Compressing Binary Decision Diagrams

The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances.Comment: Full (tech-report) version of ECAI 2008 short pape

Universal depinning force fluctuations of an elastic line: Application to finite temperature behavior

The depinning of an elastic line in a random medium is studied via an extremal model. The latter gives access to the instantaneous depinning force for each successive conformation of the line. Based on conditional statistics the universal and non-universal parts of the depinning force distribution can be obtained. In particular the singular behavior close to a (macroscopic) critical threshold is obtained as a function of the roughness exponent of the front. We show moreover that the advance of the front is controlled by a very tenuous set of subcritical sites. Extension of the extremal model to a finite temperature is proposed, the scaling properties of which can be discussed based on the statistics of depinning force at zero temperature.Comment: submitted to Phys. Rev.

Oil and Gas Exploitation on Arctic Indigenous Peoples’ Territories Human Rights, International Law and Corporate Social Responsibility

The Resource Centre for the Rights of Indigenous Peoples’ Gáldu Čála nr 4/2006 con- tains two articles addressing certain core social, legal and economic questions related to oil and gas operations in indigenous areas, written by Mr. Rune Sverre Fjellheim and Mr. John B. Henriksen respectively. Around the world, including in the Arctic, there are disputes about ownership, utiliza- tion, management and conservation of traditional indigenous lands and resources - often caused by decisions or attempts to use traditional indigenous lands and resources for industrial purposes, including oil and gas exploration. This situation represents an enor- mous challenge, and in some cases threatens indigenous societies and their economies, cultures and ways of life. Indigenous peoples have been, and in many cases still are, deprived of their human rights and fundamental freedoms as distinct peoples. This has resulted in the dispos- session of their lands, territories and resources, and prevented them from exercising their right to development in accordance with their needs and interests. The interests of commercial development normally prevail over indigenous peoples’ rights and interests, despite the fact that the survival of indigenous peoples − as distinct peoples – depends on their possibility to manage their own traditional lands and resources in a manner and mode appropriate to their specific circumstances. The article “Arctic Oil and Gas – Corporate Social Responsibility” discusses the re- sponsibilities of the industrial operators in the Arctic. The Arctic holds 25% of the known remaining global Oil and Gas resources. Industrial development in the Arctic poses seri- ous environmental and Human Rights challenges. It is one of the most pristine and vul- nerable ecosystems in the world and the home of 40-50 distinct Indigenous Peoples. The author shows examples of Corporate Policies designed to address their responsibilities relating to Indigenous Peoples, and discusses the difficulties in turning corporate policies into practice. The article entitled “Oil and Gas Operations in Indigenous Peoples’ Lands and Ter- ritories in the Arctic: A Human Rights Perspective” – written by Mr. John B. Henriksen – elaborates on the international human rights protection accorded to indigenous lands and resource rights, with particular reference to oil and gas exploration