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A novel 2-D magnetic resonant actuator is presented, and the influences of frequency and phase of the input voltage waveform on the trajectory of the armature are computed using the three-dimensional finite element method. Index Terms--Three-dimensional finite element method, 2-D magnetic resonant actuator, trajectory analysis.

Al Ecuador se lo considera como el país que tiene un sector productivo con un gran desarrollo y crecimiento económico debido a que este se dedica a muchas actividades como, la industria textil, alimenticia, maderera entre otras, por esta razón en la actualidad se han constituido cada vez más pequeñas y medianas empresas (PYMES) ya que de estas dependen la economía del país, pero lamentablemente el promedio de vida de estas empresas es de cinco años aproximadamente, un 70% de estas fracasan a los tres años y el 10% que relativamente es bajo, supera con éxito los cinco años. La mala administración económica–financiera es la responsable del 50% de todos los fracasos de los empresas ecuatorianas. Esto se debe a que no existe una interrelación con todos los ejecutivos de la empresa, en especial los directivos comerciales y financieros, provocando de esta forma la iliquidez en una empresa y su posterior quiebra.

This paper proposes a computational method for predicting the electron trajectories of a field emitter array (FEA) for a light source by the 3-D finite element method (FEM). Using this method, the equation of the electron motion is coupled with the equation of the electric field to compute electron trajectories. Some useful results were obtained by applying this method to a starlike FEA, which the authors have been studying, and by investigating the structure with effective emissions. Index terms - Field emitter array, finite element method, electron trajectory, light source, electric field.

Turning performances of fighter aircrafts, such as F-18, X-29 and X-31, are compared using functional agility metrics. Combat cycle time metric, dynamic speed turn plots and relative energy state metric are some of the agility metrics used for comparison in the study. Optimal test trajectory data is used for performance comparisons, as it eliminates sensitivity to pilot input techniques and effects of control system limiters. Performance improves after using optimal test technique.

The second victim phenomenon (SVP) refers to workers negatively impacted by involvement in unanticipated adverse events or errors. While this phenomenon has been extensively studied in healthcare since its acknowledgment over 20 years ago, its presence and management in other high-risk industries have remained unclear. We conducted a scoping review aiming to map the SVP in non-healthcare industries, as well as to explore the available interventions or support programs addressed to help second victims (SVs). A total of 5818 unique records were identified and, after the screening process, 18 studies from eight sectors were included. All industries acknowledged the existence of the SVP, though many did not use a specific term for defining the SV. Similarities in psychological and emotional consequences were found across sectors. Support strategies varied, with the aviation sector implementing the most comprehensive programs. Self-care and peer support were the most reported interventions, while structured clinical support was not mentioned in any industry. Our review highlighted a lack of standardized terminology and industry-specific, evidence-based support interventions for the SVP outside of healthcare. Healthcare appears to be at the forefront of formally recognizing and addressing the SVP, despite traditionally learning from other high-reliability industries in safety practices. This presents opportunities for reciprocal learning and knowledge transfer between healthcare and other high-risk sectors. [ABSTRACT FROM AUTHOR]

Background: The physical and mental health of corporate employees is equally important, especially for international salespeople in the in vitro diagnostic (IVD) medical device industry. The rapid growth of the IVD market is driven by the increasing prevalence of chronic and infectious diseases. This study aims to determine the prevalence of depression, anxiety, and somatic symptoms among international salespeople in China's IVD industry and identify the association of socio-demographic, occupational, organizational, and psychosocial factors with mental health outcomes for depression, anxiety, and somatic symptoms in Chinese IVD international salespeople. Methods: The study was a cross-sectional survey of international salespeople (ISs) in IVD companies officially registered in China. An online survey was designed to collect data through email contact with IVD companies and social media between August 2022 and March 2023. Measured factors included effort-reward imbalance (ERI), health-promoting leadership (HPL), health climate (HC), inner strength (IS), and perceived social support (PSS). Mental health outcomes assessed using the Core Symptom Index (CSI) were depression, anxiety, and somatic symptoms. Results: A total of 244 salespeople responded to the survey. CSI scores indicated that 18.4% (n = 45) and 10.2% (n = 25) of the respondents had symptoms of major depression and anxiety, respectively. ERI was positively correlated, while the IS and PSS were negatively correlated with major depression, anxiety, and somatic symptoms (p < 0.01). The health climate was negatively correlated with major depression (p < 0.05). Education background was associated with somatic symptoms (p < 0.05). ERI, IS, and gender were significant predictors of major depression, anxiety, and somatic symptoms (p < 0.05). Conclusion: The prevalence of depression and anxiety in China's IVD international salespeople was considered low compared with the prevalence in Chinese populations during COVID-19 but higher than those before the pandemic. Effort–reward imbalance, inner strength, and gender were significant factors in major depression, anxiety, and somatic symptoms among IVD international salespeople. [ABSTRACT FROM AUTHOR]

The understanding and description of object behaviors is a hot topic in computer vision. Trajectory analysis is one of the basic problems in behavior understanding, and the learning of trajectory patterns that can be used to detect anomalies and predict object trajectories is an interesting and important problem in trajectory analysis. In this paper, we present a hierarchical self-organizing neural network model and its application to the learning of trajectory distribution patterns for event recognition. The distribution patterns of trajectories are learnt using a hierarchical self-organizing neural network. Using the learned patterns, we consider anomaly detection as well as object behavior prediction. Compared with the existing neural network structures that are used to learn patterns of trajectories, our network structure has smaller scale and faster learning speed, and is thus more effective. Experimental results using two different sets of data demonstrate the accuracy and speed of our hierarchical serf-organizing neural network in learning the distribution patterns of object trajectories. Index Terms--Hierarchical self-organizing neural network, trajectory analysis and learning, anomaly detection, behavior prediction.

The paper presents a method for the design and optimization of a multi-element airfoil-based inertial particle separator. To facilitate design in an interactive manner, a MATLAB graphical user interface was developed with the following capabilities: 1) design of individual airfoil elements; 2) orientation and arrangement of the airfoils to form a multi-element airfoil-based inertial particle separator system by employing translational, sealing, and rotational functions; 3) analysis of the inertial particle separator system; and 4) optimum design of the inertial particle separator system using an evolutionary algorithm-based direct-search optimization technique. The design of individual airfoils was achieved through the use of the PROFOIL code, a state-of-the-art multipoint inverse airfoil design program. Multiple airfoils were arranged to form a multi-element airfoil-based inertial particle separator system subject to geometric constraints. A two-dimensional analysis tool for the multi-element airfoil was linked to the synthesis component of the graphical user interface to carry out flow and particle trajectory analysis component of the program. For the optimization component of the program, a computational objective function was implemented and coupled with a pattern search optimizer of the Direct Search Toolbox in MATLAB. Design and optimization was achieved using multivariable optimization. The paper presents two design examples to demonstrate the design method. DOI: 10.2514/1.40921

During the last years, the task of automatic event analysis in video sequences has gained an increasing attention among the research community. The application domains are disparate, ranging from video surveillance to automatic video annotation for sport videos or TV shots. Whatever the application field, most of the works in event analysis are based on two main approaches: the former based on explicit event recognition, focused on finding high-level, semantic interpretations of video sequences, and the latter based on anomaly detection. This paper deals with the second approach, where the final goal is not the explicit labeling of recognized events, but the detection of anomalous events differing from typical patterns. In particular, the proposed work addresses anomaly detection by means of trajectory analysis, an approach with several application fields, most notably video surveillance and traffic monitoring. The proposed approach is based on single-class support vector machine (SVM) clustering, where the novelty detection SVM capabilities are used for the identification of anomalous trajectories. Particular attention is given to trajectory classification in absence of a priori information on the distribution of outliers. Experimental results prove the validity of the proposed approach. Index Terms--Anomaly detection, event analysis, support vector machines (SVMs), trajectory clustering.

We present a novel multifeature video object trajectory clustering algorithm that estimates common patterns of behaviors and isolates outliers. The proposed algorithm is based on four main steps, namely the extraction of a set of representative trajectory features, non-parametric clustering, cluster merging and information fusion for the identification of normal and rare object motion patterns. First we transform the trajectories into a set of feature spaces on which mean-shift identifies the modes and the corresponding clusters. Furthermore, a merging procedure is devised to refine these results by combining similar adjacent clusters. The final common patterns are estimated by fusing the clustering results across all feature spaces. Clusters corresponding to reoccurring trajectories are considered as normal, whereas sparse trajectories are associated to abnormal and rare events. The performance of the proposed algorithm is evaluated on standard data-sets and compared with state-of-the-art techniques. Experimental results show that the proposed approach outperforms state-of-the-art algorithms both in terms of accuracy and robustness in discovering common patterns in video as well as in recognizing outliers. Index Terms--Anomaly detection, clustering, mean-shift, trajectory analysis.

Given a large spatio-temporal database of events, where each event consists of the fields event ID, time, location, and event type, mining spatio-temporal sequential patterns identifies significant event-type sequences. Such spatio-temporal sequential patterns are crucial to the investigation of spatial and temporal evolutions of phenomena in many application domains. Recent research literature has explored the sequential patterns on transaction data and trajectory analysis on moving objects. However, these methods cannot be directly applied to mining sequential patterns from a large number of spatio-temporal events. Two major research challenges still remain: 1) the definition of significance measures for spatio-temporal sequential patterns to avoid spurious ones and 2) the algorithmic design under the significance measures, which may not guarantee the downward closure property. In this paper, we propose a sequence index as the significance measure for spatio-temporal sequential patterns, which is meaningful due to its interpretability using spatial statistics. We propose a novel algorithm called Slicing-STS-Miner to tackle the algorithmic design challenge using the spatial sequence index, which does not preserve the downward closure property. We compare the proposed algorithm with a simple algorithm called STS-Miner that utilizes the weak monotone property of the sequence index. Performance evaluations using both synthetic and real-world data sets show that the Slicing-STS-Miner is an order of magnitude faster than STSMiner for large data sets. Index Terms--Spatio-temporal sequential pattern, density ratio, sequence index, slicing, performance.

An innovative projectile design is proposed using body-conformal oblique wing/tails with smart-structure control. With optimal deployments of the oblique wing, this guided projectile would maintain the maximum lift-to-drag ratio throughout its gliding phase, from supersonic through transonic to subsonic, and aehleve an extended range which exceeds the maximum range required for the baseline rocket-assisted projectile. To search for the optimal sweepback positions of the oblique wing during the supersonic and transonic gliding phases, intensive thin-layer Reynolds-averaged Navier-Stokes computations are performed using the overset-grid approach. Based on the optimal scheduling of the oblique wing obtained from the Reynolds-averaged Navier-Stokes computations, our preliminary two degrees-of-freedom trajectory analysis indicates that the target 100 n mile range is achievable without rocket assistance.

A semantic-based video retrieval framework is proposed for visual surveillance and a cluster-based tracking algorithm is developed for acquiring motion trajectories. Trajectory analysis and video retrieval are combined effectively in this framework and the workload of manual annotation is greatly reduced.

It is known that the optimal carrier based approach for modulating a multilevel converter is to use a phase disposition (PD) carrier arrangement with a common mode offset added to the reference waveforms to centre the implicitly selected space vectors. However, this strategy does not fully utilize all available voltage levels at lower modulation depths, with an odd level system only using odd voltage levels and an even level system only using even voltage levels as the modulation depth varies. Recent work has suggested that this is not the harmonically optimal approach at reduced modulation depths. This paper shows how up to a 40% reduction in harmonic distortion can be achieved if all available voltage levels are used throughout the linear modulation range. The improvement is achieved by adding a simple (1/2) carrier magnitude common mode dc offset in key modulation regions, which allows the converter to use all available voltage levels. The paper uses analytical spectral decomposition and harmonic flux trajectory analysis to propose a theoretical basis for this improvement, and to determine the precise points at which the (1/2) carrier magnitude offset should be added to achieve the harmonic improvement. Index Terms--Double Fourier series, harmonic flux trajectory, multilevel converter, pulsewidth modulation (PWM), space vector modulation (SVM).

A droplet trajectory analysis model was combined with heat transfer calculations to predict glaze or rime ice during flight. The model determines the collection efficiency of various sized cloud droplets on representative airfoils. Critical liquid water contents for the rime to glaze transition were calculated.

The commanded acceleration appling in the direction normal to the line of sight (LOS) between the interceptor and its target is called true proportional navigation (TPN). The main goal of this work is to derive the complete analytical solutions of three-dimensional (3D) TPN for nonmaneuvering and maneuvering targets. Three coupled nonlinear second-order state equations describing the relative motion are solved analytically without any linearization for performance and trajectory analysis. Properties of 3D TPN such as capture region, range-to-go, time-to-go, and two aspect angles within spherical coordinates are all obtained in closed form. Furthermore, the comparison between 3D TPN and 3D realistic true proportional navigation (RTPN) is investigated analytically in the two-player game where a TPN.guided missile is commanded to pursue a RTPN-guided target, and vice versa.

The magnitude and structure of the ion wakefield potential below a single negatively-charged dust particle levitated in the plasma sheath region was calculated and measured. Attractive and repulsive components of the interaction force were extracted from a trajectory analysis of low-energy collisions between different mass particles in a well-defined electrostatic potential. Index Terms--Dust plasma, ion wakefield charging, plasma crystal.

Atmospheric pollution can have significant impacts on human and ecosystem health, visibility, and climate. Control strategies require knowledge of the chemical and physical transformations that pollutants undergo as they are [...]

Droughts are complex and may be triggered by different mechanisms, such as atmospheric circulation, moisture transport, and thermodynamic processes. Significant research has been completed to characterize precipitation in the Intergovernmental [...]

The National Oceanic and Atmospheric Administration (NOAA) Deep Space Climate Observatory (DSCOVR) spacecraft was launched on 11 February 2015 and in June 2015 achieved its orbit at the first Lagrange [...]

ABSTRACT The stratospheric response to climate forcing, such as an increase in greenhouse gases, is often unpredictable because of interactions between radiation, dynamics, and chemistry. Climate models are unsuccessful in [...]

ABSTRACT North Africa is the world's largest source of dust, a large part of which is transported across the Atlantic to the Caribbean and beyond where it can impact radiation [...]

The introduction of tablets in online retailing has created an additional touchpoint through which e-commerce firms can interact with consumers. In this paper, we seek to understand and measure the causal impact of tablets on e-commerce sales. In doing so, we examine the complementary and substitution impact of the tablet channel on the smartphone and PC channels. We rely on a unique data set from Alibaba, the largest e-commerce firm in the world, and exploit a natural experiment via the iPad app introduction to empirically identify our results. The results show that users' adoption of tablets enhanced the overall growth of Alibaba's e-commerce market, with an annual increase of approximately US$923.5 million. Our results demonstrate that the tablet channel acts as a substitute for the PC channel while it acts as a complement for the smartphone channel. Furthermore, the use of tablets spurs casual browsing, which leads to the purchase of more impulse products and a wider diversity of products. Cross-device browsing behavior is found to enhance sales outcomes, and the degree of interrelationships between devices varies across the course of the day. We provide insights for retailers about how they can increase their sales volume and revenue in the emerging tablet economy. History: Accepted by Anandhi Bharadwaj, information systems. Funding: A. Ghose acknowledges generous funding from a Google faculty research award and a Marketing Science Institute grant. K. Xu ackowledges financial support from the National Science Foundation of China [NSF 71301071, 71572074, 71471083, 71171106], the Natural Science Foundation of Jiangsu Province [BK20130590], and the project of the First-Class University Construction from Nanjing University (the Fundamental Research Funds for the Central Universities). Keywords: mobile * Internet commerce * channels * long tail * natural experiment, 1. Introduction The rapid adoption of smartphones and tablets as well as the widespread use of mobile applications has fueled the growth of mobile commerce around the world. According to [...]

The February-March 2014 deployment of the National Aeronautics and Space Administration (NASA) Airborne Tropical Tropopause Experiment (ATTREX) provided unique in situ measurements in the western Pacific tropical tropopause layer (TTL). [...]

The foehn effect is well known as the warming, drying, and cloud clearance experienced on the lee side of mountain ranges during 'flow over' conditions. Foehn flows were first described [...]

The Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), developed by NOAA's Air Resources Laboratory, is one of the most widely used models for atmospheric trajectory and dispersion calculations. We present [...]

ABSTRACT The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009December 2010) comprehensive dataset documenting clouds, aerosols, [...]

While atmospheric reanalysis datasets are widely used in climate science, many technical issues hinder comparing them to each other and to observations. The reanalysis fields are stored in diverse file architectures, data formats, and resolutions. Their metadata, such as variable name and units, can also differ. Individual users have to download the fields, convert them to a common format, store them locally, change variable names, regrid if needed, and convert units. Even if a dataset can be read via the Open-Source Project for a Network Data Access Protocol (commonly known as OPeNDAP) or a similar protocol, most of this work is still needed. All of these tasks take time, effort, and money. Our group at the Cooperative Institute for Research in the Environmental Sciences at the University of Colorado and affiliated colleagues at the NOAA's Earth System Research Laboratory Physical Sciences Division have expertise both in making reanalysis datasets available and in creating web-based climate analysis tools that have been widely used throughout the meteorological community. To overcome some of the obstacles in reanalysis intercomparison, we have created a set of web-based Reanalysis Intercomparison Tools (WRIT) at www.esrl.noaa.gov/psd/data /writ/. WRIT allows users to easily plot and compare reanalysis datasets, and to test hypotheses. For standard pressure-level and surface variables there are tools to plot trajectories, monthly mean maps and vertical cross sections, and monthly mean time series. Some observational datasets are also included. Users can refine date, statistics, and plotting options. WRIT also facilitates the mission of the Reanalyses.org website as a convenient toolkit for studying the reanalysis datasets., MOTIVATION. Reanalysis (or retrospective analysis) is a scientific technique whereby observations taken over a long time period are combined objectively with a model forecast to form time series of fields [...]

In order to minimize a closed convex function that is approximated by a sequence of better behaved functions, we investigate the global convergence of a general hybrid iterative algorithm, which [...]

Recent reports have raised serious concerns about the rapid declines of historically productive marine fishery resources and the degradation of essential fish habitats. This global crisis has spurred development of innovative management strategies to rebuild depleted fisheries and marine ecosystems. One highly touted strategy involves the design and creation of marine reserves (areas off limits to extractive uses) to rebuild fisheries and conserve marine biodiversity. In this paper, we propose an integrated sequence of methodologies that provides an objective, quantitative framework for the design of marine reserves in spatially heterogeneous coastal ocean environments. The marine reserve designs proposed here satisfy the multiple, often-conflicting criteria of disparate resource user groups. This research is the first attempt to explicitly explore the trade-off between the conservation goals of fishery management and coral reef protection and the consumptive interests of commercial and recreational fishing fleets. The spatial distribution and size abundance of reef fish stocks throughout the Florida Keys coral reef ecosystem were estimated from a database consisting of more than 18,000 visual samples taken from 1979 to 2002. These distributions of multispecies abundance and biomass, in conjunction with a geographic database of coral reef habitats, are used to demonstrate an integer goal programming methodology for the design of networks of marine reserves, called plans. Once multiple plans are proposed, a simulation model is used to assess the effects of reserve size and shape on select Florida Keys reef fish populations under dynamic spatial and temporal conditions. Key words: integer goal programming; simulation; fisheries management; marine reserves; Florida Keys, 1. Introduction The goals of the policymakers for the world's fisheries traditionally have been concerned with food production and employment. Concomitantly, widespread declines and, in some cases, collapses of major [...]

Lidar observations collected during the Lidar In-space Technology Experiment experiment in conjunction with the Meteosat and European Centre for Medium-Range Weather Forecasts data have been used not only to validate the Saharan dust plume conceptual model constructed from the GARP (Global Atmospheric Research Programme) Atlantic Tropical Experiment data, but also to examine the vicissitudes of the Saharan aerosol including their optical depths across the west Africa and east Atlantic regions. Optical depths were evaluated from both the Meteosat and lidar data. Back trajectory calculations were also made along selected lidar orbits to verify the characteristic anticyclonic rotation of the dust plume over the eastern Atlantic as well as to trace the origin of a dust outbreak over West Africa. A detailed synoptic analysis including the satellite-derived optical depths, vertical lidar backscattering cross section profiles, and back trajectories of the 16-19 September 1994 Saharan dust outbreak over the eastern Atlantic and its origin over West Africa during the 12-15 September period have been presented. In addition, lidar-derived backscattering profiles and optical depths were objectively analyzed to investigate the general features of the dust plume and its geographical variations in optical thickness. These analyses validated many of the familiar characteristic features of the Saharan dust plume conceptual model such as (i) the lifting of the aerosol over central Sahara and its subsequent transport to the top of the Saharan air layer (SAL), (ii) the westward rise of the dust layer above the gradually deepening marine mixed layer and the sinking of the dust-layer top, (iii) the anticyclonic gyration of the dust pulse between two consecutive trough axes, (iv) the dome-shaped structure of the dust-layer top and bottom, (v) occurrence of a middle-level jet near the southern boundary of the SAL, (vi) transverse-vertical circulations across the SAL front including their possible role in the initiation of a squall line to the southside of the jet that ultimately developed into a tropical storm, and (vii) existence of satellite-based high optical depths to the north of the middle-level jet in the ridge region of the wave. Furthermore, the combined analyses reveal a complex structure of the dust plume including its origin over North Africa and its subsequent westward migration over the Atlantic Ocean. The dust plume over the west African coastline appears to be composed of two separate but narrow plumes originating over the central Sahara and Lake Chad regions, in contrast to one single large plume shown in the conceptual model. Lidar observations clearly show that the Saharan aerosol over North Africa not only consist of background dust (Harmattan haze) but also wind-blown aerosol from fresh dust outbreaks. They further exhibit maximum dust concentration near the middle-level jet axis with downward extension of heavy dust into the marine boundary layer including a clean dust-free trade wind inversion to the north of the dust layer over the eastern Atlantic region. The lidar-derived optical depths show a rapid decrease of optical depths away from land with maximum optical depths located close to the midlevel jet, in contrast to north of the jet shown by satellite estimates and the conceptual model. To reduce the uncertainties in estimating extinction-to-backscattering ratio for optical depth calculations from lidar data, direct aircraft measurements of optical and physical properties of the Saharan dust layer are needed., 1. Introduction In September of 1994, the National Aeronautics and Space Administration (NASA) conducted an experiment known as the Lidar In-space Technology Experiment (LITE) on board the space shuttle, not [...]