Orientation Characteristics Research Articles

Infrared and visible image fusion based on saliency detection and deep multi-scale orientational features

Infrared and visible image fusion based on saliency detection and deep multi-scale orientational features

Dynamics modeling and simulation for satellites with optoelectronic tracking system

Abstract The optoelectronic tracking system has a strong coupling between the tracking platform and the satellite platform when rapidly capturing and precisely tracking targets. The high-precision coordinated pointing control between the two platforms is a key technology in the fields of space laser communication, debris monitoring, and astronomical observation. Firstly, a multi-level coupled dynamics model of spacecraft with two-dimensional (2D) motion platforms is derived based on the principles of momentum and angular momentum. Secondly, the coupling effects between the motion platform and the satellite platform are theoretically analyzed, highlighting the impact of platform orientation, configuration, mass properties, and motion characteristics on the coupling. Finally, a multi-level platform cooperative control strategy is proposed, and the model and control strategy are validated through mathematical simulations. The results show that the model is consistent with simulation results from ADAMS software, and the satellite attitude accuracy under the cooperative control strategy can be improved by 80%.

Heterogeneous Nucleation Regulation Amends Unfavorable Crystallization Orientation and Defect Features of Antimony Selenosulfide Film for High-Efficient Planar Solar Cells.

Antimony selenosulfide (Sb2(S,Se)3) has obtained widespread concern for photovoltaic applications as a light absorber due to superior photoelectric features. Accordingly, various deposition technologies have been developed in recent years, especially hydrothermal deposition method, which has achieved a great success. However, device performances are limited with severe carrier recombination, relating to the quality of absorber and interfaces. Herein, bulk and interface defects are simultaneously suppressed by regulating heterogeneous nucleation kinetics with barium dibromide (BaBr2) introduction. In details, the Br adsorbs and dopes on the polar planes of cadmium sulfide (CdS) buffer layer, promoting the exposure of nonpolar planes of CdS, which facilitates the favorable growth of [hk1]-Sb2(S,Se)3 films possessing superior crystallinity and small interface defects. Additionally, the Se/S ratio is increased due to the replacement of Se by Br, causing a downshift of the Fermi levels with a benign band alignment and a shallow-level defect. Moreover, Ba2+ is located at grain boundaries by coordination with S and Se ions, passivating grain boundary defects. Consequently, the efficiency is increased from 7.70 % to 10.12 %. This work opens an avenue towards regulating the heterogeneous nucleation kinetics of Sb2(S,Se)3 film deposited via hydrothermal deposition approach to optimize its crystalline orientation and defect features.

Heterogeneous Nucleation Regulation Amends Unfavorable Crystallization Orientation and Defect Features of Antimony Selenosulfide Film for High‐Efficient Planar Solar Cells

AbstractAntimony selenosulfide (Sb2(S,Se)3) has obtained widespread concern for photovoltaic applications as a light absorber due to superior photoelectric features. Accordingly, various deposition technologies have been developed in recent years, especially hydrothermal deposition method, which has achieved a great success. However, device performances are limited with severe carrier recombination, relating to the quality of absorber and interfaces. Herein, bulk and interface defects are simultaneously suppressed by regulating heterogeneous nucleation kinetics with barium dibromide (BaBr2) introduction. In details, the Br adsorbs and dopes on the polar planes of cadmium sulfide (CdS) buffer layer, promoting the exposure of nonpolar planes of CdS, which facilitates the favorable growth of [hk1]‐Sb2(S,Se)3 films possessing superior crystallinity and small interface defects. Additionally, the Se/S ratio is increased due to the replacement of Se by Br, causing a downshift of the Fermi levels with a benign band alignment and a shallow‐level defect. Moreover, Ba2+ is located at grain boundaries by coordination with S and Se ions, passivating grain boundary defects. Consequently, the efficiency is increased from 7.70 % to 10.12 %. This work opens an avenue towards regulating the heterogeneous nucleation kinetics of Sb2(S,Se)3 film deposited via hydrothermal deposition approach to optimize its crystalline orientation and defect features.

Directional Characteristic Enhancement of an Omnidirectional Detection Sensor Enabled by Strain Partitioning Effects in a Periodic Composite Hole Substrate.

An omnidirectional stretchable strain sensor with high resolution is a critical component for motion detection and human-machine interaction. It is the current dominant solution to integrate several consistent units into the omnidirectional sensor based on a certain geometric structure. However, the excessive similarity in orientation characteristics among sensing units restricts orientation recognition due to their closely matched strain sensitivity. In this study, based on strain partition modulation (SPM), a sensitivity anisotropic amplification strategy is proposed for resistive strain sensors. The stress distribution of a sensitive conductive network is modulated by structural parameters of the customized periodic hole array introduced underneath the elastomer substrate. Meanwhile, the strain isolation structures are designed on both sides of the sensing unit for stress interference immune. The optimized sensors exhibit excellent sensitivity (19 for 0-80%; 109 for 80%-140%; 368 for 140%-200%), with nearly a 7-fold improvement in the 140%-200% interval compared to bare elastomer sensors. More importantly, a sensing array composed of multiple units with different hole configurations can highlight orientation characteristics with amplitude difference between channels reaching up to 29 times. For the 48-class strain-orientation decoupling task, the recognition rate of the sensitivity-differentiated layout sensor with the lightweight deep learning network is as high as 96.01%, superior to that of 85.7% for the sensitivity-consistent layout. Furthermore, the application of the sensor to the fitness field demonstrates an accurate recognition of the wrist flexion direction (98.4%) and spinal bending angle (83.4%). Looking forward, this methodology provides unique prospects for broader applications such as tactile sensors, soft robotics, and health monitoring technologies.

Religion, politics and jingle bells: examining contextual factors influencing the impact of workplace holiday practices

PurposeWhile Christmas and the holidays are widely celebrated in society at large in the US, the question arises whether doing so has value in today’s organizations. In this light, the present study examined the relationship of workplace holiday practices with positive affect and emotional engagement, along with some boundary conditions of these relationships. Specifically, this research examined the moderating influences of religious orientation, political orientation and political environment.Design/methodology/approachData were collected at two points in time via an online survey. At time 1, the participant survey included measures of workplace holiday practices, political orientation and demographic characteristics. At time 2 (approximately two weeks afterward), the participant survey included measures of positive affect and emotional engagement.FindingsWorkplace holiday practices were related to both positive affect and emotional engagement. There were slightly stronger effects for the impact of workplace holiday practices among individuals who reside in more conservative (“red”) states in the US on emotional engagement, but not positive affect. Individual political orientation did not moderate the relationships between workplace holiday practices and the outcomes. Counter to expectations, the absence of workplace holiday practices had a stronger negative effect on non-Christians’ emotional engagement than Christians. The interaction between workplace holiday practices and religious orientation with positive affect was nonsignificant.Research limitations/implicationsThe data from this research were obtained via a survey methodology. Although data on the independent and dependent variables were obtained at two different points in time, future research could experimentally manipulate features of the work environment related to the celebration of the holidays to more definitively establish cause-and-effect relationships.Practical implicationsThis research highlights the value of celebrating Christmas and the holidays. In this light, organizations should not underestimate the potential value of such celebratory activity in promoting employee goodwill. At the same time, organizations must be cognizant that some individuals may value the celebration of Christmas and the holidays more so than others.Originality/valueThis research provides a framework for further research on workplace holiday practices and identifies theories that can be used in future research to explore the mechanisms that influence how and under what conditions workplace holiday practices impact employees’ experiences at work.

Stable and unstable fall motions of plate-like ice crystal analogues

Abstract. The orientation of ice crystals affects their microphysical behaviour, growth, and precipitation. Orientation also affects interaction with electromagnetic radiation, and through this it influences remote sensing signals, in situ observations, and optical effects. Fall behaviours of a variety of 3D-printed plate-like ice crystal analogues in a tank of water–glycerine mixture are observed with multi-view cameras and digitally reconstructed to simulate the falling of ice crystals in the atmosphere. Four main falling regimes were observed: stable, zigzag, transitional, and spiralling. Stable motion is characterised by no resolvable fluctuations in velocity or orientation, with the maximum dimension oriented horizontally. The zigzagging regime is characterised by a back-and-forth swing in a constant vertical plane, corresponding to a time series of inclination angle approximated by a rectified sine wave. In the spiralling regime, analogues consistently incline at an angle between 7 and 28°, depending on particle shape. Transitional behaviour exhibits motion in between spiral and zigzag, similar to that of a falling spherical pendulum. The inclination angles that unstable planar ice crystals make with the horizontal plane are found to have a non-zero mode. This observed behaviour does not fit the commonly used Gaussian model of inclination angle. The typical Reynolds number when oscillations start is strongly dependent on shape: solid hexagonal plates begin to oscillate at Re =237, whereas several dendritic shapes remain stable throughout all experiments, even at Re > 1000. These results should be considered within remote sensing applications wherein the orientation characteristics of ice crystals are used to retrieve their properties.

Application of Microseismic Monitoring in Fracturing Process Evaluation

Abstract Fracture-mesh control technologies, such as modified liquid system (controlled fracture technology), pulse fracturing reform and directional perforation technology, have been adopted in the large-scale fracturing process of well Qaiping 1 in Qaidam Basin. However, whether the technology has achieved the predetermined goal needs to be verified. In order to fully grasp the fracture morphology in each stage of fracturing construction, the underground microseismic fracture monitoring technology is used to reveal the fracture length, height, width, orientation and spatial distribution characteristics. Based on the analysis of monitoring results, the following conclusions are obtained. (1) The collection of microseismic event data plays a key role in interpreting the properties of fractures, so as to more accurately understand and predict the formation and development of fractures. (2) Real-time microseismic monitoring reveals the application value of a variety of special processes in the formation reconstruction effect, and the transformation of liquid system (controlled fracture process), pulse fracturing and directional perforating process have significant effects on fracture morphology.

An Interdisciplinary Panel of Scientists Discuss Trans- and Gender-Nonconforming-Inclusion in STEM

In June 2024, the American Statistical Association (ASA) LGBTQ+ Advocacy Committee hosted a webinar on “An Interdisciplinary Look at Trans and Gender-non-conforming Inclusion in STEM”. The webinar consisted of three presentations that approached inclusion in STEM via different viewpoints and concluded with a panel discussion. This article provides the panelists with more space to reflect upon the questions that were asked. It is the ASA LGBTQ+ Advocacy Committee’s hope that with increased awareness and understanding around SOGISC (Sexual orientation, gender identity, and sex characteristics) data, assumptions that impact data collection, data analysis, and the representation of such data as well as the treatment of the individuals who willingly identify themselves as minorities, will be reexamined.

Point cloud data-driven modelling of high-strength steel wire corrosion pits considering orientation features

We propose a corrosion pit modelling approach of high-strength steel wires considering orientation features using surface point cloud data, collected by three-dimensional laser scanning. Corrosion pits were identified through density-based spatial clustering of applications with noise (DBSCAN). The identified corrosion pits could be modelled as a semiellipsoid considering orientation features. The Gaussian copula model was utilised to describe the joint distribution of the geometric parameters of the corrosion pits. This approach will be valuable for simulation of the surface morphology of corroded high-strength steel wires.

Regional, rural and remote medicine attracts students with a similar approach to learning in both the Northern and Southern hemisphere

ABSTRACT Doctors who work in areas of workforce shortage, such as regional, rural and remote areas or areas of low socioeconomic means need to be more self-motivated, adaptable and self-directed than their metropolitan counterparts. This study aimed to examine the goal orientation and learning characteristics of students recruited into two medical programmes, one from the Northern hemisphere and one from the Southern hemisphere; both with a commitment to producing doctors to practice medicine in rural locations. Three survey tools were administered to 263 medical students: 1. achievement goal orientation survey; 2. learning characteristics survey and 3. the study process questionnaire. Medical students from both cohorts showed a learning goal orientation, which significantly increased with age (P0.007). In terms of learning characteristics, the students from the south had significantly higher scores for curiosity (P0.003), while the northern students had significantly higher scores for methodical (p < 0.001). Both cohorts were similar for adaptability and consciousness. Across the entire student cohort, three of the four learning disposition characteristics were also seen to correlate with learning goal orientation. In both cohorts of medical students deep learning scores exceeded surface learning scores. Selection of students with a learning goal orientation and learning characteristics of curiosity, adaptability and conscientiousness could potentially help students to flourish in rural placement environments.

Enhanced comprehensive mechanical properties of laser additive manufactured TC17 by design of new heat treatment based on continuous cooling transition

Heat treatment is critical for enhancing the mechanical properties of high strength titanium alloys, especially for exploiting the potential of laser additive manufactured titanium alloys. In this work, the influence of the cooling rate of continuous cooling transition on microstructure evolution and mechanical behavior was investigated in TC17 titanium alloy fabricated by laser directed energy deposition (LDED) technology. It was found that the number density and orientation characteristics of grain boundary α phases (αGB) are jointly influenced by the cooling rate and the structure of β/β grain boundaries (GBs). The average number density (λavg) of αGB has a consistent trend with the degree of variant selection (DVS) for precipitated α clusters subsequently, which is attributed to the autocatalytic effect of the pre-existing α on the post-precipitated α phases. The largest λavg of αGB and the highest DVS of α clusters could be simultaneously obtained at a suitable cooling rate (4 °C/min). In that case, plenty of α/β phase interfaces and dominant variant type ensure high strength, meanwhile, the combinations of activated multi-slip systems and varied crack propagation paths extend work-hardening to maintain greater plastic deformation. This paper provides a novel thought for designing customized heat treatments of LDEDed high strength titanium alloys, and more importantly, promotes the engineering applications of large and complex components prepared by additive manufacturing technology.

Breast Ultrasound Computer-Aided Diagnosis System Based on Mass Irregularity Features in Frequency Domain

Our study develops a computer-aided diagnosis (CAD) system for breast ultrasound by presenting an innovative frequency domain technique for extracting mass irregularity features, thereby significantly boosting tumor classification accuracy. The experimental data consists of 5252 ultrasound breast tumor images, including 2745 benign tumors and 2507 malignant tumors. A Support Vector Machine was employed to classify the tumor as either benign or malignant, and the effectiveness of the proposed features set in distinguishing malignant masses from benign ones was validated. For the constructed CAD system, the performance indices’ accuracy, sensitivity, specificity, PPV, and NPV were 92.91%, 89.94%, 91.38%, 90.29%, and 91.45%, respectively, and the area index in the ROC analysis (AUC) was 0.924, demonstrating our method’s superiority over traditional spatial gray level dependence (SGLD), the ratio of depth to width, the count of depressions, and orientation features. Therefore, the constructed CAD system with the proposed features will be able to provide a precise and quick distinction between benign and malignant breast tumors with minimal training time in clinical settings.

Multiscale modeling of microstructural and hygrothermal effects on vibrations of CNT-enhanced fiber-reinforced polymer composites

This work presents a multi-scale analytical and computational approach designed to predict the hygro-thermo-mechanical vibrational response of laminated composite structures reinforced with multi-walled carbon nanotubes (MWCNTs). Employing the modified Halpin-Tsai model, this study estimates the elastic properties of the MWCNT-enhanced epoxy matrix, incorporating the impacts of MWCNT agglomeration, orientation, waviness, and size-dependent characteristics. Additionally, the Chamis micromechanical model is utilized to ascertain the independent elastic constants of the nanocomposite lamina, considering environmental variables such as temperature and humidity. Subsequent analysis involves the determination of natural frequencies for both pristine and MWCNT-integrated laminated composite structures via the Finite Element Method (FEM), addressing various design-related parameters. This investigation further explores the macroscopic influences of MWCNT incorporation, boundary condition and layup scheme, along with the temperature, moisture content, and the nanoscopic impact of MWCNTs on the natural frequencies of laminated composite plates. The obtained results of the proposed multiscale modeling are compared with experimental and theoretical observations. It has been demonstrated that while the incorporation of carbon nanotubes (CNTs) can enhance the mechanical properties of nanocomposite laminae, the natural frequencies of these nanocomposite plates are adversely affected by variations in temperature and moisture content. Furthermore, the findings indicate that the microstructural characteristics of CNTs play a crucial role in determining the efficacy of the reinforcement phenomenon. The developed multi-scale methodological framework offers significant potential for the design and optimization of MWCNT-based composite structures across diverse industries, including automotive and aerospace sectors.

Navigating the New Normal: How Entrepreneurial Orientation and Personal Characteristics Influence MSME Performance during the COVID-19 Crisis

Navigating the New Normal: How Entrepreneurial Orientation and Personal Characteristics Influence MSME Performance during the COVID-19 Crisis

Near-α titanium alloy dwell load-induced deformation twinning to coordinate the deformation mechanism associated with crack initiation

In this study, we identified a specific phenomenon of coordinated deformation of twins in near-α titanium alloys during dwell fatigue (DF). The main crack source regions and internal cracks in the micro-texture region (MTR) and no-MTR samples with inconsistent orientation characteristics were characterized. The results demonstrate that the main cracks in all specimens are aligned with the (0001) basal plane, which is associated with basal slip. Notably, twins are found and confirmed to be involved in the DF crack initiation process in high Al content near-α Ti60 alloys where deformation twins are rare, and tend to nucleate at the DF basal cracks. Further in-situ dwell investigation reveals and proposes that the dislocation pile-up and prismatic-basal (PB) interfacial features between soft/hard grains lead to deformation twin nucleation and growth from hard grain boundaries. Concurrently, the pyramidal 〈c+a〉 dislocation slip is observed to be in concurrent operation with the induced twins. These findings suggest that deformation twins not only coordinate basal grain deformation but also hinder the initiation and propagation of basal cracks caused by basal 〈a〉 slip. Moreover, a high density of pyramidal 〈c+a〉 dislocations within the twin and their dissociation to form basal stacking faults (SFTs) with a specific nanometric spacing make the twinning process accompanied by significant lattice distortions inside the twin. These newly formed nanotwin boundaries and SFTs act as barriers to dislocation motion, enhancing the strength and DF lifetime of near-α Ti60 alloys and effectively reducing the dwell sensitivity of no-MTR alloys. Our findings extend the understanding of the coordinated roles of dislocation slip, twin nucleation and formation of basal SFTs in near-α titanium alloys in dwell fatigue.

Composite fixed-length ordered features with index-of-max transformation for high-performing and secure palmprint template protection

Palmprint recognition has attracted considerable attention due to its advantages over other biometric modalities such as fingerprints, in that it is larger in area, richer in information and able to work at a distance. However, the issue of palmprint privacy and security (especially palmprint template protection) remains under-studied. Among the very few research works, most of them only use orientational features of the palmprint with transformation processing, yielding unsatisfactory recognition and protection performance. Thus, this research work proposes a palmprint feature extraction method for palmprint template protection that is fixed-length and ordered in nature, by fusing point features and orientational features. Firstly, dual orientations are extracted and encoded with more accuracy based on the modified finite Radon transform (MFRAT). Then, SURF feature points are extracted and converted to be fixed-length and ordered features. Finally, composite fixed-length ordered features that fuse up the dual orientations and SURF points are transformed using the irreversible transformation of index-of-max (IoM) to generate the revocable palmprint templates. Experiments show that the matching accuracy of the proposed method of fixed-length and ordered point features are superior to all other feature extraction methods on the PolyU and CASIA datasets. It is also demonstrated that the EERs before and after IoM transformation are better than all other representative template protection methods. A thorough security and privacy analysis including brute-force attack, false accept attack, birthday attack, attack via record multiplicity, irreversibility, unlinkability and revocability is also given, which proves that our proposed method has both high performance and security.

Distribution characteristics of Purkinje fibres in the canine left ventricle.

Purkinje-related ventricular arrhythmias have been increasingly reported, and with the development of catheter ablation techniques, intervention for Purkinje-related arrhythmias has been shown to be effective. The characteristics of Purkinje fibres orientation in the 12 canine left ventricles were observed at a gross level by staining the endocardium with Lugol's solution. Purkinje fibres were observed microscopically by HE, Masson's, PAS glycogen, and Cx40 immunohistochemical staining. Staining was successful, and the transverse orientation characteristics of Purkinje fibres were observed by Lugol's staining, and the longitudinal distribution was observed microscopically. The distribution of Purkinje fibres in the canine left ventricle is 'graded', 'layered', and 'networked', which can guide catheter ablation of Purkinje-related ventricular arrhythmia.

Reimagining LGBTIQ+ research – Acknowledging differences across subpopulations, methods, and countries

AbstractInequalities and discrimination based on gender identity, sexual orientation, and sex characteristics remain pervasive worldwide. Scholars have collaborated to address structural and social barriers in LGBTIQ+ research, creating a substantial literature base. However, much of this work focuses on specific segments of the population, overlooks resilience‐ and strengths‐based approaches, and is predominantly conducted in the U.S. and other Western countries. In this introduction article, we discuss how this special issue extends previous research by uniting scholars globally to collaboratively reimagine the lens through which scientists conduct LGBTIQ+ research. By exploring diverging needs across subgroups of LGBTIQ+ people, discussing the (dis)advantages of various methodological choices, and offering a better understanding of how unique legal and social landscapes affect LGBTIQ+ individuals globally, this special issue aims to provide a comprehensive picture of the current state of research combined with concrete directions for redress. Given that barriers to conducting LGBTIQ+ research differ significantly by nation, we conclude this introductory article by calling for a research community that is more aware of unequal power dynamics within academia, willing to take action to reduce disparities in the global academic system, and inclusive of voices from underrepresented groups.

In-situ synchrotron diffraction study on the anisotropic deformation and phase transformation behaviors in NiTi shape memory alloy fabricated by laser powder bed fusion

The stress-induced martensitic transformation (SIMT) and plastic deformation are the crucial factors governing the functional and mechanical properties of polycrystalline NiTi shape memory alloys. This study investigated and compared the SIMT and deformation behaviors along the building direction (BD) and horizontal direction (HD) of NiTi components fabricated by laser powder bed fusion (LPBF), using electron backscatter diffraction (EBSD) and in-situ synchrotron-based X-ray diffraction during uniaxial tension. The experimental results revealed that loading along the HD resulted in both a higher SIMT rate and increased dislocation density compared to the BD of the printed block. Additionally, both HD and BD loadings demonstrated multiple lattice correspondences from the B2-austenite to B19'-martensite phase. The BD sample, with its more complex grain boundary network, densely distributed localized stress and strain, as well as, smaller grain size, contributed to a lower SIMT rate and dislocation density. These findings underscore the impact of crystallographic orientation and microstructural characteristics on the mechanical responses and SIMTs of LPBF-fabricated NiTi alloys.