Filtering Off Research Articles

PTME: A Regular Expression Matching Engine Based on Speculation and Enumerative Computation on FPGA

Fast regular expression matching is an essential task for deep packet inspection. In previous works, the regular expression matching engine on FPGA struggled to achieve an ideal balance between resource consumption and throughput. Speculation and enumerative computation exploits the statistical properties of deterministic finite automata, allowing for more efficient pattern matching. Existing related designs mostly revolve around vector instructions and multiple processors/cores or SIMD instruction sets, with a lack of implementation on FPGA platforms. We design a parallelized two-character matching engine on FPGA for efficiently fast filtering off fields with no pattern features. We transform the state transitions with sequential dependencies to the existing problem of elements in one set, enabling the proposed design to achieve high throughput with low resource consumption and support dynamic updates. Results show that compared with the traditional DFA matching, with a maximum resource consumption of 25% for on-chip FFs (74323/1045440) and LUTs (123902/522720), there is an improvement in throughput of 8.08-229.96 × speedup and 87.61-99.56% speed-up(percentage improvement) for normal traffic, and 11.73-39.59 × speedup and 91.47-97.47% speed-up(percentage improvement) for traffic with high-frequency match hits. Compared with the state-of-the-art similar implementation, our circuit on a single FPGA chip is superior to existing multi-core designs.

The landscape of chimeric RNAs in bladder urothelial carcinoma.

Gene fusions and products have been identified as oncogenic drivers in many cancers, making them attractive diagnostic markers and therapeutic targets. However, the landscape of fusion transcripts in bladder cancer has not been fully characterized. To identify fusion transcripts with potential therapeutic or diagnostic values, TCGA bladder urothelial carcinoma RNA-sequencing dataset was used. In order to avoid false positives, we applied multiple criteria including filtering out fusions detected in normal samples from GTEx dataset. We validated a subset of candidate fusions with a collection of bladder cancer and adjacent normal samples. We identified 19,547 high confidence fusion genes from 414 bladder cancer samples. After filtering off M/M fusions, fusions in GTEx normal samples, and occurrence frequency <5, we obtained a list of 271 gene fusions, 13 of which were novel and specific to cancer samples. Six of those fusions were validated using cell lines and clinical samples. We discovered that two chimeric RNAs, BCL2L2-PABPN1 and CHFR-GOLGA3, were detected to be expressed significantly higher in bladder cancer samples compared to adjacent normal samples. Impressively, the wild-type of the parental genes were not differentially expressed. Mechanistically, we demonstrated that these two fusions are generated by cis-splicing between adjacent genes. These two fusions were detected mainly in the fraction of cell nucleus, suggesting a potential long noncoding RNA role. Our findings provide a panoramic view of the landscape of chimeric RNAs in bladder cancer. Some frequent chimeric RNAs are generated by intergenic splicing, and represent a new repertoire for potential biomarkers.

Dynamic Defense Strategy Against DoS Attacks Over Vehicular Ad Hoc Networks Based on Port Hopping

To fight against denial of services (DoS) attacks on vehicular ad hoc networks, which can cause congestion over networks and degrading the user’s experience, a lot of detective techniques and schemes have been proposed. However, the complex ones cannot keep pace with the growth of vehicle networks. In this paper, we propose a simple but effective defense strategy scheme inspired by the port-hopping mechanism, which advantage is manifested in that the detection and filtering off of malicious packets launched by attackers can be achieved without any change in existing protocol. First, we design a dynamic defense strategy scheme to puzzle a DoS attacker, where the specific defense strategy will change according to a scheme of time. To mitigate the losses caused by an attacker whose goal is to probe the vulnerable services’ ports contained in the UDP/TCP headers between vehicle-to-vehicle or vehicle-to-infrastructure, we add some security services’ ports that are valueless to attackers. Second, we give the specific construction of such a defense strategy scheme reflected as a matrix and a security analysis with respect to detecting the probed ports. At last, in comparison with the non-strategy defense scheme, simulations considering some parameters are conducted, which can show that our scheme is an effective defense scheme used for protecting VANETs.

General filtering method for electronic speckle pattern interferometry fringe images with various densities based on variational image decomposition.

Filtering off speckle noise from a fringe image is one of the key tasks in electronic speckle pattern interferometry (ESPI). In general, ESPI fringe images can be divided into three categories: low-density fringe images, high-density fringe images, and variable-density fringe images. In this paper, we first present a general filtering method based on variational image decomposition that can filter speckle noise for ESPI fringe images with various densities. In our method, a variable-density ESPI fringe image is decomposed into low-density fringes, high-density fringes, and noise. A low-density fringe image is decomposed into low-density fringes and noise. A high-density fringe image is decomposed into high-density fringes and noise. We give some suitable function spaces to describe low-density fringes, high-density fringes, and noise, respectively. Then we construct several models and numerical algorithms for ESPI fringe images with various densities. And we investigate the performance of these models via our extensive experiments. Finally, we compare our proposed models with the windowed Fourier transform method and coherence enhancing diffusion partial differential equation filter. These two methods may be the most effective filtering methods at present. Furthermore, we use the proposed method to filter a collection of the experimentally obtained ESPI fringe images with poor quality. The experimental results demonstrate the performance of our proposed method.

DETECTION OF DRY INTRUSION ON WATER VAPOR IMAGES OVER CENTRAL EUROPE – JUNE 2010 TO SEPTEMBER 2011

The knowledge of evaluation of the intensity of cyclogenesis which could be connected with the weather having a significant impact on Earth’s surface is quite useful. If, as one of the basic assumptions, the existence of connection between dry intrusions, dry bands, tropopause height and warm dark areas distribution on water vapor images (WV images) is considered, it is possible to set up a method of detecting dry intrusions on searching and tracking areas with higher brightness temperature compared with the surrounding environment. This paper covers the period between June 2010 and September 2011 over Central Europe. The ISIS method (&amp;lt;i&amp;gt;Instrument de Suivi dans I’Imagerie satellitaire&amp;lt;/i&amp;gt;), originally developed for detection of cold cloud tops, was used as an initial ideological point. Subsequently, this method was modified by Michel and Bouttier for usage on WV images. Some of the applied criteria and parameters were chosen with reference to the results published by Michel and Bouttier as well as by Novotny. The procedure can be divided into two steps: detection of warm areas and their tracking. Cases of detection of areas not evidently connected with dry intrusions can be solved by filtering off based on the connection between detected warm areas to the cyclonic side of jet streams and significant lowering of the tropopause.

DETECTION OF DRY INTRUSION ON WATER VAPOR IMAGES OVER CENTRAL EUROPE – JUNE 2010 TO SEPTEMBER 2011

Abstract. The knowledge of evaluation of the intensity of cyclogenesis which could be connected with the weather having a significant impact on Earth’s surface is quite useful. If, as one of the basic assumptions, the existence of connection between dry intrusions, dry bands, tropopause height and warm dark areas distribution on water vapor images (WV images) is considered, it is possible to set up a method of detecting dry intrusions on searching and tracking areas with higher brightness temperature compared with the surrounding environment. This paper covers the period between June 2010 and September 2011 over Central Europe. The ISIS method (Instrument de Suivi dans I’Imagerie satellitaire), originally developed for detection of cold cloud tops, was used as an initial ideological point. Subsequently, this method was modified by Michel and Bouttier for usage on WV images. Some of the applied criteria and parameters were chosen with reference to the results published by Michel and Bouttier as well as by Novotny. The procedure can be divided into two steps: detection of warm areas and their tracking. Cases of detection of areas not evidently connected with dry intrusions can be solved by filtering off based on the connection between detected warm areas to the cyclonic side of jet streams and significant lowering of the tropopause.

English

In this study, an extensive investigation was conducted to determine if declared weeds could be used as a source of water for agricultural practices in dry areas. The objective of this study was to determineif declared weeds could successfully be used as a source of water for agricultural practices in dry areas by extracting the water by means of mechanical and chemical methods. The Cereus jamacura cactus, also known as Queen of the Night, with a moisture content of 91 wt%, was selected for this study. Both mechanical and chemical extraction methods were used to determine the maximum water yield possible. Juicing, pressing with a hydraulic cold press and pressing with rollers were used as mechanical methods to extract water from the cacti and water yields of 7.0, 4.9 and 2.9 wt% were obtained respectively. The chemical extraction processes entailed the pulping of the cacti and the filtering off of the water. The effect of pectinase, cellulase and a surfactant at a fixed dosage on the amount of water extracted (mass of water per mass of cacti used) was investigated. The quality of the water was also determined. Temperature (30 to 50°C) and pH (2.5 to 6.5) were varied to find the optimum extraction conditions. The highest water yield (55 wt% of total cacti mass) was obtained using pectinase enzymes at a temperature of 40°C and a pH of 3.5 and cellulose enzymes at a temperature of 35°C and a pH of 5.5. This relates to a yield of 550 L of water per ton of cacti, making chemical water extraction a viable option if compared to the pollution created by the annual burning of the cacti. It was concluded from this study that the water that was extracted from the C. jamacaru cacti would not be suitable for either domestic or industrial application due to the high levels of potassium (up to 2,650 ppm), phosphates (up to 2,200 ppm), sulphates (up to 3,800 ppm) and nitrates (up to 670 ppm) in the water. The high concentration of phosphates and nitrates, however, makes the extracted water an excellent fertiliser for crops requiring high nitrate and phosphate dosages. Small community farmers could thus benefit by using cacti as a source of water for small scale biofuels production plants while also obtaining an excellent additional fertiliser for crop cultivation. Keywords: Cereus jamacaru , water yield, water quality. African Journal of Biotechnology Vol. 12(40), pp. 5926-5932

Interferometric study of microchamber in large area dye solar cells

Dye-sensitized solar cells (DSCs) have a typical sandwich structure, with the active layers between two conductive glass sheets. Their co-planarity could be an issue in the mass production of large area devices. The micrometric gap should be uniform all over the device, in order to maintain a good electrolyte layer. The frames of sealant, which isolate the adjacent cells in a module, usually work also as spacers. Nevertheless, the uniformity of the gap is not commonly tested in a systematic way. Here large area empty blanks and full DSCs were studied by means of optical interferometry, i.e., monochromatic surface scan and wavelength scan. The collected fringe patterns allowed retrieval of the microchamber’s absolute profile. In some cases, evident U-shaped bending was found, with edge-to-center variation up to Δh/h≈80%. Interestingly, despite the large absorption and the weak index contrast in the full DSCs, a good fringes’ visibility was achieved, by adopting near-infrared (IR) laser source and filtering off external reflections. Moreover, the IR n and k indexes of porous titania dyed and filled with electrolyte were retrieved. In summary, the results show that the bending effect must always be tackled for large area, by using the right sealing frames and thermal treatments. Further improved IR interferometry can be successfully implemented for in-line testing of DSCs structure and uniformity.

Finding hypernetworks in directed hypergraphs

The term “hypernetwork” (more precisely, s-hypernetwork and (s, d)-hypernetwork) has been recently adopted to denote some logical structures contained in a directed hypergraph. A hypernetwork identifies the core of a hypergraph model, obtained by filtering off redundant components. Therefore, finding hypernetworks has a notable relevance both from a theoretical and from a computational point of view.In this paper we provide a simple and fast algorithm for finding s-hypernetworks, which substantially improves on a method previously proposed in the literature. We also point out two linearly solvable particular cases.Finding an (s, d)-hypernetwork is known to be a hard problem, and only one polynomially solvable class has been found so far. Here we point out that this particular case is solvable in linear time.

Optimization Studies of Two-Phosphor-Coated White Light-Emitting Diodes

Three-hump InGaN-based white light-emitting diodes (LEDs) precoated with traditional yellow/green phosphors and red-emitting quantum dots (QDs), have been numerically investigated. Under variations of eight correlated color temperatures (CCTs), three wavelengths, two bandwidths, and two peak heights, optimal results of luminous efficacy radiation (LER) and color rendering index (CRI) are identified and retained through filtering off billions of unqualified candidates. These results include LER = 390 lm/W and CRI = 90 [chromaticity difference ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Duv</i> )<;0.0054] at CCT = 3000 K. In addition, our photometric and colorimetric sensitivity studies provide the dependence of LER, CRI, CCT, and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Duv</i> on LED spectral parameters affected by operating temperatures. Finally, we have discovered that higher instabilities may be induced for cool white LEDs (CCT = 6500 K) than for warm white LEDs (CCT = 3000 K) within the analysis of CCT versus spectral parameters.

Programmed temperature vaporizing injector to filter off disturbing high boiling and involatile material for on-line high performance liquid chromatography gas chromatography with on-column transfer

Insertion of a programmed temperature vaporizing (PTV) injector under conditions of concurrent solvent recondensation (CSR) into the on-line HPLC–GC interface for on-column transfer (such as the retention gap technique with partially concurrent eluent evaporation) enables filtering off high boiling or involatile sample constituents by a desorption temperature adjusted to the required cut-off. Details of this technique were investigated and optimized. Memory effects, observed when transferred liquid was sucked backwards between the transfer line and the wall of the injector liner, can be kept low by a small purge flow rate through the transfer line at the end of the transfer and the release of the liquid through a narrow bore capillary kept away from the liner wall. The column entrance should be within the well heated zone of the injector to prevent losses of solute material retained on the liner wall during the splitless period. The desorption temperature must be maintained until an elevated oven temperature is reached to prevent peak broadening resulting of a cool inlet section in the bottom part of the injector.

Fringe pattern denoising using averaging based on nonlocal self-similarity

Digital image processing for fringe patterns is an important procedure in optical interferometry. Filtering off noise from fringe patterns is one of the key tasks for extraction of the phase field. Spin filters proposed by Yu et al. [Appl. Opt. 33(1994), 41(2002), et al.] have been proven to be effective denoising methods. In this paper, we develop a nonlocal self-similarity filter, which averages similar pixels searched for in whole image instead of in a local fringe direction as the spin filters do. Although simple and free of the fringe orientation estimation, involving more pixels with higher similarity levels, our algorithm has stronger robustness against noise and thus denoises fringe patterns more effectively. Simulation and experimental results show that our algorithm outperforms related filters both in preserving smooth fringes and in reducing blurring effects and quantitative errors.

Fringe pattern denoising via image decomposition

Filtering off noise from a fringe pattern is one of the key tasks in optical interferometry. In this Letter, using some suitable function spaces to model different components of a fringe pattern, we propose a new fringe pattern denoising method based on image decomposition. In our method, a fringe image is divided into three parts: low-frequency fringe, high-frequency fringe, and noise, which are processed in different spaces. An adaptive threshold in wavelet shrinkage involved in this algorithm improves its denoising performance. Simulation and experimental results show that our algorithm obtains smooth and clean fringes with different frequencies while preserving fringe features effectively.

Scanning transmission low-energy electron microscopy

We discuss an extension to the transmission mode of the cathode-lens-equipped scanning electron microscope, enabling operation down to the lowest energies of electrons. Penetration of electrons through free-standing ultrathin films is examined along the full energy scale, and the contribution of the secondary electrons (SEs), released near the bottom surface of the sample, is shown, enhancing the apparent transmissivity of the sample to more than 100%. Provisional filtering off of the SEs, providing the dark-field signal of forward-scattered electrons, was made using an annular 3-D adjustable detector inserted below the sample. Demonstration experiments were performed on the graphene flakes and on a 3-nm-thick carbon film. Electron penetrability at the lowest energies was measured on the graphene sample.

Field-flow fractionation: An efficient approach for matrix removal of soil extract for inductively coupled plasma optical emission spectrometry

An on-line coupling between a continuous-flow sequential extraction (CFSE) unit and flow field-flow fractionation with cross flow matrix removal (FlFFF/CFM) with ICP-OES detection was developed for determination of metal leachability from soil. The use of high concentration of Mg(NO 3) 2 in exchangeable phase can cause undesirable matrix effects by shifting ionization equilibrium in the plasma, etc., resulting in a clear need for matrix removal. Therefore, the capability of FlFFF/CFM to remove Mg matrix ion from soil extract was evaluated. Poly(ethylene imine) (PEI) having molecular weight of 25,000 Da was added to form complexes with analyte elements (Cu, Mn, Pb, and Zn) but not the matrix element (Mg). The free Mg matrix ions were then removed by filtering off through the ultrafiltration membrane, having a 1000-Da molecular weight cut-off, inside the FlFFF channel. With the use of FlFFF/CFM, matrix removal efficiency was approximately 83.5%, which was equivalent to approximately 6-fold dilution of the matrix ion. The proposed hyphenated system of CFSE and FlFFF/CFM with ICP-OES detection was examined for its reliability by checking with SRM 2710 (a highly contaminated soil from Montana). The metal contents determined by the proposed method were not significantly different (at 95% confidence) from the certified values.

A high recovery microsampling device based on a microdialysis probe for peptide sampling

A high recovery microsampling probe based on microdialysis was devised. The new probe showed a high recovery (100%) of peptides in vitro at different perfusion flow rates (0.1–1.0 μl/min). At a high flow rate, 1.0 μl/min, a 10-fold increased in recovery of peptides compared to the conventional microdialysis probe was achieved. A probe made of a low molecular weight cutoff membrane is suitable for filtering off proteins. The new probe can be a useful tool for high recovery of peptides from living tissues.

Rotation speed measurement of moving particles in a CFB riser

This paper presents a study on measuring rotation speed of moving glass beads with an average diameter of 500 μm in a pilot-scale circulating fluidized bed (CFB) riser with a high-speed digital imaging system. Two methods have been developed to calculate particle rotation speed from the particle images. The first method consists of a fully automated algorithm based on cross-correlation of gray distribution of particle images for particles whose rotation axes are (nearly) perpendicular to the imaging plane, and the second method calculates the speed of particle rotation by identifying its rotation axis using two or more characteristic points on its surface. The reliability of the two methods is verified by using a small sphere with known speed and direction of rotation. The first method is shown to be capable of measuring accurately the rotation speed for the particle with a rotation axis (nearly) perpendicular to the imaging plane and filtering off other particles using an appropriate threshold of correlation coefficient. The second method is shown to be capable of yielding both the speed and direction of particle rotation, with a measurement error of less than 10%. Results of both methods on real glass beads in a CFB riser are compared against each other.

Channel adaptive CQI reporting schemes for HSDPA systems

HSDPA (high-speed downlink packet access) is an evolved UMTS packet scheme that delivers increased user peak data rates and quality of service. A key technique supporting HSDPA is adaptive modulation and coding (AMC), in which the modulation scheme and the coding rate are changed adaptively according to the downlink channel quality reported by the user equipment (UE). Therefore, the channel quality indication (CQI) reporting scheme is directly related to the accuracy of AMC and the performance of HSDPA. This letter proposes channel adaptive CQI reporting schemes in which UEs report the CQI value intelligently by using information about channel quality. With the proposed schemes, the battery capacity of UE can be conserved and the uplink interference can be lowered by filtering off redundant CQI reports or the transmission error rate can be lowered by fast CQI reports

Matrix removal before inductively coupled plasma spectrometric detection: another capability of flow field-flow fractionation

A modified flow field-flow fractionation (FlFFF) configuration was investigated for its matrix removal capability before inductively coupled plasma optical emission spectrometric (ICP-OES) detection. Poly(ethylene imine) (PEI) having a molecular weight of 25000 Da was added to test solutions (buffered at pH 9) to form complexes with analyte elements (Ag, Cd, Co, Cu, Hg, Ni, Pb and Zn) but not with the matrix elements (Ca, K, Mg and Na). With the use of a poly(ether sulfone) membrane having a 1000 Da molecular weight cut-off inside the FlFFF channel, matrix elements were removed by filtering off through the membrane, whereas the PEI–analyte complexes remained in the channel and were subsequently eluted and detected. Two approaches, i.e., cross flow matrix removal (CFM) and opposing flow matrix removal-analyte preconcentration (OFM), were evaluated for matrix removal and matrix removal with simultaneous preconcentration, respectively. With the FlFFF/CFM approach, the signal intensities of matrix elements were reduced by approximately 80–90% while those of analyte elements were only slightly reduced (∼20%). With the FlFFF/OFM approach, an unlimited sample volume can be introduced into the FlFFF channel with an elution volume of approximately 1 ml, leading to analyte preconcentration.

Matrix removal and analyte preconcentration before inductively coupled plasma spectrometric detection: use of a laboratory-made hollow fibre flow filtration unit

A hollow fibre flow filtration (HF-FF) was applied to perform matrix removal and analyte preconcentration before inductively coupled plasma optical emission spectrometric (ICP-OES) detection. Poly(ethylene imine), PEI, with a molecular weight of 750000 Da, was added to test solutions to form complexes with analyte elements (Ag, Cd, Co, Cu, Hg, Ni, Pb and Zn) but not the matrix elements (Ca, K, Mg and Na). Two flow streams were applied in opposing directions to introduce a large sample volume into the fibre membrane. With the use of a HF membrane made of poly(sulfone), having a pore size of 30000 Da, matrix elements were removed by filtering off through the membrane, whereas the PEI–analyte complexes remained in the channel and were subsequently eluted and detected. Various parameters were optimized to obtain a satisfactory matrix removal and preconcentration factor. These include PEI concentration, focusing time, and focusing point. With a PEI concentration of 200 mg l−1, focusing time of 15 min and the focusing point nearest to the detector, matrix removal efficiency was nearly 100%.