1,927 research outputs found
Formula SAE Intake System
The Formula SAE Intake System is intended to optimize the airflow into a restricted 600cc engine. The intake system is designed, fabricated, and installed in accordance with the FSAE rule book with a focus on maximizing the vehicleās acceleration. It is directly responsible for determining the drivability of the car and how much horsepower the flow restricted engine produces.
Design of the intake was conceptualized based on researching a number of factors including venturi diffusion angles, plenum volumes, and runner lengths. Initial tests were performed utilizing computational fluid dynamics for a total of 367 flow simulations and 261 running hours on various intake components in SolidWorks Flow Simulation 2016. From the beginning, it was known that the intake needed to possess certain contours that would be very difficult to create with sheet metal. It was for this reason that a composite construction was pursued for the plenum of the intake manifold, utilizing fused deposition modeling to form the mold. Flow testing and dynamometer testing will be utilized to verify the effectiveness of the design. In the end, the intake system will provide peak performance in the flow restricted system. The increased brake horsepower and improved vehicle drivability will provide a competitive advantage on any race course.https://scholarscompass.vcu.edu/capstone/1198/thumbnail.jp
Spontaneous Lung Herniation Leading to Extensive Subcutaneous Emphysema, Pneumothorax, Pneumomediastinum, and Pneumopericardium.
Spontaneous lung herniation is a rare phenomenon in which the lung parenchyma along with the pleural membranes protrudes outside their usual boundaries and can lead to a wide variety of complications. We are reporting a case of a middle-aged male who presented with chronic obstructive pulmonary disease (COPD) exacerbation with severe bouts of cough. Initial computed tomography (CT) chest was unrevealing, but two days later, he developed spontaneous lung herniation, which was initially managed conservatively, but later it progressed to pneumothorax, pneumomediastinum, with striking CT scan images showing extensive subcutaneous emphysema. Blowhole incisions were done on the anterior chest wall which led to ultimate recovery
Optical control of internal electric fields in band-gap graded InGaN nanowires
InGaN nanowires are suitable building blocks for many future optoelectronic
devices. We show that a linear grading of the indium content along the nanowire
axis from GaN to InN introduces an internal electric field evoking a
photocurrent. Consistent with quantitative band structure simulations we
observe a sign change in the measured photocurrent as a function of photon
flux. This negative differential photocurrent opens the path to a new type of
nanowire-based photodetector. We demonstrate that the photocurrent response of
the nanowires is as fast as 1.5 ps
A scalable framework for cross-lingual authorship identification
This is an accepted manuscript of an article published by Elsevier in Information Sciences on 10/07/2018, available online: https://doi.org/10.1016/j.ins.2018.07.009
The accepted version of the publication may differ from the final published version.Ā© 2018 Elsevier Inc. Cross-lingual authorship identification aims at finding the author of an anonymous document written in one language by using labeled documents written in other languages. The main challenge of cross-lingual authorship identification is that the stylistic markers (features) used in one language may not be applicable to other languages in the corpus. Existing methods overcome this challenge by using external resources such as machine translation and part-of-speech tagging. However, such solutions are not applicable to languages with poor external resources (known as low resource languages). They also fail to scale as the number of candidate authors and/or the number of languages in the corpus increases. In this investigation, we analyze different types of stylometric features and identify 10 high-performance language-independent features for cross-lingual stylometric analysis tasks. Based on these stylometric features, we propose a cross-lingual authorship identification solution that can accurately handle a large number of authors. Specifically, we partition the documents into fragments where each fragment is further decomposed into fixed size chunks. Using a multilingual corpus of 400 authors with 825 documents written in 6 different languages, we show that our method can achieve an accuracy level of 96.66%. Our solution also outperforms the best existing solution that does not rely on external resources.Published versio
StyloThai: A scalable framework for stylometric authorship identification of Thai documents
This is an accepted manuscript of an article published by ACM in ACM Transactions on Asian and Low-Resource Language Information Processing in January 2020, available online: https://doi.org/10.1145/3365832
The accepted version of the publication may differ from the final published version.Ā© 2020 Association for Computing Machinery. All rights reserved. Authorship identification helps to identify the true author of a given anonymous document from a set of candidate authors. The applications of this task can be found in several domains, such as law enforcement agencies and information retrieval. These application domains are not limited to a specific language, community, or ethnicity. However, most of the existing solutions are designed for English, and a little attention has been paid to Thai. These existing solutions are not directly applicable to Thai due to the linguistic differences between these two languages. Moreover, the existing solution designed for Thai is unable to (i) handle outliers in the dataset, (ii) scale when the size of the candidate authors set increases, and (iii) perform well when the number of writing samples for each candidate author is low.We identify a stylometric feature space for the Thai authorship identification task. Based on our feature space, we present an authorship identification solution that uses the probabilistic k nearest neighbors classifier by transforming each document into a collection of point sets. Specifically, this document transformation allows us to (i) use set distance measures associated with an outlier handling mechanism, (ii) capture stylistic variations within a document, and (iii) produce multiple predictions for a query document. We create a new Thai authorship identification corpus containing 547 documents from 200 authors, which is significantly larger than the corpus used by the existing study (an increase of 32 folds in terms of the number of candidate authors). The experimental results show that our solution can overcome the limitations of the existing solution and outperforms all competitors with an accuracy level of 91.02%. Moreover, we investigate the effectiveness of each stylometric features category with the help of an ablation study. We found that combining all categories of the stylometric features outperforms the other combinations. Finally, we cross compare the feature spaces and classification methods of all solutions. We found that (i) our solution can scale as the number of candidate authors increases, (ii) our method outperforms all the competitors, and (iii) our feature space provides better performance than the feature space used by the existing study.The research was partially supported by the Digital Economy Promotion Agency (project# MP-62- 0003); and Thailand Research Fund and Office of the Higher Education Commission (MRG6180266).Published versio
Phosphorylation at serines 104 and 106 by Erk1/2 MAPK is important for estrogen receptor-Ī± activity
Phosphorylation of estrogen receptor-Ī± (ERĪ±) at specific residues in transcription activation function 1 (AF-1) can stimulate ERĪ± activity in a ligand-independent manner. This has led to the proposal that AF-1 phosphorylation and the consequent increase in ERĪ± activity could contribute to resistance to endocrine therapies in breast cancer patients. Previous studies have shown that serine 118 (S118) in AF-1 is phosphorylated by extracellular signal-regulated kinases 1 and 2 (Erk1/2) mitogen-activated protein kinase (MAPK) in a ligand-independent manner. Here, we show that serines 104 (S104) and 106 (S106) are also phosphorylated by MAPK in vitro and upon stimulation of MAPK activity in vivo. Phosphorylation of S104 and S106 can be inhibited by the MAP-erk kinase (MEK)1/2 inhibitor U0126 and by expression of kinase-dead Raf1. Further, we show that, although S118 is important for the stimulation of ERĪ± activity by the selective ER modulator 4-hydroxytamoxifen (OHT), S104 and S106 are also required for the agonist activity of OHT. Acidic amino acid substitution of S104 or S106 stimulates ERĪ± activity to a greater extent than the equivalent substitution at S118, suggesting that phosphorylation at S104 and S106 is important for ERĪ± activity. Collectively, these data indicate that the MAPK stimulation of ERĪ± activity involves the phosphorylation not only of S118 but also of S104 and S106, and that MAPK-mediated hyperphosphorylation of ERĪ± at these sites may contribute to resistance to tamoxifen in breast cancer
The prevalence of hepatitis C virus among people of South Asian origin in Glasgow: results from a community based survey and laboratory surveillance
Background South Asians often present late with HCV or HBV related liver disease which could have been avoided with early diagnosis and subsequent treatment; however the prevalence of HCV/HBV among South Asians in Glasgow is not known. Accordingly, to inform the need for case finding among this group we aimed to examine the prevalence of Hepatitis C virus (HCV) among South Asians living in Glasgow. Methods A community-based survey recruited individuals at six mosques and four community centres serving the South Asian community during 2009-2010; participants had predominantly never been HCV tested. Laboratory surveillance data involving all individuals tested for HCV during 1993-2009 were examined and South Asians were identified using Nam Pehchan software. Results In the community-based survey, 2.6% of 1288 participants tested HCV-antibody positive; the prevalence ranged from 0.6% among those born in the UK to 3.1% among those born in Pakistan. The odds of testing HCV-antibody positive were significantly raised among those who had surgery in South Asia (aOR: 5.0, 95% CI: 2.0-12.3) and had either medical/dental treatment or an injection in South Asia (aOR: 2.2, 95% CI: 1.0-5.0). Of 6404 South Asians identified from laboratory surveillance data, 9.3% tested HCV positive. An estimated 38% (330/870) of HCV-infected South Asians living in Glasgow remain undiagnosed. Conclusions South Asians living in Glasgow, particularly those born outside the UK are at greater risk of HCV infection than the general population. Efforts to increase awareness and testing in this population are warranted.</p
The causality and stability of relativistic spin-hydrodynamics
We study the causality and stability of the relativistic hydrodynamics when
the spin degree of freedom is included as a hydrodynamic field, by considering
two specific models of spin-hydrodynamics. A linear mode analysis for the
simplest static background with no flow velocity shows that the model of
dissipative first-order spin-hydrodynamics remains acausal and admits
unphysical instabilities as reported for the relativistic Navier-Stokes (NS)
equation. Besides, the inclusion of the spin field in hydrodynamics can lead to
new kinds of linear modes in the system. These new modes also exhibit
instability and an acausal behavior. The second model of the spin-hydrodynamics
that we have considered has no dissipative fluxes and is equivalent to a
particular second-order conventional hydrodynamics \cite{Li:2020eon}. For a
static background, it is found that the linear modes of this model support the
sound waves only. However, when the background has constant vorticity, the
model can have instability in certain situations and the mode also has acausal
behavior. It is found that the spin-dynamics have an effect on the hydrodynamic
response of the fluid. These findings point toward the need for a causal and
stable theory with spin as a hydrodynamic field to describe the spin-polarized
fluid.Comment: 31 page
- ā¦