• Title/Summary/Keyword: 중계성

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A Study on the Wireless Communication Method for Emergency Broadcasting System in Metro Environments (도시철도용 비상방송시스템을 위한 무선통신방식 연구)

  • Jang, Soo-Hyun;Shin, Dae-Kyo;Yoon, Sang-Hun;Jung, Han-Gyun;Jin, Seong-Keun;Lim, Ki-Taeg
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • 제17권6호
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    • pp.202-210
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    • 2018
  • Recently, the subway running in metro environments has a problem in securing the safety of passengers due to the failure of announcement in emergency situations such as breakdown, train accidents and power outage in the underground tunnels. Thus, there is a need to develop an emergency broadcasting system that can provide the announcement to all passenger cars in any emergency situations on the railway route. In this paper, the applicability of various wireless communication technologies for the emergency broadcasting system through the measurement campaign was examined in Seoul metropolitan subway. A WAVE(Wireless Access in Vehicular Environments) is communication technology that can use 5.9GHz dedicated frequency band without charge and it is possible to directly communicate between terminals over 200m without the help of additional relay. Especially, it confirms robust communication performance in the various metro environments, and therefore, it is considered to be suitable as a communication method of a radio-connected emergency broadcasting system for urban subway.

A Study On the Clusters In the Electronic Industry Using Social Network Analysis (사회적 네트워크 분석을 이용한 전자산업 클러스터 연구)

  • Jung, Jaeheon
    • The Journal of the Korea Contents Association
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    • 제19권5호
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    • pp.48-63
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    • 2019
  • We tried new analysis including social network analysis(SNA) on the transaction network centered on electronic companies using more than 50 thousand company transaction data obtained from Korean enterprise data (KED) for the year of 2015. We found 97 clusters having more than 10 firms and remarkable 13 clusters having more than 90% sales of the electronic industry in Korea. Clusters are the groups of companies having most of their transactions in the clusters they belong to. We found 5 clusters have 83% of sales in the electronic industry. Most of clusters have main single firms having most of the sales in each clusters except a few clusters. However, we found a few firms to have high rear production linkage effect and found the firms with high linkage effect specially for the small and medium size enterprise (SME). The companies with high production linkage (specially on SMEs) should be managed in terms of (SME) growth policy. The last firm group consisting of the small clusters with less than 10 firms has high employment coefficients. The clusters or company having high production linkage effect on this last firm group should be noted in the terms of employment policy. We also note that there exist the firms with the high value of betweenness coefficients meaning high potential of technology development. They should be managed carefully in terms of technology development policy.

Determination of Resistance Factors of Load and Resistance Factor Design for Drilled Shaft Based on Load Test (LRFD 설계를 위한 현장타설말뚝의 주면지지력 저항계수 산정)

  • Kim, Seok-Jung;Kwon, Oh-Sung;Jung, Sung-Jun;Han, Jin-Tae;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • 제26권7호
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    • pp.17-24
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    • 2010
  • Load Resistance Factor Design method is used increasingly in geotechnical design world widely and resistance factors for drilled shafts are suggested by AASHTO. However, these resistance factors are determined for intact rock conditions; by comparison, most of bedrocks in Korea have weathered condition, so that applying the AASHTO resistance factors is not reasonable. Thus, this study suggests the proper resistance factors for design of drilled shaft in Korea. The 22 cases of pile load test data from 8 sites were chosen and reliability-based approach is used to analyze the data. Reliability analysis was performed by First Order Second Moment Method (FOSM) applying 4 bearing capacity equations. As a result, when the Factor of Safety (FOS) was selected as 3.0, the target reliability indexes (${\beta}_c$) were evaluated as 2.01~2.30. Resistance factors and load factors are determined from optimization based on above results. The resistance factors ranged between 0.48 and 0.56 and load factors for dead load and live load are evaluated as approximately 1.25 and 1.75 respectively. However, when the target reliabilities are considered as 3.0, the resistance factors are evaluated as approximately 50% of the results when the target reliability index was 2.0.

A Study on the Cognitive Differences and Issue Factors of Terrestrial Broadcasters on Transmission System Determinants of Digital Radio Broadcasting (디지털 지상파 라디오 방송의 전송방식 결정요인에 관한 지상파 방송사의 인식차이와 쟁점 요인에 관한 연구)

  • Chae, Su-Hyun;Lee, Yeong-Ju
    • Journal of Broadcast Engineering
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    • 제20권1호
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    • pp.122-139
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    • 2015
  • Though the digital transition of terrestrial TV has been completed, the transmission system for terrestrial radio has not been determined and terrestrial radio still keeps its analog transmission. This study, under coorientation model, aims to explore the cognitive difference in recognizing important factors to be considered in deciding the digital radio transmission system between the employees of terrestrial broadcasters and then crucial issues related to the factors are driven. It has been found that the most big cognitive difference among the employees of three major terrestrial broadcasters lies in selecting frequency band for digital radio transmission. But there was little difference of opinion on simultaneous production-transmission, efficiency of frequency usage, broadcast quality and standards of service. The most disputable point in transition to digital radio broadcasting is selecting the frequency band for digital radio between the frequency bands used for FM radio broadcast (88-108MHz), terrestrial DMB (VHF Ch7~13) and FM radio adjacent broadcast band (76~88MHz: VHF Ch5~6). So, the question concludes into the selection issue between DAB+, HD-Radio, and DRM+. To improve the quality of radio broadcasting service and enhance the satisfaction of listeners, it is desirable to allow to operate both production system and transmission station, to enhance high transmission efficiency with minimum transmission facility, and to permit new entrance of broadcasters.

Brutal history of 'The Others' : Yeon Sang-Ho's Animation ('타자'들의 잔혹사 : 연상호 애니메이션)

  • Seo, Soo-Jung
    • Cartoon and Animation Studies
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    • 통권37호
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    • pp.267-286
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    • 2014
  • Yeon Sang-Ho's Animation occupies an exceptional place in Korean Animation, being categorized as the kind of realism representing the pitiable actuality rather than the liberal and creative imagination. His animation appreciated as 'stories much more real than the reality' mainly depicts the world of 'the others' who resides on the periphery of the society in a rough and straightforward way. Yeon Sang-Ho's Animation represents the emotions and desire of characters as well as the heartless real world refusing the fantasy, through which it reflects the portraits of people living in post-capitalistic era seen from the microscopic view. This article investigates the textual characteristics, defining his animation as the Brutal history of 'The Others'. Two conditions which constitute the actual world in his works are the absurd social system and the characters who are afflicted with the trauma, belonging to the lower classes. Therefore, the landscape of real life which contains vicious victim, corrupted monster and being as 'homo sacer' looks like a painting of hell. Yeon Sang-Ho's Animation summons the shadow of ourselves which has been negated or neglected through the figure of 'the others' produced in post-capitalistic era and exposes our bare face and the uncomfortable truth by displaying the affected area of out society plainly. Furthermore, his works demonstrate the possibility of Korean animation as a representational language of facing the reality and searching for the truth.

A Reputation based Cooperative Routing Scheme for End-to-End Reliable Communications in Multi-hop Wireless Networks (다중 홉 무선 네트워크에서 종단 간 신뢰성 통신을 위한 평판 기반의 협력적 라우팅 기법)

  • Kim, Tae-Hoon;Tak, Sung-Woo
    • Journal of Korea Multimedia Society
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    • 제12권11호
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    • pp.1593-1608
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    • 2009
  • If a certain relay node in multi-hop wireless networks might become a malicious node that does not cooperate with other nodes or a selfish node, network throughput will be dramatically decreased. Most of existing ad hoc routing protocols assuming that the nodes will fully cooperate with other nodes do not resolve the problem of network performance degradation due to malicious and selfish nodes. This paper presents the CARE (Cooperative Ad hoc routing protocol based REputation) scheme incorporating the reputation management that can achieve a multi-hop wireless network with high throughput performance. The proposed scheme provides the horizontal cross-layer approach which can identify misbehaving malicious, selfish nodes dropped out of the hop-by-hop based packet processing in the network and then set up an optimal packet routing path that will detour misbehaving nodes. And the vertical cross-layer approach contained in the CARE scheme attempts to improve the quality of routing paths by exploiting the quality of link information received from the MAC layer. Besides, it provides high TCP throughput by exploiting the reputation values of nodes acquired from the network layer into the transport layer. A case study on experiments and simulations shows that the CARE scheme incorporating vertical and horizontal cross-layer approaches yields better performance in terms of the low rate of packet loss, fast average packet delivery time, and high TCP throughput between end-to-end nodes.

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The Modem Transformation of Spatial Structure in the Changjiang Delta Region: 1978~2006 (장강삼각주지구(長江三角洲地區) 공간구조(空間構造)의 현대적(現代的) 변용(變容) : 1978~2006)

  • Ryu, Je-Hun
    • Journal of the Korean association of regional geographers
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    • 제17권1호
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    • pp.1-16
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    • 2011
  • Today, the name of Changjiang (Yangtze) Delta Region is used to designate an economic region which consists of sixteen cities including Shanghai City. The region has achieved the highest rate of economic growth in the world as well as in China since China its opened its toward the world market. The aim of this study is to examine the modern transition of spatial structure in the region after the opening (1978) and the membership of WTO (2000). In the examination, the study divides the spatial structure into three aspects: industrialization, urbanization and economic integration. The outcome of examination suggests that spatial division of industry, horizontally and vertically, has not reached a satisfactory level even if it is still in progress. The study proposes that the intervention of government in the market and company activity has hindered the spatial division of industry including service sector between the cities, and thus the economic integration. It further suggests that the specialization of urban function has not entered into the maturing stage, with the shortage of mid-size cities that would mediate spatial-economically between the large-size cities and the small-size cities in the urban hierarchy.

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Influencing Factors on the Lending Intention of Online Peer-to-Peer Lending: Lessons from Renrendai.com (온라인 P2P 대출의도의 영향요인에 관한 연구: 런런다이 사례를 중심으로)

  • Yang, Qin;Lee, Young-Chan
    • The Journal of Information Systems
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    • 제25권2호
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    • pp.79-110
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    • 2016
  • Purpose Online Peer-to-peer lending (hereafter P2P lending), is a new method of lending money to unrelated individuals through an online financial intermediary. Usually in the online P2P transaction, individuals who would like to borrow money (hereafter borrowers) and those who would like to lend money (hereafter lenders) have no previous relationship. Based on enormous previous studies, this study develops an integrated model, particularly for the online P2P lending environment in China, to better understand the critical factors that influence lenders' intention to lend money through the online P2P lending platform. Design/methodology/approach In order to verify the hypotheses, we develop a questionnaire with 42 survey items. We measured all the items on a five-point Likert-type scale. We use Sojump.com to collect questionnaire and gather 246 valid responses from registered members of Renrendai.com. We analyzed the main survey data by using SPSS 18.0 and AMOS 20.0. We first estimated the reliability, validity, composite reliability and AVE and then conduct common method bias test. The mediating role of trust in platform and in borrower has been tested. Last we tested the hypotheses through the structural model. Findings The results reveal that service quality, information quality, structural assurance, awareness and reputation significantly impact lenders' trust in the online P2P lending platform. Second, awareness, reputation and perceived risk significantly impact lenders' trust in borrower and lending intention. Third, trust propensity has a positive effect on lenders' trust on borrower. Last, awareness, reputation, perceived risk, platform trust and borrower trust can directly impact lenders' lending intention.

Miniaturized λ/4 Folded Microstrip Antenna using Parasitic Element for Parking Management System (무급전 소자를 이용한 소형화된 주차장관리시스템용 λ/4 폴디드 마이크로스트립 안테나)

  • Shin, Jae-yoon;Woo, Jong-myung;Park, Chong-hwan;Keum, Jae-min
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • 제16권5호
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    • pp.144-151
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    • 2017
  • In this paper, the antenna for parking management using wireless communication in outdoor parking environment was proposed. The proposed antenna was miniaturized by using parasitic element to reduce the size of the radiating element of the basic ${\lambda}/2$ microstrip antenna. The dimensions of the proposed antenna are $35mm{\times}35mm{\times}20.1mm$ that is 98.7% smaller than $309.1mm(0.46{\lambda}){\times}296.1mm(0.441{\lambda}){\times}20.1mm(0.029{\lambda})$ of the basic ${\lambda}/2$ microstrip antenna. The electrical characteristics of the antenna are 1.1 dBi at the center frequency of 447 MHz, an omni-directional radiation pattern on the E-plane, and $87.5^{\circ}$ of HPBW on the H-plane. The miniaturized ${\lambda}/4$ folded microstrip antenna using parasitic element has proved to be easy to mount on the wireless repeater, the sensor node installed on the ground, and the strop bar in the outdoor parking environment.

Core network maintenance by NO.7 protocol analyzing (Core Network 유지 보수를 위한 NO.7 Protocol 감시 방안)

  • Yoo Jun-Mo;Kim Yun-Sung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • 제42권1호`
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    • pp.49-60
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    • 2005
  • The Back Bone of gearing portion between Core Network System which is used in wire and wireless system is No.7 Protocol. ISUP( ISDN User Part), INAP handling in Intelligent Network and MAP gearing method for linking each Network Element System in mobile network have use of No.7 signaling. Therefore, it is require for system to detect the problem - operating problem occurs in Core Network which use No.7 signaling or the existing problem that is not recognized - in shortest time. This paper study out analyzing and measuring system for No.7 protocol and analyzing out system whether out of order or not. It can abstract No.7 Signaling Message and analyze system performance and report it. This system is connected in system No.7 HW Module which is in charge of No.7 Signaling. It is not offer Emulator function and Simulation function for any scenario but offer monitoring No.7 signaling. This system perform the function about No.7 MTP, ISUP, INAP and MAP and is offered several wire and wireless network Operator. It can detect and correct SW system, HW system and operating system problem. From now on, this system may offer the function about A-interface which is gearing between BSC and MSC, so it will perform to analyze generally and prompt effective operating for Core Network system.