19,961 research outputs found
Analysis of Electrode Configuration of Underwater Electric Field Sensor on Electric-Field-based Localization for Underwater Robots
No full textThis paper addresses the effects of electrode configurations of an underwater electric field sensor (EFS) on the localization of underwater robots when the robots used electric field measurements to estimate their positions. Around an underwater electric landmark that generates a known electric field signature, an underwater robot equipped with an EFS can measure the signature to localize itself by searching for the position that minimizes the difference between the actual measurement and the theoretical calculation that should be measured when the robot is located at the position. The underwater robot's localization accuracy was analyzed in simulations when the robot was equipped with EFSs with different electrode configurations. In general, the electric field measurement accuracy and the consequent robot localization accuracy were higher when the robot was equipped with the EFS that consists of more electrodes. Depending on the measurement conditions, however, the use EFSs with less electrodes was enough to perform sufficiently accurate localization of the robot. The proposed simulation method would contribute to suggest the optimal electrode configuration of the EFS, and therefore, the robot localization with the electric field measurements would become more energy-efficient with the use of the suggested cheap and small EFS.1
Analysis of Electrode Configuration for Underwater Robot’s Navigation Utilizing Underwater Electric Field Sensor
No full textWe studied effects of electrode configurations of underwater electric field sensors (EFS) on the electro-localization accuracy of underwater robots. An underwater robot equipped with an EFS measures 3-D electric field that is induced by an electric landmark; the electric landmark generates predefined electric field signatures around itself. The paths of the underwater robot are predicted by comparing the measured electric field signatures and their theoretical calculations at the same measurement conditions. In this study, computer simulations were conducted in which an underwater robot measured electric field signatures with EFSs of different electrode configurations and performed its localization with the measurements. The results show that if the underwater robot is sufficiently close to the electric landmark, the localization accuracy when using the EFS with less number of electrodes is similar to that when using the EFS with more number of electrodes. The results would contribute to suggest the use of smaller and cheaper EFSs for navigation of underwater robots according to the robots’ exploration range and other measurement conditions.2
Feasibility test of underwater robot's navigation by using underwater electric field sensor
No full textWe propose a method to localize underwater robots by using an underwater electric field sensor (EFS) that measures underwater electric field signals. The EFS is installed at an underwater robot and measured the three-dimensional electric field signals generated by an underwater electric landmark. The position of the underwater robot is predicted by comparing the measured electric field signals and the theoretical calculations at the same measurement conditions. The optimal position of the underwater robot was predicted by using the particle swarm optimization that minimized the difference between the measurements and the theoretical calculations. The proposed method was tested in computer simulations and the positions of the underwater robot could be predicted. The proposed method would be useful for underwater robots to serve various missions, such as underwater exploration and object detection.2
Axis Calibration Method of Underwater Electric Field Measurement Sensor for Underwater Robot
No full textThis paper proposes a method to calibrate axis misalignment of underwater electric field sensors (EFS) for accurate electric signal measurements of underwater robots. An EFS measured a known electric field and the measured values were compared to their theoretical values to approximate the axis misalignment of the sensor. The approximation was optimized by using the Levenberg's optimization algorithm. The optimization algorithm searched for the axis misalignment of the EFS that minimized the difference between the measured values and the theoretical values. After the optimization, the measurements with the EFS could be calibrated. The proposed method was tested in computer simulations. The results show that the proposed method could approximate the axis misalignment of the EFS and calibrate the measured electric fields. The calibration reduced the localization errors of an underwater robot when the robot electro localized its position by using electric field signals generated by an electric landmark. The proposed method would contribute to various applications that require accurate measurements of underwater electric signals, such as electro localization of underwater robots and detection of electric objects underwater.2
Machine-Learning Based Automatic and Real-time Detection of Mouse Scratching Behaviors
No full textScratching is a main behavioral response accompanied by acute and chronic itch conditions, and has been quantified as an objective correlate to assess itch in studies using laboratory animals. Scratching has been counted mostly by human annotators, which is a time-consuming and laborious process. It has been attempted to develop automated scoring methods using various strategies, but they often require specialized equipment, costly software, or implantation of device which may disturb animal behaviors. To complement limitations of those methods, we have adapted machine learning-based strategy to develop a novel automated and real-time method detecting mouse scratching from experimental movies captured using monochrome cameras such as a webcam. Scratching is identified by characteristic changes in pixels, body position, and body size by frame as well as the size of body. To build a training model, a novel two-step J48 decision tree-inducing algorithm along with a C4.5 post-pruning algorithm was applied to three 30-min video recordings in which a mouse exhibits scratching following an intradermal injection of a pruritogen, and the resultant frames were then used for the next round of training. The trained method exhibited, on average, a sensitivity and specificity of 95.19% and 92.96%, respectively, in a performance test with five new recordings. This result suggests that it can be used as a non-invasive, automated and objective tool to measure mouse scratching from video recordings captured in general experimental settings, permitting rapid and accurate analysis of scratching for preclinical studies and high throughput drug screening. © 2019 Experimental Neurobiology.1
ClaimDiff: Comparing and Contrasting Claims on Contentious Issues
No full textWith the growing importance of detecting misinformation, many studies have focused on verifying factual claims by retrieving evidence. However, canonical fact verification tasks do not apply to catching subtle differences in factually consistent claims, which might still bias the readers, especially on contentious political or economic issues. Our underlying assumption is that among the trusted sources, one's argument is not necessarily more true than the other, requiring comparison rather than verification. In this study, we propose ClaimDiff, a novel dataset that primarily focuses on comparing the nuance between claim pairs. In ClaimDiff, we provide 2,941 annotated claim pairs from 268 news articles. We observe that while humans are capable of detecting the nuances between claims, strong baselines struggle to detect them, showing over a 19% absolute gap with the humans. We hope this initial study could help readers to gain an unbiased grasp of contentious issues through machine-aided comparison
Who Was Edmund Lee?
No full textLocal author Peggy Donoho discusses her pioneer ancestor, Edmund Lee, and her work to preserve their family cemetery
The Future of Canadian Climate Policy — with Marc Lee
No full textMarc Lee is a Senior Economist at the Canadian Centre for Policy Alternatives\u27 BC Office. In addition to tracking federal and provincial budgets and economic trends, Marc has published on a range of topics from poverty and inequality to globalization and international trade to public services and regulation. Marc is the Co-Director of the Climate Justice Project, a research partnership with UBC\u27s School of Community and Regional Planning that examines the links between climate change policies and social justice.Resources:Climate Justice Project: www.policyalternatives.ca/projects/cli…tice-projectMarc Lee\u27s Posts on Policy Note: www.policynote.ca/author/marclee/Canadian Centre for Policy Alternatives: www.policyalternatives.ca/Marc\u27s Twitter: twitter.com/MarcLeeCCPA International Panel on Climate Change, 2021 report: www.ipcc.ch/report/ar6/wg1
Dr. Aleksandra Sznajder Lee – Faculty Author Interview
No full textDr. Aleksandra Sznajder Lee, Associate Professor of Political Science, discusses her new book, Transnational Capitalism in East Central Europe’s Heavy Industry, published recently by the University of Michigan Press. Focusing on the steel industry during the post-communist transition from 1989 through 2009, Dr. Sznajder Lee traces the transformation of flagship state enterprises in the Czech Republic, Poland, Romania, and Slovakia into the subsidiaries of large, international corporations
Letter from K.W. Lee to Friends of Michi Weglyn, November 1, 1997
No full textA letter from K. W. (Kyung Won) Lee, an investigative journalist who wrote for the Sacramento Union, to the Friends of Michi Weglyn. Lee wrote that Weglyn was instrumental in the campaign to free Chol Soo Lee, a Korean American man was on death row, but later had his convictions overturned. Lee also wrote that other Japanese American activists were instrumental to the success of this campaign.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
- …
