scholarly journals Audio Enhancement of Physical Models of Musical Instruments Using Optimal Correction Factors: The Recorder Case

2021 ◽  
Vol 11 (14) ◽  
pp. 6426
Author(s):  
Konstantinos Bakogiannis ◽  
Spyros Polychronopoulos ◽  
Dimitra Marini ◽  
Georgios Kouroupetroglou

A simulation of a musical instrument is considered to be a successful one when there is a good resemblance between the model’s synthesized sound and the real instrument’s sound. In this work, we propose the integration of physical modeling (PM) methods with an optimization process to regulate a generated digital signal. Its goal is to find a new set of values of the PM’s parameters’ that would lead to a synthesized signal matching as much as possible to reference signals corresponding to the physical musical instrument. The reference signals can be: (a) described by their acoustic characteristics (e.g., fundamental frequencies, inharmonicity, etc.) and/or (b) the signals themselves (e.g., impedances, recordings, etc.). We put this method into practice for a commercial recorder, simulated using the digital waveguides’ PM technique. The reference signals, in our case, are the recorded signals of the physical instrument. The degree of similarity between the synthesized (PM) and the recorded signal (musical instrument) is calculated by the signals’ linear cross-correlation. Our results show that the adoption of the optimization process resulted in more realistic synthesized signals by (a) enhancing the degree of similarity between the synthesized and the recorded signal (the average absolute Pearson Correlation Coefficient increased from 0.13 to 0.67), (b) resolving mistuning issues (the average absolute deviation of the synthesized from the recorded signals’ pitches reduced from 40 cents to the non-noticeable level of 2 cents) and (c) similar sound color characteristics and matched overtones (the average absolute deviation of the synthesized from the recorded signals’ first five partials reduced from 41 cents to 2 cents).

2000 ◽  
Vol 78 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Karina M De Fina ◽  
Tina L Sharp ◽  
Michael A Spurgin ◽  
Ivette Chuca ◽  
William E Acree, Jr. ◽  
...  

Experimental solubilities are reported at 25.0°C for diuron (also called 3-(3,4-dichlorophenyl)-1,1-dimethyl urea) dissolved in 49 different organic nonelectrolyte solvents containing ether-, chloro-, hydroxy-, ester-, methyl-, and tert-butyl-functional groups. Results of these measurements are used to test the applications and limitations of expressions derived from Mobile Order theory. For the 28 nonalcoholic solvents for which predictions could be made computations show that Mobile Order theory does provide fairly reasonable estimates of the saturation mole fraction solubilities. Average absolute deviation between predicted and observed values is 60.1%. Diuron solubilities in the alcohol solvents are used to calculate stability constants for presumed solute-solvent hydrogen bonds that are believed to occur in solution.Key words: pesticide, diuron solubilities, organic nonelectrolyte solvents, solubility predictions.


OENO One ◽  
2017 ◽  
Vol 51 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Daniel Molitor ◽  
Lucien Hoffmann ◽  
Marco Beyer

Aims: The present analyses aimed at evaluating the performance of two models for estimating the overall effect of combining two or more measures (leaf removal, cluster division, late shoot topping, botryticide application, bioregulator application) for controlling grape bunch rot based on the efficacy of the individual measures.Methods and results: Field trials with the white Vitis vinifera cultivars Pinot gris and Riesling on the efficacy of three bunch rot control measures applied either alone or in combination were analyzed. Bunch rot disease severities prior to harvest were assessed and efficacies were calculated for each treatment. Observed efficacies of single measures were used to estimate the overall efficacies of all possible measure combinations. Calculated efficacies matched observed efficacies more accurately when assuming multiplicative interaction among the individual measures (R2 = 0.8574, p < 0.0001; average absolute deviation: 7.9%) than in case of assuming additive effects (R2 = 0.8280; average absolute deviation: 14.7%).Conclusions: The multiplicative approach assumes that each additional measure is affecting (in case of efficient measures: reducing) the disease severity level as the result of the additional treatments rather than compared to the disease severity level in the untreated control.Significance and impact of the study: The high goodness of fit as well as the observed low deviations between the estimated and the observed efficacies suggest that the multiplicative approach is appropriate for estimating the efficacy of combined viticultural measures in a complex practical bunch rot control strategy assembled of different modules.


2020 ◽  
Vol 66 (4 Jul-Aug) ◽  
pp. 504
Author(s):  
L. F. Ramirez-Verduzco

Aqueous alkanolamines solutions are widely used in petroleum refineries to remove acid gases from hydrotreated streams. The knowledge of physical properties in this kind of solutions is useful for the correct design, operation, and control of sweetening processes. Due to the above, we carried out a study on the density of the ternary mixture: 2-Amino-2-Methyl-1-Propanol (AMP) + Diethanolamine (DEA) + Water (H2O). Density was measured by means of the vibrating tube method with an uncertainty of 2×10-4 g·cm-3.  The experimental data was obtained in the entire concentration range, temperatures from 303.15 to 333.15 K, and pressure of 101.3 kPa. In addition, the following three prediction methods were tested to estimate the density of the blend: mixing rule, polynomial correlation, and excess molar volume. The best prediction was obtained by means of the excess molar volume through the Redlich-Kister and Cibulka equations, where an average absolute deviation (AAD) of 0.02%, correlation coefficient (R) of 0.9999, and standard deviation (<s>) of 3×10-4 g·cm-3 were obtained.


Author(s):  
Jonny Nordström ◽  
Hendrik J. Harms ◽  
Tanja Kero ◽  
Maryam Ebrahimi ◽  
Jens Sörensen ◽  
...  

Abstract Background Quantification of myocardial blood flow (MBF) with PET requires accurate attenuation correction, which is performed using a separate CT. Misalignment between PET and CT scans has been reported to be a common problem. The purpose of the present study was to assess the effect of PET CT misalignment on the quantitative accuracy of cardiac 15O-water PET. Methods Ten clinical patients referred for evaluation of ischemia and assessment of MBF with 15O-water were included in the study. Eleven different misalignments between PET and CT were induced in 6 different directions with 10 and 20 mm amplitudes: caudal (+Z), cranial (− Z), lateral (±X), anterior (+Y), and anterior combined with cranial (+ Y and − Z). Blood flow was quantified from rates of washout (MBF) and uptake (transmural MBF, MBFt) for the whole left ventricle and the three coronary territories. The results from all misalignments were compared to the original scan without misalignment. Results MBF was only minorly affected by misalignments, but larger effects were seen in MBFt. On the global level, average absolute deviation across all misalignments for MBF was 1.7% ± 1.4% and for MBFt 5.4% ± 3.2 Largest deviation for MBF was − 4.8% ± 5.8% (LCX, X + 20) and for MBFt − 19.3% ± 9.6% (LCX, X + 20). In general, larger effects were seen in LAD and LCX compared to in RCA. Conclusion The quantitative accuracy of MBF from 15O-water PET, based on the washout of the tracer, is only to a minor extent affected by misalignment between PET and CT.


Author(s):  
Sepehr Sadighi ◽  
Arshad Ahmad ◽  
Akbar Irandoukht

Hydrocracking is an important upgrading process in the petroleum refinery, and it is generally used to process feedstocks ranging from vacuum gas oil (VGO) to vacuum residue. In this work, hydrocracking of VGO using a dual functional amorphous catalyst was carried out at a pilot scale unit under the following reaction conditions: liquid hourly space velocity (LHSV) from 1 to 1.5 hr-1 and reaction temperatures of 360-440°C at the constant pressure and hydrogen to oil, 156 bar and 1780 Nm3/m3, respectively. The effluent of the reactor was characterized to dry gas, naphtha, kerosene, diesel and unconverted VGO or residue. The pilot tests demonstrated that performing experiments beyond the temperature, recommended by catalyst vendor, lead the process to unstable hydrocracking. To describe the yield of hydrocracking products a five-lump discrete lumping approach with ten reactions was proposed. At first, the kinetic model contained twenty kinetic constants which were estimated by using the conventional objective function. The estimated parameters showed that the tendency of the catalyst to convert VGO to gas and naphtha was negligible whilst rate constants for hydrocracking of VGO to middle distillates were considerably high which was compatible with the nature of amorphous hydrocracking catalysts. After evaluating the magnitude of reaction rates and eliminating the ignorable constants, the network was reduced to six reactions in which only nine parameters were needed. The predictions indicated that the latter network could fit the yield of products more acceptable as if the average absolute deviation between experimental and calculated yields was descended from 16.25% to 12.6%. Then, to have a better prediction, a weighted objective function was used in which weight factors were calculated by a proposed weighted least square expression. The results confirmed that this approach could reduce average absolute deviation of model to 10.75%, and it created a fairly even distribution of deviation between hydrocracking products.


2020 ◽  
Vol 840 ◽  
pp. 501-506
Author(s):  
Ardika Nurmawati ◽  
Rizky Tetrisyanda ◽  
Gede Wibawa

The addition of alcohol as an oxygenated compound in gasoline blends may increase the vapor pressure of gasoline mixture. As a result, the study of vapor-liquid equilibrium for gasoline component and alcohol is necessary. In this study, the vapor-liquid equilibrium of isobutanol – isooctane/n-heptane blends were obtained experimentally at temperatures in the range 303.15 to 323.15 K using modified simple quasi-static ebulliometer. The apparatus was validated by comparing the vapor pressure of pure isobutanol, isooctane, and n-heptane with the published data and giving average absolute deviation (AAD) between experimental and calculated ones with magnitude less than 1.0%. The addition of isobutanol with the mole fraction range from 0.2 to 0.6 would increase the vapor pressure of the isooctane and n-heptane up to 12% and 14% respectively. The vapor pressure of binary mixtures was correlated with the Wilson, Non-random two-liquid (NRTL), and Universal quasi-chemical (UNIQUAC) equations with AAD 1.6%, 1.5%, and 1.7%, respectively for isobutanol + isooctane system and 1.8%, 1.7%, and 2.0%, respectively for isobutanol + n-heptane system. The systems studied show positive deviation from Raoult’s Law.


2020 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Husam Ali Jafar

In this work the thermodynamic model of Chen and Sun which describes the adsorption of protein on a hydrophobic gel in hydrophobic interaction chromatography process is modified by substitution activity instead of protein and salt concentration in liquid phase. The model is based on two-state equilibrium of protein in solution and adsorbed phase. Also, the effect of salt concentration and type of hydrophobic gel on the amount of protein adsorption is investigated. Finally, the accuracy of model is evaluated by measuring average absolute deviation (AAD) for adsorption isotherm in different salt concentration. The results show that the modified model had high accuracy for prediction the adsorption isotherm in different type of adsorbed and salt concentration.


2015 ◽  
Vol 77 (18) ◽  
Author(s):  
Chia Min Lim ◽  
Hu Ng ◽  
Timothy Tzen Vun Yap ◽  
Chiung Ching Ho

The objective of this paper is to analyse the gait of subjects with suffering Parkinson's Disease (PD), plus to differentiate their gait from those of normal people. The data is obtained from a medical gait database known as Gaitpdb [1]. In the data set, there are 73 control subjects and 93 subjects with PD. In our study, we first obtained the gait features using statistical analysis, which include minimum, maximum, median, kurtosis, mean, skewness, standard deviation and average absolute deviation of the gait signal. Next, selection of the extracted features is performed using PSO search, Tabu search and Ranker. Finally the selected features will undergo classification using BFT, BPANN, k-NN, SVM with Ln kernel, SVM with Poly kernel and SVM with Rbf kernel. From the experimental results, the proposed model achieved average of 66.43%, 89.97%, 87.00%, 88.47%, 86.80% and 87.53% correct classification rates respectively.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad Arshad ◽  
Ahmed Easa ◽  
Hazim Qiblawey ◽  
Mustafa Nasser ◽  
Abdelbaki Benamor ◽  
...  

Abstract Measured viscosity and density data for ternary aqueous solutions of CaCl2 and KCl are presented at temperatures between 293 and 323 K with 5 K increment. A modified Jones–Dole was introduced by adding extra terms and proved to be suitable for modelling of the viscosity data. Goldsack and Franchetto, Hu and Exponential models are used to correlate the viscosity data, too. Al models are correlated as a function of temperature and concentration. All models had successfully predicted the viscosity with high precision reaching a maximum average absolute deviation (AAD) of less than 2.3%. The modified Jones–Dole showed the best results among other models. Viscosity of the ternary solution is higher than the viscosity of water by about 15% at low concentrations and reaches about 270% at the highest concentrations. The amount of CaCl2 has more significant effect on the ternary mixture viscosity compared to KCl. This has created difficulty in measuring the viscosity and consequently the challenge in finding the different models parameters. Ternary solution densities were successfully correlate with Kumar’s model with AAD of less than 0.4%. Comparison of the ternary solution density and viscosity with the few available data literature showed a good agreement.


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