Toward an efficient solution for dynamic ad hoc network interoperability

An ad hoc network is formed by an impromptu grouping of network capable nodes. The nodes forming the network have unconstrained mobility, and so provide a dynamic network topology. Current work in this research area has focused on designing routing protocols capable of efficiently forwarding packets in these dynamic network environments. This has led to several designs for ad hoc routing protocols based on various routing algorithms, each suited to specific usage characteristics. This paper will discuss issues relating to routing in ad hoc networks. We will describe an active networking based solution that provides dynamic routing protocol interoperability and enables migration of nodes between ad hoc groups. Our design is motivated by a squad and base scenario which consists of two groups wishing to communicate. These groups have contrasting deployment characteristics and so use different routing protocols

Tolling, Capacity Selection and Equilibrium Problems with Equilibrium Constraints

An Equilibrium problem with an equilibrium constraint is a mathematical construct that can be applied to private competition in highway networks. In this paper we consider the problem of finding a Nash Equilibrium regarding competition in toll pricing on a network utilising 2 alternative algorithms. In the first algorithm, we utilise a Gauss Siedel fixed point approach based on the cutting constraint algorithm for toll pricing. In the second algorithm, we extend an existing sequential linear complementarity approach for finding Nash equilibrium subject to Wardrop Equilibrium constraints. Finally we consider how the equilibrium may change between the Nash competitive equilibrium and a collusive equilibrium where the two players co-operate to form the equivalent of a monopoly operation

Market Information Services

Information is the lifeblood of most market economies. Nevertheless, attempts to jump start information flow by creating Market Information Services for food and agriculture usually fail. The author distills experiences and lessons from other studies and individual experts in the field on the reasons for such common failures and what can be done to avoid them. Critical topics such as institutional structure, dissemination methods, and funding are outlined to guide the reader through the basic issues that must be addressed in order to create a successful Market Information Service.Market Information Service; market data; price information; trade information; developing countries; marketing; agriculture, food, institutions, Market Information System

Aid and poverty: Why does aid not address poverty (much)?

Aid is not generally aimed at the poorest people, though most multilateral or bilateral agencies would like to think they get included. However, donors' strategies are generally blind to differentiation among the poor, and have not improved in this respect. The special provisions for the least developed countries, where many of the poorest people live, have not worked well. Aid to conflict-affected countries is itself in crisis. Much greater and more integrated aid is called for in both cases. Middle-income countries are themselves becoming donors, but the poorest populations of these countries have benefited from international partnerships which draw attention to the poorest and help foster innovative policy responses. Equity is far from being a strong principle of aid givers UNICEF is the exceptional agency. The human rights based approach to development, which would give much greater weight to the poorest, in practice languishes at the margins of development, though where this has been taken up in middle-income countries (e.g., India) donors have stood on the sidelines. Explanations of this fairly dismal state of affairs are offered in terms of political economy and organizational and profession incentives. Finally the paper sketches a set of issues which need to be incorporated into the post 2015 framework and its preparation if poverty is to be taken more seriously by donors

Tolling, collusion and equilibrium problems with equilibrium constraints

An Equilibrium Problem with an Equilibrium Constraint (EPEC) is a mathematical construct that can be applied to private competition in highway networks. In this paper we consider the problem of finding a Nash Equilibrium in a situation of competition in toll pricing on a network utilising two alternative algorithms. In the first algorithm, we utilise a Gauss Seidel fixed point approach based on the cutting constraint algorithm for toll pricing. The second algorithm that we propose, a novel contribution of this paper, is the extension of an existing sequential linear complementarity programming approach for finding the competitive Nash equilibrium when there is a lower level equilibrium constraint. Finally we develop an intuitive approach to represent collusion between players and demonstrate that as the level of collusion goes from none to full collusion so the solution maps from the Nash to monopolistic solution. However we also show that there may be local solutions for the collusive monopoly which lie closer to the second best welfare toll solution than does the competitive Nash equilibrium

First record of an Odontaspidid shark in Ascension Island waters

The occurrence of the poorly understood shark species Odontapsis ferox is reported at an oceanic seamount in the central south Atlantic, within the Exclusive Economic Zone of Ascension Island. The presence of the species at this location is confirmed by the discovery of a tooth embedded in scientific equipment, and footage of at least one animal on autonomous underwater video. The new record of this shark species at this location demonstrates the knowledge gaps which still exist at many remote, oceanic structures and their candidacy for status as important conservation areas.info:eu-repo/semantics/publishedVersio

A simple field based method for rapid wood density estimation for selected tree species in Western Kenya

Wood density is an important variable for accurate quantification of woody biomass and carbon stocks. Conventional destructive methods for wood density estimation are resource intensive, prohibiting their use, limiting the application of approaches that would minimize uncertainties in tree biomass estimates. We tested an alternative method involving tree coring with a carpenter's auger to estimate wood density of seven tropical tree species in Western Kenya. We used conventional water immersion method to validate results from the auger core method. The mean densities (and 95% confidence intervals) ranged from 0.36 g cm−3 (0.25–0.47) to 0.67 g cm−3 (0.61–0.73) for the auger core method, and 0.46 g cm−3 (0.42–0.50) to 0.67 g cm−3 (0.61–0.73) for the water immersion method. The auger core and water immersion methods were not significantly different for four out of seven tree species namely; Acacia mearnsii, Mangifera indica, Eucalyptus grandis and Grevillea robusta. However, wood densities estimated from the auger core method were lower (t (61) = 7.992, P = <0.001). The ease of the auger core method application, as a non-destructive method in acquiring wood density data, is a worthy alternative in biomass and carbon stocks quantification. This method could protect trees outside forests found in most parts of Africa