• Journal of Engineering Education Research
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• v.6 no.1
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• pp.5-14
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• 2003

This paper presents a simplified web-based simulator for digital logic circuits with which several important principles related to digital logic circuits can be understood and confirmed. The proposed simulator is implemented to have several simplified functions which are essential to the learning process of digital logic circuits. The learners by themselves simulate several digital logic circuits on the web under specific input conditions and the design/analysis of digital logic circuits can be available. The proposed simulator, combined with multimedia contents, can be used as an auxiliary educational tool and enhance the improved learning efficiency. The results of this paper can be widely used to improve the efficiency of web-based educations in the cyber space. Several simulation results are illustrated as examples to show the validity of the proposed web-based simulator.

• Journal of the Korean Institute of Plant Engineering
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• v.23 no.4
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• pp.29-38
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• 2018

Through process quality information, the time required for process quality analysis has been drastically shortened, the process defect rate has been reduced, and the manufacturing lead time has been shortened and the on-time delivery rate has been improved. Therefore, The purpose of this study is to develop a quality information analysis system model that effectively shortens the time required for process quality analysis in automobile safety belt parts manufacturing process. As a result of experiments on communication operation between manufacturing execution system (MES) quality server, injection machine control computer, injection machine programmable logic controller (PLC) and terminal, in analyzing quality information, the conventional handwriting input method took an average of 20 minutes, but the new multi-network method took about 2 minutes on average. In addition, the process defect rate was reduced by 13% and the manufacturing lead time was shortened from 28 hours to 20 hours. The delivery compliance rate improved from 96 to 99%.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1757-1762
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• 2003

With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.292-297
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• 2013

Nowadays, a strategy of the self-optimizing machining process is an imperative approach to improve the product quality and increase productivity of manufacturing systems. This paper presents a concept of self-optimizing forming system that allows the forming system automatically to adjust the forming parameters online for guarantee the product quality and avoiding the machine stop. An intelligent monitoring system that has the functions of observation, evaluation and diagnostic is developed to evaluate the pully quality during forming process. Any abnormal variation of forming machining parameters could be detected and adjusted by an intelligent control system aiming to maintain the machining stability and the desired product quality. This approach is being practiced on the pully forming machine for evaluating the efficiency of the proposed strategy.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.284-287
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• 2001

In this paper, we designed and implemented a precise pulse motor control chip that generates the parabolic speed pattern. This chip can control step motor[1], DC servo[2] and AC servo motors at high speed and precisely. It can reduce the mechanical vibration to the minimum at the change point of a degree of acceleration. Because the parabolic speed pattern has the continuous acceleration change. In this paper, we present the pulse generation algorithm and the parabolic pattern speed generation. We verify these algorithm using visual C++. We designed this chip with VHDL(Very High Speed Integrated Circuit Hardware Description Language) and executed a logic simulation and synthesis using Synopsys synthesis tool. We executed the pre-layout simulation and post-layout simulation with Verilog-XL simulation tool. This chip was produced with 100 pins, PQFP package by 0.35 um CMOS process and implemented by completely digital logic. We developed the hardware test board and test program using visual C++. We verify the performance of this chip by driving the servo motor and the function by GUI(Graphic User Interface) environment.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.4
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• pp.42-48
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• 2002

The case that cannot show the satisfactory control results with a modeling error and a shortage of related knowledge about a plant is if a fuzzy controller designed based on the plant model or the experience applies to an actual plant. We must adjust the scale factor which is a controller again in order to improve control performance in case of this and needs a lot of time and costs because this regulation process is carried out with a trial and error way We proposes the fuzzy controller that an automatic control adjust scale factors according to fuzzy logic and normalizer in this paper We confirmed that an automatic adjusted fuzzy controller displayed good performance than the fuzzy controller that scale factors was fixed through simulation. We implemented the controller using the DSP processor and applied in a hydraulic servo system. And then we observed an experimental results.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.110-118
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• 2007

Technology has been viewed at various stages of civilization as leading to future progress. The building, its services systems and management of the work process all contribute to the well-being of people within an organization. Productivity relies on there being a general sense of high morale and satisfaction with the workplace. Now buildings are considered as providing a milieu for human creativity. Flexibility, adaptability, service integration and high standards of finishes offer an intelligence threshold. Building Automation System(BAS) - controlled lighting systems may offer incremental energy saving. Conventional Lighting control systems often control equipment in a single room or over the limited area, because they are centralized control systems, which means that all the controlled circuits must be wired to a single control panel. The computers used by these systems are typically dedicated microprocess that perform only lighting control functions. By comparison, modern Building automation systems are distributed control system, which means that their computing hardware and software are distributed as a network that microprocessor-based control modules and standard PC. PLC(Programmable Logic controller) is extensible virtually without limits, so that all the lighting in a facility can be controlled by single, unified system - the same system that also can control and monitor the building's HVAC, security, and manufacturing processed, elevators, and more. A Building automation system can control light using schedules, manual controls, occupancy sensors, and photosensors, either singly or in combination. Building Lighting control and monitoring system will be for a energy saving and efficient building management system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1379-1386
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• 2005

For efficient welding it is necessary to maintain stability of the welding process and control the shape of the welding bead. The welding quality can be controlled by monitoring important parameters, such as, the Arc Voltage, Welding Current and Welding Speed during the welding process. Welding systems use either a vision sensor or an Arc sensor, both of which are unable to control these parameters directly. Therefore, it is difficult to obtain necessary bead geometry without automatically controlling the welding parameters through the sensors. In this paper we propose a novel approach using fuzzy logic and neural networks for improving welding qualify and maintaining the desired weld bead shape. Through experiments we demonstrate that the proposed system can be used for real welding processes. The results demonstrate that the system can efficiently estimate the weld bead shape and remove the welding detects.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.49-58
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• 2011

It is required that a developed control system should be verified using simulator in terms of functionality and reliability prior to application to a power plant that is a very critical facility in the industry. In this paper, the control model for turbine bypass system was developed for power plant simulator. In order to develop the control model for turbine bypass system, the tool that can be used to implement turbine bypass control logic was developed based on the turbine bypass control system manual. The developed tool was merged into the simulator development environment. The functionality of the developed tool was verified via the simulation based on the each function block specification. The HP turbine bypass pressure control logic was implemented using the developed tool and was integrated with process models and other control models such as boiler control model, turbine control model and boiler feed water pump turbine control model for 500 MW korean standard type fossil power plant. Finally, the validity of the developed control model was shown via simulation result under the integrated simulation environment.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.6
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• pp.20-27
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• 1993

The white-balance system for color tevision is characterized by 5 input-5 output nonlinear process. A design strategy of fuzzy control rules is treated in which it can be adopted to the white balance adjustment for color television. A fuzzy rule based on an expert's knowledge is constructed, and then a multivariable fuzzy control rule is designed. Since human has just two hands, he can manipulate two variables simutaneously. In case when the process to be controlled has more than three control variables, expert's control rule is much different from the multivariable control rule. A multivariable fuzzy control rule is constructed by utilizing the expert' knowledge and rough relations between input and output variables, and its usefulness is shown by experiments.