• Journal of the Society of Disaster Information
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• v.1 no.1
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• pp.91-119
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• 2005

When the national disaster accident is occurred, it is difficult to maintain the mutual cooperation systems. In order to solve the problems, the construction of the national unified command wireless network is necessary. In this paper, the specified state of the characteristic frequency of the digital TRS wireless network constructed recently is investigated and analyzed. Through the analysis, the problems of the construction of the national unified command wireless network are grasped. To solve the problem, it is proposed that the digital TRS wireless network is connected with the satellite communication network, and connected with the existing wireless network, LMR. In the concretely it is proposed that the natural unified wireless network should be proceeded step by step. At first, for 2 years the existing networks of the Fire Fighting Agency, the Police, the Forest Service and so on must be utilized and prepared to link with TRS. The second, for 2 years it is carried forward a scheme to maintain the properties of the agencies concerned. Further, it must be prepared to connect with satellite network. At third, for 2 years all agencies concerned with the fire fighting and the disaster prevention must be unified, and the systems have to be promoted for the p1an of linkage of TRS network and the existing network. Next the agencies concerned have to be unified and the authority has to be intensified. When a disaster is occurred, the National Emergency Management Agency has to play a central role. In a local area it has to be given the Fire Fighting Agency an authority and a duty to get ready for each emergency situation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9A
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• pp.867-875
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• 2005

In this paper, we fabricated along distance wireless communication transmitter and receiver over the 100 which used NRD technology. To make the transmitter and receiver of 400Hz band using the non radiative dielectric wave guide, transmitter was composed of gm oscillator, m modulator and antenna, receiver was composed of local gum oscillator, balanced mixer, 3dB direction coupler and antenna. Also we executed a wireless communication image transmission examination to the transmitter and receiver. We receive the image information in real-time data transmission from receiver after we send the image signal in the wireless distance of the 10km. Therefore, the 400Hz band U transmitter and receiver to be developed will be used widely for the transmission system CATV or broadband transmission system. This will be utilized also to the link device of a long distance high speed wireless communication network.

• Journal of IKEEE
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• v.6 no.1 s.10
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• pp.65-71
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• 2002

In this study, we evaluate the reliability of using bluetooth wireless communication method, the industrial, scientific, and medical standards for local wireless communications, in the medical environment. For the study, an ECG measurement system using bluetooth is developed and used in various conditions of medical environment. It is found that the bluetooth communication method has shown a reliable data transmission capability when both transmitter and receiver are positioned in the same room. However, the increase of transmission distance and the existence of a wall prevent the retailable data transmission. Therefore, it is necessary to make sure if reliable data transmission is achieved for individual environments, before we use this technology.

• Journal of Korean Institute of Industrial Engineers
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• v.38 no.3
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• pp.173-181
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• 2012

The size and layout of user interface components need to be optimally designed in terms of reachability, visibility, clearance, and compatibility in order for efficient and effective use of products. The present study develops an ergonomic design method which optimizes the size and layout of user interface components using adaptive genetic algorithm. The developed design method determines a near-optimal design which maximizes the aggregated score of 4 ergonomic design criteria (reachability, visibility, clearance, and compatibility). The adaptive genetic algorithm used in the present study finds a near-optimum by automatically adjusting the key parameter (probability of mutation) of traditional genetic algorithm according to the characteristic of current solutions. Since the adaptive mechanism partially helps to overcome the local optimality problem, the probability of finding the near-optimum has been substantially improved. To evaluate the effectiveness of the developed design method, the present study applied it to the user interface design for a portable wireless communication radio.

• Korean Management Science Review
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• v.21 no.3
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• pp.115-127
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• 2004

In this paper, we describe an intelligent monitoring and control system for pick-up/delivery service. This system applies geographical information system(GIS), global positioning system(GPS) and wireless communication technologies for managing pick-up/delivery operations more effectively. It consists of three subsystems, pick-up/delivery sequence planning system, pick-up/delivery monitoring system, and PDA execution system. Pick-up/delivery sequence planning system generates routes and schedules for pick-up/delivery using GIS and optimization techniques. Pick-up/delivery monitoring system monitors current positions of vehicles and actual pick-up/delivery results as compared with planned routes and visit times, while PDA execution system transmits information for vehicles positions and actual pick-up/delivery results using GPS and wireless communication technologies. The intelligent monitoring and control system is currently being used for the pick-up parcel service in a local post office of Korea Post.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.7
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• pp.18-27
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• 1997

A CMOS 950 MHz frequency synthesizer is designed and fabricated in a 0.8.mu.m standard CMOS process for IS-95-A CDMA mobile communication transceivers To utilize a CMOS ring VCO in a CDMA wireless communication receisver, we employed a QDC (quasi-direct conversion) receiver architecture for CDMA applications. Realized RF frequency synthesizer used as the RF local oscillator for a QDC receiver exhibits a phase noise of -92 dBc/Hz at 885kHz offset from the 950.4 MHz carrier, which complies with IS-95-A CDMA specification. It has a rms jitter of 23.7 ps, and draws 30mA from a 5V supply. Measured I/Q phase error of the 950.4 output signals is 0.7 degree.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.114-119
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• 2010

Network technology has been developed rapidly for digital service in these days. ZigBee, one of the IEEE 802.15.4 protocols, supporting local communication has become the core technology in the wireless network area. In this paper we designed an integrated fire monitoring system using a mobile robot and the ZigBee sensor nodes which are deployed to monitor fires. When a fire breaks out, the image information of the scene of a fire is transmitted by an autonomous mobile robot and we also monitor the current position of the robot. Furthermore, the data around the place where the fire breaks out and the positions of the sensor nodes can be transmitted to a server via the multi-hop communication in the real time.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.463-471
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• 2011

Cooperative communications using relays in wireless networks have similar effects of multiple-input and multiple-output without the need of multiple antennas at each node. To implement cooperation into a system, efficient protocols are desired. In IEEE 802.11 families such as a/b/g, mobile stations can automatically adjust transmission rates according to channel conditions. However throughput performance degradation is observed by low-rate stations in multi-rate circumstances resulting in so-called performance anomaly. In this paper, we propose active relay-based cooperative medium access control (AR-CMAC) protocol, in which active relays desiring to transmit their own data for cooperation participate in relaying, and it is designed to increase throughput as a solution to performance anomaly. We have analyzed the performance of the simplified AR-CMAC using an embedded Markov chain model to demonstrate the gain of AR-CMAC and to verify it with our simulations. Simulations in an infrastructure network with an IEEE 802.11b/g access point show noticeable improvement than the legacy schemes.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.689-709
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• 2010

In this paper, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors. Firstly, a miniaturized impedance measuring chip device is utilized for low cost and low power structural excitation/sensing. Then, structural damage detection/sensor self-diagnosis algorithms are embedded on the on-board microcontroller. This sensor node uses the power harvested from the solar energy to measure and analyze the impedance data. Simultaneously it monitors temperature on the structure near the piezoelectric sensor and battery power consumption. The wireless sensor node is based on the TinyOS platform for operation, and users can take MATLAB$^{(R)}$ interface for the control of the sensor node through serial communication. In order to validate the performance of this multifunctional wireless impedance sensor node, a series of experimental studies have been carried out for detecting loose bolts and crack damages on lab-scale steel structural members as well as on real steel bridge and building structures. It has been found that the proposed sensor nodes can be effectively used for local wireless health monitoring of structural components and for constructing a low-cost and multifunctional SHM system as "place and forget" wireless sensors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1524-1534
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• 2009

In recent, diagnosing and monitoring technology via in vivo information has been evolved rapidly in worldwide with such capsule-kinds means of incorporating an RFID tag as wireless communication tool. Thus circumstance is pressing local body in Korea to research and develop ingestible RFID capsule which has more miniaturized form, less low power, harmless. This paper focused to investigate new technology and patents, R&D information for adopting proper frequency and designing wireless ingestible capsule antenna system, and suggested practical assignments to implement local R&D. Descriptions are consist of introduction, technology outline, tendency for R&D, patent, market, conclusion and suggestion.