• Title/Summary/Keyword: switch.

Search Result 4,414, Processing Time 0.033 seconds

Improvement of F-GCRA Algorithm for ATM-GFR Service (ATM-GFR 서비스를 위한 F-GCRA 알고리즘 개선)

  • Park, In-Yong
    • The KIPS Transactions:PartC
    • /
    • v.13C no.7 s.110
    • /
    • pp.889-896
    • /
    • 2006
  • ATM Forum has defined a guaranteed frame rate (GFR) service to serve Internet traffic efficiently. The GFR service provides virtual connections (VCs) for minimum cell rate (MCR) guarantees and allows them to fairly share the residual bandwidth. And ATM Forum has recommended a frame-based generic cell rate algorithm (F-GCRA) as a frame classifier, which determines whether an Am cell is eligible to use the guaranteed bandwidth in a frame level. An ATM switch accommodates cells in its buffer or drops them in a frame level according to current buffer occupancy. A FIFO shared buffer has so simple structure as to be feasibly implemented in switches, but has not been able to provide an MCR guarantee for each VC without buffer management based on per-VC accounting. In this paper, we enhance the F-GCRA frame classifier to guarantee an MCR of each VC without buffer management based on per-VC accounting. The enhanced frame classifier considers burstness of TCP traffic caused by congestion control algorithm so as to enable each VC to use its reserved bandwidth sufficiently. In addition, it is able to alleviate the unfairness problem in usage of the residual bandwidth. Simulation results show that the enhanced frame classifier satisfies quality of services (QoSs) of the GFR service for the TCP traffic.

A Study on the Characteristics of Local Energy Consumption by Using Index Decomposition Analysis (지수분해분석을 이용한 지자체의 에너지 소비특성에 관한 연구)

  • Jin, Sang Hyeon;Hwang, In Chang
    • Environmental and Resource Economics Review
    • /
    • v.18 no.4
    • /
    • pp.557-586
    • /
    • 2009
  • Although energy demand management policy attracts attention internationally and domestically, the importance of local government in this policy is not so much as central government. But local government can do a role with regard to this policy because it is close to energy consumers not like central government. So local energy plan should be based on the understanding local energy consumption characteristics to activate local energy demand management policy. This paper tries to analyze energy characteristics of 16 local governments by decomposing energy consumption into population, production and intensity factors. The result of index decomposition analysis shows that energy intensity improvement has offset the increase of energy consumption caused by economic growth in the metropolitan cities, while it couldn't offset in the other provinces because of industrialization based on the manufacturing. In conclusion, this paper suggests that it will be necessary to switch to low energy society by carrying out concrete energy efficiency improvement projects in the metropolitan cities while it will be helpful to make a local development plan for low energy intensive industrialization in the other provinces.

  • PDF

Late Quaternary Deposition of Ice-Rafted Detritus in the Mid-Latitude North Atlantic: Paleoceanographic Evidence on Climatic Instability over the Past 150 Kyr (북대서양 중위도 해역의 신생대 제4기발 빙하쇄설퇴적층: 15만년 전 이후의 기후변동에 대한 고해양학적 증거)

  • 박명호;류병재
    • Economic and Environmental Geology
    • /
    • v.34 no.2
    • /
    • pp.217-226
    • /
    • 2001
  • Stable isotope, paleoceanographic and sedimentological analyses were carried out along the core Ml5612 from the Mid-Atlantic Ridge. Distinct negative ${\delta}^{18}O anomalies punctuate the planktonic isotope records and correlate with the Heinrich-IRD cvents. The IRD layer in the corc contains varying amounts of quartz, K-feldspar, plagioclase, calcite, dolomite and mica, in which detrital carbonate contributes between I and 13% (except H3 and H6). Anomalies are strongest in the N. pachydenna (sin.) isotope record. Systematic changes in the ${\delta}^{18}O offset of G. hul/aides and G. inJlata signify variations in mid-latitude thermocline structure. In conjunction with negative benthic ${\delta}^{13}C anomalies, the data document a stronger contribution of a ${\delta}^{13}C depleted, nutrient-rich water mass during the IRD events. The ${\delta}^{13}C amplitude of > 1 $\textperthousand$ between 25 and 57 ka indicates changes between northern source (NADW) and southern source (AABW) water masses at this site. The IRD layers in the core Ml56l2 are correlative with those from the core S075-26KL and DSDP 609. The IRD layers from the Portuguese margin arc coeval with HI, H2 and H4 of the open North Atlantic. This similarity (and/or synchronicity in both regions may have been resulted from common changes in a North Atlantic thermohaline switch.

  • PDF

eRF1aMC and $Mg^{2+}$ Dependent Structure Switch of GTP Binding to eRF3 in Euplotes octocarinatus

  • Song, Li;Jia, Yu-Xin;Zhu, Wen-Si;Chai, Bao-Feng;Liang, Ai-Hua
    • Journal of Microbiology and Biotechnology
    • /
    • v.22 no.2
    • /
    • pp.176-183
    • /
    • 2012
  • Eukaryotic translation termination is governed by eRF1 and eRF3. eRF1 recognizes the stop codons and then hydrolyzes peptidyl-tRNA. eRF3, which facilitates the termination process, belongs to the GTPase superfamily. In this study, the effect of the MC domain of eRF1a (eRF1aMC) on the GTPase activity of eRF3 was analyzed using fluorescence spectra and high-performance liquid chromatography. The results indicated eRF1aMC promotes the GTPase activity of eRF3, which is similar to the role of eRF1a. Furthermore, the increased affinity of eRF3 for GTP induced by eRF1aMC was dependent on the concentration of $Mg^{2+}$. Changes in the secondary structure of eRF3C after binding GTP/GDP were detected by CD spectroscopy. The results revealed changes of conformation during formation of the eRF3C GTP complex that were detected in the presence of eRF1a or eRF1aMC. The conformations of the eRF3C eRF1a GTP and eRF3C eRF1aMC GTP complexes were further altered upon the addition of $Mg^{2+}$. By contrast, there was no change in the conformation of GTP bound to free eRF3C or the eRF3C eRF1aN complex. These results suggest that alterations in the conformation of GTP bound to eRF3 is dependent on eRF1a and $Mg^{2+}$, whereas the MC domain of eRF1a is responsible for the change in the conformation of GTP bound to eRF3 in Euplotes octocarinatus.

Transport Demand Management in Developing Countries and Climate Change (개발도상국의 교통수요관리와 기후변화)

  • Lee, Shin
    • Journal of the Society of Disaster Information
    • /
    • v.14 no.3
    • /
    • pp.288-295
    • /
    • 2018
  • Purpose: The paper aims to compare the effectiveness of the two types of transport demand management measures, namely pull measures and push measures. Method: Case studies of two metropolitan areas in the developing world assess the extent to which increases in fuel prices can contribute to reducing automobile use and increasing the public transport use and the potential of urban rail transit to cause mode shift from automobiles. Within the case studies, a stated response survey of current car users has been conducted for Cairo and an on-line survey of rail transit users in Algiers. Results: There was a major proportion of car drivers who intend to switch to public transport, depending on the range of fuel prices in Cairo and a considerable proportion of rail users who have switched from automobiles resulting in a measurable reduction in CO2 emissions in Algiers. Conclusion: Investments in urban rail can be highly effective where there are demands for better public transport, but this type of pull measures can be much more effective if combined with push measures which significantly raise driving costs.

Active-RC Channel Selection Filter with 40MHz Bandwidth and Improved Linearity (개선된 선형성을 가지는 R-2R 기반 5-MS/s 10-비트 디지털-아날로그 변환기)

  • Jeong, Dong-Gil;Park, Sang-Min;Hwang, Yu-Jeong;Jang, Young-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.1
    • /
    • pp.149-155
    • /
    • 2015
  • This paper proposes 5-MS/s 10-bit digital-to-analog converter(DAC) with the improved linearity. The proposed DAC consists of a 10-bit R-2R-based DAC, an output buffer using a differential voltage amplifier with rail-to-rail input range, and a band-gap reference circuit for the bias voltage. The linearity of the 10-bit R-2R DAC is improved as the resistor of 2R is implemented by including the turn-on resistance of an inverter for a switch. The output voltage range of the DAC is determined to be $2/3{\times}VDD$ from an rail-to-rail output voltage range of the R-2R DAC using a differential voltage amplifier in the output buffer. The proposed DAC is implemented using a 1-poly 8-metal 130nm CMOS process with 1.2-V supply. The measured dynamic performance of the implemented DAC are the ENOB of 9.4 bit, SNDR of 58 dB, and SFDR of 63 dBc. The measured DNL and INL are less than +/-0.35 LSB. The area and power consumption of DAC are $642.9{\times}366.6{\mu}m^2$ and 2.95 mW, respectively.

A Performance Improvement of Linux TCP/IP Stack based on Flow-Level Parallelism in a Multi-Core System (멀티코어 시스템에서 흐름 수준 병렬처리에 기반한 리눅스 TCP/IP 스택의 성능 개선)

  • Kwon, Hui-Ung;Jung, Hyung-Jin;Kwak, Hu-Keun;Kim, Young-Jong;Chung, Kyu-Sik
    • The KIPS Transactions:PartA
    • /
    • v.16A no.2
    • /
    • pp.113-124
    • /
    • 2009
  • With increasing multicore system, much effort has been put on the performance improvement of its application. Because multicore system has multiple processing devices in one system, its processing power increases compared to the single core system. However in many cases the advantages of multicore can not be exploited fully because the existing software and hardware were designed to be suitable for single core. When the existing software runs on multicore, its performance improvement is limited by the bottleneck of sharing resources and the inefficient use of cache memory on multicore. Therefore, according as the number of core increases, it doesn't show performance improvement and shows performance drop in the worst case. In this paper we propose a method of performance improvement of multicore system by applying Flow-Level Parallelism to the existing TCP/IP network application and operating system. The proposed method sets up the execution environment so that each core unit operates independently as much as possible in network application, TCP/IP stack on operating system, device driver, and network interface. Moreover it distributes network traffics to each core unit through L2 switch. The proposed method allows to minimize the sharing of application data, data structure, socket, device driver, and network interface between each core. Also it allows to minimize the competition among cores to take resources and increase the hit ratio of cache. We implemented the proposed methods with 8 core system and performed experiment. Experimental results show that network access speed and bandwidth increase linearly according to the number of core.

A Transmission Service Method for Processing Visual Recognition of Sender Information (발신자 정보에 대한 시각적 인식 처리를 위한 전송 서비스 기법)

  • 김기현
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.10 no.4
    • /
    • pp.328-336
    • /
    • 2004
  • Recently a mobile service is changing into a system environment that offers the customer various contents service. Representative example of service is a Calling Identity Del ivory Service(CID). Such service has the problem in the case which the receiver cannot remember the phone number of the sender; it has a difficult problem that cannot easily confirm whose the phone number it is. Therefore, it is desirable to design and implement visual services that can enhance the recognition of users. In this paper, we propose the architecture that is similar to a Calling Identity Delivery Service. We propose the architecture for communication service and system that is able to visually display the information of the sender using 2D image data in mobile environment. After that we set the image information to represent the user and this method is able to visually display the information of the sender by transmitting an image data through channels from switch station or base station using the server. When the receiver receives a phone call from the sender, this method provides an efficient service by transmitting visual data with bell sound. That is, the image information of sender is appeared on liquid crystal display(LCD) of the receiver at the same time. We investigate the concepts for processing real-time transmission of image data and describe an example of the implementation result that is based on system. This technology has a potential influence on the marketing and presents an efficiency of this method.

A Indoor Management System using Raspberry Pi (라즈베리 파이를 이용한 실내관리 시스템)

  • Jeong, Soo;Lee, Jong Jin;Jung, Won Ki
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.9
    • /
    • pp.745-752
    • /
    • 2016
  • In the era of the Internet of Things, where all physical objects are connected to the Internet, we suggest a remote control system using a Raspberry Pi single-board computer with ZigBee, which can turn an indoor light-emitting diode (LED) and a multiple-tap on and off, and with a smart phone can control the brightness of the LED as well as an electronic door lock. By connecting an infrared (IR) transmitter module to the Raspberry Pi, we can control home appliances, such as an air conditioner, and we can also monitor indoor images, indoor temperatures, and illumination by using a smart phone app. We developed a method of finding out IR transmission codes required for remote-controllable appliances with an AVR micro-controller. We suggest a method to remotely open and shut an office door by novating the door lock. The brightness level of an LED (between 0 and 10) can be controlled through a PWM signal generated by an ATmega88 microcontroller. A mutiple-tap is controlled using an ATmega32, a photo-coupler, and a TRIAC. The signals for measured temperature and illumination are converted from analog to digital by using the ATtiny44A microcontroller transmitting to a Raspberry Pi through SPI communication. Then, we connect a camera to the CSI head of the Raspberry Pi. We can turn on the smart multiple-tap for a certain period of time, or we can schedule the multi-tap to turn on at a specific time. To reduce standby power, people usually pull out a power code from multiple-taps or turn off a switch. Our method helps people do the same thing with a smart phone, if they are away from home.

Design and Implementation of a Subscriber Interface Management System in ATM Network (ATM망을 위한 가입자 인터페이스 관리 시스템의 설계 및 구현)

  • Lee, Byeong-Gi;Jo, Guk-Hyeon
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.5 no.6
    • /
    • pp.782-792
    • /
    • 1999
  • 효과적인 ATM 망의 관리는 연결 지향 환경, 다양한 서비스 등급, 대규모 트래픽, 가상 망 구성 그리고 여러가지 트래픽 유형 등과 같은 다양한 ATM 특성을 다룰 수 있어야만 한다. 이를 위해 ATM 포럼에서는 ATM 장치, 사설망, 공중망 및 그들간의 상호작용을 지원하기 위한 ATM 망 관리 참조 모델을 정의하였으며, 그 중 하나가 서로 다른 판매자로부터의 ATM 장비들간의 상호동작성을 보장하기 위해 SNMP 기반 망 관리 프로토콜을 통해 상호 연결된 인터페이스를 관리할 수 있도록 정의된 통합 지역 관리 인터페이스(ILMI) 프로토콜이다. ILMI의 목적은 두 인접한 ATM 장치로 하여금 그들 간에 공통의 ATM 링크에 대한 동작 파라메타를 자동적으로 구성할 수 있도록 함으로서, 관리자에 의해 수동 구성이 아닌 ATM 장치 상호간의 플러그 앤 플러그 기능을 지원하는데 있다. 본 논문에서는 이러한 ILMI 기술을 바탕으로 공중망 ATM 교환기에 연결된 가입자의 물리 인터페이스, ATM 계층 인터페이스, VPC 및 VCC의 구성 및 상태 정보를 효율적으로 관리하며, 가입자 시스템의 ATM 주소를 자동으로 등록, 관리할 수 있도록 하는 가입자 인터페이스 관리 시스템(SIMS)을 설계하고, 구현하였다. Abstract An effective ATM management must address the various features of ATM such as connection-oriented environment, varying class of service, large scale traffic, virtual network configurations and, and multiple traffic types. For this, ATM network management reference model defined by ATM Forum describes the various types of network management needed to support ATM devices, private networks, public networks, and the interaction between them. One of these types is Integrated Local Management Interface (ILMI) defined to manage interconnected interface through SNMP-based network management protocol for ensuring the interoperability of ATM devices from different vendors. The purpose of ILMI is to enable two adjacent ATM devices to automatically configure the operation parameters of the common ATM link between them and then to provide a Plug and Plug function to any ATM devices with not a passive configuration by manager but a automatic configuration. This paper design and implement a Subscriber Interface Management System (SIMS) which provide automatic registration and management of ATM address of subscriber system and efficiently manages physical interface of subscriber who is connected to public ATM switch, ATM layer interface, configuration information and status information of VPC and VCC.