To-noise Ratio Research Articles

Research status and prospects of next generation sequencing system based on micro-nano manufacturing

Genes are the basic unit of heredity, which have specific nucleotide sequences of genetic information on DNA or RNA molecule. It is not only directly related to all life phenomena of the organism like birth, growth, sickness, and death, but also internal factors determine the life and health. The goal of next-generation sequencing machine is to significantly reduce the cost of DNA sequencing, increase sequencing speed rapidly and advance personalized medicine in genomic technologies to reality. It is believed DNA sequencing based on solid-state nanopores is physical sequencing technology most likely to achieve high-throughput sequencing, but now faces several challenges, such as low signal to noise ratio, biomolecules translocate too fast and the transport rules at nanoscale has not been established. Designing multi-mode nanopore sensors and cross-referencing multi-mode signal, while reducing the length of the nanopore is an effective method to improve the detection sensitivity. Learning from biological nanopores, using external force by means of magnetic tweezer or tuning fork to control DNA translocation speed can lay the foundation for the identification of single base. When the geometry of the nanochannel is less than the thickness of the electric double layer, Poisson-Boltzmann equation and Navier-Stokes equations based on the theory of continuous will be challenged, the transport rules of biological molecules established within nanochannel will tremendously enrich research contents of fluid mechanics.

Outage and BER analysis of dual-carrier modulation over frequency-selective Nakagami-m fading channels

PurposeThis paper aims to the increasing need for high-speed low-power data transmissions over frequency-selective fading channels has drawn attention to suggest dual-carrier modulation (DCM) for multiband orthogonal frequency division multiplexing (OFDM) transceivers for ultra wideband (UWB) wireless personal area network (WPAN).Design/methodology/approachUnder frequency-selective fading channel conditions, the decoder is not sufficient enough to decode the transmission bits of severely attenuated data tones. Hence, the authors suggest DCM for a multiband OFDM transceiver because of its multiple capability of providing both frequency diversity and coding gain. It also resulted in low bit-error-rate (BER) at a given signal- to-noise ratio when compared to conventional multiband OFDM system. To achieve an optimised BER, DCM transforms four re-ordered bits into two quaternary phase shift keying symbols and further transforms to two 16-quadrature amplitude modulation-like (16-QAM) symbols with a suitable mapping technique, and at the receiver end, they are decoded with maximum likelihood decision rule. After performing the transformation, the outage probability and average BER expressions are derived to analyse the system performance.FindingsDCM is suitable for high data rate transmission and is immune to frequency-selective fading. The outage and BER performance outstands over conventional multiband OFDM transceiver because of the inclusion of DCM mapping.Practical implicationsIt is widely used in WPANs such as high definition multimedia interface and wireless universal serial bus.Originality/valueThis paper derives novel closed-form outage probability and a tight upper bound on average BER expressions for DCM-based multiband OFDM UWB transceiver over frequency-selective Nakagami-m fading channels for any arbitrary value of m. For this, moment-generating function of sum of squared, independent and identically distributed (i.i.d.) Nakagami-m random variables are used. Further, the system performance is also validated for the case of exponential decaying power delay profile, and the simulation results are provided to check the accuracy of the derived expressions.

Codebook Design and Performance Analysis of Quantized Beamforming under Perfect and Imperfect Channel State Information

This paper presents a codebook design to multiple transmit and multiple receive antenna system with quantized feedback channel. The codebook design is based on trigonometrical expressions that give a quasi-orthogonal structure to the codes. The codebook is designed to a specific number of transmit antennas and can easily be adapted to different number of feedback bits. An instantaneous signal- to-noise ratio analysis is performed which is used to optimize the codebooks. An upper bound on the bit error rate (BER) performance for the proposed scheme is provided as well. We also investigate the system performance under more realistic conditions, and for this purpose we consider a time-varying and spatially-correlated channel model. We compare the BER performance of the proposed scheme with other closed-loop codebook-based schemes. Results show that the proposed scheme outperforms other good schemes in terms of array gain.

Removal of Random Noise in Seismic Data by Time-varying Window-length Time-frequency Peak Filtering

Time-frequency peak filtering (TFPF) is an effective tool for the removal of random noise and can be used to process seismic data with a low signal- to-noise ratio. A crucial aspect of this algorithm is the choice of window length (WL) of the time-frequency distribution. Whereas a fixed WL cannot simultaneously preserve signal and attenuate noise, timevarying WLs can achieve this goal. We propose a new method, L-DVV (delay vector variance), which successfully processes non-stationary signals by using the surrogate to measure the non-linearity of a time series. This method is sensitive to random noise and can accurately recover seismic signal masked by noise. Since the linearity criterion also meets the unbiased estimation criterion of the TFPF algorithm, the L-DVV method can be used for time-varying WL TFPF processing. Analysis of synthetic and real seismic data shows that the time-varying WL TFPF algorithm is effective at removing noise and recovering seismic signal.

Research on the enhancement of signal-to-noise ratio of light-addressable potentiometric sensor by optical focusing

For enhancing the response of light-addressable potentiometric sensor (LAPS) and further improving its signal- to-noise ratio (SNR), an optical focusing method is adopted. Experimental research and theoretical analysis reveal that the magnitude of responsive signal is increased by optical focusing, and the SNR is improved remarkably. These research results indicate that the optical focusing is an effective approach for improving SNR of LAPS.

Cooperative Dual-Hop Wireless Communication Systems With Beamforming Over <inline-formula> <tex-math notation="LaTeX">$\eta-\mu$</tex-math></inline-formula> Fading Channels

The end-to-end performance of cooperative beamforming in dual-hop relaying systems operating over η - μ fading channels is investigated. In the analysis, the source-destination node pair is equipped with multiple antennas, whereas the fixedgain relay has a single antenna. The η - μ fading channel has Nakagami-m, Rayleigh, one-sided Gaussian, and Nakagami-q (Hoyt) channels as special cases. In this paper, novel statistical expressions for the generalized moments of the end-to-end signal- to-noise ratio (SNR), cumulative density function (cdf), probability density function (pdf), and moment-generating function (mgf) are derived and evaluated. Furthermore, the obtained results are used to derive new and simple expressions for the pdf, the outage probability, and the mgf of the end-to-end SNR over Nakagami-m fading channels. In addition, we show that the derived expression for parameter C over the Nakagami-m fading channel is incorrect, and hence, it leads to inaccurate results. Also, we study the impact of the fading parameters η and μ on the end-to-end system performance. Simulation results show that, in contrast to the fading parameter η, μ has a significant impact on the system performance.

Quality assessment of restored satellite data based on signal to noise ratio

A practical concept of assessing the quality of restored data based on signal to noise ratio (SNR) is reported. The data come from remote sensing satellite and has undergone restoration process due to atmospheric haze effects. The restoration involves removing haze mean due to haze scattering and haze randomness due to haze spatial variability. The results shows that the SNR of restored data can be computed if the haze mean and haze randomness components are known.

Influence of processing parameters on warpage according to the Taguchi experiment

An automotive triangle trim was chosen as a research model, and the influence of processing parameters was determined with the Taguchi experimental method. An L27 (313) orthogonal array was constructed to investigate the significance of each factor (mold temperature, melt temperature, injection time, V/P switchover, packing pressure, and packing time). The computer-aided engineering software Moldflow was employed to determine the extent of warpage. The influence of processing parameters was analyzed by obtaining the signal- to-noise ratio and by conducting a range analysis. Furthermore, the processing parameters for minimizing warpage were optimized. Subsequently, the optimization packing condition for warpage minimization based on the filling conditions.

A 4th-Order Low-distortion Low-pass Modulator Using Timing-Sharing Technique

A 4th-Order low-distortion low-pass ΣΔ modulator structure is proposed in this paper, which uses the timing-sharing between the 3rd and 4th integrators during one clock phase. Compared with conventional cascade of integrators with distributed feed-forward (CIFF) sigma-delta modulator structure, the proposed structure not only solves the critical timing issue for the quantizer and feedback DAC path, but also eliminates an extra active adder to sum up the input feed-forward. By methods of delay redistribution structure, the time for quantization and feedback dynamic element match (DEM) operation can be extended from a non-overlapping interval for a conventional low-distortion structure to half of the sampling clock period. Capacitive input feed-forward (CIF) methodology eliminates the adder in front of the quantizer. Further, the op-amp of the last integrator is used as an active adder by op-amp sharing. Therefore, the power consumption can be reduced and the linearity of the feedback DAC is improved because of the increasing time which used for implementation of DEM algorism. The proposed 4th-Order low-distortion low-pass ΣΔ modulator with 4-bit quantizer is simulated in MATLAB. From the simulation results, the proposed structure can achieve a peak SNR (signal- to-noise ratio) of 87dB with 2.5MHz bandwidth under 32 oversampling ratio at 160MHz sampling frequency and the ENOB of 14.234bits in non-ideal condition.

실험 및 통계적 분석을 통한 L1, C/A코드 GPS의 항법 파라미터연구

This research was focused on the analysis of navigation parameters from the received L1, C/A signal of the recent GPS, which has advanced with the SA policy change and the GPS modernization policy by the United States. It was done as a first step study for a comprehensive analysis on the multiple satellite navigation systems which will be adding or separating GPS signal. In particular, the statistical analysis on the GDOP change and positional accuracy based on the geocentric and spherical coordinate systems were investigated with carrier- to-noise ratio and the satellite geometry, The obtained GDOP values of HDOP, PDOP, VDOP are 0.5, 1.2, and 1.1, respectively in deviation. In addition, the positioning accuracies with these GDOP values were analyzed in the ellipsoidal and ECEF coordinates.

IMAGE SMOOTHING MENGGUNAKAN MEAN FILTERING, MEDIAN FILTERING, MODUS FILTERING DAN GAUSSIAN FILTERING

Softening image (Image smoothing) aims to suppress the interference (noise) in the image. The disorder usually appears as a result of which is not good penerokan (sensor noise, photographic grain noise) or due to transmission line (the delivery of data) This research has resulted in an application program for image smoothing by four methods: mean filtering, median filtering, Gaussian filtering and filtering modes. Test images used in this study using a sample consisting of twenty 24-bit image and the image of 8 bits. The images are loaded and displayed on the program. Then the image smoothing process was done using the Gaussian method, the mean, median and mode, and displays histogramnya. Parameters measured are the result of image smoothing based on the four methods used, the signal to-noise ratio (SNR), and timing-run.

Evaluation of Differences in MS/MS Spectra from Two Differentgeneration Q-TOF Instruments: Implications for Metabolomic Database Use

Generating reproducible fragmentation patterns is a problem in electrospray ionization mass spectrometry. Two generations of quadrupole time-of-flight(Q-TOF) instruments were selected to evaluate the reproducibility of tandem mass spectrometry(MS/MS) spectra:an old- and a new-generation instrument. Ninety-four MS/MS and MS/MS/MS spectra with information-rich product ions were obtained in positive- or negative-ion mode with two different-generation Q-TOF instruments, BioTOF-Q and micrOTOF- Q. Two principles were selected to optimize the collision energy. On the one hand, maximal structural information is obtained when the collision energy is increased; on the other hand, when most product ions show relative abundance of more than 10%, the lowest collision energy should be selected. The Paired-Samples T Test method was used to analysis these paired-spectra. We found that most product ions were the same and the profiles of the product ions were similar with both Q-TOF instruments. Interestingly, at the low signal to-noise ratio (S/N) of the precursor ion (ion intensity low to 180 counts), the profile of the MS/MS spectrum is very similar to that at a high S/N. Furthermore, when spectra were generated with micrOTOF-Q even before and after a four-year interval, the profiles and product ions were virtually identical. In summary, databases built with different-generation Q-TOF instruments may be universally applicable. Keywords: Reproducibility, two different-generation, quadrupole time-of-flight, tandem mass spectrometry, paired-samples t test, databases built.

Modeling indirect detectors for performance optimization of a digital mammographic detector for dual energy applications

Dual Energy imaging is a promising method for visualizing masses and microcalcifications in digital mammography. The advent of two X-ray energies (low and high) requires a suitable detector. The scope of this work is to determine optimum detector parameters for dual energy applications. The detector was modeled through the linear cascaded (LCS) theory. It was assumed that a phosphor material was coupled to a CMOS photodetector (indirect detection). The pixel size was 22.5 μm. The phosphor thickness was allowed to vary between 20mg/cm2 and 160mg/cm2 The phosphor materials examined where Gd2O2S:Tb and Gd2O2S:Eu. Two Tungsten (W) anode X-ray spectra at 35 kV (filtered with 100 μm Palladium (Pd)) and 70 kV (filtered with 800 pm Ytterbium (Yb)), corresponding to low and high energy respectively, were considered to be incident on the detector. For each combination the contrast- to-noise ratio (CNR) and the detector optical gain (DOG), showing the sensitivity of the detector, were calculated. The 40 mg/cm2 and 70 mg/cm2 Gd2O2S:Tb exhibited the higher DOG values for the low and high energy correspondingly. Higher CNR between microcalcification and mammary gland exhibited the 70mg/cm2 and the 100mg/cm2 Gd2O2S:Tb for the low and the high energy correspondingly.

The NIR transmission spectrum of Jupiter from the observation of a Ganymede’s eclipse

Here, we report the NIR transmission spectrum of Jupiter, with high signal- to-noise ratio, as if it were a transiting planet. Our technique was to observe Ganymede, when crossing Jupiter's shadow. During the eclipse, the spectral features of the Jovian atmosphere are imprinted in the sunlight that, after passing through Jupiter's planetary limb, is reflected from Ganymede towards the Earth. The ratio spectrum of Ganymede before and during the eclipse removes the spectral features of the Sun, the local telluric atmosphere on top of the telescopes, and the spectral albedo of Ganymede. Ganymede is a practically atmosphere-less body and do not suffer any significant weather variability.

Highly dispersed carbon nanotube in new ionic liquid-graphene oxides aqueous dispersions for ultrasensitive dopamine detection

Graphite oxide (GO) is a pH-dependent amphiphile with hydrophilic edges and a more hydrophobic basal plane. It was found that when the hydrophobic prototype ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) was added into GO water, it experienced changes from coagulation to being redispersed in water phase by constantly turning its pH to alkali condition. Then new aqueous dispersions of GO-[BMIM][PF6] “water” formed after facile sonicate. The introduction of [BMIM][PF6] not only minimize the defects of poor electrical conductivity of GO and more interesting is that the carbon nanotube (CNT) can be highly dispersed in this GO-[BMIM][PF6] water through a simple and facile ultrasonic method at room temperature, forming a new composite of GO-[BMIM][PF6]-CNT with high dispersibility. This novel composite enhanced its electrochemical signal obviously in the measurement of dopamine (DA) in biological systems and exhibited a wider linear response ranging from 8.0×10−12–1.5×10−5M. The detection limit of 3.0×10−12M at a signal to-noise ratio of 3 was two orders of magnitude lower than that reported previously.

MODELING SIMULATION AND OPTIMISATION OF A PHARMACEUTICAL PRODUCTION LINE

Pharmaceutical companies are allowed to deal in generic or brand medications and medical devices. Thus it is essential that the product conforms to specified customer requirements. In order to analyse the performance of the process, the critical factors which influence the production are evaluated. The objective of the study is to simulate the pharmaceutical production line using ARENA software and optimize the line by Design of Experiments technique in MINITAB by considering the response factor 'work in progress'. The critical factors identified are batch size, transfer time and the number of resources. A Taguchi approach is employed to gather experimental data. Then, based on signal- to-noise (S/N) ratio, the best sets critical parameters have been determined. Using these parameters values, the 'work in progress' may be minimized.

Subjective assessment of cochlear implant users' signal-to-noise ratio requirements for different levels of wireless device usability.

In order to better inform the development and revision of the American National Standards Institute C63.19 and American National Standards Institute/Telecommunications Industry Association-1083 hearing aid compatibility standards, a previous study examined the signal strength and signal (speech)-to-noise (interference) ratio needs of hearing aid users when using wireless and cordless phones in the telecoil coupling mode. This study expands that examination to cochlear implant (CI) users, in both telecoil and microphone modes of use. The purpose of this study was to evaluate the magnetic and acoustic signal levels needed by CI users for comfortable telephone communication and the users' tolerance relative to the speech levels of various interfering wireless communication-related noise types. Design was a descriptive and correlational study. Simulated telephone speech and eight interfering noise types presented as continuous signals were linearly combined and were presented together either acoustically or magnetically to the participants' CIs. The participants could adjust the loudness of the telephone speech and the interfering noises based on several assigned criteria. The 21 test participants ranged in age from 23-81 yr. All used wireless phones with their CIs, and 15 also used cordless phones at home. There were 12 participants who normally used the telecoil mode for telephone communication, whereas 9 used the implant's microphone; all were tested accordingly. A guided-intake questionnaire yielded general background information for each participant. A custom-built test control box fed by prepared speech-and-noise files enabled the tester or test participant, as appropriate, to switch between the various test signals and to precisely control the speech-and-noise levels independently. The tester, but not the test participant, could read and record the selected levels. Subsequent analysis revealed the preferred speech levels, speech (signal)-to-noise ratios, and the effect of possible noise-measurement weighting functions. The participants' preferred telephone speech levels subjectively matched or were somewhat lower than the level that they heard from a 65 dB SPL wideband reference. The mean speech (signal)-to-noise ratio requirement for them to consider their telephone experience "acceptable for normal use" was 20 dB, very similar to the results for the hearing aid users of the previous study. Significant differences in the participants' apparent levels of noise tolerance among the noise types when the noise level was determined using A-weighting were eliminated when a CI-specific noise-measurement weighting was applied. The results for the CI users in terms of both preferred levels for wireless and cordless phone communication and signal-to-noise requirements closely paralleled the corresponding results for hearing aid users from the previous study, and showed no significant differences between the microphone and telecoil modes of use. Signal-to-noise requirements were directly related to the participants' noise audibility threshold and were independent of noise type when appropriate noise-measurement weighting was applied. Extending the investigation to include noncontinuous interfering noises and forms of radiofrequency interference other than additive audiofrequency noise could be areas of future study.

Performance Investigation of IM/DD Compatible SSB-OFDM Systems Based on Optical Multicarrier Sources

The authors investigate and compare the performance of three different optical frequency comb sources in an intensity modulated and directly detected compatible SSB OFDM system. The influence of relative intensity noise and carrier-to-noise ratio of the different multicarrier sources, on the performance of a 12.5 Gb/s compatible SSB OFDM system, were investigated experimentally and by simulation. The results obtained show that, system performance depends significantly on the relative intensity noise and carrier- to-noise ratio levels of the specific multicarrier optical source employed. However, it is shown that optical multicarrier sources with low relative intensity noise and high carrier- to-noise ratio levels can assure very good performance in a WDM-OFDM system.

Adaptive Generative Models for Digital Wireless Channels

Generative models, which can generate bursty error sequences with similar burst error statistics to those of descriptive models, have an immense impact on the wireless communications industry as they can significantly reduce the computational time of simulating wireless communication links. Adaptive generative models aim to produce any error sequences with any given signal- to-noise ratios (SNRs) by using only two reference error sequences obtained from a reference transmission system with two different SNRs. Compared with traditional generative models, this adaptive technique can further considerably reduce the computational load of generating new error sequences as there is no need to simulate the whole reference transmission system again. In this paper, reference error sequences are provided by computer simulations of a long term evolution (LTE) system. Adaptive generative models are developed from three widely used generative models, namely, the simplified Fritchman model (SFM), the Baum-Welch based hidden Markov model (BWHMM), and the deterministic process based generative model (DPBGM). It is demonstrated that the adaptive DPBGM can provide accurate burst error statistics and bit error rate (BER) performance of the LTE system, while the adaptive SFM and adaptive BWHMM fail to do so.

Application of Taguchi Methods for the Optimization of Factors Affecting Engine Performance and Emission of Exhaust Gas Recirculation in Steam-injected Diesel Engines

In this study, optimal engine performance and pollutant emission conditions are investigated by using Taguchi Design Methods. Orthogonal arrays of Taguchi, the signal- to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to find the optimal levels and to analyze the effect of the operation conditions on performance and emission values. The parameters and their levels are engine speeds at 1200, 1600, 2000 and 2400 rpm, steam ratios of 0, 10, 20 and 30% and EGR ratios of 0, 10, 20 and 30%. Confirmation tests with the optimal levels of engine parameters were carried out in order to illustrate the effectiveness of the Taguchi optimization method. While steam and EGR ratios are found effective on emission parameters, significance levels for these parameters have been found low for effective power and torque. It was thus shown that the Taguchi method is suitable to solve the problems of performance and emissions for diesel engines.