• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.183-189
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• 2014

A recent trend of 'Smart Technology' has changed the simple and normal car into smart vehicle. Smart vehicle has a complex aspects of technologies and Wireless Access in Vehicular Environment (WAVE) is the technology that is mentioned for the communication infrastructure of Smart Vehicle. The current status about WAVE in Korea, however, is not good to be used in smart vehicular communication. The reason for that is that the frequency band for WAVE is not assigned or allocated in Korea. In this paper, we will explore the current status of technology standard for WAVE and investigate the way of frequency allocation for WAVE with the survey analysis from the smart vehicle industry.

• Journal of Auto-vehicle Safety Association
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• v.14 no.3
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• pp.48-59
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• 2022

A V2X system can be a candidate as a means to increase the stability of autonomous vehicles. In particular, in order to implement a Level 4 or higher autonomous driving system, the application of the V2X system is essential. Wireless communication technologies applicable to the V2X system include WAVE and C-V2X. Currently, the V2X service most used by autonomous driving systems is a service that provides signal phase and timing information and since real-time characteristic is a very important, verification of this service must be done. In this paper, we measured the time delay characteristics for providing signal phase and timing information using WAVE and LTE communication, and proposed a TOD-based signal phase and timing information generation method without using V2X communication system. To analyze the time delay characteristics, RTT (Round Trip Time) was measured as a result of the measurement. Average RTT using WAVE communication was 5.84ms and was 104.15ms with LTE communication. As a result of measuring the error between the signal phase and timing information generated based on TOD and the actual traffic light state, it was measured to be -0.284~3.784sec.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.268-273
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• 2011

Withstanding the continuous treat from the typhoon and nasty weather from ocean, the development of the real time monitoring buoy such as ocean wave related monitoring buoy system becomes essential. In this research, the development of the ocean wave monitoring buoy system had been done domestically. The development including the data real-time monitoring (wind, temperature and pressure) added in the buoy, buoy mooring and real-time data communication system. The developed wave monitoring buoy system (drift type, wave direction and wave height type) is expected to meet the demands.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.80-85
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• 2015

The era of intelligent transportation system(ITS) has been arrived by applying information and communication technology(ICT) to the traffic. One of these technological advances is a wireless communication technology for a high speed vehicle to be connected to an infrastructure(V2I). A variety of road traffic safety services and operator comfort services are being developed by means of WAVE(Wireless Access in a Vehicular Environment) based on IEEE802.11p Standard. In this paper, the link budget is analyzed to provide a reliable quality of these ITS services. Log-distance model and two-ray model is employed for the wave propagation path loss model which is adequate for a highway environment. Reliable cell coverage is suggested for ITS services from the link budget.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1334-1340
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• 2003

In this paper, We have proposed an Heterodyne technique to generate millimeter-wave signal. Microwave signals in cellular broadband mobile communication networks and distributed networks can favorably be generated and distributed by optical techniques. In principle, these techniques have already been investigated for optical control of phase- array antennas, characterization of photo-detector and phase locking of millimeter-wave oscillators and now being applied to wireless communications. The generation and transmission of millimeter-wave radio signals by optical means is of interest for future pico-cell broadband mobile communication system, especially for systems operating at frequencies of 300Hz.

• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.162-167
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• 1996

This paper deals with an implementation method for the one chip microprocessor(8097)-based capacitance type wave recorder for a measuring real-time wave height. The system was developed to make it possible to real-time remote sensing the wave height by deploying the RS-232/422/485 communication methods. The system test results for the developed system such as linearity, system stability and robustness of the disturbance was also verified through the performance tests of the system. Furthermore, the system was developed after due consideration with connecting the public network such as satellite mobile communication system and LAN, through the deploying VLSI(Very Large Scale Integration) design techniques.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.104-107
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• 2021

The orientation of trabeculae and porosity determine the wave propagation in cancellous bone. Wave propagation, as well as charge density and piezoelectricity, stimulate bone remodeling. Also, Charged ions in the fluid affect wave propagation in cancellous bone. But the trabecular struts' piezoelectricity does not change the waveform of cancellous bone. However, the underlying mechanism is unknown yet why trabecula struts' piezoelectricity does not change wave propagation through cancellous bone. Thus, we derived the governing equation indicating that trabecular struts' piezoelectric properties show that those do not affect wave propagation in cancellous bone.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.295-299
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• 2022

In this paper, a fast numerical electromagnetic (EM) method based on the transverse wave formulation called-up Advanced Transverse Wave Approach (A-TWA) is presented. An appropriate 5G antenna is designed, simulated and investigated in the context of Millimeter-Wave Wireless Communication Systems. The obtained simulation results are found in good agreement with literature. Such a method can provide for the simulators a great library integrating the most complexly and sensitively geometry elements that can have a huge impact on the applications supported by new wireless technologies.

• ETRI Journal
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• v.44 no.6
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• pp.885-902
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• 2022

The mmWave cell-free massive MIMO (CFmMIMO), combining the advantages of wide bandwidth in the mmWave frequency band and the high- and uniform-spectral efficiency of CFmMIMO, has recently emerged as one of the enabling technologies for 6G. In this paper, we propose a novel framework for energy-efficient mmWave CFmMIMO systems that uses low-resolution digital-analog converters (DACs) and phase shifters (PSs) to introduce lowcomplexity hybrid precoding. Additionally, we propose a heuristic pilot allocation scheme that makes the best effort to slash some interference from copilot users. The simulation results show that the proposed hybrid precoding and pilot allocation scheme outperforms the existing schemes. Furthermore, we reveal the relationship between the energy and spectral efficiencies for the proposed mmWave CFmMIMO system by modeling the whole network power consumption and observe that the introduction of low-resolution DACs and PSs is effective in increasing the energy efficiency by compromising the spectral efficiency and the network power consumption.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.768-773
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• 2009

This paper demonstrates the digital communication in air using the parametric array. The stepped-plate transducer which is suitable for high-power and high-efficient radiation is used to generate the difference frequency wave with the parametric array. The primary frequencies are selected to 83 kHz and 122 kHz and the resulting difference frequency wave at the frequency of 39 kHz is used for the communication. The modulation method is selected to On-Off Keying method. The waveform and signal-to-noise ratio (SNR) is measured and analyzed to see the characteristics of the digital communication using the parametric array. The proper distance for the communication using parametric array is about 3 m. The measured beam width of the 3dB SNR reduction was $14^{\circ}$. The possibility of the communication in air using the parametric array is confirmed and the high directional characteristic of the communication using the parametric array is expected to have the advantages for the multi path and the security problems.