Feature Optimization of Exhaled Breath Signals Based on Pearson-BPSO

Feature optimization, which is the theme of this paper, is actually the selective selection of the variables on the input side at the time of making a predictive kind of model. However, an improved feature optimization algorithm for breath signal based on the Pearson-BPSO was proposed and applied to distinguish hepatocellular carcinoma by electronic nose (eNose) in the paper. First, the multidimensional features of the breath curves of hepatocellular carcinoma patients and healthy controls in the training samples were extracted; then, the features with less relevance to the classification were removed according to the Pearson correlation coefficient; next, the fitness function was constructed based on K-Nearest Neighbor (KNN) classification error and feature dimension, and the feature optimization transformation matrix was obtained based on BPSO. Furthermore, the transformation matrix was applied to optimize the test sample’s features. Finally, the performance of the optimization algorithm was evaluated by the classifier. The experiment results have shown that the Pearson-BPSO algorithm could effectively improve the classification performance compared with BPSO and PCA optimization methods. The accuracy of SVM and RF classifier was 86.03% and 90%, respectively, and the sensitivity and specificity were about 90% and 80%. Consequently, the application of Pearson-BPSO feature optimization algorithm will help improve the accuracy of hepatocellular carcinoma detection by eNose and promote the clinical application of intelligent detection.

Assembly variation analysis of the non-rigid assembly with a deformation gradient model

Purpose This paper aims to develop a mathematical method to analyze the assembly variation of the non-rigid assembly, considering the manufacturing variations and the deformation variations of the non-rigid parts during the assembly process. Design/methodology/approach First, this paper proposes a deformation gradient model, which represents the deformation variations during the assembly process by considering the forces and the self-weight of the non-rigid parts. Second, the developed deformation gradient models from the assembly process are integrated into the homogenous transformation matrix to model the deformation variations and manufacturing variations of the deformed non-rigid part. Finally, a mathematical model to analyze the assembly variation propagation is developed to predict the dimensional and geometrical variations due to the manufacturing variations and the deformation variations during the assembly process. Findings Through the case study with a crosshead non-rigid assembly, the results indicate that during the assembly process, the individual deformation values of the non-rigid parts are small. However, the cumulative deformation variations of all the non-rigid parts and the manufacturing variations present a target value (w) of −0.2837 mm as compared to a target value of −0.3995 mm when the assembly is assumed to be rigid. The difference in the target values indicates that the influence of the non-rigid part deformation variations during the assembly process on the mechanical assembly accuracy cannot be ignored. Originality/value In this paper, a deformation gradient model is proposed to obtain the deformation variations of non-rigid parts during the assembly process. The small deformation variation, which is often modeled using a finite-element method in the existing works, is modeled using the proposed deformation gradient model and integrated into the nominal dimensions. Using the deformation gradient models, the non-rigid part deformation variations can be computed and the accumulated deformation variation can be easily obtained. The assembly variation propagation model is developed to predict the accuracy of the non-rigid assembly by integrating the deformation gradient models into the homogeneous transformation matrix.

Obtaining Solutions of a Vakhnenko Lattice System by N-Fold Darboux Transformation

Using a suitable gauge transformation matrix, we present a N -fold Darboux transformation for a Vakhnenko lattice system. This transformation preserves the form of Lax pair of the Vakhnenko lattice system. Applying the obtained Darboux transformation, we arrive at an exact solution of the Vakhnenko lattice system.

Six DOF Robotic Arm Prototype Modelling By Matlab

The study in this paper allows us to control the manipulator and achieve any desired position and orientation. The Forward Kinematics was done using Denavait Hartenberg (DH) parameters, also the forward kinematics equations and homogenous transformation matrix was validated using MATLAB Toolbox. The modeling was carried out using the Peter Corke robotics toolbox. Finally, the forward kinematic study and the robot arm’s movement equations were compared with practical measurements to make sure it fulfilled the desired purpose and that it could point to the desired coordinates with a precision of ±0.5 cm.

Solving Fuzzy Error Matrix Equation based on Runge Kutta Method

Fuzzy error logic represents the object in the real world with (u, x) as <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="M2"><mml:mrow><mml:mfenced close="}" open="{"><mml:mrow><mml:mfenced close="]" open="["><mml:mrow><mml:mi>U</mml:mi><mml:mo>,</mml:mo><mml:mi>S</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced><mml:mo>,</mml:mo><mml:mtext> </mml:mtext><mml:mover><mml:mi>p</mml:mi><mml:mi>r</mml:mi></mml:mover><mml:mo>,</mml:mo><mml:mi>T</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced><mml:mo>,</mml:mo><mml:mi>L</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced></mml:mrow></mml:mfenced><mml:mo>,</mml:mo><mml:mfenced close="]" open="["><mml:mrow><mml:mi>x</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced><mml:mo>=</mml:mo><mml:mi>f</mml:mi><mml:mfenced><mml:mrow><mml:mi>u</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced><mml:mo>,</mml:mo><mml:mi>p</mml:mi></mml:mrow></mml:mfenced><mml:mo>,</mml:mo><mml:mi>G</mml:mi><mml:mi>u</mml:mi><mml:mfenced><mml:mi>t</mml:mi></mml:mfenced></mml:mrow></mml:mfenced></mml:mrow></mml:mfenced></mml:mrow></mml:math></inline-formula>, Fuzzy error transformation matrix can be used to express six transformation methods, such as decomposition, similarity, addition, replacement, destruction and unit transformation. Based on solving equation XA=B and decomposition of p, this paper studies the solution of error matrix equation based on Runge Kutta method, in order to explore the law of error transformation from the perspective of solving matrix equation.

Study on Phase Transformation Orientation Relationship of HCP-FCC during Rolling of High Purity Titanium

High purity titanium (Ti) thin strip was prepared by rolling with large deformation and was characterized by the means of Transmission Electron Microscopy (TEM), selected area diffraction (SAED) pattern, high-resolution (HRTEM) analysis, as well as Transmission Kikuchi Diffraction (TKD). It is found that there are face-centered cubic (FCC) Ti laths formed within the matrix of hexagonal close packing (HCP) Ti. This shows that the HCP-FCC phase transition occurred during the rolling, and a specific orientation relationship (OR) between HCP phase and FCC phase obeys ⟨0001⟩α// ⟨001⟩FCC and {100}α//{110}FCC. The ORs of HCP-FCC phase transition are deeply studied by TKD pole figure and phase transformation matrix. It is found that the derived results via pole figure and transformation matrix are equivalent, and are consistent with TEM-SAED analysis results, which proves that these two methods can effectively characterize the ORs of HCP-FCC phase transition and predict possible FCC phase variants.

A Three-Dimensional Phase Field Based Nonorthogonal Multiple-Relaxation-Time Lattice Boltzmann Method for Interface Tracking

Based on a conservative Allen-Cahn phase field method, a three-dimensional nonorthogonal multiple-relaxation-time (MRT) lattice Boltzmann (LB) model for interface tracking in multiphase flow is proposed in this paper. Different from the traditional MRT LB model, the transformation matrix in the present model is constructed based on a set of nonorthogonal basis vectors to simplify the transformation process between the discrete velocity space and the moment space. Therefore, a higher computational efficiency is achieved by the present model. The present model is developed on two different three-dimensional lattice sets (D3Q19 and D3Q27) to obtain a thorough perspective about the performance of the nonorthogonal matrix. Coupled with the nonorthogonal transformation matrix, simplified discrete source terms are also developed for both two lattice sets to further improve the efficiency of the present model. Numerical tests demonstrate that compared with the traditional MRT LB model, the present model shows a significantly higher computational efficiency and better stability while maintaining a comparable accuracy. It is also found that the D3Q19 nonorthogonal model does not obviously weaken the accuracy of D3Q27 nonorthogonal model while D3Q27 nonorthogonal model dose not decrease the stability of the D3Q19 nonorthogonal model, which is different from the orthogonal model.

A Novel Decoding Method for the Erasure Codes

The erasure codes are widely used in the distributed storage with low redundancy compared to the replication method. However, the current research studies about the erasure codes mainly focus on the encoding methods, while there are few studies on the decoding methods. In this paper, a novel erasure decoding method is proposed; it is a general decoding method and can be used both over the multivariate finite field and the binary finite field. The decoding of the failures can be realized based on the transforming process of the decoding transformation matrix, and it is convenient to avoid the overburdened visiting problem by tiny modification of the method. The correctness of the method is proved by the theoretical analysis; the experiments about the comparison with the traditional methods show that the proposed method has better decoding efficiency and lower reconstruction bandwidth.