• Title/Summary/Keyword: 네트워크적 영역성

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A Study on the Application of Zero Copy Technology to Improve the Transmission Efficiency and Recording Performance of Massive Data (대용량 데이터의 전송 효율 및 기록 성능 향상을 위한 Zero Copy 기술 적용에 관한 연구)

  • Song, Min-Gyu;Kim, Hyo-Ryoung;Kang, Yong-Woo;Je, Do-Heung;Wi, Seog-Oh;Lee, Sung-Mo;Kim, Seung-Rae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1133-1144
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    • 2021
  • Zero-copy is a technology that is also called no-memory copy, and through its use, context switching between the user space and the kernel space can be reduced to minimize the load on the CPU. However, this technology is only used to transmit small random files, and has not yet been widely used for large file transfers. This paper intends to discuss the practical application of zero-copy in processing large files via a network. To this end, we first developed a small test bed and program that can transmit and store data based on zero-copy. Afterwards, we intend to verify the usefulness of the applied technology in detail through detailed performance evaluation

A Study of Real-time Service on Retransmission Slot in LR-WPAN (LR-WPAN에서 재전송 슬롯 기반 실시간 서비스 연구)

  • Cho, Moo-Ho
    • Journal of Korea Society of Industrial Information Systems
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    • v.15 no.5
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    • pp.19-27
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    • 2010
  • In this paper, we propose a scheme for real-time data retransmission in LR-WPAN to support the required QoS even in the severe channel error environments. In IEEE 802.15.4a, as the user data rate is supported up to 850Kbps, the real-time streaming data can be transferred more easily. In this research, we study the beacon-enabled mode in IEEE 802.15.4 LR-WPAN standard. In the proposed scheme, special slots are dynamical1y assigned for retransmission of the packet that fails during a real-time data service, and in the severe channel error environments a time diversity is acquired. Analytical results show that the proposed scheme is more robust and achieves a much higher throughput than the previous protocol in LR-WPAN.

A Study on A* Algorithm Applying Reversed Direction Method for High Accuracy of the Shortest Path Searching (A* 알고리즘의 최단경로 탐색 정확도 향상을 위한 역방향 적용방법에 관한 연구)

  • Ryu, Yeong-Geun;Park, Yongjin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.6
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    • pp.1-9
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    • 2013
  • The studies on the shortest path algorithms based on Dijkstra algorithm has been done continuously to decrease the time for searching. $A^*$ algorithm is the most represented one. Although fast searching speed is the major point of $A^*$ algorithm, there are high rates of failing in search of the shortest path, because of complex and irregular networks. The failure of the search means that it either did not find the target node, or found the shortest path, witch is not true. This study proposed $A^*$ algorithm applying method that can reduce searching failure rates, preferentially organizing the relations between the starting node and the targeting node, and appling it in reverse according to the organized path. This proposed method may not build exactly the shortest path, but the entire failure in search of th path would not occur. Following the developed algorithm tested in a real complex networks, it revealed that this algorithm increases the amount of time than the usual $A^*$ algorithm, but the accuracy rates of the shortest paths built is very high.

An Efficient Network Resource Reservation Mechanism with Mobility in Nested Heterogeneous Mobile Networks (중첩 이종 무선 망 환경에서 단말의 이동 속도를 고려한 효과적인 망 자원 예약)

  • Park, In-Soo;Tak, Dong-Kuk;Kim, Won-Tae;Park, Yong-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.10
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    • pp.83-98
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    • 2007
  • The handover between different radio access networks, especially where their coverage overlaps, suffers various complications since the different access networks provide different service characteristics. One way to reduce service interruptions and QoS (i.e., bandwidth, throughput, delay) degradations during the inter-technology handover is to reserve the required resource in advance. The resource reservation algorithm should minimize the handover latency and maximize the resource utilization based on the accurate estimation on mobile's location, velocity, movement pattern and service requirements. In this paper, we propose a resource reservation algorithm based on the mobile terminal velocity and the cell selection probability, which maximizes resource utilization ana reduces network overhead. We compare the proposed algorithm with PMS(Predictive Mobility Support) and VCDS(Velocity and Call Duration Support scheme) based on 3-layer network model under various scenarios.

Energy-efficient query processing based on partial attribute values in wireless sensor networks (무선 센서 네트워크에서 부분 속성값을 활용한 에너지 효율적인 질의처리)

  • Kim, Sung-Suk;Kim, Hyong-Soon;Yang, Sun-Ok
    • Journal of KIISE:Databases
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    • v.37 no.3
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    • pp.137-145
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    • 2010
  • Wireless sensors play important roles in various areas as ubiquitous computing is generalized. Depending on applications properties, each sensor can be equipped with limited computing power in addition to general function of gathering environment-related information. One of main issues in this environment is to improve energy-efficiency in sensor nodes. In this paper, we devise a new attribute-query processing algorithm. Each sensor has to maintain partial information locally about attributes values gathered at its all descendent nodes. As the volume is higher, however, the maintenance cost also increases. And the update cost also has to be considered in the proposed algorithm. Thus, some bits, AVB(Attribute-Value Bits), are delivered instead of the value itself, where each bit represents a bound of attribute. Thus, the partial information can decrease the number of exchanged messages with a little cost during query processing. Through simulation works, the proposed algorithm is analyzed from several points of view.

Wireless u-PC: Personal workspace on an Wireless Network Storage (Wireless u-PC : 무선 네트워크 스토리지를 이용한 개인 컴퓨팅 환경의 이동성을 지원하는 서비스)

  • Sung, Baek-Jae;Hwang, Min-Kyung;Kim, In-Jung;Lee, Woo-Joong;Park, Chan-Ik
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.9
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    • pp.916-920
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    • 2008
  • The personal workspace consists of user- specified computing environment such as user profile, applications and their configurations, and user data. Mobile computing devices (i.e., cellular phones, PDAs, laptop computers, and Ultra Mobile PC) are getting smaller and lighter to provide personal work-space ubiquitously. However, various personal work-space mobility solutions (c.f. VMWare Pocket ACE[1], Mojopac[2], u-PC[3], etc.) are appeared with the advance of virtualization technology and portable storage technology. The personal workspace can be loaded at public PC using above solutions. Especially, we proposed a framework called ubiquitous personal computing environment (u-PC) that supports mobility of personal workspace based on wireless iSCSI network storage in our previous work. However, previous u-PC could support limited applications, because it uses IRP (I/O Request Packet) forwarding technique at filter driver level on Windows operating system. In this paper, we implement OS-level virtualization technology using system call hooking on Windows operating system. It supports personal workspace mobility and covers previous u-PC limitation. Also, it overcomes personal workspace loading overhead that is limitation of other solutions (i.e., VMWare Pocket ACE, Mojopac, etc). We implement a prototype consisting of Windows XP-based host PC and Linux-based mobile device connected via WiNET protocol of UWB. We leverage several use~case models of our framework for proving its usability.

Relation between Smartphone Addiction and Interpersonal Competence of College Students using Social Network Service (소셜네트워크서비스를 이용하는 대학생들의 스마트폰 중독과 대인관계능력의 관계)

  • Park, Soonjoo;Kwon, Min-A;Baek, Min-Ju;Han, Na-Ra
    • The Journal of the Korea Contents Association
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    • v.14 no.5
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    • pp.289-297
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    • 2014
  • The purpose of this study was to investigate the relation between smartphone addiction and interpersonal competence of college students using social network service(SNS) through smartphones. This study used a descriptive study design. The convenience sample consisted of 502 college students in six cities. The data were collected from May to June in 2012 using Korean Smartphone Addiction Proneness Scale and Interpersonal Competence Questionnaire. Descriptive statistics, ${\chi}^2$-test, t-test, analysis of variance, and Pearson correlation coefficient were used to analyze the data. The results showed that 24.8% of SNS users were considered as a risk group, while 75.2% were normal user group. There were no significant differences of interpersonal competence between risk group and normal user group in the SNS users. However, risk group had higher self-disclosure scores than normal user group. The subjects who had higher scores for virtual life, one of smartphone addiction subdomains, had lower interpersonal competence and those with higher smartphone addiction scores showed lower score of managing interpersonal conflict in subdomains of interpersonal competence. These findings would contribute in development of preventive interventions for smartphone addiction and improvement program for interpersonal competence in college students.

Design of SPS Model using Mobile Agent System (이동 에이전트 시스템을 이용한 SPS 모델 설계)

  • Park, Jin-Ho;Chung, Jin-Wook
    • Convergence Security Journal
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    • v.3 no.3
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    • pp.19-24
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    • 2003
  • This research presents the development of a certain highly efficient model for group security policy negotiation using mobile agents in the IPSec environment. The conventional IP security systems has some problems. A drawback to these systems is that the required policy between each security area is different. Another problem is not possible to guarantee whether a packet is transmitted through the same path by both directions and is protected by the same policy due to the topology of the network. Unlike conventional systems, the model developed herein can be resolved by using a mobile agent technology. If each domain needs a negotiation of security policy, a mobile agent manages the result of the negotiation in the form of a passport and guarantees the authentication and reliability each other by using the passport.

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Multi-blockchain System based on Directed Acyclic Graph for Increasing Data Throughput (데이터 처리량 향상을 위한 유향 비순환 그래프 기반의 멀티블록체인 시스템)

  • CHEN, Hao-Tian;Kim, Tae Woo;Park, Jong Hyuk
    • Annual Conference of KIPS
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    • 2021.05a
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    • pp.25-28
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    • 2021
  • 블록체인은 탈집중화, 위변조 방지, 추적 가능, 노드 간 공동 유지 및 보수가 가능한 데이터베이스로서 서로 신뢰하지 않은 노드 간 통신 신뢰 문제를 해결할 수 있는 점 대 점 통신 네트워크를 실현할 수 있다. 최근 몇 년 동안, 블록체인 기술은 지속적으로 발전하여 데이터 보안 문제를 해결하기 위한 중요한 기술로 주목받고 있다. 블록체인의 응용은 최초의 디지털 화폐 영역에서 금융·정무·공업 제조 영역으로 확대되고 있다. 블록체인의 특성에 따라 블록체인의 성능은 분산형 데이터 통신에 비해 크게 떨어지고 처리량이 제한되는 문제점이 존재한다. 본 논문에서는 최근 연구되고 있는 블록체인의 보안 구조 및 성능 분석에 대해 조사하고, 기존에 연구되었던 기술과 비교하여 블록체인의 안전성을 유지하며 성능을 향상시키는 방법에 대해 고찰한다. 이후 유향 비순환 그래프 (DAG: Directed Acyclic Graph) 및 샤딩 (Sharding)을 이용하여 안전성과 성능을 강화시키는 방법에 대해 제안한다. 제안하는 시스템은 DAG를 사용하여 위변조 방지 및 처리 속도 향상의 이점을 가지고 있으며, 샤딩을 사용함으로써 데이터 처리량을 향상시킨다. 마지막으로 제안하는 시스템은 기존 블록체인과 비교하여 안정성과 데이터 처리량 측면에서 비교 분석을 진행한다.

A Route Stability-based Direction Guided Routing Protocol in Mobile Ad-hoc Wireless Networks (모바일 Ad-hoc 무선 네트워크에서 경로 안정성 기반 방향성 안내 라우팅 프로토콜)

  • Ha, Suehyung;Le, The Dung;An, Beongku
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.6
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    • pp.257-264
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    • 2012
  • In this paper, we propose a Route Stability-based Direction Guided Routing protocol(RSDGR) in mobile ad-hoc wireless networks. The main features and contributions of the proposed routing protocol are as follows. First, it can calculate link stability between two nodes as well as route stability of multi hop quantitatively by using nodes' mobility. And this protocol can establish the most stable path between a source node and a destination node. Second, according to the route stability between a source node and a destination node, it can control and optimize the direction guided region dynamically for route setup. Third, we suggest theoretical model for quantitative calculation of link stability between two nodes and route stability of multi hop path. The performance evaluation of the proposed routing protocol is performed by simulation using OPNET(Optimized Network Engineering Tool) and theoretical analysis. The results of performance evaluation show that the patterns of PDR are similar in simulation and analysis according to route stability. The faster mobile nodes' velocity and the smaller source node's direct guided reigion, the lower route stability and PDR and the higher delay and control overhead related to this.