• Title/Summary/Keyword: OBU

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Synthesis of Monodispersed Zirconia Powder by Hydrolysis of Zirconium Alkoxides (알콕사이드의 가수분해법에 의한 단분산 지르코니아 분체의 합성)

  • Rhee Jhun;Jo, Dong-Soo
    • Journal of the Korean Ceramic Society
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    • v.28 no.2
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    • pp.167-175
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    • 1991
  • In synthesizing hydrated zirconia powder by hydrolysis of Zr-alkoxides using ethanol as mutual solvent, three experimental parameters, namely, concentration of alkoxides and hydrolysis water and addition rate of hydrolysis water were varied systematically. Spherical, monodispersed, nonagglomerated and submicrometer sized powders were prepared at 0.3 M of Zr(n-OPr)4 and 0.05M of Zr(n-OBu)4 with wide ranges of hydrolysis water conditions i.e. 0.5-2.0M concentration and 1-20ml/min addition rate. During the hydrolsis, careful attention have to be paid to maintain homogeneous reaction by controlling the agitation of the reactant and the addition of the hydrolysis water. For more improved condition of monodispersity it was found that the key point is to shorten the self-nucleation time within several seconds as rapid as possible. In both alkoxides system, with higher concentration of alkoxide and hydrolysis water and with slow addition rate of hydrolysis water, hydrated zirconia powders synthesized showed tendency to fall in worse powder conditions.

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Intelligent WAVE/DSRC Platform Technology for Efficient Data Transmission in Vehicle Communication (차량 통신에서의 효율적인 데이터 전송을 위한 지능형 WAVE/DSRC 플랫폼 기술 연구)

  • Kim, Jae Wan;Jeon, Hyun Min;Kim, Swung Ku
    • Journal of Korea Multimedia Society
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    • v.20 no.9
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    • pp.1519-1526
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    • 2017
  • The existing DSRC(Dedicated Short Range Communication) scheme has a limitation in providing various services through short-range wireless communication. Therefore, it is necessary to develop an intelligent WAVE/DSRC hybrid wireless platform that can improve data transmission speed and extend the effective communication range. This paper introduces WAVE/DSRC integrated platform technology using WAVE(Wireless Access in Vehicle Environments) to overcome the disadvantages of DSRC. First, the desinged software configuration of the WAVE/DSRC integrated platform is described. Then each task operation scheme and WAVE software design are described. By applying the WAVE/DSRC integrated platform, we can compensate the shortcomings of DSRC. It can provide more accurate and reliable services.

Sol-Gel Template Synthesis and Phase Transitions of $PbZrO_3$ Nanotubes ($PbZrO_3$ 나노튜브의 졸-겔 형판 합성과 상전이)

  • Chang, Ki-Seog;Bu, Sang-Don
    • Journal of the Korea Institute of Military Science and Technology
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    • v.8 no.4 s.23
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    • pp.85-90
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    • 2005
  • We report the phase transition temperatures of the $PbZrO_3$ perovskite nanotubes made by sol-gel template synthesis. The lead zirconate($PbZrO{_3}$) nanotubes were prepared with a chelate sol-gel of zirconium tetrabutoxide($Zr(OBu){_4}$) and leadacetate($Pb(OAc){_2}-3H_2O$). $Whatman^(r)$ anodisc membranes, with a 200nm pore size, served as the template. After removing the template in the 6M-NaOH solution, the $PbZrO{_3}$ nanotubes so far have shown an anomalous transition temperature, $123.6^{\circ}C$ as measured by DSC with a small particle size, 15.4nm determined by X-ray analysis with the aid of Scherrer's equation.

VANET cloud computing architecture (VANET 클라우드 컴퓨팅 아키텍처)

  • Kim, TaeHyeong;Song, JooSeok
    • Proceedings of the Korea Information Processing Society Conference
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    • 2014.04a
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    • pp.142-145
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    • 2014
  • 지금까지 교통사고 예방을 위한 도로 정보 등을 제공하기 위해 차량 간 통신 네트워크인 Vehicular Ad hoc NETwork (VANET)연구가 활발히 진행되어왔다. 그러나 각 자동차의 On board unit (OBU)의 계산 능력, 저장 공간 등을 효율적으로 사용하는 연구는 진행되어 오지 않았다. 2011년 Olariu et al. 가 cloud computing을 기존의 VANET에 적용하는 개념인 Autonomous Vehicular cloud[1]를 제시하면서 새로운 VANET 연구의 새로운 장을 열었다. 기존의 VANET연구는 지금까지의 각각의 자동차의 통신 성능을 높이는 것에 초점을 맞추었지만, 새로운 아이디어는 높아진 각 자동차의 능력을 효율적으로 이용하여, 유용하게 사용하는 것에 초점을 맞추었다. 이것은 Intelligent Transport System (ITS)의 구축에 한발 더 나아갈 수 있게 하였다. 그 이후 VANET cloud computing (VCC)에 관한 많은 연구들이 진행되었으나 보안적인 측면에서는 아직 연구가 미흡한 실정이다. 그래서 본 논문에서는 보안을 보완한 VCC 아키텍처를 제안한다.

Benzotriazol-1-yl Diethyl Phosphate and Benzotriazol-1-yl Diphenyl Phosphate. New Convenient Reagents for the Peptide Synthesis

  • Kim, Sung-Gak;Chang, He-Ung;Ko, Young-Kwan
    • Bulletin of the Korean Chemical Society
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    • v.8 no.6
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    • pp.471-475
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    • 1987
  • Benzotriazol-1-yl Diethyl phosphate and benzotriazol-1-yl diphenyl phosphate were conveniently prepared in essentially quantitative yields by the reaction of diethyl chlorophosphate and diphenyl chlorophosphate with equal amounts of 1-hydroxybenzotriazole and triethylamine in tetrahydrofuran at room temperature, respectively. Benzotriazol-1-yl diethylphosphate was effective for the preparation of amides from carboxylic acids amines. Young test and Anderson test for racemization studies using benzotriazol-1-yl diethyl phosphate were investigated and practically no racemization occurred. However, racemization occurred to some extent during coupling of Z-Phe-Val-OH with Pro-OBu. Several dipeptides and tripeptides were prepared without little racemization using benzotriazol-1-yl diethyl phosphate. Benzotriazol-1-yl diphenyl phosphate was less effective than benzotriazol-1-yl diethyl phosphate in terms of the degree of racemization.

A Analysis on Suitability of the Security Algorithms in VANET (차량 보안 통신 알고리즘 적합성 분석)

  • Han, Sun-Hee;Park, Min-Woo;Chung, Tai-Myoung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.04a
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    • pp.722-725
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    • 2012
  • 차량통신은 차량 내부 단말기 (OBU)를 통해 차량 간 (V2V) 통신을 제공하고, 노변 장치 (RSU)를 통해 차량과 인프라 간 (V2I) 통신을 제공하는 기술이다. 이를 통해 사용자는 교통사고 예방을 위한 서비스, 인터넷 연결 등을 통한 다양한 서비스를 제공받을 수 있다. 하지만 차량 주행 시 통신의 안전성이 보장되지 않는다면 위장공격 및 메시지 변조 공격 등으로 인해 사고를 발생 시킬 수 있다. 따라서 인증 및 무결성 제공 등 차량통신 메시지의 안전성이 보장 되어야 한다. 본 논문에서는 차량통신에서의 보안 서비스를 분석하였고, IEEE 1609.2에 정의된 보안 알고리즘의 요구조건을 만족하는지 분석하여 적합성을 판단하였다.

A Study on KOREA SCMS Analysis and Improvement Method (한국 V2X 보안인증체계 분석 및 개선방향 연구)

  • Eom, Sungwook;Kim, Donghwan;Kim, Sungsub;Cho, Sungwoo
    • Journal of Auto-vehicle Safety Association
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    • v.13 no.1
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    • pp.31-37
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    • 2021
  • SCMS is a security credential management system for V2X communication, which performs generation/ provision/validation of device's security certificates. In this paper, we will explain about the main functions of SCMS and the role of each institution, and propose the following improvement measures in the process of establishing the Korean V2X security certification system. First, connection scheme of ERA (Enrollment certificate RA) between SCMS and Vehicle Manager Information System (VIMS) will be proposed. Second part is the problem of certificate revocation and proposal of improvements.

A study of method that "One Card All Pass" applies ETCS (Electronic Toll Collection System) (자동요금징수 시스템 전국호환카드 적용방안 연구)

  • Oh, Se-Wan;Kim, Kyoung-Hwa;Cho, Yong-Sung;Lee, Heung-Pyo;Jung, Sung-Hwa
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.1
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    • pp.86-98
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    • 2014
  • Currently, many OBUs(On Board Unit)s were installed on the vehicle because ETCS(Electronic Toll Collection System) using DSRC(Dedicated Short Range Communication) was constructed in the tollgate of the whole country.A research development and the commercialization utilizing the One Card All Pass and those Infrastructures of ETCS, are promoting of ITS services. Although many studies of the application method about the One Card All Pass of ETCS have been made, standards about the application method of the One Card All Pass and payment for the provision of traffic convenience, were not made clear. So we are proposed method that One Card All Pass announced by Ministry of Land, Infrastructure and Transport, takes advantage of the existing DSRC-based to apply ETCS. We have confirmed the performance of the system through a variety of driving test using three test vehicles on trial operation site and ETCS applying application method proposed in this study. As a result of driving test, we have confirmed validity of standard application method proposed in this study through the communication success rate of about 99% and analyzed problem that may occur by applying service parts of ETCS of transportation convenience facilities because of about 1% communication failure rate.

Study on roof tiles of Iksan featuring Stamped-Roof Tiles (인각와를 통해 본 익산의 기와에 대한 연구)

  • Lee, Da-Un
    • KOMUNHWA
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    • no.70
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    • pp.89-108
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    • 2007
  • Stamped-Roof Tiles, the characteristics of Baekje Tiles are one of the most frequently excavated tiles in Iksan. Considering the types and amount of excavation of the Stamped-Roof Tiles unearthed in Iksan area, it seems that these are closely related with a Royal family. The tiles might be manufactured by a particular gorup of file maker since they are produced with same way. Referring the Ganji carved in the Stamped-Roof Tiles, I suppose that the tiles were produced and used in two time periods, the time around enthronement of The King Mu and the second quarter of the 7th century around Gichuk, AD. 629. In addition, Convex Tiles used in Wanggung-ri Site and Mireuk Site was also produced in same time as the Stamped-Roof Tiles, considering there pattern and the amount of excavation. The social background of tile production was analogized based on the technology and the time of the tile manufacture as well as the characteristics of the Stamped-Roof Tiles which represent the Obu and the Ohang. The production of the tiles was supported by Obu which aided the King Mu-oriented construction project the economic capacity of the Royal family was not enough to promote. The tile production system was totally controled by the Royal family and the inspector, neither producer nor donator, examined the quantitation of the tiles and generated the imprint of a seal with the Stamped-Roof Tiles.

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A Study on of Sancheong(山淸) Gyeongsang-Nam in the last Chosun Dynasty (조선후기 경남 산청의 누정기 연구)

  • Jo, sang-woo
    • (The)Study of the Eastern Classic
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    • no.67
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    • pp.105-128
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    • 2017
  • The purpose of the present study is to explore the significance of the Commentaries on Pavilions (樓亭記) from the Sancheong-gun area. To achieve this purpose, the study analyzes the works handed down in Sancheong-eup, Chahwang-myeon, Obu-myeon, and Geumseo-myeon, focusing on the two characteristic themes: the discipline and enlightenment of heart and mind (in Chapter 2) and the succession of integrity and the tradition of ancestor worship (in Chapter 3). The first characteristic theme "the discipline and enlightenment of heart and mind" is explicated in Chapter 2 by reviewing the Commentary on Hwanajeong Pavilion (Hwanajeonggi) written for the namesake building located in Sancheong-ri, Sancheong-eup, and the Commentary on Gyeongjeonjae Pavilion (Gyeongjeonjaegi) in Maechon-ri, Geumseo-myeon. The second theme "the succession of integrity and the tradition of ancestor worship" is examined in Chapter 3 based on the Commentary on Sulgojeongsa Pavilion (Sulgojeongsagi) from Jangwi-ri, Chahwang-myeon, and the Commentary on Maeranjeong Pavilion (Maeranjeonggi) from Yangchon-ri, Obu-myeon.