Random field sampling for a simplified model of melt-blowing considering turbulent velocity fluctuations

In melt-blowing very thin liquid fiber jets are spun due to high-velocity air streams. In literature there is a clear, unsolved discrepancy between the measured and computed jet attenuation. In this paper we will verify numerically that the turbulent velocity fluctuations causing a random aerodynamic drag on the fiber jets -- that has been neglected so far -- are the crucial effect to close this gap. For this purpose, we model the velocity fluctuations as vector Gaussian random fields on top of a k-epsilon turbulence description and develop an efficient sampling procedure. Taking advantage of the special covariance structure the effort of the sampling is linear in the discretization and makes the realization possible

Fractal compression and analysis on remotely sensed imagery

Remote sensing images contain huge amount of geographical information and reflect the complexity of geographical features and spatial structures. As the means of observing and describing geographical phenomena, the rapid development of remote sensing has provided an enormous amount of geographical information. The massive information is very useful in a variety of applications but the sheer bulk of this information has increased beyond what can be analyzed and used efficiently and effectively. This uneven increase in the technologies of gathering and analyzing information has created difficulties in its storage, transfer, and processing. Fractal geometry provides a means of describing and analyzing the complexity of different geographical features in remotely sensed images. It also provides a more powerful tool to compress the remote sensing data than traditional methods. This study suggests, for the first time, the implementation of this usage of fractals to remotely sensed images. In this study, based on fractal concepts, compression and decompression algorithms were developed and applied to Landsat TM images of eight study areas with different land cover types; the fidelity and efficiency of the algorithms and their relationship with the spatial complexity of the images were evaluated. Three research hypotheses were tested and the fractal compression was compared with two commonly used compression methods, JPEG and WinZip. The effects of spatial complexity and pixel resolution on the compression rate were also examined. The results from this study show that the fractal compression method has higher compression rate than JPEG and WinZip. As expected, higher compression rates were obtained from images of lower complexity and from images of lower spatial resolution (larger pixel size). This study shows that in addition to the fractal’s use in measuring, describing, and simulating the roughness of landscapes in geography, fractal techniques were useful in remotely sensed image compression. Moreover, the compression technique can be seen as a new method of measuring the diverse landscapes and geographical features. As such, this study has introduced a new and advantageous passageway for fractal applications and their important applications in remote sensing

A Nonlinear Mixture Autoregressive Model For Speaker Verification

In this work, we apply a nonlinear mixture autoregressive (MixAR) model to supplant the Gaussian mixture model for speaker verification. MixAR is a statistical model that is a probabilistically weighted combination of components, each of which is an autoregressive filter in addition to a mean. The probabilistic mixing and the datadependent weights are responsible for the nonlinear nature of the model. Our experiments with synthetic as well as real speech data from standard speech corpora show that MixAR model outperforms GMM, especially under unseen noisy conditions. Moreover, MixAR did not require delta features and used 2.5x fewer parameters to achieve comparable or better performance as that of GMM using static as well as delta features. Also, MixAR suffered less from overitting issues than GMM when training data was sparse. However, MixAR performance deteriorated more quickly than that of GMM when evaluation data duration was reduced. This could pose limitations on the required minimum amount of evaluation data when using MixAR model for speaker verification

Maastikumeetrika ja ökosüsteemi kultuuriteenused – ressursipõhine integreeriv lähenemine maastikuharmoonia kaardistamisele

A Thesis for applying for the degree of Doctor of Philosophy in Environmental Protection.The overall idea of PhD thesis was to explain with objective evidence and using mapping techniques, why and how people value particular visual landscapes. Mainstream mapping research usually refers to uniqueness, diversity and naturalness of landscapes as the main factors for landscape values and preferences. These variables can be easily measured using satellite imagery and cartographic materials: for example, the diversity of landscape elements can be assessed with a function of Shannon information entropy, and naturalness – as the share of relatively natural land cover within the region of interest. However, psychological background suggests other important attributes of landscape experience – harmony, unity or coherence of the scene. Mentioned aspects are usually measured subjectively with questionnaires and surveys. Measuring landscape preferences is also quite a challenging task, requiring many people involved in assessment of photographs or even having a nature trip (with obvious drawbacks in spatial coverage and replicability with other evaluators). Therefore, the PhD research was designed to make all assessments as objective, as possible. Overall landscape coherence, for the first time, was measured as the extent to which total diversity of digital landscape model (composed of landforms and land cover) exceeds the added diversity of landforms and land cover alone. In this way, coherence was directly related to system properties of landscape, making it legible and understandable. Also, for the first time colour harmony of land cover was evaluated with remotely sensed data (satellite imagery). Retrieved map-based indices were examined with geo-located photographs of landscapes and outdoor recreation, uploaded to social media, such as Flickr, VK.com and former Panoramio. The study contributes to the operationalisation of landscape beauty and, therefore, more advanced landscape management, nature protection and sustainability of land use practises.Doktoritöö eesmärk on kaardistustehnoloogiad kasutades tõenduspõhiselt selgitada, miks ja kuidas inimesed väärtustavad teatud maastikke visuaalsest seisukohast. Peavoolu kaardistusuuringud tavaliselt keskenduvad maastiku väärtuste ja eelistuste hindamisel unikaalsusele, mitmekesisusele ja looduslikkusele. Neid muutujaid saab satelliitpiltide ja kartograafilise materjali põhjal lihtsalt mõõta, näiteks maastikuelementide mitmekesisust saab hinnata Shannoni entroopiavalemiga ning looduslikkust vastava iseloomuga maakatte osakaaluga uuritaval alal. Psühholoogilisest vaatepunktist lähtudes on maastikukogemusel veel teisi olulisi omadusi, nagu vaate harmoonia, ühtsus või kooskõla sidusus. Uuringute puhul mõõdetakse neid muutujaid tavaliselt subjektiivselt. Maastikueelistuste teaduslik hindamine on tõsine metoodiline väljakutse, mis nõuab paljude hindajate osalemist näiteks maastikufotode hindamisel või vahetult looduses, kus tuleb arvestada piirangutega ruumilisel esindatusel või hinnangute replikatiivsusel. Arvestades eelnimetatud asjaolusid, on dissertatsiooni eesmärgiks seatud leida võimalikult objektiivseid teid tavaliselt subjektiivsetena käsitletavate maastikumuutujate hindamisel. Uudne on üldise maastiku kooskõla mõõdetmine digitaalse pinnavorme ja maakatet hõlmava maastikumudeliga, võrreldes nende komponentide eraldi mõõtmisega. Selliselt menetledes on koherentsus otseselt seostatav maastiku struktuursete parameetritega ja seega muudab hinnangud loetavamaks ja arusaadavamaks. Esmakordselt on kaugseire andmete (satelliitpildid) alusel hinnatud ka maakatte värviharmooniat. Määratletud kaardipõhiseid indekseid kontrolliti kohtseotud fotodega maastikuvaadetest ning välirekreatsiooni tegevustest sotsiaalmeedias (nt Flickr, VK.com ja varasem Panoramio). Uuring aitab paremini mõista ja rakendada maastiku ilu hindamise käiku ja seeläbi kasutada esteetilist kvaliteeti maastiku planeerimisel ja korraldamisel, looduskaitses ja teistes säästva maakasutuse praktilistes valdkondades.Publication of this dissertation has been supported by the Estonian University of Life Science

Photorealistic visualisation of urban greening in a low-cost high- density housing settlement.

Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.Apartheid housing policies of the pre-1994 South African government, and the low-cost highdensity housing programmes of the post-1994 government, has given rise to numerous urban environmental problems, some of which could be addressed in a cost-effective and sustainable manner through urban greening, while simultaneously promoting biodiversity. Public participation in the planning of urban greening has been identified as being of vital importance, without which urban greening projects run a high, and expensive, risk of failure. Previous studies indicate that the greening priorities of residents in low-cost high-density housing settlements may differ considerably from those of managers and experts tasked with the protection and extension of the natural environment resource base. A system of participatory decision support is therefore required to reconcile the greening requirements of the community, and the ecological benefits of biodiversity. If language, literacy, map literacy and numeracy difficulties are to be avoided, and a sense of place or belonging is to be invoked, such a participatory decision support system should, ideally, be visually based, and capable of generating realistic eye-level depictions of the urban landscape. New computer-based landscape visualisation applications, which can directly utilise GIS, CAD and DEM data to produce detailed photo-realistic viewsheds, were deemed better suited to the task of visualising urban greening than existing GIS based mapping systems, CAD and traditional landscape visualisation methods. This dissertation examines the process of constructing a 3D computer model of the Mount Royal low-cost high-density housing settlement, situated in the eThekwini Municipality, KwaZulu-Natal, South Africa. Visualisations including terrain, natural features, indigenous vegetation, houses and roads were produced and submitted, with a questionnaire, to experts from different disciplines, Mount Royal residents and neighbors. Results from the expert survey indicate moderate support for visualisation in professional decision-making. However, both experts and residents expressed strong support for the accuracy and credibility ofthe visualisations, as well as for their potential in a participatory decision support system

Theoretical Engineering and Satellite Comlink of a PTVD-SHAM System

This paper focuses on super helical memory system's design, 'Engineering, Architectural and Satellite Communications' as a theoretical approach of an invention-model to 'store time-data'. The current release entails three concepts: 1- an in-depth theoretical physics engineering of the chip including its, 2- architectural concept based on VLSI methods, and 3- the time-data versus data-time algorithm. The 'Parallel Time Varying & Data Super-helical Access Memory' (PTVD-SHAM), possesses a waterfall effect in its architecture dealing with the process of voltage output-switch into diverse logic and quantum states described as 'Boolean logic & image-logic', respectively. Quantum dot computational methods are explained by utilizing coiled carbon nanotubes (CCNTs) and CNT field effect transistors (CNFETs) in the chip's architecture. Quantum confinement, categorized quantum well substrate, and B-field flux involvements are discussed in theory. Multi-access of coherent sequences of 'qubit addressing' in any magnitude, gained as pre-defined, here e.g., the 'big O notation' asymptotically confined into singularity while possessing a magnitude of 'infinity' for the orientation of array displacement. Gaussian curvature of k(k<0) is debated in aim of specifying the 2D electron gas characteristics, data storage system for defining short and long time cycles for different CCNT diameters where space-time continuum is folded by chance for the particle. Precise pre/post data timing for, e.g., seismic waves before earthquake mantle-reach event occurrence, including time varying self-clocking devices in diverse geographic locations for radar systems is illustrated in the Subsections of the paper. The theoretical fabrication process, electromigration between chip's components is discussed as well.Comment: 50 pages, 10 figures (3 multi-figures), 2 tables. v.1: 1 postulate entailing hypothetical ideas, design and model on future technological advances of PTVD-SHAM. The results of the previous paper [arXiv:0707.1151v6], are extended in order to prove some introductory conjectures in theoretical engineering advanced to architectural analysi

Summaries of FY 1995 engineering research

The individual engineering project summaries follow the program overview. The summaries are ordered alphabetically by name of institution and so the table of contents lists all the institutions at which projects were sponsored in fiscal year 1995. Each project entry begins with an institutional-departmental heading. The names of investigators are listed immediately below the title. The funding level for fiscal year 1995 appears to the right of title; it is followed by the budget activity number. These numbers categorize the projects for budgetary purposes and the categories are described in the budget number index. A separate index of Principal Investigators includes phone number, fax number and e-mail address, where available. The fiscal year in which either the project began or was renewed and the anticipated duration in years are indicated respectively by the first two and last digits of the sequence directly below the budget activity number. The summary description of the project completes the entry