Scalable Facility Location for Massive Graphs on Pregel-like Systems

We propose a new scalable algorithm for facility location. Facility location is a classic problem, where the goal is to select a subset of facilities to open, from a set of candidate facilities F , in order to serve a set of clients C. The objective is to minimize the total cost of opening facilities plus the cost of serving each client from the facility it is assigned to. In this work, we are interested in the graph setting, where the cost of serving a client from a facility is represented by the shortest-path distance on the graph. This setting allows to model natural problems arising in the Web and in social media applications. It also allows to leverage the inherent sparsity of such graphs, as the input is much smaller than the full pairwise distances between all vertices. To obtain truly scalable performance, we design a parallel algorithm that operates on clusters of shared-nothing machines. In particular, we target modern Pregel-like architectures, and we implement our algorithm on Apache Giraph. Our solution makes use of a recent result to build sketches for massive graphs, and of a fast parallel algorithm to find maximal independent sets, as building blocks. In so doing, we show how these problems can be solved on a Pregel-like architecture, and we investigate the properties of these algorithms. Extensive experimental results show that our algorithm scales gracefully to graphs with billions of edges, while obtaining values of the objective function that are competitive with a state-of-the-art sequential algorithm

HPER Biomechanics Laboratory 2006 Annual Report, Issue 5

This issue features Peripheral Arterial Disease and Geriatrics Research Update, Lab Expands with New Personnel, Labor on NIH Grant Is, “Gratifying Labor” States Dr. Stergiou, Federal Grant On Cerebral Palsy: Joint Venture Demonstrates Progress, Evolution of Wireless Gait Analysis, Innovations of Robotic Assisted Surgery Research, Incorporating Virtual Reality, Events in the Lab, Dr. Stergiou Awarded Outstanding Graduate Mentor , Collaborations in Orthopedics, The Media Features Efforts in HPER Biomechanics Lab , Other Continuing Collaborations, Other Exciting News, Publications for 2006 and The 2006-2007 HPER Biomechanics Laboratory.https://digitalcommons.unomaha.edu/nbcfnewsletter/1004/thumbnail.jp

Nebraska Biomechanics Core Facilty 2007 Annual Report, Issue 6

This issue features UNO Announces the Nebraska Biomechanics Core Facility (NBCF), Exciting Growth, This Project was FUN!, Tours!, Welcome and Hello! - Open House for Two Colleges, Laboratory Updates, Latest Developments, Other Global Connections, and Other Exciting News.https://digitalcommons.unomaha.edu/nbcfnewsletter/1005/thumbnail.jp

Nebraska Biomechanics Core Facilty 2009 Annual Report, Issue 8

April 2009 - March 2010 This issue features Announcements, Featured News, Projects, Collaborations, Visitors, Awards, Publications, and Support.https://digitalcommons.unomaha.edu/nbcfnewsletter/1007/thumbnail.jp

HPER Biomechanics Laboratory 2005 Annual Report, Issue 4

This issue features Dr. Stergiou Receives a K25 Award from the National Institutes of Health, Training Methods to Improve Robotic Laparoscopic Surgery, Progress Update for Federal Grant: The Development of Sitting Posture in Children with Cerebral Palsy, Pioneering Gait Analysis Research, Collaboration with UNMC Department of Surgery and VA Hospital: The Effects of Peripheral Arterial Disease on Gait, Sabbatical Strengthened Collaborations in Orthopedics, Computer Modeling with Dynamic Toys Reveals Human Gait Patterns, Prestigious Awards to Dr. Stergiou, Teachers Enriched During Final Year of Banneker 2000, New Staff Joins the HPER Biomechanics Laboratory, Noteworthy Events, Internationally Recognized Bioengineer Visited HPER Biomechanics Lab April 1, Madonna Rehabilitation Center Researcher visits HPER Biomechanics Lab Nov. 4 and Other Exciting News.https://digitalcommons.unomaha.edu/nbcfnewsletter/1003/thumbnail.jp

HPER Biomechanics Laboratory 2004 Annual Report: A Surveillance of the Neuromuscular System, Issue 3

This issue features 2004 - A Great Year for External Funding: Three Grants Awarded to Dr. Stergiou, Robotic Surgery Research is Funded by the Nebraska Research Initiative, Federal Grant is Awarded for the Study of the Development of Posture in Children with Cerebral Palsy, The Nebraska Research Initiative funds our Innovative Research in Gait Analysis, Collaboration with the Department of Surgery of the University of Nebraska Medical Center on the Effects of Peripheral Arterial Disease on Gait, Omaha Media Features Nicholas Stergiou, Dr. Stergiou participates in an NIH Review Panel, Prestigious Teaching Award for Dr. Stergiou, NASA Visits HPER Biomechanics Lab, Walking, a Neural Network and a Simple Robot, Sabbatical Strengthens Collaborations with Other Laboratories, Our Lab helps High School Students and Teachers, New Textbook Published and Other Exciting News/Continuing Collaboration.https://digitalcommons.unomaha.edu/nbcfnewsletter/1002/thumbnail.jp

Nebraska Biomechanics Core Facilty 2010-2011 Annual Report, Issue 9

April 2010 - May 2011 This issue features Announcements, Featured News, Student Profiles, Projects, Collaborators, Awards, Publications, and Support.https://digitalcommons.unomaha.edu/nbcfnewsletter/1008/thumbnail.jp

HPER Biomechanics Laboratory 2003 Annual Report, Issue 2

This issue features Can chaos be used for stability in walking Robots?, Promising insights on the development of posture in infants, The effect of Parkinson’s disease in stair negotiation, How certain are the elderly in selecting a stable gait pattern?, Collaboration with UNMC to improve Robotic Surgical Techniques, Helping High School students and K-12 teachers appreciate math and science, Max Kurz receives three awards for 2003, New Textbook published, Collaborations in orthopedics and cerebral concussion, and 2003 Publications and Presentations.https://digitalcommons.unomaha.edu/nbcfnewsletter/1001/thumbnail.jp

HPER Biomechanics Laboratory 2002 Annual Report, Issue 1

This issue features Development of a gait-o-gram for the assessment of gait, Promising insights on the development of posture in children, A new understanding of Parkinson’s Disease, Assessing the stability of elderly gait, Gait analysis provides the Omaha community with relief from running injuries, Custom Palm pilot software offers scientists and teachers new technology, Helping high school students appreciate science and math, Past students achieve success, Collaborative work with the Orthopedic Center of Sports Medicine at Ioannina-Greece, and 2002 Publications and Presentationshttps://digitalcommons.unomaha.edu/nbcfnewsletter/1000/thumbnail.jp