Cohen-Macaulay oriented graphs with large girth

We classify the Cohen-Macaulay weighted oriented graphs whose underlying graphs have girth at least $5$.Comment: We correct typos in Lemma 2.

Three-Way Tensor Decompositions: A Generalized Minimum Noise Subspace Based Approach

Tensor decomposition has recently become a popular method of multi-dimensional data analysis in various applications. The main interest in tensor decomposition is for dimensionality reduction, approximation or subspace purposes. However, the emergence of “big data” now gives rise to increased computational complexity for performing tensor decomposition. In this paper, motivated by the advantages of the generalized minimum noise subspace (GMNS) method, recently proposed for array processing, we proposed two algorithms for principal subspace analysis (PSA) and two algorithms for tensor decomposition using parallel factor analysis (PARAFAC) and higher-order singular value decomposition (HOSVD). The proposed decomposition algorithms can preserve several desired properties of PARAFAC and HOSVD while substantially reducing the computational complexity. Performance comparisons of PSA and tensor decomposition of our proposed algorithms against the state-of-the-art ones were studied via numerical experiments. Experimental results indicated that the proposed algorithms are of practical values

Robust Subspace Tracking Algorithms in Signal Processing: A Brief Survey

Principal component analysis (PCA) and subspace estimation (SE) are popular data analysis tools and used in a wide range of applications. The main interest in PCA/SE is for dimensionality reduction and low-rank approximation purposes. The emergence of big data streams have led to several essential issues for performing PCA/SE. Among them are (i) the size of such data streams increases over time, (ii) the underlying models may be time-dependent, and (iii) problem of dealing with the uncertainty and incompleteness in data. A robust variant of PCA/SE for such data streams, namely robust online PCA or robust subspace tracking (RST), has been introduced as a good alternative. The main goal of this paper is to provide a brief survey on recent RST algorithms in signal processing. Particularly, we begin this survey by introducing the basic ideas of the RST problem. Then, different aspects of RST are reviewed with respect to different kinds of non-Gaussian noises and sparse constraints. Our own contributions on this topic are also highlighted

Extractive spectrophotometric methods for determination of ciprofloxacin in pharmaceutical formulations using sulfonephthalein acid dyes

Three simple, rapid, sensitive and accurate extractive-spectrophotometric method for the determination of ciprofloxacin in pharmaceutical preparation has been developed. These methods are based on the formation of yellow ion-pair complexes between the examined drug and three sulfonephthalein  acid dyes, namely; bromophenol blue (BPB), bromocresol green (BCG),  and bromothymol blue (BTB) in  acidic medium. The formed complexes were extracted with chloroform and measured at 420, the colored chromogen was stable for twenty four hours. The effect of optimum conditions via pH, dye concentration, time and solvent are studied. Beer’s law is obeyed in the concentration ranges 0.50-25.0 μg/mL with  molar absorptivity of 1.46´104, 1.83´104 and 2.07´104 L. mol-1. cm-1 and limit of detection (LOD) of 0.105, 0.101, 0.084 for BPB, BCG and BTB methods, respectively. No interference was observed from common excipients present in pharmaceutical formulations. The proposed method has been applied successfully to determine ciprofloxacin in pharmaceutical preparation (tablets, infusion and eye drops). Keywords. Ciprofloxacin, extraction-spectrophotometry, ion pair complex; sulfonephthalein  dyes

Rural tourism development in Quy river islet, Ben Tre province altogether with building new rural area

Researching and developing rural tourism in association with new rural construction has become a trending research in line with the Government\u27s orientation, towards development companies. By fieldwork method altogether with S.W.T.O analysis, the author team managed to survey and research potential in exploiting rural tourism in Con Quy, Ben Tre province in association with the new rural construction force. Since then, provide solutions through tourism to help preserve the cultural features of traditional farmers, humanism values are reserved and passed down in villages. Besides, it helps reconstructing of economy effciently and successfull

A RESEARCH ON MULTI-OBJECTIVE OPTIMIZATION OF THE GRINDING PROCESS USING SEGMENTED GRINDING WHEEL BY TAGUCHI-DEAR METHOD

In this study, the mutil-objective optimization was applied for the surface grinding process of SAE420 steel. The aluminum oxide grinding wheels that were grooved by 15 grooves, 18 grooves, and 20 grooves were used in the experimental process. The Taguchi method was applied to design the experimental matrix. Four input parameters that were chosen for each experiment were the number of grooves in cylinder surface of grinding wheel, workpiece velocity, feed rate, and cutting depth. Four output parameters that were measured for each experimental were the machining surface roughness, the system vibrations in the three directions (X, Y, Z). The DEAR technique was applied to determine the values of the input parameters to obtaine the minimum values of machining surface roughness and vibrations in three directions. By using this technique, the optimum values of grinding wheel groove number, workpiece velocity, feed-rate, cutting depth were 18 grooves, 15 m/min, 2 mm/stroke, and 0.005 mm, respectively. The verified experimental was performed by using the optimum values of input parameters. The validation results of surface roughness and vibrations in X, Y, Z directions were 0.826 (µm), 0.531 (µm), 0.549 (µm), and 0. 646 (µm), respectively. These results were great improved in comparing to the normal experimental results. Taguchi method and DEAR technique can be applied to improve the quality of grinding surface and reduce the vibrations of the technology system to restrain the increasing of the cutting forces in the grinding process. Finally, the research direction was also proposed in this stud

Computation of limit and shakedown using the NS-FEM and second-order cone programming

This paper presents a novel numerical procedure for computation of limit and shakedown using node-based smoothed finite element method (NS-FEM) in combination with second-order cone programming (SOCP). The obtained discretization formulation is then cast in a form which involves second-order cone constraints, ensuring that the underlying optimization problem can be solved by highly efficient primal-dual interior point algorithm. Furthermore, in the NS-FEM, the system stiffness matrix is computed using the smoothed strains over the smoothing domains associated with nodes. This ensures that the size of the resulting optimization problem is kept to a minimum. The efficiency of the present approach is illustrated by examining several numerical examples

An XFEM based kinematic limit analysis formulation for plane strain cracked structures using SOCP

This paper extends a numerical procedure for limit analysis based on extended finite element method (XFEM) and second-order cone programming (SOCP) to plane strain cracked structures. The cracked structures are easily modelled and simulated using XFEM because it allows discontinuities across elements, and these discontinuities are recognized by means of level set method. The resulting discretization formulation is then cast in a form which involves second-order cone constraints, ensuring that the underlying optimization problem can be solved by highly efficient primal-dual interior point algorithm. The efficiency of the present approach is illustrated by examing several numerical examples

Preliminary Result of Arthroscopic Anterior Cruciate Ligament Reconstruction Using Anterior Half of Peroneus Longus Tendon Autograft

BACKGROUND: Anthroscopic anterior cruciate ligament reconstruction is one of the most successful operations in sports medicine. At present, ligament autografts have been the best method due to good histocompatibility, rapid healing, no cross-contamination, and low cost of treatment. However, autografts do not have infinite amount and are also not always feasible. Anterior half of peroneus longus tenden autograft is likely to become a source of autograft with many advantages. This study aims to evaluate the clinical outcomes of anthroscopic anterior cruciate ligament reconstruction using anterior half of peroneus longus tendon autograft (AHPLT). AIM: To evaluate the initial outcome of ACL reconstruction arthroscopy by anterior half of peroneus longus tendon. METHODS: This is a prospective non-controlled case series. RESULTS: A prospective study on 30 patients (from 9 / 2016 to 01 / 2019) had both ACL and MCL injury who had operated ACL reconstruction using anterior half of peroneus longus tendon autograft (AHPLT) at Department of General Orthopaedic and Trauma, Viet Duc hospital. Our outcome: the year average 35.4 ys, the rate of ACL rupture combined with meniscus injury was 40%. The average diameter AHPLT autograft is 7.0 mm. The function Lysholm scores improved from 59 to 94.27 postoperative 6 months. No difference beetwen the AOFAS scale of preoperative and postoperative. CONCLUSION: Peroneus longus tendon is recommended to be a safe and practical autograft resource for anthroscopic anterior cruciate ligament reconstruction