• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.20-25
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• 2011

In this paper, we reviewed the spindle system's motor and bearing and its mode safety for optimal design of a high speed spindle system that exceeds DmN value of 1,500,000. We could verify that it has a separation margin during critical speed by performing critical speed analysis. Also, we have selected an optimal sensoring installation location and actually manufactured & installed the sensor by identifying the stress concentration position in the axial load through finite element analysis to install the built-in piezo electric type load sensor to the spindle housing that can measure and monitor the machining load during high speed rotation of the spindle. Reproducibility is also verified by calibrating the error through the sensor's sensitivity adjustment after comparing the output between the plate dynamoneters and the load sensor to confirm the reproducibility of the load sensor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.393-398
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• 2004

This paper is focused on practical applicability of the optical fiber sensor considering the machine center which is going to use them. Optical fibers may be fluctuated because the machine center operates as column moving type. This causes distortion of the sensor output signal. To reduce this problem, we have improved the sensor structure and its bracket. And we evaluated performances of the sensor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.833-835
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• 2010

The SPARTAN-3E development kit is equipped with an FPGA which holds 500 thousand logic gates and a bus system platform using MicroBlaze microprocessor system. This kind of embedded systems can be used to gather information from sensor nodes and send over to the main server periodically through the network gateway, using the microprocessor-based embedded system, so that edlers living alone under sensor coverage can send their moving information and can be applied to get help in the event of emergency situations. In this paper, we designed a simple embedded system based on a CPU and flash memories using such FPGAs which can be used to monitor those elderlies living alone. The developed hardware system can be directly combined with the web-based elders-living-alone monitoring system, making the system more efficient.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.127-133
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• 2015

In this study, an analytical model was developed for one-dimensional finite element analysis (1D FEA) of a spindle system of machine tools and then implemented to automate the FEA as a tool. FEA, with its vibration characteristics such as natural frequencies and modes, was performed using the universal FEA software ANSYS. VBA of EXCEL was used to provide the programming environment for its implementation. This enabled graphic user interfaces (GUIs) to be developed to allow interactions of users with the tool and, in addition, an EXCEL spreadsheet to be linked with the tool for data arrangement. The language of ANSYS was used to develop a code to perform the FEA. It generates an analytical model of the spindle system based on the information at the GUIs and subsequently performs the FEA based on the model. Automation helps identify the near-optimal design of the spindle system with minimum time and efforts.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.103-105
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• 2003

ebXML은 UN/CEFACT와 OASIS가 주축으로 제정한 전자상거래 표준으로 XML 기반의 인프라를 제공하여 글로벌 e-비즈니스가 가능하도록 하는 것을 목적으로 한다. 최근 여러 ebXML 레지스트리간의 Cooperation이 중요해지면서 2003년 6월에 제정된 ebXML RIM(Registry Information Model) 버전 2.5와 ebXML RS(Registry Service) 버전 2.5 스펙**에서는 Federation, Object Relocation, Object Replication을 포함하는 레지스트리 간의 Cooperation 기능과 더불어 Content-based 질의, Event Notification, Iterative 질의와 같은 기능들이 새로 추가되었다. 따라서. 본 논문에서는 ebXML 버전 3.0 레지스트리를 구현하기 위해서 ebXML 버전 3.0 레지스트리의 시스템 구조를 설계하였으며, 버전 3.0에서 가장 중요한 기능인 Federation을 효율적으로 관리하는 방안을 분석, 설계하고 사용자가 보낸 Federation에 대한 질의를 처리하기 위한 알고리즘을 설계하였다.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.213-219
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• 2002

A cone-shaped active magnetic healing spindle system for high speed internal grinding with built-in motor that has 7.5kW power and maximum rotational speed of 50,000 rpm is designed and built. Using cone-shaped AMB(Active Magnetic Bearing) system, the axial rotor dick and magnets of conventional 5-axis actuating design can be eliminated. so this concept of design provides a simple magnetic bearing system. In this paper, the cone-shaped electromagnets are designed by magnetic circuit theory, and a de-coupled direct feedback PID controller is applied to control the coupled magnetic bearings. The designed crone-shaped AMB spindle system is built and constructed with a digital control system, which has TMS320C6702 DSP, 16 bit AD/DA, switching power amplifier and gap sensors. As the AMB system provides high damping ratio eliminating overshoot and resonance speed, this spindle runs up to 40,000 rpm stably with about 5${\mu}{\textrm}{m}$ of runout.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.38-48
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• 2004

Recently the use of high-speed equipment in machine-tool industry has greatly increased, which requires the development of prognostics and prediction methods on the design stage. Conversion of the test/experiments stage from real to virtual reality will not only significantly reduce the design and manufacturing cost, but will also increase design quality. This paper shows how it is possible to develop the automated system for the design calculations of the air-bearing spindles. First, the general calculation method is introduced. It contains several steps, namely, geometry identification, pressure calculation, stiffiness calculation, dynamics characteristics calculation. For geometry identification reducing spindle shaft to rings was proposed, which helps to automate the calculation process. For pressure calculation the Peshti method was implemented. For stiffiness calculation the analysis was made, which shown the necessity of correct calculation step selection. Then the system of ordinary differential equations containing influence coefficients was evolved, which is used for trjectories calculation. The graphical representation of the calculation results shows the dynamic behavior of the spindle unit concerning various working conditions. Finally, this automated system is illustrated by an example of the air-bearing spindle calculation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.281-284
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• 2003

Development of internet had centered on that offer universality of expression. But, graphic processing of expression center has many inconveniences because of method that is not structural in World Wide Web. Announced SVG that is XML application to permit efficient expression and storage of vector graphic expression, share in W3C to supplement these things. Therefore, because using SVG document in this treatise, edit vector graphic through interface that could edit expressed graphic object directly structural edit and screen that is offered in graphic edit system form and designed SVG edit system to express. This system may use usefully to efficient XML graphics processing on the GIS system and Mobile service environment and so on.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.740-741
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• 2017

사물인터넷 기술은 다양한 제품과 서비스를 통해 우리생활 곳곳에서 빠르게 현실화되고 있으며, 특히 사물인터넷을 기반으로 하는 스마트홈 시장이 급속도로 성장하고 있는 중이다. 여러 글로벌 제조사들은 이러한 흐름에 따라 스마트홈 서비스를 주축으로 소비자 중심의 다양한 스마트홈 제품들을 출시하고 있다. 그러나 현재 스마트홈은 제조사마다 독립적인 플랫폼을 개발하고 이에 연동되는 특정 디바이스 및 서비스만 제공하기 때문에 소비자 입장에서는 폐쇄적인 시스템이라 할 수 있다. 본 논문에서는 단순히 스마트홈 디바이스의 제어뿐만 아니라 IFTTT 플랫폼과 연동하여 자동화 서비스를 지원하고, DIY 제품을 등록하여 사용자 환경에 따라 커스텀 디자인이 가능하도록 하는 스마트 홈서비스 서버를 설계하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1497-1508
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• 1993

Real-time mobile robot controllers usually have been designed focused on control theory without paying attention to the importance of system integration. This paper demonstrates that autonomous mobile robots require a real-time controller with a wide range of capabilities in addition to control theory. An architectural frame work supporting these capabilities has been designed in actual hardware environments. Individual modules such as a path planner, a path tracking controller, position estimators, wheel controllers and other cruical elements have been successfully integrated into the control system using this frame work. The overall performance of the system was investigated via a series of tracking experiments with a prototype mobile robot named LCAR deveoped in the laboratory. The context of the research involves the architecture, its implementation and experimental results.