scholarly journals Extending Non-Termination Proof Techniques to Asynchronously Communicating Concurrent Programs

10.29007/c7v2 ◽  
2018 ◽  
Author(s):  
Matthias Kuntz ◽  
Stefan Leue ◽  
Christoph Scheben
Keyword(s):  
Case Studies ◽  
Data Structures ◽  
Theorem Proving ◽  
Asynchronous Communication ◽  
Control Flow ◽  
Concurrent Programs ◽  
Prototype Tool ◽  
Proof Techniques ◽  
High Level ◽  
Termination Proofs

Currently, there are no approaches known that allow for non-termination proofs of concurrent programs which account for asynchronous communication via FIFO message queues. Those programs may be written in high-level languages such as Java or Promela. We present a first approach to prove non-termination for such programs. In addition to integers, the programs that we consider may contain queues as data structures. We present a representation of queues and the operations on them in the domain of integers, and generate invariants that help us prove non-termination of selected control flow loops using a theorem proving approach. We illustrate this approach by applying a prototype tool implementation to a number of case studies.

scholarly journals Critical Issues and Opportunities for Producing Biomethane in Italy

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2431
Author(s):  
Roberto Murano ◽  
Natascia Maisano ◽  
Roberta Selvaggi ◽  
Gioacchino Pappalardo ◽  
Biagio Pecorino
Keyword(s):  
Anaerobic Digestion ◽  
Case Studies ◽  
Regulatory Framework ◽  
Biofuel Production ◽  
Political Incentives ◽  
Critical Issues ◽  
Biogas Plants ◽  
High Level ◽  
By Products ◽  
Lack Of Knowledge

Nowadays, most Italian biogas produces electricity even though recent political incentives are promoting biomethane from biogas by “upgrading” it. The aim of this paper is to focus on the regulatory framework for producing biomethane from new or already-existent anaerobic digestion plants. The complexity and lack of knowledge of the regulations on biofuel production and of anaerobic digested biomethane from waste and by-products create difficulties of both interpretation and application. Consequently, the aim of this paper is to analyze the regulations for producing biomethane, underline the critical issues and opportunities, and evaluate whether an electrical plant built in the last 10 years in Italy can really be converted to a biomethane plant, thereby lengthening its lifespan. Three case studies were considered to look more closely into applying Italian biomethane incentives and to simulate the types of incentivization in agriculture with examples based on certain fuel types typical of a standard biomethane plant of 500 standard cubic meter per hour. All the considered cases put in evidence that biomethane is a further opportunity for development with a high level of efficiency for all biogas producers, especially for many biogas plants whose incentivization period is about to finish.

Immersion, interactivity and three-dimensionality: virtual reality documentation of media art installations

2021 ◽  
Author(s):  
Kira A. Brown
Keyword(s):  
Virtual Reality ◽  
Case Studies ◽  
Three Dimensional ◽  
Research Paper ◽  
Sensory Experience ◽  
Three Dimensions ◽  
Media Art ◽  
Essential Information ◽  
Art Installation ◽  
High Level

This research paper explores the possibilities for virtual reality (VR) documentation of media art installations. Based on an analysis of the characteristics of media art, and a survey of current documentation strategies, this paper investigates the viability of three-dimensional documentation. Four cross-disciplinary case studies are presented and analysed to demonstrate that VR documentation provides an immersive and richer reconstruction of a media art installation in three dimensions. In addition, the interactive components can be simulated within the VR environment, offering the possibility for curators and visitors to virtually re-experience the artwork. The case studies show that, although the creation of VR documentation can be costly and time-consuming, and currently requires a high-level of expertise, it can be a useful addition to established documentation strategies by providing essential information about the visual aspects of the artwork, its environment and the user’s multi-sensory experience.

Doing the strategy hard yards

2019 ◽  
Vol 35 (1) ◽  
pp. 19-21
Keyword(s):  
Case Studies ◽  
Design Methodology ◽  
Reading Time ◽  
Cutting Edge ◽  
The Internet ◽  
Content Type ◽  
Successful Strategy ◽  
Pertinent Information ◽  
High Level ◽  
Practical Implications

Purpose This paper reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings If you search images of the word “strategy” on the internet, three of the first seven images to appear on Google (other search engines are available) include chess pieces, while two of the top ten hits involve light bulbs. Aside from the obvious conclusions that any strategic discussion should either involve chess grand masters or well-lit rooms, it is clear that most people assume winning games with lots of moves are possible is the key to a successful strategy. But is this a valid analogy, even at a high level? Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

scholarly journals Buffer Placement and Sizing for High-Performance Dataflow Circuits

2022 ◽  
Vol 15 (1) ◽  
pp. 1-32
Author(s):  
Lana Josipović ◽  
Shabnam Sheikhha ◽  
Andrea Guerrieri ◽  
Paolo Ienne ◽  
Jordi Cortadella
Keyword(s):  
Performance Optimization ◽  
Optimization Model ◽  
High Performance ◽  
Control Flow ◽  
High Level Synthesis ◽  
Software Applications ◽  
Marked Graphs ◽  
Variable Latency ◽  
High Level ◽  
Strong Contrast

Commercial high-level synthesis tools typically produce statically scheduled circuits. Yet, effective C-to-circuit conversion of arbitrary software applications calls for dataflow circuits, as they can handle efficiently variable latencies (e.g., caches), unpredictable memory dependencies, and irregular control flow. Dataflow circuits exhibit an unconventional property: registers (usually referred to as “buffers”) can be placed anywhere in the circuit without changing its semantics, in strong contrast to what happens in traditional datapaths. Yet, although functionally irrelevant, this placement has a significant impact on the circuit’s timing and throughput. In this work, we show how to strategically place buffers into a dataflow circuit to optimize its performance. Our approach extracts a set of choice-free critical loops from arbitrary dataflow circuits and relies on the theory of marked graphs to optimize the buffer placement and sizing. Our performance optimization model supports important high-level synthesis features such as pipelined computational units, units with variable latency and throughput, and if-conversion. We demonstrate the performance benefits of our approach on a set of dataflow circuits obtained from imperative code.

scholarly journals Drug shops for stronger health systems: learning from initiatives in six LMICs

2021 ◽  
Vol 14 (S1) ◽  
Author(s):  
Geetanjali Lamba ◽  
Zubin Cyrus Shroff ◽  
Zaheer-Ud-Din Babar ◽  
Abdul Ghaffar
Keyword(s):  
Case Studies ◽  
Health Systems ◽  
Access To Medicines ◽  
Health System Strengthening ◽  
Essential Medicines ◽  
Middle Income ◽  
Positive Attitudes ◽  
Drug Shops ◽  
Client Pressure ◽  
High Level

Abstract Background Private sector retail pharmacies, or drug shops, play an important role in access to essential medicines and services in low-and-middle-income countries. Recognising that they have the potential to contribute to health system strengthening efforts, many recent initiatives to engage with drug shops have been launched. These include initiatives that focus on changes in policy, regulation and training. However, the specific factors that influence their success remain poorly understood. Seven country case studies supported under the Alliance’s programme of work ‘Strengthening health systems: the role of drug shops’ help to explore this issue. Methods Country case studies from the above programme of research from Bangladesh, Indonesia, Myanmar, Nigeria, Tanzania and Zambia were used as the main sources of data for this paper. A modified version of Bigdeli et al.’s Access to Medicines framework was applied within a partially grounded approach to analyze each country case study and compare themes between countries. Results Many factors may help initiatives targeting drug shops successfully achieve their intended outcomes. At the micro level, these include community demand for drug shops and a positive relationship between drug shops and their clients. At the meso level, facilitators of initiative success include training and positive attitudes from drug shops towards the initiative. Barriers include client pressure, procurement challenges and financial and administrative costs associated with initiatives. At the macro level, collaboration between stakeholders, high-level buy in and supervision, monitoring and regulation may influence initiative success. These factors are inter-dependent and interact with each other in a dynamic way. Conclusions Using a framework approach, these country case studies demonstrate common factors that influence how drug shops can strengthen health systems. These learnings can help inform the design and implementation of successful strategies to engage drug shops towards sustainable systems change.

scholarly journals TaDA Live: Compositional Reasoning for Termination of Fine-grained Concurrent Programs

2021 ◽  
Vol 43 (4) ◽  
pp. 1-134
Author(s):  
Emanuele D’Osualdo ◽  
Julian Sutherland ◽  
Azadeh Farzan ◽  
Philippa Gardner
Keyword(s):  
Case Studies ◽  
Separation Logic ◽  
Proof System ◽  
Concurrent Programs ◽  
Semantic Model ◽  
Compositional Reasoning ◽  
Fine Grained ◽  
Fundamental Innovation ◽  
Concurrent Separation Logic

We present TaDA Live, a concurrent separation logic for reasoning compositionally about the termination of blocking fine-grained concurrent programs. The crucial challenge is how to deal with abstract atomic blocking : that is, abstract atomic operations that have blocking behaviour arising from busy-waiting patterns as found in, for example, fine-grained spin locks. Our fundamental innovation is with the design of abstract specifications that capture this blocking behaviour as liveness assumptions on the environment. We design a logic that can reason about the termination of clients that use such operations without breaking their abstraction boundaries, and the correctness of the implementations of the operations with respect to their abstract specifications. We introduce a novel semantic model using layered subjective obligations to express liveness invariants and a proof system that is sound with respect to the model. The subtlety of our specifications and reasoning is illustrated using several case studies.

Efficient Implementation of Application-Aware Spinlock Control in MPSoCs

2013 ◽  
Vol 4 (1) ◽  
pp. 64-84 ◽  
Author(s):  
Diandian Zhang ◽  
Li Lu ◽  
Jeronimo Castrillon ◽  
Torsten Kempf ◽  
Gerd Ascheid ◽  
...  
Keyword(s):  
High Efficiency ◽  
A Priori ◽  
Control Flow ◽  
Specific Information ◽  
Centralized Control ◽  
Shared Resources ◽  
Complete Control ◽  
Application Aware ◽  
High Level ◽  
Application Specific

Spinlocks are a common technique in Multi-Processor Systems-on-Chip (MPSoCs) to protect shared resources and prevent data corruption. Without a priori application knowledge, the control of spinlocks is often highly random which can degrade the system performance significantly. To improve this, a centralized control mechanism for spinlocks is proposed in this paper, which utilizes application-specific information during spinlock control. The complete control flow is presented, which starts from integrating high-level user-defined information down to a low-level realization of the control. An Application-Specific Instruction-set Processor (ASIP) called OSIP, which was originally designed for task scheduling and mapping, is extended to support this mechanism. The case studies demonstrate the high efficiency of the proposed approach and at the same time highlight the efficiency and flexibility advantages of using an ASIP as the system controller in MPSoCs.

Agent-Based Negotiation in E-Marketing

2005 ◽  
pp. 88-92
Author(s):  
V. K. Murthy ◽  
E. V. Krishnamurthy
Keyword(s):  
Data Structures ◽  
Agent Based ◽  
Object Based ◽  
Level Data ◽  
Rule System ◽  
High Level ◽  
Two Stages ◽  
Active Objects

This article describes in brief the design of agent-based negotiation system in e-marketing. Such a negotiation scheme requires the construction of a suitable set of rules, called protocol, among the participating agents. The construction of the protocol is carried out in two stages: first expressing a program into an object-based rule system and then converting the rule applications into a set of agent-based transactions on a database of active objects represented using high-level data structures.

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