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ERGODICITY OF THE GEODESIC FLOW ON SYMMETRIC SURFACES

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arXiv 2022年

作者： Pandazis, Michael Šarić, Dragomir PhD Program in Mathematics The Graduate Center CUNY 365 Fifth Ave. NY10016 United States Department of Mathematics Queens College CUNY 65–30 Kissena Blvd. FlushingNY11367 United States

We consider conditions on the Fenchel-Nielsen parameters of a Riemann surface X that guarantee the surface X is of parabolic type. An interesting class of Riemann surfaces for this problem is the one with finitely many topological ends. In this case the length part of the Fenchel-Nielsen coordinates can go to infinity for parabolic X. When the surface X is end symmetric, we prove that X being parabolic is equivalent to the covering group being of the first kind. Then we give necessary and sufficient conditions on the Fenchel-Nielsen coordinates of a half-twist symmetric surface X such that X is parabolic. As an application, we solve an open question from the prior work of Basmajian, Hakobyan and the second *** Codes 30F20, 30F25, 30F45, 57K20 Copyright © 2022, The Authors. All rights reserved.

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Exploring Barriers to the Use of Evidence-Based Instructional Practices

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Journal of College Science Teaching 2021年第2期51卷 56-66页

作者： Gardner, Grant E. Brown, Evelyn Grimes, Zachary Bishara, Gina Department of Biology and doctoral faculty in the Interdisciplinary Mathematics and Sciences Education Research PhD program at Middle Tennessee State University United States North Carolina State University United States Crowley’s Ridge College United States Department of Biology at Middle Tennessee State University United States

Recent reform documents in postsecondary science, technology, engineering, and mathematics (STEM) fields recommend the use of evidence-based instructional practices (EBIPs) in the classroom. National surveys in the United States suggest a continued reliance on instructorcentered practices that have little evidentiary support for long-term impacts on student learning. This study utilized a cross-sectional survey research design to explore the awareness and use of EBIPs by STEM instructors at two large universities (n = 104) in the southeastern United States. Participants’ perceived individual and situational barriers impaired their use of EBIPs. We also examined how these barriers may be related to faculty use of these instructional practices. Results indicate high awareness of many EBIPs but with little subsequent classroom use. Results also suggest that STEM faculty’s gender and pedagogical beliefs may mediate what they perceive as significant barriers to EBIP implementation. © 2021 National Science Teaching Association.

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ON THE DERIVATIVES OF THE LIOUVILLE CURRENTS

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arXiv 2024年

作者： Dong, Xinlong Šarić, Dragomir Wang, Zhe Department of Mathematics Kingsborough Community College The City University of New York 2001 Oriental Blvd BrooklynNY11235 United States Department of Mathematics Queens College The City University of New York 65–30 Kissena Blvd. FlushingNY11367 United States DS: Mathematics PhD. Program Graduate Center of the City University of New York 365 Fifth Avenue New YorkNY10016-4309 United States Department of Mathematics Bronx Community College The City University of New York 2155 University Ave BronxNY10453 United States

The Liouville map, introduced by Bonahon, assigns to each point in the Teichmüller space a natural Radon measure on the space of geodesics of the base surface. The Liouville map is real analytic and it even extends to a holomorphic map of a neighborhood of the Teichmüller space in the Quasi-Fuchsian space of an arbitrary conformally hyperbolic Riemann surface. The earthquake paths and by their extension quake-bends, introduced by Thurston, are particularly nice real-analytic and holomorphic paths in the Teichmüller and the Quasi-Fuchsian space, respectively. We find a geometric expression for the derivative of the Liouville map along earthquake paths. Copyright © 2024, The Authors. All rights reserved.

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Potential of water hyacinth (Eichhornia crassipes (Mart.) Solms) in Rawapening lake as raw material for fish feed 10

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Potential of water hyacinth (Eichhornia crassipes (Mart.) So...

10th International Seminar on New Paradigm and Innovation of Natural Sciences and itsApplication, ISNPINSA 2020

作者： Prasetyo, S. Anggoro, S. Soeprobowati, T.R. PhD Program of Environmental Studies School of Postgraduate Studies Diponegoro University Semarang Indonesia Faculty of Fisheries and Marine Sciences Diponegoro University Semarang Indonesia Departement of Biology Faculty of Sciences and Mathematics Diponegoro University Semarang Indonesia School of Postgraduate Studies Diponegoro University Semarang Indonesia

Feed is a major factor in determining the success of aquaculture business. The quality and quantity of feeding properly will maximize the growth of fish. Various research and application of technology has been made to obtain alternative feed source so as to reduce the level of dependence on the food production industry. The eutrophication condition of Rawapening Lake has triggered the water hyacinth (Eichhornia crassipes (Mart.) Solms) to grow out of control. It speeds up the loss of water weeds, cover the surface of the water into the fishing area and degrade water quality. The purpose of this study was to determine the potential of water hyacinth as an alternative fish feed ingredient. In addition, it is also an effort to control the growth of water hyacinth in Rawapening Lake. The descriptive analysis method with a quantitative approach was chosen in this study. After making flour, water hyacinth has a protein content of 12.51%. Water hyacinth fine flour mixed with other ingredients including fish meal and fish feed bisamenghasilkan rice bran protein content of 30.2477%. The results of testing the stability of feed in water (Water Stability Feed) showed that the feed was destroyed after being immersed in cold water for 17 hours. The buoyancy test shows the feed is classified as a submerged type. The feed sinks because it has a specific gravity which is greater than the specific gravity of water. The feed hardness test shows that the feed is not destroyed after being given a load of 500 grams. The heavier the load that the feed can hold, it means the feed is getting harder. Protein content of 30.2477% indicates that alternative fish feed has competitive quality because it is able to meet the protein needs of cultivated fish. Especially fish cultivated in tropical areas which have lower protein requirements (20-30%). © Published under licence by IOP Publishing Ltd.

关键词： Lakes

BRAIN-TO-TEXT BENCHMARK’24: LESSONS LEARNED

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arXiv 2024年

作者： Willett, Francis R. Li, Jingyuan Le, Trung Fan, Chaofei Chen, Mingfei Shlizerman, Eli Chen, Yue Zheng, Xin Okubo, Tatsuo S. Benster, Tyler Lee, Hyun Dong Kounga, Maxwell Buchanan, E. Kelly Zoltowski, David Linderman, Scott W. Henderson, Jaimie M. Department of Neurosurgery Stanford University United States Department of Electrical & Computer Engineering University of Washington United States Department of Computer Science Stanford University United States Department of Applied Mathematics University of Washington United States China Neurosciences Phd Program Stanford University United States Wu Tsai Neurosciences Institute Department of Statistics Stanford University United States

Speech brain-computer interfaces aim to decipher what a person is trying to say from neural activity alone, restoring communication to people with paralysis who have lost the ability to speak intelligibly. The Brain-to-Text Benchmark’24 and associated competition was created to foster the advancement of decoding algorithms that convert neural activity to text. Here, we summarize the lessons learned from the competition ending on June 1, 2024 (the top 4 entrants also presented their experiences in a recorded webinar). The largest improvements in accuracy were achieved using an ensembling approach, where the output of multiple independent decoders was merged using a fine-tuned large language model (an approach used by all 3 top entrants). Performance gains were also found by improving how the baseline recurrent neural network (RNN) model was trained, including by optimizing learning rate scheduling and by using a diphone training objective. Improving upon the model architecture itself proved more difficult, however, with attempts to use deep state space models or transformers not yet appearing to offer a benefit over the RNN baseline. The benchmark will remain open indefinitely to support further work towards increasing the accuracy of brain-to-text algorithms. © 2024, CC BY.

关键词： Recurrent neural networks

Systematic designs of single metal compounds synthesized using ammonia fluoride-based complex as structure directing agents for energy storage

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Journal of Colloid and Interface Science 2023年第PartA期652卷 294-304页

作者： Kuo, Tsung-Rong Zher Yu, You Wu, Chung-Hsien Lee, Pin-Yan Kongvarhodom, Chutima Chen, Hung-Ming Husain, Sadang Yougbaré, Sibidou Lin, Lu-Yin International PhD Program in Biomedical Engineering College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Graduate Institute of Nanomedicine and Medical Engineering College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Department of Chemical Engineering and Biotechnology National Taipei University of Technology Taipei Taiwan Department of Chemical Engineering King Mongkut's University of Technology Thonburi 126 Pracha-u-thit Toong-kru Bangkok10140 Thailand Gingen technology Co. LTD. Rm. 7 10F. No.189 Sec. 2 Keelung Rd. Xinyi Dist. Taipei11054 Taiwan Department of Physics Faculty of Mathematics and Natural Science Lambung Mangkurat University Banjarmasin70124 Indonesia /Nanoro 03 B.P 7192 Ouagadougou 03 Burkina Faso

Tailoring morphology and composition of metal organic frameworks (MOF) can improve energy storage by establishing high surface area, large porosity and multiple redox states. Structure directing agents (SDA) is functional of designing surface properties of electroactive materials. Ammonium fluoride has functional abilities for designing MOF derivatives with excellent energy storage abilities. Systematic design of MOF derivatives using ammonia fluoride-based complex as SDA can essentially create efficient electroactive materials. Metal species can also play significant roles on redox reactions, which are the main energy storage mechanism for battery-type electrodes. In this work, 2-methylimidazole, two novel SDAs of NH4BF4 and NH4HF2, and six metal species of Al, Mn, Co, Ni, Cu and Zn are coupled to synthesize MOF derivatives for energy storage. Metal species-dependent compositions including hydroxides, oxides, and hydroxide nitrates are observed. The nickel-based derivative (Ni-HBF) shows the highest specific capacitance (CF) of 698.0F/g at 20 mV/s, due to multiple redox states and advanced flower-like surface properties. The diffusion and capacitive-control contributions of MOF derivatives are also analyzed. The battery supercapacitor hybrid with Ni-HBF electrode shows a maximum energy density of 27.9 Wh/kg at 325 W/kg. The CF retention of 170.9% and Coulombic efficiency of 93.2% are achieved after 10,000 cycles. © 2023 Elsevier Inc.

关键词： Supercapacitor

Genie: A new, fast, and outlier-resistant hierarchical clustering algorithm

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arXiv 2022年

作者： Gagolewski, Marek Bartoszuk, Maciej Cena, Anna Systems Research Institute Polish Academy of Sciences ul. Newelska 6 Warsaw01-447 Poland Faculty of Mathematics and Information Science Warsaw University of Technology ul. Koszykowa 75 Warsaw00-662 Poland International PhD Studies Program Institute of Computer Science Polish Academy of Sciences Poland

The time needed to apply a hierarchical clustering algorithm is most often dominated by the number of computations of a pairwise dissimilarity measure. Such a constraint, for larger data sets, puts at a disadvantage the use of all the classical linkage criteria but the single linkage one. However, it is known that the single linkage clustering algorithm is very sensitive to outliers, produces highly skewed dendrograms, and therefore usually does not reflect the true underlying data structure - unless the clusters are well-separated. To overcome its limitations, we propose a new hierarchical clustering linkage criterion called Genie. Namely, our algorithm links two clusters in such a way that a chosen economic inequity measure (e.g., the Gini- or Bonferroni-index) of the cluster sizes does not increase drastically above a given threshold. The presented benchmarks indicate a high practical usefulness of the introduced method: it most often outperforms the Ward or average linkage in terms of the clustering quality while retaining the single linkage speed. The Genie algorithm is easily parallelizable and thus may be run on multiple threads to speed up its execution further on. Its memory overhead is small: there is no need to precompute the complete distance matrix to perform the computations in order to obtain a desired clustering. It can be applied on arbitrary spaces equipped with a dissimilarity measure, e.g., on real vectors, DNA or protein sequences, images, rankings, informetric data, etc. A reference implementation of the algorithm has been included in the open source genie package for R. [See https://genieclust. gagolewski. com for a new implementation - available for both R and Python.]. © 2022, CC BY.

关键词： Clustering algorithms

Mutually beneficial confluence of structure-based modeling of protein dynamics and machine learning methods

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Current Opinion in Structural Biology 2023年 78卷 102517页

作者： Banerjee, Anupam Saha, Satyaki Tvedt, Nathan C. Yang, Lee-Wei Bahar, Ivet Computational and Systems Biology University of Pittsburgh School of Medicine Pittsburgh 15261 PA United States Computational and Applied Mathematics and Statistics The College of William and Mary Williamsburg 23185 VA United States Institute of Bioinformatics and Structural Biology and PhD Program in Biomedical Artificial Intelligence National Tsing Hua University Hsinchu 300044 Taiwan Physics Division National Center for Theoretical Sciences Taipei 106319 Taiwan

Proteins sample an ensemble of conformers under physiological conditions, having access to a spectrum of modes of motions, also called intrinsic dynamics. These motions ensure the adaptation to various interactions in the cell, and largely assist in, if not determine, viable mechanisms of biological function. In recent years, machine learning frameworks have proven uniquely useful in structural biology, and recent studies further provide evidence to the utility and/or necessity of considering intrinsic dynamics for increasing their predictive ability. Efficient quantification of dynamics-based attributes by recently developed physics-based theories and models such as elastic network models provides a unique opportunity to generate data on dynamics for training ML models towards inferring mechanisms of protein function, assessing pathogenicity, or estimating binding affinities. © 2022 The Authors

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Modifying BiVO4 as a photocatalyst for water oxidation using constant-duration alkaline-etched post treatments

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New Journal of Chemistry 2023年第2期48卷 569-577页

作者： Hsu, Chuan-Chih Chuang, Kai-Jie Huang, Hsiao-Wen Pan, Bo-Jin Chen, Hung-Ming Husain, Sadang Yougbaré, Sibidou Hsiao, Yu-Cheng Wu, Yung-Fu Lin, Lu-Yin Division of Cardiovascular Surgery Department of Surgery School of Medicine College of Medicine Taipei Medical University Taiwan Division of Cardiovascular Surgery Department of Surgery Taipei Medical University Hospital Taiwan Department of Chemical Engineering and Biotechnology National Taipei University of Technology Taipei Taiwan Department of Chemical Engineering Ming Chi University of Technology New Taipei City24301 Taiwan Gingen Technology Co. Ltd. Rm. 7 10F. No. 189 Sec. 2 Keelung Rd. Xinyi Dist. Taipei11054 Taiwan Department of Physics Faculty of Mathematics and Natural Science Lambung Mangkurat University Banjarmasin70124 Indonesia /Nanoro Ouagadougou03 Burkina Faso International PhD Program in Biomedical Engineering College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Stanford Byers Center for Biodesign Stanford University CA94305-5428 United States Graduate Institute of Biomedical Optomechatronics College of Biomedical Engineering Taipei Medical University Taipei11031 Taiwan Cell Physiology and Molecular Image Research Center Wan Fang Hospital Taipei Medical University Taipei11696 Taiwan

BiVO4 with suitable band edges and a small band gap is considered an efficient photocatalyst for the oxygen evolution reaction (OER), but short charge-transfer lengths limit its photocatalytic ability. Increasing active sites can essentially enhance oxidation reactions and photocatalytic ability. The alkaline etching technique can refine the surface properties of BiVO4 by introducing oxygen vacancies and possibly establishing a heterojunction, but suitable alkaline etching methods are rarely discussed. In this study, three alkaline etching methods, including hydrothermal, soaking, and electrodeposition processes, are first applied for a constant duration to tailor the surface properties of BiVO4 as a photocatalyst for the OER. Alkaline-etched BiVO4 prepared using hydrothermal and soaking processes shows better photocatalytic abilities due to the generation of additional oxygen vacancies, while poor photocatalytic ability is found for that fabricated using electrodeposition due to the formation of less photocatalytic VO2. The highest photocurrent density of 2.38 mA cm−2 is obtained at 1.23 V versus a reversible hydrogen electrode in an electrolyte without a hole scavenger for the BiVO4 etched in the hydrothermal process, while the untreated BiVO4 presents a photocurrent density of 0.58 mA cm−2. A photocurrent retention of 92.3% is achieved after 5000 seconds of continuous illumination. The study supplies blueprints for establishing effective alkaline etching methods for enhancing the photocatalytic ability of BiVO4, with the exception of time costs. © 2024 The Royal Society of Chemistry.

关键词： Charge transfer