Complete Matrix Research Articles

Synthesis, Crystal Structure and IR Spectrum studies of 2-(4-Methyl-2-phenyl-4,5-dihydro-oxazol-4-ylmethyl)- isoindole-1,3-dione

The organo-amino compound of title 2-(4-methyl-2-phenyl-4,5-dihydro-oxazol-4-ylmethyl)-isoindole-1,3-dione was synthesized by the mixture of (4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl-4-methylbenzenesulfonate and isoindoline-1,3-dione in N,N-dimethylformamide with a yield of around 65%. The structural study of the compound, C19H16N2O3, is realized using single crystal X-Ray diffraction which shows that this compound crystallizes in the monoclinic system (P21/c, Z = 4) with the unit cell parameters: a = 14.3728 (13) Å, b = 9.6829 (10) Å, c = 11.8964 (12) Å and β = 107.384 (3). The refinement of the structure by the least-squares method with complete matrix leads to the following reliability factors R/Rw are 0.044/0.130.In the crystal, the molecules are linked together by hydrogen bonds and π…π interactions.The Infrared spectroscopic studies show the bands confirming the presence of the groups C=O, C-O, C-N, -CH3, -CH2 and =CH.

Influence of Solid-To-Liquid Ratio on Properties of Fly Ash Geopolymer Ceramics

Ceramics has come to be progressively very important in industry because of their exceptional mechanical and physical properties The motivation to develop fly ash geopolymer ceramics was to overcome the problem associated with the conventional technical ceramics like alumina, silicon, carbide, aluminium nitride that fracture easily under mechanical or thermo-mechanical loads. The novelties of this research were providing new material to fabricate geopolymer as ceramic precursor and move towards green technology. Geopolymer substrates were activate by adding the alkaline activator gradually with different ratios of solid to liquid ranged from 0.5, 1.0, 2.0 and 3.0 into fly ash at ambient temperature. The samples were cured before undergo powder metallurgy method. The best and optimum solid to liquid ratio is determined at ratio 2.0 based on flexural strength. The broad, amorphous peak showed by phase analysis indicates that geopolymerization has occurred. The formation of almost fully crystalline phase such as albite has been detected which contributes to the flexural strength of fly ash geopolymer ceramic. Microstructure image shows smoother and complete geopolymer matrix which gives denser structure as supported by the excellent density.

Accuracy and Efficiency of Updated FRF Coupling for the Dynamic Behaviour Investigation of an Assembled Structure

The frequency based substructuring (FBS) method allows the combination between the experimental and analytical frequency response function (FRF). The combined FRF is then used for calculation of the dynamic behaviour of an assembled structure which usually consists of a large number structural components or substructures. However, the accuracy of the dynamic behaviour calculated using the FBS method relies heavily on the quality of experimental FRF data of the interfaces on which, in practice, it is very problematic to be attained. Furthermore, in most cases, some parts of rotational FRF data are not included in the FBS method due to the complex measurement process. The exclusion of the rotational FRF data will usually lead to numerous errors in the combined FRF data. Therefore, this paper proposes a new frequency response function (FRF) coupling of the FBS method that may uniquely address the difficulties and improve the quality of predicted results of the FBS method. The proposed coupling was formulated based on the finite element method, model updating method and FRF synthesize method. The finite element model of the physical test substructure was developed and reconciled based on the mode shapes obtained from experimental modal analysis. The FRF synthesize method was performed on the updated finite element model to obtain a complete matrix with a full degree of freedom FRF data containing all the translational and rotational FRF data required. It was found that the proposed coupling has allowed generating full translational and rotational FRF data. The generation has improved significantly the FRF coupling process and the quality of the predicted dynamic behaviour of the FBS method.

Collision-energy dependence of second-order off-diagonal and diagonal cumulants of net-charge, net-proton, and net-kaon multiplicity distributions in Au + Au collisions

We report the first measurements of a complete second-order cumulant matrix of net-charge, net-proton, and net-kaon multiplicity distributions for the first phase of the beam energy scan program at RHIC. This includes the centrality and, for the first time, the pseudorapidity window dependence of both diagonal and off-diagonal cumulants in Au+Au collisions at \sNN~= 7.7-200 GeV. Within the available acceptance of $|\eta|<0.5$, the cumulants grow linearly with the pseudorapidity window. Relative to the corresponding measurements in peripheral collisions, the ratio of off-diagonal over diagonal cumulants in central collisions indicates an excess correlation between net-charge and net-kaon, as well as between net-charge and net-proton. The strength of such excess correlation increases with the collision energy. The correlation between net-proton and net-kaon multiplicity distributions is observed to be negative at \sNN~= 200 GeV and change to positive at the lowest collision energy. Model calculations based on non-thermal (UrQMD) and thermal (HRG) production of hadrons cannot explain the data. These measurements will help map the QCD phase diagram, constrain hadron resonance gas model calculations, and provide new insights on the energy dependence of baryon-strangeness correlations. An erratum has been added to address the issue of self-correlation in the previously considered efficiency correction for off-diagonal cumulant measurement. Previously considered unidentified (net-)charge correlation results ($\sigma^{11}_{Q,p}$ and $\sigma^{11}_{Q,k})$ are now replaced with identified (net-)charge correlation ($\sigma^{11}_{Q^{PID},p}$ and $\sigma^{11}_{Q^{PID},k}$)

HYTREES: combining matrix elements and parton shower for hypothesis testing

We present a new way of performing hypothesis tests on scattering data, by means of a perturbatively calculable classifier. This classifier exploits the “history tree” of how the measured data point might have evolved out of any simpler (reconstructed) points along classical paths, while explicitly keeping quantum–mechanical interference effects by copiously employing complete leading-order matrix elements. This approach extends the standard Matrix Element Method to an arbitrary number of final state objects and to exclusive final states where reconstructed objects can be collinear or soft. We have implemented this method into the standalone package hytrees and have applied it to Higgs boson production in association with two jets, with subsequent decay into photons. hytrees allows to construct an optimal classifier to discriminate this process from large Standard Model backgrounds. It further allows to find the most sensitive kinematic regions that contribute to the classification.

Mean Square Stabilization for Sampled-Data T–S Fuzzy Systems With Random Packet Dropout

This paper investigates the problem of mean square stabilization for sampled-data Takagi-Sugeno (T-S) fuzzy networked control systems with random packet dropouts. The packet dropout process is modeled as a discrete-time Markovian chain with complete or incomplete accessible transition probability matrix. Based on the Lyapunov function approach, sufficient conditions are derived for the mean square stability. The corresponding sampled-data fuzzy controller design algorithm formulated in terms of linear matrix inequalities is also given based upon the stability conditions. The numerical examples and simulations are provided to illustrate the usefulness of the developed theory.

Investigation of the flight behavior of a flare-stabilized projectile using 6DoF simulations coupled with CFD

PurposeThe present work aims to investigate the capabilities of accurately predicting the six-degrees-of-freedom (6DoF) trajectory and the flight behavior of a flare-stabilized projectile using computational fluid dynamics (CFD) and rigid body dynamics (RBD) methods.Design/methodology/approachTwo different approaches are compared for calculating the trajectory. First, the complete matrix of static and dynamic aerodynamic coefficients for the projectile is determined using static and dynamic CFD methods. This discrete database and the data extracted from free-flight experiments are used to simulate flight trajectories with an in-house developed 6DoF solver. Second, the trajectories are simulated solving the 6DoF motion equations directly coupled with time resolved CFD methods.FindingsVirtual fly-out simulations using RBD/CFD coupled simulation methods well reproduce the motion behavior shown by the experimental free-flight data. However, using the discrete database of aerodynamic coefficients derived from CFD simulations shows a slightly different flight behavior.Originality/valueA discrepancy between CFD 6DoF/RBD simulations and results obtained by the MATLAB 6DoF-solver based on discrete CFD data matrices is shown. It is assumed that not all dynamic effects on the aerodynamics of the projectile are captured by the determination of the force and moment coefficients with CFD simulations based on the classical aerodynamic coefficient decomposition.

Frontal weld lines in injection‐molded short fiber‐reinforced PBT: Extensive microstructure characterization for mechanical performance evaluation

AbstractDifferent factors contribute to the weakness of weld lines (WLs) induced by injection molding such as unsuitable fiber orientation (FO), incomplete polymer matrix diffusion, voids and V‐notches. This study aims to characterize the contribution of each factor on the weakness of frontal WLs in a short glass fiber‐reinforced polybutylene‐terephthalate characterized by extensive X‐ray computed tomography and mechanical tensile testing assisted with digital image correlation. A reduction of 50% of the stress at break and almost 40% of the strain at break is observed despite the complete matrix healing at the WL interface and the absence of V‐notches. Frontal WLs induce a FO gradient starting 2 to 3 mm before the WL plane. The fibers in the WL region mainly orient in transverse‐to‐flow and thickness direction. This FO gradient localizes the deformations, which leads to failure at a strength near to the one of the unreinforced variant. Voids formation in frontal WLs seems to be driven by large gradients of FO and subsequent anisotropic shrinkage. In addition, this shrinkage behavior at the WL causes an increase of thickness. By applying higher packing pressures, the fibers orient more in flow direction at the core of the WL, leading to a higher tensile strength and a lower content of voids. Finally, we can conclude that the FO is the dominant factor controlling the mechanical performance in frontal WLs.

An online dynamic traffic matrix completion method in software defined networks

Online temporal Traffic Matrix (TM) estimation is important for network management and traffic engineering. However, current estimation methods are insufficient in estimation accuracy and measurement cost. In this paper, by combining the low rank feature of the traffic matrix and the flow measurement capability in Software Defined Networks (SDN), we propose a novel online dynamic temporal traffic matrix completion mechanism DTMC. DTMC evaluates the impact of different Origin–Destination (OD) flows on improving the traffic matrix estimation accuracy from the perspective of uncertainty and temporal stability, selects an appropriate number of “most-informative” flows to construct the measurement set, and finally recovers the complete traffic matrix by using the partially measured OD flow information dynamically. The experiment results on two Internet measurement datasets show that DTMC can estimate the dynamic temporal traffic matrix accurately only by consuming a small amount of measurement resources.

One-way propagators based on matrix multiplication in arbitrarily lateral varying media with GPU implementation

Conventional one-way migration methods have some shortcomings, such as their limitations in imaging large angles. A novel strategy is presented here to solve these issues. The Helmholtz operator of the two-way wave equation is a power of the square root operator of the one-way wave equation. Based on this connectivity, the computation of the square root of the Helmholtz operator based on matrix multiplication and the calculation of a one-way propagator with a Taylor series expansion, is studied. The one-way propagators used in this paper involve complete matrix multiplication, which is a distinct feature of this method and is suitable for parallel implementation. Analysing the values of matrix square roots generated by the classical eigenvalues decomposition method and an algorithm of computing matrix square roots with matrix multiplication, we prove that our algorithm can calculate a stable result, which lays a solid foundation for further study. The impulse response test proves the advantage of our proposed method over conventional one-way migration in describing the wavefield propagation of large angles in a medium with a strong lateral velocity variation. Moreover, we implement GPU and CPU versions of the algorithm and compared their efficiencies. The post-stack migration result of the Salt model and the pre-stack migration result of the Marmousi model further illustrate the superiority of our proposed migration method in imaging the complex and fine-scale structures compared to the conventional one-way migration method. This provides a promising practical application in seismic exploration.

A matrix-based method for the structural analysis of diagrid systems

Diagrid systems have been frequently employed in the last few decades for the construction of tall buildings because of their high lateral stiffness and for their capability to realize complex-shaped structures. Considering mainly diagrid structures with regular forms, many researchers have developed different methods to perform the structural analysis. In this paper, a matrix-based method (MBM) for the analysis of generic freeform diagrid systems is proposed. Unlike existing methodologies, that take into account only shear and bending stiffness, and Finite Element Method approach, the proposed procedure is based on the direct calculation of the complete structure stiffness matrix, without the assemblage of local sub-matrices. This method allows to solve automatically the structural problem, providing both the structure displacements and the axial forces in the diagonals. Then, some comparisons with the Finite Element Method are reported, both for two-dimensional and three-dimensional diagrid systems. In order to show the method capabilities, the analysis concerning the Swiss Re Tower in London is performed. Finally, an application of the MBM is shown regarding the distribution of lateral actions between an external diagrid system and a central core, according to the General Algorithm theory.

Ship Detection From PolSAR Imagery Using the Complete Polarimetric Covariance Difference Matrix

In this paper, we proposed a complete polarimetric covariance difference matrix [ $CP$ ]-based algorithm for ship detection in polarimetric synthetic aperture radar (PolSAR) imagery. To calculate [ $CP$ ], we first developed a scheme to reflect the polarimetric scattering differences between ship pixel (SP) and its neighboring pixels (ISPs) and, then, dividedly accumulated the amplitude and phase differences between SP and ISPs. Compared to the polarimetric covariance difference matrix [ $P$ ] developed in our earlier work, [ $CP$ ] effectively overcomes the drawback of the lack of the phase information in [ $P$ ]. To demonstrate the effectiveness of the proposed algorithm, we applied the [ $CP$ ]-based ship detection algorithm to four PolSAR data sets, including one UAVSAR L-band data set with 21 ships, two AIRSAR L-band data sets with 11 and 22 ships, respectively, and one Radarsat-2 C-band data set with 8 ships. Experimental results show that: 1) the proposed algorithm can effectively detect ships with high target-to-clutter ratio (TCR) values and 2) [ $CP$ ] has a better performance than the traditional polarimetric covariance matrix [ $C$ ] and [ $P$ ] on ship detection. To be more specific, the average TCR value of the proposed algorithm (23.86 dB) is 6.07 and 7.47 dB higher than PNF $_{C}$ (i.e., the geometrical perturbation-polarimetric notch filter) and RS $_{C}$ (i.e., the reflection symmetry method), respectively.

Acujoint™, a highly efficient formulation with natural bioactive compounds, exerts potent anti-arthritis effects in human osteoarthritis – A pilot randomized double blind clinical study compared to combination of glucosamine and chondroitin

The aim of the study was to evaluate the efficacy and safety of Acujoint™ - a supplement for articular cartilage degradation- in the treatment of patients with Osteoarthritis (OA) by comparing it with glucosamine and chondroitin formulation, which is a popular supplement used to treat OA. Acujoint™ is a health supplement prepared with extracts of 3-O-acetyl-11-keto-β-boswellic acid from Boswellia serrata, β-Caryophyllene from Piper nigrum, aqueous extract of Kaempferia galangal and Cureit™ - a bioavailable curcumin formulation- in a fixed ratio based on complete natural matrix, which has been used to treat osteoarthritis. A randomized, double blind, active controlled, single centre, clinical study was carried out using Acujoint™ during 90 days of treatment in 24 patients (1:1 ratio) with symptoms of moderate to mild OA along with combination of Glucosamine (1500 mg) and Chondroitin (1200 mg). The study shows that Acujoint™ can provide significant improvement in relieving the symptoms and the pain associated with active OA between the groups as well as within the groups. Active OA patients, who received Acujoint™ at 250 mg per day for a treatment period of 90 days, reported statistically significant changes/decreases in their clinical symptoms and pain. This was evident from significant changes in the total Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) score, pain score, functional ability score, visual analog scale (VAS) score and Lequesne functional index values at P < 0.05 level. Acujoint™ promises beneficial effects for the treatment of human knee osteoarthritis by controlling inflammatory responses as well as the pain without any adverse effects.

Impact of intensity integration time distribution on the measurement precision of Mueller polarimetry

Mueller polarimetry is an important technology to characterize the physical property of materials (such as thin films and scattering particles etc.). Therefore, the high measurement precision is significant for various applications. In this paper, a modified model considering integration time of intensity measurement is proposed to verify the impact of intensity integration time distribution on the measurement precision of Mueller polarimetry. In the presence of additive Gaussian noise, the optimal integration time distribution, which is determined by instrument matrix, that minimizes the noise propagation (and thus estimation variance) is also proposed for both complete Mueller matrix polarimetry and some common partial (or incomplete) Mueller matrix polarimetry. Furthermore, we found that the estimation variance can be further reduced by optimizing the integration time distribution for some given instrument matrices. However, we also verify that, for the first time to our knowledge, the existing minimal estimation variance, and thus the upper bound of measurement precision cannot be broken by optimizing intensity integration time distribution.

Ranking Hits From Saturation Transfer Difference Nuclear Magnetic Resonance-Based Fragment Screening.

Fragment-based screening is an established route to identify low-molecular-weight molecules to generate high-affinity inhibitors in drug discovery. The affinities of these early hits from fragment screenings require a highly sensitive biophysical screening technique. Saturation transfer difference (STD) nuclear magnetic resonance (NMR) is one of the most popular methods owing to its high sensitivity for low-affinity ligands. It would be highly beneficial if rank-ordering of hits according to their affinity from an initial or counter-screen could be performed—a selection criterion found in the literature. We applied Complete Relaxation and Conformational Exchange Matrix (CORCEMA) theory adapted for saturation transfer (ST) measurements (CORCEMA-ST) calculations to predict STD NMR results from a large set of fragment/receptor pairs to investigate the boundaries under which the assumption holds true that a high STD effect can be applied to select for higher-affinity fragments. Overall, we come to the conclusion that this assumption is invalid.

A New Mathematical Method to Study the Singularity of 3-RSR Multimode Mobile Parallel Mechanism

In the process of parallel mechanism design, it is difficult to avoid the singularity, especially in the mobile parallel mechanism. Therefore, a new mathematical method to study the singularity of multimode mobile parallel mechanism is proposed. In this paper, the singularity of 3-RSR parallel mechanism (PM) is analyzed by using reciprocal screw methods and linear geometry theory from two aspects of fixed mode and all-attitude multiple motion modes. Specifically, the complete Jacobian matrix of the PM is obtained by using the screw theory, and the reciprocal screw of each branch is expressed with algebraic method and geometric drawing method. Furthermore, the singularity of the PM can be obtained by analyzing the reciprocal screw correlation and using the spatial linear geometry theory. Finally, we analyze the singular configuration of the PM under various modes, which provide theoretical guidance for the gait planning of the multimode mobile PM and will be useful for the selection of mechanism drive and time-sharing control.

Fully Coupled Smoothed Particle Hydrodynamics-Finite Element Method Approach for Fluid–Structure Interaction Problems With Large Deflections

Abstract In this study, a combination of the smoothed particle hydrodynamics (SPH) and finite element method (FEM) solving the complex problem of interaction between fluid with free surface and an elastic structure is studied. A brief description of SPH and FEM is presented. Contact mechanics is used for the coupling between fluid and structure, which are simulated with SPH and FEM, respectively. In the proposed method, to couple mesh-free and mesh-based methods, fluid and structure are solved together by a complete stiffness matrix instead of iterative predictive–corrective or master–slave methods. In addition, fully dynamic large-deformation analysis is carried out in FEM by taking into account mass and damping of the elastic structure. Accordingly, a two-dimensional fluid–structure interaction (FSI) code is developed and validated with two different experiments available in the literature. The results of the numerical method are in good agreement with the experiments. In addition, a novel laboratory experiment on a dam break problem with elastic gate in which the length of the initial water column is larger than its height is conducted. The main difference between the previous experiments and the one conducted in this study is that an upward water motion parallel to the elastic gate is observed at the upstream side of the gate. This motion is captured with the numerical method.

Application of the Taguchi Method in the Investigation of Influential Heat Treatment Factors in Steel Wires

Statistical methods have been used to improve processes and accelerate industrial technological development. This study contributed to the investigation of the causes that can alter the mechanical properties in steel wires during the tempering process only for diameters 3.00 mm and 5.00 mm, used in the manufacture of valve springs and clutch for automobile follow-up. This research will show the application of the Taguchi Method, Desirability Method and Generalized Reduced Gradient to investigate the mechanical properties tensile strength, area reduction and hardness, in SAE 9254drawn steel wires. Data were generated from application of Design of Experiments Methodology (by means of the Minitab Statistical Software) and the results revealed which variables were considered influential. The Multiple Linear regressions were also used to create mathematical models of the process. It was concluded that the tempering temperature and diameter are the factors that cause the increase or reduction of the variable responses' tensile strength and hardness of drawn steel wire SAE 9254 during the tempering process and that the factors investigated have not influence on the variable response area reduction. It was observed that with the application of the Taguchi Method it was possible to reduce the number of experiments to be carried out and thus it was possible to reduce the costs significantly. If instead of using the Taguchi Method a complete matrix 24 would be required to perform 16 experiments with at least one repetition for each situation (so that it was possible to calculate the standard error). With this, 32 experiments would be carried out. In this case, with the use of the Taguchi method, the quantity of experiments was reduced to 8 experiments (without the need repetition), which represented the reduction of 75% in the costs of experimentation. It has been found that the statistical methods and optimization methods studied in academic environments and often employed only on a small scale of production, in research laboratories or in simulators in universities, can also be applied In an industrial environment of large scale production, contributing to the solution of complex problems and being of important value for future technological innovations in the industries.

Dynamic estimation in the extended marginal Rasch model with an application to mathematical computer-adaptive practice.

We introduce a general response model that allows for several simple restrictions, resulting in other models such as the extended Rasch model. For the extended Rasch model, a dynamic Bayesian estimation procedure is provided, which is able to deal with data sets that change over time, and possibly include many missing values. To ensure comparability over time, a data augmentation method is used, which provides an augmented person‐by‐item data matrix and reproduces the sufficient statistics of the complete data matrix. Hence, longitudinal comparisons can be easily made based on simple summaries, such as proportion correct, sum score, etc. As an illustration of the method, an example is provided using data from a computer‐adaptive practice mathematical environment.

3184 Development of a Leadership Assessment Scale in Translational Science

OBJECTIVES/SPECIFIC AIMS: To create the instrument, we employed a modified Delphi approach by conducting a thorough literature review on Leadership to help concretize the relevant constructs, and then usied these extracted constructs as a springboard for the Rockefeller Team Science Educators (TSE’s) to discuss and refine the leadership domain areas, collectively creating domain-specific survey items, and then further discussed and refining the number, grouping, and wording of the items. METHODS/STUDY POPULATION: We piloted the Leadership Survey by having all of the Rockefeller TSEs rate Clinical Scholars. Each item was answered using a six-point Likert scale where a low score indicated poor expression of the specific leadership attribute and a high score represented excellent expression of the specific leadership attribute. RESULTS/ANTICIPATED RESULTS: Means, medians, standard deviations, and ranges of each item were calculated and tabulated. A complete (Pearson) correlation matrix was computed so that the raw inter-item relationships can be observed. For each a priori Domain an equal weighted summary scale was created and tabulated for review. The internal consistency of each a priori scale was assessed by calculating Cronbach’s Alpha (α). Items with low Item to Construct coefficients were candidates for elimination or modification, and overall scales with low’s will undergo further discussion. To challenge our assumptions of the construction and integrity of each domain, we employed exploratory Principal Components Analysis (PCA), followed by orthogonally rotated Factor Analysis (FA). We also forced the PCA / FA analysis to extract the a priori dimensions that allowed us to compare if the empirical and a priori structures match. DISCUSSION/SIGNIFICANCE OF IMPACT: We are partnering with the CTSA programs at Penn and Yale to assess issues of generalizability and scalability. We are working with Vanderbilt to install survey onto REDCap for ease of dissemination. Will continue to assess psychometric properties and refine as we receive more input.