Search results for " Sensor."
showing 10 items of 1700 documents
Optimization of Linearized Belief Propagation for Distributed Detection
2020
In this paper, we investigate distributed inference schemes, over binary-valued Markov random fields, which are realized by the belief propagation (BP) algorithm. We first show that a decision variable obtained by the BP algorithm in a network of distributed agents can be approximated by a linear fusion of all the local log-likelihood ratios. The proposed approach clarifies how the BP algorithm works, simplifies the statistical analysis of its behavior, and enables us to develop a performance optimization framework for the BP-based distributed inference systems. Next, we propose a blind learning-adaptation scheme to optimize the system performance when there is no information available a pr…
Modeling and Mitigating Errors in Belief Propagation for Distributed Detection
2021
We study the behavior of the belief-propagation (BP) algorithm affected by erroneous data exchange in a wireless sensor network (WSN). The WSN conducts a distributed multidimensional hypothesis test over binary random variables. The joint statistical behavior of the sensor observations is modeled by a Markov random field whose parameters are used to build the BP messages exchanged between the sensing nodes. Through linearization of the BP message-update rule, we analyze the behavior of the resulting erroneous decision variables and derive closed-form relationships that describe the impact of stochastic errors on the performance of the BP algorithm. We then develop a decentralized distribute…
Agents driven smart sensors
2017
Any physical area (like schools, home, hospitals etc.) that uses either mobile devices, sensors, embedded systems or computers to gather information from the users and the environment and eventually, adapt according to the new information gained. [1] Smart spaces compromises of heterogeneous hardware which often leads to the issues of interoperability. One way of reducing the heterogeneity between the sensors is to introduce the semantic interface as sensors default interface. Semantic Web provides a common interface and for-mat for data representation so that one can decrease the heterogeneity of data and increase data reusability. [2] With the Smart Spaces, it is important to use only the…
Minimum detection limits and applications of proton and helium induced X-ray emission using transition-edge sensor array
2017
Abstract We have determined minimum detection limits, MDLs, for elements 14 ⩽ Z ⩽ 86 using a transition-edge sensor array, TES array, and as a comparison using an Amptek X-123SDD silicon drift detector, SDD. This was done using a 3 MeV proton beam and a 5.1 MeV helium beam. MDLs were determined for a thin film sample on top of C substrate, and for a bulk sample containing mostly Al. Due to the higher peak-to-background ratio, lower detection limits were obtainable using the TES array for most of the elements. However, for elements 30 ⩽ Z ⩽ 45 the performance of the TES array was not as good as the SDD performance. This is due to the limitations of the TES used at energies >10 keV. The great…
Alkylthio-tetrasubstituted μ-Nitrido Diiron Phthalocyanines: Spectroelectrochemistry, Electrical Properties, and Heterojunctions for Ammonia Sensing.
2020
Alkylthio-tetrasubstituted μ-nitrido diiron phthalocyanine complexes are synthesized with n-butyl, iso-butyl, tert-butyl, and n-hexadecyl alkyl moieties. For the first time, a spectroelectrochemical investigation of μ-nitrido diiron phthalocyanines is achieved at all the redox steps. The complexes are stable in all their redox states, unlike their unsubstituted analogues. The interest of the present complexes is to prepare sensing devices by a solution processing method. Films are characterized by electronic absorption and Raman spectroscopies. Electrical measurements on resistors show the highly resistive behavior of these complexes, whatever the chain length. However, when combined with t…
Krūšu rajonā novietoto sensoru pielietojums slimnīcā iegūto izgulējumu novēršanas pasākumos
2020
Darba aktualitāte: Izgulējumi ir viena no visizplatītākajām slimnīcā iegūtām slimībām, kas var novest līdz dzīves pasliktināšanai un pat nāvei. Profilaktiskie pasākumi var samazināt izgulējumu biežumu veidošanos. Darba mērķis: Izvērtēt valkājamo sensoru nozīmi slimnieka pozas vērtēšanā 24 stundu laika periodā pētot pacienta pagriešanās laiku un apjomu. Materiāli un metodes: Prospektīvājā pētijumā tika pētīti RAKUS Stacionāra ”Biķernieki” iegūti dati no 15 valkājamiem Movesense sensoriem, kas tika novietoti uz pacienta krūšu kaula laika posmā no 10.02.20 līdz 12.03.20, pēc kā tika ieviesta ārkārtējā situācija un visi klīniskie pētījumi tika apstādināti. Sensors tika novietots uz krūšu kaula …
Miniature MOEMS hyperspectral imager with versatile analysis tools
2019
The Fabry-Perot interferometers (FPI) are essential components of many hyperspectral imagers (HSI). While the Piezo-FPI (PFPI) are still very relevant in low volume, high performance applications, the tunable MOEMS FPI (MFPI) technology enables volume-scalable manufacturing, thus having potential to be a major game changer with the advantages of low costs and miniaturization. However, before a FPI can be utilized, it must be integrated with matching optical assembly, driving electronics and imaging sensor. Most importantly, the whole HSI system must be calibrated to account for wide variety of unwanted physical and environmental effects, that significantly influence quality of hyperspectral…
Where do food likes and dislikes come from?
2020
Where do food likes and dislikes come from ? In other words, what are the factors that could explain why someone likes or dislikes a given food ? Most of the hedonic reactions to sensory stimulations brought by foods and, as a result reactions to foods carrying these sensory properties are learned through different learning mechanisms. The efficiency of these learning mechanisms mat depend on individual characteristics, in particular on the sensitivity to different sensory properties. Not all learnings are related to experiments with the food itself; many leamings depend on interactions within the family or social environment. Finally, cognitive determinants play also a role and, in particu…
Idrogeli a base di xyloglucano per la produzione di medicazioni avanzate nel trattamento delle ferite
2018
In questo lavoro sono stati preparati film sottili di idrogelo (reticolati fisicamente o chimicamente) a base di xyloglucano (XG) e XG/polivinilalcol (PVA), a cui si è aggiunto glicerolo come plasticizzante. Lo xyloglucano è un polisaccaride di origine vegetale, caratterizzato da una catena principale di (1,4)--Dglucosio con ramificazioni laterali di (1-6)-α-xilosio, parzialmente sostituite con (1-2)–β galattosio. E’ stata indagata la possibilità di modulare la densità di reticolazione dell’idrogelo per ottenere il miglior compromesso tra resistenza meccanica e flessibilità, l’integrità strutturale nel tempo e la capacità di assorbire fluidi biologici o trattenere l’umidità. Inoltre, ne è …
Iegultās iekārtas un programmatūra veselības datu pārraudzībai rehabilitācijas laikā
2015
Bakalaura darbs apskata sekojošu problēmu: pacientu veselības rādītāju pārraudzība rehabilitācijas iziešanas laikā. Autors apskata menisku bojājumu pēcoperāciju rehabilitācijas procesu ar mērķi definēt pārraudzībai nepieciešamus veselības rādītājus. Pirms risinājuma izstrādes tika veikta veselības speciālistu un bijušo pacientu intervēšana. Tas palīdzēja autoram aplūkot un izanalizēt situāciju no abām pusēm – saprast kādas grūtības pastāv fizioterapeitu darbā un atrast ar kādām problēmām saskarās pacienti pēc ceļa locītavas operācijas. Darba ietvaros tika veikta esošo risinājumu analīze ar mērķi aplūkot izmantotas tehnoloģijas un atrast šo izstrāžu priekšrocības un nepilnības. Apskatot un s…