TCP throughput guarantee in the DiffServ Assured Forwarding service: what about the results?

Since the proposition of Quality of Service architectures by the IETF, the interaction between TCP and the QoS services has been intensively studied. This paper proposes to look forward to the results obtained in terms of TCP throughput guarantee in the DiffServ Assured Forwarding (DiffServ/AF) service and to present an overview of the different proposals to solve the problem. It has been demonstrated that the standardized IETF DiffServ conditioners such as the token bucket color marker and the time sliding window color maker were not good TCP traffic descriptors. Starting with this point, several propositions have been made and most of them presents new marking schemes in order to replace or improve the traditional token bucket color marker. The main problem is that TCP congestion control is not designed to work with the AF service. Indeed, both mechanisms are antagonists. TCP has the property to share in a fair manner the bottleneck bandwidth between flows while DiffServ network provides a level of service controllable and predictable. In this paper, we build a classification of all the propositions made during these last years and compare them. As a result, we will see that these conditioning schemes can be separated in three sets of action level and that the conditioning at the network edge level is the most accepted one. We conclude that the problem is still unsolved and that TCP, conditioned or not conditioned, remains inappropriate to the DiffServ/AF service

Mixed integer nonlinear programming (MINLP)-based bandwidth utility function on internet pricing scheme with monitoring and marginal cost

The development of the internet in this era of globalization has increased fast. The need for internet becomes unlimited. Utility functions as one of measurements in internet usage, were usually associated with a level of satisfaction of users for the use of information services used. There are three internet pricing schemes used, that are flat fee, usage based and two-part tariff schemes by using one of the utility function which is Bandwidth Diminished with Increasing Bandwidth with monitoring cost and marginal cost. Internet pricing scheme will be solved by LINGO 13.0 in form of non-linear optimization problems to get optimal solution. The optimal solution is obtained using the either usage-based pricing scheme model or two-part tariff pricing scheme model for each services offered, if the comparison is with flat-fee pricing scheme. It is the best way for provider to offer network based on usage based scheme. The results show that by applying two part tariff scheme, the providers can maximize its revenue either for homogeneous or heterogeneous consumers

Resilient networking in wireless sensor networks

This report deals with security in wireless sensor networks (WSNs), especially in network layer. Multiple secure routing protocols have been proposed in the literature. However, they often use the cryptography to secure routing functionalities. The cryptography alone is not enough to defend against multiple attacks due to the node compromise. Therefore, we need more algorithmic solutions. In this report, we focus on the behavior of routing protocols to determine which properties make them more resilient to attacks. Our aim is to find some answers to the following questions. Are there any existing protocols, not designed initially for security, but which already contain some inherently resilient properties against attacks under which some portion of the network nodes is compromised? If yes, which specific behaviors are making these protocols more resilient? We propose in this report an overview of security strategies for WSNs in general, including existing attacks and defensive measures. In this report we focus at the network layer in particular, and an analysis of the behavior of four particular routing protocols is provided to determine their inherent resiliency to insider attacks. The protocols considered are: Dynamic Source Routing (DSR), Gradient-Based Routing (GBR), Greedy Forwarding (GF) and Random Walk Routing (RWR)

Human-Related Factors Regulate the Spatial Ecology of Domestic Cats in Sensitive Areas for Conservation

Background: Domestic cats ranging freely in natural areas are a conservation concern due to competition, predation, disease transmission or hybridization with wildcats. In order to improve our ability to design effective control policies, we investigate the factors affecting their numbers and space use in natural areas of continental Europe. Methodology/Principal Findings: We describe the patterns of cat presence, abundance and space use and analyse the associated environmental and human constraints in a well-preserved Mediterranean natural area with small scattered local farms. We failed in detecting cats in areas away from human settlements (trapping effort above 4000 trap-nights), while we captured 30 individuals near inhabited farms. We identified 130 cats, all of them in farms still in use by people (30% of 128 farms). All cats were free-ranging and very wary of people. The main factor explaining the presence of cats was the presence of people, while the number of cats per farm was mostly affected by the occasional food provisioning with human refuse and the presence of people. The home ranges of eight radio tagged cats were centred at inhabited farms. Males went furthest away from the farms during the mating season (3.8 km on average, maximum 6.3 km), using inhabited farms as stepping-stones in their mating displacements (2.2 km of maximum inter-farm distance moved). In their daily movements, cats notably avoided entering in areas with high fox density. Conclusions: The presence, abundance and space use of cats were heavily dependent on human settlements. Any strategy aiming at reducing their impact in areas of conservation concern should aim at the presence of settlements and their spatial spread and avoid any access to human refuse. The movements of domestic cats would be limited in areas with large patches of natural vegetation providing good conditions for other carnivore mammals such as red foxes.Peer reviewe

Effects of anticompetitive practices on trade in developing countries

Programa de Doctorado en Derecho por la Universidad Carlos III de MadridPresidenta: Eva María Domínguez Pérez.- Secretario: Marcos Araújo Boyd.- Vocal: Carmen Herrero Suáre

Labor Market Structures, Trade and their Effect on Unemployment: A Theoretical Analysis and Empirical Investigation

This paper investigates the effects of different labor market structures on the level of unemployment. A theoretical interpretation of an open economy version of the Calmfors and Driffill framework with traded good sector and sheltered non traded good sector is presented, in which different wage-employment trade-offs faced by unions in traded and non traded goods sector as well as the degree of openness is taken into account. From a theoretical point of view the framework supports the idea of the hump-shaped relationship between the degree of centralization of the bargaining process and the level of unemployment, which is sustained even with increased openness. Countries with an intermediate level of bargaining are expected to benefit most in terms of lower unemployment from an increase in openness. In an empirical part, the model is applied to a panel of 20 OECD countries over the period 1970-2000 and the predictions of the model are tested. I find empirical support for both of the main hypothesis, particularly if the strength of the employment protection is additionally taken into account. The results render also support to the literature on the interaction of product market regulations and labor market institutions, as countries which face stronger competition in the product market from foreign producers stand to benefit more from a deregulation in the labor market via a weakening of the employment protection legislation.Labor Market Institutions, Unemployment, Openness to Trade, Product Market Competition

Continuing Education at Purdue University, 1975–2019

Continuing Education at Purdue University, 1975–2019 is intended to provide a follow-up to the monograph written by Dr. Frank K. Burrin after his retirement as director of Purdue Continuing Education in 1984, Continuing Education at Purdue University: The First Hundred Years (1874–1974). Burrin became ill shortly after his retirement, and he was not able to complete his project. His notes were later compiled, edited, and published by Elizabeth Boyd Thompson. This monograph presents forty-five years of the history of Continuing Education and Conferences at Purdue under the leadership of eight deans and directors.https://docs.lib.purdue.edu/continuinged/1001/thumbnail.jp