• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.109-120
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• 2017

It is important to estimate objectively in the driving test. Especially, the driving test is examined by totally driving ability, rule observation and situational judgement. For this, a grading automation system for driving test was presented by using GPS, sensor data and equipment operation informations. This system is composed of vehicle mounted module, automatic grading terminal, data controller, data storage and processing server. The vehicle mounted module gathters sensor data in the car. The terminal performs automatic grading using the received sensor data according the driving test criterion. To overcome the misposition of vehicle in the map due to GPS error, we proposed the automatic grading system by map matching method, path deviation and return algorithm. In the experimental results, it was possible to grade automatically, display the right position of the car, and return to the right path under 10 seconds when the vehicle was out of the shadow region of the GPS. This system can be also applied to the driving education.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.329-338
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• 1999

In this paper we propose a WATM MAC protocol called DTDD/PS (Dynamic Time Division Duplex using Poll/Select scheme). The idea of the DTDD/PS protocol is based that a radio cell is considered as queueing system. The MAC controller in base station is charged in coordinating terminals for the QoS requirement from each terminal. For that reason, terminals send it's own dynamic parameter represented its status, and controller controls the access of terminals and assigns time slots dynamically using received parameters. Therefore this system can satisfy the QoS of real-time service in wireless environments. To evaluate DTDD/PS protocol simulations are executed. In 25Mbps channel capacity, the voice and data coexist traffic situation, as the total number of terminal is increased, the delay of data terminals is increased rapidly. But the case of only increasing data terminals, the number of supported voice terminals is not varying. Therefore we can expect that DTDD/PS protocol can applied to multimedia traffic effectively.

• Journal of Drive and Control
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• v.10 no.2
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• pp.7-12
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• 2013

In this study, a wire/wireless communication system transmitting the operation data of engine from the ER (Engine Room) to the engine controller of ECR(Engine Control Room) has been developed through the communication of ISM(Industrial Science Medical) Band for the test operation environment improvement of medium speed engine. This wire/wireless communication system is composed of the RTU (Remote Terminal Unit) gathering and transmitting engine data as well as the MCU (Master Control Unit) receiving engine status information from the RTU to be sent to the engine controller (PLC). Through this study, a trial product of RTU and MCU has been manufactured. A test bench that has made temperature, pressure and pick-up sensor into a module for the local test of prototype was produced a test bench. In addition, at the same time save the data to a Web server and the smart phone real-time monitoring system has been developed using Wi-Fi communications. The ultimate objective of this study is to develop a wireless smart phone monitoring system of engine for the operator of engine to be able to monitor and control engine status even from the outside of engine room and control room based on this study.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.15-16
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• 2015

According to 2014 fire statistical yearbook in the National Fire Data System, a main cause of fire is electrical fire except carelessness fire. Joint/contact badness is the one of the main cause of electrical fire. Furthermore, power relays which are used in electric panel board, motor control center and automation controller, are main element of automation system in the industry field. Overload, voltage unbalance and open-phase due to joint/contact badness of terminal make electric accidents or electrical fires. In order to prevent joint/contact badness of terminal, this paper proposes a sensing circuit of chattering, tracking, arc current, voltage unbalance and open-phase etc. Some experimental tests of the proposed apparatus confirm practicality and validity of the theoretical results.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.57-62
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• 2012

The purpose of this paper is to find dangerous factors of a water purifier when water leaks due to inappropriate use and analyze the patterns of damaged parts in order to provide data for the examination of the cause of the problem. If the water purifier is inspected and managed by a non-specialist, when the FLC(Float Level Controller) at the top is inclined, water leakage may occur to the water purifier. The leaked water flows onto the cables and hoses and enters the thermostat terminal, heater, PCB, power supply connection connector, etc., becoming a dangerous factor that may cause a system failure, fire, etc. Due to the water that entered the input terminal, low noise and white smoke were generated at first. However, the flame gradually propagated due to the continuous inflow of moisture. It was found that when moisture reached the PCB, a carbonized conductive path was formed at the varistor terminal, input terminal, semiconductor device terminal, etc., and the flame became larger, which might result in a fire. From the metal microscope analysis of a damaged condenser terminal, it was found that the amorphous structure unique to copper cable disappeared, and voids, boundary surface and disorderly fine particles occurred. Also, in the case of the connector into which moisture penetrated, fusion and deformation occurred at the cable connection clips. The result of analysis of the power supply cable connector using a thermal image camera showed that most of the heat was generated from the cable connection clips and the temperature at the connection center was normal.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2390-2392
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• 1998

In this paper, we discuss the development of monitoring system with data process equipment which transfers data from Remote Terminal Unit(RTU) to monitoring computer. The RTUs sense temperature, pressure and PLC(Programmable Logic Controller) nodes conditions of scrubber in semiconductor manufacture processing. The data Process equipment is connected every RTU and a monitoring computer through serial communication. This equipment receives informations from RTU, process data, and transfers them to monitoring computer. To avoid congestion in data communication, task scheduling algorithm used RT O/S(Real-Time Operating System) is embedded in ROM which is a part of data Process equipment.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.4
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• pp.209-214
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• 2011

This study suggests a Healthcare System for elderly and disabled who have mobility impairment and use a wheelchair for long time. Seating long time in a wheelchair without reducing pressure causes high risk of developing pressure sores. Pressure sores come with great deal of pain and often lead to develop complication. Not only it takes time and effort to treat pressure sores but also increases medical expenses. Therefore, we will develop a device to help to prevent pressure sores by measuring pressure distribution while seating in a wheelchair and wirelessly send information to user device to check pressure distribution in real time. The equipment to measure body pressure is composed of FSR sitting mat which is a sensor measuring part and an user terminal which is a monitoring part. The designed mat is matrix formed FSR sensor to measure pressure. The sensor send measured data to the controller which is connected to the end of the mat, and then the collected data are sent to an user terminal through a bluetooth. Developing a pressure monitoring system will help to prevent those who have mobility impairment to manage pressure sores and furthermore relieve their burden of medical expenses.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.385-390
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• 2015

Quay cranes are considered core equipment for container terminal operation. However, unmanned operation systems have not as yet been announced due to the technological difficulties of implementation. In this paper, we developed a wireless controller to control a quay crane simulator remotely and conducted its performance test, a first step toward unmanned operation of quay cranes. The communication delay of a developed wireless controller was about 9.4ms on average while that of existing wired controllers was about 5.6ms. The same functions were implemented and tested on a smart phone where the average communication delay was 7.3ms. In addition, to apply the developed system into a real environment, we proposed a network architecture based on IEEE 802.11ac and carried out its performance evaluation. When the distance between two nodes was 50m apart, the throughputs of the TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) were 57Mbps and 189Mbps, respectively. The communication delay of the control data was 9.1ms through the TCP channel. These results reveal the proper working of remote quay crane operation if we adopt the IEEE 802.11ac network.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.10
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• pp.10-20
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• 1994

This paper presents a CATV SMS (Status Monitoring System) using HDLC (High Level Data Link Contorl) protocol and the system implementation.The system specifications were derived from the analysis of technical status and requirement of the domestic CATV industry. For the interoperability with a global network management system in the future, HDLC protocol was adopted in the system. The system performance was improved by using the communication controller chip and the large data buffer. For reducting the communication problems induced by accumulated noise in up-stream data channels, the system was designed that the different communication channel can be assigned to each proper mass of terminal. The operating software was designed with menu driven user interface and have various functions for the convenience of users. The test result of the implemented system at the experimental network showed good performance and suitability for a coaxial CATV Status Monitoring System.

• Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.67-72
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• 2020

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, on ships and aircraft, mobile communications requiring base stations are either unavailable or restricted in their use. In this paper, we used a Raspberry Pi board as the terminal device to communicate network through satellite modem and PPP protocol, and implemented two-way data link using the text message of the modem to connect to the Thuraya geo-stationary orbit network. In addition, I/O devices were connected to the controller of the terminal equipment to design and implement an IoT device system for ships that can remotely access the system under control and control I/Os and transmit measured data through various sensors.