Nonlinear disturbance attenuation control of hydraulic robotics

This paper presents a novel nonlinear disturbance rejection control for hydraulic robots. This method requires two third-order filters as well as inverse dynamics in order to estimate the disturbances. All the parameters for the third-order filters are pre-defined. The proposed method is nonlinear, which does not require the linearization of the rigid body dynamics. The estimated disturbances are used by the nonlinear controller in order to achieve disturbance attenuation. The performance of the proposed approach is compared with existing approaches. Finally, the tracking performance and robustness of the proposed approach is validated extensively on real hardware by performing different tasks under either internal or both internal and external disturbances. The experimental results demonstrate the robustness and superior tracking performance of the proposed approach

Teaching Natural Resource Economics with Digital Learning Objects: Evolution from Chalk to Digital Ink

Over the past 8 years faculty at UT Martin have experimented with various tools to deliver online content to students at a distance. The most common tool used by faculty is the use of a plug-in for PowerPoint that allows voice annotation of slides. These tools are effective at delivering materials that are in a traditional format with the instructor’s recorded voice. However, these types of tools do not allow you to develop dynamic mathematical problem solving examples for students without working out the problems in advance. The natural resource economics course, like most classes is dependent upon the ability to demonstrate mathematical problems and construct meaningful graphs to explain concepts. As a result of this need, faculty used Tablet PC technology along with a screen capture program to develop a pen-based solution for demonstrating math type problems to students. As technology changed and became less expensive new options became available that did not require a Tablet PC and a screen capture technology. Several UTM faculty tested digital pen products to determine the effectiveness for developing math type tutorials that included instructor voice. The latest generation of digital pen technology has been in place for the past 3 years. The important issue related to the use of the digital ink is its effectiveness at conveying information to students in an online learning environment and its acceptance among faculty. To answer these questions a survey of students (n=22) and faculty (n=27) was conducted to determine the effectiveness of the technology. Results of faculty surveys revealed that 84% of respondents indicated that the digital pen saved time when developing online course materials and that it enhanced their ability to convey information. The majority of faculty felt the technology had a minimal learning curve. Student surveys coupled with actual assignment and exam scores revealed that 90% of students who viewed the digital ink learning objects had a positive experience. The final exam scores of students who viewed the digital ink learning objects had a significantly higher final exam score than non-viewers in the same course

Avifauna of Boni-Dodori National Reserves, Lamu and Garissa Counties, Kenya

A comprehensive avian survey was conducted between April 2012 and November 2013 in Boni and Dodori National reserves, the connecting Aweer Community Conservancy corridor, and the adjacent forests. Survey methods were Timed Species Counts (TSCs), mist netting and opportunistic observations. Six different habitat types were identified and sampled: 1) grassland with Hyphaene palms 2) a mosaic of forest groves, grassland and Hyphaene palm savanna 3) dense thickets 4) wetlands 5) forest with dense undergrowth and 6) acacia woodlands. A total of 184 bird species was recorded, including two near threatened bird species (Southern Banded Snake Eagle Circaetus fasciolatus and Fischer’s Turaco Tauraco fischeri), 19 Palaearctic migrants, two Afrotropical migrants and 14 East African coastal biome species. There were eight forest specialist and 29 forest generalist species. We recorded sightings of a form of Red-naped Bushshrike Laniarius ruficeps that is not illustrated in bird guidebooks for Africa, and presumed to be of the subspecies kismayensis. Data from this survey led to the upgrading of the Boni-Dodori area from a potential IBA to full IBA status. Even though these forests have species of conservation importance and sufficient habitats to conserve these species, immediate actions need to be taken to ensure their protection. We recommend comprehensive biodiversity surveys in these forests in order to obtain more scientific information such as population trends to enhance the conservation of these important, but neglected sites

A Review of Eviction Protections in Dallas, Texas

The Institute for Urban Policy Research partnered with the Texas Tenants Union to better understand the impact of eviction remediation programs on the plight of tenants in the City of Dallas. In Dallas, roughly three of every five households rent their home; programs aimed at preventing eviction are pertinent to most of Dallas's population (U. S. Census Bureau, 2020). Financial impacts of the Coronavirus pandemic threatened many households in Dallas and the early days of the pandemic saw multiple policy and procedure interventions, including court closures and the CARES Act. Dallas City Council was among the first localities to act, pass an eviction ordinance to protect renters from losing their homes.In this study, we pursue a mixed-methods approach, embracing both qualitative and quantitative research tools. Working with Dallas County, whose Justice of the Peace courts are the courts of original jurisdictions for evictions in Texas, we secured case filing data for January through June of 2019 and 2020. This data was used to perform a series of regression analyses comparing the volume of evictions in Dallas and surrounding cities. Next, we randomly sampled cases filed in one Dallas County Justice of the Peace court, including portions of Dallas and surrounding communities. We conducted a systematic record review of the entire case file for each of the randomly sampled cases. Finally, we engaged a purposive sample of local government and non-profit leaders, as well as affected tenants, in a focus group setting to understand their experiences with eviction in Dallas.While the quantitative results do suggest some impact of these policy responses, the findings are not encouraging. First, the milieu of policies enacted offered no universal protection to any broad segment of renting households. Second, many of those protected by these policies did not know their status, and efforts to educate them were not universally deployed. Finally, even when protected tenants were aware of their protection, their attempts to assert their rights were met by a system often confused on how to respect them

Protocol for single-cell isolation and genome amplification of environmental microbial eukaryotes for genomic analysis

We describe environmental microbial eukaryotes (EMEs) sample collection, single-cell isolation, lysis, and genome amplification, followed by the rDNA amplification and OTU screening for recovery of high-quality species-specific genomes for de novo assembly. These protocols are part of our pipeline that also includes bioinformatic methods. The pipeline and its application on a wide range of phyla of different sample complexity are described in our complementary paper. In addition, this protocol describes optimized lysis, genome amplification, and OTU screening steps of the pipeline. For complete details on the use and execution of this protocol, please refer to Ciobanu et al. (2021)