• Title/Summary/Keyword: connection time

Search Result 1,965, Processing Time 0.036 seconds

Bluetooth Network for Mobile System Control (이동 시스템 제어를 위한 블루투스 네트워크)

  • 임준홍;곽재혁
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.10 no.11
    • /
    • pp.1052-1057
    • /
    • 2004
  • Bluetooth technology is essentially a method for wireless connectivity of a diverse set of devices ranging from PDAs, mobile phone, notebook computers, to another equipments, The bluetooth system both point-to point connection and point-to multipoint connection. In point-to multipoint connection, the channel is shared among several bluetooth devices. Two or more devices sharing the same channel form a piconet. There one master device and up to seven active slave devices in a piconet. The radio operates in the unlicensed 2.45GHz ISM band. This allows users who travel world-wide to use bluetooth equipments anywhere. Since the link is based on frequency-hop spread spectrum, multiple channels can exist at the same time. The bluetooth standard ha s been suggested that bluetooth equipments can be used in the short-range, maximum 100 meters. It has been defined that the time takes to setup and establish a bluetooth connection among devices is 10 seconds. It is a long time and may be a cause to lose a chance of finding other non-fixed devices. We propose a routing protocols for scatternets which can be used to control a mobile units(MUs) in this network. The proposed routing protocol is composed of two kinds of bluetooth information, access point(AP) and MU.

Performance Improvement of Video Prefix-caching Techniques (비디오 프리픽스-캐슁 기법의 성능 개선)

  • Lim, Hyo-Taek;They, Yu-Shu;Lee, Hoon-Jae
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.32 no.7B
    • /
    • pp.431-437
    • /
    • 2007
  • Web proxy caching provides an effective way to reduce access latency and bandwidth requirement. In particular, prefix caching is considered as an alternative for improving video delivery over wide area networks because video objects are usually too large to be cached in their entirety. Nevertheless, many studies have pointed that the user-perceived latency is often not dominated by object transmission time, but rather by setup process such as TCP connection time that precedes it. We propose pre-connecting techniques and show that the techniques can be used efficiently in TCP splicing. Our analysis shows the pre-connection significantly reduces start-up latency and TCP connection time in simple analytical model. The deployment of the proposed pre-connection does not require protocol modification or the cooperation of other entities.

A Load Distribution Technique of Web Clustering System based on the Real Time Status of Real Server (웹 클러스터 시스템의 실시간 서버 상태를 기반으로 한 부하분산 방안)

  • Youn, Chun-Kyun
    • The KIPS Transactions:PartA
    • /
    • v.12A no.5 s.95
    • /
    • pp.427-432
    • /
    • 2005
  • I studied about existent load distribution algorithms and the WLC(Weighted Least Connection) algerian that is using much at present to distribute the connection request of users to real servers efficiently in web cluster system. The efficiency of web cluster system is fallen by load imbalance between servers, because there is problem In inaccurate load status measuring of servers and measuring timing at these load distribution algorithms. In this paper, I suggest an algorithm that distributes load base on various load state of servers by real time using broadcasting RPC(Remote Procedure Call) when a user requests connection, and implement a prototype and experiment its performance. The experiment result shows that load imbalance phenomenon between reai sowers was improved greatly than existing method, and performance of web cluster system was improved by efficiency that response time is shortened.

The Size Reduction of Artificial Neural Network by Destroying the Connections (연결선 파괴에 의한 인공 신경망의 크기 축소)

  • 이재식;이혁주
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.27 no.1
    • /
    • pp.33-51
    • /
    • 2002
  • A fully connected Artificial Neural Network (ANN) contains many connections. Compared to the pruned ANN with fewer connections, the fully connected ANN takes longer time to produce solutions end may not provide appropriate solutions to new unseen date. Therefore, by reducing the sloe of ANN, we can overcome the overfitting problem and increase the computing speed. In this research, we reduced the size of ANN by destroying the connections. In other words, we investigated the performance change of the reduced ANN by systematically destroying the connections. Then we found the acceptable level of connection-destruction on which the resulting ANN Performs as well as the original fully connected ANN. In the previous researches on the sloe reduction of ANN, the reduced ANN had to be retrained every time some connections were eliminated. Therefore, It tool lolly time to obtain the reduced ANN. In this research, however, we provide the acceptable level of connection-destruction according to the size of the fully connected ANN. Therefore, by applying the acceptable level of connection-destruction to the fully connected ANN without any retraining, the reduced ANN can be obtained efficiently.

An Experiment on On-Demand Circuit Provisioning in SONET/SDH ASON Networks (지능형 광 전달망에서의 on-demand 회선 생성 성능 분석 실험)

  • Nga, Kinh Thi Thuy;Kim, Byung-Jae;Lee, Yong-Gi;Kang, Min-Ho
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2005.08a
    • /
    • pp.174-179
    • /
    • 2005
  • In the SONET/SDH based ASON, one VC3 connection contains 21 VC12 calls. Hence, it can serve up to 21 VC12 calls. When a new VC12 call arrives, if there exists at least one available VC3 connection in the network, that VC12 call is severed immediately. However, if there is no available VC3 connection, that VC12 call has to wait a certain time, called setup latency, for the a new VC3 connection to be established. This is inconvenient for the customers. On the other hand, if there are more VC3 connections than the network requires, this can waste network resources. In this paper, we proposed the solution for these problems. In order to reduce the number of VC12 calls which have to wait, we setup a new VC3 before all VC12 time slots are occupied. Furthermore, to avoid the waste of the network resources, we do not establish all VC3 connections at the same time, but do establish step by step.

  • PDF

Design of watermark trace-back system to supplement connection maintenance problem

  • Kim, Hwan-Kuk;Han, Seung-Wan;Seo, Dong-Il;Lee, Sang-Ho
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.2151-2154
    • /
    • 2003
  • Internet is deeply rooted in everyday life and many things are performed using internet in real-world, therefore internet users increased because of convenience. Also internet accident is on the increase rapidly. The security vendor developed security system to protect network and system from intruder. Many hackings can be prevented and detected by using these security solutions. However, the new hacking methods and tools that can detour or defeat these solutions have been emerging and even script kids using these methods and tools can easily hack the systems. In consequence, system has gone through various difficulties. So, Necessity of intruder trace-back technology is increased gradually. Trace-back technology is tracing back a malicious hacker to his real location. trace-back technology is largely divided into TCP connection trace-back and IP packet trace-back to trace spoofed IP of form denial-of-service attacks. TCP connection trace-back technology that autonomously traces back the real location of hacker who attacks system using stepping stone at real time. In this paper, We will describe watermark trace-back system using TCP hijacking technique to supplement difficult problem of connection maintenance happened at watermark insertion. Through proposed result, we may search attacker's real location which attempt attack through multiple connection by real time.

  • PDF

A Variability Design Technique based on Component Architecture for Dynamic Component Integration (컴포넌트 아키텍쳐 기반의 동적 컴포넌트 조합을 위한 가변성 설계 기법)

  • Kim Chul Jin;Cho Eun Sook
    • Journal of Internet Computing and Services
    • /
    • v.6 no.2
    • /
    • pp.13-24
    • /
    • 2005
  • Software development by component integration is the mainstream for time-to-market and is the solution for overcoming the short lifecycle of software. Therefore, the effective techniques for component integration have been working. However, the systematic and practical technique has not been proposed. One of main issues for component integration is how to specify integration and the component architecture for operating the specification, in this paper, we propose a workflow variability design technique for component integration, This technique focuses on designing to a connection contract based on the component architecture. The connection contract is designed to use the provided interface of component and the architecture can assemble and customize components by the connection contract dynamically.

  • PDF

The effect of beam section property on the behavior of modular prefabricated steel moment connection

  • Kazemi, Seyed Morteza;Sohrabi, Mohammad Reza;Kazemi, Hasan Haji
    • Steel and Composite Structures
    • /
    • v.32 no.6
    • /
    • pp.769-778
    • /
    • 2019
  • The specially prefabricated steel moment connections with pyramid head is one of the significant innovations in the steel structures forms to improve the installation time and simplify the construction procedure. The beams in this structure form are supported by two top and bottom angles and web double angles. Such a configuration despite its advantages increases the welding operation and filed installation time and costs. In this paper, the effect of using beams with channel and I section in three classes of seismically compact, seismically non-compact, and slender section according to width-to-thickness ratio on the behavior of the connection was investigated under monotonic and cyclic loading. Modeling was performed by ABAQUS and verified by the results of an experimental specimen. The findings indicated that using I and channel section instead of angle section reduces the amount of welding materials as well as easing the installation procedure. However, it has no significant effect on the ultimate strength and ductility of the connection. Furthermore, if the beam section is seismically compact, this form is considered as a special moment frame that has a rotation capacity up to 0.04 radians without any reduction in connection moment resistance.

Case Study on Deciding a Time for Repairing Asphalt Pavement of Incheon International Airport (인천국제공항 아스팔트 포장 보수시기 결정 사례 연구)

  • Lee, Jae-Ho;Kim, Jang-Rack;Mun, Hyung-Chul;Cho, Nam-Hyun
    • International Journal of Highway Engineering
    • /
    • v.15 no.6
    • /
    • pp.49-60
    • /
    • 2013
  • PURPOSES : The evaluation of the pavement condition of the asphalt concrete pavement of No. 2 runway of Inchon International Airport through PMS, a supporting system for making a decision of pavement, maintenance and repair, was made, and the proper time for repair according to the PCI reduction rate was suggested. METHODS : By comparing and analyzing the evaluation results of pavements built in 2009, 2010, 2011, PCI change in each facility (No. 2 runway, C parallel taxiway, connection taxiway) was calculated. By applying the calculated change to PCI deduction rate model, the pavement condition of the target sections was estimated, and then the necessary section and time for repair were chosen. RESULTS : After careful consideration of the time for pavement and maintenance, based on the result of PCI prediction, it was estimated that the southern takeoff and landing section of No. 2 runway was required to be repaired in 2012; connection taxiway in 2013; and C parallel taxiway in 2014; however, the section which is the main moving route of connection taxiway and C parallel taxiway was needed to be repaired in 2012. CONCLUSIONS : For maintenance and repair of airport pavements, the optimal alternative should be chosen by considering economics and operability, via examining the time for repair and the aspect of management all together on the basis of this study.

Examination of Two-Dimensional Magnetic Properties in a 5-Leg-Different- Volume- V-Connection- Transformer Core

  • Urata Shinya;Shimoji Hiroyasu;Todaka Takashi;Enokizono Masato
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
    • /
    • v.5B no.3
    • /
    • pp.243-247
    • /
    • 2005
  • The Different-volume- V-connection transformer is known as an electric power source that can supply 3-phase electric power and single-phase electric power at the same time. Usually, we use two single-phase transformers that have different volumes. In this paper, we propose the use of a 3-phase 5-leg transformer with the different-volume- V-connection. And, we examine the magnetic properties of the 5-leg core model with the different-volume- V-connection. The magnetic properties of cores with the different-volume- V-connection are compared with those with the delta-connection. In order to express the magnetic anisotropy of the core materials and to calculate the iron loss directly, the two-dimensional vector magnetic property is considered with the E&SS modeling in the simulation.