Hole Patching In 3D Unstructured Surface Mesh

A three-dimensional object of interest in a volumetric data can be visualized using direct surface rendering methods or volume rendering approaches. Volume rendering is a visualization technique without providing the geometry information at all. However, an engineering analysis requires watertight surface geometry information of the object. Thus a three-dimensional object representation for the visualization using direct surface rendering may not necessarily be valid for engineering analysis, as such models are not necessarily watertight. Obtaining watertight surfaces has been a challenging task in the field of computational engineering due to presence of deficiencies such as gaps and holes in the surfaces. The focus of this thesis is to address the need to patch holes in the surfaces to obtain a watertight geometry. Most of the methods available for hole patching today are limited in their utility, in most cases, by the method with which the geometric model has been originally obtained. This research work provides an innovative and original method of creating surface patches for topologically simple holes in unstructured discrete geometry using parametric NURBS (Non-Uniform Rational B-Spline) surface formulation and Delaunay criteria for point insertion and edge swapping. Surface patches are generated using existing points surrounding the holes without altering the surrounding geometry. This study is to introduce the mathematic foundation and the computer algorithm developed, along with several examples to demonstrate the success of this approach. The watertight geometry so produced has a iii wide range of engineering applications in the field of mechanical simulation studies, using either computational fluid dynamics or computational structural mechanics

Hole Patching In Unstructured Mesh And Parallelization Using Graphics Processing Units

Engineering analysis of a three-dimensional geometric model using mesh-based computational technologies requires the model to be topologically watertight. However, achieving watertight geometry is considered to be a challenging task in the field of computational engineering due to the potential presence of geometric deficiencies, such as gaps and holes on the surfaces. This dissertation aims to repair the defective geometric model with the presence of holes irrespective of their complexities. Presented in this dissertation are novel research and implementation of a hybrid surface and volume-based technique for geometry repair. It utilizes a NURBS-based surface-patching algorithm for topologically simple holes and incorporates a volumetric hole-patching algorithm for complex holes. The volume-based hole-patching algorithm solves the diffusion equation using an explicit forward difference scheme in time and a centered difference scheme in space. A robust and efficient algorithm has been developed to both identify and extract a localized hole region. An automated mesh generation process has been implemented to construct individual column grids for each isolated hole region. The diffusion equation is solved using finite-difference techniques to generate a scalar solution field from which isosurfaces are extracted with an isovalue that represents the repaired surfaces for the local regions. Finally, a Poisson surface reconstruction is used to create a reconstructed watertight surface. The graphics processing unit (GPU) has emerged as the most powerful chip in a computer in the last decade but has only in the past few years received extensive attention from the research community for its use in high performance computing. This research explores a GPU-based implementation of a diffusion equation solution to better harness its computation potential and to facilitate the computational needs of geometry repair. Comparisons of the speedup gains for diffusion solutions using GPGPU with that of conventional single and multi-threaded implementations are presented, and their performance characteristics are discussed in this dissertation

Teneligliptin add on to monotherapy treatment in patients with type 2 diabetes

Background: In patient with type 2 diabetes (T2D) inadequately controlled on monotherapy, teneligliptin is efficacious and safe as add-on to treatment with oral antidiabetic drugs (OADs) or insulin. Data on efficacy of teneligliptin in Indian patients is relatively sparse. Aim of the study was to assess the efficacy of teneligliptin used as add-on treatment in patients inadequately controlled on monotherapy with OADs or insulin.Methods: We retrospectively evaluated the electronic database at our endocrinology clinic from East India. Patients who were treated with teneligliptin (20 mg/day) as add-on to monotherapy with OADs or insulin were identified, and data analysed. Primary assessment parameters were change in glycosylated haemoglobin (HbA1c %), fasting plasma glucose (FPG, mg/dL) and post-prandial plasma glucose (PPG, mg/dL) over 12-week from the addition of teneligliptin. Paired t test and McNemar test applied to derive statistical significance of paired continuous and categorical variables respectively.Results: In 88 patients, teneligliptin was used as add-on treatment in 77.3% and 22.7% patients receiving OAD and insulin as monotherapy respectively. Mean age of population was 48.3±15.1 years and 67% were males. From baseline to 12-weeks, there was significant change in HbA1c (9.6±2.1 to 8.4±1.2%, P<0.001), FPG (181.4±54.5 to 140.9±27.1 mg/dL, P<0.001) and PPG (273.7±75.6 to 201.1±47.7 mg/dL, P<0.001). Reduction in these glycemic parameters was significant in patients with teneligliptin as add-on to either OADs or insulin. Overall, 12.5% patients reached the target HbA1c of <7% after 12-week treatment (P=0.004).Conclusions: In patients who are uncontrolled on monotherapy with either OADs or insulin, addition of teneligliptin resulted in significant reduction of HbA1c, FPG and PPG after 12-week treatment. This establishes usefulness of teneligliptin in Indian patients with T2D. A larger, randomized, comparative study with other gliptins is warranted

Coding Estimation based on Rate Distortion Control of H.264 Encoded Videos for Low Latency Applications

In the field of video processing, advancements in video compression at various temporal and spatial resolutions which are needed in our research to quantify estimation of video quality whereabouts within spatial and temporal domain itself. It was necessary in our research to study the impacts of related video coding conditions upon perceptual quality due to issue raised by User Experience community regarding poor coding. But most of research studies are concerned with coding distortions affected by mostly due to poor coding which address high spatio-temporal resolutions. This paper presents overall 120 test scenarios for video sequences having low spatial and temporal spectral information were studied. Finally we concluded that even after achieving consistency within subjective scores, we got relevant data consistency after refining subjective scores, so it is not poor coding its due channel capacity which was traced out by rate distortion control

Early Detection System for Water Quality Monitoring of Cyanobacteria and Hexavalent Chromium using UV-Vis Derivative Spectrophotometry and Improvement of Detection Limit by Changing Pathlength

This work explores the use of readily available spectrophotometry to detect and monitor cyanobacteria and hexavalent chromium (Cr (VI)) under different water matrices. Research has shown that these parameters have been increasing in frequency worldwide with growing anthropological activities and aggravating climate change, resulting in unwanted source water contamination. The aim was to evaluate the potential of derivative spectrophotometry with changing cuvette pathlength (10-, 50-, and 100-mm) to be used as an early warning system for sensitive determination of the aforementioned parameters. Initially, Microcystis aeruginosa (cyanobacteria) and Chlorella vulgaris (green algae) were inoculated in deionized (D.I.) water individually and mixed in an equal concentration setting, respectively. The effect of increasing cuvette pathlength was investigated and results indicated a 15-, and 13-fold improvement in sensitivity with absorbance and derivative of absorbance from 10 mm to 100 mm pathlength, respectively. The lowest method detection limit (MDL) was observed using 100 mm and the concentration was found to be 4,916 cells/mL (for cyanobacteria), which is well below the WHO guideline for low probability of adverse health effects (< 20,000 cells/mL). Additionally, the mixed culture test demonstrated the potentiality of spectrophotometry to be able to identify cyanobacteria in mixed setting indicating applicability. Further microalgal testing was performed using longer pathlengths (50- and 100-mm), to investigate robustness of the developed methodology in surface water and under varying water quality parameters (WQPs) aka salinity, dissolved organic carbon (DOC), and turbidity, for realistic determination. 100 mm pathlength while employing derivative spectrophotometry were found to be most sensitive and concentration as low as 8,546 cells/mL could be detected. As expected, with increasing concentration of WQPs the sensitivity decreased, but overall, spectrophotometry was able to detect cyanobacteria in different water matrices. Lastly, similar methodology as before was exercised but it was applied for early detection of Cr (VI). Derivative spectrophotometry with longest pathlength was primarily utilized to investigate Cr (VI) response in D.I. water, pH water matrices, varying DOC, surface and tap water. Results indicated excellent MDLs as low as 2-, and 5-µg/L for tap and surface water, respectively, implicating practical viability

Dump slope stability analysis

In this modern world mining has become an integral part of our life. Mining activities effect in generation of both economic and noneconomic materials. The noneconomic materials are stored at selected places known as waste dumps. The stability of the waste dump has been of a matter of great concern over the years. The problems increases with limiting availability of land. In this project work the slope stability analysis is carried out for the waste dump of a selected iron ore open cast mine. In this process samples are collected and tests are carried out on these samples to get different geotechnical parameters. The factor of safety of different sections of the existing design of the selected mine are calculated by the help of GALENA software. In the end new design of dump slope are proposed by optimising the bench dimensions and material properties by the help of back analysis of GALENA. Then conclusion and various recommendation are given on the basis of new design of the dump slope