Cosine Law Research Articles

Single and Multiple Cell Upsets in 25-nm NAND Flash Memories

We analyzed floating-gate upsets in 25-nm multilevel cell NAND Flash memories irradiated with heavy ions, including alpha particles. Compared to multilevel cell memories of previous generations, these devices show no apparent error dependence on the program level, adherence to the cosine law, and a large number of multiple cell upsets (MCUs). Floating-gate errors were mapped to their physical location, and MCUs were studied as a function of their multiplicity, direction, particle linear energy transfer, irradiation angle, and program level.

Computing semantic relatedness using Wikipedia features

Measuring semantic relatedness is a critical task in many domains such as psychology, biology, linguistics, cognitive science and artificial intelligence. In this paper, we propose a novel system for computing semantic relatedness between words. Recent approaches have exploited Wikipedia as a huge semantic resource that showed good performances. Therefore, we utilized the Wikipedia features (articles, categories, Wikipedia category graph and redirection) in a system combining this Wikipedia semantic information in its different components. The approach is preceded by a pre-processing step to provide for each category pertaining to the Wikipedia category graph a semantic description vector including the weights of stems extracted from articles assigned to the target category. Next, for each candidate word, we collect its categories set using an algorithm for categories extraction from the Wikipedia category graph. Then, we compute the semantic relatedness degree using existing vector similarity metrics (Dice, Overlap and Cosine) and a new proposed metric that performed well as cosine formula. The basic system is followed by a set of modules in order to exploit Wikipedia features to quantify better as possible the semantic relatedness between words. We evaluate our measure based on two tasks: comparison with human judgments using five datasets and a specific application “solving choice problem”. Our result system shows a good performance and outperforms sometimes ESA (Explicit Semantic Analysis) and TSA (Temporal Semantic Analysis) approaches.

Research on Classification Algorithm of News Pages Based on Domain Ontology

This paper proposes the classification algorithm of news pages based on domain Ontology. In order to improve the shortage of current classification algorithm that only considers the content similarity, this paper presents the semantic classification method which considers both content similarity and structural correlation. Firstly, it parses the Ontology to get Ontology category vector, extracts keywords of news pages texts and drops semantic dimension. At this time, finding out the same vocabulary and ontology category vector in page texts to constitute the text expectation vector, and then calculating the content similarity between ontology category vector and expectation vector of text by using the law of cosines. Secondly, the common vocabularies are mapped to the ontology hierarchy chart, and the structural relevancy is obtained by calculating weighted path of this directed acyclic graph. Finally, it calculates the correlation degree of the news pages and Ontology by combining both, and determines the category of news pages by judging the size relationship between the result and the initial threshold value.

97.26 The cosine rule in three dimensions and de Gua's theorem

97.26 The cosine rule in three dimensions and de Gua's theorem

Scrape-off layer properties of ITER-like limiter start-up plasmas in JET

Recent experiments at JET combining reciprocating probe measurements upstream and infrared thermography at the plasma-facing components (PFC) on plasmas in limiter configurations show that the common approach to predicting the power load on the limiter underestimates the heat flux at the contact point by a factor 1.5–3. The current model and scaling laws used for predicting the power load onto the first wall during limiter current ramp-up/down in ITER are uncertain and a better understanding of the heat transport to the PFCs is required. The heat loads on PFCs are usually predicted by projecting the parallel heat flux associated with scrape-off layer (SOL) properties at the outer mid-plane (upstream) along the magnetic field lines to the limiter surface and deducing the surface heat flux through a cosine law, thus ignoring any local effect of the PFC on transport within the SOL. The underestimate of the heat flux is systematic in inner wall limiter configurations, independent of the plasma parameters, whereas in outer limiter configuration this is not observed, probably because of the much shorter SOL power decay length. Models that can explain this enhanced heat flux around the contact point are proposed and discussed although no definitive conclusion can be drawn.

Laser-scanning Doppler photoacoustic microscopy based on temporal correlation

We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow and repeatedly applied the law of cosines. To measure flow velocity along the ultrasonic detection axis, we calculated the time shift between two consecutive photoacoustic waves at the same scanning point, then converted the time shift to velocity according to the sound velocity and time interval between two laser illuminations. We verified our method by imaging flow phantoms.

Analysis of the Motor Vehicles Manufacturing Sector in Cataluña: Implementation with Radar Charts

The representation of the average periods of maturation in the axes of a radial chart allows us to know the financial position reached by companies at the end of an economic year or in a certain period. The angular indicators obtained from the application of the cosine and sine theorems, according to plane geometry principles verify the deduction obtained from the observation of the radial chart and establish whether the result of each management areas displayed offers liquidez to the developed trading activity, or it is the financial positions regardless trading activity the ones which verifies the displayed financial position in the radial chart. The indicated ratio explains why companies’ balances adopt a specific structure. The analysis of the industrial sector of Cataluna has been developed considering the group of the sector’s companies classified according to the nomenclature of economic activities of the European Union (NACE) 2009 and using SABI database information. At the end of the study of the sector, a comparative analysis of different companies is made, using as a contrast tool the radial charts for the years selected for this purpose.

DYNAMIC SYNTHESIS OF THE ROTARY CAM AND TRANSLATED TAPPET WITH ROLL

This paper presents an original method to determine the dynamic parameters at the camshaft (the distribution mechanisms). The authors introduce a new pressure angle, alpha, and a new method to determine the two pressure angles, alpha and delta, at the rotary cam and tappet with translational motion with roll, with a great precision. We determine initially the mass moment of inertia (mechanical) of the mechanism, reduced to the element of rotation, ie at cam (basically using kinetic energy conservation, the system 1). The rotary cam with translated follower with roll (Figure 1), is synthesized dynamic. We considered the law of motion of the tappet classic version already used the cosine law (both ascending and descending). The angular velocity is a function of the cam position (j) but also its rotation speed (2). Where ωm is the nominal angular velocity of cam and express at the distribution mechanisms based on the motor shaft speed (3). We start the simulation with a classical law of motion, namely the cosine law. To climb cosine law system is expressed by relations (4). With the relation (5) is expressed the first derivative of the reduced mechanical moment of inertia. It is necessary to determine the angular acceleration (6). Relations (2) and (6) a general nature and is basically two original equations of motion crucial for mechanical mechanisms. For a rotary cam and translated tappet with roll mechanism (without valve), dynamic movement tappet is expressed by equation (7). Where x is the dynamic movement of the pusher, while s is its normal, kinematics movement. K is the spring constant of the system, and k is the spring constant of the tappet spring. It note, with x0 the tappet spring preload, with mT the mass of the tappet, with ω the angular rotation speed of the cam (or camshaft), where s’ is the first derivative in function of j of the tappet movement, s. Differentiating twice successively, the expression (7) in the angle j, we obtain a reduced tappet speed (equation 8), and reduced tappet acceleration (9). Further the acceleration of the tappet can be determined directly real (dynamic) using the relation (10). For a good work one proposes to make a new geometro-kinematics synthesis of the cam profile, using some new relationships (16).

Spherical geometry and integrable systems

We prove that the cosine law for spherical triangles and spherical tetrahedra defines integrable systems, both in the sense of multidimensional consistency and in the sense of dynamical systems.

A web service matching algorithm based on semantic similarity

PurposeThe purpose of this paper is to obtain more accurate matching between the request and the release of web service.Design/methodology/approachThis paper adopts Levenshtein distance algorithm to calculate the name similarity between publishing service and request service, employs cosine theorem to compute the text similarity, and uses semantic distance to count the input‐output similarity, then filters out the low similarity and bad reputation services to structure the candidate service set.FindingsThe qualitative and quantitative analysis of the scheme is given in this paper. The experimental results show that the multi‐level matching filtering algorithm can obviously improve the recall ratio and precision ratio of web service discovery.Originality/valueThis paper proposes a similarity‐based filtering algorithm for multi‐level matching.

Friction Analysis on Vane of an Existing and of a Novel Multi Vane Rotary Compressor

This paper presents results of a frictional analysis on a new rotating sleeve multi-vane rotary (RSMVR) compressor. The new five-vane rotary compressor is adapted from the existing concept of a rotating sleeve single-vane rotary (RSSVR) compressor, in which the extended rounded end of one vane is embedded into the inner surface of the sleeve which allows the vane to swing within a certain small angle. As the rotor rotates, this vane drives the sleeve which in turn pushes and pulls the vane into and out of the slot in the rotor, respectively. The other four vanes are similarly pushed into the respective slots in the rotor but slide out only when a sufficient centrifugal force is developed. The driving vane ensures that suction, compression and discharge of the gas occur at all speeds of rotation. Although the sleeve rotates along, due to eccentricity between the rotor and the sleeve, each tip of the four vanes still rubs against the inner surface of the sleeve. The focus of the present study limits its analysis on to only frictions between the vane tip and the inner surface of the sleeve and between the vane sides and the respective slot walls. The frictional analysis is carried out by first determining the instantaneous pressure inside the compression cell and all the associated forces that exist. This involves an analysis on the dynamics of each vane when it reciprocates and at the same time rotates eccentrically with the sleeve. The kinematics of the vane are modelled using cosine and sine rules taking the cell leading vane as a reference to the angle of rotation. In the operation the model estimates a dramatic reduction in friction which is up to 82% lower than that occurs in an existing design of an equivalent conventional multi-vane rotary compressor (MVR). A friction between the rotating sleeve and the two opposite end plates exists in the RSMVR compressor but does not in that of the MVR. This will be included in a later study but on a new integrated brushless DC motor RSMVR compressor concept and on that of the existing shaft driven MVR, to see the overall difference in the frictions exerted.

Simulation of a nonstationary flow in a channel with a distributed blow from the channel walls and forced pressure oscillations

UDC 532.529 A nonstationary flow in a channel with a blow was simulated on the basis of the Reynolds-averaged Navier- Stokes equations and the two-parameter k-e model of turbulence. The pressure near the left end of the chan- nel changes by the harmonic law. It was established that the k-e model of turbulence can be used for calculating the nonstationary flows formed in the indicated channel by a blow. Introduction. The oscillations of the parameters of a working substance in the combustion chamber of a solid-propellant engine (SPE) represent a dangerous effect that can disturb the normal working conditions of the en- gine and, in some cases, cause its failure. These oscillations are due to the vibrating combustion or the hydrodynamic instability of the flow of the fuel combustion products. A model of a fluid flow in a channel with permeable walls can be used for simulation of a flow of combus- tion products in the channel of an SPE charge because this model reflects the significant process of transfer of a solid fuel from the burning surface of the charge. However, in the indicated model, the decomposition and combustion of the fuel in the thin near-surface layer of the charge are not taken into account. The inner flow of a working substance in the channel of an SPE is turbulent, and complex physical processes proceed in the working space of the SPE against the background of its general gasdynamic state. The turbulence of the gas flow in the indicated channel influences its characteristics and intensifies the heat transfer at the surfaces of the prenozzle space and the nozzle unit of the SPE. The nonstationarity of this gas flow can be caused, e.g., by a change in the rate of gas blow along the generatrix of the channel or by the forced oscillations of the pressure near the left (closed) end of the channel. A laminar flow of an incompressible viscous fluid in a straight round tube with a nonstationary blow was in- vestigated in (1, 2). The stationary solution of this problem obtained in (3) (the rate of blow along the generatrix of the cylinder was assumed to be constant) shows that the disturbances arising near the left closed end of the tube lead to the formation of a plane acoustic field in it. The interaction of this field with the fluid blown into the tube leads to the generation of a vortex along its side surface. Between the side surface of the tube and the line found at a distance of half the radius of the tube from its symmetry axis, there arise large radial gradients of the axial flow velocity (4). The nonstationary calculations carried out in (5) show that the vorticity of a flow of an incompressible vis- cous fluid in a tube is inversely proportional to the Mach number, which is in agreement with the theoretical data (3, 6) and the numerical calculations (7). The axial derivative of the radial flow velocity is of the order of O(M 3 ), which is smaller than the radial derivative of the axial flow velocity. For simplicity, in (5), the case of disturbance of the rate of a fluid flow by the cosine law was considered. It has been established that the distribution of the vorticity front and its form are determined by the diffusion processes in the radial direction and the convective transfer in the axial direction. The diffusion of the vorticity in the direction of the tube axis results in the velocity of movement of the vorticity front of the compressible fluid being increased as compared to that of a nonviscous flow. The movement of the vorticity front in the nonstationary flow of an incompressible viscous fluid in a plane channel with a closed left end at small Mach numbers was investigated in (8), where the parabolic formulation of the problem was used. External nonstationary disturbances with different wave numbers were imposed on the rate of the blow. In the case of nonstationary blow, at the wall of the channel there arise comparatively large velocity and tem-

Comparative Analysis of Enterprises of Covering Floors and Walls by Applying the Radar Charts Methodology

The radial chart is a graphic that shows the financial situation of different management areas displayed on it. So we can take decisions in order to get company goals and to measure their effects through the obtained indicators from the application of sine and cosine theorem. The effects are multidirectional, so it is possible to see how the decision taken by a management area affects the display on the radial chart. At same time, the financial structure is linked to geometric figures obtained when the maturation average periods are measured on a radial axis.

Discussion Measurement Models and Algorithms of the Wind Vector Field Based on Satellite Images

This article aims to discuss the strike two-dimensional wind vector on geostationary satellite imageries. The magnitude and direction of the wind vector are decided by the moving speed of the clouds. First, based on the features of the cloud map, we extract the characteristics of clouds and establish matching model for the clouds image. Maximum correlation coefficient between the target modules and tracking module is obtained by using infrared brightness temperature cross-correlation coefficient method. Then, the beginning and end of the wind vector can be ascertained. Using the spherical triangles of the law of cosines, we determine the magnitude and direction of the wind vector.

An orientation method and analysis of optical radiation sources based on polyhedron and parallel incident light

The spatial orientation of optical radiation sources has long been the hot topic in the aerospace and the military applications. Current researches mainly focus on the high precision orientation on the partial field of view. Thus, combination of several partial fields of view is required to achieve orientation when the field of view exceeds 180°, which results in the increase of size, weight, power consumption and the cost. By defining radiation energy and direction of the optical radiation source as a vector and applying the cosine law of radiation and vector theorem, it is shown that the vector can be obtained from unit normal vectors on the three un-coplanar surfaces and from the energy projected by the optical radiation source. Based on this, an orientation method with 360° full field of view by a polyhedron is suggested, the mathematical formula for anti-multipath interference is supposed and the error upper limit is derived. The feasibility and effectiveness of this method are validated by measurements and simulation. An accuracy better than 2.866° and 0.574° is achieved when the ratio of measurement error of energy on arbitrary surface and the true value are 5% and 1%, respectively, given the matrix composed of unit normal vectors on three measurement surfaces is orthogonal.

Analysis and Development of Walking Algorithm Kinematic Model for 5-Degree of Freedom Bipedal Robot

A design of walking diagram and the calculation of a bipedal robot have been developed. The bipedal robot was designed and constructed with several kinds of servo bracket for the legs, two feet and a hip. Each of the bipedal robot leg was 5-degrees of freedom, three pitches (hip joint, knee joint and ankle joint) and two rolls (hip joint and ankle joint). The walking algorithm of this bipedal robot was based on the triangle formulation of cosine law to get the angle value at each joint. The hip height, height of the swinging leg and the step distance are derived based on linear equation. This paper discussed the kinematic model analysis and the development of the walking diagram of the bipedal robot. Kinematics equations were derived, the joint angles were simulated and coded into Arduino board to be executed to the robot.

Non-linear Petrov–Galerkin methods for reduced order modelling of the Navier–Stokes equations using a mixed finite element pair

A new nonlinear Petrov–Galerkin approach has been developed for proper orthogonal decomposition (POD) reduced order modelling (ROM) of the Navier–Stokes equations. The new method is based on the use of the cosine rule between the advection direction in Cartesian space–time and the direction of the gradient of the solution. A finite element pair, P1DGP2, which has good balance preserving properties is used here, consisting of a mix of discontinuous (for velocity components) and continuous (for pressure) basis functions. The contribution of the present paper lies in applying this new non-linear Petrov–Galerkin method to the reduced order Navier–Stokes equations, and thus improving the stability of ROM results without tuning parameters. The results of numerical tests are presented for a wind driven 2D gyre and the flow past a cylinder, which are simulated using the unstructured mesh finite element CFD model in order to illustrate the numerical performance of the method. The numerical results obtained show that the newly proposed POD Petrov–Galerkin method can provide more accurate and stable results than the POD Bubnov–Galerkin method.

Non-linear Petrov–Galerkin methods for reduced order hyperbolic equations and discontinuous finite element methods

A new Petrov–Galerkin approach for dealing with sharp or abrupt field changes in discontinuous Galerkin (DG) reduced order modelling (ROM) is outlined in this paper. This method presents a natural and easy way to introduce a diffusion term into ROM without tuning/optimising and provides appropriate modelling and stablisation for the numerical solution of high order nonlinear PDEs. The approach is based on the use of the cosine rule between the advection direction in Cartesian space–time and the direction of the gradient of the solution. The stabilization of the proper orthogonal decomposition (POD) model using the new Petrov–Galerkin approach is demonstrated in 1D and 2D advection and 1D shock wave cases. Error estimation is carried out for evaluating the accuracy of the Petrov–Galerkin POD model. Numerical results show the new nonlinear Petrov–Galerkin method is a promising approach for stablisation of reduced order modelling.

AVOCADO: A numerical code to calculate gas pressure distribution

A code for efficient and accurate gas pressure calculation named AVOCADO is described in this paper. The non-collisional gas flow is resolved at steady-state considering only the solid boundaries of the domain (gas–wall interaction), where the gas pressure is defined. The mutual interactions between elements of the three-dimensional discretized surfaces are evaluated in terms of fluxes considering the cosine law as scattering operator. A coefficient matrix, which describes the geometry of the model, is parallel computed using view factors; correction factors accounting for gas species and specified boundary conditions are then applied, before the degree of freedom inversion is carried out. The developed tool includes also an efficient BiCGstab (biconjugate gradient stabilized method) implementation for sparse matrix inversion, to solve the system of equations. This surface finite element method reduces the degrees of freedom of the linear system and allows for fast solution of gas pressure distributions in both well-detailed and complex geometries. Overall results and pressure distribution obtained with the application of the code on typical analytical cases are presented and discussed.

Hardness of hexagonal tungsten carbide crystals as a function of orientation

A new depth-sensing microhardness mapping system has been used to measure the variation in microhardness with applied load and orientation of WC crystals. The orientations of the individual crystals were measured using an electron backscatter diffraction (EBSD) technique. The WC crystals were ∼100μm in size, embedded in a copper alloy matrix, to enable arrays of multiple microhardness indents to be implanted in each grain, thus generating good statistical validity for the results. It was found that the most significant effect on microhardness was the angle between the plane of measurement and either the basal or prism planes. A simple cosine rule, in line with resolved shear stresses, was used to correlate the data. The results are compared with previous studies using Knoop, Vickers and Berkovitch indenters, and some discussion is included of observed deformation around indentations using electron imaging associated with the EBSD technique.