88 research outputs found
Information management in an integrated space telerobot
The in-orbit operations, like space structures inspection, servicing and repairing, is expected to be one of the most significant technological area for application and development of Robotics and Automation in Space Station environment. The Italian National Space Plan (PSN) has started up its strategic programme SPIDER (Space Inspection Device for Extravehicular Repairs), which is scheduled in three phases, with the final goal of performing docking and precision repairing in the Space Station environment. SPIDER system is an autonomous integrated space robot, using mature Artificial Intelligence tools and technics for its operational control. The preliminary results of a study on the information architecture of the spacecraft are described
Planetary stations and Abyssal Benthic Laboratories: An overview of parallel approaches for long-term investigation in extreme environments
In spite of the apparent great differences between deep ocean and space environment, significant similarities can be recognized when considering the possible solutions and technologies enabling the development of remote automatic stations supporting the execution of scientific activities. In this sense it is believed that mutual benefits shall be derived from the exchange of experiences and results between people and organizations involved in research and engineering activities for hostile environments, such as space, deep sea, and polar areas. A significant example of possible technology transfer and common systematic approach is given, which describes in some detail how the solutions and the enabling technologies identified for an Abyssal Benthic Laboratory can be applied for the case of a lunar or planetary station
RTZen: Highly Predictable, Real-Time Java Middleware for Distributed and Embedded Systems
Distributed real-time and embedded (DRE) applications possess stringent quality of service (QoS) requirements, such as predictability, latency, and throughput constraints. Real-Time CORBA, an open middleware standard, allows DRE applications to allocate, schedule, and control resources to ensure predictable end-to-end QoS. The Real-Time Specification for Java (RTSJ) has been developed to provide extensions to Java so that it can be used for real-time systems, in order to bring Java's advantages, such as portability and ease of use, to real-time applications.In this paper, we describe RTZen, an implementation of a Real-Time CORBA Object Request Broker (ORB), designed to comply with the restrictions imposed by RTSJ. RTZen is designed to eliminate the unpredictability caused by garbage collection and improper support for thread scheduling through the use of appropriate data structures, threading models, and memory scopes. RTZen's architecture is also designed to hide the complexities of RTSJ related to distributed programming from the application developer. Empirical results show that RTZen is highly predictable and has acceptable performance. RTZen therefore demonstrates that Real-Time CORBA middleware implemented in real-time Java can meet stringent QoS requirements of DRE applications, while supporting safer, easier, cheaper, and faster development in real-time Java
Incorporating temporal-bounded CBR techniques in real-time agents
Nowadays, MAS paradigm tries to move Computation to a new level of abstraction: Computation as interaction,
where large complex systems are seen in terms of the services they offer, and consequently in
terms of the entities or agents providing or consuming services. However, MAS technology is found to
be lacking in some critical environments as real-time environments. An interaction-based vision of a
real-time system involves the purchase of a responsibility by any entity or agent for the accomplishment
of a required service under possibly hard or soft temporal conditions. This vision notably increases the
complexity of these kinds of systems. The main problem in the architecture development of agents in
real-time environments is with the deliberation process where it is difficult to integrate complex
bounded deliberative processes for decision-making in a simple and efficient way. According to this, this
work presents a temporal-bounded deliberative case-based behaviour as an anytime solution. More specifically,
the work proposes a new temporal-bounded CBR algorithm which facilitates deliberative processes
for agents in real-time environments, which need both real-time and deliberative capabilities.
The paper presents too an application example for the automated management simulation of internal
and external mail in a department plant. This example has allowed to evaluate the proposal investigating
the performance of the system and the temporal-bounded deliberative case-based behaviour.
2010 Elsevier Ltd. All rights reserved.This work is supported by TIN2006-14630-C03-01 projects of the Spanish government, GVPRE/2008/070 project, FEDER funds and CONSOLIDER-INGENIO 2010 under Grant CSD2007-00022.Navarro Llácer, M.; Heras Barberá, SM.; Julian Inglada, VJ.; Botti Navarro, VJ. (2011). Incorporating temporal-bounded CBR techniques in real-time agents. Expert Systems with Applications. 38(3):2783-2796. https://doi.org/10.1016/j.eswa.2010.08.070S2783279638
Rigorous Analysis of Available Data from Cerro Prieto and Las Tres Virgenes Geothermal Fields with Calculations for Expanded Electricity Generation
Global Dynamics of Three Anticompetitive Systems of Difference Equations in the Plane
We investigate the global dynamics of several anticompetitive systems of rational difference equations which are special cases of general linear fractional system of the forms ., where all parameters and the initial conditions are arbitrary nonnegative numbers, such that both denominators are positive. We find the basins of attraction of all attractors of these systems
Multilevel Static Real-Time Scheduling Algorithms Using Graph Partitioning
5th International Conference on Computational Science - ICCS 2005; Atlanta, GA; United States; 22 May 2005 through 25 May 2005We propose static task allocation algorithms for the periodic tasks of a distributed real-time system. The cyclic task consists of task threads which may communicate and share resources. A graph partitioning process and a thread sequencing algorithm are applied to these threads to yield local schedules. The exact analysis is then obtained and further refinements are performed if the worst case response time of a task is greater than its deadline
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