XP Values Research Articles

Wide variations in Medieval French unambiguous V2 configurations are due to register

Abstract Quantitative studies of V2 in Medieval French have produced diverging results with respect to the rate of use of V2 and the informational value of the initial XP. These divergences are hypothesized to relate to the register of investigated texts. The hypothesis is verified by the systematic analysis of unambiguous V2 (with an expressed post-verbal subject) with respect to rates of use and informational value of XPs in three register-differentiated Anglo-Norman prose legal texts from the 1260–1300 period. On rates, unambiguous V2 is three times more frequent in the most formal, legal treatise text than it is in the less formal, court dialogues. On informational value, indications are provided that the XP tends to have a Focus value more often in more formal texts. Register thus impacts the behavior of unambiguous V2 configurations in Medieval French; using data less remote from the primary competence of speakers helps in approaching the effective curve of change.

Earth rotation parameter estimation from LLR

Lunar Laser Ranging (LLR) measures the distance between observatories on Earth and retro-reflectors on Moon since 1969. In this paper, we estimate the Earth Rotation Parameters (ERP; terrestrial pole offsets, xp and yp, and Earth rotation phase, ΔUT1) using LLR data. We estimate the values of ΔUT1, and the pole offsets separately for nights selected from subsets of the LLR time series which have a minimum of 5, 10, and 15 normal points obtained per night. For the pole offsets, we estimate the values of xp and yp simultaneously as well as separately. Overall, the uncertainties of ERP from the new LLR data (after 2000.0) have significantly improved compared to ERP from LLR data reported previously by Biskupek (2015) and Hofmann et al. (2018). The Weighted Root Mean Square (WRMS) value (after 2000.0) of the uncertainty for estimation of ΔUT1 lies between 17.03 μs and 24.49 μs for different subsets of nights. The WRMS values (after 2000.0) of the uncertainty for estimation of the terrestrial pole coordinates (estimated separately) for different subsets of nights lie between 1.30 mas and 3.46 mas for xp and between 1.63 mas and 4.21 mas for yp. The WRMS of differences between the estimated ΔUT1 values from LLR analysis and those from the a-priori ERP series lie between 59.38 μs and 115.35 μs for a subset of NPs from all LLR observatories post 2000.0. For xp, the differences are between 1.18 mas and 2.18 mas, and for yp, the differences are between 1.01 mas and 1.76 mas (xp and yp estimated separately). The differences of the obtained ERP from LLR analysis to the a-priori ERP series (for all subsets) become smaller with a stricter selection criteria (i.e. more number of NPs per night). Additionally, we see that the simultaneous estimation of the terrestrial pole offsets leads to high correlations between the estimated values of xp and yp of the same night. Furthermore, we estimate that the addition of non-tidal loading improves the uncertainties (3σ values) of the estimated ERPs by about 1%.

Compact FIN defected ground structure for improved cross polarisation in array antenna

ABSTRACT In this article, a 2 × 2 microstrip array antenna integrated with FIN defected ground structure (DGS) is investigated, which is designed for 3.24 GHz band operation. The FIN-DGS has been etched from the ground plane in the H-plane direction between two contiguous elements in a symmetric manner. Therefore, it suppresses the cross-polarisation (XP) radiation in the antenna without affecting its co-polarisation (CP) radiation characteristics. A proposed antenna has been designed and experimentally verified and shows <35 dB XP (±50º) radiation around boresight of the radiating elements in the H-plane with 10.7 dBi gain. The variation of XP fields has been investigated using the modal field distribution. The designed antenna provides a wide range of applications in adaptive arrays and space antennas, where 3D coverage with decreased XP values is the primary constraint.

Suppression of Cross-Polarized Fields of Microstrip Patch Across All Skewed and Orthogonal Radiation Planes

This letter explores a novel technique to minimize cross-polarized (XP) fields of a microstrip patch across all radiation planes. This inherent issue is more challenging to mitigate over the skewed, i.e., around the diagonal plane of radiation. A possible way to address this specific challenge by controlling the ground plane (GP) current has been discussed. Strategic but simple engineering has been demonstrated with a representative S-band rectangular patch. It shows the possibility of removing as much as 45% metal from the GP cladding, maintaining its impedance and the primary radiations unaltered. The targeted reduction in XP fields has been experimentally demonstrated by a maximum of 10 dB over the diagonal planes and 13 dB in H-plane. This approach should find potential applications in adaptive arrays and space antennas where three-dimensional (3-D) coverage with reduced XP values is an important requirement.

Enabling and Limiting factors in eXtreme Programming (XP) with Evaluation Framework

As agile software development methodologies are used in many domains and come with different shapes and sizes, it is one of the complex human endeavors. Extreme Programming (XP) is one of the well-known agile software development methodologies and is driven by a set of values including simplicity, communication, feedback and courage, but lacks the mechanism to measure these values demanding the evaluation framework to make it measurable and attainable. The main aim of this study is to build the software process improvement model that can be used for evaluating XP values and practices. The proposed XP evaluation framework in this study is XP focused and evaluates the XP project, product and practices. The XP evaluation framework is a collection of some new and validated metrics used for evaluating XP projects, XP practices, XP products and some additional factors concerned with XP. The evaluation framework for extreme programming is basically based on the assessment and evaluation of various project characteristics, extreme programming characteristics, product characteristics and other additional characteristics. The metrics used for assessments and evaluations of XP are designed to be simple, precise, understandable, economical, timely, consistent, accountable, unambiguous, suitable and reliable.

Choosing Automated or Manual Testing in Extreme Programming with the Analytical Hierarchy Process

Extreme Programming (XP) has been called one of the most successful methods in software development. XP comprises a set of practices designed to work together to provide value to the customer. During the XP lifecycle, developers and customers regularly encounter situations in which they need to make decisions or evaluate factors. This affects the development process and team productivity. We propose to use the Analytic Hierarchy Process (AHP) as a means to systematize and streamline the decision process. AHP eliminates conflict because it elaborates input from every member of the team. Thus, the adoption of AHP can help accomplish XP values and fulfill team needs. This paper presents an example of applying the AHP to decide which testing technique to adopt depending on a series of project-specific parameters.

Calculation model of coal comminution energy consumption

Experiments on comminution energy of different coals under conditions for CFB (circulating fluidized bed) boilers were carried out in a jaw crusher and a parallel roller crusher. The R–R (Rosin–Rammler) distribution was used to describe the size distribution of the crushing product. The size distribution of the product has a significant influence on comminution energy. With lower values of xP=63.2% (size modulus) or α (distribution modulus), the comminution energy increases. With a fixed particle size distribution of the product, the comminution energy increases gradually with the increasing of feed coal size, while, when the feed coal size is larger than 15mm, the effect can be neglected. With a fixed outlet width of the crusher, the average product size tends to be finer when smaller sized particles or coal with higher HGI (Hardgrove grindability index) are fed into the crusher. Therefore, in coal preparation process, the adjustment of the crusher should be performed considering coal grindability or crushability and the feed coal size distribution. At last, an empirical model of comminution energy was proposed and validated by the measured values with ±25% of accuracy.

Perturbation Technique to Improve Purity of Modal Fields in Dielectric Resonator Antenna Resulting in Reduced Cross-Polarized Radiation

Metallic perturbation in a body of a dielectric resonator antenna (DRA) has been explored with a view to improve the purity of modal fields leading to considerable reduction in unwanted cross-polarized (XP) radiations. A coax-fed cylindrical DRA (CDRA) has been examined with a pair of horizontally oriented metal pins protruded symmetrically face to face through it. The concept behind the design has been discussed and established using simulated results followed by a series of experimental verifications. As much as 10 dB reduction in principal plane XP values without affecting the primary radiation has been demonstrated. Purity in the modal fields is accounted for in terms of achieved isolation between co- and cross-polarized radiations, which attains 25–40 dB over 100° beamwidth.

Improved Cross-Polarization Characteristics of Circular Microstrip Antenna Employing Arc-Shaped Defected Ground Structure (DGS)

Application of defected ground structure (DGS) to suppress cross-polarized (XP) radiation from a microstrip patch antenna has been reinvestigated using a new DGS geometry for much improved characteristics. Arc-shaped defect has been used in pair, symmetrically located under a circular patch. A number of optimization parameters have been examined using simulated results, leading to a design indicating improved XP behavior. A set of identical prototypes, with and without DGS, have been experimentally studied. The presence of the DGS shows as much as 30 dB isolation of the XP level from its peak radiation, and that compared to an identical patch without DGS indicates an improvement by as much as 12 dB. The relative suppression in XP values are found to be around 7-12 dB over ±75° elevation around the boresight of the patch.

The influence of organizational culture on the adoption of extreme programming

The adoption of extreme programming (XP) method requires a very peculiar cultural context in software development companies. However, stakeholders do not always consider this matter and tend to stand to technical requirements of the method. Hence this paper aims at identifying aspects of organizational culture that may influence favorably or unfavorably the use of XP. In order to identify those aspects, this study analyzes dimensions of organizational culture under the perspective of practices and values of XP. This paper is based on the review of the literature of the area and empirical observations carried out with six software companies. This study does not intend to develop a tool for measurement of XP’s compatibility with the organizational culture of each company. It intends to provide parameters (favorable and unfavorable aspects) for previous consideration of the convenience of XP implementation.

Respiratory Syncytial Virus Detection by Remel Xpect, Binax Now RSV, Direct Immunofluorescent Staining, and Tissue Culture

The performance characteristics of Xpect RSV (XP) and Binax Now RSV (BN) were compared to those of direct fluorescent-antibody staining and/or tissue culture for detection of respiratory syncytial virus (RSV) in nasopharyngeal aspirate and wash samples from children (n = 110) and adults (n = 66). The sensitivity, specificity, positive predictive value, and negative predictive value of XP were 75%, 98%, 95%, and 90%, respectively; and those of BN were 74%, 100%, 100%, and 90%, respectively. The performances of the assays were similar within a given age group and specimen type (nasopharyngeal aspirate or wash specimen). XP and BN are useful for screening for RSV in respiratory specimens when large volumes are tested or low levels of staffing occur.

Do bimanual isometric push efforts in humans stop as a consequence of postural muscle exhaustion?

The purpose of this study was to explore whether global efforts stop as a consequence of postural muscle exhaustion. To this end, seated adults were asked to exert 75% maximal voluntary contractions bimanual push efforts until exhaustion. A dynamometer was used to measure the horizontal force exerted on a bar (Fx) and a custom-designed force plate measured the antero-posterior displacement of the centre of pressure (Xp). Electromyograms were picked up by bipolar surface electrodes from the primum movens (serratus anterior) and four postural muscles (trapezius superior, erectores spinae, rectus abdominis, rectus femoris). Root mean square and mean power frequency were calculated over 2-s intervals and compared to corresponding Fx and Xp values. It was shown that the effort stops as a consequence of exhaustion of postural muscles (rectus abdominis and rectus femoris), and not of the primum movens. It is concluded that postural muscles make a major contribution to global efforts, in that they allow compliance to biomechanical requirements, that is, to preserve the distance between the centre of pressure and the centre of gravity, which must be proportional to the external force.

Shift in the magnetic percolation threshold of phase separated Co-rich CoAg very thin films due to reduced dimensionality

An investigation of the structural and magnetic properties of phase separated Co-rich CoAg very thin films (5 nm–50 nm) as a function of film thickness and Co concentration is presented. In the as-deposited state the films are very fine grained and the coercive field is relatively low (Hc&amp;lt;20 Oe). However, after annealing at 420 °C for half an hour in high vacuum, grain growth is promoted and a drastic change in the magnetic properties is observed. The coercivity now has a strong thickness dependence with a maximum at approximately 15 nm. The largest room temperature value of coercivity, Hc=850 Oe, was found for a CoAg 70:30 volume percent alloy. The concentration of maximum coercivity is usually associated with the percolation threshold, xp, of the ferromagnetic element and is much higher than the ∼50 vol % value normally observed in thick film and bulk granular ferromagnets. Values of xp≲0.65 were found for 30 nm thick films increasing up to xp∼0.75 for 10 nm films. This behavior is explained as a shift in the percolation limit to higher values associated with the reduced dimensionality of very thin films. This shift implies that the volume fraction of the ferromagnetic component should be larger than its bulk counterpart if granular ferromagnets are to be used as thin film media for magnetic recording. The temperature dependence of Hc was also studied and coercivities exceeding 1800 Oe have been found at 50 K. The presence of a thin antiferromagnetic oxide layer is manifested as a shift in the low temperature hysteresis loops due to the anisotropic exchange coupling interaction with ferromagnetic Co.

97/01611 Coal hydrogenation catalysis using industrial catalyst (MoO3-NiO/Al2O3) ‘waste’

Experiments on comminution energy of different coals under conditions for CFB (circulating fluidized bed) boilers were carried out in a jaw crusher and a parallel roller crusher. The R–R (Rosin–Rammler) distribution was used to describe the size distribution of the crushing product. The size distribution of the product has a significant influence on comminution energy. With lower values of xP=63.2% (size modulus) or α (distribution modulus), the comminution energy increases. With a fixed particle size distribution of the product, the comminution energy increases gradually with the increasing of feed coal size, while, when the feed coal size is larger than 15 mm, the effect can be neglected. With a fixed outlet width of the crusher, the average product size tends to be finer when smaller sized particles or coal with higher HGI (Hardgrove grindability index) are fed into the crusher. Therefore, in coal preparation process, the adjustment of the crusher should be performed considering coal grindability or crushability and the feed coal size distribution. At last, an empirical model of comminution energy was proposed and validated by the measured values with ±25% of accuracy.

The dynamics of plume‐ridge interaction: 2. Off‐ridge plumes

A variety of geophysical and geochemical evidence indicates that ascending mantle plumes can interact with ocean ridges located up to 1400 km away. I investigate the dynamics of this interaction using a simple model in which a point source with volume flux Q (analogous to a plume “stem”) releases buoyant fluid into a viscous corner flow driven by the divergence of rigid surface plates with thickness ∼(kx/U)1/2, where U is the half spreading rate. The point source is located at a distance xp from the ridge, and ridge migration is neglected. The buoyant fluid forms a thin sublithospheric layer whose thickness S(x, y) satisfies a nonlinear advection‐diffusion equation describing the balance of advection by the corner flow, buoyancy‐driven “self‐spreading,” flow toward the ridge along the sloping base of the lithosphere, and continuous accretion into the lithosphere. Numerical solutions of this equation yield scaling laws for the lateral extent W (“waist width”) of plume material along the ridge, the fraction R of the plume flux that crosses the ridge, and the maximum value of xp beyond which interaction ceases. The sloping base of the lithosphere has only a minor (few tens of percent) influence on these quantities, which are determined principally by the balance of advection and self‐spreading. An extension of the model to include plume‐induced lithospheric thinning shows that this process increases the waist width by an amount of order 10%. Finally, the model provides a new explanation for the observation that plumes interact primarily with ridges that are migrating away from them, rather than toward them.

The prompt-shock supernova mechanism. I - The effect of the free-proton mass fraction and the neutrino transport algorithm

view Abstract Citations (91) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Prompt-Shock Supernova Mechanism. I. The Effect of the Free-Proton Mass Fraction and the Neutrino Transport Algorithm Bruenn, Stephen W. Abstract Results are presented of an extensive numerical investigation of the prompt-shock supernova mechanism. This paper focuses on the effect of the free-proton mass fraction Xp given by the equation of state (EOS) and of the various levels of standard neutrino physics on the success of the bounce shock in producing a supernova-like explosion in a prompt manner. When neutrino-electron scattering (NES) is turned off and only e-type neutrinos are transported, vigorous explosions are produced for a wide range of values for Xp. The inclusion of NES considerably restricts the possible values of Xp for successful explosions. The additional inclusion of all neutrino flavors further restricts the possible values of Xp. Successful shocks can still be produced (depending on how the shock energy is defined), but only for very small values of Xp. Publication: The Astrophysical Journal Pub Date: May 1989 DOI: 10.1086/167450 Bibcode: 1989ApJ...340..955B Keywords: Neutrinos; Nuclear Astrophysics; Shock Wave Propagation; Supernovae; Astronomical Models; Electron Scattering; Equations Of State; Transport Theory; Astrophysics; NEUTRINOS; SHOCK WAVES; STARS: INDIVIDUAL ALPHANUMERIC: SN 1987A; STARS: INTERIORS; STARS: SUPERNOVAE full text sources ADS | data products SIMBAD (1) Related Materials (1) Part 2: 1989ApJ...341..385B

Two-fluid Euler theory of sound dispersion in gas mixtures of disparate masses

The suitability of an Euler-level two-fluid theory to describe the behaviour of gas mixtures with disparate masses is explored for the problem of sound propagation at frequencies high enough that dispersion effects are important. The determination of the speed of propagation is reduced to solving a quadratic equation in the complex plane. The model leads to small errors of the order of the molecular mass ratio M when the molar fraction xp of the heavy gas is small (xp = O(M)), becoming increasingly inaccurate at larger values of xp. Yet agreement with He-Xe experiments is excellent for the whole range of frequencies tested, up to values of xp = 0.4. For values of xp above 0.5 our quantitative results become poorer but they still agree qualitatively with experiments, predicting small and negative dispersion coefficients and the presence of a bifurcation at critical values of the frequency and the composition. It is concluded that this generalized Euler theory provides an excellent framework within which to develop a two-fluid boundary-layer description of the peculiar dynamics of disparate-mass mixtures in the region of parameters of greatest industrial interest.

Adsorption of phosphate ion by hydroxyapatite in water.

The amount of phosphate ion, xp, adsorbed by synthetic hydroxyapatite (HAP) was measured under various conditions in water. A long time was required to reach adsorption equilibrium, and the adsorption process was largely irreversible with respect to concentration. The adsorption isotherm was not of Langmuir type, but was dominated by the ionic product of adsorbate, depending on the species of counter ion. The value of xp decreased with pH due to mutual electrostatic repulsion between adsorbed phosphate ions, which are deprotonated, and due to competitive adsorption between phosphate ion and OH-ion. The adsorption process was also found to be endothermic, because the adsorption increased with temperature. The adsorbate ion and adsorbent surface may be dehydrated when they are bound together. From all these results, it was concluded that the adsorbate phosphate ion is oriented and coordinated to calcium ion on the surface of HAP, and this is the reason why the adsorption of phosphate ion is irreversible.

Range and standard deviation of ion-implanted Si in GaAs

Carrier-concentration profiles of Si in semi-insulating GaAs have been obtained by C-V measurement techniques. Si+ or Si++ ions were implanted at energies ranging from 50 to 600 keV, and annealing was carried out with Si3N4 encapsulants. Range parameters such as the projected range Xp and the projected standard deviation ΔXp were experimentally determined by use of depths at the peak carrier concentration and at the 1/√e value of the peak carrier concentration of the profiles. It was found that ΔXp was strongly dependent on the Cr contents of substrates while Xp was not. The measured carrier concentrations could be approximated by the Gaussian distribution, and values of Xp were in good agreement with the theoretical value of the projected range Rp. However, ΔXp tended to saturate as the incident energies increased and deviated from the theoretical value of the projected standard deviation ΔRp.

Interpolation with the Aid of a Plot of First Differences

Given the values of y−1, y0, y1, and y2 corresponding to x−1, x0, x1, and x2, we first plot Δy/Δx, the ratio of first difference to abscissa interval, as a function of mean abscissa x̄, and then draw a smooth curve through the graph points which gives the values of a function S(x̄). To determine the value of yp for any value of xp between x0 and x1, we substitute values of S(x̄′) and S(x̄″), obtained from the curve, in the following equations: y′=y0+fΔx·S(x̄′); y″=y1−(1−f)Δx·S(x̄″);yp=y′+(y″−y′)(1+f)/3; where x̄′=12(x0+xp); x̄″=12(x1+xp) and f=(xp−x0)/Δx. With a carefully drawn smooth curve, the error in the result is only about one-sixth of the fourth difference term in the Newton-Bessel interpolation formula. In a simpler variation of the method, the function L(x̄), whose values are given by straight lines connecting the graph points, is substituted for S(x̄) in the equations; however, the accuracy of the result is only about one-sixth. It is shown that the accuracy obtainable in any case can be estimated from the sagittas σ1 and σ0 for x̄ equal to x1 and x0, respectively, where σ1 = L(x̄1) − S(x̄1) and σ0 = L(x̄0) − S(x̄0), since the error is proportional to (y″ − y′) times (σ1 − σ0) / (σ1 + σ0). This is true for unequal datum point intervals as well as for equal intervals. When the sagittas are equal or approximately so, the results may be as accurate if the rectilinear variation is used. Taking advantage of this fact, a diagram is given which enables the logarithm of any number to be determined to eight places by substituting values of L(x̄), obtained by linear interpolation between given figures, in certain equations. The method has been found useful when a number of interpolations are required in a single set of data. An important advantage is that it can be used as easily when the abscissa intervals between datum points are unequal as when they are equal.