• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2253-2260
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• 2009

BACnet is an international standard communication protocol especially designed for building automation and control systems. In this paper, a reference model of network management system for BACnet is proposed and its implementation method is introduced. In order to evaluate the feasibility and validity of proposed network management system, it is applied to a real experimental model of BACnet network system. Proposed network management system complies with standard BACnet protocol and its functions are implemented in software without hardware dependencies so that it can be applied not only to newly installed BACnet system but also to already installed BACnet system by software upgrade. The network management system and its implementation method introduced in this paper will help BACnet-based automation system to be managed efficiently and they can be practically applied in real BACnet-based automation systems.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.189-202
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• 2019

During thermal power coal-fired boiler operation, it is very important to detect the pulverized coal concentration in the air pipeline for the boiler combustion stability and economic security. Because the current measurement methods used by power plants are often involved with large measurement errors and unable to monitor the pulverized coal concentration in real-time, a new method is needed. In this paper, a new method based on microwave circular waveguide is presented. High Frequency Electromagnetic Simulation (HFSS) software was used to construct a simulation model for measuring pulverized coal concentration in power plant pipeline. Theoretical analysis and simulation experiments were done to find the effective microwave emission frequency, installation angle, the type of antenna probe, antenna installation distance and other important parameters. Finally, field experiment in Jilin Thermal Power Plant proved that with selected parameters, the measuring device accurately reflected the changes in the concentration of pulverized coal.

• Journal of Korea Multimedia Society
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• v.25 no.5
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• pp.695-702
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• 2022

In this paper, we propose the method of a table structure recognition in various table types for document processing automation. A table with items surrounded by ruled lines are analyzed by detecting horizontal and vertical lines for recognizing the table structure. In case of a table with items separated by spaces, the table structure are recognized by analyzing the arrangement of row items. After recognizing the table structure, the areas of the table items are input into OCR engine and the character recognition result output to a text file in a structured format such as CSV or JSON. In simulation results, the average accuracy of table item recognition is about 94%.

• Journal of Power Electronics
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• v.14 no.1
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• pp.125-134
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• 2014

This paper presents a robust and speed-sensorless stator flux estimation for induction motor direct torque control. The proposed observer is based on sliding mode approach. Stator electrical equations are used in the rotor orientation reference frame to eliminate the observer dependence on rotor speed. Lyapunov's concept for systems stability is adopted to confine the observer gain. Furthermore, the sensitivity of the observer to parameter mismatch is recovered with an adaptation technique. The nonlinearities of the pulse width modulation voltage source inverter are estimated and compensated to enhance stability at low speeds. Therefore, a new method based on the model reference adaptive system is proposed. Simulation and experimental results are shown to verify the feasibility and effectiveness of the proposed algorithms.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.2
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• pp.69-80
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• 1992

This paper deals with the evaluation methods for flexible automated assembly systems based on characteristics of automation and flexibility. In this study, the degrees of automation and flexibility are calculated quantitatively as the means of evaluating assembly systems. The degree of automation is grasped wheter the detailed assembly flexibility can be calculated indirectly14 by the estimation of cost and time which are caused to adapt the changed environment of the assembly system. As a case study, an assembly system is evaluated for showing the procedures of the developed method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.418-421
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• 2007

For Shock obsorber piston led is launched to the market through luring, milling, grooving, rolling, inspection and finally packing processes, To this time around 11 items, that is, out diameter and length etc..for the piston lod are inspected strictly as a total inspection. Piston Lod is being produced 30,000 a day and its excessively repeating inspection is getting induce repetition strain injury and reduce production rate as fatigue accumulation of worker increase inspection errors. Therefore, for the inspection process is severely needed a progressive improvement through the automation. In this study, we consider automation method of piston led inspection process and suggest an efficient automation strategy as improving the various problems in present manual inspection way.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1395-1399
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• 2005

Lately, the demand for automation in the industries has increased and automation system has continuously installed in various industrial fields. But automation for shipbuilding industries is more difficult than others. Because we must cope with diverse ship types and owner's various requirements. Nevertheless, for the past several years a steady development on welding robot for shipbuilding has been going on. Existing automatic welding robots are operated separately and do not communicate with each other. In the existing facilities, although a unit of robot has a good performance, and if all of units are not operated systematically, we are not satisfied with results of our system. So we suggest an integration and operation method of system units. System integration methods applied to our system have in many cases lead to lower cost and shorter lead time.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.172-179
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• 2001

The effects of the interface and two holes located near the crack path in the hybrid specimen on the dynamic crack propagation behavior have been investigated using dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system. The dynamic stress field around the dynamically propagating interface crack tip in the three point bending specimens under a dynamic load applied by a hammer dropped from 0.6m high without initial velocity are recorded. The complex stress intensity factors for the dynamically propagating interface crack are extracted by using a overdeterministic least square method. Theoretical dynamic interface isochromatic fringe loops generated by using the numerically determined complex stress intensity factors are compared with the experimental results. Furthermore, the influence of the hole to the dynamic interface crack velocities has been investigated experimentally.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1752-1756
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• 2003

Welding automation in shipbuilding process, especially in the assembly line is considered to be a difficult job because welding part is too huge , various and unstructured for a welding robot to weld the whole part automatically. We developed an automatic welding robot to improve those difficult process. This paper show how to systematically operate the integrated automation system which consists of several robots. We introduce our software and system integration method. Specially we focus that network communication and operating process. The developed system visualizes the operation environment using Open Inventor and communicates with the entire system via TCP/IP and FTP.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.433-436
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• 2000

우편물 자동구분 처리의 범위를 확장시키기 위하여 집배원의 배달순서로 구분하기 위한 방법이 요구된다. 이는 우편 자동구분처리를 위하여 우편봉투에 인쇄된 주소 및 우편번호를 인식하고 이에 대응하는 자동구분정보를 우편물상에 바코드 인쇄하고 판독하여 구분하게 된다. 또한, 다량우편 이용자들에 의하여 우편물 상에 고객 바코드가 사전에 인쇄된 경우에는 바코드를 판독하여 구분한다. 본 논문에서는 우편물 자동구분 처리를 위하여 적용될 4-state 바코드에 정보수록 밀도를 향상시키기 위한 방법을 적용한 것이다. 시험 결과에 의하면, 4-state 바코드의 정보수록밀도는 기존의 16.67% 보다 약 27.79% 향상시킬 수 있었다.