Analysis of priority-based packet schedulers for proportional delay diferentiation

Master'sMASTER OF ENGINEERIN

Optimal tax policy and expected longevity: a mean and variance approach

This paper studies the normative problem of redistribution between agents who can influence their survival probability through private health spending, but who differ in their attitude towards the risks involved in the lotteries of life to be chosen. For that purpose, we develop a two-period model where agents's preferences on lotteries of life can be represented by a mean and variance utility function allowing, unlike the expected utility form, some – agent-specific – sensitivity to what Allais (1953) calls the 'dispersion of psychological values'. It is shown that if agents ignore the impact of their health expenditures on the return of their savings, the decentralization of the first-best optimum requires not only intergroup lump-sum transfers, but, also, group-specific taxes on health spending. Under asymmetric information, we find that a subsidy on savings is optimal, whereas group-specific taxes on health spending are of ambiguous signs.longevity, risk, lotteries of life, expected utility theory, health spending.

Networking Mechanisms for Delay-Sensitive Applications

The diversity of applications served by the explosively growing Internet is increasing. In particular, applications that are sensitive to end-to-end packet delays become more common and include telephony, video conferencing, and networked games. While the single best-effort service of the current Internet favors throughput-greedy traffic by equipping congested links with large buffers, long queuing at the congested links hurts the delay-sensitive applications. Furthermore, while numerous alternative architectures have been proposed to offer diverse network services, the innovative alternatives failed to gain widespread end-to-end deployment. This dissertation explores different networking mechanisms for supporting low queueing delay required by delay-sensitive applications. In particular, it considers two different approaches. The first one assumes employing congestion control protocols for the traffic generated by the considered class of applications. The second approach relies on the router operation only and does not require support from end hosts

Ensuring Service Level Agreements for Composite Services by Means of Request Scheduling

Building distributed systems according to the Service-Oriented Architecture (SOA) allows simplifying the integration process, reducing development costs and increasing scalability, interoperability and openness. SOA endorses the reusability of existing services and aggregating them into new service layers for future recycling. At the same time, the complexity of large service-oriented systems negatively reflects on their behavior in terms of the exhibited Quality of Service. To address this problem this thesis focuses on using request scheduling for meeting Service Level Agreements (SLAs). The special focus is given to composite services specified by means of workflow languages. The proposed solution suggests using two level scheduling: global and local. The global policies assign the response time requirements for component service invocations. The local scheduling policies are responsible for performing request scheduling in order to meet these requirements. The proposed scheduling approach can be deployed without altering the code of the scheduled services, does not require a central point of control and is platform independent. The experiments, conducted using a simulation, were used to study the effectiveness and the feasibility of the proposed scheduling schemes in respect to various deployment requirements. The validity of the simulation was confirmed by comparing its results to the results obtained in experiments with a real-world service. The proposed approach was shown to work well under different traffic conditions and with different types of SLAs

Higher education reform: getting the incentives right

This study is a joint effort by the Netherlands Bureau for Economic Policy Analysis (CPB) and the Center for Higher Education Policy Studies. It analyses a number of `best practices¿ where the design of financial incentives working on the system level of higher education is concerned. In Chapter 1, an overview of some of the characteristics of the Dutch higher education sector is presented. Chapter 2 is a refresher on the economics of higher education. Chapter 3 is about the Australian Higher Education Contribution Scheme (HECS). Chapter 4 is about tuition fees and admission policies in US universities. Chapter 5 looks at the funding of Danish universities through the so-called taximeter-model, that links funding to student performance. Chapter 6 deals with research funding in the UK university system, where research assessments exercises underlie the funding decisions. In Chapter 7 we study the impact of university-industry ties on academic research by examining the US policies on increasing knowledge transfer between universities and the private sector. Finally, Chapter 8 presents food for thought for Dutch policymakers: what lessons can be learned from our international comparison

The Role of Consumer Behaviour in Service Operations Management

In this thesis, I study the impact of consumer behaviour on service providers’ operations. In the first study, I consider service systems where customers do not know the distribution of uncertain service quality and cannot estimate it fully rationally. Instead, they form their beliefs by taking the average of several anecdotes, the size of which measures their level of bounded rationality. I characterise the customers’ joining behaviour and the service provider’s pricing, quality control, and information disclosure decisions. Bounded rationality induces customers to form different estimates of the service quality and leads the service provider to use pricing as a market segmentation tool, which is radically different from the full rationality setting. When the service provider also has control over quality, I find that it may reduce both quality and price as customers gather more anecdotes. In addition, a high-quality service provider may not disclose quality information if the sample size is small. In the second study, I analyse the performance of opaque selling in countering the negative revenue impact from consumers’ strategic waiting behaviour in vertically differentiated markets. The advantage of opaque selling is to increase the firm’s regular price, whereas the disadvantage lies in the inflexibility of segmenting different types of consumers. Both the advantage and the disadvantage are radically different from their counterparts in horizontally differentiated markets, and this contrast generates opposite policy recommendations across the two settings. In the third study, I investigate an online store’s product return policy when competing with a physical store, in which consumers can try the product before purchase. I find that the online store should offer product return only if it is socially efficient. Moreover, it should allocate product return cost between the online store and the consumers to minimise the total return cost

Proceedings of the First Karlsruhe Service Summit Workshop - Advances in Service Research, Karlsruhe, Germany, February 2015 (KIT Scientific Reports ; 7692)

Since April 2008 KSRI fosters interdisciplinary research in order to support and advance the progress in the service domain. KSRI brings together academia and industry while serving as a European research hub with respect to service science. For KSS2015 Research Workshop, we invited submissions of theoretical and empirical research dealing with the relevant topics in the context of services including energy, mobility, health care, social collaboration, and web technologies

Free to improve? The impact of free school attendance in England

We investigate the impact of attending a free school in England - that is, a new start-up school that enjoys considerable autonomy while remaining in the state sector. We analyse the effects of two secondary free schools with different teaching philosophies: one follows a 'no excuse' paradigm, while the other one adopts a 'classical liberal', knowledge-rich approach. We establish causal effects exploiting admission lotteries and a distance-based regression discontinuity design. Both schools have a strong positive impact on student test scores on average. However, we also find heterogeneous effects: the 'no excuse' school mostly benefits boys, while the 'classical liberal' school mainly benefits White British and non-poor students. Both schools similarly reduce student absences and school mobility. Peer quality, teacher characteristics, and inspectorate ratings cannot fully explain the schools' effectiveness. Instead, a quantitative text analysis of the schools' 'vision and ethos' statements shows that the 'no excuse' and 'classical liberal' philosophies adopted by the two free schools clearly set them apart from the counterfactual schools where rejected applicants enrol, and likely explain their heterogeneous effects

Performance Tuning of Dual-priority Delta Networks through Queuing Scheduling Disciplines

Differentiated Services (DiffServ) and other scheduling strategies are now widespread in the traditional, “best effort” Internet. These Internet Architectures offer Quality of Service (QoS) guarantees for important customers at the same time as supporting less critical applications of lower priority. Strict priority queuing (PQ), weighted round robin (WRR), and class-based weighted fair queuing (CBWFQ) are three common scheduling disciplines for differentiation of services in telecommunication networks. In this paper, a comparative performance study of the above PQ, WRR and CBWFQ queuing scheduling policies applied on a double-buffered, 6-stage Multistage Interconnection Network (MIN) that natively supports a 2-class priority mechanism is presented and analyzed using simulation experiments. We also consider a 10-stage MIN, to validate that the conclusions drawn from the 6-stage MIN apply to MINs of different sizes. The findings of this paper can be used by MIN designers to optimally configure their networks