• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.9 s.112
• /
• pp.852-859
• /
• 2006

This paper suggests a developing approach of EHF TWTA for satellite communications. In order to improve RF performance and gain, we design and realize an EHF TWTA using a linearizer and drive amplifiers. Through the embodiment and experiment of 80 W EHF TWTA, this method satisfies the design specifications. Therefore, this approach is very useful and can be used to develop the similar equipments.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.4
• /
• pp.469-475
• /
• 2009

TMMR(Tactical Multiband Multirole Radio) is one of the important equipments for TICN which is our next military tactical communication system and it supplies to the distribution of traffic of C2(Command & Control) and SA(Situation Awareness) for unit of Brigade and below. In this paper, we define the tactical needs of military communication, and evaluate MANET(Mobile Ad-hoc Network) protocol for the future digital battle-field through performance comparison with a network simulator.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1817-1823
• /
• 2007

In this study, we have studied rail infrastructure related to emergency action to manage the risk when emergency caused by faults of facility or rail vehicle during operation happens. Especially we have compared the effect of emergency action with examining the structure of vehicle, tunnel, bridge and access road, etc which are related to emergency action. Also, we have tried to analyze effects of radio and communication equipment, lifesaving and refuge which could be used for rolling stock, station, control room, tunnel, bridge and etc, and we have presented the way of reporting the emergency to the train driver or crew, control room, outside networks which could be used by passengers in vehicle, station, railroad line. Based on these, we have analyzed the conduct of emergency action in length of time when emergency happens in railway and high-speed railway, and studied the method of which passengers could be guided safely and escape from the scene of the accident.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.435-441
• /
• 2005

Recently, IMO(International Maritime Organization) have provided the recommendation of EMI and EMS for radio communication and equipments of marine from SOLAS convention at July 1st 2002. In this paper, we measured EMC environment on the HANBADA, which is Korea Maritime University training ship, and the 88KUMEO of a fishing boat for basic EMC environment of a ship. Measured Band is from 30 MHz to 2 GHz, polarization measurement is processed both vertical and horizontal polarization. We analysed the results in consideration of permissible criteria.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.1
• /
• pp.138-144
• /
• 2011

L(2, 1)-labeling problem of a graph G = (V, E) is a problem to find an efficient way to distribute radio frequencies to various wireless equipments in wireless networks. In this work, we suggest a Simulated Annealing algorithm that can be applied to the L(2, 1)-labeling problem. By applying the suggested algorithm to various graphs we will try to show the efficiency of our algorithm.

• Proceedings of the IEEK Conference
• /
• 2003.11c
• /
• pp.247-250
• /
• 2003

Mobile wire technology is a publicly available general purpose for Radio Frequency(RF) communication for short-range and point-to-multi point voice and data transfer. In this paper, we proposed a new technology of the synchronized frame structure which is based on the CDMA technique, and it's implemented into the VLSI design by FPGA. The developmental technique consists of an assigned coded type mobile communication equipments and available local mobile or wireless communication scheme quasi BT(Blue Tooth)'s functions as multiplexer or do-multiplexer for each other applications. We implement this architecture with special proposed frame structure in the local area network. Also, we expect the above proposed structure extend into the DS3 network architecture and applicable to the TE(Terminal Equipment) in the local communication area and the other one etc.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.28 no.3
• /
• pp.115-120
• /
• 2005

In this paper, we propose a personal-computer-based wireless data access system, which use DS/SS(Direct Sequence Spread Spectrum) method and the ISM band of 2.44GHz radio frequency. By applying hi-directional transmission between wireless handy terminals and PCs or servers, it can be easily connected with any kinds of database systems such as Oracle, MS-SQL and MS-ACCESS. Therefore, it could be economically adopted as peripheral equipments for ERP or SCM systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.539-542
• /
• 2005

In this paper, we propose a wireless data access system, which used direct sequence spread spectrum method and the ISM band with 900MHz radio frequency. By applying bi-directional transmission between wireless transmitter and receiver, it can be effectively connected with any kinds of RF-ID with 900MHz ISM band. Therefore it could economically be used as peripheral equipments for RF-ID system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.10
• /
• pp.1236-1239
• /
• 2016

In this paper, we propose a new incentive mechanism for hybrid access in cognitive femtocell networks. The purpose of the proposed incentive mechanism is to guarantee the QoS of macro user equipments (MUEs) and to increase femtocell capacity. MUEs channel condition report triggers bidding procedure by neighbor femtocell base stations (FBS). Macro base station (MBS) can offer some subchannels as rewards to encourage FBSs to reliably support its MUEs. Simulation results validate the effectiveness of our proposed scheme.

• Journal of Aerospace System Engineering
• /
• v.3 no.4
• /
• pp.35-40
• /
• 2009

The first purpose of this study is to develop a GCS(Ground Control System) by using RF(Radio Frequency) wireless communication equipments for UAV(Unmanned Aerial Vehicle). The second goal is to develop an antenna tracking system operating automatically. UAV receives flight data from a RF wireless system. So the role of antenna tracking system is very important to keep good communication state between UAV and GCS. GCS can check flight data and display a aviation state of UAV in real-time. The flight data displayed in real-time by GCS include the latitude, longitude, altitude, speed and so on. Experiments that measure a communication range and reliability are needed to develop a RF wireless communication system.