Social issues of power harvesting as key enables of WSN in pervasive computing

Pervasive systems have gained popularity and open the door to new applications that will improve the quality of life of the users. Additionally, the implementation of such systems over an infrastructure of Wireless Sensor Networks has been proven to be very powerful. To deal with the WSN problems related to the battery of the elements or nodes that constitute the WSN, Power Harvesting techniques arise as good candidates. With PH each node can extract the energy from the surrounding environment. However, this energy source could not be constant, affecting the continuity and quality of the services provided. This behavior can have a negative impact on the user's perception about the system, which could be perceived as unreliable or faulty. In the current paper, some related works regarding pervasive systems within the home environment are referenced to extrapolate the conclusions and problems to the paradigm of Power Harvesting Pervasive Systems from the user perspective. Besides, the paper speculates about the approach and methods to overcome these potential problems and presents the design trends that could be followed.<br/

Metallic Triple Beam Resonator with Thick-film Printed Drive and Pickup

A triple beam resonator fabricated in 430S17 stainless steel with thick-film piezoelectric elements to drive and detect the vibrations is presented. The resonator substrate was fabricated by a simultaneous, double-sided photochemical etching technique and the thick-film piezoelectric elements were deposited by a standard screen-printing process. The combination of these two batch-fabrication processes provides the opportunity for mass production of the device at low cost. The resonator, a dynamically balanced triple beam tuning fork (TBTF) structure 23.5 mm long and 6.5 mm wide, has a favoured mode at 4.96 kHz with a Q-factor of 3630 operating in air

Photoresist patterned thick-film piezoelectric elements on silicon

A fundamental limitation of screen printing is the achievable alignment accuracy and resolution. This paper presents details of a thick-resist process that improves both of these factors. The technique involves exposing/developing a thick resist to form the desired pattern and then filling the features with thick film material using a doctor blading process. Registration accuracy comparable with standard photolithographic processes has been achieved resulting in minimum feature sizes of &lt;50 ?m and a film thickness of 100 ?m. Piezoelectric elements have been successfully poled on a platinised silicon wafer with a measured d 33 value of 60 pCN?1

On the Continuity Mathematics Curriculum Between Primary and Secondary School

AbstractIn this paper we intend to present a review of the National Curriculum continuity in mathematics, in terms of content, from the primary to the secondary. The issues on which we have committed are related to “outputs” learning mathematics fourth class and “inputs” appropriate grade. Because a complete analysis of mathematics curricular content can not be included in an article like this, we summarize only the learning content “fraction”. As far we know, continuity issues relating to both the content of their purchases to specific skills training to students, standards and performance descriptors etc., relative to a subject or a curriculum area, in recent formulation, not be found treated in the literature, even in the didactics of discipline

Microelectromechanical systems vibration powered electromagnetic generator for wireless sensor applications

This paper presents a silicon microgenerator, fabricated using standard silicon micromachining techniques, which converts external ambient vibrations into electrical energy. Power is generated by an electromagnetic transduction mechanism with static magnets positioned on either side of a moving coil, which is located on a silicon structure designed to resonate laterally in the plane of the chip. The volume of this device is approximately 100 mm3. ANSYS finite element analysis (FEA) has been used to determine the optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft’s Maxwell 3D software have been performed to determine the voltage generated from a single beam generator design. The predicted voltage levels of 0.7–4.15 V can be generated for a two-pole arrangement by tuning the damping factor to achieve maximum displacement for a given input excitation. Experimental results from the microgenerator demonstrate a maximum power output of 104 nW for 0.4g (g=9.81 m s1) input acceleration at 1.615 kHz. Other frequencies can be achieved by employing different geometries or material

Steps to Better Cardiovascular Health: How Many Steps Does It Take to Achieve Good Health and How Confident Are We in This Number?

Pedometers and other types of step-counting devices are growing in popularity with both researchers and practitioners. The focus of this article is on describing the most recent pedometer-related advances in terms of cardiovascular health. The emergent body of evidence suggests that pedometer-determined physical activity is related to a number of cardiovascular health outcomes and that intervention participants can realize modest changes in body mass index and blood pressure. Taking into consideration individual baseline values, tailored messages congruent with public health recommendations should promote incremental increases in steps/day on the order of an extra 3,000 to 4,000 (approximately 30 min) of at least moderate intensity and taken in at least 10-minute bouts. Additional health benefits accrue with greater increases. Of course, even more benefits are possible from engaging in vigorous physical activity, but this seems less appealing for most people. Pedometer-based guidelines are not intended to supplant existing public health recommendations, but rather supplement them

the rare bone disorders use case

Background Lately, ontologies have become a fundamental building block in the process of formalising and storing complex biomedical information. The community-driven ontology curation process, however, ignores the possibility of multiple communities building, in parallel, conceptualisations of the same domain, and thus providing slightly different perspectives on the same knowledge. The individual nature of this effort leads to the need of a mechanism to enable us to create an overarching and comprehensive overview of the different perspectives on the domain knowledge. Results We introduce an approach that enables the loose integration of knowledge emerging from diverse sources under a single coherent interoperable resource. To accurately track the original knowledge statements, we record the provenance at very granular levels. We exemplify the approach in the rare bone disorders domain by proposing the Rare Bone Disorders Ontology (RBDO). Using RBDO, researchers are able to answer queries, such as: “What phenotypes describe a particular disorder and are common to all sources?” or to understand similarities between disorders based on divergent groupings (classifications) provided by the underlying sources