Design of a Modified Wilkinson Power Divider with Size Reduction and Harmonics Suppression using Triangle-Shaped Resonators

Wireless Personal Communications - Over the past few years, Internet of Things security has attracted the attention of many researchers due to its challenging and constrained nature. Particularly...     

PHEV powertrain co-design with vehicle performance considerations using MDSDO

Structural and Multidisciplinary Optimization - The complexity of plug-in hybrid-electric vehicles (PHEVs) motivates the simultaneous integration of component design and supervisory control...     

Secure image sharing method over unsecured channels

Image sharing has become a prominent field in large and small networks. However, in order to deliver the shares to their respective shareholders, we need a secure channel to protect the shares from potential attacks by other users on the network. These users can locate the shares and retrieve the image using the Lagrange interpolation method if they are able to locate the minimum required number of shares. This paper proposes a method to protect the privacy and security of the shares when sending them through unsecured channels. The proposed method is divided into three phases. In the first phase, image pixels are changed using the column and row indices, then the shares are created using Shamir’s secret sharing (SSS) method. Then a relationship is created between the shares using a linear independence function. In the second phase, the first part of the image is encrypted to hide the solver data. Finally, in the third phase, the data is shared using the SSS method. Participants can retrieve the whole image by applying the reverse order of the proposed method using only the information from the sender through the same channel. The simulation results show that the proposed method is efficient and robust against different types of attacks and can be used to send the shares over unsecured channels.     

Coaxial cavity waveguide antennas excited by stacked circular microstrip patches for use as prime‐focus reflector feeds

A coaxial cavity antenna excited by a stacked circular microstrip antenna is investigated as a feed for prime‐focus parabolic reflector antennas. The radiation pattern of the proposed cavity‐backed antenna is saddle shaped, which widens the ?10 dB beamwidths and increases the reflector efficiency especially for deep reflectors with small focal length‐to‐diameter ratios. With a single‐probe feed, the co‐polar radiation pattern is slightly asymmetric in the E‐plane, but is made symmetric by a differential feeding technique, using two probes. The impedance bandwidth of the proposed feed antenna is 20%. The antenna was fabricated and tested, and it exhibited good agreement between simulation and measurement results. The gain factor of the feed was also studied with a circular‐symmetric reflector and provided a gain factor of 79% at f/D = 0.375. This type of feed can be used as an alternative to conventional horn or waveguide feeds, where reduced size and light‐weight are desirable with added advantage of easy integration with electronics.     

TBM,a transformation based method for microaggregation of large volume mixed data

Due to recent advances in data collection and processing, data publishing has emerged by some organizations for scientific and commercial purposes. Published data should be anonymized such that staying useful while the privacy of data respondents is preserved. Microaggregation is a popular mechanism for data anonymization, but naturally operates on numerical datasets. However, the type of data in the real world is usually mixed i.e., there are both numeric and categorical attributes together. In this paper, we propose a novel transformation based method for microaggregation of mixed data called TBM. The method uses multidimensional scaling to generate a numeric equivalent from mixed dataset. The partitioning step of microaggregation is performed on the equivalent dataset but the aggregation step on the original data. TBM can microaggregate large mixed datasets in a short time with low information loss. Experimental results show that the proposed method attains better trade-off between data utility and privacy in a shorter time in comparison with the traditional methods.     

Using learning automata in brain emotional learning for speech emotion recognition

We propose an improved version of brain emotional learning (BEL) model trained via learning automata (LA) for speech emotion recognition. Inspiring from the limbic system in mammalian brain, the original BEL model is composed of two neural network components, namely amygdala and orbitofrontal cortex. In this modified BEL model, named brain emotional learning based on learning automata (BELBLA), we have employed the theory of the stochastic LA in error back-propagation to train the BEL model in decreasing the high computational complexity of the traditional gradient method. Hence, the performance of the model can be enhanced. For a speech emotion recognition task, we extract the usual features, such as energy, pitch, formants, amplitude, zero crossing rate and MFCC, from average short-term signals of the emotional Berlin dataset. The experimental results show that the BELBLA outperforms some opponents, like hidden Markov model, Gaussian mixture model, k-nearest neighbor, support vector machines and artificial neural networks, for this application.     

Risk-Based Design of Flood Control Systems Considering Multiple Dependent Uncertainties

Due to random behavior of flood events and inaccuracies in measurements, design, analysis, and operation of flood control systems are subjected to several uncertainties. An important aspect in developing stochastic models for evaluating and analyzing more than one uncertainty is the dependence or independence of them. In flood control projects, hydrologic, hydraulic, geotechnical, and economic uncertainties are important considerations. In this paper, a stochastic Monte-Carlo simulation – optimization modeling approach is described for risk-based design of flood control levees (as a common structural flood control measure): considering multiple dependent uncertainties. It has been applied to the Leaf River reach in Hattiesburg, Mississippi for testing and evaluation of modeling results. Unlike a deterministic model that yields just one set of values for system dimensions, the stochastic model solution gives a range of values for each of them. One of the major reasons for limited field application of uncertainty analysis is difficulties in performing the modeling results in real world contexts. For closing the gap between theory and reality, design charts are developed in this study. This helps decision makers in identifying design values with desired and accepted risks.     

Hydrological Assessment of the 1973 Treaty on the Transboundary Helmand River,Using the SWAT Model and a Global Climate Database

Exploitation of the water resources of the Helmand River has been challenging for Iran and Afghanistan. Debates on this issue finally led to a treaty in 1973 between the two countries, in which a total amount of 26 m³/s water from the Helmand River should be delivered to Iran in a normal (or an above normal) water year. The treaty also specifies that a “normal water year” means the year during which the total volume of water at the hydrometric station of Dehrawud (upstream of the Kajakai Dam) is 5661.7 million cubic meter (MCM). This paper aims to assess the long term hydrological conditions of the Upper Helmand River, to detect the occurrence of any non-stationary process in its streamflow time series and compare the possible changes with the content of the 1973 water treaty. Due to very date scarce situation of this region, the SWAT (Soil & Water Assessment Tool) model and CRU (Climatic Research Unit) global dataset were applied to create the long term time series. The results showed that there has been no significant change in annual mean flows in the Upper Helmand River basin. However, there is a consistent increase in monthly flows from November to February and a decrease of the flows in June and July. The monthly changes can be attributed to an increasing trend in temperature in the study area, earlier snowmelts during winter and less snow pack in summer. The applied methodology of this study is useful to cope with the region’s data scarcity and can be applied for similar studies requiring long term time series of hydrological variables.     

Safety evaluation and antimicrobial properties of <Emphasis Type="Italic">Lactobacillus pentosus</Emphasis> 22C isolated from traditional yogurt

Traditional dairy products are the main source of probiotic microorganisms. Hence, this study aimed to evaluate the safety and antimicrobial potential of Lactobacillus pentosus 22C, isolated from traditional yogurt from Kermanshah province, Iran. Strain 22C showed no undesirable amino acid decarboxylase and β-hemolytic activities. Virulence associated genes were detected in the isolate. The strain produced an antimicrobial molecule named pentocin 22C, a small peptide with a relative mass between 5 and 10 kDa. Bacterial inhibition was pH-independent, with greater activity at pH 4–6. Purified or semi-purified antimicrobial agents can be used as bio-preservatives, and the producing strain can be used as a starter culture to improve food safety. Therefore, a biosafety assessment should be conducted. L. pentosus 22C, isolated from a traditional dairy product, has antimicrobial ability, although its safety must be evaluated.     

Design and performance evaluation of a novel square ion trap with mass analysis in the radial a axial directions

A novel three-dimensional square ion trap is reported as a mass analyzer or an ion transfer device. The square ion trap was constructed with six square planar electrodes while the electric field was optimized by changing their relative positions to arrange the strength of higher-order fields. Ion trajectory simulations demonstrate the square ion trap efficiently operates with radial and axial excitation. Additionally, ions ejected from the radial direction contained lower kinetic energies and their energy distribution were more centralized. These properties may improve the ion transfer efficiency.