Zero Robotics Tournaments

Total Page:16

File Type:pdf, Size:1020Kb

Zero Robotics Tournaments Collaborative Competition for Crowdsourcing Spaceflight Software and STEM Education using SPHERES Zero Robotics by Sreeja Nag B.S. Exploration Geophysics, Indian Institute of Technology, Kharagpur, 2009 M.S. Exploration Geophysics, Indian Institute of Technology, Kharagpur, 2009 Submitted to the Department of Aeronautics and Astronautics and the Engineering Systems Division in Partial Fulfillment of the Requirements for the Degrees of Master of Science in Aeronautics and Astronautics and Master of Science in Technology and Policy at the Massachusetts Institute of Technology June 2012 © 2012 Massachusetts Institute of Technology. All rights reserved Signature of Author ____________________________________________________________________ Department of Aeronautics and Astronautics and Engineering Systems Division May 11, 2012 Certified by __________________________________________________________________________ Jeffrey A. Hoffman Professor of Practice in Aeronautics and Astronautics Thesis Supervisor Certified by __________________________________________________________________________ Olivier L. de Weck Associate Professor of Aeronautics and Astronautics and Engineering Systems Thesis Supervisor Accepted by __________________________________________________________________________ Eytan H. Modiano Professor of Aeronautics and Astronautics Chair, Graduate Program Committee Accepted by __________________________________________________________________________ Joel P. Clark Professor of Materials Systems and Engineering Systems Acting Director, Technology and Policy Program 1 2 Collaborative Competition for Crowdsourcing Spaceflight Software and STEM Education using SPHERES Zero Robotics by Sreeja Nag Submitted to the Department of Aeronautics and Astronautics and the Engineering Systems Division On May 11, 2012 in Partial Fulfillment of the Requirements for the Degrees of Master of Science in Aeronautics and Astronautics and Master of Science in Technology and Policy ABSTRACT Crowdsourcing is being researched as a technique to develop small-scale spaceflight software by issuing open calls for solutions to large crowds of people with the incentive of prizes. There is widespread investment of resources in the fields of Science, Technology, Engineering, Mathematics (STEM) education to improve STEM interests and skills. This thesis tackles the dual objectives of building crowdsourcing cluster flight software and educating students using collaborative gaming and competition, both in virtual simulation environments and on real hardware in space. The concept is demonstrated using the SPHERES Zero Robotics Program which is a robotics programming competition. The robots are nanosatellites called SPHERES – an experimental testbed to test navigation, formation flight and control algorithms - onboard the International Space Station (ISS). Zero Robotics allows students to access SPHERES through a web-based interface and the robust programs run on the hardware in microgravity, supervised by astronauts. The apparatus to investigate the influence of collaboration was developed by (1) building new web infrastructure and an Integrated Development Environment where intensive inter- participant collaboration is possible, (2) designing and programming a game to solve a relevant formation flight problem, collaborative in nature - and (3) structuring a tournament such that inter-team collaboration is mandated. The web infrastructure was built using crowdsourcing competitions too, to demonstrate feasibility of building software end-to-end through crowdsourcing. The multi-objective design of experiments had three types of collaborations as variables – within matches (to achieve game objectives), inter-team alliances and unstructured communication on online forums. The data used to evaluate objective achievement were simulation competition scores, website usage statistics, post- competition surveys and satellite telemetry from ISS hardware demonstrations. All types of collaboration showed positive influence on the quality of solutions achieved. Educationally, they showed mixed results and lessons on improving their process of implementation for more impact have been documented. Overall, this thesis ratifies the applicability of the developed framework for crowdsourcing spaceflight software and educating students and maps the utility of collaboration in this framework. A systems dynamics model for generalizing the framework into other programs for simultaneous crowdsourcing and education outreach has been proposed and management policy concerns highlighted. Thesis Supervisor: Jeffrey A. Hoffman Title: Professor of Practice of Aeronautics and Astronautics Thesis Supervisor: Olivier L. de Weck Title: Associate Professor of Aeronautics and Astronautics and Engineering Systems 3 4 Everything I am and ever hope to be, I owe to my mother. 5 6 Acknowledgements First and foremost, I want to sincerely thank my MIT advisors, Prof. Olivier de Weck and Prof. Jeffrey Hoffman for consistent belief in my capabilities and for their guidance. I am particularly grateful to them for going out of their way on many occasions to provide unwavering support of my pursuit of unexpected opportunities and ever-evolving interests. Their dedication to their students is admirable and very deeply appreciated. I particularly acknowledge Jacob Katz and Alvar Saenz-Otero from the Zero Robotics (ZR) team, without whose leadership and creative, hard work, this program would have reached even close to the heights it is at today. Alvar and Prof. Dave Miller inducted me into the SSL and to the SPHERES ZR team and gave me an opportunity in the awesomeness called “space” - an experience I can never be grateful enough for. In the last two years, I have learned more from Jake on a day-to- day basis than I have from any other person at MIT, be it on technology, programming or the American professional culture. ZR would be incomplete without the consistent support of our collaborators. As student lead of the program for over a year, I identify with the program and my cohort has grown to identify the program with me. I would like to acknowledge Ira Heffan and Jason Crusan for helping with the program and indirectly my thesis. Last but not least, the data and conclusions mentioned here would be incomplete without the hundreds of students and mentors who have participated in, provided feedback and helped improve ZR. Very deep thanks to Alan Natapoff for helping with my statistical analysis. Social science research was a new field and books could teach me only so much in the short period, his input was timely and very helpful. A part of Chapter 3 in this thesis has been read through and improved by Dave Scott from NASA Marshall Space Flight Center as part of a review board for my IEEE Aerospace 2012 paper, thank you. A special thanks to the Technology and Policy Program (TPP) family. It is one of the most international programs at MIT and an incredible opportunity to meet and absorb cultures from all over the world. TPP is not just about the classroom; but so much more through culture nights, iAmbassador lunches, leadership retreats, personal guidance from Ed, Sydney and Krista and the always-active OS mailing lists! When I first saw the program’s flyer the summer of 2007 and googled 7 it, I felt an instant connection. And the program has been everything I had imagined and more. My summer internship of 2010 was an especially rewarding experience, thanks to Leopold Summerer for supervising my first work experience in Europe and allowing a ton of travel along with. Generous funding for my work and study at MIT has come from the MITEI-Total Energy Fellowship, NASA Headquarters, DARPA InSPIRE and the MIT Gordon Leadership Program. Work can never be satisfying through content alone. Colleagues have played an integral part of my educational experience. Thank you, Daniel for support whenever I called for it, Zoe and Danielle who have helped me navigate the internship arena outside MIT very successfully, Sydney for being the last man standing with me when the sun sets on the SSL cluster, Farah for spearheading the Quals movement and introducing me to Aero/Astro-related social events, Alessandra for being my advice-offering sounding board, Gireeja for helping me formulate my ZR crowdsourcing ideas in the larger context of the field and many other SSLers and SERGers for making my association with the two groups a very memorable one. Finally, and most importantly, I would like to thank my family and friends for being my rock through the turbulent sea of excitement and the directionless free-fall called Grad School. A special mention for Diviya for being my Cambridge family, for Nihit, Harshad, Siddharth, Shamel, Aditya, Arun, William, DC, Srinath, Abhijit, Deepak, Amrit, Sohail, Rachel, Grace, Sheekha, Sharmistha, Farrah and Sayamindu for being fun company as well as friends in need. My world would be incomplete without my parents, grandparents and Arish, I owe the contented solace behind my energy and passion to them. 8 Table of Contents Acknowledgements ............................................................................................................................................ 7 List of Figures ................................................................................................................................................... 13 List of Tables ...................................................................................................................................................
Recommended publications
  • Maintenance Strategy and Its Importance in Rocket Launching System-An Indian Prospective
    ISSN(Online) : 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 5, Issue 5, May 2016 Maintenance Strategy and its Importance in Rocket Launching System-An Indian Prospective N Gayathri1, Amit Suhane2 M. Tech Research Scholar, Mechanical Engineering, M.A.N.I.T, Bhopal, M.P. India Assistant Professor, Mechanical Engineering, M.A.N.I.T, Bhopal, M.P. India ABSTRACT: The present paper mainly describes the maintenance strategies followed at rocket launching system in India. A Launch pad is an above-ground platform from which a rocket or space vehicle is vertically launched. The potential for advanced rocket launch vehicles to meet the challenging , operational, and performance demands of space transportation in the early 21st century is examined. Space transportation requirements from recent studies underscoring the need for growth in capacity of an increasing diversity of space activities and the need for significant reductions in operational are reviewed. Maintenance strategies concepts based on moderate levels of evolutionary advanced technology are described. The vehicles provide a broad range of attractive concept alternatives with the potential to meet demanding operational and maintenance goals and the flexibility to satisfy a variety of vehicle architecture, mission, vehicle concept, and technology options. KEY WORDS: Preventive Maintenance, Rocket Launch Pad. I. INTRODUCTION A. ROCKET LAUNCH PAD A Launch pad is associate degree above-ground platform from that a rocket ballistic capsule is vertically launched. A launch advanced may be a facility which incorporates, and provides needed support for, one or a lot of launch pads.
    [Show full text]
  • SPEAKERS TRANSPORTATION CONFERENCE FAA COMMERCIAL SPACE 15TH ANNUAL John R
    15TH ANNUAL FAA COMMERCIAL SPACE TRANSPORTATION CONFERENCE SPEAKERS COMMERCIAL SPACE TRANSPORTATION http://www.faa.gov/go/ast 15-16 FEBRUARY 2012 HQ-12-0163.INDD John R. Allen Christine Anderson Dr. John R. Allen serves as the Program Executive for Crew Health Christine Anderson is the Executive Director of the New Mexico and Safety at NASA Headquarters, Washington DC, where he Spaceport Authority. She is responsible for the development oversees the space medicine activities conducted at the Johnson and operation of the first purpose-built commercial spaceport-- Space Center, Houston, Texas. Dr. Allen received a B.A. in Speech Spaceport America. She is a recently retired Air Force civilian Communication from the University of Maryland (1975), a M.A. with 30 years service. She was a member of the Senior Executive in Audiology/Speech Pathology from The Catholic University Service, the civilian equivalent of the military rank of General of America (1977), and a Ph.D. in Audiology and Bioacoustics officer. Anderson was the founding Director of the Space from Baylor College of Medicine (1996). Upon completion of Vehicles Directorate at the Air Force Research Laboratory, Kirtland his Master’s degree, he worked for the Easter Seals Treatment Air Force Base, New Mexico. She also served as the Director Center in Rockville, Maryland as an audiologist and speech- of the Space Technology Directorate at the Air Force Phillips language pathologist and received certification in both areas. Laboratory at Kirtland, and as the Director of the Military Satellite He joined the US Air Force in 1980, serving as Chief, Audiology Communications Joint Program Office at the Air Force Space at Andrews AFB, Maryland, and at the Wiesbaden Medical and Missile Systems Center in Los Angeles where she directed Center, Germany, and as Chief, Otolaryngology Services at the the development, acquisition and execution of a $50 billion Aeromedical Consultation Service, Brooks AFB, Texas, where portfolio.
    [Show full text]
  • MAIB Annual Report 2020
    2020 Marine Accident Recommendations and Statistics ANNUAL REPORT ANNUAL H NC RA N B IO GAT TI S INVE T DEN ACCI This document is posted on our website: www.gov.uk/maib Marine Accident Investigation Branch Email: [email protected] RINE First Floor, Spring Place, 105 Commercial Road Telephone: 023 8039 5500 MA Southampton, SO15 1GH United Kingdom 9 June 2021 MARINE ACCIDENT INVESTIGATION BRANCH The Marine Accident Investigation Branch (MAIB) examines and investigates all types of marine accidents to or on board UK vessels worldwide, and other vessels in UK territorial waters. Located in ofices in Southampton, the MAIB is a separate, independent branch within the Department for Transport (DfT). The head of the MAIB, the Chief Inspector of Marine Accidents, reports directly to the Secretary of State for Transport. © Crown copyright 2021 This publication, excluding any logos, may be reproduced free of charge in any format or medium for research, private study or for internal circulation within an organisation. This is subject to it being reproduced accurately and not used in a misleading context. The material must be acknowledged as Crown copyright and the title of the publication specified. Details of third party copyright material may not be listed in this publication. Details should be sought in the corresponding accident investigation report or [email protected] contacted for permission to use. CONTENTS CHIEF INSPECTOR'S STATEMENT 1 PART 1 - 2020: CASUALTY REPORTS TO MAIB 5 Statistical overview 5 Summary of investigations started
    [Show full text]
  • SPHERES Interact - Human-Machine Interaction Aboard the International Space Station
    SPHERES Interact - Human-Machine Interaction aboard the International Space Station Enrico Stoll Steffen Jaekel Jacob Katz Alvar Saenz-Otero Space Systems Laboratory Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge Massachusetts, 02139-4307, USA [email protected] [email protected] [email protected] [email protected] Renuganth Varatharajoo Department of Aerospace Engineering University Putra Malaysia 43400 Selangor, Malaysia [email protected] Abstract The deployment of space robots for servicing and maintenance operations, which are tele- operated from ground, is a valuable addition to existing autonomous systems since it will provide flexibility and robustness in mission operations. In this connection, not only robotic manipulators are of great use but also free-flying inspector satellites supporting the oper- ations through additional feedback to the ground operator. The manual control of such an inspector satellite at a remote location is challenging since the navigation in three- dimensional space is unfamiliar and large time delays can occur in the communication chan- nel. This paper shows a series of robotic experiments, in which satellites are controlled by astronauts aboard the International Space Station (ISS). The Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES) were utilized to study several aspects of a remotely controlled inspector satellite. The focus in this case study is to investigate different approaches to human-spacecraft interaction with varying levels of autonomy under zero-gravity conditions. 1 Introduction Human-machine interaction is a wide spread research topic on Earth since there are many terrestrial applica- tions, such as industrial assembly or rescue robots. Analogously, there are a number of possible applications in space such as maintenance, inspection and assembly amongst others.
    [Show full text]
  • HOGAN-THESIS-2019.Pdf (2.824Mb)
    EVALUATION OF FLIGHT CONTROL TECHNIQUES USING VIRTUAL REALITY IN AN ARTIFICIAL GRAVITY ROTATING ENVIRONMENT A Thesis by ROBERT DALLAS HOGAN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Chair of Committee, Gregory Chamitoff Committee Members, Nancy Currie-Gregg Kristi Shryock Head of Department, Rodney Bowersox August 2019 Major Subject: Aerospace Engineering Copyright 2019 Robert Dallas Hogan ABSTRACT The purpose of this thesis is to develop a collaborative virtual reality (VR) engineering platform for space system and mission design and to demonstrate its utility in the context of evaluating human interfaces for future control systems. Much of the work for this project was the development of the platform itself (called SpaceCRAFT). Additionally, a user study was done with 33 subjects to examine the potential advantages of designing and testing systems in virtual environments that otherwise may be difficult to replicate on Earth. The task evaluated was flying a drone in a rotating artificial gravity environment, which involves numerous unfamiliar forces. Different control strategies were tested using VR in comparison to flat screen interfaces. This particular challenge was chosen to emphasize the difference between immersive and non-immersive environments, and the results demonstrate that VR is a promising tool for human-interface system design and evaluation. The 50-meter radius space station simulated an open-air, long-term habitable environment and was designed with considerations of human factors for rotating reference frames. A quadrotor control model was developed and simulated a variety of stabilization and sensitivity modes.
    [Show full text]
  • Critical Systems
    Critical Systems ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 3 Slide 1 Objectives ● To explain what is meant by a critical system where system failure can have severe human or economic consequence. ● To explain four dimensions of dependability - availability, reliability, safety and security. ● To explain that, to achieve dependability, you need to avoid mistakes, detect and remove errors and limit damage caused by failure. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 3 Slide 2 Topics covered ● A simple safety-critical system ● System dependability ● Availability and reliability ● Safety ● Security ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 3 Slide 3 Critical Systems ● Safety-critical systems • Failure results in loss of life, injury or damage to the environment; • Chemical plant protection system; ● Mission-critical systems • Failure results in failure of some goal-directed activity; • Spacecraft navigation system; ● Business-critical systems • Failure results in high economic losses; • Customer accounting system in a bank; ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 3 Slide 4 System dependability ● For critical systems, it is usually the case that the most important system property is the dependability of the system. ● The dependability of a system reflects the user’s degree of trust in that system. It reflects the extent of the user’s confidence that it will operate as users expect and that it will not ‘fail’ in normal use. ● Usefulness and trustworthiness are not the same thing. A system does not have to be trusted to be useful. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 3 Slide 5 Importance of dependability ● Systems that are not dependable and are unreliable, unsafe or insecure may be rejected by their users.
    [Show full text]
  • 20110015353.Pdf
    ! ! " # $ % & # ' ( ) * ! * ) + ' , " ! - . - ( / 0 - ! Interim Report Design, Cost, and Performance Analyses Executive Summary This report, jointly sponsored by the Defense Advanced Research Projects Agency (DARPA) and the National Aeronautics and Space Administration (NASA), is the result of a comprehensive study to explore the trade space of horizontal launch system concepts and identify potential near- and mid-term launch system concepts that are capable of delivering approximately 15,000 lbs to low Earth orbit. The Horizontal Launch Study (HLS) has produced a set of launch system concepts that meet this criterion and has identified potential subsonic flight test demonstrators. Based on the results of this study, DARPA has initiated a new program to explore horizontal launch concepts in more depth and to develop, build, and fly a flight test demonstrator that is on the path to reduce development risks for an operational horizontal take-off space launch system. The intent of this interim report is to extract salient results from the in-process HLS final report that will aid the potential proposers of the DARPA Airborne Launch Assist Space Access (ALASA) program. Near-term results are presented for a range of subsonic system concepts selected for their availability and relatively low development costs. This interim report provides an overview of the study background and assumptions, idealized concepts, point design concepts, and flight test demonstrator concepts. The final report, to be published later this year, will address more details of the study processes, a broader trade space matrix including concepts at higher speed regimes, operational analyses, benefits of targeted technology investments, expanded information on models, and detailed appendices and references.
    [Show full text]
  • Cal Poly Alum Gregory Chamitoff Scheduled to Reside on International Space Station in April
    Cal Poly Alumnus Headed for Space Station Mission http://www.calpolynews.calpoly.edu/news_releases/2008/January/ch... Skip to Content Search Cal Poly News News C a l i f o rn i a P o l y t e c h n i c S t a t e U n i v e rs i t y January 16, 2008 MEDIA ADVISORY Contact for media only: Amy Hewes 805-756-6402 [email protected] Cal Poly Alum Gregory Chamitoff Scheduled to Reside On International Space Station in April SAN LUIS OBISPO -- Cal Poly Alum Gregory Chamitoff will soon have quite a view out of the closest window. The 1984 Electrical Engineering graduate has been selected to work and live onboard the International Space Station, another remarkable step in what has proven to be an incredible professional career. Chamitoff will begin his journey in late April on Space Shuttle mission STS-124. He will stay on the ISS until September, returning back to earth with Shuttle mission STS-126. As an undergraduate student at Cal Poly, Chamitoff taught lab courses in circuit design and worked summer internships at Atari Computers and IBM. Chamitoff fondly remembers Cal Poly Mathematics Professor James Mueller, who he contacted recently about his upcoming Space Station trip. From Cal Poly, Chamitoff went on to earn master’s degrees from the California Institute of Technology and the University of Houston Clear Lake, and his Ph.D. in aeronautics and astronautics from the Massachusetts Institute of Technology. While at MIT, Chamitoff worked on the Hubble Space Telescope, flight control upgrades for the Space Shuttle autopilot and the altitude control system for the Space Station.
    [Show full text]
  • Ask Magazine | 1
    National Aeronautics and Space Administration Academy Sharing Knowledge The NASA Source for Project Management and Engineering Excellence | APPEL SUMMER | 2013 Inside THE KNOWLEDGE MANAGEMENT JOURNEY KSC SWAMP WORKS PREDICTABLE PROJECT SURPRISES gnarta SuhsoJn amrir AoineS, ecroFr i. AS.: Utidero CtohP Utidero AS.: i. ecroFr AoineS, amrir SuhsoJn gnarta ON THE COVER Above Bear Lake, Alaska, the Northern Lights, or aurora borealis, are created by solar radiation entering the atmosphere at the magnetic poles. The appearance of these lights is just one way solar radiation affects us; it can also interfere with NASA missions in low-Earth orbit. To achieve long-duration human spaceflight missions in deeper space, several NASA centers are working to find better safety measures and solutions to protect humans from space radiation. ASK MAGAZINE | 1 Contents 21 5 9 DEPARTMENTS INSIGHTS STORIES 3 9 5 In This Issue Predictable Surprises: Back to the Future: BY DON COHEN Bridging Risk-Perception Gaps KSC Swamp Works BY PEDRO C. RIBEIRO Concerns about BY KERRY ELLIS Kennedy’s new Swamp project-threatening risks are often ignored Works encourages innovation through 4 or unspoken. experimentation and knowledge sharing. From the NASA CKO Our Knowledge Legacy BY ED HOFFMAN 21 13 The Knowledge Management Journey University Capstone Projects: BY EDWARD W. ROGERS Goddard’s CKO Small Investments, Big Rewards 42 reflects on what ten years on the job have BY LAURIE STAUBER Glenn’s partnership The Knowledge Notebook taught him. with universities generates first-rate Big Data—The Latest Organizational space-medicine research. Idea-Movement BY LAURENCE PRUSAK 25 Creating NASA’s Knowledge Map 17 BY MATTHEW KOHUT AND HALEY STEPHENSON One Person’s Mentoring Experience 44 A new online tool helps show who knows BY NATALIE HENRICH The author explains ASK Interactive what at NASA.
    [Show full text]
  • The Annual Compendium of Commercial Space Transportation: 2012
    Federal Aviation Administration The Annual Compendium of Commercial Space Transportation: 2012 February 2013 About FAA About the FAA Office of Commercial Space Transportation The Federal Aviation Administration’s Office of Commercial Space Transportation (FAA AST) licenses and regulates U.S. commercial space launch and reentry activity, as well as the operation of non-federal launch and reentry sites, as authorized by Executive Order 12465 and Title 51 United States Code, Subtitle V, Chapter 509 (formerly the Commercial Space Launch Act). FAA AST’s mission is to ensure public health and safety and the safety of property while protecting the national security and foreign policy interests of the United States during commercial launch and reentry operations. In addition, FAA AST is directed to encourage, facilitate, and promote commercial space launches and reentries. Additional information concerning commercial space transportation can be found on FAA AST’s website: http://www.faa.gov/go/ast Cover art: Phil Smith, The Tauri Group (2013) NOTICE Use of trade names or names of manufacturers in this document does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the Federal Aviation Administration. • i • Federal Aviation Administration’s Office of Commercial Space Transportation Dear Colleague, 2012 was a very active year for the entire commercial space industry. In addition to all of the dramatic space transportation events, including the first-ever commercial mission flown to and from the International Space Station, the year was also a very busy one from the government’s perspective. It is clear that the level and pace of activity is beginning to increase significantly.
    [Show full text]
  • Orbital Debris: a Chronology
    NASA/TP-1999-208856 January 1999 Orbital Debris: A Chronology David S. F. Portree Houston, Texas Joseph P. Loftus, Jr Lwldon B. Johnson Space Center Houston, Texas David S. F. Portree is a freelance writer working in Houston_ Texas Contents List of Figures ................................................................................................................ iv Preface ........................................................................................................................... v Acknowledgments ......................................................................................................... vii Acronyms and Abbreviations ........................................................................................ ix The Chronology ............................................................................................................. 1 1961 ......................................................................................................................... 4 1962 ......................................................................................................................... 5 963 ......................................................................................................................... 5 964 ......................................................................................................................... 6 965 ......................................................................................................................... 6 966 ........................................................................................................................
    [Show full text]
  • |||GET||| Group Interaction in High Risk Environments 1St Edition
    GROUP INTERACTION IN HIGH RISK ENVIRONMENTS 1ST EDITION DOWNLOAD FREE Rainer Dietrich | 9781351932097 | | | | | Looking for other ways to read this? Computational methods such as resampling and bootstrapping are also used when data are insufficient for direct statistical methods. There is little point in making highly precise computer calculations on numbers that cannot be estimated accurately Group Interaction in High Risk Environments 1st edition. Categories : Underwater diving safety. Thus, the surface-supplied diver is much less likely to have an "out-of-air" emergency than a scuba diver as there are normally two alternative air sources available. Methods for dealing with Group Interaction in High Risk Environments 1st edition risks include Provision for adequate contingencies safety factors for budget and schedule contingencies are discussed in Chapter 6. This genetic substudy included Two Sister Study participants and their parents, and some Sister Study participants who developed incident breast cancer invasive or DCIS before age 50 during the follow-up period. In terms of generalizability, our sample is predominantly non-Hispanic white women, and the results may not apply to other racial or ethnic groups. This third parameter may give some management support by establishing early warning indicators for specific serious risks, which might not otherwise have been established. ROVs may be used together with divers, or without a diver in the water, in which case the risk to the diver associated with the dive is eliminated altogether. Suitable equipment can be selected, personnel can be trained in its use and support provided to manage the foreseeable contingencies. However, taken together, there is the possibility that many of the estimates of these factors would prove to be too optimistic, leading.
    [Show full text]