• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.494-500
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• 2010

In this paper, we newly propose a wireless optical identification system and carried out experiments. A wireless optical identification system consists of a reader and a transponder. The configuration of a reader is the same as that of a transponder, which uses LED light as transmission media and detects the signal light with a solar cell. Optical alignment with a lens is not required because the absorption area of a solar cell is wide and flat, and it is very easy to attach a solar cell on the surface of an object. As the light wavelength does not interfere with radio frequency, a wireless optical identification system shows stable operation. In experiments, we realized a wireless optical identification system that automatically identifies the transponder data at a distance of 1 m using solar cells.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.89-96
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• 2010

In this paper, "a wireless camera image transmission system" is aimed for the free camera shooting in the indoor and outdoor environments. Currently in broadcasting program production environments, because the cable connections between TV OB VAN(outside broadcasting VAN) and EFP camera or ENG camera have many obstacles and limits of distances, it is very unconvienent for the free camera shooting. Therefore in this paper, wireless image transmission device and receiving device in DVB-T broadcasting are developed. In this paper, analog composite image signal output camera, image signal compression MPEG-2 system and COFDM mage transmission system are produced and experimented. The results for the image and transmission system had good QoS values and from this results, it is possible to apply TV program productions and wireless CCTV device industries.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.989-996
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• 2008

Recently, a few types of fish-cage in open sea are researched. This fish-cage has to operate monitoring system for keeping an optimum living condition for fish. The most efficient monitoring system is WVMS(Wireless Vision Monitoring System) for fish-cage in open sea. WVMS should be able to transmit video signal and communicate with each controller. So. it needs to be based on WLAN(Wireless LAN) which has characteristic of higher transfer-rate, In this paper, we propose a structure of WVMS using WLAN equipments for maritime environment and prove its effectiveness. We present the propagation loss model of WVMS's communication channel. measured by field test, and discuss its validity compared with the predictive value based on the Friss propagation model and Plane earth reflection model. We present the number of frames that is received from WLAN modem connecting with underwater-camera in field test spots. As a result, we confirmed that proposed WVMS is suitable for maritime environment and it is possible to be applied to fish-cage in open sea on 'seogwipo'.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.143-151
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• 2016

In this paper, a real-time air quality monitoring system based on wireless network is designed and implemented for industrial park or multiuse facilities. The existing gas detector is high price and hard to apply the remote monitoring system. On the other hand, demand for air quality monitoring is increasing because of industrial gas accident, air pollution, and so on. In Korea, indoor air regulation was established by law. According to indoor air regulation, CO2, CO, and NO2 are important gases as the air quality standard. So we study the gas detector for indoor air quality and the wireless network system. The wireless network consist of sensor network and WCDMA to apply various place. To verify the performance of the implemented gas detector, the gas measurement experiment is performed in laboratory environment by using the realized gas detecting wireless sensor node. And we evaluate the experiment results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.251-255
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• 2012

In recent years, according to improvement of various vehicle instruments, railway also has been developed in various fields. As a result, to transmit accurate information to each railway system, the efficient communication system is required. In railway communication system, mitigation of wireless fading is very important. So, in this paper we introduced the cooperative relay channel model and cooperative relay scheme. Also we analyzed and simulated the cooperative relay scheme which is suitable for railway communication systems.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.2
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• pp.79-85
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• 2020

IIoT stands for Industrial Internet of Things used in manufacturing, healthcare, and transportation in networked smart factories. Recently, IIoT's environment requires an automated control system through intelligent cognition to improve efficiency. In particular, IIoT can be applied to automatic calibration of production equipment for improved management in industrial environments. Such automation systems require a wireless network for transmitting industrial data. Self-calibration systems in laser transmission paths using wireless networks can save resources and improve production quality by real-time monitoring and remote control of laser transmission path. In this paper, we propose a wireless networked system for self-calibration of laser equipment that requires a laser transmission path, and we show the results of the prototype evaluation. The self-calibration system of laser equipment measures the coordinates of the laser points with sensors and sends them to the host using the proposed application protocol. We propose a wireless network service for the wired motor controller to align the laser coordinates. Using this wireless network, the host controls the motor by sending a control command of the motor controller in an HTTP message based on the received coordinate values. Finally, we build a prototype system of the proposed design to verify the detection performance and analyze the network performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.2 s.3
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• pp.55-64
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• 2003

This research is about executing the suitability evaluation of the data through wireless communication system in comparison with the data through the wire system used in National Highway Traffic Management System. The communication system for the evaluation was established on Peoyngteak-Anjung section(about 19 Km) at Route 38 in southern National Highway of the National Capital region where image detectors with the communication by wire were set up. In the situation, the comparison of the data transmission rates between the wire system and the proposed system was accomplished. Before we evaluate the possibility of application about the proposed system, the elements of wireless systems performed the spot investigations. Traffic data transmission test among the equipments was accomplished on the section of the Route 38 where wireless communication equipments were set up. And then, the test of traffic data transmission between the field equipment and the data collective center of wireless communication system was carried out. It evaluated the reliability of wireless communication data for the suitability evaluation of cable/wireless data collected while 73 days.

• Journal of information and communication convergence engineering
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• v.4 no.1
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• pp.13-17
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• 2006

In this paper a design and implementation method of remote control system for automobile is presented. For this, we used the Bluetooth technology for remote and wireless communications and microcontroller for system control. By using these techniques, we can design and implement automobile remote control system to improve data error rate, security and application.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.6
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• pp.31-39
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• 2016

In this paper, we propose a new system for wireless remote control over single-tasking operating systems such as Microsoft's disk operating system(DOS). In order to control a DOS device in a windows operating system, the proposed architecture uses a video transmitter, a virtual network driver, and a wireless keyboard module. Analysis shows that the proposed system, over 15Mbps wireless LAN(802.11n), can transmit at least 10 to 15 video frames, achieves speed up to a maximum of 8Mbps roughly, and is able to satisfy real time processing with respect to key input. Therefore, the proposed system is well suited to a remote control solution based on DOS devices.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.331-346
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• 2004

A new sensor system is proposed for measuring damage indexes. The damage index is a physical value that is well correlated to a critical damage in a device or a structure. The mechanism proposed here utilizes elastic buckling of a thin wire and does not require any external power supply for memorizing the index. The mechanisms to detect peak strain, peak displacement, peak acceleration and cumulative deformation as examples of damage indexes are presented. Furthermore, passive and active wireless data retrieval mechanisms using electromagnetic induction are proposed. The passive wireless system is achieved by forming a closed LC circuit to oscillate at its natural frequency. The active wireless sensor can transmit the data much further than the passive system at the sacrifice of slightly complicated electric circuit for the sensor. For wireless data retrieval, no wire is needed for the sensor to supply electrical power. For the active system, electrical power is supplied to the sensor by radio waves emitted from the retrieval system. Thus, external power supply is only needed for the retrieval system when the retrieval becomes necessary. Theoretical and experimental studies to show excellent performance of the proposed sensor are presented. Finally, a prototype damage index sensor installed into a 7 storey base-isolated building is explained.