Angelo Perkusich

Broadcast routing in wireless sensor networks with dynamic power management and multi-coverage backbones

In a wireless sensor network (WSN), nodes are power constrained. As a consequence, protocols must be energy efficient to prolong the network lifetime while keeping some quality-of-service (QoS) requirements. In WSNs, most protocols resort to the broadcast of control messages like, for example, for the topology control (TC) of the network. On its turn, TC itself can be applied to improve the broadcast of data packets in the network, and because only a subset of nodes need to be active at any time, it is possible to extend the network lifetime. We investigate some alternatives to improve broadcasting in WSN for an extended network lifetime. This is accomplished in two ways. First, we adapt the dynamic power management with scheduled switching modes (DPM-SSM) technique to a blind flooding protocol (i.e., FLOOD). To capture the battery capacity recovery effect as a result of applying DPM, we consider a more realistic battery model (i.e., Rakhmatov-Vrudhula battery model). Second, we implement a multi-coverage TC solution for computing an energy efficient broadcast backbone. Extensive simulation results using the NS2 network simulator show that it is possible to extend the network lifetime while keeping good broadcasting performance.

Dynamic Power Management with Scheduled Switching Modes

A Wireless Sensor Network (WSN) comprises many sensor nodes each one containing a processing unit, one or more sensors, a power unit, and a radio for data communication. Nodes are power constrained, because they run on batteries which usually cannot be replaced due to the nature of the applications. We present a novel dynamic power management approach, named Dynamic Power Management with Scheduled Switching Modes (DPM-SSM), derived from a more realistic analysis of the battery capacity recovery effect and the switching energy. This was only possible thanks to the application of a more realistic battery model (i.e., Rakhmatov-Vrudhula battery model). We also devised a Hybrid Differential Petri Nets formalism to evaluate our power management solution. Preliminary results showed the potential for improving the battery lifetime by taking advantage of the battery recovery effect when a node transitions to a sleeping state mostly after packet transmissions. DPM-SSM provides several DPM modes which are triggered depending on the battery remaining capacity. Simulations results show that, depending on the scheduling approach, DPM-SSM can provide real battery power recovery without compromising the timeliness of the applications running on the sensor network.

A UPnP extension for enabling user authentication and authorization in pervasive systems

The Universal Plug and Play (UPnP) specification defines a set of protocols for promoting pervasive network connectivity of computers and intelligent devices or appliances. Nowadays, the UPnP technology is becoming popular due to its robustness to connect devices and the large number of developed applications. One of the major drawbacks of UPnP is the lack of user authentication and authorization mechanisms. Thus, control points, those devices acting as clients on behalf of a user, and UPnP devices cannot communicate based on user information. This paper introduces an extension of the UPnP specification called UPnP-UP, which allows user authentication and authorization mechanisms for UPnP devices and applications. These mechanisms provide the basis to develop customized and secure UPnP pervasive services, maintaining backward compatibility with previous versions of UPnP.

Dynamic Power Management with Scheduled Switching Modes in Wireless Sensor Networks

A wireless sensor network (WSN) comprises many sensor nodes each one containing a processing unit, one or more sensors, a power unit, and a radio for data communication. Nodes are power constrained, because they run on batteries, that in many cases cannot be easily replaced. This paper presents a novel dynamic power management technique, named Dynamic Power Management with Scheduled Switching Modes (DPM-SSM), derived from a more realistic analysis of the battery capacity recovery effect and the switching energy. This was only possible thanks to the application of a more realistic battery model (i.e., Rakhmatov-Vrudhula battery model). Preliminary results showed the potential for improving the battery lifetime by taking advantage of the battery recovery effect when a node transitions to a sleeping state, and mostly when transitions are scheduled after packet transmissions. DPM-SSM provides several DPM modes which are triggered depending on the battery remaining capacity. Simulations results show that DPM-SSM can provide real battery power recovery without compromising the timeliness of the applications running on the wireless sensor network.

A personal connected health system for the Internet of Things based on the Constrained Application Protocol

Display Omitted We present a system that enables Personal Health Devices to share information in home networks and with the Internet.The Constrained Application Protocol (CoAP) is used as underlying protocol.The CoAP communication model was adapted to the ISO/IEEE 11073 model in the proposed system.Results showed how the network overhead is around 50% lighter when compared to other protocols.Interoperability experiments demonstrated how the proposed solution can work with legacy systems. The increasing costs of healthcare along with the increasing availability of new Personal Health Devices (PHDs) are the ingredients of the connected health vision. Also, a growing number of consumer electronic and mobile devices are becoming capable of taking the role of a health gateway, thus operating as a data collector for PHDs. In this context, we present a system that enables PHDs to share information in home networks and with the Internet based on a new Internet of Things protocol, namely the Constrained Application Protocol (CoAP). CoAP is used along with the IEEE 11073 family of standards, which is the main exchange data model for PHD communication. We discuss how the proposed system can be integrated to other connected health systems, such as a Universal Plug and Play healthcare system. We detail how the CoAP communication model was adapted to the IEEE 11073 model. We also present a real PHD prototype and its evaluation results. These results demonstrated the feasibility of the proposed solution, showing how its network overhead is around 50% lighter when compared to other protocols. Finally, we tested the proposed solution based on different scenarios, including a proof-of-concept integration with a service in the cloud, using different wireless physical interfaces.

Integrating MQTT and ISO/IEEE 11073 for health information sharing in the Internet of Things

The Internet of Things (IoT) paradigm allows small and resource constrained devices to send data through complex networks like the Internet. Bringing the IoT paradigm to the healthcare area, we can expand the connected health vision, enabling new Personal Health Devices (PHD) to share health information directly through the Internet. In this paper we explore the use of the MQTT (Message Queue Telemetry Transport) lightweight protocol together with the ISO/IEEE 11073 standard. We present new ways of connecting PHDs in home networks and the Internet by the use of MQTT Brokers, which will reduce the amount of data traffic.

Emotion Recognition Based on Brain-Computer Interface Systems

Emotions are intrinsically related to the way that individuals interact with each other as well as machines [1]. A human being can understand the emotional state of another human being and behave in the best manner to improve the communication in a certain situation. This is because emotions can be recognized through words, voice intonation, facial expressions and body language. In contrast, machines cannot understand the feelings of an individual.

On the performance of TCP, UDP and DCCP over 802.11 g networks

This paper presents an experimental study of streaming multimedia packets using DCCP transport protocol over 802.11 g networks. Our main focus is to study the behavior of DCCP flows over real-time multimedia applications. The approach taken was to use DCCP flows in the presence of TCP and UDP flows, then analyze the behavior of each protocol, mainly in regards to the congestion control algorithms of both protocols. Furthermore, we also considered end-points mobility requirements, such as hand-off between multiples access points. Needless to say, the DCCP protocol was recently standardized by IETF as an alternative for streaming multimedia flows on computer networks. The results presented in this paper show that TCP and DCCP protocols can share the network bandwidth without affecting each other. On the other hand, UDP flows can aggressively degrade TCP and DCCP flows due to the absence of any kind of flow control. Although UDP flows reach high bandwidth throughput, it loses a considerable amount of data taking into account limited bandwidth channels, such as 802.11g networks. Finally, this work also shows that TCP and DCCP can think of loss of packets as network congestion while experimenting hand-offs, thus decreasing their throughput.

From a Tridimensional View of Domain Knowledge to Multi-agent Tutoring System

This paper focus on results related to the design of a model of a Computer-based Interactive Learning Environment adopting a multi-agent approach. Questions related to why and how adopt this approach are addressed. We begin presenting and emphasizing the definition of both a view of the domain knowledge structure and a model for it. Then, we show the consequences of this toward the definition of a multi-agent system, leading to a complete learning environment. Related to this environment we define its characteristics and its agent model. Moreover, we discuss both the interaction model among agents and between a human learner and the System. Finally, we focus on the interactions among agents during Problem solving activities, discussing the interaction language and the interaction protocols.

A model to detect problems on scrum-based software development projects

There is a high rate of software development projects that fails. Whenever problems can be detected ahead of time, software development projects may have better chances of success, and therefore save money and time. In this paper, we present a probabilistic model to help ScrumMasters to apply Scrum in organizations. The models goal is to provide information to the projects ScrumMaster to help him to be aware of the projects problems and have enough information to guide the team and improve the projects chances of success. We published a survey to collect data for this study and validated the model by applying it to scenarios. The results obtained so far show that the model is promising.