Search results for "Wire"
showing 10 items of 1383 documents
Electrical and photoelectrical measurements on ZnO-Nanowires coated with PEDOT:PSS for Dye-Sensitized Solar Cells
2011
ABSTRACTDye-sensitized solar cells composed of an n-doped ZnO nanowire array and a p-doped polymer layer appears to be a promising candidate for low-cost production of environment-friendly solar cells. In this work, we investigate hybrid devices consisting of a transparent conducting oxide (TCO) substrate, ZnO-nanowires (ZnO-NW) or a sol-gel prepared ZnO layer, a ruthenium dye (N719) and a PEDOT:PSS or P3HT layer. The dense polycrystalline ZnO layer is able to prevent short circuits, which have a strong effect on the performance of the solar cells. This is demonstrated by the use of only the ZnO layer which improves the open circuit voltage by a factor of 2 and the efficiency by a factor of…
A Novel Energy Model for MANETs based on Graphs with Activation Windows
2005
Energy usage optimization is still an important issue and a critical design factor for mobile ad hoc networks (MANETs). Only recently a few proposals appeared that consider energy-aware optimizations for routing protocols. In this paper we describe an analytical model for MANETs which is based on graphs with activation windows. The activation windows allow to model the on-off status of the network devices. Moreover, we propose an algorithm with pseudo-polynomial complexity, called STP algorithm (STPA), that based on the current position and state of the nodes determines the shortest time path between the source node and the destination node.
Lifespan-Aware Routing for Wireless Sensor Networks
2010
Wireless Sensor Networks (WSNs) have the capability to become the eyes and ears for the future networked society allowing monitoring of any habitat or object's properties remotely and independently of an energy source. Services based on this technology may change the way we monitor and control remote areas and objects. In this paper we propose a different approach to routing data across Wireless Sensor Networks. We argue that a distance-vector protocol using a lifespan-aware metric is a plausible solution to the task of routing information in WSN in a manner that both saves energy of the individual node and manages summarized energy of the system equally and fairly. The concept is designed …
Stability Analysis of Routing Strategies for the Maximum Lifetime Problem in One-Dimensional Ad-Hoc Wireless Networks
2017
In the paper we discuss solutions of the maximum network lifetime problem in one-dimensional, regular ad-hoc wireless networks. For the problem, nodes of the network generate given amount of data and send it possibly via other nodes to the data collector. To extend the network lifetime the data should be transmitted in such a way, that the energy utilized by the most overloaded node is minimized. We assume, that the nodes use the point-to-point data transmission scheme and the cost of transmission of one unit of data is arbitrary superadditive function of a distance between transmitter and receiver. We show that for the one-dimensional network in which the nodes are evenly distributed on th…
TBRA: A scalable routing algorithm in highly mobile large scale pure ad hoc wireless mesh networks
2009
In highly mobile pure ad-hoc wireless mesh networks, fast rerouting within low routing discovery delay is a mandatory requirement for routing algorithm to support interactive applications such as VoIP. Also, the communication overhead should be thwarted when networks grow to a large scale. We propose a Tree-Based Routing Algorithm - TBRA to facilitate such two goals. On one hand, TBRA has very low routing discovery delay due to its proactive property. On the other hand, TBRA performs more efficiently than other proactive protocols with respect to low communication overhead, which thanks to its short routing packet length, less numbers and smaller routing table size. Our modeling analysis an…
A flexible and tunable route discovery mechanism for on-demand protocols
2004
Mobile ad-hoc networks are characterized by multihop wireless links and absence of cellular infrastructure. For the last years, routing has been the area under most intensive research. In particular, on-demand routing protocols proposed are extremely attractive due to their low-overhead and efficiency. Currently, wireless ad-hoc networks lack multipath routing protocols. Multipath routing enables increased QoS support, load balancing and enhanced route stability. In this paper we present a new route discovery solution that increases the number of routes found, while reducing the routing overhead when compared to previous proposals. Simulation results show that the additional routing overhea…
Experimental Characterization of a Double Receiver Dynamic Wireless Charging System
2020
The aim of this work is the characterization of a dynamic wireless charging system low power prototype and the validation of a simplified mathematical model of the employed double D coils. The difference between a single receiver and a dual receiver system is also shown, highlighting how the last one can significantly reduce the costs of the charging infrastructure.
Wearable photoplethysmography device prototype for wireless cardiovascular monitoring
2014
The aim of the study was to develop a prototype system of the smart garment for real time telemetric monitoring of human cardiovascular activity. Two types of photoplethysmography (PPG) sensors for low noise and artefact free signal recording from various sites of the human body that were suitable for integration into smart textile were investigated. The reflectance sensors with single and multiple photodiodes based on "pulse-duration-based signal conversion" signal acquisition principle were designed and evaluated. The technical parameters of the system were measured both on bench and in vivo. Overall, both types of PPG sensors showed acceptable signal quality SNR 86.56±3.00 dB, dynamic ra…
The MOBI-Kids Study Protocol: Challenges in Assessing Childhood and Adolescent Exposure to Electromagnetic Fields from Wireless Telecommunication Tec…
2014
The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF). MOBI-Kids, a multinational case–control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10–24 years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure an…
Compression Methods for Microclimate Data Based on Linear Approximation of Sensor Data
2019
Edge computing is currently one of the main research topics in the field of Internet of Things. Edge computing requires lightweight and computationally simple algorithms for sensor data analytics. Sensing edge devices are often battery powered and have a wireless connection. In designing edge devices the energy efficiency needs to be taken into account. Pre-processing the data locally in the edge device reduces the amount of data and thus decreases the energy consumption of wireless data transmission. Sensor data compression algorithms presented in this paper are mainly based on data linearity. Microclimate data is near linear in short time window and thus simple linear approximation based …