Search results for "anturit"

Managing sensor data streams in a smart home application

2020

A challenge in developing an ambient activity recognition system for use in elder care is finding a balance between the sophistication of the system and a cost structure that fits within the budgets of public and private sector healthcare organisations. Much activity recognition research in the context of elder care is based on dense networks of sensors and advanced methods, such as supervised machine learning algorithms. This paper presents the data processing aspects of an activity recognition system based on a simpler, knowledge-based unsupervised approach, designed for a sparse network of sensors. By structuring sensor data management as a streaming system, we provide a simple programmi…

A Multi-Position Calibration Method for Consumer-Grade Accelerometers, Gyroscopes, and Magnetometers to Field Conditions

2017

This paper presents a calibration method for consumer-grade accelerometers, gyroscopes, and magnetometers. Considering the calibration of consumer-grade sensors, it is essential that no specialized equipment is required to create reference signals. In addition, the less is required from the reference signals, the more suitable the method is on the field. In the proposed method, the novelty in the calibration of the gyroscopes lies in the exploitation of only the known net rotations between the positions in a multi-position calibration. For accelerometers and magnetometers, the innovation is that the direction of reference signals, the gravity and the magnetic field of the Earth, are estimat…

Calibration of in situ chlorophyll fluorometers for organic matter

2019

AbstractOrganic matter (OM) other than living phytoplankton is known to affect fluorometric in situ assessments of chlorophyll in lakes. For this reason, calibrating fluorometric measurements for OM error is important. In this study, chlorophyll (Chl) fluorescence was measured in situ in multiple Finnish lakes using two sondes equipped with Chl fluorometers (ex.470/em.650–700 nm). OM absorbance (A420) was measured from water samples, and one of the two sondes was also equipped with in situ fluorometer for OM (ex.350/em.430 nm). The sonde with Chl and OM fluorometers was also deployed continuously on an automated water quality monitoring station on Lake Konnevesi. For data from multiple lake…

Käsivedon muuttujien yhteys viidenkymmenen metrin vapaauinnin aikaan : uuden anturiteknologiaan perustuvan tehomittarin testaus

2017

Johdanto. Uimari on uidessaan käytännössä lähes koko vartalollaan kosketuksissa veteen. Vesi on väliaine, joka vastustaa uimarin etenemistä ja josta voiman ja vastavoiman periaatteen mukaisesti uimaria eteenpäin vievien voimien tukipinnat tulisi löytää. Veden viskoelastinen luonne luo omat erityispiirteensä eteenpäin suuntautuvien ja vastustavien voimien välille. Tässä tutkimuksessa keskitytään vapaauinnin käsivedon muuttujiin, joiden avulla pyritään arvioimaan uimarin käsivedon eteenpäin vieviä voimia ja niiden yhteyttä uintinopeuteen. Tämän lisäksi tutkitaan anturiteknologiaan perustuvan tehomittarin reliabiliteettia ja arvioidaan validiteettia. Menetelmät. Koehenkilöinä oli kansallisen j…

Automaattisen vedenlaadun seurantajärjestelmän luotettavuus ja toimivuus Kyrönjoella

2009

Simultaneous Noise and Impedance Fitting to Transition-Edge Sensor Data Using Differential Evolution

2020

We discuss a robust method to simultaneously fit a complex multi-body model both to the complex impedance and the noise data for transition-edge sensors. It is based on a differential evolution (DE) algorithm, providing accurate and repeatable results with only a small increase in computational cost compared to the Levenberg–Marquardt (LM) algorithm. Test fits are made using both DE and LM methods, and the results compared with previously determined best fits, with varying initial value deviations and limit ranges for the parameters. The robustness of DE is demonstrated with successful fits even when parameter limits up to a factor of 10 from the known values were used. It is shown that the…

Nanodevices by DNA based gold nanostructures

2017

In this thesis DNA based structures were utilized to create gold nanostructures for nanosensing and nanoelectronic applications. In the past, both of these fields have been dominated by the conventional lithography methods, e.g., electron beam lithography and UV-lithography, but more recently scaling down the components by these techniques has become increasingly more complex and costly. Especially in the micro- and nanoelectronics, the increase in the component density and thus computational power would require fabrication of sub-10-nm components, which is challenging for the top-down approaches. Aforementioned developments have led researchers to seek alternative methods to fabricate these…

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…

Laser-induced tuning of graphene field-effect transistors for pH sensing

2023

Here we demonstrate, using pulsed femtosecond laser-induced two-photon oxidation (2PO), a novel method of locally tuning the sensitivity of solution gated graphene field-effect transistors (GFETs) without sacrificing the integrity of the carbon network of chemical vapor deposition (CVD) grown graphene. The achieved sensitivity with 2PO was (25 ± 2) mV pH−1 in BIS-TRIS propane HCl (BTPH) buffer solution, when the oxidation level corresponded to the Raman peak intensity ratio I(D)/I(G) of 3.58. Sensitivity of non-oxidized, residual PMMA contaminated GFETs was 20–22 mV pH−1. The sensitivity decreased initially by 2PO to (19 ± 2) mV pH−1 (I(D)/I(G) = 0.64), presumably due to PMMA residue remova…

Covalent and non-covalent coupling of a Au102 nanocluster with a fluorophore : energy transfer, quenching and intracellular pH sensing

2021

Interactions between an atomically precise gold nanocluster Au102(p-MBA)44 (p-MBA = para mercaptobenzoic acid) and a fluorescent organic dye molecule (KU, azadioxatriangulenium) are studied. In solution, the constituents form spontaneously a weakly bound complex leading to quenching of fluorescence of the KU dye via energy transfer. The KU can be separated from the complex by lowering pH, leading to recovery of fluorescence, which forms a basis for an optical reversible pH sensor. However, the sensor is not a stable entity, which could be delivered inside cells. For this purpose, a covalently bound hybrid is synthesized by linking the KU dye to the ligand layer of the cluster via an ester b…