745 research outputs found
Seismotectonic content by the source parameters of the 10 June 2012 Ölüdeniz-Fethiye (Dodecanese Islands) Mw 6.1 earthquake and aftershocks (southwestern Turkey)
Prediction of groundwater levels from lake levels and climate data using ann approach
There are many environmental concerns relating to the quality and quantity of surface and groundwater. It is very important to estimate the quantity of water by using readily available climate data for managing water resources of the natural environment. As a case study an artificial neural network (ANN) methodology is developed for estimating the groundwater levels (upper Floridan aquifer levels) as a function of monthly averaged precipitation, evaporation, and measured levels of Magnolia and Brooklyn Lakes in north-central Florida. Groundwater and surface water are highly interactive in the region due to the characteristics of the geological structure, which consists of a sandy surficial aquifer, and a highly transmissive limestoneconfined aquifer known as the Floridan aquifer system (FAS), which are separated by a leaky clayey confining unit. In a lake groundwater system that is typical of many karst lakes in Florida, a large part of the groundwater outflow occurs by means of vertical leakage through the underlying confining unit to a deeper highly transmissive upper Floridan aquifer. This providesa direct hydraulic connection between the lakes and the aquifer, which creates fast and dynamic surface water/groundwater interaction. Relationships among lake levels, groundwater levels, rainfall, and evapotranspiration were determined using ANN-based models and multiple-linear regression (MLR) and multiple-nonlinear regression (MNLR) models. All the models were fitted to the monthly data series and their performances were compared. ANN-based models performed better than MLR and MNLR models in predicting groundwater levels.Keywords: groundwater, surface water, interaction, artificial neural networ
A Comparison of Heuristic Methods for Optimum Power Flow Considering Valve Point Effect
Optimum Power Flow (OPF) is one of the key considerations for planning, generation control and management of electric utility. Hence it is of major importance to solve OPF with minimum cost within reasonable computing time. This paper presents solutions of OPF with Valve Point Effect (OPF-VPE) using Genetic Algorithm (GA), Differential Evolution (DE), Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). When steam valve starts to open in a turbine it changes generation curve. The valve point effect is considered by adding sine component to the quadratic cost function for OPF-VPE. Also, penalty function is added for generator violations. The common parameters of algorithms such as population size and the iteration number are selected same values for the comparison of algorithms for solving OPFVPE. Specific parameters are stated and used for each algorithm. The heuristic algorithms are examined on IEEE-30 bus system and convergence curves are demonstrated with the system results. Performances of each algorithm are discussed as regards optimizing fuel cost, iteration time and other system results
Über multiple Wasserstoffbrücken orthogonal koordinierende Bausteine für supramolekulare Strukturen
Im Rahmen dieser Promotionsarbeit erfolgte die Darstellung von fünf (ADDA)2-Verbindungen, bei denen zwei Erkennungsdomänen mit der Wasserstoffbrückensequenz Akzeptor-Donor-Donor-Akzeptor (ADDA) über Alkyl- bzw. Dioxaalkylarme mit einem Iodaromaten kovalent verknüpft wurden. Anschließend wurden diese (ADDA)2-Verbindungen in kupplungsfähige Derivate überführt und sollten mit Hilfe von Palladium-katalysierten Kreuzkupplungen mit einem 5-substituierten N,N'-Bis(6-valeroylaminopyrid-2-yl)-isophthalsäurediamid (Hamilton-Rezeptor) verknüpft werden. Diese Synthese eines (DAD^DAD)-(ADDA)2-Moleküls gelang trotz Anwendung verschiedener Kupplungsmethoden wie der Sonogashira-, der Suzuki- und der Stille-Kupplung leider nicht im präparativen Maßstab; ein solches Verzweigungsstück konnte aber massenspektrometrisch nachgewiesen werden. Eine weitere Aufgabe dieser Arbeit bestand in der Synthese eines polymerisierbaren Hamilton-Rezeptors und in der Darstellung eines ebenfalls polymerisierbaren, aber zum Hamilton-Rezeptor nur teilkomplementären Gegenmoleküls
Comparison of uterine, endometrial and ovarian blood flow by transvaginal color Doppler ultrasound in ovulatory and anovulatory cycles
Objectives: Blood flow to uterus and ovaries is demonstrated to be altered during mensturation. Studies has been published stating that blood flow differs also in ovulatory and anovulatory cycles. In this study, using color Doppler ultrasound, we aim to compare uterine, endometrial and ovarian blood flow during ovulatory and anovulatory cycles.
Material and methods: Women volunteers who are aged between 18–40 had no endocrinological problem and not recieving exogenous hormone therapy were included to study. Blood levels of FSH, LH, E2, prolactine, DHEAS, free T4 were collected in early follicular phase. Uterina, subendometrial and intraovarian artery blood flow pulsatility and resistance indexes were analysed using Doppler USG technique. Patients were called out to control on 21st of cycle and progesterone levels were analysed. Patients who has ovulation signs in USG and progesterone level above 5 ng/mL were included to ovulatory cycle group. Patient who has no signs of ovulation in ultrasound and has not enough progesterone level were included to anovulatory cycle group.
Results: LH and E2 levels were significantly higher in anovulatory patients. No correlation was found between endometrial blood flow resistance and basal E2, prolactine, testosterone levels. However, DHEAS levels were related to endometrial blood flow resistance in anovulatory cycles. No correlation was found between ovarian blood flow resistance/uterine blood flow resistance and basal E2, prolactine, testosterone, DHEAS levels.
Conclusions: There is statistically significant difference between endometrial, ovarian, uterine artery blood flow resistance in ovulatory and anovulatory cycles. Blood flow resistance was found to be increased in anovulatory patients. Increased E2 levels in anovulatory cycles were related to endometrial linethickness and endometrial volum
Comparison of posterior cranial fossa morphometric measurements in Chiari type I patients with and without syrinx cavity on magnetic resonance imaging
Purpose: To compare the posterior fossa measurements of Chiari type I malformation (CHM1) patients with and without syrinx and with a control group. Material and methods: The patients with syrinx were divided into 2 groupd according to syrinx width/cord width (S/C) ratios: group 1 – S/C ratio 50%. The length of the clivus, the AP length of the foramen magnum, the AP length of the posterior fossa, the perpendicular distance between the McRae line and (a) the splenium of corpus callosum, (b) the pons, and (c) the fastigium of the 160 patients and of the 160 control patients were statistically compared. In addition, the measurements of the patients with and without syrinx, according to the S/C ratio, were statistically compared. Results: Syrinx was present in 59 (36.8 %) of the 160 patients. The S/C ratio was 50% in 29 (49.1%) of them. All the measurements in the patient group, except of the AP length of the foramen magnum, were statistically significantly lower than in the control group (p = 0.001). There was no signif icant difference in the measurements of the patients with syrinx group 1 and the patients without syrinx, but the AP length of posterior fossa was statistically significantly lower in the patients with syrinx group 2 than the patients without syrinx (p = 0.03). Conclusion: The S/C ratio can be a guide to the underlying aetiology
No-reference depth map quality evaluation model based on depth map edge confidence measurement in immersive video applications
When it comes to evaluating perceptual quality of digital media for overall quality of
experience assessment in immersive video applications, typically two main approaches stand out:
Subjective and objective quality evaluation. On one hand, subjective quality evaluation offers the
best representation of perceived video quality assessed by the real viewers. On the other hand, it
consumes a significant amount of time and effort, due to the involvement of real users with lengthy
and laborious assessment procedures. Thus, it is essential that an objective quality evaluation model
is developed. The speed-up advantage offered by an objective quality evaluation model, which can
predict the quality of rendered virtual views based on the depth maps used in the rendering process,
allows for faster quality assessments for immersive video applications. This is particularly
important given the lack of a suitable reference or ground truth for comparing the available depth
maps, especially when live content services are offered in those applications. This paper presents a
no-reference depth map quality evaluation model based on a proposed depth map edge confidence
measurement technique to assist with accurately estimating the quality of rendered (virtual) views
in immersive multi-view video content. The model is applied for depth image-based rendering in
multi-view video format, providing comparable evaluation results to those existing in the literature,
and often exceeding their performance
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