Inledning: Personer i det utökade privata nätverket (PUPN) bjuds in till nätverksmöten runt en individ eller familj i syfte att vara till hjälp i en svår situation. Studier som undersöker hur PUPN själva påverkas av deltagande i nätverksmöten saknas i hög grad. Frågeställningar: Hur upplever PUPN att de har påverkats av deltagande i närståendes nätverksmöten? Hur upplever PUPN att deltagande i nätverksmöten påverkar möjligheten att vara till hjälp för närstående? Hur upplever PUPN sig som belastade av huvudpersonens/ernas problematik? Metod: Studien har gjorts med kvalitativ undersökningsmetod. Intervjuer med 6 PUPN har genomförts. Resultat: Resultaten visar att PUPN fungerar som både praktiskt och känslomässigt stöd till närstående. Samtidigt upplever de sig själva som känslomässigt belastade av närståendes problematik. Deltagande i närståendes nätverksmöten har lett till minskad känslomässig belastning för egen del, men det förekommer också till viss del oförändrad och delvis ökad belastning. I några fall har deltagande i nätverksmöten gett effekter mer fristående från de närståendes problem i form av känsla av ökad status, ökad självkänsla och förändrad upplevelse av relationen till den närstående. Det finns upplevelser hos intervjupersonerna av att ha kunnat vara till bättre hjälp för sina närstående efter deltagande i nätverksmöten. Några olika typer av hjälparidentitet har kunnat urskiljas bland intervjupersonerna. De mest kontrasterande typerna skiljer sig markant åt vad gäller upplevelse av egen belastning, möjlighet att vara till stöd och hjälp och inställning till nätverksmöten. Diskussion: PUPN med position mellan direkt berörda och yrkeshjälpare diskuteras som möjlig brobyggare mellan mikronivåer runt nätverksmötets huvudperson. Att nätverksmöten kan ge minskad belastning hos PUPN lyfts fram som en positiv bieffekt av arbete med nätverksmöten. / Introduction: Members of the extended private network (MEPNs) are invited to network meetings around an individual or a family in order to help in a difficult situation. There are very few studies that investigates how MEPN themselves are affected by their participation in network meetings. Research questions: How does participation in a closely related person’s (CRP’s) network meetings affect the MEPN? How does participation in network meetings influence how the MEPN can be of help for the CRP? In what ways do the MEPN experience burden of care related to the CRP’s problematic situation? Method: A qualitative research method has been used, and the study is based on interviews with 6 MEPNs. Results: The results shows that MEPNs give both practical and emotional support to their CRPs. At the same time MEPNs experience emotional burden related to the problematic situation of their friend or relative. Participation in the CRP’s network meetings has led to emotional relief, but there are also examples of partly unchanged or partly increased burden. In some cases participation in network meetings has given effects not directly related to the CRP’s problems, in the forms of feelings of increased social status, increased self confidence and changed relations to the CRP. There are experiences among the interviewed persons that they can be of better help for their friends and relatives after participation in network meetings. Different types of helpers have been identified among the interview persons. The most contrasting ones show differences in terms of experienced burden, ability to be of help and support and attitude towards network meetings. Discussion: The MEPN’s position between the suffering person/family and the professional network is discussed as possible bridges between microlevels around the CRP. The potential to bring relief to the MEPN is considered as a positive side effect of participation in network meetings.

This research investigates the Twitter network sphere of the 112th U.S. House of Representatives and the 18th Korean National Assembly members. Drawing from social network analysis, this study explores and compares structural characteristics of each legislative political network at diverse network levels – legislative, party and personal network. Mapping these networks highlights the major features of these two elite political networks grounded in a new social medium. Findings indicate that U.S. and Korean lawmakers have created and are enjoying affluent and multi-layered digital networks. Dynamic legislative-body networks, strong party networks, and a variety of personal networks with diverse partisan and bipartisan relationships demonstrate how politicians are agile at using new mediums. This research confirmed that these newly created legislative networks go beyond partisanship. Complicated structures demonstrate active and mutual interactions among lawmakers, and the political networks with large numbers of bipartisan tie relationships indicate that the political elite communicate, interact, and build relationships with each other rather than remaining disconnected or isolated. This research revealed new types of leaders – digital opinion leaders – emerging from newly created digital legislative networks: the most connected lawmakers; lawmakers who have great potential to coordinate party politics; the most sought after leaders; and most sociable lawmakers. By examining lawmakers’ patterns of relationship building in the network, this research tests whether these relationships are dependent on party position, ruling or opposition, in the network. In turn, this provides evidence for different uses of this new medium by party position in both legislative bodies. Detailed examination of Twitter use by political elites in Korea and the U.S. illuminate how this new media platform is being adopted by and changing politics in two distinct social and cultural settings. This new political arena, a fully digitalized and networked sphere where dynamic competition and cooperation occurs between political elites, has emerged as one of the political battlefields in politics today. / text

Verksamheten ombord på fartyg blir mer beroende av datakommunikation och många av arbetsuppgifterna ombord underlättas genom att besättningen kan nå information lagrad på annan plats. Fartygens bredbandsanslutning sker till största delen via satellitkommunikation där långa avstånd och begränsad datahastighet resulterar i att datakommunikationen blir ineffektiv. I denna studie undersöks vilken prestandaförbättring som utrustning för nätverksoptimering kan innebära för långsamma WAN-förbindelser via satellit. Undersökningen visade att det största problemet med anslutningar via satellit är den signalfördröjning som uppkommer vid långa sändningsavstånd. Detta medför att det blir prestandaproblem för datatrafiken och användare upplever anslutningen som långsam. För att åtgärda detta finns utrustning som hanterar datatrafiken och genom olika tekniker kan öka prestandan på anslutningen. För att undersöka hur stor prestandaförbättringen kan vara genomfördes ett antal olika experiment med utrustning för nätverksoptimering. Experimenten genomfördes genom att utvärdera filöverföringar med och utan nätverksoptimering. Resultaten visar att utrustningen för nätverksoptimering ger en stor prestandaförbättring vid filöverföringar. / Shipboard operations have become more reliant of data communication and many of the duties on board may be facilitated if the crew can access information stored elsewhere. The broadband connection between ship and shore is mostly done via satellite communication where long distances and limited data rate results in inefficient data communication. This study examines network optimization and the performance improvement this can have regarding slow WAN connections via satellite. The survey showed that the biggest issue with data communication via satellite is the signal delay caused by the long transmission distance which means that there will be performance degradation for data traffic and users will experience the data communication as slow. To solve this there is equipment that enhances the performance of the connection and handles the data communication by implementing various techniques. To investigate how much the performance improvement can be this study carried out a number of experiments with network optimization equipment.  The experiments evaluated file transfer with and without network optimization. The results show that the network optimization gives a major performance improvement regarding file transfer.

No description available.

Ring networks are appropriate for the full range of network levels, including multiprocessor systems, local area computer networks and high speed backbones. The most well known and widely implemented examples are the IBM token ring and FDDI networks. Ring networks have the advantages of high channel utilisation and bounded delay if an n-limited service policy is used. The packet transfer delay, defined as the average time a packet spends in the network from the time it is generated until the time it is received at its destination node, improves with the number of rings on which a node is connected. However, many ring connections are not economically feasible since the cost of the ring interface increases with the number of rings. There has been an abundance of previous work on single token ring networks. A number of papers on slotted rings, register insertion rings and more complex ring architectures have also been published. However, there is very little existing literature on multiple ring networks as well as ring networks in clustered traffic environments, i.e. where nodes from the same cluster tend to communicate more with each other than with other nodes in the network. This thesis focuses on two network topologies that make use of multiple rings and are well suited to clustered traffic environments: the two-connected multiple ring (2-MR) and the destination removal double ring (DRDR). For the 2-MR network, three different practical token-based protocols are investigated in an attempt to optimise performance. It is further shown that significant performance improvements can be achieved by employing a slotted ring protocol rather than the token ring protocol. The DRDR network is also examined and its performance compared to the aforementioned architectures. For each of the six cases, both random and clustered traffic patterns are considered and compared. Analytical results are derived which are verified by results obtained from computer simulations. Furthermore, we look at exact methods of analysing ring networks. A mean value analysis of a single token ring network with a I-limited service discipline is performed, which clearly shows the complexity exact methods introduce. Finally, although it has been stated in the literature that an exact analysis of a multiple symmetrical token ring network is intractable, we present a novel Markov chain approach that gives exact results for near zero loads. / Thesis (M.Sc.-Electronic Engineering)-University of Natal, 1998.

Disertacijoje nagrinėjama interneto tinklo infrastruktūros patikimumo problematika, analizei naudojant tinklo topologijos tyrimus, grafų teorijos taikymą ir tinklo modeliavimą. Tyrimų objektas, interneto tinklo infrastruktūra, kurios pagrindą sudaro autonominės sistemos ir tarptinklinių sujungimų linijos. Nuo stabilios interneto tinklo veiklos priklauso informacijos pasiekiamumas, elektroninė komercija, nutolusių objektų valdymas ir t. t. Pagrindinis disertacijos tikslas – sukurti metodikas ir algoritmus, skirtus interneto tinklo infrastruktūros analizei bei veiklos patikimumo kontrolei. Tyrimų taikymo sritis – interneto tinklo veiklos tęstinumo priežiūra ir reguliavimas. Darbe sprendžiami šie pagrindiniai uždaviniai: interneto tinklo topologijos analizės modelio ir priemonių sudarymas; interneto junglumo tyrimas siekiant identifikuoti kritinius elementus, kurių pažeidimai susiję su tinklo funkcionalumo praradimu; kritinių interneto tinklo elementų stebėsenos modelio sudarymas; eksperimentiniai kibernetinių atakų simuliacijos bandymai; bei interneto tinklo infrastruktūros patikimo stiprinimo parinkimas. Disertaciją sudaro įvadas, 5 skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai bei priedai. / The dissertation investigates the issues of dependability of the Internet network infrastructure that were studied by using the network topology analysis, graph theory and network modelling. The object of the study is the Internet network infrastructure, based on autonomous systems and interconnecting lines. Stable functioning of the Internet network determines the availability of information, electronic commerce, control of remote objects, etc. The main objective is to develop the methodologies and algorithms for analysing the Internet network infrastructure and controlling the reliability of functioning. The scope of application of the study is the supervision and regulation of continuity of the Internet. The following main tasks are solved: development of the topological scheme of the Internet network, selection of models and tools for analysis; the Internet network connectivity analysis for the purpose of identification of the critical network elements, whose violations would result in loss of connectivity of the network; as well as development of the model for monitoring of the critical elements of the Internet network and cyber-attacks simulation experiments. The scientific work consists of the general characteristic of the dissertation, 5 chapters, conclusions, list of literature, list of publications and annexes.

The dissertation investigates the issues of dependability of the Internet network infrastructure that were studied by using the network topology analysis, graph theory and network modelling. The object of the study is the Internet network infrastructure, based on autonomous systems and interconnecting lines. Stable functioning of the Internet network determines the availability of information, electronic commerce, control of remote objects, etc. The main objective is to develop the methodologies and algorithms for analysing the Internet network infrastructure and controlling the reliability of functioning. The scope of application of the study is the supervision and regulation of continuity of the Internet. The following main tasks are solved: development of the topological scheme of the Internet network, selection of models and tools for analysis; the Internet network connectivity analysis for the purpose of identification of the critical network elements, whose violations would result in loss of connectivity of the network; as well as development of the model for monitoring of the critical elements of the Internet network and cyber-attacks simulation experiments. The scientific work consists of the general characteristic of the dissertation, 5 chapters, conclusions, list of literature, list of publications and annexes. / Disertacijoje nagrinėjama interneto tinklo infrastruktūros patikimumo problematika, analizei naudojant tinklo topologijos tyrimus, grafų teorijos taikymą ir tinklo modeliavimą. Tyrimų objektas, interneto tinklo infrastruktūra, kurios pagrindą sudaro autonominės sistemos ir tarptinklinių sujungimų linijos. Nuo stabilios interneto tinklo veiklos priklauso informacijos pasiekiamumas, elektroninė komercija, nutolusių objektų valdymas ir t. t. Pagrindinis disertacijos tikslas – sukurti metodikas ir algoritmus, skirtus interneto tinklo infrastruktūros analizei bei veiklos patikimumo kontrolei. Tyrimų taikymo sritis – interneto tinklo veiklos tęstinumo priežiūra ir reguliavimas. Darbe sprendžiami šie pagrindiniai uždaviniai: interneto tinklo topologijos analizės modelio ir priemonių sudarymas; interneto junglumo tyrimas siekiant identifikuoti kritinius elementus, kurių pažeidimai susiję su tinklo funkcionalumo praradimu; kritinių interneto tinklo elementų stebėsenos modelio sudarymas; eksperimentiniai kibernetinių atakų simuliacijos bandymai; bei interneto tinklo infrastruktūros patikimo stiprinimo parinkimas. Disertaciją sudaro įvadas, 5 skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai bei priedai.

In recent years network intrusions have become a severe threat to the privacy and safety of computer users. Recent cyber attacks compromise a large number of hosts to form botnets. Hackers not only aim at harvesting private data and identity information from compromised nodes, but also use the compromised nodes to launch attacks such as distributed denial-of-service (DDoS) attacks. As a counter measure, Intrusion Detection Systems (IDS) are used to identify intrusions by comparing observable behavior against suspicious patterns. Traditional IDSs monitor computer activities on a single host or network traffic in a sub-network. They do not have a global view of intrusions and are not effective in detecting fast spreading attacks, unknown, or new threats. In turn, they can achieve better detection accuracy through collaboration. An Intrusion Detection Network (IDN) is such a collaboration network allowing IDSs to exchange information with each other and to benefit from the collective knowledge and experience shared by others. IDNs enhance the overall accuracy of intrusion assessment as well as the ability to detect new intrusion types. Building an effective IDN is however a challenging task. For example, adversaries may compromise some IDSs in the network and then leverage the compromised nodes to send false information, or even attack others in the network, which can compromise the efficiency of the IDN. It is, therefore, important for an IDN to detect and isolate malicious insiders. Another challenge is how to make efficient intrusion detection assessment based on the collective diagnosis from other IDSs. Appropriate selection of collaborators and incentive-compatible resource management in support of IDSs' interaction with others are also key challenges in IDN design. To achieve efficiency, robustness, and scalability, we propose an IDN architecture and especially focus on the design of four of its essential components, namely, trust management, acquaintance management, resource management, and feedback aggregation. We evaluate our proposals and compare them with prominent ones in the literature and show their superiority using several metrics, including efficiency, robustness, scalability, incentive-compatibility, and fairness. Our IDN design provides guidelines for the deployment of a secure and scalable IDN where effective collaboration can be established between IDSs.

Techn. Univ., Diss.--Berlin, 2002.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.