• Title/Summary/Keyword: hub network

Search Result 319, Processing Time 0.03 seconds

Hub-and-spokes service network design for rail freight transportation (철도화물운송을 위한 Hub-and-spokes서비스네트워크 디자인모형의 개발)

  • 정승주
    • Proceedings of the KOR-KST Conference
    • /
    • 2003.02a
    • /
    • pp.75-93
    • /
    • 2003
  • Hub-and-spokes전략은 교통분야에서 널리 이용되는 네트워크전략이지만, 철도의 경우 대개 이 전략을 이용하기 어려운 네트워크구조를 가지고 있어 그 적용사례를 찾아보기 어렵다. 그러나 유럽에서는 철도망이 도로망처럼 조밀하게 형성되어 있다는 점과 환적 처리기술의 발달로 90년대 초부터 이 전략이 철도화물운송부문에도 도입되기 시작했다. 이러한 관점에서 본 논문은 철도화물운송망에서의 hub-and-spokes전략을 구현하는 서비스네트워크 디자인모형을 개발하고, 모델의 실제철도망에의 적용성을 평가한다. 개발되는 모형이 전략모형임에도 불구하고 모형에서는 일반화된 운영비용 외에 열차속도, 서비스빈도, 터미널에서의 화물처리속도 등에 따른 시간지체비용도 고려되었다. 시간지체비용의 고려에 따라 야기되는 비선형 목적함수는 빈도별 서비스결정변수의 설정을 통해 선형화되어 결과적으로 모형은 선형 binary정수 최적화문제로 표현되었다. 규모가 큰 네트워크의 경우 해도출의 어려움 때문에 본 논문은 전체문제의 분할(decomposition)에 기초한 휴리스틱방법((heuristic method)으로 해결한다. 해도출의 효율성을 높이기 위해 서비스빈도개선과 관련하여 세 알고리즘이 개발되었다. 개발된 알고리즘은 유럽의 실제네트워크를 기초로 도출한 4개의 테스트문제에 적용되어, 해의 정확도와 해 도출의 효율성이 비교·평가되었다.

  • PDF

The Way of IoT Management Hub Connection for Convenient IoT Service (편리한 사물인터넷 서비스를 위한 IoT 관리 허브 연결 방법)

  • Kim, Sang-hyun;Kim, Young-don;Lee, Chang-seok;Lee, Dong-ho;Park, Hyun-ju
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.11
    • /
    • pp.2656-2664
    • /
    • 2015
  • IoT management hub has to request the WLAN AP list of the accessible areas in a place that is installed, or choose a specific WLAN AP you want to connect in order to be connected to the Internet. the specific method also is required to input the password when the security key was set. As that way, IoT management hub needs both the display device and the input device to see the list of WLAN AP and to input the security key. If the IoT management hub is consist of them, It is difficult to achieve the objective of the miniaturization and cost reduction. In this paper, we propose a method to connect to a WLAN AP network using a smart-phone without the display device and the input device.

Evolution of Internet Interconnections and System Architecture Design for Telecom Bandwidth Trading (인터넷 상호접속 진화에 따른 대역폭 거래(Bandwidth Trading)의 필요성 및 거래시스템 아키텍처 설계)

  • Kim, Do-Hoon
    • Journal of Information Technology Services
    • /
    • v.7 no.1
    • /
    • pp.131-149
    • /
    • 2008
  • Bandwidth Trading(BT) represents a potential market with over 1 trillion USD across the world and high growth potential. BT is also likely to accelerate globalization of the telecommunications industry and massive restructuring driven by unbundling rush. However, systematic researches on BT remain at an infant stage. This study starts with structure analysis of the Internet industry, and discusses significance of Internet interconnection with respect to BT Issues. We also describe the bandwidth commoditization trends and review technical requirements for effective Internet interconnection with BT capability. Taking a step further, this study explores the possibility of improving efficiency of network providers and increasing user convenience by developing an architectural prototype of Hub-&-Spoke interconnection model required to facilitate BT. The BT market provides an Innovative base to ease rigidity of two-party contract and Increase service efficiency. However, as fair, efficient operation by third party is required, this research finally proposes an exchanging hub named NIBX(New Internet Business eXchange).

Improvement of WEP Key transmission between APs, during STA Movement in Wireless Environment (무선 LAN 환경에서 단말 이동시 전송되는 AP간 WEP 키 전송 개선 방안)

  • Song, Il-Gyu;Hong, Choong-Seon;Lee, Dae-Young
    • The KIPS Transactions:PartC
    • /
    • v.11C no.2
    • /
    • pp.219-228
    • /
    • 2004
  • Wireless LAN(wireless Local Area Network) is constructed network environment by radio in indoors or outdoors environment and that to use electric wave or light instead of wire to client such as PC(Personal Computer), notebook, PDA in hub(Hub) in technological side. Now, among IEEE 802.11 WG(Working Group), there is TGf(Task Group F) that develop standard protocol between AP's(Access Point). In this group, proposed IAPP(Inter Access Point Protocol) to secure interoperability between AP producing in different manufacturer, this offers seamless connectivity between STA by sharing Security Context information or Layer 2 forwarding information between AP without passing through re-authentication process when STAs(Station) move by protocol to secure mobility between AP that differ in equal serve network. In this paper, I wish to suggest method that change avenue of communication of message to block information leakage that can occur at security message or WEP Key transmission between above AP, and uses public key to offer wireless area security little more.

The Lifespan of Social Hub In Social Networking Sites: The Role of Reciprocity, Local Dominance and Social Interaction

  • Han, Sangman;Magee, Christopher L.;Kim, Yunsik
    • Asia Marketing Journal
    • /
    • v.17 no.1
    • /
    • pp.69-95
    • /
    • 2015
  • This paper examines a highly used social networking site (SNS) by studying the behavior of more than 11 million members over a 20 month period. The importance of the most highly active members to the overall network is demonstrated by the significant fraction of total visits by extremely active members in a given period but such members have surprisingly short lifespans (an average of only 2.5 months) as social hubs. We form and test a number of hypotheses concerning these social hubs and the determinants of their lifespan. We find that the speed of achieving social hub status increases the lifespan of a social hub. The norm of reciprocity is strongly confirmed to be present in the social hub population as visits are reciprocated. We also find that increasing local dominance in terms of activities over neighboring agents leads to a longer lifespan of a social hub. Contrary to expectations, local clustering in the vicinity of social hubs is smaller (rather than larger) than overall clustering. We discuss managerial implications in the paper.

Discovery of Anticancer Activity of Amentoflavone on Esophageal Squamous Cell Carcinoma: Bioinformatics, Structure-Based Virtual Screening, and Biological Evaluation

  • Chen, Lei;Fang, Bo;Qiao, Liman;Zheng, Yihui
    • Journal of Microbiology and Biotechnology
    • /
    • v.32 no.6
    • /
    • pp.718-729
    • /
    • 2022
  • Esophageal squamous cell carcinoma (ESCC) is the most common primary esophageal malignancy with poor prognosis. Here, due to the necessity for exploring potential therapies against ESCC, we obtained the gene expression data on ESCC from the TCGA and GEO databases. Venn diagram analysis was applied to identify common targets. The protein-protein interaction network was constructed by Cytoscape software, and the hub targets were extracted from the network via cytoHubba. The potential hub nodes as drug targets were found by pharmacophore-based virtual screening and molecular modeling, and the antitumor activity was evaluated through in vitro studies. A total of 364 differentially expressed genes (DEGs) in ESCC were identified. Pathway enrichment analyses suggested that most DEGs were mainly involved in the cell cycle. Three hub targets were retrieved, including CENPF, CCNA2 (cyclin A), and CCNB1 (cyclin B1), which were highly expressed in esophageal cancer and associated with prognosis. Moreover, amentoflavone, a promising drug candidate found by pharmacophore-based virtual screening, showed antiproliferative and proapoptotic effects and induced G1 in esophageal squamous carcinoma cells. Taken together, our findings suggested that amentoflavone could be a potential cell cycle inhibitor targeting cyclin B1, and is therefore expected to serve as a great therapeutic agent for treating esophageal squamous cell carcinoma.

A Study of limitation of Service Area by transmission delay in LMDS System (LMDS 시스템에서 전파지연시간이 서비스 영역에 미치는 영향에 관한 연구)

  • 박두일;김동현최광주오성환
    • Proceedings of the IEEK Conference
    • /
    • 1998.10a
    • /
    • pp.347-350
    • /
    • 1998
  • 본 논문에서는 최근 광대역 무선 가입자망으로 각광받고 있는 LMDS(Local Multipoint distribution Service)시스템에서 Head-End 의 AIU(Air Interface Unit)와 HUB 사이의 거리에 따른 전송지연 시간과 HUB 와 가입자 장치(CPE:Customer Premises Equipment)내의 NIU(Network Interface Unit)간의 전송 지연 시간에 의하여 서비스 반경이 제한되어 지는 것에 관하여 살펴보고 적절한 서비스 반경에 대하여 제안하였다.

  • PDF

The Research about Literature Museum Network Organization and Operation plan for Establishment of Literature Promotion Infrastructure (문학 진흥 인프라 구축을 위한 문학관 네트워크 조직 및 운영 방안 연구)

  • Che, Keunbyung
    • 지역과문화
    • /
    • v.7 no.2
    • /
    • pp.57-84
    • /
    • 2020
  • The Literature Museum Network aims to realize the legislative purpose of the Literature Promotion Act and achieve balanced development of local literature centers across the country. In the Literature Museum Network, the literature museum network support center will be established by region to take charge of cooperation projects between local literature centers, which will be the culmination of the National Literature Museum of Korea. It is intended to test-run various projects planned by the Munhakwan Network Support Center to create derivative contents, or to establish a regional hub literature center in charge of education and other affairs of the literature museum's workforce. If the existing metropolitan administrative districts are used to form zones, the entire country can be organized into four zones. They include the Seoul-Gyeonggi Literature Museum Network (23 local literature centers), the Gangwon Chungcheong Literature Museum Network (32 local literature centers), the Yeongnam Literature Museum Network (30 local literature centers), and the Honam Jeju Literature Museum Network (22 local literature centers). One literature museum network support center will be established for each region and one local literature center will be selected as the hub literature center. The Literature Hall Network Support Center is in charge of collecting and managing literary materials, developing contents and programs, promoting and foreign cooperation, etc. The hub literature museum will be in charge of pilot operation of content and programs, training and education of experts in the literature museum, and running joint storage facilities. This structural system and efficient operation of the literature museum network will ultimately provide an opportunity for the formation of cultural governance in which the power and public nature of the establishment of literary promotion infrastructure are secured.

Differences in Large-scale and Sliding-window-based Functional Networks of Reappraisal and Suppression

  • Jun, Suhnyoung;Lee, Seung-Koo;Han, Sanghoon
    • Science of Emotion and Sensibility
    • /
    • v.21 no.3
    • /
    • pp.83-102
    • /
    • 2018
  • The process model of emotion regulation suggests that cognitive reappraisal and expressive suppression engage at different time points in the regulation process. Although multiple brain regions and networks have been identified for each strategy, no articles have explored changes in network characteristics or network connectivity over time. The present study examined (a) the whole-brain network and six other resting-state networks, (b) their modularity and global efficiency, which is an index of the efficiency of information exchange across the network, (c) the degree and betweenness centrality for 160 brain regions to identify the hub nodes with the most control over the entire network, and (d) the intra-network and inter-network functional connectivity (FC). Such investigations were performed using a traditional large-scale FC analysis and a relatively recent sliding window correlation analysis. The results showed that the right inferior orbitofrontal cortex was the hub region of the whole-brain network for both strategies. The present findings of temporally altering functional activity of the networks revealed that the default mode network (DMN) activated at the early stage of reappraisal, followed by the task-positive networks (cingulo-opercular network and fronto-parietal network), emotion-processing networks (the cerebellar network and DMN), and sensorimotor network (SMN) that activated at the early stage of suppression, followed by the greater recruitment of task-positive networks and their functional connection with the emotional response-related networks (SMN and occipital network). This is the first study that provides neuroimaging evidence supporting the process model of emotion regulation by revealing the temporally varying network efficiency and intra- and inter-network functional connections of reappraisal and suppression.