We study the inapproximability of the induced disjoint paths problem on an arbitrary n-node m-edge undirected graph, which is to connect the maximum number of the k sourcesink pairs given in the graph via induced disjoint paths. It is known that the problem is NP-hard to approximate within m 1 2 −ε for a general k and any ε > 0. In this paper, we prove that the problem is NP-hard to approximate...

Functional structural botanical tree models are one of the most difficult models in biology. We introduce IMapple, a model for ‘Golden Delicious’ apple (Malus × domestica) trees based on source-sink descriptions of plant resources. Our model uses precise geometrical representations with high quality polygonal meshes and geometric details. We introduce a novel simulation algorithm that provides ...

The concept of alliance or preferably ‘alignment’, as I shall explain below – is central to the conduct of international politics, and thus the discipline of International Relations (IR). Duffield et al. (2008: 291) identify that ‘Alliances are one of the most significant phenomena in security studies and world politics more generally’, while Modelski (1963: 773) considers them ‘one of a dozen ...

In this article I locate some of the fundamental problems of self-determination within the context of an evolving international society. First, I argue that one particular manifestation of self-determination, that of national self-determination, is both a solution to the enduring problem of territorial legitimation in international relations as well as the source of subsequent challenges to ter...

Historically, issues of gender, race and the environment have received little attention in mainstream International Relations (IR) scholarship. Great strides have been made, however, in interrogating the inadequacies of the field in these areas and, similarly, in demonstrating the necessity of expanded definitions of security and violence in IR. Despite these strides, mainstream environmental s...

The state plays a central position in theoretical debates in International Relations (IR). Both Realists and Liberals see the state as the central actor in the international system and thereby follow a Western understanding of the state as the holder of the monopoly of force. In the IRsub discipline of security studies new categories such as weak state, quasi state or state failure have created...

The authors used an event-contingent daily recording strategy, the Rochester Interaction Record (RIR), to examine the motivational dynamics of interpersonal relations. Using hierarchical linear modeling, the authors demonstrated that social interactions were more pleasant when participants felt autonomous, competent, and related. Autonomy, competence, and relatedness consistently predicted inte...