Equivalent Maps Research Articles

Effect of particle damping on high-power gear transmission with dynamic coupling for continuum and non-continuum

High-power gears are widely used in various engineering fields. The vibration and noise produced in the process of gear transmission are a major problem that restricts the development of high-power gears. Particle damping technology has been proven to be effective in steady-state vibration suppression, but it is rarely applied to the centrifugal field due to the nonlinear dynamics. In this study, internal excitation is calculated through stiffness and error excitation generated by system stiffness and comprehensive error. In order to calculate the exciting force, a dumbbell-shaped damper was installed in the lightening hole. Based on the nonlinear energy dissipation mechanism, the damping force was used as the external excitation. And the damping effect of which is discussed in this paper. Using the dynamic coupling method of continuum and non-continuum, the equivalent displacement mapping of contact loads from the discontinuous domain to the continuous element node of the gear was realized and the transformation of the local coordinate to the global coordinate was carried out. The effect of particle diameter on the nonlinear dynamic characteristics of gears with different speeds and loads was explored and verified by the experiment. A diameter of 3 mm for the stainless-steel particles exhibited the best damping effect. Finally, an optimal allocation for high-power gear vibration reduction was sought. It was possible to reduce vibration by a maximum of 47% under a low load and a rotational speed of 1200 rpm.

Correlation Power Analysis of KASUMI and Power Resilience Analysis of Some Equivalence Classes of KASUMI S-Boxes

The KASUMI block cipher imparts confidentiality and integrity to the 3G mobile communication systems. In this paper, we present power analysis attack on KASUMI as a two-pronged attack: first, the FL function is targeted, and subsequently the recovered output of FL function is used to mount attack on 7 × 7 and 9 × 9 S-boxes embedded in the FO function of the cipher. Our attack recovers all 128 bits of the secret key of KASUMI. Furthermore, we present a countermeasure for this attack which requires lesser resource footprint as compared with existing countermeasures, rendering such implementations practically feasible for resource-constrained applications, such as IoT and RFID devices. In addition, we propose linear equivalent mappings and Permutation-XOR equivalent mappings of 7 × 7 S-boxes which have stronger resilience against power analysis attacks with respect to the improved transparency order and confusion coefficient parameters while restoring the classical cryptographic properties. We point out some properties of linear equivalence (LE) classes of these S-boxes with respect to these metrics as well.

Graphic map load comparison of two Czech school atlases using edge detection

Abstract. Map complexity has been studied by cartographers for decades. Unfortunately, it is not being systematically measured as an essential map property and used to optimize cartographic products during the map-making process. Therefore, the appropriate load of map content in a map usually remains dependent only on the subjective assessment of the cartographer designing the map.The paper aims to describe and examine newly developed easy-to-use metric for graphic map load evaluation. A plugin for an open-source software Gimp was developed to provide an accessible tool to measure graphic map load of various geospatial visualizations in an image file format. This tool was then used to compare two Czech school atlases produced by Kartografie PRAHA, a.s. publisher in terms of their graphic map load. The examined atlases include: the latest World School Atlas (in Czech Školní atlas světa) and the new equivalent called Pupil’s Atlas (originally Školní atlas světa) intended to fit especially to younger pupils. Both the atlases are captured in Figure 1.The equivalent maps (the same or very similar map extents, scales, captured regions and map types) in both atlases were compared to investigate differences in graphic map load. For this, a developed metric implemented in the form of an extension to well-known image processing software Gimp was used. The extension advances an edge detection filter to identify both sharp and smooth edges in order to estimate the graphic map load of map samples. Also, a distribution of map load across the map layout is shown. Subsequently, measured values were compared and used to estimate the differences in the potential readability of those products.

Impact of the Transition from ICD-9-CM to ICD-10-CM on the Identification of Pregnancy Episodes in US Health Insurance Claims Data.

BackgroundBefore October 2015, pregnancy cohorts assembled from US health insurance claims have relied on medical encounters with International Classification of Diseases-ninth revision-clinical modification (ICD-9-CM) codes. We aimed to extend existing pregnancy identification algorithms into the ICD-10-CM era and evaluate performance.MethodsWe used national private insurance claims data (2005–2018) to develop and test a pregnancy identification algorithm. We considered validated ICD-9-CM diagnosis and procedure codes that identify medical encounters for live birth, stillbirth, ectopic pregnancy, abortions, and prenatal screening to identify pregnancies. We then mapped these codes to the ICD-10-CM system using general equivalent mapping tools and reconciled outputs with literature and expert opinion. Both versions were applied to the respective coding period to identify pregnancies. We required 45 weeks of health plan enrollment from estimated conception to ensure the capture of all pregnancy endpoints.ResultsWe identified 7,060,675 pregnancy episodes, of which 50.1% met insurance enrollment requirements. Live-born deliveries comprised the majority (76.5%) of episodes, followed by abortions (20.3%). The annual prevalence for all pregnancy types was stable across the ICD transition period except for postterm pregnancies, which increased from 0.5% to 3.4%. We observed that ICD codes indicating gestational age were available for 86.8% of live-born deliveries in the ICD-10 era compared to 23.5% in the ICD-9 era. Patterns of prenatal tests remained stable across the transition period.ConclusionTranslation of existing ICD-9-CM pregnancy algorithms into ICD-10-CM codes provided reasonable consistency in identifying pregnancy episodes across the ICD transition period. New codes for gestational age can potentially improve the precision of conception estimates and minimize measurement biases.

How does the language acquisition period affect simultaneous interpreters’ language processing?

Abstract This study aims to identify the similarities and differences in cognitive-psychological semantic (Translation Equivalent) mapping employed by early, and late balanced bilinguals at the adult level. The subjects of lexical-semantic recognition tasks were limited to fourth-semester learners at graduate school of interpreting and translation to analyze the effect that the L2 acquisition period (or Age of Acquisition, AOA) and immersive education may have on cross-language processing among highly-proficient bilinguals. The experimental words were composed of non-cognate abstract words with two levels, and in four language directions (L1 > L1, L1 > L2, L2 > L1, L2 > L2) to compare monolingual, and bilingual priming effects. Early, and Late Balanced Bilingual groups (i.e., EBB and LBB) were comparable in many ways. However, mid balanced bilinguals who had exposure of more than six years after the critical period showed distinctive features. With a low lexical difficulty in the L1 to L2 direction, Mid Balanced Bilingual group (MBB) showed a similar tendency with EBB, while it was analogous to LBB when the lexical difficulty was high, and the language direction was from L2 to L1. Such results can be interpreted as evidence against the critical period hypothesis, indicating that language dominance may change due to the L2 acquisition period and immersive education. In contrast to their subjective perception, the mother tongue of all subject groups turned out to be Korean since all subjects, without exception, were faster in deciding words from English to Korean. The parental factor was limited to be all Koreans in order to control biological differences, from which the parental factor is reversely inferred most influential for early balanced bilinguals’ language dominance.

Impact of Obesity on Outcomes of Patients With Coronavirus Disease 2019 in the United States: A Multicenter Electronic Health Records Network Study

Impact of Obesity on Outcomes of Patients With Coronavirus Disease 2019 in the United States: A Multicenter Electronic Health Records Network Study

Thermal performance of a novel dual-serpentine-channel flat-plate oscillating heat pipe used for multiple heat sources and sinks

A novel dual-serpentine-channel flat-plate oscillating heat pipe (FPOHP) is designed and fabricated for electronic cooling with multiple heat sources and sinks. The FPOHP has two mirror symmetric tandem branches of capillary serpentine square channel with a hydraulic diameter of 2 mm (i.e., Bond number Bo = 1.137~1.265 here), which is made of 6063 aluminum alloy and 55% partially filled with acetone. A corresponding experimental study is conducted to investigate the start-up characteristics and quasi-steady thermal performance of the FPOHP with arrangement of “uniform heating by multiple heat sources at center and air cooling at both ends” under different inclination angles. The combined flow pattern diagrams as well as thermal resistance and equivalent thermal conductivity contour maps are provided for two mirror symmetric tandem sections of the FPOHP, based on which the thermo-hydrodynamic performance deviations between these two sections are compared and analyzed. The results show that the quasi-steady fluid motions in the FPOHP can be characterized by intermittent or independent occurrence of three elements, namely, stop, oscillation, and circulation, depending on the heat load and inclination angle. Significantly, the thermo-hydrodynamic behaviors in two tandem sections of the FPOHP both cooperate and compete with each other, as a result of the heat, mass and momentum exchanges via the tandem structure. The FPOHP can start up successfully under all inclination angles from 0° to 90° with no obvious difference, and its start-up temperature increases smoothly and approximately reaches a plateau of 41~46 °C as the heat load goes up. For the 175 tested conditions, the coefficients of variation for the thermal resistance of two tandem sections are smaller than 21.5% with the average value of 6.8%, showing a fine heat transfer uniformity of the FPOHP over a wide range of operating conditions. Significantly, in general, the FPOHP has much larger overall equivalent thermal conductivity (about 5.8 times on average) and possesses only a weight 83.6% of a pure 6063 aluminum alloy plate with the same geometry. In addition, the FPOHP exhibits a well gravity adaptability with the relative deviation ranging from 7.1% to 25.2% in the total thermal resistances for all inclination angles. Accordingly, the FPOHP shows a good potential for the high-heat-flux electronic cooling applications with multiple heat sources and sinks.

In-depth comparison between pure diesel and diesel methanol dual fuel combustion mode

Diesel Methanol Dual Fuel (DMDF) could achieve high efficiency and low emissions simultaneously at part of engine conditions, but the reason of this has not been clarified. In order to find the reason behind this phenomenon, Pressure-Volume (P-V) map, equivalence ratio (φ)-temperature (T) map and three-dimensional simulation software were used to compare diesel and DMDF mode, and two test conditions were selected to fulfill in-depth comparison of two combustion modes. Based on the analysis of P-V map, the reason of higher thermal efficiency at DMDF mode is as follows: lower cylinder pressure in compression stroke contributes to compression work reduction. Meanwhile, higher combustion rate of DMDF mode could reduce cylinder temperature and pressure in the late power stroke, which would further decrease exhaust loss and heat loss. Based on the analysis of φ-T map, higher methanol substitution percent could reduce the intersection area between cylinder φ-T map and nitric oxide & soot generation region. And after analyzing in-cylinder temperature, hydroxy mole fraction together with the equivalent ratio three-dimensional cloud map, it is found that the inhibitory effect of methanol on diesel low-temperature combustion prolongs diesel ignition delay, which helps to form the homogeneous charge in the cylinder. Under DMDF mode, fuel rich areas are significantly reduced, so is the maximum in-cylinder temperature. This is the key to achieve ultra-low nitrogen oxides and soot emissions for DMDF mode.

On the sensitivity of the equivalent dynamic stiffness mapping technique to measurement noise and modelling error

The objective of this study is to investigate the sensitivity of the Equivalent Dynamic Stiffness Mapping (EDSM) identification method to typical types of inaccuracy that are often present during the identification process. These sources of inaccuracy may include the presence of noise in the simulated/measured data, expansion error in the estimation of unmeasured coordinates, modelling error in the updated underlying linear model, and the error due to neglecting the higher harmonics in the nonlinear response of the system. An analytical study is performed to identify the structural nonlinearities of two nonlinear systems, a discrete three-DOF Duffing system and a cantilever beam with a nonlinear restoring force applied to the tip of the beam, considering the presence of all the aforementioned sources of inaccuracy. First, the EDSM technique is utilized to identify the nonlinear elements of two example systems to verify the accuracy of the EDSM technique. Finite Element modelling, the Modified Complex Averaging Technique (MCXA), and arc-length continuation are exploited in this study to obtain the steady state dynamics of the nonlinear systems. Numerical models of the two systems are then simulated in MATLAB and the numerical results of the simulation are used to identify the unknown nonlinear elements using the EDSM technique and investigate the effect of different sources of error on the outcome of the identification process. The nonlinear response of the system has been regenerated using the identified parameters with the sources of error present and the generated response has been compared to the simulated response in the absence of any noise or error. The EDSM technique is capable of identifying accurately the nonlinear elements in the absence of any source of inaccuracy although, based on the results, this method is highly sensitive to the aforementioned sources of inaccuracy that results in significant error in the identified model of the nonlinear system. Finally, an optimization-based framework, developed by the authors, is utilized to identify the nonlinear cantilever beam and the results are compared with the results of the EDSM technique. It is shown that by using the optimization method, the inaccuracy due to different sources of noise and error is significantly reduced. Indeed, by using the optimization method, the necessity to use an expansion method and consider the higher harmonics of the response is eliminated.

Torque Calculation of Stator Modular PMa-SynRM With Asymmetric Design for Electric Vehicles

This article proposes a modular asymmetrical permanent magnet-assisted synchronous reluctance machine (PMa-SynRM) combining segmented stator and distributed winding. Meanwhile, an analytical model is investigated for the modular PMa-SynRM, considering the effects of stator slots and flux gaps (FGs). First, the rotor magnetomotive force (MMF) generated by permanent magnets and stator MMF are analyzed by combining the magnetic equivalent circuit (MEC) and conformal mapping. Moreover, an armature reaction magnetic field model is presented considering the influence of the shifted end slots on the winding factor. Besides, the torque of the modular PMa-SynRM is calculated under asymmetrical rotor poles. Finally, a modular PMa-SynRM prototype is manufactured, and the comparison conclusion is validated by the finite-element method (FEM) and experimental results.

A standardized Physical Equivalent Temperature urban heat map at 1-m spatial resolution to facilitate climate stress tests in the Netherlands

In the Netherlands, municipalities and other sub-national governments have to conduct climate stress tests to examine the societal impact of heat load by citizens. So far, these parties have been hindered by the abundance of contrasting urban heat maps produced with different metrics and methods by different agencies. To unify the stress tests, we present a methodology for a standardized urban heat map at 1-m spatial resolution by selecting the Physical Equivalent Temperature (PET) as metric for heat stress.First we present an empirical regression model for PET, based on a variety of weather data and street configurations in the human thermal energy balance model Rayman. Thereafter, this empirical PET-model is evaluated for the midsized town Wageningen (the Netherlands). Meteorological observations taken at a nearby reference site and straightforward geographical data have been used as model input. Also, established methods were applied and elaborated to account for the urban heat island effect and wind speed reduction in the city. The presented method is validated against bike traverse observations of PET. Wind speed is the most challenging feature to map, due to its unsteady and local behaviour in cities.As a result, an afternoon averaged PET heat map is demonstrated as standard for an extreme heat day (1:1000 summer half year days), and a cumulative exceedance PET heat map for a representative year. Furthermore, a heat map is projected for 2050 according a warm climate change scenario.

Risk of Severe Coronavirus Disease 2019 in Patients With Inflammatory Bowel Disease in the United States: A Multicenter Research Network Study

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Design of mechanical heterogeneous specimens using topology optimization

Nowadays, the development and design of new parts require an increasing knowledge of the materials’ behaviour. Additionally, for the current sophisticated numerical modeling tools, accurate material characterization is critical for the correct calibration of their constitutive models. The constitutive behaviour of a material can be characterized via macroscopic mechanical tests. However, the full material characterization is expensive due to a large number of required tests. Therefore, there is a need to reduce the number of tests by increasing (quantitatively and qualitatively) the information available on a single test. To this end, heterogeneous strain field specimens can provide an answer. In the scope of this work, an innovative numerical methodology to design heterogeneous specimens using Topology Optimization (TO) is presented, together with its formulation and implementation. Numerous designs are presented and assessed through a performance indicator that evaluates the uniformity of the equivalent stress maps and the presence of various stress states (tension, compression and shear) in the specimen. Finally, the most adequate design is redrawn, analyzed and evaluated in an elastoplasticity framework. Validation of the test is also made by comparison.

Subspace method for solving large-scale equivalent layer and density mapping problems

The equivalent layer technique explores an intrinsic property of potential fields that any observed field at the ground surface can be reconstituted from a fictitious continuous distribution at an arbitrary flat surface that is indistinguishable from the field of the true sources. This continuous distribution can be represented by a set of discrete cells of known position and size but unknown physical property by solving a linear system, with size proportional to the number of data points measured. The density distribution at the equivalent layer carries information about the true sources because it is a scaled and downward-continued version of the field generated by the true sources at the level that the geophysical survey was undertaken. The computation of this downward-continued field is unstable, and an equivalent source evaluation is constrained by the intense computational demand required to solve the associated large linear system. A new formulation is developed to directly solve large-scale gravity equivalent layer problems using a subspace representation for the unknown density distribution. This subspace basis is constructed by applying the singular value decomposition to the matrix containing the gridded data set. A procedure to diminish (by two orders of magnitude) the number of forward model evaluations is introduced by exploring the symmetry of the gravity kernel and its evaluation on a regular mesh. The density distribution at the equivalent layer is used to outline the spatial distribution of contrasting underlying sources, to discriminate regions with predominant positive or negative density contrast, and to estimate the mass excess or deficiency for sources with positive or negative density contrast. This technique is applied to determine density models for the Carajás airborne gravity survey and to analyze density distributions associated with banded iron formations and structures of the Carajás Mineral Province, Brazil, providing mass estimates for specific geologic unities.

PCV58 DEFINING THROMBOEMBOLIC EVENTS USING ADMINISTRATIVE CLAIMS DATA

Through the Center for Biologics Evaluation and Research Biologics Effectiveness and Safety (BEST) Initiative, we sought to develop administrative claims-based definitions, referred to as algorithms, to facilitate identification of adverse events potentially associated with exposure to biologic products. The objectives of this study were to (1) develop algorithms for a series of thromboembolic events (TEEs), including pulmonary embolism (PE), deep vein thrombosis (DVT), and acute myocardial infarction (AMI), and (2) determine whether the 2015 transition to the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) affected the frequency of TEE reporting. Authors conducted a literature review using PubMed. Findings were leveraged to develop initial algorithms that were mapped from the International Classification of Diseases, Ninth Revision, Clinical Modification to ICD-10-CM via forward–backward mapping using General Equivalence Mappings. Clinical subject matter experts reviewed draft algorithms. Each algorithm was characterized in the IBM® MarketScan® Research Databases using the IBM MarketScan Treatment Pathways tool. Descriptive statistics, including the annual frequency of diagnosis for each algorithm, were generated for 2014–2017. DVT was the most common TEE, with the annual number of individuals with a relevant diagnosis code ranging from 4.36 to 4.96/1,000 enrolled/year; this was followed by AMI (2.83–3.16 individuals/1,000 enrolled/year) and PE (2.26–2.41 individuals/1,000 enrolled/year). A qualitative assessment of annual reporting frequency suggests that the transition to ICD-10-CM did not substantially affect the proportion of the enrolled population receiving an AMI, DVT, or PE diagnosis. Three new ICD-based TEE algorithms were developed and—though not subject to validation—were applied to generate statistics on the frequency of reporting for each category for 2014–2017. Annual proportions showed no indication that the ICD-10-CM transition meaningfully affected the frequency of TEE reporting. This effort is intended to support subsequent epidemiologic safety and effectiveness studies of biologics.

An experimental investigation of oil-water flow in a serpentine channel

The co-current oil-water flow in a horizontal serpentine channel is studied experimentally by high-speed imaging. Due to the channel geometry, the flow exhibits curved streamlines, which can induce secondary flows and alter the flow pattern transition boundaries in comparison with those observed in straight channels. This can have important applications in the development of microfluidic mixing devices. The serpentine channel was cut out in a black polypropylene sheet sandwiched between two transparent polypropylene sheets and bonded by selective laser welding. Different flow patterns were generated by changing independently the superficial velocities of the two fluids using a dual-drive syringe pump. Results enable the construction of a flow pattern map, which shows significant differences with the equivalent map obtained for straight microchannels.

Comparative Study of the Photoelastic Anisotropy of Si and GaAs

In this paper we present the results of experiments on single-crystalline (100)Si and (100)GaAs wafers which allow us to determine the degree of photoelastic anisotropy Ape in the near-infrared range (probing laser wavelength λ ≈ 1.3 μm). Ape is introduced as the absolute value of (π11 − π12 − π44)/(π11 − π12 + π44). π11, π12 and π44 are the piezo-optical coefficients. The experiments were carried out using a scanning infrared depolarization imager (SIRD) measurement system equipped with special calibration setups. These setups produce a defined diametrical loading of the wafer. The different measurement and analysis strategies are explicated. The generated birefringence and shear stress equivalent maps impressively illustrate the respective opposite photoelastic properties of Si and GaAs. The experimental results are compared with simulation data on the basis of a classic 2D stress model, taking into account the crystallographic anisotropy by applying the full tensor calculus. For GaAs, Ape is determined to be 0.41 ± 0.02. This value and the best-matching coefficients πij which were used for simulation are compared with data available from publications of the past few decades.

Meshless reconstruction technique for digital tomosynthesis

A novel meshless reconstruction algorithm for digital tomosynthesis (DT) is presented and assessed against experimental data. The algorithm does not require a three-dimensional grid or mesh allocation and performs a slice-by-slice reconstruction where each slice position can be chosen at runtime. The methodology is based on the filtered backprojection algorithm adapted to DT. However, in the traditional approach the backprojection comes first and the filtering follows. Because the backprojection requires ray tracing, in our case it is replaced with an equivalent image mapping procedure. The idea to swap the filtering and backprojection had been introduced earlier for computerized tomography (CT). Here we use this idea but develop it differently. Contrary to CT imaging, where the source and detector are rotated, in DT the subject and the flat panel detector are fixed in space. This imaging geometry allows reconstruction in planes parallel to the flat panel detector, which results in a significant simplification of the filter of backprojection algorithm. Moreover, the algorithm is not memory demanding and can be used with very large datasets. Two versions of the meshless algorithm are presented. One of them is based on convolution type filtering, while another uses filtering in the Fourier domain. Both versions are assessed and compared against the cone beam algorithm.

Design method for a bionic wrist based on tensegrity structures

The traditional bionic upper limb structure design is limited by the motion pair and cannot guarantee the flexibility of the mechanical structure. The tensegrity structure has the characteristics of high deformability, strong self-adaptability, and resistance to multi-directional impact. According to the biological characteristics of the upper limbs of the human body, an anatomical study is performed on the upper limb wrist joints that achieve adduction/abduction, flexion/extension, to obtain the relationship between the movements of the related bones and muscles, and to simplify the shape and structure of the wrist. Equivalent mapping of a mechanical model based on two-bar tensile properties. Through the contraction and stretching of the spring, the movement characteristics of the human muscles are realised, and the optimised bionic upper limb wrist tensioning robot without motion pair is further obtained. Adams simulation is used to verify that the bionic tensile wrist can simulate the change movement of the human wrist. The experimental platform was built and a physical prototype was made and the prototype was tested. The results show that the bionic tensile wrist can realise the adaptive motion characteristics of the human wrist well and stably, which proves the validity and feasibility of this design method.

An XMM-Newton X-Ray View of Supernova Remnant W49B: Revisiting Its Recombining Plasmas and Progenitor Type

Abstract We present a comprehensive X-ray spectroscopy and imaging study of supernova remnant W49B using archival XMM-Newton observations. The overionization state of the shocked ejecta in W49B is clearly indicated by the radiative recombination continua of Si xiv, S xv, and Fe xxv, combined with the Lyα lines of Ca and Fe. The line flux images of W49B indicate high emission measures of the central bar-like region for almost all of the emission lines, while the equivalent width maps reveal a stratified structure for the metal abundance distributions. The global spectrum of W49B is well reproduced by a model containing one collisional ionization equilibrium (CIE) plasma component and two recombining plasma (RP) components. The CIE plasma represents the shocked interstellar medium, which dominates the X-ray emitting volume in W49B with a mass ∼450 . The two RP components with a total mass ∼4.6 are both dominated by the ejecta material, but characterized by different electron temperatures (∼1.60 and ∼0.64 keV). The recombination ages of the RP components are estimated as ∼6000 yr and ∼3400 yr, respectively. We then reveal the possibility of a thermal conduction origin for the high-temperature RP in W49B by calculating the conduction timescale. The metal abundance ratios of the ejecta in W49B are roughly consistent with a core-collapse explosion model with a ≲15 progenitor, except for a rather high Mn/Fe. A Type Ia origin can explain the Mn abundance, while it predicts much higher ejecta masses than observed values for all of the metal species considered in our analysis.