Salt-and-pepper noise removal by adaptive median-based lifting filter using second-generation wavelets

In this paper, we propose a novel adaptive median-based lifting filter for image de-noising which has been corrupted by homogeneous salt and pepper noise. The median-based lifting filter removes the noise of the input image by calculating the median of the neighboring significant pixels. The algorithm for image noise removal uses the lifting scheme of the second-generation wavelets in conjunction with the proposed adaptive median-based lifting filter. The experimental results demonstrate the efficiency of the proposed method. The proposed algorithm is compared with all the basic filters, and it is found that our method outperforms many other algorithms and it can remove salt and pepper noise with a noise level as high as 90%. The algorithm works exceedingly well for all levels of noise, as illustrated in terms of peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) measures.     

Using Planar Embedded DRAM in Memory Intensive Signal Processing Circuits: Case Studies on LDPC Decoding and Motion Estimation

This paper studies the feasibility and potential of using planar embedded DRAM (eDRAM), which is completely compatible with CMOS logic process, to improve circuit implementation efficiency of memory-hungry signal processing algorithms. In spite of its apparent cell area efficiency advantage over SRAM, planar eDRAM is not being widely used in practice, mainly due to its very short retention time (e.g., few $\upmu $ s and even a few hundreds ns). In this work, we contend that short retention time may not necessarily be a fundamental issue for implementing signal processing algorithms because they typically handle streaming data, which exhibits regular and predictable data access patterns, and has a large algorithm/architecture design space. This study elaborates on the rationale and application of using a planar eDRAM in memory-hungry signal processing circuit implementations, and discusses the possible algorithm and architecture design strategies to better embrace the use of planar eDRAM. For the purpose of demonstration, we use low-density parity-check (LDPC) code decoding and motion estimation in video encoding as test vehicles. Beyond a straightforward SRAM replacement, we propose an interleaved read/write page-mode DRAM operation to reduce planar eDRAM energy consumption by leveraging LDPC code decoding data access pattern, and we investigate the potential of using planar eDRAM to enable a higher degree of image data reuse in motion estimation by proposing a folded scan structure to further improve its effectiveness. We carried out detailed planar eDRAM SPICE simulations at 45 nm node to obtain its characteristics, based on which we quantitatively evaluate the effectiveness of using planar eDRAM in these two case studies.     

Mathematical modeling and verification of pulse electrochemical micromachining of microtools

Pulse electrochemical micromachining (PECMM) is an unconventional manufacturing method suitable for the production of micro-sized components on a wide range of electrically conductive materials. PECMM in this study has been used to manufacture microtools. The non-contact nature of PECMM has necessitated the modeling of the process to estimate the anodic profile (microtool profile). This paper presents a mathematical model for predicting the diameter of the microtools fabricated by PECMM process. Tungsten microtools of diameters less than 100 μm were fabricated using an in-house built microelectrochemical machining system. Experimental results confirm the theoretical prediction of reduction in tool diameter with respect to increasing machining time. Further, from the experimental verification, it was found that the deviations in the tool diameters were within 9 % of the theoretical predictions.     

A Study on Process Parameters of Ultrasonic Assisted Micro EDM Based on Taguchi Method

Experimental investigation of ultrasonic assisted micro electro discharge machining was performed by introducing ultrasonic vibration to workpiece. The Taguchi experimental design has been applied to investigate the optimal combinations of process parameters to maximize the material removal rate and minimize the tool wear. Analysis of variance (ANOVA) was performed and signal-to-noise (S/N) ratio was determined to know the level of importance of the machining parameters. Based on ANOVA, ultrasonic vibration at 60% of the peak power with capacitance of 3300 PF was found to be significant for best MRR. The machining time plays a significant role in the tool wear. The results were confirmed experimentally at 95% confidence interval.     

The Visceral City and the Theatre of Fear

Over the last decade in India, intensive urbanisation, with the aid of the mass media, has unleashed a new culture of fear. Widespread access to TV, text messaging and the Internet have heightened and played upon individuals' anxieties. Ravi Sundaram describes how in Delhi, in particular, the media provided the catalyst for ‘mass hysteria’ and ‘psychosis’ during the summer of 2002. Copyright © 2007 John Wiley & Sons, Ltd.     

Shifting of research trends in islanding detection method - a comprehensive survey

The augmentation in electricity demand, power system privatization as well as efficacy of renewable resources has paved the way for power system companies and researchers to exploit the field of grid connected distributed generation (DG) and its issues, islanding being a dominant one. Several research works have been conducted to mitigate the issues of islanding detection (ID). In context of this, the paper gives a comprehensive review of islanding issues, standard test systems, criteria and shifting of research trends in islanding detection methods (IDMs). The significant contributions pertain to categorization of IDMs, evaluation of non-detection zone (NDZ) for each test system, disquisition on evolution and advancement of IDMs and its comparisons based on criteria such as NDZ, run on time, nuisance tripping percentage, applicability in multi DG system and implementation cost to draw out the strength and shortcomings of individual methods that will come to aid to the companies or researchers for establishing the applicability and appropriateness of such method for their concerned domain.     

LSPR-based colorimetric biosensing for food quality and safety

Ensuring consistently high quality and safety is paramount to food producers and consumers alike. Wet chemistry and microbiological methods provide accurate results, but those methods are not conducive to rapid, onsite testing needs. Hence, many efforts have focused on rapid testing for food quality and safety, including the development of various biosensors. Herein, we focus on a group of biosensors, which provide visually recognizable colorimetric signals within minutes and can be used onsite. Although there are different ways to achieve visual color-change signals, we restrict our focus on sensors that exploit the localized surface plasmon resonance (LSPR) phenomenon of metal nanoparticles, primarily gold and silver nanoparticles. The typical approach in the design of LSPR biosensors is to conjugate biorecognition ligands on the surface of metal nanoparticles and allow the ligands to specifically recognize and bind the target analyte. This ligand–target binding reaction leads to a change in color of the test sample and a concomitant shift in the ultraviolet-visual absorption peak. Various designs applying this and other signal generation schemes are reviewed with an emphasis on those applied for evaluating factors that compromise the quality and safety of food and agricultural products. The LSPR-based colorimetric biosensing platform is a promising technology for enhancing food quality and safety. Aided by the advances in nanotechnology, this sensing technique lends itself easily for further development on field-deployable platforms such as smartphones for onsite and end-user applications.     

Understanding Substrate Selectivity of Phoslactomycin Polyketide Synthase by Using Reconstituted in Vitro Systems

Polyketide synthases (PKSs) use simple extender units to synthesize complex natural products. A fundamental question is how different extender units are site-specifically incorporated into the growing polyketide. Here we established phoslactomycin (Pn) PKS, which incorporates malonyl- and ethylmalonyl-CoA, as an in vitro model to study substrate specificity. We combined up to six Pn PKS modules with different termination sites for the controlled release of tetra-, penta- and hexaketides, and challenged these systems with up to seven different extender units in competitive assays to test for the specificity of Pn modules. While malonyl-CoA modules of Pn PKS exclusively accept their natural substrate, the ethylmalonyl-CoA module PnC tolerates different α-substituted derivatives, but discriminates against malonyl-CoA. We show that the ratio of extender transacylation to hydrolysis controls incorporation in PnC, thus explaining site-specific selectivity and promiscuity in the natural context of Pn PKS.     

An Efficient 2.45 GHz Spiral Rectenna Without a Matching Circuit for RF Energy Harvesting

Wireless Personal Communications - This paper presents an efficient spiral rectenna to be used for radio frequency energy harvesting application. This rectenna is simple, low cost and an efficient...     

Giant oyster mushroom,Pleurotus giganteus (Agaricomycetes): Current status of the cultivation methods,chemical composition,biological, and health-promoting properties

Pleurotus giganteus (Berk.) Karunarathna & Hyde is one of the largest edible mushrooms which can be found either in groups or solitary and in soil and buried woods, but seldom in grassland. It has been recorded in Southeast Asia, Australasia, and China by either its common names or local names. Previously known as Lentinus/Panus giganteus, its unique physical characteristics and the utilization of molecular tools have since anchored its taxonomical position in the Pleurotus genus. A sawdust-based substrate coupled with soil casing method is described as a standard cultivation procedure for P. giganteus. The basidiocarp of P. giganteus is found to be rich in carbohydrates, proteins, polyunsaturated fatty acids, and polysaccharides. Both ethanol and aqueous extracts of P. giganteus have been studied in vitro for its antioxidative, antifungal, anticancer, hepatoprotective, and neurite outgrowth capabilities. The review covers the optimum cultivation methods of P. giganteus, as well as its various biological activities and medicinal properties that have been studied by different approaches. Available data in regards to the chemical compounds present in P. giganteus are also compiled for future references. Overall, both in vitro and in vivo studies have shown significant bioactivity comparable to other recognized Pleurotoid mushrooms.