Browsing by Author "Rocha, Rafael"
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- Current advancements on maintenance for household appliancesPublication . Lino Ferreira, Luis; Albano, Michele; Rocha, Rafael; Costa, Miguel; Machado Silva, Ana; Silva, Marlos; Matos, Luísa; Afonso Landeck, JorgeThis communication describes research and development directions that are being explored for the creation of a maintenance system for home appliances. The solution will enable a faster and more accurate automation of after-sale services for home appliances. It will be based on three tiers: data acquisition, data analysis and business tiers. The communication provides a context for the work, both regarding the application area in general and the three tiers, and then describes the objectives of the system being designed.
- Improving and modeling the performance of a Publish-Subscribe message brokerPublication . Rocha, Rafael; Maia, Cláudio; Lino Ferreira, Luis; Varga, PalThe Event Handler – a publish-subscribe broker implemented over REST/HTTP(S) – is an auxiliary system of the Arrowhead framework for IoT applications. During this work we found that the existing implementation of the Event Handler suffers from serious performance issues. This paper describes the reengineering effort that ultimately enabled it to reach much more acceptable levels of performance, by using appropriate software configurations and design patterns. Additionally, we also illustrate how this enhanced version of the Event Handler can be modeled using Petri nets, to depict the performance impact of different thread pool configurations and CPU core availability. The main objective of this modeling process is to enable the estimation of the system’s performance to guarantee the required quality of service.
- Improving the performance of a Publish-Subscribe message brokerPublication . Rocha, Rafael; Lino Ferreira, Luis; Maia, Claudio; Souto, Pedro; Varga, PalThe Arrowhead Framework, a SOA-based framework for IoT applications, provides the Event Handler system: a publish/subscribe broker implemented with REST/HTTP(S). However, the existing implementation of the Event Handler suffers from message latency problems that are not acceptable for industrial applications. Thus, this paper describes the refactoring process of this system that enabled it to reach acceptable levels of latency.
- Reengineering and development of IoT Systems for Home AutomationPublication . Rocha, Rafael; Ferreira, Luís Miguel Moreira Lino; Albano, Michele; Silva, José BrunoWith the increasing adoption of technology in today’s houses, electricity is at an all-time high demand. In fact, given the plethora of vital electricity-powered appliances used every day, such as refrigerators, washing machines, and so forth, it has been proven difficult to even handle all devices’ electric consumption. To reduce consumption costs and turn it into a more manageable process, the concept of flex-offers was created. A flex-offer is built around scheduling energy usage in conjunction with the prices of electricity, as provided by an energy market. More specifically, a flex-offer is an energy consumption offer containing the user’s energy consumption flexibility, which is sent to an entity called the Aggregator, who aggregates together flex-offers from multiple parties, bargains with the energy market, and responds to each flex-offer with a schedule that meets the lowest prices for consumption, while still satisfying the users’ needs. By using flex-offers on a house’s equipment, the idea of FlexHousing was born. The aspired goal of the CISTER Research Center’s FlexHousing project is to deliver a platform where users can register their smart appliances, regardless of its brand and distributor, set up preferences for the devices’ usage, and let the system manage the energy consumption and device activation schedules based on the energy market prices. A previous project had already built a prototype of the FlexHousing system. Nevertheless, the original platform had many limitations and lacked maturity from a software engineering point of view, and the goal of this internship is to apply a reengineering process on the FlexHousing project, while also adding new features to it. Thus, the project’s domain model, its database, and class structures were altered to satisfy the new requirements. Furthermore, its web platform was rebuilt from the ground up. Also, a new interface was developed to facilitate support for devices of different brands. As a proof of concept for the benefits provided by this new interface, a connection with a new device (Sonoff Pow) was also established. Moreover, a new functionality was developed to identify a device’s type of appliance based on its energy consumption, in other words, to specify if a device is, for instance, a refrigerator or not. Finally, another new feature was added in which, based on a device’s type and its energy consumption pattern, the flex-offer creation is automated, minimizing user input. As planned, the FlexHousing platform now supports multiple types of devices, and has a software interface to support more types in the future with minimal effort. The flex-offer creation process has been simplified and is now partially automated. Finally, the web platform’s UI has been updated, becoming more intuitive and appealing to the user.
- The Arrowhead Framework applied to Energy ManagementPublication . Rocha, Rafael; Albano, Michele; Lino Ferreira, Luis; Relvas, Flávio; Matos, LuisaEnergy management in buildings can provide massive benefits in financial and energy saving terms. It is possible to optimize energy usage with smart grid techniques, where the benefits are enhanced when the energy consumer can trade the energy on energy markets, since it forces energy providers to compete with each other on the energy price. However, two hurdles oppose this approach: the devices providing control over appliances do not interoperate with each other; and energy markets limit trading activities to large quantities of energy, thus impeding access for small consumers. This work considers using the FlexOffer (FO) concept to allow the consumer to express its energy needs, and FO-related mechanisms to aggregate energy requests into quantities relevant for energy markets. Moreover, the presented system, named FlexHousing, is based on the Arrowhead Framework – a framework that simplifies design and implementation of distributed applications by means of normalizing communication via services – and exploits its Service Oriented mechanisms to provide device interoperability. The implemented FlexHousing system uses multi-level FO aggregation to empower either the final user, for example the owner of an apartment, to manage its own energy by defining their flexibilities, or to offload this responsibility to an energy manager who takes care of all the apartments in a building or set of buildings.