Full Moments Research Articles

Reduced‐Order Modeling for Linearized Representations of Microphysical Process Rates

AbstractRepresenting cloud microphysical processes in large scale atmospheric models is challenging because many processes depend on the details of the droplet size distribution (DSD, the spectrum of droplets with different sizes in a cloud). While full or partial statistical moments of droplet size distributions are the typical variables used in bulk models, prognostic moments are limited in their ability to represent microphysical processes across the range of conditions experienced in the atmosphere. Microphysical parameterizations employing prognostic moments are known to suffer from structural uncertainty in their representations of inherently higher dimensional cloud processes, which limit model fidelity and lead to forecasting errors. Here we investigate how data‐driven reduced‐order modeling can be used to learn predictors for microphysical process rates in bulk microphysics schemes in an unsupervised manner from higher dimensional bin distributions. Using simulations characteristic of marine stratiform clouds, we simultaneously learn lower dimensional representations of droplet size distributions and predict the evolution of the microphysical state of the system. Droplet collision‐coalescence, the main process for generating warm rain, is estimated to have an intrinsic dimension of three. This intrinsic dimension provides a lower limit on the number of degrees of freedom needed to accurately represent collision‐coalescence in models. We demonstrate how deep learning based reduced‐order modeling can be used to discover intrinsic coordinates describing the microphysical state of the system, where process rates such as collision‐coalescence are globally linearized. These implicitly learned representations of the DSD retain more information about the DSD than typical moment‐based representations.

First-passage times under frequent stochastic resetting.

We determine the full distribution and moments of the first passage time for a wide class of stochastic search processes in the limit of frequent stochastic resetting. Our results apply to any system whose short-time behavior of the search process without resetting can be estimated. In addition to the typical case of exponentially distributed resetting times, we prove our results for a variety of resetting time distributions. We illustrate our results in several examples and show that the errors of our approximations vanish exponentially fast in typical scenarios of diffusive search.

Slowest first passage times, redundancy, and menopause timing.

Biological events are often initiated when a random "searcher" finds a "target," which is called a first passage time (FPT). In some biological systems involving multiple searchers, an important timescale is the time it takes the slowest searcher(s) to find a target. For example, of the hundreds of thousands of primordial follicles in a woman's ovarian reserve, it is the slowest to leave that trigger the onset of menopause. Such slowest FPTs may also contribute to the reliability of cell signaling pathways and influence the ability of a cell to locate an external stimulus. In this paper, we use extreme value theory and asymptotic analysis to obtain rigorous approximations to the full probability distribution and moments of slowest FPTs. Though the results are proven in the limit of many searchers, numerical simulations reveal that the approximations are accurate for any number of searchers in typical scenarios of interest. We apply these general mathematical results to models of ovarian aging and menopause timing, which reveals the role of slowest FPTs for understanding redundancy in biological systems. We also apply the theory to several popular models of stochastic search, including search by diffusive, subdiffusive, and mortal searchers.

A study on the lived experience of Koinōnia in a post-apartheid, post-Armstrong congregation: A transition from power-imbalance to Koinōnia

The triune God reaches from within his perichoretic unity (Eugenio, 2014:156), into his creation, inviting all of humanity to participate in the Triune community of “shared participation—a participation together—in the perichoretic community of Trinitarian persons” (Grenz, 2003:268). Within this community, humanity finds it is made-in-God’s-image value and can live in the freedom of God’s communion (Knight, 2007:1).This article considers the experience of koinōnia in a church where membership lived through transitions of both apartheid and legalistic religion simultaneously, based on the research question, “What is the lived experience of koinōnia in the post-apartheid, post-Armstrong Grace Communion International Johannesburg Congregation”. Where genuine, evangelical, Trinitarian koinōnia exists, there appear to be blockages in the progressively deepening life in community. With significant input from the work of Lincoln (Lincoln, 2009) Koinōnia is explored through five considerations: identity, common life of believers, virtuous life, ubuntu, and practical sharing. Koinōnia in the lived experience of people who have traversed the ills of apartheid and the transitions of legalistic religion are encountered, exposing the beauty of diversity, the need for common values, and the commitment of time together in Scripture. Responding to meaning full moments (Frankl, 2006) towards Christlikeness by the power of the Spirit, not the flesh (Galatians 5:13–22), appears to significantly draw believers into the unity that Jesus prays in John 17. A more faithful practice is envisioned where believers build trust in the Spirit’s unifying power and presence and, from within the identity of Christ, are encouraged to explore various responses to meaningful moments towards Christlikeness. As the article and antecedent research suggests, widening and deepening individuals’ awareness of common life may build the connectivity of the visible vessel fulfilling its mandate to reflect God to the world. The Church is like a diverse tapestry attending to the calling of mending what was broken by harmful religious and political practices.

Evaluation of Behavior of Hybrid Beam Combining Steel Inverted T-Section and RC Flange

This paper deals with flexural investigation of a type of steel-concrete composite beam structure able to provide an adequate bond between steel and concrete elements through the application of a simple steel reinforcement shear connector design, steel reinforcing bars bent into L-shapes. The cross sections involve inverted steel T-beam being embedded within reinforced concrete (RC) flange of the slab. The paper concentrates on elastic and elastic-plastic behaviour of steel inverted T-beam entrenched within a reinforced concrete flange at the top. In addition, shear connection was investigated in detail. Finally, some suggested designing equations and curves simulating the elastic, elastoplastic and full plastic experimental moments were developed. The plastic theoretical study results coincides with the experimental behaviour of the developed model.

Detection of infestation by striped stem‐borer (Chilo suppressalis) in rice based on hyperspectral imaging

AbstractStriped stem‐borer (SSB) larvae are one of the most serious insect pests that damages rice. In this study, the combined hyperspectral imaging and chemometric method are proposed detect the early SSB larvae infestation in rice stems. Firstly, hyperspectral reflectance data (390–1040 nm) of rice stems were collected for normal, 3 days of infection, 6 days of infection, and 9 days of infection, respectively. On the spectra, the average spectra of the region of interest of the rice stalk samples were extracted, and 19 characteristic wavelengths were screened by the successive projection algorithm (SPA). Morphological processing was performed on the pseudo‐color (generally known as RGB) images of rice stalk samples on the images. Then five image texture features based on the gray‐scale co‐occurrence matrix (GLCM) and nine image color features based on color moments were obtained. The evaluation models of SSB larval infestation based on full spectra, characteristic wavelengths, GLCM, color moments, and data fusion were developed using partial least squares discriminant analysis (PLS‐DA), respectively. The results show that performance of the PLS‐DA model based on the fusion of characteristic wavelengths and GLCM is best. The accuracy of both the comprehensive modeling set and the prediction set is above 97%. The accuracy of the degree of infestation classification is good for all categories, and only the samples on the third day of infection are slightly less accurate. In conclusion, the hyperspectral imaging technology can be used to effectively detect the infection degree situation of early SSB larval infestation.Practical ApplicationsChemical control using insecticides to manage SSB infestation on rice is still the farmers' first choice. However, in the middle and late stages of rice growth, SSB larvae may moth into the inside of the rice stalk, and the rice provides a shelter for SSB so that the sprayed pesticides cannot reach SSB larvae, which produce a large number of overwintering SSB. This leads to the misuse of chemical pesticides, which causes serious pollution to the environment, pesticide residues also cause serious harm to the human body, and it also makes the pest resistance to pesticides rapidly increase. Therefore, it is necessary to find a rapid and effective detection method to detect the early infestation of SSB larvae on rice to reduce the use of pesticides and improve rice yield.

Discharging the medial knee compartment: comparison of pressure distribution and kinematic shifting after implantation of an extra-capsular absorber system (ATLAS) and open-wedge high tibial osteotomy—a biomechanical in vitro analysis

PurposeYoung and active patients suffering early degenerative changes of the medial compartment with an underlying straight-leg axis do face a therapeutical gap as unloading of the medial compartment cannot be achieved by high tibial osteotomy. Extracapsular absorbing implants were developed to close this existing therapeutical gap. Purpose of the present cadaveric biomechanical study was to compare the unloading effect of the knee joint after implantation of an extra-articular absorber system (ATLAS) in comparison to open-wedge high tibial osteotomy (OW-HTO) under physiological conditions. The hypothesis of the study was that implantation of an extra-capsular absorber results in an unloading effect comparable to the one achievable with OW-HTO.MethodsEight fresh-frozen cadaveric knees were tested under isokinetic flexion–extension motions and physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment. The tibiofemoral superior–inferior, latero-medial translation and varus/valgus rotation were measured with a 3D tracking system Polaris. Pressures and kinematics changes were measured after native testing, ATLAS System implantation and OW-HTO (5° and 10° correction angles) performed with an angular stable internal fixator (TomoFix).ResultsThe absorber device decreased the pressure in the medial compartment near full extension moments. Implantation of the ATLAS absorbing system according to the manufacturers’ instruction did not result in a significant unloading effect. Deviating from the surgery manual provided by the manufacturer the implantation of a larger spring size while applying varus stress before releasing the absorber resulted in a significant pressure diminution. Contact pressure decreased significantly Δ0.20 ± 0.04 MPa p = 0.044. Performing the OW-HTO in 5° correction angle resulted in significant decreased contact pressure (Δ0.25 ± 0.10 MPa, p = 0.0036) and peak contact pressure (Δ0.39 ± 0.38 MPa, p = 0.029) compared with the native test cycle. With a 10° correction angle, OW-HTO significantly decreased area contact pressure by Δ0.32 ± 0.09 MPa, p = 0.006 and peak contact pressure by Δ0.48 ± 0.12 MPa, p = 0.0654 compared to OW-HTO 5°. Surgical treatment did not result in kinematic changes regarding the superior–inferior translation of the medial joint section. A significant difference was observed for the translation towards the lateral compartment for the ATLAS system Δ1.31 ± 0.54 MPa p = 0.022 and the osteotomy Δ3.51 ± 0.92 MPa p = 0.001. Furthermore, significant shifting varus to valgus rotation of the treated knee joint was verified for HTO 5° about Δ2.97–3.69° and for HTO 10° Δ4.11–5.23° (pHTO 5 = 0.0012; pHTO 10 = 0.0007) over the entire extension cycle.ConclusionOW-HTO results in a significant unloading of the medial compartment. Implantation of an extra-capsular absorbing device did not result in a significant unloading until the implantation technique was applied against the manufacturer’s recommendation. While the clinical difficulty for young and active patients with straight-leg axis and early degenerative changes of the medial compartment persists further biomechanical research to develop sufficient unloading devices is required.

Investigation of conformational structures of gemcitabine and its 2′,2′-difluoro 2′-deoxy derivatives: A computational study

This study investigates the electronic structure of natural DNA nucleosides and their 2′-difoluoro analogues to assess the possible substitution effects of two hydrogen atoms with fluorine ones in the positions of sugar moiety. Gemcitabine representing an analogue with specific features was utilized in this study. To conduct proper calculations, DFT method at the B3LYP/6-31+G* level was accordingly used. In terms of conformational characteristics of gemcitabine and other analogues, full geometry optimizations, atomic charges, dipole moments, NBO, and HOMO & LUMO were duly made. PROSIT was also used to calculate the pseudorotational parameters of gemcitabine and the DNA analogues. The outcome proved that all the 2-difoluoro DNA nucleosides have slight differences in geometrical parameters with natural nucleosides.

Local spin moments, valency, and long-range magnetic order in monocrystalline and ultrathin films of Y3Fe5O12 garnet

We investigate and compare the electronic structure of a bulk single crystal of ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ garnet [YIG, a high-${T}_{C}$ (= 560 K) ferrimagnet] with that of an epitaxial ultrathin (3.3 nm) film of YIG with a reduced ferrimagnetic temperature ${T}_{C}=380\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, using bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES), x-ray absorption spectroscopy (XAS), and x-ray magnetic circular dichroism (XMCD). The Fe $2p$ HAXPES spectrum of the bulk single crystal exhibits a purely trivalent ${\mathrm{Fe}}^{3+}$ state for octahedral and tetrahedral sites. The Fe $3s$ spectrum shows a clear splitting which allows us to estimate the on-site Fe $3s\text{\ensuremath{-}}3d$ exchange interaction energy. The valence band HAXPES spectrum shows Fe $3d$, O $2p$, and Fe $4s$ derived features and a band gap of $\ensuremath{\sim}2.3\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$ in the occupied density of states, consistent with the known optical band gap of $\ensuremath{\sim}2.7\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$. Fe $L$-edge XAS identifies the octahedral ${\mathrm{Fe}}^{3+}$ and tetrahedral ${\mathrm{Fe}}^{3+}$ site features. XMCD spectra at the Fe ${L}_{2,3}$ edges show that bulk single-crystal YIG exhibits antiferromagnetic coupling between the octahedral- and tetrahedral-site spins. The calculated Fe $2p$ HAXPES, Fe $L$-edge XAS, and XMCD spectra using full multiplet cluster calculations match well with the experimental results and confirm the full local spin moments. In contrast, HAXPES, XAS, and XMCD of the Pt/YIG (3.3 nm) ultrathin epitaxial film grown by a pulsed laser deposition method show a finite ${\mathrm{Fe}}^{2+}$ contribution and a reduced ${\mathrm{Fe}}^{3+}$ local spin moment. The ${\mathrm{Fe}}^{2+}$ state is attributed to a combination of oxygen deficiency and charge transfer effects from the Pt capping layer to the ultrathin film. However, the conserved XMCD spectral shape for the ultrathin film indicates that the 3.3-nm epitaxial film is genuinely ferrimagnetic, in contrast to recent studies on films grown by radio-frequency magnetron sputtering which have shown a magnetic dead layer of $\ensuremath{\sim}6$ nm. The presence of ${\mathrm{Fe}}^{2+}$ and the reduced local spin moment in the epitaxial ultrathin film lead to a reduced Curie temperature, quantitatively consistent with well-known mean-field theory. The results establish a coupling of the local Fe spin moments, valency, and long-range magnetic ordering temperature in bulk single crystal and epitaxial ultrathin-film YIG.

Ultraspherical moments on a set of disjoint intervals

Moment evaluations are important for the study of non-classical orthogonal polynomial systems for which explicit representations are not known. In this paper we compute, in terms of the hypergeometric function, the moments associated with a generalized ultraspherical weight on a collection of intervals with two symmetric gaps. These moments, parametrized by the endpoints of the gaps, are identified as a one parameter deformation between the full range ultraspherical moments and the half range ultraspherical moments.

Modeling potencijala pojedinaca i timova - Toyota

Toyota Company that is able to puzzle thousands of thinkers around the world. The key question is how did Toyota keep and still keeps its focus throughout decades of continuous development and improvement of their world known TPS? To understand it better it is necessary to know how Toyota recruits, how they build capabilities, and how they engage employees. Toyota uses a formula to evaluate each one's potential and the team's potential. Toyota uses DOJOs, learning areas within the plants, at the gemba, to train workers. Those are replicas of the real work lines and work context, where, for instance, all the new hires train for a full month, with practical and theoretical evaluation moments. As a conclusion one's can say that their people are their biggest asset.

Structural behavior of beam-to-column connections of circular CFST columns by using mixed diaphragms

Concrete Filled Steel Tube (CFST) is a structure made of a steel tube filled with concrete, in which the rigidity of the member can be increased as the steel tube confines the concrete and the concrete reduces the local buckling of the steel tube. The object of this study is a mixed diaphragm which uses a penetrated diaphragm and an exterior diaphragm in combination at beam-tocolumn connections of circular CFST columns to improve the concrete filling property. Verifying that the resistance force of mixed diaphragm is same as or superior to that of current type, the study has been conducted on the optimal dimension of mixed diaphragm of which the validity and superiority at connections of circular CFST structure have been confirmed. A size of the circular CFST column of which the yield moment is bigger than that of the beam has been selected. A type of circular CFST which exceeds the yield and full plastic moments of the beam and satisfies the condition of maintaining the initial rigidity and the maximum resistance force has been selected through finite element analysis, and a regression analysis has been conducted to obtain an approximate expression used to calculate the optimal diaphragm. The reliability and validity of the obtained approximate expression have been confirmed through a statistical theory based analysis and an approximate plane analysis. This approximate expression can be used to calculate the optimal size of the mixed diaphragm required at the beam-to-column connection of a circular CFST column.

高炉スラグ高含有セメントを用いたコンクリート充填鉄筋内蔵大径厚比円形鋼管柱の構造性能

Use of new concrete named ECM (Energy and Carbon dioxide Minimum) concrete that contains high amount of granulated blast-furnace slag is currently expected to substantially reduce emission of carbon dioxide. This study deals with the structural behavior of ECM concrete-filled circular thin tubular (CFT) steel columns with reinforcing bars distributed near their inner face. Specimens were subjected to reverse-cyclic shear loading tests under various levels of constant axial loads to investigate the following items: (1) full plastic bending moments of the ECM-CFT columns, (2) deformation capacity of the columns, (3) shear strength of the beam-column joints, (4) bond failure strength of the axial reinforcing steel bars within the joint, and (5) shear strength of the columns. The test results of the ECM-CFT columns exhibit no significant difference with the test results of CFT columns of normal concrete, and the structural performance of ECM-CFT columns can be evaluated by a procedure proposed in this paper.

Microscopic destruction of a structural homogeneous bar of a finite length under some length-wise directed impact loading

The majority of structures in modern technology, industry and production are subjected to the influence of loads. Nowa­days, a wide use of polymers and composite materials requires the study of long preservation of hardness and a problem of de­struction of the structures made of such materials and subjected to the influence of loads.Using a characteristic method, the destruction of a struc­tural inhomogeneous bar, which is subjected to an impact in its left end in the direction of its axis, was studied, and the depen­dences of the first and full moments of destruction after various mechanical characteristics were found by a numerical compu­tation. Finding of an analytical solution, characterizing the study, is rather difficult and, therefore, the problem was solved approximately. The results show that the effect of proportions of mechanical characteristics of the bar parts on the destruction process is significant.

Magnetic Ordering with Small Moments

We discuss the reason why the magnetic ordering with small moments is realized in the heavy fermion systems. The reason is that almost full localized moments cannot be created without destroying the heavy fermion states but only small localized moments can be created within the heavy fermion states. Then, we discuss the conditions of the magnetic instability in the heavy fermion system and point out the tendency that the ordering temperature is inversely proportional to the enhanced electron mass. The critical temperature of the superconductivity is also reduced in the same way.

Parameterization of Cloud Microphysics Based on Full Integral Moments

Abstract This paper describes a microphysics parameterization based on integral moments of the full drop size distributions (DSDs) as opposed to a partial moments approach (sometimes referred to as Kessler-type parameterization) based on the moments integrated separately over the cloud and rain drop portion of the drop spectrum. This approach does not assume a prescribed form of a DSD but employs as model variables full moments that have clear physical meaning: drop concentration and surface area, water content, precipitation flux, and radar reflectivity. These variables can be directly measured and assimilated into the model forecast cycle without intermediate retrievals. The approach avoids division of DSDs into cloud and rain drops. This eliminates the problem of defining the threshold between these two categories and subdivision of the physical coagulation process into artificial processes of autoconversion, accretion, and self-collection. The development and testing of the parameterization was made using the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) large-eddy simulation (LES) explicit warm rain microphysical model. The conversion and sedimentation rates were parameterized in the form of a product of power functions using nonlinear regression analysis to determine exponents of the approximated expressions. The comparison of bulk and explicit microphysics models demonstrated reasonably good prediction of both thermodynamic and microphysical parameters of the stratocumulus-topped boundary layer (STBL). The weaknesses and problems of the numerical implementation of the full moment approach are also discussed.

非対称鉄骨を内蔵したSRC柱部材の耐力評価法

Exterior columns of Steel-Reinforced Concrete (SRC) structures are often composed of non-symmetric steel sections (e.g., tee section) embedded in concrete. However, due to the non-symmetricity, the full plastic moments in the weak-axis bending are not explicitly available for such SRC columns. The current design code (i.e., the AIJ standard for structural calculation of SRC structures) has a provision for weak-axis calculations but, in some cases, may lead to significant underestimation of member strength due to its poor approximation. This paper proposes new approximate design formulas with good accuracy for the weak-axis bending and bi-axial bending full plastic moments for non-symmetric SRC columns. The proposed design formula shows great agreements with high-fidelity numerical solutions.

Non-Gaussian extrema counts for CMB maps

In the context of the geometrical analysis of weakly non Gaussian CMB maps, the 2D differential extrema counts as functions of the excursion set threshold is derived from the full moments expansion of the joint probability distribution of an isotropic random field, its gradient and invariants of the Hessian. Analytic expressions for these counts are given to second order in the non Gaussian correction, while a Monte Carlo method to compute them to arbitrary order is presented. Matching count statistics to these estimators is illustrated on fiducial non-Gaussian "Planck" data.

First principles study on spin and orbital magnetism of 3d transition metal monatomicnanowires (Mn, Fe and Co)

We have demonstrated the electronic structure and magnetic properties of 3d transitionmetal nanowires (Mn, Fe and Co) in the framework of relativistic density functionaltheory. The equilibrium bond lengths were optimized using the generalized gradientapproximation. In a full relativistic regime individual spin and orbital moments inducedfrom spin polarization via spin–orbit coupling were calculated. In order to get an upperestimate for orbital moments, we used an orbital polarization correction to ourexchange–correlation functional. We found that the orbital magnetic moments of Fe and Colinear chains are strongly enhanced in the presence of an orbital polarization correction. Wehave calculated the exchange coupling parameters between two nearest-neighbormagnetic atoms according to a Heisenberg-like model in the presence of the orbitalpolarization correction. We found that the Co and Fe nanowires behave like aferromagnetic linear chain whereas a Mn monatomic nanowire remains antiferromagnetic.

Agglomeration Process Modeling Based on a PDE Approximation of the Safronov Agglomeration Equation

A one-dimensional dynamic partial differential equation (PDE) agglomeration model is derived based on the continuous Safronov agglomeration equation. A regularized PDE agglomeration model, represented by a set of convection−reaction−diffusion PDEs, can be solved within a standard adaptive-mesh implicit numerical framework that does not require additional quadrature assumptions to evaluate the aggregation integral. The PDE agglomeration model is solved numerically using a general Newton’s-method-based implicit Galerkin finite-element algorithm. The applied algorithm uses an automatic Gear-type time step and nonuniform adaptive-mesh strategies, which aids solution convergence. A numerical solution of the model for an agglomeration degree of 99.9% closely matches an asymptotic analytic solution of the original Safronov equation, which confirms the accuracy of the numerical procedure used. It is also shown that the number density function predicted by the new PDE agglomeration model satisfactorily agrees with the analytic solution of the Smoluchowski agglomeration equation. For small particle sizes and first and zeroth full moments, the two models give similar solutions. However, for larger particle sizes and the second full moment, the difference between the two models increases with increasing degree of agglomeration. Industrially important gibbsite agglomeration is used as a case study to demonstrate the application of the new numerical approach for agglomeration modeling.