An intelligent system for electrical energy management in buildings

Recent studies have highlighted that a significant part of the electrical energy consumption in residential and business buildings is due to an improper use of the electrical appliances. In this context, an automated power management system - capable of reducing energy wastes while preserving the perceived comfort level - would be extremely appealing. To this aim, we propose GreenBuilding, a sensor-based intelligent system that monitors the energy consumption and automatically controls the behavior of appliances used in a building. GreenBuilding has been implemented as a prototype and has been experimented in a real household scenario. The analysis of the experimental results highlights that GreenBuilding is able to provide significant energy savings

E-Net-Manager: a Power Management System for Networked PCs based on Soft Sensors

The overall energy consumption due to ICT equipment has followed an increasing trend over the last years. A considerable fraction of the consumed energy is caused by user devices, such as Personal Computers (PCs) and displays. However, a large part of this energy is wasted due to an inefficient use. Users leave their PCs on for long periods even when unused, especially in workplaces. Hence, significant energy savings could be achieved just turning them off. However, it is not wise to rely on user collaboration, and, thus, automated tools are needed. In this paper, we present E-Net-Manager, a power management system for large environments, which turns unused PCs off and switches them on when the user is about to use them. To this end, E-Net-Manager leverages soft sensors, i.e., software/hardware tools already in use by the users, thus not introducing any additional cost. E-Net-Manager combines information provided by the users and data obtained from a number of these soft sensors. This way, it is possible to accurately determine the user presence/activity near her/his PC and, therefore, eliminate wastes also due to short periods of inactivity

On Evaluating the Performance Impact of the IEEE 802.15.4 Security Sub-layer

Nowadays, wireless sensor networks (WSNs) are used in a wide range of application scenarios ranging from structural monitoring to health-care, from surveillance to industrial automation. Most of these applications require forms of secure communication. On the other hand, security has a cost in terms of reduced performance. In this paper we refer to the IEEE 802.15.4 standard and investigate the impact of the 802.15.4 security sub-layer on the WSN performance. Specifically, we analyze the impact that security mechanisms and options, as provided by the standard, have on the overall WSN performance, in terms of latency, goodput, and energy consumption. To this end, we develop an analytical model and a security enabled simulator. We also use a real testbed, based on a complete open-source implementation of the standard, to validate simulation and analytical results, as well as to better understand the limits of the current WSN technology

Sarcoglycan subcomplex: state of the art

More than 15 years have elapsed since the discovery of the sarcoglycan complex (SGC) [1] and the characteristics of this original complex have been fairly studied in succeeding years later [2]. In details, sarcoglycan (SG) is a component of the larger dystrophin-associated glycoproteins complex (DAGC) called DGC also [1]. The DAGC is composed of at least ten proteins links laminin2 (merosin) of the extracellular matrix and actin, stabilizing the cell membrane during muscle activity. Three subcomplex can be identified in the DAGC on the basis of different biochemical characteristic and localization: the sarcoplasmic subcomplex, made up of the dystrophin, dystrobrevin and syntrophin complex; the dystroglycan subcomplex, made up of a- and b-dystroglycan; the SGC, composed of six SG subunits (a, b, g, d, e and z-SG). SGC subcomplex is an independent complex that is not directly associated with dystrophin and it plays a key role in signalling functions maintaining sarcolemma viability in muscle fiber membrane. As mutations in any one of SG subunits cause autosomal recessive limb-girdle muscular dystrophy (LGMD), characterized by integrity of dystrophin, SGC can be considered as associated system of DAGC and for this, it seems to be functionally as important as dystrophin. Moreover, previous reports have demonstrated that SGs are localized in skeletal and cardiac muscle forming the costameres, also showing that these proteins are co-localized with integrins in these regions in skeletal muscle in the region of the sarcolemma over I or A bands on the basis of the fiber types, slow or fast respectively [3,4]. These results have reinforced the hypothesis of a functional connection between SGs and integrins through a bidirectional signalling [5] which seems to be important to alleviate muscle diseases and to improve the survival of a severely dystrophic mouse model of Duchenne muscular dystrophy. For this, in our opinion the study of SGs implies also the consequent analysis of the integrins in many different tissues. Furthermore, it was demonstrated the presence of all SGs, and then of an exameric arrangement of SGC, in smooth muscle fibers of many districts [6,7] emphasizing an important correlation between SGs and frequency of contraction force [7,8]. Whereas the expression of a and g-SG is restricted to striated muscle cells, the other SGs are widely expressed in various tissues as levels of b, d and e-SG were highest in lung, moderate in brain, heart, and low, but detectable in kidney and liver [9]. Then, since this complex is not considered as muscle-specific, previously we have analyzed the SGs in non-muscle tissues, as well as digestive, respiratory and urinary epithelial cells. Interestingly, our immunohistochemical results showed the presence of all SGs in all tested tissues. About this, recently, we analyzed SGC in biopsies obtained from human breast and prostate in normal and pathological conditions in order to study these proteins also in glandular epithelium. Our results showed, for the first time, that in normal conditions, staining pattern for all SGs has been detectable and distributed in both epithelial and myoepithelial cells. Moreover, observations on samples of pathological tissues have shown that immunofluorescence for all SGs appears to be severely reduced in benign diseases, and almost absent in malignant syndromes. These results were confirmed also by data obtained on gingival epithelium in normal and pathological conditions. Particularly, our results on normal gingival epithelium showed the presence of SGC in this tissue confirming that SGs are ubiquitously distributed; in gingival epithelium, obtained from patients during inflammatory processes, due to treatment with bisphosphonates, staining pattern for SGs was decreased. Then, SGs could play a crucial role in oncogenesis since it is possible to hypothesize that these diseases could be due to lack of SGs in epithelial cells; moreover, the invasivity of malignant syndromes could be provoke by homology of SGs sequences with that of cadherins, transmembrane glycoproteins that are essential for cell-cell adhesion [10]. Additionally, it is known that even in the central nervous system the DGC exists but differs in composition from the DGC core present in muscle for the presence of several isoforms of dystrophin and for the existence of a SGC which is made up only for ε- and ζ-SG. On this, in our previous study we have analyzed the SGs expression and localization in rat’s cerebral cortex and our results showed that all SGs are present with a staining pattern in relation to the cerebral cortex area observed. In particular we think that they could be associated with synapse sites such as inhibitory GABAA Rε and D5DR receptors. Furthermore, the same analysis carried out on the brain of the WAG/Rij rats, a model of absence epilepsy, confirmed this role for SGs. On this basis, in order to understand the real function of SGs and integrins and their relationship with contraction forces, we studied these proteins in masseter muscle which, as well known, is highly unusual compared with other muscles; in fact, in addition to normal slow and fast fibers, this muscle contains fibers types which are typical for developing or cardiac muscle. Many fibers are hybrid, and they are important for the specific functional demands of masseter; these fibers probably increase the capacity of the masseter muscle to generate a large variety of motor tasks. First, to evaluate differences in muscles with different functions, we analyzed SGs and integrins in normal human masseter muscle compared with masseter muscle affected by unilateral right crossbite. Our results, in according to electromyographic evaluations, showed a decrease of SGs and integrins in crossbite side in respect to counterpart and to control subjects. Interestingly, in the crossbite side we observed an increase of b1D-integrin, an isoform detected in differentiating myofibers, playing a key role in muscle regeneration and appearing to have a minor role in mature skeletal muscle. Moreover, to comprehend the different role playing by SGC and integrins and to individuate a phylogenetic diversity in the expression of these proteins, we studied these proteins also in non human species. Particularly, we obtained masseter muscle biopsies from chimpanzees and baboons, individuating different classes of dominance, high and low dominance, for baboons, and alpha and non-alpha male for chimpanzees. About chimpanzees, our results have shown a different quantitative composition of integrins in alpha male in respect to non-alpha male hypothesizing a key role for integrins and SGs in the determination of contraction force. About baboons, Our immunohistochemical results, confirmed also by Western Blotting analysis, show that, in high dominance subjects, stainings for SGs and integrins were normal; interestingly, in low dominance subjects, stainings for these proteins were normal, lower or absent in different fibers of the same microscopic field. Thus, preliminary analysis on cell cultures of myoblasts and myotubes, at different days of differentiation, immunolabelled with antibodies against SGs and integrins, have demonstrated a similar behaviour, showing cells with an higher or lower staining for these proteins providing a first suggestion that integrins and SGs in masseter muscle play a key role regulating muscular functional activity and allowing the optimization of contractile forces of this muscle

Sarcoglycan are not muscle-specific: hypothetical roles

The sarcoglycan complex is a multimember transmembrane complex interacting with other proteins to provide a mechano-signaling connection from the cytoskeleton to the extracellular matrix in myofibers. This complex plays a key role at the membrane and is crucial in maintaining sarcolemma viability in muscle fibers. Recent observations have demonstrated that in the lung this glycoprotein is associated with both alveoli and bronchioles, and that the urogenital and digestive tracts are e-sarcoglycan positive. Further addressing this issue, in this work we extend our previous studies to better verify whether the sarcoglycan complex also exists in epithelial tissue. All our observations showed staining for all sarcoglycans to be a normal pattern in all tested epithelial cells. We hypothesize a key role for sarcoglycans in bidirectional signaling between cells and extracellular matrix, and an important role in the regulation of inhibitory synapses and of blood brain barrier

IEEE 802.15.4e: a Survey

Several studies have highlighted that the IEEE 802.15.4 standard presents a number of limitations such as low reliability, unbounded packet delays and no protection against interference/fading, that prevent its adoption in applications with stringent requirements in terms of reliability and latency. Recently, the IEEE has released the 802.15.4e amendment that introduces a number of enhancements/modifications to the MAC layer of the original standard in order to overcome such limitations. In this paper we provide a clear and structured overview of all the new 802.15.4e mechanisms. After a general introduction to the 802.15.4e standard, we describe the details of the main 802.15.4e MAC behavior modes, namely Time Slotted Channel Hopping (TSCH), Deterministic and Synchronous Multi-channel Extension (DSME), and Low Latency Deterministic Network (LLDN). For each of them, we provide a detailed description and highlight the main features and possible application domains. Also, we survey the current literature and summarize open research issues

Energy Efficient and Reliable Data Delivery in Urban Sensing Applications: A Performance Analysis

Urban sensing is an emerging application field for Wireless Sensor Networks (WSNs), where a number of static sensors is sparsely deployed in an urban area to collect environmental information. Data sensed by each sensor are, then, opportunistically transmitted to Mobile Nodes (MNs) that happen to be in contact. In the considered scenario, communications between MNs and sensors require paradigms with a minimal synchronization between devices, extremely fast and energy efficient, especially at the sensor side. To deal with the above issues, in [1] we proposed a hybrid protocol for data delivery from sensors to MNs, named Hybrid Adaptive Interleaved Data Protocol (HI). By combining Erasure Coding (EC) with an Automatic Repeat reQuest (ARQ) scheme, the proposed protocol maximizes the reliability of communications while minimizing the energy consumed by sensors. In this paper, we present an in-depth analysis of the HI performance. We provide an analytical evaluation by defining a flexible model to derive the probability of data delivery and exploiting it to investigate the performance over a wide range of parameters. Moreover, we avail of an experimental study to evaluate the HI effectiveness on real sensor platforms. Specifically, we analyze the impact of resource constraints imposed by sensors on data delivery and provide a careful characterization of its actual consumption of resources

A Localized Slot Allocation Algorithm for Wireless Sensor Networks

While energy efficiency is typically considered the major concern in wireless sensor networks (WSNs), many real-life applications also require reliability, timeliness, and scalability. In such scenarios, Time Division Multiple Access (TDMA) is typically used for data communication, as it avoids collisions and provides predictable latency and minimum energy consumption. TDMA requires a slot scheduling algorithm to allocate transmission slots to sensor nodes. In this paper, we propose a decentralized slot allocation algorithm which is localized and self adaptive, i.e., each node selects its slot(s) and adapts its behavior only basing on locally-available information. We derive analytically the time taken by the algorithm and the average energy consumed by the network to achieve a complete schedule. We also show that our solution performs significantly better than another previous similar algorithm

A Hybrid Adaptive Protocol for Reliable Data Delivery in WSNs with Multiple Mobile Sinks

In this paper we deal with reliable and energy-efficient data delivery in sparse Wireless Sensor Networks with multiple Mobile Sinks (MSs). This is a critical task, especially when MSs move randomly, as interactions with sensor nodes are unpredictable, typically of short duration, and affected by message losses. In this paper we propose an adaptive data delivery protocol that combines efficiently erasure coding with an ARQ scheme. The key features of the proposed protocol are: (i) the use of redundancy to cope efficiently with message losses, and (ii) the ability of adapting the level of redundancy based on feedbacks sent back by MSs through ACKs. We observed by simulation that our protocol outperforms an alternative protocol that relies only on an ARQ scheme, even when there is a single MS. We also validated our simulation results through a set of experimental measurements based on real sensor nodes. Our results show that the adoption of encoding techniques is beneficial to energy-efficient (and reliable) data delivery in WSNs with Mobile Sinks