Generation-free Agent-based Evolutionary Computing

AbstractMetaheuristics resulting from the hybridization of multi-agent systems with evolutionary computing are efficient in many optimization problems. Evolutionary multi-agent systems (EMAS) are more similar to biological evolution than classical evolutionary algorithms. However, technological limitations prevented the use of fully asynchronous agents in previous EMAS implementations. In this paper we present a new algorithm for agent-based evolutionary computations. The individuals are represented as fully autonomous and asynchronous agents. Evolutionary operations are performed continuously and no artificial generations need to be distinguished. Our results show that such asynchronous evolutionary operators and the resulting absence of explicit generations lead to significantly better results. An efficient implementation of this algorithm was possible through the use of Erlang technology, which natively supports lightweight processes and asynchronous communication

Acute: high-level programming language design for distributed computation

Existing languages provide good support for typeful programming of standalone programs. In a distributed system, however, there may be interaction between multiple instances of many distinct programs, sharing some (but not necessarily all) of their module structure, and with some instances rebuilt with new versions of certain modules as time goes on. In this paper we discuss programming language support for such systems, focussing on their typing and naming issues. We describe an experimental language, Acute, which extends an ML core to support distributed development, deployment, and execution, allowing type-safe interaction between separately-built programs. The main features are: (1) type-safe marshalling of arbitrary values; (2) type names that are generated (freshly and by hashing) to ensure that type equality tests suffice to protect the invariants of abstract types, across the entire distributed system; (3) expression-level names generated to ensure that name equality tests suffice for type-safety of associated values, e.g. values carried on named channels; (4) controlled dynamic rebinding of marshalled values to local resources; and (5) thunkification of threads and mutexes to support computation mobility. These features are a large part of what is needed for typeful distributed programming. They are a relatively lightweight extension of ML, should be efficiently implementable, and are expressive enough to enable a wide variety of distributed infrastructure layers to be written as simple library code above the byte-string network and persistent store APIs. This disentangles the language runtime from communication intricacies. This paper highlights the main design choices in Acute. It is supported by a full language definition (of typing, compilation, and operational semantics), by a prototype implementation, and by example distribution libraries

Proceedings of International Workshop "Global Computing: Programming Environments, Languages, Security and Analysis of Systems"

According to the IST/ FET proactive initiative on GLOBAL COMPUTING, the goal is to obtain techniques (models, frameworks, methods, algorithms) for constructing systems that are flexible, dependable, secure, robust and efficient. The dominant concerns are not those of representing and manipulating data efficiently but rather those of handling the co-ordination and interaction, security, reliability, robustness, failure modes, and control of risk of the entities in the system and the overall design, description and performance of the system itself. Completely different paradigms of computer science may have to be developed to tackle these issues effectively. The research should concentrate on systems having the following characteristics: • The systems are composed of autonomous computational entities where activity is not centrally controlled, either because global control is impossible or impractical, or because the entities are created or controlled by different owners. • The computational entities are mobile, due to the movement of the physical platforms or by movement of the entity from one platform to another. • The configuration varies over time. For instance, the system is open to the introduction of new computational entities and likewise their deletion. The behaviour of the entities may vary over time. • The systems operate with incomplete information about the environment. For instance, information becomes rapidly out of date and mobility requires information about the environment to be discovered. The ultimate goal of the research action is to provide a solid scientific foundation for the design of such systems, and to lay the groundwork for achieving effective principles for building and analysing such systems. This workshop covers the aspects related to languages and programming environments as well as analysis of systems and resources involving 9 projects (AGILE , DART, DEGAS , MIKADO, MRG, MYTHS, PEPITO, PROFUNDIS, SECURE) out of the 13 founded under the initiative. After an year from the start of the projects, the goal of the workshop is to fix the state of the art on the topics covered by the two clusters related to programming environments and analysis of systems as well as to devise strategies and new ideas to profitably continue the research effort towards the overall objective of the initiative. We acknowledge the Dipartimento di Informatica and Tlc of the University of Trento, the Comune di Rovereto, the project DEGAS for partially funding the event and the Events and Meetings Office of the University of Trento for the valuable collaboration

A mobile agent approach for distributed train control and monitoring system.

by Wong, Wan-Lung.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 88-92).Abstract also in Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Mobile Agent Systems --- p.1Chapter 1.2 --- Distributed Control Systems --- p.2Chapter 1.3 --- Motivation of the Dissertation --- p.3Chapter 1.4 --- Related Work --- p.3Chapter 1.5 --- Overview of the Dissertation --- p.5Chapter 2 --- Mobile Agents --- p.6Chapter 2.1 --- Definition of an Agent --- p.7Chapter 2.1.1 --- A Weak Notion of Agents --- p.8Chapter 2.1.2 --- A Stronger Notion of Agents --- p.9Chapter 2.1.3 --- Other Attributes of Agents --- p.9Chapter 2.2 --- Characteristics of Mobile Agents --- p.10Chapter 2.3 --- Programming Languages for Mobile Agents --- p.11Chapter 3 --- A Mobile Agent Framework --- p.16Chapter 3.1 --- The Framework --- p.16Chapter 3.1.1 --- Agent Operations --- p.19Chapter 3.1.2 --- Agent Life Cycle --- p.23Chapter 3.1.3 --- Agent Migration Server --- p.26Chapter 3.1.4 --- Communication Server --- p.28Chapter 3.1.5 --- Facilitator --- p.30Chapter 3.2 --- April as a Mobile Agent Language --- p.30Chapter 4 --- An Agent Based Distributed Train Control and Monitoring Sys- tem --- p.32Chapter 4.1 --- Introduction to DiTCAMS --- p.33Chapter 4.2 --- Terminology in DiTCAMS --- p.34Chapter 4.3 --- Architecture of DiTCAMS --- p.34Chapter 4.3.1 --- Active Agents --- p.36Chapter 4.3.2 --- Passive Agents --- p.38Chapter 4.4 --- Agent Collaborations --- p.41Chapter 4.4.1 --- Track Resource Allocation --- p.41Chapter 4.4.2 --- Sensor Triggering --- p.42Chapter 4.4.3 --- Hardware Control --- p.42Chapter 4.4.4 --- Train Migration --- p.42Chapter 4.5 --- Other Implementation Issues --- p.46Chapter 4.5.1 --- Track Resource Management --- p.47Chapter 4.5.2 --- Railway Topology Encoding --- p.50Chapter 4.5.3 --- Train Location Determination --- p.54Chapter 4.5.4 --- Train Speed Control --- p.62Chapter 4.5.5 --- Collision Prevention and Recovery --- p.64Chapter 4.5.6 --- Improving Efficiency of April for Real-time Execution --- p.65Chapter 5 --- Discussions --- p.72Chapter 5.1 --- On Enabling Mobile Agents --- p.72Chapter 5.2 --- Cost in Achieving Mobile Agents --- p.74Chapter 5.3 --- On Using April as a Mobile Agent Language --- p.75Chapter 5.4 --- History of DiTCAMS --- p.76Chapter 6 --- Concluding Remarks --- p.79Chapter 6.1 --- Contributions --- p.79Chapter 6.2 --- Limitations --- p.80Chapter 6.3 --- Future Work --- p.81Chapter A --- Hardware Components --- p.83Chapter B --- A Concurrent Administrator Based Train System Using C --- p.85Bibliography --- p.8

Generic Distribution Support for Programming Systems

This dissertation provides constructive proof, through the implementation of a middleware, that distribution transparency is practical, generic, and extensible. Fault tolerant distributed services can be developed by using the failure detection abilities of the middleware. By generic we mean that the middleware can be used for many different programming languages and paradigms. Distribution for each kind of language entity is done in terms of consistency protocols, which guarantee that the semantics of the entities are preserved in a distributed setting. The middleware allows new consistency protocols to be added easily. The efficiency of the middleware and the ease of integration are shown by coupling the middleware to a programming system, which encompasses the object oriented, the functional, and the concurrent-declarative programming paradigms. Our measurements show that the distribution middleware is competitive with the most popular distributed programming systems (JavaRMI, .NET, IBM CORBA)

ENABLING MOBILE DEVICES TO HOST CONSUMERS AND PROVIDERS OF RESTFUL WEB SERVICES

The strong growth in the use of mobile devices such as smartphones and tablets in Enterprise Information Systems has led to growing research in the area of mobile Web services. Web services are applications that are developed based on network standards such as Services Oriented Architecture and Representational State Transfer (REST). The mobile research community mostly focused on facilitating the mobile devices as client consumers especially in heterogeneous Web services. However, with the advancement in mobile device capabilities in terms of processing power and storage, this thesis seeks to utilize these devices as hosts of REST Web services. In order to host services on mobile devices, some key challenges have to be addressed. Since data and services accessibility is facilitated by the mobile devices which communicate via unstable wireless networks, the challenges of network latency and synchronization of data (i.e. the Web resources) among the mobile participants must be addressed. To address these challenges, this thesis proposes a cloud-based middleware that enables reliable communication between the mobile hosts in unreliable Wi-Fi networks. The middleware employs techniques such as message routing and Web resources state changes detection in order to push data to the mobile participants in real time. Additionally, to ensure high availability of data, the proposed middleware has a cache component which stores the replicas of the mobile hosts’ Web resources. As a result, in case a mobile host is disconnected, the Web resources of the host can be accessed on the middleware. The key contributions of this thesis are the identification of mobile devices as hosts of RESTful Web services and the implementation of middleware frameworks that support mobile communication in unreliable networks