• 한국정밀공학회지
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• 제31권2호
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• pp.125-131
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• 2014

Winding is an integral operation in almost every roll-to-roll continuous process and center-winding is suitable and general scheme in the winding system. However, the internal stresses within center-wound rolls can cause damage such as buckling, spoking, cinching, etc. It is therefore necessary to analyze the relationship between taper tension in winding section and internal stress distribution within center-wound roll to prevent the winding failure. In this study, an optimal taper tension control method with parabolic taper tension profile for producing high quality wound roll was developed. The new logic was designed from analyzing the winding mechanism by using the stress model in center-wound rolls. The performance of the proposed taper tension profile was verified experimentally.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.420-424
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• 1998

A new type of controller for DC-DC converters is presented. The proposed neuro-fuzzy controller combines fuzzy logic with neural networks to adjust parameters of the fuzzy controller to the most appropriate. Neither the exact mathematical models of the DC-DC converters nor the tuning process of the parameters of the fuzzy controller are needed in the proposed scheme. Simulation results are presented to show the above process and transient, steady state responses, and load regulation of the given system.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권10호
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• pp.575-582
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• 2003

A new FDOs (fault diagnostic observers) and the residual generation schemes using the FDOs are suggested for the process fault detection and isolation of linear (control) systems. The design method of the FDO is described, first, for the full measurement systems. Then it is extended for the systems with unmeasurable state variables. An unknown input observer is proposed and applied for the extension. The size of the observer bank may be the smallest, specially in full measurement systems, because the order of the proposed FDO is very low. In spite of the simplicity, the scheme provides the same information for the detection and isolation of the anticipated faults as the conventional multiple observer based schemes. The residuals may be structured so that fault isolation can be performed by pre-selected logic. An FDIS using the proposed scheme is constructed for the model of the four-tank system. Simulation results show the practical feasibility of the proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.481-484
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• 2002

In recent, the contactless IC card is widely used in traffic, access control system and so forth. And its use becomes a general tendency more and more because of the development of RF technology and improvement of requirement for user convenience. This paper describes the hardware module to process contactless protocol for implementation contactless IC card. And the hardware module consists of specific digital logic circuits that analyze digital signal from analog circuit and then generate data & status signal for CPU, and that convert the data from CPU into digital signal for analog circuit.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.322-327
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• 2007

Dedicated outdoor air-conditioning(DOA) system that utilizes pre-cooling and desiccant dehumidification can be superior to conventional cooling and reheating system with respect to energy consumption and indoor thermal comfort. In this work, simulation has been conducted to study various factors that affect the performance of DOA. Dynamic simulation shows the transient variation of temperature and humidity as the on/off control logic is imposed. Exit humidity of process air and flow rate are varied to study the effect on exit temperature of process air, dehumidification quantity, required regeneration temperature and exit humidity of regeneration air. For an outdoor air condition of $28.5^{\circ}C$ temperature, 16 g/kg humidity ratio and 2000 cmh flow rate, the dehumidification efficiency is increased by 4.6% as the flow rate is doubled.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권3호
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• pp.220-224
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• 2008

This paper presents the polygon-based Q-leaning and Parallel SVM algorithm for object search with multiple robots. We organized an experimental environment with one hundred mobile robots, two hundred obstacles, and ten objects. Then we sent the robots to a hallway, where some obstacles were lying about, to search for a hidden object. In experiment, we used four different control methods: a random search, a fusion model with Distance-based action making (DBAM) and Area-based action making (ABAM) process to determine the next action of the robots, and hexagon-based Q-learning, and dodecagon-based Q-learning and parallel SVM algorithm to enhance the fusion model with Distance-based action making (DBAM) and Area-based action making (ABAM) process. In this paper, the result show that dodecagon-based Q-learning and parallel SVM algorithm is better than the other algorithm to tracking for object.

• 한국멀티미디어학회논문지
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• 제25권8호
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• pp.1085-1096
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• 2022

The manufacturing industry is continuously pursuing advanced technology and smartization as it converges with innovative technology. Improvement of manufacturing productivity is achieved by monitoring, analyzing, and controlling the facilities and processes of the manufacturing site in real time through a network. In this paper, we proposed a new OPC-UA based digital twin model for smart factory facilities. A testbed system for USB flash drive packaging facility was implemented based on the proposed digital twin model and OPC-UA data communication scheme. Through OPC-UA based digital twin model, equipment and process status information is transmitted and received from PLC to monitoring and control 3D digital models and physical models in real time. The usefulness of the developed digital twin testbed system was evaluated through usability test.

• Journal of Biosystems Engineering
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• 제37권1호
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• pp.19-27
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• 2012

Purpose: Utilizing air thermal energy during over-heated time in the greenhouse is a necessary component to save greenhouse heating costs for nighttime. However, there is no practical way to implement the related principles. Methods: In this study, a heating and cooling system which utilizes the surplus air thermal energy in a greenhouse was developed. Available air thermal energy and heating load for this experimental glasshouse were estimated based on temperature conditions of the plant growth and weather data. Results: Estimated values were 400 MJ/day for maximum surplus air thermal energy and 340 MJ/day for maximum heating energy which were target values of the design as well. The system consists of a heat pump, fan-coil units and heat storage tanks which are divided into low and high temperature tanks. Moreover, a new control logic was developed for surplus air thermal energy utilization. Conclusions: This paper explains the details of conceptual design process of the system. Results of test operations showed that the developed system performed the recovery and supply of the thermal energy according to design purposes.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.617-622
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• 2018

자동차, 반도체, 플랜트 등 다양한 산업현장에서 PLC(Programmable Logic Controller) 기반으로 생산자동화 시스템을 제어하여 제품 양산이 이루어지고 있다. 이에 따라 산업현장에서는 PLC를 능숙하게 사용할 수 있는 전문 인력과 PLC 교육을 위한 교육 플랫폼이 필요하다. 기존에 개발된 교육 플랫폼들의 경우 PLC를 기반으로 하여 다양한 액추에이터와 센서를 제어할 수 있다. 하지만 화면상 나타나는 생산자동화 시스템이 화면에 2D로만 나타나 현실성이 결여되기 때문에 학습 시 정확한 이해가 힘들다는 단점이 있다. 본 논문에서는 이러한 단점을 보완하여 가상현실에서 학습이 가능한 교육용 V-Factory 시스템을 제안한다. 개발한 V-Factory 시스템은 가상 I/O 드라이버를 도입하여 다양한 종류의 센서 및 액추에이터를 제어할 수 있고, 가상현실에서 가시화된 생산자동화 시스템이 구동되는 모습을 확인할 수 있다. 또한 HMD(Head Mounted Display)를 사용하여 현실적인 PLC 시뮬레이션이 가능하다. 개발한 V-Factory 시스템을 통해 가상현실에서 효과적인 PLC 학습이 이루어질 것으로 기대한다.

• 한국정보통신학회논문지
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• 제14권8호
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• pp.1877-1886
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• 2010

본 논문에서는 전기적인 퓨즈 프로그래밍을 이용한 1T-SRAM 리페어용 리던던시 제어 회로를 설계하였다. 공급전원이 낮아지더라도 외부 프로그램 전원을 사용하여 높은 프로그램 파워를 eFuse (electrical fuse)에 공급하면서 셀의 읽기 전류를 줄일 수 있는 듀얼 포트 eFuse 셀을 제안하였다. 그리고 제안된 듀얼 포트 eFuse 셀은 파워-온 읽기 기능으로 eFuse의 프로그램 정보가 D-래치에 자동적으로 저장되도록 설계하였다. 또한 메모리 리페어 주소와 메모리 액세스 주소를 비교하는 주소 비교 회로는 dynamic pseudo NMOS 로직으로 구현하여 기존의 CMOS 로직을 이용한 경우 보다 레이아웃 면적을 19% 정도 줄였다. 전기적인 퓨즈 프로그래밍을 이용한 1T-SRAM 리페어용 리던던시 제어 회로는 동부하이텍 $0.11{\mu}m$ Mixed Signal 공정을 이용하여 설계되었으며, 레이아웃 면적은 $249.02{\times}225.04{\mu}m^{2}$이다.