Communication Networks

— Today’s growing number of security threats to computers and networks also increase the importance of log inspections to support the detection of possible breaches. The investigation and assessment of security incidents becomes more and more a dai-ly business. Further, the manual log analysis is essentially in the context of developing signatures for intrusion detection systems (IDS), which allow for an automated defense against security attacks or incidents. But the analysis of log data in the context of fo-rensic investigations and IDS signature development is a tedious and time-consuming task, due to the large amount of textual data. Moreover, this task requires a skilled knowledge to differentiate between the important and the non-relevant information. In this paper, we propose an approach for log resp. audit data representation, which aims at simplifying the analysis process for the secu-rity officer. For this purpose audit data and existing relations between audit events are ...

n this article, we argue for the usefulness of relational event network analysis to study online communication networks. Unlike other network analytic techniques that require online communication data to be summarized prior to analysis, relational event network analysis uses un-summarized time-stamped data to track the dynamic evolution of communication networks. To illustrate, we use relational event network analysis to analyze the evolution of a communication network within the virtual world Second Life. Results suggest that there are different patterns of communication among nonfriends and friends within the network. Nonfriends tend to communicate with those they have communicated with in the past, reciprocate communication, and close communication triads. Friends tend not to communicate with those they have communicated with in the past, instead preferring to reciprocate communication and close triads. We discuss implications for the study of online communication and identify directions for future research using relational event network analysis.

To make future tactical battlefield networks more agile, flexible and robust, nodes must rapidly configure themselves with little or no human intervention; moreover they must reconfigure automatically as the environment changes. We present our approach to configuring and reconfiguring an entire network domain, possibly consisting of tens of thousands of hosts and routers, based on a new Dynamical Configuration Distribution Protocol (DCDP). DCDP automatically distributes address-pools and other IP configuration information to every subnet in a domain, where a subnet configuration protocol can configure each node in a subnet. This paper describes the first implementation of DCDP and shows how, with the subnet configuration protocol DRCP, it rapidly configured IP addresses to Linux hosts and routers.

Betweenness centrality measure is often used in social and computer communication networks to estimate the potential monitoring and control capabilities a vertex may have on data flowing in the network. In this paper we define the Routing Betweenness Centrality (RBC) measure which generalizes previously well known Betweenness measures such as the Shortest Path Betweenness, Flow Betweenness, and Traffic Load Centrality by considering network flows created by arbitrary loop-free routing strategies.

We present a new approach for conformance testing of protocols specified as a collection of communicating finite state machines (FSM's). Our approach uses a guided random walk procedure. This procedure attempts to cover all transitions in the component FSM's. We also introduce the concept of observers that check some aspect of protocol behavior. We present the result of applying our method to two example protocols: full-duplex alternating bit protocol and the ATM-adaptationlayer-convergence protocol. Applying our procedure to the ATM adaptation layer, 99% of component FSM's edges can be covered in a test with 11692 input steps. Previous approaches cannot do conformance test generation for standard protocols (such as asynchronous transfer mode (ATM) adaptation layer) specified as a collection of communicating FSM's.

In this paper, we present a basis for treating, evaluating and measuring knowledge as an energy acquired by knowledge centric objects in society. The energy level acquired is indicated as their knowledge potential or KnP. Some objects get more charged in the knowledge domain and exhibit a longer and/or more intense energy trail. The Rate of knowledge acquisition, intellectual caliber and need intensity driving to acquire knowledge all play a role in the knowledge energy (Kenergy) thus acquired. Bounded by established principles of measurement, units, quantification and equations for dealing with knowledge, it becomes amenable to its own (knowledge) science with laws derived from the many disciplines and their own distinctive principles. We fall back on equations from thermodynamics, electrical engineering, fluid mechanics and transmission theory to quantify the flow-properties of knowledge. Though not completely precise and accurate at this stage of development in the science of kno...

In this paper we consider a stochastic server (modeling a multiclass communication switch) fed by a set of parallel buffers. The dynamics of the system evolve in discrete-time and the generalized processor sharing (GPS) scheduling policy of [25] is implemented. The arrival process in each buffer is an arbitrary, and possibly autocorrelated, stochastic process. We obtain a large deviations asymptotic for the buffer overflow probability at each buffer. In the standard large deviations methodology, we provide a lower and a matching (up to first degree in the exponent) upper bound on the buffer overflow probabilities. We view the problem of finding a most likely sample path that leads to an overflow as an optimal control problem. Using ideas from convex optimization we analytically solve the control problem to obtain both the asymptotic exponent of the overflow probability and a characterization of most likely modes of overflow. These results have important implications for traffic management of high-speed networks. They extend the deterministic, worst-case analysis of to the case where a detailed statistical model of the input traffic is available and can be used as a basis for an admission control mechanism. A preliminary version of these results was reported in . The results in this paper are included in .

This paper introduces AntNet, a new routing algorithm for telecommunication networks. AntNet is an adaptive, distributed, mobile-agents-based algorithm which was inspired by recent work on the ant colony metaphor. We apply AntNet in a datagram network and compare it with both static and adaptive state-of-the-art routing algorithms. We ran experiments for various paradigmatic temporal and spatial traffic distributions. AntNet showed both very good performances and robustness under all the experimental conditions with respect to its competitors.

The current 3GPP working assumption on the Evolved Universal Terrestrial Radio Access (E-UTRA) physical layer is that it will be based on single carrier frequency division multiple access (SC-FDMA) for the uplink and orthogonal frequency division multiple access (OFDMA) for the downlink. According to the concept specification, inter-cell interference mitigation techniques applicable to SC-FDMA and OFDMA systems are expected to be the key radio resource management techniques for E-UTRA. In this paper we propose and analyze a simple reuse partitioning technique (assuming coordinated subcarrier allocation in the cells) that is able to minimize intercell interference. We propose a model that is able to take into account that sessions dynamically enter and leave the system. Rigid sessions require a class-specific fixed number of subcarriers, while elastic sessions can enter the system if a minimum number of sub-carriers is allocated to them. In this rather general setting we analyze the system performance in terms of the expected number of sub-carrier collisions, the session blocking probabilities and the signal-to-noise-and-interference ratio performance. We present numerical results on the various trade-offs between these measures that provide insight into the behavior of OFDM based cellular systems and help dimension the parameters of a reuse partitioned system.

Biomass co-firing with lignite represents an attractive solution for operating lignite-fired thermal power plants (TPP) with the dual advantage of using local renewable resources and  imultaneously reducing emissions. The subject of this study is technical and environmental investigation of the feasibility of the cofiring of Soma lignite with some dried agricultural residues in the Soma thermal power plant from the exergy analysis perspective, using THERMOFLEX simulation software. The use of biomass cofiring with poor quality coal could allow Turkey to comply with Kyoto commitments while benefiting from using indigenous fuel resources and reducing biomass waste disposal problems. Two technologies are considered; (1) direct cofiring, in which biomass is mixed with lignite in the same mill and fed into the boiler furnace and (2) parallel cofiring method, in which biomass is fired in a separate circulating fluidized bed boiler and produced steam is supplemented into the steam network of the power plant. The investigations reveal that both direct and parallel co-firing of the biomass could result in a significant decrease in fuel consumption, emissions and exergy destruction and a slight increase in the exergy efficiency of the Soma TPP. Olive waste, in particular, has a positive effect on general performance and emissions of the TPP, with fuel consumption, CO2 , SO2
and dust emissions, in direct co-firing dropping by approximately 20, 4, 19 and 18 percent, respectively, and in parallel co-firing by 26, 3, 20 and 25 percent, respectively.

Select 'Configure ACLs'. Configure the access-list that references the VPN in question. Select the 'Permit' link to change the VPN selectors. Change the Protocol to 'gre'. Change the Source IP Address to the source IP of the GRE tunnel, with a 255.255.255.255 mask. Change the Destination IP Address to the destination IP of the GRE tunnel, with a 255.255.255.255 mask. Click 'Apply'. *** The 255.255.255.255 subnet mask selects the IP address entered and that address only.

Vehicle-to-vehicle communication is a very actual and challenging topic which attracts a considerable attention from there search community. Vehicles are able to exchange information within these networks without the need of installing any infrastructure along the road side. To evaluate a Vehicular Ad Hoc Networks (VANETs) in traffic city, we present a simple model of simulation based on a Cellular Automaton technique specified by the rules which control communication exchange and the mobility of vehicles. Moreover, in a Cellular Automaton, space and time are divided into discrete cells and steps which can reduces the complexity of the system and cost of deployment. The model used here is based on the cellular automata(CA) model proposed by Biham-Middleton-Levine(BML). It considers two kinds of drivers which obeys the traffic light rules. Each vehicle generates an amount of data and hope to send it to the base station (BS) located in the middle of the network. In this work, we examine the performance of VANET in terms of average throughput. Simulation results show that the traffic patterns have an important impact over data communication at the base station as well as in the whole capacity of the communication network.

The performance of a photovoltaic (PV) panel is affected by its orientation and its tilt angle with the horizontal plane. This is because both of these parameters change the amount of solar energy received by the surface of the PV panel. A mathematical model was used to estimate the total solar radiation on the tilted PV surface, and to determine optimum tilt angles for a PV panel installed in Sanliurfa, Turkey. The optimum tilt angles were determined by searching for the values of angles for which the total radiation on the PV surface was maximum for the period studied. The study also investigated the effect of two-axis solar tracking on energy gain compared to a fixed PV panel. This study determined that the monthly optimum tilt angle for a PV panel changes throughout the year with its minimum value as 13° in June and maximum value as 61° in December. The results showed that the gains in the amount of solar radiation throughout the year received by the PV panel mounted at monthly optimum tilt angles with respect to seasonal optimum angles and tilt angel equal to latitude were 1.1% and 3.9%, respectively. Furthermore, daily average of 29.3% gain in total solar radiation results in an daily average of 34.6% gain in generated power with two-axis solar tracking compared to a south facing PV panel fixed at 14° tilt angle on a particular day in July in Sanliurfa, Turkey.

The importance of the acquisition and provision of information within knowledge work such as engineering is widely acknowledged. This article reports an extensive empirical study of such information behaviors in engineers, using a novel and effective work sampling method. Seventy-eight design engineers each carried a portable handheld computer (PDA) for 20 working days. Once every hour, they were prompted to enter data concerning the task they were currently performing, including the information behaviors in which they were engaging. The resultant data represent a comprehensive picture of engineers' information behaviors and the percentage of their working time for which each of these behaviors accounts (55.75% in total). Specific hypotheses concerning the time spent engaged in these behaviors were also tested. Accordingly, it was found that participants spent substantially more time receiving information they had not requested than information they had, and this pattern was also reflected when they provided others with information. Furthermore, although there was no difference found between the time participants spent searching for information from other people compared with nonhuman sources, in the former case they spent relatively less time locating the information source and information within that source, and relatively more time engaged in problem solving and decision making. The results are discussed in terms of their implications for theory and organizational practice.

Odessa, berceau de la Grèce moderne : Aux origines secrètes de la Philiki Eteria

Stella GHERVAS
(CES, Harvard University)

Résumé

C’est à Odessa, ville neuve au bord de la mer Noire, que fut fondée en septembre 1814 la célèbre Société des Amis (Philiki Eteria), qui fut à l’origine du mouvement grec de libération qui mena à la Guerre d’indépendance et à la constitution de l’Etat grec moderne. Et pourtant, si l’on excepte quelques tentatives récentes de la part d’historiens grecs (notamment Papoulidis, Prousis) et russes (Arsh) de resituer le mouvement de la Philiki Eteria, sa genèse recèle encore bien des points d’ombre. Cette communication, basée sur de multiples documents inédits tirés des archives russes et ukrainiennes (notamment sur la correspondance politique de Ioannis Capodistrias et Alexandre Stourdza), jette un nouveau regard  sur les origines de la Philiki Heteria, ses conceptions initiales, ses financements, ainsi que ses relations contrastées avec les autorités russes.

Elle s’interroge en particulier sur le cadre d’Odessa comme berceau de cette société secrète. Pourquoi est-ce dans cette ville portuaire, si loin des frontières de la Grèce continentale, qu'a pu se développer cette société secrète, et pourquoi son action a-t-elle eu des retombées si importantes ? Qu’y faisaient ses membres et comment s’étaient-ils connus ? Par reflet, nous examinerons les traces que cette organisation a laissées dans la mémoire et le patrimoine culturel de la ville d’Odessa.

Plus généralement, l’action de la Philiki Eteria à Odessa s’inscrit dans la vaste question d’Orient, un enjeu de la géopolitique russe auquel le sort de la Grèce fut intimement lié. C’est l’occasion d’examiner dans quelle mesure ce mouvement fut une cause passionnelle chez les haut fonctionnaires et les diplomates russes, ou au contraire l’instrument d’un Etat décidé à imposer son hégémonie sur les Détroits et en Méditerranée orientale, au détriment de l’Empire ottoman et des autres puissances européennes.

Bibliographie sélective :

- Stella GHERVAS, Réinventer la tradition. Alexandre Stourdza et l’Europe de la Sainte-Alliance, Paris, Honoré Champion, 2008, 625 p.

- Stella GHERVAS, « Odessa et les confins de l’Europe: un éclairage historique », in Lieux d’Europe : Mythes et limites, Stella Ghervas et François Rosset (éds.), Paris, Editions de la Maison des sciences de l'homme, 2008, pp. 107-124.

- Stella GHERVAS, « Philhellénisme et ambitions russes dans le contexte de la question d’Orient », in Φιλελληνισμός. Το ενδιαφέρον για την Ελλάδα και τους Έλληνες από την Επανάσταση ως σήμερα, Anna Mandilara, Georgios Nikolaou, Lambros Filitouris et Nikolais Anastassopoulos (éds.), Athènes, Hérodote, 2014, à paraître.

- Stella GHERVAS, « Le philhellénisme d’inspiration conservatrice en Europe et en Russie », in Peuples, Etats et nations dans le Sud-Est de l’Europe, Bucarest, éd. Anima, 2004, pp. 98-110.

- Stella GHERVAS, « Le philhellénisme russe : union d’amour ou d’intérêt ? », in Regards sur le philhellénisme, Cléopâtre Montandon (éd.), Geneva, Permanent Mission of Greece to the United Nations, 2008, pp. 33-41.

This article describes a computational framework, which can run almost on every computer connected to a IP based network, to study teleoperatiort techniques. The paper discussw the teleoperation of a mobile platform from ii remote computer, both connected by the Internet communication network. To obtain a cheap and portable solution, the user interface and communication management was developed using Java language. The development based on this language gave us, a cheap, portable and easily to improve software package that is useful to test new control techniques with large time delays. Since the real time control over Internet can suffer from unpredictable delays and bandwidth constraints, we use the RTP protocol to overconne some of these problems. I. IN'I'RODUCTION Several research groups have recently turned their attention to the develop nent of teleoperated systems due to the every day appearance of new potential applications that can benefit from the use of this kind of solutions. The recent evolution of microprocessors and communication systerns, and the wide availability of simple and cheap solutions using these systems, have also attracted many people .to an area that traditionally was only accessible to restricted groups with strong financial support. Among the applicaiions of teleoperated systems we find those related with the exploration and manipulation in hazardous environments, like nuclear power plants [9, lo]. The research activities in this area are quite diverse, going from the development of communication links, to the search for an optimum user interface for a certain application. Here we can cite some of the major works that have been developed in the recent years: 0 Space applicatiors: NASA JPL labs are developing techniques since the beginning of space exploration. These techniques are being used on the development of a mobile vehicle that will integrate "This work was partially financed by NATO Scientific Affairs Division on the framework of the NATO Science for Stability Program, PO-ROBOT project.

In this chapter, I first reconstruct the premises to networked politics to then illustrate the main forms it can take. I continue with an overview of current research trends on digital communication networks as political networks – a key application of network approaches to the study of politics. I conclude by looking at future perspectives on the study of the nexus between social networks and politics, reflecting in particular upon the implications of “big data” approaches to investigation.

The article analyzes the media logic of urban acts of communication in early modern German cities. As is demonstrated by Cologne and Hamburg in the late seventeenth and early eighteenth centuries, the growing use of print (particularly pamphlets) moved local conflict away from face-to-face confrontation into progressively more multifaceted modes of communication, increasingly expressed in both manuscript and print. In highlighting the mediality of early modern urban culture, the changing relationship between the urban community, public opinion, and forms of communication is addressed. The resulting effect from the interplay and complementation of oral, written, and printed means of communication is described as echoes that formed an urban resonating box—a constant polyphonic state including both the literate and illiterate.

ABSTRACT The modern Great Basin of the interior western United States is characterized by surface winds with considerable spatial and temporal variabilities. Wind records from the second half of the 20th century for 12 Great Basin localities, analyzed with standard aeolian-sediment transport methods developed elsewhere in the world, reflect this complexity. The drift potential (DP) for aeolian deposits is generally moderate (DP 200– 400) in the western Great Basin and weak (DP b 200) in the central Great Basin where winds are
predominantly west-southwesterly. DP is relatively high (DP N 300) at the eastern edge of the Great Basin where the dominant prevailing wind direction is south-southwesterly. Both DP and resultant drift direction (RDD) are consistent with synoptic meteorological observations of the evolution of cold fronts in the Great Basin. Meteorological observations show that effective winds to produce dunes are most commonly the result of late winter–early spring cyclogenesis. There has been considerable temporal variability of DP in the latter half of the 20th century. Most of the Great Basin has experienced decreasing wind strength since 1973, consistent with recent studies of wind strength in North America and elsewhere. Dune morphology matches both localized RDD and temporal variations in DP reasonably well in the Great Basin. The results demonstrate that local topography can have an important influence on wind directionality, thus providing a cautionary note on the interpretation of dune morphology in the paleoclimatic and stratigraphic record.

This article examines how anti–corporate globalization
activists have used new digital technologies to coordinate
actions, build networks, practice media activism,
and physically manifest their emerging political ideals.
Since theWorld Trade Organization protests in Seattle,
and through subsequent mobilizations against multilateral
institutions and forums in Prague, Quebec, Genoa,
Barcelona, and Porto Alegre, activists have used e-mail
lists, Web pages, and open editing software to organize
and coordinate actions, share information, and produce
documents, reflecting a general growth in digital collaboration.
Indymedia has provided an online forum for
posting audio, video, and text files, while activists have
also created temporary media hubs to generate alternative
information, experiment with new technologies,
and exchange ideas and resources. Influenced by anarchism
and peer-to-peer networking logics, anti–corporate
globalization activists have not only incorporated
digital technologies as concrete tools, they have also
used them to express alternative political imaginaries
based on an emerging network ideal.

Phronetic organizational research is an approach to the study of management and organizations focusing on ethics and power. It is based on a contemporary interpretation of the Aristotelian concept phronesis, usually as ‘prudence’. Phronesis is the ability to think and act in relation to values, to deliberate about ‘things that are good or bad for humans’ in the words of Aristotle (1976:1140a24–b12). Phronetic organizational research effectively provides answers to the following four value-rational questions, for specific problematics in management and organization studies: 1. Where are we going with this specific management problematic? 2. Who gains and who loses, and by which mechanisms of power? 3. Is this development desirable? 4. What, if anything, should we do about it?

Channel models for E Nanocommunication THE INTERNET OF THINGS from the communication and information theoretic perspective, by highlighting the major research challenges in terms of channel modeling, information encoding and protocols for nanonetworks and the Internet of Nano-Things.

This article presents results from the first statistically significant study of cost escalation in transportation infrastructure projects. Based on a sample of 258 transportation infrastructure projects worth US$90 billion and representing different project types, geographical regions, and historical periods, it is found with overwhelming statistical significance that the cost estimates used to decide whether such projects should be built are highly and systematically misleading. Underestimation cannot be explained by error and is best explained by strategic misrepresentation, that is, lying. The policy implications are clear: legislators, administrators, investors, media representatives, and members of the public who value honest numbers should not trust cost estimates and cost-benefit analyses produced by project promoters and their analysts.

We propose to implement a communication network between two robots. Large number of simple robots can perform complex tasks in a more efficient way than a single robot, giving robustness and flexibility to the group. The robots can work in different group sizes, from few individuals to thousands of them. The communication could be in any form such as the robots trying to follow a particular path, or simply mimicking the other, via communicating with each other by transmitting data over radio frequencies(RF) and direction of motion being controlled using Bluetooth via an external device.

Thermal energy storage technologies can facilitate the transition to an energy system based largely on renewable sources and enable efficiency gains for industrial processes in general. Due to their specific advantages, various concepts of thermo-chemical storage systems are being developed. They share characteristic features of mass and heat transport that are strongly coupled through a variety of physical and chemical phenomena. To facilitate the understanding of the coupled multi-physics processes inside such systems, a versatile conceptual model for directly permeated reactive beds was developed in part 1 of this work. It was based on thermodynamic principles and the Theory of Porous Media. The model was then implemented into OpenGeoSys, a scientific finite element simulation software. In this article, the model is specified to the well-studied calcium hydroxide reaction system to illustrate its practical applicability. Sensitivity analyses reveal the influence of particle diameter, porosity, permeability, mass flux, and reaction rate. Two distinct "reaction waves" are identified to migrate through the reactor. The power required to pump the gas stream was decomposed into parts related to the classical mechanical pressure drop and to the chemical reaction. The results can be used for the optimization of thermochemical heat storage systems.