High-Performance Reachability Query Processing under Index Size Restrictions

In this paper, we propose a scalable and highly efficient index structure for the reachability problem over graphs. We build on the well-known node interval labeling scheme where the set of vertices reachable from a particular node is compactly encoded as a collection of node identifier ranges. We impose an explicit bound on the size of the index and flexibly assign approximate reachability ranges to nodes of the graph such that the number of index probes to answer a query is minimized. The resulting tunable index structure generates a better range labeling if the space budget is increased, thus providing a direct control over the trade off between index size and the query processing performance. By using a fast recursive querying method in conjunction with our index structure, we show that in practice, reachability queries can be answered in the order of microseconds on an off-the-shelf computer - even for the case of massive-scale real world graphs. Our claims are supported by an extensive set of experimental results using a multitude of benchmark and real-world web-scale graph datasets.Comment: 30 page

Pedagogy: training, a guide to stand by

The People’s Manual on the Guidelines on Governance of Land, Fisheries and Forests is a useful tool for civil society organizations

Evaluation of Geo-Social Networking Application Use Among Young Adults

Background: Since 2009 geosocial networking applications (GNAs) have rapidly emerged as a new technological platform for users to communicate, date, and meet for sex. Popular GNAs include Tinder, Grindr, Bumble, Plenty of Fish, and many more. GNA’s are unique to traditional dating websites in that they allow users to connect with each other based on geographic proximity of their mobile phones. Given the pervasiveness of technology usage among young adults, it is important to understand the potential risks and benefits that GNA-facilitated communication poses on sexual health, emotional well-being, and safety. Popular GNA’s, like Tinder, estimate the majority of users are 16 to 34 years-old. Coincidentally the CDC reports half of the 20 million new sexually transmitted infections each year are among 15 to 24 year-olds. Examination of GNA use and its association with high-risk behaviors and sexual health outcomes among heterosexual young adults is warranted. Methods: A focus-group was held with Western Connecticut State University’s (WCSU) Collegiate Health Service Corps Club (CHSCC) in an effort to create a survey for undergraduate and graduate students on campus. WCSU Institutional review board granted an exempt review status for the project. Through a collaborative effort, a 26-question survey was developed and administered to WCSU students ranging from 18 to 25 years-old. The number of surveys distributed was stratified based on three age groupings: 18-20 years-old (n = 19), 21-23 years-old (n = 20), and 24-25 years-old (n = 20). The survey contained questions regarding GNA’s usage and practice, student sexual health and practice, and overall safety and wellness. Results: A total of 26/60 (43.3%) young adults surveyed reported using geo-social dating applications. The distribution of GNA use among the three age groupings did not differ significantly. The most popular applications used: Tinder (58%), Plenty of Fish (15%), OkCupid (12%), and Bumble (6%). The vast majority of students report using the apps for 11 months or less. A total of 80% of students stated they were sexually active, however over half reported either inconsistent or none-existent barrier method contraceptive use. The primary reasons for using GNAs was “curiosity/fun” and “companionship,” however a smaller minority reported seeking either romantic relationship, casual hook-ups, or sexual intercourse. Of the GNA users, a total of 48% reported they meet-up with other users either “sometimes” (29%), “somewhat often” (15%), or “often” (4%). The nature of these encounters included mostly conversation, texting, social activity, and a smaller minority reported dating, ‘hooking-up,’ oral sex, and sexual intercourse. Interestingly, over half the GNA users have worried about their safety at some point. Conclusion: Survey results cannot directly equate GNAs with STD risk or prevalence, however they do encourage app-users to think about whether their own app-use places them at a sexual, emotional, and/or safety risk. Given the demonstrated prevalence of GNA use among young adults, it is important for the general public, health care providers, and app-users to understand the potential risks and benefits of this type of social networking platform.https://scholarworks.uvm.edu/fmclerk/1172/thumbnail.jp

Quality of experience and access network traffic management of HTTP adaptive video streaming

The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.Die Doktorarbeit beschäftigt sich mit Quality of Experience (QoE) – der subjektiv empfundenen Dienstgüte – von adaptivem HTTP Videostreaming (HAS) und mit Verkehrsmanagement, das in Zugangsnetzwerken eingesetzt werden kann, um die QoE des adaptiven Videostreamings zu verbessern. Zuerst wurde der Einfluss von Adaptionsparameters und der Zeit pro Qualitätsstufe auf die QoE von adaptivem Videostreaming mittels subjektiver Crowdsourcingstudien untersucht. Die Ergebnisse wurden benutzt, um die QoE-optimale Adaptionsstrategie für gegebene Videos und Netzwerkbedingungen zu berechnen. Dies ermöglicht Dienstanbietern von Videostreaming verbesserte Adaptionsstrategien für adaptives Videostreaming zu entwerfen und zu benchmarken. Weiterhin untersuchte die Arbeit Konzepte zum Überwachen von QoE von Videostreaming in der Applikation und im Netzwerk, die von Netzwerkbetreibern im Kreislauf des QoE-bewussten Verkehrsmanagements eingesetzt werden können. Außerdem wurde eine analytische und simulative Leistungsbewertung von QoE-bewusstem Verkehrsmanagement auf einer Engpassverbindung durchgeführt. Schließlich untersuchte diese Arbeit sozialbewusstes Verkehrsmanagement für adaptives Videostreaming mittels WLAN Offloading, also dem Auslagern von mobilen Videoflüssen über WLAN Netzwerke. Es wurde ein Modell für die Verteilung von öffentlichen WLAN Zugangspunkte und eine Plattform für sozialbewusstes Verkehrsmanagement auf privaten, häuslichen WLAN Routern vorgestellt. Abschließend untersuchte eine simulative Leistungsbewertung den Einfluss von WLAN Offloading auf die QoE und den Energieverbrauch von mobilem adaptivem Videostreaming

Turkey shifts the focus of its foreign policy: from Syria to the eastern Mediterranean and Libya

On 27 November 2019, Turkish President Recep Tayyip Erdoğan declared that Turkey had concluded a treaty on military assistance and cooperation with the government of Fayez al-Sarraj in Libya. The agreement permits the deployment of Turkish troops into the civil-war-torn country. The announcement was met with almost unanimous criticism in Western Europe. The indignation grew even greater when it became known that Turkey was controlling and financing the smuggling of Islamic Syrian fighters into Libya. Reports of a dominant influence of the Muslim Brotherhood on the Libyan gov­ern­ment seemed to complete the picture of a strongly Islamist-motivated Turkish policy. However, Turkey's engagement in Libya is not driven by ideology, but rather by stra­tegic considerations and economic interests. Ankara is thus reacting to its isolation in the eastern Mediterranean, where the dispute over the distribution of gas resources is intensifying. At the same time, Turkey is drawing lessons from the war in Syria. An­kara has lost this war, but through its engagement in Syria, it has been able to estab­lish a conflictual - but viable - working relationship with Russia. The bottom line is that Turkey’s commitment to Libya is a shift in the focus of its foreign policy from the Middle East to the Mediterranean, a shift that will present entirely new challenges to Europe, the European Union (EU), and the North Atlantic Treaty Organization (NATO). (author's abstract

The return of the Kurdish question: on the situation of the Kurds in Iraq, Syria and Turkey

For decades, the roughly twenty-nine million Kurds living in Turkey, Iran, Iraq and Syria were regarded primarily as a threat to the territorial integrity of those states and thus to the stability of the Middle East. Today the region is marked by state collapse, rampant terrorism, and signs of unravelling in the established system of states. These developments have brought about fundamental changes in the position of the Kurds and the role they play in regional politics. (author's abstract

Ever further from the West: why Ankara looks to Moscow

A bloody coup attempt, the government responding by dismantling the state of law and an unending series of terror attacks have turned Turkey into a different country. In foreign policy, Ankara’s rapprochement with Moscow raises the question of whether the West can still consider Turkey a reliable partner. Officially, the country continues to be a candidate for membership of the European Union. However, for some time now the talk has been more of the dangers that an unstable and anti-Western Turkey creates for the EU than of how Brussels might influence Turkish politics. NATO too is concerned about Turkey. Will it remain in the Western camp? Can it recover domestically? What sort of future do the more recent developments in foreign and domestic policy predict for Turkey? (author's abstract

Is the Fethullah Gülen movement overstretching itself? A Turkish religious community as a national and international player

"The movement led by the preacher Fethullah Gülen is regarded as the fastest-growing religious trend within Turkish Islam. This accounts also for citizens and denizens with Turkish backgrounds in Western European countries, including Germany, where approximately 300 organisations close to Gülen operate 24 state-approved private schools and around 150 extracurricular tuition centres. Against the background of the diaspora, Gülen's philosophy of adopting modern knowledge, modes of action and attitudes, climbing the social ladder and thus making an effective contribution to social moral reform assumes a new dimension. For one thing, in contrast to Turkey, personal social advancement cannot be linked with the undertaking regarding the conquest of the state. For another, and again in contrast to Turkey, to concentrate on the preservation of one's traditional religious (Muslim) and national (Turkish) identity does not automatically create harmony with the majority of the population, but is indeed at least partially opposed to the same. As a result, the Turkish-Muslim diaspora is under pressure to develop a new understanding of religious and national identity compatible with attitudes prevailing in European societies. For the movement's supporters, this is just as much a prerequisite for their individual advancement as the reconciliation of their religious world view with its scientific equivalent. Gülen's prompt that service to society constitutes a significant form of a lifestyle justifiable in the eyes of God could prove to be the key to resolving the principal conflict of interest between Islam and the West both within the European diaspora and in the USA, repeatedly emphasised by him with insistence in his early writings." (author's abstract

Erdoğans "New Turkey": restoring the authoritarian state in the name of democracy

"European and American commentators warn that Turkey is drifting back into authoritarianism, citing excessive police violence against demonstrators, restrictions on freedom of the press and internet, government interference in the judiciary, purges in the bureaucracy, and an anti-European policy shift. They note with astonishment that former prime minister Recep Tayyip Erdoğan was able to win the presidency on an increased share of the vote despite credible accusations of corruption, strife within the conservative camp and foreign policy failures. Erdoğan himself speaks of the 'New Turkey' having succeeded the old, authoritarian Kemalist republic and brought forth a progressive democracy. How broad is support for Erdoğan's Justice and Development Party (AKP) across society? What can be expected of the new government? How fundamental is the reconstruction of the political system, and what does the it mean for the future of democracy? How can and should Europe respond?" (author's abstract