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In this article we provide a theoretically informed empirical analysis of the introduction and use of information and communication technology (ICT) within the primary health care (PHC) sector of Mozambique. The theoretical lens for this analysis is developed from Manuel Castells' (1996, 1997, 2001) ideas on the network society and counter domination. These ideas help us to conceptualize the communicative action required to strengthen the PHC sector as a “counter network,” which has the normative aim to strengthen the health information system (HIS) as a key strategy to improve health care delivery. Taking an informational perspective, the role of communication is highlighted as playing an important constitutive basis in the strengthening of this network. These conceptual ideas are applied to the empirical analysis of an ongoing project (the Health Information Systems Programme or HISP), and to analyze some key constraints and strategies for strengthening these networks. This study makes key contributions to both the theoretical and practical domains of HIS in developing countries. © 2005 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Researchers have suggested that businesses are undergoing a paradigm shift due to the emergence of Internet; a ubiquitous information platform. There is no doubt that its emergence has had and will continue to have considerable impact on business processes and practices. In this special issue of the JMM we address Internet's impact upon the personal selling and sales management processes and practices of contemporary firms. As co-editors of this special issue, we have had a chance to only publish a small set of papers. Therefore, in this editorial we attempt to explicate the lessons learned from the development of the Internet and associated information platforms, with the aim to address the broader issues that have emerged in this area. We specifically divide our discussion into Business to Consumer (B2C), Peer to Peer (P2P), and Business to Business (B2B) lesson. We first review learning from existing practices in the B2C, P2P, and B2B domains. This is followed by a discussion on the impact of the Internet on personal selling and sales management practices. At the end of this editorial, papers in this special issue are discussed with respect to their learning and positioning. [ABSTRACT FROM AUTHOR]

The history of computer networks is relatively well described in Western literature but some parts of the world have been neglected. This paper explores the first ways in which computer networks were used in Yugoslavia, since these are different from the modes used in the West or Russia, because the dissolution of the country -- mixed with its transition from communism to democracy and the wars for independence -- created an environment which allowed computer networks to be used in unprecedented ways. The paper uses a mix of historical method, computational methods for collecting and analysing USENET data, semi-structured interview, archival research, and qualitative online observation. The main findings show that access to Western technology and participation in academic networks enabled Yugoslavian STEM academia and hackers to use computer networks for the first computer networks' propaganda war. Slovenians, Croatians, and Serbians created electronic mailing lists through which they tried to manipulate international actors and to bond the diaspora for a common cause, and they additionally fought in USENET discussion groups by implementing trolling techniques. [ABSTRACT FROM AUTHOR]

With large-scale Cyber-Physical Systems (Internet of Things) deployments, the low-cost networked devices are becoming ubiquitous. Time stamping of events is a basic requirement and it is crucial for distributed/isolated systems/devices to work in unison. The system clocks of these devices are not very stable and their behaviour is affected by ageing and environmental conditions. A clock’s timing behaviour is generally analysed independently by comparison to a highly stable standard reference clock using specialized instruments. Network Time Protocol (NTP) is widely used for time synchronization over computer networks. As the NTP server clock is more stable in comparison to a client’s system clock, the variation in the end device’s clock offset values with respect to the NTP server clock over a long time can be considered for analysing the behaviour of the end device’s clock. This paper presents a method for analysing clock behaviour based on NTP messages. A computer programme is developed, which utilizes an open-source NTP client library to exchange NTP messages and records end device’s system clock’s offset variations over time for a given periodicity to analyse the behaviour. This black box analysis approach does not require any direct access to the end device’s clock circuit. The solution may be useful for analysing clock behaviour for long-term stability under actual environmental conditions, for deciding time synchronization periodicity to optimize the number of synchronization packet exchanges, and for pre-deployment timing stability assessment of devices for deployment scenarios having intermittent/non-availability of periodic time synchronization. [ABSTRACT FROM AUTHOR]

How can digital covert action be attributed? This paper revisits one of the most complex, most significant, and most mysterious digital covert actions of our time: a 2015 hack-and-leak case known among investigators as 'WikiSaudiLeaks' that so far has evaded attribution. We argue that WikiSaudiLeaks was not a stand-alone event, but a puzzle piece in a larger covert action campaign that involved advanced computer network exploitation, computer network attack, persistent deception, and a creative influence and disinformation effort. By disintegrating the larger event into its components, limited attribution becomes possible. We present the most detailed and comprehensive investigation of this case to date, attribute at least one component of the larger event to Iranian intelligence, and draw conceptional conclusions. [ABSTRACT FROM AUTHOR]

Trust allows collaborating entities to cope with their uncertainty especially when these collaborations are the bedrock of the network existence such as in Mobile Ad hoc NETworks (MANET). The trustworthiness of collaborators can be evaluated using reputations. Reputation is an appreciation of the node credibility created through past actions. It can be calculated using direct observations and/or using other nodes appreciations exchanged through recommendations. Unfortunately, some nodes may be attempted to disturb the network by sending faked recommendations in order to decrease the reputation of a benevolent node or to increase the one of an attacker. That's collusion attack. The main contribution of this paper concerns then, the proposition of collusion prevention and detection process in a trust based MANET. [ABSTRACT FROM AUTHOR]

Peer-to-peer (P2P) networks have become ubiquitous due to their synonymous association with illicit file sharing. Although P2P networks offer the unique ability for users to work and share data directly with each other, they also have become a harbor for those illegally trading copyright-protected material. These concerns have led to a variety of court actions that have taken P2P technology itself to the verge of being declared illegal. This paper explores the developments in the P2P marketplace and investigates the hypothesis that commercial opportunities exist for this unique medium. Through a review of past and current research, legal issues, and existing and developing applications, the researcher explores the potential for P2P networks to facilitate legitimate, e-commerce-based applications. [ABSTRACT FROM AUTHOR]

The author's experiences over a span of more than 50 years are characterised as a journey. Early interests in computer system performance modelling, information storage and retrieval, and computer networks become secondary to research topics in computer simulation. Organisations, events, and, most important, people define the paths, waysides, excursions, side roads, and major stops along the way. Editorial positions constitute an enduring thread throughout the journey. Capturing and preserving the history of the modelling and simulation discipline, frequently a topical sojourn, emerges as a dominant activity in the latter years. Two evocative questions, based on the prediction of a prominent computing pioneer, conclude the paper. 1955 Oldsmobile Starfire (98 Convertible) [ABSTRACT FROM AUTHOR]

Advancement of mobile technologies has enabled economical collection, storage, processing, and sharing of traffic data. These data are made accessible to intended users through various application program interfaces (API) and can be used to recognize and mitigate congestion in real time. In this paper, quantitative (time of arrival) and qualitative (color-coded congestion levels) data were acquired from the Google traffic APIs. New parameters that reflect heterogeneous traffic conditions were defined and utilized for real-time control of traffic signals while maintaining the green-to-red time ratio. The proposed method utilizes a congestion-avoiding principle commonly used in computer networking. Adaptive congestion levels were observed on three different intersections of Delhi (India), in peak hours. It showed good variation, hence sensitive for the control algorithm to act efficiently. Also, simulation study establishes that proposed control algorithm decreases waiting time and congestion. The proposed method provides an economical alternative to expensive sensing and tracking technologies. [ABSTRACT FROM AUTHOR]

How did the National Security Agency (NSA) adopt the practice of hacking? This paper explores how NSA confronted the digital age by focusing on arguably NSA's key organizational innovation as a microcosm of these broader changes: the Office of Tailored Access Operations (TAO). This paper develops a pragmatist model of organizational change showing how the practice of hacking became a practical solution to deal with the problems posed by a globally networked world through TAO's case history. TAO's aggressive expansion by developing a scalable Computer Network Exploitation (CNE) architecture was designed to keep NSA relevant in the twenty-first century. [ABSTRACT FROM AUTHOR]

The pandemic situation banned the presence of teachers and students in the classrooms disrupting the typical teaching process. Videoconferencing services have been used successfully for lectures, but they are insufficient for hands-on laboratories where the physical presence is a requirement (i.e. to access specific hardware). Enabling remote access to the equipment allows to overcome this issue, but the students must share resources (temporarily or physically) and lack full control on the equipment. This is not optimal for some subjects, such as the practical labs on datacenter management, which are increasingly being added into the IT higher education curriculum. In this paper, we present the design and implementation of a distributed laboratory environment, so-called Remote DasaLAB, to create and deploy virtual datacenters using the student's owned resources to support the practical training of students in remote (or hybrid) mode. This environment is flexible, cheap, easy to implement with available commodity resources (the students' computers) and provides full control over the platform. We also present a specific use case on leveraging Remote DasaLAB for the practical assignments of an Operating Systems subject, in which the students build a virtual datacenter composed of multiple nodes and can properly run a containerized application distributed in these nodes. [ABSTRACT FROM AUTHOR]

The DCC linear congruential (DCCLC) graphs are a family of promising interconnection topologies. This paper addresses the conditional diagnosability of DCCLC graphs under the comparison model. We prove that, under reasonable assumptions, a 2t-regular DCCLC graph is conditionally [image omitted] -diagnosable. This result shows that DCCLC graphs possess strong self-diagnosing abilities. [ABSTRACT FROM AUTHOR]

The article discusses various papers presented within the issue, including "Dynamics of gossip-like information dissemination in complex computer networks," by Nekovee and Moreno and "Dealing with network complexity in real-time networked control," by Tian and Levy.

Since the Internet was opened for public and commercial use, companies have pushed their information systems departments to expand the capabilities of electronic communication and e-commerce. Businesses grew based upon their own management of technology, each bringing new ideas and developments to the table. By 2006, it was difficult to find any business that does not have a presence on the Internet. Mere presence is not enough to make a business stand out anymore. To maintain competitiveness in this highly connected world, companies are looking for faster and more secure ways to conduct business. This includes not only the ability to communicate with the customers, but also includes the way different divisions of a company interact with each other electronically. In this paper, I will discuss how one company (referred to as the ABC Corp.) has developed and secured a content management system containing a product information database that produces and controls every sales piece used internally and externally from paper catalogs and sales flyers, to content ready for display on the World Wide Web. [ABSTRACT FROM AUTHOR]

With advances in computer and networking technologies, along with the increasing dependency on interconnected cyber-physical components, the threat of cyber-physical attacks against manufacturing is on the rise. As opposed to traditional cyber-attacks, cyber-physical attacks go beyond intellectual property theft and can affect the physical world. In manufacturing, such attacks can result in changed product designs, manipulated manufacturing equipment, and altered final products. For over a century, manufacturing systems have relied heavily on Quality Control (QC) systems to ensure stable processes and product integrity. However, previous research has suggested that current QC tools could be exploited by an adversary, making it difficult or even impossible to detect attacks. Unfortunately, there has been little to no effort to identify/understand opportunities where QC tools could be exploited, which is an essential step toward developing new cyber-security solutions for manufacturing. In response, this paper establishes a systematic approach to effectively categorize QC tool vulnerabilities. Furthermore, to highlight the importance of this research to the manufacturing community, the negative effects of exploiting QC tools by cyber-physical attacks are demonstrated in this paper. Finally, best practices and guidelines for better cyber-physical security in manufacturing are also presented. [ABSTRACT FROM AUTHOR]

Computer networking is an important subject in the computer science curriculum. However, owing to its constant evolutionary nature and inherent complexity, learning and teaching new paradigms in computer networking can be difficult. The design and implementation of a fully operational SDN (software defined networking) network is practically illustrated using a virtualisation environment, which is aimed at learning the fundamentals of routing management of SDN networks. We describe the virtualisation environment, software tools, SDN controllers, and programming details of networking equipment for the implementation of an SDN network. For educational purposes, a detailed description of the network configuration process in also presented. The level of details presented in this paper can be useful for both instructors and students to grasp the fundamental concepts of SDN routing management at an educational level in a friendly manner. A virtualised environment, as the one described in this paper, can also be useful for understanding other advanced computer networking concepts. [ABSTRACT FROM AUTHOR]

Buffer allocation in serial production lines is one of the important design issues, and hence it has been studied extensively in the literature. In this paper, we analyse the problem to characterise the optimal buffer allocation; specifically, we study the cases with single and multiple bottleneck stations under various experimental conditions. In addition, we develop an efficient heuristic procedure to allocate buffers in serial production lines to maximise throughput. The results of the computational experiments indicate that the proposed algorithm is very efficient in terms of both solution quality and CPU time requirements. Moreover, the characterisation study yields interesting findings that may lead to important practical implications. A comprehensive bibliography is also provided in the paper. [ABSTRACT FROM AUTHOR]

Modern organizations offer services through multiple channels, such as branches, ATMs, telephones, and Internet sites, and are supported by multifunctional software architectures. Different functional modules share data, which are typically stored in multiple local databases. Functional modules are usually not integrated across channels, as channels are implemented at different times within independent software projects and are subject to varying requirements of availability and performance. This lack of channel and functional integration raises data quality problems that can impact the quality of the products and services of an organization. In particular, in complex systems in which data are managed in multiple databases, timeliness is critical. This paper focuses on time-related factors of data quality and provides a model that can help companies to evaluate data currency, accuracy, and completeness in software architectures with different degrees of integration across channels and functionalities. The model is validated through simulation based on empirical data on financial information systems. Results indicate how architectural choices on the degree of data integration have a varying impact on currency, accuracy, and completeness depending on the type of financial institution and on customer profiles. [ABSTRACT FROM AUTHOR]

Totalisation of operations and functions is a subject of great importance in the precise sciences at large, and in particular, in computer science, where computed functions must be totalised to account for edge cases and prevent system failures. In this paper, we investigate the totalisation of computable functions in the general and abstract setting of the axiomatic theory of computing systems, such as automata, computer networks, and algorithms, allowing us to define characteristics and discover relations which resonate true through many computational models – from individual automata through complex distributed systems with concurrent functioning. We explore the possible types of totalisations, the complexes of computing systems that do (or do not) have totalisations, and the behaviour of totalisation in various transformations and compositions. In addition, we point to a few interesting directions for future research. [ABSTRACT FROM AUTHOR]

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Performance sharing is a common technique to save energy and increase system reliability. This paper considers a multi-state system with hierarchical performance sharing groups. The system has several subsystems connected with a primary common bus, and each subsystem has some groups of components connected with a secondary common bus. Each component group has a demand to satisfy. The groups within the same subsystem can share performance through the secondary common bus, whereas the different subsystems can share capacity with each other through the primary common bus. Both primary and secondary common buses have a maximum transmission capacity. The system fails if the demand for any group cannot be satisfied. The system reliability is evaluated with a universal generating function technique, and the optimal allocation of components which maximises the system reliability is studied. [ABSTRACT FROM AUTHOR]

Prefabricated construction heavily relies on the effective transportation of precast components, and efficient prefabrication transportation can benefit the whole construction process from many aspects, such as saving cost, time, and spaces. However, current practices of prefabrication transportation are inefficient due to various involved stakeholders, outdated decision support tools, scarce real-time data, and ineffective information sharing mechanisms. To tackle these problems, and facilitate the management and operations of prefabrication transportation, this paper proposes a cloud-based fleet management platform through integrating the advantages of Internet of Things (iot) and cloud technology. A Transportation Management Service Sharing (TMSS) mechanism is proposed, which enables the platform to be easily and economically used by various transportation service providers, and could benefit all the other stakeholders involved. Besides, relation-based data extraction approach is proposed to extract sufficient transportation data during the whole process, and the transportation data synchronization mechanism is also worked out to ensure the data consistency. Finally, based on a real-life prefabricated construction project for public housing production in Hong Kong, a case study is conducted to verify the effectiveness of the proposed platform. [ABSTRACT FROM AUTHOR]

Twisted cubes are an important class of hypercube-variant interconnection networks for parallel computing. In this paper, we evaluate the fault-tolerant mesh/torus embedding abilities of twisted cubes. By reducing the fault-tolerant mesh/torus embedding problem to the fault-tolerant pancyclicity, we propose several schemes for embedding meshes/tori in faulty twisted cubes. The obtained results reveal another appealing fault-tolerant feature of twisted cubes. [ABSTRACT FROM AUTHOR]

Multiuser diversity (MUD) can be exploited in multiuser networks to improve performance. In this paper, the outage probability (OP) of amplify-and-forward relaying multiuser networks with transmit antenna selection (TAS) over N-Nakagami fading channels is investigated. Exact closed-form OP expressions are derived for two TAS schemes. These expressions are used to evaluate the effect of the power allocation on the OP. Monte Carlo simulation is used to verify the analysis. The results show that MUD has a significant effect on the OP. [ABSTRACT FROM AUTHOR]

An electronic community system encodes and manipulates the range of knowledge and values necessary to function effectively in a community or organization. The knowledge includes both formal data and literature and informal results and news. The manipulation includes both browsing through the available knowledge, and recording and sharing interrelationships between the items. A large-scale experiment is underway to build an electronic community system for the community of scientists studying the nematode worm C. elegans, a model organism in molecular biology. This paper discusses a model for community systems and previous such systems in science, the biology experiment and a previous system, the enabling technology for handling the knowledge, the enabling mechanisms for handling the values, the state of the prototype, and speculations on future applications in supporting organizational memory. [ABSTRACT FROM AUTHOR]

This paper relates developments in the use of Internet-based communication technologies to contemporary exchanges of geographical ideas and content. A brief history of the Internet provides the basis for a review of uses of broadband Internet in contemporary Geography. Two themes are explored: the first is the concept of virtual communities of practice, and the second describes the nature and use of virtual research networks, with a focus on Access Grid. The key argument is that the enhanced Internet capabilities facilitate virtual communities in Geographical Education. The paper is based on five years of experience in developing in-service support at the University of Waikato and the in-class use of tutorial software over the Internet. [ABSTRACT FROM AUTHOR]

To improve the overall system performance for distributed systems using mesh as their underlying structure, a hierarchical approach was proposed in [7]. The hierarchical configuration divides the mesh into clusters, thus allowing for processing to occur in small local groups at the lower levels. After local operations, the results are passed to higher logical levels. This method has been shown to be able to significantly reduce the total communication cost for the entire system. This paper is concerned with the hierarchical system's ability to handle node failure. When using a hierarchical configuration, certain nodes in the mesh become more important to the overall system than others. It is important that the hierarchical system have a reorganising mechanism in case of node failure, in such a way that the performance gain from hierarchical configuration is salvaged as much as possible. The work presented in this paper focuses on minimising the loss of performance in the system hierarchy due to the presence of failing nodes. We will propose fault-tolerance schemes for that purpose. The performance results will be compared to that of an ideal, fault-free system. We will present strategies to reconstruct the hierarchy, accommodating to the situation that some nodes in the original hierarchy are not functioning anymore. To that end, new local heads may be selected and local nodes regrouped. We will also present experiment results that examine the effectiveness of the proposed schemes. Examples of both faulty and fault-free hierarchical mesh systems will be tested to quantify how good the proposed schemes are. [ABSTRACT FROM AUTHOR]

The author, a middle-aged woman, was originally diagnosed with "Congenital Absence of Vagina"-at age thirteen. Since that time, she underwent four exploratory and corrective surgeries, without ever receiving a correct diagnosis that explained her condition, Mayer- Rokitansky-Kiister-Hauser Syndrome (MRKH). The author describes personal experiences with the medical profession and her emotional response to the diagnosis and treatment. The author made contact with an MRKH Internet support group and conducted a survey of its members. This paper discusses the qualitative results of this survey, confirming the need for awareness of atypical reproductive issues. This paper concludes with recommendations on the medical and psychological treatment of MRKH. [ABSTRACT FROM AUTHOR]

Notwithstanding impressive developments in SDI in exchange, sharing, accessibility, and use of spatial data, its operational implementation appears sometimes problematic. This paper explores conditions and factors for effective and sustainable use of SDI and suggests that the inherent complexity of SDI requires a multi-faceted way of monitoring and evaluation rather than confinement to the limited scope of objective oriented performance only. Critical issues, challenges, and dilemmas can be identified while looking at SDI as facilitator of communication, as networked infrastructure, as socio-technical actor-network, as common-pool resource, and as community of practice. Finally, the paper suggests institutionalization of SDI within a spatial data community as a unifying concept towards effectiveness and sustainability of SDI initiatives while recognizing their inherent complexities. Institutionalization is the process in which the SDI will gain an institutional (structural) role within the spatial data community in which it is embedded and consequently contributes to effective exchange, sharing, accessibility, and use of spatial data. The paper also discusses some operational conditions to this end. [ABSTRACT FROM AUTHOR]

This paper proposes anew architecture for wide area networks. The architecture is based on the concept of independent islands connected via adynamically reconfigured core. Reconfiguration can take place at the level of the physical layer and data link layer, which forces the reconfiguration of other network protocols. During normal network operation, the currently available alternative connections are permanently analysed and an optimal core structure is developed. To evaluate the next variants of the core topology, amulticriteria evaluation of various technical, economic, and operational parameters is applied. [ABSTRACT FROM AUTHOR]

Augmented reality (AR) fur assembly processes is a new kind of computer support for a traditional industrial domain. This flew application of AR technology is called ARsemsbly. The intention of this article is to describe a typical scenario for assembly and service personnel and how they might be supported by AR. For this purpose. tasks with different degrees of difficulty were selected from an authentic assembly process. In addition, 2 other kinds of assembly support media (a paper manual and a tutorial by an expert) were examined in order to compare them with ARsembly. The results showed that the assembly fines varied according to the different support conditions. AR support proved to be more suitable for difficult tasks than the paper manual, Whereas for easier Lasts the use of a paper manual did not differ significantly hum AR support. Tasks done under the guidance of an expert were completed most rapidly Some of the information obtained in this investigation also indicated important considerations for improving future ARsembly applications. [ABSTRACT FROM AUTHOR]

This paper offers an inventory of Internet resources on the history of medicine. Some sites are bibliographic; they supply book and journal citations. Some provide leads (or links) to more specific information, and some include full-text articles or historical essays. Because this material is intended to furnish librarians with reference direction, more attention is given to bibliographic and ''linked'' sites. This paper updates a previous version published in Medical Reference Services Quarterly in Spring 1998. [ABSTRACT FROM PUBLISHER]

Many software firms, especially mobile app providers, offer perpetually free basic products to users, but premiums are charged for access to the additional features or functionalities. While the free offering helps capture potential customers, it might cannibalize the sales of premium goods or services. This paper adopts a game theoretical approach to examine the impact of free offering on the competition between two firms in the presence of network effects. The firms can either offer a free core product and a paid service or offer them as a bundle. The core product has stand-alone value and can be used separately but the value-added service has no value without the core product. We derive the market equilibria and present conditions under which the free offering strategy outperforms the bundling strategy. We show that when a firm’s core product has a sufficient advantage in product quality, it is better for this firm to sell the bundle but for the other to use free strategy. However, if the core products are similar in terms of quality, it is optimal for them to use the same strategies. Whether to offer a free product depends largely on the core products’ quality. We also show that the firms may be caught in a prisoner’s dilemma when both adopt the free strategy. Finally, we find that the profitability of the firm that offers a free product always increases in network effects intensity and market size, but this is not the case for the firm that sells the bundle. This study contributes to understanding the behavior of feature-limited free offering in a duopoly setting. Our findings also provide insights into the design of free product and the impact of network effects on the firms’ offering decisions. [ABSTRACT FROM PUBLISHER]

Optimization of traffic management in data networks is typically oriented towards maximizing throughput in congested networks, while providing for adequate transmission quality. Nowadays, energy awareness is an important aspect of the development of modern networks. Novel control and optimization strategies may be used to save the energy through adaptation of network capacity and resources to the current traffic load, while ensuring quality of service. In this paper, two control frameworks – centralized and hierarchical – for reducing energy consumption in computer networks are presented. The implementations of these frameworks provide the local control mechanisms that are implemented in the network devices level and network-wide control strategies implemented in the central control level. We discuss the limitations of these approaches and problems with their application to power control in real networks. Finally, we propose an efficient heuristic algorithm for calculating the power status of network devices and the energy-aware routing for recommended network configuration. The efficiency of presented control frameworks have been verified by simulations carried out on a number of synthetic network topologies. The implementation of the centralized control framework in the testbed network and results of laboratory tests are presented in the final part of the paper. [ABSTRACT FROM AUTHOR]

This paper's aim is to present a novel design technique for distributed estimation in networked systems. The problem assumes a network of interconnected agents each one having partial access to measurements from a linear plant and broadcasting their estimations to their neighbours. The objective is to reach a reliable estimation of the plant state from every agent location. The observer's structure implemented in each agent is based on local Luenberger-like observers in combination with consensus strategies. The paper focuses on the following network related issues: delays, packet dropouts and communication policy (time and event-driven). The design problem is solved via linear matrix inequalities and stability proofs are provided. The technique is of application for sensor networks and large scale systems where centralized estimation schemes are not advisable and energy-aware implementations are of interest. Simulation examples are provided to show the performance of the proposed methodologies. [ABSTRACT FROM PUBLISHER]

The allocation problem is considered for a computer communication network with network links being shared among multiple transmissions running at the same time. Typically, each transmission brings benefit to a network owner proportional to the transmission rate allowed. Since the link capacities are limited and the minimal rates defined by Quality of Service (QoS) requirements have to be preserved, the rate allocation problem is defined here as a problem of maximizing the overall benefit (utility) under capacity and QoS constraints. In this paper, we consider the uncertain version of the problem, in which unknown utility function parameters and unknown link capacities are treated as uncertain variables characterized by certainty distributions. We present a method for solving the problem in a unified way, with both uncertainties combined in a single certainty index. [ABSTRACT FROM AUTHOR]

In this paper, a two-level algorithm is proposed to solve the distribution network reconfiguration with an objective of minimum power loss. In the first level reconfiguration, switches of maximum power loss reduction are disconnected by the branch exchange (BE) algorithm. Based on the results, neighbourhoods of disconnected switches are constructed by the deterministic transform method in the second level. The variable neighbourhood search (VNS) algorithm keeps searching the neighbourhoods to obtain a better solution with a lower power loss. Simulations are carried out on IEEE33 and PG&69 distribution networks to verify the superiority of the proposed algorithm. The obtained results are compared with the other methods available in the paper. It can be concluded that the presented method has both high stability and rapidity. [ABSTRACT FROM AUTHOR]

With the advancement of information and communication technology and proliferation of smart devices, an enormous amount of contents is being added to the Internet every minute. Efficient routing procedures have a crucial role to navigate through all contents with minimal overhead. Named Data Networking (NDN) is the new paradigm to meet up the new requirements and challenges of current Internet. However, NDN routing is mainly based on controlled Interest flooding which depends on the hop-count field in NDN Interest packet. Current hop-count update procedure reduces the hop count by a single hop at each routing node. Subsequently, flooding arises question on the ability of NDN to manage the data explosion. Second, a redundant copy of specific contents may increase the possibility of congestion. In this paper, we propose two schemes to alleviate flooding and congestion. First, we describe a novel hop-count update procedure using a history database called Info-Base. Next, we propose an extension to Link State Routing for NDN to avoid congestion caused by the redundant copy of data in the network. Our simulation results show that the proposed method can reduce flooding up to 30% while maintaining proper hit ratio. [ABSTRACT FROM AUTHOR]

This article focuses on evaluation methods in engineering. This is a multifaceted activity both in terms of the level of detail of the activity and in terms of when the activity takes place within the overall design process. The final papers work at a very detailed level, investigating the evaluation of the errors that can occur in computer-aided design models, particularly when they are moved between systems and computers. This is increasingly important as engineering design is undertaken across globally distributed networks and models have to be moved across applications, so that the full benefits from integrated computer-aided engineering systems can be obtained.

Copyright of INFOR is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In system identification, a data set needs to beinformativeto guarantee that the identification criterion has a unique global minimum asymptotically and the parameter estimation is consistent. In this paper, we study theinformativityof the data set in a multiple-input and multiple-output (MIMO) networked control system (NCS), which contains possible network-induced delays, packet dropout, transmission scheduling, or a combination of these factors in network transmission. Moreover, to guarantee the data set of this MIMO NCS to beinformative, a group of conditions for network transmission and controller's proportional term are developed. Finally, simulation studies are given to illustrate the result. [ABSTRACT FROM AUTHOR]

This paper presents the Event Analysis of Systemic Teamwork (EAST) method as a means of modelling distributed cognition in systems. The method comprises three network models (i.e. task, social and information) and their combination. This method was applied to the interactions between the sound room and control room in a submarine, following the activities of returning the submarine to periscope depth. This paper demonstrates three main developments in EAST. First, building the network models directly, without reference to the intervening methods. Second, the application of analysis metrics to all three networks. Third, the combination of the aforementioned networks in different ways to gain a broader understanding of the distributed cognition. Analyses have shown that EAST can be used to gain both qualitative and quantitative insights into distributed cognition. Future research should focus on the analyses of network resilience and modelling alternative versions of a system. Practitioner summary: This paper presents a practical method for analysing and evaluating distributed cognition in complex systems. The Event Analysis of Systemic Teamwork (EAST) method presents task, social and information network models both individually and combined. The network models can be analysed qualitatively by visual inspection and quantitatively using network analysis metrics. [ABSTRACT FROM AUTHOR]

In this paper, the synchronisation problems of multi-agent systems with asynchronous and synchronous event-triggered control under a novel event-triggered condition are solved. Our event-triggered control protocols only require each agent to send its state information to its neighbouring agents when an event-triggered condition is satisfied. Such control protocols substantially reduce the cost of communication. It is worth mentioning that the proposed protocols also ensure that the synchronisation of the multi-agent system with asynchronous and synchronous event-triggered can be achieved asymptotically without Zeno-behaviour. Meanwhile, an ultimate synchronisation trajectory is given. Moreover, our results are applied to solve the formation control problem. Some numerical simulations are presented to illustrate the effectiveness of our protocols. [ABSTRACT FROM AUTHOR]

This paper studies the consensus problem of the switched multi-agent system composed of continuous-time and discrete-time subsystems. Communication among agents is modelled as a random network where the existence of any information channel is probabilistic and independent of other channels. Then, some necessary and sufficient conditions are presented for solving average consensus of the switched multi-agent system under arbitrary switching. Furthermore, we show that the average consensus in different sense (mean square, almost surely and in probability, respectively) are equivalent. Finally, simulations are provided to illustrate the effectiveness of our theoretical results. [ABSTRACT FROM AUTHOR]

Fault localization is an important part in communication networks. Faults are unwanted and unavoidable in communication systems, and hence, their quick detection and localization is essential for sustaining the health of the network. This paper proposes an end-to-end approach that uses passive measurements for fault localization in communication networks. We formulate the fault localisation issue as an optimisation problem and then employ the genetic algorithm technique to solve it. Extensive simulation results show that although our algorithm needs to test only a small set of network components to localise all faults, it can infer the faulty nodes in at least 97% of cases. This simulation shows that the proposed algorithm, called genetic algorithm-based fault localisation is superior to the other approaches to localise all faults in a network. [ABSTRACT FROM AUTHOR]

This paper explores the use of combination of flexible alternating current transmission system (FACTS) devices, demand response (DR) programs, and generation redispatch (GR) in short-term congestion management as well as minimization of operation costs under contingency conditions in power systems. To achieve this, a multi-stage market clearing procedure is formulated. At the first stage, the market is cleared based on generation cost minimization, without considering network constraints. Market clearing formulation for the second stage is developed considering congestion and generation costs, in which FACTS device (Thyristor Controlled Series Capacitor) and DR programs (Direct Load Control besides Time-Of-Use) are optimally coordinated with GR in the presence of network constrains, to manage the congestion at minimum costs. In addition, to make conditions more realistic, the operational conditions spanning for a year (four seasons, day by day) are considered in this study. Finally, the paper prioritizes utilizing these approaches for different contingencies. The proposed formulation is verified on IEEE 14-bus and IEEE 30-bus test systems with supporting numerical and graphical results. Results show that applying GR with DR programs is the prioritized strategy in relieving congestion and reducing generation costs in the outage of the most sensitive lines contingency. [ABSTRACT FROM AUTHOR]

This paper is concerned with a reverse obnoxious (undesirable) center location problem on networks in which the aim is to modify the edge lengths within an associated budget such that a predetermined facility location on the underlying network becomes as far as possible from the existing customer points under the new edge lengths. Exact combinatorial algorithms with linear time complexities are developed for the problem under the weighted rectilinear norm and the weighted Hamming distance. Furthermore, it is shown that the problem with integer decision variables can also be solved in linear time. [ABSTRACT FROM AUTHOR]

Multicavity multigap sheet beam klystron in W-band is an ideally portable coherent radiation source for nonlethal warfare system. In general, the beam–wave interaction circuit employs multigap structures operating with TM110-2π-mode. In this paper, compared investigation of TM110-2π-mode and TM110-π-mode interacting with sheet beam is demonstrated. Analysis indicates that although TM110-2π-mode has higher cavity impendenceR/Q, TM110-π-mode possesses wider frequency spacing interval with the adjacent competition modes, larger beam–wave coupling coefficientMandM2(R/Q), which is profitable to improve beam–wave interaction efficiency, reduce mode oscillation and shorten the circuit length. Furthermore, cold characteristics, includingR/Q,M,M2(R/Q), operating frequency, and electric-field uniformity, with different gap distance and variable displacements along electron beam propagation and the perpendicular direction are explained in detail. It also turns out TM110-π-mode is not sensitive to the fluctuations of cold characteristics as TM110-2π-mode. This paper provides a confident evidence for TM110-π-mode interacting with sheet beam in the WSBK design. [ABSTRACT FROM AUTHOR]