Empirical model for quasi direct current interruption with a convoluted arc

This contribution considers various aspects of a quasi direct current, convoluted arc produced by a magnetic field (B-field) connected in parallel with an RLC circuit that have not been considered in combination. These aspects are the arc current limitation due to the arc convolution, changes in arc resistance due to the B-field and material ablation, and the relative significance of the RLC circuit in producing an artificial current zero. As a result, it has been possible to produce an empirical equation for predicting the current interruption capability in terms of the B-field magnitude and RLC components

Robust Object Classification Approach using Spherical Harmonics

Point clouds produced by either 3D scanners or multi-view images are often imperfect and contain noise or outliers. This paper presents an end-to-end robust spherical harmonics approach to classifying 3D objects. The proposed framework first uses the voxel grid of concentric spheres to learn features over the unit ball. We then limit the spherical harmonics order level to suppress the effect of noise and outliers. In addition, the entire classification operation is performed in the Fourier domain. As a result, our proposed model learned features that are less sensitive to data perturbations and corruptions. We tested our proposed model against several types of data perturbations and corruptions, such as noise and outliers. Our results show that the proposed model has fewer parameters, competes with state-of-art networks in terms of robustness to data inaccuracies, and is faster than other robust methods. Our implementation code is also publicly available1

Robust pooling through the data mode: Robust Point cloud Classification and Segmentation Through Mode Pooling

The task of learning from point cloud data is always challenging due to the often occurrence of noise and outliers in the data. Such data inaccuracies can significantly influence the performance of state-of-the-art deep learning networks and their ability to classify or segment objects. While there are some robust deep-learning approaches, they are computationally too expensive for real-time applications. This paper proposes a deep learning solution that includes novel robust pooling layers which greatly enhance network robustness and perform significantly faster than state-of-the-art approaches. The proposed pooling layers replace conventional pooling layers in networks with global pooling operations such as PointNet and DGCNN. The proposed pooling layers look for data mode/cluster using two methods, RANSAC, and histogram, as clusters are indicative of models. We tested the proposed pooling layers on several tasks such as classification, part segmentation, and points normal vector estimation. The results show excellent robustness to high levels of data corruption with less computational requirements as compared to robust state-of-the-art methods. our code can be found at https://github.com/AymanMukh/ModePooling

Flicker Transfer in Radial Power Systems

Loads which exhibit continuous and rapid variations in their current can cause voltage fluctuations that are often referred to as flicker. One good example for such loads is arc furnaces which are usually fed by dedicated feeders from the high voltage busbars in transmission systems. The flicker generated from such loads will propagate to the upstream HV point of common coupling (PCC), and from there to the downstream through the transmission and sub transmission systems. This paper demonstrates how the generated flicker is propagated from the HV PCC to the downstream in radial networks exhibiting different levels of attenuation depending upon the load composition of the downstream. Theoretical investigations on flicker transfer have been carried out using simple and more advanced modelling of loads and simulations of radial transmission and sub transmission networks having different load types. The behaviour predicted by the theoretical work is supported through field measurements that have been carried out in an actual network

Gender Inequality in Digital Transformation: Evidence from Business Process Management Industry in Sri Lanka

This research examines whether gender inequality exists in Leadership Style, Organizational Culture, and Digital Competence of digital transformation of the Business Process Management (BPM) industry. Data were collected from 507 employees of 40 Sri Lankan BPM companies through a web-based survey. Mann-Whitney U test with descriptive statistics provided evidence to strengthen the findings. The findings confirmed that gender inequality exists in Leadership Style, Organizational Culture, and Digital Competence of digital transformation in the BPM industry in Sri Lanka. This research contributes to "Acker's Theory of Gendered Organizations" by identifying areas that reproduce gender inequality in the new digital economy workplace. This study recommends controlling if not eradicating the gender inequality through proper Human Resource (HR) policies and procedures since it may hinder organizational performance. Digital workplace will improve employee retention, satisfaction, and productivity. Keywords: Business Process Management, Gender Inequality, Leadership Style, Organizational Culture, Digital Competenc

Habitat Fragmentation and Isolation-by-Distance Driven Population Divergence of Oryza rufipogon in Sri Lanka

Wild relatives of rice are an important genetic resources in rice breeding. Oryza rufipogon is a diploid perennial species belongs to AA genome group and sexually compatible with cultivated rice. The putative ancestor of Asian cultivated rice (Oryza sativa) is endangered in Sri Lanka due to habitat loss and land fragmentation. However, no proper studies have been performed on population diversity and habitat fragmentation of the Sri Lankan wild rice species used in our breeding programs. In this study, we explore the genetic diversity of five Oryza rufipogon populations using 33 microsatellite loci to infer the effects of habitat fragmentation and isolation by-distance (IBD) on genetic structure. Results of AMOVA revealed among population variance (43.7%) and within population (56.31%) variance. Partial Mantel tests (r2=0.306; p value=0.027) showed that population divergence of Sri Lankan O. rufipogon based on isolation by distance was statistically significant. Genetic diversity of O. rufipogon was recorded at population level (0.41) and the individual level (0.62). Preferred habitats of O. rufipogon are swampy areas like marshes, open ditches, swamps, ponds, pools, along river banks, at the edges of lakes and in or at the margins of rice fields. Some populations grow under submergence and saline conditions. The water depth preferences are between 0.2-4.0 m. As a result of human activities such as agriculture, urbanization and industry have destroyed natural habitats, leading to increasing habitat fragmentation. Conclusively, these results indicate that IBD due to historical rather than recent fragmentation, followed by local adaptation, has driven population divergence in O. rufipogon. Understanding genetic diversity and eco-geographic variation of wild rice in Sri Lanka is timely requirement it provides opportunities to design conservation strategies and basic information for proper utilization of wild genetic resources in rice genetic improvement and breeding.Keywords: Crop improvement, Habitat, Mantel test, Genetic structure, Wild ric

Vortices in vibrated granular rods

We report the experimental observation of novel vortex patterns in vertically vibrated granular rods. Above a critical packing fraction, moving ordered domains of nearly vertical rods spontaneously form and coexist with horizontal rods. The domains of vertical rods coarsen in time to form large vortices. We investigate the conditions under which the vortices occur by varying the number of rods, vibration amplitude and frequency. The size of the vortices increases with the number of rods. We characterize the growth of the ordered domains by measuring the area fraction of the ordered regions as a function of time. A {\em void filling} model is presented to describe the nucleation and growth of the vertical domains. We track the ends of the vertical rods and obtain the velocity fields of the vortices. The rotation speed of the rods is observed to depend on the vibration velocity of the container and on the packing. To investigate the impact of the direction of driving on the observed phenomena, we performed experiments with the container vibrated horizontally. Although vertical domains form, vortices are not observed. We therefore argue that the motion is generated due to the interaction of the inclination of the rods with the bottom of a vertically vibrated container. We also perform simple experiments with a single row of rods in an annulus. These experiments directly demonstrate that the rod motion is generated when the rods are inclined from the vertical, and is always in the direction of the inclination.Comment: 6 pages, 10 figure, 2 movies at http://physics.clarku.edu/vortex uses revtex

Environmental microbial contaminants in selected retail pharmacies of Sri Lanka

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Intravenous lidocaine as a non-opioid adjunct analgesic for traumatic rib fractures.

INTRODUCTION: Pain management is the pillar of caring for patients with traumatic rib fractures. Intravenous lidocaine (IVL) is a well-established non-opioid analgesic for post-operative pain, yet its efficacy has yet to be investigated in trauma patients. We hypothesized that IVL is associated with decreased inpatient opioid requirements among patients with rib fractures. METHODS: We retrospectively evaluated adult patients presenting to our Level 1 trauma center with isolated chest wall injuries. After 1:1 propensity score matching patients who received vs did not receive IVL, we compared the two groups\u27 average daily opioid use, opioid use in the last 24 hours of admission, and pain scores during admissions hours 24-48. We performed multivariable linear regression for these outcomes (with sensitivity analysis for the opioid use outcomes), adjusting for age as a moderating factor and controlling for hospital length of stay and injury severity. RESULTS: We identified 534 patients, among whom 226 received IVL. Those who received IVL were older and had more serious injury. Compared to propensity-score matched patients who did not receive IVL, patients who received IVL had similar average daily opioid use and pain scores, but 40% lower opioid use during the last 24 hours of admission (p = 0.002). Multivariable regression-with and without sensitivity analysis-did not show an effect of IVL on any outcomes. CONCLUSION: IVL was crudely associated with decreased opioid requirements in the last 24 hours of admission, the time period associated with opioid use at 90 days post-discharge. However, we did not observe beneficial effects of IVL on multivariable adjusted analyses; we are conducting a randomized control trial to further evaluate IVL\u27s opioid-sparing effects for patients with rib fractures