Search results for "Pd"
showing 10 items of 1971 documents
Zīmolu "DPD", "Omniva" un "Pasta Stacija" komunikācijas ietekme uz patērētāju izvēli: pakomātu pakalpojumu piemērs
2018
Bakalaura darba tēma ir “Zīmolu “DPD”, “Omniva” un “Pasta Stacija” komunikācijas ietekme uz patērētāju izvēli: pakomātu pakalpojumu piemērs”. Pētījuma mērķis ir izpētīt zīmolu komunikācijas aktivitāšu nozīmi un izprast kopējos patērētāju pakomātu pakalpojumu izvēles kritērijus. Latvijā savā starpā pašlaik konkurē trīs lielākie pakomātu pakalpojumu sniedzēji – “DPD”, “Omniva” un “Pasta Stacija”, kas piedāvā vienāda rakstura pakalpojumus. Līdz ar to, šī bakalaura darba pētījuma problēma ir tas, kā un ar kādām metodēm, katrs no pētāmajiem zīmoliem cenšas panākt, ka tiek izmantoti konkrēti viņu pakomātu pakalpojumi. Darbs sastāv no teorētiskās, metodoloģiskās, empīriskās daļas un pielikumiem. T…
Association between clusters of diseases and polypharmacy in hospitalized elderly patients: results from the REPOSI study.
2011
BACKGROUND: Although the association between multimorbidity and polypharmacy has been clearly documented, no study has analyzed whether or not specific combinations of diseases influence the prescription of polypharmacy in older persons. We assessed which clusters of diseases are associated with polypharmacy in acute-care elderly in-patients. METHODS: This cross-sectional study was held in 38 Italian internal medicine and geriatric wards participating in the Registro Politerapie SIMI (REPOSI) study during 2008. The study sample included 1155 in-patients aged 65 years or older. Clusters of diseases, defined as two or more co-occurring specific chronic diseases, were identified using the odds…
Apdrošināšanas sistēmas komponenšu modernizācija
2022
Kvalifikācijas darba ietvaros tika veikta divu apdrošināšanas sistēmas komponentu modernizācija uz .Net Core standartu, saglabājot esošo funkcionalitāti. Izstrādātās komponentes nodrošina iespēju sistēmas administratoram apskatīt esošas sistēmas lietotājus, veidot jaunus lietotājus, pārvaldīt lietotajā grupas un lomas, ka arī sistēmas lietotajam apskatīt polises apdrošināšanas atlīdzības un tai pievienotus failus. Šī darba mērķis: • modernizēt esošas .Net framework sistēmas komponentus uz jaunu .Net Core standartu, dodot iespēju kontainerizēt šīs komponentes izvietošanai makoņpakalpojumā • pārrakstīt lapas no ASP.NET Web Forms uz ASP.NET Core MVC izmantojot Razor pages. • atvieglināt sistēm…
Derivation of a Homogenized Two-Temperature Model from the Heat Equation
2014
This work studies the heat equation in a two-phase material with spherical inclusions. Under some appropriate scaling on the size, volume fraction and heat capacity of the inclusions, we derive a coupled system of partial differential equations governing the evolution of the temperature of each phase at a macroscopic level of description. The coupling terms describing the exchange of heat between the phases are obtained by using homogenization techniques originating from [D. Cioranescu, F. Murat: Coll\`ege de France Seminar vol. 2. (Paris 1979-1980) Res. Notes in Math. vol. 60, pp. 98-138. Pitman, Boston, London, 1982.]
On asymptotic behavior of solutions to higher-order sublinear Emden–Fowler delay differential equations
2017
Abstract We study asymptotic behavior of solutions to a class of higher-order sublinear Emden–Fowler delay differential equations. Our theorems improve several results reported recently in the literature. Two examples are provided to illustrate the importance and advantages of new criteria.
Inverse problems for $p$-Laplace type equations under monotonicity assumptions
2016
We consider inverse problems for $p$-Laplace type equations under monotonicity assumptions. In two dimensions, we show that any two conductivities satisfying $\sigma_1 \geq \sigma_2$ and having the same nonlinear Dirichlet-to-Neumann map must be identical. The proof is based on a monotonicity inequality and the unique continuation principle for $p$-Laplace type equations. In higher dimensions, where unique continuation is not known, we obtain a similar result for conductivities close to constant.
Partial discharges behavior under different rectified waveforms
2017
In this work, a previous software used to simulate partial discharges (PDs) under Alternating Current (AC) stress has been modified in order to evaluate the PDs behavior under a voltage stress close to the Direct Current (DC) waveform. By using a full-wave and a half-wave rectifier, the specimen with an air void defects has been subjected to a gradual constant stress. Finally, a capacitive filter has been inserted in order to produce a steadier voltage supply. Simulation results show that under an almost DC waveform, the PDs activity become less compared to AC stress.
Partial discharge detection and localization along medium voltage cables
2017
In the last years different partial discharge (PD) measuring techniques have been developed because PD diagnostic is the most widely tool to evaluate the insulation condition of a power cable. Recently non-conventional methods and sensors have been used in order to reach improved results in PD measurements. The purpose of this work is to perform measurements that allow to study the variation of pulses when they travel along a MV cable and to locate the pulse source through the time arrival difference of the pulses obtained from two sensors installed separately.
Critical issues in the PD testing methodology for XLPE-insulated MV cables: An experimental case
2017
This paper describes some critical issues arising during the partial discharge (PD) testing of a 500m delivery length of an XLPE-insulated MV cable. At first, conventional PD measurements were performed on the whole length by using a standard acquisition system; PDs activity was detected, but the system allowed the operator to localize the PDs only on a length of 70 m. A visual inspection of this section highlighted the presence of an excoriation in the outer sheet. Aiming at a more accurate pin-pointing of the defect, more measurements were carried out in the proximity of the outer defect using a portable PD detection system. These measurements showed PDs activity, whose source was located…
The Effect of the Harmonic Content Generated by AC/DC Modular Multilevel Converters on HVDC Cable Systems
2019
With the increasing penetration of renewable and decentralized energy sources into the power grid, an extended use of DC voltages is expected on both distribution and transmission levels. Generation of DC voltages by means of voltage source converters is associated with a wide spectrum of harmonic distortions at converter terminals, both on the ac and on the dc sides. This can lead to partial discharges in power cables, which deteriorate insulation material thus weakening its performance and reducing cable life-time. In the previously published paper, the effect of harmonic distortion on appearance of partial discharges in cable insulation was evaluated. Here, the study related to the PD be…