Stator flux optimization on direct torque control with fuzzy logic

The Direct Torque Control (DTC) is well known as an effective control technique for high performance drives in a wide variety of industrial applications and conventional DTC technique uses two constant reference value: torque and stator flux. In this paper, fuzzy logic based stator flux optimization technique for DTC drives that has been proposed. The proposed fuzzy logic based stator flux optimizer self-regulates the stator flux reference using induction motor load situation without need of any motor parameters. Simulation studies have been carried out with Matlab/Simulink to compare the proposed system behaviors at vary load conditions. Simulation results show that the performance of the proposed DTC technique has been improved and especially at low-load conditions torque ripple are greatly reduced with respect to the conventional DTC.Comment: 8 pages, 8 figures, Itca 2012 conferenc

Commutators, Lefschetz fibrations and the signatures of surface bundles

We construct examples of Lefschetz fibrations with prescribed singular fibers. By taking differences of pairs of such fibrations with the same singular fibers, we obtain new examples of surface bundles over surfaces with non-zero signature. From these we derive new upper bounds for the minimal genus of a surface representing a given element in the second homology of a mapping class group.Comment: 20 pages, 7 figures, accepted for publication in Topolog

Economic importance of Gypsophila L., Ankyropetalum Fenzl and Saponaria L. (Caryophyllaceae) taxa of Turkey

Gypsophila L. is the third biggest genus of Caryophyllaceae family in Turkey. The genus has 55 species in the country. 33 species are endemics and total number of the taxa is 58. Ankyropetalum Fenzl is a small genus with 3 species and 1 of them is endemic. Saponaria L. has 20 taxa of 18 species and 10 taxa of them are endemics to Turkey. Turkey is the gene center of all the genera. All of the genera are known as coven, female coven and halva root and developed roots or rhizomes are economically very important. Extract produced from the roots are known as fire extinguisher, gold polishing, cleaner and softener of delicate fabrics and crispness giving to halva. The extracts are often used for making liqueur, herbal cheese, ice cream and some foods. Some taxa are Boron (B) hyperacumulators, so they can be planted and used for destroyed agriculture to control erosion. Gypsophila paniculata L. is very important in horticulture. Gypsophila bicolor, Gypsophila arrostii, Gypsophila perfoliata, Ankyropetalum gypsophiloides and Saponaria officinalis L. are very important because of their saponin contents. In this paper, economic importance of the plants in the light of our observations and literatures was given.Key words: Gypsophila, Ankyropetalum, Saponaria, economy, saponin

A RESEARCH ON THE UREA HYDROLYSIS RATE IN THE SOILS OF THRACE REGION

It seems that urea fertilizers have advantages over ammonium nitrate fertilizers in terms of leaching losses when they are applied in February. On the other hand, the losses from the urea fertilizers in the form of NH3 gas when they are applied in February which is damp and cool, may be considered to be non signifi cant, which becomes a profound idea. Conducting fi eld trials on the investigation of suitable time and rate of urea fertilizers application may be suggested a way to be followed. According to the diagnosis from the research, hydrolyse of urea is bound to features of the soil. In the beginning of the incubation for the fact hydrolysis of urea is fast that features of soil. Dry wheat agriculture which takes major part in our agriculture, urea’s progress of hydrolysis ensure suitable and balanced fertilizing and also ensure the amount and quality of crop increase in a fi eld. It has to be emphasized with processing of an adequate and balanced program of fertilizing is useful both our economy and environment

Topp-Leone Nadarajah Haghighi dağılımı

In this paper, a three parameter model which can be used in modeling survival data, reliability problems and fatigue life studies has been studied. We derived explicit expressions for some of its statistical and mathematical identifying properties such as ordinary moments, generating function, incomplete moments and order statistics. The maximum likelihood estimations of model parameters were also obtained -being based on complete sample. We assessed the performance of the maximum likelihood estimators in terms of standard deviations, bias and mean squared errors by means of a simulation study. The usefulness of the model was illustrated by using a real data set. The proposed distribution provides better fits than some wellknown generalized distributions under the same criteria of comparison.Bu çalışmada yaşam verileri, güvenirlik problemleri ve yorulma ömrü çalışmalarında kullanılabilecek üç parametreli bir model üzerinde çalışılmıştır. Bu modele ait momentler, üreten fonksiyonlar, tamamlanmamış momentler ve sıra istatistikleri gibi istatistiksel ve matematiksel özellikler türetilmiştir. Tam örneklem durumuna dayalı olarak, model parametrelerinin sıradan en çok olabilirlik tahminleri elde edilmiştir. Bir simülasyon çalışması ile model parametrelerinin en çok olabilirlik tahmin edicilerinin performansları, standart sapma, yan ve hata kareler ortalamaları ile değerlendirilmiştir. Modelin kullanışlılığı, bir gerçek veri setine dayalı olarak gösterilmiştir. Önerilen dağılım bazı karşılaştırma kriterleri altında, literatürde iyi iyi bilinen birtakım dağılımlardan daha iyi uyum sağlamıştır

Oransal lindley fréchet dağılımının bazı teorik ve hesaplamalı yönleri

In this article, we study an extension of the Fréchet model by using the the odd Lindley-G family of distributions, which was introduced by [17]. Its some statistical properties such as quantile function, density shapes, moments, generating functions and order statistics are obtained. We estimate its parameters by maximum likelihood method. The Monte Carlo simulation is used for assessing the performance of the maximum likelihood method. The usefulness of the odd Lindley Fréchet model is illustrated by means of three real data sets.Bu çalışmada, Fréchet modelinin genişletilmiş bir versiyonu [17] tarafından önerilen oransal Lindley dağılım ailesi kullanılarak çalışılmıştır. Bu modele ait kuantil fonksiyonu, yoğunluk biçimi, momentler, üreten fonksiyon ve sıra istatistikleri gibi istatistiksel özellikleri elde edilmiştir. Model parametrelerinin en çok olabilirlik tahminleri elde edildi. En çok olabilirlik parametre tahminleri için bir simülasyon çalışılması verilmiştir. Önerilen modelin gerçek veri seti üzerindeki uygunluğu için üç veri analizi yapılmıştır

Seroepidemiological Investigation of Toxocariasis in the Isparta Region of Turkey

Background: Toxocariasis is a common disease around the world. Our objective was to determine Toxocara seroprevalence in humans in the city of Isparta, Southwest Turkey, in respect of some determinants such as age, socio-economic level, residence in city center or rural area etc.Methods: Five hundred and thirty four individual participants from Isparta center and 85 from Asagi Gokdere village were included in the study. T. cati specific antibodies were ana­lyzed using excretory-secretory (ES)-enzyme-linked immunosorbent assay (ELISA) method.Results: T. cati antibodies were detected as positive in 73 (13.6%) of 534 samples which were collected from subjects living in the city center and 24 (28.2%) of 85 samples from Asagi Gokdere village. Toxocara seropositivity was detected among 15.6% of whole study group. The seroprevalence of toxocariasis was significantly higher among subjects from vil­lage than in subjects from city center (P=0.001). While gender, high school education, source of the water which is used, family income and geophagia/eating nail behaviors were the fea­tures which were detected as being associated with toxocariasis seropositivity (odds ratios= 0.5; 6.52; 3.61; 0.43; 0.13 respectively), owning dogs or cats and hand washing were de­tected as being not associated with toxocariasis seropositivity (P > 0.05). Furthermore, Toxo­cara seropositivity was significantly higher among subjects in 0-10 than >40 year-old group (P=0.02).Conclusion: It can be suggested that untreated lost pet population, environmental contamination, and way of life have influence on the epidemiology of toxocariasis

Occurrence of Fumonisins B₁ and B₂ in homemade medicinal plants: Exposure assessment in northern Turkey

This study was conducted to determine the recent level of contamination with Fumonisin B1 (FB1) and Fumonisin B2 (FB2) in major medicinal plants and to assess consumer exposure in northern Turkey. FB1 and FB2 were investigated by using high performance liquid chromatography (HPLC) with fluorescence detection after derivatization with o-phthaldialdehyde (OPA). A total of 78 homemade medicinal plant samples from 14 species were analysed. The recovery in thyme was 67.2±5.2% for FB1 and 80.8±14.3% for FB2 spiked with 1 μg g–1 of each analyte. The minimum detectable amount for the OPA derivatives of FB1 and FB2 were 1 ng per injection and 2.5 ng per injection, respectively. The limit of quantitation (LOQ) S/N=10 was 0.078 and 0.313 μg g–1, and the limit of detection (LOD) S/N=3 was 0.023 and 0.093 μg g–1 for FB1 and FB2, respectively. FB1 was detected in thyme (0.125) and mint (0.125 and 0.256 μg g–1) samples; however. FB2 toxin was below the detection limit in all samples. These results indicate that toxins might be present in homemade medicinal plants; however, the risk of exposure to fumonisins by the consumption of those plants was lower than the estimated TDI limits (–1 bw)

Automorphisms of graphs of cyclic splittings of free groups

We prove that any isometry of the graph of cyclic splittings of a finitely generated free group $F_N$ of rank $N\ge 3$ is induced by an outer automorphism of $F_N$. The same statement also applies to the graphs of maximally-cyclic splittings, and of very small splittings.Comment: 22 pages, 5 figures. Small modifications. To appear in Geometriae Dedicat