and-tie models are realized by using a typical SIMP method of topology optimization methods. In tradition strut-and-tie model designs find the appropriate strut-and-tie trusses along force paths with respect to elastic stress distribution, and then engineers or designers determine the most proper truss models by experience and intuition. It is linked to a trial-and-error procedure based on heuristic strategies. The presented strut-and tie model design by using SIMP provides that belt truss models are automatically and robustly produced by optimal layout information of struts-and-ties conforming to force paths without any trial-and-error. Numerical applications are studied to verify that outrigger belt trusses for tall buildings are optimally chosen by the proposed method for both static and dynamic responses.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.98-104
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• 2011

The introduction of a diesel engine into the passenger car and light duty applications in the United States involves significant technical challenges for the automotive makers. This paper describes the SCR System optimization procedure for such a diesel engine application to meet Tier2 Bin5 emission regulation. A urea SCR system, a representative $NO_x$ reduction after-treatment technique, is applied to a 3.0 liter diesel engine. To achieve the maximum $NO_x$ reduction performance, the exhaust system layout was optimized using series of the computational fluid dynamics and the urea distribution uniformity test. Furthermore a comprehensive simulation model for the key factors influencing $NO_x$ reduction performance was developed and embedded in the Simulink/Matlab environment. This model was then applied to the urea SCR system and played a key role to shorten the time needed for SCR control parameter calibration. The potential of a urea SCR system for reducing diesel $NO_x$ emission is shown for FTP75 and US06 emission standard test cycle.