• Journal of Digital Contents Society
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• v.3 no.2
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• pp.245-254
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• 2002

Currently, communication field for automation system can be divided by simple serial communication for communication between each internal devices and network base remote control system that is based on TCP/IP. In spite of great development of network, communication part for internal control is using simple RS232 base until present. Also, development techniques of system developed by object oriented program in modular programming techniques of each function unit. Currently, it developed by component base development technique that is parts unit of software. This is presented by the new alternative of software development techniques as techniques to composition independent operation unit including business logic and is connected to development of new system. Therefore, this research implemented internal communication Emulate in RS232C based on GUI that apply development techniques of component base. that is, I maked component to commnication control part between receiving and sending and, as composite it, Control part did to handling between send and receive data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.984-995
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• 1996

Data errors according to the various noises caused in the satellite communication links are corrected by the Viterbi decoding algorithm which has extreme error correcting capability. In this paper, we designed and implemented a convolutional encoder and Viterbi decoder ASIC which is used to encode the input data at the transmit side and correct the errors of the received data at the receive side for use in the VSAT communication system. And this chip may be used in any BPSK, QPSK, or OQPSK transmission system. The ambiguity resolver corrects PSK modem ambiguities by delaying, interting, and/or exchanging code symbol to restore their original sequence and polarity. In case of previous decoding system, ambiguity state(AS) of data is resolved by external control logic and extra redundancy data are needed to resolve AS. But, by adopting decoder proposed in this paper, As of data is resolved automatically by internal logic of decoder in case of continuous mode, and by external As line withoug extra redudancy data in burst mode case. So, decoding parts are simple in continuous mode and transmission efficiency is increased in bust mode. The features of this chip are full duplex operation with independent transmit and receive control and clocks, start/stop inputs for use in burst mode systems, loopback function to verify encoder and decoder, and internal or external control to resolve ambinguity state. For verification of the function and performance of a fabricated ASIC chip, we equiped this chip in the Central and Remote Earth Station of VSAT system, and did the performance test using the commerical INTELSAT VII under the real satellite link environmens. The results of test were demonstrated the superiority of performance.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.239-245
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• 2004

Electrocardiogram and phonocardiogram acquired from ECG and stethoscope by a non-invasive method are bio-signals which laue been a great role in patients diagnosis and used extensively by doctors. And these are mainly used at the examination room or first-and room of hospital. When the patients are located at some places far away from hospital like a car, an airplane and a vessel under way, there are some difficulties in confirming their cardiac sound Especially the patient of ocean going vessel might not have a medical treatment from the professional doctor at times. In this paper, we developed the digital ECG and stethoscope system based on personal computer which can easily measure the patient's cardiac sound and ECG signal, and this might shorten the appearance of the remote maritime telemedicine.

• Journal of the Korean Institute of Educational Facilities
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• v.9 no.5
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• pp.5-12
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• 2002

High-speed telecommunication has brought variety of changes in every field of the world at large. In the field of education, use of multimedia has been positively introduced as teaching and learning tools. In addition, introduction of remote education as well as information and communication technology (ICT) has led an educational system gone into melting pot. These changes have known to be impossible without the provision of the infrastructure of telecommunications such as cabling, cable pathway, telecommunication equipments, and space for the equipments. Although the infrastructure of telecommunications should be fully considered from the early stage of the building design, most of the existing buildings have only cabling for voice communication such as telephone. As a result, heavy expenses are required for the installation of new telecommunication equipments. Such problems as defilement of the appearance of the building and a falling-off in reliability of telecommunication line are caused by the exposed cabling, when the cabling pathway and/or the space for the equipments are not reserved. Considering over 70% of error in telecommunication is coming from the cabling in building, it is necessary to reserve the space for efficient maintenance of the cabling and the equipments. In recent years, the national standard(TTAS.KO-04.0005) on the reservation of space for telecommunication cabling and equipments in residential and commercial building is established and applied for the building design. As well, the standard is in force for the educational buildings. In this study, we try to provide the guidelines for the design of telecommunications infrastructure in educational buildings for the purpose of efficient operation of education information and ICT.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.520-527
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• 1988

Liquid ejectors are widely used as marine pumps, inducer stage for the boiler feed water pump, boiler recirculating pump, cooling water recirculating pump in boiling water type nuclear reactor and a deep well pump, because of their high working confidence and simplicity. Furthermore, it requires only a modest net positive suction head for cavitation-free operation and it can be installed in remote location from mechanical power source. It is not easy to presume the friction losses, because it is complicately affected by area ratio, flowrate ratio, nozzle spacing, throat length, shape of liquid ejector and so on. Therefore, the optimization of liquid ejector design is still dependent, to a large extent, on the experimental results and empirical procedures. On the design of the liquid ejector, the area ratio and the nondimensional throat length are the most important design factors among the mentioned above. In this experiment, the effects of the area ratio and the nondimensional throat length to ejector efficiency are carried out systematically by the combination of 4 kinds of motive nozzle and 2 kinds of throat length. In this paper, the present experimental results are compared with the calculated ones by the previous computer aided design program based on one dimensional flow equation. And also, an empirical equation for the working limit of liquid ejector is reported.

• Journal of IKEEE
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• v.24 no.2
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• pp.392-402
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• 2020

This paper proposes a solar tracking system without photo-sensors. The system can be classified into four modules: Solar Tracking, MPPT, ESS, and Real-Time Monitoring. Nine solar panels, as a basic unit, are adopted with grid structures of different heights to reduce wind influence and to enable solar tracking without photo-sensors. The low-cost MCU implements MPPT method which generates PWM switching signal for boost converter. The unit of ESS consists of three-series and four-parallel lithium-ion batteries in order to enable monitoring for abnormalities in temperature and electrical characteristics of battery. Four MCUs used in the system consists of two AVR Atmega128, and two Raspberry PI, and they exchanges operation informations. Experimental results of the proposed system show the solar tracking performance, the possibility of on-site and remote monitoring and the convenience of maintenance based on IoT technology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.145-151
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• 2017

In this paper, we propose the design and implementation of the system that is predicting the failure of ballast water treatment system by analysing its sensor datum and is reserving the most effective service center for sellecting the repair location on the way to the destination port. These data are collected in real time during draining or filling up the sea water from/to the ship, and it is essential to preliminarily repair the equipment showing unstable characteristics by analyzing the normal and abnormal data characteristics. We proposed a software platform for predicting and repairing faults by selecting the most efficient repair center based on this e-Navigation while the vessel is navigating to the next destination port. This system, as announced by the IMO Convention for the Prevention of Marine Pollution in 2017, provides a stable economic impact from stable cargo operation and stable out/in from/to port and marine ecosystem.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.17-25
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• 2020

In this paper, we deal with a system that provides temperature, humidity and fine dust data around infants to parents through Arduino and Raspberry Pi. It controls the operation of the mobiles remotely through applications. Android applications can perform the following functions. First, the infant's surrounding temperature, humidity and fine dust data are received. Second, mobile controls the smart mobile remotely. Third, recording and playing the voices of parents and enhancing the convenience of parenting. Through the experiment of measuring the operating time of the remote control module, it was confirmed that the application can quickly access the system. Existing products on the market do not provide environmental information around the infants and application that has various functions. The system covered in this paper is expected to improve child-rearing convenience by providing parents environmental information around infants, remotely controllable function and convenient functions of the application.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.73-80
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• 2008

The recent trend in home network system includes intelligent home environments that remote monitoring and control service is achieved without restrictions by device types, time, and place. Also the use of a vacuum robot in homes is gradually generalized on account of the convenience of the use. In this paper, we proposed and realized new home-monitoring system with the employment of an self-movement robot as one trial for realizing an intelligent home under home network environment. The proposed system can freely monitor every where in home, because the system effectively overcame the surveillance limitations of the existing monitoring system by attaching a Wireless Router and WebCam to a commercial vacuum robot. The outdoor users of this system can readily monitor any place which they want to supervise by controlling a vacuum robot with mobile telecommunication devices such as PDA. The wireless router installed with Linux operation system "OpenWrt" made it possible for the system users to transmit images and to control a vacuum robot with RS-232 communication.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1191-1202
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• 2013

The former researches on earthwork automation were mainly focused on GPS and sensor application, environment modelling, equipment path planning, work information management, and remote control etc. Recently, reducing $CO_2$ emission becomes one of main focuses for an automation research. In the case of earthwork operations, many kinds of construction machines or robots are involved, which can cause high level of $CO_2$ in a construction site. An effective earthwork plan and construction machine operation can both increase productivity and safety and decrease $CO_2$ emission level. In this research, some automation concepts for green earthworks are suggested such as a 3D construction site model, a 3D earthwork distribution based on two different earthwork methods, and an earthwork package construction method. A excel-based simulator is developed to generate the 3D earthwork distribution and to estimate the level of $CO_2$ emission for the given earthwork.