Pass Filter Research Articles

Electrostatically assisted air coarse filtration for energy efficient ambient particles removal: Long-term performance in real environment and influencing factors

Electrostatically assisted air (EAA) coarse filter can improve the particle filtration performance of low efficiency filters without increasing their pressure drop. In this study, we investigated the long-term single pass filtration efficiency for 0.3–10 μm ambient particles, pressure drop, PM2.5 collecting amount, and energy consumption of an EAA coarse filter during a 51-day operation period. We found that the efficiency of EAA coarse filter varied with average values of 87.6%–97.1% for 0.3–10 μm particles, respectively, while the pressure drop increased from 14.6 Pa to 63.1 Pa at face air velocity of 1 m/s. Using K-means clustering and principal components analysis methods, we discovered that before 33 days, the significant influencing factors of the efficiency for 0.3–0.5 μm particles included air temperature, air moisture content, 3–10 μm particle number concentration, and PM2.5 collecting amount. While after 33 days, only PM2.5 mass collecting amount has a significant negative correlation with the efficiency for 0.3–0.5 μm particles. The efficiency became relatively unsteady and the PM2.5 collecting amount reached 131 g/m2 after 33 days. The total energy consumption of EAA coarse filter rose more slowly as PM2.5 collecting amount increased when compared with that of a conventional electret filter (KAFPO78A4, Daikin Inc., Japan). We suggest the high efficiency EAA coarse filtration as an energy efficient method for ambient particle removal in the view of its long-term performance.

Observation Of Clay Settlement Of Consolidation In Petarukan District Pemalang Regency Stabilized By Using Salt (Nacl)

Soil stability is an effort made to improve the properties of the origin of the soil, basically stabilization using salt has the same principle as stabilization using other chemicals. Based on the research on native soil combat, the value of 42.25% is categorized into soil types have high plasticity therefore the soil needs repair or stabilization. In this study chemical stabilization was carried out by adding ingredients to stability of salt (Nacl) with a percentage of 4% , 8%, and 12% of the weight of the sample. The research method used is divided into two, namely physical properties test consisting of water content test, density test, atterberg test and filter analysis test and mechanical properties test consisting of compacting test and consolidation test . The results of physical properties test showed that the greater the percentage of NaCl addition in water content, plastic limit, shrinkage limit increased while the specific gravity value, liquid limit, plasticity index and pass filter No. 200 decreased. While in the compaction test the weight value of the maximum dry volume increases and the optimum water content value decreases along with the percentage addition of NaCl. The maximum weight value of maximum dry volume is 1.675 gr / cm3 and the lowest optimum water content is 15.509% in mixed soil with the percentage of addition of 12% NaCl. Meanwhile the consolidation test results showed that the greater percentage percentage of NaCl consolidation coefficient (Cv) increases , while for the Cc index value and the consolidation decrease (Sc) decreases. Keywords : clay soil, Stablizing,Consolidation , salt (NaCl).

Estimation of Beat-to-Beat Interval and Systolic Time Intervals Using Phono- and Seismocardiograms.

Systolic time intervals Pre-Ejection Period (PEP) and Left Ventricular Ejection Time (LVET) are widely used indicators of cardiac functions. While accurate assessment of them requires costly equipment such as echocardiography devices, a satisfactory estimation can be done by analyzing signals from simple accelerometer and microphone attached to human chest. This paper reports a study where heart rate and the systolic intervals were derived from phonocardiogram (PCG) and seismocardiogram (SCG) simultaneously. Both sensors, the microphone for PCG and the accelerometer for SCG were attached on the chest wall, close to sternum (PCG) and apex of the heart (SCG). The signals were acquired from 10 participants in a 33-minute laboratory protocol with synchronized ECG measurements. Both signals went through an identical processing path: band pass filtering, envelope extraction with Hilbert transformation and peak detection from the envelope signal. In heart rate estimation, PCG and SCG reached 84% and 93% accuracy, respectively. The systolic interval accuracy estimation was based on deviation analysis as the absolute reference values for PEP and LVET were not available. In PEP estimation, the average standard deviations during the rest periods of the protocol were 4 ms for PCG and 8 ms for SCG. In LVET estimation, the deviations were nearly 10 fold compared to PEP. However, the results show that both methods can be used for accurate heart rate estimation and with careful mechanical attachment also PEP can be accurately derived from both. Due to sharper envelope signal waveform, PEP estimation was more accurate with PCG than with SCG.

Simplified and relatively precise back-calculation method for the pavement excitation of the monorail

ABSTRACT In order to establish a more accurate model to simulate actual working conditions, a back-calculation method for road excitation of monorail is introduced and dynamic transcendental equations are set up in this paper. By neglecting the subtle influence of the pitching angle on the vertical acceleration of the bogies, this dynamic model (i.e. the dynamic transcendental equations) is greatly simplified. Besides, the calculation result shall be closer to the measured data. Comparison between the back-calculation results of the two vehicles in a monorail proves that this method can be applied to experiments accurately. Through validating the model by comparing the experiment data and the simulated results, it can be noticed that the simulated result of the acceleration under the action of the back-calculated road irregularities is consistent with the experimental data, which indicates the back-calculation process is precise enough. Band pass filtering is applied to the measured acceleration data to get the signals in the frequency range of 0.5–10 Hz as per the standard, which proves that the model is valid only in low frequencies but good enough for researches of vehicle stability.

Hybrid optoelectronic synaptic functionality realized with ion gel-modulated In2O3 phototransistors

Abstract Artificial synaptic devices have raised the concern of many researchers in the field of neural computing and artificial neural network. Ion gel-modulated synaptic transistors with solution-processed In2O3 semiconductors are demonstrated in this paper. The devices show good electrical performance, including a low operating voltage of 3 V and a large Ion/Ioff ratio of 3.86 × 105. More importantly, a series of basic biosynaptic behaviors, such as excitatory post-synaptic current (EPSC), synaptic plasticity, high pass filtration, and memory can be generated applying a presynaptic voltage or light pulses. Furthermore, a dynamic logic function was demonstrated by applying spatiotemporally related hybrid optoelectronic pulses. This study can pave a way for the development of hybrid optoelectronic artificial neural networks and open up a new strategy for further advances in synaptic electronics.

Active biquad tunable filter design

This paper presents the technique of single differential stage op-amp which is used for the active biquad filter design with the inclusion of buffers at the output of op-amp. This procedure provides the advantage of low power and low area requirement with reduction of propagation delay. The buffer circuit proffers the tunability of the filter by modulating the transconductance of the output buffer. This approach has been established to design a second order active biquad filter. The two biquad high pass and low pass sections are used to design a fourth order band pass and band stop filter with 0.18 µm CMOS process technology which consumes significantly less power than conventional approaches.

A bi-patch loaded microstrip line based 1-D periodic structure with enhanced stop bandwidth and band switching characteristics

ABSTRACTA one-dimensional periodic structure comprising of eight unit cells each having two metallic patches sandwiched between microstrip line and ground plane has been investigated. Patches bearing dissimilar dimensions present distinct reactive loads, determined by their respective areas, to generate relatively wider bandgap. Patches can be selectively connected to ground or left floating through a combination of vias and externally controlled FET switches. Dispersion analysis of the structure has been carried out to determine the propagating modes of the line for all four possible states of the unit cell. A top-down, design guide approach has been adopted with the effect of parameters determining performance attributes captured. The proposed structure acts as an all pass filter from DC to 19.5 GHz with all patches floating and exhibits stopband characteristics from 6 to 19.5 GHz with different combinations of the switches offering an overall stop bandwidth greater than 100%. The proposed structure offers tunability from no bandgap to bandgap with added advantages of band switching capability with double the number of unique reconfigurable switch patterns as compared to conventional single patch structures.

Variant of the charged system search algorithm for the design of optimal linear phase finite impulse response filters

ABSTRACT Digital signal filtering is one of the prime area which is frequently used in practical applications. In the class of digital filters, the prominent filters include – filters with finite impulse response (FIR) and filters with infinite impulse response (IIR). Low pass, high pass, band pass and band stop filters are the different types of filters that are currently employed for carrying out filtering actions. Filters are used for practical applications to reduce the noise incurred while processing the signals received, whether it may be an audio signal, video signal, bio-medical signal and so on. The key features for the design of filters include the optimization of coefficients and in turn the design of coefficients is based on attaining maximum stop band attenuation with less ripple rates. This paper proposes the soft computing based wavelet concept being introduced in the charged system search algorithm at the updation process. The scaling factor in the updation equation is implemented with a wavelet introduced to improve the exploration and exploitation capability of the algorithm. This introduction of wavelet into the algorithm results in faster convergence of the algorithm and proves its effectiveness in comparison with that of the other approaches as available in the literature.

Bradycardia Detection using ECG Signal Processing and MATLAB

Electrocardiogram is the record of electrical activity of heart. ECG is a test to detect and study normal rhythmic activity of the heart. Signal processing are very often used methods in a biomedical engineering research. This paper presents Bradycardia detection by utilization of digital signal filtering on electrocardiogram (ECG) using MATLAB. MATLAB was used to analyze and process ECG dataset gotten from Physionet online database with focus on R-R peaks to calculate the heartbeat, by applying high pass filtering and squaring the signal. The results obtained using MATLAB for ECG analysis and detection of arrhythmia is very fast and useful.

Miniaturized half‐mode SIW band‐pass filter design integrating dumbbell DGS cells

AbstractThis paper presents the numerical and experimental results of a miniaturized half‐mode substrate integrated waveguide HMSIW C‐band pass filter with defected ground structure DGS, using two slots and dumbbell shape defected ground structure. These two slots which are etched on the upper plane of the SIW cavity are used to constitute a multiple‐mode resonator, and the dumbbell‐shape fractal DGS etched on the bottom plane can considerably enhance the filter's performances. The manufactured band‐pass filter in half mode based on SIW technology has a size nearly half of that of a normal filter. The measurements results obtained by CST in C‐band show that the manufactured filter has a large transmitted bandwidth of about 1.53 GHz from 5.97 to 7.5 GHz. The higher measured insertion is about −2.6 dB and the lower return loss measured is about −34 dB. The size of filter design achieved is 7.48 × 38.12 mm2 which make it the more compact in comparison with some published works at the C‐band frequency.

Toward energy saving and high efficiency through an optimized use of a PET coarse filter: The development of a new electrostatically assisted air filter

Efficient particle removal technology with minimal pressure drop is urgently needed for both air purification and energy conservation. Compact electrostatically assisted air (cEAA) coarse filters can significantly enhance the filtration efficiency of low-efficiency filters without increasing the pressure drop, thus greatly reducing the energy consumption of ventilation fans. In this study, we developed a new structure for an electrostatically assisted air (EAA) filter, in which the corona charging and polarizing fields were separated and independently controlled. We experimentally evaluated the influencing factors on both single pass filtration efficiency and energy consumption of 6 EAA PET coarse fibrous filters: charging field intensity (Ec), polarizing field intensity (Ep), and PET filters’ characteristics. The EAA filter device increased the single pass filtration efficiency for 0.3–0.5 µm particles of a PET coarse filter from 0.4% (Ec = Ep = 0) to 57.0% (Ec = 5.9 kV/cm, Ep = 0) by particle charging, and then up to 99.0% (Ec = 5.9 kV/cm, Ep = 12.5 kV/cm) by filter polarizing. Increasing Ep enhanced filtration efficiency and reduced power dissipation of EAA filters at the same time. Although all filters are made of PET, several filter characteristics – including thickness, filling power, electrostatic half period, morphology and fiber diameter – strongly influence filtration efficiency. We compared the six EAA PET filters to traditional filters reported in the literature, and found that to have a more than 90% filtration efficiency for PM0.3–0.5, commercial filters (91.0%) need total power use per unit area (Pt) of at least 327 W/m2, while filters described in the literature (94.1%) need at least Pt = 76 W/m2, and EAA PET coarse filters (93.2%) need at least Pt = 39 W/m2. This study gives an understanding of the importance of media optimizing for EAA coarse filtration to achieve energy saving and high efficiency.

A Novel Neutrosophic Subsets Definition for Dermoscopic Image Segmentation

Dermoscopic images suffer from irregular and vague boundaries. New directions established the neutrosophic set (NS) approaches for clustering, and segmenting the dermoscopic images. In this work, an accurate segmentation process was developed by mapping initially the dermoscopic images to the NS domain. Thus, the neutrosophic image was defined by three subsets, namely True (T), Indeterminacy (I) and False (F). For accurate boundary detection and segmentation, different high pass (HP) filter types were used in the definition of I subset and low pass (LP) filter types in the definition of T. These filters form a new way to obtain an NS image for segmenting dermoscopy images. A comparative study was carried on the ISIC2016 skin lesion dermoscopic images dataset using different combinations of NS filter types and sizes. The results depicted the superiority of using an unsharp filter in implementing the I subset and an average filter for the T subset. 96% segmentation accuracy was reported using the proposed design compared to 92% accuracy using the default NS definition.

Discussion of Starting Method for Position Sensorless Controlled IPMSM by All Pass Filters

Discussion of Starting Method for Position Sensorless Controlled IPMSM by All Pass Filters

Development of Marker-Free Night-Vision Displacement Sensor System by Using Image Convex Hull Optimization.

Vision-based displacement sensors (VDSs) have the potential to be widely used in the structural health monitoring field, because the VDSs are generally easier to install and have higher applicability to the existing structures compared to the other conventional displacement sensors. However, the VDS also has disadvantages, in that ancillary markers are needed for extracting displacement data and data reliability is significantly lowered at night. In this study, a night vision displacement sensor (NVDS) was proposed to overcome the aforementioned two limitations. First, a non-contact NVDS system is developed with the installation of the infrared (IR) pass filter. Since it utilizes the wavelength of the infrared region and it is not sensitive to the change of a visible ray, it can precisely extract the shape information of the structure even at night. Second, a technique to extract the feature points from the images without any ancillary marker was formulated through an image convex hull optimization. Finally, the experimental tests of a three-story scaled model were performed to investigate the effectiveness of proposed NVDS at night. The results demonstrate that the NVDS has sufficiently high accuracy even at night and it can precisely measure the dynamic characteristics such as mode shapes and natural frequencies of the structure. The proposed system and formulation would extend the applicability of vision sensor not only into night-time measure but also marker-free measure.

Computational Generalization of Mixed Models on Large-Scale Data with Applications to Genetic Studies


 
 
 
 Aims: To discuss different LMM-based approaches applied in GWAS and software packages implementation and Classify different computational tools that applies LMM approaches according to their applicability and performance. To identify possible SNPs associated to a particular disease using different computational tools based on LMM approaches. To estimate genetic and residual variance parameters that account phenotypic variation of the disease.
 Study Design: Case control study
 Place and Duration of Study: The research was carried out in Tanzania at African Institute of Mathematical Science for six months.
 Methodology: Linear Mixed Models (LMMs) are widely applied in genomic wide associations studies (GWAS) owing to their effectiveness of correcting hidden relationship, population structure and family structure. This essay is aimed at exploring different mathematical approaches of LMMs in GWAS. These approaches are linear mixed model with inclusion of all markers (LMMi) and linear mixed model with exclusion of all markers (LMMe) when calculating genetic relationship matrix. LMMi is more efficient as compared to LMMe when applied in studies of randomly ascertained quantitative traits. The LMM approaches are classified based on their applicability and performance. Two computational GWAS tools namely, PLINK and EMMAX were used which were based on LMM approaches to analyze unpublished real data from West Africa (Gambia and Ghana). Genetic and residual variance parameters were estimated that accounted for the phenotypic variation of the disease to be 0.0594 and 0.0723. A total of 338408 variants and 959 people (484 males, 405 females and 70 missing phenotypes) pass filters and quality control using PLINK was used in the study. Among the remaining phenotypes, 864 are cases and 95 are controls. The performance of different mathematical approaches of LMMs and their software implementation, including EMMAX and Plink via the application to a GWAS of tuberculosis (TB) in 959 individuals in West Africa (Ghana and Gambia) was compared. Of these 864 cases of TB and 95 healthy individuals retained after quality control (QC) using Plink, and 329601 autosome single nucleotide polymorphisms (from chromosome 1 to chromosome 22) included in the analysis after 288 duplicands ID individuals removed after QC. The LMM approaches are classified based on their applicability and performance. Two computational GWAS tools, namely Plink and EMMAX were used in the analysis of data. Genetic and residual variance parameters were estimated that accounted for the phenotypic variation of the disease to be 0.0594 and 0.0723.
 Results: Result showed that SNPs associated with tuberculosis were on chromosome 17 and SNP on chromosome 13 with both having false discovery rate with step up significance value. Plink failed to correct hidden relatedness. Although EMMAX reduced the false positive rate, it still exhibited very low presence of stratification.
 Conclusion: This study aimed at understanding and exploring different approaches of mixed models as applied in genetic studies. Overview of genetic variation, advantages, successes and application of mixed models and current challenges of mixed models in GWAS were discussed. Moreover, the study showed that SNPs was associated with a particular disease using computational tools that applies LMM approaches. The summary statistics from PLINK and EMMAX found two causal SNPs associated with the TB. These SNPs were rs7225581 on chromosome 17 and SNP rs4941412 on chromosome 13 with both having 0.69% FDR H. However, PLINK failed to correct hidden relatedness. This phenotypic variation showed that all common single nucleotide polymorphisms (SNPs) expressed approximately 18.52% of phenotypic variation of the disease.
 
 
 
 

A Novel User Interface for Text Dependent Human Voice Recognition System

In an effort to provide a more efficient representation of the speech signal, the application of the wavelet analysis is considered. This research presents an effective and robust method for extracting features for speech processing. Here, we proposed a novel user interface for Text Dependent Human Voice Recognition (TD-HVR) system. The proposed HVR model utilizes decimated bi-orthogonal wavelet transform (DBT) approach to extract the low level features from the given input voice signal, then the noise elimination will be done by band pass filtering followed by normalization for better quality of a voice signal and finally the formants of a train and test voices will be calculated by using the Additive Prognostication (AP) algorithm. Simulation results have been compared with the existing HVR schemes, and shown that the proposed user interface system has performed superior to the conventional HVR systems with an accuracy rate of approximately 99 %.

A Novel User Interface for Text Dependent Human Voice Recognition System

In an effort to provide a more efficient representation of the speech signal, the application of the wavelet analysis is considered. This research presents an effective and robust method for extracting features for speech processing. Here, we proposed a novel user interface for Text Dependent Human Voice Recognition (TD-HVR) system. The proposed HVR model utilizes decimated bi-orthogonal wavelet transform (DBT) approach to extract the low level features from the given input voice signal, then the noise elimination will be done by band pass filtering followed by normalization for better quality of a voice signal and finally the formants of a train and test voices will be calculated by using the Additive Prognostication (AP) algorithm. Simulation results have been compared with the existing HVR schemes, and shown that the proposed user interface system has performed superior to the conventional HVR systems with an accuracy rate of approximately 99 %.

Strategies for suppressing elastically scattered laser light in ungated laser-induced breakdown spectroscopy

When an ungated detector is used for recording the signal in laser-induced breakdown spectroscopy (LIBS), elastically scattered laser light can represent a severe interference significantly limiting the dynamic range. Hence, a suitable filter must be selected from a variety of choices. In this Note, we compare different filter types and demonstrate that the filter needs to be chosen taking the experimental setup and the measurement object into account. For this purpose, dichroic and colored glass long pass filters, a dielectric Notch filter and three polarization filtering approaches are considered. Regarding the latter, a novel approach employing a half-wave plate in the laser beam is introduced and tested. Reckoning experimental data and the physical filter mechanisms allows providing guidelines for making an informed choice.

Design of Analog Front-end Circuit for Audio-frequency Magnetotelluric Instrument

High-performance audio-frequency magnetotelluric (AMT) instrument is one means of obtaining high-quality electromagnetic (EM) data. To improve the ability of AMT system to obtain high-quality data, this paper presents a design for a high-performance analog front-end circuit for AMT instrument. It mainly consists of the input protection, preamplifier, passive high pass filter, power frequency notch filter, programmable amplifier, and active low pass filter. In addition, this paper proposes a design of low-noise, high-performance preamplifier, which improves the common-mode rejection ratio (CMRR) of analog front-end circuit and effectively enhances the signal-to-noise ratio (SNR) of the circuit. The front-end circuit utilized two-stage twin-T notch filter to effectively suppress the strong interference of fundamental component of power frequency. Also, it used signal relays to control circuit gain and selection of cutoff frequency of anti-aliasing filter, resulting in the improvement of the capability of the analog-to-digital Converter (ADC) to distinguish weak EM signal. The measured results of the electric field and magnetic field channel showed that: 1) The circuit works in frequency range of 1 Hz∼100 kHz; 2) The CMRR values of the preamplifier of electric field channel at low frequencies (1 Hz∼1 kHz) are 111 dB and 97 dB when the gains are 20 dB and 6 dB respectively; 3) The maximum attenuation fundamental power frequency can reach −39.46 dB and −39.04 dB respectively; 4) The total harmonic distortion rate at 1 kHz is 0.022% and 0.029% respectively; 5) The input noise levels of electric field channel are 12.67nV / [Formula: see text] @10Hz and 8.15V / [Formula: see text] @1kHz, while the input noise levels of magnetic field channel are 8.97nV / [Formula: see text] @10Hz and 6.16V / [Formula: see text] @1kHz; and 6) In conclusion, the analog front-end circuit is superior to meet the requirements of the AMT methods, and provides a useful reference for the development of AMT instrument.

대형 컨테이너 선박의 구조 응답에 미치는 휘핑 영향도 분석

Recently, it has been reported that the whipping response, which is the elastic phenomenon of the ship, may be one of the causes of the ship accident. Unfortunately, the commonly used methodology for evaluating the whipping effect effectively has not been developed yet. In this study, we developed a procedure to estimate the whipping effect of hull in actual design stage. Fluid –structure interaction analysis was performed for a dominant short term sea state to obtain the time series data of vertical wave bending moment including the whipping response by slamming. In order to estimate the whipping effect by using the time series, some signal processing and statistical techniques such as low pass filtering, Weibull fitting and so on, were applied. the hydro-elasticity analysis was performed on container ships of various sizes to evaluate the whipping effect. The parameters that can affect the response of the hull vibration was selected and the effect of these parameters on whipping was analyzed.