Robust Image Watermarking Using LWT and Stochastic Gradient Firefly Algorithm

Watermarking of digital images is required in diversified applications ranging from medical imaging to commercial images used over the web. Usually, the copyright information is embossed over the image in the form of a logo at the corner or diagonal text in the background. However, this form of visible watermarking is not suitable for a large class of applications. In all such cases, a hidden watermark is embedded inside the original image as proof of ownership. A large number of techniques and algorithms are proposed by researchers for invisible watermarking. In this paper, we focus on issues that are critical for security aspects in the most common domains like digital photography copyrighting, online image stores, etc. The requirements of this class of application include robustness (resistance to attack), blindness (direct extraction without original image), high embedding capacity, high Peak Signal to Noise Ratio (PSNR), and high Structural Similarity Matrix (SSIM). Most of these requirements are conflicting, which means that an attempt to maximize one requirement harms the other. In this paper, a blind type of image watermarking scheme is proposed using Lifting Wavelet Transform (LWT) as the baseline. Using this technique, custom binary watermarks in the form of a binary string can be embedded. Hu’s Invariant moments’ coefficients are used as a key to extract the watermark. A Stochastic variant of the Firefly algorithm (FA) is used for the optimization of the technique. Under a prespecified size of embedding data, high PSNR and SSIM are obtained using the Stochastic Gradient variant of the Firefly technique. The simulation is done using Matrix Laboratory (MATLAB) tool and it is shown that the proposed technique outperforms the benchmark techniques of watermarking considering PSNR and SSIM as quality metrics.     

Micro-hotplate based temperature stabilization system for CMOS SAW resonators

Due to the sensitivity of the piezoelectric layer in surface acoustic wave (SAW) resonators to temperature, a method of achieving device stability as a function of temperature is required. This work presents two methods of temperature control for CMOS SAW resonators using embedded polysilicon heaters. The first approach employs the oven control temperature stabilization scheme. Using this approach, the device’s temperature is elevated using on-chip heaters to T_max = 42°C to maintain constant device temperature. Both DC and RF measurements of the heater together with the resonator were conducted. Experimental results have indicated that the TCF of the CMOS SAW resonator of −97.2 ppm/°C has been reduced to −23.19 ppm/°C when heated to 42°C. The second scheme uses a feedback control circuit to switch the on-chip heaters on and off depending on the ambient temperature. This method provided reduction of the TCF from −165.38 ppm/°C, to −93.33 ppm/°C. Comparison of both methods was also provided.     

Dissipative analysis and control of state-space symmetric systems

The paper addresses the problem of analysis and static output feedback control synthesis for strict quadratic dissipativity of linear time-invariant systems with state-space symmetry. As a particular case of dissipative systems, we consider the mixed H_∞ and positive real performance criterion and we develop an explicit expression for calculating the H_∞ norm of these systems. Subsequently, an explicit parametrization of the static output feedback control gains that solve the mixed H_∞ and positive real performance problem is obtained. Numerical examples demonstrate the use and computational advantages of the proposed explicit solutions.     

Histopathological graded liver lesions: what role does the IVIM analysis method have?

Magnetic Resonance Materials in Physics, Biology and Medicine - This study aims to investigate three different image processing methods on quantitative parameters of IVIM sequence, as well as...     

Parent Functioning in Families of Preadolescents With Spina Bifida: Longitudinal Implications for Child Adjustment.

The purpose of this study was to test a strength-of-association model regarding possible longitudinal and bidirectional associations between parent functioning and child adjustment in families of children with spina bifida (n = 68) and families of able-bodied children (n = 68). Parent functioning was assessed across 3 domains: parenting stress, individual psychosocial adjustment, and marital satisfaction. Child adjustment was indexed by teacher-reported internalizing and externalizing symptoms, self-reported depressive symptoms, and observed adaptive behavior. Findings revealed that all 3 parent functioning variables predicted child adjustment outcomes, and that such results were particularly strong for externalizing symptoms. Associations between parent functioning and child adjustment tended to be in the direction of parent to child and were similar across both groups. These findings have implications for potential interventions targeted at helping families manage the transition into early adolescence in families of children with spina bifida as well as families of healthy children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An analysis of web proxy logs with query distribution pattern approach for search engines

This study presents an analysis of users' queries directed at different search engines to investigate trends and suggest better search engine capabilities. The query distribution among search engines that includes spawning of queries, number of terms per query and query lengths is discussed to highlight the principal factors affecting a user's choice of search engines and evaluate the reasons of varying the length of queries. The results could be used to develop long to short term business plans for search engine service providers to determine whether or not to opt for more focused topic specific search offerings to gain better market share.     

Influence of Phosphorus Content on the Interfacial Microstructure Between Sn–3.5Ag Solder and Electroless Ni–P Metallization on Cu Substrate

Under bump metallization (UBM), which usually consists of a few thin metallic layers, provides good solderable surface while protecting the underlying metallization from reacting with solder. Electroless nickel (Ni-P) with a thin layer of immersion gold has been considered as one of the promising candidates for under bump and substrate metallizations. However, the presence of P in electroless Ni-P causes more complicated interfacial reactions with solder than pure Ni. The amount of P in the Ni-P layer affects the soldering reaction in terms of microstructure and reaction kinetics. In this paper, influence of P content on the interfacial microstructure between Sn-3.5Ag solder and electroless Ni-P metallization on Cu substrate has been investigated. Electroless Ni-P layers of three different P contents (6.1, 8.8, and 12.3 wt.%) with the same thickness were plated on Cu substrate. Multilayered samples with Sn-3.5Ag/Ni-P/Cu stack were then prepared and subjected to multiple reflows. Various types of interfacial compounds (IFCs) such as Ni₃Sn₄, Ni₃P, Ni-Sn-P, Cu-Sn, and Ni-Cu-Sn formed depending upon the number of reflows. Ni₃Sn₄ intermetallic compound that formed in the low P sample was found to be more stable, whereas, Ni₃Sn₄ that formed in the medium and high P samples mostly spalled off into the molten solder during reflow. The Ni ₃Sn₄ spallation was found responsible for thicker Cu-Sn and Ni-Cu-Sn intermetallics in the medium and high P samples as compared to that of low P sample. Explanation for the observed interfacial microstructure is proposed in the paper in detail     

Improving Thermal Stability and Electrical Insulation of Gamma‐Irradiated Silicone Rubber Nanocomposites

Room temperature vulcanized silicone rubber (RTVSR) nanocomposites were prepared by mixing of surface‐modified montmorillonite nanoclay or nano fumed silica, or both of them with RTVSR to improve thermal stability, electrical insulation, and flame retardant. Their tensile strength, elongation, swelling, and solubility properties at different doses of gamma radiation were investigated to study the effect of gamma radiation on the properties of the nanocomposites. The thermal stability, flammability properties, and volume resistivity of the nanocomposites were also investigated. The nanocomposite which containing fumed silica has the best thermal, mechanical properties, electrical insulation and fire retardancy. The thermal characteristics, namely, T_onset, T_10%, T_comp, and T_max, of the nanocomposite sample containing fumed silica were 22, 23, 13, and 11 °C higher than those of the blank, respectively. The tensile strength (TS) increased when the radiation dose was increased up to 100 kGy, but elongation, swelling, and solubility decreased when the radiation dose was increased up to 150 kGy. It can be generally concluded that the nanocomposites containing fumed silica and irradiated to 100 kGy are characterized by having outstanding mechanical, thermal, fire retardant, and electrical insulation properties and hence, they may have wide industrial applications as good thermal and electrical insulating materials. J. VINYL ADDIT. TECHNOL., 26:354–361, 2020. © 2019 Society of Plastics Engineers     

Fuzzy logic control based maximum power tracking of a wind energy system

In this paper a utility interactive wind energy conversion system (WECS) with an asynchronous (AC–DC–AC) link is described. The control system has the objective of identifying and extracting the maximum power from the wind energy system and transferring this power to utility. A fuzzy logic control (FLC) technique has been implemented to design the tracking controller of the WECS. A wind speed step model was used in the design phase. The performance of the WECS with the proposed fuzzy logic controller is tested using real meteorological data. Its robustness and effectiveness are demonstrated by the simulation results of the controlled system.     

Rice Bran Oil Improves Insulin Resistance by Affecting the Expression of Antioxidants and Lipid‐Regulatory Genes

The present study investigated the molecular effects of rice bran oil (RBO) on lipid‐regulatory genes (sterol regulatory element binding protein‐1 [Srebf1] and peroxisome proliferator‐activated receptors‐α [Ppara]) and the expression of catalase (CAT) and superoxide dismutase (SOD1) genes in insulin‐resistant rats. Rats were divided into five groups: animals that received standard diet (control); rats fed standard diet containing RBO as the sole source of fat (RBO); a high‐fructose diet (HFD) group, which was further divided into two subgroups: rats fed HFD either for only 1 month (HFD1) or for 2 months (HFD2) and rats fed HFD containing RBO for 1 month; while rats in the last group fed HFD for 30 days then treated with RBO for another 30 days. The HFD induced a state of insulin resistance (IR) as indicated by the hyperinsulinemia and elevated homeostasis model assessment insulin resistance index. Hepatic lipid levels and radical scavenging enzymes were altered by the HFD. Lipid‐regulatory genes, Srebf1 and Ppara, were upregulated while Sod1 and Cat were downregulated in insulin‐resistant rats. Addition of RBO to the two diet regimens alleviated the disorders of IR to some extent. RBO reduced the hepatic levels of triacylglycerol, malondialdehyde, SREBP, and PPAR‐α mRNA. Hepatic SOD and CAT were elevated at gene and protein levels. The HFD induces de novo lipogenesis by upregulating the lipid‐regulatory genes resulting in increased serum and hepatic triacylglycerol. Moreover, IR induced by the HFD caused a state of oxidative stress. Supplementation of RBO to fructose‐fed rats not only improves insulin resistance but also downregulates lipogenic genes and improves the unbalanced oxidative status.