Web Conferencing Traffic - An Analysis using DimDim as Example

In this paper, we present an evaluation of the Ethernet traffic for host and attendees of the popular opensource web conferencing system DimDim. While traditional Internet-centric approaches such as the MBONE have been used over the past decades, current trends for web-based conference systems make exclusive use of application-layer multicast. To allow for network dimensioning and QoS provisioning, an understanding of the underlying traffic characteristics is required. We find in our exemplary evaluations that the host of a web conference session produces a large amount of Ethernet traffic, largely due to the required control of the conference session, that is heavily-tailed distributed and exhibits additionally long-range dependence. For different groups of activities within a web conference session, we find distinctive characteristics of the generated traffic

Computing in the RAIN: a reliable array of independent nodes

The RAIN project is a research collaboration between Caltech and NASA-JPL on distributed computing and data-storage systems for future spaceborne missions. The goal of the project is to identify and develop key building blocks for reliable distributed systems built with inexpensive off-the-shelf components. The RAIN platform consists of a heterogeneous cluster of computing and/or storage nodes connected via multiple interfaces to networks configured in fault-tolerant topologies. The RAIN software components run in conjunction with operating system services and standard network protocols. Through software-implemented fault tolerance, the system tolerates multiple node, link, and switch failures, with no single point of failure. The RAIN-technology has been transferred to Rainfinity, a start-up company focusing on creating clustered solutions for improving the performance and availability of Internet data centers. In this paper, we describe the following contributions: 1) fault-tolerant interconnect topologies and communication protocols providing consistent error reporting of link failures, 2) fault management techniques based on group membership, and 3) data storage schemes based on computationally efficient error-control codes. We present several proof-of-concept applications: a highly-available video server, a highly-available Web server, and a distributed checkpointing system. Also, we describe a commercial product, Rainwall, built with the RAIN technology

Distributed data acquisition and control system based on low cost Embedded Web servers

In the present IT age, we are in need of fully automated industrial system. To design of Data Acquisition System (DAS) and its control is a challenging part of any measurement, automation and control system applications. Advancement in technology is very well reflected and supported by changes in measurement and control instrumentation. To move to highspeed serial from Parallel bus architectures has become prevalent and among these Ethernet is the most preferred switched Serial bus, which is forward-looking and backwardcompatible. Great stride have been made in promoting Ethernet use for industrial networks and factory automation. The Web based distributed measurement and control is slowly replacing parallel architectures due to its non-crate architecture which reduces complexities of cooling, maintenance etc. for slow speed field processing. A new kind of expandable, distributed large I/O data acquisition system based on low cost microcontroller based electronic web server[1] boards has been investigated and developed in this paper, whose hardware boards use 8-bit RISC processor with Ethernet controller, and software platform use AVR-GCC for firmware and Python for OS independent man machine interface. This system can measure all kinds of electrical and thermal parameters such as voltage, current, thermocouple, RTD, and so on. The measured data can be displayed on web pages at different geographical locations, and at the same time can be transmitted through RJ-45 Ethernet network to remote DAS or DCS monitoring system by using HTTP protocol. A central embedded single board computer (SBC) can act as a central CPU to communicate between web servers automatically

WebFlow - A Visual Programming Paradigm for Web/Java Based Coarse Grain Distributed Computing

We present here the recent work at NPAC aimed at developing WebFlow---a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We view WebFlow/WEbVM as a promising programming paradigm and coordination model for the exploding volume of Web/Java software, and we illustrate it in a set of ongoing application development activities

Optimal Economic Schedule for a Network of Microgrids With Hybrid Energy Storage System Using Distributed Model Predictive Control

Artículo Open Access en el sitio web el editor. Pago por publicar en abierto.In this paper, an optimal procedure for the economic schedule of a network of interconnected microgrids with hybrid energy storage system is carried out through a control algorithm based on distributed model predictive control (DMPC). The algorithm is specifically designed according to the criterion of improving the cost function of each microgrid acting as a single system through the network mode operation. The algorithm allows maximum economical benefit of the microgrids, minimizing the degradation causes of each storage system, and fulfilling the different system constraints. In order to capture both continuous/discrete dynamics and switching between different operating conditions, the plant is modeled with the framework of mixed logic dynamic. The DMPC problem is solved with the use of mixed integer linear programming using a piecewise formulation, in order to linearize a mixed integer quadratic programming problem.Ministerio de Economía, Industria y Competitivadad DPI2016-78338-RComisión Europea 0076-AGERAR-6-

A Distributed System for Parallel Simulations

We presented the technologies and algorithms to build a web-based visualization and steering system to monitor the dynamics of remote parallel simulations executed on a Linux Cluster. The polynomial time based algorithm to optimally utilize distributed computing resources over a network to achieve maximum frame-rate was also proposed. Keeping up with the advancements in modern web technologies, we have developed an Ajax-based web frontend which allows users to remotely access and control ongoing computations via a web browser facilitated by visual feedbacks in real-time. Experimental results are also given from sample runs mapped to distributed computing nodes and initiated by users at different geographical locations. Our preliminary results on frame-rates illustrated that system performance was affected by network conditions of the chosen mapping loop including available network bandwidth and computing capacities. The underlying programming framework of our system supports mixed-programming mode and is flexible to integrate most serial or parallel simulation code written in different programming languages such as Fortran, C and Java

DESIGNING DISTRIBUTED CONTROLLING TESTBED SYSTEM FOR SUPPLY CHAIN AND LOGISTICS IN AUTOMOTIVE INDUSTRY

The arrival of the era of autonomous robots is indisputable. In this paper, innovations in the distributed control systems realized by autonomous guided vehicles in the automotive industry are provided as proof of concept. The main goal of the considered distributed control system design is to bring all-in-one dependent and independent VDA 5050 compliant robots that are easily configurable and manageable with the web-based high-quality user interface responsive business-critical application. Special attention is paid to applying a platform to manage all autonomous IoT based robots in one seamless system. In addition, a "single point of truth" as one of the main issues of modern distributed controlled systems has been considered.

Distributed negotiation in future power networks : rapid prototyping using multi-agent system

Technologies like multi-agent system (MAS) have the capability to deal with future power grid requirements such as frequency management and voltage control under a flexible, intelligent and active feature. Based on web of cells (WoC) architecture proposed by European Liaison on Electricity Committed Towards longer-term Research Activity Integrated Research Programme (ELECTRA IRP), a distributed MAS with distributed negotiation ability for future distributed control (including frequency management and voltage control) is proposed. Each cell is designed as an intelligent agent and is investigated in case studies with constraints, where each agent can only communicate with its neighbouring agents. The interaction logic among agents is according to the distributed negotiation algorithm under consideration by the authors. Simulation results indicate that the WoC architecture could negotiate resources in a distributed manner and achieve successful exchange of resources by coordinating distributed agents. Moreover, the prototype reported in this paper can be extended further for future grids' distributed control regimes. The option of MAS to be exploited for the support of the development and integration of novel power system concepts is explored

The Relational Database Aspects of Argonne's ATLAS Control System

The Relational Database Aspects of Argonnes ATLAS Control System Argonnes ATLAS (Argonne Tandem Linac Accelerator System) control system comprises two separate database concepts. The first is the distributed real-time database structure provided by the commercial product Vsystem [1]. The second is a more static relational database archiving system designed by ATLAS personnel using Oracle Rdb [2] and Paradox [3] software. The configuration of the ATLAS facility has presented a unique opportunity to construct a control system relational database that is capable of storing and retrieving complete archived tune-up configurations for the entire accelerator. This capability has been a major factor in allowing the facility to adhere to a rigorous operating schedule. Most recently, a Web-based operator interface to the control systems Oracle Rdb database has been installed. This paper explains the history of the ATLAS database systems, how they interact with each other, the design of the new Web-based operator interface, and future plans.Comment: ICALEPCS 2001 Conference, PSN WEAP066, 3 pages, 3 figure

Development of a remote IoT laboratory for cyber physical systems

A remote Internet of Things (IoT) laboratory has been developed for use in teaching and research of cyber physical systems. The laboratory is configured such that users interact via the web to control and collect data from connected devices. The concept and technology of the remote IoT lab is successfully demonstrated in two applications. First the laboratory is configured for UTChattSat, a ground model small-satellite system (CubeSat) designed to enhance K-12 learning in the space sciences. The system utilizes real-time communication and web-based user control to create a distributed multi-user interface. Second, the laboratory is configured for a distributed sensor network with a single-user interface. The interconnected, real time, and smart system with embedded sensors and processors is used to provide data for assessment of current building energy models. Finally, challenges posed by interconnected and reconfigurable systems and the implementable future works are discussed