• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.395-398
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• 2018

we propose a design method and process for hardware and software of hybrid V2X communication systems that support both C-ITS communication protocol and Legacy LTE communication technology. The hybrid V2X communication systems support multiple communication technologies of WAVE and LTE, in which WAVE supports multiple channels, so that it is designed to transmit road information such as LDM and positioning correction information to an autonomous vehicle in real time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1691-1699
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• 2014

IEEE developing WAVE specifications are able to support V2V and V2I wireless communications, and these functionalities can be used to enhance vehicle operational safety. To overcome any security weaknesses that are inherent in wireless communications, WAVE specification should support message encryption and authentication functions. In this study, we have implemented WAVE security algorithms in IEEE P1609.2 with openssl library and C language. We have verified the normal operation of implemented software, using the test vectors of related specifications, and measured their performance. Our software is platform independent, and can be used for the full implementation of WAVE specification.

• Information and Communications Magazine
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• v.34 no.6
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• pp.3-10
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• 2017

최근 운전자의 편의성과 안전성 향상을 위한 커넥티드 카 및 자율주행 차량에 대한 관심과 연구가 집중되고 있다. 이러한 커넥티드 카와 자율주행 차량의 경우 대용량의 멀티미디어 전송 및 센서 데이터 공유 등 다양한 서비스를 위해 높은 전송용량과 신뢰성을 보장할 수 있는 vehicle-to-vehicle (V2V) 통신과 vehicle-to- infrastructure (V2I) 통신에 대한 기본적인 연구와 구현이 필수적이다. 이러한 요구사항을 만족시키기 위해서 최근 mmWave 기반의 V2V, V2I에 대한 연구가 큰 주목을 받고 있다. 본고에서는 mmWave 대역 V2V 및 V2I 기술의 필요성과 채널에 관련된 기존 연구를 살펴보고, 이를 기반으로 현재까지 연구된 mmWave 대역 V2V, V2I 관련 연구에 대해 살펴보고자 한다. 또한 기존 연구의 한계점을 확인하고, 향후 연구방향과 주제에 대해 논의하고자 한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.163-166
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• 2001

In this paper, the superposition of ultrasonic signals which were generated by multi-source in a transformer was presented. For analysis of ultrasonic superposition, V$_{peak-peak}$ and pulse number of ultra-sonic signal were used. As a result, the wave form of ultrasonic superposition was classified into three types ; First type was the wave form whose V$_{peak-peak}$ was increased by the superposition of each signal's V$_{peak-peak}$. Second type was wave form whose V$_{peak-peak}$ was decreased by the superposition of each signal's V$_{peak-peak}$. And the other type was wave form whose peals were two or mere. And V$_{peak-peak}$ of superposed ultrasonic wave wads mostlv increased or decreased and pulse number of supe게osed u1trasonic wave was mostly increased.y increased.

• Journal of electromagnetic engineering and science
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• v.16 no.4
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• pp.225-228
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• 2016

KRISS-V, a V-band millimeter-wave source module for a primary RF power standard and calibration system developed by the Korea Research Institute of Standards and Science is here presented. The output power of KRISS-V is several times higher than that of commercial amplifier/multiplier chains and is highly stable (the standard deviations of output power are less than 0.01% in the worst case). The spectral purity of KRISS-V is high enough to consider it a single-tone signal generator. We also added programmable attenuation capability to KRISS-V for remote power control. Moreover, the in-house source module is cost-effective and adaptable to various measurement schemes. The structure of the model as well as detailed component information are introduced so that it can be reproduced.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.69-73
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• 2002

We have designed and fabricated a low-cost, V-band CPW receiver chip set using GaAs PHEMT technology for the application of millimeter-wave wireless communication systems. Low noise amplifiers and down-converters were developed for this chip set. The fabricated low noise amplifier showed an S$\sub$21/ gain of 14.9 ㏈ at 60 ㎓ and a noise figure of 4.1 ㏈ at 52 ㎓. The down-converter exhibited a high conversion gain of 2 ㏈ at the low LO Power of 0 ㏈m. This work demonstrates that the GaAs PHEMT technology is a viable low-cost solution for V-band applications.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.96-102
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• 2013

In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. The development of ITS services is accelerating by V2X communication technologies for high-speed vehicles. In this paper, WAVE communication devices based on the IEEE802.11p standard is introduced as a solution of V2X communication technologies. The H/W and S/W structures of the WAVE communication device and the characteristics of RF/antenna are described. The performance is evaluated in the test road by measuring throughput, PER and latency. The implemented WAVE communication device has 6~7 Mbps throughput with 10% PER at 1km coverage. The packet latency is less than 3ms for the whole test road. It is shown that the implemented WAVE technology is satisfactory to provide ITS services and Internet video-streaming services.

• Korean Journal of Mathematics
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• v.21 no.2
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• pp.203-212
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• 2013

We investigate the existence of solutions of the one-dimensional wave system $$u_{tt}-u_{xx}+{\mu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\v_{tt}-v_{xx}+{\nu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ with Dirichlet boundary condition. We find them by applying linking inequlaities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.54-57
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• 2010

Vehicular Ad-hoc Network the core technology of ITS supports safety service or information service to driver and passenger on the roads utilizing V2V and V2I communication. WAVE, the standard of the vehicular ad hoc networks, adopts IEEE 802.11p as MAC protocol and includes the channel coordination algorithm to utilize multiple channels. However, this standard shows the problem related with QoS guarantee of urgent data for driver's safety and the limitation of the performance improvement. In this paper, we introduce WAVE-based Multi-channel MAC protocols that have proposed to resolve above problems and describe their features.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.526-531
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• 2014

Vehicular communications have been receiving much attention in intelligent transport systems(ITS) by combining communication technology with automobile industries. In general, vehicular communication can be used for vehicle-to-vehicle(V2V) and vehicle-to-infrastructure( V2I) communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environment(WAVE). WAVE system transmits signal in 5.835~5.925 GHz frequency band with orthogonal frequency division multiplexing(OFDM) signaling. In this paper, after 32 bit processed the channel monitoring in MAC(Media Access Control) layer of WAVE system implemented according to IEEE 802.11p standard, data were received and we evaluated the performance, we built the test bed consisting of OBU(On Board Unit) in the real expressway. We transmitted WSM(WAVE Short Message) and received WSM between OBU wirelessly. And then, we calculated channel occupancy time per one frame and throughput, and evaluated the performance.