A new arc detection method based on fuzzy logic using S-transform for pantograph–catenary systems

pantograph–catenary system is one of the critical components used in electrical trains. It ensures the transmission of the electrical energy to the train taken from the substation that is required for electrical trains. The condition monitoring and early diagnosis for pantograph–catenary systems are very important in terms of rail transport disruption. In this study, a new method is proposed for arc detection in the pantograph–catenary system based signal processing and S-transform. Arc detection and condition monitoring were achieved by using current signals received from a real pantograph–catenary system. Firstly, model based current data for pantograph–catenary system is obtained from Mayr arc model. The method with S-transform is developed by using this current data. Noises on the current signal are eliminated by applying a low pass filter to the current signal. The peak values of the noiseless signals are determined by taking absolute values of these signals in a certain frequency range. After the data of the peak points has been normalized, a new signal will be obtained by combining these points via a linear interpolation method. The frequency-time analysis was realized by applying S-transform on the signal obtained from peak values. Feature extraction that obtained by S-matrix was used in the fuzzy system. The current signal is detected the contdition as healthy or faulty by using the outputs of the fuzzy system. Furthermore the real-time processing of the proposed method is examined by applying to the current signal received from a locomotive.     

Response surface-based robust parameter design optimization with both qualitative and quantitative variables

The response surface-based robust parameter design, with its extensive use of optimization techniques and statistical tools, is known as an effective engineering design methodology for improving production processes, when input variables are quantitative on a continuous scale. In many engineering settings, however, there are situations where both qualitative and quantitative variables are considered. In such situations, traditional response surface designs may not be effective. To rectify this problem, this article lays out a foundation by embedding those input variables into a factorial design with pseudo-centre points. A 0–1 mixed-integer nonlinear programming model is then developed and the solutions found using three optimization tools, namely the outer approximation method, the branch-and-bound technique and the hybrid branch-and-cut algorithm, are compared with traditional counterparts. The numerical example shows that the proposed models result in better robust parameter design solutions than the traditional models.     

Synthesis and Properties of Polyimides from 1,3-di(p- dimethylamino benzyl)-imidazolidine-2-thion

Summary A synthetic strategy is presented that allows the preparation of dimethylamino functionalized heterocyclic system 1,3-di (p-dimethylaminobenzy1)-imidazolidine-2-thion that was then used to prepare polyimides by the two-stage polycondensation method. The key to this success was the development of an efficient procedure leading highly pure dimethylamino monomer. Polyimides derived from 1,3-di(p-dimethylaminobenzyl)-imidazolidine-2-thion and commercial dianhydrides exhibited excellent solubility in various polar solvents. These polymers showed glass transition temperatures between 290–360°C, and initial decomposition temperature 490–485 °C and 10% mass loss ranging from 505–75°C in air. Received: 17 April 2002/Revised version: 25 January 2003/ Accepted: 14 March 2003 Correspondence to Turgay Seckin     

Open pollinated and hybrid sunflower seed structures that may affect processing for oil

Oil and wax contents of confectionery (non-oil) and oilseed, open-pollinated and hybrid sunflower seed and their hulls, testae, and kernels were determined. Wax content inversely correlated with hull content, and the degree to which the seeds were compressed corre-lated with hull thickness. Light and electron microscopy showed increased connective tissue in the hybrid seed. This combination of higher wax content in the dehulled hybrids and increased connective tissue between hull and kernel could explain the reports of high wax content of the oil from newly developed hybrid seed.     

Dynamically adaptive real-time disparity estimation hardware using iterative refinement

The computational complexity of disparity estimation algorithms and the need of large size and bandwidth for the external and internal memory make the real-time processing of disparity estimation challenging, especially for High Resolution (HR) images. This paper proposes a hardware-oriented adaptive window size disparity estimation (AWDE) algorithm and its real-time reconfigurable hardware implementation that targets HR video with high quality disparity results. Moreover, an enhanced version of the AWDE implementation that uses iterative refinement (AWDE-IR) is presented. The AWDE and AWDE-IR algorithms dynamically adapt the window size considering the local texture of the image to increase the disparity estimation quality. The proposed reconfigurable hardware architectures of the AWDE and AWDE-IR algorithms enable handling 60 frames per second on a Virtex-5 FPGA at a 1024×768 XGA video resolution for a 128 pixel disparity range.     

Calibrating multibody ulno-humeral joint cartilage using a validated finite element model

Correct prediction of contact characteristic in multibody models is a challenging issue, which requires both employing an appropriate contact model and choosing its corresponding contact parameters. This study employed two subject specific multibody models of the ulno-humeral joint where the humerus cartilage was discretized and interacted with the ulna cartilage through a deformable contact. Parameters for the deformable contact were optimized by matching the maximum predicted contact pressure in the multibody models with contact pressures predicted in identical finite element models under axial 110 N compressive load. The performance of the optimized contact parameters and employed approach was evaluated under two other loading conditions of 80 and 140 N. Moreover, the effect of discretized element size on the contact prediction was also addressed. After optimization of the contact parameters, the difference between the multibody and FE models in terms of peak and average contact pressure, and contact area was significantly reduced (more than a factor of 10). Smaller discretization size of the humerus cartilage in the multibody models resulted in better predictions especially on highly curved regions. However, the optimized parameters of our study were different between the two elbows. This indicates that optimized contact parameters can be different not only among different joints, but also among different specimens and optimization conditions. Therefore, in order to improve contact predictions, separate contact optimization should be performed for each subject.     

Real emission and virtual exchange of gravitons and unparticles in Pythia8

Models with large extra dimensions as well as unparticle models could give rise to new phenomena at collider experiments due to real emission or virtual exchange of gravitons or unparticles. In this paper we present the common implementation of these processes in the Monte Carlo generator Pythia8, using relations between the parameters of the two models. The program offers several options related to the treatment of the UV region of the effective theories, including the possibility of using a form factor for the running gravitational coupling. Characteristic results obtained with Pythia8 have been used to validate the implementations as well as to illustrate the key features and effects of the model parameters. The results presented in this paper are focused on mono-jet, di-photon and di-lepton final states at the LHC.     

The Applications of ‘active packaging and chlorine dioxide’ for extended shelf life of fresh strawberries

Fresh strawberries are highly perishable because of their high respiration rates. Three alternative packaging approaches were investigated to maintain the high quality and to extend the shelf life of strawberries. These were active packaging using chlorine dioxide (ClO₂) and ethylene‐moisture sachets. The quality properties of four groups of samples were measured over 3 weeks at 4°C. The groups were: control, active packaging without ClO₂ treatment, active packaging with low‐dose (5 ppm) ClO₂ treatment and active packaging with high‐dose (10 ppm) ClO₂ treatment. Measured properties were weight loss, gas concentration, pH, titratable acidity (TA), soluble solids content, texture profile and colour. Active packaging with low‐dose (5 ppm) ClO₂ treatment was found to be the most effective for TA retention and for maintaining (L) brightness values. The control group showed the largest total soluble solids reduction from 7.60 to 6.57. Active packaging without ClO₂ treatment showed the lowest weight loss (0.33%), while the control group showed the highest (1.86%) at the end of the storage. Active packaging with high‐dose ClO₂ treatment showed the highest preference value in global appearance, colour and firmness properties. The low‐ and high‐dose active packaging groups had greater firmness, gumminess and chewiness than that of all other treatments. The results from this study showed that active packaging treatment with ClO₂ and the ethylene‐moisture sachets had a beneficial effect on the quality of strawberries and could be used commercially. Copyright © 2010 John Wiley & Sons, Ltd.     

Some compositional properties of main Malatya apricot (Prunus armeniaca L.) varieties

Malatya apricot (Prunus armeniaca L.) varieties are among the most important agricultural products of Turkey and protected as a geographical indication. In this research, it was aimed to determine some important analytical properties (dry matter, soluble solid content, a_w, ash, titratable acidity, pH, color, total phenolics, total carotenoids, β-carotene, sugars, organic acids, and mineral content) of Malatya apricots and to reveal the characteristic properties that differ these products from the similar ones. The apricot varieties, namely Hac?halilo?lu, Hasanbey, So?anc?, Kabaa??, Çatalo?lu, Çölo?lu, and Hac?k?z that are widely cultivated in Malatya region and other regions (Ere?li, ?zmir, I?d?r, and Bursa) of Turkey were involved in the study. All analytical properties were found to be significantly different (p < 0.05) among different apricot varieties. The results have shown that dry matter and sugar content of Malatya apricot varieties are considerably higher than the other apricot varieties investigated in this study, as well as the data of other researches on apricots. All apricot varieties were found to be a good source of phenolic compounds (4233.70–8180.49 mg of gallic acid equiv/100 g of dry weight), carotenoids (14.83–91.89 mg of β-carotene equiv/100 g of dry weight), and β-carotene (5.74–48.69 mg/100 g of dry weight). Sucrose, glucose, and fructose were determined as the major sugars in all apricot varieties. In addition, sorbitol contents (16.91–26.84 mg/100 g of dry weight) of Malatya apricots were remarkably higher than the other apricot varieties. This was considered to be the one of the unique properties of Malatya apricots. Malic acid was the predominant organic acid in all Malatya apricot varieties. The results have also shown that the potassium content of Malatya apricots was significantly high and these apricots were important sources of Mg, Zn, and Se. This study has revealed that Malatya apricot contains functional food components with high nutritional value.