Cautious Weight Tuning for Link State Routing Protocols

Link state routing protocols are widely used for intradomain routing in the Internet. These protocols are simple to administer and automatically update paths between sources and destinations when the topology changes. However, finding link weights that optimize network performance for a given traffic scenario is computationally hard. The situation is even more complex when the traffic is uncertain or time-varying. We present an efficient heuristic for finding link settings that give uniformly good performance also under large changes in the traffic. The heuristic combines efficient search techniques with a novel objective function. The objective function combines network performance with a cost of deviating from desirable features of robust link weight settings. Furthermore, we discuss why link weight optimization is insensitive to errors in estimated traffic data from link load measurements. We assess performance of our method using traffic data from an operational IP backbone

Entrepreneurship: A Weak Link in the Welfare State

Entrepreneurship is largely ignored or treated in a highly simplified way in endogenous growth theory. Still, it is now widely recognized that the supply of entrepreneurial talent is likely to be important for economic growth, innovation and job creation. This study consists of an in-depth examination of how the supply of productive entrepreneurship is likely to be affected by the kind of tax and welfare arrangements that typically prevail in a mature welfare state. Sweden, allegedly the most extensive of all welfare states, is the object of the empirical analysis. It is shown how key welfare state institutions have systematically reduced economic incentives both for opportunity-based and necessity entrepreneurship. Both aggregate economic performance and data on firm growth and direct measures of entrepreneurial activity are consistent with the identified structure of payoffs. A number of measures can be implemented to strengthen entrepreneurial incentives within extensive welfare states, but the fact still remains that an entrepreneurial culture and a welfare state are very remotely related. As a result, the respective cultures are unlikely to be promoted by a similar set of institutions.Economic growth; Entrepreneurship; Innovation; Swedish model; Welfare state

Accounting and the welfare-state: The missing link

In recent years, accounting regulation has been internationalized with the extensive use and adoption of International Financial Reporting Standards (IFRS) by nation-states, which points at least to a formal convergence between accounting regulatory systems. However, major differences between national accounting systems persist. In this paper, it is argued that a country's accounting system is influenced by the type of the welfare-state. This allows us to see accounting in a broader social perspective. The societal attitudes influencing the accounting system are captured by using the Esping-Andersen (1990) classification of welfare states. To show that there is a connection between the typology of welfare-states and the way in which various corporate constituencies' interests are balanced, we compare Germany as an example of a conservative welfare-state and the UK as an example of a liberal welfare-state. This comparison shows that the type of welfare state exerts an influence on the system of accounting and, therefore, can be seen as an explanatory variable for persisting differences between accounting regulatory systems. -- In den letzten Jahren deuten zahlreiche Veränderungen im Bereich der nationalen Regulierung der Rechnungslegung zumindest auf eine formale Konvergenz zwischen den regulatorischen Systemen der Rechnungslegung hin. Abgeleitet werden kann dies aus der mittlerweile weitreichenden Anwendung und Einführung des internationalen Rechnungslegungsstandardwerkes IFRS durch zahlreiche Nationalstaaten. Allerdings bestehen auch weiterhin wesentliche Unterschiede zwischen nationalen Rechnungslegungssystemen fort. Mit diesem Arbeitspapier wird die Hypothese vertreten, dass das Rechungslegungssystem in einem Land und damit die Unterschiede zwischen Ländern maßgeblich durch den Typ des Wohlfahrtsstaates beeinflusst werden. Dieses erlaubt eine weitergefasste gesellschaftliche Perspektive auf den Bereich der Rechungslegungsregulierung. Die einflussnehmenden gesellschaftlichen Werte werden hierbei durch die Wohlfahrtsstaatentypologie von Esping-Andersen (1990) erfasst. In einem abschließenden Länderfallbeispiel werden Deutschland (konservativer Wohlfahrtsstaatstyp) sowie Großbritannien (liberaler Wohlfahrtsstaatstyp) miteinander verglichen. Hierbei soll gezeigt werden, dass eine Verbindung zwischen dem Typ des Wohlfahrtsstaates und der Art und Weise besteht, wie Interessen verschiedener Anspruchsgruppen des Unternehmens ausgeglichen werden. Der Vergleich zeigt, dass ein Zusammenhang zwischen dem Wohlfahrtsstaatstyp und der Rechungslegungsregulierung hergestellt werden kann. Der Wohlfahrtsstaatstyp ist dementsprechend als ein wesentlicher Erklärungsfaktor für den Fortbestand von nationalen Unterschieden in der Rechnungslegungsregulierung zu sehen.

Link-State Based Decode-Forward Schemes for Two-way Relaying

In this paper, we analyze a composite decode-and-forward scheme for the two-way relay channel with a direct link. During transmission, our scheme combines both block Markov coding and an independent coding scheme similar to network coding at the relay. The main contribution of this work is to examine how link state impacts the allocation of power between these two distinct techniques, which in turn governs the necessity of each technique in achieving the largest transmission rate region. We analytically determine the link-state regimes and associated relaying techniques. Our results illustrate an interesting trend: when the user-to-relay link is marginally stronger than the direct link, it is optimal to use only independent coding. In this case, the relay need not use full power. However, for larger user-to-relay link gains, the relay must supplement independent coding with block Markov coding to achieve the largest rate region. These link-state regimes are important for the application of two-way relaying in 5G networks, such as in D2D mode or relay-aided transmission.Comment: To be presented at Globecom 2014, Emerging Technologies for 5G Wireless Cellular Networks (Wi5G

Multipath optimized link state routing for mobile ad hoc networks

International audienceMultipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints

Link Prediction in Social Networks: the State-of-the-Art

In social networks, link prediction predicts missing links in current networks and new or dissolution links in future networks, is important for mining and analyzing the evolution of social networks. In the past decade, many works have been done about the link prediction in social networks. The goal of this paper is to comprehensively review, analyze and discuss the state-of-the-art of the link prediction in social networks. A systematical category for link prediction techniques and problems is presented. Then link prediction techniques and problems are analyzed and discussed. Typical applications of link prediction are also addressed. Achievements and roadmaps of some active research groups are introduced. Finally, some future challenges of the link prediction in social networks are discussed.Comment: 38 pages, 13 figures, Science China: Information Science, 201

Multi-Boundary Entanglement in Chern-Simons Theory and Link Invariants

We consider Chern-Simons theory for gauge group $G$ at level $k$ on 3-manifolds $M_n$ with boundary consisting of $n$ topologically linked tori. The Euclidean path integral on $M_n$ defines a quantum state on the boundary, in the $n$-fold tensor product of the torus Hilbert space. We focus on the case where $M_n$ is the link-complement of some $n$-component link inside the three-sphere $S^3$. The entanglement entropies of the resulting states define framing-independent link invariants which are sensitive to the topology of the chosen link. For the Abelian theory at level $k$ ($G= U(1)_k$) we give a general formula for the entanglement entropy associated to an arbitrary $(m|n-m)$ partition of a generic $n$-component link into sub-links. The formula involves the number of solutions to certain Diophantine equations with coefficients related to the Gauss linking numbers (mod $k$) between the two sublinks. This formula connects simple concepts in quantum information theory, knot theory, and number theory, and shows that entanglement entropy between sublinks vanishes if and only if they have zero Gauss linking (mod $k$). For $G = SU(2)_k$, we study various two and three component links. We show that the 2-component Hopf link is maximally entangled, and hence analogous to a Bell pair, and that the Whitehead link, which has zero Gauss linking, nevertheless has entanglement entropy. Finally, we show that the Borromean rings have a "W-like" entanglement structure (i.e., tracing out one torus does not lead to a separable state), and give examples of other 3-component links which have "GHZ-like" entanglement (i.e., tracing out one torus does lead to a separable state).Comment: 37 pages, 19 figure