Non-blind watermarking of network flows

Linking network flows is an important problem in intrusion detection as well as anonymity. Passive traffic analysis can link flows but requires long periods of observation to reduce errors. Active traffic analysis, also known as flow watermarking, allows for better precision and is more scalable. Previous flow watermarks introduce significant delays to the traffic flow as a side effect of using a blind detection scheme; this enables attacks that detect and remove the watermark, while at the same time slowing down legitimate traffic. We propose the first non-blind approach for flow watermarking, called RAINBOW, that improves watermark invisibility by inserting delays hundreds of times smaller than previous blind watermarks, hence reduces the watermark interference on network flows. We derive and analyze the optimum detectors for RAINBOW as well as the passive traffic analysis under different traffic models by using hypothesis testing. Comparing the detection performance of RAINBOW and the passive approach we observe that both RAINBOW and passive traffic analysis perform similarly good in the case of uncorrelated traffic, however, the RAINBOW detector drastically outperforms the optimum passive detector in the case of correlated network flows. This justifies the use of non-blind watermarks over passive traffic analysis even though both approaches have similar scalability constraints. We confirm our analysis by simulating the detectors and testing them against large traces of real network flows

Career Service work in Germany during the Bologna Process

The roots of today Career Service (CS) work can be traced back to the education policy of the 1960s and 1970s. The work then focused on the relation between universities, working environment and society. University graduates were increasingly seen as economical growth and innovation factors and education with a practical orientation became the main aspect. During the late 80s the first “job preparation initiatives” developed at German universities. These were the stepping stones for today CS work. One of the securely established institutions in this field in Germany is the Career Service “Studierende & Arbeitswelt (S&A)” founded in 1989 at the University of Cologne. Since 1999 there has been an increasing interest in CS work in the course of the Bologna reform. This growing interest is also a result of introducing a new degree system. The focus of CS is to improve the students' employability. Practical, vocational oriented qualification should be an integral part of occupational bachelor-degree programs as well as of scientifical master-degree programs. CS-centers function as gateways between university and work environment and have expertise and competence in the field of applied learning. As service and transfer units they form nodal points for students, teachers, administration and employers. With its segments of information, advising, qualification, and contact management, CS offers a wide range of services in order to provide links to the working world. The increasing formation and expansion of CS at German universities was promoted by academic political referral engines. At present, structural and contentual changes in CS areas are being carried out

Combined Structural Interventions for Gender Equality and Livelihood Security: A Critical Review of the Evidence from Southern and Eastern Africa and the Implications for Young People

This document presents information on how young people in southern and eastern Africa remain disproportionately vulnerable to HIV with gender inequalities and livelihood insecurities being key drivers of this. Behavioural HIV prevention interventions have had weak outcomes and a new generation of structural interventions have emerged seeking to challenge the wider drivers of the HIV epidemic, including gender inequalities and livelihood insecurities. We searched key academic data bases to identify interventions that simultaneously sought to strengthen people's livelihoods and transform gender relationships that had been evaluated in southern and eastern Africa. Our initial search identified 468 articles. We manually reviewed these and identified nine interventions that met our criteria for inclusion. We clustered the nine interventions into three groups: microfinance and gender empowerment interventions; supporting greater participation of women and girls in primary and secondary education; and gender empowerment and financial literacy interventions. We summarise the strengths and limitations of these interventions, with a particular focus on what lessons may be learnt for young people

Changing Nigerian cultures: two films against witchcraft and an impossible dialogue

The prominent place of witchcraft in Nollywood films produced in the 1990s is widely acknowledged, and has prompted a number of comments from critics. While filmmakers’ opinion is divided on the subject, these films obviously echo familiar situations. The dissemination of Nigerian films outside Africa and their entering new geographical and cultural areas, and the didactic nature of Nollywood, have led to a clash between Nigerian and the British cultures in the bid to fight the widespread practice of witchcraft and its attendant casualties, which now affect both worlds. This paper reflects on the difficulty of intercultural communication on the subject as illustrated by the recent controversy sparked by a British NGO’s discovery of Nollywood in 2008. The film born of this culture-shock presents a novel way of dealing with screen-mediated witchcraft and its impact

Stepping stones for biological invasion: A bioeconomic model of transferable risk

Herein we model the widespread dispersal and management of an invasive species as a weak-link public good. The risk of introduction is driven in part by economic activity, is influenced by policies directed at the risk, and economic activity responds/adapts to the risk. Framed around recent introductions and rapid spread of dreissenid mussels in the Western United States, we find three key results. First, partial equilibrium estimates of welfare loss are significantly overestimated relative to general equilibrium estimates. If ecosystem services and market goods are substitutes the partial equilibrium bias is greater than if they are compliments. Second, well-intended policies do not necessarily reduce overall risk; risk reduction actions can transfer risk to another time or location, or both, which may increase total risk. Third, policies of quotas and inspections have to be extreme to improve welfare, with inspections having advantages over quotas.bioeconomic, invasive species, risk, weak-link, welfare, Environmental Economics and Policy, Risk and Uncertainty, Q2, Q26, Q57,