Verification of Well-formedness in Message-Passing Asynchronous Systems modeled as Communicating Finite-State Machines

Asynchronous systems with message-passing communication paradigm have made major inroads in many application domains in service-oriented computing, secure and safe operating systems and in general, distributed systems. Asynchrony and concurrency in these systems bring in new challenges in verification of correctness properties. In particular, the high-level behavior of message-passing asynchronous systems is modeled as communicating finite-state machines (CFSMs) with unbounded communication buffers/channels. It has been proven that, in general, state-space exploration based automatic verification of CFSMs is undecidable - specifically, reachability and boundedness problems for CFSMs are undecidable. In this context, we focus on an important path-based property for CFSMs, namely well-formedness - every message sent can be eventually consumed. We show that well-formedness is undecidable as well, and present decidable sub-classes for which verification of well-formedness can be automated. We implemented the algorithm for verifying the well-formedness for the decidable subclass, and present our results using several case studies such as service choreographies and Singularity OS contracts

An evaluation of REDD+ in community managed forests: a case study from Nepal

Deforestation and forest degradation contribute between 10 and 25% of total annual greenhouse gas emissions. The REDD+ program for reducing emissions from deforestation and forest degradation and promoting forest conservation, sustainable management of the forests and enhancement of forest carbon stocks is one mechanism developed in an attempt to mitigate greenhouse gas emissions. Various REDD+ initiatives have been trialled in developing countries, including for community forests (CFs), which are an increasingly common form of resource management. Through the program, incentives are provided to community forest user groups (CFUGs) to encourage changes in management practices likely to increase sequestration stocks. There is, however, limited knowledge about the factors responsible for enhancing carbon stocks in CFs, the likely trade-offs within communities and the potential for increasing sequestration stocks. The overarching goal of this research is to evaluate the impacts and potential of REDD+ projects in CF systems. Results from this study provide information for the design and development of programs to increase sequestration and conservation benefits in developing countries. This study estimated carbon stocks and change in carbon stock, technical potential (maximum stocks), key factors affecting carbon stock and trade-offs between gains in sequestration and other foregone community benefits. The study covered 105 CFUGs operating within five major dominant vegetation types. Annual data of carbon pools comprising above and below ground biomass were used to analyse carbon stocks and stock changes. Where sufficient data and models for key species were available, the potential carbon stock was estimated. Social, economic and management data, including a review of existing relevant documents, key informant survey and focus group discussion were used to identify major drivers of forest carbon stock changes in CFs and added community effort and foregone cost added for REDD+. Total costs of REDD+ participation were compared with the potential carbon benefits to enable trade-offs to be identified. This study found variations in sequestration rates between CFUGs. Key variables were species type, canopy cover, elevation, age, forest scale, agriculture landholding size, disturbance levels, biomass extraction and the use of alternative energy sources. In comparing present carbon stock with the technical potential of carbon stock in forests, the study identified significant potential for REDD+ projects to increase carbon stock in CFs. On the negative side, changes in management practices added costs to communities, either through loss of forest products or through additional REDD+ activities, to the extent that the pilot REDD + projects were generally not economically beneficial for CFUGs. However, they could be made more beneficial with a reduction in the opportunity cost of community engagement (through scheduling) and the bundling of other non-carbon benefits together with carbon benefits. Outcomes could be improved through reducing ‘leakages’ resulting from a high dependency on forest resources through strategies such as the promotion of alternative energy sources (e.g. improved cooking stove and biogas)

Periodic behaviors

This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R^n. These properties - in particular the Nullstellensatz describing the Willems closure - are closely related to integral and rational points on affine algebraic varieties.Comment: 13 page

SAM-e AND ITS THERAPEUTIC PRINCIPLES

S-Adenosylmethionine (SAM-e) which is an well-known super nutrient in countries like Europe , Italy, but unfortunately it is unknown in many countries, which is mainly available as nutrient supplement, same though it is not a completely  new compound but can be found in our tissues performing trans methylation reaction(methyl donor) with  Iupac name as  [(3S)-3-amino-3-carboxypropyl]({[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl})methylsulfanium .SAM-e stands first among all other drugs in treating depression, cirrhosis, osteoarthritis, Alzheimer disease, Though it was discovered in 1952 it self but it does not came in to lime light, much more studies are to be conducted to evaluate it uses and even the way it works can be inspiring to us in preparing its derivatives. Alcoholic cirrhosis patients when given SAM-e miraculously cured just by increasing the regeneration efficacy of the liver, this article mainly discuss the uses of SAMe and the principle mechanism involved in it