A Machine-Checked, Type-Safe Model of Java Concurrency : Language, Virtual Machine, Memory Model, and Verified Compiler

The Java programming language provides safety and security guarantees such as type safety and its security architecture. They distinguish it from other mainstream programming languages like C and C++. In this work, we develop a machine-checked model of concurrent Java and the Java memory model and investigate the impact of concurrency on these guarantees. From the formal model, we automatically obtain an executable verified compiler to bytecode and a validated virtual machine

CORPORATE SOCIAL RESPONSIBILITY IN ROMANIA

The purpose of this paper is to identify the main opportunities and limitations of corporate social responsibility (CSR). The survey was defined with the aim to involve the highest possible number of relevant CSR topics and give the issue a more wholesome perspective. It provides a basis for further comprehension and deeper analyses of specific CSR areas. The conditions determining the success of CSR in Romania have been defined in the paper on the basis of the previously cumulative knowledge as well as the results of various researches. This paper provides knowledge which may be useful in the programs promoting CSR.Corporate social responsibility, Supportive policies, Romania

Computer Aided Verification

The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency

Computer Aided Verification

The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency

RISK MANAGEMENT IN LIQUEFIED NATURAL GAS PORTS AND MARINE TERMINALS SUPPLY CHAINS

Due to its environmental attributes, Liquefied Natural Gas (LNG) as a clean fossil fuel source of energy has witnessed a steady increase in demand worldwide over the last decade. This increase is mainly attributed to higher demand from the power generation sector as well as from domestic and industrial usages .This growing role of LNG among competing energy sources has raised concerns over the safety and security of the LNG chain of production, transport and distribution and its related infrastructure. Within this context, LNG ports and marine terminals, being strategically located at the midstream of the LNG Supply Chain (SC), are further exposed to safety and security risks and represent credible targets for international terrorism. Ensuring uninterrupted, robust and resilient LNG SC requires first, adequate management of safety and security risks in LNG ports and marine terminals. While each discipline of risk, be it safety or security, has received significant attention both in theory and practice, less attention was given to the management of interfaces and shared impacts among LNG Ports safety and security risks which led to the existence of gaps in the risk management (RM) systems of LNG ports and may represent a major source of risk and disruption to LNG ports. This research addresses such gaps which are poorly addressed in the current literature and proposes a holistic and integrated approach to the issues of LNG ports safety and security risks assessment and management. It also aims to model safety and security RM from a SC perspective and examines the relationships and shared impacts among LNG ports safety and security risks in the present context of increased LNG demand worldwide in the post 9/11 terrorism era. A unique combination of multiple methods within port and maritime SCs, including a Delphi survey, quantitative survey, Soft Systems Methodology (SSM) and a focus group expert consultation, is applied to reformulate the prevailing RM approach marked by dichotomy and a disciplinary silo and to propose a more enhanced and holistic approach to safety and security RM. The results of the study confirm that an integrated and holistic approach to the issue of RM in LNG ports and marine terminals is necessary to cost-effectively address safety and security risks and ensure reliable and resilient LNG SCs. Furthermore, a practical framework, in the form of a conceptual model, for LNG ports risks and emergencies management is proposed which integrates all facets of safety and security risks and emergencies management, including risk prevention, mitigation, emergency planning and response and port business continuity. The proposed conceptual model shows how the proposed RM approach can be practically applied in the context of LNG ports in the Middle East and North Africa (MENA) region, as well as in any LNG port worldwide which lacks an integrated approach to risks and emergencies management.Sel

The productivity of polymorphic stream equations and the composition of circular traversals

This thesis has two independent parts concerned with different aspects of laziness in functional programs. The first part is a theoretical study of productivity for very restricted stream programs. In the second part we define a programming abstraction over a recursive pattern for defining circular traversals modularly. Productivity is in general undecidable. By restricting ourselves to mutually recursive polymorphic stream equations having only three basic operations, namely "head", "tail", and "cons", we aim to prove interesting properties about productivity. Still undecidable for this restricted class of programs, productivity of polymorphic stream functions is equivalent to the totality of their indexing function, which characterise their behaviour in terms of operations on indices. We prove that our equations generate all possible polymorphic stream functions, and therefore their indexing functions are all the computable functions, whose totality problem is indeed undecidable. We then further restrict our language by reducing the numbers of equations and parameters, but despite those constraints the equations retain their expressiveness. In the end we establish that even two non-mutually recursive equations on unary stream functions are undecidable with complexity $Π_2^0$. However, the productivity of a single unary equation is decidable. Circular traversals have been used in the eighties as an optimisation to combine multiple traversals in a single traversal. In particular they provide more opportunities for applying deforestation techniques since it is the case that an intermediate datastructure can only be eliminated if it is consumed only once. Another use of circular programs is in the implementation of attribute grammars in lazy functional languages. There is a systematic transformation to define a circular traversal equivalent to multiple traversals. Programming with this technique is not modular since the individual traversals are merged together. Some tools exist to transform programs automatically and attribute grammars have been suggested as a way to describe the circular traversals modularly. Going to the root of the problem, we identify a recursive pattern that allows us to define circular programs modularly in a functional style. We give two successive implementations, the first one is based on algebras and has limited scope: not all circular traversals can be defined this way. We show that the recursive scheme underlying attribute grammars computation rules is essential to combine circular programs. We implement a generic recursive operation on a novel attribute grammar abstraction, using containers as a parametric generic representation of recursive datatypes. The abstraction makes attribute grammars first-class objects. Such a strongly typed implementation is novel and make it possible to implement a high level embedded language for defining attribute grammars, with many interesting new features promoting modularity