This report focuses on finding best practices and a better methodology when performing computer network analysis and troubleshooting. When network analysis is performed, computer network data packets are captured using data capturing software. The data packets can then be analysed through a user interface to reveal potential faults in the network. Network troubleshooting is focusing more on methodology when finding a fault in a network. The thesis work was performed at Cygate where they have recently identified needs for an updated network analysis methodology and a documentation template when documenting the network analysis results. Thus, the goal of this thesis has been to develop an elaborated methodology and discover best practices for network analysis and to write a documentation template for documenting network analysis work. As a part of discovering best practices and a methodology for network analysis, two laboratory tests were performed to gather results and analyse them. To avoid getting too many results but to still keep the tests within the scope of this thesis, the laboratory tests were limited to four network analysis tools and two test cases that are explained below. In the first laboratory test during three different test sequences, voice traffic (used in IP-phones and Skype etc.) is sent in the network using a computer program. In two of the test sequences other traffic is also congesting the network to disturb the sensitive voice traffic. The program used to send the voice traffic then outputs values; packet delay, jitter (variation in delay) and packet loss. Looking at these values, one can decide if the network is fit for carrying the sensitive voice traffic. In two of the test cases, satisfying results were gathered, but in one of them the results were very bad due to high packet loss. The second laboratory test focused more on methodology than gathering and analysing results. The goal of the laboratory test was to find and prove what was wrong with a slow network, which is a common fault in today’s networks due to several reasons. In this case, the network was slow due to large amounts of malicious traffic congesting the network; this was proven using different commands in the network devices and using different network analysis tools to find out what type of traffic was flowing in the network. The documentation template that was written as part of this thesis contains appealing visuals and explains some integral parts for presenting results when network analysis has been performed. The goal of the documentation template was an easy-to-use template that could be filled in with the necessary text under each section to simplify the documentation writing. The template contains five sections (headlines) that contain an explanation under it with what information is useful to have under that section. Cygate’s network consultants will use the documentation template when they are performing network analysis. For future work, the laboratory test cases could be expanded to include Quality of Service (QoS) as well. QoS is a widely deployed technology used in networks to prioritise different types of traffic. It could be used in the test cases to prioritise the voice traffic, in which case the results would be completely different and more favourable.

This study examines the potential for the Internet, or more specifically the World Wide Web, to enhance local democracy and local governance by providing a networked public sphere. It is located in post-industrial theories of social and political transformation, which see a new, uncertain and complex society emerging which may transform the political significance of the 'local'. Whilst a number of causes are identified as culpable in this process, it is the ICT revolution and the development of the Web in particular, that is seen as possessing a democratising potential that, if realised, may bring greater resilience to geographic localities. The potential of the Web to provide a new networked public sphere is based upon contested views that its topography, its hyperlinked structure, can enable the ordinary citizen's voice to be heard above those that traditionally dominate political discourse. However, there has been no attention paid to this potential being realised at a local governance level within which, this study argues, a favourable environment should exist for a local online networked public sphere to prosper. Accordingly, this prospect is empirically explored here through a case study of the use made of the Web by a variety of local civic, political and institutional actors during a 2008 local (Manchester, UK) referendum on introducing the largest traffic congestion charging scheme in the country. This research applies a distinctive mixed method approach within a conceptually defined internet mediated domain of local governance. Relational Hyperlink Analysis is used to analyse the structural significance of the captured congestion charge. This analysis uses Social Network Analysis (SNA) and an associated statistical technique, Exponential Random Graph Modelling (ERGM) to render the network visible and understandable. To further illuminate how the network was used by local civic and institutional actors involved in the referendum the research draws upon a network ethnography approach which uses SNA to identify subjects for qualitative investigation. The study offers some evidence of the Web providing 'just enough' links in this local context to suggest the structural existence of a networked public sphere. However, further evidence from the narratives and the statistical model paint an alternative picture. This suggests that, in the main, hyperlinking behaviour and use made of the network corresponds to a 'politics as usual' scenario where cliques are more likely to proliferate and powerful economic and media interests dominate online as they do offline. If the ordinary citizen's voice is to be heard in this context then there is a requirement for policy intervention to establish a trusted local networked public sphere or online civic space, independent of vested interests but linked to the local governance decision making process. In addition to this there is a requirement for greater education, particularly aimed at senior local governance policy makers, in the culture of online engagement.

This study explores potential bias in the editorial peer-review system within the context of the field of comparative and international education. Assuming the role as “Guardian of Science” and “social status judge” (Zuckerman & Merton, 1971), peer-review, the quality control system of science, directly affects the growth of science, scientists' academic career and their institutions. The very basic tenet of the peer review system is its assumed objectivity. Bias in editorial peer review process, however, is inevitable. The constitution of the blind peer review mechanism is itself a simply undeniable acknowledgement of that fact. Therefore, this study investigated potential peer-review bias by examining the core peer-reviewed academic journal publications of the field between 1994 and 2003, through the methods of social network analysis. In addition to some descriptive analysis on the overall state of the field, based on the criterion of centrality, focus was specifically given to two networks (co-authorship network and institutional network) and the network structure for patterns that might indicate bias in terms of author, gender, author-affiliated institution, country, number of articles published and number of journals in which the author published. Findings of this research revealed no discernable patterns nor network-wide centralization in either the co-authorship network or the institution network. Thus, no reason exists to suspect the objectivity of the peer-review process of the five core academic journals of comparative and international education 1994 – 2003 on the base of centrality. Further descriptive analyses, however, did reveal patterns that may represent norms of the field and, thus, may suggest potential sources of bias. Findings indicated that 1) scholars of the field tend to research independently and publish in relative isolation, and single-authored journal articles are the norm of the field; 2) the field is dominated by the scholars and institutions of Western countries, especially the U.K and the U.S; and 3) journals of the field tend to publish more authors from the hosting countries of the journal. The implications of these findings were also discussed.

The British cattle population hosts a diverse community of endemic pathogens that impact the sustainability of beef and dairy production. As such, there has been a tremendous amount of ongoing research to develop more cost-effective strategies for controlling disease at the industry level. Cattle movements have come under particular scrutiny over the past decade both because of their role in spreading many economically important diseases and because the movements of individual cattle in Great Britain have been explicitly recorded in a centralized electronic database since 1998. Numerous studies have shown that these cattle movements organize into complex networks with key structural and temporal features that influence transmission dynamics. Building on previous work, this thesis used a variety of epidemiological and statistical models to highlight limitations in the current approaches to controlling disease as well as opportunities for reducing endemic disease prevalence through targeted interventions. Empirical disease data from the national bovine tuberculosis (bTB) control programme and from two seroprevalence studies of bovine viral diarrhoea virus (BVDV) in Scottish cattle herds were used in conjunction with movement data from the Cattle Tracing System (CTS) database. Endemic diseases are often challenging to control due to lack of affordable and accurate diagnostic tests as well as the presence of subclinically infected carriers that can easily escape detection. There was evidence that combined issues with the sensitivity and specificity of routine surveillance methods for bTB were contributing to a low level of disease transmission within and between Scottish cattle herds from 2002 to 2009. For BVDV, herds that purchased pregnant beef dams, beef dams with a calf at foot, and open dairy heifers were significantly more likely to be seropositive even though these movements were responsible for only a small number of network contacts. In both cases, targeting the subset of high risk movements with disease specific biosecurity measures may be a more cost-effective use of limited national disease control resources. Other researchers have suggested that control strategies should target multiple diseases simultaneously to reduce trade-offs in resource allocation. Using key indicators of herd reproductive performance derived from the CTS database, it was shown that improving the reproductive management of herds operating below industry standards could reduce endemic disease prevalence by reducing the movements of replacement breeding cattle. A series of network generation algorithms were also developed to study the effects of restricting contact formation based on key demographic and network characteristics of actively trading cattle farms. Strategies that increased network fragmentation either by forcing highly connected farms to form contacts with other highly connected farms or preventing the formation of movements with a high predicted betweenness centrality were found to be particularly effective in limiting disease transmission. For these models to be useful in guiding future policy decisions, it is important to incorporate financial and behavioural drivers of dynamic network change. Following the introduction of pre- and post-movement testing requirements for cattle imported into Scotland from endemic bTB regions, there was a significant decline in cross-border movements, which has likely contributed to the decreasing risk of bTB outbreaks as much as testing itself. Many endemic cattle diseases such as BVDV also spread through local transmission mechanisms, which may undermine the success of disease control programmes that exclusively target cattle movements. There was also evidence that in the absence of national animal legislation, few farmers were likely to adopt biosecurity measures against BVDV. This may be related to the perceived inefficacy of recommendations as well as general unawareness of farm disease status due to the non-specific clinical signs of BVDV outbreaks. Although the CTS database was originally intended for use in slaughter traceback investigations, results from this thesis show how the basic records of births, deaths, and movements can be used to generate valuable insights into the epidemiology of endemic cattle diseases. The findings also emphasize that the management decisions of individual herds can have a substantial impact on industry level transmission dynamics, which offers unique opportunities to develop novel and more cost-effective disease control programmes.

published_or_final_version / abstract / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

最先，網路(Net work)是被利用於電路網上的，但實際上，整個交通路線不啻就是個完整的網路，人口密集的地方可視為一個結點(Node)，通路即可視為連線(Arc)，連線的負荷量(Capacity)就是通路的最大流量，受地形、路面狀況、寬度、視野等因素的影響。 一個完整的運輸模式，應該包括三個部份： 1.總體經濟模式。包括運輸供給、需要之預測，總體運輸成本的計算等等。 2.網路分析。 3.效益評估。 本文名為“網路分析往交通上之運用”，自然重點在第二及第三部份，第一部份則略而不談，必須用到的地方，只做簡單的引述，並加註可供參考之書籍而已。 據此，本文可分為兩大部份。第一部份是網路分析理論及實例，共包含三章：第一章談論最大流最問題，第二章實是第一章之延續，論述多終點流量問題。第三章是最短路線問題，因為編幅較少，故將多終點最短路線問題直接合併在內。第二部份是運輸網路之評估，包括第四、第五、第六、第七，共四章，第四章談論運量分配問額，分別闡述運輸方式之運量分配及交通指派問題，第五章可說是第四章的延續，論及要逕的指派問題。但因其甚為重要，故特將其獨立出來；第六章論及運輸方案之改進與選擇，利用網路分析技術及成本與效益方法將可行的方案做一番改進與選擇；第七章，也是最後一章，將整個運輸網路依混合運輸方式，做一種系統(System)性的評估，這也是第二部份的壓軸，蓋因不同的利益團體，對於不同運輸方式的價值觀念是不同的，我們不能一概而視之，站在整個國家社會的立場，交通是不是只需做到便宜、省時、方便、安全、舒適就行了？公共環境衛生要不要考慮？社會大眾是否願意以空氣污染為犧牲而來換取上述之便宜、省時、方便、安全與舒適？如果願意其邊際(Margin)又有多大？在生態學(Ecology)逐漸抬頭的今天，這尤其是必須考慮的。 任何一門社會科學，用數學模式來表示必有其缺點存往，假設的種種條件是否能囊括全體所有的情況是一問題，不變的條件事實上又是瞬息萬變的，因而，無法像自然科學在實驗室裡實驗一樣，得出的結果是非常精確的，但是我們如果因此而畏縮不前，也必永無完成之日。

Molecular dynamics (MD) simulation, which employs an empirical potential energy function to describe the interactions between the atoms in a system, is used to investigate atomistic motions of proteins. However, the timescale of many biological processes exceeds the reach of standard MD due to computational limitations. To circumvent these limitations, steered molecular dynamics (SMD), which applies external forces to the simulated system, can be used.Dynamical properties of the gonococcal type IV pilus (GC-T4P) from the bacteria Neisseria gonorrhoeae are first considered. T4 pili are long, filamentous proteins constructed from a subunit (pilin) found to emanate from the surface of pathogenic bacteria. They can withstand large forces (~100 pN), and are implicated in infection. SMD simulations are performed to study the response of the filament to an applied force. Our simulations reveal that stability of the pilus likely results from hydrophobic contacts between pilin domains buried within the filament core. Along the filament surface, gaps are formed between pilin globular head domains. These gaps reveal an amino acid sequence that was also observed to become exposed in the experimentally stretched filament. We propose two other regions initially hidden in the native filament that might become exposed upon stretching.The multidrug resistance transporter EmrD, found in the inner membrane of Escherichia coli is also the target of our studies. EmrD removes harmful drugs from the bacterial cell. We use MD to explore equilibrium dynamics of the protein, and MD/SMD to study drug interactions and transport along its central cavity. Motions supporting a previously proposed lateral diffusion pathway for substrate from the cytoplasmic membrane leaflet into the central cavity were observed. Additionally, interactions of a few specific residues with CCCP have been identified.Finally, we describe network analysis as an approach for analyzing conformational sampling by MD simulations. We demonstrate for several model systems that networks can be used to visualize both the dominant conformational substates of a trajectory and the connectivity between them. Specifically, we compare the results of various clustering algorithms to the network layouts and show how information from both methods can be combined.

This case study examined the spread of ideas in a Gr. 5/6 classroom in which the teacher was attempting to foster a knowledge building community. The goal of the research was to explore the relationship between the social network of the classroom (in terms of face-to-face and computer-mediated interactions), the teacher’s role, and the spread of ideas. Further, the thesis examined how social network tools may help teachers better understand the pedagogical implications of Scardamalia and Bereiter’s (1991) Teacher A, B, C models. Analyses of videotaped lessons revealed the teacher used a complex mix of traditional instructional methods and knowledge building strategies while trying to shift the locus of control of learning to students. Critical teacher-driven processes included the class-wide adoption of knowledge building vocabulary and practices, and efforts to foster higher levels of student-student discourse. Analyses of online interactions provided strong evidence of highly interconnected student-student online networks, with the note reading network being especially dense. Longitudinal studies revealed these network established themselves early in the unit, and persisted during the course of the inquiry. There was evidence that idea improvement was present in addition to idea spread. In face-to-face classroom communication, the teacher’s role was more central, particularly in "Knowledge Building Talk" sessions. However, here too, the teacher made efforts to shift the locus of control. Overall the analyses suggest that social network tools are potentially useful for helping teachers make the difficult transition from "Teacher A" and "Teacher B" strategies, in which the locus of control is with the teacher, to "Teacher C" strategies, in which strategic cognitive processes are turned over to students. This dissertation proposes that movement toward Teacher C practices may be illustrated, in part, by a shift in classroom network topologies from that of a star-shaped network, centered on the teacher, to a highly interconnected student-student network. Finally, the thesis recounts a number of ways in which the use of social network tools uncovered discourse patterns of which the teacher was unaware, including gender differences in reading, building-on, and contribution patterns.

The mechanisms and functions of shark grouping behaviour have received relatively little scientific attention to date. The current widespread use of social network analysis to study animal groups, in concert with rapid advances in animal tracking technology, now allows us to test specific hypotheses about how and why sharks form groups. This thesis uses replicated laboratory experiments to investigate some of the mechanisms underpinning aggregation in a model species of benthic, oviporous elasmobranch, the small spotted catshark (Scyliorhinus canicula L. 1758; Scyliorhinidae). Acoustic tracking of this species in the wild is also conducted to explore how network analyses can be adopted to study the localized movements, habitat connectivity and ranging behaviour of adult sharks. Groups of juvenile S. canicula were characterized by non-random social preferences, crucially, only when individuals were familiar with one another suggesting social recognition is important in young sharks of this species. Genetic analyses of parent and offspring DNA revealed very high levels of multiple paternity in this species, likely due to male sexual harassment and multiple mating, which leads to increased genetic diversity between juvenile sharks. Perhaps unsurprisingly, there was no evidence of kin relatedness structuring social interactions between conspecifics. Furthermore, testing the effects of environment on social behaviour provided evidence that these juveniles aggregated more in structurally complex environments than simple ones. However, at the individual level sharks showed consistency in their social network positions through time and across different habitat types. This result is indicative of personality traits in S. canicula. Using data gathered via passive acoustic telemetry of wild shark behaviour, network analysis provided a useful tool with which to quantify movement between receivers. One chapter has been dedicated to the application of these methods, highlighting a number of different analyses for predicting movement behaviour from such data. Finally, these methods were adopted to address ecological questions in this sexually segregated species. Persistent site fidelity to a localised inshore area by both male and female sharks suggested that segregation occurred at a relatively small spatial and temporal scale. Despite strong evidence of segregation, analyses of movement networks and individual co-occurrences revealed distinct periods of behavioural synchronicity during the months of March, April and May. In addition, habitat complexity appeared to be a significant driver of female behavioural strategy. Enhancing our knowledge of the social and environmental drivers of aggregation and movement in sharks is of great importance given the ecological threat facing many of our ocean’s top elasmobranch predators.

SNA provides a wide range of tools that allow examination of telecommunications graphs. Those graphs contain vertices representing cell phone users and lines standing for established connections. Many sna tools do not incorporate the intensity of interaction. This may lead to wrong conclusions because the difference between best friends and random contacts can be defined by the accumulated duration of talks. To solve this problem, we propose a closeness centrality measure (ewc) that incorporates line values and compare it to Freeman's closeness. Small exemplary networks will demonstrate the characteristics of the weighted closeness compared to other centrality measures. Finally, the ewc will be tested on a real-world telecommunications graph provided by a large Austrian mobile service provider and the advantages of the ewc will be discussed. / Series: Research Report Series / Department of Statistics and Mathematics