Search results for " frequency"
showing 8 items of 1398 documents
Building and Testing a Comparative Interface on Northwest European Historical Parliamentary Debates : Relative Term Frequency Analysis of British Rep…
2022
Tensions between the people and parliament over representation are a normal feature of representative democracies. In this paper, we demonstrate how digital humanities analysis tools help in answering questions about the timing of debates on popular representation, tensions over its realization, and representatives’ changing perceptions on their parliamentary role. Our long-term approach to the conceptual history of political representation is based on the analysis of digitized parliamentary debates as nexuses of multi-sited political discourse. We combine computer-assisted distant and context-sensitive close reading to consider diachronic trends and synchronic political struggles surroundi…
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 Effects of Consumer Demographics and Payment Method Preference on Product Return Frequency and Reasons in Online Shopping
2021
In online shopping, product returns are very common. In order to reduce them, one must first understand who are making them and why are they being made. In this study, we aim to address these questions by examining product return behaviour from a consumer-centric rather than the more traditional product-centric, retailer-centric, and order-centric perspectives. More specifically, we focus on the effects of four demographic characteristics of consumers (i.e., gender, age, education, and income) as well as their payment method preference on their product return frequency and product return reasons. As the data, we use the responses from 560 Finnish online consumers, which were collected with …
Structure and dynamics in liquid bismuth and Bin clusters: A density functional study
2014
Density functional/molecular dynamics simulations with more than 500 atoms have been performed on liquid bismuth at 573, 773, 923, and 1023 K and on neutral Bi clusters with up to 14 atoms. There are similar structural patterns (coordination numbers, bond angles, and ring patterns) in the liquid and the clusters, with significant differences from the rhombohedral crystalline form. We study the details of the structure (structure factor, pair, and cavity distribution functions) and dynamical properties (vibration frequencies, diffusion constants, power spectra), and compare with experimental results where available. While the three short covalent bonds typical to pnictogens are characteristi…
Sensitivity Analysis and Frequency Dynamics of Grid-Connected Converters with Virtual Inertia
2021
For the participation in the frequency control of the system, power converters can be controlled with different strategies and methods, sharing the common concept of virtual inertia capability. In this work, a sensitivity analysis of two main categories of converter controls with virtual inertia is presented. The considered schemes are a grid-following current vector control with additional virtual inertia block and a grid-forming control scheme based on virtual synchronous machine concept. A proper basis for the comparison is first assessed providing an analytical correlation between the control parameters of the two schemes. For the two control strategies, the sensitivity analysis of the …
Energy Efficient Optimization for Wireless Virtualized Small Cell Networks With Large-Scale Multiple Antenna
2017
Wireless network virtualization is envisioned as a promising framework to provide efficient and customized services for next-generation wireless networks. In wireless virtualized networks (WVNs), limited radio resources are shared among different services providers for providing services to different users with heterogeneous demands. In this paper, we propose a resource allocation scheme for an orthogonal frequency division multiplexing-based WVN, where one small cell base station equipped with a large number of antennas serves the users with different service requirements. In particular, with the objective to obtain the energy efficiency in the uplink, a joint power, subcarrier, and antenn…
Pastāvīgo vārdu biežums laikrakstu tiešsaistes publikācijas un to diskusiju ziņās
2016
Šis darbs iepazīstina ar laikraksta The Guardian tiešsiastes publikāciju analīzi. Šī darba mērķis ir izanalizēt pastāvīgo vārdu (lietvārdu, darbības vārdu un īpašības vārdu) biežumu laikrakstu publikācijas un to diskusiju ziņās. Galvenā pētījuma metode bija korpusa-lingvistiskā metode, kas balstīta uz Makenerija (2006) teoriju. Šī darba autors izveidoja mini-korpusu, kas sastāvēja no divām teksta grupām: laikrakstu publikācijām un diskusiju ziņām. Vārdšķiru biežuma sadalījums korpusā, norāda uz formalitātes līmeņu atšķirību starp laikrakstu publikācijām un to diskusiju ziņām. Iegūtie rezultāti norāda uz reģistra variāciju izanalizētājos korpusa žanra tekstos. Lai identificētu līdzības un at…
Vain yksi voimaharjoitus viikossa riittää toimintakyvyn ylläpitämiseen ikääntyneillä
2018
Tutkimuksella selvitimme, parantaako voimaharjoittelu iäkkäiden toimintakykyä, ja onko harjoitusmäärillä vaikutusta toimintakyvyn muutoksiin. Tutkimukseen osallistui 106 koehenkilöä (65–75 v.), jotka satunnaistettiin neljään ryhmään: 1x/vko (H1, n=26), 2x/vko (H2, n=27) ja 3x/vko (H3, n=28) harjoitteleviin ja kontrolliryhmään (K, n=25). Ensimmäisen kolmen kuukauden ajan kaikki harjoitteluryhmät voimaharjoittelivat valvotusti kahdesti viikossa (H, n=81), jonka jälkeen ryhmät harjoittelivat kuusi kuukautta (3 kk–9 kk) nimensä mukaisesti kerran, kahdesti tai kolmesti viikossa. Koehenkilöille suoritettiin testit 0 kk, 3 kk ja 9 kk. Toimintakykyä testattiin etuperinkävelyllä (E), takaperinkävely…