Translation Matrix Research Articles

FAST DYNAMIC MESHING METHOD BASED ON DELAUNAY GRAPH AND INVERSE DISTANCE WEIGHTING INTERPOLATION

A novel mesh deformation technique is developed based on the Delaunay graph mapping method and the inverse distance weighting (IDW) interpolation. The algorithm maintains the advantages of the efficiency of Delaunay-graph-mapping mesh deformation while possess the ability for better controlling the near surface mesh quality. The Delaunay graph is used to divide the mesh domain into a number of sub-domains. On each of the sub-domains, the inverse distance weighting interpolation is applied to build a much smaller sized translation matrix between the original mesh and the deformed mesh, resulting a similar efficiency for the mesh deformation as compared to the fast Delaunay graph mapping method. The paper will show how the near-wall mesh quality is controlled and improved by the new method while the computational time is compared with the original Delaunay graph mapping method.

Exponential degenerate kernel function for electromagnetic scattering problems

An efficient exponential degenerate kernel function is proposed for electromagnetic scattering problem in this Letter, which provides another diagonal form of the translation matrix. The exponential degenerate kernel function is numerically determined for kernel independency. The error analysis verifies that less expansion terms are needed for the given accuracy for simulations. Numerical results validate the accuracy of the proposed degenerate kernel. It can be concluded that the proposed kernel approximation outperforms the expansion in the fast multipole method in both computational time and storage.

Calibration method for a vision guiding-based laser-tracking measurement system

Laser-tracking measurement systems (laser trackers) based on a vision-guiding device are widely used in industrial fields, and their calibration is important. As conventional methods typically have many disadvantages, such as difficult machining of the target and overdependence on the retroreflector, a novel calibration method is presented in this paper. The retroreflector, which is necessary in the normal calibration method, is unnecessary in our approach. As the laser beam is linear, points on the beam can be obtained with the help of a normal planar target. In this way, we can determine the function of a laser beam under the camera coordinate system, while its corresponding function under the laser-tracker coordinate system can be obtained from the encoder of the laser tracker. Clearly, when several groups of functions are confirmed, the rotation matrix can be solved from the direction vectors of the laser beams in different coordinate systems. As the intersection of the laser beams is the origin of the laser-tracker coordinate system, the translation matrix can also be determined. Our proposed method not only achieves the calibration of a single laser-tracking measurement system but also provides a reference for the calibration of a multistation system. Simulations to evaluate the effects of some critical factors were conducted. These simulations show the robustness and accuracy of our method. In real experiments, the root mean square error of the calibration result reached 1.46 mm within a range of 10 m, even though the vision-guiding device focuses on a point approximately 5 m away from the origin of its coordinate system, with a field of view of approximately 200 mm × 200 mm.

Association of Protein Translation and Extracellular Matrix Gene Sets with Breast Cancer Metastasis: Findings Uncovered on Analysis of Multiple Publicly Available Datasets Using Individual Patient Data Approach.

IntroductionMicroarray analysis has revolutionized the role of genomic prognostication in breast cancer. However, most studies are single series studies, and suffer from methodological problems. We sought to use a meta-analytic approach in combining multiple publicly available datasets, while correcting for batch effects, to reach a more robust oncogenomic analysis.AimThe aim of the present study was to find gene sets associated with distant metastasis free survival (DMFS) in systemically untreated, node-negative breast cancer patients, from publicly available genomic microarray datasets.MethodsFour microarray series (having 742 patients) were selected after a systematic search and combined. Cox regression for each gene was done for the combined dataset (univariate, as well as multivariate – adjusted for expression of Cell cycle related genes) and for the 4 major molecular subtypes. The centre and microarray batch effects were adjusted by including them as random effects variables. The Cox regression coefficients for each analysis were then ranked and subjected to a Gene Set Enrichment Analysis (GSEA).ResultsGene sets representing protein translation were independently negatively associated with metastasis in the Luminal A and Luminal B subtypes, but positively associated with metastasis in Basal tumors. Proteinaceous extracellular matrix (ECM) gene set expression was positively associated with metastasis, after adjustment for expression of cell cycle related genes on the combined dataset. Finally, the positive association of the proliferation-related genes with metastases was confirmed.ConclusionTo the best of our knowledge, the results depicting mixed prognostic significance of protein translation in breast cancer subtypes are being reported for the first time. We attribute this to our study combining multiple series and performing a more robust meta-analytic Cox regression modeling on the combined dataset, thus discovering 'hidden' associations. This methodology seems to yield new and interesting results and may be used as a tool to guide new research.

Ferminoic Casimir effect between spheres

We consider the Casimir interaction between two spheres corresponding to massless Dirac fields with MIT-bag boundary conditions. Using operator approach, we derive the TGTG-formula for the Casimir interaction energy between the two spheres. A byproduct is the explicit formula for the translation matrix that relates the fermionic spherical waves in different coordinate systems. In the large separation limit, it is found that the order of the Casimir interaction energy is $L^{-5}$, where $L$ is the separation between the centers of the spheres. This order is intermediate between that of two Dirichlet spheres (of order $L^{-3}$) and two Neumann spheres (of order $L^{-7}$). In the small separation limit, we derive analytically the asymptotic expansion of the Casimir interaction energy up to the next-to-leading order term. The leading term agrees with the proximity force approximation. The result for the next-to-leading order term is compared to the corresponding results for scalar fields and electromagnetic fields.

Delaunay graph and radial basis function for fast quality mesh deformation

A novel mesh deformation technique is developed based on the Delaunay graph mapping (DGM) method and the radial basis function (RBF) method. The algorithm combines the advantages of the efficiency of DGM mesh deformation and the better control of the near surface mesh quality from the RBF method. The Delaunay graph is used to divide the mesh domain into a number of sub-domains. On each of the sub-domains, the radial basis function is applied to build a much smaller sized translation matrix between the original mesh and the deformed mesh, resulting in a similar efficiency for the mesh deformation as compared to the fast Delaunay graph mapping method. Furthermore, by separating the translation and rotation motion, the mesh quality near the wall can be substantially improved for extremely large rotational deformation. The paper will show how the near-wall mesh quality is controlled and improved by the new method while the computational time is maintained to be comparable to the original Delaunay graph mapping method.

Pose Self-Measurement of Noncooperative Spacecraft Based on Solar Panel Triangle Structure

Aiming at the recognition and location of noncooperative spacecraft, this paper presents a monocular vision pose measurement method based on solar triangle structure. First of all, an autonomous recognition algorithm of feature structure based on sliding window Hough transformation (SWHT) and inscribed circle of a triangle is proposed, and the image coordinates of feature points on the triangle can be obtained relying on this algorithm, combined with the P4P algorithm and the structure of spacecraft, calculating the relative pose of target expressed by rotation and translation matrix. The whole algorithm can be loaded into the prewritten onboard program, which will get the autocomplete feature structure extraction and relative pose measurement without human intervention, and this method does not need to mount any markers on the target. Then compare the measured values with the accurate value of the laser tracker, so that a conclusion can be drawn that the maximum position error is lower than 5% and the rotation error is lower than 4%, which meets the requirements of noncooperative spacecraft’s pose measurement for observations, tracking, and docking in the final rendezvous phase.

Identification, Validation and Classification of the Genus Phyllanthus in Nigeria Using ITS Genetic Marker and the Taxonomic Implication

An extraction, purification, PCR amplification and sequencing of DNA from five species of Phyllanthus in Nigeria namely P. amarus Schum and Thonn, P. urinaria Linn., P. odontadenius Mull-Arg., P. niruroides Mull-Arg. and P. muellerianus (O. Ktze) Excel belonging to the family of Phyllanthaceae were carried out using nuclear ribosomal Internal Transcribed Spacer (ITS 4-5) genetic marker to identify unknown Phyllanthus species. The nuclear region revealed that the Phyllanthus species were able to be amplified optimally for sequencing. The results of the nucleotide sequences were further compared on Basic Local Alignment Sequence Tool (BLAST) on GenBank and BoldSystems for validation. Results revealed that the closely related species, P. niruroides Mull_Arg. and P. odontadenius Mull-Arg. had no DNA record to separate them on both GenBank and BoldSystems while P. amarus Schum and Thonn, P. muellerianus (O. Ktze) Excel and P. urinaria Linn. were clearly compatible with other works. The sequence data were analyzed and classified with tree-based analyses of Mr.Bayes 3.2.1. in order to reveal their phylogenetic relationship. Results of the nucleotide sequences and fragment analysis were published on BoldSystems for barcoding as non-coding marker translation matrix.

Analysis of the Kinematic Accuracy Reliability of a 3-DOF Parallel Robot Manipulator

Kinematic accuracy reliability is an important performance index in the evaluation of mechanism quality. By using a 3-DOF 3-PUU parallel robot manipulator as the research object, the position and orientation error model was derived by mapping the relation between the input and output of the mechanism. Three error sensitivity indexes that evaluate the kinematic accuracy of the parallel robot manipulator were obtained by adapting the singular value decomposition of the error translation matrix. Considering the influence of controllable and uncontrollable factors on the kinematic accuracy, the mathematical model of reliability based on random probability was employed. The measurement and calculation method for the evaluation of the mechanism's kinematic reliability level was also provided. By analysing the mechanism's errors and reliability, the law of surface error sensitivity for the location and structure parameters was obtained. The kinematic reliability of the parallel robot manipulator was statistically computed on the basis of the Monte Carlo simulation method. The reliability analysis of kinematic accuracy provides a theoretical basis for design optimization and error compensation.

Novel Calibration Method for the Multi-Camera Measurement System

In a multi-camera measurement system, the determination of the external parameters is one of the vital tasks, referred to as the calibration of the system. In this paper, a new geometrical calibration method, which is based on the theory of the vanishing line, is proposed. Using a planar target with three equally spaced parallel lines, the normal vector of the target plane can be confirmed easily in every camera coordinate system of the measurement system. By moving the target into more than two different positions, the rotation matrix can be determined from related theory, i.e., the expression of the same vector in different coordinate systems. Moreover, the translation matrix can be derived from the known distance between the adjacent parallel lines. In this paper, the main factors effecting the calibration are analyzed. Simulations show that the proposed method achieves robustness and accuracy. Experimental results show that the calibration can reach 1.25 mm with the range about 0.5m. Furthermore, this calibration method also can be used for auto-calibration of the multi-camera mefasurement system as the feature of parallels exists widely.

Overcoming Asymmetry in Entity Graphs

This paper studies the problem of mining named entity translations by aligning comparable corpora. Current state-of-the-art approaches mine a translation pair by aligning an entity graph in one language to another based on node similarity or propagated similarity of related entities. However, they, building on the assumption of “symmetry”, quickly deteriorate on “weakly” comparable corpora with some asymmetry. In this paper, we pursue two directions for overcoming relation and entity asymmetry respectively. The first approach starts from weakly comparable corpora (for high recall) then ensures precision by selective propagation only to entities of symmetric relations. The second approach starts from parallel corpora (for high precision) then enhances recall by extending the translation matrix based on node similarity and contextual similarity. Our experimental results on English-Chinese corpora show that both approaches are effective and complementary. Our combined approach outperforms the best-performing baseline in terms of F1-score by up to 0.28.

Study on Camera Pose Estimation

A common need in photogrammetry, robotics and computer vision is performing camera pose estimation. A comparative analysis is presented here for three classical and representative algorithms, including direct linear transform (DLT), EPNP and Cayley method, each of which computes the translation and rotation matrix using non-iterative method with six or more point correspondences. The comparison shows qualitative and quantitative experimental results to determine (1) the accuracy and robustness under the influence of different levels of noise, (2) the accuracy, robustness and efficiency for different sizes of point correspondences.

Phase Correlation based Local Illumination-invariant Method for Multi-Tempro Remote Sensing Image Matching

Abstract. This paper aims at image matching under significantly different illumination conditions, especially illumination angle changes, without prior knowledge of lighting conditions. We investigated the illumination impact on Phase Correlation (PC) matrix by mathematical derivation and from which, we decomposed PC matrix as the multiplication product of the illumination impact matrix and the translation matrix. Thus the robustness to illumination variation of the widely used Absolute Dirichlet Curve-fitting (AD-CF) algorithm for pixel-wise disparity estimation is proved. Further, an improved PC matching algorithm is proposed: Absolute Dirichlet SVD (AD-SVD), to achieve illumination invariant image alignment. Experiments of matching DEM simulated terrain shading images under very different illumination angles demonstrated that AD-SVD achieved 1/20 pixels accuracy for image alignment and it is nearly entirely invariant to daily and seasonal solar position variation. The AD-CF algorithm was tested for generating disparity map from multi-illumination angle stereo pairs and the results demonstrated high fidelity to the original DEM and the Normalised Correlation Coefficient (NCC) between the two is 0.96.

“Clinical brain profiling”: A neuroscientific diagnostic approach for mental disorders

Clinical brain profiling is an attempt to map a descriptive nosology in psychiatry to underlying constructs in neurobiology and brain dynamics. This paper briefly reviews the motivation behind clinical brain profiling (CBP) and presents some provisional validation using clinical assessments and meta-analyses of neuroscientific publications.The paper has four sections. In the first, we review the nature and motivation for clinical brain profiling. This involves a description of the key aspects of functional anatomy that can lead to psychopathology. These features constitute the dimensions or categories for a profile of brain disorders based upon pathophysiology. The second section describes a mapping or translation matrix that maps from symptoms and signs, of a descriptive sort, to the CBP dimensions that provide a more mechanistic explanation. We will describe how this mapping engenders archetypal diagnoses, referring readers to tables and figures. The third section addresses the construct validity of clinical brain profiling by establishing correlations between profiles based on clinical ratings of symptoms and signs under classical diagnostic categories with the corresponding profiles generated automatically using archetypal diagnoses. We then provide further validation by performing a cluster analysis on the symptoms and signs and showing how they correspond to the equivalent brain profiles based upon clinical and automatic diagnosis.In the fourth section, we address the construct validity of clinical brain profiling by looking for associations between pathophysiological mechanisms (such as connectivity and plasticity) and nosological diagnoses (such as schizophrenia and depression). Based upon the mechanistic perspective offered in the first section, we test some particular hypotheses about double dissociations using a meta-analysis of PubMed searches. The final section concludes with perspectives for the future and outstanding validation issues for clinical brain profiling.

Aperiodic 3D tiling by self-similar substitution method using solid unit

"There are two important aperiodic tiling methods. One is a projection method and the other is self-similar substitution method. Author applied projection and substitution method to several quasi-periodic tiling [1a] [1b] [1c] [2a] [2b] [2c]. Quantity of the information for research of aperiodic tiling except quasi-periodic tiling is not so large as that of quasi-periodic tiling. Author shows one of the substitution example. that is a ""pentomino tile"" which is made of five unit squares. First generation of a ""pentomino tile"" is composed of two original pentominos and chiral two original pentominos [3]. Author considered 3D solid body unit similar to exterior view of car-body as shown in figure, then succeeded in first generation tile using the body unit. In this study, author consider a relation between substitution and crystallographic rotation matrix and translation matrix and discuss general formulation of self-similar substitution. Caption of Figure: (left-hand) original generation, (center) First generation, (right-hand) Second generation"

Discrete Point Cloud Registration using the 3D Normal Distribution Transformation based Newton Iteration

The technology of three-dimensional reconstruction based on visual sensor has become an important research aspect. Based on Newton iteration algorithm, the improved 3D normal distribution transformation algorithm” (NI-3DNDT) is put forward, aiming to fix the problem of discrete point cloud registration algorithm in poor astringency and being open to local optimum. The discrete 3d point cloud adopts one order and two order derivative of piecewise smooth functions on surface, divides the point cloud space into Cubic grids, and calculate corresponding value of the mean and covariance matrix. To downgrade algorithm complexity, the Gauss function approximation of the log likelihood function is introduced, the probability density function parameters of 3D normal distribution transformation algorithm is simplified, and the Hessian matrix and gradient vector is solved through translation, rotation relation and Jacobean matrix; to make sure algorithm is converged to one certain point after a small number of iterations, it proposes that Newton iterative algorithm step be improved by employing better line search. Finally, the algorithm is put on simulation experiment and compared with other ways, the result of which proves that the suggested algorithm is able to achieve better registration effect, and Improve accuracy and efficiency

Wavefield Analysis Over Large Areas Using Distributed Higher Order Microphones

Successful recording of large spatial soundfields is a prevailing challenge in acoustic signal processing due to the enormous numbers of microphones required. This paper presents the design and analysis of an array of higher order microphones that uses 2D wavefield translation to provide a mode matching solution to the height invariant recording problem. It is shown that the use of Mth order microphones significantly reduces the number of microphone units by a factor of 1/(2M + 1) at the expense of increased complexity at each microphone unit. Robustness of the proposed array is also analyzed based on the condition number of the translation matrix while discussing array configurations that result in low condition numbers. The white-noise gain (WNG) of the array is then derived to verify that improved WNG can be achieved when the translation matrix is well conditioned. Furthermore, the array's performance is studied for interior soundfield recording as well as exterior soundfield recording using appropriate simulation examples.

Study on Internal and External Parameters’ Calibration of Camera Based on Hyperchaos Least Square Method

To Solve how to Calibrate Rapidly and Accurately in Camera, it Proposed the Method of Hyperchaos Least Square and Implemented by Labview through Analyzing the Camera Model and the Calibration Principle. it is that Measuring Image Coordinate and World Coordinate, then Calculating the Important Camera Internal and External Parameters which are R Rotation Matrix and T Translation Matrix Solutions Based on Hyperchaos Least Square Method.

Robot Calibration for Cooperative Process under Typical Installation

A method with easy operation procedure and simple calibration condition is presented in this paper to solve the base frame calibration problem for cooperative robots. It is carried out through constructing a series of handclasp configurations and recording coordinates of the contact points, respectively, in base frame of each robot. Then the rotation matrix and translation matrix between base frame of cooperative robots can be calculated which is just the calibration result for cooperative robots. Based on typical installation mode for industrial robot, the floor mounted, wall mounted and ceiling mounted, constraints between base frames of these robots are further explored. These constraints are used to improve the calibration results for base frame calibration problem. In order to validate the correctness and effectiveness of our method, experiments on two industrial robots (Motoman VA1400 and HP20) are carried out at the end of the paper. The calibration errors are less than 8 mm in most cases, which satisfies the requirement of positioning accuracy for most industrial process, such as arc welding, transporting, and cutting. These experiment results assert the correctness of our method which can be used effectively to solve the base frame calibration problem for cooperative robots in manufacturing process.

Planar surface area transformation using modified homography matrix

This research targets a problem of planar area size inconsistency after image warping to the top view. An orientation sensor attached to a camera was used to acquire the camera’s orientation in real time. Then, extrinsic parameters derived from the sensor and pre-computed intrinsic parameters were used to generate a homography matrix. The homography matrix was modified to eliminate the effect of an angle change, by avoiding the use of shift parameters. In doing so, an area size stays the same regardless of any change in such an angle. A separately required translation matrix was used to shift the top view image. In the shifted top view image, the number of target pixels can be directly counted. Finally, the number of pixel was converted to an area size in real-world units.