On weak structures due to Császár

In [4], Császár has introduced the notions of weak structures and the structures α(w), π(w), σ(w), β(w). The main aim of this paper is to introduce and study properties of the structures r(w), α(w), π(w), σ(w) and β(w).     

The adjacency-Jacobsthal-Hurwitz sequences in groups

In [3 Deveci, O., Aküzüm, Y. (in press). The adjacency-Jacobsthal-Hurwitz type numbers. Filomat. [Google Scholar]], Deveci and Aküzüm defined the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind. In this work, firstly we produce the cyclic groups from the multiplicative orders of the generating matrices of the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind when read modulo λ and we study the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind modulo λ. Then, we give the relationship between the orders of the cyclic groups obtained and the periods of the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind modulo λ. Further, we extend the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind to groups and then we examine these sequences in the quaternion group Q₈ in detail.     

Gas chromatographic-mass spectrometric analysis of essential oils from Pimpinella species gathered from Central and Northern Turkey

Essential oils from 15 Pimpinella species were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. One species, Pimpinella anisum, in which only fruits were evaluated, was also included in the study. A total of 140 different compounds were identified and significant qualitative and quantitative differences were observed among the samples. Pimpinella essential oils were characterized as having mono-, sesqui- and trinorsesquiterpenoids, propenylphenols, and pseudoisoeugenols. Trinorsesquiterpenoids and phenylpropanoids appear to be chemical markers of Pimpinella species analyzed thus far. Essential oils obtained from Pimpinella roots share the same principal compound, epoxypseudoisoeugenyl-2-methylbutyrate at concentrations from 20 to 82.6%.     

Comparative spectral analysis of veterinary powder product by continuous wavelet and derivative transforms

Comparative simultaneous determination of chlortetracycline and benzocaine in the commercial veterinary powder product was carried out by continuous wavelet transform (CWT) and classical derivative transform (or classical derivative spectrophotometry). In this quantitative spectral analysis, two proposed analytical methods do not require any chemical separation process. In the first step, several wavelet families were tested to find an optimal CWT for the overlapping signal processing of the analyzed compounds. Subsequently, we observed that the coiflets (COIF-CWT) method with dilation parameter, a=400, gives suitable results for this analytical application. For a comparison, the classical derivative spectrophotometry (CDS) approach was also applied to the simultaneous quantitative resolution of the same analytical problem. Calibration functions were obtained by measuring the transform amplitudes corresponding to zero-crossing points for both CWT and CDS methods. The utility of these two analytical approaches were verified by analyzing various synthetic mixtures consisting of chlortetracycline and benzocaine and they were applied to the real samples consisting of veterinary powder formulation. The experimental results obtained from the COIF-CWT approach were statistically compared with those obtained by classical derivative spectrophotometry and successful results were reported.     

A numerical solution of 3D inviscid rotational flow in turbines and ducts

The numerical solutions of inviscid rotational (Euler) flows were obtained using an explicit hexahedral unstructured cell vertex finite volume method. A second-order-accurate, one-step Lax–Wendroff scheme was used to solve the unsteady governing equations discretized in conservative form. The transonic circular bump, in which the location and the strength of the captured shock are well predicted, was used as the first test case. The nozzle guide vanes of the VKI low-speed turbine facility were used to validate the Euler code in highly 3D environment. Despite the high turning and the secondary flows which develop, close agreements have been obtained with experimental and numerical results associated with these test cases. © 1998 John Wiley & Sons, Ltd.     

Learnability of the Boolean Innerproduct in Deep Neural Networks

In this paper, we study the learnability of the Boolean inner product by a systematic simulation study. The family of the Boolean inner product function is known to be representable by neural networks of threshold neurons of depth 3 with only 2n+1 units (n the input dimension)—whereas an exact representation by a depth 2 network cannot possibly be of polynomial size. This result can be seen as a strong argument for deep neural network architectures. In our study, we found that this depth 3 architecture of the Boolean inner product is difficult to train, much harder than the depth 2 network, at least for the small input size scenarios n≤16. Nonetheless, the accuracy of the deep architecture increased with the dimension of the input space to 94% on average, which means that multiple restarts are needed to find the compact depth 3 architecture. Replacing the fully connected first layer by a partially connected layer (a kind of convolutional layer sparsely connected with weight sharing) can significantly improve the learning performance up to 99% accuracy in simulations. Another way to improve the learnability of the compact depth 3 representation of the inner product could be achieved by adding just a few additional units into the first hidden layer.     

Generalized submaximal spaces

The notion of generalized submaximal spaces is introduced and studied. Properties and characterizations of generalized submaximal spaces are discussed.     

MEIR-KEELER TYPE CONTRACTIONS FOR TRIPLED FIXED POINTS

In 2011,Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces.In our paper,we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction.     

Prediction of characteristic properties of crude oil blending with ANN

Mineral oil is one of the most important materials on earth and it is used widely for its several features. Mineral oils derived from petroleum products are commonly used to decrease the friction effects in machine parts and, thus, they both prevent wear/overheating and facilitate power transmission. In this study, various binary mixtures of various base oils (SN-80, SN-100, SN-150, SN-50, SN-500) were prepared at different volumetric ratios. Kinematic viscosity (at 40°C and 100°C), viscosity index, flash point, pour point, and density (at 20°C) measurements were performed for characterization of the prepared mixtures. These values were modeled by an artificial neural network (ANN) and the model was tested with root mean squared error (RMSE), mean absolute percentage error (MAPE, %), and regression coefficient (R) values. A higher value of correlation coefficient and smaller values of MAPE and RMSE indicate that the model performs better. For predicting kinematic viscosity at 40°C, correlation coefficients were calculated for training and testing the network as 0.9999 and 0.9995, respectively. Respective MAPE values were determined as 1.011% and 1.8771%.     

Oxidative Stress Parameters of L929 Cells Cultured on Plasma-Modified PDLLA Scaffolds

Oxidative stress may produce high level of reactive oxygen species (ROS) following cell exposure to endogenous and exogenous factors. Recent experiments implicate oxidative stress as playing an essential role in cytotoxicity of many materials. The aim of this study was to measure intracellular malondialdehyde (MDA), advanced oxidation protein product (AOPP) levels, and superoxide dismutase (SOD) activities of L929 fibroblasts cultured on PDLLA, polyethylene glycol (PEG), or ethylenediamine (EDA) grafted PDLLA by plasma polymerization method. Cell proliferation on these scaffolds was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The study showed that MDA, AOPP levels, and SOD activities in L929 fibroblast cells cultured on all scaffolds were significantly different compared to the control group and each other. The highest MDA (0.42 ± 0.76 nmol/mg protein), AOPP (14.99 ± 4.67 nmol/mg protein) levels, and SOD activities (7.49 ± 3.74 U/mg protein) were observed in cells cultured on non-modified scaffolds; meanwhile, the most cell proliferation was obtained in EDA-modified scaffolds (MDA 0.15 ± 0.14 nmol/mg protein, AOPP 13.12 ± 3.86 nmol/mg protein, SOD 4.82 ± 2.64 U/mg protein). According to our finding, EDA- or PEG-modified scaffolds are potentially useful as suitable biomaterials in tissue engineering.