Search results for "Estimation"
showing 10 items of 924 documents
Biomass estimator for NIR image with a few additional spectral band images taken from light UAS
2012
A novel way to produce biomass estimation will offer possibilities for precision farming. Fertilizer prediction maps can be made based on accurate biomass estimation generated by a novel biomass estimator. By using this knowledge, a variable rate amount of fertilizers can be applied during the growing season. The innovation consists of light UAS, a high spatial resolution camera, and VTT's novel spectral camera. A few properly selected spectral wavelengths with NIR images and point clouds extracted by automatic image matching have been used in the estimation. The spectral wavelengths were chosen from green, red, and NIR channels.
Optical measurement of virtual reality headset performance
2018
Virtuaalitodellisuussilmikoiden päänseurantajärjestelmän suorituskyvyn mittaamista varten kehitettiin mittausmenetelmä ja sulautettu kameramoduuli. Kyse on päästä päähän mittauksesta (engl. end-to-end measurement), jossa robotti liikuttaa silmikkoa ja kamera mittaa sisällön muutoksia näytöllä. Tavoitteena on optisesti mitata päänseurantajärjestelmän tarkkuutta kuvaamalla näytön sisältöä näytön virkistykseen tahdistettuna. Työssä keskityttiin kameramoduulin ja siihen liittyvien konenäköalgoritmien kehittämiseen. Mittauksessa näytöllä on kolmiulotteinen kohde, jossa on tunnistettavia pisteitä. Paikallistamalla nämä pisteet kuvassa voidaan määrittää grafiikkamoottorin virtuaalisen kameran asen…
Time estimation in Alzheimer and the role of the central executive
2004
The aim of this study was to evaluate the role of short-term memory and attention in time estimation. For this purpose we studied prospective time verbal estimation in 21 patients with Alzheimer's disease (AD), and compared their performance with that of 21 matched normal controls in two different conditions: during a digit span task and during an attentional task. Results showed that the performance of AD patients was significantly worse than that of the controls; the interaction between group and condition was significant. We suggest a role of attentional-executive functions in prospective time estimation.
Estimation of the Time-Variant Velocity of a Single Walking Person in Two-Dimensional Non-Stationary Indoor Environments Using Radio-Frequency Techni…
2020
Accurate estimation of the time-variant (TV) velocity of moving persons/objects in indoor spaces is of crucial importance for numerous wireless indoor applications. This article introduces a novel iterative procedure to estimate the TV velocity, i.e., TV speed and TV angle-of-motion (AOM), of a single moving person in 2D indoor environments by using radio-frequency (RF) techniques. The indoor area is equipped with a distributed 2 × 2 multiple-input multiple-output (MIMO) system. The proposed method is divided into two parts. In the first part, we estimate the path gains and the instantaneous Doppler frequencies by fitting the exact spectrograms of the complex channel gains of a 2D no…
The forecasting of the roadside pollutant levels to evaluate traffic management measures in Palermo.
2015
The road transport has become the major source of environmental degradation in urban centres. It produces negative externalities (i.e. pollution, delay, etc.) that are usually connected with the queues of traffic flows and the congestion of the road network. The quantitative estimation of roadside pollutant levels is very complex. Many variables are involved such as the type of vehicle (characterized by different antipollution devices, used fuels, engine temperatures, maintenance level of engines, etc.), the different cinematic conditions of the flows, the urban/road network structure, the weather conditions, etc. Therefore it is important to develop scientific tools able to predict roadsid…
Weight Reduction Behaviors Among European Adolescents : Changes From 2001/2002 to 2017/2018
2020
Purpose The purpose of this study was to analyze changes in the prevalence of weight reduction behaviors (WRBs) among European adolescents from 26 countries between 2001/2002 and 2017/2018. The impact of the perception of body weight on WLB was also analyzed, with particular attention being paid to overestimation. Methods The data of 639,194 European adolescents aged 11, 13, and 15 years who participated in the Health Behaviour in School-aged Children survey were analyzed. Age-standardized prevalence rates of WRB were estimated separately by survey round and gender for each country, using the overall 2017/2018 Health Behaviour in School-aged Children study population as the standard. Multiv…
Adaptīvās nošķeltās vidējās vērtības metode
2022
Darbā tiek izpētītas zinātniskajā literatūrā līdz šim zināmas adaptīvās nošķeltās vidējās vērtības metodes, kā arī vispārīgi aprakstītas robustās statistikas metodes.
Variance Estimation for the Horvitz-Thompson Total Estimator in Unequal Probability Sampling Designs
DISCHARGE HYDROGRAPH ASSESSMENT THROUGH REVERSE ROUTING MODEL IN RIVERS WITH SIGNIFICANT LATERAL INFLOW
Author Correction: Evaluation of three methods for biomass estimation in small invertebrates, using three large disparate parasite species as model o…
2018
Invertebrate biomass is considered one of the main factors driving processes in ecosystems. It can be measured directly, primarily by weighing individuals, but more often indirect estimators are used. We developed two indirect and non-destructive approaches to estimate biomass of small invertebrates in a simple manner. The first one was based on clay modelling and the second one was based on image analysis implemented with open-source software. Furthermore, we tested the accuracy of the widely used geometric approximation method (third method). We applied these three different methods to three morphologically disparate model species, an acanthocephalan worm, a crustacean and a flatworm. To …