stewart
- North America > United States > New York (0.04)
- Asia > Afghanistan > Parwan Province > Charikar (0.04)
- North America > United States > Wisconsin > Dane County > Madison (0.04)
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- North America > United States > Wisconsin > Dane County > Madison (0.14)
- North America > United States > California > San Diego County > San Diego (0.04)
- North America > United States > California > San Diego County > La Jolla (0.04)
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A Literature Review On Stewart-Gough Platform Calibrations A Literature Review On Stewart-Gough Platform Calibrations
Karmakar, Sourabh, Turner, Cameron J.
Researchers have studied Stewart-Gough platforms, also known as Gough-Stewart platforms or hexapod platforms extensively for their inherent fine control characteristics. Their studies led to the potential deployment opportunities of Stewart-Gough Platforms in many critical applications such as the medical field, engineering machines, space research, electronic chip manufacturing, automobile manufacturing, etc. Some of these applications need micro and nano-level movement control in 3D space for the motions to be precise, complicated, and repeatable; a Stewart-Gough platform fulfills these challenges smartly. For this, the platform must be more accurate than the specified application accuracy level and thus proper calibration for a parallel robot is crucial. Forward kinematics-based calibration for these hexapod machines becomes unnecessarily complex and inverse kinematics complete this task with much ease. To experiment with different calibration techniques, various calibration approaches were implemented by using external instruments, constraining one or more motions of the system, and using extra sensors for auto or self-calibration. This survey paid attention to those key methodologies, their outcome, and important details related to inverse kinematic-based parallel robot calibrations. It was observed during this study that the researchers focused on improving the accuracy of the platform position and orientation considering the errors contributed by one source or multiple sources. The error sources considered are mainly kinematic and structural, in some cases, environmental factors also are reviewed, however, those calibrations are done under no-load conditions. This study aims to review the present state of the art in this field and highlight the processes and errors considered for the calibration of Stewart-Gough platforms.
- North America > United States > New York > New York County > New York City (0.04)
- Europe > Switzerland (0.04)
- North America > United States > Michigan > Washtenaw County > Ann Arbor (0.04)
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- Research Report (1.00)
- Overview (1.00)
Outlier-Robust High-Dimensional Sparse Estimation via Iterative Filtering
Ilias Diakonikolas, Daniel Kane, Sushrut Karmalkar, Eric Price, Alistair Stewart
We study high-dimensional sparse estimation tasks in a robust setting where a constant fraction of the dataset is adversarially corrupted. Specifically, we focus on the fundamental problems of robust sparse mean estimation and robust sparse PCA. We give the first practically viable robust estimators for these problems. In more detail, our algorithms are sample and computationally efficient and achieve near-optimal robustness guarantees. In contrast to prior provable algorithms which relied on the ellipsoid method, our algorithms use spectral techniques to iteratively remove outliers from the dataset. Our experimental evaluation on synthetic data shows that our algorithms are scalable and significantly outperform a range of previous approaches, nearly matching the best error rate without corruptions.
- Asia > Afghanistan > Parwan Province > Charikar (0.04)
- North America > United States > Wisconsin > Dane County > Madison (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
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- North America > United States > Wisconsin > Dane County > Madison (0.14)
- North America > United States > California > San Diego County > San Diego (0.04)
- North America > United States > California > San Diego County > La Jolla (0.04)
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Digital resurrection: fascination and fear over the rise of the deathbot
Rod Stewart had a few surprise guests at a recent concert in Charlotte, North Carolina. His old friend Ozzy Osbourne, the lead singer of Black Sabbath who died last month, was apparently beamed in from some kind of rock heaven, where he was reunited with other departed stars including Michael Jackson, Tina Turner and Bob Marley. The AI-generated images divided Stewart's fans. Some denounced them as disrespectful and distasteful; others found the tribute beautiful. At about the same time, another AI controversy erupted when Jim Acosta, a former CNN White House correspondent, interviewed a digital recreation of Joaquin Oliver, who was killed at the age of 17 in a 2018 high school shooting in Florida.
- North America > United States > North Carolina > Mecklenburg County > Charlotte (0.25)
- Asia > China (0.05)
- Education > Health & Safety > School Safety & Security > School Violence (0.89)
- Media > Music (0.55)
Far-right extremists guilty of planning attacks
Three far-right extremists who amassed hundreds of weapons and planned to carry out attacks on targets including a mosque have been convicted of terrorism offences. Brogan Stewart, 25, from West Yorkshire, Christopher Ringrose, 34, from Staffordshire, and Marco Pitzettu, 25, from Derbyshire, were part of an online group who "idolised the Nazi regime". Sheffield Crown Court was told how Stewart had detailed torturing a Muslim leader using an "information extraction kit". All three were found guilty of terrorism offences at the same court on Wednesday and are due to be sentenced on 17 July.Counter Terrorism Policing North EastThe trio had amassed a cache of weapons as part of their planning During the nine-week trial, the court heard more than 200 weapons including machetes, hunting knives, swords and crossbows were found at their homes. Ringrose had also begun to build a 3D-printed semi-automatic firearm, which counter-terror police said would have been a "lethal weapon".
- Europe > United Kingdom > England > West Yorkshire (0.27)
- Europe > United Kingdom > England > Staffordshire (0.25)
- South America (0.16)
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What the Assault on Public Education Means for Kids with Disabilities
President Donald Trump, winner of the Battle of the Billionaires at WrestleMania 23, has maintained close ties with Linda McMahon, the former C.E.O. of World Wrestling Entertainment, for decades. During the President's first term, she served for two years as head of the Small Business Administration, stepping down in 2019 to lead America First Action, a pro-Trump super PAC. Now McMahon is Trump's nominee to run the U.S. Department of Education, although she may appear to lack conventional bona fides for the position. If McMahon is confirmed by the Senate, her odd task will be to take charge of an agency in order to euthanize it. "I told Linda, 'Linda, I hope you do a great job and put yourself out of a job,' " Trump said, on February 4th.
- North America > United States > Arizona (0.06)
- North America > United States > Nebraska (0.05)
- North America > United States > Kentucky (0.05)
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- Government > Regional Government > North America Government > United States Government (1.00)
- Education (1.00)
'Ghost Ship of the Pacific' rediscovered with underwater drones
An autonomous drone fleet overseen by Ocean Infinity has rediscovered the USS Stewart, the only US Navy destroyer ever captured by Japanese forces during World War II. The marine robotics company's trio of orange, 20-foot-long underwater robots found the historic vessel while mapping what is now the 1,286-square-mile Cordell Bank national marine sanctuary off the California coast. Also known as the "Ghost Ship of the Pacific," the 314-foot-long ship has spent the past 78 years resting roughly 3,500 feet below the ocean's surface, and appears to remain almost completely intact and upright. "This level of preservation is exceptional for a vessel of its age and makes it potentially one of the best-preserved examples of a US Navy'four-piper' destroyer known to exist," Maria Brown, superintendent for both Cordell Bank and Greater Farallones national marine sanctuaries, said in a statement to The New York Times on October 1. The USS Stewart's story is unique in US maritime history, making it one of the most sought-after wrecks for decades.
- North America > United States > California (0.26)
- Oceania > Guam (0.06)
- North America > United States > Nevada (0.06)
- Asia > Japan (0.06)
Large-scale digital phenotyping: identifying depression and anxiety indicators in a general UK population with over 10,000 participants
Zhang, Yuezhou, Stewart, Callum, Ranjan, Yatharth, Conde, Pauline, Sankesara, Heet, Rashid, Zulqarnain, Sun, Shaoxiong, Dobson, Richard J B, Folarin, Amos A
Digital phenotyping offers a novel and cost-efficient approach for managing depression and anxiety. Previous studies, often limited to small-to-medium or specific populations, may lack generalizability. We conducted a cross-sectional analysis of data from 10,129 participants recruited from a UK-based general population between June 2020 and August 2022. Participants shared wearable (Fitbit) data and self-reported questionnaires on depression (PHQ-8), anxiety (GAD-7), and mood via a study app. We first examined the correlations between PHQ-8/GAD-7 scores and wearable-derived features, demographics, health data, and mood assessments. Subsequently, unsupervised clustering was used to identify behavioural patterns associated with depression or anxiety. Finally, we employed separate XGBoost models to predict depression and anxiety and compared the results using different subsets of features. We observed significant associations between the severity of depression and anxiety with several factors, including mood, age, gender, BMI, sleep patterns, physical activity, and heart rate. Clustering analysis revealed that participants simultaneously exhibiting lower physical activity levels and higher heart rates reported more severe symptoms. Prediction models incorporating all types of variables achieved the best performance ($R^2$=0.41, MAE=3.42 for depression; $R^2$=0.31, MAE=3.50 for anxiety) compared to those using subsets of variables. This study identified potential indicators for depression and anxiety, highlighting the utility of digital phenotyping and machine learning technologies for rapid screening of mental disorders in general populations. These findings provide robust real-world insights for future healthcare applications.
- Europe > United Kingdom > England > Greater London > London (0.14)
- Asia > Nepal (0.04)
- Oceania > Australia (0.04)
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