Small Corners Research Articles

Challenges faced by the pre start ups in hilly areas of Uttarkhand

Abstract Start-ups is not the new terminology used now a days in India as there are tremendous number of start-ups are blooming in each and every small corners of villages and towns of India and Uttarkahand. The small Hilly state is also not far behind its performance in the star-up enterprises. Start ups means the new business started with some new ideas which are innovative and full of creativity. The start ups are those business units which are initially started with the financial help of their family, friends, relatives, acquaintances and through the government financial schemes mainly formulated for assisting the start up business units. Later on these start ups can grow their business with the financial help taken from the angel investors and from any other sources of finance. There are mainly three stages have been found for the business entrepreneurs such as existence, survival and success. This first stage is called the pre start up and second and third as start up. This paper states the present status and the problems faced by the pre start-ups of Uttarakhand to mobile towards start up and scale up their enterprises This paper also explain the suggestive measures to reduce these hindrances in order to enhance their scale of production and sale. Key Words: start up, scalable business, pre start up, challenges etc.

A Three-Grid High-Order Immersed Finite Element Method for the Analysis of CAD Models

The automated finite element analysis of complex CAD models using boundary-fitted meshes is rife with difficulties. Immersed finite element methods are intrinsically more robust but usually less accurate. In this work, we introduce an efficient, robust, high-order immersed finite element method for complex CAD models. Our approach relies on three adaptive structured grids: a geometry grid for representing the implicit geometry, a finite element grid for discretising physical fields and a quadrature grid for evaluating the finite element integrals. The geometry grid is a sparse VDB (Volumetric Dynamic B+ tree) grid that is highly refined close to physical domain boundaries. The finite element grid consists of a forest of octree grids distributed over several processors, and the quadrature grid in each finite element cell is an octree grid constructed in a bottom-up fashion. The resolution of the quadrature grid ensures that finite element integrals are evaluated with sufficient accuracy and that any sub-grid geometric features, like small holes or corners, are resolved up to a desired resolution. The conceptual simplicity and modularity of our approach make it possible to reuse open-source libraries, i.e. openVDB and p4est for implementing the geometry and finite element grids, respectively, and BDDCML for iteratively solving the discrete systems of equations in parallel using domain decomposition. We demonstrate the efficiency and robustness of the proposed approach by solving the Poisson equation on domains described by complex CAD models and discretised with tens of millions of degrees of freedom. The solution field is discretised using linear and quadratic Lagrange basis functions.

Trans*agrarian Marxisms?

This article recasts agrarian studies’ concerns with nature, productivity, and subjectivity through the provocations raised by transgender Marxism. Transgender Marxism has interrogated how normative gender, sexuality, and racial dynamics are inseparable from the material and reproductive matrices required for capital. Critical agrarian studies has a long history of carefully tracing out the political economy of agrarian capitalism and resistance to it. Engaging with the unruly materialisms of transgender Marxism would further the work of critical agrarian studies, particularly in regard to the ways gender and sexuality are taken up in the field. The project of transgender Marxism offers a scathing critique of rights-based recognition, hetero- and homonormativity, apoliticized science, and the ways in which the biological family figures at the heart of capitalist reproduction. Such questions have been taken up in small corners of queer and feminist critical agrarian studies, particularly those rooted in the United States, but transgender Marxism offers a new opportunity to bring together the material and historical concerns of the ways agrarian capitalism takes place and creates conditions for unruly forms of resistance. The article demonstrates their possible interconnectivities by exploring three themes: theories of change, the centrality of gender/sex in the agrarian, and unruly, ungrounded materialisms. While primarily a theoretical intervention, the article draws some insights from the authors’ ethnographic work in Paraguay and Colombia to ground the theoretical possibilities in place.

Concave and convex small radius bending behavior of single and multiple layers reinforcement fabrics

Multilayer reinforcement fabrics are increasingly used for manufacturing structural polymer composites. In liquid molding processes, dry reinforcement fabrics are draped on a mold first, and infused with a liquid resin such as an epoxy in a subsequent manufacturing step. This presents major advantages in terms of operational flexibility and costs. However, draping multilayer reinforcement fabrics on complex mold geometries is challenging. Small radius mold corners constitute a major manufacturing challenge as they lead to variability in dry fabric positioning and resin-rich corners in polymer composite parts. Spring-back of fabrics bent over or into single curvature mold corners is a widespread industrial concern. However, contrary to draping over double-curvature surfaces, bending spring-back from convex or concave single-curvature corners has received very limited attention. No testing method is available. This paper quantifies reinforcement fabric bending spring-back. Single and multiple layer stacks were bent along three directions over convex and into concave 90° corners with five radii spanning 1.59 mm to 12.70 mm. In all cases, five replicated tests enabled variability quantification. Fabric stacks were also quantified using cantilevered bending tests for comparison purposes. Mold radius was found to affect the behavior to a larger extent than testing direction, number of layers or use of a binder.

The dynamics of a bicycle on a pump track – first results on modeling and optimal control

Abstract We investigate the dynamics of a bicycle on an uneven mountain bike track split into straight sections with small jumps (kickers) and banked corners. A basic model of the interaction of bicycle and rider proposed and used to derive equations of motion, which capture the possibilities to accelerate the bicycle without pedaling. Since this is a first approach to the problem, only corners connected by straight lines are considered to compute optimal riding strategies. The simulation is validated with experimental data obtained on a real pump track. It is demonstrated that the model effectively captures the longitudinal bike acceleration resulting from the relative vertical motion between the rider’s upper body and the bicycle. Our numerical results are in good analogy with real rider’s actions on similar tracks.

3D elasticity solutions for stress field around square hole in functionally graded plate

Since the square holes are widely used in many structures and machines, the purpose of this work is to obtain analytical solutions for the three-dimensional (3D) elastic stress field of transversely isotropic functionally graded (FG) infinite plates containing a single square hole with small round corners subjected to far-field loads or on the edges of the holes. Based on the generalized England-Spencer plate theory, material parameters can vary continuously and arbitrarily along the thickness direction of the plate, the solutions are obtained by using the conformal mapping technology combined with the Cauchy integral method. Concentration factors of internal forces Kij around the square hole are explicitly expressed. The obtained explicit expressions of solutions can be validated against the classical two-dimensional (2D) solutions when the material degenerates into an isotropic and homogeneous material. The detailed numerical examples are given to further investigate the influence of several parameters such as the material gradient factor and load conditions on the stress field around the hole. The present 3D analytical solutions can not only provide an in-depth understanding of the 3D stress field of FG plates with holes, but also be utilized as a benchmark to verify the numerical solutions of the same problems.

Modern Scanning Electron Microscopy. 2. Test objects for Scanning Electron Microscopy

The review of the test objects intended for calibration of scanning electron microscopes and researches to secondary electronic emission of a relief surface of a solid state in scanning electron microscope is carried out. The test objects are divided on two parameters – kind of a relief and structure of a relief. By the form of relief the test objects are divided on single, pitch and periodic. On a structure of a relief of the test objects are divided into objects with a rectangular structure and objects with a trapezoid structure with the large and small corners of an inclination of lateral walls. The examples of such the test objects are given. Their characteristics and methods of certification of parameters are described. The advantages and lacks of the test objects are considered. Is shown, that the best characteristics have the tests objects representing pitch structures consisting of trapezoid trenches with the large corners of an inclination of lateral walls. The test objects are created in monosilicon with of a surface orientation by {100} by method liquid anisotropic etching of silicon. These test objects allow defining all characteristics scanning electron microscopes, influencing on measurement of the linear sizes of relief structures used in microelectronics and nanotechnology. With their help it is possible to carry out correlation measurements, which raise accuracy of calibration scanning electron microscopes up to ten times.

Reflect, Reframe, and Re-Imagine Theory and Practice in Speech, Language, and Hearing Sciences: Introduction to the Forum.

Reflect, Reframe, and Re-Imagine Theory and Practice in Speech, Language, and Hearing Sciences: Introduction to the Forum.

Numerical solution of dissimilar inclusion problem for square notch with small round corners in plane elasticity

In this paper, the stress solution for a square notch with small round corners is studied. The square notch is composed of two portions, or the matrix and the inclusion. The elastic property of the inclusion portion is different to that of the matrix. Remote loading is applied. When the dissimilar inclusion is embedded in the matrix, the stress state in the inclusion will be changed significantly. The interface conditions along interface are formulated exactly. Complex variable function method is used to solve the problem. The complex potentials in the matrix and the inclusion are assumed in different structure. In the formulation, the number of the equations is larger than that of the unknowns. Therefore, the weight residue technique is used to solve the algebraic equation. The tangential, normal and shear stress components along the interface from the matrix and inclusion side are evaluated from the solution of the algebraic equation. In the computation, significant stress concentration has been found for the tangential stress component.

Design of Bibliographic Data Management Tool for Small Book Corners

Design of Bibliographic Data Management Tool for Small Book Corners

Finite element analysis of circle-to-rectangle roll forming of thick-walled rectangular tubes with small rounded corners

Finite element analysis of circle-to-rectangle roll forming of thick-walled rectangular tubes with small rounded corners

A numerical technique for the solution of eigenstrain problem for square notch with small round corners in plane elasticity

A numerical technique for the solution of eigenstrain problem for square notch with small round corners in plane elasticity

SAR Image Segmentation Based on Constrained Smoothing and Hierarchical Label Correction

Synthetic aperture radar (SAR) is widely used in the field of modern remote sensing due to its high resolution for a comparatively small antenna. However, there are still some difficulties in the processing of SAR images. In particular, accurate segmentation of small targets and image corners remains an important challenge, as these can easily be lost during conventional image smoothing and denoising methods. To address this, we propose an SAR image segmentation algorithm based on constrained smoothing and hierarchical label correction (CSHLC). First, a Canny algorithm is used to extract the edges of SAR images, and the Gaussian smoothing is performed on SAR images under edge constraints to achieve noise reduction so that the edges of small and big targets are well preserved. Second, a preliminary K-means clustering is conducted on the smoothing results, and then, a Markov random field (MRF) model is used on the clustering results (“original label” results), iteratively calculating a maximum likelihood set of pixel labels. Finally, through two label correction methods, pixel group counting comparison (PGCC) and gray similarity comparison (GSC), the labels of the MRF output are further checked and corrected to obtain final segmentation results. Compared with seven state-of-the-art algorithms, simulation results on both simulated SAR images and real SAR images show that the proposed CSHLC delivers higher accuracy while better retaining corners and small targets.

Solution for square notch problem with small round corners in plane elasticity under remote loading (technical note)

In the paper, the solution for square notch problem with small round corners in plane elasticity under remote loading is studied. Based on the two obtained particular solutions and the extrapolation technique, the general relation between the stress concentration and the small radius at the corner point is obtainable. It is emphasized here that this relation can be used to the arbitrary small radius case.

Near-source characteristics of two-phase gas\u2013solid outbursts in roadways

Coal and gas outbursts compromise two-phase gas–solid mixtures as they propagate as shock waves and flows from their sources. Propagation is influenced by the form of the outburst, proximity to source, the structure and form of the transmitting roadways and the influence of obstacles. The following characterizes the propagation of coal and gas outbursts as two-phase gas–solid flows proximal to source where the coupled effects of pulverized coal and gas flows dominate behavior. The characteristics of shock wave propagation and attenuation were systematically examined for varied roadway geometries using experiments and numerical models. The results demonstrate that the geometry of roadway obstructions is significant and may result in partial compression and sometimes secondary overpressurization in blocked and small corner roadways leading to significant attenuation of outburst shock waves. The shock waves attenuate slowly in both straight and abruptly expanding roadways and more significantly in T-shaped roadways. The most significant attenuation appears in small angle corners and bifurcations in roadways with the largest attenuation occurring in blocked roadways. These results provide basic parameters for simplifying transport in complex roadway networks in the far-field, and guidance for the design of coal and gas outburst prevention facilities and emergency rescue.

Universality of capillary rising in corners

Abstract

Investigating microstructure and defects evolution in laser deposited single-walled Ti6Al4V structures with sharp and non-sharp features

The laser directed energy deposition (laser-DED) Additive Manufacturing (AM) has unique capability of being able to deposit functional geometries on existing components. Many times the required geometries contain sharp features such as abrupt turns. During deposition such features introduces heterogeneity in the build-part and adversely the structural integrity of the part. The slower deposition speeds due to the deceleration and acceleration of the motion controller around sharp features in a geometry leads to defects such as variable wall thickness, porosity, lack of fusion, and cracks. In many cases, the functional geometries are single-walled and there is not enough material volume to machine the deposited material. Such cases pose a unique challenge to the laser-DED techniques capabilities. In this work, single walled cubical Ti6Al4V structure with sharp and rounded corners were fabricated using laser Directed Energy Deposition (DED). Cross sectional and build plane coupons were extracted from each sample for microstructure and defect analysis. Results show that inclusion of small rounded corners (radii of 0.5 and1.0 mm) leads to consistent deposition speeds. Defect density measurements, using optical microscope, showed reduction of defects from 6.8 ± 0.35 % to a virtually defect-free structure for samples with the rounded corners. The results also indicated that consistent deposition speed around rounded corners improved homogeneity in the resulting microstructure as compared to the geometry with sharp corners when processed under identical parameters.

Comparison of Estimated-1RM and 225-lb (102-kg) bench press performance between starters and non-starters among a NCAA Division I college football team

The estimated one-repetition maximum (1RM) bench press and NFL-225 (225-lb or 102-kg) repetition test are commonly used to assess upper-body muscular strength and endurance among football players. However, little research has been focused on the relationship of these tests to playing status. Therefore, the purpose of this study was to determine if significant relationships exist between these tests and playing status in Division I football athletes. Archival data from 31 NCAA Division I football players (age: 20.1±1.4 yrs., height: 188.07 ± 5.93 cm, body mass: 112.4 ± 19.5 kg) on the 1RM Bench press test, NFL-225 test and playing status were utilized for this analysis. A one-way ANOVA was used to detect any differences in 1RM and NFL-225 performance between skill groups: big (linemen), medium (linebackers, quarterbacks, tight ends) and small (receivers, backs, and corners) (p < 0.05). Playing status (starters vs. non-starters) were compared within position groups. A point bi-serial correlation was then utilized to examine the relationship in test performance between groups, as well as between starters and non-starters. Significant differences were discovered in NFL-225 test performance between big and small skill groups. Moderate-to-strong relationships between playing status and performance on the 1RM bench press (r = .660) and the NFL-225 test (r = .685) for the big skills group. The results of this study suggest that playing status and upper-body strength and endurance are strongly related for the big skills position group.

Theoretical and experimental analysis of machining errors on small arced corners during WEDM finishing stages

Accurate machining in small-radius paths is a challenge associated with Wire Electrical Discharge Machining (WEDM). This article experimentally and theoretically analyzes the machining errors of the arced paths through successive machining stages. The machining errors of a three-stage WEDM on both straight and arced paths are first experimentally analyzed. Mathematical expressions are derived to relate new theoretical concepts, including spark angle and spark density, for each finishing stage on both straight and arced paths. Then, the effects of these concepts on machining errors of the finishing stages are determined. The causes of the machining errors of the first and second finishing stages on male and female arced paths are theoretically analyzed, and a novel mathematical methodology for the prediction of these errors is developed. The experimental machining errors of the first and second finishing stages on the different arced paths are compared and evaluated with related theoretical ones. Results reveal that the mathematical methodology predicts and compensates the machining errors of the first finishing stage with the accuracy of 78% and of the second finishing stage with the accuracy of 83%. There is a good improvement which can be employed in WEDM applications and to increase the wire electrical discharge (WED) machine capability.

Interest Point Detection by Limiting Form of Median Log Filter

Interest point detection has been widely used in image analysis applications. However, some interest points, including small structures and large angle corners, could not be effectively extracted. This paper proposes a limiting form of median Laplacian of Gaussian (LMLG) filter, which combines the superiority of the traditional Laplacian of Gaussian (LoG) filter and a limiting form of the weighted median LoG filter. A detector is also proposed based on the LMLG filter. The LMLG filter aims to improve the detection of LoG-based methods for interest points, especially small structures and large angle corners. Also, it could detect blobs, edges, and local structures. We conduct the repeatability and discrimination experiments on the Oxford dataset. Moreover, we conduct the recall rate experiment on the DTU dataset. The experiments show that the proposed method achieves comparable performance with state-of-the-art methods. In order to verify the utility of the LMLG detector, we carry out a series of interest point detector-based applications: face recognition, infrared-visible image registration, and image classification. The results demonstrate that the LMLG detector performs better than the nine detectors in face recognition. The LMLG detector outperforms the nine detectors and Hrkac’s, Han’s and Liu’s methods in infrared-visible image registration. Our method also gives a comparable result on image classification. The source code of the proposed LMLG detector is made publicly available at https://github.com/chenjzBUAA/LMLG-detector .