Lee, H.; Haimson, B.
2007-12-01
drillhole wall conditions is drastically different from that conventionally expected, but is compatible with breakout formation mechanism in granite (Haimson, Int. J. Rock Mech., 2007). All the 'unjacketed' true triaxial strength data can be fitted by a simple function in the octahedral shear stress versus octahedral normal stress domain, yielding a Nadai-type true triaxial strength criterion. The criterion can be used in conjunction with breakouts that have been located within the cored zone to yield the maximum horizontal in situ stress σH when the other two principal stress are known. Assuming that the state of stress at breakout-drillhole intersections (located for example by BHTV logging) is sufficient to bring about brittle failure (Vernik and Zoback, 1992), one can substitute the known principal stresses there (obtained from the Kirsch solution) for the corresponding values in the criterion. The in situ σv is given by the overburden density, σh is typically obtained from hydrofrac shut-in pressures, breakout width is extracted from BHTV logs, borehole fluid pressure is a function of its density, and the Poisson's ratio is obtained from mechanical lab testing. The only unknown, σH, is thus readily computed. An actual computation was not carried out because data on hydrofrac pressures and breakout dimensions were not available at the time of this submission.
Malinverno, A.; Saito, S.; Vannucchi, P.
2016-01-01
The Costa Rica Seismogenesis Project (CRISP) drilled the Pacific margin of the Middle America Trench just north of where the Cocos Ridge enters the subduction zone, resulting in basal erosion of the upper plate. Here we report the orientations of the maximum horizontal principal stress (SHmax) from borehole breakouts detected by logging-while-drilling and wireline downhole measurements. All SHmax directions were estimated in the sediment cover of the margin, above the deeper rocks of the deformed margin wedge. We observe three overall SHmax orientations: NNE-SSW (25° azimuth) in the deepest interval drilled at the upper slope Site U1379; ENE-WSW (82°) in the rest of Site U1379 and in Site U1413, also drilled in the upper slope; and NNW-SSE (157°) in the mid-slope Site U1378. Our preferred interpretation is that the deepest interval of Site U1379 records the stress conditions in the underlying margin wedge, as SHmax is parallel to the direction of the Cocos-Caribbean plate convergence and of the compressional axes of plate boundary fault earthquakes. The variable SHmax directions observed elsewhere are likely due to the effect of a network of normal faults that subdivide the sediment cover into a number of independently deforming blocks. In addition, the observed SHmax directions may be influenced by the subducting Cocos Ridge, which acts as an indenter causing oblique deformation, and by the transition to seismogenic subduction along the plate boundary fault.
S. Pascale
2012-01-01
Full Text Available The objective of this paper is to reconsider the Maximum Entropy Production conjecture (MEP in the context of a very simple two-dimensional zonal-vertical climate model able to represent the total material entropy production due at the same time to both horizontal and vertical heat fluxes. MEP is applied first to a simple four-box model of climate which accounts for both horizontal and vertical material heat fluxes. It is shown that, under condition of fixed insolation, a MEP solution is found with reasonably realistic temperature and heat fluxes, thus generalising results from independent two-box horizontal or vertical models. It is also shown that the meridional and the vertical entropy production terms are independently involved in the maximisation and thus MEP can be applied to each subsystem with fixed boundary conditions. We then extend the four-box model by increasing its resolution, and compare it with GCM output. A MEP solution is found which is fairly realistic as far as the horizontal large scale organisation of the climate is concerned whereas the vertical structure looks to be unrealistic and presents seriously unstable features. This study suggest that the thermal meridional structure of the atmosphere is predicted fairly well by MEP once the insolation is given but the vertical structure of the atmosphere cannot be predicted satisfactorily by MEP unless constraints are imposed to represent the determination of longwave absorption by water vapour and clouds as a function of the state of the climate. Furthermore an order-of-magnitude estimate of contributions to the material entropy production due to horizontal and vertical processes within the climate system is provided by using two different methods. In both cases we found that approximately 40 mW m^{−2} K^{−1} of material entropy production is due to vertical heat transport and 5–7 mW m^{−2} K^{−1} to horizontal heat transport.
Kirkpatrick Mark
2005-01-01
Full Text Available Abstract Principal component analysis is a widely used 'dimension reduction' technique, albeit generally at a phenotypic level. It is shown that we can estimate genetic principal components directly through a simple reparameterisation of the usual linear, mixed model. This is applicable to any analysis fitting multiple, correlated genetic effects, whether effects for individual traits or sets of random regression coefficients to model trajectories. Depending on the magnitude of genetic correlation, a subset of the principal component generally suffices to capture the bulk of genetic variation. Corresponding estimates of genetic covariance matrices are more parsimonious, have reduced rank and are smoothed, with the number of parameters required to model the dispersion structure reduced from k(k + 1/2 to m(2k - m + 1/2 for k effects and m principal components. Estimation of these parameters, the largest eigenvalues and pertaining eigenvectors of the genetic covariance matrix, via restricted maximum likelihood using derivatives of the likelihood, is described. It is shown that reduced rank estimation can reduce computational requirements of multivariate analyses substantially. An application to the analysis of eight traits recorded via live ultrasound scanning of beef cattle is given.
Kernel principal component and maximum autocorrelation factor analyses for change detection
Nielsen, Allan Aasbjerg; Canty, Morton John
2009-01-01
in Nevada acquired on successive passes of the Landsat-5 satellite in August-September 1991. The six-band images (the thermal band is omitted) with 1,000 by 1,000 28.5 m pixels were first processed with the iteratively re-weighted MAD (IR-MAD) algorithm in order to discriminate change. Then the MAD image......Principal component analysis (PCA) has often been used to detect change over time in remotely sensed images. A commonly used technique consists of finding the projections along the eigenvectors for data consisting of pair-wise (perhaps generalized) differences between corresponding spectral bands...... covering the same geographical region acquired at two different time points. In this paper kernel versions of the principal component and maximum autocorrelation factor (MAF) transformations are used to carry out the analysis. An example is based on bi-temporal Landsat-5 TM imagery over irrigation fields...
Kolodziejczyk, Nicolas; Hernandez, Olga; Boutin, Jacqueline; Reverdin, Gilles
2015-01-01
International audience; The horizontal thermohaline seasonal variability of the surface ocean is investigated in the subtropical North Atlantic Surface Salinity Maximum (SSSmax) region. Satellite sea surface temperature and salinity are used, along with high-resolution thermosalinograph data, and Argo interpolated products, to study the horizontal two-dimensional field of density and thermohaline variability. During late winter, compensated temperature and salinity gradients at large and meso...
Konstantinou, K. I.
2015-08-01
This study investigates the hazard posed by Volcanic Ballistic Projectiles (VBPs) to the Santorini islands considering eruption scenarios that include low (VEI = 2-3) and higher energy (VEI > 3) eruptions. A model that describes rapid decompression of pressurized magma below a caprock along with its fragmentation and acceleration of particles is utilized for estimating initial velocities during vulcanian-style eruptions. These initial velocities are inserted into the ballistic equations assuming that VBPs have a cube-like shape, are subjected to gravity/drag forces and are launched into a zone of reduced drag. Four different diameters of VBPs are considered (0.35 m, 1.0 m, 2.0 m, 3.0 m) and also different values of gas fractions and extent of the reduced drag zone are investigated. The results of these calculations show that an area of 1-2 km width along the western coast of Thera will be within the maximum range of VBPs, provided that the eruptive vent will develop either on Nea Kameni or between Nea Kameni and Thera. Initial velocities for higher energy eruptions are estimated by considering the conversion efficiency of thermal to kinetic energy. For the case of an eruption with VEI = 4 and a number of vents centered between Nea and Palea Kameni, calculations show that the coastal areas of Thera and Therasia are within the maximum horizontal range of VBPs with diameter larger than 0.35 m. As the exact position of the eruptive vent seems to be of crucial importance for determining the areas at risk, continuous seismic and geodetic monitoring of the caldera is needed in order to decipher its likely location.
Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Sawada, Shun; Suekuni, Hiroshi; Kido, Tomoyuki; Yokoi, Takahiro; Miyagawa, Masao; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon City, Ehime (Japan); Uetani, Teruyoshi; Inoue, Katsuji [Ehime University Graduate School of Medicine, Department of Cardiology, Pulmonology, Hypertension and Nephrology, Toon City, Ehime (Japan)
2017-04-15
To evaluate the feasibility of three-dimensional (3D) maximum principal strain (MP-strain) derived from cardiac computed tomography (CT) for detecting myocardial infarction (MI). Forty-three patients who underwent cardiac CT and magnetic resonance imaging (MRI) were retrospectively selected. Using the voxel tracking of motion coherence algorithm, the peak CT MP-strain was measured using the 16-segment model. With the trans-mural extent of late gadolinium enhancement (LGE) and the distance from MI, all segments were classified into four groups (infarcted, border, adjacent, and remote segments); infarcted and border segments were defined as MI with LGE positive. Diagnostic performance of MP-strain for detecting MI was compared with per cent systolic wall thickening (%SWT) assessed by MRI using receiver-operating characteristic curve analysis at a segment level. Of 672 segments excluding16 segments influenced by artefacts, 193 were diagnosed as MI. Sensitivity and specificity of peak MP-strain to identify MI were 81 % [95 % confidence interval (95 % CI): 74-88 %] and 86 % (81-92 %) compared with %SWT: 76 % (60-95 %) and 68 % (48-84 %), respectively. The area under the curve of peak MP-strain was superior to %SWT [0.90 (0.87-0.93) vs. 0.80 (0.76-0.83), p < 0.05]. CT MP-strain has a potential to provide incremental value to coronary CT angiography for detecting MI. (orig.)
ZHONG; Chunping
2005-01-01
［1］Wu, H., Bochner technique in differential geometry, Advance in Math. (in Chinese), 1981, 10(1): 57-76.［2］Morrow, J., Kodaira, K., Complex Manifolds, New York: Holt, Rinehart & Winston, 1971.［3］Abate, M., Aikou, T., Patrizio, G., Preface for Complex Finsler Geometry, Cont. Math., Vol. 196, Providence,RI: Amer. Math. Soc., 1996, 97-100.［4］Abate, M., Patrizio, G., Finsler Metrics-A global approach with applications to geometric function theory,Lecture Notes in Mathematics, Vol. 1591, Bedin: Springer-Verlag, 1994.［5］Antonelli, P. L., Lackey, B.(eds.), The Theory of Finslerian Laplacians and Applications, MAIA 459, Dordrecht:Kluwer Academic Publishers, 1998.［6］Bao, D., Lackey, B., A Hodge decomposition theorem for Finsler spaces, C. R. Acad. Sci. Paris, t. 323, Serie 1,1996, 51-56.［7］Munteanu, O., Weitzenbock formulas for horizontal and vertical Laplacians, Houston Journal of Mathematics,2003, 29(4): 889-900.［8］Faran, J. J., The equivalence problem for complex Finsler Hamiltonians, Cont. Math.,Vol. 196, Providence, RI:Amer. Math. Soc., 1996, 133-144.［9］Kobayashi, S., Complex Finsler vector bundles, Cont. Math., Vol. 196, Providence, RI: Amer. Math. Soc.,1996,145-153.［10］Aikou, T., On complex Finsler manifolds, Rep. Fac. Sci. Kagoshima Univ. (Math. Phys. & Chem.), 1991, 24:9-25.
Gu, Fei; Wu, Hao
2016-09-01
The specifications of state space model for some principal component-related models are described, including the independent-group common principal component (CPC) model, the dependent-group CPC model, and principal component-based multivariate analysis of variance. Some derivations are provided to show the equivalence of the state space approach and the existing Wishart-likelihood approach. For each model, a numeric example is used to illustrate the state space approach. In addition, a simulation study is conducted to evaluate the standard error estimates under the normality and nonnormality conditions. In order to cope with the nonnormality conditions, the robust standard errors are also computed. Finally, other possible applications of the state space approach are discussed at the end.
Faris, Allison T.; Seed, Raymond B.; Kayen, Robert E.; Wu, Jiaer
2006-01-01
During the 1906 San Francisco Earthquake, liquefaction-induced lateral spreading and resultant ground displacements damaged bridges, buried utilities, and lifelines, conventional structures, and other developed works. This paper presents an improved engineering tool for the prediction of maximum displacement due to liquefaction-induced lateral spreading. A semi-empirical approach is employed, combining mechanistic understanding and data from laboratory testing with data and lessons from full-scale earthquake field case histories. The principle of strain potential index, based primary on correlation of cyclic simple shear laboratory testing results with in-situ Standard Penetration Test (SPT) results, is used as an index to characterized the deformation potential of soils after they liquefy. A Bayesian probabilistic approach is adopted for development of the final predictive model, in order to take fullest advantage of the data available and to deal with the inherent uncertainties intrinstiic to the back-analyses of field case histories. A case history from the 1906 San Francisco Earthquake is utilized to demonstrate the ability of the resultant semi-empirical model to estimate maximum horizontal displacement due to liquefaction-induced lateral spreading.
Guimaraes, Flavio Borsato; Nasser, Ivana Costa [Wise Systems, Sao Paulo, SP (Brazil); Andrade, Danielle Bueno de; Machado, Renato Simoes; Morozowski Filho, Marciano [Empresa de Pesquisa Energetica (EPE), Rio de Janeiro, RJ (Brazil)
2010-07-01
Planning the future hydro capacity in Brazil includes considering power reinforcements in the peak hours due to the increasing numbers of run-of-river plants. It means that the Brazilian's reservoir profile has been changing over the years from five years regularization to monthly regularization. This article presents a deterministic methodology to evaluate the capacity reserve of the Brazilian power system. It is based on the 'capacity reserve margin' calculation done by a monthly comparison between peak availability and maximum peak load. This methodology was applied to the Decennial Energy Expansion Plan 2019 (PDE 2019) and its final results are shown here through Peak Balances considering different operation conditions and the whole inflows historical records. Additionally, it is presented a suggestion about the evolution of peak evaluation criteria to be applied to the Brazilian power system on its expansion planning. (author)
Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...
唐经文; 王林豪; 高诚; 梁鑫俐; 李佳
2009-01-01
对水平环缝内冷水自然对流换热性能进行了实验研究.水平环缝宽度为6～18 mm,外壁温度维持0℃,换热温差为2～24℃.结果表明,在实验范围内,内壁面的平均表面传热系数随环缝宽度的增大而增加;当温差小于4℃或大于8℃时,平均表面传热系数随温差的增大而增大,在4～8℃范围内,随温差的增大而减小.采用逐步线性回归方法,得到了内壁传热关联式.%This paper conducts the experimental study on the natural convection characteristics of cold water near the maximum density in horizontal annulus with the fixed inner radius r_i=14 mm and different width l = 6～18 mm. The temperature at outer wall is maintained at 0 ℃, and the temperature differences between the inner and outer walls range from 2 to 24 ℃. The results show that the heat transfer coefficient at inner wall increases with the increase of the annulus width. When the temperature difference is bellow 4 ℃ or above 8 ℃, the heat transfer coefficient increases with the increase of the temperature difference. When the temperature difference is between 4 ℃ and 8 ℃, it. decreases with the increase of the temperature difference. The formula of heat transfer at inner walls is obtained by using the method of linear regression.
Well Spacing for Horizontal Wells
C.D.S. Keuengoua
2011-06-01
Full Text Available In the developing phase of a hydrocarbon reservoir and planning for drilling the production wells, it is necessary to drill the wells in an appropriate spacing to achieve maximum economic revenues during the reservoir life span. Well spacing which is the real location and interrelationship between producing oil or gas wells in an oil field is an important parameter. It is determined for the maximum ultimate production of a given reservoir and should be taken in consideration during well planning to avoid drilling of unnecessary wells. This study presents the concept of drainage area on horizontal well and horizontal productivity indices with different equations and their applications. A user friendly Excel Spreadsheet program was developed to calculate the productivity values of horizontal wells using three major available productivity equations. Also, the developed spreadsheet program was used to evaluate the effect of well spacing on the productivities of horizontal wells using productivity index approach and drainage area concept. It also helps to review the comparison between vertical and horizontal wells spacing based on drainage area concept. This program was validated, and then was used to study the effect of horizontal well length on the ratio of horizontal well productivity to vertical well productivity. The results show that higher ratio of horizontal well productivity to vertical well productivity values are obtained with increase length of the horizontal well. It is a very useful tool for making decision about the application of well spacing for horizontal wells.
Zurcher, Ulrich
2005-04-01
We study the motion of object sliding on a rough incline plane. The coefficient of kinetic friction between the surface and the object is such that the magnitude of the gravitational force along the incline F is equal to the magnitude of the kinetic friction S. If the initial velocity of the object is along the incline, the object slides down the incline with constant velocity. We study the case when the object in launched in horizontal direction. We derive exact expressions for the terminal speed of the object and the maximum horizontal displacement of the object.
Oriented cluster perforating technology and its application in horizontal wells
Huabin Chen
2016-11-01
Full Text Available An oriented cluster perforating technology, which integrates both advantages of cluster and oriented perforating, will help solve a series of technical complexities in horizontal well drilling. For realizing its better application in oil and gas development, a series of technologies were developed including perforator self-weight eccentricity, matching of the electronic selective module codes with the surface program control, axial centralized contact signal transmission, and post-perforation intercluster sealing insulation. In this way, the following functions could be realized, such as cable-transmission horizontal well perforator self-weight orientation, dynamic signal transmission, reliable addressing & selective perforation and post-perforation intercluster sealing. The combined perforation and bridge plug or the multi-cluster perforation can be fulfilled in one trip of perforation string. As a result, the horizontal-well oriented cluster perforating technology based on cable conveying was developed. This technology was successfully applied in unconventional gas reservoir exploitation, such as shale gas and coalbed methane, with accurate orientation, reliable selective perforation and satisfactory inter-cluster sealing. The horizontal-well oriented cluster perforating technology benefits the orientation of horizontal well drilling with a definite target and direction, which provides a powerful support for the subsequent reservoir stimulation. It also promotes the fracturing fluid to sweep the principal pay zones to the maximum extent. Moreover, it is conductive to the formation of complex fracture networks in the reservoirs, making quality and efficient development of unconventional gas reservoirs possible.
Radim Uhlář
2009-09-01
Full Text Available BACKGROUND: There are several factors (the initial ski jumper's body position and its changes at the transition to the flight phase, the magnitude and the direction of the velocity vector of the jumper's center of mass, the magnitude of the aerodynamic drag and lift forces, etc., which determine the trajectory of the jumper ski system along with the total distance of the jump. OBJECTIVE: The objective of this paper is to bring out a method based on Pontryagin's maximum principle, which allows us to obtain a solution of the optimization problem for flight style control with three constrained control variables – the angle of attack (a, body ski angle (b, and ski opening angle (V. METHODS: The flight distance was used as the optimality criterion. The borrowed regression function was taken as the source of information about the dependence of the drag (D and lift (L area on control variables with tabulated regression coefficients. The trajectories of the reference and optimized jumps were compared with the K = 125 m jumping hill profile in Frenštát pod Radhoštěm (Czech Republic and the appropriate lengths of the jumps, aerodynamic drag and lift forces, magnitudes of the ski jumper system's center of mass velocity vector and it's vertical and horizontal components were evaluated. Admissible control variables were taken at each time from the bounded set to respect the realistic posture of the ski jumper system in flight. RESULTS: It was found that a ski jumper should, within the bounded set of admissible control variables, minimize the angles (a and (b, whereas angle (V should be maximized. The length increment due to optimization is 17%. CONCLUSIONS: For future work it is necessary to determine the dependence of the aerodynamic forces acting on the ski jumper system on the flight via regression analysis of the experimental data as well as the application of the control variables related to the ski jumper's mental and motor abilities. [V
Carlos Augusto de Miranda Gomide
2002-11-01
Full Text Available Buscando-se avaliar morfofisiologicamente a rebrota do capim-mombaça, quatro desfolhas foram impostas ao perfilho principal, sendo estudado o comportamento da planta em termos da taxa de expansão da área foliar, crescimento do sistema radicular, nível de carboidratos totais não estruturais (CTNE da raiz e do colmo, taxa de crescimento relativo (TCR, taxa de assimilação líquida (TAL e razão de área foliar (RAF às idades de 2, 5, 9 e 16 dias após as desfolhas, bem como da taxa fotossintética máxima às idades de 2, 6 e 13 dias das folhas remanescentes à desfolha. As desfolhas foram as seguintes: remoção de todas as lâminas foliares (desfolha total, a remoção da lâmina da folha adulta mais jovem (desfolha superior, a remoção das lâminas das duas folhas adultas mais velhas (desfolha inferior e controle (sem desfolha, juntamente com o corte dos demais perfilhos, realizado a 8 cm do solo. Foram observadas cinco repetições por tratamento, segundo o delineamento inteiramente casualizado. As folhas adultas não diferiram quanto às taxas fotossintéticas máximas, que exibiram aumento nos primeiros dias após a desfolha, e queda aos 13 dias. A desfolha reduziu os teores de CTNE da base do colmo, principalmente nas plantas sob desfolha total. Comprometimento do crescimento do sistema radicular e do teor de CTNE das raízes foi observado nas plantas sob desfolha total, que também tiveram sua TCR reduzida nos primeiros dias de rebrotação. Entretanto, o aumento na RAF possibilitou a estas plantas recuperação da TCR e alta taxa de expansão da área foliar, igualando a área foliar das demais plantas aos 16 dias de rebrota.An experiment was carried out to evaluate morphophysiological aspects of Mombaçagrass growth after defoliation. Defoliation treatments were performed when the number of green completely expanded leaves on main tiller had stabilized around 3. Four defoliation treatments were imposed to the main tiller: T1 - no
Kinkhabwala, Ali
2013-01-01
The most fundamental problem in statistics is the inference of an unknown probability distribution from a finite number of samples. For a specific observed data set, answers to the following questions would be desirable: (1) Estimation: Which candidate distribution provides the best fit to the observed data?, (2) Goodness-of-fit: How concordant is this distribution with the observed data?, and (3) Uncertainty: How concordant are other candidate distributions with the observed data? A simple unified approach for univariate data that addresses these traditionally distinct statistical notions is presented called "maximum fidelity". Maximum fidelity is a strict frequentist approach that is fundamentally based on model concordance with the observed data. The fidelity statistic is a general information measure based on the coordinate-independent cumulative distribution and critical yet previously neglected symmetry considerations. An approximation for the null distribution of the fidelity allows its direct conversi...
Rosid, M. S.; Siregar, H.
2017-07-01
Fault is an important parameter in both hydrocarbon and geothermal exploration. It could be able as a secondary permeability that controlee and improve fluid flow within a reservoir. Fault zone is usually related to high permeability zone as well as indicated by any high-density contrast. There is a relatively new HVDM method that could be applied to determine and indicate a subsurface normal or reverse fault. This study is comparing the method with the conventional ones, the FHD method. Both methods are principally working based on the existing of lateral density contrast of gravity data. The FHD value is obtained from root sum square of horizontal X first derivative and horizontal Y first derivative of gravity data, meanwhile the HVDM value is obtained by horizontal, vertical and diagonal coefficient root sum square of 2-Dimensional DWT. The comparison of both, FHD and HVDM, methods are applied toward synthetic model and real gravity data. Identification of fault structure on FHD and HVDM are shown by maximum value. Based on the result of synthetic model gravity data, the FHD could determine fault structure in a better way than HVDM whereas on gravity real data FHD and HVDM have a slightly similar response. As we do not have supported proven geology and geophysical data, the study could not verify and justify yet the real gravity data.
Gomide Carlos Augusto de Miranda
2002-01-01
Full Text Available Buscando-se avaliar morfofisiologicamente a rebrota do capim-mombaça, quatro desfolhas foram impostas ao perfilho principal, sendo estudado o comportamento da planta em termos da taxa de expansão da área foliar, crescimento do sistema radicular, nível de carboidratos totais não estruturais (CTNE da raiz e do colmo, taxa de crescimento relativo (TCR, taxa de assimilação líquida (TAL e razão de área foliar (RAF às idades de 2, 5, 9 e 16 dias após as desfolhas, bem como da taxa fotossintética máxima às idades de 2, 6 e 13 dias das folhas remanescentes à desfolha. As desfolhas foram as seguintes: remoção de todas as lâminas foliares (desfolha total, a remoção da lâmina da folha adulta mais jovem (desfolha superior, a remoção das lâminas das duas folhas adultas mais velhas (desfolha inferior e controle (sem desfolha, juntamente com o corte dos demais perfilhos, realizado a 8 cm do solo. Foram observadas cinco repetições por tratamento, segundo o delineamento inteiramente casualizado. As folhas adultas não diferiram quanto às taxas fotossintéticas máximas, que exibiram aumento nos primeiros dias após a desfolha, e queda aos 13 dias. A desfolha reduziu os teores de CTNE da base do colmo, principalmente nas plantas sob desfolha total. Comprometimento do crescimento do sistema radicular e do teor de CTNE das raízes foi observado nas plantas sob desfolha total, que também tiveram sua TCR reduzida nos primeiros dias de rebrotação. Entretanto, o aumento na RAF possibilitou a estas plantas recuperação da TCR e alta taxa de expansão da área foliar, igualando a área foliar das demais plantas aos 16 dias de rebrota.
Horizontally oriented plates in clouds
Bréon, François-Marie
2011-01-01
Horizontally oriented plates in clouds generate a sharp specular reflectance signal in the glint direction, often referred to as "subsun". This signal (amplitude and width) may be used to analyze the relative area fraction of oriented plates in the cloud top layer and their characteristic tilt angle to the horizontal. We make use of spaceborne measurements from the POLDER instrument to provide a statistical analysis of these parameters. More than half of the clouds show a detectable maximum reflectance in the glint direction, although this maximum may be rather faint. The typical effective fraction (area weighted) of oriented plates in clouds lies between 10-3 and 10-2. For those oriented plates, the characteristic tilt angle is less than 1 degree in most cases. These low fractions imply that the impact of oriented plates on the cloud albedo is insignificant. The largest proportion of clouds with horizontally oriented plates is found in the range 500-700 hPa, in agreement with typical in situ observation of p...
Horizontal drilling in Ontario
Sidey, P.; Precul, L. [Sproule Associates Ltd., Calgary, AB (Canada)
2002-07-01
A review of oil and gas production in Ontario was presented with particular reference to drilling activity between 1987 to mid 2002 when 1450 vertical wells were drilled, of which 1100 were for petroleum production and the remainder were for gas storage, observation wells, private gas wells and stratigraphic tests. Of the 1100 vertical wells drilled for petroleum production, 40 per cent became gas wells, 16 per cent became oil wells, 4 per cent became oil and gas wells, and 40 per cent were dry. During the same time period, 133 horizontal wells were also drilled, mostly for petroleum. The most active operator was Talisman Energy, which drilled 101 of the 133 horizontal wells. The remainder were drilled by 12 other companies. Of the horizontal wells, 64 per cent became oil wells, 19 per cent became gas wells, and 17 per cent were dry. This presentation included graphs depicting which oil and gas pools saw vertical or horizontal drilling during the designated time period, and explained how the wells were classified. Both horizontal and vertical well targets were illustrated. Particular reference was made to Talisman Energy's Lake Erie Drilling program which revealed that horizontal wells have an initial production rate that is 5 times that expected from vertical wells. The Hillman Pool case study revealed that the initial rate of the average horizontal well is less than half that of the average vertical well. Horizontal drilling in the Lake Erie Morpeth Gas pool has also been a commercial success. This paper demonstrates that operators have maintained Ontario's oil and gas production at high levels. In 1997 widespread horizontal drilling began taking place in Ontario, and since then, approximately 30 per cent of the wells drilled in the province have been horizontal. 16 figs.
InSAR derived horizontal subsidence gradient as a tool for hazard assessment in urban areas.
Cabral-Cano, E.; Dixon, T.; Diaz-Molina, O.
2007-05-01
Mexico City's subsidence has been recognized for over a century, after the first well battery was drilled to supply water to the rapidly growing city at the end of the XIX century. Consequences of the subsidence process are costly but the economic consequences of subsidence in urban areas is hard to assess due to the fact that their costs are generally factored into yearly maintenance budgets rather than accounting for them as a unique natural disaster. It has thus become increasingly important to assess the extent and magnitude of damage due to ground subsidence in the Mexico City metropolitan area. Periodic InSAR and GPS measurements including data from an 8 site permanent GPS network in Mexico City has enabled us to derive an integrated composite displacement map for Mexico City. This image was used to calculate the horizontal subsidence gradient for areas smaller than 100x100m throughout the city by computing the observed displacement difference divided by the respective pixel to pixel horizontal distance and comparing similarly calculated values from all adjacent pixels in order to select the maximum gradient. Both empiric and analytical approaches can been used to correlate the potential for surface faulting in high horizontal subsidence gradient zones and show that the principal factor for constraining these areas can be successfully determined using a combined Differential InSAR and GPS approach. We present surface faulting risk maps for several cities in central Mexico derived from the horizontal subsidence gradient approach as an example of this technique.
Ros Ferré, Rosa Maria
2009-01-01
El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical).
Bro, R.; Smilde, A.K.
2014-01-01
Principal component analysis is one of the most important and powerful methods in chemometrics as well as in a wealth of other areas. This paper provides a description of how to understand, use, and interpret principal component analysis. The paper focuses on the use of principal component analysis
Elementary School Principal Effectiveness.
Cross, Ray
A review of research linking elementary principal "antecedents" (defined as traits), behaviors, school conditions, and student outcomes furnishes few supportable generalizations. The studies relating principal antecedents with behavior and principal antecedents with organizational variables reveals that the trait theory of leadership has…
Horizontal Connection and Horizontal Mean Curvature in Carnot Groups
Kang Hai TAN; Xiao Ping YANG
2006-01-01
In this paper we give a geometric interpretation of the notion of the horizontal mean curvature which is introduced by Danielli-Garofalo-Nhieu and Pauls who recently introduced sub-Riemannian minimal surfaces in Carnot groups. This will be done by introducing a natural nonholonomic connection which is the restriction (projection) of the natural Riemannian connection on the horizontal bundle. For this nonholonomic connection and (intrinsic) regular hypersurfaces we introduce the notions of the horizontal second fundamental form and the horizontal shape operator. It turns out that the horizontal mean curvature is the trace of the horizontal shape operator.
Principal Ports and Facilities
California Department of Resources — The Principal Port file contains USACE port codes, geographic locations (longitude, latitude), names, and commodity tonnage summaries (total tons, domestic, foreign,...
Horizontally mounted solar collector
Black, D. H. (Inventor)
1979-01-01
Solar energy is collected by using a vertical deflector assembly, a stationary reflector and a horizontally mounted solar collector. The deflector assembly contains a plurality of vanes which change the direction of the solar energy to the vertical, while constantly keeping the same side of the deflector facing the sun. The vertical rays are then reflected off the stationary reflector and are then absorbed by the collector.
Murphy, Lee Ann
2006-01-01
Some principals have personalities that can drive teachers around the bend and back again. Sure, most are wonderful bosses who support teachers in any way, but woe betide teachers if they are unlucky enough to run across one of the six dreaded "problem principals" identified in this article. Teachers do not have to be held hostage by difficult…
Principal Preparation Programs
Butler, Kevin
2008-01-01
A school principal's job has never been tougher. The accountability movement--culminating with the federal No Child Left Behind law in 2001--has put pressure on principals to improve student performance, resulting in school leaders' transitioning from a more administrative role to becoming more heavily involved in assessment, instruction,…
Horizontal drilling activity in Manitoba
Fox, J.
1997-04-01
An update of horizontal well drilling in Manitoba was provided. Manitoba`s productive formations are: (1) the Bakken Formation, (2) the Lodgepole Formation, (3) the Mission Canyon Formation, (4) the Amaranth Formation, and (5) the Melita Formation. A total of 28 exploratory wells and 29 development wells, including 11 horizontal wells were drilled in 1996. The 11 horizontal wells accounted for 30 per cent of the drilling meterage. The leading drillers for horizontal wells in Manitoba are Tundra Oil and Gas, Chevron, Anderson and HCO. Production from horizontal wells in 1996 totaled 310 cubic meter per day. To date, no horizontal wells have been drilled in the Bakken Formation. The least successful horizontal well application has been in the Lodgepole Formation. A summary of horizontal well production was provided for each Formation. 4 tabs., 10 figs.
Principal noncommutative torus bundles
Echterhoff, Siegfried; Nest, Ryszard; Oyono-Oyono, Herve
2008-01-01
In this paper we study continuous bundles of C*-algebras which are non-commutative analogues of principal torus bundles. We show that all such bundles, although in general being very far away from being locally trivial bundles, are at least locally trivial with respect to a suitable bundle version...... of bivariant K-theory (denoted RKK-theory) due to Kasparov. Using earlier results of Echterhoff and Williams, we shall give a complete classification of principal non-commutative torus bundles up to equivariant Morita equivalence. We then study these bundles as topological fibrations (forgetting the group...... action) and give necessary and sufficient conditions for any non-commutative principal torus bundle being RKK-equivalent to a commutative one. As an application of our methods we shall also give a K-theoretic characterization of those principal torus-bundles with H-flux, as studied by Mathai...
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...
Evaluation of horizontal magnification on panoramic images
Maryam Raoof
2013-01-01
Full Text Available Aims: This study evaluated the horizontal magnification of images taken from adults and pediatrics with PM 2002 CC Planmeca analogue machine. Materials and Methods: A series of 120 panoramic radiographs were obtained of 60 adults and 60 pediatrics. For all patients, negative impressions were used to make positive casts of the teeth. A caliper was used to measure the maximum mesiodistal length of the buccal surface of all teeth except canines on both casts and radiographs. The horizontal magnification factor was calculated for incisor, premolar, and molar regions by dividing the values obtained from the casts by the values obtained from the radiographs. Statistical Analysis: Independent t-test and one-way analysis of variance (ANOVA were used. Results: The results indicated that with regard to adults, maxillary and mandibular incisor regions, unlike the other two sessions, didn′t show significant difference of the mean magnification of horizontal dimension (P = 0.5. In pediatrics, the comparison between mean magnification factors of all subgroups showed significant difference (P < 0.0001. Despite the adults′ radiographs, the results of pediatrics′ radiographs showed significantly higher magnification than the index listed by the manufacturer of the radiographic machine used. Conclusion: The present study results point to the fact that PM 2002 CC Proline panoramic machine makes possible precise measurements on radiographs of adults′ jaws in the horizontal dimension.
PRODUCTIVITY OF FRACTURED HORIZONTAL WELLS
Stjepan Antolović
2009-12-01
Full Text Available The interest and performance of horizontal drilling and completions has increased during the last two decades. Horizontal wells are advantageous compared to vertical wells in thin reservoirs, reservoirs with favorable vertical permeability and reservoirs with water and gas coning problems. In many reservoirs, the ratio of horizontal permeability to the vertical permeability is substantially larger than one and often is close to 10. Thus, these reservoirs are very good candidates for hydraulic fracturing. By hydraulic fracturing one or more fractures are created, which can be longitudinal or orthogonal. By that, flow is altered and it mostly conducts horizontally through reservoir toward horizontal wellbore. With this altered flow, fluid is produced faster, with less pressure loss by fluid unit of produced fluid. Some of the existing mathematical models to determine the productivity of multifractured horizontal wells are presented in this work (the paper is published in Croatian.
Hollar, Charlie
2004-01-01
They may never grace the pages of The Wall Street Journal or Fortune magazine, but they might possibly be the most important CEOs in our country. They are elementary school principals. Each of them typically serves the learning needs of 350-400 clients (students) while overseeing a multimillion-dollar facility staffed by 20-25 teachers and 10-15…
Strategic Principal Communication
Henry, Jake; Woody, Aaron
2013-01-01
As communities become increasingly diverse and criticism of traditional public schools intensifies, some states, such as North Carolina, have enacted legislation that encourages alternative forms of schooling. This condition has resulted in new challenges for principals to communicate broadly and often with stakeholders in an effort to build…
Challenges in reservoir engineering from prospects for horizontal wells
Fayers, F.J.; Arbabi, S.; Aziz, K. [Stanford Univ., CA (United States). Dept. of Petroleum Engineering
1995-01-01
In this review paper, a variety of reservoir applications are illustrated where horizontal wells can have advantages over the use of conventional vertical wells. It is stressed that one of the key advantages relates to the opportunities to optimize the orientation and position of horizontal wells with respect to the principal directions for the reservoir depositional environment, but this may interact with natural fracture or fault directions, and the principal stress direction if hydraulic fracturing is to be considered. Analytical methods for calculating critical coning rates in homogeneous reservoirs are reviewed, and shown to give a very large range of results for horizontal wells. The potential significance of two-phase pressure drop within the wellbore on GOR performance is discussed, and a range of uncertainty by a factor of six is indicated between the use of various correlations for calculating the well pressure drop. In the final section studies are summarized for a gas coning application using ECLIPSE, a commercial simulator. The simulation results indicated an apparently invariant behaviour on GOR history with respect to the effects of wellbore two-phase pressure drop when the horizontal well was produced at constant rate in a homogeneous reservoir. However, when the controlling conditions on the horizontal well were made more representative, and reservoir non-uniformity was introduced, it was then found that the two-phase pressure drop became very significant. Some areas for further research are indicated. (Author)
Current horizontal strain field in Chinese mainland derived from GPS data
杨国华; 李延兴; 韩月萍; 胡新康; 巩曰沐
2002-01-01
The current crustal horizontal strain field is given in the paper based on the horizontal movement rates obtained from about 400 GPS stations located in Chinese mainland and its surrounding areas. The results show: a) The horizontal strain in Chinese mainland is "strong in the west and weak in the east" and the shear strain is larger than the normal strain (absolute magnitude). The general strain magnitude is 10-8/a and in local regions is 10-7/a, but the strain distribution is not homogeneous; b) The regions with the most significant NS-trending strains are the Himalayas belt along the western segment of Chinese southern boundary, the segment of 36°N～42°N along the western boundary and the northern margin of Qaidam block; c) The EW-trending strain variation along the western margin is the maximum and it is characterized by the alternatively positive and negative variations from the west to the east; d) The regions with larger magnitudes of REN (NE-trending shear strain) and Rmax (maximum shear strain) are Himalayas belt, the segment of 36°N～42°N along the western boundary, the western part of Qaidam block, Sichuan-Yunnan (Chuan-Dian) rhombic block and the border area of Alxa, Qilian and Tarim blocks; e) The surrounding area of Qinghai-Xizang (Qingzang) block is mainly superfacial contraction and its interior is basically superfacial expansion. The area to its north is mainly superfacial contraction with the maximum magnitude along the western boundary and the minimum magnitude in the eastern part (except Yanshan tectonic zone); f) In the west of the western part, the principal compressive strain is in the SN direction and the principal tensile strain is in the EW direction, while in the eastern margin area of the western part, the principal compressive strain is proximate EW and the principal tensile strain is about SN. The principal strain direction of Chuan-Dian rhombic block has changed greatly. In the northern part, it is compression in the EW and
Phu, D. X.; Choi, S. B.; Lee, Y. S.; Han, M. S.
2014-10-01
This paper presents a new design of a magnetorheological fluid (MR) mount for vibration control considering both vertical forces and horizontal moments such as are met in various engine systems, including a medium high-speed engine of ship. The newly designed mount, called a MR brake mount, offers several salient benefits such as small size and relatively high load capacity compared with a conventional MR engine mount that can control vertical vibration only. The principal design parameters of the proposed mount are optimally determined to achieve maximum torque with geometric and spatial constraints. Subsequently, the proposed MR mount is designed and manufactured based on the optimized design parameters. It is shown from experimental testing that the proposed mount, which combines MR mount with MR brake, can produce the desired force and torque to reduce unwanted vibration of a medium high-speed engine system of ship subjected to both vertical and horizontal exciting motions. In addition, it is verified that there is no large difference between experiment results and simulation results that are obtained from an analytical model derived in this work.
Stable Principal Component Pursuit
Zhou, Zihan; Wright, John; Candes, Emmanuel; Ma, Yi
2010-01-01
In this paper, we study the problem of recovering a low-rank matrix (the principal components) from a high-dimensional data matrix despite both small entry-wise noise and gross sparse errors. Recently, it has been shown that a convex program, named Principal Component Pursuit (PCP), can recover the low-rank matrix when the data matrix is corrupted by gross sparse errors. We further prove that the solution to a related convex program (a relaxed PCP) gives an estimate of the low-rank matrix that is simultaneously stable to small entrywise noise and robust to gross sparse errors. More precisely, our result shows that the proposed convex program recovers the low-rank matrix even though a positive fraction of its entries are arbitrarily corrupted, with an error bound proportional to the noise level. We present simulation results to support our result and demonstrate that the new convex program accurately recovers the principal components (the low-rank matrix) under quite broad conditions. To our knowledge, this is...
Robust Principal Component Analysis?
Candes, Emmanuel J; Ma, Yi; Wright, John
2009-01-01
This paper is about a curious phenomenon. Suppose we have a data matrix, which is the superposition of a low-rank component and a sparse component. Can we recover each component individually? We prove that under some suitable assumptions, it is possible to recover both the low-rank and the sparse components exactly by solving a very convenient convex program called Principal Component Pursuit; among all feasible decompositions, simply minimize a weighted combination of the nuclear norm and of the L1 norm. This suggests the possibility of a principled approach to robust principal component analysis since our methodology and results assert that one can recover the principal components of a data matrix even though a positive fraction of its entries are arbitrarily corrupted. This extends to the situation where a fraction of the entries are missing as well. We discuss an algorithm for solving this optimization problem, and present applications in the area of video surveillance, where our methodology allows for th...
Transforming Principal Preparation. ERIC Digest.
Lashway, Larry
In the current climate of accountability, the responsibilities of principals have increased. The new role of principals requires new forms of training, and standards-based reform is generating major changes in principal-preparation programs. This digest examines some of those changes. First, it looks at the effectiveness of principal-preparation…
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.; Steenfelt, Agnete
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from an ordinary non-spatial factor analysis, and they are interpreted in a geological context. It is demonstrated that MAF analysis contrary to ordinary non-spatial factor analysis gives an objective discrimina...
Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation
R. Thane Papke
2015-05-01
Full Text Available The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.
Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation
Papke, R. Thane; Corral, Paulina; Ram-Mohan, Nikhil; de la Haba, Rafael R.; Sánchez-Porro, Cristina; Makkay, Andrea; Ventosa, Antonio
2015-01-01
The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria. PMID:25997110
Recursive principal components analysis.
Voegtlin, Thomas
2005-10-01
A recurrent linear network can be trained with Oja's constrained Hebbian learning rule. As a result, the network learns to represent the temporal context associated to its input sequence. The operation performed by the network is a generalization of Principal Components Analysis (PCA) to time-series, called Recursive PCA. The representations learned by the network are adapted to the temporal statistics of the input. Moreover, sequences stored in the network may be retrieved explicitly, in the reverse order of presentation, thus providing a straight-forward neural implementation of a logical stack.
Principal Contradictions and Changes
Wang Zaibang
2006-01-01
@@ The September 11 terrorist attacks are the most notable events that occurred since the end of the Cold War. It is not only a logical outcome of world development post Cold War but is also an important variable influencing world development. In order to evaluate the influence of the development of the international relations in these five years, the international background after the Cold War must be taken into consideration and the characteristics and changes of the three principal contradictions described below need to be understood.
Alexander V. Zubovich
2015-09-01
Full Text Available A new method is proposed to define piecewise continuous fields of velocity gradients of recent horizontal movements of the Earth’s crust from spatially discrete data on horizontal velocities of such movements. The method is designed to identify spatial inhomogeneities in the field of horizontal strain rates (e.g., zones of localized deformation and boundaries between areas with different strain rates in considerable detail. It is applied to determine the field of horizontal velocity gradient in the region of the Central Asian GPS network which covers vast territories of the Kyrgyz Tien-Shan and Pamirs mountain ranges, the T arim depression, and the Kazakh Shield (Fig. 1. Calculations are based on GPS survey data obtained at 308 sites from 1995 to 2006 (Fig. 4. The resolution of the proposed method is increased by using a triangulation grid which is much denser than a conventional one (Fig. 2 and 3. As a result, point x on the surface under study is covered by several triangles rather than one (Fig. 5. Strain characteristics at point x are calculated by weighted summation of corresponding characteristics in the cover triangles. Thus, for each point we estimate spin tensor W, which defines angular velocity ω, and components of horizontal strain rate tensor E. These components provide for direct calculation of orientation of principal axes and invariants of E, i.e. maximum stretching E1, maximum shortening E2, velocity divergence E=E1+E2, and maximum shear rates Γ=⎪E1−E2⎪/2 (Fig. 6 to 11. The calculated values are presented in maps which demonstrate that spatial distribution of such values is highly inhomogeneous. Regions with increased values of kinematic characteristics mentioned above stand out sharply against the background. At the same time, spatial distribution of the kinematical characteristics in the Tien Shan region is quite regular: zones of increased absolute values of E2 are mainly oriented in the ENE direction, while the NNW
Horizontal and Vertical Line Designs.
Johns, Pat
2003-01-01
Presents an art lesson in which students learn about the artist Piet Mondrian and create their own abstract artworks. Focuses on geometric shapes using horizontal and vertical lines. Includes background information about the artist. (CMK)
Experimental investigation of horizontal convection
Muñoz Córdoba, Lucía
2015-01-01
Fluid circulation driven by buoyancy forces due to a thermal gradient on a horizontal boundary, known as horizontal convection, is experimentally studied. For that purpose, a methacrylate box with inner dimensions 300x150x150 mm3 (LxWxH) whose bottom is composed by a heat exchanger and a printed circuit board is lled with water. The heat exchanger provides a uniform temperature boundary condition while the printed circuit board provides a boundary condition of uniform heat ...
[The evolution of principal drugs in prescription compatibility].
Yuan, Bing; Shi, Dong-ping
2009-01-01
The principal drugs of principal, adjuvant, auxiliary and conductant compatiblity in prescriptions recorded in the ancient literatures had different meaning and quantities. According to the current literatures, Zhuangzi Xu Wugui took the one can cure diseases as the principal drug; The principal, adjuvant, auxiliary and conductant drugs in Shennong Bencao Jing (Shennong's Classic of Materia Medica) can be used to differentiate the good and bad of drugs; Yaoxing Lun (Treatise on medicinal property) of Zheng quan (Tang dynasty) stipulated some drugs as principal drugs; Zazhu Bencao of Jiang Xiaowan (Tang dynasty) took the one can cure yin diseases as the principal drugs; Yixue Qiyuan (the origination of medicine) of Zhang Yuansu (Jin dynasty) took the one of maximum dosage as principal drugs; Piwei Lun (Treatise on Spleen and Stomach) of LI gao (Jin dynasty) took the powerful one as the principal drug; The principal drugs in Yi Lun (medicine treatise) of Wang Kentang (Ming dynasty) changed according to different ages. The quantities of principal drugs can had two and three ingredients even took one prescription as principal drug instead of one ingredient.
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...
The Skills of Exemplary Principals.
Walker, John E.
1990-01-01
NASSP's Assessment Center Project has identified 12 key skills for successful principals: problem analysis, judgment, organizational ability, decisiveness, leadership, sensitivity, stress tolerance, oral communication, written communication, wide-ranging interests, personal motivation, and educational values. Effective principals succeed by…
Horizontal fiscal imbalance in Germany
Paweł Kowalik
2015-04-01
Full Text Available Regional inequalities are currently a challenge for the majority of the countries, in particular the large ones. The problem of public income redistribution emerges due to possible differentiation of the economic development level of territorial units. The most often considered problem is the vertical distribution. The horizontal division of income is far less frequently considered. Horizontal fiscal imbalance or regional tax inequalities seem to be graver than the vertical imbalance, particularly in developing countries. The public finance system, in particular in federations, is often very complex. Public finance of federations and federated states are not often based on the same assumptions. This leads to differences among regions, both vertical and horizontal. The use of the presented measures helps identify those differences and permits developing mechanisms equalising those inequalities. It should be remembered that those measures may have certain drawbacks, and they mainly focus on certain specific values of income redistribution. Thereby several measures should be applied in measurements and the obtained results should be compared. There are no up-to-date measurements and comparisons of horizontal fiscal imbalance among countries.. The aim of this paper is to measure horizontal fiscal imbalance in Germany, especially after reunification, which represents one of two models of federalism. At the beginning it shows the static and dynamic measurements presented in the literature that can be used to measure the horizontal fiscal imbalance. And then it is followed by the results of calculations for Germany in the period 1970-2013. As expected, horizontal imbalance was much lower before than after the reunification of Germany. After the reunification there were large disparities between "old" and "new" länder. This imbalance is gradually reduced. In comparison with the results obtained for the USA [Kowalik 2014, pp. 144-148] it can be said
Hu, Xiexiaomen; Tutuncu, Azra; Eustes, Alfred; Augustine, Chad
2017-05-01
Enhanced Geothermal Systems (EGS) could potentially use technological advancements in coupled implementation of horizontal drilling and multistage hydraulic fracturing techniques in tight oil and shale gas reservoirs along with improvements in reservoir simulation techniques to design and create EGS reservoirs. In this study, a commercial hydraulic fracture simulation package, Mangrove by Schlumberger, was used in an EGS model with largely distributed pre-existing natural fractures to model fracture propagation during the creation of a complex fracture network. The main goal of this study is to investigate optimum treatment parameters in creating multiple large, planar fractures to hydraulically connect a horizontal injection well and a horizontal production well that are 10,000 ft. deep and spaced 500 ft. apart from each other. A matrix of simulations for this study was carried out to determine the influence of reservoir and treatment parameters on preventing (or aiding) the creation of large planar fractures. The reservoir parameters investigated during the matrix simulations include the in-situ stress state and properties of the natural fracture set such as the primary and secondary fracture orientation, average fracture length, and average fracture spacing. The treatment parameters investigated during the simulations were fluid viscosity, proppant concentration, pump rate, and pump volume. A final simulation with optimized design parameters was performed. The optimized design simulation indicated that high fluid viscosity, high proppant concentration, large pump volume and pump rate tend to minimize the complexity of the created fracture network. Additionally, a reservoir with 'friendly' formation characteristics such as large stress anisotropy, natural fractures set parallel to the maximum horizontal principal stress (SHmax), and large natural fracture spacing also promote the creation of large planar fractures while minimizing fracture complexity.
The strong maximum principle revisited
Pucci, Patrizia; Serrin, James
In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.
Maximum information photoelectron metrology
Hockett, P; Wollenhaupt, M; Baumert, T
2015-01-01
Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are a high-information, coherent observable. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, 3D, photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyse the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et. al., Phys. Rev. Lett. 112, 223001 (2014)] over the main spectral features, but also indicate unexpected symmetry-breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum information measurements of th...
Deformation quantization of principal bundles
Aschieri, Paolo
2016-01-01
We outline how Drinfeld twist deformation techniques can be applied to the deformation quantization of principal bundles into noncommutative principal bundles, and more in general to the deformation of Hopf-Galois extensions. First we twist deform the structure group in a quantum group, and this leads to a deformation of the fibers of the principal bundle. Next we twist deform a subgroup of the group of authomorphisms of the principal bundle, and this leads to a noncommutative base space. Considering both deformations we obtain noncommutative principal bundles with noncommutative fiber and base space as well.
Horizontal distribution of mixed cloud type scene
Guillaume, A.; Kahn, B. H.; Yue, Q.; Wong, S.; Manipon, G.; Hua, H.; Wilson, B. D.; Wang, T.; Fetzer, E. J.
2016-12-01
We describe a novel method to uniquely characterize and quantify the scale dependence of mixed cloud scene geometry using cloud type classification reported with the 94GHz CloudSat radar. Only a fraction of all possible combinations of cloud types are observed at any along-track length scale considered. Cloud scenes most frequently contain only one or two cloud types. We show how cloud occurrence depends on the grid cell spatial resolution used to define cloud scenes. A maximum number of observed cloud scenes occur near 100 km with fewer cloud type combinations at smaller and larger scales. We then quantify the cloud lengths along the CloudSat track using both the cloud top classification and the vertical structure of cloud classification separately for each of the nine cloud types defined by CloudSat and for all clouds considered independent of cloud type. While the individual cloud types do not follow a clear power law behavior as a function of horizontal or vertical scale, a robust power law scaling of cloud geometry is observed when cloud type is not considered. The power law scaling exponent of horizontal length is approximated by β ≈ -5/3 over two to three orders of magnitude. The power law scaling exponent of vertical length is approximated by β ≈ -7/3 over two orders of magnitude. These exponents are in agreement with previous studies using numerical models, satellite, and in situ aircraft observations. In particular, the anisotropy in the horizontal and vertical scaling are nearly identical to recent aircraft observations of wind kinetic energy spectra, suggesting the underlying three-dimensional cloud geometry is strongly related to kinetic energy spectra.
Ferrari, Jérôme
2015-01-01
Fasciné par la figure du physicien allemand Werner Heisenberg (1901-1976), fondateur de la mécanique quantique, inventeur du célèbre "principe d'incertitude" et Prix Nobel de physique en 1932, un jeune aspirant-philosophe désenchanté s'efforce, à l'aube du XXIe siècle, de considérer l'incomplétude de sa propre existence à l'aune des travaux et de la destinée de cet exceptionnel homme de sciences qui incarne pour lui la rencontre du langage scientifique et de la poésie, lesquels, chacun à leur manière, en ouvrant la voie au scandale de l'inédit, dessillent les yeux sur le monde pour en révéler la mystérieuse beauté que ne cessent de confisquer le matérialisme à l'œuvre dans l'Histoire des hommes.
DRILL BITS FOR HORIZONTAL WELLS
Paolo Macini
1996-12-01
Full Text Available This paper underlines the importance of the correct drill bit application in horizontal wells. Afler the analysis of the peculiarities of horizontal wells and drainholes drilling techniques, advantages and disadvantages of the application of both roller cone and fixed cutters drill bits have been discussed. Also, a review of the potential specific featuries useful for a correct drill bit selection in horizontal small diameter holes has been highlighted. Drill bits for these special applications, whose importance is quickly increasing nowadays, should be characterised by a design capable to deliver a good penetration rate low WOB, and, at the same time, be able to withstand high RPM without premature cutting structure failure and undergauge. Formation properties will also determine the cutting structure type and the eventual specific features for additional gauge and shoulder protection.
Problems That Principals Face In School Administration
Engin Aslanargun
2012-12-01
Full Text Available Transformation is the key concept in this century that should be taken into consideration in organization anyway. Educational organizations are also under the influence of such transformation as in the case for others, the role of administrators have taken more significance that leads them to apply emerging approaches in organizational life. The purpose of this study is to define the communicative problems that principals experience in school settings and possible problem solving behaviors towards teachers. 7 principals administering schools in the town of Akçakoca, in Düzce, included the study with qualitative case design and purposive, maximum sampling procedure. It was appeared that principals have displayed in some cases similar and different administrative behaviors while tackling with communicative and problem solving conditions. It was revealed that principals tend to do their jobs within limited scope and structure based administrative style instead of consideration as a result of this study. School climate that is essential for effective learning and teaching process have been asserted to be ignored or taken less significance behind the structural and material matters
Maximum Likelihood Associative Memories
Gripon, Vincent; Rabbat, Michael
2013-01-01
Associative memories are structures that store data in such a way that it can later be retrieved given only a part of its content -- a sort-of error/erasure-resilience property. They are used in applications ranging from caches and memory management in CPUs to database engines. In this work we study associative memories built on the maximum likelihood principle. We derive minimum residual error rates when the data stored comes from a uniform binary source. Second, we determine the minimum amo...
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and....../or having different derivative orders. Although the principle is applicable to a wide variety of image models, the main focus here is on the Brownian model and its use for scale selection in natural images. Furthermore, in the examples provided, the simplifying assumption is made that the behavior...... of the measurements is completely characterized by all moments up to second order....
Prediction of three dimensional maximum isometric neck strength.
Fice, Jason B; Siegmund, Gunter P; Blouin, Jean-Sébastien
2014-09-01
We measured maximum isometric neck strength under combinations of flexion/extension, lateral bending and axial rotation to determine whether neck strength in three dimensions (3D) can be predicted from principal axes strength. This would allow biomechanical modelers to validate their neck models across many directions using only principal axis strength data. Maximum isometric neck moments were measured in 9 male volunteers (29±9 years) for 17 directions. The 3D moments were normalized by the principal axis moments, and compared to unity for all directions tested. Finally, each subject's maximum principal axis moments were used to predict their resultant moment in the off-axis directions. Maximum moments were 30±6 N m in flexion, 32±9 N m in lateral bending, 51±11 N m in extension, and 13±5 N m in axial rotation. The normalized 3D moments were not significantly different from unity (95% confidence interval contained one), except for three directions that combined ipsilateral axial rotation and lateral bending; in these directions the normalized moments exceeded one. Predicted resultant moments compared well to the actual measured values (r2=0.88). Despite exceeding unity, the normalized moments were consistent across subjects to allow prediction of maximum 3D neck strength using principal axes neck strength.
Horizontal Diplopia Following Upper Blepharoplasty
Tomás Ortiz-Basso
2014-09-01
Full Text Available Diplopia is an infrequent complication after blepharoplasty. Most of the cases are in its vertical form due to trauma of the extraocular muscles. In this article, we present a case of horizontal diplopia following cosmetic upper blepharoplasty; we review the literature on this unexpected complication and offer some recommendations to avoid it.
F. TopsÃƒÂ¸e
2001-09-01
Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over
Regularized maximum correntropy machine
Wang, Jim Jing-Yan
2015-02-12
In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.
Principally Left Hereditary and Principally Left Strong Radicals
S. Tumurbat; R. Wiegandt
2001-01-01
A radical γ is normal if and only if γ is principally left hereditary and principally left strong (i.e., γ(L) = L e A and Lz ∈γ for all z ∈ L imply L γ(A)). Let a radical γ satisfy that A°∈γ and S° A° imply S°∈γ.Then γ is a hereditary normal radical if and only if γ is principally left strong and γ {A | (A, +,◇a) ∈γ a ∈ A}, where the multiplication ◇a is defined by x ◇a y ＝ xay. The Behrens radical class B is the largest principally left hereditary subclass of the Brown-McCoy radical class G. Neither3 nor G is principally left strong.
Film condensation of steam on externally finned horizontal tubes.
Flook, Frederick A.
1985-01-01
Approved for public release; distribution is unlimited Filmwise condensation measurements of steam were made on horizontal finned tubes under vacuum and near-atmospheric conditions. Data were obtained for copper tubes with fins of rectangular, triangular, trapezoidal, and parabolic cross sections, and for a commercially-available finned tube. A stainless steel finned tube was also tested to investigate the effect of thermal conductivity. Maximum enhancements of about 4.8 were obtained...
We Need Principals Who Understand.
Fineman, Sharon
1981-01-01
Describes the need for principals to have a greater understanding both of the needs of special education students and of effective ways of handling their problems. Special education survey courses and practical experiences for administrators might help close the gap between principals and special education teachers. (WD)
Time Management for New Principals
Ruder, Robert
2008-01-01
Becoming a principal is a milestone in an educator's professional life. The principalship is an opportunity to provide leadership that will afford students opportunities to thrive in a nurturing and supportive environment. Despite the continuously expanding demands of being a new principal, effective time management will enable an individual to be…
The Effective and Reflective Principal
Ritchie, John M.
2013-01-01
For a "Kappan" issue focusing on the job of the principal, this is an essay from a retired, longtime principal and superintendent. "I have notebooks full of advice that I've collected over the years: tips, mantras, cautions, and quotations appropriate for any occasion," the author says. "I learned to focus less on…
Burnout among Elementary School Principals
Combs, Julie; Edmonson, Stacey L.; Jackson, Sherion H.
2009-01-01
As the understanding of burnout continues to be refined, studies that examine school principals and burnout will be helpful to those who provide support to school leaders and are concerned about principal attrition and pending shortages. The purpose of this study was to examine the relationship between burnout and gender, age, and years experience…
What Principals Think Motivates Teachers
Diamantes, Thomas
2004-01-01
How did a graduate class of teachers and principals come to explore what was really important to teachers? They had an idea that they all shared the same values (both teachers and principals) and would agree on what rewards teachers prize. Would administrators rate the motivation rewards the same way the teachers would? To find out, five schools…
The Principal as Formative Coach
Nidus, Gabrielle; Sadder, Maya
2011-01-01
Formative coaching, an approach that uses student work as the foundation for mentoring and professional development, can help principals become more effective instructional leaders. In formative coaching, teaches and coaches analyze student work to determine next steps for instruction. This article shows how a principal can use the steps of the…
Principals and SRO's: Defining Roles.
Bond, Bill
2001-01-01
Many principals have recently acquired school resource officers, police officers who are stationed in schools and report to local sheriffs or police chiefs. Working effectively with a resource officer requires that principals and officers understand each other's role and express partnership details in a memorandum of understanding. (MLH)
The Principal as Adult Developer.
Levine, Sarah L.
1989-01-01
Restructuring of the principalship must include the principal's role as an adult developer aware of the inextricable link between teacher growth and student development. Principal and teacher should work together to learn how adults develop, to discover conditions fostering growth, and to encourage each other to face new challenges. (MLH)
Time Management for New Principals
Ruder, Robert
2008-01-01
Becoming a principal is a milestone in an educator's professional life. The principalship is an opportunity to provide leadership that will afford students opportunities to thrive in a nurturing and supportive environment. Despite the continuously expanding demands of being a new principal, effective time management will enable an individual to be…
Innovation Management Perceptions of Principals
Bakir, Asli Agiroglu
2016-01-01
This study is aimed to determine the perceptions of principals about innovation management and to investigate whether there is a significant difference in this perception according to various parameters. In the study, descriptive research model is used and universe is consisted from principals who participated in "Acquiring Formation Course…
Great Principals at Scale: Toolkit
Ikemoto, Gina; Taliaferro, Lori; Fenton, Benjamin; Davis, Jacquelyn
2014-01-01
School leaders are critical in the lives of students and to the development of their teachers. Unfortunately, in too many instances, principals are effective in spite of--rather than because of--district conditions. To truly improve student achievement for all students across the country, well-prepared principals need the tools, support, and…
Equalized near maximum likelihood detector
2012-01-01
This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.
Cheeseman, Peter; Stutz, John
2005-01-01
A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].
Partial Horizontal Laryngectomy and Epiglottiplasty
无
2006-01-01
In order to evaluate the availability of the lateral horizontal laryngectomy and anaplasty of epiglottis to treat somepatients with specific supraglottic carcinomas and hypopharyngeal carcinomas, 17 cases of laryngeal and hypopharyngeal carcinomas were retrospectively analyzed, whose tumors were located at the lateral margin of epiglottis, aryepiglottic fold, medial wall of piriformfossa and were treated by the lateral horizontal laryngectomy and anaplasty of epiglottis. The results showed that all cases took food by mouth in postoperative 9-14 days and subjected to decannulation in postoperative 9-15 days. Three cases had postoperative hoarse voice. The free-disease survival rate of 3 years was 71.4 % in 14 cases followed up after the first surgical therapy, and the overall free-disease survival rate of 3 years was 85.7 % after the second surgical therapy. It was concluded that the manipulations of the lateral horizontal laryngectomy and epiglottiplasty were simple. It could alleviate the postoperative symptoms of aspiration and bucking remarkably and shorten their postoperative recovery time, yet does not lower the survival rate of patients if laryngocarcinoma or hypopharyngeal carcinoma cases were properly selected.
Principal -bundles on Nodal Curves
Usha N Bhosle
2001-08-01
Let be a connected semisimple affine algebraic group defined over . We study the relation between stable, semistable -bundles on a nodal curve and representations of the fundamental group of . This study is done by extending the notion of (generalized) parabolic vector bundles to principal -bundles on the desingularization of and using the correspondence between them and principal -bundles on . We give an isomorphism of the stack of generalized parabolic bundles on with a quotient stack associated to loop groups. We show that if is simple and simply connected then the Picard group of the stack of principal -bundles on is isomorphic to ⊕ , being the number of components of .
Directional Amplification of Horizontal Motion at Rock Sites
Pischiutta, M.; Cianfarra, P.; Salvini, F.; Rovelli, A.
2016-12-01
Directional amplifications of horizontal ground motion along site-dependent azimuths are often unexpectedly found in rocky environments and in stiff-rock conditions. Directional amplification has been studied by several authors at sites with fractured rocks across fault damage zones (e.g. Pischiutta et al., 2013), or close to gravitational instabilities (e.g. Burjanek et al, 2012). In the majority of the cases, a transversal relation between the maximum amplification and the orientation of the predominant fracture field is recognized, interpreted as the effect of the stiffness anisotropy. Cracks in fault damage zones also cause the reduction of rock velocity (especially near-surface Vs). Studies performed on high number of rocky sites revealed that directional amplification effects are much more diffuse than expected. A systematic study involving 258 seismological stations of the Italian Seismic Network points out that 56 of stations (20%) are clearly affected by directional site amplification effects. This station sample was studied by analyzing the surface topography in order to unravel the role of topographic irregularities on ground motion amplifications. Models proposed in literature predict amplification at wavelengths comparable to the mountain width (e.g. Géli et al, 1988) and the scatter of wavefield that is polarized in the direction orthogonal to the relief elongation (e.g. Spudich et al., 1996). Since some bias exists in the objective quantification morphological parameters, we use an original methodology that combines morphometric analysis of digital elevation models and principal component analysis to define the dimension and elongation orientation of pronounced ridges. This study showed that the expected relations between the shape/dimension of relief and ground motion were found only at 5 stations (out of 56) , suggesting a major of local morphology, geological complexities and subsurface properties on directional amplification, consistently with
Principal metals online property data
Principal Metals is a leading supplier of specialty metals. This database contains complete materials property data on more than 5000 ferrous and non-ferrous materials (chemistry, mechanicals, general description, applications, welding, machining, an
Principal modes in fiber amplifiers
Fridman, Moti; Dubinskii, Mark; Friesem, Asher A; Davidson, Nir
2010-01-01
The dynamics of the state of polarization in single mode and multimode fiber amplifiers are presented. The experimental results reveal that although the state of polarizations at the output can vary over a large range when changing the temperatures of the fiber amplifiers, the variations are significantly reduced when resorting to the principal states of polarization in single mode fiber amplifiers and principal modes in multimode fiber amplifiers.
Principal Fibrations from Noncommutative Spheres
Landi, Giovanni; Suijlekom, Walter Van
2005-11-01
We construct noncommutative principal fibrations Sθ7→Sθ4 which are deformations of the classical SU(2) Hopf fibration over the four sphere. We realize the noncommutative vector bundles associated to the irreducible representations of SU(2) as modules of coequivariant maps and construct corresponding projections. The index of Dirac operators with coefficients in the associated bundles is computed with the Connes-Moscovici local index formula. "The algebra inclusion is an example of a not-trivial quantum principal bundle."
Early Career Principals: Working Productively with Difficult and Resistant Staff
Eller, John F.; Eller, Sheila A.
2012-01-01
Effective leaders must find ways to motivate their employees to provide maximum success for the organization. In today's world of high accountability, this ability is paramount to the success and survival of schools, and is an especially important skill for early career principals to master. Knowledge of the factors that might have contributed to…
Panspermia and horizontal gene transfer
Klyce, Brig
2009-08-01
Evidence that extremophiles are hardy and ubiquitous is helping to make panspermia a respectable theory. But even if life on Earth originally came from space, biologists assume that the subsequent evolution of life is still governed by the darwinian paradigm. In this review we show how panspermia could amend darwinism and point to a cosmic source for, not only extremophiles but, all of life. This version of panspermia can be called "strong panspermia." To support this theory we will discuss recent evidence pertaining to horizontal gene transfer, viruses, genes apparently older than the Earthly evolution of the features they encode, and primate-specific genes without identifiable precursors.
Horizontal gene transfer in chromalveolates
Bhattacharya Debashish
2007-09-01
Full Text Available Abstract Background Horizontal gene transfer (HGT, the non-genealogical transfer of genetic material between different organisms, is considered a potentially important mechanism of genome evolution in eukaryotes. Using phylogenomic analyses of expressed sequence tag (EST data generated from a clonal cell line of a free living dinoflagellate alga Karenia brevis, we investigated the impact of HGT on genome evolution in unicellular chromalveolate protists. Results We identified 16 proteins that have originated in chromalveolates through ancient HGTs before the divergence of the genera Karenia and Karlodinium and one protein that was derived through a more recent HGT. Detailed analysis of the phylogeny and distribution of identified proteins demonstrates that eight have resulted from independent HGTs in several eukaryotic lineages. Conclusion Recurring intra- and interdomain gene exchange provides an important source of genetic novelty not only in parasitic taxa as previously demonstrated but as we show here, also in free-living protists. Investigating the tempo and mode of evolution of horizontally transferred genes in protists will therefore advance our understanding of mechanisms of adaptation in eukaryotes.
Horizontal versus vertical plate motions
M. Cuffaro
2006-07-01
Full Text Available We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr than the vertical component (0.01–1 mm/yr in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate boundaries supports dominating tangential forces acting on plates. This suggests a passive role of plate boundaries with respect to far field forces determining the velocity of plates. The forces acting on the lithosphere can be subdivided in coupled and uncoupled, as a function of the shear at the lithosphere base. Higher the asthenosphere viscosity, more significant should be the coupled forces, i.e., the mantle drag and the trench suction. Lower the asthenosphere viscosity, more the effects of uncoupled forces might result determinant, i.e., the ridge push, the slab pull and the tidal drag. Although a combination of all forces acting on the lithosphere is likely, the decoupling between lithosphere and mantle suggests that a torque acts on the lithosphere independently of the mantle drag. Slab pull and ridge push are candidates for generating this torque, but, unlike these boundary forces, the advantage of the tidal drag is to be a volume force, acting simultaneously on the whole plates, and being the decoupling at the lithosphere base controlled by lateral variations in viscosity of the low-velocity layer.
Quasispecies theory for horizontal gene transfer and recombination
Muñoz, Enrique; Park, Jeong-Man; Deem, Michael W.
2008-12-01
We introduce a generalization of the parallel, or Crow-Kimura, and Eigen models of molecular evolution to represent the exchange of genetic information between individuals in a population. We study the effect of different schemes of genetic recombination on the steady-state mean fitness and distribution of individuals in the population, through an analytic field theoretic mapping. We investigate both horizontal gene transfer from a population and recombination between pairs of individuals. Somewhat surprisingly, these nonlinear generalizations of quasispecies theory to modern biology are analytically solvable. For two-parent recombination, we find two selected phases, one of which is spectrally rigid. We present exact analytical formulas for the equilibrium mean fitness of the population, in terms of a maximum principle, which are generally applicable to any permutation invariant replication rate function. For smooth fitness landscapes, we show that when positive epistatic interactions are present, recombination or horizontal gene transfer introduces a mild load against selection. Conversely, if the fitness landscape exhibits negative epistasis, horizontal gene transfer or recombination introduces an advantage by enhancing selection towards the fittest genotypes. These results prove that the mutational deterministic hypothesis holds for quasispecies models. For the discontinuous single sharp peak fitness landscape, we show that horizontal gene transfer has no effect on the fitness, while recombination decreases the fitness, for both the parallel and the Eigen models. We present numerical and analytical results as well as phase diagrams for the different cases.
Attracting Principals to the Superintendency
Aimee Howley
2002-10-01
Full Text Available Responding to a perceived shortage of school superintendents in Ohio as well as elsewhere in the nation, this study examined the conditions of the job that make it attractive or unattractive as a career move for principals. The researchers surveyed a random sample of Ohio principals, receiving usable responses from 508 of these administrators. Analysis of the data revealed that principals perceived the ability to make a difference and the extrinsic motivators (e.g., salary and benefits associated with the superintendency as conditions salient to the decision to pursue such a job. Furthermore, they viewed the difficulties associated with the superintendency as extremely important. Among these difficulties, the most troubling were: (1 increased burden of responsibility for local, state, and federal mandates; (2 need to be accountable for outcomes that are beyond an educator’s control; (3 low levels of board support, and (4 excessive pressure to perform. The researchers also explored the personal and contextual characteristics that predisposed principals to see certain conditions of the superintendency as particularly attractive or particularly troublesome. Only two such characteristics, however, proved to be predictive: (1 principals with fewer years of teaching experience were more likely than their more experienced counterparts to rate the difficulty of the job as important to the decision to pursue a position as superintendent, and (2 principals who held cosmopolitan commitments were more likely than those who did not hold such commitments to view the salary and benefits associated with the superintendency as important. Findings from the study provided some guidance to those policy makers who are looking for ways to make the superintendency more attractive as a career move for principals. In particular, the study suggested that policy makers should work to design incentives that address school leaders’ interest in making a difference at the
Principal Curves on Riemannian Manifolds.
Hauberg, Soren
2016-09-01
Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.
Horizontal gene transfer in silkworm, Bombyx mori
Li Bin
2011-05-01
Full Text Available Abstract Background The domesticated silkworm, Bombyx mori, is the model insect for the order Lepidoptera, has economically important values, and has gained some representative behavioral characteristics compared to its wild ancestor. The genome of B. mori has been fully sequenced while function analysis of BmChi-h and BmSuc1 genes revealed that horizontal gene transfer (HGT maybe bestow a clear selective advantage to B. mori. However, the role of HGT in the evolutionary history of B. mori is largely unexplored. In this study, we compare the whole genome of B. mori with those of 382 prokaryotic and eukaryotic species to investigate the potential HGTs. Results Ten candidate HGT events were defined in B. mori by comprehensive sequence analysis using Maximum Likelihood and Bayesian method combining with EST checking. Phylogenetic analysis of the candidate HGT genes suggested that one HGT was plant-to- B. mori transfer while nine were bacteria-to- B. mori transfer. Furthermore, functional analysis based on expression, coexpression and related literature searching revealed that several HGT candidate genes have added important characters, such as resistance to pathogen, to B. mori. Conclusions Results from this study clearly demonstrated that HGTs play an important role in the evolution of B. mori although the number of HGT events in B. mori is in general smaller than those of microbes and other insects. In particular, interdomain HGTs in B. mori may give rise to functional, persistent, and possibly evolutionarily significant new genes.
Principal Curves on Riemannian Manifolds
Hauberg, Søren
2015-01-01
Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only...... in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimize a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend...... from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls...
Explorando nuevos horizontes en NASA
Villanueva, G. L.
A pesar de la incesante expansión del Universo iniciada con el Big Bang 14 mil millones de años atrás, nuestro Universo se siente cada día más cercano. La inquebrantable vocación de la humanidad por descubrir nuevos horizontes ha permitido el acercamiento de civilizaciones en nuestro planeta y nos ha permitido conocer nuestro lugar en el Universo como nunca antes. En este artículo presento una breve sinopsis de nuestro trabajo que se relaciona con diversas investigaciones con implicaciones astrobiológicas, desde el origen de los ingredientes de la "sopa de la vida", hasta la evolución y composición de la atmósfera de Marte.
Uplift Pressure of Waves on A Horizontal Plate
周益人; 陈国平; 黄海龙; 王登婷
2003-01-01
Uplift pressures of waves acting on horizontal plates are the important basis for design of maritime hollow-trussed structures. In this paper, an experimental study on the uplift pressures of waves on a horizontal plate is conducted by use of a series of model tests. Detailed analysis has been given to the formation mechanism of uplift pressures of waves. It is considered that the impact pressure intensity is mainly affected by geometrical factors (tangential angle of waves), dynamic factors (wave height, wave velocity, etc.) and air cushion. Based on the test results, an equation for calculation of the maximum uplift pressure intensity of waves on a plate is presented. A large quantity of test data shows good agreement of the present equation with the test results.
Principal bundles the classical case
Sontz, Stephen Bruce
2015-01-01
This introductory graduate level text provides a relatively quick path to a special topic in classical differential geometry: principal bundles. While the topic of principal bundles in differential geometry has become classic, even standard, material in the modern graduate mathematics curriculum, the unique approach taken in this text presents the material in a way that is intuitive for both students of mathematics and of physics. The goal of this book is to present important, modern geometric ideas in a form readily accessible to students and researchers in both the physics and mathematics communities, providing each with an understanding and appreciation of the language and ideas of the other.
Surface analysis the principal techniques
Vickerman, John C
2009-01-01
This completely updated and revised second edition of Surface Analysis: The Principal Techniques, deals with the characterisation and understanding of the outer layers of substrates, how they react, look and function which are all of interest to surface scientists. Within this comprehensive text, experts in each analysis area introduce the theory and practice of the principal techniques that have shown themselves to be effective in both basic research and in applied surface analysis. Examples of analysis are provided to facilitate the understanding of this topic and to show readers how they c
Integrating Data Transformation in Principal Components Analysis
Maadooliat, Mehdi
2015-01-02
Principal component analysis (PCA) is a popular dimension reduction method to reduce the complexity and obtain the informative aspects of high-dimensional datasets. When the data distribution is skewed, data transformation is commonly used prior to applying PCA. Such transformation is usually obtained from previous studies, prior knowledge, or trial-and-error. In this work, we develop a model-based method that integrates data transformation in PCA and finds an appropriate data transformation using the maximum profile likelihood. Extensions of the method to handle functional data and missing values are also developed. Several numerical algorithms are provided for efficient computation. The proposed method is illustrated using simulated and real-world data examples.
DOES THE VARIATION OF THE SOLAR INTRA-NETWORK HORIZONTAL FIELD FOLLOW THE SUNSPOT CYCLE?
Jin, C. L.; Wang, J. X., E-mail: cljin@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
2015-07-01
The ubiquitousness of the solar inter-network horizontal magnetic field has been revealed by space-borne observations with high spatial resolution and polarization sensitivity. However, no consensus has been achieved on the origin of the horizontal field among solar physicists. For a better understanding, in this study, we analyze the cyclic variation of the inter-network horizontal field by using the spectro-polarimeter observations provided by the Solar Optical Telescope on board Hinode, covering the interval from 2008 April to 2015 February. The method of wavelength integration is adopted to achieve a high signal-to-noise ratio. It is found that from 2008 to 2015 the inter-network horizontal field does not vary when solar activity increases, and the average flux density of the inter-network horizontal field is 87 ± 1 G, In addition, the imbalance between horizontal and vertical fields also keeps invariant within the scope of deviation, i.e., 8.7 ± 0.5, from the solar minimum to maximum of solar cycle 24. This result confirms that the inter-network horizontal field is independent of the sunspot cycle. The revelation favors the idea that a local dynamo is creating and maintaining the solar inter-network horizontal field.
Optimization of horizontal well staggered patterns
Zhao Chunsen; Li Peijing; Guan Dan; Liu Qingjuan
2008-01-01
Staggered line-drive patterns are widely used in oilfields. In this paper, to optimize a staggered pattern of horizontal wells, a 3D problem was divided into two 2D (x-y plane and y-z plane) problems with the pseudo-3D method, conformal transformation and superposition principle. A productivity equation for a horizontal well was deduced, which can be used to optimize the well pattern. A relationship between the length of horizontal wells and the shape factor of well patterns was established. The result shows that optimized well patterns can improve oil production from horizontal wells. This provides a theoretical basis for horizontal well applications to the development of oilfieids, especially for overall development of oilfields by horizontal wells.
School Uniforms: Guidelines for Principals.
Essex, Nathan L.
2001-01-01
Principals desiring to develop a school-uniform policy should involve parents, teachers, community leaders, and student representatives; beware restrictions on religious and political expression; provide flexibility and assistance for low-income families; implement a pilot program; align the policy with school-safety issues; and consider legal…
How Principals Support Teacher Effectiveness
Gallagher, Michael
2012-01-01
The current standards and accountability regime describes effective teaching as the ability to increase student achievement on standardized tests. This narrow definition of effectiveness can lead principals to create school cultures myopically focused on student achievement data. A "laser-like focus on academic achievement," if employed too…
Widespread horizontal transfer of retrotransposons.
Walsh, Ali Morton; Kortschak, R Daniel; Gardner, Michael G; Bertozzi, Terry; Adelson, David L
2013-01-15
In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes.
On the Hydraulics of Flowing Horizontal Wells
Bian, A.; Zhan, H.
2003-12-01
A flowing horizontal well is a special type of horizontal well that does not have pumping/injecting facility. The discharge rate of a flowing horizontal well is controlled by the hydraulic gradient between the aquifer and the well and it generally varies with time if the hydraulic head of the aquifer is transient. This type of well has been used in landslide control, mining dewatering, water table control, underground water transportation through a horizontal tunnel, agricultural water drainage, and other applications. Flowing horizontal wells have quite different hydrodynamic characteristics from horizontal wells with fixed pumping or injecting rates because their discharge rates are functions of the aquifer hydraulic heads (Zhan et al, 2001; Zhan and Zlotnik, 2002). Hydraulics of flowing horizontal wells have rarely been studied although the hydraulics of flowing vertical wells have been extensively investigated before. The purpose of this paper is to obtain analytical solutions of groundwater flow to a flowing horizontal-well in a confined aquifer, in a water table aquifer without precipitation, and in a water table aquifer with precipitation. The functions of the flowing horizontal well discharge rates versus time will be obtained under above mentioned different aquifer conditions. The relationships of the aquifer hydraulic heads versus the discharge rates of the well will be investigated. The rate of water table decline due to the dewatering of the well will also be computed, and this solution is particularly useful for landslide control and mining dewatering. The theoretical solutions will be compared with results of experiments that will be conducted in the hydrological laboratory at Texas A&M University. Reference: Zhan, H., Wang, L.V., and Park, E, On the horizontal well pumping tests in the anisotropic confined aquifers, J. hydrol., 252, 37-50, 2001. Zhan, H., and Zlotnik, V. A., Groundwater flow to a horizontal or slanted well in an unconfined aquifer
Horizontal Directional Drilling (HDD) Technology and Applications
J. G. Cai; X. N. Wang
2004-01-01
@@ 1 What is Horizontal Directional Drilling? Horizontal Directional Drilling, accurately steered drilling, has become state -of- the -art drilling technique in the world. Specially- designed directionsteerable corebarrel and accurate direction measurement tool are available for the use together with wire line core drilling machine. That makes it feasible to extract cores and to measure the drill travel line &length while drilling in a curve.
Using Telecommunications for Principals' Professional Development.
Long, Claudia A.; Terry, Patricia D.
This paper describes the development, operations, and effectiveness of the Principals' Computer Network (PCN)--an experimental program created (1) to allow principals to use their schools' microcomputers to access other principals' solutions to common instructional management problems; (2) to enable principals to request suggestions from their…
Three Principals Who Make a Difference.
Sagor, Richard D.
1992-01-01
Principals who are transformative leaders consistently use three building blocks to promote school success: a clear, unified purpose; a common cultural perspective; and a constant push for improvement. In one study, an opinionated, assertive middle school principal; a nurturing, supportive principal; and a high-energy, charismatic principal all…
Horizontal and vertical changes in anchor molars after extractions in bimaxillary protrusion cases
Pratik Chandra
2016-01-01
Full Text Available Objective: To evaluate changes in the anchor molar position (horizontal, vertical after retraction in bimaxillary protrusion maximum anchorage cases. Materials and Methods: Thirty patients requiring maximum anchorage after extraction of the first premolars were selected for this study. The second molars were banded in both arches along with trans-palatal arch in the maxillary arch and lingual arch in the mandibular arch. En mass retraction was done using sliding mechanics. Horizontal and vertical positions of the anchor first molars were evaluated cephalometrically before and after orthodontic retraction. Results: In the horizontal plane, maxillary first molars showed net mesial movement of 1.72 mm, and there was a statistical difference between the pre- and post-values (P < 0.001. The mandibular molars showed a net horizontal movement of 2.26 mm, and there was a statistically significant difference between the pre- and post-values (P < 0.001. In the vertical plane, there was vertical movement of the maxillary anchor molars by a net value of 0.95 mm which was statistically significant (P < 0.001. The mandibular anchor molars moved vertically by a net value of 0.45 mm. This difference was statistically not significant. Conclusion: There was anchorage loss seen in both the planes (horizontal, vertical of the maxillary anchor molars. In the mandibular anchor molars, there was anchorage loss seen only in the horizontal plane. No anchorage loss was seen in the vertical plane.
Intra-firm Horizontal Knowledge Transfer Management
WANG Yaowu; WANG Yanhang
2009-01-01
Knowledge transfer is widely emphasized as a strategic issue for firm competition. A model for intra-firm horizontal knowledge transfer is proposed to model horizontal knowledge transfer to solve some demerits in current knowledge transfer researches. The concept model of intra-firm horizontal knowledge transfer was described and a framework was provided to define the main components of thetransfer process. Horizontal knowledge transfer is that knowledge is transferred from the source to the same hierarchical level recipients as the target. Horizontal knowledge transfer constitutes a strategic area of knowledge management research. However, little is known about the circumstances under which one particular mechanism is the most appropriate. To address these issues, some significant conclusions are drawn concerning knowledge transfer mechanisms in a real-world setting.
Horizontal Canal Benign Positional Vertigo
Mohtaram Najafi
1998-03-01
Full Text Available Benign paroxysmal positional vertigo (BPPV is a syndrome characterized by transient episodes of vertigo in association with rapid changes in head position in Dix-Halpike Maneuver. This kind of vertigo is thought to be caused by migration of otoconial debris into canals other than the posterior canal, such as the anterior or lateral canals. It is also theoretically possible for many aberrant patterns of BPPV to occur from an interaction of debris in several canals, location of debris within the canal, and central adaptation patterns to lesions. The symptoms of BPPV are much more consistent with free-moving densities (canaliths in the posterior SCC rather than fixed densities attached to the cupula. While the head is upright, the particles sit in the PSC at the most gravity-dependent position. The best method to induce and see vertigo and nystagmus in BPPV of the lateral semicircular canal is to rotate head 90°while patient is in the supine position, nystagmus would appear in the unaffected side weaker but longer than the affected side. canal paresis has been described in one third of the patients with BPPV. Adaptation which is one of the remarkable features of BPPV in PSC is rarely seen in LSC. Rotations of 270° or 360° around the yaw axis (the so-called barbecue maneuver toward the unaffected ear are popular methods for the treatment of geotropic HC-BPPV. These maneuvers consist of sequential head turning of 90° toward the healthy side while supine. With these maneuvers, the free-floating otoconial debris migrates in the ampullofugal direction, finally entering the utricle through the nonampullated end of the horizontal canal. This kind of vertigo recovers spontaneously more rapidly and suddenly.
Wenjun Huang
2017-01-01
Full Text Available Mechanical extending limit in horizontal drilling means the maximum horizontal extending length of a horizontal well under certain ground and down-hole mechanical constraint conditions. Around this concept, the constrained optimization model of mechanical extending limits is built and simplified analytical results for pick-up and slack-off operations are deduced. The horizontal extending limits for kinds of tubular strings under different drilling parameters are calculated and drawn. To improve extending limits, an optimal design model of drill strings is built and applied to a case study. The results indicate that horizontal extending limits are underestimated a lot when the effects of friction force on critical helical buckling loads are neglected. Horizontal extending limits firstly increase and tend to stable values with vertical depths. Horizontal extending limits increase faster but finally become smaller with the increase of horizontal pushing forces for tubular strings of smaller modulus-weight ratio. Sliding slack-off is the main limit operation and high axial friction is the main constraint factor constraining horizontal extending limits. A sophisticated installation of multiple tubular strings can greatly inhibit helical buckling and increase horizontal extending limits. The optimal design model is called only once to obtain design results, which greatly increases the calculation efficiency.
OECD Maximum Residue Limit Calculator
With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.
Accurate structural correlations from maximum likelihood superpositions.
Douglas L Theobald
2008-02-01
Full Text Available The cores of globular proteins are densely packed, resulting in complicated networks of structural interactions. These interactions in turn give rise to dynamic structural correlations over a wide range of time scales. Accurate analysis of these complex correlations is crucial for understanding biomolecular mechanisms and for relating structure to function. Here we report a highly accurate technique for inferring the major modes of structural correlation in macromolecules using likelihood-based statistical analysis of sets of structures. This method is generally applicable to any ensemble of related molecules, including families of nuclear magnetic resonance (NMR models, different crystal forms of a protein, and structural alignments of homologous proteins, as well as molecular dynamics trajectories. Dominant modes of structural correlation are determined using principal components analysis (PCA of the maximum likelihood estimate of the correlation matrix. The correlations we identify are inherently independent of the statistical uncertainty and dynamic heterogeneity associated with the structural coordinates. We additionally present an easily interpretable method ("PCA plots" for displaying these positional correlations by color-coding them onto a macromolecular structure. Maximum likelihood PCA of structural superpositions, and the structural PCA plots that illustrate the results, will facilitate the accurate determination of dynamic structural correlations analyzed in diverse fields of structural biology.
The optimal polarizations for achieving maximum contrast in radar images
Swartz, A. A.; Yueh, H. A.; Kong, J. A.; Novak, L. M.; Shin, R. T.
1988-01-01
There is considerable interest in determining the optimal polarizations that maximize contrast between two scattering classes in polarimetric radar images. A systematic approach is presented for obtaining the optimal polarimetric matched filter, i.e., that filter which produces maximum contrast between two scattering classes. The maximization procedure involves solving an eigenvalue problem where the eigenvector corresponding to the maximum contrast ratio is an optimal polarimetric matched filter. To exhibit the physical significance of this filter, it is transformed into its associated transmitting and receiving polarization states, written in terms of horizontal and vertical vector components. For the special case where the transmitting polarization is fixed, the receiving polarization which maximizes the contrast ratio is also obtained. Polarimetric filtering is then applies to synthetic aperture radar images obtained from the Jet Propulsion Laboratory. It is shown, both numerically and through the use of radar imagery, that maximum image contrast can be realized when data is processed with the optimal polarimeter matched filter.
Application of aqueous nanofluids in a horizontal mesh heat pipe
ZhenHua Liu [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); QunZhi Zhu [School of Energy Sources and Environment Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)
2011-01-15
An experimental study was carried out to investigate the effects of aqueous CuO nanofluids on thermal performance of a horizontal mesh heat pipe working at steady sub-atmospheric pressures. The nanofluid was composed of deionized water and CuO nanoparticles with an average diameter of 50 nm. The experimental results show that adding CuO nanoparticles into deionized water can significantly enhance heat transfer coefficients of both evaporator and condenser, and the maximum heat flux of the heat pipe. There is an optimal mass concentration of nanoparticles corresponding to the maximum heat transfer enhancement. The operating pressure has an apparent impact on both the evaporating and condensing heat transfer enhancements. The heat transfer enhancement effects increase distinctly with the decrease of the pressure. The present investigation discovers that the thermal performance of a mesh heat pipe can be evidently strengthened by substituting CuO nanofluids for deionized water under sub-atmospheric pressures. (author)
Application of aqueous nanofluids in a horizontal mesh heat pipe
Liu Zhenhua, E-mail: liuzhenh@sjtu.edu.c [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Zhu Qunzhi [School of Energy Sources and Environment Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)
2011-01-15
An experimental study was carried out to investigate the effects of aqueous CuO nanofluids on thermal performance of a horizontal mesh heat pipe working at steady sub-atmospheric pressures. The nanofluid was composed of deionized water and CuO nanoparticles with an average diameter of 50 nm. The experimental results show that adding CuO nanoparticles into deionized water can significantly enhance heat transfer coefficients of both evaporator and condenser, and the maximum heat flux of the heat pipe. There is an optimal mass concentration of nanoparticles corresponding to the maximum heat transfer enhancement. The operating pressure has an apparent impact on both the evaporating and condensing heat transfer enhancements. The heat transfer enhancement effects increase distinctly with the decrease of the pressure. The present investigation discovers that the thermal performance of a mesh heat pipe can be evidently strengthened by substituting CuO nanofluids for deionized water under sub-atmospheric pressures.
Existence of a principal eigenvalue for the Tricomi problem
Daniela Lupo
2000-10-01
Full Text Available The existence of a principal eigenvalue is established for the Tricomi problem in normal domains; that is, the existence of a positive eigenvalue of minimum modulus with an associated positive eigenfunction. The argument here uses prior results of the authors on the generalized solvability in weighted Sobolev spaces and associated maximum/minimum principles cite{[LP2]} coupled with known results of Krein-Rutman type.
Study on Scattering Wave Force of Horizontal and Vertical Plate Type Breakwaters
WANG Ke; ZHANG Xi; GAO Xin
2011-01-01
The interaction between wave and horizontal and vertical plates is investigated by the boundary element method,and the relations of wave exciting force with plate thickness,submergence and length are obtained.It is found that:1)The efficient wave exciting force exists while plate submergence is less than 0.5 m,and the plate is very thin with order O(0.005 m).2) The maximum heave wave exciting force exists,and it is the main factor for surface and submerged horizontal plate while the roll force can be ignored.3) The maximum sway wave exciting force exists,it is the main factor for surface or submerged vertical plate,and the roll force is about 20 times of horizontal plate.
Fast Steerable Principal Component Analysis
Zhao, Zhizhen; Shkolnisky, Yoel; Singer, Amit
2016-01-01
Cryo-electron microscopy nowadays often requires the analysis of hundreds of thousands of 2D images as large as a few hundred pixels in each direction. Here we introduce an algorithm that efficiently and accurately performs principal component analysis (PCA) for a large set of two-dimensional images, and, for each image, the set of its uniform rotations in the plane and their reflections. For a dataset consisting of $n$ images of size $L \\times L$ pixels, the computational complexity of our a...
Principal chiral model on superspheres
Mitev, V.; Schomerus, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Quella, T. [Amsterdam Univ. (Netherlands). Inst. for Theoretical Physics
2008-09-15
We investigate the spectrum of the principal chiral model (PCM) on odd-dimensional superspheres as a function of the curvature radius R. For volume-filling branes on S{sup 3} {sup vertical} {sup stroke} {sup 2}, we compute the exact boundary spectrum as a function of R. The extension to higher dimensional superspheres is discussed, but not carried out in detail. Our results provide very convincing evidence in favor of the strong-weak coupling duality between supersphere PCMs and OSP(2S+2 vertical stroke 2S) Gross-Neveu models that was recently conjectured by Candu and Saleur. (orig.)
Effect of Horizontal Nonuniformity of Diabatic Heating on Tropical Cyclone Intensity and Structure
YU Hui; DUAN Yihong; LIANG Xudong
2005-01-01
The effect of the horizontal variation of diabatic heating on the tropical cyclone intensity and structure is studied in this paper. According to the potential vorticity (PV) equation in axis-symmetric cylindrical coordinates, PV disturbance caused by the radial difference of diabatic heating is positive (negative) inside (outside) the maximum heating radius, implying that the radial nonuniformity of diabatic heating should contribute positively to the intensity of a tropical cyclone while negatively to its size.A primitive equation model is then used to get some quantitative ideas on the problem. Results show that the modeled tropical cyclone weakens by about 20% but is larger in size if the effect of horizontal variety of convective heating is excluded in thermodynamic and dynamic equations. The PV disturbance originated from the horizontal nonuniformity of diabatic heating is positive inside the maximum heating radius and negative outside, in consistent with the PV equation analyses. The maximum disturbance (both negative and positive) appears around the maximum heating level and their magnitude is comparable to that generated by vertical variance of heating. It is concluded that the effect of the horizontal heat nonuniformity on the intensity and structure of TC cannot be neglected.
Maximum margin Bayesian network classifiers.
Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian
2012-03-01
We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.
Maximum Entropy in Drug Discovery
Chih-Yuan Tseng
2014-07-01
Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.
Optimizing of Culture Conditionin Horizontal Rotating Bioreactor
无
2005-01-01
1 IntroductionBioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world. 2 Rotating bioreactors2.1 Working principleThere are two kinds of horizontal rotating bioreactor: HARV(high aspect ratio vessel) and RCCS (rotary cell culture system). It is drived by step motor with horizontal rotation, the culture medium and cell is filled between ...
Horizontal gene transfer and bacterial diversity
Chitra Dutta; Archana Pan
2002-02-01
Bacterial genomes are extremely dynamic and mosaic in nature. A substantial amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character of bacterial species and thereby promotes microbial diversification and speciation. This review discusses how the recent influx of complete chromosomal sequences of various microorganisms has allowed for a quantitative assessment of the scope, rate and impact of horizontally transmitted information on microbial evolution.
Using Kernel Principal Components for Color Image Segmentation
Wesolkowski, Slawo
2002-11-01
Distinguishing objects on the basis of color is fundamental to humans. In this paper, a clustering approach is used to segment color images. Clustering is usually done using a single point or vector as a cluster prototype. The data can be clustered in the input or feature space where the feature space is some nonlinear transformation of the input space. The idea of kernel principal component analysis (KPCA) was introduced to align data along principal components in the kernel or feature space. KPCA is a nonlinear transformation of the input data that finds the eigenvectors along which this data has maximum information content (or variation). The principal components resulting from KPCA are nonlinear in the input space and represent principal curves. This is a necessary step as colors in RGB are not linearly correlated especially considering illumination effects such as shading or highlights. The performance of the k-means (Euclidean distance-based) and Mixture of Principal Components (vector angle-based) algorithms are analyzed in the context of the input space and the feature space obtained using KPCA. Results are presented on a color image segmentation task. The results are discussed and further extensions are suggested.
Parametric functional principal component analysis.
Sang, Peijun; Wang, Liangliang; Cao, Jiguo
2017-03-10
Functional principal component analysis (FPCA) is a popular approach in functional data analysis to explore major sources of variation in a sample of random curves. These major sources of variation are represented by functional principal components (FPCs). Most existing FPCA approaches use a set of flexible basis functions such as B-spline basis to represent the FPCs, and control the smoothness of the FPCs by adding roughness penalties. However, the flexible representations pose difficulties for users to understand and interpret the FPCs. In this article, we consider a variety of applications of FPCA and find that, in many situations, the shapes of top FPCs are simple enough to be approximated using simple parametric functions. We propose a parametric approach to estimate the top FPCs to enhance their interpretability for users. Our parametric approach can also circumvent the smoothing parameter selecting process in conventional nonparametric FPCA methods. In addition, our simulation study shows that the proposed parametric FPCA is more robust when outlier curves exist. The parametric FPCA method is demonstrated by analyzing several datasets from a variety of applications. © 2017, The International Biometric Society.
Interpretable functional principal component analysis.
Lin, Zhenhua; Wang, Liangliang; Cao, Jiguo
2016-09-01
Functional principal component analysis (FPCA) is a popular approach to explore major sources of variation in a sample of random curves. These major sources of variation are represented by functional principal components (FPCs). The intervals where the values of FPCs are significant are interpreted as where sample curves have major variations. However, these intervals are often hard for naïve users to identify, because of the vague definition of "significant values". In this article, we develop a novel penalty-based method to derive FPCs that are only nonzero precisely in the intervals where the values of FPCs are significant, whence the derived FPCs possess better interpretability than the FPCs derived from existing methods. To compute the proposed FPCs, we devise an efficient algorithm based on projection deflation techniques. We show that the proposed interpretable FPCs are strongly consistent and asymptotically normal under mild conditions. Simulation studies confirm that with a competitive performance in explaining variations of sample curves, the proposed FPCs are more interpretable than the traditional counterparts. This advantage is demonstrated by analyzing two real datasets, namely, electroencephalography data and Canadian weather data.
Great Assistant Principals and the (Great) Principals Who Mentor Them: A Practical Guide
Goodman, Carole C.; Berry, Christopher S.
2011-01-01
Written for principals and assistant principals to read and reflect on together, this book describes the most common challenges facing today's assistant principals--and provides practical solutions. Authors Carole Goodman and Christopher Berry examine how principals and assistant principals can develop the kinds of relationships that serve to meet…
Great Assistant Principals and the (Great) Principals Who Mentor Them: A Practical Guide
Goodman, Carole C.; Berry, Christopher S.
2011-01-01
Written for principals and assistant principals to read and reflect on together, this book describes the most common challenges facing today's assistant principals--and provides practical solutions. Authors Carole Goodman and Christopher Berry examine how principals and assistant principals can develop the kinds of relationships that serve to meet…
Female Traditional Principals and Co-Principals: Experiences of Role Conflict and Job Satisfaction
Eckman, Ellen Wexler; Kelber, Sheryl Talcott
2010-01-01
This paper presents a secondary analysis of survey data focusing on role conflict and job satisfaction of 102 female principals. Data were collected from 51 female traditional principals and 51 female co-principals. By examining the traditional and co-principal leadership models as experienced by female principals, this paper addresses the impact…
Berry, Vincent; Nicolas, François
2006-01-01
Given a set of evolutionary trees on a same set of taxa, the maximum agreement subtree problem (MAST), respectively, maximum compatible tree problem (MCT), consists of finding a largest subset of taxa such that all input trees restricted to these taxa are isomorphic, respectively compatible. These problems have several applications in phylogenetics such as the computation of a consensus of phylogenies obtained from different data sets, the identification of species subjected to horizontal gene transfers and, more recently, the inference of supertrees, e.g., Trees Of Life. We provide two linear time algorithms to check the isomorphism, respectively, compatibility, of a set of trees or otherwise identify a conflict between the trees with respect to the relative location of a small subset of taxa. Then, we use these algorithms as subroutines to solve MAST and MCT on rooted or unrooted trees of unbounded degree. More precisely, we give exact fixed-parameter tractable algorithms, whose running time is uniformly polynomial when the number of taxa on which the trees disagree is bounded. The improves on a known result for MAST and proves fixed-parameter tractability for MCT.
Experimental investigation of coarse particles-water mixture flow in horizontal and inclined pipes
Vlasák Pavel
2014-09-01
Full Text Available The effect of solid concentration and mixture velocity on the flow behaviour, pressure drops, and concentration distribution of coarse particle-water mixtures in horizontal, vertical, and inclined smooth stainless steel pipes of inner diameter D = 100 mm was experimentally investigated. Graded basalt pebbles were used as solid particles. The study revealed that the coarse-grained particle-water mixtures in the horizontal and inclined pipes were significantly stratified. The solid particles moved principally in a layer close to the pipe invert; however for higher and moderate flow velocities, particle saltation became the dominant mode of particle conveyance. Frictional pressure drops in the horizontal pipe were found to be markedly higher than in the vertical pipe, while the frictional pressure drops in the ascending pipe increased with inclination angle up to about 30°.
Horizontal cooperation in transport and logistics
Cruijssen, F.C.A.M.
2006-01-01
This thesis deals with horizontal cooperation in transport and logistics. It contains a comprehensive discussion of the available academic literature on this topic, many practical examples, and an empirical investigation of opportunities and impediments. Furthermore, three enabling concepts for
Greenslade, Thomas B., Jr.
1985-01-01
Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)
Abolishing the maximum tension principle
Dabrowski, Mariusz P
2015-01-01
We find the series of example theories for which the relativistic limit of maximum tension $F_{max} = c^2/4G$ represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Abolishing the maximum tension principle
Mariusz P. Da̧browski
2015-09-01
Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Evaluation of extremely small horizontal emittance
T. Okugi
1999-02-01
Full Text Available The KEK Accelerator Test Facility (KEK-ATF was constructed to develop technologies for producing a low-emittance beam which will be required by future linear colliders. The KEK-ATF consists of an injector linac, a damping ring, and a beam extraction line. The basic optical structure of the damping ring is a FOBO lattice, which reduces the horizontal dispersion at the center of the bending magnets and, as a consequence, can produce an extremely small emittance beam. To verify the performance of such a unique, low-emittance lattice, it is crucial to measure the horizontal emittance. The horizontal emittance was measured using wire scanners in the beam extraction line. Since the horizontal beam position was not stable, we established a method to correct the measured beam size for position fluctuation (“jitter” and we succeeded in the observation of the so far smallest horizontal emittance in any accelerator. The measured horizontal emittance was 1.37±0.03nm at a beam energy of 1.285 GeV and a bunch population of \\(3–5\\×10^{9}, in agreement with the design value of 1.27–1.34 nm at the beam energy and the bunch population.
Magellan: Principal Venus science findings
Saunders, R. Stephen
1993-01-01
This is a brief summary of the science findings of the Magellan mission, principally based on data from the radar system. Future plans for Magellan include acquisition of high resolution gravity data from a nearly circular orbit and atmospheric drag and occultation experiments. The Magellan science results represent the combined effort of more than 100 Magellan investigators and their students and colleagues. More extensive discussions can be found in the August and October, 1992 issues of the Journal of Geophysical Research, Planets. The Magellan mission's scientific objectives were to provide a global characterization of landforms and tectonic features; to distinguish and understand impact processes; to define and explain erosion, deposition, and chemical processes; and to model the interior density distribution. All but the last objective, which requires new global gravity data, have been accomplished, or we have acquired the data that are required to accomplish them.
Fast Steerable Principal Component Analysis.
Zhao, Zhizhen; Shkolnisky, Yoel; Singer, Amit
2016-03-01
Cryo-electron microscopy nowadays often requires the analysis of hundreds of thousands of 2-D images as large as a few hundred pixels in each direction. Here, we introduce an algorithm that efficiently and accurately performs principal component analysis (PCA) for a large set of 2-D images, and, for each image, the set of its uniform rotations in the plane and their reflections. For a dataset consisting of n images of size L × L pixels, the computational complexity of our algorithm is O(nL(3) + L(4)), while existing algorithms take O(nL(4)). The new algorithm computes the expansion coefficients of the images in a Fourier-Bessel basis efficiently using the nonuniform fast Fourier transform. We compare the accuracy and efficiency of the new algorithm with traditional PCA and existing algorithms for steerable PCA.
Hu, W; Hu, Wayne; Okamoto, Takemi
2004-01-01
We study the physical limitations placed on CMB temperature and polarization measurements of the initial power spectrum by geometric projection, acoustic physics, gravitational lensing and the joint fitting of cosmological parameters. Detailed information on the spectrum is greatly assisted by polarization information and localized to the acoustic regime k = 0.02-0.2 Mpc^{-1} with a fundamental resolution of Delta k/k>0.05. From this study we construct principal component based statistics, which are orthogonal to cosmological parameters including the initial amplitude and tilt of the spectrum, that best probe deviations from scale-free initial conditions. These statistics resemble Fourier modes confined to the acoustic regime and ultimately can yield ~50 independent measurements of the power spectrum features to percent level precision. They are straightforwardly related to more traditional parameterizations such as the the running of the tilt and in the future can provide many statistically independent measu...
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Principal. 919.995 Section 919.995 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 919.995 Principal. Principal means— (a) An...
12 CFR 561.39 - Principal office.
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Principal office. 561.39 Section 561.39 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY DEFINITIONS FOR REGULATIONS AFFECTING ALL SAVINGS ASSOCIATIONS § 561.39 Principal office. The term principal office means the...
New Principal Coaching as a Safety Net
Celoria, Davide; Roberson, Ingrid
2015-01-01
This study examines new principal coaching as an induction process and explores the emotional dimensions of educational leadership. Twelve principal coaches and new principals--six of each--participated in this qualitative study that employed emergent coding (Creswell, 2008; Denzin, 2005; Glaser & Strauss, 1998; Spradley, 1979). The major…
Teacher Supervision Practices and Principals' Characteristics
April, Daniel; Bouchamma, Yamina
2015-01-01
A questionnaire was used to determine the individual and collective teacher supervision practices of school principals and vice-principals in Québec (n = 39) who participated in a research-action study on pedagogical supervision. These practices were then analyzed in terms of the principals' sociodemographic and socioprofessional characteristics…
A principal-agent model of corruption
Groenendijk, Nico
1997-01-01
One of the new avenues in the study of political corruption is that of neo-institutional economics, of which the principal-agent theory is a part. In this article a principal-agent model of corruption is presented, in which there are two principals (one of which is corrupting), and one agent (who is
Lin, W.; Masago, H.; Yamamoto, K.; Kawamura, Y.; Saito, S.; Kinoshita, M.
2007-12-01
By means of introduction of the drilling vessel 'CHIKYU', riser drilling operations using mud fluid will be carried out in NanTroSEIZE Stage 2 for the first time as an oceanic scientific-drilling. For determining drilling operation parameter such as a mud density, a downhole experiment, leak-off test (LOT) or extended leak-off test (XLOT), is going to be implemented next to casing and cementing at each casing shoe during the drilling process. Data of the downhole experiment aimed for operation can also be used for an important scientific application to obtain in-situ stress information which is necessary for various cases of scientific drillings such as seismogenic zone drillings etc. In order to examine feasibility of the application of the LOT or XLOT data, we analyzed an example of XLOT conducted by the riser vessel CHIKYU during its Shimokita shakedown cruise, 2006; and then estimated magnitude of minimum principal stress in horizontal plane, Shmin. Moreover, we will propose the test procedures to possibly improve the quality of stress result from the applications of LOT or XLOT. The XLOT of Shimokita cruise was conducted under following conditions; 1180 m water depth, 525 mbsf (meter below seafloor) depth, 1030 kg/m3 fluid density (seawater) and 80 litter/min injection flow-rate. Estimated magnitude of the Shmin is equal to 18.3 MPa based on the assumption that fracture closure pressure balances with the minimum principal stress perpendicular to the fracture plane. For comparison, the vertical stress magnitude at the depth was estimated from density profile of core samples retrieved from the same borehole; and was equal to 20 MPa approximately. These two values can be considered to be not disagreement. Therefore, we can say that the XLOT data is valuable and practical for estimating the magnitude of minimum horizontal stress. From the viewpoint of determining stress magnitude, the XLOT is more essential rather than the LOT because it might be hardly to obtain
Maximum Genus of Strong Embeddings
Er-ling Wei; Yan-pei Liu; Han Ren
2003-01-01
The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.
Remizov, Ivan D
2009-01-01
In this note, we represent a subdifferential of a maximum functional defined on the space of all real-valued continuous functions on a given metric compact set. For a given argument, $f$ it coincides with the set of all probability measures on the set of points maximizing $f$ on the initial compact set. This complete characterization lies in the heart of several important identities in microeconomics, such as Roy's identity, Sheppard's lemma, as well as duality theory in production and linear programming.
Horizontal roof gap of backfill hydraulic support
张强; 张吉雄; 邰阳; 方坤; 殷伟
2015-01-01
For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body’s compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs (II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.
The Testability of Maximum Magnitude
Clements, R.; Schorlemmer, D.; Gonzalez, A.; Zoeller, G.; Schneider, M.
2012-12-01
Recent disasters caused by earthquakes of unexpectedly large magnitude (such as Tohoku) illustrate the need for reliable assessments of the seismic hazard. Estimates of the maximum possible magnitude M at a given fault or in a particular zone are essential parameters in probabilistic seismic hazard assessment (PSHA), but their accuracy remains untested. In this study, we discuss the testability of long-term and short-term M estimates and the limitations that arise from testing such rare events. Of considerable importance is whether or not those limitations imply a lack of testability of a useful maximum magnitude estimate, and whether this should have any influence on current PSHA methodology. We use a simple extreme value theory approach to derive a probability distribution for the expected maximum magnitude in a future time interval, and we perform a sensitivity analysis on this distribution to determine if there is a reasonable avenue available for testing M estimates as they are commonly reported today: devoid of an appropriate probability distribution of their own and estimated only for infinite time (or relatively large untestable periods). Our results imply that any attempt at testing such estimates is futile, and that the distribution is highly sensitive to M estimates only under certain optimal conditions that are rarely observed in practice. In the future we suggest that PSHA modelers be brutally honest about the uncertainty of M estimates, or must find a way to decrease its influence on the estimated hazard.
Alternative Multiview Maximum Entropy Discrimination.
Chao, Guoqing; Sun, Shiliang
2016-07-01
Maximum entropy discrimination (MED) is a general framework for discriminative estimation based on maximum entropy and maximum margin principles, and can produce hard-margin support vector machines under some assumptions. Recently, the multiview version of MED multiview MED (MVMED) was proposed. In this paper, we try to explore a more natural MVMED framework by assuming two separate distributions p1( Θ1) over the first-view classifier parameter Θ1 and p2( Θ2) over the second-view classifier parameter Θ2 . We name the new MVMED framework as alternative MVMED (AMVMED), which enforces the posteriors of two view margins to be equal. The proposed AMVMED is more flexible than the existing MVMED, because compared with MVMED, which optimizes one relative entropy, AMVMED assigns one relative entropy term to each of the two views, thus incorporating a tradeoff between the two views. We give the detailed solving procedure, which can be divided into two steps. The first step is solving our optimization problem without considering the equal margin posteriors from two views, and then, in the second step, we consider the equal posteriors. Experimental results on multiple real-world data sets verify the effectiveness of the AMVMED, and comparisons with MVMED are also reported.
Principal component regression analysis with SPSS.
Liu, R X; Kuang, J; Gong, Q; Hou, X L
2003-06-01
The paper introduces all indices of multicollinearity diagnoses, the basic principle of principal component regression and determination of 'best' equation method. The paper uses an example to describe how to do principal component regression analysis with SPSS 10.0: including all calculating processes of the principal component regression and all operations of linear regression, factor analysis, descriptives, compute variable and bivariate correlations procedures in SPSS 10.0. The principal component regression analysis can be used to overcome disturbance of the multicollinearity. The simplified, speeded up and accurate statistical effect is reached through the principal component regression analysis with SPSS.
Coriolis effects are principally caused by gyroscopic angular acceleration.
Isu, N; Yanagihara, M; Mikuni, T; Koo, J
1994-07-01
A cause of nausea evoked by cross-coupled rotation (termed Coriolis stimulus) was determined. Subjects were provided with two types of cross-coupled rotations: neck-forward flexion (Neck Flx) and upper body-forward flexion (Body Flx) during horizontal whole body rotation at a constant angular velocity. These Coriolis stimuli were given alternatively in an experimental sequence, and the severity of the nausea they evoked was compared by the subjects. The results indicated that the same quality of nausea was evoked by a slightly higher angular velocity during Body Flx (100.5 degrees/s) than during Neck Flx (90 degrees/s). While Body Flx generated Coriolis linear acceleration several times larger than Neck Flx, both the stimuli generated a similar magnitude of gyroscopic angular acceleration in this condition. Therefore, it was inferred that the nausea evoked by a Coriolis stimulus is principally caused by gyroscopic angular acceleration.
Horizontal alveolar bone loss: A periodontal orphan
Jayakumar A
2010-01-01
Full Text Available Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician′s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs (of patients diagnosed with chronic periodontitis and seeking periodontal care, which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36% OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2% teeth, and vertical defects were found only in 264 (7.8% of the teeth, which was statistically significant (P<.001. Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3% have addressed vertical bone loss, and 18 (3.7% have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment
Cacti with maximum Kirchhoff index
Wang, Wen-Rui; Pan, Xiang-Feng
2015-01-01
The concept of resistance distance was first proposed by Klein and Randi\\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of connected cacti possessing $n$ vertices and $t$ cycles, where $0\\leq t \\leq \\lfloor\\frac{n-1}{2}\\rfloor$. In this paper, the maximum kirchhoff index of cacti are characterized, as well...
Generic maximum likely scale selection
Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo
2007-01-01
The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....
Diffuser Augmented Horizontal Axis Tidal Current Turbines
Nasir Mehmood
2012-09-01
Full Text Available The renewal energy technologies are increasingly popular to ensure future energy sustenance and address environmental issues. The tides are enormous and consistent untapped resource of renewable energy. The growing interest in exploring tidal energy has compelling reasons such as security and diversity of supply, intermittent but predictable and limited social and environmental impacts. The tidal energy industry is undergoing an increasing shift towards diffuser augmented turbines. The reason is the higher power output of diffuser augmented turbines compared to conventional open turbines. The purpose of this study is to present a comprehensive review of diffuser augmented horizontal axis tidal current turbines. The components, relative advantages, limitations and design parameters of diffuser augmented horizontal axis tidal current turbines are presented in detail. CFD simulation of NACA 0016 airfoil is carried out to explore its potential for designing a diffuser. The core issues associated with diffuser augmented horizontal axis tidal current turbines are also discussed.
HORIZONTAL WELL DRILL-IN FLUIDS
Nediljka Gaurina-Međimurec
1998-12-01
Full Text Available Main objective of horizontal driling is to place a drain-hole for a long distance within the pay zone to enhance productivity or injectivity. In drilling horizontal wells, more serious problems appear than in drilling vertical wells. These problems are: poor hole cleaning, excessive torque and drag, hole filling, pipe stucking, wellbore instability, loss of circulation, formation damage, poor cement job, and difficulties at logging jobs. From that reason, successful drilling and production of horizontal well depends largely on the fluid used during drilling and completion phases. Several new fluids, that fulfill some or all of required properties (hole cleaning, cutting suspension, good lubrication, and relative low formation damage, are presented in this paper.
Horizontal stirring in the global ocean
Hernández-Carrasco, I; Hernández-García, E; Turiel, A
2011-01-01
Horizontal mixing and the distribution of coherent structures in the global ocean are analyzed using Finite-Size Lyapunov Exponents (FSLE), computed for the surface velocity field derived from the Ocean general circulation model For the Earth Simulator (OFES). FSLEs measure horizontal stirring and dispersion; additionally, the transport barriers which organize the oceanic flow can roughly be identified with the ridges of the FSLE field. We have performed a detailed statistical study, particularizing for the behaviour of the two hemispheres and different ocean basins. The computed Probability Distributions Functions (PDFs) of FSLE are broad and asymmetric. Horizontal mixing is generally more active in the northern hemisphere than in the southern one. Nevertheless the Southern Ocean is the most active ocean, and the Pacific the less active one. A striking result is that the main currents can be classified in two 'activity classes': Western Boundary Currents, which have broad PDFs with large FSLE values, and Eas...
Utility Independent Privacy Preserving Data Mining - Horizontally Partitioned Data
E Poovammal
2010-06-01
Full Text Available Micro data is a valuable source of information for research. However, publishing data about individuals for research purposes, without revealing sensitive information, is an important problem. The main objective of privacy preserving data mining algorithms is to obtain accurate results/rules by analyzing the maximum possible amount of data without unintended information disclosure. Data sets for analysis may be in a centralized server or in a distributed environment. In a distributed environment, the data may be horizontally or vertically partitioned. We have developed a simple technique by which horizontally partitioned data can be used for any type of mining task without information loss. The partitioned sensitive data at 'm' different sites are transformed using a mapping table or graded grouping technique, depending on the data type. This transformed data set is given to a third party for analysis. This may not be a trusted party, but it is still allowed to perform mining operations on the data set and to release the results to all the 'm' parties. The results are interpreted among the 'm' parties involved in the data sharing. The experiments conducted on real data sets prove that our proposed simple transformation procedure preserves one hundred percent of the performance of any data mining algorithm as compared to the original data set while preserving privacy.
Horizontal spacing, depletion, and infill potential in the Austin chalk
Kyte, D.G.; Meehan, D.N.
1996-12-31
Estimated ultimate recoveries on a barrels per acre basis for Austin chalk wells were discussed. The study showed that the maximum six months consecutive production through the life of the well can be used to estimate ultimate recovery in horizontally drilled reservoirs. A statistical approach was used to help identify where the Austin chalk has been overdrilled and areas where infill potential exists. The barrels per acre data were analyzed by a method known as `moving domain`. This procedure involves stepping through the reservoir well by well and looking at it with respect to its nearest neighbors. To analyze for depletion, barrels per acre is compared to date of first production for groups of wells in an area, looking for declining values with time. Areas showing no evidence of depletion and having good recoveries are further studied for infill potential. By comparing effective densities in areas which are not yet being fully drained, an optimum spacing between wells can be determined for horizontal wells in a fractured chalk reservoir. An artificial neural network can also be used to provide qualitative predictions of well performance in developed reservoirs. 6 refs., 15 figs.
Perniola, Mario
2004-01-01
La existencia de un horizonte estético depende de la coexistencia de múltiples factores de distinta naturaleza que interactúan entre ellos. No bastan las reflexiones en torno a lo bello y al arte para crear un horizonte estético. La palabra “estética” es introducida en el Settecento por la filosofía para indicar una articulación disciplinar propia que pudiera ubicarse cerca de la lógica; esta circunstancia histórica, sin embargo, no debe hacernos olvidar que la filosofía es desde su nacimient...
Fourth international seminar on horizontal steam generators
Tuomisto, H. [ed.] [IVO Group, Vantaa (Finland); Purhonen, H. [ed.] [VTT, Espoo (Finland); Kouhia, V. [ed.] [Lappeenranta Univ. of Technology (Finland)
1997-12-31
The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.
Horizontal Roll Vortices and Crown Fires.
Haines, Donald A.
1982-06-01
Observational evidence from nine crown fires suggests that horizontal roll vortices are a major mechanism in crown-fire spread. Post-burn aerial photography indicates that unburned tree-crown streets are common with crown fire. Investigation of the understory of these crown streets after two fires showed uncharred tree trunks along a center line. This evidence supports a hypothesis of vortex action causing strong downward motion of air along the streets. Additionally, photographs of two ongoing crown fires show apparent horizontal roll vortices. Discussion also includes laboratory and numerical studies in fluid dynamics that may apply to crown fires.
Economics and Maximum Entropy Production
Lorenz, R. D.
2003-04-01
Price differentials, sales volume and profit can be seen as analogues of temperature difference, heat flow and work or entropy production in the climate system. One aspect in which economic systems exhibit more clarity than the climate is that the empirical and/or statistical mechanical tendency for systems to seek a maximum in production is very evident in economics, in that the profit motive is very clear. Noting the common link between 1/f noise, power laws and Self-Organized Criticality with Maximum Entropy Production, the power law fluctuations in security and commodity prices is not inconsistent with the analogy. There is an additional thermodynamic analogy, in that scarcity is valued. A commodity concentrated among a few traders is valued highly by the many who do not have it. The market therefore encourages via prices the spreading of those goods among a wider group, just as heat tends to diffuse, increasing entropy. I explore some empirical price-volume relationships of metals and meteorites in this context.
Optimization model for rotor blades of horizontal axis wind turbines
LIU Xiong; CHEN Yan; YE Zhiquan
2007-01-01
This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry out the search process.Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a 1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better aerodynamic performance.
Gonzalez Diaz, O.; Hernandez Marrero, J. [Centro de Investigaciones Hidraulicas. La Habana. Cuba (Cuba); Rodriguez Pastor, M.; Prats Rico, D. [Universidad de Alicante (Spain)
2000-07-01
The conventional wastewater treatments are expensive and required high-energy consumption. Those systems in most of the cases do not eliminate nutrients like nitrogen and phosphorous, principals agents for eutrophication in water bodies. As an alternative of conventional treatment in recent years has been develop techniques, based on the natural mechanism, those system required the same amount of energy that the conventional system, but this energy is take from the nature. The objective of the present work is to study the subsurface horizontal flow wetland and it is ability to reduce the organic loading rate expressed as BOD5 in Cuban conditions, using different emergent plants species. (Author) 29 refs.
Semiactive Vibration Control for Horizontal Axis Washing Machine
Barış Can Yalçın
2015-01-01
Full Text Available A semiactive vibration control method is developed to cope with the dynamic stability problem of a horizontal axis washing machine. This method is based on adjusting the maximum force values produced by the semiactive suspension elements considering a washing machine’s vibration data (three axis angular position and three axis angular acceleration values in time. Before actuation signals are received by the step motors of the friction dampers, vibration data are evaluated, and then, the step motors start to narrow or expand the radius of bracelets located on the dampers. This changes the damping properties of the damper in the suspension system, and thus, the semiactive suspension system absorbs unwanted vibrations and contributes to the dynamic stability of the washing machine. To evaluate the vibration data, the angular position and angular acceleration values in three axes are defined in a function, and the maximum forces produced by semiactive suspension elements are calculated according to the gradient of this function. The relation between the dynamic stability and the walking stability is also investigated. A motion (gyroscope and accelerometer sensor is installed on the top-front panel of the washing machine because a mathematical model of a horizontal axis washing machine suggests that the walking behavior starts around this location under some assumptions, and therefore, calculating the vibrations occurring there is crucial. Semiactive damping elements are located under the left and right sides of the tub. The proposed method is tested during the spinning cycle of washing machine operation, increasing gradually from 200 rpm to 900 rpm, which produces the most challenging vibration patterns for dynamic stability. Moreover, the sound power levels produced by the washing machine are measured to evaluate the noise performance of the washing machine while the semiactive suspension system is controlled. The effectiveness of the
Sparse Principal Component Analysis with missing observations
Lounici, Karim
2012-01-01
In this paper, we study the problem of sparse Principal Component Analysis (PCA) in the high-dimensional setting with missing observations. Our goal is to estimate the first principal component when we only have access to partial observations. Existing estimation techniques are usually derived for fully observed data sets and require a prior knowledge of the sparsity of the first principal component in order to achieve good statistical guarantees. Our contributions is threefold. First, we establish the first information-theoretic lower bound for the sparse PCA problem with missing observations. Second, we propose a simple procedure that does not require any prior knowledge on the sparsity of the unknown first principal component or any imputation of the missing observations, adapts to the unknown sparsity of the first principal component and achieves the optimal rate of estimation up to a logarithmic factor. Third, if the covariance matrix of interest admits a sparse first principal component and is in additi...
Objects of maximum electromagnetic chirality
Fernandez-Corbaton, Ivan
2015-01-01
We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.
Maximum mutual information regularized classification
Wang, Jim Jing-Yan
2014-09-07
In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.
A Case Study of Horizontal Teacher Evaluation.
Johnson, Trav D.
Horizontal teacher evaluation increases understanding of teaching through the critical examination of educational goals and classroom practices. This examination includes teachers' classroom observations of one another coupled with in-depth teacher conversations or dialogue about teaching aims and practices. A qualitative case study of a…
Third international seminar on horizontal steam generators
NONE
1995-12-31
The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.
Parametric study for horizontal steam generator modelling
Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)
1995-12-31
In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.
Fermion mass hierarchy and global horizontal symmetries
Gelmini, G.B.; Gerard, J.M.; Yanagida, T.; Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))
1984-02-02
We present a mechanism for quark mass generation in zeroth order using induced representations rather than the minimization of the horizontal potential. Using a simplicity criterion, we derive a realistic mass matrix. We also discuss a possible application of the mechanism to various models.
Horizontal gene transfer in the phytosphere
Elsas, van J.D.; Turner, S.; Bailey, M.J.
2003-01-01
Here, the ecological aspects of gene transfer processes between bacteria in the phytosphere are examined in the context of emerging evidence for the dominant role that horizontal gene transfer (HGT) has played in the evolutionary shaping of bacterial communities. Moreover, the impact of the putative
Flow mapping for ESS horizontal target
Takeda, Y.; Kikura, H.; Taishi, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1997-09-01
Flow behaviour for ESS horizontal target is studied experimentally using two dimensional water model. A velocity field of stationary flow in reaction zone has been obtained. Three dimensional effect was also studied as a spanwise flow structure. (author) 3 figs., 3 refs.
Buoyancy Driven Natural Ventilation through Horizontal Openings
Heiselberg, Per
2009-01-01
An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...
Teaching Activities on Horizontal Nuclear Proliferation.
Zola, John
1990-01-01
Provides learning activities concerning the horizontal proliferation of nuclear weapons. Includes step-by-step directions for four activities: (1) the life cycle of nuclear weapons; (2) nuclear nonproliferation: pros and cons; (3) the nuclear power/nuclear weapons connection; and (4) managing nuclear proliferation. (NL)
Mud and cement for horizontal wells
Zurdo, C.; Georges, C.; Martin, M.
1986-01-01
High-angle and horizontal well bores raise many questions concerning the characteristics of mud and cement. This paper is a summary of the authors' knowledge and work on these two subjects. For all research carried out, large or full-scale laboratory test plants were used. Cutting transport is not only a problem in horizontal conditions but hole angles of 25 to 65/sup 0/ can be even more critical when parameters such as mud rheological properties and velocities are not optimized. Drilling a long horizontal drain creates a dynamic annulus pressure unbalance. This can lead to a loss and kick situation. Two test benches were thus used to obtain a good understanding of the inefficiency of conventional plugging methods and of the difficulties of gas migration control in subhorizontal well bores. High concentrations of LCM, high rheological properties of fluids and low flow rates increase the changes of solving the first problem. The results of the second bench demonstrate the difficulties of annulus gas evacution for angles varying from 90 to 100 degrees, or from over-gauged sections in horizontal holes.
Gemma Rutten
Full Text Available In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866-4550 m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.
Rutten, Gemma; Ensslin, Andreas; Hemp, Andreas; Fischer, Markus
2015-01-01
In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866-4550 m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.
Effects of reverse waves on the hydrodynamic pressure acting on a dual porous horizontal plate
Kweon Hyuck-Min
2014-03-01
Full Text Available The seaward reverse wave, occurring on the submerged dual porous horizontal plate, can contribute to the reduction of the transmitted wave as it reflects the propagating wave. However, the collision between the propa¬gating and seaward reverse waves increases the water level and acts as a weight on the horizontal plate. This study investigated the characteristics of the wave pressure created by the seaward reverse wave through the analysis of expe¬rimental data. The analysis confirmed the following results: 1 the time series of the wave pressure showed reverse phase phenomena due to the collision, and the wave pressures acted simultaneously on both upper and lower surfaces of the horizontal plate; 2 the horizontal plate became repeatedly compressed and tensile before and after the occur¬rence of the seaward reverse wave; and 3 the seaward reverse wave created the total wave pressure to the maximum towards the direction of gravity, primarily on the upper plate. It was also confirmed that the wave distributions showed a similar trend to the wave steepness. Such outcome of the analysis will provide basic information to the structural analysis of the horizontal plate as a wave dissipater of the steel-type breakwater (STB.
Untapped Resources: Assistant Principals as Instructional Leaders
Bartholomew, Selma K.; Melendez-Delaney, Genis; Orta, Awilda; White, Sharon
2005-01-01
Assistant principals are often overlooked as a resource for creating, advancing, and sustaining a compelling vision for mathematics. The Math Collaborative Project developed in New York City examined the process of developing and implementing programs designed to help assistant principals network and strengthen their instructional leadership…
New Principals' Perspectives of Their Multifaceted Roles
Gentilucci, James L.; Denti, Lou; Guaglianone, Curtis L.
2013-01-01
This study utilizes Symbolic Interactionism to explore perspectives of neophyte principals. Findings explain how these perspectives are modified through complex interactions throughout the school year, and they also suggest preparation programs can help new principals most effectively by teaching "soft" skills such as active listening…
Perceived Educational Values of Omani School Principals
Al-Ani, Wajeha Thabit; Al-Harthi, Aisha Salim
2017-01-01
This qualitative study investigated the perceived educational values of Omani school principals. Data were collected using a semi-structured interview form which focused on the core values of school administration as perceived by a sample of 44 school principals; a focus group interview was also held. Data were analysed using Nvivo software. The…
Principals: Human Capital Managers at Every School
Kimball, Steven M.
2011-01-01
Being a principal is more than just being an instructional leader. Principals also must manage their schools' teaching talent in a strategic way so that it is linked to school instructional improvement strategies, to the competencies needed to enact the strategies, and to success in boosting student learning. Teacher acquisition and performance…
Assistant Principals: Their Readiness as Instructional Leaders
Searby, Linda; Browne-Ferrigno, Tricia; Wang, Chih-hsuan
2017-01-01
This article reports findings from a study investigating the capacity of assistant principals to be instructional leaders. Analyses of survey responses yielded four interesting findings: (a) years of experience as a teacher and age had no significance on assistant principals' perceived readiness as an instructional leader; (b) those completing…
Career Paths of Female Elementary Assistant Principals
Baier, Hope C.
2013-01-01
The purpose of this research was to explore the worklife experiences and personal issues of female elementary assistant principals and examine the influence of these factors on their intent to remain in their position or leave. The worklife experiences and perceptions of female elementary assistant principals were categorized as institutional or…
Assistant Principals and Reform: A Socialization Paradox?
Best, Marguerita L.
2013-01-01
Framed in the critical race theory of structuration (CRTS), this sequential explanatory mixed methods study seeks to identify the socialization practices by examining the realities of practices of assistant principals and the ways in which they impact the disciplinary actions of assistant principals at middle and high schools. The mixed methods…
Principals as Maverick Leaders: Rethinking Democratic Schools
Walker, Sharron Goldman; Chirichello, Michael
2011-01-01
After her school wins the coveted United States National Secondary Education Award, a school principal embarks upon an educational odyssey. The principal discovers that the reasons for winning the award are a sham! As her school falls apart, she begins to reflect on the stagnant school organization and the ineffective prescriptions for…
Principals' Perceptions of School Public Relations
Morris, Robert C.; Chan, Tak Cheung; Patterson, Judith
2009-01-01
This study was designed to investigate school principals' perceptions on school public relations in five areas: community demographics, parental involvement, internal and external communications, school council issues, and community resources. Findings indicated that principals' concerns were as follows: rapid population growth, change of…
Principals' Pupil Control Behavior and School Robustness.
Smedley, Stanley R.; Willower, Donald J.
1981-01-01
A survey of 3,100 students, teachers, and principals in 47 elementary and secondary schools in the Middle Atlantic region, using the Pupil Control Behavior Form, revealed a positive association between principals' humanistic pupil control behavior and schools'"robustness" (the degree of meaning and excitement students find in school).…
Geographical Distribution of Principals in Israeli Schools
Lebental, Dana M.
2015-01-01
This quantitative investigation focuses on women high school principals at Jewish secular schools throughout Israel. Despite challenges, Israeli women have succeeded in obtaining over half of the principal positions at Jewish secular high schools, but the degree to which there is equal gender access to leadership roles in the school system remains…
Principals: Human Capital Managers at Every School
Kimball, Steven M.
2011-01-01
Being a principal is more than just being an instructional leader. Principals also must manage their schools' teaching talent in a strategic way so that it is linked to school instructional improvement strategies, to the competencies needed to enact the strategies, and to success in boosting student learning. Teacher acquisition and performance…
A Latina Principal Leading for Social Justice
Hernandez, Frank; Murakami, Elizabeth T.; Cerecer, Patricia Quijada
2014-01-01
In this study, the role that racial identity plays among Latina school principals is examined through a case study of a principal in a K-3 elementary school. Based on a Latina/o critical race framework and a phenomenological research approach, the study explores the degree to which having a strong understanding of one's racial identity…
Instructional Leadership: Are Women Principals Better?
Andrews, Richard L.; Basom, Margaret R.
1990-01-01
A 1984 study found that female elementary school principals spent 38.4 percent of their time on instructional leadership activities, while their male counterparts spent only 21.8 percent. A 1989 follow-up study found that women principals were more likely to be seen by their staffs as instructional leaders. A sidebar examines sex discrimination in…
Evaluation of Principals; Leadership Excellence Achievement Plan.
Redfern, George B.; Hersey, Paul W.
1981-01-01
The Leadership Excellence Achievement Plan (LEAP) presented here is a way for principals to improve leadership ability with an emphasis on evaluation. It first recommends formulating a precise definition of the principal's job divided into three areas: technical competencies, administrative skills, and performance goals. Among the technical…
Assistant Principals and Reform: A Socialization Paradox?
Best, Marguerita L.
2013-01-01
Framed in the critical race theory of structuration (CRTS), this sequential explanatory mixed methods study seeks to identify the socialization practices by examining the realities of practices of assistant principals and the ways in which they impact the disciplinary actions of assistant principals at middle and high schools. The mixed methods…
Micropolitics: Empowering Principals to Accomplish Goals.
Cilo, Daniel C.
1994-01-01
Examines how principals manage in situations that defy conventional administrative authority and methods. Fully 80% of the 30 Pennsylvania high school principals interviewed admitted using at least 1 micropolitical strategy, such as exchange theory, divide and conquer, information control, cooptation, displacement, and discretionary behavior. Most…
Elementary Principals' Role in Science Instruction
Casey, Patricia; Dunlap, Karen; Brown, Kristen; Davison, Michele
2012-01-01
This study explores the role elementary school principals play in science education. Specifically, the study employed an online survey of 16 elementary school principals at high-performing campuses in North Texas to explore their perceptions of how they influenced science education on their campuses. The survey used a combination of Likert-type…
Permutation Tests in Principal Component Analysis.
Pohlmann, John T.; Perkins, Kyle; Brutten, Shelia
Structural changes in an English as a Second Language (ESL) 30-item reading comprehension test were examined through principal components analysis on a small sample (n=31) of students. Tests were administered on three occasions during intensive ESL training. Principal components analysis of the items was performed for each test occasion.…
Social Media Strategies for School Principals
Cox, Dan; McLeod, Scott
2014-01-01
The purpose of this qualitative study was to describe, analyze, and interpret the experiences of school principals who use multiple social media tools with stakeholders as part of their comprehensive communications practices. Additionally, it examined why school principals have chosen to communicate with their stakeholders through social media.…
Women Principals Leading Learning at "Poverty's Edge"
Lyman, Linda L.
2008-01-01
The author profiles two women principals of color who have successfully enhanced student learning in high-poverty schools. In their leadership narratives, the principals address how the complexity of poverty affects their work, how they affirm the worth and dignity of all, how they influence beliefs and attitudes of staff, why they think their…
Women Principals Leading Learning at "Poverty's Edge"
Lyman, Linda L.
2008-01-01
The author profiles two women principals of color who have successfully enhanced student learning in high-poverty schools. In their leadership narratives, the principals address how the complexity of poverty affects their work, how they affirm the worth and dignity of all, how they influence beliefs and attitudes of staff, why they think their…
Instructional or Managerial Leadership: The Principal Role!
Jazzar, Michael
2004-01-01
"Instructional Or Managerial Leadership: The Principal Role" is a case study written to challenge the beliefs of graduate students preparing for educational leadership roles and educational leaders already in these positions as to the importance of the principal as an instructional leader. This case explores communication between superintendents…
A Latina Principal Leading for Social Justice
Hernandez, Frank; Murakami, Elizabeth T.; Cerecer, Patricia Quijada
2014-01-01
In this study, the role that racial identity plays among Latina school principals is examined through a case study of a principal in a K-3 elementary school. Based on a Latina/o critical race framework and a phenomenological research approach, the study explores the degree to which having a strong understanding of one's racial identity formation…
Superintendents' Perceptions of the Principal Shortage
Pijanowski, John C.; Hewitt, Paul M.; Brady, Kevin P.
2009-01-01
The research literature on the principal shortage is inconsistent regarding the actual scope of the shortage and a clear articulation of factors contributing to the successful recruitment and retention of today's school leaders. Often, critical data related to the principal shortage are ignored, including the number of younger principals…
Exploring Principals' Perceptions of Supervised Agricultural Experience
Rayfield, John; Wilson, Elizabeth
2009-01-01
This study explored the perceptions of principals at high schools with agricultural education programs in regard to Supervised Agricultural Experience (SAE). There is evidence that suggests that high school principals' attitudes may both directly and indirectly affect factors that influence school climate and student achievement. In this study,…
Investigating Roles of Online School Principals
Quilici, Sarah B.; Joki, Russell
2012-01-01
This study explores the instructional leadership skills required from online principals, as defined by one state's (Idaho) adaptation of the Interstate School Leaders Licensure Consortium (ISLLC) standards (1996) as a requirement for professional certification. Specifically, this qualitative study examined six sets of paired online principals and…
School Principal Speech about Fiscal Mismanagement
Hassenpflug, Ann
2015-01-01
A review of two recent federal court cases concerning school principals who experienced adverse job actions after they engaged in speech about fiscal misconduct by other employees indicates that the courts found that the principal's speech was made as part of his or her job duties and was not protected by the First Amendment.
Social Media Strategies for School Principals
Cox, Dan; McLeod, Scott
2014-01-01
The purpose of this qualitative study was to describe, analyze, and interpret the experiences of school principals who use multiple social media tools with stakeholders as part of their comprehensive communications practices. Additionally, it examined why school principals have chosen to communicate with their stakeholders through social media.…
Estimating Principal Effectiveness. Working Paper 32
Branch, Gregory; Hanushek, Eric; Rivkin, Steven
2009-01-01
Much has been written about the importance of school leadership, but there is surprisingly little systematic evidence on this topic. This paper presents preliminary estimates of key elements of the market for school principals, employing rich panel data on principals from Texas State. The consideration of teacher movements across schools suggests…
Framing Research on School Principals' Identities
Crow, Gary; Day, Christopher; Møller, Jorunn
2017-01-01
This paper provides a basis for a tentative framework for guiding future research into principals' identity construction and development. It is situated in the context of persisting emphases placed by government policies on the need for technocratic competencies in principals as a means of demonstrating success defined largely as compliance with…
Should Principals Know More about Law?
Doctor, Tyrus L.
2013-01-01
Educational law is a critical piece of the education conundrum. Principals reference law books on a daily basis in order to address the wide range of complex problems in the school system. A principal's knowledge of law issues and legal decision-making are essential to provide effective feedback for a successful school.
Principals as Maverick Leaders: Rethinking Democratic Schools
Walker, Sharron Goldman; Chirichello, Michael
2011-01-01
After her school wins the coveted United States National Secondary Education Award, a school principal embarks upon an educational odyssey. The principal discovers that the reasons for winning the award are a sham! As her school falls apart, she begins to reflect on the stagnant school organization and the ineffective prescriptions for…
New and Modified Equations for Planning Two-Buildup Directional and Horizontal Wells
Sun Tengfei
2013-03-01
Full Text Available Two-buildup directional and horizontal well is usually used for the type trajectory that the target zone is accurate but build rate is not. In the past and at present, the petroleum engineers use the Karlsson method and equations to design the two-buildup directional and horizontal well. But through rigid derivation and analysis, we have found some places that need to be improved. This study has put forward new and modified equations on the basis of Karlsson method. The new method considers the maximum and minimum build rates expected in the first and second curves and supposes that the upper and lower bound trajectory are all two-build up trajectory type. This study also has considered the difference of the maximum and minimum build rates expected in the second curve and the first curve. The new and modified method and equations are tested through two examples.
Maximum entropy production in daisyworld
Maunu, Haley A.; Knuth, Kevin H.
2012-05-01
Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.
Maximum stellar iron core mass
F W Giacobbe
2003-03-01
An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is signiﬁcantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.
Maximum Matchings via Glauber Dynamics
Jindal, Anant; Pal, Manjish
2011-01-01
In this paper we study the classic problem of computing a maximum cardinality matching in general graphs $G = (V, E)$. The best known algorithm for this problem till date runs in $O(m \\sqrt{n})$ time due to Micali and Vazirani \\cite{MV80}. Even for general bipartite graphs this is the best known running time (the algorithm of Karp and Hopcroft \\cite{HK73} also achieves this bound). For regular bipartite graphs one can achieve an $O(m)$ time algorithm which, following a series of papers, has been recently improved to $O(n \\log n)$ by Goel, Kapralov and Khanna (STOC 2010) \\cite{GKK10}. In this paper we present a randomized algorithm based on the Markov Chain Monte Carlo paradigm which runs in $O(m \\log^2 n)$ time, thereby obtaining a significant improvement over \\cite{MV80}. We use a Markov chain similar to the \\emph{hard-core model} for Glauber Dynamics with \\emph{fugacity} parameter $\\lambda$, which is used to sample independent sets in a graph from the Gibbs Distribution \\cite{V99}, to design a faster algori...
2011-01-10
...: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and... facilities of their responsibilities, under Federal integrity management (IM) regulations, to perform... system, especially when calculating Maximum Allowable Operating Pressure (MAOP) or Maximum Operating...
Time series analysis by the Maximum Entropy method
Kirk, B.L.; Rust, B.W.; Van Winkle, W.
1979-01-01
The principal subject of this report is the use of the Maximum Entropy method for spectral analysis of time series. The classical Fourier method is also discussed, mainly as a standard for comparison with the Maximum Entropy method. Examples are given which clearly demonstrate the superiority of the latter method over the former when the time series is short. The report also includes a chapter outlining the theory of the method, a discussion of the effects of noise in the data, a chapter on significance tests, a discussion of the problem of choosing the prediction filter length, and, most importantly, a description of a package of FORTRAN subroutines for making the various calculations. Cross-referenced program listings are given in the appendices. The report also includes a chapter demonstrating the use of the programs by means of an example. Real time series like the lynx data and sunspot numbers are also analyzed. 22 figures, 21 tables, 53 references.
The Sherpa Maximum Likelihood Estimator
Nguyen, D.; Doe, S.; Evans, I.; Hain, R.; Primini, F.
2011-07-01
A primary goal for the second release of the Chandra Source Catalog (CSC) is to include X-ray sources with as few as 5 photon counts detected in stacked observations of the same field, while maintaining acceptable detection efficiency and false source rates. Aggressive source detection methods will result in detection of many false positive source candidates. Candidate detections will then be sent to a new tool, the Maximum Likelihood Estimator (MLE), to evaluate the likelihood that a detection is a real source. MLE uses the Sherpa modeling and fitting engine to fit a model of a background and source to multiple overlapping candidate source regions. A background model is calculated by simultaneously fitting the observed photon flux in multiple background regions. This model is used to determine the quality of the fit statistic for a background-only hypothesis in the potential source region. The statistic for a background-plus-source hypothesis is calculated by adding a Gaussian source model convolved with the appropriate Chandra point spread function (PSF) and simultaneously fitting the observed photon flux in each observation in the stack. Since a candidate source may be located anywhere in the field of view of each stacked observation, a different PSF must be used for each observation because of the strong spatial dependence of the Chandra PSF. The likelihood of a valid source being detected is a function of the two statistics (for background alone, and for background-plus-source). The MLE tool is an extensible Python module with potential for use by the general Chandra user.
Vestige: Maximum likelihood phylogenetic footprinting
Maxwell Peter
2005-05-01
Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational
The Rookie's Playbook: Insights and Dirt for New Principals.
Tooms, Autumn
2003-01-01
Principal shares lessons and insights with beginning principals. Discusses differences between principals and assistant principals, staff relationships, competition for resources, giving and receiving loyalty, identifying and following a moral compass. (PKP)
Characteristics of Buoyancy Driven Natural Ventilation through Horizontal Openings
Li, Zhigang
and smoke. Air flow through vertical openings has been widely investigated but little is known about the flow in the horizontal openings, especially when they are driven by buoyancy. A literature survey shows that the brine-water system and the scale model are normally used forthe research work of air flow...... through horizontal openings. Two cases of full-scale measurements of buoyancy driven natural ventilation through horizontal openings are performed: one horizontal opening and one horizontal opening combined with one vertical opening. For the case of one horizontal opening, the measurements are made...
The horizontal plane appearances of scoliosis
Illés, Tamás S.; Burkus, Máté; Somoskeőy, Szabolcs
2017-01-01
Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two-/three-dimen......Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two...... of scoliosis. The approach used is simple. These results are sufficient for a first visual analysis furnishing significant clinical information in all three anatomical planes. This visualization represents a reasonable compromise between mathematical purity and practical use....
Kinematics of horizontal and vertical caterpillar crawling.
van Griethuijsen, Linnea I; Trimmer, Barry A
2009-05-01
Unlike horizontal crawling, vertical crawling involves two counteracting forces: torque rotating the body around its center of mass and gravity resisting forward movement. The influence of these forces on kinematics has been examined in the soft-bodied larval stage of Manduca sexta. We found that crawling and climbing are accomplished using the same movements, with both segment timing and proleg lift indistinguishable in horizontal and vertical locomotion. Minor differences were detected in stride length and in the delay between crawls, which led to a lower crawling speed in the vertical orientation. Although these differences were statistically significant, they were much smaller than the variation in kinematic parameters between animals. The ability of Manduca to crawl and climb using the same movements is best explained by Manduca's relatively small size, slow speed and strong, controlled, passive grip made possible by its proleg/crochets.
Detecting series periodicity with horizontal visibility graphs
Núñez, Angel M; Valero, Eusebio; Gómez, Jose Patricio; Luque, Bartolo
2011-01-01
The horizontal visibility algorithm has been recently introduced as a mapping between time series and networks. The challenge lies in characterizing the structure of time series (and the processes that generated those series) using the powerful tools of graph theory. Recent works have shown that the visibility graphs inherit several degrees of correlations from their associated series, and therefore such graph theoretical characterization is in principle possible. However, both the mathematical grounding of this promising theory and its applications are on its infancy. Following this line, here we address the question of detecting hidden periodicity in series polluted with a certain amount of noise. We first put forward some generic properties of horizontal visibility graphs which allow us to define a (graph theoretical) noise reduction filter. Accordingly, we evaluate its performance for the task of calculating the period of noisy periodic signals, and compare our results with standard time domain (autocorre...
Buoyancy Driven Natural Ventilation through Horizontal Openings
Heiselberg, Per; Li, Zhigang
2009-01-01
An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... injection tracer gas technique. Smoke visualizations showed that the airflow patterns are highly transient and unstable, and that the airflow rate oscillates with time. Correlations between the Froude (Archimedes) number Fr (Ar) and the L/D ratio are presented. In some cases the measured airflow rates fit...
Horizontal Bilayer for Electrical and Optical Recordings
Alf Honigmann
2012-12-01
Full Text Available Artificial bilayer containing reconstituted ion channels, transporters and pumps serve as a well-defined model system for electrophysiological investigations of membrane protein structure–function relationship. Appropriately constructed microchips containing horizontally oriented bilayers with easy solution access to both sides provide, in addition, the possibility to investigate these model bilayer membranes and the membrane proteins therein with high resolution fluorescence techniques up to the single-molecule level. Here, we describe a bilayer microchip system in which long-term stable horizontal free-standing and hydrogel-supported bilayers can be formed and demonstrate its prospects particularly for single-molecule fluorescence spectroscopy and high resolution fluorescence microscopy in probing the physicochemical properties like phase behavior of the bilayer-forming lipids, as well as in functional studies of membrane proteins.
Grissom, Jason A.; Loeb, Susanna; Mitani, Hajime
2015-01-01
Purpose: Time demands faced by school principals make principals' work increasingly difficult. Research outside education suggests that effective time management skills may help principals meet job demands, reduce job stress, and improve their performance. The purpose of this paper is to investigate these hypotheses. Design/methodology/approach:…
What Is a "Good" Principal? Perspectives of Aspiring Principals in Singapore
Ng, Pak Tee
2016-01-01
This paper presents the findings of an exploratory research project that examines what aspiring principals in Singapore think a good principal is, based on a framework of personal, interpersonal, and organizational dimensions of school leadership. According to the findings, a good principal has a moral purpose centered on personal values, a humble…
Principal Self-Efficacy and Work Engagement: Assessing a Norwegian Principal Self-Efficacy Scale
Federici, Roger A.; Skaalvik, Einar M.
2011-01-01
One purpose of the present study was to develop and test the factor structure of a multidimensional and hierarchical Norwegian Principal Self-Efficacy Scale (NPSES). Another purpose of the study was to investigate the relationship between principal self-efficacy and work engagement. Principal self-efficacy was measured by the 22-item NPSES. Work…
Principals and Blogs: In What Ways Does Blogging Support the Practices of School Principals?
Engebritson, Reggie Marie
2011-01-01
This study paper explores the factors that motivate school principals to blog and the effectiveness of those blogs in terms of instructional and technology leadership. Participants were school principals who blog and were sent a web-based survey. Fifty responded. Results indicate that principals blog to communicate to others, including parents,…
Grissom, Jason A.; Loeb, Susanna; Mitani, Hajime
2015-01-01
Purpose: Time demands faced by school principals make principals' work increasingly difficult. Research outside education suggests that effective time management skills may help principals meet job demands, reduce job stress, and improve their performance. The purpose of this paper is to investigate these hypotheses. Design/methodology/approach:…
Gas reservoir evaluation for underbalanced horizontal drilling
Li Gao
2014-01-01
Full Text Available A set of surface equipment for monitoring the parameters of fluid and pressure while drilling was developed, and mathematical models for gas reservoir seepage and wellbore two-phase flow were established. Based on drilling operation parameters, well structure and monitored parameters, the wellbore pressure and the gas reservoir permeability could be predicted theoretically for underbalanced horizontal drilling. Based on the monitored gas production along the well depth, the gas reservoir type could be identified.
Horizontal Symmetry: Bottom Up and Top Down
Lam, C S
2011-01-01
A group-theoretical connection between horizontal symmetry $\\G$ and fermion mixing is established, and applied to neutrino mixing. The group-theoretical approach is consistent with a dynamical theory based on $U(1)\\times \\G$, but the dynamical theory can be used to pick out the most stable mixing that purely group-theoretical considerations cannot. A symmetry common to leptons and quarks is also discussed. This higher symmetry picks $A_4$ over $S_4$ to be the preferred symmetry for leptons.
Convection in horizontally shaken granular material
Saluena, Clara; Poeschel, Thorsten
1998-01-01
In horizontally shaken granular material different types of pattern formation have been reported. We want to deal with the convection instability which has been observed in experiments and which recently has been investigated numerically. Using two dimensional molecular dynamics we show that the convection pattern depends crucial on the inelastic properties of the material. The concept of restitution coefficient provides arguments for the change of the behaviour with variing inelasticity.
R&D investments fostering horizontal mergers
Cabolis, C.; Manasakis, C.; MORENO, Diego; Petrakis, Emmanuel
2016-01-01
We study a homogenous good triopoly in which firms first choose their cost-reducing R&D investments and consider alternative merger proposals, and then compete à la Cournot in the ensuing industry. We identify conditions under which both horizontal mergers and non integration are sustained by Coalition-Proof Nash equilibria (CPNE). These conditions involve the effectiveness of the R&D technology, as well as the distribution of the bargaining power between the acquirer and the acquiree, which ...
Establishment and analyses on the unified horizontal crustal velocity fields in the Chinese mainland
无
2001-01-01
The related data of GPS networks in the Chinese mainland and its peripheral areas are collected from internet sites in the paper. And various data fusion methods are presented based on the collected GPS data. Thus the unified horizontal crustal velocity fields can be established in the Chinese mainland and its peripheral areas. The available data of 423 GPS sites are applied to the velocity fields and its area gets to 1.2′107 km2. By analyzing the velocity fields, the basic spatial distribution feature of the horizontal crustal motion in the Chinese mainland and its peripheral area can be obtained preliminarily. Meanwhile, the range of the velocity fields in the Chinese mainland affected by the collision force of India plate to Eurasia plate and the problem of principal direction of the force from India plate are discussed.
Thermal transient analysis applied to horizontal wells
Duong, A.N. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada)
2008-10-15
Steam assisted gravity drainage (SAGD) is a thermal recovery process used to recover bitumen and heavy oil. This paper presented a newly developed model to estimate cooling time and formation thermal diffusivity by using a thermal transient analysis along the horizontal wellbore under a steam heating process. This radial conduction heating model provides information on the heat influx distribution along a horizontal wellbore or elongated steam chamber, and is therefore important for determining the effectiveness of the heating process in the start-up phase in SAGD. Net heat flux estimation in the target formation during start-up can be difficult to measure because of uncertainties regarding heat loss in the vertical section; steam quality along the horizontal segment; distribution of steam along the wellbore; operational conditions; and additional effects of convection heating. The newly presented model can be considered analogous to pressure transient analysis of a buildup after a constant pressure drawdown. The model is based on an assumption of an infinite-acting system. This paper also proposed a new concept of a heating ring to measure the heat storage in the heated bitumen at the time of testing. Field observations were used to demonstrate how the model can be used to save heat energy, conserve steam and enhance bitumen recovery. 18 refs., 14 figs., 2 appendices.
Vertical and horizontal seismometric observations of tides
Lambotte, S.; Rivera, L.; Hinderer, J.
2006-01-01
Tidal signals have been largely studied with gravimeters, strainmeters and tiltmeters, but can also be retrieved from digital records of the output of long-period seismometers, such as STS-1, particularly if they are properly isolated. Horizontal components are often noisier than the vertical ones, due to sensitivity to tilt at long periods. Hence, horizontal components are often disturbed by local effects such as topography, geology and cavity effects, which imply a strain-tilt coupling. We use series of data (duration larger than 1 month) from several permanent broadband seismological stations to examine these disturbances. We search a minimal set of observable signals (tilts, horizontal and vertical displacements, strains, gravity) necessary to reconstruct the seismological record. Such analysis gives a set of coefficients (per component for each studied station), which are stable over years and then can be used systematically to correct data from these disturbances without needing heavy numerical computation. A special attention is devoted to ocean loading for stations close to oceans (e.g. Matsushiro station in Japon (MAJO)), and to pressure correction when barometric data are available. Interesting observations are made for vertical seismometric components; in particular, we found a pressure admittance between pressure and data 10 times larger than for gravimeters for periods larger than 1 day, while this admittance reaches the usual value of -3.5 nm/s 2/mbar for periods below 3 h. This observation may be due to instrumental noise, but the exact mechanism is not yet understood.
Pullback load simulation on large Horizontal Directional Drilling (HDD)
Avesani Neto, Jose O.; Placido, Rafael R.; Martins, Pedro R.R.; Rocha, Ronaldo [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo (IPT), Sao Paulo, SP (Brazil)
2009-07-01
One of the most popular trenchless technology currently used for pipeline construction in Brazil and worldwide is Horizontal Directional Drilling (HDD). The principal application of HDD is in crossings of water bodies. However this technology has applications in several situations as environmental sensitive areas, densely populated areas, areas prone to mass movement and anywhere the traditional technology is not suitable because of potential risks . One of the problems in HDD of large lengths is the strength of product pipes. During the pullback stage, the product pipe may be subjected to high loads that can be harmful to its structure and endanger the installation. This paper presents evaluations of pullback loads during large HDD installations. The calculations were carried out using the PRCI (Petroleum Research Council International) model, which is traditionally used by HDD designers for predicting pulling loads. The predictions were performed varying the pipe diameter from 10 inches to 40 inches and the pipeline length from 2000 m to 10000 m. The results showed that under the aspects of pipe load capacity and currently available equipment, pipelines larger than 20 inches diameter and 5000 m length are possible to be installed by HDD. (author)
Small scale wind energy harvesting with maximum power tracking
Joaquim Azevedo
2015-07-01
Full Text Available It is well-known that energy harvesting from wind can be used to power remote monitoring systems. There are several studies that use wind energy in small-scale systems, mainly with wind turbine vertical axis. However, there are very few studies with actual implementations of small wind turbines. This paper compares the performance of horizontal and vertical axis wind turbines for energy harvesting on wireless sensor network applications. The problem with the use of wind energy is that most of the time the wind speed is very low, especially at urban areas. Therefore, this work includes a study on the wind speed distribution in an urban environment and proposes a controller to maximize the energy transfer to the storage systems. The generated power is evaluated by simulation and experimentally for different load and wind conditions. The results demonstrate the increase in efficiency of wind generators that use maximum power transfer tracking, even at low wind speeds.
Genetics Home Reference: horizontal gaze palsy with progressive scoliosis
... Health Conditions HGPPS horizontal gaze palsy with progressive scoliosis Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Horizontal gaze palsy with progressive scoliosis ( HGPPS ) is a disorder that affects vision and ...
Families in Crisis: What Principals Say.
National Elementary Principal, 1979
1979-01-01
Of principals responding to a survey, 95 percent agreed that children show behavioral and academic problems when their parents are undergoing separation or divorce. Offered are specific suggestions to help one-parent families adjust. (Author/LD)
Principal Hawaiian Islands Geoid Heights (GEOID96)
National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for the Principal Hawaiian Islands is distributed as a GEOID96 model. The computation used 61,000 terrestrial and marine gravity data held...
A Comparative Study of Principals' Administrative Behaviour.
Chung, Kyung Ae
1989-01-01
Compared are the managerial behaviors and beliefs of Korean and American secondary school principals. Generalizations are proposed in the areas of work hours, work pace, communication skills, organizational style, instructional leadership, and other managerial behaviors. (16 references) (SI)
Principal Leader Behaviour and Shared Decision Making.
Moyle, Colin R. J.
1979-01-01
The leadership of the principal is a crucial factor in the functioning of the Instructional Improvement Committees (IICs) in the multiunit schools studies. IICs are representative cabinet-type leadership committees. (Author/IRT)
Noncommutative principal bundles through twist deformation
Aschieri, Paolo; Pagani, Chiara; Schenkel, Alexander
2016-01-01
We construct noncommutative principal bundles deforming principal bundles with a Drinfeld twist (2-cocycle). If the twist is associated with the structure group then we have a deformation of the fibers. If the twist is associated with the automorphism group of the principal bundle, then we obtain noncommutative deformations of the base space as well. Combining the two twist deformations we obtain noncommutative principal bundles with both noncommutative fibers and base space. More in general, the natural isomorphisms proving the equivalence of a closed monoidal category of modules and its twist related one are used to obtain new Hopf-Galois extensions as twists of Hopf-Galois extensions. A sheaf approach is also considered, and examples presented.
Check List: Are You a Gifted Principal?
Taylor, Vicki L.
1984-01-01
An 18-item check list is provided for principals to evaluate themselves relative to encouraging gifts and talents of their most able students. Suggestions are given in the areas of educational needs, specialized materials, and counseling. (MC)
Paranoia: Perceptions of Public School Principals.
Salmon, Daniel A.
1980-01-01
Examines forces which are undermining the principal's leadership role and ability to effectively administer the school: teachers and unions; the competency movement; political and community interest groups; and media pundits. (SJL)
1 Reevaluation of the integrated horizontal flux approach
Neftel, Albrecht; Häni, Christoph; Hensen, Arjan
2017-04-01
The integrated horizontal flux (IHF) method is a simplified mass balance approach frequently used to determine emissions from confined source areas, e.g. NH3 emissions from slurry spread to a circular plot (Denmead, 2008). With a mast in the center of the circle with radius R, the total flux F of the upwind emitted NH3 is approximated from the measured vertical (z) profiles of concentration (c) and horizontal wind speed (u) as (Denmead 1983): F = 1/R\\intz=zplz=0\\overline{u(c - cbgd)}dz where cbgd is the ``background'' concentration upwind of the emitting area and zpl is the maximum height of the emission plume (where the concentration c equals cbgd).The IHF method is a robust approach, as it is independent of surface characteristics and the state of atmospheric diffusion (Denmead, 2008; Laubach,2010). Ryden and McNeill (1984) published guidelines on how to evaluate IHF measurements, which have been used in many investigations that followed. In the following we analyze systematic biases that might occur by applying different recipes to both modelled concentration profiles as well as measured profiles from a recent field experiment in the Netherlands. Typical differencs using the approach by Ryden et al. (1984) are in the order +10% to +30% compared to the reference values from the model or alternative determination of the emissions based on the experimental values. The positive biases consist of several contributions: horizontal diffusion, logarithmic fit of the concentration profile, displacement height. References Denmead, O. T., 1983. Micrometeorological methods for measuring gaseous losses of nitrogen in the field. In: Gaseous Loss of Nitrogen from Plum-Soil Systems (Freney, J. R.; Simpson, J. R., Eds) Martinus Nijhof/Dr W. Junk, The Hague, pp. 133-157. Denmead, O. T., 2008. Approaches to measuring fluxes of methane and nitrous oxide between landscapes and the atmosphere. Plant Soil 309 (1-2), 5a\\euro 24.Laubach, J., 2010. Testing of a lagrangian model of
General frame structures on quantum principal bundles
Durdevic, M
1996-01-01
A noncommutative-geometric generalization of the classical formalism of frame bundles is developed, incorporating into the theory of quantum principal bundles the concept of the Levi-Civita connection. The construction of a natural differential calculus on quantum principal frame bundles is presented, including the construction of the associated differential calculus on the structure group. General torsion operators are defined and analyzed. Illustrative examples are presented.
A Geometric Approach to Noncommutative Principal Bundles
Wagner, Stefan
2011-01-01
From a geometrical point of view it is, so far, not sufficiently well understood what should be a "noncommutative principal bundle". Still, there is a well-developed abstract algebraic approach using the theory of Hopf algebras. An important handicap of this approach is the ignorance of topological and geometrical aspects. The aim of this thesis is to develop a geometrically oriented approach to the noncommutative geometry of principal bundles based on dynamical systems and the representation theory of the corresponding transformation group.
Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local
Ros, Rosa M.
2009-12-01
The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)
Immorally obtained principal increases investors’ risk preference
Chen, Jiaxin; He, Guibing
2017-01-01
Capital derived from immoral sources is increasingly circulated in today’s financial markets. The moral associations of capital are important, although their impact on investment remains unknown. This research aims to explore the influence of principal source morality on investors’ risk preferences. Three studies were conducted in this regard. Study 1 finds that investors are more risk-seeking when their principal is earned immorally (through lying), whereas their risk preferences do not change when they invest money earned from neutral sources after engaging in immoral behavior. Study 2 reveals that guilt fully mediates the relationship between principal source morality and investors’ risk preferences. Studies 3a and 3b introduce a new immoral principal source and a new manipulation method to improve external validity. Guilt is shown to the decrease the subjective value of morally flawed principal, leading to higher risk preference. The findings show the influence of morality-related features of principal on people’s investment behavior and further support mental account theory. The results also predict the potential threats of “grey principal” to market stability. PMID:28369117
Nutrition education for adolescents: principals' views.
Lai-Yeung, Wai-Ling Theresa
2011-01-01
This study aimed to examine school principals' perceptions of the school environment in Hong Kong as a context for the dissemination of food knowledge and inculcation of healthy eating habits. A questionnaire survey was administered in secondary schools in Hong Kong to survey Principals' views of students' food choices, operation of the school tuck shop, and promotion of healthy eating at school. Questionnaires were disseminated to all the secondary schools offering Home Economics (300 out of 466), and 188 schools responded, making up a response rate of 63%. Collected data were analyzed using SPSS. Most of the schools (82%) claimed to have a food policy to monitor the operation of the school canteen, and about half (52%) asserted there were insufficient resources to promote healthy eating at school. Principals (88%) generally considered it not acceptable for the school tuck shop to sell junk food; however, 45% thought that banning junk food at school would not help students develop good eating habits. Only 4% of the principals believed nutrition education influenced eating habits; whereas the majority (94%) felt that even with acquisition of food knowledge, students may not be able to put theory into practice. Cooking skills were considered important but principals (92%) considered transmission of cooking skills the responsibility of the students' families. Most of the principals (94%) believed that school-family collaboration is important in promoting healthy eating. Further efforts should be made to enhance the effectiveness of school food policies and to construct healthy school environments in secondary schools.
Horizontal routes: current paths of literary criticism in Latin America
Ariadne Costa da Mata
2013-07-01
Full Text Available In the last decades, the tendency towards horizontality became visible, particularly (but not only in social movements. Horizontality implies a new architecture in human organizations and pushes for changes in the way knowledge is produced and organized. More than a simple erosion of frontiers between fields, horizontality means the decentralization and dissemination of power.
Application of Horizontal Well Technology to Liaohe Oilfield
HanYun
2008-01-01
@@ Horizontal well technology has become one of the main technologies enabling Liaohe Oilfield to realize stable development. By the end of 2006, 296 horizontal wells of various kinds had been completed in Liaohe Oil Field,273 wells had been put into production, Among uhich 237 were horizontal wells (see Table 1).
YPF uses horizontal reentry to aid thin bed production
Acosta, M.R.; Leiro, F.A.; Sesano, G.S. [Yacimientos Petroliferos Fiscales, La Paz (Bolivia); Hill, D.
1997-01-01
Reentry and horizontal drilling/completion techniques have proven themselves useful in exploiting thin beds. A pilot horizontal reentry contracted by Yacimiento Petroliferos Fiscales (YPF) for a marginal well in its Lomita Sur field resulted in decreased water coning and production rates four times greater than expected. Further horizontal reentries in this thin-bed field are planned.
Variation in terminology: capoeira in Belo Horizonte
César Nardelli Cambraia
2014-12-01
Full Text Available In this pilot study we analyzed the variation in the terminology of capoeira in Belo Horizonte. The terms referring to 69 videotaped movements of capoeira were collected from 10 informants (5 men and 5 women, aged between 25 and 32 years, capoeira teachers. As a result we obtained 294 different terms whose patterns of variation are distributed among 15 types. We tested the hypothesis that the figurative terms tend to be replaced by non-figurative ones, and it was confirmed by the collected data. This trend was the result of a search for transparency in terminology, making the terms more descriptive in relation to capoeira’s movements.
Impulse absorption by horizontal magnetic granular chain
Dingxin Leng
2016-02-01
Full Text Available The granular medium is known as a protecting material for shock mitigation. We study the impulse absorption of an alignment of magnetic spheres placed horizontally under a non-uniform magnetic field. The phenomenon of the wave dispersion is presented. This system can absorb 85% ∼ 95% (88% ∼ 98% of the incident peak force (energy under the applied magnetic field strength in 0.1 T ∼ 1.0 T. The shock attenuation capacities are enhanced by the increment of field strength. With an intelligent control system, it is conceivable that the magnetic granular chain may offer possibilities in developing adaptive shock protectors.
Does horizontal transmission invalidate cultural phylogenies?
Greenhill, Simon J; Currie, Thomas E; Gray, Russell D
2009-06-22
Phylogenetic methods have recently been applied to studies of cultural evolution. However, it has been claimed that the large amount of horizontal transmission that sometimes occurs between cultural groups invalidates the use of these methods. Here, we use a natural model of linguistic evolution to simulate borrowing between languages. The results show that tree topologies constructed with Bayesian phylogenetic methods are robust to realistic levels of borrowing. Inferences about divergence dates are slightly less robust and show a tendency to underestimate dates. Our results demonstrate that realistic levels of reticulation between cultures do not invalidate a phylogenetic approach to cultural and linguistic evolution.
Fluidization of a horizontally driven granular monolayer.
Heckel, Michael; Sack, Achim; Kollmer, Jonathan E; Pöschel, Thorsten
2015-06-01
We consider the transition of a horizontally vibrated monodisperse granular monolayer between its condensed state and its three-dimensional gaseous state as a function of the vibration parameters, amplitude, and frequency as well as particle number density. The transition is characterized by an abrupt change of the dynamical state which leaves its fingerprints in several measurable quantities including dissipation rate, sound emission, and a gap size which characterizes the sloshing motion of the material. The transition and its pronounced hysteresis is explained through the energy due to the collective motion of the particles relative to the container.
Horizontal stability of a bouncing ball
McBennett, Brendan G.; Harris, Daniel M.
2016-09-01
We present an investigation of a partially elastic ball bouncing on a vertically vibrated concave parabolic surface in two dimensions. In particular, we demonstrate that simple vertical motion, wherein the ball bounces periodically at the parabola's vertex, is unstable to horizontal perturbations when the parabolic coefficient defining the surface shape exceeds a critical value. The result is a new periodic solution where the ball bounces laterally over the vertex. As the parabola is further steepened, this new solution also becomes unstable which gives rise to other complex periodic and chaotic bouncing states, all characterized by persistent lateral motion.
Receiver function estimated by maximum entropy deconvolution
吴庆举; 田小波; 张乃铃; 李卫平; 曾融生
2003-01-01
Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.
13 CFR 107.845 - Maximum rate of amortization on Loans and Debt Securities.
2010-01-01
... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum rate of amortization on... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES Financing of Small Businesses by Licensees Structuring... rate of amortization on Loans and Debt Securities. The principal of any Loan (or the loan portion...
Maximum Power from a Solar Panel
Michael Miller
2010-01-01
Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.
Stratigraphic control and formation evaluation of horizontal wells with MWD
Hammons, L.R.B. (Eastman Teleco (United States)); Sellers, D.H.; Fisher, E.K. (Texaco Inc. (United States))
1992-10-01
Sandstone reservoirs in the Gulf of Mexico typically do not form horizontal planes, and a predetermined course for a horizontal well cannot ensure that the well path will remain within the producing interval throughout the horizontal section. Detecting approaching bed boundaries and fluid contacts early enough to make the changes necessary to keep the well path in the producing interval is an important technical issue during the planning and drilling of horizontal wells. This paper reports that the first two horizontal wells drilled in the Gulf of Mexico achieved this objective with measurement-while-drilling (MWD) resistivity measurements and with supporting computer modeling for bed boundary detection.
Generation of large-scale winds in horizontally anisotropic convection
von Hardenberg, J; Provenzale, A; Spiegel, E A
2015-01-01
We simulate three-dimensional, horizontally periodic Rayleigh-B\\'enard convection between free-slip horizontal plates, rotating about a horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind.
Novel "Superspreader" Bacteriophages Promote Horizontal Gene Transfer by Transformation.
Keen, Eric C; Bliskovsky, Valery V; Malagon, Francisco; Baker, James D; Prince, Jeffrey S; Klaus, James S; Adhya, Sankar L
2017-01-17
entities and kill vast numbers of bacteria in natural environments. Many of these bacteria carry plasmids, extrachromosomal DNA elements that frequently encode antibiotic resistance. However, it is largely unknown whether plasmids are destroyed during phage infection or released intact upon phage lysis, whereupon their encoded resistance could be acquired and manifested by other bacteria (transformation). Because phages are being developed to combat antibiotic-resistant bacteria and because transformation is a principal form of horizontal gene transfer, this question has important implications for biomedicine and microbial evolution alike. Here we report the isolation and characterization of two novel Escherichia coli phages, dubbed "superspreaders," that promote extensive plasmid transformation and efficiently disperse antibiotic resistance genes. Our work suggests that phage superspreaders are not suitable for use in medicine but may help drive bacterial evolution in natural environments. Copyright © 2017 Keen et al.
Wang, Hongzhao; Huo, Ming; An, Xiangde; Li, Yong; Onoda, Ko; Li, Desheng; Huang, Qiuchen; Chen, De; Yin, Lu; Maruyama, Hitoshi
2016-01-01
[Purpose] The aim of this study was to measure the changes in forefoot maximum medial/lateral rotation in the horizontal plane during progressive pace barefoot racewalking on a treadmill after a physically demanding aerobic exercise load (a fatigue protocol). [Subjects] Eleven junior racewalking men participated in this study. [Methods] To identify changes in forefoot maximum medial/lateral rotation in the horizontal plane after physically demanding aerobic exercise load, an 8 ch wireless Motion Recorder (MVP-RF8-BC) was utilized. [Results] Forefoot maximum medial/lateral rotation in the horizontal plane was significantly associated with increased paces during progressive pace treadmill racewalking. Significant increases in forefoot maximum medial/lateral rotation were observed during progressive pace barefoot racewalking on the instrumented treadmill at 8 km/h and 10 km/h after a physically demanding aerobic exercise load. [Conclusion] The findings of this study indicated that forefoot maximum medial/lateral rotation increased during progressive pace barefoot racewalking in the fatigue state after a physically demanding aerobic exercise load, which implies that the kinematic features of the forefoot are changed in the fatigue state.
Horizontal Air Bearing Experiment Number 1
Clauson, T.L.
1999-08-31
The Horizontal Air Bearing Experiment No.1 is a series of tests intended to further the understanding of rotational dynamics. A simple experimental assembly is rotated using the Horizontal Air Bearing and allowed to spin freely as the internal rotational damping is measured. The low friction of the bearing effectively isolates the test assembly, allowing the internal damping of the test object to be evaluated. The experimental assembly is composed of an aluminum ball within a spherical cavity. A flanged pipe section and an auxiliary adapter plate secure the assembly to the Air Bearing interface plate. Three aluminum balls are interchanged to vary test parameters. The aluminum balls are free to move independently as the entire assembly rotates. The aluminum balls vary in diameter and/or surface finish. While the diameter and surface finish is varied, the space between the ball and socket is dry. To examine the effect of viscosity, the space is filled with a lubricant while the ball diameter and surface finish is held constant.
The origin of extreme horizontal branch stars
Dorman, B; O'Connell, R W; Dorman, Ben; Rood, Robert T; O'Connell, Robert W
1995-01-01
Strong mass loss on the red giant branch (RGB) can result in the formation of extreme horizontal branch (EHB) stars. The EHB stars spend most of their He core and shell burning phase at high temperatures and produce copious ultraviolet flux. They have very small hydrogen envelopes and occupy a small range in mass. We have computed evolutionary RGB models with mass loss for stars with a range of metallicities at initial masses < 1.1 Msun corresponding to populations ages between 12.5 and 14.5 Gyr. We used the Reimers formula to characterize mass loss, but investigated a larger range of the mass loss efficiency parameter, eta, than is common. To understand how the number of EHB stars varies with metallicity in a stellar population we considered how the zero-age horizontal branch (ZAHB) is populated. The range in eta producing EHB stars is comparable to that producing `mid-HB' stars. Somewhat surprisingly, neither the range nor magnitude of eta producing EHB stars varies much metallicity. In contrast, the ran...
Applying GPS to check horizontal control quality
Jakub Vincent
2004-03-01
Full Text Available GPS technologies can also be used for check quality in available horizontal point set with coordinates CJ of the frame S-JTSK. When survey and setting-out tasks should be performed in certain area, one can found in it allways some points of the fundamental and detail state controls. To use these points for some actual aims, it is necessary to investigate their compatibility (among the point mark positions and the point coordinate of control points. This can be done using GPS surveying that may be at the same time employed to determine the new point in the relevant area.Principle of quality investigatingf an existing control is founded on determination of point coordinates CJt from GPS measurements. Then, based on discrepancies among the "official" netpoint coordinates CJ and coordinates CJt "given by GPS", it can be estimated the degree and the real compatibility dislocations in the network structure of the existing points.Realisation procedure for the introduced investigation is demonstrated on GPS checking (by SOKKIA STRATUS receivers horizontal control for reconstruction of a railway bridge on river Bodrog in East Slovakia.It can be shown from the results in Table 3, that points P3 and P7 are useless due to their incompatibility (inconsistency in the inspected point set. For other 7 points (Table 7 the average measure of incompatibility reads 9.8 mm that make possible applying these points for precise setting-out
Pattern selection in a horizontally vibrated container
Porter, J; Tinao, I; Laveron-Simavilla, A; Lopez, C A, E-mail: jeff.porter@upm.es [E.T.S.I. Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, 28040 Madrid (Spain)
2012-10-15
We present results of an experimental and numerical investigation of the patterns realized by surface waves within an open rectangular container subjected to horizontal vibrations at frequencies of 40-100 Hz. The first instability exhibited by the primary harmonic wave field is subharmonic, and may be identified with the cross-wave instability often seen in wave tank experiments. We show that, contrary to common theoretical and experimental assumptions, and despite their name, these subharmonic waves are not oriented crosswise, but at an intermediate angle with respect to the axis of vibration. Hence, the pattern selection problem for horizontally forced Faraday waves is more complex than has previously been assumed. We establish the robustness of this obliquely oriented surface wave pattern by varying the forcing frequency and amplitude, the fluid viscosity, the fluid depth, and the boundary conditions. Previous work on cross-waves is reviewed and discussed in relation to the current results. Finally, numerical simulations using a reduced model with an appropriate forcing term are used to support the generality of the experimental observations. (paper)
Role of Vibrio cholerae exochitinase ChiA2 in horizontal gene transfer.
Mondal, Moumita; Chatterjee, Nabendu Sekhar
2016-03-01
Vibrio cholerae exochitinase ChiA2 plays a key role in acquisition of nutrients by chitin hydrolysis in the natural environment as well as in pathogenesis in the intestinal milieu. In this study we demonstrate the importance of ChiA2 in horizontal gene transfer in the natural environment. We found that the expression of ChiA2 and TfoX, the central regulator of V. cholerae horizontal gene transfer, varied with changes in environmental conditions. The activity of ChiA2 was also dependent on these conditions. In 3 different environmental conditions tested here, we observed that the supporting environmental condition for maximum expression and activity of ChiA2 was 20 °C, pH 5.5, and 100 mmol/L salinity in the presence of chitin. The same condition also induced TfoX expression and was favorable for horizontal gene transfer in V. cholerae. High-performance liquid chromatography analysis showed that ChiA2 released a significant amount of (GlcNAc)2 from chitin hydrolysis under the favorable condition. We hypothesized that under the favorable environmental condition, ChiA2 was upregulated and maximally active to produce a significant amount of (GlcNAc)2 from chitin. The same environmental condition also induced tfoX expression, followed by its translational activation by the (GlcNAc)2 produced, leading to efficient horizontal gene transfer.
CHEN Jian-gang; ZHANG Jian-min; XU Wei-lin; LI Shuai; HE Xiao-long
2013-01-01
Measurements of turbulent flow fields in a stilling basin of multi-horizontal submerged jets were made with the singlecamera Particle Image Velocimetry (PIV).The particle images were captured,processed,and subsequently used to characterize the flow in terms of the 2-D velocity and vorticity distributions.This study shows that the maximum close-to-bed velocity in the stilling basin is approximately reduced by 60％,comparing to the jet velocity at the outlet of orifices.The jet velocity is distributed evenly at the latter half of the stilling basin and the time-averaged velocity of the cross section is reduced by 77％-85％,comparing to the jet velocity at the outlet of orifices.These results show that the vortices with horizontal axes are continuously repeated during the form-merge-split-disappear process.The vertical vortices are continuously formed and disappeared,they appear randomly near the slab and intermittently reach the slab of the stilling basin.The range of these vortices is small.Vortices with horizontal axes and vertical vortices do not coincide in space and the vortices with horizontal axes only affect the position of the tail of the vertical vortices attached to the slab of the stilling basin.
Li, Fuyu; Collins, William D.; Wehner, Michael F.; Leung, Lai-Yung R.
2013-06-02
High-resolution climate models have been shown to improve the statistics of tropical storms and hurricanes compared to low-resolution models. The impact of increasing horizontal resolution in the tropical storm simulation is investigated exclusively using a series of Atmospheric Global Climate Model (AGCM) runs with idealized aquaplanet steady-state boundary conditions and a fixed operational storm-tracking algorithm. The results show that increasing horizontal resolution helps to detect more hurricanes, simulate stronger extreme rainfall, and emulate better storm structures in the models. However, increasing model resolution does not necessarily produce stronger hurricanes in terms of maximum wind speed, minimum sea level pressure, and mean precipitation, as the increased number of storms simulated by high-resolution models is mainly associated with weaker storms. The spatial scale at which the analyses are conducted appears to have more important control on these meteorological statistics compared to horizontal resolution of the model grid. When the simulations are analyzed on common low-resolution grids, the statistics of the hurricanes, particularly the hurricane counts, show reduced sensitivity to the horizontal grid resolution and signs of scale invariant.
ZHANG Dongli; WANG Xinhai
2005-01-01
The mechanism of production increasing for the pinnate horizontal well is analyzed with the simulation technique. It is pointed out that the whole horizontal wellbore spreading widely and evenly in coal layers makes the stratum pressure drop evenly and fast, which increases the chance of desorption and diffusion and area controlled. This is the basic reason that the pinnate horizontal well can increase production. How such stratum parameters as permeability, Langmuir constants and adsorption time constant affect the gas production for the pinnate horizontal well is also studied with numerical simulations. Either for the vertical well or the pinnate horizontal well, bigger stratum permeability, steeper relative permeability curve, smaller residual gas saturation, higher gas content and stratum pressure are more favorable for gas production increasing. Langmuir constants decide the change of desorption quantity and influence the gas production through changing the extent of steep of isothermal adsorption curves in the pressure dropping area. The adsorption time constant only influences the time that gas production arrives at the maximum value for the vertical well, but it almost has no influence on the gas production for the pinnate horizontal well because the equivalent adsorption time constant is reduced.
Choreographies with Secure Boxes and Compromised Principals
Carbone, Marco; 10.4204/EPTCS.12.1
2009-01-01
We equip choreography-level session descriptions with a simple abstraction of a security infrastructure. Message components may be enclosed within (possibly nested) "boxes" annotated with the intended source and destination of those components. The boxes are to be implemented with cryptography. Strand spaces provide a semantics for these choreographies, in which some roles may be played by compromised principals. A skeleton is a partially ordered structure containing local behaviors (strands) executed by regular (non-compromised) principals. A skeleton is realized if it contains enough regular strands so that it could actually occur, in combination with any possible activity of compromised principals. It is delivery guaranteed (DG) realized if, in addition, every message transmitted to a regular participant is also delivered. We define a novel transition system on skeletons, in which the steps add regular strands. These steps solve tests, i.e. parts of the skeleton that could not occur without additional regu...
Principal component regression for crop yield estimation
Suryanarayana, T M V
2016-01-01
This book highlights the estimation of crop yield in Central Gujarat, especially with regard to the development of Multiple Regression Models and Principal Component Regression (PCR) models using climatological parameters as independent variables and crop yield as a dependent variable. It subsequently compares the multiple linear regression (MLR) and PCR results, and discusses the significance of PCR for crop yield estimation. In this context, the book also covers Principal Component Analysis (PCA), a statistical procedure used to reduce a number of correlated variables into a smaller number of uncorrelated variables called principal components (PC). This book will be helpful to the students and researchers, starting their works on climate and agriculture, mainly focussing on estimation models. The flow of chapters takes the readers in a smooth path, in understanding climate and weather and impact of climate change, and gradually proceeds towards downscaling techniques and then finally towards development of ...
EXPERIMENTAL STUDY ON TOTAL UPLIFT FORCES OF WAVES ON HORIZONTAL PLATES
ZHOU Yi-ren; CHEN Guo-ping; WANG Deng-ting
2004-01-01
The total uplift forces of waves acting on hori zontal plates are the important basis for the design of maritime hollow-trussed structures. In this paper, an experimental study on the total uplift forces of waves on horizontal plates was conducted by a series of model tests. The results show that the maximum total uplift forces do not necessarily occur with the maximum impact pressure intensity synchronously.On the basis of the test results, formation mechanism of the total uplift forces of waves as well as its influencing factors were analyzed in detail, and an equation for calculation of the maximum total uplift forces of waves on plates was put forward. Lots of test data shows the present equation is in good agreement with the test results.
Lassa serology in natural populations of rodents and horizontal transmission.
Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Koivogui, Lamine; Günther, Stephan
2014-09-01
Lassa virus causes hemorrhagic fever in West Africa. Previously, we demonstrated by PCR screening that only the multimammate mouse, Mastomys natalensis, hosts Lassa virus in Guinea. In the present study, we used the same specimen collection from 17 villages in Coastal, Upper, and Forest Guinea to investigate the Lassa virus serology in the rodent population. The aim was to determine the dynamics of antibody development in M. natalensis and to detect potential spillover infections in other rodent species. Immunoglobulin G (IgG) antibody screening was performed using the indirect immunofluorescence assay with the Guinean Lassa virus strain Bantou 289 as antigen. The overall seroprevalence was 8% (129/1551) with the following rodents testing positive: 109 M. natalensis, seven Mastomys erythroleucus, four Lemniscomys striatus, four Praomys daltoni, three Mus minutoides, and two Praomys rostratus. Nearly all of them (122/129) originated from Bantou, Tanganya, and Gbetaya, where Lassa virus is highly endemic in M. natalensis. The antibody seroprevalence in M. natalensis from this high-endemic area (27%; 108/396) depended on the village, habitat, host age, and host abundance. A main positive factor was age; the maximum seroprevalence reached 50% in older animals. Our data fit with a model implicating that most M. natalensis rodents become horizontally infected, clear the virus within a period significantly shorter than their life span, and develop antibodies. In addition, the detection of antibodies in other species trapped in the habitats of M. natalensis suggests spillover infections.
Outlier Mining Based on Principal Component Estimation
Hu Yang; Ting Yang
2005-01-01
Outlier mining is an important aspect in data mining and the outlier mining based on Cook distance is most commonly used. But we know that when the data have multicollinearity, the traditional Cook method is no longer effective. Considering the excellence of the principal component estimation, we use it to substitute the least squares estimation, and then give the Cook distance measurement based on principal component estimation, which can be used in outlier mining. At the same time, we have done some research on related theories and application problems.
Principal Component Analysis in ECG Signal Processing
Andreas Bollmann
2007-01-01
Full Text Available This paper reviews the current status of principal component analysis in the area of ECG signal processing. The fundamentals of PCA are briefly described and the relationship between PCA and Karhunen-Loève transform is explained. Aspects on PCA related to data with temporal and spatial correlations are considered as adaptive estimation of principal components is. Several ECG applications are reviewed where PCA techniques have been successfully employed, including data compression, ST-T segment analysis for the detection of myocardial ischemia and abnormalities in ventricular repolarization, extraction of atrial fibrillatory waves for detailed characterization of atrial fibrillation, and analysis of body surface potential maps.
NUMERICAL DETERMINATION OF HORIZONTAL SETTLERS PERFORMANCE
M. M. Biliaiev
2015-08-01
Full Text Available Purpose.Horizontal settlers are one of the most important elements in the technological scheme of water purification. Their use is associated with the possibility to pass a sufficiently large volume of water. The important task at the stage of their designing is evaluating of their effectiveness. Calculation of the efficiency of the settler can be made by mathematical modeling. Empirical, analytical models and techniques that are currently used to solve the problem, do not allow to take into account the shape of the sump and various design features that significantly affects the loyalty to a decision on the choice of the size of the settling tank and its design features. The use of analytical models is limited only to one-dimensional solutions, does not allow accounting for nonuniform velocity field of the flow in the settler. The use of advanced turbulence models for the calculation of the hydrodynamics in the settler complex forms now requires very powerful computers. In addition, the calculation of one variant of the settler may last for dozens of hours. The aim of the paper is to build a numerical model to evaluate the effectiveness of horizontal settling tank modified design. Methodology. Numerical models are based on: 1 equation of potential flow; 2 equation of inviscid fluid vortex flow; 3 equation of viscous fluid dynamics; 4 mass transfer equation. For numerical simulation the finite difference schemes are used. The numerical calculation is carried out on a rectangular grid. For the formation of the computational domain markers are used. Findings.The models allow calculating the clarification process in the settler with different form and different configuration of baffles. Originality. A new approach to investigate the mass transfer process in horizontal settler was proposed. This approach is based on the developed CFD models. Three fluid dynamics models were used for the numerical investigation of flows and waste waters purification
The inverse maximum dynamic flow problem
BAGHERIAN; Mehri
2010-01-01
We consider the inverse maximum dynamic flow (IMDF) problem.IMDF problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic flow.After discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut problem.Then an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.
Pengyu Gao
2016-03-01
Full Text Available It is difficult to forecast the well productivity because of the complexity of vertical and horizontal developments in fluvial facies reservoir. This paper proposes a method based on Principal Component Analysis and Artificial Neural Network to predict well productivity of fluvial facies reservoir. The method summarizes the statistical reservoir factors and engineering factors that affect the well productivity, extracts information by applying the principal component analysis method and approximates arbitrary functions of the neural network to realize an accurate and efficient prediction on the fluvial facies reservoir well productivity. This method provides an effective way for forecasting the productivity of fluvial facies reservoir which is affected by multi-factors and complex mechanism. The study result shows that this method is a practical, effective, accurate and indirect productivity forecast method and is suitable for field application.
THEORETICAL ANALYSIS AND PRACTICE ON THE SELECTION OF KEY PARAMETERS FOR HORIZONTAL BIAS BURNER
刘泰生; 许晋源
2003-01-01
The air flow ratio and the pulverized-coal mass flux ratio between the rich and lean sides are the key parameters of horizontal bias burner. In order to realize high combustion efficiency, excellent stability of ignition, low NOx emission and safe operation, six principal demands are presented on the selection of key parameters. An analytical model is established on the basis of the demands, the fundamentals of combustion and the operation results. An improved horizontal bias burner is also presented and applied. The experiment and numerical simulation results show the improved horizontal bias burner can realize proper key parameters, lower NOx emission, high combustion efficiency and excellent performance of part load operation without oil support. It also can reduce the circumfluence and low velocity zone existing at the downstream sections of vanes, and avoid the burnout of the lean primary-air nozzle and the jam in the lean primary-air channel. The operation and test results verify the reasonableness and feasibility of the analytical model.
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)
2014-06-15
Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
Quality Aware Compression of Electrocardiogram Using Principal Component Analysis.
Gupta, Rajarshi
2016-05-01
Electrocardiogram (ECG) compression finds wide application in various patient monitoring purposes. Quality control in ECG compression ensures reconstruction quality and its clinical acceptance for diagnostic decision making. In this paper, a quality aware compression method of single lead ECG is described using principal component analysis (PCA). After pre-processing, beat extraction and PCA decomposition, two independent quality criteria, namely, bit rate control (BRC) or error control (EC) criteria were set to select optimal principal components, eigenvectors and their quantization level to achieve desired bit rate or error measure. The selected principal components and eigenvectors were finally compressed using a modified delta and Huffman encoder. The algorithms were validated with 32 sets of MIT Arrhythmia data and 60 normal and 30 sets of diagnostic ECG data from PTB Diagnostic ECG data ptbdb, all at 1 kHz sampling. For BRC with a CR threshold of 40, an average Compression Ratio (CR), percentage root mean squared difference normalized (PRDN) and maximum absolute error (MAE) of 50.74, 16.22 and 0.243 mV respectively were obtained. For EC with an upper limit of 5 % PRDN and 0.1 mV MAE, the average CR, PRDN and MAE of 9.48, 4.13 and 0.049 mV respectively were obtained. For mitdb data 117, the reconstruction quality could be preserved up to CR of 68.96 by extending the BRC threshold. The proposed method yields better results than recently published works on quality controlled ECG compression.
Horizon-T Experiment Calibrations - Cables
Beznosko, D; Iakovlev, A; Makhataeva, Z; Vildanova, M I; Yelshibekov, K; Zhukov, V V
2016-01-01
An innovative detector system called Horizon-T is constructed to study Extensive Air Showers (EAS) in the energy range above 1016 eV coming from a wide range of zenith angles (0o - 85o). The system is located at Tien Shan high-altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. The detector consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector to view the Vavilov-\\v{C}erenkov light from the EAS. Each detector connects to the Data Acquisition system via cables. The calibration of the time delay for each cable and the signal attenuation is provided in this article.
Modelling the horizontal steam generator with APROS
Ylijoki, J. [VTT Energy, Espoo (Finland); Palsinajaervi, C.; Porkholm, K. [IVO International Ltd, Vantaa (Finland)
1995-12-31
In this paper the capability of the five- and six-equation models of the simulation code APROS to simulate the behaviour of the horizontal steam generator is discussed. Different nodalizations are used in the modelling and the results of the stationary state runs are compared. Exactly the same nodalizations have been created for the five- and six-equation models. The main simulation results studied in this paper are void fraction and mass flow distributions in the secondary side of the steam generator. It was found that quite a large number of simulation volumes is required to simulate the distributions with a reasonable accuracy. The simulation results of the different models are presented and their validity is discussed. (orig.). 4 refs.
Horizontal gene exchange in environmental microbiota
Rustam I Aminov
2011-07-01
Full Text Available Horizontal gene transfer (HGT plays an important role in the evolution of life on the Earth. This view is supported by numerous occasions of HGT that are recorded in the genomes of all three domains of living organisms. HGT-mediated rapid evolution is especially noticeable among the Bacteria, which demonstrate formidable adaptability in the face of recent environmental changes imposed by human activities, such as the use of antibiotics, industrial contamination, and intensive agriculture. At the heart of the HGT-driven bacterial evolution and adaptation are highly sophisticated natural genetic engineering tools in the form of a variety of mobile genetic elements (MGEs. The main aim of this review is to give a brief account of the occurrence and diversity of MGEs in natural ecosystems and of the environmental factors that may affect MGE-mediated HGT.
Multimodal Distributions along the Horizontal Branch
Ferraro, F R; Pecci, F F; Dorman, B; Rood, R T; Ferraro, Francesco R.; Paltrinieri, Barbara; Pecci, Flavio Fusi; Dorman, Ben; Rood, Robert T.
1997-01-01
We report on HST/WFPC2 U,V and far-ultraviolet observations of two Galactic Globular Clusters (GGCs), NGC 6205 = M13 and NGC 6093 = M80. Both of these clusters have horizontal-branch (HB) tails that extend to the helium-burning main sequence, with the hottest stars reaching theoretical effective temperatures above 35,000 K. In both clusters, groups of stars are found to be separated by narrow gaps along the blue HB sequence. These gaps appear at similar locations in the color-magnitude diagrams of the two clusters. While stochastic effects may give rise to variations in the color distribution along the HB, the coincidence of gaps in different clusters effectively rules this out as the primary cause. The comparison among the clusters strongly suggests that there are separate physical processes operating during the earlier red-giant phase of evolution to produce mass loss.
Horizontal stresses below two agricultural vehicles
Lamande, Mathieu André Maurice; Munkholm, Lars Juhl; Nielsen, Janne Aalborg
, while shear stress larger than soil strength may affect intensity soil properties (i.e. air permeability) by soil deformation not necessarily associated with compaction. In previous experiments in field conditions, isotropic compaction was observed below the center of tires, while shearing took place...... below the edge of tires. Stress distribution at the tire/soil contact is not uniform. Dimensions and inflation pressure are key factors for the ability of agricultural tires to distribute the wheel load. Our hypothesis was that the risk of shearing increases with the tire inflation pressure...... and the number of wheels. We measured horizontal stress at two depths (0.3 and 0.5 m) below tires of two slurry spreaders: one self-propelled machine equipped with wide tires (1.050 m) and low inflation pressure (150 kPa) but carrying a high wheel load (120 kN), and one tractor towing a three-axle slurry...
Passive magnetic bearing for a horizontal shaft
Post, Richard F.
2003-12-02
A passive magnetic bearing is composed of a levitation element and a restorative element. The levitation element is composed of a pair of stationary arcuate ferromagnetic segments located within an annular radial-field magnet array. The magnet array is attached to the inner circumference of a hollow shaft end. An attractive force between the arcuate segments and the magnet array acts vertically to levitate the shaft, and also in a horizontal transverse direction to center the shaft. The restorative element is comprised of an annular Halbach array of magnets and a stationary annular circuit array located within the Halbach array. The Halbach array is attached to the inner circumference of the hollow shaft end. A repulsive force between the Halbach array and the circuit array increases inversely to the radial space between them, and thus acts to restore the shaft to its equilibrium axis of rotation when it is displaced therefrom.
Numerical Investigation on Submerged Horizontal Plate
康海贵; 王科
2001-01-01
Hydrodynamic characters on a horizontal, thin, rigid plate located beneath the free surface are numerically investigated. Assuming a linear, time-harmonic potential flow and utilizing Green identity, the governing Laplace equation can be simplified into Fredholm integral equation ofthe second kind. Supposing linear-order discontinuous elements along intersecting vertical boundaries, and by use of the boundary element method, numerical solution about source strength distribution on the plate can be changed into a series of algebraic equations. The 3D Green function is introduced to set up the integral equations, and the GMRES solver is performed for solving the large dense linear system of equations. The added-mass, damping force and exciting force are evaluated directly from the equations. It is found that the added-mass coefficient becomes negative for a range of frequencies when the plate is sufficiently close to the free surface.
The Principals' Center Movement: When School Leaders Become Learners.
Levine, Sarah L.
1986-01-01
This article describes principals' centers and the principals' center movement, identifying key issues raised by them. Future directions and persistent questions for the principals' center movement are developed. (MT)
Haller, Alicia; Hunt, Erika
2016-01-01
Research has demonstrated that principals have a powerful impact on school improvement and student learning. Principals play a vital role in recruiting, developing, and retaining effective teachers; creating a school-wide culture of learning; and implementing a continuous improvement plan aimed at increasing student achievement. Leithwood, Louis,…
Knuth, Richard K.
2004-01-01
Probably no effort has been more successful than the Interstate School Leaders Licensure Consortium (ISLLC) in capturing the current complexity of the principal's role and in providing direction for the professional development and selection of principals. As more states require universities to restructure training programs to align with the ISLLC…
Principal Self-Efficacy, Teacher Perceptions of Principal Performance, and Teacher Job Satisfaction
Evans, Molly Lynn
2016-01-01
In public schools, the principal's role is of paramount importance in influencing teachers to excel and to keep their job satisfaction high. The self-efficacy of leaders is an important characteristic of leadership, but this issue has not been extensively explored in school principals. Using internet-based questionnaires, this study obtained…
Talbot, Danny; Crow, Gary M.
Researchers who have focused on issues of interpersonal communication in organizations have concluded that it is an essential component of organizational life. This paper presents findings of a study that examined the role conceptions of principals in the Centenial Schools Program (CSP) and those of principals in non-CSP schools. Communicator…
Great Principals at Scale: Creating District Conditions That Enable All Principals to Be Effective
Ikemoto, Gina; Taliaferro, Lori; Fenton, Benjamin; Davis, Jacquelyn
2014-01-01
School leaders are critical in the lives of students and to the development of their teachers. Unfortunately, in too many instances, principals are effective in spite of--rather than because of--district conditions. To truly improve student achievement for all students across the country, well-prepared principals need the tools, support, and…
Principal Self-Efficacy, Teacher Perceptions of Principal Performance, and Teacher Job Satisfaction
Evans, Molly Lynn
2016-01-01
In public schools, the principal's role is of paramount importance in influencing teachers to excel and to keep their job satisfaction high. The self-efficacy of leaders is an important characteristic of leadership, but this issue has not been extensively explored in school principals. Using internet-based questionnaires, this study obtained…
Alejandra Moreno-Letelier
2011-01-01
Full Text Available The high affinity phosphate transport system (pst is crucial for phosphate uptake in oligotrophic environments. Cuatro Cienegas Basin (CCB has extremely low P levels and its endemic Bacillus are closely related to oligotrophic marine Firmicutes. Thus, we expected the pst operon of CCB to share the same evolutionary history and protein similarity to marine Firmicutes. Orthologs of the pst operon were searched in 55 genomes of Firmicutes and 13 outgroups. Phylogenetic reconstructions were performed for the pst operon and 14 concatenated housekeeping genes using maximum likelihood methods. Conserved domains and 3D structures of the phosphate-binding protein (PstS were also analyzed. The pst operon of Firmicutes shows two highly divergent clades with no correlation to the type of habitat nor a phylogenetic congruence, suggesting horizontal gene transfer. Despite sequence divergence, the PstS protein had a similar 3D structure, which could be due to parallel evolution after horizontal gene transfer events.
novos elementos e horizontes para o cuidado
Rosa Lúcia Rocha Ribeiro
2007-01-01
Full Text Available La condición crónica ha sido un tema de importancia extrema para la reflexión del proceso de vivir humano. En el artículo se presenta la síntesis de una investigación realizada con la finalidad de comprender cómo los niños con Síndrome Nefrótico son cuidados, buscando identificar nuevos elementos y horizontes para reconstruir el cuidado de enfermería, teniendo como foco la familia. Para la presente investigación, se realizó un estudio cualitativo que utilizó como referente teórico metodológico, la hermenéutica basada en Gadamer y Ricouer. De la investigación realizada en 2004, participaron 42 personas pertenecientes a las familias de niños y adolescentes con Síndrome Nefrótico, usuarias del Servicio de Nefrología Pediátrica del Hospital Universitario Júlio Müller, en Cuiabá, Brasil. En la discusión son presentadas: una síntesis de las familias, sus proyectos, personajes y contexto; la trayectoria de la enfermedad del niño en la familia, y el cuidado del niño nefrótico en la familia. Se muestran también los horizontes de los cuidadores, familiares y profesionales de salud, y el cuidado posible a partir de los arreglos de la familia. Se puede concluir que el diálogo es la primera condición para la comprensión y también para el cuidado.
Keith Walker
2003-09-01
Full Text Available This paper reports the findings related to the International Beginning Principals study, which examined factors perceived by first year principals to both complicate, and account for, first year principalship successes in rural jurisdictions. Specifically, for this paper we deal with factors seen as significant in establishing oneself as a first time principal in a rural Canadian school. The general findings from this study centred on training and experience related to administration of schools. Many first time principals in rural schools had limited specific preparation for the principalship, or other related administrative roles such as the vice principalship. Such findings have taken on more importance in the last several years as school districts find it increasingly difficult to recruit principals for smaller rural schools.
Sex Education: The Principle and the Principal.
Wayne, Joseph E.
1981-01-01
The school principal is in a propitious position to offer leadership in developing a sex education program. His position of leadership and respect can facilitate the development of a Citizens Advisory Committee which, in turn, can ensure cooperation and leadership in setting the goals for developing a sex education program. (Author/CM)
Transformational Leadership Behaviors in Elementary School Principals
Ergle, Barbara
2012-01-01
School leaders face high expectations from society for leadership effectiveness. While it is commonly accepted that leadership practices contribute to school excellence, specific behaviors of effective elementary principals in the local context were not well understood. The purpose of this mixed methods study was to investigate self-reported…
Quantum principal bundles and corresponding gauge theories
Durdevic, M
1995-01-01
A generalization of classical gauge theory is presented, in the framework of a noncommutative-geometric formalism of quantum principal bundles over smooth manifolds. Quantum counterparts of classical gauge bundles, and classical gauge transformations, are introduced and investigated. A natural differential calculus on quantum gauge bundles is constructed and analyzed. Kinematical and dynamical properties of corresponding gauge theories are discussed.
Principals and the Power of Recommending Students
无
2009-01-01
Attending one of China’s most prestigious institutions of higher learning, Peking University (PKU), is a dream for the vast majority of China’s middle school graduates. On November 16, the university released a list of 39 senior middle schools across the country whose principals have been
Principals in Partnership with Math Coaches
Grant, Catherine Miles; Davenport, Linda Ruiz
2009-01-01
One of the most promising developments in math education is the fact that many districts are hiring math coaches--also called math resource teachers, math facilitators, math lead teachers, or math specialists--to assist elementary-level teachers with math instruction. What must not be lost, however, is that principals play an essential role in…
Principals' Transformational Leadership in School Improvement
Yang, Yingxiu
2013-01-01
Purpose: This paper aims to contribute experience and ideas of the transformational leadership, not only for the principal want to improve leadership himself (herself), but also for the school at critical period of improvement, through summarizing forming process and the problem during the course and key factors that affect the course.…
The Relationship between Principals' Managerial Approaches and ...
Nekky Umera
Cell phone - +254 724 249 730; Office - +254 065 32369 ... Ultimately, student discipline may be affected. This paper focuses on findings of a study to establish the ... behaviour is an essential variable in enhancing school outcomes (Nasibi, .... Three questionnaires were used to collect data from principals, teachers and.
Principal component analysis implementation in Java
Wójtowicz, Sebastian; Belka, Radosław; Sławiński, Tomasz; Parian, Mahnaz
2015-09-01
In this paper we show how PCA (Principal Component Analysis) method can be implemented using Java programming language. We consider using PCA algorithm especially in analysed data obtained from Raman spectroscopy measurements, but other applications of developed software should also be possible. Our goal is to create a general purpose PCA application, ready to run on every platform which is supported by Java.
Principals' Leadership Styles and Student Achievement
Harnish, David Alan
2012-01-01
Many schools struggle to meet No Child Left Behind's stringent adequate yearly progress standards, although the benchmark has stimulated national creativity and reform. The purpose of this study was to explore teacher perceptions of principals' leadership styles, curriculum reform, and student achievement to ascertain possible factors to improve…
What Principals Should Know About Food Allergies.
Munoz-Furlong, Anne
2002-01-01
Describes what principals should know about recent research findings on food allergies (peanuts, tree nuts, milk, eggs, soy, wheat) that can produce severe or life-threatening reactions in children. Asserts that every school should have trained staff and written procedures for reacting quickly to allergic reactions. (PKP)
Teachers' Perceptions Regarding School Principals' Coaching Skills
Yirci, Ramazan; Özdemir, Tuncay Yavuz; Kartal, Seçil Eda; Kocabas, Ibrahim
2014-01-01
The purpose of this study was to find out teachers' perceptions about school principals' coaching skills. The study was carried out within qualitative research methods. The study group included 76 teachers in Elazig and 73 teachers in Kahramanmaras provinces of Turkey. All the data were processed using Nvivo 9 software. The results indicate that…
Principal Bundles on the Projective Line
V B Mehta; S Subramanian
2002-08-01
We classify principal -bundles on the projective line over an arbitrary field of characteristic ≠ 2 or 3, where is a reductive group. If such a bundle is trivial at a -rational point, then the structure group can be reduced to a maximal torus.
Managerial Leadership and the Effective Principal.
Yukl, Gary
To help relate management ideas and knowledge to educational administration, the author reviews the major theories and findings from the last 20 years on managerial leadership and discusses their relevance for school principals. He first summarizes findings from three approaches: the traits approach, emphasizing managerial motivation and skills;…
Principal Connection / Amazon and the Whole Teacher
Hoerr, Thomas R.
2015-01-01
A recent controversy over Amazon's culture has strong implications for the whole child approach, and it offers powerful lessons for principals. A significant difference between the culture of so many businesses today and the culture at good schools is that in good schools, the welfare of the employees is very important. Student success is the…
Conceptualizing Social Justice: Interviews with Principals
Wang, Fei
2015-01-01
Purpose: Today, as the understanding of diversity is further expanded, the meaning of social justice becomes even more complicated, if not confusing. The purpose of this paper is to explore how school principals with social justice commitment understand and perceive social justice in their leadership practices. Design/methodology/approach: A…
Principal component analysis of phenolic acid spectra
Phenolic acids are common plant metabolites that exhibit bioactive properties and have applications in functional food and animal feed formulations. The ultraviolet (UV) and infrared (IR) spectra of four closely related phenolic acid structures were evaluated by principal component analysis (PCA) to...
Principal component analysis of psoriasis lesions images
Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær
2003-01-01
A set of RGB images of psoriasis lesions is used. By visual examination of these images, there seem to be no common pattern that could be used to find and align the lesions within and between sessions. It is expected that the principal components of the original images could be useful during future...
An Exploration of Principal Instructional Technology Leadership
Townsend, LaTricia Walker
2013-01-01
Nationwide the demand for schools to incorporate technology into their educational programs is great. In response, North Carolina developed the IMPACT model in 2003 to provide a comprehensive model for technology integration in the state. The model is aligned to national educational technology standards for teachers, students, and principals.…
Principal component analysis of symmetric fuzzy data
Giordani, Paolo; Kiers, Henk A.L.
2004-01-01
Principal Component Analysis (PCA) is a well-known tool often used for the exploratory analysis of a numerical data set. Here an extension of classical PCA is proposed, which deals with fuzzy data (in short PCAF), where the elementary datum cannot be recognized exactly by a specific number but by a
The Role of Principals in Politics.
Yingling, Walter S.
This talk uses humor to draw attention to the principal's responsibility and potential in promoting adequate education legislation. Knowledge of the issues in current legislation, contact with legislators, and organized action by administrators' associations are among the topics commented on. (PGD)
The Principal Kids Love To Hug.
Collins, Patrick
2000-01-01
David Nufer, Alaska's National Distinguished Principal for 1999, uses collaboration to create a family atmosphere at Finger Lake (Alaska) Elementary School. He turned the scheduling process over to teachers, involved teachers and parents in implementing a two-track system of mixed and single-age classrooms, brought in senior citizens to supplement…
The Principal's Mind-Set for Data
Fox, Dennis
2013-01-01
Is there a school leader anywhere who hasn't been directed, or at least encouraged, to "analyze the data" and practice what has been termed "data-driven decision-making"? Today's principal is expected to be able to skillfully collect, organize, analyze, interpret and use a variety of data in order to improve instruction, services and programs for…
Principal normal indicatrices of closed space curves
Røgen, Peter
1999-01-01
A theorem due to J. Weiner, which is also proven by B. Solomon, implies that a principal normal indicatrix of a closed space curve with nonvanishing curvature has integrated geodesic curvature zero and contains no subarc with integrated geodesic curvature pi. We prove that the inverse problem alw...
Elementary Teachers' Perceptions of Elementary Principals' Effectiveness
Fridenvalds, Kriss R.
2012-01-01
This dissertation examined the beliefs of elementary teachers to determine if their perceptions of effective principal leadership align to transformational leadership theory vis-a-vis the Educational Leadership Policy Standards (ELPS). A phenomenological, single-case study approach was utilized by means of a mixed-methodological, Web-based survey,…
Autocrats, Bureaucrats, and Buffoons: Images of Principals.
Glanz, Jerry
1998-01-01
A content analysis of over 35 American motion pictures and television sitcoms since the 1950s showed principals most often portrayed as autocrats, bureaucrats, or buffoons. Sometimes, as in the TV movie "Kidz in the Woods," a single show depicts all three characteristics. Promoting instructional leadership and an ethic of caring among…
The Principal as Chief Executive Officer.
Dubin, Andrew E., Ed.
This book was predicated on the idea that an effective principal must be proactive in decision making and have available appropriate information sources to make good decisions. Each chapter analyzes decision making from the perspective of different professionals in education and business management. Through the use of personal accounts and case…
Burnout And Lifestyle Of Principals And Entrepreneurs
Jasna Lavrenčič
2014-12-01
Full Text Available Research Question (RQ: What kind of lifestyle do the principals and entrepreneurs lead? Does the lifestyle of principals and entrepreneurs influence burnout? Purpose: To find out, based on the results of a questionnaire, what kind of lifestyle both researched groups lead. Does lifestyle have an influence on the occurrence of the phenomenon of burnout. Method: We used the method of data collection by questionnaire. Acquired data were analyzed using SPSS, descriptive and inference statistics. Results: Results showed, that both groups lead a similar lifestyle and that lifestyle influences burnout with principals, as well as entrepreneurs. Organization: School principals and entrepreneurs are the heads of individual organizations or companies, the goal of which is success. To be successful in their work, they must adapt their lifestyle, which can be healthy or unhealthy. If their lifestyle is unhealthy, it can lead to burnout. Society: With results of the questionnaire we would like to answer the question about the lifestyle of both groups and its influence on the occurrence of burnout. Originality: The study of lifestyle and the occurrence of burnout in these two groups is the first study in this area. Limitations/Future Research: In continuation, research groups could be submitted to the research fields of effort physiology and tracking of certain haematological parameters, such as cholesterol, blood sugar and stress hormones - adrenaline, noradrenalin, cortisol. Thus, we could carry out an even more in depth research of the connection between lifestyle and burnout.
The Principal's Playbook: Tackling School Improvement
Protheroe, Nancy
2010-01-01
"The Principal's Playbook: Tackling School Improvement" brings together the best thinking on successful schools and classrooms to help school administrators engage their faculty in discussion about effective school improvement strategies. Designed to support both school improvement efforts and professional development, each chapter includes…
Real-Time Principal-Component Analysis
Duong, Vu; Duong, Tuan
2005-01-01
A recently written computer program implements dominant-element-based gradient descent and dynamic initial learning rate (DOGEDYN), which was described in Method of Real-Time Principal-Component Analysis (NPO-40034) NASA Tech Briefs, Vol. 29, No. 1 (January 2005), page 59. To recapitulate: DOGEDYN is a method of sequential principal-component analysis (PCA) suitable for such applications as data compression and extraction of features from sets of data. In DOGEDYN, input data are represented as a sequence of vectors acquired at sampling times. The learning algorithm in DOGEDYN involves sequential extraction of principal vectors by means of a gradient descent in which only the dominant element is used at each iteration. Each iteration includes updating of elements of a weight matrix by amounts proportional to a dynamic initial learning rate chosen to increase the rate of convergence by compensating for the energy lost through the previous extraction of principal components. In comparison with a prior method of gradient-descent-based sequential PCA, DOGEDYN involves less computation and offers a greater rate of learning convergence. The sequential DOGEDYN computations require less memory than would parallel computations for the same purpose. The DOGEDYN software can be executed on a personal computer.
Primary School Principals' Experiences with Smartphone Apps
Çakir, Rahman; Aktay, Sayim
2016-01-01
Smartphones are not just pieces of hardware, they at same time also dip into software features such as communication systems. The aim of this study is to examine primary school principals' experiences with smart phone applications. Shedding light on this subject means that this research is qualitative. Criterion sampling has been intentionally…
Probabilistic Principal Component Analysis for Metabolomic Data.
Nyamundanda, Gift
2010-11-23
Abstract Background Data from metabolomic studies are typically complex and high-dimensional. Principal component analysis (PCA) is currently the most widely used statistical technique for analyzing metabolomic data. However, PCA is limited by the fact that it is not based on a statistical model. Results Here, probabilistic principal component analysis (PPCA) which addresses some of the limitations of PCA, is reviewed and extended. A novel extension of PPCA, called probabilistic principal component and covariates analysis (PPCCA), is introduced which provides a flexible approach to jointly model metabolomic data and additional covariate information. The use of a mixture of PPCA models for discovering the number of inherent groups in metabolomic data is demonstrated. The jackknife technique is employed to construct confidence intervals for estimated model parameters throughout. The optimal number of principal components is determined through the use of the Bayesian Information Criterion model selection tool, which is modified to address the high dimensionality of the data. Conclusions The methods presented are illustrated through an application to metabolomic data sets. Jointly modeling metabolomic data and covariates was successfully achieved and has the potential to provide deeper insight to the underlying data structure. Examination of confidence intervals for the model parameters, such as loadings, allows for principled and clear interpretation of the underlying data structure. A software package called MetabolAnalyze, freely available through the R statistical software, has been developed to facilitate implementation of the presented methods in the metabolomics field.
Technology Leadership Conditions among Nebraska School Principals
Curnyn, Molly A.
2013-01-01
As visionary leaders, school administrators are responsible for leading their schools into the 21st century by integrating technology to enhance learning and teaching. As technology leaders, principals must apply rigorous thought into the overall role that technology plays in the enhancement of student learning. Leveraging technology will assist…
Principals in Partnership with Math Coaches
Grant, Catherine Miles; Davenport, Linda Ruiz
2009-01-01
One of the most promising developments in math education is the fact that many districts are hiring math coaches--also called math resource teachers, math facilitators, math lead teachers, or math specialists--to assist elementary-level teachers with math instruction. What must not be lost, however, is that principals play an essential role in…
California Testing: How Principals Choose Priorities.
Bushman, James; Goodman, Greg; Brown-Welty, Sharon; Dorn, Shelly
2001-01-01
The Central Valley (California) Educational Research Consortium asked 118 area principals what they were doing to improve their lowest achieving students' education. Respondents are focusing on individualizing instruction, aligning curricula to standards, advocating teaching to standards and tests, promoting new curriculum methodologies, and…
The mechanics of granitoid systems and maximum entropy production rates.
Hobbs, Bruce E; Ord, Alison
2010-01-13
A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isotherm, which is the control valve for the behaviour of the complete granitoid system. Melt transport occurs in conduits initiated as sheets or tubes comprising melt inclusions arising from Gurson-Tvergaard constitutive behaviour. Such conduits appear as leucosomes parallel to lineations and foliations, and ductile and brittle dykes. The melt flux generated at the melt isotherm controls the position of the melt solidus isotherm and hence the physical height of the Transport/Emplacement Zone. A conduit width-selection process, driven by changes in melt viscosity and constitutive behaviour, operates within the Transport Zone to progressively increase the width of apertures upwards. Melt can also be driven horizontally by gradients in topography; these horizontal fluxes can be similar in magnitude to vertical fluxes. Fluxes induced by deformation can compete with both buoyancy and topographic-driven flow over all length scales and results locally in transient 'ponds' of melt. Pluton emplacement is controlled by the transition in constitutive behaviour of the melt/magma from elastic-viscous at high temperatures to elastic-plastic-viscous approaching the melt solidus enabling finite thickness plutons to develop. The system involves coupled feedback processes that grow at the expense of heat supplied to the system and compete with melt advection. The result is that limits are placed on the size and time scale of the system. Optimal characteristics of the system coincide with a state of maximum entropy production rate.
Stochastic convex sparse principal component analysis.
Baytas, Inci M; Lin, Kaixiang; Wang, Fei; Jain, Anil K; Zhou, Jiayu
2016-12-01
Principal component analysis (PCA) is a dimensionality reduction and data analysis tool commonly used in many areas. The main idea of PCA is to represent high-dimensional data with a few representative components that capture most of the variance present in the data. However, there is an obvious disadvantage of traditional PCA when it is applied to analyze data where interpretability is important. In applications, where the features have some physical meanings, we lose the ability to interpret the principal components extracted by conventional PCA because each principal component is a linear combination of all the original features. For this reason, sparse PCA has been proposed to improve the interpretability of traditional PCA by introducing sparsity to the loading vectors of principal components. The sparse PCA can be formulated as an ℓ1 regularized optimization problem, which can be solved by proximal gradient methods. However, these methods do not scale well because computation of the exact gradient is generally required at each iteration. Stochastic gradient framework addresses this challenge by computing an expected gradient at each iteration. Nevertheless, stochastic approaches typically have low convergence rates due to the high variance. In this paper, we propose a convex sparse principal component analysis (Cvx-SPCA), which leverages a proximal variance reduced stochastic scheme to achieve a geometric convergence rate. We further show that the convergence analysis can be significantly simplified by using a weak condition which allows a broader class of objectives to be applied. The efficiency and effectiveness of the proposed method are demonstrated on a large-scale electronic medical record cohort.
Generalised maximum entropy and heterogeneous technologies
Oude Lansink, A.G.J.M.
1999-01-01
Generalised maximum entropy methods are used to estimate a dual model of production on panel data of Dutch cash crop farms over the period 1970-1992. The generalised maximum entropy approach allows a coherent system of input demand and output supply equations to be estimated for each farm in the sam
20 CFR 229.48 - Family maximum.
2010-04-01
... month on one person's earnings record is limited. This limited amount is called the family maximum. The family maximum used to adjust the social security overall minimum rate is based on the employee's Overall..., when any of the persons entitled to benefits on the insured individual's compensation would, except...
The maximum rotation of a galactic disc
Bottema, R
1997-01-01
The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously
Decomposition of spectra using maximum autocorrelation factors
Larsen, Rasmus
2001-01-01
into classification or regression type analyses. A featured method for low dimensional representation of multivariate datasets is Hotellings principal components transform. We will extend the use of principal components analysis incorporating new information into the algorithm. This new information consists......This paper addresses the problem of generating a low dimensional representation of the variation present in a set of spectra, e.g. reflection spectra recorded from a series of objects. The resulting low dimensional description may subseque ntly be input through variable selection schemes...... Fourier decomposition these new variables are located in frequency as well as well wavelength. The proposed algorithm is tested on 100 samples of NIR spectra of wheat....
Bilateral horizontal Vogt’s striae in keratoconus
Inci Ulu Güngör
2008-10-01
Full Text Available Inci Ulu Güngör, Ümit Beden, Baris SönmezOndokuz Mayis University, School of Medicine, Department of Ophthalmology, Samsun, TurkeyPurpose: To report a keratoconus case with bilateral horizontal Vogt’s striae.Method: The clinical findings of the patient and the development of the direction of striae are discussed.Results: Vogt’s striae, defined as vertical stress lines, are rarely horizontal. One patient with unilateral horizontal stress lines on his left eye has been reported in the literature. Our patient has horizontal Vogt’s striae in both eyes.Conclusion: Horizontal Vogt’s striae may be seen in keratoconus as a rare slit-lamp biomicroscopic finding.Keywords: keratoconus, Vogt’s striae, horizontal stress lines
Duality of Maximum Entropy and Minimum Divergence
Shinto Eguchi
2014-06-01
Full Text Available We discuss a special class of generalized divergence measures by the use of generator functions. Any divergence measure in the class is separated into the difference between cross and diagonal entropy. The diagonal entropy measure in the class associates with a model of maximum entropy distributions; the divergence measure leads to statistical estimation via minimization, for arbitrarily giving a statistical model. The dualistic relationship between the maximum entropy model and the minimum divergence estimation is explored in the framework of information geometry. The model of maximum entropy distributions is characterized to be totally geodesic with respect to the linear connection associated with the divergence. A natural extension for the classical theory for the maximum likelihood method under the maximum entropy model in terms of the Boltzmann-Gibbs-Shannon entropy is given. We discuss the duality in detail for Tsallis entropy as a typical example.
Characterizing local variability in long‐period horizontal tilt noise
Rohde, M.D.; Ringler, Adam; Hutt, Charles R.; Wilson, David; Holland, Austin; Sandoval, L.D; Storm, Tyler
2017-01-01
Horizontal seismic data are dominated by atmospherically induced tilt noise at long periods (i.e., 30 s and greater). Tilt noise limits our ability to use horizontal data for sensitive seismological studies such as observing free earth modes. To better understand the local spatial variability of long‐period horizontal noise, we observe horizontal noise during quiet time periods in the Albuquerque Seismological Laboratory (ASL) underground vault using four small‐aperture array configurations. Each array comprises eight Streckeisen STS‐2 broadband seismometers. We analyze the spectral content of the data using power spectral density and magnitude‐squared coherence (γ2‐coherence). Our results show a high degree of spatial variability and frequency dependence in the long‐period horizontal wavefield. The variable nature of long‐period horizontal noise in the ASL vault suggests that it might be highly local in nature and not easily characterized by simple physical models when overall noise levels are low, making it difficult to identify locations in the vault with lower horizontal noise. This variability could be limiting our ability to apply coherence analysis for estimating horizontal sensor self‐noise and could also complicate various indirect methods for removing long‐period horizontal noise (e.g., collocated rotational sensor or microbarograph).
Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling
Na Wei
2013-01-01
Full Text Available Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport mathematical model according to gas-liquid-solid flow mechanism and large plane dunes particle transport theory.
COPD phenotype description using principal components analysis
Roy, Kay; Smith, Jacky; Kolsum, Umme
2009-01-01
BACKGROUND: Airway inflammation in COPD can be measured using biomarkers such as induced sputum and Fe(NO). This study set out to explore the heterogeneity of COPD using biomarkers of airway and systemic inflammation and pulmonary function by principal components analysis (PCA). SUBJECTS...... AND METHODS: In 127 COPD patients (mean FEV1 61%), pulmonary function, Fe(NO), plasma CRP and TNF-alpha, sputum differential cell counts and sputum IL8 (pg/ml) were measured. Principal components analysis as well as multivariate analysis was performed. RESULTS: PCA identified four main components (% variance...... associations between the variables within components 1 and 2. CONCLUSION: COPD is a multi dimensional disease. Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased Fe...
Principals' transformational leadership and teachers' collective efficacy.
Dussault, Marc; Payette, Daniel; Leroux, Mathieu
2008-04-01
The study was designed to test the relationship of principals' transformational, transactional, and laissez-faire leadership with teachers' collective efficacy. Bandura's theory of efficacy applied to the group and Bass's transformational leadership theory were used as the theoretical framework. Participants included 487 French Canadian teachers from 40 public high schools. As expected, there were positive and significant correlations between principals' transformational and transactional leadership and teachers' collective efficacy. Also, there was a negative and significant correlation between laissez-faire leadership and teachers' collective efficacy. Moreover, regression analysis showed transformational leadership significantly enhanced the predictive capabilities of transactional leadership on teachers' collective efficacy. These results confirm the importance of leadership to predict collective efficacy and, by doing so, strengthen Bass's theory of leadership.
Quantum principal bundles and their characteristic classes
Durdevic, M
1996-01-01
A brief exposition of the general theory of characteristic classes of quantum principal bundles is given. The theory of quantum characteristic classes incorporates ideas of classical Weil theory into the conceptual framework of non-commutative differential geometry. A purely cohomological interpretation of the Weil homomorphism is given, together with a standard geometrical interpretation via quantum invariant polynomials. A natural spectral sequence is described. Some quantum phenomena appearing in the formalism are discussed.
Principal Portfolios: Recasting the Efficient Frontier
M. Hossein Partovi; Michael Caputo
2004-01-01
A new method of analyzing the efficient portfolio problem under the assumption that short sales are allowed is presented. It is based on the remarkable finding that the original asset set can be reorganized as a set of uncorrelated portfolios, here named principal portfolios. The original problem of portfolio selection from the existing, correlated assets is thereby traded for the reduced problem of choosing from a set of uncorrelated portfolios. These portfolios constitute a new investment e...
Magneto-convective instabilities in horizontal cavities
Mistrangelo, Chiara; Bühler, Leo
2016-02-01
A linear stability analysis is performed to investigate the onset of convective motions in a flat cavity filled with liquid metal. A volumetric heat source is uniformly distributed in the fluid and a horizontal magnetic field is imposed. Walls perpendicular to the magnetic field are thermally insulating, and the top wall is isothermal and the bottom adiabatic. When a magnetic field is applied, electromagnetic forces tend to transform 3D convective flow structures into quasi-2D rolls aligned to the magnetic field. By integrating 3D equations along magnetic field lines, a quasi-2D mathematical model has been derived. A dissipation term in the 2D equations accounts for 3D viscous effects in boundary layers at Hartmann walls perpendicular to the magnetic field. The influence of various parameters on flow stability is investigated. The flow is stabilized by increasing the magnetic field intensity or the electric conductance of Hartmann walls and by reducing the aspect ratio of the cavity. Numerical simulations are performed to verify the analytical results and to describe the main convective flow patterns in the non-linear regime.
Analysis of Near Horizontal Muons at HAWC
Barber, Ahron; HAWC Collaboration
2017-01-01
The HAWC (High Altitude Water Cherenkov) gamma ray observatory observes muons with nearly horizontal trajectories. HAWC is located at an altitude of 4100 meters a.s.l. on Sierra Negra in Mexico. The Gamma and Cosmic Ray detector is composed of 300 water tanks, 7.3 m in diameter and 4.5 m tall, spread over a physical area of 22,000 m2. Due to its thickness of 4.5 m, HAWC acts as a hodoscope capable of observing muons with trajectories at zenith angles greater than 75 degrees to just over 90 degrees. These muon trajectories have a unique signal in that they are linear and travel at nearly the speed of light. CORSIKA simulations indicate that these muons originate from high zenith angle cosmic ray events, where the air shower core is located at great distance from HAWC. I will present the angular distribution and rate at which HAWC observes these muon events. High Altitude Water Cherenkov Observatory.
Horizontal Drop of 21- PWR Waste Package
A.K. Scheider
2001-04-26
The objective of this calculation is to determine the structural response of the waste package (WP) dropped horizontally from a specified height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in terms of stress intensities. The information provided by the sketches (Attachment I) is that of the potential design of the type of WP considered in this calculation, and all obtained results are valid for that design only. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 16). AP-3.12Q, ''Calculations'' (Ref. 11) is used to perform the calculation and develop the document. The sketches attached to this calculation provide the potential dimensions and materials for the 21-PWR WP design.
Yaw dynamics of horizontal axis wind turbines
Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))
1992-05-01
Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.
Horizontal plane head stabilization during locomotor tasks.
Cromwell, R L; Newton, R A; Carlton, L G
2001-03-01
Frequency characteristics of head stabilization were examined during locomotor tasks in healthy young adults(N = 8) who performed normal walking and 3 walking tasks designed to produce perturbations primarily in the horizontal plane. In the 3 walking tasks, the arms moved in phase with leg movement, with abnormally large amplitude, and at twice the frequency of leg movement. Head-in-space angular velocity was examined at the predominant frequencies of trunk motion. Head movements in space occurred at low frequencies ( 4.0 Hz) when the arms moved at twice the frequency of the legs. Head stabilization strategies were determined from head-on-trunk with respect to trunk frequency profiles derived from angular velocity data. During natural walking at low frequencies (head-on-trunk movement was less than trunk movement. At frequencies 3.0 Hz or greater, equal and opposite compensatory movement ensured head stability. When arm swing was altered, compensatory movement guaranteed head stability at all frequencies. Head stabilization was successful for frequencies up to 10.0 Hz during locomotor tasks. Maintaining head stability at high frequencies during voluntary tasks suggests that participants used feedforward mechanisms to coordinate head and trunk movements. Maintenance of head stability during dynamic tasks allows optimal conditions for vestibulo-ocular reflex function.
Horizontal visibility graphs from integer sequences
Lacasa, Lucas
2016-09-01
The horizontal visibility graph (HVG) is a graph-theoretical representation of a time series and builds a bridge between dynamical systems and graph theory. In recent years this representation has been used to describe and theoretically compare different types of dynamics and has been applied to characterize empirical signals, by extracting topological features from the associated HVGs which have shown to be informative on the class of dynamics. Among some other measures, it has been shown that the degree distribution of these graphs is a very informative feature that encapsulates nontrivial information of the series's generative dynamics. In particular, the HVG associated to a bi-infinite real-valued series of independent and identically distributed random variables is a universal exponential law P(k)=(1/3){(2/3)}k-2, independent of the series marginal distribution. Most of the current applications have however only addressed real-valued time series, as no exact results are known for the topological properties of HVGs associated to integer-valued series. In this paper we explore this latter situation and address univariate time series where each variable can only take a finite number n of consecutive integer values. We are able to construct an explicit formula for the parametric degree distribution {P}n(k), which we prove to converge to the continuous case for large n and deviates otherwise. A few applications are then considered.
The peculiar Horizontal Branch of NGC 2808
Dalessandro, E; Ferraro, F R; Cassisi, S; Lanzoni, B; Rood, R T; Pecci, F Fusi; Sabbi, E
2010-01-01
We present an accurate analysis of the peculiar Horizontal Branch (HB) of the massive Galactic globular cluster NGC 2808, based on high-resolution far-UV and optical images of the central region of the cluster obtained with HST. We confirm the multimodal distribution of stars along the HB: 4 sub-populations separated by gaps are distinguishable. The detailed comparison with suitable theoretical models showed that (i) it is not possible to reproduce the luminosity of the entire HB with a single helium abundance, while an appropriate modeling is possible for three HB groups by assuming different helium abundances in the range 0.24 < Y < 0.4 that are consistent with the multiple populations observed in the Main Sequence; (ii) canonical HB models are not able to properly match the observational properties of the stars populating the hottest end of the observed HB distribution, the so called "blue-hook region". These objects are probably "hot-flashers" , stars that peel off the red giant branch before reachi...
Shallow water model for horizontal centrifugal casting
Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.
2012-07-01
A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.
Speech disorders in students in Belo Horizonte.
Rabelo, Alessandra Terra Vasconcelos; Alves, Claudia Regina Lindgren; Goulart, Lúcia Maria H Figueiredo; Friche, Amélia Augusta de Lima; Lemos, Stela Maris Aguiar; Campos, Fernanda Rodrigues; Friche, Clarice Passos
2011-12-01
To describe speech disorders in students from 1st to 4th grades, and to investigate possible associations between these disorders and stomatognathic system and auditory processing disorders. Cross-sectional study with stratified random sample composed of 288 students, calculated based on an universe of 1,189 children enrolled in public schools from the area covered by a health center in Belo Horizonte. The median age was 8.9 years, and 49.7% were male. Assessment used a stomatognathic system protocol adapted from the Myofunctional Evaluation Guidelines, the Phonology task of the ABFW - Child Language Test, and a simplified auditory processing evaluation. Data were statistically analyzed. From the subjects studied, 31.9% had speech disorder. From these, 18% presented phonetic deviation, 9.7% phonological deviation, and 4.2% phonetic and phonological deviation. Linguistic variation was observed in 38.5% of the children. There was a higher proportion of children with phonetic deviation in 1st grade, and a higher proportion of children younger than 8 years old with both phonetic and phonological deviations. Phonetic deviation was associated to stomatognathic system disorder, and phonological deviation was associated to auditory processing disorder. The prevalence of speech disorders in 1st to 4th grade students is considered high. Moreover, these disorders are associated to other Speech-Language Pathology and Audiology alterations, which suggest that one disorder may be a consequence of the other, indicating the need for early diagnosis and intervention.
Wang, Shu Meir; Geller, Marvin A.
2016-09-01
Previous works have shown that a dry, idealized general circulation model could produce many features of the extratropical Tropopause Inversion Layer (TIL). In particular, the following have been shown, but no explanations were given for these results. (1) A sharper extratropical TIL resulted more from increased horizontal resolution than from increased vertical resolution. (2) If the Equator-to-Pole temperature gradient was varied, the annual variation of the extratropical TIL found in observations could be reproduced. (3) The extratropical TIL altitude showed excellent correlation with the upper tropospheric relative vorticity, as had been previously proposed. (4) Increased horizontal model resolutions led to extratropical TILs that were at lower altitudes. We show that these conclusions follow from baroclinic mixing of high stratospheric potential vorticity into the troposphere being the principal sharpening mechanism for the extratropical TIL and the increased baroclinic activity occurring in higher horizontal resolution models. We furthermore suggest that the distance from the jet exerts a greater influence on the height and sharpness of the extratropical TIL than does the upper tropospheric relative vorticity, and this accounts for the annual behavior of the extratropical TIL found in observations and reproduced with a dry, mechanistic, global model.
Principal component analysis for authorship attribution
Amir Jamak
2012-01-01
Full Text Available Background: To recognize the authors of the texts by the use of statistical tools, one first needs to decide about the features to be used as author characteristics, and then extract these features from texts. The features extracted from texts are mostly the counts of so called function words. Objectives: The data extracted are processed further to compress as a data with less number of features, such a way that the compressed data still has the power of effective discriminators. In this case feature space has less dimensionality then the text itself. Methods/Approach: In this paper, the data collected by counting words and characters in around a thousand paragraphs of each sample book, underwent a principal component analysis performed using neural networks. Once the analysis was complete, the first of the principal components is used to distinguish the books authored by a certain author. Results: The achieved results show that every author leaves a unique signature in written text that can be discovered by analyzing counts of short words per paragraph. Conclusions: In this article we have demonstrated that based on analyzing counts of short words per paragraph authorship could be traced using principal component analysis. Methodology could be used for other purposes, like fraud detection in auditing.
Multilevel sparse functional principal component analysis.
Di, Chongzhi; Crainiceanu, Ciprian M; Jank, Wolfgang S
2014-01-29
We consider analysis of sparsely sampled multilevel functional data, where the basic observational unit is a function and data have a natural hierarchy of basic units. An example is when functions are recorded at multiple visits for each subject. Multilevel functional principal component analysis (MFPCA; Di et al. 2009) was proposed for such data when functions are densely recorded. Here we consider the case when functions are sparsely sampled and may contain only a few observations per function. We exploit the multilevel structure of covariance operators and achieve data reduction by principal component decompositions at both between and within subject levels. We address inherent methodological differences in the sparse sampling context to: 1) estimate the covariance operators; 2) estimate the functional principal component scores; 3) predict the underlying curves. Through simulations the proposed method is able to discover dominating modes of variations and reconstruct underlying curves well even in sparse settings. Our approach is illustrated by two applications, the Sleep Heart Health Study and eBay auctions.
Feizbakhsh, Masood; Kadkhodaei, Mahmoud; Zandian, Dana; Hosseinpour, Zahra
2017-01-01
One of the most effective ways for distal movement of molars to treat Class II malocclusion is using extraoral force through a headgear device. The purpose of this study was the comparison of stress distribution in maxillary first molar periodontium using straight pull headgear in vertical and horizontal tubes through finite element method. Based on the real geometry model, a basic model of the first molar and maxillary bone was obtained using three-dimensional imaging of the skull. After the geometric modeling of periodontium components through CATIA software and the definition of mechanical properties and element classification, a force of 150 g for each headgear was defined in ABAQUS software. Consequently, Von Mises and Principal stresses were evaluated. The statistical analysis was performed using T-paired and Wilcoxon nonparametric tests. Extension of areas with Von Mises and Principal stresses utilizing straight pull headgear with a vertical tube was not different from that of using a horizontal tube, but the numerical value of the Von Mises stress in the vertical tube was significantly reduced (P 0/05). Based on the results, when force applied to the straight pull headgear with a vertical tube, Von Mises stress was reduced significantly in comparison with the horizontal tube. Therefore, to correct the mesiolingual movement of the maxillary first molar, vertical headgear tube is recommended.
The Teaching Principal: An Untenable Position or a Promising Model?
Newton, Paul M.; Wallin, Dawn
2013-01-01
This paper reports on an interpretive study that examined the role of the teaching principal, particularly as it relates to principals' moral and legal requirement to work as instructional leaders for student learning. A teaching principal is defined as a principal who has a "double load" or dual roles in teaching and administration…
19 CFR 113.33 - Corporations as principals.
2010-04-01
... 19 Customs Duties 1 2010-04-01 2010-04-01 false Corporations as principals. 113.33 Section 113.33... TREASURY CUSTOMS BONDS Principals and Sureties § 113.33 Corporations as principals. (a) Name of corporation on the bonds. The name of a corporation executing a Customs bond as a principal, may be printed...
Principal Role Changes and Implications for Principalship Candidates.
Whitaker, Kathryn S.
1999-01-01
A principal who exchanged jobs with a university professor explores changing principal roles, using a case-study approach. Principals' working world is characterized by overwhelming responsibilities, information perplexity, and emotional anxiety. Principals would appreciate intrinsic and extrinsic rewards, support networks, university-school…
Principal Role Changes and Implications for Principalship Candidates.
Whitaker, Kathryn S.
1999-01-01
A principal who exchanged jobs with a university professor explores changing principal roles, using a case-study approach. Principals' working world is characterized by overwhelming responsibilities, information perplexity, and emotional anxiety. Principals would appreciate intrinsic and extrinsic rewards, support networks, university-school…
A dual method for maximum entropy restoration
Smith, C. B.
1979-01-01
A simple iterative dual algorithm for maximum entropy image restoration is presented. The dual algorithm involves fewer parameters than conventional minimization in the image space. Minicomputer test results for Fourier synthesis with inadequate phantom data are given.
Maximum Throughput in Multiple-Antenna Systems
Zamani, Mahdi
2012-01-01
The point-to-point multiple-antenna channel is investigated in uncorrelated block fading environment with Rayleigh distribution. The maximum throughput and maximum expected-rate of this channel are derived under the assumption that the transmitter is oblivious to the channel state information (CSI), however, the receiver has perfect CSI. First, we prove that in multiple-input single-output (MISO) channels, the optimum transmission strategy maximizing the throughput is to use all available antennas and perform equal power allocation with uncorrelated signals. Furthermore, to increase the expected-rate, multi-layer coding is applied. Analogously, we establish that sending uncorrelated signals and performing equal power allocation across all available antennas at each layer is optimum. A closed form expression for the maximum continuous-layer expected-rate of MISO channels is also obtained. Moreover, we investigate multiple-input multiple-output (MIMO) channels, and formulate the maximum throughput in the asympt...
Photoemission spectromicroscopy with MAXIMUM at Wisconsin
Ng, W.; Ray-Chaudhuri, A.K.; Cole, R.K.; Wallace, J.; Crossley, S.; Crossley, D.; Chen, G.; Green, M.; Guo, J.; Hansen, R.W.C.; Cerrina, F.; Margaritondo, G. (Dept. of Electrical Engineering, Dept. of Physics and Synchrotron Radiation Center, Univ. of Wisconsin, Madison (USA)); Underwood, J.H.; Korthright, J.; Perera, R.C.C. (Center for X-ray Optics, Accelerator and Fusion Research Div., Lawrence Berkeley Lab., CA (USA))
1990-06-01
We describe the development of the scanning photoemission spectromicroscope MAXIMUM at the Wisoncsin Synchrotron Radiation Center, which uses radiation from a 30-period undulator. The article includes a discussion of the first tests after the initial commissioning. (orig.).
Maximum-likelihood method in quantum estimation
Paris, M G A; Sacchi, M F
2001-01-01
The maximum-likelihood method for quantum estimation is reviewed and applied to the reconstruction of density matrix of spin and radiation as well as to the determination of several parameters of interest in quantum optics.
The maximum entropy technique. System's statistical description
Belashev, B Z
2002-01-01
The maximum entropy technique (MENT) is applied for searching the distribution functions of physical values. MENT takes into consideration the demand of maximum entropy, the characteristics of the system and the connection conditions, naturally. It is allowed to apply MENT for statistical description of closed and open systems. The examples in which MENT had been used for the description of the equilibrium and nonequilibrium states and the states far from the thermodynamical equilibrium are considered
19 CFR 114.23 - Maximum period.
2010-04-01
... 19 Customs Duties 1 2010-04-01 2010-04-01 false Maximum period. 114.23 Section 114.23 Customs... CARNETS Processing of Carnets § 114.23 Maximum period. (a) A.T.A. carnet. No A.T.A. carnet with a period of validity exceeding 1 year from date of issue shall be accepted. This period of validity cannot be...
Maximum-Likelihood Detection Of Noncoherent CPM
Divsalar, Dariush; Simon, Marvin K.
1993-01-01
Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.
Anglo-American views of Gavrilo Princip
Markovich Slobodan G.
2015-01-01
Full Text Available The paper deals with Western (Anglo-American views on the Sarajevo assassination/attentat and Gavrilo Princip. Articles on the assassination and Princip in two leading quality dailies (The Times and The New York Times have particularly been analysed as well as the views of leading historians and journalists who covered the subject including: R. G. D. Laffan, R. W. Seton-Watson, Winston Churchill, Sidney Fay, Bernadotte Schmitt, Rebecca West, A. J. P. Taylor, Vladimir Dedijer, Christopher Clark and Tim Butcher. In the West, the original general condemnation of the assassination and its main culprits was challenged when Rebecca West published her famous travelogue on Yugoslavia in 1941. Another Brit, the remarkable historian A. J. P. Taylor, had a much more positive view on the Sarajevo conspirators and blamed Germany and Austria-Hungary for the outbreak of the Great War. A turning point in Anglo-American perceptions was the publication of Vladimir Dedijer’s monumental book The Road to Sarajevo (1966, which humanised the main conspirators, a process initiated by R. West. Dedijer’s book was translated from English into all major Western languages and had an immediate impact on the understanding of the Sarajevo assassination. The rise of national antagonisms in Bosnia gradually alienated Princip from Bosnian Muslims and Croats, a process that began in the 1980s and was completed during the wars of the Yugoslav succession. Although all available sources clearly show that Princip, an ethnic Serb, gradually developed a broader Serbo-Croat and Yugoslav identity, he was ethnified and seen exclusively as a Serb by Bosnian Croats and Bosniaks and Western journalists in the 1990s. In the past century imagining Princip in Serbia and the West involved a whole spectrum of views. In interwar Anglo-American perceptions he was a fanatic and lunatic. He became humanised by Rebecca West (1941, A. J. P. Taylor showed understanding for his act (1956, he was fully
SEXUAL DIMORPHISM OF MAXIMUM FEMORAL LENGTH
Pandya A M
2011-04-01
Full Text Available Sexual identification from the skeletal parts has medico legal and anthropological importance. Present study aims to obtain values of maximum femoral length and to evaluate its possible usefulness in determining correct sexual identification. Study sample consisted of 184 dry, normal, adult, human femora (136 male & 48 female from skeletal collections of Anatomy department, M. P. Shah Medical College, Jamnagar, Gujarat. Maximum length of femur was considered as maximum vertical distance between upper end of head of femur and the lowest point on femoral condyle, measured with the osteometric board. Mean Values obtained were, 451.81 and 417.48 for right male and female, and 453.35 and 420.44 for left male and female respectively. Higher value in male was statistically highly significant (P< 0.001 on both sides. Demarking point (D.P. analysis of the data showed that right femora with maximum length more than 476.70 were definitely male and less than 379.99 were definitely female; while for left bones, femora with maximum length more than 484.49 were definitely male and less than 385.73 were definitely female. Maximum length identified 13.43% of right male femora, 4.35% of right female femora, 7.25% of left male femora and 8% of left female femora. [National J of Med Res 2011; 1(2.000: 67-70
Ratio between vertical and horizontal mandibular range of motion
Dijkstra, P.U.; Kropmans, T.J.B.; Stegenga, B; de Bont, L.G.M.
1998-01-01
Mandibular range of motion (ROM), vertical and horizontal, is often measured as a part of a diagnostic assessment of temporomandibular joint disorders. Ln the literature, a fixed ratio between the vertical and the horizontal ROM has been suggested, i.e. 4:1. The ratio is frequently used to predict t
Horizontal drilling methods proven in three test wells
Dorel, M.
1983-05-01
The practice of drilling horizontally through a reservoir by deviating the wellbore 90/sup 0/ from vertical requires precise planning and sound engineering practices. This article takes a look at the operational, engineering and planning aspects of three successfully drilled drainholes. It also presents a field-tested horizontal well logging procedure that may help extend and improve this technology.
Horizontal Coherence of Wave Forces on Vertical Wall Breakwaters
Archetti, R.; Frigaard, Peter; Lamberti, A.
2001-01-01
of breaking waves for increasing wave height are estimated and compared with existing empirical formulae. The horizontal dimension of the breaker is investigated using two different methodologies: the first analyses the decreasing of the highest 1/250 force with increasing horizontal dimension of the caisson...
Dan WU
2009-06-01
Full Text Available The principal-subordinate hierarchical multi-objective programming model of initial water rights allocation was developed based on the principle of coordinated and sustainable development of different regions and water sectors within a basin. With the precondition of strictly controlling maximum emissions rights, initial water rights were allocated between the first and the second levels of the hierarchy in order to promote fair and coordinated development across different regions of the basin and coordinated and efficient water use across different water sectors, realize the maximum comprehensive benefits to the basin, promote the unity of quantity and quality of initial water rights allocation, and eliminate water conflict across different regions and water sectors. According to interactive decision-making theory, a principal-subordinate hierarchical interactive iterative algorithm based on the satisfaction degree was developed and used to solve the initial water rights allocation model. A case study verified the validity of the model.
Dan WU; Feng-ping WU; Yan-ping CHEN
2009-01-01
The principal-subordinate hierarchical multi-objective programming model of initial water rights allocation was developed based on the principle of coordinated and sustainable development of different regions and water sectors within a basin. With the precondition of strictly controlling maximum emissions rights, initial water rights were allocated between the first and the second levels of the hierarchy in order to promote fair and coordinated development across different regions of the basin and coordinated and efficient water use across different water sectors, realize the maximum comprehensive benefits to the basin, promote the unity of quantity and quality of initial water rights allocation, and eliminate water conflict across different regions and water sectors. According to interactive decision-making theory, a principal-subordinate hierarchical interactive iterative algorithm based on the satisfaction degree was developed and used to solve the initial water rights allocation model. A case study verified the validity of the model.
Steerable vertical to horizontal energy transducer for mobile robots
Spletzer, Barry L.; Fischer, Gary J.; Feddema, John T.
2001-01-01
The present invention provides a steerable vertical to horizontal energy transducer for mobile robots that less complex and requires less power than two degree of freedom tilt mechanisms. The present invention comprises an end effector that, when mounted with a hopping actuator, translates along axis (typically vertical) actuation into combined vertical and horizontal motion. The end effector, or foot, mounts with an end of the actuator that moves toward the support surface (typically a floor or the earth). The foot is shaped so that the first contact with the support surface is off the axis of the actuator. Off-axis contact with the support surface generates an on-axis force (typically resulting in vertical motion) and a moment orthogonal to the axis. The moment initiates a horizontal tumbling motion, and tilts the actuator so that its axis is oriented with a horizontal component and continued actuation generates both vertical and horizontal force.
A horizontal well analysis from a view of its productivity
Lucia Sciranková
2006-10-01
Full Text Available The 1990s may become known in the oil field as the decade of the horizontal well. Horizontal wells can increase the production rate and the ultimate recovery, and can reduce the number of platforms on wells required to develop a reservoir.An empirical equation to calculate the inflow performance of two-phase flow for a vertical and a horizontal well in regime of dissolved gas presented by Vogel in 1968. His equation was based on the results of reservoir simulation. The created model whore result (output is the ratio of the productivity of a horizontal well to the productivity of a vertical well for a given area expressed by anumber of vertical wells the replaced by one horizontal well. The model is applied for a concrete ideological model.
Horizontal crustal movement in Chinese mainland from 1999 to 2001
顾国华; 符养; 王武星
2004-01-01
The paper introduces the horizontal crustal movement obtained from GPS observations in the regional networks(including the basic network and the fiducial network) of the Crustal Movement Observation Network of China(CMONOC) carried out in 1999 and 2001. This paper is characterized by the acquisition of the horizontal dis-placement velocities during the period from 1999 to 2001 at the observation stations in the regional networks withdatum definition of a group of stable stations with small mutual displacements in east China. Based on the mostdetailed map of horizontal crustal movement in Chinese mainland, the division of blocks, their displacements anddeformations are studied. An approach to analysis of the intensity of the horizontal crustal deformation is proposed.The general characteristics of the recent horizontal crustal movement in Chinese mainland and that before theKunlunshan earthquake of M=8.1 on November 14, 2001 are analyzed.
Ozer, Niyazi
2013-01-01
The purpose of this study was to determine the primary school principals' views on trust in students and parents and also, to explore the relationships between principals' levels of professional burnout and their trust in students and parents. To this end, Principal Trust Survey and Friedman Principal Burnout scales were administered on…
Simulations and scaling of horizontal convection
Mehmet ILIcak
2012-05-01
Full Text Available In this paper we describe the results of various numerical simulations of sideways or horizontal convection. Specifically, a two-dimensional Boussinesq fluid is both heated and cooled from its upper surface, but the walls and the bottom of the tank are insulating and have no flux of heat through them. We perform experiments with a range of Rayleigh numbers up to 1011, obtained by systematically reducing the diffusivity. We also explore the effects of a nonlinear equation of state and of a mechanical force imposed on the top surface at a fixed Rayleigh number. We find that, when there is no mechanical forcing, both the energy dissipation and the strength of the circulation itself monotonically fall with decreasing diffusivity. At Rayleigh numbers greater than 1010 the flow is unsteady; however, the eddying flow is still much weaker than the steady flow at smaller Rayleigh numbers. At high Rayleigh numbers, the stratification and the mean circulation are increasingly confined to a thin layer at the upper surface, with the layer thickness decreasing according to Ra−1/5. There is no evidence that the flow ever enters a regime that is independent of Rayleigh number. Using a nonlinear equation of state makes little difference to the flow phenomenology at a moderate Rayleigh number. The addition of an imposed stress at the upper surface makes a significant difference in the flow. A strong, energy-dissipating circulation can be maintained even at Ra = 109, and the stratification extends more deeply into the fluid than in the unstressed case. Overall, our results are consistent with the notion that in the absence of mechanical forcing a fluid that is heated and cooled from above cannot maintain a deep stratification or a strong sustained flow at high Rayleigh numbers, even if the interior flow is unsteady.
Steam Flooding after Steam Soak in Heavy Oil Reservoirs through Extended-reach Horizontal Wells
Ning Zhengfu; Liu Huiqing; Zhang Hongling
2007-01-01
This paper presents a new development scheme of simultaneous injection and production in a single horizontal well drilled for developing small block reservoirs or offshore reservoirs.It is possible to set special packers within the long completion horizontal interval to establish an injection zone and a production zone.This method can also be used in steam flooding after steam soak through a horizontal well.Simulation results showed that it was desirable to start steam flooding after six steam soaking cycles and at this time the oil/steam ratio was 0.25 and oil recovery efficiency was 23.48%.Steam flooding performance was affected by separation interval and steam injection rate.Reservoir numerical simulation indicated that maximum oil recovery would be achieved at a separation section of 40-50 m at steam injection rate of 100-180 t/d; and the larger the steam injection rate,the greater the water cut and pressure difference between injection zone and production zone.A steam injection rate of 120 t/d was suitable for steam flooding under practical injection-production conditions.All the results could be useful for the guidance of steam flooding projects.
Use of an adjustable hand plate in studying the perceived horizontal plane during simulated flight.
Tribukait, Arne; Eiken, Ola; Lemming, Dag; Levin, Britta
2013-07-01
Quantitative data on spatial orientation would be valuable not only in assessing the fidelity of flight simulators, but also in evaluation of spatial orientation training. In this study a manual indicator was used for recording the subjective horizontal plane during simulated flight. In a six-degrees-of-freedom hexapod hydraulic motion platform simulator, simulating an F-16 aircraft, seven fixed-wing student pilots were passively exposed to two flight sequences. The first consisted in a number of coordinated turns with visual contact with the landscape below. The visually presented roll tilt was up to a maximum 670. The second was a takeoff with a cabin pitch up of 100, whereupon external visual references were lost. The subjects continuously indicated, with the left hand on an adjustable plate, what they perceived as horizontal in roll and pitch. There were two test occasions separated by a 3-d course on spatial disorientation. Responses to changes in simulated roll were, in general, instantaneous. The indicated roll tilt was approximately 30% of the visually presented roll. There was a considerable interindividual variability. However, for the roll response there was a correlation between the two occasions. The amplitude of the response to the pitch up of the cabin was approximately 75%; the response decayed much more slowly than the stimulus. With a manual indicator for recording the subjective horizontal plane, individual characteristics in the response to visual tilt stimuli may be detected, suggesting a potential for evaluation of simulation algorithms or training programs.
Mahmood Husain Ali
2013-05-01
Full Text Available In this paper, numerical solution is presented for the steady state, two dimensional natural convection heat transfer from two parallel horizontal cylinders enclosed by circular cylinder. The inner cylinders are heated and maintained at constant surface temperature, while the outer cylinder is cooled at constant surface temperature. Boundary fitted coordinate system is used to solve governing equations. The vorticity-stream function and energy equations is solved using explicit finite deference method and stream function equation solved by successive iteration method. (20Deferent cases are studied cover rang of Rayleigh number from (1,000 to (25,000 based on the inner cylinder diameter. These cases study the effect of the varying inner cylinders position horizontally and vertically within outer cylinder on the heat transfer and buoyancy that causes the flow. Outputs are displayed in terms of streamline, isothermal contours and local and average Nusselt number. The results showed that the position of the inner cylinders highly affects the heat transfer and flow movements in the gap. At low Rayleigh numbers the average Nusselt number increases with increase of horizontal distance between inner cylinders but the state is reversed at high Rayleigh numbers, while the average Nusselt number is increases with inner cylinder moving down at all Rayleigh numbers. The optimal position of inner cylinders for maximum and minimum heat transfer is located at each Rayleigh number so can be employed in isolation process or cooling process.
Rate limits in silicon sheet growth - The connections between vertical and horizontal methods
Thomas, Paul D.; Brown, Robert A.
1987-01-01
Meniscus-defined techniques for the growth of thin silicon sheets fall into two categories: vertical and horizontal growth. The interactions of the temperature field and the crystal shape are analyzed for both methods using two-dimensional finite-element models which include heat transfer and capillarity. Heat transfer in vertical growth systems is dominated by conduction in the melt and the crystal, with almost flat melt/crystal interfaces that are perpendicular to the direction of growth. The high axial temperature gradients characteristic of vertical growth lead to high thermal stresses. The maximum growth rate is also limited by capillarity which can restrict the conduction of heat from the melt into the crystal. In horizontal growth the melt/crystal interface stretches across the surface of the melt pool many times the crystal thickness, and low growth rates are achievable with careful temperature control. With a moderate axial temperature gradient in the sheet a substantial portion of the latent heat conducts along the sheet and the surface of the melt pool becomes supercooled, leading to dendritic growth. The thermal supercooling is surpressed by lowering the axial gradient in the crystal; this configuration is the most desirable for the growth of high quality crystals. An expression derived from scaling analysis relating the growth rate and the crucible temperature is shown to be reliable for horizontal growth.
Xiao, Xifeng; Voelz, David G; Toselli, Italo; Korotkova, Olga
2016-05-20
Experimental and theoretical work has shown that atmospheric turbulence can exhibit "non-Kolmogorov" behavior including anisotropy and modifications of the classically accepted spatial power spectral slope, -11/3. In typical horizontal scenarios, atmospheric anisotropy implies that the variations in the refractive index are more spatially correlated in both horizontal directions than in the vertical. In this work, we extend Gaussian beam theory for propagation through Kolmogorov turbulence to the case of anisotropic turbulence along the horizontal direction. We also study the effects of different spatial power spectral slopes on the beam propagation. A description is developed for the average beam intensity profile, and the results for a range of scenarios are demonstrated for the first time with a wave optics simulation and a spatial light modulator-based laboratory benchtop counterpart. The theoretical, simulation, and benchtop intensity profiles show good agreement and illustrate that an elliptically shaped beam profile can develop upon propagation. For stronger turbulent fluctuation regimes and larger anisotropies, the theory predicts a slightly more elliptical form of the beam than is generated by the simulation or benchtop setup. The theory also predicts that without an outer scale limit, the beam width becomes unbounded as the power spectral slope index α approaches a maximum value of 4. This behavior is not seen in the simulation or benchtop results because the numerical phase screens used for these studies do not model the unbounded wavefront tilt component implied in the analytic theory.
Relative azimuth inversion by way of damped maximum correlation estimates
Ringler, A.T.; Edwards, J.D.; Hutt, C.R.; Shelly, F.
2012-01-01
Horizontal seismic data are utilized in a large number of Earth studies. Such work depends on the published orientations of the sensitive axes of seismic sensors relative to true North. These orientations can be estimated using a number of different techniques: SensOrLoc (Sensitivity, Orientation and Location), comparison to synthetics (Ekstrom and Busby, 2008), or by way of magnetic compass. Current methods for finding relative station azimuths are unable to do so with arbitrary precision quickly because of limitations in the algorithms (e.g. grid search methods). Furthermore, in order to determine instrument orientations during station visits, it is critical that any analysis software be easily run on a large number of different computer platforms and the results be obtained quickly while on site. We developed a new technique for estimating relative sensor azimuths by inverting for the orientation with the maximum correlation to a reference instrument, using a non-linear parameter estimation routine. By making use of overlapping windows, we are able to make multiple azimuth estimates, which helps to identify the confidence of our azimuth estimate, even when the signal-to-noise ratio (SNR) is low. Finally, our algorithm has been written as a stand-alone, platform independent, Java software package with a graphical user interface for reading and selecting data segments to be analyzed.
Effect of Horizontal Vibration on the Interfacial Instability in a Horizontal Hele-Shaw Cell
Souhar M.
2012-07-01
Full Text Available The effect of periodic oscillations on the interfacial instability of two immiscible fluids, confined in a horizontal Hele-Shaw cell, is investigated. A linear stability analysis of the basic state leads to a periodic Mathieu oscillator corresponding to the amplitude of the interface. Then, the threshold of parametric instability of the interface is characterized by harmonic or subharmonic periodic solutions. We show that the relevant parameters that control the interface are the Bond number, density ratio, Weber number and amplitude and frequency of oscillations.
Maximum Likelihood Estimation of Time-Varying Loadings in High-Dimensional Factor Models
Mikkelsen, Jakob Guldbæk; Hillebrand, Eric; Urga, Giovanni
In this paper, we develop a maximum likelihood estimator of time-varying loadings in high-dimensional factor models. We specify the loadings to evolve as stationary vector autoregressions (VAR) and show that consistent estimates of the loadings parameters can be obtained by a two-step maximum...... likelihood estimation procedure. In the first step, principal components are extracted from the data to form factor estimates. In the second step, the parameters of the loadings VARs are estimated as a set of univariate regression models with time-varying coefficients. We document the finite...
Principal semantic components of language and the measurement of meaning.
Alexei V Samsonovich
Full Text Available Metric systems for semantics, or semantic cognitive maps, are allocations of words or other representations in a metric space based on their meaning. Existing methods for semantic mapping, such as Latent Semantic Analysis and Latent Dirichlet Allocation, are based on paradigms involving dissimilarity metrics. They typically do not take into account relations of antonymy and yield a large number of domain-specific semantic dimensions. Here, using a novel self-organization approach, we construct a low-dimensional, context-independent semantic map of natural language that represents simultaneously synonymy and antonymy. Emergent semantics of the map principal components are clearly identifiable: the first three correspond to the meanings of "good/bad" (valence, "calm/excited" (arousal, and "open/closed" (freedom, respectively. The semantic map is sufficiently robust to allow the automated extraction of synonyms and antonyms not originally in the dictionaries used to construct the map and to predict connotation from their coordinates. The map geometric characteristics include a limited number ( approximately 4 of statistically significant dimensions, a bimodal distribution of the first component, increasing kurtosis of subsequent (unimodal components, and a U-shaped maximum-spread planar projection. Both the semantic content and the main geometric features of the map are consistent between dictionaries (Microsoft Word and Princeton's WordNet, among Western languages (English, French, German, and Spanish, and with previously established psychometric measures. By defining the semantics of its dimensions, the constructed map provides a foundational metric system for the quantitative analysis of word meaning. Language can be viewed as a cumulative product of human experiences. Therefore, the extracted principal semantic dimensions may be useful to characterize the general semantic dimensions of the content of mental states. This is a fundamental step
The maximum rotation of a galactic disc
Bottema, R
1997-01-01
The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously rising rotation curve until the outermost measured radial position. That is why a general relation has been derived, giving the maximum rotation for a disc depending on the luminosity, surface brightness, and colour of the disc. As a physical basis of this relation serves an adopted fixed mass-to-light ratio as a function of colour. That functionality is consistent with results from population synthesis models and its absolute value is determined from the observed stellar velocity dispersions. The derived maximum disc rotation is compared with a number of observed maximum rotations, clearly demonstrating the need for appreciable amounts of dark matter in the disc region and even more so for LSB galaxies. Matters h...
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.
2014-06-01
Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
Computing Rooted and Unrooted Maximum Consistent Supertrees
van Iersel, Leo
2009-01-01
A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.
Maximum magnitude earthquakes induced by fluid injection
McGarr, Arthur F.
2014-01-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
Maximum magnitude earthquakes induced by fluid injection
McGarr, A.
2014-02-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
Principal normal indicatrices of closed space curves
Røgen, Peter
1997-01-01
A theorem due to J. Weiner, which also is proven by B. Solomon, implies that a principal normal indicatrix of a closed space curve with non-vanishing curvature has integrated geodesic curvature zero and contains no sub arc with integrated geodesic curvature Pi. We prove that the inverse problem...... always has solutions if one allows zero and negative curvature of space curves and explain why this not is true if non-vanishing curvature is required. This answers affirmatively an open question asked by W. Fenchel in 1950 under the above assumptions but in general this question is found to be answered...
Principal symbol of Euler-Lagrange operators
Fatibene, L.; Garruto, S.
2016-07-01
We shall introduce the principal symbol for quite a general class of (quasi linear) Euler-Lagrange operators and use them to characterise well-posed initial value problems in gauge covariant field theories. We shall clarify how constraints can arise in covariant Lagrangian theories by extending the standard treatment in GR and without resorting to Hamiltonian formalism. Finally as an example of application, we sketch a quantisation procedure based on what is done in LQG by framing it in a more general context which applies to general gauge covariant field theories.
Principal $G$-bundles over elliptic curves
Friedman, R; Witten, Edward; Friedman, Robert; Morgan, John W.; Witten, Edward
1997-01-01
Let $G$ be a simple and simply connected complex Lie group. We discuss the moduli space of holomorphic semistable principal $G$-bundles over an elliptic curve $E$. In particular, we give a new proof of a theorem of Looijenga and Bernshtein-Shvartsman, that the moduli space is a weighted projective space. The method of proof is to study the deformations of certain unstable bundles coming from special maximal parabolic subgroups of $G$. We also discuss the associated automorphism sheaves and universal bundles, as well as the relation between various universal bundles and spectral covers.
Radar fall detection using principal component analysis
Jokanovic, Branka; Amin, Moeness; Ahmad, Fauzia; Boashash, Boualem
2016-05-01
Falls are a major cause of fatal and nonfatal injuries in people aged 65 years and older. Radar has the potential to become one of the leading technologies for fall detection, thereby enabling the elderly to live independently. Existing techniques for fall detection using radar are based on manual feature extraction and require significant parameter tuning in order to provide successful detections. In this paper, we employ principal component analysis for fall detection, wherein eigen images of observed motions are employed for classification. Using real data, we demonstrate that the PCA based technique provides performance improvement over the conventional feature extraction methods.
Maximum Multiflow in Wireless Network Coding
Zhou, Jin-Yi; Jiang, Yong; Zheng, Hai-Tao
2012-01-01
In a multihop wireless network, wireless interference is crucial to the maximum multiflow (MMF) problem, which studies the maximum throughput between multiple pairs of sources and sinks. In this paper, we observe that network coding could help to decrease the impacts of wireless interference, and propose a framework to study the MMF problem for multihop wireless networks with network coding. Firstly, a network model is set up to describe the new conflict relations modified by network coding. Then, we formulate a linear programming problem to compute the maximum throughput and show its superiority over one in networks without coding. Finally, the MMF problem in wireless network coding is shown to be NP-hard and a polynomial approximation algorithm is proposed.
Horizontal gene transfer from Agrobacterium to plants
Tatiana V. Matveeva
2014-08-01
Full Text Available Most genetic engineering of plants uses Agrobacterium mediated transformation to introduce novel gene content. In nature, insertion of T-DNA in the plant genome and its subsequent transfer via sexual reproduction has been shown in several species in the genera Nicotiana and Linaria. In these natural examples of horizontal gene transfer from Agrobacterium to plants, the T-DNA donor is assumed to be a mikimopine strain of A.rhizogenes. A sequence homologous to the T-DNA of the Ri plasmid of Agrobacterium rhizogenes was found in the genome of untransformed Nicotiana glauca about 30 years ago, and was named cellular T-DNA (cT-DNA. It represents an imperfect inverted repeat and contains homologues of several T-DNA oncogenes (NgrolB, NgrolC, NgORF13, NgORF14 and an opine synthesis gene (Ngmis. A similar cT-DNA has also been found in other species of the genus Nicotiana. These presumably ancient homologues of T-DNA genes are still expressed, indicating that they may play a role in the evolution of these plants. Recently T-DNA has been detected and characterized in Linaria vulgaris and L. dalmatica. In Linaria vulgaris the cT-DNA is present in two copies and organized as a tandem imperfect direct repeat, containing LvORF2, LvORF3, LvORF8, LvrolA, LvrolB, LvrolC, LvORF13, LvORF14, and the Lvmis genes. All L. vulgaris and L. dalmatica plants screened contained the same T-DNA oncogenes and the mis gene. Evidence suggests that there were several independent T-DNA integration events into the genomes of these plant genera. We speculate that ancient plants transformed by A. rhizogenes might have acquired a selective advantage in competition with the parental species. Thus, the events of T-DNA insertion in the plant genome might have affected their evolution, resulting in the creation of new plant species. In this review we focus on the structure and functions of cT-DNA in Linaria and Nicotiana and discuss their possible evolutionary role.
Horizontal versus familial transmission of Helicobacter pylori.
Sandra Schwarz
2008-10-01
Full Text Available Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large population samples and to the extensive genetic diversity between isolates, the transmission and spread of H. pylori remain poorly understood. We studied the genetic relationships of H. pylori isolated from 52 individuals of two large families living in a rural community in South Africa and from 43 individuals of 11 families living in urban settings in the United Kingdom, the United States, Korea, and Colombia. A 3,406 bp multilocus sequence haplotype was determined for a total of 142 H. pylori isolates. Isolates were assigned to biogeographic populations, and recent transmission was measured as the occurrence of non-unique isolates, i.e., isolates whose sequences were identical to those of other isolates. Members of urban families were almost always infected with isolates from the biogeographic population that is common in their location. Non-unique isolates were frequent in urban families, consistent with familial transmission between parents and children or between siblings. In contrast, the diversity of H. pylori in the South African families was much more extensive, and four distinct biogeographic populations circulated in this area. Non-unique isolates were less frequent in South African families, and there was no significant correlation between kinship and similarity of H. pylori sequences. However, individuals who lived in the same household did have an increased probability of carrying the same non-unique isolates of H. pylori, independent of kinship. We conclude that patterns of spread of H. pylori under conditions of high prevalence, such as the rural South African families, differ from those in developed countries. Horizontal transmission occurs frequently between persons who do not belong to a core family, blurring the pattern of familial
How can horizontal wells help in naturally fractured reservoir characterization?
Mazouzi, A.; Deghmoum, A.; Azzouguen, A. [Sonatrach Inc., Hydra (Algeria); Oudjida, A. [Anadarko Inc., (Algeria)
2000-11-01
Two successfully drilled horizontal gas wells in the Tin Fouye Tabankort (TFT) fractured reservoir in Algeria were described. The productivity index of horizontal wells compared to vertical wells depends on the pay zone height, vertical anisotropy, lateral anisotropy, the length of the horizontal drain and the amplitude of the damaged zone. Transient tests in horizontal wells can solve the problem of quantifying the vertical and lateral anisotropies. Horizontal wells also minimize the turbulence effects in the vicinity of the wellbore, particularly in gas wells. The two horizontal wells in the TFT reservoir provide an important gas flow rate. The productivity index for each well is triple that of a vertical well. The permeability tensor on the TFT reservoir is established on the basis of transient test reconstitution using numerical simulation. The vertical permeability yields the best match for pressure response. It can be shown as a translation effect in time at the beginning of the linear flow regime. The horizontal anisotropy reacts to the translation of pressure and its derivative in the vertical direction. The configuration of the reservoir shows a high lateral anisotropy with regards to permeability. The vertical permeability can be considered as the composite permeability of both the matrix and fractures. Numerical and laboratory studies show that low permeability is due to fracture opening. Therefore, fracture doesn't necessarily enhance permeability. 8 refs., 3 tabs., 13 figs.
Yazdani, S.; Ashjaee, M. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Mechanical Engineering; Yousefi, T. [Razi Univ., Kermanshah (Iran, Islamic Republic of). Dept. of Mechanical Engineering
2009-07-01
Natural convection heat transfer from a horizontal isothermal cylinder located above an adiabatic surface is encountered in many technological applications, including heating, ventilating and air conditioning systems. Therefore, an understanding of how a ceiling can influence free convection heat transfer from a heated cylinder is important. This study investigated the local and average free convection heat transfer from a horizontal surface at different cylinder-to-surface spacing (L/D) and Rayleigh number experimentally using a Mach-Zehnder interferometer. Experiments were carried out using Mach-Zehnder interferometer at Rayleigh numbers in the range between 500 and 15000. The effect of the Rayleigh number and spacing from the adiabatic bottom surface on both local and the average Nusselt numbers around the cylinder were investigated. The experimental data showed that the average Nusselt number decreased to a minimum and then increased to a maximum as L/D increased. The maximum in average Nusselt number moved closer to the cylinder's surface as the Rayleigh number increased. 26 refs., 8 figs.
Numerical investigation of flow and heat transfer performances of horizontal spiral-coil pipes
季家东; 葛培琪; 毕文波
2016-01-01
The flow and heat transfer performances of horizontal spiral-coil pipes of circular and elliptical cross-sections are studied. The numerical results are compared with the experimental data, to verify the numerical method. The effects of the inlet water mass flow rate, the structural parameters, the helical pitch and the radius ratio on the heat transfer performances are investigated. Perfor- mances of the secondary fluid flow with different radius ratios are also investigated. Numerical results demonstrate that the heat transfer coefficient and the Nusselt number increase with the increase of the water mass flow rate or the helical pitch. The maximum heat transfer coefficient and the maximum Nusselt number are obtained when the radius ratio isequal to 1.00. In addition, the fluid particle moves spirally along the pipe and the velocity changes periodically. The particle flow intensity and the spiral movement frequency decrease significantly with the increase of the radius ratio. Besides, the secondary flow profile in the horizontal spiral-coil pipe contains two oppositely rotating eddies, and the eddy intensity decreases significantly along the pipe owing to the change of curvature. The decreasing tendency of the eddy intensity along the pipe increases with the increase of the radius ratio.
Simulation of Rock Mass Horizontal Displacements with Usage of Cellular Automata Theory.
Sikora, Paweł
2016-12-01
In the article there was presented two dimensional rock mass model as a deterministic finite cellular automata. Used to describe the distribution of subsidence of rock mass inside and on its surface the theory of automata makes it relatively simple way to get a subsidence trough profile consistent with the profile observed by geodetic measurements on the land surface. As a development of an existing concept of the rock mass model, as a finite cellular automaton, there was described distribution function that allows, simultaneously with the simulation of subsidence, to simulate horizontal displacements inside the rock mass model and on its surface in accordance with real observations. On the basis of the results of numerous computer simulations there was presented fundamental mathematical relationship that determines the ratio of maximum horizontal displacement and maximum subsidence, in case of full subsidence trough, in relation to the basic parameters of the rock mass model. The possibilities of presented model were shown on the example of simulation results of deformation distribution caused by extraction of abstract coal panel. Obtained results were consistent with results obtained by geometric-integral theory.
The Wiener maximum quadratic assignment problem
Cela, Eranda; Woeginger, Gerhard J
2011-01-01
We investigate a special case of the maximum quadratic assignment problem where one matrix is a product matrix and the other matrix is the distance matrix of a one-dimensional point set. We show that this special case, which we call the Wiener maximum quadratic assignment problem, is NP-hard in the ordinary sense and solvable in pseudo-polynomial time. Our approach also yields a polynomial time solution for the following problem from chemical graph theory: Find a tree that maximizes the Wiener index among all trees with a prescribed degree sequence. This settles an open problem from the literature.
Maximum confidence measurements via probabilistic quantum cloning
Zhang Wen-Hai; Yu Long-Bao; Cao Zhuo-Liang; Ye Liu
2013-01-01
Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states.In this paper,we show that if incorrect copies are allowed to be produced,linearly dependent quantum states may also be cloned by the PQC.By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states,we derive the upper bound of the maximum confidence measure of a set.An explicit transformation of the maximum confidence measure is presented.
Maximum floodflows in the conterminous United States
Crippen, John R.; Bue, Conrad D.
1977-01-01
Peak floodflows from thousands of observation sites within the conterminous United States were studied to provide a guide for estimating potential maximum floodflows. Data were selected from 883 sites with drainage areas of less than 10,000 square miles (25,900 square kilometers) and were grouped into regional sets. Outstanding floods for each region were plotted on graphs, and envelope curves were computed that offer reasonable limits for estimates of maximum floods. The curves indicate that floods may occur that are two to three times greater than those known for most streams.
Revealing the Maximum Strength in Nanotwinned Copper
Lu, L.; Chen, X.; Huang, Xiaoxu
2009-01-01
The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...
The Maximum Resource Bin Packing Problem
Boyar, J.; Epstein, L.; Favrholdt, L.M.
2006-01-01
Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...
Maximum entropy analysis of EGRET data
Pohl, M.; Strong, A.W.
1997-01-01
EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....
Revealing the Maximum Strength in Nanotwinned Copper
Lu, L.; Chen, X.; Huang, Xiaoxu
2009-01-01
The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...
Maximum phytoplankton concentrations in the sea
Jackson, G.A.; Kiørboe, Thomas
2008-01-01
A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collected...... in the North Atlantic as part of the Bermuda Atlantic Time Series program as well as data collected off Southern California as part of the Southern California Bight Study program. The observed maximum particulate organic carbon and volumetric particle concentrations are consistent with the predictions...
Boosting Principal Component Analysis by Genetic Algorithm
Divya Somvanshi
2010-07-01
Full Text Available This paper presents a new method of feature extraction by combining principal component analysis and genetic algorithm. Use of multiple pre-processors in combination with principal component analysis generates alternate feature spaces for data representation. The present method works out the fusion of these multiple spaces to create higher dimensionality feature vectors. The fused feature vectors are given chromosome representation by taking feature components to be genes. Then these feature vectors are allowed to undergo genetic evolution individually. For genetic algorithm, initial population is created by calculating probability distance matrix, and by applying a probability distance metric such that all the genes which lie farther than a defined threshold are tripped to zero. The genetic evolution of fused feature vector brings out most significant feature components (genes as survivours. A measure of significance is adapted on the basis of frequency of occurrence of the surviving genes in the current population. Finally, the feature vector is obtained by weighting the original feature components in proportion to their significance. The present algorithm is validated in combination with a neural network classifier based on error backpropagation algorithm, and by analysing a number of benchmark datasets available in the open sources.Defence Science Journal, 2010, 60(4, pp.392-398, DOI:http://dx.doi.org/10.14429/dsj.60.495
HUANG Fei; WANG Hong; QIAN Junping; WANG Guofu
2006-01-01
Based on the atmospheric horizontal visibility data from forty-seven observational stations along the eastern coast of China near the Taiwan Strait and simultaneous NOAA/AVHRR multichannel satellite data during January 2001 to December 2002, the spectral characters associated with visibility were investigated.Successful retrieval of visibility from multichannel NOAA/AVHRR data was performed using the principal component regression (PCR) method.A sample of retrieved visibility distribution was discussed with a sea fog process.The correlation coefficient between the observed and retrieved visibility was about 0.82, which is far higher than the 99.9% confidence level by statistical test.The rate of successful retrieval is 94.98% of the 458 cases during 2001- 2002.The error distribution showed that high visibilities were usually under-estimated and low visibilities were over-estimated and the relative error between the observed and retrieved visibilities was about 21.4%.
The development and psychometric testing of the horizontal violence scale.
Longo, Joy; Newman, David
2014-12-01
Inappropriate behaviors of healthcare workers can threaten the delivery of safe, quality care. The purpose of this research was to develop a research instrument specific to the construct of horizontal violence and conduct foundational psychometric testing of the newly developed instrument. The overall findings on the fit indices suggest that this model does adequately measure the underlying construct of horizontal violence. The instrument can be used as a way to determine the existence and extent of horizontal violence in practice settings and used to augment the study of the work environment, particularly in relation to healthy work environments.
MWD resistivity tool guides bit horizontally in thin bed
Fagin, R.A. (Teleco Oilfield Services, Inc., Houston, TX (US))
1991-12-09
This paper reports on the MWD dual processing resistivity (DPR) measurements and modelling which helped steer a horizontal well through a thin oil zone to avoid a nearby oil/water contact. The horizontal well came on-line flowing 380 bo/d with no water production. Offset vertical wells produce an average of 33 bo/d with an 83% saltwater cut. Until recently, horizontal drilling efforts have been focused on thick reservoirs in which the stratigraphic position of the well bore within the target formation was not critical. Navigation through much thinner reservoirs is now possible with a technique that uses an electromagnetic propagation resistivity tool.
A selection method of the horizontal wells completion
Ivica Ristović
2006-10-01
Full Text Available The completion of horizontal wells can be done by different ways and depends on production constraints and the reservoir characteristics.The selection of a completon method is directly influenced by the degree of rock consolidation, the need for water or gas shut off,the anticipated flow rate, the completion longevity, the shale reactivity and the stability, the degree of grain sorting and the lamination.In this article, the possible methods for the horizontal well completion are shown. Also, it is presented the horizontal well completion selection flowchart. This algorithm is made on the basis of a large number of wells’ analysis considering reservoir characteristics and production constraints.
Evaluation of Parameters Affecting Horizontal Stability of Landing Mats
1976-09-01
1974. A rmathematical 11aodel tio silluatet the buckling response oif thte tria’i to th;: hora /ttntal ltAds way, atso elp. 1 h reuls o th...NO. 19R-20-0 MAT XU19, 4-FT X 4*PT ZERO ECCENTRICITY WIT420T EJGH48F NOTE NUMBERS SL LINES .RE HORIZONTAL FORC~E (LEFT) AND HORIZONTAL MOVEMENT ,RIGH...connector bars 14- TEST NO. 19-20-0 MAT XM19, 4-FT X 4-FT WIDTH 20-FT, LENGTH 48-FT ZERO ECCENTRICITY S-NG NUMBERS BYLINES ARE HORIZONTAL FORCE (LEFT) AND
Analysis of Photovoltaic Maximum Power Point Trackers
Veerachary, Mummadi
The photovoltaic generator exhibits a non-linear i-v characteristic and its maximum power point (MPP) varies with solar insolation. An intermediate switch-mode dc-dc converter is required to extract maximum power from the photovoltaic array. In this paper buck, boost and buck-boost topologies are considered and a detailed mathematical analysis, both for continuous and discontinuous inductor current operation, is given for MPP operation. The conditions on the connected load values and duty ratio are derived for achieving the satisfactory maximum power point operation. Further, it is shown that certain load values, falling out of the optimal range, will drive the operating point away from the true maximum power point. Detailed comparison of various topologies for MPPT is given. Selection of the converter topology for a given loading is discussed. Detailed discussion on circuit-oriented model development is given and then MPPT effectiveness of various converter systems is verified through simulations. Proposed theory and analysis is validated through experimental investigations.
On maximum cycle packings in polyhedral graphs
Peter Recht
2014-04-01
Full Text Available This paper addresses upper and lower bounds for the cardinality of a maximum vertex-/edge-disjoint cycle packing in a polyhedral graph G. Bounds on the cardinality of such packings are provided, that depend on the size, the order or the number of faces of G, respectively. Polyhedral graphs are constructed, that attain these bounds.
Hard graphs for the maximum clique problem
Hoede, Cornelis
1988-01-01
The maximum clique problem is one of the NP-complete problems. There are graphs for which a reduction technique exists that transforms the problem for these graphs into one for graphs with specific properties in polynomial time. The resulting graphs do not grow exponentially in order and number. Gra
Maximum Likelihood Estimation of Search Costs
J.L. Moraga-Gonzalez (José Luis); M.R. Wildenbeest (Matthijs)
2006-01-01
textabstractIn a recent paper Hong and Shum (forthcoming) present a structural methodology to estimate search cost distributions. We extend their approach to the case of oligopoly and present a maximum likelihood estimate of the search cost distribution. We apply our method to a data set of online p
Weak Scale From the Maximum Entropy Principle
Hamada, Yuta; Kawana, Kiyoharu
2015-01-01
The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\
Weak scale from the maximum entropy principle
Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu
2015-03-01
The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.
Global characterization of the Holocene Thermal Maximum
Renssen, H.; Seppä, H.; Crosta, X.; Goosse, H.; Roche, D.M.V.A.P.
2012-01-01
We analyze the global variations in the timing and magnitude of the Holocene Thermal Maximum (HTM) and their dependence on various forcings in transient simulations covering the last 9000 years (9 ka), performed with a global atmosphere-ocean-vegetation model. In these experiments, we consider the i
Instance Optimality of the Adaptive Maximum Strategy
L. Diening; C. Kreuzer; R. Stevenson
2016-01-01
In this paper, we prove that the standard adaptive finite element method with a (modified) maximum marking strategy is instance optimal for the total error, being the square root of the squared energy error plus the squared oscillation. This result will be derived in the model setting of Poisson’s e
Maximum phonation time: variability and reliability.
Speyer, Renée; Bogaardt, Hans C A; Passos, Valéria Lima; Roodenburg, Nel P H D; Zumach, Anne; Heijnen, Mariëlle A M; Baijens, Laura W J; Fleskens, Stijn J H M; Brunings, Jan W
2010-05-01
The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia versus a group of healthy control subjects matched by age and gender. Over a period of maximally 6 weeks, three video recordings were made of five subjects' maximum phonation time trials. A panel of five experts were responsible for all measurements, including a repeated measurement of the subjects' first recordings. Patients showed significantly shorter maximum phonation times compared with healthy controls (on average, 6.6 seconds shorter). The averaged interclass correlation coefficient (ICC) over all raters per trial for the first day was 0.998. The averaged reliability coefficient per rater and per trial for repeated measurements of the first day's data was 0.997, indicating high intrarater reliability. The mean reliability coefficient per day for one trial was 0.939. When using five trials, the reliability increased to 0.987. The reliability over five trials for a single day was 0.836; for 2 days, 0.911; and for 3 days, 0.935. To conclude, the maximum phonation time has proven to be a highly reliable measure in voice assessment. A single rater is sufficient to provide highly reliable measurements.
Maximum Phonation Time: Variability and Reliability
R. Speyer; H.C.A. Bogaardt; V.L. Passos; N.P.H.D. Roodenburg; A. Zumach; M.A.M. Heijnen; L.W.J. Baijens; S.J.H.M. Fleskens; J.W. Brunings
2010-01-01
The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia v
Maximum likelihood estimation of fractionally cointegrated systems
Lasak, Katarzyna
In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...
Maximum likelihood estimation for integrated diffusion processes
Baltazar-Larios, Fernando; Sørensen, Michael
EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...
Maximum gain of Yagi-Uda arrays
Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.
1971-01-01
Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....
Vu Duy Kien
2014-08-01
Full Text Available Background: A health system that provides equitable health care is a principal goal in many countries. Measuring horizontal inequity (HI in health care utilization is important to develop appropriate and equitable public policies, especially policies related to non-communicable diseases (NCDs. Design: A cross-sectional survey of 1,211 randomly selected households in slum and non-slum areas was carried out in four urban districts of Hanoi city in 2013. This study utilized data from 3,736 individuals aged 15 years and older. Respondents were asked about health care use during the previous 12 months; information included sex, age, and self-reported NCDs. We assessed the extent of inequity in utilization of public health care services. Concentration indexes for health care utilization and health care needs were constructed via probit regression of individual utilization of public health care services, controlling for age, sex, and NCDs. In addition, concentration indexes were decomposed to identify factors contributing to inequalities in health care utilization. Results: The proportion of healthcare utilization in the slum and non-slum areas was 21.4 and 26.9%, respectively. HI in health care utilization in favor of the rich was observed in the slum areas, whereas horizontal equity was achieved among the non-slum areas. In the slum areas, we identified some key factors that affect the utilization of public health care services. Conclusion: Our results suggest that to achieve horizontal equity in utilization of public health care services, policy should target preventive interventions for NCDs, focusing more on the poor in slum areas.
Ancient horizontal gene transfer from bacteria enhances biosynthetic capabilities of fungi.
Imke Schmitt
Full Text Available BACKGROUND: Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive. METHODOLOGY/PRINCIPAL FINDINGS: We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6-methylsalicylic acid (6-MSA-type PKSs and their closest bacterial relatives. To assess the role of symbiotic fungi in the evolution of this gene we generated 24 6-MSA synthase sequence tags from lichen-forming fungi. Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by gene duplication. CONCLUSIONS/SIGNIFICANCE: Given that actinobacteria are unrivaled producers of biologically active compounds, such as antibiotics, it appears particularly promising to study biosynthetic genes of actinobacterial origin in fungi. The large number of 6-MSA-type PKS sequences found in lichen-forming fungi leads us hypothesize that the evolution of typical lichen compounds, such as orsellinic acid derivatives, was facilitated by the gain of this bacterial polyketide synthase.
Chunyang Li; Ying Wang; Hao Peng; Hejiao Bian; Mingwei Min; Longfei Chen; Qian Liu; Jinku Bao
2009-01-01
Horizontal gene transfer(HGT)has long been considered as a principal force for an organism to gain novel genes in genome evolution. Homology search, phylogenetic analysis and nucleotide composition analysis are three major objective approaches to arguably determine the occurrence and directionality of HGT. Here, 21 genes that possess the potential to horizontal transfer were acquired from the whole genome of Magnaporthe grisea according to annotation, among which three can-didate genes(corresponding protein accession numbers are EAA55123, EAA47200 and EAA52136)were selected for further analysis. According to BLAST homology results, we subsequently conducted phylogenetic analysis of the three candidate HGT genes. Moreover, nucleotide composition analysis was conducted to further validate these HGTs. In addition, the functions of the three candidate genes were searched in COG database. Consequently, we conclude that the gene encoding protein EAA55123 is transferred from Clostridium perfringens. Another HGT event is between EAA52136 and a certain metazoan's corresponding gene, but the direction remains uncertain. Yet, EAA47200 is not a transferred gene.
Sustainable Horizontal Bioventing and Vertical Biosparging Implementation (Invited)
Leu, J.; Lin, J.; Ferris, S.
2013-12-01
A former natural gas processing site with total petroleum hydrocarbons (TPH) and benzene, toluene, ethylbenzene, and xylene (BTEX) impacts in both soil and groundwater was partially excavated to remove 2,400 cubic yards of impacted soil. However, due to active natural gas pipelines within the impacted footprint, excavation was discontinued and an area of impacted soil containing maximum concentrations of 5,000 mg/kg gasoline-range organics (GRO), 8,600 mg/kg diesel-range organics (DRO), and 130 mg/kg motor oil-range organics (ORO). Groundwater was impacted with concentrations up to 2,300 μg/L GRO and 4,200 μg/L DRO remained in place. Taking advantage of the open excavation, horizontal-screened piping was placed in the backfill to deliver air for bioventing, which resulted in successful remediation of soil in a physically inaccessible area. The combined use of excavation of the source area, bioventing of surrounding inaccessible soil, and biosparging of the groundwater and smear zone resulted in nearing a no-further-action status at the site. The sustainable bioventing system consisted of one 3-HP blower and eight horizontal air injection wells. Five dual-depth nested vapor monitoring points (VMPs) were installed at 5 feet and 10 feet below ground surface as part of the monitoring system for human health and system performance. The bioventing system operated for one year followed by a three-month rebound test. During the one-year operation, air flow was periodically adjusted to maximize removal of volatile organic compounds (VOCs) from the vent wells with elevated photo-ionization detector readings. After the bioventing successfully remediated the inaccessible impacted soil, the biosparging system incorporated the pre-existing bioventing unit with an upgraded 5-HP blower and three vertical biosparging wells to biodegrade dissolved phase impacts in the groundwater. The subsequent monitoring system includes the VMPs, the air injection wells, and four groundwater
Nonlinear principal component analysis and its applications
Mori, Yuichi; Makino, Naomichi
2016-01-01
This book expounds the principle and related applications of nonlinear principal component analysis (PCA), which is useful method to analyze mixed measurement levels data. In the part dealing with the principle, after a brief introduction of ordinary PCA, a PCA for categorical data (nominal and ordinal) is introduced as nonlinear PCA, in which an optimal scaling technique is used to quantify the categorical variables. The alternating least squares (ALS) is the main algorithm in the method. Multiple correspondence analysis (MCA), a special case of nonlinear PCA, is also introduced. All formulations in these methods are integrated in the same manner as matrix operations. Because any measurement levels data can be treated consistently as numerical data and ALS is a very powerful tool for estimations, the methods can be utilized in a variety of fields such as biometrics, econometrics, psychometrics, and sociology. In the applications part of the book, four applications are introduced: variable selection for mixed...
Regional principal color based saliency detection.
Jing Lou
Full Text Available Saliency detection is widely used in many visual applications like image segmentation, object recognition and classification. In this paper, we will introduce a new method to detect salient objects in natural images. The approach is based on a regional principal color contrast modal, which incorporates low-level and medium-level visual cues. The method allows a simple computation of color features and two categories of spatial relationships to a saliency map, achieving higher F-measure rates. At the same time, we present an interpolation approach to evaluate resulting curves, and analyze parameters selection. Our method enables the effective computation of arbitrary resolution images. Experimental results on a saliency database show that our approach produces high quality saliency maps and performs favorably against ten saliency detection algorithms.
Principal aspects of the Ordovician biotic radiation
无
2010-01-01
The Ordovician radiation is among the major bioevents in earth history that have drawn great attention from geologists all over the world, and there have been hundreds of publications treating various aspects of this radiation. The study of the event involves a broad spectrum of research fields and concerns many scientific questions. Many opinions and hypotheses have been proposed on the triggering and controlling factors of the radiation. Herein the authors critically review the study of the Ordovician radiation and dissect four principal aspects by synthesizing the studies over the past years: (1) relationships of the radiation to fossil clades, ecotypes, and environments, such as water depth, latitude, and climate; (2) the ecological structure and food webs of Ordovician marine organisms; (3) fossil records and true biodiversities; and (4) likely triggering and controlling factors of the Ordovician radiation. The authors also recommend approaches to furthering studies of these aspects.
Face Recognition Based on Principal Component Analysis
Ali Javed
2013-02-01
Full Text Available The purpose of the proposed research work is to develop a computer system that can recognize a person by comparing the characteristics of face to those of known individuals. The main focus is on frontal two dimensional images that are taken in a controlled environment i.e. the illumination and the background will be constant. All the other methods of person’s identification and verification like iris scan or finger print scan require high quality and costly equipment’s but in face recognition we only require a normal camera giving us a 2-D frontal image of the person that will be used for the process of the person’s recognition. Principal Component Analysis technique has been used in the proposed system of face recognition. The purpose is to compare the results of the technique under the different conditions and to find the most efficient approach for developing a facial recognition system
Principal components analysis of Jupiter VIMS spectra
Bellucci, G.; Formisano, V.; D'Aversa, E.; Brown, R.H.; Baines, K.H.; Bibring, J.-P.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.
2004-01-01
During Cassini - Jupiter flyby occurred in December 2000, Visual-Infrared mapping spectrometer (VIMS) instrument took several image cubes of Jupiter at different phase angles and distances. We have analysed the spectral images acquired by the VIMS visual channel by means of a principal component analysis technique (PCA). The original data set consists of 96 spectral images in the 0.35-1.05 ??m wavelength range. The product of the analysis are new PC bands, which contain all the spectral variance of the original data. These new components have been used to produce a map of Jupiter made of seven coherent spectral classes. The map confirms previously published work done on the Great Red Spot by using NIMS data. Some other new findings, presently under investigation, are presented. ?? 2004 Published by Elsevier Ltd on behalf of COSPAR.
Reinvention and the Principal-Agent Model
J. Ramón Gil García
2003-01-01
Full Text Available Existe una interesante polémica en el sector público, derivada de las tensiones existentes entre desempeño y flexibilidad administrativa por un lado, y rendición de cuentas y control, por el otro. El propósito de este artículo es discutir la utilidad del modelo agente principal para un mejor entendimiento de las tensiones entre desempeño y rendición de cuentas, así como analizar las similitudes y contradicciones de esta perspectiva teórica en comparación con el movimiento de reinvención del gobierno de la década de los noventa en Estados Unidos.
Principal Component Pursuit with Reduced Linear Measurements
Ganesh, Arvind; Wright, John; Ma, Yi
2012-01-01
In this paper, we study the problem of decomposing a superposition of a low-rank matrix and a sparse matrix when a relatively few linear measurements are available. This problem arises in many data processing tasks such as aligning multiple images or rectifying regular texture, where the goal is to recover a low-rank matrix with a large fraction of corrupted entries in the presence of nonlinear domain transformation. We consider a natural convex heuristic to this problem which is a variant to the recently proposed Principal Component Pursuit. We prove that under suitable conditions, this convex program guarantees to recover the correct low-rank and sparse components despite reduced measurements. Our analysis covers both random and deterministic measurement models.
Principal Components Analysis In Medical Imaging
Weaver, J. B.; Huddleston, A. L.
1986-06-01
Principal components analysis, PCA, is basically a data reduction technique. PCA has been used in several problems in diagnostic radiology: processing radioisotope brain scans (Ref.1), automatic alignment of radionuclide images (Ref. 2), processing MRI images (Ref. 3,4), analyzing first-pass cardiac studies (Ref. 5) correcting for attenuation in bone mineral measurements (Ref. 6) and in dual energy x-ray imaging (Ref. 6,7). This paper will progress as follows; a brief introduction to the mathematics of PCA will be followed by two brief examples of how PCA has been used in the literature. Finally my own experience with PCA in dual-energy x-ray imaging will be given.
Heat transfer to near-critical helium in horizontal channels
Dolgoy, M.L.; Kirichenko, Y.A.; Sklovsky, Y.B.; Troyanov, A.M.; Chernyakov, P.S. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur)
1983-03-01
Experimental results on heat transfer and pressure losses during a forced motion of helium of near-critical state parameters in a horizontal channel are reported. A method of calculation of temperature and pressure distributions along the channel is proposed.
Vertical Array in Space for Horizontal Air-Showers
Fargion, D
2009-01-01
We consider the guaranteed physics of horizontal (hadron) air-showers, HAS, developing at high (tens km) altitudes. Their morphology and information traces are different from vertical ones. Hundreds of km long HAS are often split by geomagnetic fields in a long (fan-like) showering with a twin spiral tail. The horizontal fan-like airshowers are really tangent and horizontal only at North and South poles. At different latitude these showering plane are turned and inclined by geomagnetic fields. In particular at magnetic equator such tangent horizontal East-West airshowers are bent and developed into a vertical fan air-shower, easily detectable by a vertical array detector (hanging elements by gravity). Such "medusa" arrays maybe composed by inflated floating balloons chains. The light gas float and it acts as an calorimeter for the particles, while it partially sustains the detector weight. Vertically hanging chains as well as rubber doughnut balloons (whose interior may record Cherenkov lights) reveal bundles...
Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)
Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.
2006-06-01
This report presents the results of a project at the Alternative Energy Institute (AEI) which measured and calculated the elastic twist of three representative composite horizontal-axis blades: Carter 300, Gougeon ESI 54, and UTRC 8 kW.
Horizontal Bulk Material Pressure in Silo Subjected to Impulsive Load
Radosław Tatko
2008-01-01
Full Text Available This paper describes laboratory tests carried out in the steel flat-bottomed silo model filled with sand, subjected to external dynamic loads. The model was placed on a system of springs, which represent subsoil. The loads in the form of horizontal impulses were applied to the bottom plate of the silo. Horizontal pressure-time courses were used to analyze the influence of subsoil vibrations on the distribution changes of these pressures. Basic conclusion: (1 the subsoil vibrations cause two types of changes of the horizontal pressures: stable changes which are observed when the model vibrations finish and cyclic of short duration (brief changes; (2 the subsoil vibrations either generate stable increase or stable decrease of the pressures from before vibrations or do not generate any essential stable change; (3 the cyclic dynamic changes of the horizontal pressures depend on the direction of the silo wall displacements and they are the function of the values of these displacements.
Nurse Against Nurse: Horizontal Bullying in the Nursing Profession.
Granstra, Katherine
2015-01-01
Healthcare professionals are not immune to bullying; in fact, they experience bullying at an alarming rate. Sometimes the bullying is passed down from superiors, but frequently bullying occurs between coworkers. This is known as "horizontal bullying," and it has become a serious issue within the nursing profession. Horizontal bullying between nurses can cause negative consequences for everyone involved, in particular the nurses, patients, and the entire organization. To fully address and resolve horizontal bullying in the nursing profession, we must consider many factors. The first step is to establish what constitutes bullying and to develop a clear process for dealing with it when it occurs. Before it is possible to eliminate the problem, we need to understand why bullying takes place. To be effective, solutions to the problem of horizontal bullying in the nursing profession must include the entire healthcare industry.
Optimizing of Culture Condition in Horizontal Rotating Bioreactor
Yan-Fang ZHANG; Huai-Qing CHEN; Hua HUANG
2005-01-01
@@ 1 Introduction Bioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world.
Horizontal Branch stars as AmFm/HgMn stars
Michaud, G
2008-01-01
Recent observations and models for horizontal branch stars are briefly described and compared to models for AmFm stars. The limitations of those models are emphasized by a comparison to observations and models for HgMn stars.
Regulation of mammalian horizontal gene transfer by apoptotic DNA fragmentation
Yan, B; Wang, H; Li, F; Li, C-Y
2006-01-01
Previously it was shown that horizontal DNA transfer between mammalian cells can occur through the uptake of apoptotic bodies, where genes from the apoptotic cells were transferred to neighbouring cells phagocytosing the apoptotic bodies. The regulation of this process is poorly understood. It was shown that the ability of cells as recipient of horizontally transferred DNA was enhanced by deficiency of p53 or p21. However, little is known with regard to the regulation of DNA from donor apoptotic cells. Here we report that the DNA fragmentation factor/caspase-activated DNase (DFF/CAD), which is the endonuclease responsible for DNA fragmentation during apoptosis, plays a significant role in regulation of horizontal DNA transfer. Cells with inhibited DFF/CAD function are poor donors for horizontal gene transfer (HGT) while their ability of being recipients of HGT is not affected. PMID:17146478
Maximum speeds and alpha angles of flowing avalanches
McClung, David; Gauer, Peter
2016-04-01
um/√H0--; um/√S0- are greater than 2.0 and 1.3 respectively. In addition, to: um/√H0--; um/√S0--, we collected 105 companion values of the αangle for runout positions defined by tanα = H0/X0where X0is horizontal reach calculated from start position to stop position of the tip of the avalanches. The αangle is a very simple measure of runout introduced by Scheidegger (1973) for rock avalanches. McClung and Mears (1991) collected αangles from more than 500 paths with maximum runout estimated for return periods on the order of 100 years and the range of values was: 18o - 42owhich is close to that here: (20o - 45o). The results showed that runout increases(α decreases) with maximum speed but there is considerable scatter in the relationship. The Spearman rank correlation is -0.54 (p < 0.005).Rank correlations of α vs. um/√S0-;um/√H0- are - 0.44;.- 0.56 (both with p < 0.005
Francis Bacon’s Qualification As A Principal Empiricist Philosopher
2011-01-01
The purpose of this paper is to determine if there is any basis for regarding FrancisBacon as a principal empiricist philosopher. This involves effort to determine whatconstitutes, in essence, the qualities of a principal empiricist philosopher. Are thereany criteria that qualify one as a principal empiricist philosopher? Proceeding with thisinquiry, our paper examines, on the one hand, the views of those who argue in defenceof Bacon’s qualification as a principal empiricist philosopher. Here...
Francis Bacons Qualification As A Principal Empiricist Philosopher
2011-01-01
The purpose of this paper is to determine if there is any basis for regarding Francis Bacon as a principal empiricist philosopher. This involves effort to determine what constitutes, in essence, the qualities of a principal empiricist philosopher. Are there any criteria that qualify one as a principal empiricist philosopher? Proceeding with this inquiry, our paper examines, on the one hand, the views of those who argue in defence of Bacon’s qualification as a principal empiricist philosopher....
Allocation of Decision-Making Authority with Principal's Reputation Concerns
Tsung-Sheng Tsai; Yasunari Tamada
2004-01-01
This paper analyzes the allocation of decision-making authority when the principal has reputation concerns. The principal can either keep the authority and consult the agent (an expert), or delegate the authority to the agent; however, the outside evaluator cannot observe the allocation of authority. Hence, delegation can provide a way to manipulate the principal's ex post reputation. In general, the principal keeps the authority too often when she has the opportunity of delegation. When the ...
A Preliminary Examination of the Impact of a Structured Principal Network on Principal Burnout
Tillery, Denise Artus
2012-01-01
This study examined the extent to which participation in a formal network has on a principal's personal perception of burnout as measured by the Maslach Burnout Inventory for Educators (MBI-E). The MBI-E consists of 22 questions with responses indicated on a 7 point Likert scale ranging from 0-6. It measures three constructs of emotional…
Hager, Rhonda Keever
2012-01-01
The importance of leadership is critical with current accountability for student performance. The increased accountability for school leaders has caused a change in leadership roles to incorporate collaboration and shared leadership. Assistant principals are included in the concept of distributive leadership. A review of the literature shows…
Quality M.Ed. Principal Licensure Degrees + Conscientious Students = Leader Principals
Guillaume, Cindy; Vitucci, Alanna
2015-01-01
Effective educational leadership at the principal level positively correlates with quality classroom teachers and improved student achievement (Portin et al., 2009). It also fosters a caring, supportive and inter-connected environment that inspires students and engages teachers (Seashore et al., 2010). Preparing competent, effective, and caring…
Principals' and Teachers' Views of Spirituality in Principal Leadership in Three Primary Schools
Gibson, Alaster
2014-01-01
This article discusses key findings from my doctoral research involving a qualitative case study inquiring into the lived experiences of spirituality in principal leadership and its influence on teachers and their teaching within three public primary school contexts in New Zealand. Spirituality is understood in this article as a complex and…
A Preliminary Examination of the Impact of a Structured Principal Network on Principal Burnout
Tillery, Denise Artus
2012-01-01
This study examined the extent to which participation in a formal network has on a principal's personal perception of burnout as measured by the Maslach Burnout Inventory for Educators (MBI-E). The MBI-E consists of 22 questions with responses indicated on a 7 point Likert scale ranging from 0-6. It measures three constructs of emotional…
Horizontal Bulk Material Pressure in Silo Subjected to Impulsive Load
Radosław Tatko; Sylwester Kobielak
2008-01-01
This paper describes laboratory tests carried out in the steel flat-bottomed silo model filled with sand, subjected to external dynamic loads. The model was placed on a system of springs, which represent subsoil. The loads in the form of horizontal impulses were applied to the bottom plate of the silo. Horizontal pressure-time courses were used to analyze the influence of subsoil vibrations on the distribution changes of these pressures. Basic conclusion: (1) the subsoil vibrations cause two ...
Horizontal gaze palsy with progressive scoliosis: CT and MR findings
Bomfim, Rodrigo C.; Tavora, Daniel G.F.; Nakayama, Mauro; Gama, Romulo L. [Sarah Network of Rehabilitation Hospitals, Department of Radiology, Ceara (Brazil)
2009-02-15
Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare congenital disorder characterized by absence of conjugate horizontal eye movements and progressive scoliosis developing in childhood and adolescence. We present a child with clinical and neuroimaging findings typical of HGPPS. CT and MRI of the brain demonstrated pons hypoplasia, absence of the facial colliculi, butterfly configuration of the medulla and a deep midline pontine cleft. We briefly discuss the imaging aspects of this rare entity in light of the current literature. (orig.)
Equilibrium type of competition with horizontal product innovation
Negriu, A.
2015-01-01
Singh and Vives (1984) consider a game where duopolists first commit to a strategic variable quantity or pice, and then compete in selling horizontally differentiated products. Here product substitutability is endogenized by allowing firms to undertake R&D investments to increase differentitation. Whereas in the original model Cournot competition always ensued in equilibrium, horizontal product innovation allows all types of market competition to be an equilibrium, depending on model paramete...
Mapping Proprioception across a 2D Horizontal Workspace
2010-01-01
Relatively few studies have been reported that document how proprioception varies across the workspace of the human arm. Here we examined proprioceptive function across a horizontal planar workspace, using a new method that avoids active movement and interactions with other sensory modalities. We systematically mapped both proprioceptive acuity (sensitivity to hand position change) and bias (perceived location of the hand), across a horizontal-plane 2D workspace. Proprioception of both the le...
Principals' Perceptions of Instructional Stages Based on Felt Teaching Characteristics.
DeMoulin, Donald F.; Guyton, John W.
Whether principals could identify teaching traits and categorize these consistently as descriptors of instructional stages was studied by asking 145 randomly selected principals in public schools throughout Illinois and Indiana to characterize teacher behavior based on experience. Principals were asked to list instructional stages, yielding 161…
Suicide in Middle Level Schools: Implications for Principals.
Toepfer, Conrad F., Jr.
1986-01-01
Prevention of teenage suicide and coping with it when it occurs is an increasing concern for middle-level principals. This article focuses on specific implications of the youth suicide problem for middle-level principals with considerations for other principals as well. (Author/TE)
Leadership Behaviors and Its Relation with Principals' Management Experience
Mehdinezhad, Vali; Sardarzahi, Zaid
2016-01-01
This paper aims at studying the leadership behaviors reported by principals and observed by teachers and its relationship with management experience of principals. A quantitative method was used in this study. The target population included all principals and teachers of guidance schools and high schools in the Dashtiari District, Iran. A sample…
The Development of Assistant Principals: A Literature Review
Oleszewski, Ashley; Shoho, Alan; Barnett, Bruce
2012-01-01
Purpose: The purpose of this review is to add to the discussion of assistant principals (APs), a position that has been under-represented in the professional literature. Design/methodology/approach: An extensive search was undertaken on assistant principals, vice principals, and deputy head teachers from various sources, including journals,…
Consejeria de los directores (Principal Mentoring). ERIC Digest.
Malone, Robert J.
To help new principals succeed, school districts are capitalizing on senior administrators' expertise by adding mentor programs to the practical training programs for beginning principals. This ERIC Digest in Spanish examines the nature of mentorships and discusses how they can prepare principals for the next stage of their careers. Although…
New Principals in Africa: Preparation, Induction and Practice
Bush, Tony; Oduro, George K. T.
2006-01-01
Purpose: This paper aims to examine the challenges facing new principals in Africa. Design/methodology/approach: Based on recent research and literature, the paper analyses the experience of principals and proposes an induction model for principalship in Africa. Findings: School principals in Africa face a daunting challenge. They often work in…
Principal Socialization in One Virginia School District: A Phenomenological Investigation
Joppy, Dalphine A.
2013-01-01
This phenomenological investigation examines the lived experiences of school principals to discover how principals hired from within their school division perceive and make meaning of their organizational socialization experiences--their thoughts, feelings, beliefs, values, and assumptive worlds. Nineteen public school principals participated in…
Training the Trainers: Learning to Be a Principal Supervisor
Saltzman, Amy
2017-01-01
While most principal supervisors are former principals themselves, few come to the role with specific training in how to do the job effectively. For this reason, both the Washington, D.C., and Tulsa, Oklahoma, principal supervisor programs include a strong professional development component. In this article, the author takes a look inside these…
What It Takes to Be an Empowering Principal.
Peel, Henry A.; Walker, Bradford L.
1994-01-01
An ongoing cooperative research project in North Carolina provides some revealing data on principals who have successfully introduced school-based management. The project tracks 26 principals committed to teacher empowerment. The most supportive principals were strongly committed to school improvement, unafraid of risks or open communication lines…
Is School Value Added Indicative of Principal Quality?
Chiang, Hanley; Lipscomb, Stephen; Gill, Brian
2016-01-01
States across the country are developing systems for evaluating school principals on the basis of student achievement growth. A common approach is to hold principals accountable for the value added of their schools--that is, schools' contributions to student achievement growth. In theory, school value added can reflect not only principals'…