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Sample records for lynn dahm slide

  1. Wolbachia in two populations of Melittobia digitata Dahms (Hymenoptera: Eulophidae)

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Claudia S.; Sivinski, John [United States Dept. of Agriculture, Gainesville, FL (United States). Center for Medical, Agriculture and Veterinary Entomology]. E-mails: cclaudia@bioinf.uni-leipzig.de; john.sivinski@ars.usda.gov; Matthews, Robert W. [University of Georgia, Athens, GA (United States). Dept. of Entomology]. E-mail: rmatthew@uga.edu; Gonzalez, Jorge M. [Texas A and M Univ., College Station, TX (United States). Dept. of Entomology]. E-mail: jmgonzalez@neo.tamu.edu; Aluja, Martin [Instituto de Ecologia A.C., Veracruz (Mexico)]. E-mail: martin.aluja@inecol.edu.mx

    2008-11-15

    We investigated two populations of Melittobia digitata Dahms, a gregarious parasitoid (primarily upon a wide range of solitary bees, wasps, and flies), in search of Wolbachia infection. The first population, from Xalapa, Mexico, was originally collected from and reared on Mexican fruit fly pupae, Anastrepha ludens Loew (Diptera: Tephritidae); the other, from Athens, Georgia, was collected from and reared on prepupae of mud dauber wasps, Trypoxylon politum Say (Hymenoptera: Crabronidae). PCR studies of the ITS2 region corroborated that both parasitoid populations were the same species; this potentially provides a useful molecular taxonomic profile since females of Melittobia species are superficially similar. Amplification of the Wolbachia surface protein gene (wsp) confirmed the presence of this endosymbiont in both populations. Sequencing revealed that the Wolbachia harbored in both populations exhibited a wsp belonging to a unique subgroup (denoted here as Dig) within the B-supergroup of known wsp genes. This new subgroup of wsp may either belong to a different strain of Wolbachia from those previously found to infect Melittobia or may be the result of a recombination event. In either case, known hosts of Wolbachia with a wsp of this subgroup are only distantly related taxonomically. Reasons are advanced as to why Melittobia - an easily reared and managed parasitoid - holds promise as an instructive model organism of Wolbachia infection amenable to the investigation of Wolbachia strains among its diverse hosts. (author)

  2. Zona Lynn Unveiled in CBD

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On September 29,many fashion industry elites gathered at the Beijing Fortune Plaza at the heart of the Beijing Central Business District(CBD) for a press conference on Zona Lynn,a high-end tailor-made clothing brand.Amid beautiful flowers and applauses,

  3. Lynne Cherry's World: A Celebration of Nature.

    Science.gov (United States)

    Winarski, Diana L.

    1995-01-01

    Profiles Lynne Cherry, author-illustrator whose books convey her interest in environmentalism and preserving natural resources. Describes her career, process of illustrating several recent books, and founding of the Center for Children's Environmental Literature in 1992. (TM)

  4. Reducing slide sheet injury.

    Science.gov (United States)

    Varcin-Coad, Lynn

    2008-12-01

    Slide sheets are often stated to be the cause of hand and forearm injuries. While there are many other possible reasons injuries to nursing staff, carer and client occur, the most important linking factors relating to musculoskeletal disorders and manual handling of people is the ongoing inappropriateness or lack of suitably designed and equipped work areas. As physiotherapist Lynn Varcin-Coad writes, staff are bearing the brunt of inefficiencies of design and lack of high order risk control.

  5. 76 FR 58105 - Regulated Navigation Area; Saugus River, Lynn, MA

    Science.gov (United States)

    2011-09-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Saugus River, Lynn, MA AGENCY... River in Lynn, MA. Establishing this temporary rule will allow the necessary stabilization work to be... on the Energy Systems Pipeline Bridge on the Saugus River in Lynn, MA. The regulated area...

  6. Obituary: Lynne Karen Deutsch, 1954-2004

    Science.gov (United States)

    Sprague, Ann L.

    2004-12-01

    It is with deep sadness and regret that we note the passing of our dear friend and colleague Prof. Lynne K. Deutsch. Lynne died on 2 April 2004 after a protracted illness and lengthy battle with complications caused by the blood disease Polycythaemia Vera. Lynne was born in Chicago on 26 November 1956 to Victor and Ailsa Deutsch. She lived with her family in the town of Morton Grove, IL until she was 8 years old, when they moved to Beverly Hills, CA. She was an outgoing child who played basketball and excelled in her studies. She graduated from Beverly Hills High School at the age of 16 after completing all high school requirements in only three years. Lynne had a beautiful singing voice, and was in the chorus in high school and college. Lynne earned her first bachelor's degree in philosophy from the University of California at Berkeley in 1977. She then returned to Berkeley and received a second bachelor's degree, this time in physics, in 1981. She was a graduate student and teaching assistant at MIT and earned an MS in physics from MIT in 1983. Lynne then attended the astronomy graduate program at Harvard University, where she earned her MA in 1985 and PhD in 1990. During her degree studies she began crafting mid-infrared instrumentation. These instruments were destined to be used by a host of eager observers to discover, identify, and study many emissions from the Solar System, and galactic and extragalactic sources. Lynne was a National Research Council Post-doctoral Fellow at NASA Ames Research Center from 1990 - 1992, where she played an important role in the development of the Smithsonian Astrophysical Observatory/University of Arizona Mid-Infrared Array Camera (MIRAC), a well-known and much sought after instrument frequently used in studies of Mercury, Jupiter, the Moon, planetary nebulae, star formation regions, galactic center, young stellar objects, and extragalactic objects. After leaving NASA Ames Research Center, Lynne taught for several years (1993

  7. AFSC/ABL: Lynn Canal Echo-Integrated Trawl Surveys, 2001-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

  8. AFSC/ABL: Lynn Canal Overwinter Acoustic Survey, 2004-2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

  9. Repair of acute Achilles tendon ruptures using Lynn method

    Directory of Open Access Journals (Sweden)

    Tolga Tolunay

    2013-09-01

    Full Text Available Objectives: Efficiency assessment of Lynn method onopen primary repair of acute Achilles tendon ruptures.Methods: Data were evaluated from 19 patients whotreated with the Lynne method due to acute Achilles tendonrupture. Average follow-up length was 12.3 months(range 8-15 months. Dominant side was the right sideby all patients and all patients were males. Plantaris tendonaugmentation was applied after end-to-end repair bymodified Kessler suture technique.Results: The mean postoperative AOFAS score (TheAmerican Orthopaedic Foot and Ankle Society hindfootclinical outcome scores was 93.5 (range 82-100. Theaverage of Achilles tendon postoperative assessmentscore, as developed by Thermann and colleagues, was93.3. Both assessment scores were between 90-100 andwere evaluated as very good. None of the patients developedpost-operative wound infection. The Thompson testwas negative on all patients and bilateral motor strengthwas 5/5.Conclusion: Lynn method, especially in young and activepatients with acute Achilles tendon rupture is a methodthat should be considered in treatment protocols.Key words: Achilles tendon, Lynn method, AOFAS score

  10. Reality versus fantasy: reply to Lynn et al. (2014).

    Science.gov (United States)

    Dalenberg, Constance J; Brand, Bethany L; Loewenstein, Richard J; Gleaves, David H; Dorahy, Martin J; Cardeña, Etzel; Frewen, Paul A; Carlson, Eve B; Spiegel, David

    2014-05-01

    We respond to Lynn et al.'s (2014) comments on our review (Dalenberg et al., 2012) demonstrating the superiority of the trauma model (TM) over the fantasy model (FM) in explaining the trauma-dissociation relationship. Lynn et al. conceded that our meta-analytic results support the TM hypothesis that trauma exposure is a causal risk factor for the development of dissociation. Although Lynn et al. suggested that our meta-analyses were selective, we respond that each omitted study failed to meet inclusion criteria; our meta-analyses thus reflect a balanced view of the predominant trauma-dissociation findings. In contrast, Lynn et al. were hypercritical of studies that supported the TM while ignoring methodological problems in studies presented as supportive of the FM. We clarify Lynn et al.'s misunderstandings of the TM and demonstrate consistent superiority in prediction of time course of dissociative symptoms, response to psychotherapy of dissociative patients, and pattern of relationships of trauma to dissociation. We defend our decision not to include studies using the Dissociative Experiences Scale-Comparison, a rarely used revision of the Dissociative Experiences Scale that shares less than 10% of the variance with the original scale. We highlight several areas of agreement: (a) Trauma plays a complex role in dissociation, involving indirect and direct paths; (b) dissociation-suggestibility relationships are small; and (c) controls and measurement issues should be addressed in future suggestibility and dissociation research. Considering the lack of evidence that dissociative individuals simply fantasize trauma, future researchers should examine more complex models of trauma and valid measures of dissociation.

  11. Mentor-Mentee Relationship in an Educational Leadership Doctoral Program at Lynn University

    Science.gov (United States)

    Reedy, Katherine; Taylor-Dunlop, Korynne

    2015-01-01

    Lynn University embraces the Carnegie Project on the Education Doctorate (CPED) initiative, signature pedagogies and the development of scholarly practitioners. In response to the evolution of educational leadership, Lynn University values the need for doctoral candidates to understand the group process and to be able to work within a diverse…

  12. Another Failure to Replicate Lynn's Estimate of the Average IQ of Sub-Saharan Africans

    Science.gov (United States)

    Wicherts, Jelte M.; Dolan, Conor V.; Carlson, Jerry S.; van der Maas, Han L. J.

    2010-01-01

    In his comment on our literature review of data on the performance of sub-Saharan Africans on Raven's Progressive Matrices, Lynn (this issue) criticized our selection of samples of primary and secondary school students. On the basis of the samples he deemed representative, Lynn concluded that the average IQ of sub-Saharan Africans stands at 67…

  13. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North...

  14. Saugus River and Tributaries Flood Damage Reduction Study: Lynn, Malden, Revere and Saugus, Massachusetts. Section 1. Feasibility Report.

    Science.gov (United States)

    1989-12-01

    Flood Damage Reduction Study: Lynn, Malden, Revere, and Saugus, MassachusetLs: Section I Feasibility Report 12. PERSONAL AUTHOR(S) Robert Hunt - Project...employ- Problem Identification 20 ment in the communities is characterized by personal services, rather than higher paying professional services. Many...Formulation 50 LYNN BEACH LYNN DIKES AND gLYNN HARBOR -GE FL~TIA 1w IVER FODAE U -~z~POINT OF EAST SAUGUSWALREEMN PROTECT STORAGE PONDING AREA SAUGUS91

  15. 76 FR 60489 - Lynn E. Stevenson; Notice of Termination of License by Implied Surrender and Soliciting Comments...

    Science.gov (United States)

    2011-09-29

    ... Energy Regulatory Commission Lynn E. Stevenson; Notice of Termination of License by Implied Surrender and... No.: 8866-009. c. Date Initiated: September 23, 2011 (notice date). d. Licensee: Lynn E. Stevenson. e... Lynn E. Stevenson.\\1\\ The project has not operated since a downstream landslide in 1993 and has...

  16. Saugus River and Tributaries, Lynn Malden, Revere and Saugus, Massachusetts. Flood Damage Reduction. Volume 6. Appendix I. Planning Correspondence: Lynn, Malden, Revere, Saugus, Interest Groups, and News Articles

    Science.gov (United States)

    1989-06-01

    TUMORS . LOBSTER HAD HIGH LEVELS OF CANCER CAUSING PCB"S AND CLAMS SHOWED HIGH LEVELS OF VIRUSES AND DISEASES. THIS IS FACT IN BOSTON HARBOR AND QUINCY BAY...te corp IsI ’paring plans far I. An Is million Roughans Peb VIATTL. - Par I 1-9 DAILY EVENING ITEM. Lynn, Mama .. Friday, May 16, 1986 Flood control

  17. Lynn White Jr. and the greening-of-religion hypothesis.

    Science.gov (United States)

    Taylor, Bron; Van Wieren, Gretel; Zaleha, Bernard Daley

    2016-10-01

    Lynn White Jr.'s "The Historical Roots of Our Ecologic Crisis," which was published in Science in 1967, has played a critical role in precipitating interdisciplinary environmental studies. Although White advances a multifaceted argument, most respondents focus on his claim that the Judeo-Christian tradition, especially Christianity, has promoted anthropocentric attitudes and environmentally destructive behaviors. Decades later, some scholars argue contrarily that Christianity in particular and the world's predominant religions in general are becoming more environmentally friendly, known as the greening-of-religion hypothesis. To test these claims, we conducted a comprehensive review of over 700 articles-historical, qualitative, and quantitative-that are pertinent to them. Although definitive conclusions are difficult, we identified many themes and dynamics that hinder environmental understanding and mobilization, including conservative theological orientations and beliefs about the role of divine agency in preventing or promoting natural events, whether the religion is an Abrahamic tradition or originated in Asia. On balance, we found the thrust of White's thesis is supported, whereas the greening-of-religion hypothesis is not. We also found that indigenous traditions often foster proenvironmental perceptions. This finding suggests that indigenous traditions may be more likely to be proenvironmental than other religious systems and that some nature-based cosmologies and value systems function similarly. Although we conclude White's thesis and subsequent claims are largely born out, additional research is needed to better understand under what circumstances and communication strategies religious or other individuals and groups may be more effectively mobilized to respond to contemporary environmental challenges. © 2016 Society for Conservation Biology.

  18. 77 FR 32625 - William J. Stevenson, Estate of Lynn E. Stevenson, Black Canyon Bliss, LLC; Notice of Application...

    Science.gov (United States)

    2012-06-01

    ... Energy Regulatory Commission William J. Stevenson, Estate of Lynn E. Stevenson, Black Canyon Bliss, LLC... 23, 2012, William J. Stevenson, Estate of Lynn E. Stevenson (transferor) and Black Canyon Bliss, LLC (transferee) filed an application for the transfer of license for the Stevenson No. 2 Project (FERC No....

  19. 76 FR 43997 - N. Stanley Standal and Loretta M. Standal; Lynn E. Stevenson; Notice of Change in Docket Numbers

    Science.gov (United States)

    2011-07-22

    .... Stanley Standal and Loretta M. Standal; Lynn E. Stevenson; Notice of Change in Docket Numbers 1. On March 18, 1986, the Commission issued two licenses to the Lynn E. Stevenson, one for Project No. 1, FERC... (1986). \\2\\ 34 FERC ] 62,530 (1986). 2. Several years later, Mr. Stevenson died and, on March 18,...

  20. 76 FR 21330 - Lynn Canal/Icy Straits Resource Advisory Committee

    Science.gov (United States)

    2011-04-15

    ...The Lynn Canal/Icy Straits Resource Advisory Committee will meet in Juneau, Alaska, April 25, 2011. The purpose of this meeting is to orient the new appointees as to the Secure Rural Schools and Community Self-Determination Act of 2008, provide operational guidelines, discuss and adopt specific bylaws for the RAC, and elect a RAC...

  1. 78 FR 18849 - Drawbridge Operation Regulations; Saugus River, Saugus and Lynn, MA

    Science.gov (United States)

    2013-03-28

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Saugus and Lynn, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  2. 77 FR 42433 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2012-07-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  3. 76 FR 73510 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2011-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  4. 78 FR 9588 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2013-02-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulation. SUMMARY: The U.S....

  5. An Adolescent's Best Friend: The Roles of Animals in Lynn Hall's Fiction.

    Science.gov (United States)

    Brown, Joanne

    1994-01-01

    Discusses the way Lynn Hall uses animals in her novels. Shows how her use of animals varies from background to the focus of the story, often as central object of the heroine's affection. Analyzes Hall's animal novels as archetypically romantic in pattern. (HB)

  6. An Interview Forum on Interlibrary Loan/Document Delivery with Lynn Wiley and Tom Delaney

    Science.gov (United States)

    Hasty, Douglas F.

    2003-01-01

    The Virginia Boucher-OCLC Distinguished ILL Librarian Award is the most prestigious commendation given to practitioners in the field. The following questions about ILL were posed to the two most recent recipients of the Boucher Award: Tom Delaney (2002), Coordinator of Interlibrary Loan Services at Colorado State University and Lynn Wiley (2001),…

  7. 3-AMINOPROPYLTRIETHOXYSILANE TREATED SLIDES

    OpenAIRE

    2014-01-01

    Author: University of Nottingham Medical School Division of Histopathy ### METHOD: 1. Wash glass slides in detergent for 30 minutes. - Wash glass slides in running tap water for 30 minutes. - Wash glass slides in distilled water 2x5 minutes. - Wash glass slides in 95% alcohol 2x5 minutes. - Air dry for 10 minutes. - Immerse slides in a freshly prepared 2% solution for 3-aminopropyltriethoxysilane in dry acetone for 5 seconds. - Wash briefly in distilled water twi...

  8. 77 FR 55452 - Lynn Canal-Icy Strait Resource Advisory Committee

    Science.gov (United States)

    2012-09-10

    ...The Lynn Canal-Icy Strait Resource Advisory Committee (LC-IS RAC) will meet in Juneau, AK. The committee is authorized under the Secure Rural Schools and Community Self-Determination Act (Pub. L. 112- 141) (the Act) and operates in compliance with the Federal Advisory Committee Act. The purpose of the committee is to improve collaborative relationships and to provide advice and recommendations......

  9. Sliding vane geometry turbines

    Science.gov (United States)

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  10. Common Sense, Ontology and Time: A Critique of Lynne Rudder Baker's View of Temporal Reality

    Directory of Open Access Journals (Sweden)

    L. Nathan Oaklander

    Full Text Available ABSTRACT The aim of this paper is twofold: First, to critically discuss Lynne Rudder's Baker BA-theory of time, and second to contrast it with the R-theory (after Russell. In the course of my discussion I will contrast three different methodological approaches regarding the relation between common sense and ontology; clarify Russell's authentic view in contrast to the B-theory which is McTaggart's misrepresentation of Russell, and consider how the R-theory can respond to objections Baker makes to eternalism (as she understands it.

  11. Designing Good Slides. Revised.

    Science.gov (United States)

    Center for Disease Control (DHEW/PHS), Atlanta, GA.

    This guide is designed to help those who want to illustrate material in a formal presentation using 35mm double-frame slides, and it is also useful as a guide for teaching students how to work with slides. The guide provides a step-by-step procedure for each format. For instance, those who want to design a slide with copy only would go through a…

  12. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  13. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  14. Slide Gate Bricks

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Peng Xigao

    2010-01-01

    @@ 1 Scope This standard specifies the classification,shape,dimension,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of slide gate bricks.

  15. Ornamental Landscape Grasses. Slide Script.

    Science.gov (United States)

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  16. Identification and Mapping of Soils, Vegetation, and Water Resources of Lynn County, Texas, by Computer Analysis of ERTS MSS Data

    Science.gov (United States)

    Baumgardner, M. F.; Kristof, S. J.; Henderson, J. A., Jr.

    1973-01-01

    Results of the analysis and interpretation of ERTS multispectral data obtained over Lynn County, Texas, are presented. The test site was chosen because it embodies a variety of problems associated with the development and management of agricultural resources in the Southern Great Plains. Lynn County is one of ten counties in a larger test site centering around Lubbock, Texas. The purpose of this study is to examine the utility of ERTS data in identifying, characterizing, and mapping soils, vegetation, and water resources in this semiarid region. Successful application of multispectral remote sensing and machine-processing techniques to arid and seminarid land-management problems will provide valuable new tools for the more than one-third of the world's lands lying in arid-semiarid regions.

  17. North American Regional Security: A Trilateral Framework. By Richard J. Kilroy, Jr., Abelardo Rodriquez Sumano, and Todd S. Hataley, Boulder, CO: Lynne Rienner Press, 2013.

    Directory of Open Access Journals (Sweden)

    Robert Stewart-Ingersoll

    2014-04-01

    Full Text Available North American Regional Security: A Trilateral Framework. By Richard J. Kilroy, Jr., Abelardo Rodriquez Sumano, and Todd S. Hataley, Boulder, CO: Lynne Rienner Press, 2013. ISBN 978-1-58826-854-9.

  18. Sliding Downhill Horizontally

    Science.gov (United States)

    Zurcher, Ulrich

    2005-04-01

    We study the motion of object sliding on a rough incline plane. The coefficient of kinetic friction between the surface and the object is such that the magnitude of the gravitational force along the incline F is equal to the magnitude of the kinetic friction S. If the initial velocity of the object is along the incline, the object slides down the incline with constant velocity. We study the case when the object in launched in horizontal direction. We derive exact expressions for the terminal speed of the object and the maximum horizontal displacement of the object.

  19. Reversing the Slide

    Science.gov (United States)

    Gallagher, Michael

    2005-01-01

    The Government is embarking on a grand market-based vision for the sector just at the moment when university enrolments will begin a long and perhaps inexorable slide. And according to Michael Gallagher, higher education is becoming a less attractive investment for the private sector even as the Government is pushing the sector towards ever higher…

  20. Preparing Slide Presentations on Computers.

    Science.gov (United States)

    Elberfeld, John K.

    1982-01-01

    Suggest use of well-organized slide presentation as effective way to introduce computers to large audiences and discusses how to get started--state objective, analyze audience, outline presentation, prepare slides--and equipment needed to obtain slides from television screens, miniature components, and book illustrations. References and sources…

  1. Wartime Women Rape: A Means of Moral Attack and Emasculation in Lynn Nottage’s Ruined

    Directory of Open Access Journals (Sweden)

    Elaff Ganim Salih

    2016-05-01

    Full Text Available Women rape at warfare was considered a consequence of war in the social, literary and political world for a long period of time. Some criminals of rape escaped justice and others were persecuted on the basis that they were involved in mass rape because it was a natural consequence of war. But, women are targeted with rape in time of war because they are the symbolic representation of a culture, ethnicity, and the unifying fabric of their people and nation. The objective of this paper is to show that war rape is not a result of war; instead it is a means of human destruction through moral attack and emasculation. It aims to show that women rape in warfare is neither a misogynist act nor a sexual violence but it is a pre-planned weapon used strategically and systematically to fulfill certain political and military agenda. The study focuses on the sexual abuse of women in the Democratic Republic of Congo in time of war in Lynn Nottage’s Pulitzer Prize play, Ruined (2007. The study applies Jonathan Gottschall’s Strategic Rape theory, which highlights war rape as a pre-planned military strategy. The enemy emasculates men and attacks them morally by raping their women. Consequently, men’s failure to protect their women causes them to give up resistance, leave their lands and families because of shame and humiliation. The study concludes that women rape in time of war is a tactic followed by conquerors intentionally to facilitate and guarantee the achievement of certain pre-planned goals as was the case of mass rape in the DRC. Keywords: women rape, strategy, emasculation, moral attack, strategic rape theory

  2. Sliding flap tracheoplasty.

    Science.gov (United States)

    Gates, G A; Tucker, J A

    1989-12-01

    The optimal method for surgical management of subglottic stenosis is based upon careful assessment of the location, caliber, length, and maturity of the stenotic segment, as well as associated conditions. For patients with a mature stenosis of short length, excision of the anterior arch of the cricoid and first ring and immediate reconstruction by means of a sliding flap of the next two to three rings of trachea offer a one-stage definitive treatment without the need for grafting. We report four cases of subglottic stenosis and one case of cricoid chondroblastoma in which reconstruction of the airway was successful and prompt. For carefully selected cases, sliding flap tracheoplasty may be a useful alternative to procedures in which the airway is expanded by means of grafting.

  3. Presentation = Speech + Slides

    Directory of Open Access Journals (Sweden)

    Derik Badman

    2008-12-01

    Full Text Available Back in October, Aaron Schmidt posted “HOWTO give a good presentation” to his blog walking paper. His second bullet point of “thoughts” on good presentations is: Please don’t fill your slides with words. Find some relevant and pretty pictures to support what you’re saying. You can use the pictures to remind yourself what you’re going [...

  4. Rezension zu: Stephanie Lynn Budin: The Myth of Sacred Prostitution in Antiquity. Cambridge u.a.: Cambridge University Press 2008.

    Directory of Open Access Journals (Sweden)

    Julian Herbert Köck

    2010-01-01

    Full Text Available Stephanie Lynn Budin liefert mit vorliegender Studie einen wichtigen Beitrag zur Debatte um die Existenz von Tempelprostitution im Altertum. Systematisch untersucht sie die Quellen zur Tempelprostitution und kann weitgehend überzeugend darlegen, dass die betreffenden Stellen nicht für die Existenz von Tempelprostitution im Altertum sprechen, sondern nur aufgrund von tendenziösen Interpretationen so verstanden wurden. Dabei greift die Studie die Ergebnisse anderer Wissenschaftler/-innen auf, bietet aber – besonders zu Herodot und Strabon – auch neue Erkenntnisse.

  5. Stephanie Lynn Budin: The Myth of Sacred Prostitution in Antiquity. Cambridge u.a.: Cambridge University Press 2008. Stephanie Lynn Budin: The Myth of Sacred Prostitution in Antiquity. Cambridge u.a.: Cambridge University Press 2008.

    Directory of Open Access Journals (Sweden)

    Julian Herbert Köck

    2010-03-01

    Full Text Available Stephanie Lynn Budin liefert mit vorliegender Studie einen wichtigen Beitrag zur Debatte um die Existenz von Tempelprostitution im Altertum. Systematisch untersucht sie die Quellen zur Tempelprostitution und kann weitgehend überzeugend darlegen, dass die betreffenden Stellen nicht für die Existenz von Tempelprostitution im Altertum sprechen, sondern nur aufgrund von tendenziösen Interpretationen so verstanden wurden. Dabei greift die Studie die Ergebnisse anderer Wissenschaftler/-innen auf, bietet aber – besonders zu Herodot und Strabon – auch neue Erkenntnisse.Stephanie Lynn Budin’s study offers up an important contribution to the debate on the existence of temple prostitution during antiquity. She systematically examines the sources on temple prostitution and can demonstrate, fairly convincingly, that the passages in question do not prove the existence of temple prostitution during antiquity, but instead have been merely understood to do so based on tendentious interpretations. In so doing, the study takes up conclusions offered by other scholars, but it also provides – especially when it comes to Herodotus and Strabo – new insights.

  6. SLIDES: a program to draw slides and posters

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, R.; Schofield, J.

    1977-04-01

    SLIDES is a program which takes text and commands as input and prepares lettered slides and posters. When run on the time-sharing computer, the program can display its output on an interactive graphics terminal; in batch, it can direct its graphical output to a variety of plotters. The program uses DISSPLA graphical subroutines and standard ANL plotter subroutines. This report contains material written for the beginning user, who should be able to produce useful slides or posters by following the examples. This report also serves as a complete reference for the SLIDES program. 4 figures.

  7. Holographic sliding stripes

    Science.gov (United States)

    Jokela, Niko; Järvinen, Matti; Lippert, Matthew

    2017-04-01

    Holographic models provide unique laboratories to investigate nonlinear physics of transport in inhomogeneous systems. We provide a detailed account of both dc and ac conductivities in a defect conformal field theory with spontaneous stripe order. The spatial symmetry is broken at large chemical potential, and the resulting ground state is a combination of a spin and charge density wave. An infinitesimal applied electric field across the stripes will cause the stripes to slide over the underlying density of smeared impurities, a phenomenon which can be associated with the Goldstone mode for the spontaneously broken translation symmetry. We show that the presence of a spatially modulated background magnetization current thwarts the expression of some dc conductivities in terms of horizon data.

  8. Using Scrap Slides for Art.

    Science.gov (United States)

    Hanlon, Heather

    1979-01-01

    Using scrap slides for an art lesson can be an exciting, creative experience for people of all ages, and many techniques are applicable in both primary and secondary grades. Scrap slides are an inexpensive means to unique, original, and stimulating discoveries about film as an art form. (Author)

  9. Appearance normalization of histology slides.

    Science.gov (United States)

    Vicory, Jared; Couture, Heather D; Thomas, Nancy E; Borland, David; Marron, J S; Woosley, John; Niethammer, Marc

    2015-07-01

    This paper presents a method for automatic color and intensity normalization of digitized histology slides stained with two different agents. In comparison to previous approaches, prior information on the stain vectors is used in the plane estimation process, resulting in improved stability of the estimates. Due to the prevalence of hematoxylin and eosin staining for histology slides, the proposed method has significant practical utility. In particular, it can be used as a first step to standardize appearance across slides and is effective at countering effects due to differing stain amounts and protocols and counteracting slide fading. The approach is validated against non-prior plane-fitting using synthetic experiments and 13 real datasets. Results of application of the method to adjustment of faded slides are given, and the effectiveness of the method in aiding statistical classification is shown.

  10. Digital slide reproduction using densitometry

    Science.gov (United States)

    Fornaro, Peter R.; Gschwind, Rudolf; Rosenthaler, Lukas; Laurenson, Pip

    2002-06-01

    Many contemporary art collections contain important art installations where artists have used 35 mm slides as the primary medium. The number of ours these works are on show makes it necessary to regularly change the slides due to light fading. With funding from the Henry Moore Foundation. The conservation department at Tate initiated a project to examine ways in which digital technology could be used to aid the conservation of these works. The aim of the project was to place the original slides in cold storage and explored the possibility of using digital technology to make duplicate sets for display in the gallery. The reproductions needed to be of very high quality both in terms of resolution and color management. This paper discusses the use of densitometry to calibrate both device dependent and device independent systems for digitally reproducing 35 mm slides using a scanner and a film recorder and the effect of metamery when using slide films which employ different dyes.

  11. Private I: The Protagonists in Lynne Rae Perkins' Newbery-Winning Novel Are Shy, Talented, and Extremely Thoughtful--Kind of Like the Author

    Science.gov (United States)

    Barstow, Barb

    2006-01-01

    Lynne Rae Perkins is the author of "Criss Cross," which won the Newbery Medal, the nation's most prestigious prize for children's book. Perkins grew up in Cheswick, PA, near Pittsburgh, majored in printmaking at Penn State, and attended grad school at the University of Wisconsin-Milwaukee. She moved to Leelanau County, MI, in 1987 with her…

  12. Theory Meets Theatre Practice: Making a Difference to Public Health Programmes in Southern Africa. Professor Lynn Dalrymple--South African Scholar, Activist, Educator

    Science.gov (United States)

    Durden, Emma; Tomaselli, Keyan

    2012-01-01

    Lynn Dalrymple is a pioneer in the field of communication about HIV and AIDS in South Africa. Her work has influenced practitioners, researchers and thinkers in South Africa and beyond. This review explores Dalrymple's background as a teacher in the rural areas of Zululand in South Africa, and how she came to apply theatre theory for one of the…

  13. Discrete-time nonlinear sliding mode controller

    African Journals Online (AJOL)

    user

    : Discrete-time delay system, Sliding mode control, nonlinear sliding ... The concept of the sliding mode control in recent years has drawn the ...... His area of interest is dc-dc converters, electrical vehicle and distributed generation application.

  14. Line copy presentation slides with Kodalith.

    Science.gov (United States)

    Kraushar, M F; Bailey, B A

    1978-08-01

    Line copy presentation slides with white letters on a blue background can be produced with a two-step process. The slides are more permanent than diazo slides, and the process is faster and less expensive.

  15. SLIDE INVENTORY IN DUBRACINA RIVER BASIN

    Directory of Open Access Journals (Sweden)

    Aleksandar Toševski

    2013-12-01

    Full Text Available he slide inventory in Dubračina river basin consists of 39 slides. They have been detected by field geomorphological mapping and visual analysis of 1 meter digital elevation model. The slides detected using elevation model are validated by the field checking as well. The outline of all slides is generated using digital elevation model. The total area affected by sliding is 81873 m2 which is 0,44% of researched area. The area, volume, total lenght, width of displaced mass, dip angle of slope on the slide location and dip direction of sliding have been defined for each slide. Slides areas are ranging from 150 to 12956 m2. Minimal total slide lenght from the crown to the tip is 20 m and maximal is 226 m. Angles of slope dip on slide locations are ranging from 10,1° to 28,6° focusing that 76,7% total area affected by sliding has slope dip angle on slide location up to 20°. According to weighting factor calculations lithological unit flysch (E2,3 is marked as the most significant lithological factor of the sliding. All slides are located in the flysch weathering zone where zone crop out. It has been shown that terrain tendency for excessive erosion is very limitative factor in using digital elevation model for the remote slide mapping (the paper is published in Croatian.

  16. Mapping stain distribution in pathology slides using whole slide imaging

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Yeh

    2014-01-01

    Full Text Available Background: Whole slide imaging (WSI offers a novel approach to digitize and review pathology slides, but the voluminous data generated by this technology demand new computational methods for image analysis. Materials and Methods: In this study, we report a method that recognizes stains in WSI data and uses kernel density estimator to calculate the stain density across the digitized pathology slides. The validation study was conducted using a rat model of acute cardiac allograft rejection and another rat model of heart ischemia/reperfusion injury. Immunohistochemistry (IHC was conducted to label ED1 + macrophages in the tissue sections and the stained slides were digitized by a whole slide scanner. The whole slide images were tessellated to enable parallel processing. Pixel-wise stain classification was conducted to classify the IHC stains from those of the background and the density distribution of the identified IHC stains was then calculated by the kernel density estimator. Results: The regression analysis showed a correlation coefficient of 0.8961 between the number of IHC stains counted by our stain recognition algorithm and that by the manual counting, suggesting that our stain recognition algorithm was in good agreement with the manual counting. The density distribution of the IHC stains showed a consistent pattern with those of the cellular magnetic resonance (MR images that detected macrophages labeled by ultrasmall superparamagnetic iron-oxide or micron-sized iron-oxide particles. Conclusions: Our method provides a new imaging modality to facilitate clinical diagnosis. It also provides a way to validate/correlate cellular MRI data used for tracking immune-cell infiltration in cardiac transplant rejection and cardiac ischemic injury.

  17. SlideDog / Siim Sein

    Index Scriptorium Estoniae

    Sein, Siim

    2015-01-01

    SlideDog on multimeediumi esitluse tööriist, mis võimaldab ühendada PowerPointi esitlused, PDF-failid, Prezi esitlused, videoklipid, helifailid, veebilehed ja palju muud üheks sujuvaks esitluskogemuseks konverentsil, seminaril või muul üritusel

  18. Slide-based ergometer rowing

    DEFF Research Database (Denmark)

    Vinther, Anders; Alkjær, T; Kanstrup, I-L

    2012-01-01

    Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along...

  19. Heavy duty complete extension slides

    Science.gov (United States)

    Bueno, José Ignacio; Vázquez, Javier

    2001-09-01

    The selection from available commercial market of a set of slides to be used in an habitable pressurised module in space, to draw a 660 mm box out of a rack, up to a completely extracted position in a safely supported configuration, seems in principle not to be a complicated task. That was the first approach taken in the design process of the telescopic guides of the Crew Work Bench (CWB) included in the Fluid Science Laboratory (FSL), part of "ESA Microgravity Facilities for Columbus" within the Columbus Orbital Facility (COF) of the International Space Station (ISS). Nevertheless, common space compatible requirements such as materials, specific environmental loads, available envelope, total weight, etc., can make the selection of telescopic slides from commercial market unfeasible. A specific development to design space compatible telescopic slides for the CWB was undertaken. A set of heavy duty space compatible telescopic slides were designed, manufactured and tested. They should be operative in both, 1-g environment and in orbit, and additionally should withstand an inadvertent astronaut kick or bump of 556 N in any direction.

  20. SlideDog / Siim Sein

    Index Scriptorium Estoniae

    Sein, Siim

    2015-01-01

    SlideDog on multimeediumi esitluse tööriist, mis võimaldab ühendada PowerPointi esitlused, PDF-failid, Prezi esitlused, videoklipid, helifailid, veebilehed ja palju muud üheks sujuvaks esitluskogemuseks konverentsil, seminaril või muul üritusel

  1. Automobile Road Vibration Reproduction using Sliding Modes

    NARCIS (Netherlands)

    Monsees, G.; Scherpen, J.M.A.

    2001-01-01

    Sliding mode controllers have a reputation for their robustness against parameter variations, modeling errors and disturbances. They have been successfully applied in several practical situations which demonstrated the potential of sliding mode control for other control problems. However research ha

  2. Comprehensive Smokefree Indoor Air PDF Slides

    Data.gov (United States)

    U.S. Department of Health & Human Services — Download the comprehensive smokefree indoor air slides. These slides are available in PDF and PowerPoint formats. The PowerPoint version can be found at:...

  3. Fuzzy Sliding Mode Control of Plate Vibrations

    OpenAIRE

    Manu Sharma; Singh, S. P.

    2010-01-01

    In this paper, fuzzy logic is meshed with sliding mode control, in order to control vibrations of a cantilevered plate. Test plate is instrumented with a piezoelectric sensor patch and a piezoelectric actuator patch. Finite element method is used to obtain mathematical model of the test plate. A design approach of a sliding mode controller for linear systems with mismatched time-varying uncertainties is used in this paper. It is found that chattering around the sliding surface in the sliding ...

  4. Diseases of Landscape Ornamentals. Slide Script.

    Science.gov (United States)

    Powell, Charles C.; Sydnor, T. Davis

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with recognizing and controlling diseases found on ornamental landscape plants. Included in the script are narrations for use with a total of 80 slides illustrating various foliar diseases (anthracnose, black spot, hawthorn leaf blight,…

  5. Linear Classification of Dairy Cattle. Slide Script.

    Science.gov (United States)

    Sipiorski, James; Spike, Peter

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with principles of the linear classification of dairy cattle. Included in the guide are narrations for use with 63 slides, which illustrate the following areas that are considered in the linear classification system: stature, strength,…

  6. Approved Practices in Dairy Reproduction. Slide Script.

    Science.gov (United States)

    Roediger, Roger D.; Barr, Harry L.

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with approved practices in dairy reproduction. Included in the guide are narrations for use with 200 slides dealing with the following topics: the importance of good reproduction, the male and female roles in reproduction, selection of…

  7. Study on distribution rule of sliding pushing force and remnant resistant sliding force acting on anti-sliding pile

    Institute of Scientific and Technical Information of China (English)

    Qingyang YU; Lei NIE

    2006-01-01

    Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages. It plays important role in administering landslide. It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock. To determine the sliding force and remnant resistant sliding force, according to need of study, this paper sets up the geological model and mechanics model in term of a typical landslide, and analyzes the effect rule of sliding body distortion, strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model. The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.

  8. Sliding Mode Control Design for a Class of SISO Systems with Uncertain Sliding Surface

    Directory of Open Access Journals (Sweden)

    Guofeng Wang

    2013-01-01

    Full Text Available The problem of designing a sliding mode controller with uncertain sliding surface for a class of uncertain single-input-single-output systems is studied. The design case is handled by using the invariant transformation first in order to separate the sliding mode and the reaching mode of the sliding mode control system. It is shown that the sliding mode design needs not to consider the uncertainties of the sliding surface, which can be handled in the reaching phase design. The results generalize the robust design of the reaching phase such that one specific reaching phase design may agree with several sliding surfaces.

  9. Support for coal slide workings

    Energy Technology Data Exchange (ETDEWEB)

    Alkhimovich, V.P.; Arsenov, N.S.; Boldin, B.M.; Donskov, Yu.I.; Lindenau, N.I.; Zubareva, V.A.

    1980-12-10

    The support for coal slide working includes carrying frames consisting of wooden supports in the form of a cage. In order to increase the durability of the support and prevent piping of the workings it is equipped with slabs with brackets which are mounted between adjacent carrying frames and which feature lugs and wedges for fixing the plates relative to the carrying frames and on the plate asymmetrically relative to its transverse axis.

  10. Applications of sliding mode control

    CERN Document Server

    Ghommam, Jawhar; Zhu, Quanmin

    2017-01-01

    This book presents essential studies and applications in the context of sliding mode control, highlighting the latest findings from interdisciplinary theoretical studies, ranging from computational algorithm development to representative applications. Readers will learn how to easily tailor the techniques to accommodate their ad hoc applications. To make the content as accessible as possible, the book employs a clear route in each paper, moving from background to motivation, to quantitative development (equations), and lastly to case studies/illustrations/tutorials (simulations, experiences, curves, tables, etc.). Though primarily intended for graduate students, professors and researchers from related fields, the book will also benefit engineers and scientists from industry. .

  11. Wolbachia in Two Populations of Melittobia digitata Dahms (Hymenoptera: Eulophidae)

    Science.gov (United States)

    Melittobia sp. (Eulophidae), gregarious parasitoids of various species of bees, wasps, and flies, exhibit among other characteristics highly female-biased sex ratios. Several factors have been proposed that could give rise to these distorted sex ratios, including lethal male combat, inheritance asy...

  12. Review of Calculation vs. Context: Quantitative Literacy and Its Implications for Teacher Education by Bernard L. Madison and Lynn Arthur Steen (Editors

    Directory of Open Access Journals (Sweden)

    Maura B. Mast

    2009-07-01

    Full Text Available Madison, Bernard L. and Steen, Lynn Arthur (Eds.. Calculation vs. Context: Quantitative Literacy and Its Implications for Teacher Education. (Washington, DC: Mathematical Association of America, 2009. 197 pp. Softcover. ISBN 978-0-88385-908-7. Available free on the MAA website at http://www.maa.org/ql/calcvscontext.htmlThe papers in Calculation vs. Context discuss the role of quantitative literacy in the K-12 curriculum and in teacher education. The papers present a varied set of perspectives and address three themes: the changing environment of education in American society; the challenges, and the necessity, of preparing teachers to teach quantitative literacy and of including quantitative literacy in the K-12 education; and cross-disciplinary approaches to quantitative literacy. While the conclusion reached by several of the authors is that the best place to teach quantitative literacy is at the college level, the book offers serious considerations of how quantitative literacy can and should inform the K-12 curriculum. The book also marks a turning point in the quantitative literacy movement as “QL explorers,” as Lynn Steen calls them, move beyond issues of definitions and content to a discussion of how to bring quantitative literacy into a broader setting.

  13. Sliding mode control for mobile welding robot

    Institute of Scientific and Technical Information of China (English)

    Lü Xueqin; Zhang Ke; Wu Yixiong

    2006-01-01

    The sliding mode controller of mobile welding robot is established in this paper through applying the method of variable structure control with sliding mode into the control of the mobile welding robot.The traditional switching function smooth method is improved by combining the smoothed switching function with the time-varying control gain.It is shown that the proposed sliding mode controller is robust to bounded external disturbances.Experimental results demonstrate that sliding mode controller algorithm can be used into seam tracking and the tracking system is stable with bounded uncertain disturbance.In the seam tracking process, the robot moves steadily without any obvious chattering.

  14. eSlide suite: an open source software system for whole slide imaging.

    Science.gov (United States)

    Della Mea, V; Bortolotti, N; Beltrami, C A

    2009-08-01

    This short report briefly describes the principles underlying the telepathology technique known as whole slide imaging, and the design and implementation of a system for acquisition and visualisation of digital slides. The developed system, including an acquisition module and a visualisation module, is available as an open source on the Internet, together with sample acquired slides.

  15. Peeling, sliding, pulling and bending

    Science.gov (United States)

    Lister, John; Peng, Gunnar

    2016-11-01

    The peeling of an elastic sheet away from thin layer of viscous fluid is a simply-stated and generic problem, that involves complex interactions between the flow and elastic deformation on a range of length scales. Consider an analogue of capillary spreading, where a blister of injected viscous fluid spreads due to tension in the overlying elastic sheet. Here the tension is coupled to the deformation of the sheet, and thus varies in time and space. A key question is whether or not viscous shear stresses ahead of the blister are sufficient to prevent the sheet sliding inwards and relieving the tension. Our asymptotic analysis reveals a dichotomy between fast and slow spreading, and between two-dimensional and axisymmetric spreading. In combination with bending stresses and gravity, which may dominate parts of the flow but not others, there is a plethora of dynamical regimes.

  16. Glass slides to DNA microarrays

    Directory of Open Access Journals (Sweden)

    Samuel D Conzone

    2004-03-01

    Full Text Available A tremendous interest in deoxyribonucleic acid (DNA characterization tools was spurred by the mapping and sequencing of the human genome. New tools were needed, beginning in the early 1990s, to cope with the unprecedented amount of genomic information that was being discovered. Such needs led to the development of DNA microarrays; tiny gene-based sensors traditionally prepared on coated glass microscope slides. The following review is intended to provide historical insight into the advent of the DNA microarray, followed by a description of the technology from both the application and fabrication points of view. Finally, the unmet challenges and needs associated with DNA microarrays will be described to define areas of potential future developments for the materials researcher.

  17. Sliding Over a Phase Transition

    Science.gov (United States)

    Tosatti, Erio; Benassi, Andrea; Vanossi, Andrea; Santoro, Giuseppe E.

    2011-03-01

    The frictional response experienced by a stick-slip slider when a phase transition occurs in the underlying solid substrate is a potentially exciting, poorly explored problem. We show, based on 2-dimensional simulations modeling the sliding of a nanotip, that indeed friction may be heavily affected by a continuous structural transition. First, friction turns nonmonotonic as temperature crosses the transition, peaking at the critical temperature Tc where fluctuations are strongest. Second, below Tc friction depends upon order parameter directions, and is much larger for those where the frictional slip can cause a local flip. This may open a route towards control of atomic scale friction by switching the order parameter direction by an external field or strain, with possible application to e.g., displacive ferroelectrics such as BaTi O3 , as well as ferro- and antiferro-distortive materials. Supported by project ESF FANAS/AFRI sponsored by the Italian Research Council (CNR).

  18. Using Sliding Modes in Control Theory

    Directory of Open Access Journals (Sweden)

    Renata Wagnerová

    2008-03-01

    Full Text Available The paper deals with sliding modes control design. The described control algorithms were applied to position control of the levitating systems in magnetic field. The designed control algorithms were verified by using computer simulations. The results achieved confirm suitable technical means and synthesis by using sliding modes for nonlinear control tasks.

  19. [Heritage Education Lesson Plans and Slide Presentations].

    Science.gov (United States)

    Van Buren, Maurie

    Field tested in 27 schools and in grades four through twelve, this teaching unit stresses heritage education through the study of southern U.S. architectural styles for homes from the pioneer log structures to the 1950s ranch home. Each of the four lessons in this unit focuses around a slide presentation of 20 slides designed to fit into one…

  20. The Cancer Digital Slide Archive - TCGA

    Science.gov (United States)

    Dr. David Gutman and Dr. Lee Cooper developed The Cancer Digital Slide Archive (CDSA), a web platform for accessing pathology slide images of TCGA samples. Find out how they did it and how to use the CDSA website in this Case Study.

  1. [Heritage Education Lesson Plans and Slide Presentations].

    Science.gov (United States)

    Van Buren, Maurie

    Field tested in 27 schools and in grades four through twelve, this teaching unit stresses heritage education through the study of southern U.S. architectural styles for homes from the pioneer log structures to the 1950s ranch home. Each of the four lessons in this unit focuses around a slide presentation of 20 slides designed to fit into one…

  2. Study on the Sliding Displacement of a Sliding Structure Subjected to Multi-directional Earthquake Excitation

    Institute of Scientific and Technical Information of China (English)

    Fan Aiwu; Tang Jiaxiang; Li Li; Yang Jun

    2005-01-01

    Transient dynamic analysis is used to study the effect of the bidirectional interaction of friction on the response of sliding displacement of a sliding structure subjected to bidirectional earthquake ground motion. The analysis varies the parameters of amplitude ratio of earthquake excitation, the period of the superstructure, and the coefficient of friction in the sliding support. Numerical results show that the sliding structure is significantly influenced by the interaction of frictional forces. So the sliding displacement may be underestimated and the acceleration of the superstructure may be overrated if the bidirectional interaction of frictional forces is neglected.

  3. Fuzzy Sliding Mode Control of Plate Vibrations

    Directory of Open Access Journals (Sweden)

    Manu Sharma

    2010-01-01

    Full Text Available In this paper, fuzzy logic is meshed with sliding mode control, in order to control vibrations of a cantilevered plate. Test plate is instrumented with a piezoelectric sensor patch and a piezoelectric actuator patch. Finite element method is used to obtain mathematical model of the test plate. A design approach of a sliding mode controller for linear systems with mismatched time-varying uncertainties is used in this paper. It is found that chattering around the sliding surface in the sliding mode control can be checked by the proposed fuzzy sliding mode control approach. With presented fuzzy sliding mode approach the actuator voltage time response has a smooth decay. This is important because an abrupt decay can excite higher modes in the structure. Fuzzy rule base consisting of nine rules, is generated from the sliding mode inequality. Experimental implementation of the control approach verify the theoretical findings. For experimental implementation, size of the problem is reduced using modal truncation technique. Modal displacements as well as velocities of first two modes are observed using real-time kalman observer. Real time implementation of fuzzy logic based control has always been a challenge because a given set of rules has to be executed in every sampling interval. Results in this paper establish feasibility of experimental implementation of presented fuzzy logic based controller for active vibration control.

  4. Whole slide imaging for educational purposes

    Directory of Open Access Journals (Sweden)

    Liron Pantanowitz

    2012-01-01

    Full Text Available Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy. Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI. As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools, training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology, for virtual tracking and tutoring, tele-education (tele-conferencing, e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed.

  5. Whole slide imaging for educational purposes.

    Science.gov (United States)

    Pantanowitz, Liron; Szymas, Janusz; Yagi, Yukako; Wilbur, David

    2012-01-01

    Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy). Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI). As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools), training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology), for virtual tracking and tutoring, tele-education (tele-conferencing), e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed.

  6. Ergometer rowing with and without slides

    DEFF Research Database (Denmark)

    Larsen, Anders Holsgaard; Jensen, K

    2010-01-01

    A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars......-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke...

  7. SLIDING MODE CONTROL FOR ACTIVE AUTOMOBILE SUSPENSIONS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Nonlinear control methods are presented based on theory of sliding mode control (SMC) or variable structure control (VSC) for application to active automobile suspensions. Requirements of reducing manufacturing cost and energy consumption of the active suspension system may be satisfiedby reasonable design of the sliding surface and hydraulic servo system. Emphasis is placed on the study of the discrete sliding mode control method (DSMC) applicable for a new sort of speed on-off solenoid valves of anti-dust capability and low price. Robustness and effectiveness of the feedback linearized controller in typical road conditions are demonstrated by numerical results fora quarter-car suspension model.

  8. Sliding mode control for synchronous electric drives

    CERN Document Server

    Ryvkin, Sergey E

    2011-01-01

    This volume presents the theory of control systems with sliding mode applied to electrical motors and power converters. It demonstrates the methodology of control design and the original algorithms of control and observation. Practically all semiconductor devices are used in power converters, that feed electrical motors, as power switches. A switching mode offers myriad attractive, inherent properties from a control viewpoint, especially a sliding mode. Sliding mode control supplies high dynamics to systems, invariability of systems to changes of their parameters and of exterior loads in combi

  9. Backstepping Sliding Mode Control for Induction Motor

    Directory of Open Access Journals (Sweden)

    Othmane Boughazi

    2014-12-01

    Full Text Available This work treats the modeling and simulation of non-linear system behavior of an induction motor using backstepping sliding mode control. First, the direct field oriented control IM is derived. Then, a sliding for direct field oriented control is proposed to compensate the uncertainties, which occur in the control.Finally, the study of Backstepping sliding controls strategy of the induction motor drive. Our non linear system is simulated in MATLAB SIMULINK environment, the results obtained illustrate the efficiency of the proposed control with no overshoot, and the rising time is improved with good disturbances rejections comparing with the classical control law.

  10. Sliding wear resistance of iron aluminides

    Indian Academy of Sciences (India)

    Garima Sharma; M Sundararaman; N Prabhu; G L Goswami

    2003-04-01

    Room temperature dry sliding wear behaviour of iron aluminides containing 28% aluminium and various amounts of chromium has been investigated using pin on disk wear tester. The aluminides were heat treated to have ordered 3 structure. It was found that wear rate of the aluminides increased with the increase of applied normal load and sliding speed. Wear resistance of the aluminides increased with increase in chromium content. SEM observation of the worn surface showed that the microcutting and microploughing were the dominant sliding wear mechanisms.

  11. The Earth surface slide movement at Soledad

    Science.gov (United States)

    Moreno, A.

    1986-11-01

    The Earth surface slide movement at Soledad is a mountain-slide type of movement. Estimations of the thickness of the layer which is moving range between 10 and 100 m. There is no proof that the movement is water induced, but it could be influenced by the water household. The slope of the slide area is H: D = 1: 2. The height difference in the moving area studied, according to this paper, is 1 km. The actual rate of movement is about 12 cm/yr.

  12. SlideToolkit: an assistive toolset for the histological quantification of whole slide images.

    Directory of Open Access Journals (Sweden)

    Bastiaan G L Nelissen

    Full Text Available The demand for accurate and reproducible phenotyping of a disease trait increases with the rising number of biobanks and genome wide association studies. Detailed analysis of histology is a powerful way of phenotyping human tissues. Nonetheless, purely visual assessment of histological slides is time-consuming and liable to sampling variation and optical illusions and thereby observer variation, and external validation may be cumbersome. Therefore, within our own biobank, computerized quantification of digitized histological slides is often preferred as a more precise and reproducible, and sometimes more sensitive approach. Relatively few free toolkits are, however, available for fully digitized microscopic slides, usually known as whole slides images. In order to comply with this need, we developed the slideToolkit as a fast method to handle large quantities of low contrast whole slides images using advanced cell detecting algorithms. The slideToolkit has been developed for modern personal computers and high-performance clusters (HPCs and is available as an open-source project on github.com. We here illustrate the power of slideToolkit by a repeated measurement of 303 digital slides containing CD3 stained (DAB abdominal aortic aneurysm tissue from a tissue biobank. Our workflow consists of four consecutive steps. In the first step (acquisition, whole slide images are collected and converted to TIFF files. In the second step (preparation, files are organized. The third step (tiles, creates multiple manageable tiles to count. In the fourth step (analysis, tissue is analyzed and results are stored in a data set. Using this method, two consecutive measurements of 303 slides showed an intraclass correlation of 0.99. In conclusion, slideToolkit provides a free, powerful and versatile collection of tools for automated feature analysis of whole slide images to create reproducible and meaningful phenotypic data sets.

  13. An Electric Method for Qualifying Cytogenetic Slides

    Directory of Open Access Journals (Sweden)

    Saeed Khamnei

    2011-01-01

    Full Text Available Cytogenetics is a branch of genetics that involves critical applications in medical decisions. The procedures involved take cells with chromosomes and rupture them on the slide to release their chromosomes in metaphase spreadings. Usually the slide contains few metaphase spreadings and plenty of intact cells, so finding and analyzing metaphase spreadings are difficult. It is for this reason that many investigations search for innovations that optimize chromosome spreading and facilitate cytogenetic studies. To aid rupturing cells in cytogenetic slide preparation, Pulsed Electric Fields (PEFs could be used. PEFs are a kind of electric fields, which affect the cell membrane in a way that can lead to cell lysis. These effects are currently the basis of applications such as nonthermal pasteurization. Therefore, applying PEFs to cell suspension of the cytogenetic experiments would probably lyse all the cells, yielding a clear slide with many metaphase spreadings.

  14. Variations of the Sliding Ladder Problem

    Science.gov (United States)

    Kapranidis, Stelios; Koo, Reginald

    2008-01-01

    This article takes another look at the sliding ladder problem that students meet in the study of related rates in calculus. Physically realistic situations with both constrained and understrained ladders are explored.

  15. Stereoscopic Projection of 35mm Slides.

    Science.gov (United States)

    Carey, Edward F.

    1978-01-01

    Describes ways of projecting stereoscopic images of geologic environments for students with difficulty reasoning in three-dimensions. The photographic procedures needed to produce stereo slides are included. (MA)

  16. FUZZY SLIDING MODE CONTROLLER FOR DOUBLY FED ...

    African Journals Online (AJOL)

    2010-12-31

    Dec 31, 2010 ... motor (DFIM) with a fuzzy sliding mode controller (FSMC). ... becoming a major candidate in high-performance motion control applications, where ..... residual vibrations in high frequencies [17] (chattering phenomenon).

  17. Long-term subglacial sliding patterns based on a sliding law with cavitation

    DEFF Research Database (Denmark)

    Ugelvig, Sofie Vej; Egholm, D.L.

    -water pressures are relatively low, whereas fast sliding spreads to the valley bottoms when melt-water pressure increases. We couple equations for glacial sliding to a model for subglacial bedrock erosion and test the implications of the sliding law for long-term glacial landscape evolution. Schoof, C. The effect...... of cavitation on glacier sliding. Proc. R. Soc. A , 461, 609-627 (2005). Egholm et al. Modeling the flow of glaciers in steep terrains: The integrated second-order shallow ice approximation (iSOSIA). Journal of Geophysical Research, 116, F02012 (2011).......In ice-sheet models and glacial landscape evolution models, subglacial sliding rates are often related to basal shear stress by a power-law. However, the power-law relationship implies that the subglacial bed can provide unlimited levels of basal drag as sliding rates increases, which is recognized...

  18. Adaptive Fuzzy Integral Sliding-Mode Regulator for Induction Motor Using Nonlinear Sliding Surface

    Directory of Open Access Journals (Sweden)

    Yong-Kun Lu

    2015-02-01

    Full Text Available An adaptive fuzzy integral sliding-mode controller using nonlinear sliding surface is designed for the speed regulator of a field-oriented induction motor drive in this paper. Combining the conventional integral sliding surface with fractional-order integral, a nonlinear sliding surface is proposed for the integral sliding-mode speed control, which can overcome the windup problem and the convergence speed problem. An adaptive fuzzy control term is utilized to approximate the uncertainty. The stability of the controller is analyzed by Lyapunov stability theory. The effectiveness of the proposed speed regulator is demonstrated by the simulation results in comparison with the conventional integral sliding-mode controller based on boundary layer.

  19. Sliding mode controller with modified sliding function for DC-DC Buck Converter.

    Science.gov (United States)

    Naik, B B; Mehta, A J

    2017-09-01

    This article presents design of Sliding Mode Controller with proportional integral type sliding function for DC-DC Buck Converter for the controlled power supply. The converter with conventional sliding mode controller results in a steady state error in load voltage. The proposed modified sliding function improves the steady state and dynamic performance of the Convertor and facilitates better choices of controller tuning parameters. The conditions for existence of sliding modes for proposed control scheme are derived. The stability of the closed loop system with proposed sliding mode control is proved and improvement in steady state performance is exemplified. The idea of adaptive tuning for the proposed controller to compensate load variations is outlined. The comparative study of conventional and proposed control strategy is presented. The efficacy of the proposed strategy is endowed by the simulation and experimental results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. A CLINICAL STUDY ON SLIDING INGUINAL HERNIAS

    Directory of Open Access Journals (Sweden)

    Sobha Rani

    2015-09-01

    Full Text Available INTRODUCTION: A sliding hernia is a type of hernia in which posterior wall of the sac is not only formed by the parietal peritoneum, but also by sigmoid colon with its mesentery on its left side; caecum on right side and often with portion of bladder in both sides. During surgery care is taken not t o separate the content from the sac as the posterior wall of the sac is formed by the sliding component itself and attempts to dissect it from wall results in vascular injury to the structure and end in ischemic insult of the sliding component. Thus slidin g hernia is important for the special surgical technique and care during intraoperative period which decreases the morbidity. AIMS AND OBJECTIVE S : To study the incidence of sliding hernia in S.V.R.R.G. General Hospital Tirupati . To know the presentation, o rgan involved in the sliding, post - operative complications in the management of sliding hernias. METHODOLOGY : STUDY DESIGN: Prospective Clinical Study , STUDY AREA: Sri Venka teswara Medical College Tirupat i . SOURCE OF DATA: This study is an observational study in which 600 patients with hernia were studied and 40 patients with sliding component during intra operative period were studied in a period of 12 months. S AMPLE SIZE: 40 patients fulfilling the inclusion criteria . METHOD OF COLLECTION OF DATA: Detai led history taking , Complete clinical examination , Appropriate Investigations Blood & Urine Examination, USG , Surgery is performed & Operative findings were recorded. INCLUSION CRITERIA: Patients more than 13 years, with inguinal hernia giving written inform ed consent. EXCLUSION C RITERIA: Patients less than 13 yrs. Patients with comorbid conditions like heart diseases, liver and renal diseases. SOFTWARE: Statistical software mainly SPSS 11.0 and Systat 8.00 was used for the analysis of the data and Microsoft word and excel have been used to generate graphs tables etc. CONCLUSION: In the observational study done on 40 ca ses of

  1. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

    Ruol, Piero; Martin, Paolo; Andersen, Thomas Lykke;

    2014-01-01

    weight and same geometries are tested under regular and irregular waves. It is found that, under breaking conditions, the expected inaccuracy of the prediction of the force, inherent on the variability of the breaking process, induce unacceptable errors in the prediction of the sliding. This observation...... endorses other previous experimental results. Conversely, when the actual measured input force is used as input, the analytical Shimosako formula fit quite well the experimental sliding distance....

  2. Projector slides - preparation, construction and use.

    Science.gov (United States)

    Galer, I A

    1976-12-01

    Projector slides are used widely as visual aids in lectures and meetings. However, they are often difficult to read and to interpret, and can bring about more confusion than illumination to an audience. A framework is offered for the non-specialist in graphic design, within which the preparation, construction and presentation of projector slides may be placed in a systematic fashion. Summary recommendations are also given.

  3. Chaos control using sliding-mode theory

    Energy Technology Data Exchange (ETDEWEB)

    Nazzal, Jamal M. [Faculty of Engineering, Al-Ahliyya Amman University, Post Code 19328 Amman (Jordan)]. E-mail: jnazzal@ammanu.edu.jo; Natsheh, Ammar N. [Faculty of Engineering, Al-Ahliyya Amman University, Post Code 19328 Amman (Jordan)

    2007-07-15

    Chaos control means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, a nonlinear Sliding-Mode Controller (SMC) is presented. Two nonlinear chaotic systems are chosen to be our case study in this paper, the well known Chua's circuit and Lorenz system. The study shows the effectiveness of the designed nonlinear Sliding-Mode Controller.

  4. Tribology of the lubricant quantized sliding state.

    Science.gov (United States)

    Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

    2009-11-07

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.

  5. Speckle tracking technology for quantifying lung sliding.

    Science.gov (United States)

    Dori, Guy; Jakobson, Daniel J

    2016-06-01

    Ultrasound (US) is gaining recognition as a useful tool for assessing lung physiology and pathology. Yet, currently the skill of performing lung US is taught by experienced operators to novice ones, mainly by recognizing expected patterns. Recognizing the latter may be difficult and subjective. In this hypothesis we propose to apply a well-known and used image processing technology in echocardiography, speckle tracking (ST), to lung sliding - the marker of normal lung function. If implementing ST to lung sliding is technically feasible, several outcomes are expected: (1) Lung sliding will become an objective, operator-independent marker of normal lung function. (2) Subsequently, ST will provide normal values for lung sliding. (3) Lastly, the effects of pulmonary pathologies on lung sliding may be assessed. It is stressed, however, that the preliminary idea suggested here is limited to a single physiological phenomenon (lung sliding). Only when technical feasibility is demonstrated then ST technology may potentially be applied and investigated in other clinical settings of lung diseases. Copyright © 2016. Published by Elsevier Ltd.

  6. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  7. Whole Slide Images for primary diagnostics in pathology

    NARCIS (Netherlands)

    Al-Janabi, S.

    2013-01-01

    Whole slide imaging is the process of digitizing glass slides resulting in the creation of Whole Slide Images (WSI). WSI are usually explored with the aid of an image viewer in a manner that closely simulates examining glass slides with a conventional microscope, permitting the manipulation of an

  8. Creation of a fully digital pathology slide archive by high-volume tissue slide scanning

    NARCIS (Netherlands)

    Huisman, Andre; Looijen, Arnoud; van den Brink, Steven M.; van Diest, Paul J.

    2010-01-01

    Digital slide scanners for scanning glass slides are becoming increasingly popular because current scanners are fast enough and produce good enough images for diagnostic purposes, education, and research. Also, the price for storing vast amounts of data has decreased over the last years, and this tr

  9. Frictional sliding tests on combined coal-rock samples

    Institute of Scientific and Technical Information of China (English)

    Tao Wang; Yaodong Jiang; Shaojian Zhan; Chen Wang

    2014-01-01

    A test system was developed to understand the sliding mechanism of coal-rock structure. The test system was composed by a double-shear testing model and an acousto-optic monitoring system in association with a digital camera and an acoustic emission (AE) instrument. The tests can simulate the movement of activated faults and the sliding in coal-rock structure. In this regard, instable sliding conditions of coal-rock samples, sliding types under different conditions, displacement evolution law, and AE character-istics during sliding process were investigated. Several sliding types were monitored in the tests, including unstable continuous sliding, unstable discontinuous sliding, and stable sliding. The sliding types have close relation with the axial loads and loading rates. Larger axial load and smaller loading rate mean that unstable sliding is less likely to occur. The peak shear stress was positively correlated with the axial load when sliding occurred, whereas the displacement induced by unstable sliding was uncorre-lated with the axial load. A large number of AE events occurred before sliding, and the AE rate decreased after stable sliding. The results show that the tests can well simulate the process of structural instability in a coal bump, and are helpful in the understanding of fault activation and the physical processes during squeezing process of roof and floor.

  10. Terminal sliding mode fuzzy control based on multiple sliding surfaces for nonlinear ship autopilot systems

    Science.gov (United States)

    Yuan, Lei; Wu, Han-Song

    2010-12-01

    A terminal sliding mode fuzzy control based on multiple sliding surfaces was proposed for ship course tracking steering, which takes account of rudder characteristics and parameter uncertainty. In order to solve the problem, the controller was designed by employing the universal approximation property of fuzzy logic system, the advantage of Nussbaum function, and using multiple sliding mode control algorithm based on the recursive technique. In the last step of designing, a nonsingular terminal sliding mode was utilized to drive the last state of the system to converge in a finite period of time, and high-order sliding mode control law was designed to eliminate the chattering and make the system robust. The simulation results showed that the controller designed here could track a desired course fast and accurately. It also exhibited strong robustness peculiarly to system, and had better adaptive ability than traditional PID control algorithms.

  11. Analysis of slide exploration strategy of cytologists when reading digital slides

    Science.gov (United States)

    Pantanowitz, Liron; Parwani, Anil; Tseytlin, Eugene; Mello-Thoms, Claudia

    2012-02-01

    Cytology is the sub-domain of Pathology that deals mainly with the diagnosis of cellular changes caused by disease. Current clinical practice involves a cytotechnologist that manually screens glass slides containing fixed cytology material using a light microscope. Screened slides are then forwarded to a specialized pathologist, a cytopathologist, for microscopic review and final diagnostic interpretation. If no abnormalities are detected, the specimen is interpreted as "normal", otherwise the abnormalities are marked with a pen on the glass slide by the cytotechnologist and then are used to render a diagnosis. As Pathology is migrating towards a digital environment it is important to determine whether these crucial screening and diagnostic tasks can be performed as well using digital slides as the current practice with glass slides. The purpose of this work is to make this assessment, by using a set of digital slides depicting cytological materials of different disease processes in several organs, and then to analyze how different cytologists including cytotechnologists, cytopathologists and cytotechnology-trainees explored the digital slides. We will (1) collect visual search data from the cytologists as they navigate the digital slides, as well as record any electronic marks (annotations) made by the cytologists; (2) convert the dynamic visual search data into a static representation of the observers' exploration strategy using 'search maps'; and (3) determine slide coverage, per viewing magnification range, for each group. We have developed a virtual microscope to collect this data, and this interface allows for interactive navigation of the virtual slide (including panning and zooming), as well as annotation of reportable findings. Furthermore, all interactions with the interface are time stamped, which allows us to recreate the cytologists' search strategy.

  12. Better slides needed at AGU Meetings

    Science.gov (United States)

    Jacobson, Randall S.

    Recent AGU meetings show a dangerous trend in the quality of presentations. A fair percentage of slides used during oral presentations consisted of a black background and colored lines and/or words for data. Such slides are illegible and serve to undercut the speaker's points by not demonstrating the data clearly.A typical example consisted of dark red, dark blue, and green data on a black background. Even the author had difficulty in pointing out the data using his light arrow. Line drawings, in particular, should not use colors, but instead use high-contrast white-on-black for the following reasons: dark colors on black backgrounds provide little contrast, making it difficult to discern patterns; people who are colorblind are at a disadvantage; and the same information can be obtained using a variety of line weights (dotdash, solid, dotted, etc.) with single color slides.

  13. Saugus River and Tributaries, Lynn Malden, Revere and Saugus, Massachusetts. Flood Damage Reduction. Volume 7. Appendix J. Feasibility Study and EIS/EIR Comments and Responses. Section B. Attachments

    Science.gov (United States)

    1989-12-01

    project also provides the o~portunity to further protect the valuable resources in the estuary, not otherwise afforded without the project. Miese ...Lynn side of the Saucus River about 700 feet easterly of the General Edwards Bridge, traverses in a generally southerly direction for approximately...of Carey Circle and would traverse in an easterly direction a distance of about 230 feet ending at Reach "B". A stone revetment at elevation 13.2 feet

  14. Develop and Manufacture an airlock sliding tray

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Cindy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-26

    Objective: The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already tested and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.

  15. Frictional coupling between sliding and spinning motion

    CERN Document Server

    Farkas, Z; Unger, T; Wolf, D E; Farkas, Zeno; Bartels, Guido; Unger, Tamas; Wolf, Dietrich E.

    2002-01-01

    We show that the friction force and torque, acting at a dry contact of two objects moving and rotating relative to each other, are inherently coupled. As a simple test system, a sliding and spinning disk on a horizontal flat surface is considered. We calculate, and also measure, how the disk is slowing down, and find that it always stops its sliding and spinning motion at the same moment. We discuss the impact of this coupling between friction force and torque on the physics of granular materials.

  16. Accurate Sliding-Mode Control System Modeling for Buck Converters

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2007-01-01

    This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively mod...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter.......This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...

  17. Sliding mode control of wind-induced vibrations using fuzzy sliding surface and gain adaptation

    Science.gov (United States)

    Thenozhi, Suresh; Yu, Wen

    2016-04-01

    Although fuzzy/adaptive sliding mode control can reduce the chattering problem in structural vibration control applications, they require the equivalent control and the upper bounds of the system uncertainties. In this paper, we used fuzzy logic to approximate the standard sliding surface and designed a dead-zone adaptive law for tuning the switching gain of the sliding mode control. The stability of the proposed controller is established using Lyapunov stability theory. A six-storey building prototype equipped with an active mass damper has been used to demonstrate the effectiveness of the proposed controller towards the wind-induced vibrations.

  18. Optimal second order sliding mode control for nonlinear uncertain systems.

    Science.gov (United States)

    Das, Madhulika; Mahanta, Chitralekha

    2014-07-01

    In this paper, a chattering free optimal second order sliding mode control (OSOSMC) method is proposed to stabilize nonlinear systems affected by uncertainties. The nonlinear optimal control strategy is based on the control Lyapunov function (CLF). For ensuring robustness of the optimal controller in the presence of parametric uncertainty and external disturbances, a sliding mode control scheme is realized by combining an integral and a terminal sliding surface. The resulting second order sliding mode can effectively reduce chattering in the control input. Simulation results confirm the supremacy of the proposed optimal second order sliding mode control over some existing sliding mode controllers in controlling nonlinear systems affected by uncertainty.

  19. Arc discharge sliding over a conducting surface

    NARCIS (Netherlands)

    Goor, van F.A.; Mitko, S.V.; Ochkin, V.N.; Paramonov, A.P.; Witteman, W.J.

    1997-01-01

    Results of experimental and theoretical studies of the arc discharge which slides over the surface of a conductor are reported. Experiments were performed in air and argon ambients at various pressures. It is found that the velocity of the discharge plasma front depends linearly on the strength of t

  20. Simulation of sliding of liquid droplets

    Science.gov (United States)

    Alen, Saif Khan; Farhat, Nazia; Rahman, Md. Ashiqur

    2016-07-01

    Numerical simulations of sliding behavior of liquid droplets on flat and periodic microgrooved surfaces with a range of groove geometry are conducted. A numerical model is developed which is capable of predicting the critical sliding angle of the drop by comparing the advancing and the receding angles obtained from numerical and experimental findings. The effect of microgroove topography, droplet size and inclination angle on the droplet sliding characteristics is analysed. Using an open-source platform (Surface Evolver), a 3D drop-shape model is developed to numerically determine the drop stability and contact angle hysteresis on tilted surfaces. In this numerical model, the three phase contact line of the drop is obtained by numerically calculating the vertex force and local contact angle at each vertex of the base contour. Several numerical models are developed based on various assumptions of base contour shape (circular or elliptical) and implementation of gravitational force to the droplet. Droplet shapes and critical sliding angles, obtained from these numerical models, are compared with those of experimental results and are found to be in very good agreement.

  1. Liquid drops sliding down an inclined plane

    CERN Document Server

    Kim, Inwon

    2012-01-01

    We investigate a one-dimensional model describing the motion of liquid drops sliding down an inclined plane (the so-called quasi-static approximation model). We prove existence and uniqueness of a solution and investigate its long time behavior for both homogeneous and inhomogeneous medium (i.e. constant and non-constant contact angle). We also obtain some homogenization results.

  2. Edit Distance to Monotonicity in Sliding Windows

    DEFF Research Database (Denmark)

    Chan, Ho-Leung; Lam, Tak-Wah; Lee, Lap Kei

    2011-01-01

    of a data stream is becoming well-understood over the past few years. Motivated by applications on network quality monitoring, we extend the study to estimating the edit distance to monotonicity of a sliding window covering the w most recent items in the stream for any w ≥ 1. We give a deterministic...

  3. A thermodynamic model of sliding friction

    Directory of Open Access Journals (Sweden)

    Lasse Makkonen

    2012-03-01

    Full Text Available A first principles thermodynamic model of sliding friction is derived. The model predictions are in agreement with the observed friction laws both in macro- and nanoscale. When applied to calculating the friction coefficient the model provides a quantitative agreement with recent atomic force microscopy measurements on a number of materials.

  4. Enhancing Creative Thinking through Designing Electronic Slides

    Science.gov (United States)

    Mokaram, Al-Ali Khaled; Al-Shabatat, Ahmad Mohammad; Fong, Fook Soon; Abdallah, Andaleeb Ahmad

    2011-01-01

    During the shifting of teaching and learning methods using computer technologies, much emphasis was paid on the knowledge content more than the thinking skills. Thus, this study investigated the effects of a computer application, namely, designing electronic slides on the development of creative thinking skills of a sample of undergraduate…

  5. Simulations of atomic-scale sliding friction

    DEFF Research Database (Denmark)

    Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel; Stoltze, Per

    1996-01-01

    Simulation studies of atomic-scale sliding friction have been performed for a number of tip-surface and surface-surface contacts consisting of copper atoms. Both geometrically very simple tip-surface structures and more realistic interface necks formed by simulated annealing have been studied. Ki...

  6. Sliding Mode Control of Induction Motor Phase Currents

    DEFF Research Database (Denmark)

    Hansen, R.B.; Hattel, T.; Bork, J

    1995-01-01

    Sliding mode control of induction motor phase currents are investigated through development of two control concepts.......Sliding mode control of induction motor phase currents are investigated through development of two control concepts....

  7. Current Cigarette Use Among Adults (BRFSS) PDF Slides

    Data.gov (United States)

    U.S. Department of Health & Human Services — Download the current cigarette use among adults slides. These slides are available in PDF and PowerPoint formats. The PowerPoint version can be found at:...

  8. Applications of sliding mode control in science and engineering

    CERN Document Server

    Lien, Chang-Hua

    2017-01-01

    Gathering 20 chapters contributed by respected experts, this book reports on the latest advances in and applications of sliding mode control in science and engineering. The respective chapters address applications of sliding mode control in the broad areas of chaos theory, robotics, electrical engineering, physics, chemical engineering, memristors, mechanical engineering, environmental engineering, finance, and biology. Special emphasis has been given to papers that offer practical solutions, and which examine design and modeling involving new types of sliding mode control such as higher order sliding mode control, terminal sliding mode control, super-twisting sliding mode control, and integral sliding mode control. This book serves as a unique reference guide to sliding mode control and its recent applications for graduate students and researchers with a basic knowledge of electrical and control systems engineering.

  9. Excise Tax Rates On Packs Of Cigarettes PDF Slides

    Data.gov (United States)

    U.S. Department of Health & Human Services — Download the current excise tax rates on packs of cigarettes slides. These slides are available in PDF and PowerPoint formats. The PowerPoint version can be found...

  10. Sliding Mode Control of Induction Motor Phase Currents

    DEFF Research Database (Denmark)

    Hansen, R.B.; Hattel, T.; Bork, J

    1995-01-01

    Sliding mode control of induction motor phase currents are investigated through development of two control concepts.......Sliding mode control of induction motor phase currents are investigated through development of two control concepts....

  11. From Peru to Pamplona: Integrating Slides into the Lesson Plan.

    Science.gov (United States)

    Kiss, Marilyn

    1989-01-01

    For a visual generation of students, slides are an effective learning and teaching tool and a constant stimulus for writing, reading, and speaking activities. Ways in which slides have been effectively incorporated into foreign language instruction lessons are described. (CB)

  12. Slide stability of hydraulic structures on subbed soil

    Institute of Scientific and Technical Information of China (English)

    Zhou Junliang

    2013-01-01

    The study on slide stability of hydraulic structures on subbed soil was made. Using the slide test results of dragged concreting base plates on subbed soil pits,the decreased value of bearing capacity on slide after re-bound and repression influence of subbed soil was determined,and the envelope of ultimate slide shear resistance was also quantitatively determined. Due to the lack of similar mechanisms of slide stability on subbed soil and base plate of hydraulic structures,different safety coefficients for the slide stability were adopted. It was suggested to use the maximum compressive stress σmax of eccentric load to predict structure displacement,slide and creepy slippage of subbed soil,to determine the sliding creepy contour and limit the maximum load on subbed soil. Two hydraulic structures that had been put into operation were reviewed by this method,and the results accorded with the real conditions.

  13. Sliding Mode Control Design via Reduced Order Model Approach

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a design of continuous-time sliding mode control for the higher order systems via reduced order model. It is shown that a continuous-time sliding mode control designed for the reduced order model gives similar performance for the higher order system. The method is illustrated by numerical examples. The paper also introduces a technique for design of a sliding surface such that the system satisfies a cost-optimality condition when on the sliding surface.

  14. Fuzzy Sliding Mode Control for Discrete Nonlinear Systems

    Institute of Scientific and Technical Information of China (English)

    F.Qiao.Q.M.Zhu; A.Winfield; C.Melhuish

    2003-01-01

    Sliding mode control is introduced into classical model free fuzzy logic control for discrete time nonlinear systems with uncertainty to the design of a novel fuzzy sliding mode control to meet the requirement of necessary and sufficient reaching conditions of sliding mode control. The simulation results show that the proposed controller outperforms the original fuzzy sliding mode controller and the classical fuzzy logic controller in stability, convergence and robustness.

  15. Adaptive Sliding Mode Control for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    This paper presents a new adaptive sliding mode controller generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The proposed control scheme requires limited knowledge on system parameters, and employs only piston- and valve spool position feedback....... The main target is to overcome problems with linear controllers deteriorating performance due to the inherent nonlinear nature of such systems, without requiring extensive knowledge on system parameters nor advanced control theory. In order to accomplish this task, an integral sliding mode controller...... employing parameter adaption through a recursive algorithm is presented. This is based on a reduced order model approximation of a VCD with unmatched valve flow- and cylinder asymmetries. Bounds on parameters are obtained despite lack of parameter knowledge, and the proposed controller demonstrates improved...

  16. Automated sliding susceptibility mapping of rock slopes

    Directory of Open Access Journals (Sweden)

    A. Günther

    2004-01-01

    Full Text Available We present a suite of extensions for ARCVIEW GIS™ (ESRI that allows to map the spatial distribution of first-order mechanical slope-properties in hard rock terrain, e.g. for large slope areas like water reservoir slopes. Besides digital elevation data, this expert-system includes regional continuous grid-based data on geological structures that might act as potential sliding or cutoff planes for rockslides. The system allows rapid automated mapping of geometrical and kinematical slope properties in hard rock, providing the basis for spatially distributed deterministic sliding-susceptibility evaluations on a pixel base. Changing hydrostatic slope conditions and rock mechanical parameters can be implemented and used for simple predictive static stability calculations. Application is demonstrated for a study area in the Harz Mts., Germany.

  17. Terminal Sliding Modes In Nonlinear Control Systems

    Science.gov (United States)

    Venkataraman, Subramanian T.; Gulati, Sandeep

    1993-01-01

    Control systems of proposed type called "terminal controllers" offers increased precision and stability of robotic operations in presence of unknown and/or changing parameters. Systems include special computer hardware and software implementing novel control laws involving terminal sliding modes of motion: closed-loop combination of robot and terminal controller converge, in finite time, to point of stable equilibrium in abstract space of velocity and/or position coordinates applicable to particular control problem.

  18. Sliding Mode Control of Steerable Needles

    OpenAIRE

    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.

    2013-01-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little...

  19. Virtual slides: application in pulmonary pathology consultations.

    Directory of Open Access Journals (Sweden)

    Michał Wojciechowski

    2008-02-01

    Full Text Available The Virtual Slide (VS is an interactive microscope emulator that presents a complete digitized tissue section via the Internet. A successful implementation of VS has been observed for educational, research venues and quality control. VS acquisition for consultative pathology is not so common. The purpose of this study was to explore the efficacy and usability of VS in the consultative pulmonary telepathology. 20 lung tumors entered the study. The performance was programmed for 2 medical centers specialized in pulmonary pathology (beginner and advancer in telepathology. A high-quality VSs were prepared by Coolscope (Nikon, Eclipsnet VSL, Japan, and were evaluated via the Internet. The cases were reviewed for the second time with conventional light microscope. VS diagnostic accuracy and the interobserver variability were evaluated. Also the time taken by examiners to render the diagnoses and time needed to scan the microscopic slide were analyzed. Percentage concordance between original glass-slides diagnosis and diagnosis for VSs was very high. Pathologists found the download speed of VSs adequate; experience in telepathology reduced the time of VS diagnosis. VS implementation suggests advantages for teleconsulation and education but also indicate some technical limitations. This is the first Polish trial of VS implementation in telepathology consultative service.

  20. Managing and querying whole slide images

    Science.gov (United States)

    Wang, Fusheng; Oh, Tae W.; Vergara-Niedermayr, Cristobal; Kurc, Tahsin; Saltz, Joel

    2012-02-01

    High-resolution pathology images provide rich information about the morphological and functional characteristics of biological systems, and are transforming the field of pathology into a new era. To facilitate the use of digital pathology imaging for biomedical research and clinical diagnosis, it is essential to manage and query both whole slide images (WSI) and analytical results generated from images, such as annotations made by humans and computed features and classifications made by computer algorithms. There are unique requirements on modeling, managing and querying whole slide images, including compatibility with standards, scalability, support of image queries at multiple granularities, and support of integrated queries between images and derived results from the images. In this paper, we present our work on developing the Pathology Image Database System (PIDB), which is a standard oriented image database to support retrieval of images, tiles, regions and analytical results, image visualization and experiment management through a unified interface and architecture. The system is deployed for managing and querying whole slide images for In Silico brain tumor studies at Emory University. PIDB is generic and open source, and can be easily used to support other biomedical research projects. It has the potential to be integrated into a Picture Archiving and Communications System (PACS) with powerful query capabilities to support pathology imaging.

  1. An Efficient Method for Distributing Animated Slides of Web Presentations

    Directory of Open Access Journals (Sweden)

    Yusuke Niwa

    2016-01-01

    Full Text Available Attention control of audience is required for suc-cessful presentations, therefore giving a presentation with im-mediate reaction, called reactive presentation, to unexpected changes in the context given by the audience is important. Examples of functions for the reactive presentation are shape animation effects on slides and slide transition effects. Understanding the functions that realize the reactive pre-sentation on the Web can be useful. In this work, we present an effective method for synchronizing shape animation effects on the Web, such as moving the objects and changing the size and color of the shape objects. The main idea is to make a video of animated slides, called Web Slide Media, including the page information of slides as movie chapter information for synchronization. Moreover, we explain a method to reduce the file size of the Web slide media by removing all shape animation effects and slide transition effects from a Web slide media item, called Sparse Web Slide Media. We demonstrate that the performance of the system is enough for practical use and the file size of the Sparse Web Slide Media is smaller than the file size of the Web Slide Media.

  2. Computer generated slides: a need to curb our enthusiasm.

    Science.gov (United States)

    Dalal, M D; Daver, B M

    1996-12-01

    The popular use of computer generated slides for presentations during plastic surgery scientific meetings has opened a fresh chapter in audiovisual techniques. Although the profusion of colours seen during presentations is a visual treat, the information imparted by these slides leaves much to be desired and raises the question of whether such attractive and apparently professionally made slides are visual aids during such presentations. Presentation slides are displayed for a very short time (10-15 seconds) as compared to slides displayed during a lecture and therefore these presentation slides should have the ability to impart their information very quickly. We conducted a study wherein 36 slides, each having a different colour combination, were displayed to a class of third year medical students who were asked to judge the efficacy of each slide. The attractiveness, clarity and recall of each slide was graded by every student and, with the information obtained, the most effective format and colour combinations to be used while making slides for presentations were established. We conclude that the best format for slides is a plain dark coloured background (blue, purple or green) and a separate, contrasting plain dark coloured title text background (red, green or purple), with white letters for the text and yellow letters for the title.

  3. Adaptive Sliding Mode Control Method Based on Nonlinear Integral Sliding Surface for Agricultural Vehicle Steering Control

    Directory of Open Access Journals (Sweden)

    Taochang Li

    2014-01-01

    Full Text Available Automatic steering control is the key factor and essential condition in the realization of the automatic navigation control of agricultural vehicles. In order to get satisfactory steering control performance, an adaptive sliding mode control method based on a nonlinear integral sliding surface is proposed in this paper for agricultural vehicle steering control. First, the vehicle steering system is modeled as a second-order mathematic model; the system uncertainties and unmodeled dynamics as well as the external disturbances are regarded as the equivalent disturbances satisfying a certain boundary. Second, a transient process of the desired system response is constructed in each navigation control period. Based on the transient process, a nonlinear integral sliding surface is designed. Then the corresponding sliding mode control law is proposed to guarantee the fast response characteristics with no overshoot in the closed-loop steering control system. Meanwhile, the switching gain of sliding mode control is adaptively adjusted to alleviate the control input chattering by using the fuzzy control method. Finally, the effectiveness and the superiority of the proposed method are verified by a series of simulation and actual steering control experiments.

  4. Slide-specific models for segmentation of differently stained digital histopathology whole slide images

    Science.gov (United States)

    Brieu, Nicolas; Pauly, Olivier; Zimmermann, Johannes; Binnig, Gerd; Schmidt, Günter

    2016-03-01

    The automatic analysis of whole slide images (WSIs) of stained histopathology tissue sections plays a crucial role in the discovery of predictive biomarkers in the field on immuno-oncology by enabling the quantification of the phenotypic information contained in the tissue sections. The automatic detection of cells and nuclei, while being one of the major steps of such analysis, remains a difficult problem because of the low visual differentiation of high pleomorphic and densely cluttered objects and of the diversity of tissue appearance between slides. The key idea of this work is to take advantage of well-differentiated objects in each slide to learn about the appearance of the tissue and in particular about the appearance of low-differentiated objects. We detect well-differentiated objects on a automatically selected set of representative regions, learn slide-specific visual context models, and finally use the resulting posterior maps to perform the final detection steps on the whole slide. The accuracy of the method is demonstrated against manual annotations on a set of differently stained images.

  5. Fuzzy fractional order sliding mode controller for nonlinear systems

    Science.gov (United States)

    Delavari, H.; Ghaderi, R.; Ranjbar, A.; Momani, S.

    2010-04-01

    In this paper, an intelligent robust fractional surface sliding mode control for a nonlinear system is studied. At first a sliding PD surface is designed and then, a fractional form of these networks PDα, is proposed. Fast reaching velocity into the switching hyperplane in the hitting phase and little chattering phenomena in the sliding phase is desired. To reduce the chattering phenomenon in sliding mode control (SMC), a fuzzy logic controller is used to replace the discontinuity in the signum function at the reaching phase in the sliding mode control. For the problem of determining and optimizing the parameters of fuzzy sliding mode controller (FSMC), genetic algorithm (GA) is used. Finally, the performance and the significance of the controlled system two case studies (robot manipulator and coupled tanks) are investigated under variation in system parameters and also in presence of an external disturbance. The simulation results signify performance of genetic-based fuzzy fractional sliding mode controller.

  6. Validation of diagnostic accuracy using digital slides in routine histopathology

    Directory of Open Access Journals (Sweden)

    Fónyad László

    2012-03-01

    Full Text Available Abstract Background Robust hardware and software tools have been developed in digital microscopy during the past years for pathologists. Reports have been advocated the reliability of digital slides in routine diagnostics. We have designed a retrospective, comparative study to evaluate the scanning properties and digital slide based diagnostic accuracy. Methods 8 pathologists reevaluated 306 randomly selected cases from our archives. The slides were scanned with a 20× Plan-Apochromat objective, using a 3-chip Hitachi camera, resulting 0.465 μm/pixel resolution. Slide management was supported with dedicated Data Base and Viewer software tools. Pathologists used their office PCs for evaluation and reached the digital slides via intranet connection. The diagnostic coherency and uncertainty related to digital slides and scanning quality were analyzed. Results Good to excellent image quality of slides was recorded in 96%. In half of the critical 61 digital slides, poor image quality was related to section folds or floatings. In 88.2% of the studied cases the digital diagnoses were in full agreement with the consensus. Out of the overall 36 incoherent cases, 7 (2.3% were graded relevant without any recorded uncertainty by the pathologist. Excluding the non-field specific cases from each pathologist's record this ratio was 1.76% of all cases. Conclusions Our results revealed that: 1 digital slide based histopathological diagnoses can be highly coherent with those using optical microscopy; 2 the competency of pathologists is a factor more important than the quality of digital slide; 3 poor digital slide quality do not endanger patient safety as these errors are recognizable by the pathologist and further actions for correction could be taken. Virtual slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1913324336747310.

  7. Validation of diagnostic accuracy using digital slides in routine histopathology.

    Science.gov (United States)

    Fónyad, László; Krenács, Tibor; Nagy, Péter; Zalatnai, Attila; Csomor, Judit; Sápi, Zoltán; Pápay, Judit; Schönléber, Júlia; Diczházi, Csaba; Molnár, Béla

    2012-03-31

    Robust hardware and software tools have been developed in digital microscopy during the past years for pathologists. Reports have been advocated the reliability of digital slides in routine diagnostics. We have designed a retrospective, comparative study to evaluate the scanning properties and digital slide based diagnostic accuracy. 8 pathologists reevaluated 306 randomly selected cases from our archives. The slides were scanned with a 20× Plan-Apochromat objective, using a 3-chip Hitachi camera, resulting 0.465 μm/pixel resolution. Slide management was supported with dedicated Data Base and Viewer software tools. Pathologists used their office PCs for evaluation and reached the digital slides via intranet connection. The diagnostic coherency and uncertainty related to digital slides and scanning quality were analyzed. Good to excellent image quality of slides was recorded in 96%. In half of the critical 61 digital slides, poor image quality was related to section folds or floatings. In 88.2% of the studied cases the digital diagnoses were in full agreement with the consensus. Out of the overall 36 incoherent cases, 7 (2.3%) were graded relevant without any recorded uncertainty by the pathologist. Excluding the non-field specific cases from each pathologist's record this ratio was 1.76% of all cases. Our results revealed that: 1) digital slide based histopathological diagnoses can be highly coherent with those using optical microscopy; 2) the competency of pathologists is a factor more important than the quality of digital slide; 3) poor digital slide quality do not endanger patient safety as these errors are recognizable by the pathologist and further actions for correction could be taken. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1913324336747310.

  8. Cable Sliding at Supports in Cable Structures

    Institute of Scientific and Technical Information of China (English)

    魏建东

    2004-01-01

    To develop an effective numerical method for the cable sliding problem in cable structures, two-node catenary cable element was built to model the cables based on analytical solution of elastic catenary. Cooperated with Newton method, continuation method was used to solve the nonlinear equations. This approach is more efficient than using Newton method only and has a wider range to select initial values for the process to converge. The relationship between the tension on a cable segment and its unstrained length was derived and used to calculate the unbalanced cable tensions at the supports. An example is presented to show the correctness and efficiency of the proposed method.

  9. Probabilistic fault localization with sliding windows

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cheng; LIAO JianXin; LI TongHong; ZHU XiaoMin

    2012-01-01

    Fault localization is a central element in network fault management.This paper takes a weighted bipartite graph as a fault propagation model and presents a heuristic fault localization algorithm based on the idea of incremental coverage,which is resilient to inaccurate fault propagation model and the noisy environment.Furthermore,a sliding window mechanism is proposed to tackle the inaccuracy of this algorithm in the presence of improper time windows.As shown in the simulation study,our scheme achieves higher detection rate and lower false positive rate in the noisy environment as well as in the presence of inaccurate windows,than current fault localization algorithms.

  10. Collective sliding states for colloidal molecular crystals

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia [Los Alamos National Laboratory

    2008-01-01

    We study the driving of colloidal molecular crystals over periodic substrates such as those created with optical traps. The n-merization that occurs in the colloidal molecular crystal states produces a remarkably rich variety of distinct dynamical behaviors, including polarization effects within the pinned phase and the formation of both ordered and disordered sliding phases. Using computer simulations, we map the dynamic phase diagrams as a function of substrate strength for dimers and trimers on a triangular substrate, and correlate features on the phase diagram with transport signatures.

  11. The histological slides and drawings of Cajal

    Directory of Open Access Journals (Sweden)

    Pablo Garcia-Lopez

    2010-03-01

    Full Text Available Ramon y Cajal´s studies in the world of neuroscience provoked a radical change in the course of its history. For this reason he is considered as the father of modern neuroscience. Some of his items are housed at the Cajal Museum (Cajal Institute, CSIC, Madrid, Spain. In this article, we will present an analysis of Cajal’s effects used in his research that could help to understand his enormous scientific production, and that offers some curious insights into his work and his legacy. Furthermore, we present some images relating Cajal’s scientific drawings with his histological slides.

  12. Effect of Thermal Radiation on the Integrity of Pressurized Aircraft Evacuation Slides and Slide Materials

    Science.gov (United States)

    1981-03-01

    Pres sureI 19. Security Classif. (of this reort) 20. Security Classif. (of this pegs ) 21. No. of Pagos J~ ’E tce UnlsiidUnclassified :179 Ffig DOT F... deta from the new integrity of pressurized evacuation laboratory test method. slide materials exposed to thermal radiation; (2) develop a practical

  13. Sliding wear and friction behaviour of zircaloy-4 in water

    Science.gov (United States)

    Sharma, Garima; Limaye, P. K.; Jadhav, D. T.

    2009-11-01

    In water cooled nuclear reactors, the sliding of fuel bundles in fuel channel handling system can lead to severe wear and it is an important topic to study. In the present study, sliding wear behaviour of zircaloy-4 was investigated in water (pH ˜ 10.5) using ball-on-plate sliding wear tester. Sliding wear resistance zircaloy-4 against SS 316 was examined at room temperature. Sliding wear tests were carried out at different load and sliding frequencies. The coefficient of friction of zircaloy-4 was also measured during each tests and it was found to decrease slightly with the increase in applied load. The micro-mechanisms responsible for wear in zircaloy-4 were identified to be microcutting, micropitting and microcracking of deformed subsurface zones in water.

  14. Optimal second order sliding mode control for linear uncertain systems.

    Science.gov (United States)

    Das, Madhulika; Mahanta, Chitralekha

    2014-11-01

    In this paper an optimal second order sliding mode controller (OSOSMC) is proposed to track a linear uncertain system. The optimal controller based on the linear quadratic regulator method is designed for the nominal system. An integral sliding mode controller is combined with the optimal controller to ensure robustness of the linear system which is affected by parametric uncertainties and external disturbances. To achieve finite time convergence of the sliding mode, a nonsingular terminal sliding surface is added with the integral sliding surface giving rise to a second order sliding mode controller. The main advantage of the proposed OSOSMC is that the control input is substantially reduced and it becomes chattering free. Simulation results confirm superiority of the proposed OSOSMC over some existing.

  15. Pre-Stressed Rope Reinforced Anti-Sliding Pile

    Institute of Scientific and Technical Information of China (English)

    XU Jun; WANG Chenghua

    2006-01-01

    Pre-stressed rope reinforced anti-sliding pile is a composite anti-sliding structure. It is made up of pre-stressed rope and general anti-sliding pile. It can bring traditional anti-sliding pile's retaining performance into full play, and to treat with landslide fast and economically. The difference between them is that the pre-stressed rope will transfix the whole anti-sliding pile through a prearranged pipe in this structure. The working mechanics, the design method and economic benefit are studied. The results show that the pre-stressed rope reinforced anti-sliding pile can treat with the small and middle landslides or high slopes well and possess the notable advantage of technology and economic.

  16. Presentation video retrieval using automatically recovered slide and spoken text

    Science.gov (United States)

    Cooper, Matthew

    2013-03-01

    Video is becoming a prevalent medium for e-learning. Lecture videos contain text information in both the presentation slides and lecturer's speech. This paper examines the relative utility of automatically recovered text from these sources for lecture video retrieval. To extract the visual information, we automatically detect slides within the videos and apply optical character recognition to obtain their text. Automatic speech recognition is used similarly to extract spoken text from the recorded audio. We perform controlled experiments with manually created ground truth for both the slide and spoken text from more than 60 hours of lecture video. We compare the automatically extracted slide and spoken text in terms of accuracy relative to ground truth, overlap with one another, and utility for video retrieval. Results reveal that automatically recovered slide text and spoken text contain different content with varying error profiles. Experiments demonstrate that automatically extracted slide text enables higher precision video retrieval than automatically recovered spoken text.

  17. Streamers sliding on a water surface

    Science.gov (United States)

    Akishev, Yuri Semenov; Karalnik, Vladimir; Medvedev, Mikhail; Petryakov, Alexander; Trushkin, Nikolay; Shafikov, Airat

    2017-06-01

    The features of an electrical interaction between surface streamers (thin current filaments) sliding on a liquid and liquid itself are still unknown in many details. This paper presents the experimental results on properties of the surface streamers sliding on water with different conductivity (distilled and tap water). The streamers were initiated with a sharpened thin metallic needle placed above the liquid and stressed with a periodical or pulsed high voltage. Two electrode systems were used and tested. The first of them provides in advance the existence of the longitudinal electric field above the water. The second one imitates the electrode geometry of a pin-to-plane dielectric barrier discharge in which the barrier is a thick layer of liquid. The electrical and optical characteristics of streamers were complemented with data on the spectroscopic measurements. It was revealed that surface streamers on water have no spatial memory. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  18. A frictional sliding algorithm for liquid droplets

    Science.gov (United States)

    Sauer, Roger A.

    2016-12-01

    This work presents a new frictional sliding algorithm for liquid menisci in contact with solid substrates. In contrast to solid-solid contact, the liquid-solid contact behavior is governed by the contact line, where a contact angle forms and undergoes hysteresis. The new algorithm admits arbitrary meniscus shapes and arbitrary substrate roughness, heterogeneity and compliance. It is discussed and analyzed in the context of droplet contact, but it also applies to liquid films and solids with surface tension. The droplet is modeled as a stabilized membrane enclosing an incompressible medium. The contact formulation is considered rate-independent such that hydrostatic conditions apply. Three distinct contact algorithms are needed to describe the cases of frictionless surface contact, frictionless line contact and frictional line contact. For the latter, a predictor-corrector algorithm is proposed in order to enforce the contact conditions at the contact line and thus distinguish between the cases of advancing, pinning and receding. The algorithms are discretized within a monolithic finite element formulation. Several numerical examples are presented to illustrate the numerical and physical behavior of sliding droplets.

  19. Sliding viscoelastic drops on slippery surfaces

    Science.gov (United States)

    Xu, H.; Clarke, A.; Rothstein, J. P.; Poole, R. J.

    2016-06-01

    We study the sliding of drops of constant-viscosity dilute elastic liquids (Boger fluids) on various surfaces caused by sudden surface inclination. For smooth or roughened hydrophilic surfaces, such as glass or acrylic, there is essentially no difference between these elastic liquids and a Newtonian comparator fluid (with identical shear viscosity, surface tension, and static contact angle). In contrast for embossed polytetrafluoroethylene superhydrophobic surfaces, profound differences are observed: the elastic drops slide at a significantly reduced rate and complex branch-like patterns are left on the surface by the drop's wake including, on various scales, beads-on-a-string like phenomena. Microscopy images indicate that the strong viscoelastic effect is caused by stretching filaments of fluid from isolated islands, residing at pinning sites on the surface pillars, of the order ˜30 μm in size. On this scale, the local strain rates are sufficient to extend the polymer chains, locally increasing the extensional viscosity of the solution, retarding the drop and leaving behind striking branch-like structures on much larger scales.

  20. Markov state modeling of sliding friction

    Science.gov (United States)

    Pellegrini, F.; Landes, François P.; Laio, A.; Prestipino, S.; Tosatti, E.

    2016-11-01

    Markov state modeling (MSM) has recently emerged as one of the key techniques for the discovery of collective variables and the analysis of rare events in molecular simulations. In particular in biochemistry this approach is successfully exploited to find the metastable states of complex systems and their evolution in thermal equilibrium, including rare events, such as a protein undergoing folding. The physics of sliding friction and its atomistic simulations under external forces constitute a nonequilibrium field where relevant variables are in principle unknown and where a proper theory describing violent and rare events such as stick slip is still lacking. Here we show that MSM can be extended to the study of nonequilibrium phenomena and in particular friction. The approach is benchmarked on the Frenkel-Kontorova model, used here as a test system whose properties are well established. We demonstrate that the method allows the least prejudiced identification of a minimal basis of natural microscopic variables necessary for the description of the forced dynamics of sliding, through their probabilistic evolution. The steps necessary for the application to realistic frictional systems are highlighted.

  1. Hypersonic sliding target tracking in near space

    Directory of Open Access Journals (Sweden)

    Xiang-yu Zhang

    2015-12-01

    Full Text Available To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA, constant turning (CT and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

  2. Finite time convergent control using terminal sliding mode

    Institute of Scientific and Technical Information of China (English)

    Yiguang HONG; Guowu YANG; Daizhan CHENG; Sarah SPURGEON

    2004-01-01

    A method for terminal sliding mode control design is discussed. As we know, one of the strong points of terminal sliding mode control is its finite-time convergence to a given equilibrium of the system under consideration, which may be useful in specific applications. The proposed method, different from many existing terminal sliding model control design methods, is studied, and then feedback laws are designed for a class of nonlinear systems, along with illustrative examples.

  3. A Collection of Slides on Rural Development and Public Policy

    OpenAIRE

    Debertin, David L.

    2013-01-01

    The slides that follow provide an introduction to rural economic development and public policy. I have scanned the original slides and inserted them into modern PDF and PowerPoint presentations. Some of the hand-made charts have older data, but could be easily updated. These color slides were created in 1979-1980, before the widespread use of personal computers and computer graphics. Programs such as Harvard Graphics were unavailable, let alone in PowerPoint. The Department of Agricultural Ec...

  4. Design Gradient Descent Optimal Sliding Mode Control of Continuum Robots

    OpenAIRE

    Farzin Piltan; Shahnaz Tayebi Haghighi

    2012-01-01

    In this research, a new approach for gradient descent optimal sliding mode controller for continuum robots is proposed. Based on the new dynamic models developed, a novel technique for nonlinear control of continuum manipulators to be employed in various situations has also been proposed and developed. A section of a continuum arm is modeled using lumped model elements (masses, springs and dampers) and control by nonlinear methodology (sliding mode method) and optimization the sliding surface...

  5. Sliding Mode Speed Control for DC Drive Systems

    OpenAIRE

    Guldemir, H.

    2003-01-01

    In this study, the Sliding Mode Control theory of the Variable Structure System has been applied to the speed control of a de motor. The dynamic performance of the sliding mode speed control system has been studied against system parameter variations and external load disturbance and the simulation results are given. The application of the sliding mode control theory to controller design for DC drive control system shows a robust system performance.

  6. On Chattering-Free Dynamic Sliding Mode Controller Design

    OpenAIRE

    Jeang-Lin Chang

    2012-01-01

    For a class of linear MIMO uncertain systems, a dynamic sliding mode control algorithm that avoids the chattering problem is proposed in this paper. Without using any differentiator, we develop a modified asymptotically stable second-order sliding mode control law in which the proposed controller can guarantee the finite time convergence to the sliding mode and can show that the system states asymptotically approach to zero. Finally, a numerical example is explained for demonstrating the appl...

  7. A Sliding Mode Multimodel Control for a Sensorless Photovoltaic System

    OpenAIRE

    Rhif, Ahmed; Kardous, Zohra; Braiek, Naceur BenHadj

    2013-01-01

    In this work we will talk about a new control test using the sliding mode control with a nonlinear sliding mode observer, which are very solicited in tracking problems, for a sensorless photovoltaic panel. In this case, the panel system will has as a set point the sun position at every second during the day for a period of five years; then the tracker, using sliding mode multimodel controller and a sliding mode observer, will track these positions to make the sunrays orthogonal to the photovo...

  8. Second order sliding mode control for a quadrotor UAV.

    Science.gov (United States)

    Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang

    2014-07-01

    A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method.

  9. Sliding Mode Robustness Control Strategy for Shearer Height Adjusting System

    Directory of Open Access Journals (Sweden)

    Xiuping Su

    2013-09-01

    Full Text Available This paper firstly established mathematical model of height adjusting hydro cylinder of the shearer, as well as the state space equation of the shearer height adjusting system. Secondly we designed a shearer automatic height adjusting controller adopting the sliding mode robustness control strategy. The height adjusting controller includes the sliding mode surface switching function based on Ackermann formula, as well as sliding mode control function with the improved butterworth filter. Then simulation of the height adjustment controller shows that the sliding mode robustness control solves buffeting of typical controller, and achieves automatic control for the rolling drum of the shearer.

  10. Slide less pathology”: Fairy tale or reality?

    Directory of Open Access Journals (Sweden)

    M Indu

    2016-01-01

    Full Text Available Pathology practice is significantly advanced in various frontiers. Therefore, “slide less digital” pathology will not be a mere imagination in near future. Digitalization of histopathological slides (whole slide imaging [WSI] is possible with the help of whole slide scanner. The WSI has a positive impact not only in routine practice but also in research field, medical education and bioindustry. Even if digital pathology has definitive advantages, its widespread use is not yet possible. As it is an upcoming technology in our field, this article is aimed to discussessential aspects of WSI.

  11. Was the Scanner Calibration Slide used for its intended purpose?

    Science.gov (United States)

    2011-01-01

    In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response [1]. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported. PMID:21510874

  12. Was the Scanner Calibration Slide used for its intended purpose?

    Directory of Open Access Journals (Sweden)

    Zong Yaping

    2011-04-01

    Full Text Available Abstract In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response 1. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

  13. Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model

    Science.gov (United States)

    Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L.

    2015-12-01

    Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic

  14. Screening and dotting virtual slides: A new challenge for cytotechnologists

    Directory of Open Access Journals (Sweden)

    Walid E Khalbuss

    2013-01-01

    Full Text Available Digital images are increasingly being used in cytopathology. Whole-slide imaging (WSI is a digital imaging modality that uses computerized technology to scan and convert entire cytology glass slides into digital images that can be viewed on a digital display using the image viewer software. Digital image acquisition of cytology glass slides has improved significantly over the years due to the use of liquid-based preparations and advances in WSI scanning technology such as automatic multipoint pre-scan focus technology or z-stack scanning technology. Screening cytotechnologists are responsible for every cell that is present on an imaged slide. One of the challenges users have to overcome is to establish a technique to review systematically the entire imaged slide and to dot selected abnormal or significant findings. The scope of this article is to review the current user interface technology available for virtual slide navigation when screening digital slides in cytology. WSI scanner vendors provide tools, built into the image viewer software that allow for a more systematic navigation of the virtual slides, such as auto-panning, keyboard-controlled slide navigation and track map. Annotation tools can improve communication between the screener and the final reviewer or can be used for education. The tracking functionality allows recording of the WSI navigation process and provides a mechanism for confirmation of slide coverage by the screening cytotechnologist as well as a useful tool for quality assurance. As the WSI technology matures, additional features and tools to support navigation of a cytology virtual slide are anticipated.

  15. Frictional Sliding without Geometrical Reflection Symmetry

    Science.gov (United States)

    Aldam, Michael; Bar-Sinai, Yohai; Svetlizky, Ilya; Brener, Efim A.; Fineberg, Jay; Bouchbinder, Eran

    2016-10-01

    The dynamics of frictional interfaces plays an important role in many physical systems spanning a broad range of scales. It is well known that frictional interfaces separating two dissimilar materials couple interfacial slip and normal stress variations, a coupling that has major implications on their stability, failure mechanism, and rupture directionality. In contrast, it is traditionally assumed that interfaces separating identical materials do not feature such a coupling because of symmetry considerations. We show, combining theory and experiments, that interfaces that separate bodies made of macroscopically identical materials but lack geometrical reflection symmetry generically feature such a coupling. We discuss two applications of this novel feature. First, we show that it accounts for a distinct, and previously unexplained, experimentally observed weakening effect in frictional cracks. Second, we demonstrate that it can destabilize frictional sliding, which is otherwise stable. The emerging framework is expected to find applications in a broad range of systems.

  16. Frictional sliding with geometrically broken reflection symmetry

    CERN Document Server

    Aldam, Michael; Svetlizky, Ilya; Brener, Efim A; Fineberg, Jay; Bouchbinder, Eran

    2016-01-01

    The dynamics of frictional interfaces play an important role in many physical systems spanning a broad range of scales. It is well-known that frictional interfaces separating two dissimilar materials couple interfacial slip and normal stress variations, a coupling that has major implications on their stability, failure mechanism and rupture directionality. In contrast, interfaces separating identical materials are traditionally assumed not to feature such a coupling due to symmetry considerations. We show, combining theory and experiments, that interfaces which separate bodies made of identical materials, but lack geometric reflection symmetry, generically feature such a coupling. We discuss two applications of this novel feature. First, we show that it accounts for a distinct and previously unexplained weakening effect in frictional cracks observed experimentally. Second, we demonstrate that it can destabilize frictional sliding which is otherwise stable. The emerging framework is expected to find applicatio...

  17. Sliding Mode Control of Steerable Needles.

    Science.gov (United States)

    Rucker, D Caleb; Das, Jadav; Gilbert, Hunter B; Swaney, Philip J; Miga, Michael I; Sarkar, Nilanjan; Webster, Robert J

    2013-10-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation.

  18. Sliding Adjustment for 3D Video Representation

    Directory of Open Access Journals (Sweden)

    Galpin Franck

    2002-01-01

    Full Text Available This paper deals with video coding of static scenes viewed by a moving camera. We propose an automatic way to encode such video sequences using several 3D models. Contrary to prior art in model-based coding where 3D models have to be known, the 3D models are automatically computed from the original video sequence. We show that several independent 3D models provide the same functionalities as one single 3D model, and avoid some drawbacks of the previous approaches. To achieve this goal we propose a novel algorithm of sliding adjustment, which ensures consistency of successive 3D models. The paper presents a method to automatically extract the set of 3D models and associate camera positions. The obtained representation can be used for reconstructing the original sequence, or virtual ones. It also enables 3D functionalities such as synthetic object insertion, lightning modification, or stereoscopic visualization. Results on real video sequences are presented.

  19. Sliding seal materials for adiabatic engines

    Science.gov (United States)

    Lankford, J.

    1985-01-01

    The sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, loading conditions that are representative of the adiabatic engine environment. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Microhardness tests were performed on the candidate materials at elevated temperatures, and in atmospheres relevant to the piston seal application, and optical and electron microscopy were used to elucidate the micromechanisms of wear following wear testing. X-ray spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Electrical effects in the friction and wear processes were explored in order to evaluate the potential usefulness of such effects in modifying the friction and wear rates in service. However, this factor was found to be of negligible significance in controlling friction and wear.

  20. Sliding Trellis-Based Frame Synchronization

    CERN Document Server

    Ali, Usman; Kieffer, Michel

    2011-01-01

    Frame Synchronization (FS) is required in several communication standards in order to recover the individual frames that have been aggregated in a burst. This paper proposes a low-delay and reducedcomplexity Sliding Trellis (ST)-based FS technique, compared to our previously proposed trellis-based FS method. Each burst is divided into overlapping windows in which FS is performed. Useful information is propagated from one window to the next. The proposed method makes use of soft information provided by the channel, but also of all sources of redundancy present in the protocol stack. An illustration of our STbased approach for the WiMAX Media Access Control (MAC) layer is provided. When FS is performed on bursts transmitted over Rayleigh fading channel, the ST-based approach reduces the FS latency and complexity at the cost of a very small performance degradation compared to our full complexity trellis-based FS and outperforms state-of-the-art FS techniques.

  1. Sliding Mode Control of Steerable Needles

    Science.gov (United States)

    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.

    2014-01-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation. PMID:25400527

  2. Sliding through a superlight granular medium.

    Science.gov (United States)

    Pacheco-Vázquez, F; Ruiz-Suárez, J C

    2009-12-01

    We explore the penetration dynamics of an intruder in a granular medium composed of expanded polystyrene spherical particles. Three features distinguish our experiment from others studied so far in granular physics: (a) the impact is horizontal, decoupling the effects of gravity and the drag force; (b) the density of the intruder rho(i) is up to 350 times larger than the density of the granular medium rho(m); and (c) the way the intruder moves through the material, sliding at the bottom of the column with small friction. Under these conditions we find that the final penetration D scales with (rho(i)/rho(m)) and the drag force Fd and D saturate with the height of the granular bed.

  3. A Sliding Mode Control for Uncertain Time-delay Systems

    Institute of Scientific and Technical Information of China (English)

    WU Jun-sheng; WENG Zheng-xin; TIAN Zuo-hua; SHI Song-jiao

    2008-01-01

    By means of the feasibility of some linear matrix inequalities (LMIs), delay dependeat sufficient condition is derived for the existence of a linear sliding surface, which guarantees quadratic stability of the reduced-order equivalent system restricted to the sliding surface. And a reaching motion controller is proposed. A numerical simulation shows the effectiveness of the approach.

  4. Predicting Debris-Slide Locations in Northwestern California

    Science.gov (United States)

    Mark E. Reid; Stephen D. Ellen; Dianne L. Brien; Juan de la Fuente; James N. Falls; Billie G. Hicks; Eric C. Johnson

    2007-01-01

    We tested four topographic models for predicting locations of debris-slide sources: 1) slope; 2) proximity to stream; 3) SHALSTAB with "standard" parameters; and 4) debris-slide-prone landforms, which delineates areas similar to "inner gorge" and "headwall swale" using experience-based rules. These approaches were compared in three diverse...

  5. Lecture Handouts of Projected Slides in a Medical Course.

    Science.gov (United States)

    Amato, Dominick; Quirt, Ian

    1991-01-01

    In a third-year medical school hematology course, handouts reproducing all or most of the 35mm slides used during the lecture are given at the beginning of class. The slides are reproduced on the left, with room for note-taking on the right. Despite some disadvantages, the method is seen as helpful. (Author/MSE)

  6. Computer Slide Shows: A Trap for Bad Teaching

    Science.gov (United States)

    Klemm, W. R.

    2007-01-01

    Slide shows presented with software such as PowerPoint or WordPerfect Presentations can trap instructors into bad teaching practices. Research on memory suggests that slide-show instruction can actually be less effective than traditional lecturing when the teacher uses a blackboard or overhead projector. The author proposes a model of classroom…

  7. Analysis of tensioned membrane structures considering cable sliding

    Institute of Scientific and Technical Information of China (English)

    宋昌永

    2003-01-01

    In routine design of tensioned membrane structures, the membrane is generally modeled using space membrane elements and the cables by space cable elements, with no sliding allowed between the membrane and the cables. On the other hand, large deflections are expected and sliding between the membrane and the cables is inevitable. In the present paper, the general finite element code ABAQUS was employed to investigate the influence of cable sliding on membrane surface on the structural behavior. Three analysis models were devised to fulfill this purpose: (1) The membrane element shares nodes with the cable element; (2) The cable can slide on the membrane surface freely (without friction) and (3) The cable can slide on the membrane surface, but with friction between the cable and the membrane. The sliding problem is modeled using a surface - based contact algorithm. The results from three analysis models are compared, showing that cable sliding has only little influence on the structure shape and on the stress distributions in the membrane. The main influence of cable sliding may be its effect on the dynamic behavior of tensioned membrane structures.

  8. Optimizing Student Learning: Examining the Use of Presentation Slides

    Science.gov (United States)

    Strauss, Judy; Corrigan, Hope; Hofacker, Charles F.

    2011-01-01

    Sensory overload and split attention result in reduced learning when instructors read slides with bullet points and complex graphs during a lecture. Conversely, slides containing relevant visual elements, when accompanied by instructor narration, use both the visual and verbal channels of a student's working memory, thus improving the chances of…

  9. Robust spatiotemporal matching of electronic slides to presentation videos.

    Science.gov (United States)

    Fan, Quanfu; Barnard, Kobus; Amir, Arnon; Efrat, Alon

    2011-08-01

    We describe a robust and efficient method for automatically matching and time-aligning electronic slides to videos of corresponding presentations. Matching electronic slides to videos provides new methods for indexing, searching, and browsing videos in distance-learning applications. However, robust automatic matching is challenging due to varied frame composition, slide distortion, camera movement, low-quality video capture, and arbitrary slides sequence. Our fully automatic approach combines image-based matching of slide to video frames with a temporal model for slide changes and camera events. To address these challenges, we begin by extracting scale-invariant feature-transformation (SIFT) keypoints from both slides and video frames, and matching them subject to a consistent projective transformation (homography) by using random sample consensus (RANSAC). We use the initial set of matches to construct a background model and a binary classifier for separating video frames showing slides from those without. We then introduce a new matching scheme for exploiting less distinctive SIFT keypoints that enables us to tackle more difficult images. Finally, we improve upon the matching based on visual information by using estimated matching probabilities as part of a hidden Markov model (HMM) that integrates temporal information and detected camera operations. Detailed quantitative experiments characterize each part of our approach and demonstrate an average accuracy of over 95% in 13 presentation videos.

  10. Design Your Organization's Own Slide-Tape Show

    Science.gov (United States)

    Tilden, Scott W.

    1975-01-01

    Slide-tape shows offer a relatively inexpensive, easy-to-assemble means of informing a wide variety of groups interested in education. This article outlines a seven-step procedure to produce a coherent, professional-looking slide-tape presentation. (DS)

  11. Focusing in on the Slide: Its Practical Applications

    Science.gov (United States)

    Runte, Roseann

    1977-01-01

    Slides can be used in the foreign language classroom as a free conversation stimulus, for vocabulary building and grammar exercises as well as in composition, culture, and literature. No more than ten slides should be used. Students should participate fully, not merely listen to the teacher's monologue. (CFM)

  12. Sliding mode control the delta-sigma modulation approach

    CERN Document Server

    Sira-Ramírez, Hebertt

    2015-01-01

    This monograph presents a novel method of sliding mode control for switch-regulated nonlinear systems. The Delta Sigma modulation approach allows one to implement a continuous control scheme using one or multiple, independent switches, thus effectively merging the available linear and nonlinear controller design techniques with sliding mode control.   Sliding Mode Control: The Delta-Sigma Modulation Approach, combines rigorous mathematical derivation of the unique features of Sliding Mode Control and Delta-Sigma modulation with numerous illustrative examples from diverse areas of engineering. In addition, engineering case studies demonstrate the applicability of the technique and the ease with which one can implement the exposed results. This book will appeal to researchers in control engineering and can be used as graduate-level textbook for a first course on sliding mode control.

  13. Advances in sliding mode control concept, theory and implementation

    CERN Document Server

    Janardhanan, S; Spurgeon, Sarah

    2013-01-01

    The sliding mode control paradigm has become a mature technique for the design of robust controllers for a wide class of systems including nonlinear, uncertain and time-delayed systems. This book is a collection of plenary and invited talks delivered at the 12th IEEE International Workshop on Variable Structure System held at the Indian Institute of Technology, Mumbai, India in January 2012. After the workshop, these researchers were invited to develop book chapters for this edited collection in order to reflect the latest results and open research questions in the area. The contributed chapters have been organized by the editors to reflect the various themes of sliding mode control which are the current areas of theoretical research and applications focus; namely articulation of the fundamental underpinning theory of the sliding mode design paradigm, sliding modes for decentralized system representations, control of time-delay systems, the higher order sliding mode concept, results applicable to nonlinear an...

  14. Effects of induced vibration modes on droplet sliding phenomena

    Science.gov (United States)

    Mejia, Jose Eduardo; Alvarado, Jorge; Yao, Chun-Wei; Dropwise Condensation Collaboration; Engineered Surfaces Collaboration

    2016-11-01

    An analytical and experimental investigation has been undertaken to understand the effects of induced vibration modes on droplet sliding phenomena. A mathematical model has been postulated which is capable of estimating accurately droplet sliding angles when using hydrophobic and hydrophilic surfaces. The model, which takes into account equilibrium contact angle, contact angle hysteresis, and droplet volume, has been validated using experimental data. The model has been modified to be able to estimate droplet sliding angle when different modes of vibrations are imposed on the surfaces. Experimental results to date reveal that when resonance modes of vibrations are imposed, the droplet sliding angles decrease considerably. The results also indicate that the modified model can be used effectively to relate imposed resonance frequencies to the critical sliding angle of droplets. LSAMP sponsored NSF Fellowship.

  15. Sliding Threshold Identification of a Deep-Seated Potential Landslide

    Science.gov (United States)

    Wang, K.-L.; Liao, J.-T.; Chen, C.-W.; Lin, M.-L.; Lin, H.-H.

    2012-04-01

    The process for a creep landslide to rapid landslide is quite difficult to solve owing to each landslide is unique. The initiation of landslide probably results from heavy rainfall, seismic force, or even cut off at toe. However, the sliding deformation can be monitored once the sliding is still happening. The index to identify sliding usually uses displacement especially one directional displacement. Thus the design of landslide warning system usually includes displacement across stale part and sliding part, GPS, and rainfall. A deep-seated potential landslide site is selected to develop a relationship between rainfall, groundwater level, 3-D deformation, tilting. Monitored data was documented from 2005 to 2011, including at least three heavy rainfall events. Measured deformation data such as GPS data, slope indicators, scar displacement, in-hole displacement, terrestrial LiDAR, and photogrammetry are summed to discuss sliding process. Threshold indexes such as 3-D deformation and tilting angle under extreme conditions will be proposed in this study.

  16. Teaching Veterinary Histopathology: A Comparison of Microscopy and Digital Slides.

    Science.gov (United States)

    Brown, Peter J; Fews, Debra; Bell, Nick J

    2016-01-01

    Virtual microscopy using digitized slides has become more widespread in teaching in recent years. There have been no direct comparisons of the use of virtual microscopy and the use of microscopes and glass slides. Third-year veterinary students from two different schools completed a simple objective test, covering aspects of histology and histopathology, before and after a practical class covering relevant material presented as either glass slides viewed with a microscope or as digital slides. There was an overall improvement in performance by students at both veterinary schools using both practical formats. Neither format was consistently better than the other, and neither school consistently outperformed the other. In a comparison of student appraisal of use of digital slides and microscopes, the digital technology was identified as having many advantages.

  17. Sliding inguinal hernia is a risk factor for recurrence

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Bisgaard, Thue; Rosenberg, Jacob

    2015-01-01

    PURPOSE: A sliding inguinal hernia is defined as a hernia where part of the hernial sac wall is formed by an organ, e.g., the colon or bladder. Thus, repair of a sliding inguinal hernia may have higher risk of complications and recurrence compared with non-sliding inguinal hernia. The aim...... of this study was to investigate the incidence and reoperation rates following sliding inguinal hernia repair. METHODS: This study was based on data from the Danish Hernia Database covering the period between January 1, 1998 and February 22, 2012. Data were collected prospectively and nationwide. RESULTS......: In total, 70,091 primary hernia repairs were included for analysis. The occurrence of sliding inguinal hernias of the total group of included hernia repairs was 9.4 % among males and 2.9 % among females (p inguinal hernias had a higher cumulated reoperation rate...

  18. DPS Discovery Slide Sets for the Introductory Astronomy Instructor

    Science.gov (United States)

    Meinke, Bonnie K.; Jackson, Brian; Buxner, Sanlyn; Horst, Sarah; Brain, David; Schneider, Nicholas M.

    2016-10-01

    The DPS actively supports the E/PO needs of the society's membership, including those at the front of the college classroom. The DPS Discovery Slide Sets are an opportunity for instructors to put the latest planetary science into their lectures and for scientists to get their exciting results to college students.In an effort to keep the astronomy classroom apprised of the fast moving field of planetary science, the Division for Planetary Sciences (DPS) has developed "DPS Discoveries", which are 3-slide presentations that can be incorporated into college lectures. The slide sets are targeted at the Introductory Astronomy undergraduate level. Each slide set consists of three slides which cover a description of the discovery, a discussion of the underlying science, and a presentation of the big picture implications of the discovery, with a fourth slide that includes links to associated press releases, images, and primary sources. Topics span all subdisciplines of planetary science, and 26 sets are available in Farsi and Spanish. We intend for these slide sets to help Astronomy 101 instructors include new developments (not yet in their textbooks) into the broader context of the course. If you need supplemental material for your classroom, please checkout the archived collection: http://dps.aas.org/education/dpsdiscMore slide sets are now in development and will be available soon! In the meantime, we seek input, feedback, and help from the DPS membership to add fresh slide sets to the series and to connect the college classroom to YOUR science. It's easy to get involved - we'll provide a content template, tips and tricks for a great slide set, and pedagogy reviews. Talk to a coauthor to find out how you can disseminate your science or get involved in E/PO with your contributions.

  19. Second-order sliding mode control with experimental application.

    Science.gov (United States)

    Eker, Ilyas

    2010-07-01

    In this article, a second-order sliding mode control (2-SMC) is proposed for second-order uncertain plants using equivalent control approach to improve the performance of control systems. A Proportional + Integral + Derivative (PID) sliding surface is used for the sliding mode. The sliding mode control law is derived using direct Lyapunov stability approach and asymptotic stability is proved theoretically. The performance of the closed-loop system is analysed through an experimental application to an electromechanical plant to show the feasibility and effectiveness of the proposed second-order sliding mode control and factors involved in the design. The second-order plant parameters are experimentally determined using input-output measured data. The results of the experimental application are presented to make a quantitative comparison with the traditional (first-order) sliding mode control (SMC) and PID control. It is demonstrated that the proposed 2-SMC system improves the performance of the closed-loop system with better tracking specifications in the case of external disturbances, better behavior of the output and faster convergence of the sliding surface while maintaining the stability.

  20. Analysis of tensioned membrane structures considering cable sliding

    Institute of Scientific and Technical Information of China (English)

    宋昌永

    2003-01-01

    In routine design of tensioned membrane st ructures, the membrane is gen erally modeled using space membrane elements and the cables by space cable eleme nts, with no sliding allowed between the membrane and the cables. On the other h and, large deflections are expected and sliding between the membrane and the cab les is inevitable. In the present paper, the general finite element code ABAQUS was employed to investigate the influence of cable sliding on membrane surface o n the structural behavior. Three analysis models were devised to fulfill this pu rpose: (1) The membrane element shares nodes with the cable element; (2) The cab le can slide on the membrane surface freely (without friction) and (3) The cable can slide on the membrane surface, but with friction between the cable and the membrane. The sliding problem is modeled using a surface-based contact algorithm . The results from three analysis models are compared, showing that cable slidin g has only little influence on the structure shape and on the stress distributio ns in the membrane. The main influence of cable sliding may be its effect on the dynamic behavior of tensioned membrane structures.

  1. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  2. Design Gradient Descent Optimal Sliding Mode Control of Continuum Robots

    Directory of Open Access Journals (Sweden)

    Farzin Piltan

    2012-08-01

    Full Text Available In this research, a new approach for gradient descent optimal sliding mode controller for continuum robots is proposed. Based on the new dynamic models developed, a novel technique for nonlinear control of continuum manipulators to be employed in various situations has also been proposed and developed. A section of a continuum arm is modeled using lumped model elements (masses, springs and dampers and control by nonlinear methodology (sliding mode method and optimization the sliding surface slope by gradient descent method. It is shown that this type of control methodology, although used to a certain model, can be used to conveniently control the dynamics of the arm with suitable tradeoff in accuracy of modeling. This relatively controller is more plausible to implement in an actual real-time when compared to other techniques of nonlinear controller methodology of continuum arms. Principles of sliding mode methodology is based on derive the sliding surface slope and nonlinear dynamic model and applied in the system. Based on the gradient descent optimization method, the sliding surface slope and gain updating factor has been developed in certain and partly uncertain continuum robots. This methodology is represented in certain and uncertain area whose only optimization for certain area and test this optimization for uncertainty. The new techniques proposed and methodologies adopted in this paper supported by MATLAB/SIMULINK results represent a significant contribution to the field of design an optimized nonlinear sliding mode controller for continuum robots.

  3. Static and dynamic friction in sliding colloidal monolayers

    Science.gov (United States)

    Vanossi, Andrea; Manini, Nicola; Tosatti, Erio

    2013-03-01

    In a recent experimental breakthrough, the controlled sliding of 2D colloidal crystals over perfectly regular, laser generated periodic or quasi-periodic `corrugation` potentials has been realized in Bechinger's group. Based on realistic MD simulations which reproduce the main experimentally observed features, we explore the potential impact of colloid monolayer sliding in nanotribology. The free motion of edge-spawned kinks and antikinks in smooth incommensurate sliding is contrasted with the kink-antikink pair nucleation at the large static friction threshold in the commensurate case. The Aubry pinning/depinning transition is also demonstrated, e.g., as a function of the corrugation amplitude. Simulated sliding data allow the extraction of frictional work directly from particles coordinates and velocities as a function of classic friction parameters, primarily speed, and corrugation strength. Analogies with sliding charge-density waves, driven Josephson systems, sliding of rare gas islands, and other novel features suggest further experiments and insights, which promote colloid sliding to a novel friction study instrument. Research partly sponsored by Sinergia Project CRSII2 136287/1.

  4. Edit Distance to Monotonicity in Sliding Windows

    CERN Document Server

    Chan, Ho-Leung; Lee, Lap-Kei; Pan, Jiangwei; Ting, Hing-Fung; Zhang, Qin

    2011-01-01

    Given a stream of items each associated with a numerical value, its edit distance to monotonicity is the minimum number of items to remove so that the remaining items are non-decreasing with respect to the numerical value. The space complexity of estimating the edit distance to monotonicity of a data stream is becoming well-understood over the past few years. Motivated by applications on network quality monitoring, we extend the study to estimating the edit distance to monotonicity of a sliding window covering the $w$ most recent items in the stream for any $w \\ge 1$. We give a deterministic algorithm which can return an estimate within a factor of $(4+\\eps)$ using $O(\\frac{1}{\\eps^2} \\log^2(\\eps w))$ space. We also extend the study in two directions. First, we consider a stream where each item is associated with a value from a partial ordered set. We give a randomized $(4+\\epsilon)$-approximate algorithm using $O(\\frac{1}{\\epsilon^2} \\log \\epsilon^2 w \\log w)$ space. Second, we consider an out-of-order strea...

  5. Depth Estimation Using a Sliding Camera.

    Science.gov (United States)

    Ge, Kailin; Hu, Han; Feng, Jianjiang; Zhou, Jie

    2016-02-01

    Image-based 3D reconstruction technology is widely used in different fields. The conventional algorithms are mainly based on stereo matching between two or more fixed cameras, and high accuracy can only be achieved using a large camera array, which is very expensive and inconvenient in many applications. Another popular choice is utilizing structure-from-motion methods for arbitrarily placed camera(s). However, due to too many degrees of freedom, its computational cost is heavy and its accuracy is rather limited. In this paper, we propose a novel depth estimation algorithm using a sliding camera system. By analyzing the geometric properties of the camera system, we design a camera pose initialization algorithm that can work satisfyingly with only a small number of feature points and is robust to noise. For pixels corresponding to different depths, an adaptive iterative algorithm is proposed to choose optimal frames for stereo matching, which can take advantage of continuously pose-changing imaging and save the time consumption amazingly too. The proposed algorithm can also be easily extended to handle less constrained situations (such as using a camera mounted on a moving robot or vehicle). Experimental results on both synthetic and real-world data have illustrated the effectiveness of the proposed algorithm.

  6. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  7. Geomorphology, stability and mobility of the Currituck slide

    Science.gov (United States)

    Locat, J.; Lee, H.; ten Brink, U.S.; Twichell, D.; Geist, E.; Sansoucy, M.

    2009-01-01

    Over the last 100,000??years, the U.S. Atlantic continental margin has experienced various types of mass movements some of which are believed to have taken place at times of low sea level. At one of these times of low sea level a significant trigger caused a major submarine mass movement off the coast of Virginia: the Currituck slide which is believed to have taken place between 24 and 50??ka ago. This slide removed a total volume of about 165??km3 from this section of the continental slope. The departure zone still shows a very clean surface that dips at 4?? and is only covered by a thin veneer of postglacial sediment. Multibeam bathymetric and seismic survey data suggest that this slide took place along three failures surfaces. The morphology of the source area suggests that the sediments were already at least normally consolidated at the time of failure. The slide debris covers an area as much as 55??km wide that extends 180??km from the estimated toe of the original slope. The back analysis of slide initiation indicates that very high pore pressure, a strong earthquake, or both had to be generated to trigger slides on such a low failure plane angle. The shape of the failure plane, the fact that the surface is almost clear of any debris, and the mobility analysis, all support the argument that the slides took place nearly simultaneously. Potential causes for the generation of high pore pressures could be seepage forces from coastal aquifers, delta construction and related pore pressure generation due to the local sediment loading, gas hydrates, and earthquakes. This slide, and its origin, is a spectacular example of the potential threat that submarine mass movements can pose to the US Atlantic coast and underline the need to further assess the potential for the generation of such large slides, like the Grand Banks 1927 landslide of similar volume. ?? 2008 Elsevier B.V.

  8. SurfaceSlide: a multitouch digital pathology platform.

    Directory of Open Access Journals (Sweden)

    Yinhai Wang

    Full Text Available BACKGROUND: Digital pathology provides a digital environment for the management and interpretation of pathological images and associated data. It is becoming increasing popular to use modern computer based tools and applications in pathological education, tissue based research and clinical diagnosis. Uptake of this new technology is stymied by its single user orientation and its prerequisite and cumbersome combination of mouse and keyboard for navigation and annotation. METHODOLOGY: In this study we developed SurfaceSlide, a dedicated viewing platform which enables the navigation and annotation of gigapixel digitised pathological images using fingertip touch. SurfaceSlide was developed using the Microsoft Surface, a 30 inch multitouch tabletop computing platform. SurfaceSlide users can perform direct panning and zooming operations on digitised slide images. These images are downloaded onto the Microsoft Surface platform from a remote server on-demand. Users can also draw annotations and key in texts using an on-screen virtual keyboard. We also developed a smart caching protocol which caches the surrounding regions of a field of view in multi-resolutions thus providing a smooth and vivid user experience and reducing the delay for image downloading from the internet. We compared the usability of SurfaceSlide against Aperio ImageScope and PathXL online viewer. CONCLUSION: SurfaceSlide is intuitive, fast and easy to use. SurfaceSlide represents the most direct, effective and intimate human-digital slide interaction experience. It is expected that SurfaceSlide will significantly enhance digital pathology tools and applications in education and clinical practice.

  9. Sliding mode control of switching power converters techniques and implementation

    CERN Document Server

    Tan, Siew-Chong; Tse, Chi-Kong

    2011-01-01

    Sliding Mode Control of Switching Power Converters: Techniques and Implementation is perhaps the first in-depth account of how sliding mode controllers can be practically engineered to optimize control of power converters. A complete understanding of this process is timely and necessary, as the electronics industry moves toward the use of renewable energy sources and widely varying loads that can be adequately supported only by power converters using nonlinear controllers.Of the various advanced control methods used to handle the complex requirements of power conversion systems, sliding mode c

  10. Active magnetic bearing system based on sliding mode control

    Science.gov (United States)

    Zhang, Yanhong

    2017-07-01

    A new sliding mode variable structure control algorithm suitable for active magnetic bearing is proposed, which is widely used for nonlinear control system. The model and controller is designed, simulation and experimental parts are also made, according to the switching function and the sliding mode control law. The current of electromagnet is adjusted to realize stable levitation of the rotor. The experimental result shows that the sliding mode variable structure controller is an effective way for magnetic bearing control, and the active magnetic bearing system is a highly nonlinear and advanced control method that can reduce the setting time and the cost.

  11. Applications of Fuzzy Sliding Mode Control for a Gyroscope System

    Directory of Open Access Journals (Sweden)

    Shih-Chung Chen

    2013-01-01

    Full Text Available The study proposed the application of the fuzzy sliding mode for a gyroscope system status control. The state response analysis of the gyroscope system revealed highly nonlinear and chaotic subharmonic motions of 2T during state formation. The current study discussed the use of tracking control on the sliding mode control and fuzzy sliding mode control of a gyroscope control system. Consequently, the gyroscope system drives from chaotic motion to periodic motion. The numerical simulation results confirm that the proposed controller provides good system stability and convergence without chattering phenomena.

  12. Affective responses of high and low body satisfied men to viewing physique slides.

    Science.gov (United States)

    Hausenblas, Heather A; Janelle, Christopher M; Gardner, Rebecca Ellis; Hagan, Amy L

    2003-01-01

    The purpose of this study was to examine the acute affective responses of high and low body satisfied (BS) men who viewed physique slides of the male ideal (model-slides), physique slides of themselves (self-slides), and nonphysique slides (control-slides). During three laboratory visits the participants viewed the slides from one of the three conditions, and they completed pre-, in-, and post-task affective measures. It was found that the: (a) high BS group reported less mood disturbance than the low BS group; (b) participants reported an increase in depression, anger, and body dissatisfaction after viewing the self-slides; (c) participants indicated a decrease in body dissatisfaction after viewing the model-slides; and (d) viewing the control-slides did not result in affective changes. Findings suggest that viewing physique slides results in increased mood disturbance, regardless of BS level.

  13. No further risk of underwater slides?; Skredfaren over?

    Energy Technology Data Exchange (ETDEWEB)

    Haarvik, Linda; Kvalstad, Tore

    2002-07-01

    The Ormen Lange oil field of the Norwegian Sea is situated in the middle of the enormous Storegga submarine slide that occurred about 8000 years ago. The danger is probably over, but it is unclear what caused the slide. The Norwegian Geotechnical Institute has begun a comprehensive research project in order to increase the knowledge of how oil- and gas exploitation at great depths can be safeguarded against geological hazards like slides, earthquakes, flood waves and clay volcanos. This is motivated by the fact that oil exploration has moved to greater depths, where the conditions for development are very different from those at shallower depths. Future developers will have to consider the discovery of traces of old slides along the Norwegian continental shelf all the way to Spitsbergen.

  14. Sliding mode control on electro-mechanical systems

    Directory of Open Access Journals (Sweden)

    Vadim I. Utkin

    2002-01-01

    Full Text Available The first sliding mode control application may be found in the papers back in the 1930s in Russia. With its versatile yet simple design procedure the methodology is proven to be one of the most powerful solutions for many practical control designs. For the sake of demonstration this paper is oriented towards application aspects of sliding mode control methodology. First the design approach based on the regularization is generalized for mechanical systems. It is shown that stability of zero dynamics should be taken into account when the regular form consists of blocks of second-order equations. Majority of applications in the paper are related to control and estimation methods of automotive industry. New theoretical methods are developed in the context of these studies: sliding made nonlinear observers, observers with binary measurements, parameter estimation in systems with sliding mode control.

  15. Fuzzy Backstepping Sliding Mode Control for Mismatched Uncertain System

    Directory of Open Access Journals (Sweden)

    H. Q. Hou

    2014-06-01

    Full Text Available Sliding mode controllers have succeeded in many control problems that the conventional control theories have difficulties to deal with; however it is practically impossible to achieve high-speed switching control. Therefore, in this paper an adaptive fuzzy backstepping sliding mode control scheme is derived for mismatched uncertain systems. Firstly fuzzy sliding mode controller is designed using backstepping method based on the Lyapunov function approach, which is capable of handling mismatched problem. Then fuzzy sliding mode controller is designed using T-S fuzzy model method, it can improve the performance of the control systems and their robustness. Finally this method of control is applied to nonlinear system as a case study; simulation results are also provided the performance of the proposed controller.

  16. Sliding Mode Thermal Control System for Space Station Furnace Facility

    Science.gov (United States)

    Jackson Mark E.; Shtessel, Yuri B.

    1998-01-01

    The decoupled control of the nonlinear, multiinput-multioutput, and highly coupled space station furnace facility (SSFF) thermal control system is addressed. Sliding mode control theory, a subset of variable-structure control theory, is employed to increase the performance, robustness, and reliability of the SSFF's currently designed control system. This paper presents the nonlinear thermal control system description and develops the sliding mode controllers that cause the interconnected subsystems to operate in their local sliding modes, resulting in control system invariance to plant uncertainties and external and interaction disturbances. The desired decoupled flow-rate tracking is achieved by optimization of the local linear sliding mode equations. The controllers are implemented digitally and extensive simulation results are presented to show the flow-rate tracking robustness and invariance to plant uncertainties, nonlinearities, external disturbances, and variations of the system pressure supplied to the controlled subsystems.

  17. Fuzzy Sliding Mode Control for Hyper Chaotic Chen System

    Directory of Open Access Journals (Sweden)

    SARAILOO, M.

    2012-02-01

    Full Text Available In this paper, a fuzzy sliding mode control method is proposed for stabilizing hyper chaotic Chen system. The main objective of the control scheme is to stabilize unstable equilibrium point of the system by controlling the states of the system so that they converge to a pre-defined sliding surface and remain on it. A fuzzy control technique is also utilized in order to overcome the main disadvantage of sliding mode control methods, i.e. chattering problem. It is shown that the equilibrium point of the system is stabilized by using the proposed method. A stability analysis is also performed to prove that the states of the system converge to the sliding surface and remain on it. Simulations show that the control method can be effectively applied to Chen system when it performs hyper chaotic behavior.

  18. Temperature rise and wear of sliding contact of alloy steels

    Science.gov (United States)

    Goswami, Arindam Roy; Sardar, Santanu; Karmakar, Santanu Kumar

    2016-07-01

    The tribo-failure of machine elements under relative sliding velocities is greatly affected by frictional heating and resultant contact temperature rise. Nevertheless, the tribo-failure of automotive components is a combined effect of mechanical, thermal and chemical phenomena. Over the decades, there have been developed a number of different mathematical models for predicting surface temperature rise at sliding contact under different geometries of asperity contacts and operating conditions. The experimental investigation is still relevant today to find out the surface temperature rise at sliding contact along with the outcomes of friction and wear under various operating conditions for real time applications. The present work aims at finding average surface temperature rise at different sliding velocities, normal loads with different surface roughness experimentally. It also involves to prepare two different rough surfaces of alloy steels and to study their influences in the process of generating contact temperature rise under a given operating conditions.

  19. Piecewise Sliding Mode Decoupling Fault Tolerant Control System

    Directory of Open Access Journals (Sweden)

    Rafi Youssef

    2010-01-01

    Full Text Available Problem statement: Proposed method in the present study could deal with fault tolerant control system by using the so called decentralized control theory with decoupling fashion sliding mode control, dealing with subsystems instead of whole system and to the knowledge of the author there is no known computational algorithm for decentralized case, Approach: In this study we present a decoupling strategy based on the selection of sliding surface, which should be in piecewise sliding surface partition to apply the PwLTool which have as purpose in our case to delimit regions where sliding mode occur, after that as Results: We get a simple linearized model selected in those regions which could depict the complex system, Conclusion: With the 3 water tank level system as example we implement this new design scenario and since we are interested in networked control system we believe that this kind of controller implementation will not be affected by network delays.

  20. Thermal imaging on simulated faults during frictional sliding

    CERN Document Server

    Mair, Karen; Gundersen, Olav

    2008-01-01

    Heating during frictional sliding is a major component of the energy budget of earthquakes and represents a potential weakening mechanism. It is therefore important to investigate how heat dissipates during sliding on simulated faults. We present results from laboratory friction experiments where a halite (NaCl) slider held under constant load is dragged across a coarse substrate. Surface evolution and frictional resistance are recorded. Heat emission at the sliding surface is monitored using an infra-red camera. We demonstrate a link between plastic deformations of halite and enhanced heating characterized by transient localized heat spots. When sand 'gouge' is added to the interface, heating is more diffuse. Importantly, when strong asperities concentrate deformation, significantly more heat is produced locally. In natural faults such regions could be nucleation patches for melt production and hence potentially initiate weakening during earthquakes at much smaller sliding velocities or shear stress than pre...

  1. Device for Measuring Sliding Friction on Highloft Nonwovens

    Directory of Open Access Journals (Sweden)

    Stephen Michielsen

    2006-08-01

    Full Text Available When measuring the sliding friction on highly compliant materials such as fabric batting and foam rubber, a substantial portion of the apparent friction is due to the deformation of the substrate. A new friction instrument consisting of a sled within a sled has been developed that eliminates the contribution of this deformation and provides the true sliding friction as well as the force required to deform the substrate. The friction coefficient as measured using a conventional steel sled sliding on high loft polyester batts increased as the number of polyester batts increased. Using the new, guarded friction sled, the friction coefficient was independent of the number of supporting batts, thus separating the deformation forces from the sliding forces.

  2. Hierarchical Fuzzy Feature Similarity Combination for Presentation Slide Retrieval

    Directory of Open Access Journals (Sweden)

    A. Kushki

    2009-02-01

    Full Text Available This paper proposes a novel XML-based system for retrieval of presentation slides to address the growing data mining needs in presentation archives for educational and scholarly settings. In particular, contextual information, such as structural and formatting features, is extracted from the open format XML representation of presentation slides. In response to a textual user query, each extracted feature is used to compute a fuzzy relevance score for each slide in the database. The fuzzy scores from the various features are then combined through a hierarchical scheme to generate a single relevance score per slide. Various fusion operators and their properties are examined with respect to their effect on retrieval performance. Experimental results indicate a significant increase in retrieval performance measured in terms of precision-recall. The improvements are attributed to both the incorporation of the contextual features and the hierarchical feature combination scheme.

  3. Slide presentation at wilderness public hearing : Laguna Atascosa

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a layout for the presentation to be given at the public hearing for the Laguna Atascosa National Wildlife Refuge. It details the slides that will be...

  4. Adaptive sliding mode control and its application in chaos control

    Directory of Open Access Journals (Sweden)

    Liqun Shen

    2014-12-01

    Full Text Available The sliding motion of sliding mode control system is studied in this paper. Using the measure concept, two new quantities about the sliding motion are introduced, and a new relationship about the sliding motion is derived with the new quantities. According to this relationship, an adaptive law of the magnitude of the controller’s switching part is proposed, which can minimize the chattering phenomenon according to the predefined robust margin. To verify the effectiveness of the proposed control scheme, it is applied to Rössler system with uncertain disturbances. Simulation results show that the proposed control method can stabilize Rössler system with the magnitude of the controller’s switching part adjusted adaptively with the disturbances.

  5. Slide Mode Control for Integrated Electric Parking Brake System

    OpenAIRE

    Bin Wang; Xuexun Guo; Chengcai Zhang; Zhe Xiong; Huan Xia; Jie Zhang

    2013-01-01

    The emerging integrated electric parking brake (IEPB) system is introduced and studied. Through analyzing the various working stages, the stages switched IEPB system models are given with the consideration of the friction and system idle inertia. The sliding mode control (SMC) method is adopted to control the clamping force by the widely used motor angle and clamping force relationship method. Based on the characteristics of the state equations, two sliding surfaces are built to control the m...

  6. Sliding Mode Control for Trajectory Tracking of an Intelligent Wheelchair

    Directory of Open Access Journals (Sweden)

    Razvan SOLEA

    2009-12-01

    Full Text Available This paper deal with a robust sliding-mode trajectory tracking controller, fornonholonomic wheeled mobile robots and its experimental evaluation by theimplementation in an intelligent wheelchair (RobChair. The proposed control structureis based on two nonlinear sliding surfaces ensuring the tracking of the three outputvariables, with respect to the nonholonomic constraint. The performances of theproposed controller for the trajectory planning problem with comfort constraint areverified through the real time acceleration provided by an inertial measurement unit.

  7. On homogeneity and its application in sliding mode control

    OpenAIRE

    Bernuau, Emmanuel; Efimov, Denis; Perruquetti, Wilfrid; Polyakov, Andrey

    2014-01-01

    International audience; The paper is reviewing the tools to handle high-order sliding mode design and robustness. The main ingredient is homogeneity which can be checked using an algebraic test and which helps us in obtaining one of the most desired properties in sliding mode control that is finite-time stability. This paper stresses some recently obtained results about homogeneity for differential inclusions and robustness with respect to perturbations in the context of input-to-state stabil...

  8. A generalized regular form for multivariable sliding mode control

    Directory of Open Access Journals (Sweden)

    Perruquetti W.

    2001-01-01

    Full Text Available The paper shows how to compute a diffeomorphic state space transformation in order to put the initial mutivariable nonlinear model into an appropriate regular form . This form is an extension of the one proposed by Lukyanov and Utkin [9], and constitutes a guidance for a “natural” choice of the sliding surface. Then stabilization is achieved via a sliding mode strategy. In order to overcome the chattering phenomenon, a new nonlinear gain is introduced.

  9. A generalized regular form for multivariable sliding mode control

    Directory of Open Access Journals (Sweden)

    W. Perruquetti

    2001-01-01

    Full Text Available The paper shows how to compute a diffeomorphic state space transformation in order to put the initial mutivariable nonlinear model into an appropriate regular form. This form is an extension of the one proposed by Lukyanov and Utkin [9], and constitutes a guidance for a “natural” choice of the sliding surface. Then stabilization is achieved via a sliding mode strategy. In order to overcome the chattering phenomenon, a new nonlinear gain is introduced.

  10. A generalized regular form for multivariable sliding mode control

    OpenAIRE

    Perruquetti, W.; Richard, J. P.; P. Borne

    2001-01-01

    The paper shows how to compute a diffeomorphic state space transformation in order to put the initial mutivariable nonlinear model into an appropriate regular form . This form is an extension of the one proposed by Lukyanov and Utkin [9], and constitutes a guidance for a “natural” choice of the sliding surface. Then stabilization is achieved via a sliding mode strategy. In order to overcome the chattering phenomenon, a new nonlinear gain is introduced.

  11. Sliding Mode Reference Coordination of Constrained Feedback Systems

    OpenAIRE

    Alejandro Vignoni; Fabricio Garelli; Jesús Picó

    2013-01-01

    This paper addresses the problem of coordinating dynamical systems with possibly different dynamics (e.g., linear and nonlinear, different orders, constraints, etc.) to achieve some desired collective behavior under the constraints and capabilities of each system. To this end, we develop a new methodology based on reference conditioning techniques using geometric set invariance and sliding mode control: the sliding mode reference coordination (SMRCoord). The main idea is to coordinate the sys...

  12. An adaptive sliding mode control technology for weld seam tracking

    Science.gov (United States)

    Liu, Jie; Hu, Youmin; Wu, Bo; Zhou, Kaibo; Ge, Mingfeng

    2015-03-01

    A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.

  13. Grooved organogel surfaces towards anisotropic sliding of water droplets.

    Science.gov (United States)

    Zhang, Pengchao; Liu, Hongliang; Meng, Jingxin; Yang, Gao; Liu, Xueli; Wang, Shutao; Jiang, Lei

    2014-05-21

    Periodic micro-grooved organogel surfaces can easily realize the anisotropic sliding of water droplets attributing to the formed slippery water/oil/solid interface. Different from the existing anisotropic surfaces, this novel surface provides a versatile candidate for the anisotropic sliding of water droplets and might present a promising way for the easy manipulation of liquid droplets for water collection, liquid-directional transportation, and microfluidics.

  14. Adaptive sliding mode control for a class of chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Farid, R.; Ibrahim, A.; Zalam, B., E-mail: ramy5475@yahoo.com [Menofia University, Faculty of Electronic Engineering, Department of Industrial Electronics and Control, Menuf, Menofia (Egypt)

    2015-03-30

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  15. Sliding Mode Control Design: a Sum of Squares Approach

    OpenAIRE

    Sanjari, Sina; Ozgoli, Sadjaad

    2016-01-01

    This paper presents an approach to systematically design sliding mode control and manifold to stabilize nonlinear uncertain systems. The objective is also accomplished to enlarge the inner bound of region of attraction for closed-loop dynamics. The method is proposed to design a control that guarantees both asymptotic and finite time stability given helped by (bilinear) sum of squares programming. The approach introduces an iterative algorithm to search over sliding mode manifold and Lyapunov...

  16. Hybrid Fuzzy Sliding Mode Controller for Timedelay System

    OpenAIRE

    Yadav, N K; R. K. Singh,

    2013-01-01

    This paper is concerned with the problems of stability analysis and stabilization control design for a class of discrete-time T-S fuzzy systems with state-delay for multi-input and multi-output. The nonlinear fuzzy controller helps to overcome the problems of the ill - defined model of the systems, which are creating the undesirable performance. . Here sliding surface is being designed for error function of nonlinear system and sliding mode control is being designed here. The swit...

  17. Adaptive sliding mode control for a class of chaotic systems

    Science.gov (United States)

    Farid, R.; Ibrahim, A.; Zalam, B.

    2015-03-01

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  18. Sliding mode observers for automotive alternator

    Science.gov (United States)

    Chen, De-Shiou

    Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link

  19. A Neuro-fuzzy-sliding Mode Controller Using Nonlinear Sliding Surface Applied to the Coupled Tanks System

    Institute of Scientific and Technical Information of China (English)

    Ahcene Boubakir; Fares Boudjema; Salim Labiod

    2009-01-01

    The aim of this paper is to develop a neuro-fuzzy-sliding mode controller (NFSMC) with a nonlinear sliding surface for a coupled tank system.The main purpose is to eliminate the chattering phenomenon and to overcome the problem of the equivalent control computation.A first-order nonlinear sliding surface is presented,on which the developed sliding mode controller (SMC) is based.Mathematical proof for the stability and convergence of the system is presented.In order to reduce the chattering in SMC,a fixed boundary layer around the switch surface is used.Within the boundary layer,where the fuzzy logic control is applied,the chattering phenomenon,which is inherent in a sliding mode control,is avoided by smoothing the switch signal.Outside the boundary,the sliding mode control is applied to drive the system states into the boundary layer.Moreover,to compute the equivalent controller,a feed-forward neural network (NN) is used.The weights of the net are updated such that the corrective control term of the NFSMC goes to zero.Then,this NN also alleviates the chattering phenomenon because a big gain in the corrective control term produces a more serious chattering than a small gain.Experimental studies carried out on a coupled tank system indicate that the proposed approach is good for control applications.

  20. A comparison of base running and sliding techniques in collegiate baseball with implications for sliding into first base

    Institute of Scientific and Technical Information of China (English)

    Travis Ficklin; Jesus Dapena; Alexander Brunfeldt

    2016-01-01

    Purpose: The purpose of this study was to compare 4 techniques for arrival at a base after sprinting maximally to reach it:sliding head-first, sliding feet-first, running through the base without slowing, and stopping on the base. A secondary purpose of the study was to determine any advantage there may be to diving into first base to arrive sooner than running through the base. Methods: Two high-definition video cameras were used to capture 3-dimensional kinematics of sliding techniques of 9 intercollegiate baseball players. Another video camera was used to time runs from first base to second in 4 counterbalanced conditions:running through the base, sliding head-first, sliding feet-first, and running to a stop. Mathematical modeling was used to simulate diving to first base such that the slide would begin when the hand touches the base. Results: Based upon overall results, the quickest way to the base is by running through it, followed by head-first, feet-first, and running to a stop. Conclusion: There was a non-significant trend toward an advantage for diving into first base over running through it, but more research is needed, and even if the advantage is real, the risks of executing this technique probably outweigh the miniscule gain.

  1. SLIDING MODE CONTROL OF A CLASS OF IT(O) TYPE DISTRIBUTED PARAMETER SYSTEMS WITH DELAY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sliding mode control problem of a class of It(o) type partial differential equations with delay is probed. The variable structure controller is designed. The existence of motion of sliding mode is shown. And the character of invariance of sliding control system about uncertainty on the sliding switching surface and stability are analyzed.

  2. Optimal sliding guidance algorithm for Mars powered descent phase

    Science.gov (United States)

    Wibben, Daniel R.; Furfaro, Roberto

    2016-02-01

    Landing on large planetary bodies (e.g. Mars) with pinpoint accuracy presents a set of new challenges that must be addressed. One such challenge is the development of new guidance algorithms that exhibit a higher degree of robustness and flexibility. In this paper, the Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) optimal sliding guidance (OSG) scheme is applied to the Mars powered descent phase. This guidance algorithm has been specifically designed to combine techniques from both optimal and sliding control theories to generate an acceleration command based purely on the current estimated spacecraft state and desired final target state. Consequently, OSG yields closed-loop trajectories that do not need a reference trajectory. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of the sliding mode and using Lyapunov theory for non-autonomous systems, one can formally prove that the developed OSG law is globally finite-time stable to unknown but bounded perturbations. Here, the focus is on comparing the generalized ZEM/ZEV feedback guidance with the OSG law to explicitly demonstrate the benefits of the sliding mode augmentation. Results show that the sliding guidance provides a more robust solution in off-nominal scenarios while providing similar fuel consumption when compared to the non-sliding guidance command. Further, a Monte Carlo analysis is performed to examine the performance of the OSG law under perturbed conditions.

  3. Pine Island Glacier - local flow mechanisms and basal sliding

    Science.gov (United States)

    Wilkens, N. M.; Kleiner, T.; Humbert, A.

    2013-12-01

    Pine Island Glacier is a fast moving outlet glacier in the West Antarctic Ice Sheet. Several tributaries feeding the central ice stream characterise the flow field structure of this glacier. In the past decades the glacier has shown acceleration, thinning and a significant grounding line retreat. These ongoing processes are coinciding with a concentrated mass loss in the area around Pine Island Glacier, the Amundsen Sea Embayment. The area is of additional interest due to its retrograde bed slope. The postulated instability of the setting turns the glacier into an even more suitable object for modelling studies. One major challenge encountered when modelling the flow field of Pine Island Glacier is to reproduce the locally varying flow pattern, with its many tributaries. Commonly this difficulty is overcome by inversion for parameters controlling basal sliding. Our study is aimed at connecting basal sliding again to physical parameters. To achieve this we conduct experiments of Pine Island Glacier with the diagnostic 3D full-Stokes model COMice. The model is thermo-mechanically coupled and implemented with the commercial finite-element package COMSOL Multiphysics©. We use remotely sensed surface velocity data to validate our results. In a first step, the model is used to identify dominant local mechanisms that drive the flow of the different tributaries. We identify connections between the basal topography, the basal temperature, the driving stress and the basal roughness distribution. The thus gained information is used to confine basal sliding. Areas with similar qualitative characteristics are identified, and constant-sliding assumptions made for those. Additionally, the basal roughness distribution is matched onto a basal sliding parameter. This way the sliding law is again brought closer to its original meaning. Our results are important for prognostic model experiments, as we connect basal sliding to locally varying basal properties, which might lead to

  4. Performance of a malaria microscopy image analysis slide reading device

    Directory of Open Access Journals (Sweden)

    Prescott William R

    2012-05-01

    Full Text Available Abstract Background Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a “device” consisting of a microscope, a scanner, and a computer algorithm that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (“WHO55” test, and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test. These subjects’ blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. Results On the WHO55 test, the device scored a “Level 4” using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions In its

  5. Sliding mode controllers for a tempered glass furnace.

    Science.gov (United States)

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system's parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results.

  6. Robust observer-based adaptive fuzzy sliding mode controller

    Science.gov (United States)

    Oveisi, Atta; Nestorović, Tamara

    2016-08-01

    In this paper, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem. The plant is subjected to a square-integrable disturbance and is assumed to have mismatch uncertainties both in state- and input-matrices. Based on the classical sliding mode controller, the equivalent control effort is obtained to satisfy the sufficient requirement of sliding mode controller and then the control law is modified to guarantee the reachability of the system trajectory to the sliding manifold. In order to relax the norm-bounded constrains on the control law and solve the chattering problem of sliding mode controller, a fuzzy logic inference mechanism is combined with the controller. An adaptive law is then introduced to tune the parameters of the fuzzy system on-line. Finally, for evaluating the controller and the robust performance of the closed-loop system, the proposed regulator is implemented on a real-time mechanical vibrating system.

  7. Wide-field lensfree imaging of tissue slides

    Science.gov (United States)

    Morel, Sophie Nhu An; Delon, Antoine; Blandin, Pierre; Bordy, Thomas; Cioni, Olivier; Hervé, Lionel; Fromentin, Catherine; Dinten, Jean-Marc; Allier, Cédric

    2015-07-01

    We developed a new imaging tool that can help pathologists in recording wide-field images of tissue slides. We present a simple cost-effective lens-free imaging method to record 2-4μm resolution wide-field (10 mm2 - 6 cm2) images of stained and unstained tissue slides. To our knowledge, our method is the first technique that enables fast (less than 5 minutes) wide-field lens-free imaging of such dense samples. Multiple holograms are recorded with different wavelength illumination, and a multispectral algorithm is used to retrieve both amplitude and phase. Our method can be used to retrieve images of stained tissue slides. For such absorbing object, the useful information is included in the modulus of the reconstructed complex field. Our method can also be applied to retrieve images of unstained tissue slides, where the useful information is in the retrieved phase. This technique is much cheaper and compact than a conventional microscope and could be made portable. Moreover, it enables wide field unstained tissue slides imaging, which could quickly provide useful information, for example on frozen section biopsies, when a rapid diagnosis is needed during surgery.

  8. RecA filament sliding on DNA facilitates homology search

    Science.gov (United States)

    Ragunathan, Kaushik; Liu, Cheng; Ha, Taekjip

    2012-01-01

    During homologous recombination, RecA forms a helical filament on a single stranded (ss) DNA that searches for a homologous double stranded (ds) DNA and catalyzes the exchange of complementary base pairs to form a new heteroduplex. Using single molecule fluorescence imaging tools with high spatiotemporal resolution we characterized the encounter complex between the RecA filament and dsDNA. We present evidence in support of the ‘sliding model’ wherein a RecA filament diffuses along a dsDNA track. We further show that homology can be detected during sliding. Sliding occurs with a diffusion coefficient of approximately 8000 bp2/s allowing the filament to sample several hundred base pairs before dissociation. Modeling suggests that sliding can accelerate homology search by as much as 200 fold. Homology recognition can occur for as few as 6 nt of complementary basepairs with the recognition efficiency increasing for higher complementarity. Our data represents the first example of a DNA bound multi-protein complex which can slide along another DNA to facilitate target search. DOI: http://dx.doi.org/10.7554/eLife.00067.001 PMID:23240082

  9. A sliding mode controller for vehicular traffic flow

    Science.gov (United States)

    Li, Yongfu; Kang, Yuhao; Yang, Bin; Peeta, Srinivas; Zhang, Li; Zheng, Taixong; Li, Yinguo

    2016-11-01

    This study proposes a sliding mode controller for vehicular traffic flow based on a car-following model to enhance the smoothness and stability of traffic flow evolution. In particular, the full velocity difference (FVD) model is used to capture the characteristics of vehicular traffic flow. The proposed sliding mode controller is designed in terms of the error between the desired space headway and the actual space headway. The stability of the controller is guaranteed using the Lyapunov technique. Numerical experiments are used to compare the performance of sliding mode control (SMC) with that of feedback control. The results illustrate the effectiveness of the proposed SMC method in terms of the distribution smoothness and stability of the space headway, velocity, and acceleration profiles. They further illustrate that the SMC strategy is superior to that of the feedback control strategy, while enabling computational efficiency that can aid in practical applications.

  10. Suitable Friction Sliding Materials for Base Isolation of Masonry Buildings

    Directory of Open Access Journals (Sweden)

    Radhikesh P. Nanda

    2012-01-01

    Full Text Available A feasibility study of friction base isolation system for seismic protection has been performed. Four different sliding interfaces, namely, green marble/High Density Poly Ethylene (HDPE, green marble/green marble, green marble/geosynthetic, and green marble/ rubber layers have been studied through experimental and analytical investigations. The experimental investigations show that the coefficient of friction values of these interfaces lies in the desirable range for seismic protection, i.e., 0.05 to 0.15. The analytical investigation reveals that most of these sliding interfaces are effective in reducing spectral accelerations up to 50% and the sliding displacement is restricted within plinth projection of 75 mm (3 in. Green marble and geosynthetic are found to be better alternatives for use in friction isolation system with equal effectiveness of energy dissipation and limiting the earthquake energy transmission to super structure during strong earthquake leading to a low cost, durable solution for earthquake protection of masonry buildings.

  11. Sliding mode tracking control for miniature unmanned helicopters

    Directory of Open Access Journals (Sweden)

    Bin Xian

    2015-02-01

    Full Text Available A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID and linear-quadratic regulator (LQR cascaded controller in the presence of wind gust disturbances.

  12. Composite fuzzy sliding mode control of nonlinear singularly perturbed systems.

    Science.gov (United States)

    Nagarale, Ravindrakumar M; Patre, B M

    2014-05-01

    This paper deals with the robust asymptotic stabilization for a class of nonlinear singularly perturbed systems using the fuzzy sliding mode control technique. In the proposed approach the original system is decomposed into two subsystems as slow and fast models by the singularly perturbed method. The composite fuzzy sliding mode controller is designed for stabilizing the full order system by combining separately designed slow and fast fuzzy sliding mode controllers. The two-time scale design approach minimizes the effect of boundary layer system on the full order system. A stability analysis allows us to provide sufficient conditions for the asymptotic stability of the full order closed-loop system. The simulation results show improved system performance of the proposed controller as compared to existing methods. The experimentation results validate the effectiveness of the proposed controller.

  13. Sliding mode controller for a photovoltaic pumping system

    Science.gov (United States)

    ElOugli, A.; Miqoi, S.; Boutouba, M.; Tidhaf, B.

    2017-03-01

    In this paper, a sliding mode control scheme (SMC) for maximum power point tracking controller for a photovoltaic pumping system, is proposed. The main goal is to maximize the flow rate for a water pump, by forcing the photovoltaic system to operate in its MPP, to obtain the maximum power that a PV system can deliver.And this, through the intermediary of a sliding mode controller to track and control the MPP by overcoming the power oscillation around the operating point, which appears in most implemented MPPT techniques. The sliding mode control approach is recognized as one of the efficient and powerful tools for nonlinear systems under uncertainty conditions.The proposed controller with photovoltaic pumping system is designed and simulated using MATLAB/SIMULINK environment. In addition, to evaluate its performances, a classical MPPT algorithm using perturb and observe (P&O) has been used for the same system to compare to our controller. Simulation results are shown.

  14. Sliding mode tracking control for miniature unmanned helicopters

    Institute of Scientific and Technical Information of China (English)

    Xian Bin; Guo Jianchuan; Zhang Yao; Zhao Bo

    2015-01-01

    A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS) of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID) and linear-quadratic regulator (LQR) cascaded controller in the presence of wind gust disturbances.

  15. Sliding mode control method having terminal convergence in finite time

    Science.gov (United States)

    Venkataraman, Subramanian T. (Inventor); Gulati, Sandeep (Inventor)

    1994-01-01

    An object of this invention is to provide robust nonlinear controllers for robotic operations in unstructured environments based upon a new class of closed loop sliding control methods, sometimes denoted terminal sliders, where the new class will enforce closed-loop control convergence to equilibrium in finite time. Improved performance results from the elimination of high frequency control switching previously employed for robustness to parametric uncertainties. Improved performance also results from the dependence of terminal slider stability upon the rate of change of uncertainties over the sliding surface rather than the magnitude of the uncertainty itself for robust control. Terminal sliding mode control also yields improved convergence where convergence time is finite and is to be controlled. A further object is to apply terminal sliders to robot manipulator control and benchmark performance with the traditional computed torque control method and provide for design of control parameters.

  16. Prediction of alpine glacier sliding instabilities: a new hope

    CERN Document Server

    Faillettaz, Jerome; Sornette, Didier

    2012-01-01

    Mechanical and sliding instabilities are the two processes which may lead to breaking off events of large ice masses. Mechanical instabilities mainly affect unbalanced cold hanging glaciers. For the latter case, a prediction could be achieved based on data of surface velocities and seismic activity. The case of sliding instabilities is more problematic. This phenomenon occurs on temperate glacier tongues. Such instabilities are strongly affected by the subglacial hydrology: melt water may cause (i) a lubrication of the bed and (ii) a decrease of the effective pressure and consequently a decrease of basal friction. Available data from Allalingletscher (Valais) indicate that the glacier tongue experienced an active phase during 2-3 weeks with enhanced basal motion in late summer in most years. In order to scrutinize in more detail the processes governing the sliding instabilities, a numerical model developed to investigate gravitational instabilities in heterogeneous media was applied to Allalingletscher. This ...

  17. Tensor product model transformation based decoupled terminal sliding mode control

    Science.gov (United States)

    Zhao, Guoliang; Li, Hongxing; Song, Zhankui

    2016-06-01

    The main objective of this paper is to propose a tensor product model transformation based decoupled terminal sliding mode controller design methodology. The methodology is divided into two steps. In the first step, tensor product model transformation is applied to the single-input-multi-output system and a parameter-varying weighted linear time-invariant system is obtained. Then, decoupled terminal sliding mode controller is designed based on the linear time-invariant systems. The main novelty of this paper is that the nonsingular terminal sliding mode control design is based on a numerical model rather than an analytical one. Finally, simulations are tested on cart-pole system and translational oscillations with a rotational actuator system.

  18. Structural basis of human PCNA sliding on DNA

    Science.gov (United States)

    de March, Matteo; Merino, Nekane; Barrera-Vilarmau, Susana; Crehuet, Ramon; Onesti, Silvia; Blanco, Francisco J.; de Biasio, Alfredo

    2017-01-01

    Sliding clamps encircle DNA and tether polymerases and other factors to the genomic template. However, the molecular mechanism of clamp sliding on DNA is unknown. Using crystallography, NMR and molecular dynamics simulations, here we show that the human clamp PCNA recognizes DNA through a double patch of basic residues within the ring channel, arranged in a right-hand spiral that matches the pitch of B-DNA. We propose that PCNA slides by tracking the DNA backbone via a `cogwheel' mechanism based on short-lived polar interactions, which keep the orientation of the clamp invariant relative to DNA. Mutation of residues at the PCNA-DNA interface has been shown to impair the initiation of DNA synthesis by polymerase δ (pol δ). Therefore, our findings suggest that a clamp correctly oriented on DNA is necessary for the assembly of a replication-competent PCNA-pol δ holoenzyme.

  19. Optimal Sliding Mode Controllers for Attitude Stabilization of Flexible Spacecraft

    Directory of Open Access Journals (Sweden)

    Chutiphon Pukdeboon

    2011-01-01

    Full Text Available The robust optimal attitude control problem for a flexible spacecraft is considered. Two optimal sliding mode control laws that ensure the exponential convergence of the attitude control system are developed. Integral sliding mode control (ISMC is applied to combine the first-order sliding mode with optimal control and is used to control quaternion-based spacecraft attitude manoeuvres with external disturbances and an uncertainty inertia matrix. For the optimal control part the state-dependent Riccati equation (SDRE and optimal Lyapunov techniques are employed to solve the infinite-time nonlinear optimal control problem. The second method of Lyapunov is used to guarantee the stability of the attitude control system under the action of the proposed control laws. An example of multiaxial attitude manoeuvres is presented and simulation results are included to verify the usefulness of the developed controllers.

  20. On Sliding Friction of PEEK Based Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    H. Liao; G. Zhang; C. Mateus; H. Li; C. Coddet

    2004-01-01

    Polyetheretherketone (PEEK) based composite materials become of great interest to applications as bearing and slider materials due to their excellent tribological performance. In present work, graphite and MoS2 (7%, wt) filled PEEK coatings were prepared using serigraph technique. Employing a uniform design experiment, the friction behavior of the composite coatings was systematically investigated under dry sliding conditions on a ball-on-disc arrangement. The evolution mechanism of coating friction coefficient was discussed. Correlation of coatings friction coefficient with sliding velocity and applied load was accomplished usingstepwise regression method. The results indicate that friction coefficients of PEEK + MoS2 and PEEK + graphite coating decrease while increasing applied load. Moreover, friction coefficient of PEEK + MoS2 coating increases with increasing sliding velocity.

  1. On Sliding Friction of PEEK Based Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    H.Liao; G.Zhang; C.Mateus; H.Li; C.Coddet

    2004-01-01

    Polyetheretherketone (PEEK) based composite materials become of great interest to applications as bearing and slider materials due to their excellent tribological performance. In present work, graphite and MoS2(7%,wt) filled PEEK coatings were prepared using serigraph technique. Employing a uniform design experiment, the friction behavior of the composite coatings was systematically investigated under dry sliding conditions on a ball-on-disc arrangement. The evolution mechanism of coating friction coefficient was discussed. Correlation of coatings friction coefficient with sliding velocity and applied load was accomplished using stepwise regression method. The results indicate that friction coefficients of PEEK+MoS2 and PEEK+graphite coating decrease while increasing applied load. Moreover, friction coefficient of PEEK+MoS2 coating increases with increasing sliding velocity.

  2. Routes to failure in rotating MEMS devices experiencing sliding friction

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.L.; LaVigne, G.; Rodgers, M.S.; Sniegowski, J.J.; Waters, J.P.; McWhorter, P.J.

    1997-08-01

    Gear systems rotating on hubs have been operated to failure using Sandia`s microengine as the actuation device. Conventional failure modes such as fatigue induced fracture did not occur, indicating that the devices are mechanically extremely robust. The generic route to failure observed for all rotating devices involves sticking of structures that are in sliding contact. This sticking evidently results from microscopic changes in the sliding surfaces during operation. The rate at which these changes occur is accelerated by excessive applied forces, which originate from non-optimized designs or inappropriate drive voltages. Precursors to failure are observed, enabling further understanding of the microscopic changes that occur in the sliding surfaces that ultimately lead to failure.

  3. An Axial Sliding Test for machine elements surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran

    2012-01-01

    liners. To prove the efficacy of a particular textured surface, it is paramount to perform experimental tests under controlled laboratory conditions. In this paper a new test rig simulating pure sliding conditions is presented, dubbed Axial Sliding Test. It presents four major components: a rod, a sleeve......, a housing and a stripwound container. The rod and the sleeve are the two surfaces in relative sliding motion; the stripwound container maintains a constant, but adjustable normal pressure and the housing serves as interface between the sleeve and the container. For carrying out the test, two machineries...... turned rod against a mirror-polished sleeve. Qualitatively the multifunctional surfaces improve the friction conditions, but a more structured test campaign is required....

  4. Nanolubrication of sliding components in adaptive optics used in microprojectors

    Science.gov (United States)

    Bhushan, Bharat; Lee, Hyungoo; Chaparala, Satish C.; Bhatia, Vikram

    2010-10-01

    Integrated microprojectors are being developed to project a large image on any surface chosen by the users. For a laser-based microprojector, a piezo-electric based adaptive optics unit is adopted in the green laser architecture. The operation of this unit depends on stick-slip motion between the sliding components. Nanolubrication of adaptive optics sliding components is needed to reduce wear and for smooth operation. In this study, a methodology to measure lubricant thickness distribution with a nanoscale resolution is developed. Friction, adhesion, and wear mechanisms of lubricant on the sliding components are studied. Effect of actual composite components, scan direction, scale effect, temperature, and humidity to correlate AFM data with the microscale device performance is studied.

  5. Friction Coefficient of UHMWPE During Dry Reciprocating Sliding

    Directory of Open Access Journals (Sweden)

    F. Zivic

    2014-09-01

    Full Text Available This paper deals with the friction coefficient behaviour during dry reciprocating sliding of UHMWPE in contact with alumina (Al2O3, within a range of velocities typical for hip implants. Five values of normal force (100 - 1000 mN and three values of sliding speed (4 - 12 mm/s have been observed. Real time diagrams of the friction coefficient as a function of the sliding cycles were recorded for each test. Dynamic friction coefficient curves exhibited rather uniform behavior for all test conditions. Somewhat larger values of friction coefficient could be observed during the running-in period in case of low loads (100 - 250 mN and the lowest velocity (4 mm/s. In case of high loads and speeds, friction coefficient reached steady state values shortly after the beginning of the test.

  6. Discrete Sliding Mode Control for Hypersonic Cruise Missile

    Directory of Open Access Journals (Sweden)

    Yong Hua Fan

    2016-01-01

    Full Text Available A discrete variable structure control (DVSC with sliding vector is presented to track the velocity and acceleration command for a hypersonic cruise missile. In the design an integrator is augmented to ensure the tracking with zero steady-state errors. Furthermore the sliding surface of acceleration is designed using the error of acceleration and acceleration rate to avoid the singularity of control matrix. A proper power rate reaching law is utilized in this proposal; therefore the state trajectory from any initial point can be driven into the sliding surface. Besides, in order to validate the robustness of controller, the unmolded dynamic and parameter disturbance of the missile are considered. Through simulation the proposed controller demonstrates good performance in tracking velocity and acceleration command.

  7. Reducing Sliding Friction with Liquid-Impregnated Surfaces

    Science.gov (United States)

    Habibi, Mohammad; Collier, C. Patrick; Boreyko, Jonathan; Nature Inspired Fluids; Interfaces Team; CenterNanophase Materials Sciences Team

    2015-11-01

    Liquid-impregnated surfaces are fabricated by infusing a lubricating liquid into the micro/nano roughness of a textured substrate, such that the surface is slippery for any deposited liquid immiscible with the lubricant. To date, liquid-impregnated surfaces have almost exclusively focused on repelling liquids by minimizing the contact angle hysteresis. Here, we demonstrate that liquid-impregnated surfaces are also capable of reducing sliding friction for solid objects. Ordered arrays of silicon micropillars were infused with lubricating liquids varying in viscosity by two orders of magnitude. Five test surfaces were used: two different micropillared surfaces with and without liquid infusion and a smooth, dry control surface. The static and kinetic coefficients of friction were measured using a polished aluminum cube as the sliding object. Compared to the smooth control surface, the sliding friction was reduced by at least a factor of two on the liquid-impregnated surfaces.

  8. Robust antisynchronization of chaos using sliding mode control strategy

    Indian Academy of Sciences (India)

    Amit Mondal; Mitul Islam; Nurul Islam

    2015-01-01

    The paper proposes a sliding mode control strategy-based scheme for achieving anti-synchronization between two coupled non-linear chaotic systems. The method works irrespective of whether the systems under consideration possess or lack inverse symmetry. Using a linear sliding surface, a sliding mode control input and a non-linear coupling function are designed that synchronizes the systems antiphase. Finite-time convergence of the method is established. The controller is also robust to all forms of bounded perturbations and this robustness can be easily achieved by tuning of a single controller parameter and introduction of a control vector. The controller is also made chattering-free by producing a continuous analogue of the discontinuous control input. The effectiveness of the method is established by implementing it to antisynchronize chaotic Sprott systems and Rossler systems. The results are also verified through numerical simulation work.

  9. Scale effects in sliding friction: An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.

    1991-07-24

    Solid friction is considered by some to be a fundamental property of two contacting materials, while others consider it to be a property of the larger tribosystem in which the materials are contained. A set of sliding friction experiments were designed to investigate the hypothesis that the unlubricated sliding friction between two materials is indeed a tribosystems-related property and that the relative influence of the materials properties or those of the machine on friction varies from one situation to another. Three tribometers were used: a friction microprobe (FMP), a typical laboratory-scale reciprocating pin-on-flat device, and a heavy-duty commercial wear tester. The slider material was stainless steel (AISI 440C) and the flat specimen material was an ordered alloy of Ni{sub 3}Al (IC-50). Sphere-on-flat geometry was used at ambient conditions and at normal forces ranging from 0.01 N to 100 N and average sliding velocities of 0.01 to 100.0 mm/s. The nominal, steady-state sliding friction coefficient tended to decrease with increases in normal force for each of the three tribometers, and the steady state value of sliding friction tended to increase as the mass of the machine increased. The variation of the friction force during sliding was also a characteristic of the test system. These studies provide further support to the idea that the friction of both laboratory-scale and engineering tribosystems should be treated as a parameter which may take on a range of characteristic values and not conceived as having a single, unique value for each material pair.

  10. A history of slide rules for blackbody radiation computations

    Science.gov (United States)

    Johnson, R. Barry; Stewart, Sean M.

    2012-10-01

    During the Second World War the importance of utilizing detection devices capable of operating in the infrared portion of the electromagnetic spectrum was firmly established. Up until that time, laboriously constructed tables for blackbody radiation needed to be used in calculations involving the amount of radiation radiated within a given spectral region or for other related radiometric quantities. To rapidly achieve reasonably accurate calculations of such radiometric quantities, a blackbody radiation calculator was devised in slide rule form first in Germany in 1944 and soon after in England and the United States. In the immediate decades after its introduction, the radiation slide rule was widely adopted and recognized as a useful and important tool for engineers and scientists working in the infrared field. It reached its pinnacle in the United States in 1970 in a rule introduced by Electro Optical Industries, Inc. With the onset in the latter half of the 1970s of affordable, hand-held electronic calculators, the impending demise of the radiation slide rule was evident. No longer the calculational device of choice, the radiation slide rule all but disappeared within a few short years. Although today blackbody radiation calculations can be readily accomplished using anything from a programmable pocket calculator upwards, with each device making use of a wide variety of numerical approximations to the integral of Planck's function, radiation slide rules were in the early decades of infrared technology the definitive "workhorse" for those involved in infrared systems design and engineering. This paper presents a historical development of radiation slide rules with many versions being discussed.

  11. National Difference in Intelligence: A Review of the Work of Lynn and Vanhanen%国民智商:有关智力国别差异的研究

    Institute of Scientific and Technical Information of China (English)

    Lynn R.; Vanhanen T; 周静; 谢天(译)

    2012-01-01

    国民智商是某国家或地区民众智商的平均值。RichardLynn与TatuVanhanen教授调查了近两百个国家,给出了全球的国民智商。他们发现,国民智商与国家经济、文化、政治,及国民健康等均呈正高度正相关,并以一个两阶因果模型解释该现象。%National Intelligence is the average intelligence in a country or region. Richard Lynn and Tatu Vanhanen surveyed almost 200 countries in the world, and reported the national intelligence differences in the world. They found that the national IQs correlated highly and positively with national economics, cultural, politics, and national health. They also proposed a two-stage causal model to account for these phenomena.

  12. Geometry of the free-sliding Bernoulli beam

    Directory of Open Access Journals (Sweden)

    Moreno Giovanni

    2016-12-01

    Full Text Available If a variational problem comes with no boundary conditions prescribed beforehand, and yet these arise as a consequence of the variation process itself, we speak of the free boundary values variational problem. Such is, for instance, the problem of finding the shortest curve whose endpoints can slide along two prescribed curves. There exists a rigorous geometric way to formulate this sort of problems on smooth manifolds with boundary, which we review here in a friendly self-contained way. As an application, we study the particular free boundary values variational problem of the free-sliding Bernoulli beam.

  13. Teaching Physical Based Animation via OpenGL Slides

    Science.gov (United States)

    Song, Miao; Mokhov, Serguei A.; Grogono, Peter

    This work expands further our earlier poster presentation and integration of the OpenGL Slides Framework (OGLSF) - to make presentations with real-time animated graphics where each slide is a scene with tidgets - and physical based animation of elastic two-, three-layer softbody objects. The whole project is very interactive, and serves dual purpose - delivering the teaching material in a classroom setting with real running animated examples as well as releasing the source code to the students to show how the actual working things are made.

  14. Adaptive fuzzy sliding mode control of Lorenz chaotic system

    Institute of Scientific and Technical Information of China (English)

    WU Ligang; WANG Changhong

    2007-01-01

    By using the exponential reaching law technology,a sliding mode controller was designed for Lorenz chaotic system subject to an unknown external disturbance.On this basis,considering the unknown disturbance,an adaptive law was introduced to adaptively estimate the parameters of the disturbance bounds.Furthermore,to eliminate the chattering resulting from the discontinuous switch controller and to guarantee system transient performance,a new adaptive fuzzy sliding mode controller was designed.The results of the simulation show the effectiveness of the proposed control scheme.

  15. Adaptive robust controller based on integral sliding mode concept

    Science.gov (United States)

    Taleb, M.; Plestan, F.

    2016-09-01

    This paper proposes, for a class of uncertain nonlinear systems, an adaptive controller based on adaptive second-order sliding mode control and integral sliding mode control concepts. The adaptation strategy solves the problem of gain tuning and has the advantage of chattering reduction. Moreover, limited information about perturbation and uncertainties has to be known. The control is composed of two parts: an adaptive one whose objective is to reject the perturbation and system uncertainties, whereas the second one is chosen such as the nominal part of the system is stabilised in zero. To illustrate the effectiveness of the proposed approach, an application on an academic example is shown with simulation results.

  16. The simplex method for nonlinear sliding mode control

    Directory of Open Access Journals (Sweden)

    Bartolini G.

    1998-01-01

    Full Text Available General nonlinear control systems described by ordinary differential equations with a prescribed sliding manifold are considered. A method of designing a feedback control law such that the state variable fulfills the sliding condition in finite time is based on the construction of a suitable simplex of vectors in the tangent space of the manifold. The convergence of the method is proved under an obtuse angle condition and a way to build the required simplex is indicated. An example of engineering interest is presented.

  17. Cascade Control of Magnetic Levitation with Sliding Modes

    Directory of Open Access Journals (Sweden)

    Eroğlu Yakup

    2016-01-01

    Full Text Available The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.

  18. Development of a teledermatopathology consultation system using virtual slides

    Directory of Open Access Journals (Sweden)

    Nakayama Ikunori

    2012-12-01

    Full Text Available Abstract Background An online consultation system using virtual slides (whole slide images; WSI has been developed for pathological diagnosis, and could help compensate for the shortage of pathologists, especially in the field of dermatopathology and in other fields dealing with difficult cases. This study focused on the performance and future potential of the system. Method In our system, histological specimens on slide glasses are digitalized by a virtual slide instrument, converted into web data, and up-loaded to an open server. Using our own purpose-built online system, we then input patient details such as age, gender, affected region, clinical data, past history and other related items. We next select up to ten consultants. Finally we send an e-mail to all consultants simultaneously through a single command. The consultant receives an e-mail containing an ID and password which is used to access the open server and inspect the images and other data associated with the case. The consultant makes a diagnosis, which is sent to us along with comments. Because this was a pilot study, we also conducted several questionnaires with consultants concerning the quality of images, operability, usability, and other issues. Results We solicited consultations for 36 cases, including cases of tumor, and involving one to eight consultants in the field of dermatopathology. No problems were noted concerning the images or the functioning of the system on the sender or receiver sides. The quickest diagnosis was received only 18 minutes after sending our data. This is much faster than in conventional consultation using glass slides. There were no major problems relating to the diagnosis, although there were some minor differences of opinion between consultants. The results of questionnaires answered by many consultants confirmed the usability of this system for pathological consultation. (16 out of 23 consultants. Conclusion We have developed a novel

  19. Moist Potential Vorticity and Up-Sliding Slantwise Vorticity Development

    Institute of Scientific and Technical Information of China (English)

    GUI Xiao-Peng; GAO Shou-Ting; WU Guo-Xiong

    2003-01-01

    By using the moist potential vorticity equation derived from complete atmospheric equations including the effect of mass forcing, the theory of up-sliding slantwise vorticity development (USVD) is proposed based on the theory of slantwise vorticity development. When an air parcel slides up along a slantwise isentropic surface, its vertical component of relative vorticity is developed. Based on the theory of USVD, a complete vertical vorticity equation is expected with mass forcing, which explicitly includes the effect of both internal forcings and external forcings.

  20. The Development and Application of Composite Magnesia Slide Plates

    Institute of Scientific and Technical Information of China (English)

    WEIZhongxian; WANGRuikun; 等

    2001-01-01

    High pure magnesite(MgO≥98%, CaO/SiO2≥3 with grain size≥ 50μm) was used as inner layer material and low and middle grade magnesite as out layer material to manufacture magnesia slide plates by means of direct composite ,high temperature burning,bonding,with waste paper pulp,without pitch impregnation nd steel hoop.They were successfully applied in batch in a 385 MT concasting ladle in a certain foreign steel mill,This paper describes the effects of magnesite and burning temperature on high temperature perfomance and linear change of magnesia slide plates.

  1. Induction Motor Flux Estimation using Nonlinear Sliding Observers

    Directory of Open Access Journals (Sweden)

    Hakiki Khalid

    2007-01-01

    Full Text Available A nonlinear sliding flux was proposed for an induction motor. Its dynamic observation errors converge asymptotically to zero, independently from the inputs. The aim of this work was to study the robustness of this observer with respect to the variation of the rotor resistance known to be a crucial parameter for the control. The dynamic performance of this sliding observer was compared to that of Verghese observer via a simulation of an IM driven by U/F control in open loop.

  2. Teaching Physical Based Animation via OpenGL Slides

    CERN Document Server

    Song, Miao; Grogono, Peter; 10.1145/1557626.1557647

    2009-01-01

    This work expands further our earlier poster presentation and integration of the OpenGL Slides Framework (OGLSF) - to make presentations with real-time animated graphics where each slide is a scene with tidgets - and physical based animation of elastic two-, three-layer softbody objects. The whole project is very interactive, and serves dual purpose - delivering the teaching material in a classroom setting with real running animated examples as well as releasing the source code to the students to show how the actual working things are made.

  3. Preservation of Lantern Slides for Use in Today's Technology

    Science.gov (United States)

    Hillier, A. S.

    2007-10-01

    Lantern slides will keep a long time, which is a good quality for preservation. However, as I have found, they break. Unless there is a lantern slide projector available, there is no way to show these valuable assets to others. This poster will explain my project to bring these pictures to life, to use them in education projects, and to simply show a bit of history to an attentive audience. With today's technology they can be placed on computers and stored more easily and be a joy to all.

  4. Sliding Mode Control of Robot Manipulators via Intelligent Approaches

    OpenAIRE

    Shafiei, S. Ehsan

    2010-01-01

    This chapter addressed sliding mode control (SMC) of n-link robot manipulators by using of intelligent methods including fuzzy logic and neural network strategies. In this regard, three control strategies were investigated. In the first case, design of a sliding mode control with a PID loop for robot manipulator was presented in which the gain of both SMC and PID was tuned on-line by using fuzzy approach. The proposed methodology in fact tries to use the advantages of the SMC, PID and Fuzzy c...

  5. Sliding modes in power electronics and motion control

    OpenAIRE

    Şabanoviç, Asif; Sabanovic, Asif

    2004-01-01

    In the paper the general approach to motion control systems in the sliding mode framework is discussed in details. It has been shown that, due to the fact that a motion control system with n d.o.f may be mathematically formulated in a unique way as a system composed on n 2 d.o.f systems, design of such a system may be formulated in a unique way as a requirement that the generalized coordinates must satisfy certain algebraic constrain. Such a formulation leads naturally to sliding mode methods...

  6. Artificial neural network based inverse design method for circular sliding slopes

    Institute of Scientific and Technical Information of China (English)

    丁德馨; 张志军

    2004-01-01

    Current design method for circular sliding slopes is not so reasonable that it often results in slope sliding. As a result, artificial neural network (ANN) is used to establish an artificial neural network based inverse design method for circular sliding slopes. A sample set containing 21 successful circular sliding slopes excavated in the past is used to train the network. A test sample of 3 successful circular sliding slopes excavated in the past is used to test the trained network. The test results show that the ANN based inverse design method is valid and can be applied to the design of circular sliding slopes.

  7. Experimental sliding mode control of a flexible single link manipulator

    Science.gov (United States)

    Qian, Timothy Wei Tie

    1993-09-01

    A study was conducted to explore and develop practical controller designs for a flexible manipulator based on the variable structure (VS) system and sliding mode (SM) theory. A new control design method is first proposed based on the continuous time VSSM theory, which can significantly simplify the VS system design process. Moreover, the variables concerned can be assigned separate gains. Direct application of the VSSM control system to the flexible arm, however, has limitations due to the inherent properties of the system. To solve this problem, facilitate digital implementation, and eliminate undesirable chattering in conventional VS system control, the discrete time quasi sliding mode control (DQSMC) is developed. Two control algorithms are derived satisfying the conditions for existence of discrete time sliding hypersurfaces. It is proven that the DQSMC design is equivalent to a full state feedback with its steady state motion constrained to the sliding hypersurfaces, and that DQSMC provides a general structure unifying the three different kinds of discrete time SM control. Experimental testing of the DQSMC controller showed good results, which compared favorably to the linear quadratic Gaussian controller under the same load variations. A novel approach was then devised to realize the proposed new controller designs.

  8. The Gouging Phenomenon at Low Relative Sliding Velocities.

    Science.gov (United States)

    1995-12-01

    1976), pp. 233 - 240. [18] E. Rabinowicz , "The Temperature Rise at Sliding Electrical Contacts," Wear 78 (1982), pp. 29 - 37. [19] C. Persad and D. R... Rabinowicz , Friction and Wear of Materials, John Wiley & Sons, Inc., New York, 1965, pp. 32-36, 235. [29] R. A. Marshall, "Multi-Point Packed Wire, and

  9. Numerical Modeling of Sliding Stability of RCC dam

    Science.gov (United States)

    Mughieda, O.; Hazirbaba, K.; Bani-Hani, K.; Daoud, W.

    2017-06-01

    Stability and stress analyses are the most important elements that require rigorous consideration in design of a dam structure. Stability of dams against sliding is crucial due to the substantial horizontal load that requires sufficient and safe resistance to develop by mobilization of adequate shearing forces along the base of the dam foundation. In the current research, the static sliding stability of a roller-compacted-concrete (RCC) dam was modelled using finite element method to investigate the stability against sliding. A commercially available finite element software (SAP 2000) was used to analyze stresses in the body of the dam and foundation. A linear finite element static analysis was performed in which a linear plane strain isoperimetric four node elements was used for modelling the dam-foundation system. The analysis was carried out assuming that no slip will occur at the interface between the dam and the foundation. Usual static loading condition was applied for the static analysis. The greatest tension was found to develop in the rock adjacent to the toe of the upstream slope. The factor of safety against sliding along the entire base of the dam was found to be greater than 1 (FS>1), for static loading conditions.

  10. Sliding mode control based guidance law with impact angle constraint

    Institute of Scientific and Technical Information of China (English)

    Zhao Yao; Sheng Yongzhi; Liu Xiangdong

    2014-01-01

    The terminal guidance problem for an unpowered lifting reentry vehicle against a sta-tionary target is considered. In addition to attacking the target with high accuracy, the vehicle is also expected to achieve a desired impact angle. In this paper, a sliding mode control (SMC)-based guidance law is developed to satisfy the terminal angle constraint. Firstly, a specific sliding mode function is designed, and the terminal requirements can be achieved by enforcing both the sliding mode function and its derivative to zero at the end of the flight. Then, a backstepping approach is used to ensure the finite-time reaching phase of the sliding mode and the analytic expression of the control effort can be obtained. The trajectories generated by this method only depend on the initial and terminal conditions of the terminal phase and the instantaneous states of the vehicle. In order to test the performance of the proposed guidance law in practical application, numerical simulations are carried out by taking all the aerodynamic parameters into consideration. The effec-tiveness of the proposed guidance law is verified by the simulation results in various scenarios.

  11. Reusable Launch Vehicle Control In Multiple Time Scale Sliding Modes

    Science.gov (United States)

    Shtessel, Yuri; Hall, Charles; Jackson, Mark

    2000-01-01

    A reusable launch vehicle control problem during ascent is addressed via multiple-time scaled continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. Overall stability of a two-loop control system is addressed. An optimal control allocation algorithm is designed that allocates torque commands into end-effector deflection commands, which are executed by the actuators. The dual-time scale sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. Simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. This is a significant advancement in performance over that achieved with linear, gain scheduled control systems currently being used for launch vehicles.

  12. Sliding-Mode Control of PEM Fuel Cells

    CERN Document Server

    Kunusch, Cristian; Mayosky, Miguel

    2012-01-01

    Recent advances in catalysis technologies and new materials make fuel cells an economically appealing and clean energy source with massive market potential in portable devices, home power generation and the automotive industry. Among the more promising fuel-cell technologies are proton exchange membrane fuel cells (PEMFCs). Sliding-Mode Control of PEM Fuel Cells demonstrates the application of higher-order sliding-mode control to PEMFC dynamics. Fuel-cell dynamics are often highly nonlinear and the text shows the advantages of sliding modes in terms of robustness to external disturbance, modelling error and system-parametric disturbance using higher-order control to reduce chattering. Divided into two parts, the book first introduces the theory of fuel cells and sliding-mode control. It begins by contextualising PEMFCs both in terms of their development and within the hydrogen economy and today’s energy production situation as a whole. The reader is then guided through a discussion of fuel-cell operation pr...

  13. Studying the Activities of Microorganisms in Soil Using Slides.

    Science.gov (United States)

    Cullimore, D. Roy; Pipe, Annette E.

    1980-01-01

    Two implanted slide techniques are described by which activity of proteolylic bacteria and the growth of algae in the soil can be readily studied by school students using simple apparatus and methods. Variations are suggested for studying the effects of agricultural practices and environmental conditions on the soil bacteria and algae. (Author/DS)

  14. Dynamic trapping of sliding drops on wetting defects

    NARCIS (Netherlands)

    Cavalli, A.; Musterd, M.; Mannetje, 't D.J.C.M.; Ende, van den H.T.M.; Mugele, F.

    2014-01-01

    Abstract Submitted for the DFD14 Meeting of The American Physical Society Dynamic trapping of sliding drops on wetting defects ANDREA CAVALLI, University of Twente, MICHIEL MUSTERD, TU Delft, DIETER ’T MANNETJE, DIRK VAN DEN ENDE, FRIEDER MUGELE, University of Twente —We present a numerical analysi

  15. Sliding response of gravity dams including vertical seismic accelerations

    Institute of Scientific and Technical Information of China (English)

    Constantin Christopoulos; Pierre Léger; André Filiatrault

    2003-01-01

    Seismic safety assessment of gravity dams has become a major concern in many regions of the world while the effects of vertical seismic accelerations on the response of structures remain poorly understood. This paper first investigates the effect of including vertical accelerations in the sliding response analysis of gravity dams subjected to a range of historical ground motion records separated in two groups according to their source-to-site distance. Analyses showed that the incidence of vertical accelerations on the sliding response of gravity dams is significantly higher for near-source records than for farsource records. The pseudo-static 30% load combination rule, commonly used in practice to account for the non-simultaneous occurrence of the peak horizontal and vertical accelerations, yielded good approximations of the minimum safety factors against sliding computed from time-history analyses. A method for empirically estimating the vertical response spectra based on horizontal spectra, accounting for the difference in frequency content and amplitudes between the two components is investigated. Results from analyses using spectrum compatible horizontal and vertical synthetic records also approximated well the sliding response of a gravity dam subjected to series of simultaneous horizontal and vertical historical earthquake records.

  16. Structural changes in polytetrafluoroethylene molecular chains upon sliding against steel

    NARCIS (Netherlands)

    Shen, J.T.; Pei, Y.T.; Hosson, J.Th.M. De

    2014-01-01

    In this work, the influence of dry sliding between a steel counterpart ball and polytetrafluoroethylene (PTFE) plate sample on the transformation of PTFE molecular structure is investigated. With X-ray diffraction, differential scanning calorimetry, Fourier transform infrared (FT-IR) spectroscopy an

  17. Measurement of deformation in rolling and sliding contacts

    NARCIS (Netherlands)

    Tasan, Yusuf Caner

    2005-01-01

    In this work, mechanisms behind micro-scale changes on the surfaces in rolling and sliding contacts are studied both experimentally and numerically. For the experimental study a wear and deformation measurement system is designed and produced. This system is composed of an interference microscope, a

  18. Linear-grating triboelectric generator based on sliding electrification.

    Science.gov (United States)

    Zhu, Guang; Chen, Jun; Liu, Ying; Bai, Peng; Zhou, Yu Sheng; Jing, Qingshen; Pan, Caofeng; Wang, Zhong Lin

    2013-05-08

    The triboelectric effect is known for many centuries and it is the cause of many charging phenomena. However, it has not been utilized for energy harvesting until very recently. (1-5) Here we developed a new principle of triboelectric generator (TEG) based on a fully contacted, sliding electrification process, which lays a fundamentally new mechanism for designing universal, high-performance TEGs to harvest diverse forms of mechanical energy in our daily life. Relative displacement between two sliding surfaces of opposite triboelectric polarities generates uncompensated surface triboelectric charges; the corresponding polarization created a voltage drop that results in a flow of induced electrons between electrodes. Grating of linear rows on the sliding surfaces enables substantial enhancements of total charges, output current, and current frequency. The TEG was demonstrated to be an efficient power source for simultaneously driving a number of small electronics. The principle established in this work can be applied to TEGs of different configurations that accommodate the needs of harvesting energy and/or sensing from diverse mechanical motions, such as contacted sliding, lateral translation, and rotation/rolling.

  19. DNA typing from vaginal smear slides in suspected rape cases

    Directory of Open Access Journals (Sweden)

    Dayse Aparecida da Silva

    Full Text Available In an investigation of suspected rape, proof of sexual assault with penetration is required. In view of this, detailed descriptions of the genitalia, the thighs and pubic region are made within the forensic medical service. In addition, vaginal swabs are taken from the rape victim and some of the biological material collected is then transferred to glass slides. In this report, we describe two rape cases solved using DNA typing from cells recovered from vaginal smear slides. In 1999, two young women informed the Rio de Janeiro Police Department that they had been victims of sexual assaults. A suspect was arrested and the victims identified him as the offender. The suspect maintained that he was innocent. In order to elucidate these crimes, vaginal smear slides were sent to the DNA Diagnostic Laboratory for DNA analysis three months after the crimes, as unique forensic evidence. To get enough epithelial and sperm cells to perform DNA analysis, we used protocols modified from the previously standard protocols used for DNA extraction from biological material fixed on glass slides. The quantity of cells was sufficient to perform human DNA typing using nine short tandem repeat (STR loci. It was 3.3 billion times more probable that it was the examined suspect who had left sperm cells in the victims, rather than any other individual in the population of Rio de Janeiro.

  20. Shape control of distributed parameter reflectors using sliding mode control

    Science.gov (United States)

    Andoh, Fukashi; Washington, Gregory N.; Utkin, Vadim

    2001-08-01

    Sliding mode control has become one of the most powerful control methods for variable structure systems, a set of continuous systems with an appropriate switching logic. Its robustness properties and order reduction capability have made sliding mode control one of the most efficient tools for relatively higher order nonlinear plants operating under uncertain conditions. Piezo-electric materials possess the property of creating a charge when subjected to a mechanical strain, and of generating a strain when subjected to an electric field. Piezo-electric actuators are known to have a hysteresis due to the thermal motion and Coulomb interaction of Weiss domains. Because of the thermal effect the hysteresis of piezo-electric actuators is reproducible only with some uncertainty in experiments. The robustness of sliding mode control under uncertain conditions has an advantage in handling the hysteresis of piezo-electric actuators. In this research sliding mode control is used to control the shape of one- and two-dimensionally curved adaptive reflectors with piezo-electric actuators. Four discrete linear actuators for the one-dimensionally curved reflector and eight actuators for the two-dimensionally curved reflector are assumed.

  1. Digital Sliding Mode Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    MITIC, D. B.

    2013-02-01

    Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

  2. Understanding Learning Style by Eye Tracking in Slide Video Learning

    Science.gov (United States)

    Cao, Jianxia; Nishihara, Akinori

    2012-01-01

    More and more videos are now being used in e-learning context. For improving learning effect, to understand how students view the online video is important. In this research, we investigate how students deploy their attention when they learn through interactive slide video in the aim of better understanding observers' learning style. Felder and…

  3. Survey: interpolation methods for whole slide image processing.

    Science.gov (United States)

    Roszkowiak, L; Korzynska, A; Zak, J; Pijanowska, D; Swiderska-Chadaj, Z; Markiewicz, T

    2017-02-01

    Evaluating whole slide images of histological and cytological samples is used in pathology for diagnostics, grading and prognosis . It is often necessary to rescale whole slide images of a very large size. Image resizing is one of the most common applications of interpolation. We collect the advantages and drawbacks of nine interpolation methods, and as a result of our analysis, we try to select one interpolation method as the preferred solution. To compare the performance of interpolation methods, test images were scaled and then rescaled to the original size using the same algorithm. The modified image was compared to the original image in various aspects. The time needed for calculations and results of quantification performance on modified images were also compared. For evaluation purposes, we used four general test images and 12 specialized biological immunohistochemically stained tissue sample images. The purpose of this survey is to determine which method of interpolation is the best to resize whole slide images, so they can be further processed using quantification methods. As a result, the interpolation method has to be selected depending on the task involving whole slide images.

  4. Global Trends in Environment and Development. Presentation Set [Slides].

    Science.gov (United States)

    World Resources Inst., Washington, DC.

    This 50 slide set of presentation graphs and maps illustrates some of the major conditions and trends in population, agriculture, biodiversity, forests, water resources, energy, climate, and social and economic development that determine the state of the world's environment. Graphs and maps can be used by those in academic, professional, and…

  5. Introduction slides for RecSysTEL workshop

    NARCIS (Netherlands)

    Drachsler, Hendrik; Manouselis, Nikos; Santos, Olga; Verbert, Katrien

    2012-01-01

    Drachsler, H., Manouselis, N., Santos, O., & Verbert, K. (2012, 19 September). Introduction slides for RecSysTEL workshop. Presentation at the 2nd Workshop on Recommender Systems for Technolgy Enhancend Learning (RecSysTEL 2012) at EC-TEL 2012, Saarbrücken, Germany.

  6. Slide crown lengthening procedure using wide surface incisions and cyanoacrylate.

    Science.gov (United States)

    Szymaitis, Dennis W

    2011-01-01

    This article introduces the slide crown lengthening procedure (SCLP), which incorporates surgical design features to overcome present crown lengthening procedure (CLP) shortcomings. The result is a 75% decrease in required surgery on adjacent teeth and a corresponding 75% reduction in surgical time. Other advantages include a reduction in surgical morbidity, improvement in terminal esthetics, and fewer teeth subject to papillae removal and apically repositioned gingiva. The 20 to 30 degree incision forming the slide is the pivotal feature; it allows effortless flap positioning. This incision angle enables wide surface incisions to adhere flaps together by producing stronger fibrin clots, decreasing tissue retraction angles, and reforming disrupted fibrin clots as incision sides slide while maintaining contact. This enhanced fibrin clot eliminates the need for sutures. The slide produced by the 20 to 30 degree incision functions for crown lengthening on all sites (facial, lingual, or palatal). This versatile surgical design introduces a new healing dimension that adapts to and provides benefits for other dental surgeries, such as gingival grafts, endodontic surgery, implants, and extractions.

  7. Producing Slide and Tape Presentations: Readings from "Audiovisual Instruction"--4.

    Science.gov (United States)

    Hitchens, Howard, Ed.

    Designed to serve as a reference and source of ideas on the use of slides in combination with audiocassettes for presentation design, this book of readings from Audiovisual Instruction magazine includes three papers providing basic tips on putting together a presentation, five articles describing techniques for improving the visual images, five…

  8. Efficient sliding spotlight SAR raw signal simulation of extended scenes

    Directory of Open Access Journals (Sweden)

    Huang Pingping

    2011-01-01

    Full Text Available Abstract Sliding spotlight mode is a novel synthetic aperture radar (SAR imaging scheme with an achieved azimuth resolution better than stripmap mode and ground coverage larger than spotlight configuration. However, its raw signal simulation of extended scenes may not be efficiently implemented in the two-dimensional (2D Fourier transformed domain. This article presents a novel sliding spotlight raw signal simulation approach from the wide-beam SAR imaging modes. This approach can generate sliding spotlight raw signal not only from raw data evaluated by the simulators, but also from real data in the stripmap/spotlight mode. In order to obtain the desired raw data from conventional stripmap/spotlight mode, the azimuth time-varying filtering, which is implemented by de-rotation and low-pass filtering, is adopted. As raw signal of extended scenes in the stripmap/spotlight mode can efficiently be evaluated in the 2D Fourier domain, the proposed approach provides an efficient sliding spotlight SAR simulator of extended scenes. Simulation results validate this efficient simulator.

  9. Avalanche Statistics of Driven Granular Slides in a Miniature Mound

    CERN Document Server

    Juanico, D E; Batac, R; Monterola, C

    2008-01-01

    We examine avalanche statistics of rain- and vibration-driven granular slides in miniature soil mounds using experimental and numerical approaches. A crossover from power-law to non power-law avalanche-size statistics is demonstrated as a generic driving rate $\

  10. The Use of Slides to Study Flowering Plants

    Science.gov (United States)

    Rozenshtein, A. M.

    1976-01-01

    Seven-slide series produced by the Diafilm Studio are discussed as they are used as demonstration material for teaching students detailed familiarity with the morphology of the plants in given families and with the variety of their representatives. (Author/ND)

  11. Adaptive Sliding Mode Control Based on Uncertainty and Disturbance Estimator

    Directory of Open Access Journals (Sweden)

    Yue Zhu

    2014-01-01

    Full Text Available This paper presents an original adaptive sliding mode control strategy for a class of nonlinear systems on the basis of uncertainty and disturbance estimator. The nonlinear systems can be with parametric uncertainties as well as unmatched uncertainties and external disturbances. The novel adaptive sliding mode control has several advantages over traditional sliding mode control method. Firstly, discontinuous sign function does not exist in the proposed adaptive sliding mode controller, and it is not replaced by saturation function or similar approximation functions as well. Therefore, chattering is avoided in essence, and the chattering avoidance is not at the cost of reducing the robustness of the closed-loop systems. Secondly, the uncertainties do not need to satisfy matching condition and the bounds of uncertainties are not required to be unknown. Thirdly, it is proved that the closed-loop systems have robustness to parameter uncertainties as well as unmatched model uncertainties and external disturbances. The robust stability is analyzed from a second-order linear time invariant system to a nonlinear system gradually. Simulation on a pendulum system with motor dynamics verifies the effectiveness of the proposed method.

  12. Robust Neural Sliding Mode Control of Robot Manipulators

    Science.gov (United States)

    Hiep, Nguyen Tran; cat, Pham Thuong

    2009-03-01

    This paper proposes a robust neural sliding mode control method for robot tracking problem to overcome the noises and large uncertainties in robot dynamics. The Lyapunov direct method has been used to prove the stability of the overall system. Simulation results are given to illustrate the applicability of the proposed method

  13. GA-Based Fuzzy Sliding Mode Controller for Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    W. L. Chiang

    2008-11-01

    Full Text Available Generally, the greatest difficulty encountered when designing a fuzzy sliding mode controller (FSMC or an adaptive fuzzy sliding mode controller (AFSMC capable of rapidly and efficiently controlling complex and nonlinear systems is how to select the most appropriate initial values for the parameter vector. In this paper, we describe a method of stability analysis for a GA-based reference adaptive fuzzy sliding model controller capable of handling these types of problems for a nonlinear system. First, we approximate and describe an uncertain and nonlinear plant for the tracking of a reference trajectory via a fuzzy model incorporating fuzzy logic control rules. Next, the initial values of the consequent parameter vector are decided via a genetic algorithm. After this, an adaptive fuzzy sliding model controller, designed to simultaneously stabilize and control the system, is derived. The stability of the nonlinear system is ensured by the derivation of the stability criterion based upon Lyapunov's direct method. Finally, an example, a numerical simulation, is provided to demonstrate the control methodology.

  14. Understanding Learning Style by Eye Tracking in Slide Video Learning

    Science.gov (United States)

    Cao, Jianxia; Nishihara, Akinori

    2012-01-01

    More and more videos are now being used in e-learning context. For improving learning effect, to understand how students view the online video is important. In this research, we investigate how students deploy their attention when they learn through interactive slide video in the aim of better understanding observers' learning style. Felder and…

  15. Whole slide imaging of unstained tissue using lensfree microscopy

    Science.gov (United States)

    Morel, Sophie Nhu An; Hervé, Lionel; Bordy, Thomas; Cioni, Olivier; Delon, Antoine; Fromentin, Catherine; Dinten, Jean-Marc; Allier, Cédric

    2016-04-01

    Pathologist examination of tissue slides provides insightful information about a patient's disease. Traditional analysis of tissue slides is performed under a binocular microscope, which requires staining of the sample and delays the examination. We present a simple cost-effective lensfree imaging method to record 2-4μm resolution wide-field (10 mm2 to 6 cm2) images of unstained tissue slides. The sample processing time is reduced as there is no need for staining. A wide field of view (10 mm2) lensfree hologram is recorded in a single shot and the image is reconstructed in 2s providing a very fast acquisition chain. The acquisition is multispectral, i.e. multiple holograms are recorded simultaneously at three different wavelengths, and a dedicated holographic reconstruction algorithm is used to retrieve both amplitude and phase. Whole tissue slides imaging is obtained by recording 130 holograms with X-Y translation stages and by computing the mosaic of a 25 x 25 mm2 reconstructed image. The reconstructed phase provides a phase-contrast-like image of the unstained specimen, revealing structures of healthy and diseased tissue. Slides from various organs can be reconstructed, e.g. lung, colon, ganglion, etc. To our knowledge, our method is the first technique that enables fast wide-field lensfree imaging of such unlabeled dense samples. This technique is much cheaper and compact than a conventional phase contrast microscope and could be made portable. In sum, we present a new methodology that could quickly provide useful information when a rapid diagnosis is needed, such as tumor margin identification on frozen section biopsies during surgery.

  16. PowerPoint Slides as Speaking Notes: The Influence of Speaking Anxiety on the Use of Text on Slides

    NARCIS (Netherlands)

    Woerkum, van C.M.J.; Hertz, B.; Kerkhof, P.

    2016-01-01

    PowerPoint presentations are often criticized for the excessive use of text on the
    slides. In a study of 97 academic scholars, we found that presenters indeed used
    substantially more text than is advised. Speaking anxiety was found to be related to
    the time spent on preparing and rehears

  17. Adaptive Control of MEMS Gyroscope Based on Global Terminal Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Weifeng Yan

    2013-01-01

    Full Text Available An adaptive global fast terminal sliding mode control (GFTSM is proposed for tracking control of Micro-Electro-Mechanical Systems (MEMS vibratory gyroscopes under unknown model uncertainties and external disturbances. To improve the convergence rate of reaching the sliding surface, a global fast terminal sliding surface is employed which can integrate the advantages of traditional sliding mode control and terminal sliding mode control. It can be guaranteed that sliding surface and equilibrium point can be reached in a shorter finite time from any initial state. In the presence of unknown upper bound of system nonlinearities, an adaptive global fast terminal sliding mode controller is derived to estimate this unknown upper bound. Simulation results demonstrate that the tracking error can be attenuated efficiently and robustness of the control system can be improved with the proposed adaptive global fast terminal sliding mode control.

  18. Design and Implementation of a Magnetic Levitation System Controller using Global Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Rudi Uswarman

    2014-07-01

    Full Text Available This paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. Sliding mode control will be robusting when in sliding mode condition. However, it is not necessarily robust at attaining phase. In the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. However, the value of the parameter uncertainties needs to be limited. Besides that, the common problem in sliding mode control is high chattering phenomenon. If the chattering is too large, it can make the system unstable due the limited ability of electronics component. The strategy to overcome the chattering phenomenon is needed. Based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control.  

  19. Excise Tax Rates On Packs Of Cigarettes PowerPoint Slides

    Data.gov (United States)

    U.S. Department of Health & Human Services — Download the current cigarette excise tax rates on packs of cigarettes slides. These slides are available in PDF and PowerPoint formats. The PDF version can be found...

  20. Demand management in urine cytology: a single cytospin slide is sufficient

    OpenAIRE

    2000-01-01

    Aims—Current practice in most laboratories stipulates the preparation of duplicate slides for the analysis of urine cytology specimens. This study evaluates whether the duplicate slide is necessary.

  1. Robust Stabilization of T-S Fuzzy Stochastic Descriptor Systems via Integral Sliding Modes.

    Science.gov (United States)

    Li, Jinghao; Zhang, Qingling; Yan, Xing-Gang; Spurgeon, Sarah K

    2017-09-19

    This paper addresses the robust stabilization problem for T-S fuzzy stochastic descriptor systems using an integral sliding mode control paradigm. A classical integral sliding mode control scheme and a nonparallel distributed compensation (Non-PDC) integral sliding mode control scheme are presented. It is shown that two restrictive assumptions previously adopted developing sliding mode controllers for Takagi-Sugeno (T-S) fuzzy stochastic systems are not required with the proposed framework. A unified framework for sliding mode control of T-S fuzzy systems is formulated. The proposed Non-PDC integral sliding mode control scheme encompasses existing schemes when the previously imposed assumptions hold. Stability of the sliding motion is analyzed and the sliding mode controller is parameterized in terms of the solutions of a set of linear matrix inequalities which facilitates design. The methodology is applied to an inverted pendulum model to validate the effectiveness of the results presented.

  2. Sliding Mode Control for Fractional Differential Systems with State-delay

    Institute of Scientific and Technical Information of China (English)

    SI Jia-fang; JIANG Wei

    2012-01-01

    The problem of sliding mode control for fractional differential systems with statedelay is considered.A novel sliding surface is proposed and a controller is designed correspondingly,such that the state starting from any initial value will move toward the switching surface and reach the sliding surface in finite time and the state variables on the sliding surface will converge to equilibrium point.And the stability of the proposed control design is discussed.

  3. Management of Automotive Engine Based on Stable Fuzzy Technique with Parallel Sliding Mode Optimization

    Directory of Open Access Journals (Sweden)

    Mansour Bazregar

    2013-12-01

    Full Text Available Both fuzzy logic and sliding mode can compensate the steady-state error of proportional-derivative (PD method. This paper presents parallel sliding mode optimization for fuzzy PD management. The asymptotic stability of fuzzy PD management with first-order sliding mode optimization in the parallel structure is proven. For the parallel structure, the finite time convergence with a super-twisting second-order sliding-mode is guaranteed.

  4. Stable Fuzzy PD Control with Parallel Sliding Mode Compensation with Application to Rigid Manipulator

    Directory of Open Access Journals (Sweden)

    Farzin Piltan

    2013-06-01

    Full Text Available Both fuzzy logic and sliding mode can compensate the steady-state error of proportional-derivative (PD control. This paper presents parallel sliding mode compensations for fuzzy PD controllers. The asymptotic stability of fuzzy PD control with first-order sliding mode compensation in the parallel structure is proven. For the parallel structure, the finite time convergence with a super-twisting second-order sliding-mode is guaranteed.

  5. Synchronization of Fractional-order Chaotic Systems with Gaussian fluctuation by Sliding Mode Control

    OpenAIRE

    Yong Xu; Hua Wang

    2013-01-01

    This paper is devoted to the problem of synchronization between fractional-order chaotic systems with Gaussian fluctuation by the method of fractional-order sliding mode control. A fractional integral (FI) sliding surface is proposed for synchronizing the uncertain fractional-order system, and then the sliding mode control technique is carried out to realize the synchronization of the given systems. One theorem about sliding mode controller is presented to prove the proposed controller can ma...

  6. Chaos Control in Memristor-based Oscillators Using Intelligent Sliding Mode Control

    OpenAIRE

    Amir Hossein Abolmasoumi; Somayeh Khosravinejad

    2014-01-01

    In this paper, Intelligent Sliding Mode Control of chaos in a memristor- based Chua’s oscillator is investigated. In order to gain stabilization and tracking of a sinusoidal input, an appropriate sliding surface is proposed and sliding gain is tuned. Also, to avoid the chattering phenomenon in traditional sliding mode controller, and to reduce the hitting time of the controlled system, an especial genetic algorithm optimization method is suggested. By defining a new objective func...

  7. Singular Value Decomposition-Based Method for Sliding Mode Control and Optimization of Nonlinear Neutral Systems

    OpenAIRE

    Heli Hu; Dan Zhao; Qingling Zhang

    2013-01-01

    The sliding mode control and optimization are investigated for a class of nonlinear neutral systems with the unmatched nonlinear term. In the framework of Lyapunov stability theory, the existence conditions for the designed sliding surface and the stability bound ${\\alpha }^{\\ast }$ are derived via twice transformations. The further results are to develop an efficient sliding mode control law with tuned parameters to attract the state trajectories onto the sliding surface in finit...

  8. Anomaly Detection in Test Equipment via Sliding Mode Observers

    Science.gov (United States)

    Solano, Wanda M.; Drakunov, Sergey V.

    2012-01-01

    Nonlinear observers were originally developed based on the ideas of variable structure control, and for the purpose of detecting disturbances in complex systems. In this anomaly detection application, these observers were designed for estimating the distributed state of fluid flow in a pipe described by a class of advection equations. The observer algorithm uses collected data in a piping system to estimate the distributed system state (pressure and velocity along a pipe containing liquid gas propellant flow) using only boundary measurements. These estimates are then used to further estimate and localize possible anomalies such as leaks or foreign objects, and instrumentation metering problems such as incorrect flow meter orifice plate size. The observer algorithm has the following parts: a mathematical model of the fluid flow, observer control algorithm, and an anomaly identification algorithm. The main functional operation of the algorithm is in creating the sliding mode in the observer system implemented as software. Once the sliding mode starts in the system, the equivalent value of the discontinuous function in sliding mode can be obtained by filtering out the high-frequency chattering component. In control theory, "observers" are dynamic algorithms for the online estimation of the current state of a dynamic system by measurements of an output of the system. Classical linear observers can provide optimal estimates of a system state in case of uncertainty modeled by white noise. For nonlinear cases, the theory of nonlinear observers has been developed and its success is mainly due to the sliding mode approach. Using the mathematical theory of variable structure systems with sliding modes, the observer algorithm is designed in such a way that it steers the output of the model to the output of the system obtained via a variety of sensors, in spite of possible mismatches between the assumed model and actual system. The unique properties of sliding mode control

  9. Virtual slides in peer reviewed, open access medical publication

    Directory of Open Access Journals (Sweden)

    Kayser Klaus

    2011-12-01

    Full Text Available Abstract Background Application of virtual slides (VS, the digitalization of complete glass slides, is in its infancy to be implemented in routine diagnostic surgical pathology and to issues that are related to tissue-based diagnosis, such as education and scientific publication. Approach Electronic publication in Pathology offers new features of scientific communication in pathology that cannot be obtained by conventional paper based journals. Most of these features are based upon completely open or partly directed interaction between the reader and the system that distributes the article. One of these interactions can be applied to microscopic images allowing the reader to navigate and magnify the presented images. VS and interactive Virtual Microscopy (VM are a tool to increase the scientific value of microscopic images. Technology and Performance The open access journal Diagnostic Pathology http://www.diagnosticpathology.org has existed for about five years. It is a peer reviewed journal that publishes all types of scientific contributions, including original scientific work, case reports and review articles. In addition to digitized still images the authors of appropriate articles are requested to submit the underlying glass slides to an institution (DiagnomX.eu, and Leica.com for digitalization and documentation. The images are stored in a separate image data bank which is adequately linked to the article. The normal review process is not involved. Both processes (peer review and VS acquisition are performed contemporaneously in order to minimize a potential publication delay. VS are not provided with a DOI index (digital object identifier. The first articles that include VS were published in March 2011. Results and Perspectives Several logistic constraints had to be overcome until the first articles including VS could be published. Step by step an automated acquisition and distribution system had to be implemented to the corresponding

  10. A modified micro chamber agar spot slide culture technique for microscopic examination of filamentous fungi.

    Science.gov (United States)

    Prakash, Peralam Yegneswaran; Bhargava, Kanika

    2016-04-01

    The slide culture technique aids in the study of undisturbed microscopic morphological details of filamentous fungi. The existing methods for setting up of slide culture are quite cumbersome, time-consuming and require elaborate preparation. We describe a modified and easy to perform micro chamber agar spot slide culture technique.

  11. Passivity-based sliding mode control for a polytopic stochastic differential inclusion system.

    Science.gov (United States)

    Liu, Leipo; Fu, Zhumu; Song, Xiaona

    2013-11-01

    Passivity-based sliding mode control for a polytopic stochastic differential inclusion (PSDI) system is considered. A control law is designed such that the reachability of sliding motion is guaranteed. Moreover, sufficient conditions for mean square asymptotic stability and passivity of sliding mode dynamics are obtained by linear matrix inequalities (LMIs). Finally, two examples are given to illustrate the effectiveness of the proposed method.

  12. Hardwood Lumber Scaling [and] Hardwood Log Scaling and Grading. Slide Scripts.

    Science.gov (United States)

    Wooten, D. E.; Touse, Robert D.

    These two slide scripts, part of a series of slide scripts designed for use in vocational agriculture classes, deal with scaling and grading hardwood logs and lumber. The first script includes narrations for use with 39 slides, which explain the techniques of scaling and grading hardwood logs, and the second script contains the narrations to…

  13. Sliding Hydrogels with Mobile Molecular Ligands and Crosslinks as 3D Stem Cell Niche.

    Science.gov (United States)

    Tong, Xinming; Yang, Fan

    2016-09-01

    The development of a sliding hydrogel with mobile crosslinks and biochemical ligands as a 3D stem cell niche is reported. The molecular mobility of this sliding hydrogel allows stem cells to reorganize the surrounding ligands and change their morphology in 3D. Without changing matrix stiffness, sliding hydrogels support efficient stem cell differentiation toward multiple lineages including adipogenesis, chondrogenesis, and osteogenesis.

  14. Incorporating Concept Maps in a Slide Presentation Tool for the Classroom Environment.

    Science.gov (United States)

    Gopal, Kreshna; Morapakkam, Karthik

    This paper presents a slide presentation software that incorporates a concept map, which explicitly shows how the various slides (and other multimedia components) presented are related to each other. Furthermore, presentations are conceived as hypermedia systems, where the presenter can navigate among slides (and the concept map) instead of the…

  15. Second order sliding control with state dependent gain and its application to a hydraulic drive

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    The application of sliding modes for control of hydraulic drives appear promising due to strong robustness toward plant uncertainties and disturbances. Especially high order sliding modes may be successfully implemented avoiding the discontinuous control seen in first order sliding controls. Howe...

  16. Maximum Power Point Tracking Based on Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Nimrod Vázquez

    2015-01-01

    Full Text Available Solar panels, which have become a good choice, are used to generate and supply electricity in commercial and residential applications. This generated power starts with the solar cells, which have a complex relationship between solar irradiation, temperature, and output power. For this reason a tracking of the maximum power point is required. Traditionally, this has been made by considering just current and voltage conditions at the photovoltaic panel; however, temperature also influences the process. In this paper the voltage, current, and temperature in the PV system are considered to be a part of a sliding surface for the proposed maximum power point tracking; this means a sliding mode controller is applied. Obtained results gave a good dynamic response, as a difference from traditional schemes, which are only based on computational algorithms. A traditional algorithm based on MPPT was added in order to assure a low steady state error.

  17. Sliding mode control of a simulated MEMS gyroscope.

    Science.gov (United States)

    Batur, C; Sreeramreddy, T; Khasawneh, Q

    2006-01-01

    The microelectromechanical systems (MEMS) are penetrating more and more into measurement and control problems because of their small size, low cost, and low power consumption. The vibrating gyroscope is one of those MEMS devices that will have a significant impact on the stability control systems in transportation industry. This paper studies the design and control of a vibrating gyroscope. The device has been constructed in a Pro-E environment and its model has been simulated in the finite-element domain in order to approximate its dynamic characteristics with a lumped model. A model reference adaptive feedback controller and the sliding mode controller have been considered to guarantee the stability of the device. It is shown that the sliding mode controller of the vibrating proof mass results in a better estimate of the unknown angular velocity than that of the model reference adaptive feedback controller.

  18. Slide Mode Control for Integrated Electric Parking Brake System

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2013-01-01

    Full Text Available The emerging integrated electric parking brake (IEPB system is introduced and studied. Through analyzing the various working stages, the stages switched IEPB system models are given with the consideration of the friction and system idle inertia. The sliding mode control (SMC method is adopted to control the clamping force by the widely used motor angle and clamping force relationship method. Based on the characteristics of the state equations, two sliding surfaces are built to control the motor angle and current, respectively. And in every working stage, the control stability is guaranteed by choosing the control parameters based on Lyapunov theory and SMC reachability. The effectiveness of the proposed control system has been validated in Matlab/Simulink.

  19. Sliding Control with Chattering Elimination for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2012-01-01

    This paper presents the development of a sliding mode control scheme with chattering elimination, generally applicable for position tracking control of electro-hydraulic valve-cylinder drives. The proposed control scheme requires only common data sheet information, no knowledge on load...... characteristics, and employs piston- and valve spool positions- and load- and supply pressure feedback. The main target is to overcome problems with linear controllers deteriorating performance due to the inherent nonlinear nature of such systems. In order to accomplish this task, an integral sliding mode...... controller is developed for the control derivative based on a reduced order model. Simulation results demonstrate strong robustness when subjected to parameter perturbations and that chattering is eliminated....

  20. Robust output LQ optimal control via integral sliding modes

    CERN Document Server

    Fridman, Leonid; Bejarano, Francisco Javier

    2014-01-01

    Featuring original research from well-known experts in the field of sliding mode control, this monograph presents new design schemes for implementing LQ control solutions in situations where the output system is the only information provided about the state of the plant. This new design works under the restrictions of matched disturbances without losing its desirable features. On the cutting-edge of optimal control research, Robust Output LQ Optimal Control via Integral Sliding Modes is an excellent resource for both graduate students and professionals involved in linear systems, optimal control, observation of systems with unknown inputs, and automatization. In the theory of optimal control, the linear quadratic (LQ) optimal problem plays an important role due to its physical meaning, and its solution is easily given by an algebraic Riccati equation. This solution turns out to be restrictive, however, because of two assumptions: the system must be free from disturbances and the entire state vector must be kn...

  1. Chattering-Free Sliding Mode Control with Unmodeled Dynamics

    Science.gov (United States)

    Krupp, Don; Shtessel, Yuri B.

    1999-01-01

    Sliding mode control systems are valued for their robust accommodation of uncertainties and their ability to reject disturbances. In this paper, a design methodology is proposed to eliminate the chattering phenomenon affecting sliding mode controlled plants with input unmodeled actuator dynamics of second order or greater. The proposed controller design is based on the relative degrees of the plant and the unmodeled actuator dynamics and the ranges of the uncertainties of the plant and actuator. The controller utilizes the pass filter characteristics of the physical actuating device to provide a smoothing effect on the discontinuous control signal rather than introducing any artificial dynamics into the controller design thus eliminating chattering in the system's output response.

  2. Sliding mode control of outbreaks of emerging infectious diseases.

    Science.gov (United States)

    Xiao, Yanni; Xu, Xiaxia; Tang, Sanyi

    2012-10-01

    This paper proposes and analyzes a mathematical model of an infectious disease system with a piecewise control function concerning threshold policy for disease management strategy. The proposed models extend the classic models by including a piecewise incidence rate to represent control or precautionary measures being triggered once the number of infected individuals exceeds a threshold level. The long-term behaviour of the proposed non-smooth system under this strategy consists of the so-called sliding motion-a very rapid switching between application and interruption of the control action. Model solutions ultimately approach either one of two endemic states for two structures or the sliding equilibrium on the switching surface, depending on the threshold level. Our findings suggest that proper combinations of threshold densities and control intensities based on threshold policy can either preclude outbreaks or lead the number of infected to a previously chosen level.

  3. Advances and applications in sliding mode control systems

    CERN Document Server

    Zhu, Quanmin

    2015-01-01

    This book describes the advances and applications in Sliding mode control (SMC) which is widely used as a powerful method to tackle uncertain nonlinear systems. The book is organized into 21 chapters which have been organised by the editors to reflect the various themes of sliding mode control. The book provides the reader with a broad range of material from first principles up to the current state of the art in the area of SMC and observation presented in a clear, matter-of-fact style. As such it is appropriate for graduate students with a basic knowledge of classical control theory and some knowledge of state-space methods and nonlinear systems. The resulting design procedures are emphasized using Matlab/Simulink software.    

  4. Theoretical modeling of sliding vane compressor with leakage

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hawaj, Osama [Department of Mechanical Engineering, University of Kuwait, P.O. Box 5969, Safat 13060 (Kuwait)

    2009-11-15

    Performance of a sliding vane compressor is significantly influenced by the leakage effect occurring between adjacent cells during the compression phase of the cycle. In this paper, thermodynamic and dynamical mathematical models were formulated for a double action sliding vane compressor including leakage effect modeling. The leakage modeling is incorporated through an analytic pressure model with a single tunable parameter to be adjusted to correspond with specific compressor leakage characteristics. The effect of leakage on the cell pressure, temperature, mass, and work, and total vane torque variations were qualitatively investigated. The study illustrated the significant effect of leakage on power input requirement, discharge pressure and mass delivery, and less significant effect on mechanical efficiency and specific mass delivery. The validity of the simulation results is made by comparing the pressure work calculated from both the thermodynamic and the dynamic models. (author)

  5. Terminal Sliding Mode Control Using Adaptive Fuzzy-Neural Observer

    Directory of Open Access Journals (Sweden)

    Dezhi Xu

    2013-01-01

    Full Text Available We propose a terminal sliding mode control (SMC law based on adaptive fuzzy-neural observer for nonaffine nonlinear uncertain system. First, a novel nonaffine nonlinear approximation algorithm is proposed for observer and controller design. Then, an adaptive fuzzy-neural observer is introduced to identify the simplified model and resolve the problem of the unavailability of the state variables. Moreover, based on the information of the adaptive observer, the terminal SMC law is designed. The Lyapunov synthesis approach is used to guarantee a global uniform ultimate boundedness property of the state estimation error and the asymptotic output tracking of the closed-loop control systems in spite of unknown uncertainties/disturbances, as well as all the other signals in the closed-loop system. Finally, using the designed terminal sliding mode controller, the simulation results on the dynamic model demonstrate the effectiveness of the proposed new control techniques.

  6. Stability of sliding frictional surfaces with varying normal force

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, P.E.; Bapna, D. (Boston Univ., MA (United States))

    1994-04-01

    This paper presents the stability analysis of a single degree-of-freedom elastic system following a rate- and state-dependent friction law. Normal force is assumed to depend on the displacement, velocity, and acceleration of the sliding interface. The history dependence of friction on normal force is included in the analysis. It is shown that to achieve steady sliding, system stiffness must exceed a critical value which depends on the expression for normal force. A system in which normal force depends on spring displacement is analyzed in detail. These results indicate that the functional dependence of normal force on system state can have a significant effect on the stability of low-velocity motion. 15 refs.

  7. Hybrid sliding mode control of semi-active suspension systems

    Science.gov (United States)

    Assadsangabi, Babak; Eghtesad, Mohammad; Daneshmand, Farhang; Vahdati, Nader

    2009-12-01

    In order to design a controller which can take both ride comfort and road holding into consideration, a hybrid model reference sliding mode controller (HMRSMC) is proposed. The controller includes two separate model reference sliding mode controllers (MRSMC). One of the controllers is designed so as to force the plant to follow the ideal Sky-hook model and the other is to force the plant to follow the ideal Ground-hook model; then the outputs of these two controllers are linearly combined and applied to the plant as the input. Also, since the designed controller requires a knowledge of the terrain input, this input is approximated by the unsprung mass displacement. Finally, in the simulation section of this study, the effect of the relative ratio between the two MRSMCs and the knowledge of the terrain on the performance of the controller is numerically investigated for both steady-state and transient cases.

  8. A comparative study of input devices for digital slide navigation.

    Science.gov (United States)

    Molin, Jesper; Lundström, Claes; Fjeld, Morten

    2015-01-01

    This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Quick and seamless integration between input devices and the navigation of digital slides remains a key barrier for many pathologists to "go digital." To better understand this integration, three different input device implementations were compared in terms of time to diagnose, perceived workload and users' preferences. Six pathologists reviewed in total nine cases with a computer mouse, a 6 degrees-of-freedom (6DOF) navigator and a touchpad. The participants perceived significantly less workload (P device used on the time to diagnose was observed. Five out of six pathologists preferred the 6DOF navigator, while the touchpad was the least preferred device. While digital slide navigation is often designed to mimic microscope interaction, the results of this study demonstrate that in order to minimize workload there is reason to let the digital interaction move beyond the familiar microscope tradition.

  9. Sliding contact fracture of dental ceramics: Principles and validation.

    Science.gov (United States)

    Ren, Linlin; Zhang, Yu

    2014-07-01

    Ceramic prostheses are subject to sliding contact under normal and tangential loads. Accurate prediction of the onset of fracture at two contacting surfaces holds the key to greater long-term performance of these prostheses. In this study, building on stress analysis of Hertzian contact and considering fracture criteria for linear elastic materials, a constitutive fracture mechanics relation was developed to incorporate the critical fracture load with the contact geometry, coefficient of friction and material fracture toughness. Critical loads necessary to cause fracture under a sliding indenter were calculated from the constitutive equation, and compared with the loads predicted from elastic stress analysis in conjunction with measured critical load for frictionless normal contact-a semi-empirical approach. The major predictions of the models were calibrated with experimentally determined critical loads of current and future dental ceramics after contact with a rigid spherical slider. Experimental results conform with the trends predicted by the models.

  10. Backstepping and sliding mode control hybridized for a prosthetic hand.

    Science.gov (United States)

    Engeberg, Erik D; Meek, Sanford G

    2009-02-01

    Open loop and force controllers are compared experimentally with three robust parallel force-velocity controllers that are developed for a prosthetic hand. Robust sliding mode, backstepping, and hybrid sliding mode-backstepping (HSMBS) parallel force-velocity controllers are tested by ten able-bodied subjects. Results obtained with a myoelectrically controlled prosthesis indicate that all three robust controllers offer a statistically significant improvement over linear hand prosthesis control schemes. The robust controllers enable the human operators to more easily manipulate a delicate object. Bench top experiments combined with quantitative and qualitative evaluations from ten test subjects reveal the HSMBS controller to be the best choice to improve control of powered prosthetic hands.

  11. Morphological Transitions of Sliding Drops -- Dynamics and Bifurcations

    CERN Document Server

    Engelnkemper, Sebastian; Gurevich, Svetlana V; Thiele, Uwe

    2016-01-01

    We study fully three-dimensional droplets that slide down an incline employing a thin-film equation that accounts for capillarity, wettability and a lateral driving force in small-gradient (or long-wave) approximation. In particular, we focus on qualitative changes in the morphology and behavior of stationary sliding drops. We employ the inclination angle of the substrate as control parameter and use continuation techniques to analyze for several fixed droplet sizes the bifurcation diagram of stationary droplets, their linear stability and relevant eigenmodes. The obtained predictions on existence ranges and instabilities are tested via direct numerical simulations that are also used to investigate a branch of time-periodic behavior (corresponding to pearling-coalescence cycles) which emerges at a global instability, the related hysteresis in behavior and a period-doubling cascade. The non-trivial oscillatory behavior close to a Hopf bifurcation of drops with a finite-length tail is also studied. Finally, it ...

  12. Control of a Lightweight Flexible Robotic Arm Using Sliding Modes

    OpenAIRE

    Ibone Lizarraga; Arantza Sanz; Victor Etxebarria

    2006-01-01

    This paper presents a robust control scheme for flexible link robotic manipulators, which is based on considering the flexible mechanical structure as a system with slow (rigid) and fast (flexible) modes that can be controlled separately. The rigid dynamics is controlled by means of a robust sliding-mode approach with wellestablished stability properties while an LQR optimal design is adopted for the flexible dynamics. Experimental results show that this composite approach achieves good close...

  13. Robustness and robust stability of the active sliding mode synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Naseh, Majid Reza [Electrical Engineering Department, Islamic Azad University, Birjand Branch (Iran, Islamic Republic of)], E-mail: naseh@ee.src.aiu.ir; Haeri, Mohammad [Advanced Control System Lab., Electrical Engineering Department, Sharif University Technology, Tehran (Iran, Islamic Republic of)], E-mail: haeri@sina.sharif.edu

    2009-01-15

    We have developed relations between uncertainties and signals bounds in one side and the control parameters on the other side in the case of the active sliding mode synchronization. Using Lyapunov stability theorem, we have determined uncertainties levels for which synchronization is achieved for a given set of the control parameters. We have run a nonlinear programming algorithm to determine the control parameters for specific range of the uncertainties. Finally, numerical simulations are presented to verify the derived relations.

  14. Model reference, sliding mode adaptive control for flexible structures

    Science.gov (United States)

    Yurkovich, S.; Ozguner, U.; Al-Abbass, F.

    1988-01-01

    A decentralized model reference adaptive approach using a variable-structure sliding model control has been developed for the vibration suppression of large flexible structures. Local models are derived based upon the desired damping and response time in a model-following scheme, and variable structure controllers are then designed which employ colocated angular rate and position feedback. Numerical simulations have been performed using NASA's flexible grid experimental apparatus.

  15. Recent advances in sliding modes from control to intelligent mechatronics

    CERN Document Server

    Efe, Mehmet

    2015-01-01

    This volume is dedicated to Professor Okyay Kaynak to commemorate his life time impactful research and scholarly achievements and outstanding services to profession. The 21 invited chapters have been written by leading researchers who, in the past, have had association with Professor Kaynak as either his students and associates or colleagues and collaborators. The focal theme of the volume is the Sliding Modes covering a broad scope of topics from theoretical investigations to their significant applications from Control to Intelligent Mechatronics.  

  16. Sliding mode control of a magnetic levitation system

    Directory of Open Access Journals (Sweden)

    N. F. Al-Muthairi

    2004-01-01

    Full Text Available Sliding mode control schemes of the static and dynamic types are proposed for the control of a magnetic levitation system. The proposed controllers guarantee the asymptotic regulation of the statesof the system to their desired values. Simulation results of the proposed controllers are given to illustrate the effectiveness of them. Robustness of the control schemes to changes in the parameters of the system is also investigated.

  17. Self-Organization during Friction of Slide Bearing Antifriction Materials

    Directory of Open Access Journals (Sweden)

    Iosif S. Gershman

    2015-12-01

    Full Text Available This article discusses the peculiarities of self-organization behavior and formation of dissipative structures during friction of antifriction alloys for slide bearings against a steel counterbody. It shows that during self-organization, the moment of friction in a tribosystem may be decreasing with the load growth and in the bifurcations of the coefficient of friction with respect to load. Self-organization and the formation of dissipative structures lead to an increase in the seizure load.

  18. Adaptive Fractional Fuzzy Sliding Mode Control for Multivariable Nonlinear Systems

    OpenAIRE

    Junhai Luo; Heng Liu

    2014-01-01

    This paper presents a robust adaptive fuzzy sliding mode control method for a class of uncertain nonlinear systems. The fractional order calculus is employed in the parameter updating stage. The underlying stability analysis as well as parameter update law design is carried out by Lyapunov based technique. In the simulation, two examples including a comparison with the traditional integer order counterpart are given to show the effectiveness of the proposed method. The main contribution of th...

  19. Sliding-Mode Formation Control for Cooperative Autonomous Mobile Robots

    OpenAIRE

    Defoort, Michael; Floquet, Thierry; Kökösy, Annemarie; Perruquetti, Wilfrid

    2008-01-01

    International audience; This paper considers the control of a group of autonomous mobile robots. A coordinated control scheme based on a leader-follower approach is developed to achieve formation maneuvers. First and second order sliding mode controllers are proposed for asymptotically stabilizing the vehicles to a time-varying desired formation. The latter controller, based on the relative motion states, eliminates the need for measurement or estimation of the leader velocity. It enables for...

  20. The Wiese Knot: A Sliding-Locking Arthroscopic Knot.

    Science.gov (United States)

    Parada, Stephen A; Shaw, K Aaron; Eichinger, Josef K; Boykin, Nathan T; Gloystein, David M; Ledford, Cheryl L; Arrington, Edward D; Wiese, Paul T

    2017-02-01

    Despite recent advances in knotless suture devices for arthroscopic surgical procedures, arthroscopic knot tying remains a necessary skill for the arthroscopic surgeon. Successful completion of arthroscopic knot tying relies on a thorough understanding of the chosen technique, proper suture management, adequate knot tensioning and securement, and the ability to reproducibly create the knot. We introduce a technique that serves as both a sliding and locking knot while being simple to master and reproducible to perform.

  1. Control of a Lightweight Flexible Robotic Arm Using Sliding Modes

    OpenAIRE

    Victor Etxebarria; Arantza Sanz; Ibone Lizarraga

    2006-01-01

    This paper presents a robust control scheme for flexible link robotic manipulators, which is based on considering the flexible mechanical structure as a system with slow (rigid) and fast (flexible) modes that can be controlled separately. The rigid dynamics is controlled by means of a robust sliding-mode approach with well-established stability properties while an LQR optimal design is adopted for the flexible dynamics. Experimental results show that this composite approach achieves good clos...

  2. Sliding contacts on printed circuit boards and wear behavior

    OpenAIRE

    Le Solleu, J.-P.

    2010-01-01

    Abstract Automotive suppliers use since decades printed circuit boards (PCB) gold plating pads, as direct contact interface for low current sliding contacts. Several gold plating processes are available on the market, providing various wear behaviour. Some specific galvanic hard gold (AuCo or AuNi). plating was developed on PCB's. This specific plating generates extra costs due to the material quantity and also the process complexity. In a cost driven indust...

  3. Sliding mode control of a magnetic levitation system

    OpenAIRE

    Al-Muthairi N. F.; Zribi M.

    2004-01-01

    Sliding mode control schemes of the static and dynamic types are proposed for the control of a magnetic levitation system. The proposed controllers guarantee the asymptotic regulation of the statesof the system to their desired values. Simulation results of the proposed controllers are given to illustrate the effectiveness of them. Robustness of the control schemes to changes in the parameters of the system is also investigated.

  4. Hydrophobins as aqueous lubricant additive for a soft sliding contact

    DEFF Research Database (Denmark)

    Lee, Seunghwan; Røn, Troels; Pakkanen, Kirsi I.

    2015-01-01

    lubrication characteristic is dominant via ‘self-healing’ mechanism. FpHYD5 revealed a better lubrication than HFBI presumably due to the presence of glycans and improved hydration of the sliding interface. Two type II hydrophobins function more favorably compared to a synthetic amphiphilic copolymer, PEO......-PPO-PEO, with a similar molecular weight. This is ascribed to higher amount of adsorption of the hydrophobins to hydrophobic surfaces from aqueous solution....

  5. Glucose level regulation via integral high-order sliding modes.

    Science.gov (United States)

    Dorel, Lela

    2011-04-01

    Diabetes is a condition in which the body either does not produce enough insulin, or does not properly respond to it. This causes the glucose level in blood to increase. An algorithm based on Integral High-Order Sliding Mode technique is proposed, which keeps the normal blood glucose level automatically releasing insulin into the blood. The system is highly insensitive to inevitable parametric and model uncertainties, measurement noises and small delays.

  6. Plastic deformation of a wedge by a sliding punch

    Science.gov (United States)

    Nepershin, R. I.

    2016-11-01

    We present a self-similar solution of the problem of deformation of an ideally plastic wedge by a sliding punch with regard to contact friction; such a solution generalizes the well-known solutions of the problem of wedge penetration into a plastic half-space and of compression of an ideally plastic wedge by a plane punch. The problem is of interest for modeling the processes of plastic deformation of rough surfaces of metal pieces by a rigid tool.

  7. Experimental Measurements of Prestressed Masonry with using Sliding Joint

    Directory of Open Access Journals (Sweden)

    Stara Marie

    2014-06-01

    Full Text Available Contribution deals with experimental measurements of deformations in the place exposed to local load caused by additional pre-stressing. The measurements are made at the masonry corner built in the laboratory equipment. The laboratory equipment was designed at Faculty of Civil Engineering VŠB-Technical University of Ostrava for measurement tri-axial stress-strain conditions in masonry. In this masonry corner two pre-stressing bars are placed. These bars are in different height and are anchored to the anchor plates, which transfer pre-stressing forces to the masonry. The specimen for laboratory testing is performed in the proportion to the reality of 1:1. In the bottom part masonry is inserted asphalt strip. It operates in the masonry like a sliding joint and reduces the shear stress at interface between concrete and masonry structures. The results are compared with the results of masonry without the use of sliding joints, including comment on the effect of sliding joints on the pre-stressing masonry structures.

  8. Lempel-Ziv Compression in a Sliding Window

    DEFF Research Database (Denmark)

    Bille, Philip; Cording, Patrick Hagge; Fischer, Johannes

    2017-01-01

    We present new algorithms for the sliding window Lempel-Ziv (LZ77) problem and the approximate rightmost LZ77 parsing problem. Our main result is a new and surprisingly simple algorithm that computes the sliding window LZ77 parse in O(w) space and either O(n) expected time or O(n log log w + z log...... logσ) deterministic time. Here, w is the window size, n is the size of the input string, z is the number of phrases in the parse, and σ is the size of the alphabet. This matches the space and time bounds of previous results while removing constant size restrictions on the alphabet size. To achieve our...... result, we combine a simple modification and augmentation of the suffix tree with periodicity properties of sliding windows. We also apply this new technique to obtain an algorithm for the approximate rightmost LZ77 problem that uses O(n(log z + loglogn)) time and O(n) space and produces a (1 + ϵ...

  9. Sliding Mode Attitude Control for Magnetic Actuated Satellite

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    1998-01-01

    Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic field and magnetic field generated by a coil set in the satellite. This control principle is inherently nonlinear, and difficult to use becaus...... the spacecraft attitude using only magnetic torquing is realized in the form of the sliding mode control. A three dimensional sliding manifold is proposed, and it is shown that the satellite motion on the sliding manifold is asymptotically stable......Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic field and magnetic field generated by a coil set in the satellite. This control principle is inherently nonlinear, and difficult to use because...... control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis attitude control. This paper deals with three-axis stabilization of a low earth orbit satellite. The problem of controlling...

  10. Sliding Mode Control Applied to Reconfigurable Flight Control Design

    Science.gov (United States)

    Hess, R. A.; Wells, S. R.; Bacon, Barton (Technical Monitor)

    2002-01-01

    Sliding mode control is applied to the design of a flight control system capable of operating with limited bandwidth actuators and in the presence of significant damage to the airframe and/or control effector actuators. Although inherently robust, sliding mode control algorithms have been hampered by their sensitivity to the effects of parasitic unmodeled dynamics, such as those associated with actuators and structural modes. It is known that asymptotic observers can alleviate this sensitivity while still allowing the system to exhibit significant robustness. This approach is demonstrated. The selection of the sliding manifold as well as the interpretation of the linear design that results after introduction of a boundary layer is accomplished in the frequency domain. The design technique is exercised on a pitch-axis controller for a simple short-period model of the High Angle of Attack F-18 vehicle via computer simulation. Stability and performance is compared to that of a system incorporating a controller designed by classical loop-shaping techniques.

  11. Droplets sliding down inclined planes: unexpected dynamics on elastomer plates

    Science.gov (United States)

    Hourlier-Fargette, Aurelie; Antkowiak, Arnaud; Neukirch, Sebastien

    2016-11-01

    Droplet dynamics on an angled surface results from a competition between the weight of the droplet, capillary forces, and viscous dissipation inside the drop. The motion of droplets on stiff surfaces has been investigated for a long time, both experimentally and theoretically, while recent studies have shown the interesting physics underlying the sliding of droplets on soft surfaces. We focus on the dynamics of water-glycerol mixture droplets sliding down vertical plates of silicone elastomers, highlighting an unexpected behavior: the droplet dynamics on such a surface includes two regimes with different constant speeds. These results contrast with those found in the literature for droplets sliding on materials such as treated glass. We investigate the universality of this behavior on various elastomers, and study in detail the two regimes and the sharp transition observed between them. Different candidates can be responsible for the sudden speed change: bistability, chemical interaction with the substrate, softness of the material, etc. Our experiments to clarify the role of each of them reveal an unexpected link between microscopic phenomena at the scale of the polymer matrix and the macroscopic dynamics of a droplet.

  12. Fatigue resistant carbon coatings for rolling/sliding contacts

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Harpal; Ramirez, Giovanni; Eryilmaz, Osman; Greco, Aaron; Doll, Gary; Erdemir, Ali

    2016-06-01

    The growing demands for renewable energy production have recently resulted in a significant increase in wind plant installation. Field data from these plants show that wind turbines suffer from costly repair, maintenance and high failure rates. Often times the reliability issues are linked with tribological components used in wind turbine drivetrains. The primary failure modes in bearings and gears are associated with micropitting, wear, brinelling, scuffing, smearing and macropitting all of which occur at or near the surface. Accordingly, a variety of surface engineering approaches are currently being considered to alter the near surface properties of such bearings and gears to prevent these tribological failures. In the present work, we have evaluated the tribological performance of compliant highly hydrogenated diamond like carbon coating developed at Argonne National Laboratory, under mixed rolling/sliding contact conditions for wind turbine drivetrain components. The coating was deposited on AISI 52100 steel specimens using a magnetron sputter deposition system. The experiments were performed on a PCS Micro-Pitting-Rig (MPR) with four material pairs at 1.79 GPa contact stress, 40% slide to roll ratio and in polyalphaolefin (PAO4) basestock oil (to ensure extreme boundary conditions). The post-test analysis was performed using optical microscopy, surface profilometry, and Raman spectroscopy. The results obtained show a potential for these coatings in sliding/rolling contact applications as no failures were observed with coated specimens even after 100 million cycles compared to uncoated pair in which they failed after 32 million cycles, under the given test conditions.

  13. Fuzzy optimization of pneumatic half-floating slide ways

    Institute of Scientific and Technical Information of China (English)

    李宇鹏; 高殿荣; 单彦霞; 张海青

    2008-01-01

    Dynamic modeling was carried on by combining the dynamic of machinery with composite triology, and the critical condition in which the ways would not produce composite-friction self-excited vibration was obtained. The movement regularity and characteristic of the airflow in exhaust gas slit were analyzed, and the relationship between pressure lost and geometry parameters of exhaust gas slit was obtained. A dynamic model and a mathematical model were established for pneumatic half-floating slide ways by combining the dynamics of machinery with hydrokinetics. The objective function for the optimization of slide ways was established based on the fuzzy optimization theory. The membership function of fuzzy constraint was deduced, the fuzzy constraint limit was established by amplification coefficient method, and the optimal value was resolved by the multilevel fuzzy comprehensive evaluation method. By combining the internal penalty function method with the variable metric method, the fuzzy optimization design program of ways was designed based on the Matlab platform. The validation was carried on by an example, and ideal results of fuzzy optimization design of slide ways were obtained.

  14. Slide shows vs graphic tablet live drawing for anatomy teaching.

    Science.gov (United States)

    Alsaid, B

    2016-12-01

    Blackboard drawing is the traditional and still widely learned method for anatomy teachers. However, for practical reasons, more and more lessons are done using slide shows. New digital learning tools are developed to create a more attractive teaching method. The objective of this study was to compare the use of graphic tablet live drawing versus slide shows. Sixty-five second-year students of the Faculty of Medicine participated in this study during their first semester of 2013-2014 academic year. The selected lecture dealt about neuroanatomy; two brain sections were taught: median sagittal and transverse. The sagittal section was presented via a slide show. The transverse section was taught using a graphics tablet using drawing software. Students were evaluated three times: before the lecture, immediately after the lecture and 8 weeks later. Means were compared using a t-test. Scores were significantly higher immediately after the lecture and 8 weeks later tests in comparing the transverse section (using the graphics tablet) versus the sagittal section (using PowerPoint(®)). Student satisfaction regarding the use of the tablet was high. The graphics tablet is a usable and efficient drawing tool in anatomy teaching. This tool requires a specific teacher training and preparation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. The use of virtual slides in the EUROPALS examination.

    Science.gov (United States)

    van den Tweel, Jan G; Bosman, Fred T

    2011-03-30

    The only realistic way to improve harmonisation of European pathology training is to define the generally accepted competencies and to test them periodically during the training programme (progress test). The European Association of Pathology Chairs and Program Directors therefore decided to implement an annual on-line test using virtual slides in addition to static jpeg images and theoretical MCQ's. The EU supported this endeavour as EUROPALS (EUROpean Pathology Assessement & Learning System). To address the challenges of large scale digital testing EUROPALS teamed up with i-Path Diagnostics Ltd, a company specialising in utilisation of virtual slides in histology/pathology education and examination. Specific examination software was used in the test system. In the first 2 years we provided at five occasions progress tests, including 2 proctored tests, attracting hundreds of participants. The accessibility varied from suboptimal to good and improved with each subsequent test. It was influenced both by the hosting server capacity and the internet bandwidth at the user's location. On-line testing using virtual slides is possible but requires a good collaboration between the provider and the user. Both should be aware of the requirements and threads of large scale testing with hundreds of simultaneous users.

  16. Slide track analysis of eight contemporary hip simulator designs.

    Science.gov (United States)

    Calonius, Olof; Saikko, Vesa

    2002-11-01

    In an earlier paper, the authors presented a new method of computation of slide tracks in the relative motion between femoral head and acetabular cup of total hip prostheses. For the first time, computed tracks were verified experimentally and with an alternative method of computation. Besides being an efficient way to illustrate hip kinematics, the shapes of the slide tracks are known to be of fundamental importance regarding the wear behaviour of prostheses. The verified method was now applied to eight contemporary hip simulator designs. The use of correct motion waveforms and an Euler sequence of rotations in each case was again found to be essential. Considerable differences were found between the simulators. For instance, the shapes of the tracks drawn by the resultant contact force included a circle, ellipse, irregular oval, leaf, twig, and straight line. Computation of tracks correctly for the most widely used hip simulator, known as biaxial, was made possible by the insight that the device is actually three-axial. Slide track patterns have now been computed for virtually all contemporary hip simulators, and both for the heads and for the cups. This comparative analysis forms a valuable basis for studies on the relationship between the type of multidirectional motion and wear. These studies can produce useful information for the design of joint simulators, and improve the understanding of wear phenomena in prosthetic joints.

  17. Effects of lag screw design and lubrication on sliding in trochanteric nails.

    Science.gov (United States)

    Kummer, Frederick J

    2010-01-01

    This study compared the sliding characteristics of three lag screw designs used with trochanteric nails and determined the effects of lubrication on sliding. They were tested by an established method to measure initiation and ease of lag screw sliding. These tests were then repeated with calf serum lubrication. There were significant differences (p Lubrication did not affect either parameter. Lag screw design aspects, such as diameter and, particularly, surface finish, affect sliding. Due to the small contact area between the lag screw and nail creating high interface stresses, lubrication had no effect on lag screw sliding.

  18. Improved robustness and performance of discrete time sliding mode control systems.

    Science.gov (United States)

    Chakrabarty, Sohom; Bartoszewicz, Andrzej

    2016-11-01

    This paper presents a theoretical analysis along with simulations to show that increased robustness can be achieved for discrete time sliding mode control systems by choosing the sliding variable, or the output, to be of relative degree two instead of relative degree one. In other words it successfully reduces the ultimate bound of the sliding variable compared to the ultimate bound for standard discrete time sliding mode control systems. It is also found out that for such a selection of relative degree two output of the discrete time system, the reduced order system during sliding becomes finite time stable in absence of disturbance. With disturbance, it becomes finite time ultimately bounded.

  19. Experimental study on sliding shaft lining mechanical mechanisms under ground subsidence conditions

    Institute of Scientific and Technical Information of China (English)

    姚直书; 杨俊杰; 孙文若

    2003-01-01

    Aimed at more than 60 shaft linings damaged in Huaibei, Datun, Xuzhou and Yanzhou mine areas, this paper presents a new type of sliding shaft lining with asphalt blocks sliding layer. By model test, it is obtained that the deformation characteristics and the mechanical mechanisms of the sliding shaft lining under the condition of ground subsidence. The research results provide a testing basis for the sliding shaft lining design. By now, this kind of sliding shaft lining had been applied in 9 shafts in China and Bangladesh.

  20. Sliding without slipping under Coulomb friction: opening waves and inversion of frictional force

    CERN Document Server

    Yastrebov, Vladislav A

    2015-01-01

    An elastic layer slides on a rigid flat governed by Coulomb's friction law. We demonstrate that if the coefficient of friction is high enough, the sliding localizes within stick-slip pulses, which transform into opening waves propagating at intersonic speed in the direction of sliding or, for high Poisson's ratios, at supersonic speed in the opposite one. This sliding mode, characterized by small frictional dissipation, rapidly relaxes the shear elastic energy via stress waves and enables the contact surface slide ahead of the top one, resulting in inversion of the frictional force direction.

  1. Sliding Mode Disturbance Observer-Based Fractional Second-Order Nonsingular Terminal Sliding Mode Control for PMSM Position Regulation System

    Directory of Open Access Journals (Sweden)

    Hong-Ru Li

    2015-01-01

    Full Text Available This paper investigates the position regulation problem of permanent magnet synchronous motor (PMSM subject to parameter uncertainties and external disturbances. A novel fractional second-order nonsingular terminal sliding mode control (F2NTSMC is proposed and the finite time stability of the closed-loop system is ensured. A sliding mode disturbance observer (SMDO is developed to estimate and make feedforward compensation for the lumped disturbances of the PMSM system. Moreover, the finite-time convergence of estimation errors can be guaranteed. The control scheme combining F2NTSMC and SMDO can not only improve performance of the closed-loop system and attenuate disturbances, but also reduce chattering effectively. Simulation results show that the proposed control method can obtain satisfactory position tracking performance and strong robustness.

  2. Slide Valves for Single-Screw Expanders Working Under Varied Operating Conditions

    Directory of Open Access Journals (Sweden)

    Yuting Wu

    2016-06-01

    Full Text Available This paper fully describes the working principle of slide valves in single-screw expanders (SSEs. A geometric analysis of suction and volume ratio slide valves is presented to determine the relations between volume ratio, suction closure volume, discharge opening volume and slide valves displacement. An organic Rankine cycle (ORC thermodynamic model with SSE integrated with slide valves is developed to analyze the power output of SSE and the net power output of ORC system and variation law of slide valves displacement. Analysis of a typical ORC system under changing operating conditions shows that the power output of the expander and the net output power of the ORC system with slide valves are much better than those without slide valves. When the condensing temperature is 40 °C and the waste availability is 80 kW, the increase in output power and net output power are approximately 3.4 kW and 5 kW, respectively. The presented geometric analysis of slide valves and the thermodynamic model integrated with slide valves can be used to provide a theoretical and technical basis for designing the slide valves of SSEs and the control strategies of slide valves under varied operating conditions.

  3. A novel adaptive sliding mode control with application to MEMS gyroscope.

    Science.gov (United States)

    Fei, Juntao; Batur, Celal

    2009-01-01

    This paper presents a new adaptive sliding mode controller for MEMS gyroscope; an adaptive tracking controller with a proportional and integral sliding surface is proposed. The adaptive sliding mode control algorithm can estimate the angular velocity and the damping and stiffness coefficients in real time. A proportional and integral sliding surface, instead of a conventional sliding surface is adopted. An adaptive sliding mode controller that incorporates both matched and unmatched uncertainties and disturbances is derived and the stability of the closed-loop system is established. The numerical simulation is presented to verify the effectiveness of the proposed control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as the consistent estimation of gyroscope parameters including angular velocity and large robustness to parameter variations and external disturbances.

  4. Analysis and Synthesis of Memory-Based Fuzzy Sliding Mode Controllers.

    Science.gov (United States)

    Zhang, Jinhui; Lin, Yujuan; Feng, Gang

    2015-12-01

    This paper addresses the sliding mode control problem for a class of Takagi-Sugeno fuzzy systems with matched uncertainties. Different from the conventional memoryless sliding surface, a memory-based sliding surface is proposed which consists of not only the current state but also the delayed state. Both robust and adaptive fuzzy sliding mode controllers are designed based on the proposed memory-based sliding surface. It is shown that the sliding surface can be reached and the closed-loop control system is asymptotically stable. Furthermore, to reduce the chattering, some continuous sliding mode controllers are also presented. Finally, the ball and beam system is used to illustrate the advantages and effectiveness of the proposed approaches. It can be seen that, with the proposed control approaches, not only can the stability be guaranteed, but also its transient performance can be improved significantly.

  5. Universal Aging Mechanism for Static and Sliding Friction of Metallic Nanoparticles

    Science.gov (United States)

    Feldmann, Michael; Dietzel, Dirk; Tekiel, Antoni; Topple, Jessica; Grütter, Peter; Schirmeisen, André

    2016-07-01

    The term "contact aging" refers to the temporal evolution of the interface between a slider and a substrate usually resulting in increasing friction with time. Current phenomenological models for multiasperity contacts anticipate that such aging is not only the driving force behind the transition from static to sliding friction, but at the same time influences the general dynamics of the sliding friction process. To correlate static and sliding friction on the nanoscale, we show experimental evidence of stick-slip friction for nanoparticles sliding on graphite over a wide dynamic range. We can assign defined periods of aging to the stick phases of the particles, which agree with simulations explicitly including contact aging. Additional slide-hold-slide experiments for the same system allow linking the sliding friction results to static friction measurements, where both friction mechanisms can be universally described by a common aging formalism.

  6. Development and evaluation of an off-the-slide genotyping technique for identifying Giardia cysts and Cryptosporidium oocysts directly from US EPA Method 1623 slides

    Science.gov (United States)

    ABSTRACT Aims This study developed and systematically evaluated performance and limit of detection of an off-the-slide genotyping procedure for both Cryptosporidium oocysts and Giardia cysts. Methods and Results Slide standards containing flow sorted (oo)cysts were used to e...

  7. Mechanism of sand slide - cold lahar induced by extreme rainfall

    Science.gov (United States)

    Fukuoka, Hiroshi; Yamada, Masumi; Dok, Atitkagna

    2014-05-01

    Along with the increasing frequencies of extreme rainfall events in almost every where on the earth, shallow slide - debris flow, i.e. cold lahars running long distance often occurs and claims downslope residents lives. In the midnight of 15 October 2013, Typhoon Wilpha attacked the Izu-Oshima, a active volcanic Island and the extreme rainfall of more than 800 mm / 24 hours was recorded. This downpour of more than 80 mm/hr lasted 4 hours at its peak and caused a number of cold lahars. The initial stage of those lahars was shallow slides of surface black volcanic ash deposits, containing mostly fine sands. The thickness was only 50 cm - 1 m. In the reconnaissance investigation, author found that the sliding surface was the boundary of two separate volcanic ash layers between the black and yellow colored and apparently showing contrast of permeability and hardness. Permeability contrast may have contributed to generation of excess pore pressure on the border and trigger the slide. Then, the unconsolidated, unpacked mass was easily fluidized and transformed into mud flows, that which volcanologists call cold lahars. Seismometers installed for monitoring the active volcano's activities, succeeded to detect many tremors events. Many are spikes but 5 larger and longer events were extracted. They lasted 2 -3 minutes and if we assume that this tremors reflects the runout movement, then we can calculate the mean velocity of the lahars. Estimated velocity was 45 - 60 km/h, which is much higher than the average speed 30 - 40 km/h of debris flows observed in Japan. Flume tests of volcanic ash flows by the Forestry and Forest Products Research Institute showed the wet volcanic ash can run at higher speed than other materials. The two tremor records were compare d with the local residents witnessed and confirmed by newspaper reported that the reach of the lahar was observed at the exact time when tremor ends. We took the black volcanic ash and conducted ring shear tests to

  8. Comparing approaches for numerical modelling of tsunami generation by deformable submarine slides

    Science.gov (United States)

    Smith, Rebecca C.; Hill, Jon; Collins, Gareth S.; Piggott, Matthew D.; Kramer, Stephan C.; Parkinson, Samuel D.; Wilson, Cian

    2016-04-01

    Tsunami generated by submarine slides are arguably an under-considered risk in comparison to earthquake-generated tsunami. Numerical simulations of submarine slide-generated waves can be used to identify the important factors in determining wave characteristics. Here we use Fluidity, an open source finite element code, to simulate waves generated by deformable submarine slides. Fluidity uses flexible unstructured meshes combined with adaptivity which alters the mesh topology and resolution based on the simulation state, focussing or reducing resolution, when and where it is required. Fluidity also allows a number of different numerical approaches to be taken to simulate submarine slide deformation, free-surface representation, and wave generation within the same numerical framework. In this work we use a multi-material approach, considering either two materials (slide and water with a free surface) or three materials (slide, water and air), as well as a sediment model (sediment, water and free surface) approach. In all cases the slide is treated as a viscous fluid. Our results are shown to be consistent with laboratory experiments using a deformable submarine slide, and demonstrate good agreement when compared with other numerical models. The three different approaches for simulating submarine slide dynamics and tsunami wave generation produce similar waveforms and slide deformation geometries. However, each has its own merits depending on the application. Mesh adaptivity is shown to be able to reduce the computational cost without compromising the accuracy of results.

  9. User attitudes in analyzing digital slides in a quality control test bed: a preliminary study.

    Science.gov (United States)

    Della Mea, Vincenzo; Demichelis, Francesca; Viel, Federico; Dalla Palma, Paolo; Beltrami, Carlo Alberto

    2006-05-01

    The pathologist examines suitably stained glass slides through a bright field microscope in order to render histopathological or cytological diagnosis by looking at tissues and cells. Glass slides serve as a permanent record of the patient disease. Over the course of a patient's treatment slides may need to be reviewed at other institutions before treatment can commence. Due to their fragile nature a transportable permanent digital facsimile of the glass slide would be ideal. A digital slide is a set of digital images representing the whole slide normally used by the pathologist, or a significant part of it; it is usually made by a large amount of images, up to thousands, which makes its management difficult. The present paper provides a description of the requirements needed to reproduce glass slides and of the available technological equipment, then the features of the two systems we implemented on different hardware are described, together with those of the digital slide viewer. The viewer was evaluated in two experimental test phases, during which user behaviour and diagnostic reports were measured. Digital slides used in the two experiments were acquired with either system. Possible applications of digital slides are then discussed, including undergraduate and professional education, quality control, and image analysis on full samples as well as on tissue microarrays.

  10. Automated grading of renal cell carcinoma using whole slide imaging

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Yeh

    2014-01-01

    Full Text Available Introduction: Recent technology developments have demonstrated the benefit of using whole slide imaging (WSI in computer-aided diagnosis. In this paper, we explore the feasibility of using automatic WSI analysis to assist grading of clear cell renal cell carcinoma (RCC, which is a manual task traditionally performed by pathologists. Materials and Methods: Automatic WSI analysis was applied to 39 hematoxylin and eosin-stained digitized slides of clear cell RCC with varying grades. Kernel regression was used to estimate the spatial distribution of nuclear size across the entire slides. The analysis results were correlated with Fuhrman nuclear grades determined by pathologists. Results: The spatial distribution of nuclear size provided a panoramic view of the tissue sections. The distribution images facilitated locating regions of interest, such as high-grade regions and areas with necrosis. The statistical analysis showed that the maximum nuclear size was significantly different (P < 0.001 between low-grade (Grades I and II and high-grade tumors (Grades III and IV. The receiver operating characteristics analysis showed that the maximum nuclear size distinguished high-grade and low-grade tumors with a false positive rate of 0.2 and a true positive rate of 1.0. The area under the curve is 0.97. Conclusion: The automatic WSI analysis allows pathologists to see the spatial distribution of nuclei size inside the tumors. The maximum nuclear size can also be used to differentiate low-grade and high-grade clear cell RCC with good sensitivity and specificity. These data suggest that automatic WSI analysis may facilitate pathologic grading of renal tumors and reduce variability encountered with manual grading.

  11. Control of a Lightweight Flexible Robotic Arm Using Sliding Modes

    Directory of Open Access Journals (Sweden)

    Ibone Lizarraga

    2008-11-01

    Full Text Available This paper presents a robust control scheme for flexible link robotic manipulators, which is based on considering the flexible mechanical structure as a system with slow (rigid and fast (flexible modes that can be controlled separately. The rigid dynamics is controlled by means of a robust sliding-mode approach with wellestablished stability properties while an LQR optimal design is adopted for the flexible dynamics. Experimental results show that this composite approach achieves good closed loop tracking properties both for the rigid and the flexible dynamics.

  12. Automated single-slide staining device. [in clinical bacteriology

    Science.gov (United States)

    Wilkins, J. R.; Mills, S. M.

    1975-01-01

    An automatic single-slide Gram staining device is described. A timer-actuated solenoid controls the dispensing of gentian violet, Gram iodine solution, decolorizer, and 1% aqueous safranin in proper sequence and for the time required for optimum staining. The amount of stain or reagent delivered is controlled by means of stopcocks below each solenoid. Used stains and reagents can be flushed automatically or manually. Smears Gram stained automatically are equal in quality to those prepared manually. The time to complete one Gram cycle is 4.80 min.

  13. Steady and transient sliding under rate-and-state friction

    Science.gov (United States)

    Putelat, Thibaut; Dawes, Jonathan H. P.

    2015-05-01

    The physics of dry friction is often modelled by assuming that static and kinetic frictional forces can be represented by a pair of coefficients usually referred to as μs and μk, respectively. In this paper we re-examine this discontinuous dichotomy and relate it quantitatively to the more general, and smooth, framework of rate-and-state friction. This is important because it enables us to link the ideas behind the widely used static and dynamic coefficients to the more complex concepts that lie behind the rate-and-state framework. Further, we introduce a generic framework for rate-and-state friction that unifies different approaches found in the literature. We consider specific dynamical models for the motion of a rigid block sliding on an inclined surface. In the Coulomb model with constant dynamic friction coefficient, sliding at constant velocity is not possible. In the rate-and-state formalism steady sliding states exist, and analysing their existence and stability enables us to show that the static friction coefficient μs should be interpreted as the local maximum at very small slip rates of the steady state rate-and-state friction law. Next, we revisit the often-cited experiments of Rabinowicz (J. Appl. Phys., 22:1373-1379, 1951). Rabinowicz further developed the idea of static and kinetic friction by proposing that the friction coefficient maintains its higher and static value μs over a persistence length before dropping to the value μk. We show that there is a natural identification of the persistence length with the distance that the block slips as measured along the stable manifold of the saddle point equilibrium in the phase space of the rate-and-state dynamics. This enables us explicitly to define μs in terms of the rate-and-state variables and hence link Rabinowicz's ideas to rate-and-state friction laws. This stable manifold naturally separates two basins of attraction in the phase space: initial conditions in the first one lead to the block

  14. Synchronization of uncertain chaotic systems using active sliding mode control

    Energy Technology Data Exchange (ETDEWEB)

    Haeri, Mohammad [Advanced Control System Lab, Electrical Engineering Department, Sharif University of Technology, Azadi Avenue, 11365-9363 Tehran (Iran, Islamic Republic of)]. E-mail: haeri@sina.sharif.edu; Tavazoei, Mohammad Saleh [Advanced Control System Lab, Electrical Engineering Department, Sharif University of Technology, Azadi Avenue, 11365-9363 Tehran (Iran, Islamic Republic of); Naseh, Majid Reza [Electrical Engineering Department, Islamic Azad University of Birjand, Birjand (Iran, Islamic Republic of)

    2007-08-15

    We apply the active sliding mode controller to synchronize two uncertain chaotic systems. Uncertainties are considered both in linear and nonlinear parts of the system dynamics. We have also studied the case that the signals are contaminated by measuring channel noise. It is shown that having some conditions on the uncertainties and noise magnitude, the closed loop stability can be guaranteed. The synchronization errors are shown to be confined into some bounded value. Numerical simulations are presented to evaluate the analysis and effectiveness of the controller.

  15. Second Order Sliding Mode Control of the Coupled Tanks System

    Directory of Open Access Journals (Sweden)

    Fayiz Abu Khadra

    2015-01-01

    Full Text Available Four classes of second order sliding mode controllers (2-SMC have been successfully applied to regulate the liquid level in the second tank of a coupled tanks system. The robustness of these classes of 2-SMC is investigated and their performances are compared with a first order controller to show the merits of these controllers. The effectiveness of these controllers is verified through computer simulations. Comparison between the controllers is based on the time domain performance measures such as rise time, settling time, and the integral absolute error. Results showed that controllers are able to regulate the liquid level with small differences in their performance.

  16. Control of nonlinear systems using terminal sliding modes

    Science.gov (United States)

    Venkataraman, S. T.; Gulati, S.

    1992-01-01

    The development of an approach to control synthesis for robust robot operations in unstructured environments is discussed. To enhance control performance with full model information, the authors introduce the notion of terminal convergence and develop control laws based on a class of sliding modes, denoted as terminal sliders. They demonstrate that terminal sliders provide robustness to parametric uncertainty without having to resort to high-frequency control switching, as in the case of conventional sliders. It is shown that the proposed method leads to greater guaranteed precision in all control cases discussed.

  17. Sliding Mode Control of a Slewing Flexible Beam

    Science.gov (United States)

    Wilson, David G.; Parker, Gordon G.; Starr, Gregory P.; Robinett, Rush D., III

    1997-01-01

    An output feedback sliding mode controller (SMC) is proposed to minimize the effects of vibrations of slewing flexible manipulators. A spline trajectory is used to generate ideal position and velocity commands. Constrained nonlinear optimization techniques are used to both calibrate nonlinear models and determine optimized gains to produce a rest-to-rest, residual vibration-free maneuver. Vibration-free maneuvers are important for current and future NASA space missions. This study required the development of the nonlinear dynamic system equations of motion; robust control law design; numerical implementation; system identification; and verification using the Sandia National Laboratories flexible robot testbed. Results are shown for a slewing flexible beam.

  18. A sliding mode observer for hemodynamic characterization under modeling uncertainties

    KAUST Repository

    Zayane, Chadia

    2014-06-01

    This paper addresses the case of physiological states reconstruction in a small region of the brain under modeling uncertainties. The misunderstood coupling between the cerebral blood volume and the oxygen extraction fraction has lead to a partial knowledge of the so-called balloon model describing the hemodynamic behavior of the brain. To overcome this difficulty, a High Order Sliding Mode observer is applied to the balloon system, where the unknown coupling is considered as an internal perturbation. The effectiveness of the proposed method is illustrated through a set of synthetic data that mimic fMRI experiments.

  19. Adaptive Fractional Fuzzy Sliding Mode Control for Multivariable Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    Junhai Luo

    2014-01-01

    Full Text Available This paper presents a robust adaptive fuzzy sliding mode control method for a class of uncertain nonlinear systems. The fractional order calculus is employed in the parameter updating stage. The underlying stability analysis as well as parameter update law design is carried out by Lyapunov based technique. In the simulation, two examples including a comparison with the traditional integer order counterpart are given to show the effectiveness of the proposed method. The main contribution of this paper consists in the control performance is better for the fractional order updating law than that of traditional integer order.

  20. Adaptive second-order sliding mode control with uncertainty compensation

    Science.gov (United States)

    Bartolini, G.; Levant, A.; Pisano, A.; Usai, E.

    2016-09-01

    This paper endows the second-order sliding mode control (2-SMC) approach with additional capabilities of learning and control adaptation. We present a 2-SMC scheme that estimates and compensates for the uncertainties affecting the system dynamics. It also adjusts the discontinuous control effort online, so that it can be reduced to arbitrarily small values. The proposed scheme is particularly useful when the available information regarding the uncertainties is conservative, and the classical `fixed-gain' SMC would inevitably lead to largely oversized discontinuous control effort. Benefits from the viewpoint of chattering reduction are obtained, as confirmed by computer simulations.

  1. Observer Based Sliding Mode Attitude Control: Theoretical and Experimental Results

    Directory of Open Access Journals (Sweden)

    U. Jørgensen

    2011-07-01

    Full Text Available In this paper we present the design of a sliding mode controller for attitude control of spacecraft actuated by three orthogonal reaction wheels. The equilibrium of the closed loop system is proved to be asymptotically stable in the sense of Lyapunov. Due to cases where spacecraft do not have angular velocity measurements, an estimator for the generalized velocity is derived and asymptotic stability is proven for the observer. The approach is tested on an experimental platform with a sphere shaped Autonomous Underwater Vehicle SATellite: AUVSAT, developed at the Norwegian University of Science and Technology.

  2. Linear stability analysis reveals exclusion zone for sliding bed transport

    Directory of Open Access Journals (Sweden)

    Talmon Arnold M.

    2015-06-01

    Full Text Available A bend or any another pipe component disturbs solids transport in pipes. Longitudinal pressure profiles downstream of such a component may show a stationary transient harmonic wave, as revealed by a recent settling slurry laboratory experiment. Therefore the fundamental transient response of the two-layer model for fully stratified flow is investigated as a first approach. A linear stability analysis of the sliding bed configuration is conducted. No stationary transient harmonic waves are found in this analysis, but adaptation lengths for exponential recovery are quantified. An example calculation is given for a 0.1 m diameter pipeline.

  3. Risk Analysis for Unintentional Slide Deployment During Airline Operations.

    Science.gov (United States)

    Ayra, Eduardo S; Insua, David Ríos; Castellanos, María Eugenia; Larbi, Lydia

    2015-09-01

    We present a risk analysis undertaken to mitigate problems in relation to the unintended deployment of slides under normal operations within a commercial airline. This type of incident entails relevant costs for the airline industry. After assessing the likelihood and severity of its consequences, we conclude that such risks need to be managed. We then evaluate the effectiveness of various countermeasures, describing and justifying the chosen ones. We also discuss several issues faced when implementing and communicating the proposed measures, thus fully illustrating the risk analysis process. © 2015 Society for Risk Analysis.

  4. Control to Three-phase Inverter by Sliding Mode

    Directory of Open Access Journals (Sweden)

    Mouhamadou Thiam

    2014-03-01

    Full Text Available In this study, it is treated the modeling and the ordering of a three-phase inverter. The studied system is a load supplied with a three-phase inverter by means of a transformer. The ordering of the inverter is with PWM (pulse-width modulation/pulse-width Modulation and its regulation is made by the sliding method. This method is presented in this document with its various laws. The simulation of the unit is made and the results presented.

  5. Interpolating sliding mode observer for a ball and beam system

    Science.gov (United States)

    Luai Hammadih, Mohammad; Hosani, Khalifa Al; Boiko, Igor

    2016-09-01

    A principle of interpolating sliding mode observer is introduced in this paper. The observer incorporates multiple linear observers through interpolation of multiple estimates, which is treated as a type of adaptation. The principle is then applied to the ball and beam system for observation of the slope of the beam from the measurement of the ball position. The linearised model of the ball and beam system using multiple linearisation points is developed. The observer dynamics implemented in Matlab/Simulink Real Time Workshop environment. Experiments conducted on the ball and beam experimental setup demonstrate excellent performance of the designed novel interpolating (adaptive) observer.

  6. MPM dynamic simulation of a seismically induced sliding mass

    Science.gov (United States)

    Moormann, C.; Hamad, F.

    2015-09-01

    In some geotechnical applications, material can undergo large displacement combined with excessive deformation; e.g. the sliding mass problem. Owing to the limitations of classical Lagrangian and Eulerian finite element methods to model these problems, the Material Point Method (MPM) has been developed about two decades ago to cope with the large deformation. In MPM, the continuum field is represented by Lagrangian material points (particles), which can move through a fixed background of a computational mesh. Therefore, it can be seen as a mesh-based method formulated in arbitrary Lagrangian-Eulerian description. Although MPM represents the continuum by material points, solution is performed on the computational mesh. Thus, imposing boundary conditions is not aligned with the material representation. In this paper, a non-zero kinematic condition is introduced where an additional set of particles is incorporated, which tracks the moving boundary by carrying the time- dependent boundary evolution. Furthermore, the material point method has been adopted to simulate the progressive failure of a sliding granular slope triggered by a seismic excitation. In order to represent the topographical bottom of the sliding mass, on which the seismic motion is applied, a rigid boundary is implemented by introducing an additional set of particles. A frictional contact algorithm is defined between the boundary and the descending mass, which allows sliding and rolling with friction. The traction due to contact is incorporated into the discretised momentum equation as an external force where the solution of this equation is performed separately for each body in contact. Defining the local coordinate system accurately in this algorithm is essential to avoid interpenetration. Thus, a two-dimensional triangular discretisation is utilised within the three-dimensional tetrahedral elements to track the surface progression of each body in contact. Complying with other continuum models

  7. Flexible sliding frame for gait enhancing mechatronic system (GEMS).

    Science.gov (United States)

    Younbaek Lee; Byungjung Choi; Jongwon Lee; Minhyung Lee; Se-Gon Roh; Jeonghun Kim; Hyundo Choi; Yong-Jae Kim

    2016-08-01

    This paper presents a novel flexible sliding thigh frame for a gait enhancing mechatronic system. With its two-layered unique structure, the frame is flexible in certain locations and directions, and stiff at certain other locations, so that it can fît well to the wearer's thigh and transmit the assisting torque without joint loading. The paper describes the basic mechanics of this 3D flexible frame and its stiffness characteristics. We implemented the 3D flexible frame on a gait enhancing mechatronic system and conducted experiments. The performance of the proposed mechanism is verified by simulation and experiments.

  8. Robust Sliding Mode Fuzzy Control of a Car Suspension System

    Directory of Open Access Journals (Sweden)

    Ayman A. Aly

    2013-07-01

    Full Text Available Different characteristics can be considered in a suspension system design like: ride comfort, body travel, road handling and suspension travel. No suspension system can optimize all these parameters together but a better tradeoff among these parameters can be achieved in active suspension system.Objective of this paper is to establish a robust control technique of the active suspension system for a quarter-car model. The paper describes also the model and controller used in the study and discusses the vehicle response results obtained from a range of road input simulations. A comparison of robust suspension sliding fuzzy control and passive control is shown using MATLAB simulations.

  9. Astronaut James Irwin keeps Lunar Roving Vehicle from sliding downhill

    Science.gov (United States)

    1971-01-01

    Astronaut James B. Irwin, lunar module pilot, holds the Lunar Roving Vehicle from sliding downhill during the second Apollo 15 lunar surface extravehicular activity. Apparently, both of the Rover's rear wheels are off the ground. The Rover was parked facing downhill on a 15 to 20 degree slope. Astronaut David R. Scott, commander, took this photograph. Scott was performing other tasks while Irwin held the Rover. They were parked at a 'fresh' crater on the Apennine Front (Hadley Delta Mountain) slope. In the foreground a lunar rake lies atop a mound.

  10. RESEARCH OF A HIGH EFFICIENCY SLIDING SCREW DRIVER

    Institute of Scientific and Technical Information of China (English)

    Hu Xiaowei; Lu Huailiang; Huang Shuhuai

    2004-01-01

    A high efficiency sliding screw driver is introduced. It can improve driving efficiency obviously. As the material strength of the nut in this structure is low and the nut is the most dangerous part, so it is important to master the structure's characters of deformation and stress. The deformation and stress of this structure are researched by finite element method(FEM), and the changing law of stress concentration coefficient of the structure is gained. So the exact stress of nut teeth with highest load can be calculated directly based on this result.

  11. Dual view on sliding phases in U (1 ) symmetric systems

    Science.gov (United States)

    Vayl, S.; Kuklov, A. B.; Oganesyan, V.

    2017-03-01

    The proposal of sliding phases (SP) is revisited from the perspective of duality. A generic argument is formulated as essentially a no-go theorem for SP in translationally invariant nonfrustrated systems with short-range interactions—classical or quantum. Its validity is demonstrated on an asymmetric bilayer and its multilayer variation models where the duality allows obtaining asymptotically exact analytical solution. This solution is in drastic contrast with the perturbative renormalization group prediction and is strongly supported by Monte Carlo simulations. An alternative path toward finding SP is suggested. Its key ingredient is a long-range gauge-type interaction suppressing the interlayer Josephson coupling.

  12. Geant4 2005 10. user conference and collaboration workshop. Slides

    Energy Technology Data Exchange (ETDEWEB)

    Maire, M.; Amako, K.; Agapov, I.; Allison, J.; Amako, K.; Anah, J.; Apostolakis, J.; Asai, M.; Aso, T.; Barrand, G.; Becheva, E.; Berthoumieux, E.; Bongrand, M.; Boudard, A.; Canchel, G.; Capra, R.; Carlier, Th.; Chambon, P.; Chipaux, R.; Cognet, M.A.; Cornelius, I.; Cosmo, G.; Beenhouwer, J. de; Derreumaux, S.; Desbree, A.; Descourt, P.; Dridi, W.; Ersmark, T.; Faddegon, B.; Ferrer, L.; Flacco, A.; Folger, G.; Francis, S.; Giovinazzo, J.; Glinec, Y.; Godart, J.; Goncalves, P.; Gottschlag, H.; Grichine, V.; Guatelli, S.; Gudowska, I.; Guemnie Tafo, A.; Gueye, P.; Gumplinger, P.; Gurriaran, R.; Hannachi, F.; Heikkinen, A.; Hill, D.; Honore, P.F.; Howard, A.; Hrivnacova, I.; Hubert, X.; Incerti, S.; Ivanchenko, V.; Jacquemier, J.; Jones, F.; Kerhoas-Cavata, S.; Klem, J.; Koi, T.; Kosov, M.; Labalme, M.; Lang, N.; Lemercier, M.; Lemiere, Y.; Leroy, P.; Link, O.; Liu, B.; Lydon, J.; Maire, M.; Marchand, D.; Marquet, Ch.; Mascialino, B.; Matea, I.; Mccormick, J.; Mclaren, I.; Merchant, M.; Miceli, A.; Mine, Ph.; Moretto, Ph.; Mount, R.; Murakami, K.; Nachab, H.; Nehmeh, S.; Nieminen, P.; Paganetti, H.; Pallon, J.; Pandola, L.; Perl, J.; Perrot, F.; Pia Maria, G.; Piqueras, I.; Pouthier, Th.; Pshenichnov, I.; Raaijmakers, A.; Raaymakers, B.; Reuillon, R.; Ribon, A.; Rodrigues, P.; Rogel, G.; Salehzahi, F.; Santin, G.; Sasaki, T.; Schubert, M.; Seznec, H.; Shipley, D.; Skaza, F.; Thiam Cheick, O.; Tome, B.; Traneus, E.; Trindade, A.; Truscott, P.; Vacanti, G.; Verderi, M.; Watase, Y.; Wright, D.; Yarba, J.; Yoshida, H.; Zacharatou-Jarlskog, Ch.; Zhang, Q

    2005-07-01

    Originally developed for the simulation of large scale particle physics experiments, the field of applications of the conferences Geant4 is growing fast worldwide especially at the physics medicine biology frontier. In this framework the 2005 Geant4 conference was dedicated to simulations with a strong interest at the physics medicine biology frontier. In particular the following topics were discussed: review of simulation applications for medicine, validation of Geant4 models for medical physics, simulation of radiotherapy and irradiation setups, treatment planning in radiotherapy, dosimetry, parallelization, imaging techniques, data handling, related GRID developments and applications and the Geant4 DNA project with related Monte Carlo tools. Slides are provided. (A.L.B.)

  13. Practical quantification of necrosis in histological whole-slide images.

    Science.gov (United States)

    Homeyer, André; Schenk, Andrea; Arlt, Janine; Dahmen, Uta; Dirsch, Olaf; Hahn, Horst K

    2013-06-01

    Since the histological quantification of necrosis is a common task in medical research and practice, we evaluate different image analysis methods for quantifying necrosis in whole-slide images. In a practical usage scenario, we assess the impact of different classification algorithms and feature sets on both accuracy and computation time. We show how a well-chosen combination of multiresolution features and an efficient postprocessing step enables the accurate quantification necrosis in gigapixel images in less than a minute. The results are general enough to be applied to other areas of histological image analysis as well.

  14. Multidisciplinary sliding-gantry CT: from concept to reality.

    Science.gov (United States)

    Vogl, Thomas J; Frellesen, Claudia; Bauer, Ralf W; Kerl, Matthias; Zacharowski, Kai; Marzi, Ingo; Hellwig, Thomas; Hammerstingl, Renate; Lehnert, Thomas; Eichler, Katrin

    2015-01-01

    Sliding-gantry computed tomography offers an interesting variety of treatment options for emergency radiology and clinical routine. The Frankfurt 2-room installation provides an interdisciplinary, multifunctional, and cost-effective concept. It is based on a magnetically sealed rail system for the permanent movement of the gantry between 2 adjacent rooms with fixed-mounted tables. In case of emergency or intensive care patients, routine scanning can be performed in room 1 until computed tomography diagnosis is required in room 2 and can then be continued in room 1 again. Moreover, this concept allows the simultaneous handling of 2 emergency patients.

  15. Stability analysis of concrete gravity dam on complicated foundation with multiple slide planes

    Directory of Open Access Journals (Sweden)

    Xu-hua REN

    2008-09-01

    Full Text Available A key problem in gravity dam design is providing enough stability to prevent slide, and the difficulty increases if there are several weak structural planes in the dam foundation. Overload and material weakening were taken into account, and a finite difference strength reserve method with partial safety factors based on the reliability method was developed and used to study the anti-slide stability of a concrete gravity dam on a complicated foundation with multiple slide planes. Possible slide paths were obtained, and the stability of the foundation with possible failure planes was evaluated through analysis of the stress distribution characteristics. The results reveal the mechanism and process of sliding due to weak structural planes and their deformations, and provide a reference for anti-slide stability analysis of gravity dams in complicated geological conditions.

  16. Stability analysis of concrete gravity dam on complicated foundation with multiple slide planes

    Institute of Scientific and Technical Information of China (English)

    Ren Xuhua; Shu Jiaqing; Ben Nenghui; Ren Hongyun

    2008-01-01

    A key problem in gravity dam design is providing enough stability to prevent slide, and the difficulty increases if there are several weak structural planes in the dam foundation. Overload and material weakening were taken into account, and a finite difference strength reserve method with partial safety factors based on the reliability method was developed and used to study the anti-slide stability of a concrete gravity dam on a complicated foundation with multiple slide planes. Possible slide paths were obtained, and the stability of the foundation with possible failure planes was evaluated through analysis of the stress distribution characteristics. The results reveal the mechanism and process of sliding due to weak structural planes and their deformations, and provide a reference for anti-slide stability analysis of gravity dams in complicated geological conditions.

  17. A new optimal sliding mode controller design using scalar sign function.

    Science.gov (United States)

    Singla, Mithun; Shieh, Leang-San; Song, Gangbing; Xie, Linbo; Zhang, Yongpeng

    2014-03-01

    This paper presents a new optimal sliding mode controller using the scalar sign function method. A smooth, continuous-time scalar sign function is used to replace the discontinuous switching function in the design of a sliding mode controller. The proposed sliding mode controller is designed using an optimal Linear Quadratic Regulator (LQR) approach. The sliding surface of the system is designed using stable eigenvectors and the scalar sign function. Controller simulations are compared with another existing optimal sliding mode controller. To test the effectiveness of the proposed controller, the controller is implemented on an aluminum beam with piezoceramic sensor and actuator for vibration control. This paper includes the control design and stability analysis of the new optimal sliding mode controller, followed by simulation and experimental results. The simulation and experimental results show that the proposed approach is very effective.

  18. Nonsingular terminal sliding mode approach applied to synchronize chaotic systems with unknown parameters and nonlinear inputs

    Institute of Scientific and Technical Information of China (English)

    Mohammad Pourmahmood Aghababa; Hassan Feizi

    2012-01-01

    This paper deals with the design of a novel nonsingular terminal sliding mode controller for finite-time synchronization of two different chaotic systems with fully unknown parameters and nonlinear inputs.We propose a novel nonsingular terminal sliding surface and prove its finite-time convergence to zero.We assume that both the master's and the slave's system parameters are unknown in advance.Proper adaptation laws are derived to tackle the unknown parameters.An adaptive sliding mode control law is designed to ensure the existence of the sliding mode in finite time.We prove that both reaching and sliding mode phases are stable in finite time.An estimation of convergence time is given.Two illustrative examples show the effectiveness and usefulness of the proposed technique.It is worthwhile noticing that the introduced nonsingular terminal sliding mode can be applied to a wide variety of nonlinear control problems.

  19. Hybrid neural network fraction integral terminal sliding mode control of an Inchworm robot manipulator

    Science.gov (United States)

    Rahmani, Mehran; Ghanbari, Ahmad; Ettefagh, Mir Mohammad

    2016-12-01

    This paper proposes a control scheme based on the fraction integral terminal sliding mode control and adaptive neural network. It deals with the system model uncertainties and the disturbances to improve the control performance of the Inchworm robot manipulator. A fraction integral terminal sliding mode control applies to the Inchworm robot manipulator to obtain the initial stability. Also, an adaptive neural network is designed to approximate the system uncertainties and unknown disturbances to reduce chattering phenomena. The weight matrix of the proposed adaptive neural network can be updated online, according to the current state error information. The stability of the proposed control method is proved by Lyapunov theory. The performance of the adaptive neural network fraction integral terminal sliding mode control is compared with three other conventional controllers such as sliding mode control, integral terminal sliding mode control and fraction integral terminal sliding mode control. Simulation results show the effectiveness of the proposed control method.

  20. Projective synchronization of nonidentical fractional-order neural networks based on sliding mode controller.

    Science.gov (United States)

    Ding, Zhixia; Shen, Yi

    2016-04-01

    This paper investigates global projective synchronization of nonidentical fractional-order neural networks (FNNs) based on sliding mode control technique. We firstly construct a fractional-order integral sliding surface. Then, according to the sliding mode control theory, we design a sliding mode controller to guarantee the occurrence of the sliding motion. Based on fractional Lyapunov direct methods, system trajectories are driven to the proposed sliding surface and remain on it evermore, and some novel criteria are obtained to realize global projective synchronization of nonidentical FNNs. As the special cases, some sufficient conditions are given to ensure projective synchronization of identical FNNs, complete synchronization of nonidentical FNNs and anti-synchronization of nonidentical FNNs. Finally, one numerical example is given to demonstrate the effectiveness of the obtained results.

  1. Adaptive Global Sliding Mode Control for MEMS Gyroscope Using RBF Neural Network

    Directory of Open Access Journals (Sweden)

    Yundi Chu

    2015-01-01

    Full Text Available An adaptive global sliding mode control (AGSMC using RBF neural network (RBFNN is proposed for the system identification and tracking control of micro-electro-mechanical system (MEMS gyroscope. Firstly, a new kind of adaptive identification method based on the global sliding mode controller is designed to update and estimate angular velocity and other system parameters of MEMS gyroscope online. Moreover, the output of adaptive neural network control is used to adjust the switch gain of sliding mode control dynamically to approach the upper bound of unknown disturbances. In this way, the switch item of sliding mode control can be converted to the output of continuous neural network which can weaken the chattering in the sliding mode control in contrast to the conventional fixed gain sliding mode control. Simulation results show that the designed control system can get satisfactory tracking performance and effective estimation of unknown parameters of MEMS gyroscope.

  2. Influence of fluid pore pressure on chaotic sliding of tectonic faults

    Science.gov (United States)

    Turuntaev, Sergey; Riga, Vasily

    2016-04-01

    The problem of permeable rock pore pressure variation influence on tectonic fault sliding and generation of seismic events was studied in the scope of rate-and-state friction model with two-parametric friction law. The coupled problem of pore-elasticity and fault sliding governed by two-parametric rate-and-state equation was studied numerically. The main modes of the fault sliding were found, and transitions from one mode to another due to the fluid pore pressure change were observed. The conditions for transition from stable to chaotic sliding (considered as an analog of seismic event generations) were found. It was shown, that chaotic sliding has features of Poincare stability and can be characterized by finite values of correlation integral and embedding dimension, which depend on critical shear stresses. Change of the effective critical stresses by the pore pressure variation will result in change of the tectonic fault sliding mode and consequently change of the seismic regime.

  3. Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding

    Directory of Open Access Journals (Sweden)

    Mingyue Cui

    2012-11-01

    Full Text Available An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov-stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

  4. Sliding wear and friction behavior of zirconium alloy with heat-treated Inconel718

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H., E-mail: kimjhoon@cnu.ac.kr [Dept. of Mechanical Design Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Park, J.M. [Dept. of Mechanical Design Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Park, J.K.; Jeon, K.L. [Nuclear Fuel Technology Department, Korea Nuclear Fuel, 1047 Daedukdae-ro, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2014-04-01

    In water-cooled nuclear reactors, the sliding of fuel rod can lead to severe wear and it is an important issue to sustain the structural integrity of nuclear reactor. In the present study, sliding wear behavior of zirconium alloy in dry and water environment using Pin-On-Disk sliding wear tester was investigated. Wear resistance of zirconium alloy against heat-treated Inconel718 pin was examined at room temperature. Sliding wear tests were carried out at different sliding distance, axial load and sliding speed based on ASTM (G99-05). The results of these experiments were verified with specific wear rate and coefficient of friction. The micro-mechanisms responsible for wear in zirconium alloy were identified to be microcutting and microcracking in dry environment. Moreover, micropitting and delamination were observed in water environment.

  5. Robust fuzzy control for stochastic Markovian jumping systems via sliding mode method

    Science.gov (United States)

    Chen, Bei; Jia, Tinggang; Niu, Yugang

    2016-07-01

    This paper considers the problem of sliding mode control for stochastic Markovian jumping systems by means of fuzzy method. The Takagi-Sugeno (T-S) fuzzy stochastic model subject to state-dependent noise is presented. A key feature in this work is to remove the restricted condition that each local system model had to share the same input channel, which is usually assumed in some existing results. The integral sliding surface is constructed for every mode and the connections among various sliding surfaces are established via a set of coupled matrices. Moreover, the present sliding mode controller including the transition rates of modes can cope with the effect of Markovian switching. It is shown that both the reachability of sliding surfaces and the stability of sliding mode dynamics can be ensured. Finally, numerical simulation results are given.

  6. Highly sensitive fluorescence detection of avidin/streptavidin with an optical interference mirror slide.

    Science.gov (United States)

    Yasuda, Mitsuru; Akimoto, Takuo

    2012-01-01

    This paper presents highly sensitive fluorescence detections of avidin and streptavidin using an optical interference mirror (OIM) slide consisting of a plane mirror covered with an optical interference layer. Compared with a common glass slide, the OIM slide can enhance the fluorescence from a dye by more than 100-fold. We fabricated an OIM slide by depositing an optical interference layer of Al(2)O(3) on an Ag mirror. To enhance the fluorescence maximally, the optimal thickness of the Al(2)O(3) layer was estimated from optical interference theory. For detections of protein, avidin/streptavidin labeled with fluorescein, Cy3, and Cy5 were detected with biotin immobilized on an OIM slide with the optimal Al(2)O(3) thickness. We achieved a sensitivity improvement of more than 50-fold, comparing with a glass slide. Such a high degree of improvement would be a significant contribution to further progress in biomedical research and medical diagnostics.

  7. Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots With Unknown Sliding

    Directory of Open Access Journals (Sweden)

    Mingyue Cui

    2012-11-01

    Full Text Available An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time‐varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov‐stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed‐loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

  8. Scanning negatives and slides digitizing your photographic archive

    CERN Document Server

    Steinhoff, Sascha

    2009-01-01

    Many photographers have either moved into digital photography exclusively or use both analog and digital media in their work. In either case, there is sure to be an archive of slides and negatives that cannot be directly integrated into the new digital workflow, nor can it be archived in a digital format. Increasingly, photographers are trying to bridge this gap with the use of high-performance film scanners. In this 2nd edition, you will learn how to achieve the best possible digital image from a negative or a slide, and how to build a workflow to make this process efficient, repeatable, and reliable. The author uses Nikon's film scanners, but all steps can easily be accomplished while using a different scanner. The most common software tools for scanning (SilverFast, VueScan, NikonScan) are not only covered extensively in the book, but trial versions are also provided on a DVD, which also contains other useful tools for image editing, as well as numerous sample scans.

  9. Development of a slide agglutination assay for detection of blastomycosis.

    Science.gov (United States)

    Hatch, Wayne O; Scalarone, Gene M

    2013-11-01

    Blastomycosis, caused by the thermally dimorphic fungus Blastomyces dermatitides, which is endemic to eastern regions of the USA, is commonly misdiagnosed as a viral or bacterial infection and therefore treated improperly. Over the years, many immunodiagnostic assays to aid in the diagnosis of blastomycosis have been developed; however, a reliable assay for use in local clinics still remains elusive. Procedures for a slide agglutination assay for detection of antibody in serum from rabbits immunized with B. dermatitidis were evaluated with antigenic preparations from B. dermatitidis adsorbed to polystyrene microparticles. Yeast-phase lysates from five isolates of B. dermatitides: namely ER-593 (Eagle River, WI, USA), ER-598 (Eagle River, WI, USA), 48938 (India), B5896 (Mt. Iron, MN, USA), and T-58 (TN, USA) were evaluated for their sensitivity and specificity. Sensitivities of the lysates ranged from 29% to 83% whereas specificities ranged from 13% to 100%. Lysate ER-593 provided the most promising results with a sensitivity of 82% and specificity of 100%. This study provides suggests that a simple rapid slide agglutination assay for detecting blastomycosis may be used for screening patients with suspected B. dermatitidis infection.

  10. Adaptive backstepping slide mode control of pneumatic position servo system

    Science.gov (United States)

    Ren, Haipeng; Fan, Juntao

    2016-06-01

    With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potential in many fields. However, most existing control methods with high tracking performance need to know the model information and to use pressure sensor. This limits the application of the pneumatic servo system. An adaptive backstepping slide mode control method is proposed for pneumatic position servo system. The proposed method designs adaptive slide mode controller using backstepping design technique. The controller parameter adaptive law is derived from Lyapunov analysis to guarantee the stability of the system. A theorem is testified to show that the state of closed-loop system is uniformly bounded, and the closed-loop system is stable. The advantages of the proposed method include that system dynamic model parameters are not required for the controller design, uncertain parameters bounds are not need, and the bulk and expensive pressure sensor is not needed as well. Experimental results show that the designed controller can achieve better tracking performance, as compared with some existing methods.

  11. Adaptive backstepping slide mode control of pneumatic position servo system

    Science.gov (United States)

    Ren, Haipeng; Fan, Juntao

    2016-09-01

    With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potential in many fields. However, most existing control methods with high tracking performance need to know the model information and to use pressure sensor. This limits the application of the pneumatic servo system. An adaptive backstepping slide mode control method is proposed for pneumatic position servo system. The proposed method designs adaptive slide mode controller using backstepping design technique. The controller parameter adaptive law is derived from Lyapunov analysis to guarantee the stability of the system. A theorem is testified to show that the state of closed-loop system is uniformly bounded, and the closed-loop system is stable. The advantages of the proposed method include that system dynamic model parameters are not required for the controller design, uncertain parameters bounds are not need, and the bulk and expensive pressure sensor is not needed as well. Experimental results show that the designed controller can achieve better tracking performance, as compared with some existing methods.

  12. Adaptive suboptimal second-order sliding mode control for microgrids

    Science.gov (United States)

    Incremona, Gian Paolo; Cucuzzella, Michele; Ferrara, Antonella

    2016-09-01

    This paper deals with the design of adaptive suboptimal second-order sliding mode (ASSOSM) control laws for grid-connected microgrids. Due to the presence of the inverter, of unpredicted load changes, of switching among different renewable energy sources, and of electrical parameters variations, the microgrid model is usually affected by uncertain terms which are bounded, but with unknown upper bounds. To theoretically frame the control problem, the class of second-order systems in Brunovsky canonical form, characterised by the presence of matched uncertain terms with unknown bounds, is first considered. Four adaptive strategies are designed, analysed and compared to select the most effective ones to be applied to the microgrid case study. In the first two strategies, the control amplitude is continuously adjusted, so as to arrive at dominating the effect of the uncertainty on the controlled system. When a suitable control amplitude is attained, the origin of the state space of the auxiliary system becomes attractive. In the other two strategies, a suitable blend between two components, one mainly working during the reaching phase, the other being the predominant one in a vicinity of the sliding manifold, is generated, so as to reduce the control amplitude in steady state. The microgrid system in a grid-connected operation mode, controlled via the selected ASSOSM control strategies, exhibits appreciable stability properties, as proved theoretically and shown in simulation.

  13. Sliding mode control of electromagnetic tethered satellite formation

    Science.gov (United States)

    Hallaj, Mohammad Amin Alandi; Assadian, Nima

    2016-08-01

    This paper investigates the control of tethered satellite formation actuated by electromagnetic dipoles and reaction wheels using the robust sliding mode control technique. Generating electromagnetic forces and moments by electric current coils provides an attractive control actuation alternative for tethered satellite system due to the advantages of no propellant consumption and no obligatory rotational motion. Based on a dumbbell model of tethered satellite in which the flexibility and mass of the tether is neglected, the equations of motion in Cartesian coordinate are derived. In this model, the J2 perturbation is taken into account. The far-field and mid-field models of electromagnetic forces and moments of two satellites on each other and the effect of the Earth's magnetic field are presented. A robust sliding mode controller is designed for precise trajectory tracking purposes and to deal with the electromagnetic force and moment uncertainties and external disturbances due to the Earth's gravitational and magnetic fields inaccuracy. Numerical simulation results are presented to validate the effectiveness of the developed controller and its superiority over the linear controller.

  14. Enhanced adaptive fuzzy sliding mode control for uncertain nonlinear systems

    Science.gov (United States)

    Roopaei, Mehdi; Zolghadri, Mansoor; Meshksar, Sina

    2009-09-01

    In this article, a novel Adaptive Fuzzy Sliding Mode Control (AFSMC) methodology is proposed based on the integration of Sliding Mode Control (SMC) and Adaptive Fuzzy Control (AFC). Making use of the SMC design framework, we propose two fuzzy systems to be used as reaching and equivalent parts of the SMC. In this way, we make use of the fuzzy logic to handle uncertainty/disturbance in the design of the equivalent part and provide a chattering free control for the design of the reaching part. To construct the equivalent control law, an adaptive fuzzy inference engine is used to approximate the unknown parts of the system. To get rid of the chattering, a fuzzy logic model is assigned for reaching control law, which acting like the saturation function technique. The main advantage of our proposed methodology is that the structure of the system is unknown and no knowledge of the bounds of parameters, uncertainties and external disturbance are required in advance. Using Lyapunov stability theory and Barbalat's lemma, the closed-loop system is proved to be stable and convergence properties of the system is assured. Simulation examples are presented to verify the effectiveness of the method. Results are compared with some other methods proposed in the past research.

  15. Denuded Zones, Diffusional Creep, and Grain Boundary Sliding

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J; Ruano, O A; Sherby, O D

    2001-06-27

    The appearance of denuded zones following low stress creep in particle-containing crystalline materials is both a microstructural prediction and observation often cited as irrefutable evidence for the Nabarro-Herring mechanism of diffusional creep. The denuded zones are predicted to be at grain boundaries that are orthogonal to the direction of the applied stress. Furthermore, their dimensions should account for the accumulated plastic flow. In the present paper, the evidence for such denuded zones is critically examined. These zones have been observed during creep of magnesium, aluminum, and nickel-base alloys. The investigation casts serious doubts on the apparently compelling evidence for the link between denuded zones and diffusional creep. Specifically, denuded zones are clearly observed under conditions that are explicitly not diffusional creep. Additionally, the denuded zones are often found in directions that are not orthogonal to the applied stress. Other mechanisms that can account for the observations of denuded zones are discussed. It is proposed that grain boundary sliding accommodated by slip is the rate-controlling process in the stress range where denuded zones have been observed. It is likely that the denuded zones are created by dissolution of precipitates at grain boundaries that are simultaneously sliding and migrating during creep.

  16. The Influence of the Relative Sliding on the Surface Quality

    Directory of Open Access Journals (Sweden)

    N. Diaconu

    2011-09-01

    Full Text Available This paper presents a study on the surface quality pointing out the influence of relative sliding on the topography parameters. Traditional roughness parameters as Ra and Rq, deal only with relative high of the asperities to the mean line and they give no information on shape, slope and asperities magnitude, on their appearance frequency on the profile length. The authors analysed a set of 3D parameters including the amplitude ones (Sa, Sku, Ssk and St and functional parameters as Svk, Sk and Spk as calculated with a dedicated soft from the bearing area. Tests were done on roller-roller tribotester lubricated with the grease grade UM185Li2EP (general purpose grease for rolling bearings, the temperature of the environment being kept at 80°C. There was studied the influence of relative sliding speed on the skewness and the kurtosis of the surface topography, but also on common parameters as Sa and St. Such a study may be used for selecting a suitable surface quality and to evaluate the surface topography degradation in time, after tests under severe conditions, very close to the actual ones.

  17. Virtual slides: high-quality demand, physical limitations, and affordability.

    Science.gov (United States)

    Glatz-Krieger, Katharina; Glatz, Dieter; Mihatsch, Michael J

    2003-10-01

    Virtual slides (VSs) have been around since the beginning of telepathology. As recently as a couple of years ago, only single small images could be acquired, and their distribution was limited to e-mail at best. Today, whole slides can be acquired, covering an area up to 100,000 times larger than that possible only a few years ago. Moreover, advanced Internet and world-wide web technologies enable delivery of those images to a broad audience. Despite considerable advances in technology, few good examples of VSs for public use can be found on the web. One of the reasons for this is a lack of sophisticated and integrated commercial solutions covering the needs from acquisition to delivery at reasonable cost. This article describes physical and technical limitations of the VS technology to clarify the demands on a VS acquisition system. A new type of web-based VS viewer (vMic; http://alf3.urz.unibas.ch/vmic/) open to public use is introduced, allowing anyone to set up a VS system with high usability at low cost.

  18. Adaptive sliding mode formation control of multiple underwater robots

    Directory of Open Access Journals (Sweden)

    Das Bikramaditya

    2014-12-01

    Full Text Available This paper proposes a new adaptive sliding mode control scheme for achieving coordinated motion control of a group of autonomous underwater vehicles with variable added mass. The control law considers the communication constraints in the acoustic medium. A common reference frame for velocity is assigned to a virtual leader dynamically. The performances of the proposed adaptive SMC were compared with that of a passivity based controller. To save the time and traveling distance for reaching the FRP by the follower AUVs, a sliding mode controller is proposed in this paper that drives the state trajectory of the AUV into a switching surface in the state space. It is observed from the obtained results that the proposed SMC provides improved performance in terms of accurately tracking the desired trajectory within less time compared to the passivity based controller. A communication consensus is designed ensuring the transfer of information among the AUVs so that they move collectively as a group. The stability of the overall closed-loop systems are analysed using Lyapunov theory and simulation results confirmed the robustness and efficiency of proposed controller.

  19. Rapid mastitis detection assay on porous nitrocellulose membrane slides.

    Science.gov (United States)

    Mujawar, Liyakat Hamid; Moers, Antoine; Norde, Willem; van Amerongen, Aart

    2013-09-01

    We have developed a rapid mastitis detection test based on the immobilization of tag-specific antibody molecules, the binding of double-tagged amplicons, and as a secondary signal a conjugate of black carbon nanoparticles having molecules of a fusion protein of neutrAvidin and alkaline phosphatase at their surface. The antibodies were inkjet printed onto three different nitrocellulose membrane slides, Unisart (Sartorius), FAST (GE Whatman), and Oncyte-Avid (Grace-Biolabs), and the final assay signals on these slides were compared. The blackness of the spots was determined by flatbed scanning and assessment of the pixel gray volume using TotalLab image analysis software. The black spots could be easily read by the naked eye. We successfully demonstrated the detection of specific amplicons from mastitis-causing pathogens in less than 3 h. Using a similar protocol, we also showed that it was possible to detect specific amplicons from four different mastitis-causing pathogens (six strains) on the same pad. The influence of two different printing buffers, phosphate-buffered saline (pH 7.4) and carbonate buffer (pH 9.6), on the functionality of the primary antibodies was also compared.

  20. TOWARDS A BETTER FORECAST FOR RESERVOIR SLOPE SLIDING

    Institute of Scientific and Technical Information of China (English)

    Didier MAROT; Alain ALEXIS; Pierre THOMAS

    2003-01-01

    The siltation of reservoir causes many problems of management and environmental disturbances that are important to minimize. Solving these problems requires in particular a good knowledge of mud bank instabilities. In partnership with the Laboratoire National d'Hydraulique (LNH), a subsidiary of Electricite de France (E.D.F.), authors realize a study of soft soils sliding entailed by reservoir emptying. Using a geotechnical flat sliding mechanism, the theoretical formulation of the safety factor can be established when the sediment mass is submerged and emergent. The measurement campaign carried out makes it possible to obtain bathymetric and topographic surveys and a geotechnical characterization of the soil for the whole reservoir of Grangent dam, located on the Loire (France). The proposed model appears to agree satisfactorily with the instability of the zones emerged because of the emptying and with the stability of the profile after emptying. The use of this model within the framework of forecasts makes it possible to calculate significant minimal displaced heights.

  1. Modified robust sliding-mode control method for wafer scanner

    Directory of Open Access Journals (Sweden)

    Yiguang Wang

    2015-03-01

    Full Text Available This article studies the precision motion control of a long-stroke reticle stage driven by the permanent magnet linear motor in wafer scanner. A robust sliding-mode control method is proposed for tracking the reference trajectory in the presence of un-modeled dynamics, parametric uncertainty and external disturbances including force ripple, cogging and friction in the controlled system. A modified sliding-mode term based on the variable structure technique for eliminating the tracking error is employed in the proposed control law. The system stability and tracking convergence of the closed-loop control system are guaranteed by Lyapunov theory theoretically. The feasibility and effectiveness of the proposed method are demonstrated by comparative experiments on a linear motion testbed. The experimental results show that better tracking performance can be achieved by the proposed method compared with the conventional proportional–integral–derivative method and it can be considered as a possible alternative in the precision motion control system.

  2. Simulation research of discrete sliding mode control for active powerfilter

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-feng; SUN Bao; YANG Zhen; LI Jian

    2011-01-01

    Because of the widely-used nonlinear loads,the problems of harmonics and low power factor in power systems are becoming more and more serious.In view of the above problems,a shunt three-phase active power filter(SAPF)based on discrete sliding mode control to suppress the harmonics was designed and the power factor improved.First,built the mathematical model of SAPF.Then,controlled the switch through analyzing the harmonic current that was controlled signal using discrete sliding mode control.Through simulation using MATLAB,verified the validity of the algorithm.By the simulation waveforms,it can be found that after the load current containing a large number of harmonics passes the active power filter,the waveform of the power current approximately becomes a sine wave and the harmonics is significantly reduced.As a result,it plays a good role in purifying power systems.Moreover,from the waveforms of harmonic current and power current,it can be found that the algorithm has a faster tracking speed.The waveform can be stably tracked in the half cycle and real-time if the algorithm is perfect.

  3. Sliding Mode Control Strategy for Wind Turbine Power Maximization

    Directory of Open Access Journals (Sweden)

    Oscar Barambones

    2012-07-01

    Full Text Available The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a sliding mode control for variable speed wind turbine that incorporates a doubly fed induction generator is described. The electrical system incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the grid. In the presented design the so-called vector control theory is applied, in order to simplify the electrical equations. The proposed control scheme uses stator flux-oriented vector control for the rotor side converter bridge control and grid voltage vector control for the grid side converter bridge control. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally simulated results show, on the one hand, that the proposed controller provides high-performance dynamic characteristics, and on the other hand, that this scheme is robust with respect to the uncertainties that usually appear in the real systems.

  4. Denuded Zones, Diffusional Creep, and Grain Boundary Sliding

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J; Ruano, O A; Sherby, O D

    2001-06-27

    The appearance of denuded zones following low stress creep in particle-containing crystalline materials is both a microstructural prediction and observation often cited as irrefutable evidence for the Nabarro-Herring mechanism of diffusional creep. The denuded zones are predicted to be at grain boundaries that are orthogonal to the direction of the applied stress. Furthermore, their dimensions should account for the accumulated plastic flow. In the present paper, the evidence for such denuded zones is critically examined. These zones have been observed during creep of magnesium, aluminum, and nickel-base alloys. The investigation casts serious doubts on the apparently compelling evidence for the link between denuded zones and diffusional creep. Specifically, denuded zones are clearly observed under conditions that are explicitly not diffusional creep. Additionally, the denuded zones are often found in directions that are not orthogonal to the applied stress. Other mechanisms that can account for the observations of denuded zones are discussed. It is proposed that grain boundary sliding accommodated by slip is the rate-controlling process in the stress range where denuded zones have been observed. It is likely that the denuded zones are created by dissolution of precipitates at grain boundaries that are simultaneously sliding and migrating during creep.

  5. XY-sliding phases - mirage of the Renormalization Group

    Science.gov (United States)

    Vayl, Steven; Kuklov, Anatoly; Oganesyan, Vadim

    The so called sliding XY phases in layered systems are predicted to occur if the one loop renormalization group (RG) flow renders the interlayer Josephson coupling irrelevant, while each layer still features broken U(1) symmetry. In other words, such a layered system remains essentially two-dimensional despite the presence of inter-layer Josephson coupling. We have analyzed numerically a layered system consisting of groups of asymmetric layers where the RG analysis predicts sliding phases to occur. Monte Carlo simulations of such a system have been conducted in the dual representation by Worm Algorithm in terms of the closed loops of J-currents for layer sizes varying from 4 ×4 to 640 ×640 and the number of layers - from 2 to 40. The resulting flow of the inter-layer XY-stiffness has been found to be inconsistent with the RG prediction and fully consistent with the behavior of the 3D standard XY model where the bare inter-layer Josephson coupling is much smaller than the intra-layer stiffness. This result emphasizes the importance of the compactness of the U(1) variable for 2D to 3D transformation. This work was supported by the NSF Grant PHY1314469.

  6. Guaranteed performance in reaching mode of sliding mode controlled systems

    Indian Academy of Sciences (India)

    G K Singh; K E Holé

    2004-02-01

    Conventionally, the parameters of a sliding mode controller (SMC) are selected so as to reduce the time spent in the reaching mode. Although, an upper bound on the time to reach (reaching time) the sliding surface is easily derived, performance guarantee in the state/error space needs more consideration. This paper addresses the design of constant plus proportional rate reaching law-based SMC for second-order nonlinear systems. It is shown that this controller imposes a bounding second-order error-dynamics, and thus guarantees robust performance during the reaching phase. The choice of the controller parameters based on the time to reach a desirable level of output tracking error (OTE), rather than on the reaching time is proposed. Using the Lyapunov theory, it is shown that parameter selections, based on the reaching time criterion, may need substantially larger time to achieve the OTE. Simulation results are presented for a nonlinear spring-massdamper system. It is seen that parameter selections based on the proposed OTE criterion, result in substantially quicker tracking, while using similar levels of control effort.

  7. Thresholds in the sliding resistance of simulated basal ice

    Directory of Open Access Journals (Sweden)

    L. F. Emerson

    2007-10-01

    Full Text Available We report laboratory determinations of the shear resistance to sliding melting ice with entrained particles over a hard, impermeable surface. With higher particle concentrations and larger particle sizes, Coulomb friction at particle-bed contacts dominates and the shear stress increases linearly with normal load. We term this the sandy regime. When either particle concentration or particle size is reduced below a threshold, the dependence of shear resistance on normal load is no longer statistically significant. We term this regime slippery. We use force and mass balance considerations to examine the flow of melt water beneath the simulated basal ice. At high particle concentrations, the transition from sandy to slippery behavior occurs when the particle size is comparable to the thickness of the melt film that separates the sliding ice from its bed. For larger particle sizes, a transition from sandy to slippery behavior occurs when the particle concentration drops sufficiently that the normal load is no longer transferred completely to the particle-bed contacts. We estimate that the melt films separating the particles from the ice are approximately 0.1 µm thick at this transition. Our laboratory results suggest the potential for abrupt transitions in the shear resistance beneath hard-bedded glaciers with changes in either the thickness of melt layers or the particle loading.

  8. Sliding Mode Control of Dynamic Voltage Restorer by Using a New Adaptive Reaching Law

    Science.gov (United States)

    Pandey, Achala; Agrawal, Rekha; Mandloi, Ravindra S.; Sarkar, Biswaroop

    2017-08-01

    This paper presents a new kind of adaptive reaching law for sliding mode control of Dynamic Voltage Restorer (DVR). Such an adaptive reaching law follows under-damped sinusoidal nature that causes the initial state to reach the sliding regime in extremely less time with negligible chattering. Moreover, it is robust in the sense the trajectory does not deviate from the sliding surface. This new approach is developed and successfully applied to DVR. The simulation results are presented that show its robustness.

  9. Stability analysis of concrete gravity dam on complicated foundation with multiple slide planes

    OpenAIRE

    Xu-hua REN; Jia-qing SHU; Neng-hui BEN; Hong-yun REN

    2008-01-01

    A key problem in gravity dam design is providing enough stability to prevent slide, and the difficulty increases if there are several weak structural planes in the dam foundation. Overload and material weakening were taken into account, and a finite difference strength reserve method with partial safety factors based on the reliability method was developed and used to study the anti-slide stability of a concrete gravity dam on a complicated foundation with multiple slide planes. Possible slid...

  10. Hierarchical sliding mode control for under-actuated cranes design, analysis and simulation

    CERN Document Server

    Qian, Dianwei

    2015-01-01

    This book reports on the latest developments in sliding mode overhead crane control, presenting novel research ideas and findings on sliding mode control (SMC), hierarchical SMC and compensator design-based hierarchical sliding mode. The results, which were previously scattered across various journals and conference proceedings, are now presented in a systematic and unified form. The book will be of interest to researchers, engineers and graduate students in control engineering and mechanical engineering who want to learn the methods and applications of SMC.

  11. Slide Coagglutination for Salmonella typhi Antigens in Broths Inoculated with Feces from Typhoid Fever Patients

    Science.gov (United States)

    1981-12-01

    SLIDE COAGGLUTINATION FOR SALMONELLA TYPHI ANTIGENS IN BROTHS INOCULATED WITH FECES FROM TYPHOID FEVER PATIENTS R. C. Rockhill, L. W. Rumans and M...permission of the Editor, Southeast Asian Journal of Tropical Medicine and Public Health SLIDE COAGGLUTINATION FOR SALMONELLA TYPHI ANTIGENS IN...525 Vol. 12 No. 4 December 1981 1 1P .. .. . --U- 1- "J SLIDE COAGGLUTINATION O Salmonella typhi ANTIGFNS the Infectious Disease Hospital and cultured

  12. Analysis and Sliding Mode Control of Four-Wire Three-Leg Shunt Active Power Filter

    OpenAIRE

    Farid Hamoudi; Hocine Amimeur

    2015-01-01

    In this paper, the analysis and the sliding mode control application for a shunt active filter is presented. The active filter is based on a three-leg split-capacitor voltage source inverter which is used to compensate harmonics and unbalance in the phase currents, and therefore to cancel neutral current. The proposed sliding mode control is formulated from the multivariable state model established in dq0 frames. The selection of the sliding mode functions takes in account simultaneously, the...

  13. Shifting gears higher - digital slides in graduate education - 4 years experience at Semmelweis University

    Directory of Open Access Journals (Sweden)

    Molnár Béla

    2010-11-01

    Full Text Available Abstract Background The spreading of whole slide imaging or digital slide systems in pathology as an innovative technique seems to be unstoppable. Successful introduction of digital slides in education has played a crucial role to reach this level of acceptance. Practically speaking there is no university institute where digital materials are not built into pathology education. At the 1st. Department of Pathology and Experimental Cancer Research, Semmelweis University optical microscopes have been replaced and for four years only digital slides have been used in education. The aim of this paper is to summarize our experiences gathered with the installation of a fully digitized histology lab for graduate education. Methods We have installed a digital histology lab with 40 PCs, two slide servers - one for internal use and one with external internet access. We have digitized hundreds of slides and after 4 years we use a set of 126 slides during the pathology course. A Student satisfaction questionnaire and a Tutor satisfaction questionnaire have been designed, both to be completed voluntarily to have feed back from the users. The page load statistics of the external slide server were evaluated. Results The digital histology lab served ~900 students and ~1600 hours of histology practice. The questionnaires revealed high satisfaction with digital slides. The results also emphasize the importance of the tutors' attitude towards digital microscopy as a factor influencing the students' satisfaction. The constantly growing number of page downloads from the external server confirms this satisfaction and the acceptance of digital slides. Conclusions We are confident, and have showed as well, that digital slides have got numerous advantages over optical slides and are more suitable in education.

  14. Artificial Chattering Free on-line Modified Sliding Mode Algorithm: Applied in Continuum Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Mohammad Mahdi Ebrahimi

    2013-11-01

    Full Text Available In this research, an artificial chattering free adaptive fuzzy modified sliding mode control design and application to continuum robotic manipulator has proposed in order to design high performance nonlinear controller in the presence of uncertainties. Regarding to the positive points in sliding mode controller, fuzzy logic controller and online tuning method, the output improves. Each method by adding to the previous controller has covered negative points. The main target in this research is design of model free estimator on-line sliding mode fuzzy algorithm for continuum robot manipulator to reach an acceptable performance. Continuum robot manipulators are highly nonlinear, and a number of parameters are uncertain, therefore design model free controller by both analytical and empirical paradigms are the main goal. Although classical sliding mode methodology has acceptable performance with known dynamic parameters such as stability and robustness but there are two important disadvantages as below: chattering phenomenon and mathematical nonlinear dynamic equivalent controller part. To solve the chattering fuzzy logic inference applied instead of dead zone function. To solve the equivalent problems in classical sliding mode controller this paper focuses on applied on-line tuning method in classical controller. This algorithm works very well in certain and uncertain environment. The system performance in sliding mode controller is sensitive to the sliding function. Therefore, compute the optimum value of sliding function for a system is the next challenge. This problem has solved by adjusting sliding function of the on-line method continuously in real-time. In this way, the overall system performance has improved with respect to the classical sliding mode controller. This controller solved chattering phenomenon as well as mathematical nonlinear equivalent part by applied modified PID supervisory method in modified fuzzy sliding mode controller and

  15. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    Science.gov (United States)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  16. Dynamic Sliding Mode Control based on Fractional calculus subject to uncertain delay based chaotic pneumatic robot

    OpenAIRE

    P., Sara Gholipour; Sh, Heydar Toosian

    2013-01-01

    This paper considers the chattering problem of sliding mode control while delay in robot manipulator caused chaos in such electromechanical systems. Fractional calculus as a powerful theorem to produce a novel sliding mode; which has a dynamic essence is used for chattering elimination. To realize the control of a class of chaotic systems in master-slave configuration this novel fractional dynamic sliding mode control scheme is presented and examined on delay based chaotic robot in joint and ...

  17. Chaos control in delayed chaotic systems via sliding mode based delayed feedback

    Energy Technology Data Exchange (ETDEWEB)

    Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, Seyed Khandan Bridge, Shariati St. 16314, P.O. Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Sedigh, Ali Khaki [Faculty of Electrical Engineering, K.N. Toosi University of Technology, Seyed Khandan Bridge, Shariati St. 16314, P.O. Box 16315-1355, Tehran (Iran, Islamic Republic of)

    2009-04-15

    This paper investigates chaos control for scalar delayed chaotic systems using sliding mode control strategy. Sliding surface design is based on delayed feedback controller. It is shown that the proposed controller can achieve stability for an arbitrary unstable fixed point (UPF) or unstable periodic orbit (UPO) with arbitrary period. The chaotic system used in this study to illustrate the theoretical concepts is the well known Mackey-Glass model. Simulation results show the effectiveness of the designed nonlinear sliding mode controller.

  18. Finite-time control of DC-DC buck converters via integral terminal sliding modes

    Science.gov (United States)

    Chiu, Chian-Song; Shen, Chih-Teng

    2012-05-01

    This article presents novel terminal sliding modes for finite-time output tracking control of DC-DC buck converters. Instead of using traditional singular terminal sliding mode, two integral terminal sliding modes are introduced for robust output voltage tracking of uncertain buck converters. Different from traditional sliding mode control (SMC), the proposed controller assures finite convergence time for the tracking error and integral tracking error. Furthermore, the singular problem in traditional terminal SMC is removed from this article. When considering worse modelling, adaptive integral terminal SMC is derived to guarantee finite-time convergence under more relaxed stability conditions. In addition, several experiments show better start-up performance and robustness.

  19. Robust control of uncertain time delay system: a novel sliding mode control design via LMI

    Institute of Scientific and Technical Information of China (English)

    Qu Shaocheng; Wang Yongji

    2006-01-01

    The sliding mode control problem (SMC) is studied for a class of uncertain delay system in the presence of both parameter uncertainties and external disturbances. A novel virtual feedback control method is presented. Based on Lyapunov theory, sufficient conditions for design of the robust sliding mode plane are derived. Sliding mode controller based on reaching law concept is developed, which is to ensure system trajectories from any initial conditions asymptotically convergent to sliding mode plane. The global asymptotically stability of the closed-loop system is guaranteed. A numerical example with simulation results is given to illustrate the effectiveness of the methodology.

  20. H∞ Observer-Based Sliding Mode Control for Uncertain Stochastic Systems with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2013-01-01

    Full Text Available The paper is concerned with sliding mode control for uncertain time-delay systems subjected to input nonlinearity and stochastic perturbations. Using the sliding mode control, a robust law is derived to guarantee the reachability of the sliding surface in a finite time interval. The sufficient conditions on asymptotic stability of the error system and sliding mode dynamics with disturbance attenuation level are presented in terms of linear matrix inequalities (LMIs. Finally, an example is provided to illustrate the efficiency and effectiveness of the proposed method.

  1. Integral sliding mode control for a class of nonlinear neutral systems with time-varying delays

    Institute of Scientific and Technical Information of China (English)

    Lou Xu-Yang; Cui Bao-Tong

    2008-01-01

    This paper focuses on sliding mode control problems for a class of nonlinear neutral systems with time-varying delays. An integral sliding surface is firstly constructed. Then it finds a useful criteria to guarantee the global stability for the nonlinear neutral systems with time-varying delays in the specified switching surface, whose condition is formulated as linear matrix inequality. The synthesized sliding mode controller guarantees the reachability of the specified sliding surface. Finally, a numerical simulation validates the effectiveness and feasibility of the proposed technique.

  2. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques

    Science.gov (United States)

    Vetter, T. K.; Wells, S. R.; Hess, Ronald A.; Bacon, Barton (Technical Monitor); Davidson, John (Technical Monitor)

    2002-01-01

    A brief review of sliding model control is undertaken, with particular emphasis upon the effects of neglected parasitic dynamics. Sliding model control design is interpreted in the frequency domain. The inclusion of asymptotic observers and control 'hedging' is shown to reduce the effects of neglected parasitic dynamics. An investigation into the application of observer-based sliding mode control to the robust longitudinal control of a highly unstable is described. The sliding mode controller is shown to exhibit stability and performance robustness superior to that of a classical loop-shaped design when significant changes in vehicle and actuator dynamics are employed to model airframe damage.

  3. Robust Control of a Hydraulically Actuated Manipulator Using Sliding Mode Control

    DEFF Research Database (Denmark)

    Hansen, Michael Rygaard; Andersen, Torben Ole; Pedersen, Henrik Clemmensen

    2005-01-01

    This paper presents an approach to robust control called sliding mode control (SMC) applied to the a hydraulic servo system (HSS), consisting of a servo valve controlled symmetrical cylinder. The motivation for applying sliding mode control to hydraulically actuated systems is its robustness...... towards structured (parametric) and unstructured (unmodeled dynamics) uncertainties. A third-order model of the actuated system is used to develop a sliding mode control which is implemented and tested on a simulation model. To avoid measurement of velocity and acceleration a simple first-order model...... is furthermore used to develop a simple sliding mode control (SSMC). The performance of the two controllers are compared and discussed....

  4. Output tracking control of mobile manipulators based on dynamical sliding-mode control

    Institute of Scientific and Technical Information of China (English)

    WU Yuxiang; FENG Ying; HU Yueming

    2007-01-01

    A dynamical sliding-mode controller is devised to track the output of mobile manipulators. During the investi- gation, firstly a reduced dynamic model considering the dynamics of the driving motor is developed for mobile manipulators. Then, the system is decomposed into four lower-dimensional subsystems by means of diffeomorphism and nonlinear input transformation. Moreover, a design method of the dynamical sliding-mode controller that is applied to the output tracking of mobile manipulators is proposed. The simulation results indicate that the dynamical sliding-mode controller can not only track the given trajec- tory correctly but also reduce the chattering of sliding-mode control system considerably.

  5. Passivity-Sliding Mode Control of Uncertain Chaotic Systems with Stochastic Disturbances

    Directory of Open Access Journals (Sweden)

    Zhumu Fu

    2014-01-01

    Full Text Available This paper is concerned with the stabilization problem of uncertain chaotic systems with stochastic disturbances. A novel sliding function is designed, and then a sliding mode controller is established such that the trajectory of the system converges to the sliding surface in a finite time. Using a virtual state feedback control technique, sufficient condition for the mean square asymptotic stability and passivity of sliding mode dynamics is derived via linear matrix inequality (LMI. Finally, a simulation example is presented to show the validity and advantage of the proposed method.

  6. Reading virtual slide using web viewers: results of subjective experience with three different solutions.

    Science.gov (United States)

    Rojo, Marcial García; Gallardo, Antonio J; González, Lucía; Peces, Carlos; Murillo, Cristina; González, Jesús; Sacristán, Jose

    2008-07-15

    Virtual slides are viewed using interactive software that enables the user to simulate the behaviour of a conventional optical microscope, like adjusting magnifications and navigating to any portion of the image. Nowadays, information about the performance and features of web-based solutions for reading slides in real environments is still scarce. The objective of this study is analyzing the subjective experience of pathologists with virtual slides, comparing the time needed to read slides using different web viewers and different network connections. Eight slides were randomly selected (4 biopsies and 2 cytologies) from Hospital General de Ciudad Real (HGCR) archives. Three different virtual slide web-viewing solutions were analyzed: Aperio web server, Olympus NetImage Server, and Aurora mScope. Five pathologists studied to time needed to access images of each virtual slide, selecting a panoramic view, 10 low magnification fields, and 20 high magnification fields. Aperio viewer is very efficient in overview images. Aurora viewer is especially efficient in lower magnifications (10x). For larger magnifications (20x and 40x) no significant differences were found between different vendors. Olympus was found to be the most user-friendly interface. When comparing Internet with intranet connections, despite being slower, users also felt comfortable using virtual slides through Internet connection. Available web solutions for virtual slides have different advantages, mainly in functionalities and optimization for different magnifications. Pathologists should select the solutions adapted to their needs.

  7. Fractional-Order Fast Terminal Sliding Mode Control for a Class of Dynamical Systems

    Directory of Open Access Journals (Sweden)

    Guoliang Zhao

    2013-01-01

    Full Text Available This paper introduces a novel fractional fast terminal sliding mode control strategy for a class of dynamical systems with uncertainty. In this strategy, a fractional-order sliding surface is proposed, the corresponding control law is derived based on Lyapunov stability theory to guarantee the sliding condition, and the finite time stability of the closeloop system is also ensured. Further, to achieve the equivalence between convergence rate and singularity avoidance, a fractional-order nonsingular fast terminal sliding mode controller is studied and the stability is presented. Finally, numerical simulation results are presented to illustrate the effectiveness of the proposed method.

  8. Time-varying sliding-coefficient-based decoupled terminal sliding-mode control for a class of fourth-order systems.

    Science.gov (United States)

    Bayramoglu, Husnu; Komurcugil, Hasan

    2014-07-01

    A time-varying sliding-coefficient-based decoupled terminal sliding mode control strategy is presented for a class of fourth-order systems. First, the fourth-order system is decoupled into two second-order subsystems. The sliding surface of each subsystem was designed by utilizing time-varying coefficients. Then, the control target of one subsystem to another subsystem was embedded. Thereafter, a terminal sliding mode control method was utilized to make both subsystems converge to their equilibrium points in finite time. The simulation results on the inverted pendulum system demonstrate that the proposed method exhibits a considerable improvement in terms of a faster dynamic response and lower IAE and ITAE values as compared with the existing decoupled control methods.

  9. Sliding drops in the diffuse interface model coupled to hydrodynamics.

    Science.gov (United States)

    Thiele, U; Velarde, M G; Neuffer, K; Bestehorn, M; Pomeau, Y

    2001-12-01

    Using a film thickness evolution equation derived recently combining long-wave approximation and diffuse interface theory [L. M. Pismen and Y. Pomeau, Phys. Rev. E 62, 2480 (2000)] we study one-dimensional surface profiles for a thin film on an inclined plane. We discuss stationary flat film and periodic solutions including their linear stability. Flat sliding drops are identified as universal profiles, whose main properties do not depend on mean film thickness. The flat drops are analyzed in detail, especially how their velocity, advancing and receding dynamic contact angles and plateau thicknesses depend on the inclination of the plane. A study of nonuniversal drops shows the existence of a dynamical wetting transition with hysteresis between droplike solutions and a flat film with small amplitude nonlinear waves.

  10. Fault tolerant control schemes using integral sliding modes

    CERN Document Server

    Hamayun, Mirza Tariq; Alwi, Halim

    2016-01-01

    The key attribute of a Fault Tolerant Control (FTC) system is its ability to maintain overall system stability and acceptable performance in the face of faults and failures within the feedback system. In this book Integral Sliding Mode (ISM) Control Allocation (CA) schemes for FTC are described, which have the potential to maintain close to nominal fault-free performance (for the entire system response), in the face of actuator faults and even complete failures of certain actuators. Broadly an ISM controller based around a model of the plant with the aim of creating a nonlinear fault tolerant feedback controller whose closed-loop performance is established during the design process. The second approach involves retro-fitting an ISM scheme to an existing feedback controller to introduce fault tolerance. This may be advantageous from an industrial perspective, because fault tolerance can be introduced without changing the existing control loops. A high fidelity benchmark model of a large transport aircraft is u...

  11. Sliding Mode Control of a Thermal Mixing Process

    Science.gov (United States)

    Richter, Hanz; Figueroa, Fernando

    2004-01-01

    In this paper we consider the robust control of a thermal mixer using multivariable Sliding Mode Control (SMC). The mixer consists of a mixing chamber, hot and cold fluid valves, and an exit valve. The commanded positions of the three valves are the available control inputs, while the controlled variables are total mass flow rate, chamber pressure and the density of the mixture inside the chamber. Unsteady thermodynamics and linear valve models are used in deriving a 5th order nonlinear system with three inputs and three outputs, An SMC controller is designed to achieve robust output tracking in the presence of unknown energy losses between the chamber and the environment. The usefulness of the technique is illustrated with a simulation.

  12. Mechanism of shallow disrupted slide induced by extreme rainfall

    Science.gov (United States)

    Igwe, O.; Fukuoka, H.

    2010-12-01

    On July 16, 2010, extreme rainfall attacked western Japan and it caused very intense rainfall in Shobara city, Hiroshima prefecture, Japan. This rainfall induced hundreds of shallow disrupted slides and many of those became debris flows. One of this debris flows attacked a house standing in front of the exit of a channel, and claimed a resident’s life. Western Japan had repeatedly similar disasters in the past. Last event took place from July 19 to 26, 2009, when western Japan had a severe rainstorms and caused floods and landslides. Most of the landslides are debris slide - debris flows. Most devastated case took place in Hofu city, Japan. On July 21, extremely intense rainstorm caused numerous debris flows and mud flows in the hillslopes. Some of the debris flows destroyed residential houses and home for elderly people, and finally killed 14 residents. One of the unusual feature of both disaster was that landslides are distributed in very narrow area. In the 2010 Shobara city disaster, all of the landslides were distributed in 5 km x 3 km, and in the 2009 Hofu city disaster, most devastated zone of landslides were 10 km x 5 km. Rain radars of Meteorological Agency of Government of Japan detected the intense rainfall, however, the spatial resolution is usually larger than 5 km and the disaster area is too small to predict landslides nor issue warning. Furthermore, it was found that the growth rate of baby clouds was very quick. The geology of both areas are rhyolite (Shobara) and granite (Hofu), so the areal assessment of landslide hazard should be prepared before those intense rainfall will come. As for the Hofu city case, it was proved that debris flows took place in the high precipitation area and covered by covered by weathered granite sands and silts which is called “masa". This sands has been proved susceptible against landslides under extreme rainfall conditions. However, the transition from slide - debris flow process is not well revealed, except

  13. Sliding contacts on printed circuit boards and wear behavior

    Science.gov (United States)

    Le Solleu, J.-P.

    2010-04-01

    Automotive suppliers use since decades printed circuit boards (PCB) gold plating pads, as direct contact interface for low current sliding contacts. Several gold plating processes are available on the market, providing various wear behaviour. Some specific galvanic hard gold (AuCo or AuNi). plating was developed on PCB's. This specific plating generates extra costs due to the material quantity and also the process complexity. In a cost driven industry, the challenge is to use a standard low cost PCB for systems requesting high reliability performances. After a brief overview of standard PCB manufacturing processes and especially gold plating processes, the global experimental results of wear behaviour of three different gold plating technologies will be exposed and an explanation of the correlation between surface key parameters and wear out will be provided.

  14. Optical fiber based slide tactile sensor for underwater robots

    Institute of Scientific and Technical Information of China (English)

    TAN Ding-zhong; WANG Qi-ming; SONG Rui-han; YAO Xin; GU Yi-hua

    2008-01-01

    In the underwater environment,many visual sensors don't work,and many sensors which work well for robots working in space or on land can not be used underwater.Therefore,an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers.The principles and structure of the sensor are explained in detail.Its static and dynamic characteristics were analyzed theoretically and then simulated.A dynamic characteristic model was built and the simulation made using the GA based neural network.In order to improve sensor response,the recognition model of the sensor was designed based on the'inverse solution'principle of neural networks,increasing the control precision and the sensitivity of the manipulator.

  15. Simulations of contact angle induced pearling for sliding drops

    Science.gov (United States)

    McCue, Scott; Mayo, Lisa; Moroney, Timothy

    2015-11-01

    Droplets sliding down an incline can develop a corner or a cusp at their rear, or undergo a pearling transition whereby the tail breaks up into a number of smaller satellite droplets. These phenomena have been of interest since the experimental work of. It appears that the experimental investigation of this problem is limited due to the inherent difficulty of minimising contact angle hysteresis, whereby physical or chemical heterogeneities of the substrate cause pinning and distortion of the droplet. By applying a lubrication model with a disjoining pressure term, we investigate these flows numerically in order to further shed light on how certain conditions (such as contact angle) affect the corner-cusp-pearling transition. We acknowledge support from the ARC Linkage Project LP100200476.

  16. Dry sliding wear of Ni alloyed austempered ductile iron

    Directory of Open Access Journals (Sweden)

    E. Akbarzadeh Chiniforush

    2016-09-01

    Full Text Available Measurements of dry sliding wear are presented for ductile irons with composition Fe-3.56C-2.67Si-0.25Mo-0.5Cu and Ni contents of 0.8 and 1.5 in wt.% with applied loads of 50, 100 and 150 N for austempering temperatures of 270, 320, and 370 °C after austenitizing at 870 °C for 120 min. The mechanical property measurements show that the grades of the ASTM 897M: 1990 Standard can be satisfied for the selected austempering conditions. The results show that wear resistance is independent of austempering temperature with an applied load of 50 N, but there is a strong dependence at higher austempering temperatures with applied loads of 100 and 150 N. Observations indicate that wear is due to subsurface fatigue with cracks nucleated at deformed graphite nodules.

  17. Virtual Reality and Its Application to Slide Annimation of Landslide

    Institute of Scientific and Technical Information of China (English)

    PAN Jianping; YE Huanzhou

    2004-01-01

    A few researches adopt virtual reality in landslide. So it is significant to combine the physics-based deformable method with the process simulation of a sliding landslide, this way the dynamic process of a going landslide can be simulated. The analysis of the dynamic law of landslide provides a foundation to forecast and make it realiable to foretell disasters. After recounting the condition of VR and landsliding body simulation, this paper puts forward simulating landslide by the physics-based deformable method. The method divides landsliding into deformable body and rigid one. The deformation of deformable body can be compute by DDA and FEM, and DDA fits the great deformation and FEM is good for the tiny deformation. This paper shows it is feasible to simulate the landslide animation by this method.

  18. Longitudinal tire force estimation based on sliding mode observer

    Energy Technology Data Exchange (ETDEWEB)

    El Hadri, A.; Cadiou, J.C.; M' Sirdi, N.K. [Versailles Univ., Paris (France). Lab. de Robotique; Beurier, G.; Delanne, Y. [Lab. Central des Ponts, Centre de Nantes (France)

    2001-07-01

    This paper presents an estimation method for vehicle longitudinal dynamics, particularly the tractive/braking force. The estimation can be used to detect a critical driving situation to improve security. It can be used also in several vehicle control systems. The main characteristics of the vehicle longitudinal dynamics were taken into account in the model used to design an observer and computer simulations. The state variables are the angular wheel velocity, vehicle velocity and the longitudinal tire force. The proposed differential equation of the tractive/braking force is derived using the concept of relaxation length. The observer designed is based on the sliding mode approach using only the angular wheel velocity measurement. The proposed method of estimation is verified through a one-wheel simulation model with a ''Magic formula'' tire model. Simulations results show an excellent reconstruction of the tire force. (orig.)

  19. Influence Factors of Fractal Characterization of Reciprocating Sliding Wear Surfaces

    Institute of Scientific and Technical Information of China (English)

    周新聪; 冯伟; 严新平; 萧汉梁

    2004-01-01

    The principal purpose of this paper is to investigate influence factors of fractal characterization of reciprocating sliding wear surfaces.The wear testing was completed to simulate the real running condition of the diesel engine 8NVD48A-2U.The test results of wear surface morphology dimension characterization show that wear surface profiles have statistical self-affine fractal characteristics.In general, there are no effects of the profilometer sampling spacing and sampling length and evaluation length on the fractal dimensions of the surfaces.However, if the evaluation length is too short, the structure function logarithm of the surface profile is scattered.The sampling length acting as a filter is an important part of the fractal dimension measurement.If the sampling length is too short, the evaluation of the fractal dimension will have a larger standard deviation.The continuous wavelet transform can be used to improve surface profile dimension characterization.

  20. Robust adaptive synchronization of chaotic neural networks by slide technique

    Institute of Scientific and Technical Information of China (English)

    Lou Xu-Yang; Cui Bao-Tong

    2008-01-01

    In this paper,we focus on the robust adaptive synchronization between two coupled chaotic neural networks with all the parameters unknown and time-varying delay.In order to increase the robustness of the two coupled neural networks,the key idea is that a sliding-mode-type controller is employed.Moreover,without the estimate values of the network unknown parameters taken as an updating object,a new updating object is introduced in the constructing of controller.Using the proposed controller,without any requirements for the boundedness,monotonicity and differentiability of activation functions,and symmetry of connections,the two coupled chaotic neural networks can achieve global robust synchronization no matter what their initial states are.Finally,the numerical simulation validates the effectiveness and feasibility of the proposed technique.

  1. Feature based sliding window technique for face recognition

    Science.gov (United States)

    Javed, Muhammad Younus; Mohsin, Syed Maajid; Anjum, Muhammad Almas

    2010-02-01

    Human beings are commonly identified by biometric schemes which are concerned with identifying individuals by their unique physical characteristics. The use of passwords and personal identification numbers for detecting humans are being used for years now. Disadvantages of these schemes are that someone else may use them or can easily be forgotten. Keeping in view of these problems, biometrics approaches such as face recognition, fingerprint, iris/retina and voice recognition have been developed which provide a far better solution when identifying individuals. A number of methods have been developed for face recognition. This paper illustrates employment of Gabor filters for extracting facial features by constructing a sliding window frame. Classification is done by assigning class label to the unknown image that has maximum features similar to the image stored in the database of that class. The proposed system gives a recognition rate of 96% which is better than many of the similar techniques being used for face recognition.

  2. Speed Synchronization of web winding System with Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Hachemi Glaoui

    2013-02-01

    Full Text Available A continuous web winding system is a large-scale, complex interconnected dynamic system with numerous tension zones to transport the web while processing it. There are two control schemes for large-scale system control: the centralized scheme and the decentralized scheme. Centralized control is the traditional control method, which considers all the information about the system to be a single dynamic model and design a control system for this model. A speed synchronization control strategy for multiple induction motors, based on adjacent cross-coupling control structure, is developed by employing total sliding mode control method. The proposed control strategy is to stabilize speed tracking of each induction motor while synchronizing its speed with the speed of the other motors so as to make speed synchronization error amongst induction motors converge to zero. The global stability and the convergence of the designed controller are proved by using Lyapunov method. Simulation results demonstrate the effectiveness of the proposed method.

  3. Direct numerical simulation of the dynamics of sliding rough surfaces

    CERN Document Server

    Dang, Viet Hung; Scheibert, Julien; Bot, Alain Le

    2013-01-01

    The noise generated by the friction of two rough surfaces under weak contact pressure is usually called roughness noise. The underlying vibration which produces the noise stems from numerous instantaneous shocks (in the microsecond range) between surface micro-asperities. The numerical simulation of this problem using classical mechanics requires a fine discretization in both space and time. This is why the finite element method takes much CPU time. In this study, we propose an alternative numerical approach which is based on a truncated modal decomposition of the vibration, a central difference integration scheme and two algorithms for contact: The penalty algorithm and the Lagrange multiplier algorithm. Not only does it reproduce the empirical laws of vibration level versus roughness and sliding speed found experimentally but it also provides the statistical properties of local events which are not accessible by experiment. The CPU time reduction is typically a factor of 10.

  4. Sliding window correlation analysis for dengue-climate variable relationship

    Science.gov (United States)

    Thiruchelvam, Loshini; Asirvadam, Vijanth S.; Dass, Sarat C.; Daud, Hanita; Gill, Balvinder S.

    2016-11-01

    This study discussed building of sliding windows to analyze the relationship between dengue incidences and weather variables of mean temperature, relative humidity and rainfall, across the timeline. A window sized of 20 was selected and applied to find correlation between dengue incidences and each of the weather variable. A few time lag of zero, two, four, six, and eight is compared and the time lag with best correlation is selected for each weather variable. Study did not found a good insight for analysis using mean temperature and relative humidity. For both these variables, it was suggested dengue incidences is better measured using fluctuation of maximum and minimum values. Analysis using rainfall variable was found to vary across the timeline in magnitude and direction of the correlation. Time lag of eight was found to be the most significant explaining the relationship between dengue incidences and rainfall variable.

  5. Towards slide enhancement with the titanium-molybdenum wire?

    Science.gov (United States)

    Thiry, Pol; Barthélémi, Stéphane

    2010-12-01

    This study aims to improve the tribological properties of titanium-molybdenum wire. Following an analysis of the wire/bracket/ligation friction parameters and an overview of the technological research into means of reducing such friction,we set up several types of surface treatment in the laboratory by physical deposition in the vapor phase and using cold plasma technology. The specimens obtained underwent two types of tribological tests and were then subjected to traction and bending tests in order to determine the variations in their mechanical properties induced by the different types of treatment. For purposes of comparison, all the tests were conducted on untreated wire, TMA® Low-friction® wire and stainless steel wire and with two types of elastomeric ties. We were able to demonstrate some remarkable slide performances obtained using cold plasma nitriding while preserving the mechanical properties. A significant difference was observed relative to the other surface treatments.

  6. Failure Mechanisms of Ana Slide, Eivissa Channel, Western Mediterranean Sea

    Science.gov (United States)

    Lafuerza, S.; Sultan, N.; Canals, M.; Lastras, G.; Cattaneo, A.; Frigola, J.; Costa, S.; Berndt, C.

    2011-12-01

    Fluid seepage has been considered as the most plausible explanation to account for slope instabilities in the Eivissa Channel in between the Iberian Peninsula and the Balearic Islands, Western Mediterranean Sea. In situ geotechnical tests and sediment cores obtained in the Ana Slide area, on the Balearic slope of the Eivissa Channel, suggest that the development of the basal failure surface (BFS) was favoured by contrasting hydro-mechanical properties between a coarse unit (U7) charged with methane and a fine-grained unit above (U6). The presence of past methane seepage has been inferred from high magnetic susceptibility values found in sediments from the headwall area and is supported by seismic reflection data. Geotechnical data from piezocone tests, laboratory analyses and numerical calculations indicate degradation of the undrained shear strength generated by methane exsolution and expansion as the only plausible mechanism to explain the origin of Ana Slide. The probability of failure for different critical failure surfaces has been investigated by using the SAMU-3D slope stability model taking into account the role of free gas in the development of the landslide. According to SAMU-3D, the most probable failure surface is related to a minimum degradation of the undrained shear strength of units U6 and U7 of 95% and a basal failure surface developed at the base of U6, which acted as a weak layer. Wheeler's theory suggests that 9% of free-gas saturation in U7 is enough to reduce the undrained shear strength by 95%. However, using the theory of the undrained equilibrium behaviour of gassy sediments we conclude that the excess fluid pressure generated by gas exsolution and expansion is not relevant to bring the slope to fail.

  7. An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study.

    Science.gov (United States)

    Weinstein, Ronald S; Descour, Michael R; Liang, Chen; Barker, Gail; Scott, Katherine M; Richter, Lynne; Krupinski, Elizabeth A; Bhattacharyya, Achyut K; Davis, John R; Graham, Anna R; Rennels, Margaret; Russum, William C; Goodall, James F; Zhou, Pixuan; Olszak, Artur G; Williams, Bruce H; Wyant, James C; Bartels, Peter H

    2004-11-01

    This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a "lenslet array ensemble." The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single "miniaturized microscope." A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A.= 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete. A validation study compared the diagnostic accuracy of pathologist case readers using array microscopy (with images viewed as virtual slides) and conventional light microscopy. Four senior pathologists diagnosed 30 breast surgical pathology cases each using both imaging modes, but on separate occasions. Of 120 case reads by array microscopy

  8. Characterization, Geometry, Temporal Evolution and Controlling Mechanisms of the Jettan Rock-Slide, Northern Norway

    DEFF Research Database (Denmark)

    Blikra, Lars Harald; Christiansen, Hanne Hvidtfeldt; Kristensen, Lene

    2015-01-01

    The Jettan rockslide is an active topmost part of a large instability in paragneiss along the fjord Storfjorden in Northern Norway. It has deep back fractures in the top part with sliding planes at 45–50 m depth. The sliding planes seem to be controlled largely by SW-NE trending regional faults d...

  9. Robust Control of a Hydraulically Actuated Manipulator Using Sliding Mode Control

    DEFF Research Database (Denmark)

    Hansen, Michael Rygaard; Andersen, Torben Ole; Pedersen, Henrik Clemmensen

    2005-01-01

    This paper presents an approach to robust control called sliding mode control (SMC) applied to the a hydraulic servo system (HSS), consisting of a servo valve controlled symmetrical cylinder. The motivation for applying sliding mode control to hydraulically actuated systems is its robustness towa...

  10. An Antique Microscope Slide Brings the Thrill of Discovery into a Contemporary Biology Classroom

    Science.gov (United States)

    Reiser, Frank

    2012-01-01

    The discovery of a Victorian-era microscope slide titled "Grouped Flower Seeds" began an investigation into the scientific and historical background of the antique slide to develop its usefulness as a multidisciplinary tool for PowerPoint presentations usable in contemporary biology classrooms, particularly large-enrollment sections. The resultant…

  11. A Feedforward-Feedback Interpretation of a Sliding Mode Control Law

    NARCIS (Netherlands)

    Monsees, Govert; George, Koshy; Scherpen, Jacquelien M.A.; Verhaegen, Michel

    1999-01-01

    In this paper we provide a feedforward-feedback interpretation of a sliding mode control scheme. Given a desired trajectory, the feedforward signal is generated using a stable inversion method, and the feedback signal includes the switching term of the sliding mode control law. In this manner, we in

  12. Adaptive switching gain for a discrete-time sliding mode controller

    NARCIS (Netherlands)

    Monsees, G.; Scherpen, J.M.A.

    2002-01-01

    Sliding mode control is a well-known technique capable of making the closed loop system robust with respect to certain kinds of parameter variations and unmodelled dynamics. The sliding mode control law consists of a continuous component which is based on the model knowledge and discontinuous compon

  13. Synchronization of noise-perturbed generalized Lorenz system by sliding mode control*

    Institute of Scientific and Technical Information of China (English)

    Kong Cui-Cui; Chen Shi-Hua

    2009-01-01

    Synchronization of a noise-perturbed generalized Lorenz system by using sliding mode control method is investigated in this paper. Two sliding mode control methods are proposed to synchronize the noise-perturbed generalized Lorenz system. Numerical simulations are also provided for the illustration and verification of the methods.

  14. Adaptive Switching Gain for a Discrete-Time Sliding Mode Controller

    NARCIS (Netherlands)

    Monsees, G.; Scherpen, J.M.A.

    2000-01-01

    Sliding Mode Control is a well-known technique capable of making the closed loop system robust with respect to certain kinds of parameter variations and unmodeled dynamics. The sliding mode control law consists of the linear control part which is based on the model knowledge and the discontinuous co

  15. Effects of Exposure to Physique Slides on the Emotional Responses of Men and Women.

    Science.gov (United States)

    Hausenblas, Heather A.; Janelle, Christopher M.; Gardner, Rebecca Ellis; Hagan, Amy L.

    2002-01-01

    Examined high and low body dissatisfied (BD) men's and women's in-task emotional responses to acute exposure to sex-specific physique slides of the aesthetic ideal and of themselves. Participating college students reported their immediate in-task emotional responses to viewing the slides. Men and women, as well as high and low BD groups, reported…

  16. Roughness effects on the sliding frictional force of submonolayer liquid films on solid substrates

    NARCIS (Netherlands)

    Palasantzas, G.; Widom, A.

    1998-01-01

    The sliding frictional force of a liquid submonolayer in contact with a random rough surface in an oscillatory motion is considered. The frictional force is proportional to the square of the sliding velocity v, Ff~v^2, with a proportionality factor that depends on the particular roughness configurat

  17. Formation of metal-F bonds during frictional sliding : Influence of water and applied load

    NARCIS (Netherlands)

    Shen, J. T.; Pei, Y. T.; De Hosson, J. Th. M.

    2016-01-01

    Effects of water lubrication and applied load on the formation of PTFE transfer films and metal-F bonds during sliding when PTFE filled composites sliding against steel and Al2O3 are investigated. In water lubricated conditions, XPS analysis reveals that a thin layer of water molecules at the slidin

  18. Micro-Doppler Effect of Extended Streamlined Targets Based on Sliding Scattering Centre Model

    Directory of Open Access Journals (Sweden)

    Bo Tang

    2016-06-01

    Full Text Available The scattering center of extended streamlined targets can slide when the direction of radiation is changed. The sliding scattering center has influence on the micro-Doppler effect of micro-motion of the extended streamlined target. This paper focused on the micro-Doppler of the extended streamlined target for the bistatic radar. Based on the analysis, the analytical expressions of the micro-Doppler of coning motion with sliding scattering center model were given for bistatic radar. And the results were validated by the simulated results of the scattering field based on the full-wave method of the electromagnetic computation. The results showed that the sliding of the scattering center can make the micro-Doppler be less and distorted, and the influence of the sliding is different for two different types of the sliding scattering centers: sliding on the surface and sliding on the bottom circle. The analytical expressions of the micro-Doppler are helpful to analyze the time-frequency presentations (TFR of the coning motion of the extended streamlined target and to estimate the parameters of the target.

  19. Metallurgical investigations of dry sliding surface layer in phosphorous iron/steel friction pairs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Surface layer behaviors of composition concentration and micro-hardness were inves-tigated on phosphorous cast irons after dry sliding. The experimental results indicate that thehardness and chemical composition unevenly distribute in the surface layer. The sliding conditionand microstructure of the pin specimen have greatly effects on the distributions.

  20. An Antique Microscope Slide Brings the Thrill of Discovery into a Contemporary Biology Classroom

    Science.gov (United States)

    Reiser, Frank

    2012-01-01

    The discovery of a Victorian-era microscope slide titled "Grouped Flower Seeds" began an investigation into the scientific and historical background of the antique slide to develop its usefulness as a multidisciplinary tool for PowerPoint presentations usable in contemporary biology classrooms, particularly large-enrollment sections. The resultant…