• Journal of Broadcast Engineering
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• v.15 no.6
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• pp.830-844
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• 2010

In this paper, we propose an equalization digital on-channel repeater (EDOCR) with a feedback interference canceller (FIC) for single frequency network of the ATSC terrestrial DTV system. The proposed EDOCR with FIC does not have only high output power by cancelling feedback signals caused by insufficient antenna isolation through the FIC, but also shows better quality of output signals than the conventional on-channel repeaters (OCRs) by removing multipath signals existing between the main transmitter and the OCR, and residual feedback signals through an equalizer. In addition, computer simulations are provided to figure out the superior performance of the proposed EDOCR with FIC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.565-566
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• 2018

Conventional IoT systems are centralized systems that process information from the server on the device and most of them use a wireless LAN network. However, There may arise a problem of when the signal of the wireless LAN network is not reached, the IoT product can not be used and accessing a wireless LAN network having a stronger signal. In order to solve this problem, this paper proposes a system that a method to maintain stability of IoT products by using repeaters, and to manage IoT products and reduces the burden on the server by processing part of the data processed by the server in the repeater. The problems caused by the signal of the wireless LAN network can be solved by amplifying the signal with the repeater, and the overloading problem that can occur in the server can be solved by controlling the repeater's IoT product connected thereto to reduce the server usage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.605-612
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• 2008

This paper researches the estimating location using repeater effect adjustment method in CDMA based system. Repeaters are commonly used by commercial and amateur radio operators to extend signals in the radio frequency range from one receiver to another. The repeater signals are increasing arrival time from base station to mobile station. So if we calculates the mobile station using repeater signals, the estimating position error is increased. However nobody researched about adjusting repeater effects. This paper proposes repeater effect adjustment algorithm. For adjusting repeater effects, we make the triangle using mobile station, reference base station and neighbor base station, and then detect the repeater effects using the triangle characteristic. The proposed method system showed the improved performance in estimating parameters and locating positions by computer simulations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.107-114
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• 2017

In general, credibility for some analysis results is very important to most decision makers. Especially, it is even more critical for military commander to choose the best course of action by using the simulation results when he want to decide to allocate his available weapon system assets. Therefore, improving the credibility of simulation output is one of the key issues in military research fields. In this paper, we proposed a new simulation framework to improve the credibility of weapon's effectiveness analysis results. Multi-agent based simulation tool is applied and compare current process to the proposed framework. We also showed an example case when a communication repeaters are installed to expand the commanding area scope. The example clearly tells why this new simulation framework is more efficient and improve the credibility of simulation results.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.64-72
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• 2011

In a Single Frequency Network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences induced by the multiple transmitters and/or repeaters using same frequency are unavoidable. To ease the interference handing in the SFN for ATSC DTV system, transmitter identification (TxID) signal is recommended in the ATSC terrestrial DTV system. The TxID signal is embedded in the ATSC DTV signal and transmitted from each transmitter and repeater within the SFN and in ATSC recommended practice (RP) A/111, Kasami sequence is recommended as the TxID signal. In this paper, we propose an additional data transmission scheme using the TxID signal. In the proposed scheme, the Kasami sequence not only acts as the conventional TxID of the SFN for ATSC terrestrial DTV system but also carriers the additional data bits on its polarity and the code phase.

• Fire Science and Engineering
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• v.34 no.1
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• pp.79-88
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• 2020

This study analyzes the issue of the supply of force of fire in the high-rise buildings, and proposes an efficient method to do so. The results are as follows. First, in terms of Detect fire, it is necessary to shorten force of fire supply time by diversifying fire alarms such as alarms, vibrations, and voices from outside, clarification of fire occurrence points, and marking of fire. Second, with regard to communication signals, strengthening the installation target of wireless communication auxiliary facilities, supplementing the installation of repeaters, and constructing a multicommunications network were proposed. Third, in terms of Decide action, it is necessary to supply firefighter and firefighting equipment with the method of crossing of a river in adjacent buildings. Fourth, in terms of Respond to site, helicopters and emergency elevators are used to assist in the supply of firefighting equipment using drones. Easy-to-break glass windows and identification marks are required in every floor. Finally, in terms of applying fire suppressants, water can be supplied by means of a helicopter adjacent to the structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.25-31
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• 2004

fireless LAN can offer high data rate communication between wireless terminals. In IEEE 802.11 wireless LAN, a basic service unit is called a Basic Service Set (BSS), which consists of one AP and more than one wireless terminals. Terminals far from the AP may not communicate with high data rate because signal strength is weakened as they move away from the AP. In this paper we propose a method to permit high speed data transmission by grouping terminals and by using part of wireless terminals as repeaters. We analyze the proposed and algorithm via simulations. Our proposed grouping mechanism is shown to be an effective way to increase the distance for high rate transmission.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.8-13
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• 2020

In this paper, we study smart healthcare devices that enable active health care by building health care system with acquaintances or family members rather than single health care. The company develops health care services for families regardless of age and gender through intuitive UI design as a target for young users who serve elderly parents. Automated collection of health information and real-time feedback are available, and data can be aggregated and analyzed through repeaters. It can also utilize structured databases in the form of big data. The services offered can be used to prevent diseases and reduce medical expenses through health care, while automatic management can maximize users' convenience and increase demand. By reducing the development period of products that are based on this technology, reducing the development period of products and strengthening competitiveness, the company has the advantage of inducing generation-to-generation communication in an era when it is becoming a nuclear family.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.53-59
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• 2011

In recent years, mobile communication service is used extensively as a larger service area for the maintenance of quality of service required by the expansion of service areas and As the ever-increasing role in relays, and the location is relatively easy to install and less constrained costs, operating cost savings in terms of ICS(Interference Cancellation System) repeaters are required. However, an adaptive algorithm that is applied when updating the filter due to the increase in volume of operations increase the complexity of hardware implementation is fraught with many difficulties. In this paper, if there is a path that feedback. ICS repeater utilizing baseband signal processing for the removal of interfering signals from the feedback operation, significantly reducing the amount of reducing hardware complexity Complex Singed Signed LMS adaption algorithm is proposed. Proposed algorithm for evaluating the performance of Static channel WCDMA signal environment for the ICS, the results of the simulation algorithm, convergence speed and better performance in therms of convergence errors that are required through the implementation of the operation greatly reduces the amount of hardware complexity able to reduce the effect was visible.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1416-1426
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• 2008

In this paper, we present a small size and multiband directional dipole antenna for mobile communication repeaters. In the omni-directional dipole antenna, a planar reflector under the dipole provides improved directivity in front-direction with wide beamwidth. In order to miniaturize the directive dipole, the size of the reflector is reduced. A vertical stub on the reflector is proposed to enhance the front-directivity of the radiation pattern and mitigate the backward radiation due to the reduced reflector. Furthermore, we use horizontal stubs on edge of vertical stub to obtain additional reduction of the antenna size. To meet the current demand of wireless communication service, the designed antenna shows wideband characteristic by employing electromagnetic coupled two-dipoles with dual-resonance frequencies.