Search results for " cloud"
showing 10 items of 294 documents
Noise Robustness Analysis of Point Cloud Descriptors
2013
In this paper, we investigate the effect of noise on 3D point cloud descriptors. Various types of point cloud descriptors have been introduced in the recent years due to advances in computing power, which makes processing point cloud data more feasible. Most of these descriptors describe the orientation difference between pairs of 3D points in the object and represent these differences in a histogram. Earlier studies dealt with the performances of different point cloud descriptors; however, no study has ever discussed the effect of noise on the descriptors performances. This paper presents a comparison of performance for nine different local and global descriptors amidst 10 varying levels o…
Adapting robot paths for automated NDT of complex structures using ultrasonic alignment
2019
Automated inspection systems using industrial robots have been available for several years. The IntACom robot inspection system was developed at TWI Wales and utilizes phased array ultrasonic probes to inspect complex geometries, in particular aerospace composite components. To increase inspection speed and accuracy, off-line path planning is employed to define a series of robotic movements following the surface of a component. To minimize influences of refraction at the component interface and effects of anisotropy, the ultrasonic probe must be kept perpendicular to the surface throughout the inspection. Deviations between the actual component and computer model used for path-planning resu…
Subsurface chemistry of mantles of interstellar dust grains in dark molecular cores
2010
Context. The abundances of many observed compounds in interstellar molecular clouds still lack an explanation, despite extensive research that includes both gas and solid (dust-grain surface) phase reactions. Aims. We aim to qualitatively prove the idea that a hydrogen-poor subsurface chemistry on interstellar grains is responsible for at least some of these chemical "anomalies". This chemistry develops in the icy mantles when photodissociation reactions in the mantle release free hydrogen, which escapes the mantle via diffusion. This results in serious alterations of the chemical composition of the mantle because pores in the mantle provide surfaces for reactions in the new, hydrogen-poor …
Costs of Using Hybrid Cloud Infrastructure: Towards a General Framework
2012
Cloud computing infrastructure is a state-of-the-art computing as a utility paradigm, offering individuals and organizations instantly-available and scalable computing capacity. Organizations may deploy the cloud infrastructure in own data centers, as a private cloud, or use the public on-demand cloud infrastructure charged on a pay-per-use basis. The organizations may also adopt a hybrid solution, i.e. use public cloud capacity to complement the resources in the private cloud, e.g. during the periods of rapid growth in the demand. One of the important factors that affect the organizations’ decisions to adopt a hybrid cloud is the total cost of acquiring and managing the infrastructure. In …
Vendor lock-in problem in cloud storage
2015
Pilvitallennuspalvelut tuovat datan tallentamiseen ennennäkemättömiä etuja ja niiden hyödyntäminen on, sekä yksittäisillä kuluttajilla, että yrityksillä, yleistymässä. Teknologiassa on kuitenkin vielä ongelmia ilman ratkaisua. Turvallisuus-, sekä yksityisyysseikat ovat tunnetuimpia, ja niitä on tutkittu laajalti. Vähemmälle huomiolle on jäänyt, kuinka vaikeaa on palveluntarjoajan vaihtaminen. Palveluntarjoajan vaihtaminen aiheuttaa aina kustannuksia asiakkaalle. Tilannetta, jossa vaihtokustannukset ovat niin suuret, että ne estävät palveluntarjoajan vaihtamisen, kuvataan termillä "vendor lock-in" (toimittajaloukku). Tämän kandidaatintutkielman tavoitteena on kirjallisuuskatsauksen perusteel…
Adopting encryption to protect confidential data in public clouds: A review of solutions, implementation challenges and alternatives
2015
A shift towards use of public cloud services is ongoing and more and more enterprises will start to use them in the near future. As public cloud services certainly promise to deliver many benefits, this new way of delivering services also introduces new types of risks. Due to the NSA’s surveillance programs, non-US enterprises need to reassess the risks of public cloud services provided by US companies and look for available solutions to protect their confidential data transferred and stored in the cloud. Encryption is seen as a solution to help enterprises full fill the requirements related to security and privacy, but is often challenging to implement. Encryption has its own security prob…
Deju kolektīvu sistēmas Adance android lietotne
2016
“Adance” Android lietotne ir papildinājums deju kolektīvu pārvaldības un informācijas sistēmai “Adance”. Šajā darbā izstrādātais Android klients ietver sevī sistēmas tūlītējās saziņas pakalpojumu, kura izstrādes procesam līdztekus arī tika izveidota sistēmas publiskā lietojumprogrammas saskarne (API). Lietotājiem ir iespēja piekļūt savām sarunām ar citiem kolektīvu dalībniekiem, lasīt savas ziņas reāllaikā, kad tās pienāk, kā arī izveidot jaunas sarakstes, lai uzturētu kontaktu ar saviem kolektīva biedriem.
Evolution of dry season low cloud cover over the Atlantic coast of Central Africa from diurnal to interannual scale
2022
Despite its bioclimatic importance, few studies have focused on the stratiform low-level cloud cover ofthe dry season (June-September) of the Atlantic coast of Central Africa. Using in-situ data documenting theperiod 1971-2019, we show that this cloud cover is underestimated by SAFNWC satellite observations andCMIP6 models. We identify three types of days: clear, cloudy at night and totally cloudy, the latterbeing more frequent on the coast and inland, to the windward of the Cristal and Chaillu Mountains. Onan interannual scale, temperature anomalies in the South Tropical Atlantic, the equatorial Pacific and theCongo Basin, by modulating the meridional and zonal circulation cells, influence…
New particle formation inside ice clouds: In-situ observations in the tropical tropopause layer of the 2017 Asian Monsoon Anticyclone
2021
Abstract. From 27 July to 10 August 2017 the airborne StratoClim mission took place in Kathmandu, Nepal where eight mission flights were conducted with the M-55 Geophysica up to altitudes of 20 km. New Particle Formation (NPF) was identified by the abundant presence of ultrafine aerosols, with particle diameters dp smaller than 15 nm, which were in-situ detected by means of condensation nuclei counting techniques. NPF fields in clear-skies as well as in the presence of cloud ice particles (dp > 3 µm) were encountered at upper troposphere/lowermost stratosphere (UT/LS) levels and within the Asian Monsoon Anticyclone (AMA). NPF-generated ultrafine particles in elevated concentrations (Nuf)…