Efficient environment management for distributed simulation of large‐scale situated multi‐agent systems

Multi‐agent systems have been proven very effective for the modelling and simulation (M&S) of complex systems like those related to biology, engineering, social sciences and so forth. The intrinsic spatial character of many such systems leads to the definition of a situated agent. A situated agent owns spatial coordinates and acts and interacts with its peers in a hosting territory. In the context of parallel/distributed simulation of situated agent models, the territory represents a huge shared variable that requires careful handling. Frequent access by agents to territory information easily becomes a bottleneck degrading system performance and scalability. This paper proposes an original approach to modelling and distributed simulation of large‐scale situated multi‐agent systems. Time management is exploited for resolving conflicts and achieving data consistency while accessing the environment. The approach allows a simplification of the M&S tasks by making the modeller unaware of distribution concerns while ensuring the achievement of good scalability and performance during the distributed simulation. Practical aspects of the approach are demonstrated through some modelling examples based on Tileworld. Copyright © 2014 John Wiley & Sons, Ltd.     

Mirror‐based reflection in AmbientTalk

This paper introduces a novel mechanism to perform intercession (a form of reflection) in an object‐oriented programming language with the goal of making the language extensible from within itself. The proposed mechanism builds upon a mirror‐based architecture, leading to a reusable reflective application programming interface that cleanly separates interface from implementation details. However, support for intercession has been limited in contemporary mirror‐based architectures. This is due to the fact that mirror‐based architectures only support reflection explicitly triggered by metaprograms, while intercession requires reflection implicitly triggered by the language interpreter. This work reconciles mirrors with intercession in the context of an actor‐based, object‐oriented programming language named AmbientTalk. We describe this language's full reflective architecture, highlighting its novel mirror‐based approach to reflect upon both objects and concurrently executing actors. Subsequently, we apply AmbientTalk's mirror‐based reflection to implement two language features, which crucially depend on intercession, to wit future‐type message passing and leased object references. Copyright © 2008 John Wiley & Sons, Ltd.     

What Do We Know About Chain Actors’ Evaluation of New Food Technologies? A Systematic Review of Consumer and Farmer Studies

New food technologies, such as genetic modification, food fortification, and processing technologies, are of growing interest for future food security and safety. For ensuring successful implementation of such technologies, consumers and other food supply chain actors should embrace them. We present a systematic review to identify and compare key factors of supply chain actors’ evaluation of new food technologies. Evaluation encompasses indicators such as likelihood or intention to perform a behavior, perceived benefits/risks, willingness to pay, acceptance/adoption, and attitudes. Results from 183 studies showed several imbalances in research. Although studies mainly focused on (1) genetically modified foods, (2) by consumers, (3) in developed countries, only very few studies have targeted other food technologies, other supply chain actors such as farmers (13 studies) or processors (two studies), or developing countries (43 studies). With respect to consumers’ evaluation, key determinants were trust in institutions, information assessment, perceived risks and benefits, attitudes toward the product or technology, perceived behavioral control, quality perception of the product, and impact on health. Farmers’ evaluation of new food technologies was explained by the factors of perceived risk and benefits and of actual source of information. For the few processor evaluation studies, no convergence of factors could be reached. This systematic review contributes to a better understanding of consumers’ and farmers’ evaluation behavior and opens up avenues for future research on supply chain actors’ food technology evaluations. The differences in the conceptualization and measurement of extracted factors demonstrate the need for standardized approaches in future studies.     

DynamiCS: An Actor-Based Framework for Negotiating Mobile Agents

In this article, a framework to integrate negotiation capabilities—particularly, components implementing a negotiation strategy—into mobile agents is described. This approach is conceptually based on the notion of an actor system which decomposes an application component into autonomously executing subcomponents cooperating with each other. Technically, the framework is based on a plug-in mechanism enabling a dynamic composition of negotiating agents. Additionally, this contribution describes how interaction-oriented rule mechanisms can be deployed to control the behavior of strategy actors.     

活性氧化镁降氟的试验研究

以活性氧化镁作为吸附剂进行了降氟试验,探讨了该方法的适用水质,并对影响活性氧化镁降氟的相关因素进行了研究。     

Understanding Computer-based “Informated” Environments

The paper introduces the concept of Computer-based Informated Environments (CBIEs) to indicate an emergent form of work organisation facilitated by information technology. It first addresses the problem of inconsistent meanings of the informate concept in the literature, and it then focuses on those cases which, it is believed, show conditions of plausible informated environments. Finally, the paper looks at those factors that when found together contribute to building a CBIE. It makes reference to CBIEs as workplaces that comprise a non-technocentric perspective and questions whether CBIEs truly represent an anthropocentric route of information technology.     

ICT Governance: A Reference Framework

This article deals with information and communication technology (ICT) governance, a topic that has been discussed in the literature over the last 20 years. In order to offer a conceptualized view of the ICT governance models adopted by companies, a theoretical framework has been developed. A review of the available literature dealing with ICT governance, as well as a critical analysis of 27 case studies, was carried out, with the aim of highlighting the variables of the proposed framework.     

羊奶干酪品质的影响因素研究进展

叙述了关于干酪生产过程中原料乳、化学处理、发酵剂、温度等因素对干酪品质影响的作用机理。同时也对干酪成熟过程中这些因素对干酪品质的影响进行了分析。     

The trust paradox in food labelling: An exploration of consumers’ perceptions of certified vegetables

Trust is a key consideration when purchasing and consuming foods. Food certification is an aspect of food labelling, and is used by policymakers and marketers to increase consumers’ trust in food. Equally important, consumers’ trust in the food system and actors in its supply chain influences their overall perceptions of food safety, and which foods they choose and consume. However, the interaction between consumers’ trust in food chain actors, and consumers’ trust in food certification, has yet to be explored. This study addresses this gap by examining consumers’ perception of food certification, two examples of which are organic, and Good Agricultural Practices (GAP), and consumers’ trust in food chain actors. In doing so, we extend the literature on trust in food labelling through the inclusion of social-institutional factors in order to understand variations in trust in food. Data were collected via in-depth, semi-structured interviews and the study employed the social theory of trust as a theoretical framework to guide the analysis. Results show that organic, and GAP food certifications are perceived as a representation of the entire food system. Therefore, its trustworthiness is dependent on consumer perceptions of the food system’s capacity to guarantee organic standards along the entire food chain, which is a manifestation of abstract trust. This study contributes to the trust in food literature by showing that interpersonal trust in food actors, such as retailers or growers, can compensate for a lack of abstract trust in certification. Interpersonal trust is predominantly used to guide consumers’ food choices, particularly in the case where abstract trust in the wider institutional system’s integrity and competence is low.