On the Relative Usefulness of Fireballs

In CSL-LICS 2014, Accattoli and Dal Lago showed that there is an implementation of the ordinary (i.e. strong, pure, call-by-name) $\lambda$-calculus into models like RAM machines which is polynomial in the number of $\beta$-steps, answering a long-standing question. The key ingredient was the use of a calculus with useful sharing, a new notion whose complexity was shown to be polynomial, but whose implementation was not explored. This paper, meant to be complementary, studies useful sharing in a call-by-value scenario and from a practical point of view. We introduce the Fireball Calculus, a natural extension of call-by-value to open terms for which the problem is as hard as for the ordinary lambda-calculus. We present three results. First, we adapt the solution of Accattoli and Dal Lago, improving the meta-theory of useful sharing. Then, we refine the picture by introducing the GLAMoUr, a simple abstract machine implementing the Fireball Calculus extended with useful sharing. Its key feature is that usefulness of a step is tested---surprisingly---in constant time. Third, we provide a further optimization that leads to an implementation having only a linear overhead with respect to the number of $\beta$-steps.Comment: Technical report for the LICS 2015 submission with the same titl

(Call for Papers) Creating value through open innovation approaches : Implications for corporate sustainability and responsibility

The guest editors would welcome contributions that clearly articulate their theoretical as well as practical implications of implementing OI approaches in different contexts. Contributing authors may use different methodological approaches including quantitative or qualitative research methods to reveal new insights on open innovations and collaborative practices among stakeholders, that can ultimately add value to businesses and society. They may reveal how and to what extent OI approaches are (or are not) creating value for their business and to society, in the long run. Suitable topics of interest may include, but are not limited to, the following: ▪ OI strategies and corporate social responsibility practices; ▪ Benefits and risks of implementing OI approaches for sustainable (and social) enterprises; ▪ Impacts of OI on sustainable development and environmental, social and corporate governance performance; ▪ OI and openness cultures that could transform businesses and influence their competitiveness; ▪ Relationships between OI and sustainability-oriented approaches; ▪ Sustainable practices affected by OI approaches; ▪ Understanding the future of OI to address global challenges; ▪ Characteristics of OI approaches and their role to navigate in uncertain environments; ▪ Factors influencing OI strategies and their effects on ethical and sustainable behaviors; ▪ Ethical and responsible solutions by companies adopting OI; The call is open to all types of papers, conceptual, theoretical and empirical and to all research methods that support novel, rigorous and innovative academic analyses.peer-reviewe

Barriers to Implementing the International Integrated Reporting Framework: A Contemporary Academic Perspective

Purpose: This paper is motivated by the International Integrated Reporting Council’s (IIRC) call for feedback from all stakeholders with knowledge of the International Integrated Reporting Framework , and specifically of the enablers, incentives and barriers to its implementation. The paper synthesises insights from contemporary accounting research into integrated reporting (IR) as a general concept, and integrated reporting as espoused by the IIRC in the (IIRC, 2013). We specifically focus on possible barriers and emphasise the specific issues we feel could be rectified to advance the , along with the areas that may potentially hinder wider adoption and implementation. Design/methodology/approach: The paper draws upon and synthesises academic analysis and insights provided in the IR and academic literature as well as various directives, policy and framework pronouncements. Findings: The flexibility and lack of prescription concerning actual disclosures and metrics in the could allow it to be used for compliance, regardless of the other benefits lauded by the IIRC. Thus we see forces, both external and internal, driving adoption, with one prominent example being the European Union Directive on non-financial reporting. Because of the different ways in which IR is understood and enacted, there are numerous theoretical and empirical challenges for academics. Our paper highlights potential areas for further robust academic research, and the need to contribute to policy and practice. Research limitations/implications: The paper provides the IIRC, academics, regulators and reporting organisations with insights into current practice and the framework. We highlight the need for further development and evidence to help inform improvements both from a policy and a practice perspective. A key limitation of our work is that we draw upon a synthesis of the existing literature which is still in an early stage of development. Originality/value: The paper provides the IIRC with several insights into the current , and specifically with the enablers, incentives and barriers to its implementation. Also, it provides academic researchers with a number of important observations and an agenda upon which they can build their future research

Implementing a One Address CPU in Logisim

Most computer users have an incorrect, but useful, cognitive metaphor for computers in which the user says (or types or clicks) something and a mystical, almost intelligent or magical, behavior happens. It is not a stretch to describe computer users as believing computers follow the laws of magic, where some magic incantation is entered, and the computer responds with an expected, but magical, behavior. This magic computer does not actually exist. In reality computer are machines, and every action a computer performs reduces to a set of mechanical operations. In fact the first complete definition of a working computer was a mechanical machine designed by Charles Babbage in 1834, and would have run on steam power. Probably the biggest success of Computer Science (CS) in the 20th century was the development of abstractions that hide the mechanical nature of computers. The fact that average people use computers without ever considering that they are mechanistic is a triumph of CS designers. This purpose of this monograph is to break the abstract understanding of a computer, and to explain a computer’s behavior in completely in mechanistic terms. It will deal specifically with the Central Processing Unit (CPU) of the computer, as this is where the magic happens. All other parts of a computer can be seen as just providing information for the CPU to operate on. This monograph will deal with a specific type of CPU, a one-address CPU, and will explain this CPU using only standard gates, specifically AND, OR, NOT, NAND and XOR gates, and 4 basic Integrated Circuits (ICs), the Decoder, Multiplexer, Adder, and Flip Flop. All of these gates and components can be described as mechanical transformations of input data to output data, and the overall CPU can then be seen as a mechanical device.https://cupola.gettysburg.edu/oer/1002/thumbnail.jp

A metaobject architecture for fault-tolerant distributed systems : the FRIENDS approach

The FRIENDS system developed at LAAS-CNRS is a metalevel architecture providing libraries of metaobjects for fault tolerance, secure communication, and group-based distributed applications. The use of metaobjects provides a nice separation of concerns between mechanisms and applications. Metaobjects can be used transparently by applications and can be composed according to the needs of a given application, a given architecture, and its underlying properties. In FRIENDS, metaobjects are used recursively to add new properties to applications. They are designed using an object oriented design method and implemented on top of basic system services. This paper describes the FRIENDS software-based architecture, the object-oriented development of metaobjects, the experiments that we have done, and summarizes the advantages and drawbacks of a metaobject approach for building fault-tolerant system

Using real options to select stable Middleware-induced software architectures

The requirements that force decisions towards building distributed system architectures are usually of a non-functional nature. Scalability, openness, heterogeneity, and fault-tolerance are examples of such non-functional requirements. The current trend is to build distributed systems with middleware, which provide the application developer with primitives for managing the complexity of distribution, system resources, and for realising many of the non-functional requirements. As non-functional requirements evolve, the `coupling' between the middleware and architecture becomes the focal point for understanding the stability of the distributed software system architecture in the face of change. It is hypothesised that the choice of a stable distributed software architecture depends on the choice of the underlying middleware and its flexibility in responding to future changes in non-functional requirements. Drawing on a case study that adequately represents a medium-size component-based distributed architecture, it is reported how a likely future change in scalability could impact the architectural structure of two versions, each induced with a distinct middleware: one with CORBA and the other with J2EE. An option-based model is derived to value the flexibility of the induced-architectures and to guide the selection. The hypothesis is verified to be true for the given change. The paper concludes with some observations that could stimulate future research in the area of relating requirements to software architectures

FRIENDS - A flexible architecture for implementing fault tolerant and secure distributed applications

FRIENDS is a software-based architecture for implementing fault-tolerant and, to some extent, secure applications. This architecture is composed of sub-systems and libraries of metaobjects. Transparency and separation of concerns is provided not only to the application programmer but also to the programmers implementing metaobjects for fault tolerance, secure communication and distribution. Common services required for implementing metaobjects are provided by the sub-systems. Metaobjects are implemented using object-oriented techniques and can be reused and customised according to the application needs, the operational environment and its related fault assumptions. Flexibility is increased by a recursive use of metaobjects. Examples and experiments are also described

The Economic Benefits of Cleaning Up the Chesapeake

Information on the economic benefits of environmental improvement is an important consideration for anyone (firms, organizations, government agencies, and individuals) concerned about the cost-effectiveness of changes in management designed to achieve that improvement. In the case of the Chesapeake Bay TMDL (Total Maximum Daily Load of nitrogen, phosphorus, and sediment), these benefits would accrue due to improvements in the health, and therefore productivity, of land and water in the watershed. These productivity changes occur both due to the outcomes of the TMDL and state implementation plans, also known as a "Chesapeake Clean Water Blueprint" itself (i.e., cleaner water in the Bay) as well as a result of the measures taken to achieve those outcomes that have their own beneficial side effects. All such changes are then translated into dollar values for various ecosystem services, including water supply, food production, recreation, aesthetics, and others. By these measures, the total economic benefit of the Chesapeake Clean Water Blueprint is estimated at $22.5 billion per year (in 2013 dollars), as measured as the improvement over current conditions, or at$28.2 billion per year (in 2013 dollars), as measured as the difference between the Clean Water Blueprint and a business-as-usual scenario. (Due to lag times—it takes some time for changes in land management to result in improvements in water quality, the full measure of these benefits would begin to accrue sometime after full implementation of the Blueprint.) These considerable benefits should be considered alongside the costs and other economic aspects of implementing the Chesapeake Clean Water Blueprint