| 1. |
- Kehoe, Laura, et al.
(författare)
-
Make EU trade with Brazil sustainable
- 2019
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 2. |
|
|
| 3. |
- Berndes, Göran, 1966, et al.
(författare)
-
Expanding sugarcane ethanol production in Brazil - Socioeconomic and climate effects of expanding sugarcane ethanol production in the Pontal do Paranapanema region (State of São Paulo, Brazil)
- 2007
-
Ingår i: Proceedings of the 15th European Biomass Conference & Exhibition - From research to market Deployment, Berlin, Germany, 7-11 May 2007.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents results from a study of socioeconomic and climate effects connected to a sugarcane expansion scenario in the Pontal do Paranapanema region, São Paulo state, Brazil. Sugarcane production is expected to grow in the São Paulo state. Pontal do Paranapanema is the only region in the state where a large scale sugarcane expansion can take place and there is a concern that without guidelines the expansion might affect income growth in a negative way. A scenario where the settlers in the region gain from the sugarcane expansion was modelled. The models showed that it is possible to introduce sugarcane in the region with positive effects both on income growth and greenhouse gas emissions.
|
|
| 4. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
An agent framework to support sensor networks’ setup and adaptation
- 2009
-
Ingår i: International Multiconference on Computer Science and Information Technology, 2009. IMCSIT ’09. - Piscataway, N.J. : IEEE Press. ; , s. 619-626
-
Konferensbidrag (refereegranskat)abstract
- Sensor networks are being used in several emerging applications not even imagined some years ago due to advances in sensing, computing, and communication techniques. However, these advances also pose various challenges that must be faced. One important challenge is related to the autonomous capability needed to setup and adapt the networks, which decentralizes the control of the network, saving communication and energy resources. Middleware technology helps in addressing this kind of problem, but there is still a need for additional solutions, particularly considering dynamic changes in users' requirements and operation conditions. This paper presents an agent-based framework acting as an integral part of a middleware to support autonomous setup and adaptation of sensor networks. It adds interoperability among heterogeneous nodes in the network, by means of autonomous behavior and reasoning. These features also address the needs for system setup and adaptations in the network, reducing the communication overhead and decentralizing the decision making mechanism. Additionally, preliminary results are also presented.
|
|
| 5. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
Analyzing different levels of geographic context awareness in agent ferrying over VANETs
- 2011
-
Ingår i: Proceedings of the 2011 ACM Symposium on Applied Computing. - New York : ACM Press. - 9781450301138 ; , s. 413-418
-
Konferensbidrag (refereegranskat)abstract
- The use of mobile software agents is a promising approach to implement services over ad hoc networks. This paper presents an analysis of mobile autonomous agents with different degrees of intelligence that allow them to make usage of the positioning information of vehicle carried sensor nodes with different depth of complexity, considering the nodes’ current and future locations. The agents’ intelligence is used to decide their movement during opportunistic connections among the nodes in order to accomplish missions. In this work, the analysis is done over an application of “virtual sensors”, implemented by services provided by the mobile agents. These agents run on top of an infrastructure-less Vehicular Ad hoc Network (VANET). Simulation results are presented and discussed to support the proposed ideas.
|
|
| 6. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
Decentralized task distribution among cooperative UAVs in surveillance systems applications
- 2010
-
Ingår i: 2010 Seventh International Conference on Wireless On-demand Network Systems and Services. - New York : IEEE Press. - 9781424460595 ; , s. 121-128
-
Konferensbidrag (refereegranskat)abstract
- Teams of small Unmanned Aerial Vehicles (UAVs) are being largely proposed to be used in different areas for both military and civilian applications. Their integration in wider sensor networks is also being considered in order to provide a better cost-benefit ration. However, coordination among UAV teams is not a trivial problem in an ad hoc network. This paper presents a decentralized coordination strategy to orient the actions of a team of UAVs, which take part in a wider sensor network, relying on ad hoc network communication. The proposed sensors network inclused static sensors that issue alarms indicating the presence of possible targets that must be handled by one of the UAVs and possibly relay messages among them. Preliminary results of the proposed approach are presented and are contrasted with results provided by a centralized solution for the problem.
|
|
| 7. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
Enhanced Wireless Sensor Network Setup Strategy Supported by Intelligent Software Agents
- 2010
-
Ingår i: Sensors 2010 Hawaii. - Piscataway, N.J. : IEEE Press. - 9781424481682 ; , s. 813-816
-
Konferensbidrag (refereegranskat)abstract
- A well know problem in the Wireless Sensor Network (WSN) research area is the usage of appropriate strategies to setup the sensor nodes such that they may accomplish sensing missions. This problem refers to the selection of appropriate nodes to perform the different tasks required to the missions' accomplishment and may be thus characterized as an instance of the task and resource allocation problem. Traditional approaches consider pre-planned strategies, which are not flexible to deal with changes in the network and environment operating conditions. This paper presents an enhanced agent-oriented strategy, which consists of a usage of mobile intelligent agents to disseminate missions and nodes' information over the network, as well as stationary software agents installed in the sensor nodes to provide advanced reasoning apparatus for decision making purposes. The proposed enhancement complements the original agent-based approach with robustness features required to overcome extreme adverse conditions in which an ordinary WSN presents poor results. Results from simulations provide evidences of the efficiency of the complete enhanced approach.
|
|
| 8. |
- de Freitas, Edison Pignaton, 1979-, et al.
(författare)
-
Evaluation of coordination strategies for heterogeneous sensor networks aiming at surveillance applications
- 2009
-
Ingår i: Sensors 2009 New Zealand. - Piscataway, N.J. : IEEE Press. - 9781424445486 - 9781424453351 ; , s. 591-596
-
Konferensbidrag (refereegranskat)abstract
- A new challenge in the sensor network area is the coordination of heterogeneous sensors (with different sensing, mobility and computing capabilities) in an integrated network. This kind of sensor networks have clearly high relevance in surveillance systems, in which both low-end static ground sensor nodes and more sophisticated sensors carried by mobile platforms, such as Unmanned Aerial Vehicles (UAVs), cooperate. This paper provides an analysis of two different strategies to guide the collaboration among the sensor nodes mentioned above, applied to area surveillance systems. The first analyzed problem is related to the choice of the UAV instance that will respond to a given alarm issued by a ground sensor node. The second issue is the estimation of the response time until any UAV can be engaged in handling an alarm and effectively handles it. Two strategies are introduced and compared: one based on a pheromone inspired approach and another based on utility functions inspired on risk profiles that models decisions of investors in the stock market. ©2009 IEEE.
|
|
| 9. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
Experimental Analysis of Coordination Strategies to Support Wireless Sensor Networks Composed by Static Ground Sensors and UAV-Carried Sensors
- 2010
-
Ingår i: International Symposium on Parallel and Distributed Processing with Applications, ISPA 2010. - New York : IEEE Press. - 9780769541907 ; , s. 152-161
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a comparison among different strategies to coordinate the use of heterogeneous wireless sensors aimed for area surveillance. The heterogeneity among the sensor nodes is related to their sensing and mobility capabilities. The goal of the strategies is to provide coordination among the different nodes, in order to make the wireless sensor network perform its missions with higher efficiency. Strategies combine advantages of bio-inspired and utility-based approaches to coordination. Simulations of scenarios with different characteristics were performed and the results are compared and analyzed.
|
|
| 10. |
- de Freitas, Edison Pignaton, et al.
(författare)
-
Mobile Agents Model and Performance Analysis of a Wireless Sensor Network Target Tracking Application
- 2011
-
Ingår i: Smart spaces and next generation wired/wireless networking. - Heidelberg : Springer Berlin/Heidelberg. - 9783642228742 - 3642228747 ; , s. 274-286
-
Konferensbidrag (refereegranskat)abstract
- Advances on wireless communication and sensor systems enabled the growing usage of Wireless Sensor Networks. This kind of network is being used to support a number of new emerging applications, thus the importance in studying the efficiency of new approaches to program them. This paper proposes a performance study of an application using high-level mobile agent model for Wireless Sensor Networks. The analysis is based on a mobile object tracking system, a classical WSN application. It is assumed that the sensor nodes are static, while the developed software is implemented as mobile agents by using the AFME framework. The presented project follows a Model-Driven Development (MDD) methodology using UML (Unified Modeling Language) models. Metrics related to dynamic features of the implemented solution are extracted from the deployed application, allowing a design space exploration in terms of metrics such as performance, memory and energy consumption. © Springer-Verlag Berlin Heidelberg 2011.
|
|
