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Sample records for activity packet designed

  1. The Air We Breathe. Activity Packet.

    ERIC Educational Resources Information Center

    Connecticut State Dept. of Environmental Protection, Hartford.

    This packet of materials is intended to provide teachers with an interdisciplinary approach to integrating air quality education into the existing curriculum of Connecticut schools. The unit is designed to complement the student booklet "The Air We Breathe," which is included. A major portion of the document is comprised of teaching activities.…

  2. Oral Hygiene. Instructor's Packet. Learning Activity Package.

    ERIC Educational Resources Information Center

    Hime, Kirsten

    This instructor's packet accompanies the learning activity package (LAP) on oral hygiene. Contents included in the packet are a time sheet, suggested uses for the LAP, an instruction sheet, final LAP reviews, a final LAP review answer key, suggested activities, additional resources (student handouts), student performance checklists for both…

  3. Grooming. Instructor's Packet. Learning Activity Package.

    ERIC Educational Resources Information Center

    Stark, Pamela

    This instructor's packet accompanies the learning activity package (LAP) on grooming. Contents included in the packet are a time sheet, suggested uses for the LAP, an instruction sheet, final LAP reviews, a final LAP review answer key, suggested activities, an additional resources list, and student completion cards to issue to students as an…

  4. Issues in packet radio network design

    NASA Technical Reports Server (NTRS)

    Leiner, Barry M.; Nielson, Donald L.; Tobagi, Fouad A.

    1987-01-01

    The physical aspects of a packet radio network design, the automated management of the network, and the interface of the network to the users are examined. The networks provide data communications to users located over a broad geographic region where direct radio or wire connection between the source and destination user is not practical; the network consists of a radio, antenna, and digital controller. The physical connectivity, bandwidth-time-space management, channel access, and data link control of the network are analyzed. Consideration is given to link determination and control, routing and packet forwarding, congestion and flow control, and supported users management. The operation and management of a packet radio network, in particular network deployment and maintenance, network access methods, and its effect on the radio spectrum, are discussed. The performance and cost of a packet radio network are evaluated.

  5. Handwashing Technique. Instructor's Packet. Learning Activity Package.

    ERIC Educational Resources Information Center

    Stark, Pamela

    This instructor's packet accompanies the learning activity package (LAP) on handwashing. Contents included in the packet are a time sheet, suggested uses for the LAP, an instruction sheet, final LAP reviews, a final LAP review answer key, a student performance checklist, an additional resources list, and student completion cards to issue to…

  6. Children's Literature with a Science Emphasis: Twenty Teacher-Developed K-8 Activity Packets.

    ERIC Educational Resources Information Center

    Butler, Malcolm B.

    This document features 10 science activity packets developed for elementary students by science teachers in a graduate seminar. The activity packets were designed to cover existing commercial children's books on specific content areas. The 10 activity packets are: (1) "Bringing the Rain to Kapiti Plain," which explains the water cycle; (2)…

  7. Solid Waste Activity Packet for Teachers.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Cooperative Extension Service.

    This solid waste activity packet introduces students to the solid waste problem in Illinois. Topics explore consumer practices in the market place, packaging, individual and community garbage generation, and disposal practices. The activities provide an integrated approach to incorporating solid waste management issues into subject areas. The…

  8. Cashier/Checker Learning Activity Packets (LAPs).

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Twenty-four learning activity packets (LAPs) are provided for six areas of instruction in a cashier/checker program. Section A, Orientation, contains an LAP on exploring the job of cashier-checker. Section B, Operations, has nine LAPs, including those on operating the cash register, issuing trading stamps, and completing the cash register balance…

  9. Using Document Reading Activity Packets (DRAP) in the Classroom.

    ERIC Educational Resources Information Center

    Adomanis, James F.; Schulz, Constance

    1987-01-01

    Reviews a Document Reading Activity Packet (DRAP) revolving around the "Fort Washington Incident" of the War of 1812 and the resulting court martial of Captain Samuel T. Dyson. Explains this exercise is designed to stimulate students' interest in their own state histories as well as stimulate their curiosity for further research. (BSR)

  10. Social Security. Cooperative Work Experience Learning Activity Packet: Series on Job Entry and Adjustment; Packet Six.

    ERIC Educational Resources Information Center

    Herschbach, Dennis R.; And Others

    This student booklet is sixth in an illustrated series of eleven learning activity packets for use in teaching job hunting and application procedures and the management of wages to secondary students. Four units are included in this packet to explain (1) the different benefits social security provides and the principles behind the program; (2) the…

  11. Nature's Hitchhikers. A Fall Activity Packet for Second Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on the characteristics of…

  12. Spring Birds. A Spring Activity Packet for First Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on the characteristics of…

  13. Reading the Rocks. A Fall Activity Packet for Fifth Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on various geological…

  14. Frogs and Toads. A Spring Activity Packet for Second Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on the characteristics and…

  15. Forests and Flowers. A Spring Activity Packet for Third Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on plants and…

  16. Nature Prepares for Winter. A Fall Activity Packet for Kindergarten.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on preparations for winter…

  17. Energy Around Us. A Fall Activity Packet for Fourth Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on energy uses, energy…

  18. Michigan Natural History. A Spring Activity Packet for Fourth Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on the natural history of…

  19. Threatened and Endangered Species: Tour Packet.

    ERIC Educational Resources Information Center

    Coats, Victoria; Samia, Cory

    This resource unit contains a teacher information packet and a middle school student activity packet to be used in creating a threatened and endangered species unit. The packet of student activities is designed to help maximize a field trip to the zoo and build on students' zoo experience in the classroom. The teacher information packet covers the…

  20. French-Canadians, Acadians and the French in New England. A Learning Activity Packet.

    ERIC Educational Resources Information Center

    Maine Univ., Orono. New England - Atlantic Provinces - Quebec Center.

    The history of the French-Canadians from their beginnings to the present time is the topic of this Learning Activity Packet (LAP). Designed to acquaint students with the French, Canada's earliest permanent settlers following the Indians, the unit is divided into six objectives which include learning activities for each. Students are expected to…

  1. Office Reprographics. Instructor's Guide. Student Activity Packet. Office Occupations.

    ERIC Educational Resources Information Center

    Johnson, Diane E.

    This training package, one in a series of instructional modules consisting of an instructor's guide and a student activity packet, deals with office reprographics. Included in the instructor's guide are general directions for implementing the presentation; a detailed guide for teaching the lesson that includes performance objectives, suggestions…

  2. Canada and the United States. Perspective. Learning Activity Packet.

    ERIC Educational Resources Information Center

    Maine Univ., Orono. New England - Atlantic Provinces - Quebec Center.

    The similarities and differences of Canada and the United States are explored in this Learning Activity Packet (LAP). Ten learning objectives are given which encourage students to examine: 1) the misconceptions Americans and Canadians have about each other and their ways of life; 2) the effect and influence of French and English exploration and…

  3. [Geography Awareness Week Activity Packet, 1987 and 1988.

    ERIC Educational Resources Information Center

    Texas Alliance for Geographic Education, College Station.

    This resource packet contains materials and suggestions to integrate National Geography Awareness Week for 1987 and 1988 into elementary and secondary education in Texas. The materials for 1987 include: (1) a pamphlet for a balloon release; (2) a collection of ideas for student activities; (3) a description of two field experiences; (4) a…

  4. Business Education: Learning Activities Packet for Office Education.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    These seventeen individualized learning activities packets (LAPs) are intended to relate essential competencies needed for entry or advancement in office occupations to the secondary level office education program and to assist students in achieving occupational proficiency in business careers. Each LAP contains some or all of the following…

  5. Viva Nuestra Amistad IV: Spanish Activity Packet (Long Live our Friendship).

    ERIC Educational Resources Information Center

    Cobb, Hubert

    This Spanish activity packet was designed to be used with the map study portion of each of twelve units in a second year course in Spanish. Each unit deals with a different Spanish-speaking country or place, such as Puerto Rico, Colombia, Venezuela, or Peru. Included here are worksheets, games, map outlines, crossword puzzles, skits, and cultural…

  6. Design and implementation considerations of a MSAT packet data network

    NASA Technical Reports Server (NTRS)

    Karam, Fouad G.; Hearn, Terry; Rohr, Doug; Guibord, Arthur F.

    1993-01-01

    The Mobile Data System, which is intended to provide for packet switched data services is currently under development. The system is based on a star network topology consisting of a centralized Data Hub (DH) serving a large number of mobile terminals. Through the Data Hub, end-to-end connections can be established between terrestrial users on public or private data networks and mobile users. The MDS network will be capable of offering a variety of services some of which are based on the standard X.25 network interface protocol, and others optimized for short messages and broadcast messages. A description of these services and the trade-offs in the DH design are presented.

  7. Tropical Animal Tour Packet. Metro.

    ERIC Educational Resources Information Center

    Metro Washington Park Zoo, Portland, OR. Educational Services Div.

    This packet is designed to assist teachers in creating a tropical animals lesson plan that centers around a visit to the zoo. A teacher packet is divided into eight parts: (1) goals and objectives; (2) what to expect at the zoo; (3) student activities (preparatory activities, on-site activities, and follow-up activities); (4) background…

  8. Self-organising continuous attractor networks with multiple activity packets, and the representation of space.

    PubMed

    Stringer, S M; Rolls, E T; Trappenberg, T P

    2004-01-01

    'Continuous attractor' neural networks can maintain a localised packet of neuronal activity representing the current state of an agent in a continuous space without external sensory input. In applications such as the representation of head direction or location in the environment, only one packet of activity is needed. For some spatial computations a number of different locations, each with its own features, must be held in memory. We extend previous approaches to continuous attractor networks (in which one packet of activity is maintained active) by showing that a single continuous attractor network can maintain multiple packets of activity simultaneously, if each packet is in a different state space or map. We also show how such a network could by learning self-organise to enable the packets in each space to be moved continuously in that space by idiothetic (motion) inputs. We show how such multi-packet continuous attractor networks could be used to maintain different types of feature (such as form vs colour) simultaneously active in the correct location in a spatial representation. We also show how high-order synapses can improve the performance of these networks, and how the location of a packet could be read by motor networks. The multiple packet continuous attractor networks described here may be used for spatial representations in brain areas such as the parietal cortex and hippocampus.

  9. Animal Homes and Habitats. A Fall Activity Packet for Third Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on animal populations and…

  10. The Interesting World of Insects. A Fall Activity Packet for First Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on the characteristics and…

  11. Student Activity Packet for the California State Capitol Museum.

    ERIC Educational Resources Information Center

    2001

    This packet contains materials to help fourth and fifth grade teachers provide their students with background information for field trips to the California State Capitol Museum (Sacramento). The working museum focuses on the theme areas of California history, the state government/legislative process, and state symbols. The packet presents teacher…

  12. Recognizing Proofreaders' Marks and Using Them in Editing. Audiovisual Package. Instructor's Guide [and] Student Activity Packet. Office Occupations.

    ERIC Educational Resources Information Center

    Johnson, Diane E.

    Designed for use with 38 full-color slides and a cassette tape presentation, this instructional package consists of an instructor's guide and a student activity packet. The instructor's guide includes general instructions for presenting the instructional unit as well as specific instructions for introducing, implementing, and evaluating student…

  13. Slow-light Airy wave packets and their active control via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Hang, Chao; Huang, Guoxiang

    2013-07-01

    We propose a scheme to generate (3+1)-dimensional slow-light Airy wave packets in a resonant Λ-type three-level atomic gas via electromagnetically induced transparency. We show that in the absence of dispersion the Airy wave packets formed by a probe field consist of two Airy wave packets accelerated in transverse directions and a longitudinal Gaussian pulse with a constant propagating velocity lowered to 10-5c (c is the light speed in vacuum). We also show that in the presence of dispersion it is possible to generate another type of slow-light Airy wave packet consisting of two Airy beams in transverse directions and an Airy wave packet in the longitudinal direction. In this case, the longitudinal velocity of the Airy wave packet can be further reduced during propagation. Additionally, we further show that the transverse accelerations (or bending) of the both types of slow-light Airy wave packets can be completely eliminated and the motional trajectories of them can be actively manipulated and controlled by using a Stern-Gerlach gradient magnetic field.

  14. Architectures and Design for Next-Generation Hybrid Circuit/Packet Networks

    NASA Astrophysics Data System (ADS)

    Vadrevu, Sree Krishna Chaitanya

    Internet traffic is increasing rapidly at an annual growth rate of 35% with aggregate traffic exceeding several Exabyte's per month. The traffic is also becoming heterogeneous in bandwidth and quality-of-service (QoS) requirements with growing popularity of cloud computing, video-on-demand (VoD), e-science, etc. Hybrid circuit/packet networks which can jointly support circuit and packet services along with the adoption of high-bit-rate transmission systems form an attractive solution to address the traffic growth. 10 Gbps and 40 Gbps transmission systems are widely deployed in telecom backbone networks such as Comcast, AT&T, etc., and network operators are considering migration to 100 Gbps and beyond. This dissertation proposes robust architectures, capacity migration strategies, and novel service frameworks for next-generation hybrid circuit/packet architectures. In this dissertation, we study two types of hybrid circuit/packet networks: a) IP-over-WDM networks, in which the packet (IP) network is overlaid on top of the circuit (optical WDM) network and b) Hybrid networks in which the circuit and packet networks are deployed side by side such as US DoE's ESnet. We investigate techniques to dynamically migrate capacity between the circuit and packet sections by exploiting traffic variations over a day, and our methods show that significant bandwidth savings can be obtained with improved reliability of services. Specifically, we investigate how idle backup circuit capacity can be used to support packet services in IP-over-WDM networks, and similarly, excess capacity in packet network to support circuit services in ESnet. Control schemes that enable our mechanisms are also discussed. In IP-over-WDM networks, with upcoming 100 Gbps and beyond, dedicated protection will induce significant under-utilization of backup resources. We investigate design strategies to loan idle circuit backup capacity to support IP/packet services. However, failure of backup circuits will

  15. Learning Activity Packets for Grinding Machines. Unit II--Surface Grinding.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) is one of three that accompany the curriculum guide on grinding machines. It outlines the study activities and performance tasks for the second unit of this curriculum guide. Its purpose is to aid the student in attaining a working knowledge of this area of training and in achieving a skilled or moderately…

  16. Learning Activity Packets for Grinding Machines. Unit I--Grinding Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) is one of three that accompany the curriculum guide on grinding machines. It outlines the study activities and performance tasks for the first unit of this curriculum guide. Its purpose is to aid the student in attaining a working knowledge of this area of training and in achieving a skilled or moderately…

  17. Auto Mechanics I. Learning Activity Packets (LAPs). Section C--Engine.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains five learning activity packets (LAPs) that outline the study activities for the "engine" instructional area for an Auto Mechanics I course. The five LAPs cover the following topics: basic engine principles, cooling system, engine lubrication system, exhaust system, and fuel system. Each LAP contains a cover sheet that…

  18. Learning Activity Packets for Auto Mechanics II. Section A--Engine Rebuilding.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Eight learning activity packets (LAPs) are provided for the instructional area of engine rebuilding in the auto mechanics II program. They accompany an instructor's guide available separately. The LAPs outline the study activities and performance tasks for these eight units: (1) engine condition evaluation; (2) engine removal; (3) engine…

  19. Learning Activity Packets for Auto Mechanics II. Section C--Drive Train.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Five learning activity packets (LAPs) are provided for the instructional area of drive train in the auto mechanics II program. They accompany an instructor's guide available separately. The LAPs outline the study activities and performance tasks for these five units: (1) clutch assembly, (2) standard transmission, (3) drive lines, (4) rear axle,…

  20. Auto Mechanics I. Learning Activity Packets (LAPs). Section A--Orientation and Safety.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains seven learning activity packets (LAPs) that outline the study activities for the orientation and safety instructional area for an Auto Mechanics I course. The seven LAPs cover the following topics: orientation, safety, hand tools, arc welding, oxyacetylene cutting, oxyacetylene fusion welding, and oxyacetylene braze welding.…

  1. The Atlantic Canada-New England Region and Environment. A Learning Activity Packet.

    ERIC Educational Resources Information Center

    Maine Univ., Orono. New England - Atlantic Provinces - Quebec Center.

    In this Learning Activity Packet (LAP) students examine the geographic and ecological bases of the Eastern international region. The overall objective of activities is to help students comprehend the man-earth relationship concept. By studying this familiar relevant region students gain geographic knowledge and skills applicable to other areas.…

  2. Learning Activity Packets for Milling Machines. Unit III--Vertical Milling Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) outlines the study activities and performance tasks covered in a related curriculum guide on milling machines. The course of study in this LAP is intended to help students learn to set up and operate a vertical mill. Tasks addressed in the LAP include mounting and removing cutters and cutter holders for vertical…

  3. Learning Activity Packets for Milling Machines. Unit II--Horizontal Milling Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) outlines the study activities and performance tasks covered in a related curriculum guide on milling machines. The course of study in this LAP is intended to help students learn to set up and operate a horizontal mill. Tasks addressed in the LAP include mounting style "A" or "B" arbors and adjusting arbor…

  4. Learning Activity Packets for Milling Machines. Unit I--Introduction to Milling Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) outlines the study activities and performance tasks covered in a related curriculum guide on milling machines. The course of study in this LAP is intended to help students learn to identify parts and attachments of vertical and horizontal milling machines, identify work-holding devices, state safety rules, and…

  5. Time Management. Office Occupations. Audiovisual Package. Instructor's Guide. Student Activity Packet.

    ERIC Educational Resources Information Center

    Johnson, Diane E.

    This instructor's guide and student activity packet (together with a slide/tape presentation not available here) comprise a module for the postsecondary office occupations education competency area of time management. Modules for other competency areas are available separately. The purpose stated for the module is to help students obtain basic…

  6. Curriculum Development of Learning Activity Packets, Dental Assisting Program. Final Report.

    ERIC Educational Resources Information Center

    Hempler, Nancy A.

    A dental assisting instructor was provided with 250 hours of released time to develop standardized Learning Activity Packets (LAPs) for the Dental Assisting program at the Bellingham (Washington) Vocational Technical Institute. The instructor reviewed unit objectives, gathered input from local dental professionals, reviewed reference materials,…

  7. Math Skills for Business. Instructor's Guide. Student Activity Packet. Office Occupations.

    ERIC Educational Resources Information Center

    Johnson, Diane E.

    This training package, one in a series of instructional modules consisting of an instructor's guide and a student activity packet, deals with math skills for business. Included in the instructor's guide are general directions for implementing the presentation; a detailed guide for teaching the lesson that includes performance objectives,…

  8. Radiology/Imaging. Clinical Rotation. Instructor's Packet and Student Study Packet.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Extension Instruction and Materials Center.

    The instructor's packet, the first of two packets, is one of a series of materials designed to help students who are investigating the activities within a radiology department or considering any of the imaging technologies as a career. The material is designed to relate training experience to information studied in the classroom. This packet…

  9. Optimal design of mixed-media packet-switching networks - Routing and capacity assignment

    NASA Technical Reports Server (NTRS)

    Huynh, D.; Kuo, F. F.; Kobayashi, H.

    1977-01-01

    This paper considers a mixed-media packet-switched computer communication network which consists of a low-delay terrestrial store-and-forward subnet combined with a low-cost high-bandwidth satellite subnet. We show how to route traffic via ground and/or satellite links by means of static, deterministic procedures and assign capacities to channels subject to a given linear cost such that the network average delay is minimized. Two operational schemes for this network model are investigated: one is a scheme in which the satellite channel is used as a slotted ALOHA channel; the other is a new multiaccess scheme we propose in which whenever a channel collision occurs, retransmission of the involved packets will route through ground links to their destinations. The performance of both schemes is evaluated and compared in terms of cost and average packet delay tradeoffs for some examples. The results offer guidelines for the design and optimal utilization of mixed-media networks.

  10. Wind in the Willows--Theatre Activity Packet.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

    Part of the New York City Board of Education's Early Stages program, and intended for elementary and secondary school teachers who wish to include a unit on theater in their classes, this guide offers suggestions for lessons and activities to accompany viewing a performance of "Wind in the Willows" at the Nederlander Theater. Part one of the guide…

  11. Design of packet erasure mitigation technique using a digital fountain code for wearable wireless body area networks.

    PubMed

    Takizawa, Kenichi; Hamaguchi, Kiyoshi

    2010-01-01

    This paper presents a digital fountain code as a design criterion in order to mitigate packet erasure in wireless wearable body area networks (WBANs). First, we measure its radio propagation around the human body between two antennas attached to participants, and then analyze the measurement results from the standpoint of occurrence ratio of packet erasure. Then, we evaluate the application of digital fountain code into such WBANs where a rateless code is introduced as such code in order to provide a design criterion for the code. PMID:21096974

  12. Learn about Seabirds. Teaching Packet, Grades 4-6.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Anchorage, AK.

    This teaching packet is designed to teach Alaskan students in grades 4-6 about Alaska's seabird populations, the worldwide significance of seabirds, and the environmental conditions to which seabirds are sensitive. The packet includes a curriculum guide (containing a teacher's background story and 12 teaching activities), a separately published…

  13. Packet Format Design and Decision Directed Tracking Methods for Filter Bank Multicarrier Systems

    NASA Astrophysics Data System (ADS)

    Amini, Peiman; Farhang-Boroujeny, Behrouz

    2010-12-01

    Packetized data transmission is commonly used in wireless communication systems. Each packet starts with a preamble which is used to synchronize the receiver with carrier frequency of the incoming signal, to find a good timing phase, and to identify the channel impulse response or to adjust a set of channel equalizer parameters. In this paper, following the same philosophy, we develop a packet format for multicarrier systems that operate based on filter banks, filter bank multicarrier (FBMC) systems. The related algorithms for carrier frequency and timing recovery as well as channel identification/equalizer adjustment and methods for carrier and timing tracking loops are proposed. The proposed ideas are evaluated and their satisfactory performance are presented through computer simulations.

  14. Peninsula Humane Society Teacher's Packet. Secondary Level.

    ERIC Educational Resources Information Center

    Peninsula Humane Society, San Mateo, CA.

    Activities in this teacher's packet are designed to familiarize secondary school students with the responsibilities involved in pet ownership. Teaching plans are provided for a total of 12 lessons grouped under social studies, language arts, math, and health sciences. Activities focus on pet overpopulation, expressions of social responses in…

  15. Learning packets in nursing education: reviving the past.

    PubMed

    Xu, Yin; Martin, Madeleine; Gribbins, Ashley

    2010-05-01

    Learning packets gained popularity in nursing education in the 1960's. Recently, they have been cited as strategies for distance learning. The aim of this project was to integrate Topic Focused Learning Packets as a complementary teaching strategy for presentation of new content to large classes of undergraduate nursing students. In addition to reducing in-class content presentation time, goals included: fostering critical thinking, actively engaging the student, and providing opportunities for team-based interaction. Rationale, design process and packets will be described. The learning packet was viewed positively by the students and faculty. Among 134 students, 119 strongly agreed or agreed that the learning packet was effective in increasing their understanding of the content and achieving the course objectives.

  16. In the Public Interest: Law, Government, and Media. Maryland Women's History Resource Packet--1986.

    ERIC Educational Resources Information Center

    Maryland State Commission for Women, Baltimore.

    Designed to be used for National Women's History Week (March 2-8), this 1986 Maryland women's history resource packet centers around Maryland women who have made significant volunteer and career contributions in the areas of government, law, and the public interest media. The packet begins with suggested student activity lists and activity sheets…

  17. GUIDANCE PACKET.

    ERIC Educational Resources Information Center

    Modern Language Association of America, New York, NY.

    THIS PACKET PROVIDES VOCATIONAL AND ACADEMIC ADVICE TO THE LANGUAGE LEARNER AND USEFUL INFORMATION ABOUT LANGUAGE LEARNING TO TEACHERS, COUNSELORS, AND ADMINISTRATORS. THE DOCUMENTS, PUBLISHED FROM 1963 TO 1967, ARE--(1) "VOCATIONAL OPPORTUNITIES FOR FOREIGN LANGUAGE STUDENTS" BY GILBERT C. KETTELKAMP, (2) "ADVICE TO THE LANGUAGE LEARNER" BY…

  18. Information Packet.

    ERIC Educational Resources Information Center

    Cable Television Information Center, Washington, DC.

    Documents included in the packet are Federal Communications Commission (FCC) releases dealing with cable television and similar notices from other organizations. Among these are an interpretation of the FCC local origination decision of Dec. 9, 1974, explaining the repeal of the requirement that small cable systems originate programing while…

  19. Vocational and Industrial Arts Packets.

    ERIC Educational Resources Information Center

    Maine Audubon Society, Falmouth.

    This book is a teacher's guide to energy alternatives. It is divided into seven informational packets on the following topics: parabolic solar concentrators, solar flat plate collectors, wood as fuel, heat loss, bio-gas, wind, and water. Each packet contains background information for the teachers and learning activities for the students. The…

  20. USDA's Great Nutrition Adventure [Packet].

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    This nutrition education packet provides information to schools setting up healthy school meal programs and nutrition education programs. Team Nutrition schools will involve students, teachers, families, food service personnel, and community organizations in nutrition education activities. The packet contains fact sheets that focus on: the Great…

  1. Experience with the EURECA Packet Telemetry and Packet Telecommand system

    NASA Technical Reports Server (NTRS)

    Sorensen, Erik Mose; Ferri, Paolo

    1994-01-01

    The European Retrieval Carrier (EURECA) was launched on its first flight on the 31st of July 1992 and retrieved on the 29th of June 1993. EURECA is characterized by several new on-board features, most notably Packet telemetry, and a partial implementation of packet telecommanding, the first ESA packetised spacecraft. Today more than one year after the retrieval the data from the EURECA mission has to a large extent been analysed and we can present some of the interesting results. This paper concentrates on the implementation and operational experience with the EURECA Packet Telemetry and Packet Telecommanding. We already discovered during the design of the ground system that the use of packet telemetry has major impact on the overall design and that processing of packet telemetry may have significant effect on the computer loading and sizing. During the mission a number of problems were identified with the on-board implementation resulting in very strange anomalous behaviors. Many of these problems directly violated basic assumptions for the design of the ground segment adding to the strange behavior. The paper shows that the design of a telemetry packet system should be flexible enough to allow a rapid configuration of the telemetry processing in order to adapt it to the new situation in case of an on-board failure. The experience gained with the EURECA mission control should be used to improve ground systems for future missions.

  2. Extensible packet processing architecture

    DOEpatents

    Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

    2013-08-20

    A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

  3. Anti-Litter Curriculum Packet, Interdisciplinary, K-12.

    ERIC Educational Resources Information Center

    Tillis, Richard

    This curriculum packet consists of 20 illustrated cards with 15 activities designed to create "positive feelings" about a clean environment. Activities range from picture coloring for younger students, to lessons such as the economic and health problems litter creates for older students. Objectives include encouraging anti-litter and…

  4. Active interface debonding detection of a concrete-filled steel tube with piezoelectric technologies using wavelet packet analysis

    NASA Astrophysics Data System (ADS)

    Xu, Bin; Zhang, Ting; Song, Gangbing; Gu, Haichang

    2013-03-01

    Concrete-Filled Steel Tube (CFST) has been widely adopted in high-rise buildings and bridges as a typical structural member carrying vertical loads in recent years. The debonding between the steel tube and the concrete can dramatically reduce the confinement effect of steel tube on the concrete and decrease the load-carrying capacity and the ductility of the CFST. It is still challenging to develop reliable debonding monitoring and detection techniques for CFST because of the inaccessibility of the interface. In this study, an active interface condition monitoring approach for CFST by the use of lead zirconate titanate (PZT) piezoceramics based functional smart aggregates (SAs) embedded in concrete as actuator and PZT patches bonded on the surface of the steel tube as sensors is proposed and verified experimentally. Laboratory tests are performed on the CFST column, in which the deboning is mimicked by setting four thin styrofoam plates with different sizes on different locations of the four internal surfaces of the steel tube, respectively, before casting the concrete. The responses of the PZT sensors are measured when each SA is excited with sweep sinusoidal signals. According to the Fourier spectra and two evaluation indices based on the wavelet packet analysis on the PZT sensors measurements, the artificially mimicked debonding areas are detected successfully. Analysis on the sensitivity of the two evaluation indices shows that the indices based on wavelet packet analysis are more sensitive to the debonding defect. The proposed PZT based active debonding monitoring method provides an innovative approach to detect the debonding damage of CFST columns.

  5. Bohmian trajectories of Airy packets

    NASA Astrophysics Data System (ADS)

    Nassar, Antonio B.; Miret-Artés, Salvador

    2014-09-01

    The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space-time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject's theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.

  6. Bohmian trajectories of Airy packets

    SciTech Connect

    Nassar, Antonio B.; Miret-Artés, Salvador

    2014-09-15

    The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space–time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject’s theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.

  7. Nonspreading Wave Packets.

    ERIC Educational Resources Information Center

    Berry, M. V.; Balazs, N. L.

    1979-01-01

    Explains properties of the Airy packet that show that quantum wave functions correspond to a family of orbits and not to a single particle. Introducing the Airy packet into elementary quantum mechanics courses is recommended. (HM)

  8. Elementary Environmental Learning Packet K-3, Third Revised Edition. [Primary CEL Blocks, Student Activity Cards].

    ERIC Educational Resources Information Center

    Brevard County School Board, Cocoa, FL.

    This environmental education program consists of two levels: primary and intermediate. The learning materials are activity based and incorporate process and subject area skills with knowledge and concern for the environment. The program is also interdisciplinary including activities and skills from art, language arts, mathematics, music, science,…

  9. Sports Medicine. Clinical Rotation. Instructor's Packet and Student Study Packet.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Extension Instruction and Materials Center.

    The materials in this packet are for a course designed to provide individualized classroom study for a specific area of clinical rotation--sports medicine. The instructor's manual describes the learning objectives together with a list of reference materials that should be provided for completion of the student worksheets, and lists suggested…

  10. Dissection & Science Fairs. [Information Packet.

    ERIC Educational Resources Information Center

    National Anti-Vivisection Society, Chicago, IL.

    This collection of pamphlets and articles reprinted from other National Anti-Vivisection Society (NAVS) publications was compiled to address the issues of classroom laboratory dissection and the use of animals in science fair projects. Three of the pamphlets contained in this packet are student handbooks designed to help students of elementary,…

  11. Television Compression Algorithms And Transmission On Packet Networks

    NASA Astrophysics Data System (ADS)

    Brainard, R. C.; Othmer, J. H.

    1988-10-01

    Wide-band packet transmission is a subject of strong current interest. The transmission of compressed TV signals over such networks is possible with any quality level. There are some specific advantages in using packet networks for TV transmission. Namely, any fixed data rate can be chosen, or a variable data rate can be utilized. However, on the negative side packet loss must be considered and differential delay in packet arrival must be compensated. The possibility of packet loss has a strong influence on compression algorithm choice. Differential delay of packet arrival is a new problem in codec design. Some issues relevant to mutual design of the transmission networks and compression algorithms will be presented. An assumption is that the packet network will maintain packet sequence integrity. For variable-rate transmission, a reasonable definition of peak data rate is necessary. Rate constraints may be necessary to encourage instituting a variable-rate service on the networks. The charging algorithm for network use will have an effect on selection of compression algorithm. Some values of and procedures for implementing packet priorities are discussed. Packet length has only a second-order effect on packet-TV considerations. Some examples of a range of codecs for differing data rates and picture quality are given. These serve to illustrate sensitivities to the various characteristics of packet networks. Perhaps more important, we talk about what we do not know about the design of such systems.

  12. PROJECT SUCCESS: Art. (Introductory Packet, Drawing, Claywork, Painting).

    ERIC Educational Resources Information Center

    Petersen, Nancy

    Four packets comprise the art component of an enrichment program for gifted elementary students. The introduction packet reviews identification of children gifted in art through pre and post measures. A drawing packet reviews techniques for such activities as human figure drawing, shading, crayon rubbinqs, experimenting with perspective, and…

  13. New Teachers Packet.

    ERIC Educational Resources Information Center

    Journalism Education Association.

    This packet of information for new scholastic journalism teachers (or advisers) compiles information on professional associations in journalism education, offers curriculum guides and general help, and contains worksheets and handouts. Sections of the packet are: (1) Professional Help (Journalism Education Association Information, and Other…

  14. Intermediate SCDC Spanish Curricula Units. Spanish SL, Unit 1, Kits 1-4, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    Designed for use with the teacher's guide to the Spanish as a Second Language unit, this supplement and ditto packet includes visual aids and worksheets to help the teacher carry out the instructional and assessment activities. The illustrations are designed to help stimulate oral language and conceptual development. These visual materials…

  15. Design Activity Framework for Visualization Design.

    PubMed

    McKenna, Sean; Mazur, Dominika; Agutter, James; Meyer, Miriah

    2014-12-01

    An important aspect in visualization design is the connection between what a designer does and the decisions the designer makes. Existing design process models, however, do not explicitly link back to models for visualization design decisions. We bridge this gap by introducing the design activity framework, a process model that explicitly connects to the nested model, a well-known visualization design decision model. The framework includes four overlapping activities that characterize the design process, with each activity explicating outcomes related to the nested model. Additionally, we describe and characterize a list of exemplar methods and how they overlap among these activities. The design activity framework is the result of reflective discussions from a collaboration on a visualization redesign project, the details of which we describe to ground the framework in a real-world design process. Lastly, from this redesign project we provide several research outcomes in the domain of cybersecurity, including an extended data abstraction and rich opportunities for future visualization research. PMID:26356933

  16. Design Activity Framework for Visualization Design.

    PubMed

    McKenna, Sean; Mazur, Dominika; Agutter, James; Meyer, Miriah

    2014-12-01

    An important aspect in visualization design is the connection between what a designer does and the decisions the designer makes. Existing design process models, however, do not explicitly link back to models for visualization design decisions. We bridge this gap by introducing the design activity framework, a process model that explicitly connects to the nested model, a well-known visualization design decision model. The framework includes four overlapping activities that characterize the design process, with each activity explicating outcomes related to the nested model. Additionally, we describe and characterize a list of exemplar methods and how they overlap among these activities. The design activity framework is the result of reflective discussions from a collaboration on a visualization redesign project, the details of which we describe to ground the framework in a real-world design process. Lastly, from this redesign project we provide several research outcomes in the domain of cybersecurity, including an extended data abstraction and rich opportunities for future visualization research.

  17. All-optical packet header and payload separation for un-slotted optical packet switched networks

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Zhang, Min; Ye, Peida

    2005-11-01

    A novel all-optical header and payload separation technique that can be utilized in un-slotted optical packet switched networks is presented. The technique uses a modified TOAD for packet header extraction with differential modulation scheme and two SOAs that perform a simple XOR operation between the packet and its self-derived header to get the separated payload. The main virtue of this system is simple structure and need not any additional continuous pulses. Through numerical simulations, the operating characteristics of the scheme are illustrated. In addition, the parameters of the system are discussed and designed to optimize the operation performance.

  18. Photoelectron circular dichroism in the multiphoton ionization by short laser pulses. I. Propagation of single-active-electron wave packets in chiral pseudo-potentials

    SciTech Connect

    Artemyev, Anton N.; Müller, Anne D.; Demekhin, Philipp V.; Hochstuhl, David

    2015-06-28

    A theoretical method to study the angle-resolved multiphoton ionization of polyatomic molecules is developed. It is based on the time-dependent formulation of the Single Center (TDSC) method and consists in the propagation of single-active-electron wave packets in the effective molecular potentials in the presence of intense laser pulses. For this purpose, the time-dependent Schrödinger equation for one electron, moving in a molecular field and interacting with an arbitrary laser pulse, is solved in spherical coordinates by an efficient numerical approach. As a test, the method is applied to the one- and two-photon ionizations of a model methane-like chiral system by circularly polarized short intense high-frequency laser pulses. Thereby, we analyze the photoelectron circular dichroism (PECD) in the momentum distribution. The considered model application illustrates the capability of the TDSC method to study multiphoton PECD in fixed-in-space and randomly oriented chiral molecules.

  19. Quantum wave packet revivals

    NASA Astrophysics Data System (ADS)

    Robinett, R. W.

    2004-03-01

    The numerical prediction, theoretical analysis, and experimental verification of the phenomenon of wave packet revivals in quantum systems has flourished over the last decade and a half. Quantum revivals are characterized by initially localized quantum states which have a short-term, quasi-classical time evolution, which then can spread significantly over several orbits, only to reform later in the form of a quantum revival in which the spreading reverses itself, the wave packet relocalizes, and the semi-classical periodicity is once again evident. Relocalization of the initial wave packet into a number of smaller copies of the initial packet (‘minipackets’ or ‘clones’) is also possible, giving rise to fractional revivals. Systems exhibiting such behavior are a fundamental realization of time-dependent interference phenomena for bound states with quantized energies in quantum mechanics and are therefore of wide interest in the physics and chemistry communities. We review the theoretical machinery of quantum wave packet construction leading to the existence of revivals and fractional revivals, in systems with one (or more) quantum number(s), as well as discussing how information on the classical period and revival time is encoded in the energy eigenvalue spectrum. We discuss a number of one-dimensional model systems which exhibit revival behavior, including the infinite well, the quantum bouncer, and others, as well as several two-dimensional integrable quantum billiard systems. Finally, we briefly review the experimental evidence for wave packet revivals in atomic, molecular, and other systems, and related revival phenomena in condensed matter and optical systems.

  20. SCDC Spanish Curricula Units. Science/Math Strand, Unit 3, Grade One, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    Instructional aids and ditto masters for unit three of a science/math curriculum in Spanish for first graders are included in this supplement and ditto packet. Encompassing kits 9-12, these materials are designed for use with learning activities referred to in the teacher's guide corresponding to this unit. Illustrations and materials for both…

  1. SCDC Spanish Curricula Units. Science/Math Strand, Unit 9, Grade 3, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    Designed to help the teacher in presenting the material of unit nine's science-math strand for third graders, this supplement and ditto packet contains both group visual aids and seatwork activities for individual students. Notations in the teacher's guide indicate when the supplementary materials should be used. Concepts explored in the four kits…

  2. Plant Galls and Ecological Concepts: A Multidisciplinary Outdoor Education Teaching Resource Packet.

    ERIC Educational Resources Information Center

    Matthews, Bruce; And Others

    Designed for adaptation in primary through high school classes, the lessons in this resource packet use the development of plant galls (plant growths caused by irritation of the plant tissue) as a focus for outdoor education studies and activities. Emphasis is on science and ecology, though other disciplines are represented. Illustrations and…

  3. When I Was Hungry. A Hunger Course for High School Students. Teacher's Manual [and] Action Packet.

    ERIC Educational Resources Information Center

    Bread for the World Educational Fund, Washington, DC.

    Designed to accompany a student activity packet on issues related to world hunger, this teacher's manual provides 12 units of study at the high school level. Materials are presented from a Christian perspective. The following topics are covered in separate chapters: introduction (justice and the right to food), the dimensions and scope of the…

  4. Schools Are for All Kids. Part II: School Site Implementation. Trainer's Packet.

    ERIC Educational Resources Information Center

    Roger, Blair; And Others

    This trainer's packet, designed to be used in conjunction with the participant's manual, was prepared for a 2-day workshop to restructure schools to embrace all children, including those with disabilities. The trainer's materials include: program objectives; masters for overhead transparencies; and descriptions of learning activities, including…

  5. Hoover Dam Learning Packet.

    ERIC Educational Resources Information Center

    Bureau of Reclamation (Dept. of Interior), Washington, DC.

    This learning packet provides background information about Hoover Dam (Nevada) and the surrounding area. Since the dam was built at the height of the Depression in 1931, people came from all over the country to work on it. Because of Hoover Dam, the Colorado River was controlled for the first time in history and farmers in Nevada, California, and…

  6. PROGRAMMED LEARNING PACKET.

    ERIC Educational Resources Information Center

    Modern Language Association of America, New York, NY.

    MATERIALS CONCERNING PROGRAMED INSTRUCTION IN FOREIGN LANGUAGES, PUBLISHED FROM 1960 TO 1967, ARE COLLECTED IN THIS PACKET FOR LANGUAGE TEACHERS AND PERSONS INTERESTED IN THE FUTURE USES OF THE LANGUAGE LABORATORY. INCLUDED ARE--(1) "PROGRAMED LEARNING OF A SECOND LANGUAGE" BY HARLAN LANE, (2) "A PRIMER OF PROGRAMED INSTRUCTION IN FOREIGN LANGUAGE…

  7. Amelia Earhart Learning Packet.

    ERIC Educational Resources Information Center

    Civil Air Patrol, Maxwell AFB, AL.

    The feats of individuals who have made history in the aerospace world are often misunderstood and soon ignored or forgotten after the first notoriety has been achieved. Amelia Earhart was selected as the subject for this learning packet because of her brilliant accomplishments on the world of flight, a persistent desire to determine what really…

  8. Understanding and Minimizing Staff Burnout. An Introductory Packet.

    ERIC Educational Resources Information Center

    California Univ., Los Angeles. Center for Mental Health Schools.

    Staff who bring a mental health perspective to the schools can deal with problems of staff burnout. This packet is designed to help in beginning the process of minimizing burnout, a process that requires reducing environmental stressors, increasing personal capabilities, and enhancing job supports. The packet opens with brief discussions of "What…

  9. Langston Hughes Curriculum Packet: Dig and Be Dug in Return.

    ERIC Educational Resources Information Center

    Danielson, Susan

    Designed in a flexible format for use by college instructors, high school teachers, and community education workers, this curriculum packet serves as an introduction to the life and works of black poet Langston Hughes. The major component of the packet is a critical essay that explores the thematic highlights of Hughes's career. The remaining…

  10. Biological Diversity. Global Issues Education Packet.

    ERIC Educational Resources Information Center

    Holm, Amy E.

    Biological diversity, also commonly called genetic diversity, refers to the variety of organisms on Earth. Scientists are concerned that many species will become extinct because of extensive development in the tropical regions. This packet is designed to increase student's awareness about direct and indirect causes of extinction, endangered…

  11. Metro College for Living. Workshop Packet.

    ERIC Educational Resources Information Center

    Kreps, Alice Roelofs

    This packet contains information and materials for conducting a training workshop for working with adults who are developmentally disabled. The materials are specifically designed to train volunteer teachers in the College for Living (CFL) program, which supplements residential programs in and around Denver and aids institutions in orienting…

  12. Elementary Environmental Learning Packet Grades 4-6, Third Revised Edition. [Intermediate CEL Blocks, Student Activity Cards].

    ERIC Educational Resources Information Center

    Brevard County School Board, Cocoa, FL.

    This environmental education program consists of two levels: primary and intermediate. The learning materials are activity based and incorporate process and subject area skills with knowledge and concern for the environment. The program is also interdisciplinary including activities and skills from several areas. The materials in this set for…

  13. Wireless Avionics Packet to Support Fault Tolerance for Flight Applications

    NASA Technical Reports Server (NTRS)

    Block, Gary L.; Whitaker, William D.; Dillon, James W.; Lux, James P.; Ahmad, Mohammad

    2009-01-01

    , and the local ADI number. The destination ADI is used to route the packet to its ultimate destination. At each hop, the sending interface uses the destination address to determine the next node for the data. The sending node is the node address of the interface that is broadcasting the packet. This field is used to determine the health of the subsystem that is sending the packet. In the case of a packet that traverses several intermediate nodes, it may be the node address of the intermediate node. The target node is the node address of the next hop for the packet. It may be an intermediate node, or the final destination for the packet. The sequence number is used to identify duplicate packets. Because each interface has multiple transceivers, the same packet will appear at both receivers. The sequence number allows the interface to correlate the reception and forward a single, unique packet for additional processing. The subnet field allows data traffic to be partitioned into segregated local networks to support large networks while keeping each subnet at a manageable size. This also keeps the routing table small enough so routing can be done by a simple table lookup in an FPGA device. The subsystem class identifies members of a set of redundant subsystems, and, in a hot standby configuration, all members of the subsystem class will receive the data packets. Only the active subsystem will generate data traffic. Specific units in a class of redundant units can be identified and, if the hot standby configuration is not used, packets will be directed to a specific subsystem unit.

  14. Packet Daemon Version 12(SOPHIA)

    SciTech Connect

    2012-08-09

    Packet Daemon Version 12 is the code exclusively used by the ‘packetd’ executable. It provides packet data to the OglNet Version 12 visualization tool. It reads PCAP data and sends an abstraction of the packets to the ‘oglnet’ executable for display. ‘packetd’will run as a service on a Linux host thereby capturing data continuously and make that data available for ‘oglnet’ whenever it connects to the service.

  15. Controlled Quantum Packets

    NASA Technical Reports Server (NTRS)

    DeMartino, Salvatore; DeSiena, Silvio

    1996-01-01

    We look at time evolution of a physical system from the point of view of dynamical control theory. Normally we solve motion equation with a given external potential and we obtain time evolution. Standard examples are the trajectories in classical mechanics or the wave functions in Quantum Mechanics. In the control theory, we have the configurational variables of a physical system, we choose a velocity field and with a suited strategy we force the physical system to have a well defined evolution. The evolution of the system is the 'premium' that the controller receives if he has adopted the right strategy. The strategy is given by well suited laboratory devices. The control mechanisms are in many cases non linear; it is necessary, namely, a feedback mechanism to retain in time the selected evolution. Our aim is to introduce a scheme to obtain Quantum wave packets by control theory. The program is to choose the characteristics of a packet, that is, the equation of evolution for its centre and a controlled dispersion, and to give a building scheme from some initial state (for example a solution of stationary Schroedinger equation). It seems natural in this view to use stochastic approach to Quantum Mechanics, that is, Stochastic Mechanics [S.M.]. It is a quantization scheme different from ordinary ones only formally. This approach introduces in quantum theory the whole mathematical apparatus of stochastic control theory. Stochastic Mechanics, in our view, is more intuitive when we want to study all the classical-like problems. We apply our scheme to build two classes of quantum packets both derived generalizing some properties of coherent states.

  16. Charles A. Lindbergh Learning Packet.

    ERIC Educational Resources Information Center

    Rodriguez, Charley

    This aerospace education learning packet contains information about the famous pilot, Charles A. Lindbergh. Posters, recommended teaching methods, tests with keys, and task cards are also included. (KHR)

  17. Separated Fringe Packet Binaries

    NASA Astrophysics Data System (ADS)

    Bagnuolo, W. G.; Taylor, S. F.; McAlister, H. A.; ten Brummelaar, T.; Sturmann, L.; Sturmann, J.; Turner, N. H.; Berger, D.; Ridgway, S. T.; CenterHigh Angular Resolution Astronomy (CHARA)

    2004-12-01

    Individually resolved packets are produced by scans from the CHARA Interferometer Array for binary stars with separations from 10 to 100 milli-arcsec (mas) in the K' band. We have used this data for astrometry of the binary with the goal of improving the visual orbits for these systems. About 12 data sets of 400 scans each can be collected for a star within an hour. The intrinsic accuracy with simple linear/quadratic fits to the time-separation curve yields accuracies of 0.15 mas. But, for systems with separations less than 80 mas, the measured separation is modulated periodically by the secondary star's packet riding over the sidelobes of the primary which provides a phase reference. This "sidelobe verniering" can improve the precision to better than 50 micro-arcsec. These techniques, represents 1-2 orders of magnitude improvement in astrometic accuracy over speckle interferometry techniques. Visual orbits can then be refined via a maximum liklihood technique, which leads to revisions in the stellar masses. We present the results for several binaries that have been observed at the CHARA Array, starting in 2001.

  18. Intermediate SCDC Spanish Curricula Units. Science/Health, Unit 1, Kits 1-4, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    Visual aids and ditto masters for the first unit of a science/health curriculum for the intermediate level are included in this supplement and ditto packet. The visual aids are designed to help stimulate oral language and conceptual development through group activities and individual seatwork. Intended to help the teacher successfully carry out…

  19. On quantization of nondispersive wave packets

    SciTech Connect

    Altaisky, M. V.

    2013-10-15

    Nondispersive wave packets are widely used in optics and acoustics. We found it interesting that such packets could be also a subject of quantum field theory. Canonical commutation relations for the nondispersive wave packets are constructed.

  20. Design: a voice activated thermostat.

    PubMed

    Jacobson, S

    1992-01-01

    The voice activated thermostat was designed so the temperature in a house could be set without having to touch the thermostat. This is especially useful for a quadriplegic who would like to change the temperature of the room he is in. For simplicity, it was designed using VCP200 speaker-independent word recognizer chip. This chip comes pre-programmed with a limited number of words, so programming of words was not necessary. Every time the activation word is said the digital thermostat changes by one degree.

  1. All-optical packet header and payload separation based on two TOADs for optical packet switched networks

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Zhang, Min; Ye, Peida

    2006-09-01

    We present a novel all-optical header and payload separation technique that can be utilized in Un-Slotted optical packet switched networks. The technique uses two modified TOADs, one is for packet header extraction with differential modulation scheme and the other performs a simple XOR operation between the packet and its self-derived header to get the separated payload. The main virtue of this system is simple structure and low power consumption. Through numerical simulations, the operating characteristics of the scheme are illustrated. In addition, the system parameters are discussed and designed to optimize the performance of the proposed scheme.

  2. Rate-matching packet scheduler for real-rate applications

    NASA Astrophysics Data System (ADS)

    Li, Kang; Walpole, Jonathan; McNamee, Dylan; Pu, Calton; Steere, David C.

    2000-12-01

    A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine- grain real-location of bandwidth for flows with variable-bit- rate requirements. Unfortunately, today's packet schedulers either do not support rate and timing sensitive flows, or do so with reservation systems that are relatively coarse-grain and inflexible. This paper makes two contributions. First it shows how bandwidth requirements can be inferred directly from real-rate flows, without requiring explicit specifications from the application. Second, it presents the design, implementation and performance evaluation of a rate-matching packet scheduler that uses these inferred requirements to automatically and dynamically control the bandwidth allocation to flows.

  3. High speed packet switching

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This document constitutes the final report prepared by Proteon, Inc. of Westborough, Massachusetts under contract NAS 5-30629 entitled High-Speed Packet Switching (SBIR 87-1, Phase 2) prepared for NASA-Greenbelt, Maryland. The primary goal of this research project is to use the results of the SBIR Phase 1 effort to develop a sound, expandable hardware and software router architecture capable of forwarding 25,000 packets per second through the router and passing 300 megabits per second on the router's internal busses. The work being delivered under this contract received its funding from three different sources: the SNIPE/RIG contract (Contract Number F30602-89-C-0014, CDRL Sequence Number A002), the SBIR contract, and Proteon. The SNIPE/RIG and SBIR contracts had many overlapping requirements, which allowed the research done under SNIPE/RIG to be applied to SBIR. Proteon funded all of the work to develop new router interfaces other than FDDI, in addition to funding the productization of the router itself. The router being delivered under SBIR will be a fully product-quality machine. The work done during this contract produced many significant findings and results, summarized here and explained in detail in later sections of this report. The SNIPE/RIG contract was completed. That contract had many overlapping requirements with the SBIR contract, and resulted in the successful demonstration and delivery of a high speed router. The development that took place during the SNIPE/RIG contract produced findings that included the choice of processor and an understanding of the issues surrounding inter processor communications in a multiprocessor environment. Many significant speed enhancements to the router software were made during that time. Under the SBIR contract (and with help from Proteon-funded work), it was found that a single processor router achieved a throughput significantly higher than originally anticipated. For this reason, a single processor router was

  4. Packet-Based Protocol Efficiency for Aeronautical and Satellite Communications

    NASA Technical Reports Server (NTRS)

    Carek, David A.

    2005-01-01

    This paper examines the relation between bit error ratios and the effective link efficiency when transporting data with a packet-based protocol. Relations are developed to quantify the impact of a protocol s packet size and header size relative to the bit error ratio of the underlying link. These relations are examined in the context of radio transmissions that exhibit variable error conditions, such as those used in satellite, aeronautical, and other wireless networks. A comparison of two packet sizing methodologies is presented. From these relations, the true ability of a link to deliver user data, or information, is determined. Relations are developed to calculate the optimal protocol packet size forgiven link error characteristics. These relations could be useful in future research for developing an adaptive protocol layer. They can also be used for sizing protocols in the design of static links, where bit error ratios have small variability.

  5. Overview of wideband packet protocols

    NASA Astrophysics Data System (ADS)

    Sherif, M. H.

    1992-10-01

    Wideband packet networks operate at rates equal to, or higher than, 64 kb/s, but lower than the basic broadband rate of 150 Mb/s, on cables or satellite links. Wideband packet protocols are the transmission protocols for these networks. They define open interfaces that can be used for public and private ISDNs. The protocols are defined in CCITT Recommendations G.764 and G.765. This paper describes the objectives of the wideband protocols, and how the objectives were achieved.

  6. Packet flow monitoring tool and method

    DOEpatents

    Thiede, David R [Richland, WA

    2009-07-14

    A system and method for converting packet streams into session summaries. Session summaries are a group of packets each having a common source and destination internet protocol (IP) address, and, if present in the packets, common ports. The system first captures packets from a transport layer of a network of computer systems, then decodes the packets captured to determine the destination IP address and the source IP address. The system then identifies packets having common destination IP addresses and source IP addresses, then writes the decoded packets to an allocated memory structure as session summaries in a queue.

  7. Packet utilisation definitions for the ESA XMM mission

    NASA Technical Reports Server (NTRS)

    Nye, H. R.

    1994-01-01

    XMM, ESA's X-Ray Multi-Mirror satellite, due for launch at the end of 1999 will be the first ESA scientific spacecraft to implement the ESA packet telecommand and telemetry standards and will be the first ESOC-controlled science mission to take advantage of the new flight control system infrastructure development (based on object-oriented design and distributed-system architecture) due for deployment in 1995. The implementation of the packet standards is well defined at packet transport level. However, the standard relevant to the application level (the ESA Packet Utilization Standard) covers a wide range of on-board 'services' applicable in varying degrees to the needs of XMM. In defining which parts of the ESA PUS to implement, the XMM project first considered the mission objectives and the derived operations concept and went on to identify a minimum set of packet definitions compatible with these aspects. This paper sets the scene as above and then describes the services needed for XMM and the telecommand and telemetry packet types necessary to support each service.

  8. Old as the Hills. Morrow Mountain State Park: An Environmental Education Learning Experience Designed for Grades 5-7.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Environment, Health, and Natural Resources, Raleigh. Div. of Parks and Recreation.

    This curriculum packet was developed and designed to provide environmental education through a series of hands-on activities for the classroom and the outdoor setting of Morrow Mountain State Park, North Carolina to introduce students to the geology of the Uwharrie Mountains. Designed for grades 5 through 7, the packet meets the established…

  9. Jomeokee Geology. Pilot Mountain State Park: An Environmental Education Learning Experience Designed for Grades 9-12.

    ERIC Educational Resources Information Center

    Smith, Michael W.

    This activity packet provides educators with a series of hands-on classroom and outdoor education activities for grades 9-12 that focus on geology using the Pilot Mountain State Park. The packet was designed to meet established curriculum objectives of the North Carolina Department of Public Instruction's Standard Course of Study. Three types of…

  10. Selection of ionization paths of K2 on superfluid helium droplets by wave packet interference

    NASA Astrophysics Data System (ADS)

    Hild, Marek Bastian; Dufour, Adrien; Achazi, Georg; Patas, Alexander; Scheier, Paul; Lindinger, Albrecht

    2016-08-01

    We report on the control of wave packet dynamics for the ionization of K2 attached to the surface of superfluid helium droplets. The superfluid helium matrix acts as a heat sink and reduces the coherence time of molecular processes by dissipation. We use tailor-shaped pulses in order to activate or inhibit different ionization paths by constructive or destructive wave packet interference. A drastic change of the wave packet dynamics is observed by shifting the phase between the exciting sub pulses.

  11. Self-Interfering Wave Packets

    NASA Astrophysics Data System (ADS)

    Colas, David; Laussy, Fabrice P.

    2016-01-01

    We study the propagation of noninteracting polariton wave packets. We show how two qualitatively different concepts of mass that arise from the peculiar polariton dispersion lead to a new type of particlelike object from noninteracting fields—much like self-accelerating beams—shaped by the Rabi coupling out of Gaussian initial states. A divergence and change of sign of the diffusive mass results in a "mass wall" on which polariton wave packets bounce back. Together with the Rabi dynamics, this yields propagation of ultrafast subpackets and ordering of a spacetime crystal.

  12. Self-Interfering Wave Packets.

    PubMed

    Colas, David; Laussy, Fabrice P

    2016-01-15

    We study the propagation of noninteracting polariton wave packets. We show how two qualitatively different concepts of mass that arise from the peculiar polariton dispersion lead to a new type of particlelike object from noninteracting fields-much like self-accelerating beams-shaped by the Rabi coupling out of Gaussian initial states. A divergence and change of sign of the diffusive mass results in a "mass wall" on which polariton wave packets bounce back. Together with the Rabi dynamics, this yields propagation of ultrafast subpackets and ordering of a spacetime crystal. PMID:26824554

  13. Generation of optical pulse packet using a fiber stacker for time fiducial applications

    NASA Astrophysics Data System (ADS)

    Lin, Honghuan; Wang, Jianjun; Huang, Zhihua; Li, Qi; Xu, Lixin; Tang, Xuan; Li, Chengyu; Guo, Chao; Zhao, Pengfei; Jing, Feng

    2016-08-01

    We present the concept of multicolor optical pulse packet generation based on modified fiber stackers featured with reflection geometries. Infrared radiation, visible and ultraviolet time fiducials were obtained by the amplification and frequency-conversion of the pulse packet generated in this fiber stacker. Application for the inertial confinement fusion (ICF) experiment diagnosis with time fiducials was demonstrated. With featured reflection geometries, the shaped packet pulses with uniform sub-pulse polarization states in a temporal window of ns range were generated in the fiber stacker. The design greatly simplifies the packet pulse generation for time fiducial and could be used for laser-driven ICF experimental diagnosis.

  14. Controlling plasmonic wave packets in silver nanowires.

    SciTech Connect

    Cao, L.; Nome, R.; Montgomery, J. M.; Gray, S. K.; Scherer, N. F.

    2010-09-01

    Three-dimensional finite-difference time-domain simulations were performed to explore the excitation of surface plasmon resonances in long silver (Ag) nanowires. In particular, we show that it is possible to generate plasmonic wave packets that can propagate along the nanowire by exciting superpositions of surface plasmon resonances. By using an appropriately chirped pulse, it is possible to transiently achieve localization of the excitation at the distal end of the nanowire. Such designed coherent superpositions will allow realizing spatiotemporal control of plasmonic excitations for enhancing nonlinear responses in plasmonic 'circuits'.

  15. Environment Resource Packets Get Wide Use

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Announces the availability of the resource packet entitled "Noise Pollution," the third in the series prepared by the University of Maryland, and the main topics which will be covered in the remaining three packets. (CC)

  16. A robust coding scheme for packet video

    NASA Technical Reports Server (NTRS)

    Chen, Y. C.; Sayood, Khalid; Nelson, D. J.

    1991-01-01

    We present a layered packet video coding algorithm based on a progressive transmission scheme. The algorithm provides good compression and can handle significant packet loss with graceful degradation in the reconstruction sequence. Simulation results for various conditions are presented.

  17. A robust coding scheme for packet video

    NASA Technical Reports Server (NTRS)

    Chen, Yun-Chung; Sayood, Khalid; Nelson, Don J.

    1992-01-01

    A layered packet video coding algorithm based on a progressive transmission scheme is presented. The algorithm provides good compression and can handle significant packet loss with graceful degradation in the reconstruction sequence. Simulation results for various conditions are presented.

  18. Homelessness: A General Information Packet.

    ERIC Educational Resources Information Center

    Homelessness Exchange, Washington, DC.

    This packet contains documents that provide general information about homelessness and the need for both Federal and local action to help the homeless people in America. Sections 1 and 2 contain the following articles released by the Homelessness Information Exchange: (1) "The Problem of Homelessness Nationwide"; and "Alternative Family Housing…

  19. Dynamics of quantum wave packets

    SciTech Connect

    Gosnell, T.R.; Taylor, A.J.; Rodriguez, G.; Clement, T.S.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to develop ultrafast laser techniques for the creation and measurement of quantum vibrational wave packets in gas phase diatomic molecules. Moreover, the authors sought to manipulate the constitution of these wave packets in terms of harmonic-oscillator basis wavefunctions by manipulating the time-dependent amplitude and phase of the incident ultrashort laser pulse. They specifically investigated gaseous diatomic potassium (K{sub 2}), and discovered variations in the shape of the wave packets as a result of changing the linear chirp in the ultrashort preparation pulse. In particular, they found evidence for wave-packet compression for a specific degree of chirp. Important ancillary results include development of new techniques for denoising and deconvolution of femtosecond time traces and techniques for diagnosing the phase and amplitude of the electric field of femtosecond laser pulses.

  20. Population and Development [Issue Packet].

    ERIC Educational Resources Information Center

    American Freedom from Hunger Foundation, Washington, DC.

    A variety of informational materials is compiled in this issue packet concentrating on population and development. The materials have been assembled to understand the issues associated with the facts of the world's population and to try to invent new forms of action and thought necessary to find the possibilities hidden in the population issue.…

  1. Hunger and Development [Issue Packet].

    ERIC Educational Resources Information Center

    American Freedom from Hunger Foundation, Washington, DC.

    A variety of informational materials is compiled in this issue packet concentrating on hunger and development. They have been assembled to understand the issues associated with the facts of world hunger and to try to invent new forms of action and thought necessary to find the possibilities hidden in the hunger issue. Items include: (1) a fact and…

  2. Recycling Study Guide [Resource Packet].

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Natural Resources, Madison.

    This resource packet contains six documents developed by the Wisconsin Department of Natural Resources in order to help teachers infuse the environmental education topics of recycling and solid waste into social studies, art, English, health, mathematics, science, and environmental education classes. "Recycling Study Guide" contains 19 activities…

  3. Ancient Chinese Bronzes: Teacher's Packet.

    ERIC Educational Resources Information Center

    Smithsonian Institution, Washington, DC. Arthur M. Sackler Gallery.

    The focus of this teacher's packet is the bronze vessels made for the kings and great families of the early Chinese dynasties between 1700 B.C. and 200 A.D. The materials in the guide are intended for use by teachers and students visiting the exhibition, "The Arts of China," at the Arthur M. Sackler Gallery of the Smithsonian Institution in…

  4. 78 FR 63228 - Determination That Potassium Citrate, 10 Milliequivalents/Packet and 20 Milliequivalents/Packet...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... HUMAN SERVICES Food and Drug Administration Determination That Potassium Citrate, 10 Milliequivalents...) has determined that Potassium Citrate, 10 milliequivalents/packet (mEq/packet) and 20 mEq/ packet, was... approve abbreviated new drug applications (ANDAs) for Potassium Citrate, 10 mEq/packet and 20...

  5. Packet Radio: An Alternative Way to Connect.

    ERIC Educational Resources Information Center

    Lucas, Larry W.

    1995-01-01

    Explains packet radio as a form of telecomputing in which digital data is transported via radio waves instead of telephone lines or other cabling, and describes how it can be used by students to access the Internet. Highlights include packet bulletin board systems and equipment needed for a packet radio station. (LRW)

  6. [KIND Worksheet Packet: Wild Animals (Junior).

    ERIC Educational Resources Information Center

    National Association for Humane and Environmental Education, East Haddam, CT.

    This packet is the junior part of a series of worksheet packets available at both junior (grades 3-4) and senior (grades 5-6) levels that covers a variety of humane and environmental topics. Each packet includes 10 worksheets, all of which originally appeared in past issues of the annual teaching magazine "KIND (Kids in Nature's Defense) Teacher."…

  7. Trade Related Reading Packets for Disabled Readers.

    ERIC Educational Resources Information Center

    Davis, Beverly; Woodruff, Nancy S.

    Six trade-related reading packets for disabled readers are provided for these trades: assemblers, baking, building maintenance, data entry, interior landscaping, and warehousing. Each packet stresses from 9 to 14 skills. Those skills common to most packets include context clues, fact or opinion, details, following directions, main idea,…

  8. [KIND Worksheet Packet: Wild Animals (Senior).

    ERIC Educational Resources Information Center

    National Association for Humane and Environmental Education, East Haddam, CT.

    This packet is the senior part of a series of worksheet packets available at both junior (grades 3-4) and senior (grades 5-6) levels that covers a variety of humane and environmental topics. Each packet includes 10 worksheets, all of which originally appeared in past issues of the annual teaching magazine "KIND (Kids in Nature's Defense) Teacher."…

  9. Japanese Painting: Form and Function. A Teacher Workshop on May 14, 1994. Teacher's Packet.

    ERIC Educational Resources Information Center

    Schardt, Molly; And Others

    This packet accompanies a slide series designed to introduce students to Japanese painting from the 12th century to the late 19th century. The packet includes an essay introduction to establish a historical framework, maps of the region, a time line of the chronology of Japan from 2000 B.C. to the present, illustrations of various art forms, a…

  10. Women's Studies for Teachers and Administrators: A Packet of Inservice Education Materials.

    ERIC Educational Resources Information Center

    Froschl, Merle, Ed.; And Others

    This packet of materials is designed for elementary and secondary teachers and administrators who are engaged in inservice education and interested in the movement to eliminate sexism in schools. Two major purposes of the packet are to help a school district start an inservice course on sexism in education and to show the potential of such a…

  11. Guide to Alternative Mortgage Instruments. Teachers Instructional Packet, TIP No. 4, Spring 1985.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Texas Real Estate Research Center.

    Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand the various alternative mortgage instruments, including their major advantages and disadvantages. First, an evaluation form for the packet is presented. Next, a summary presentation on four basic…

  12. Assessing design activity in complex CMOS circuit design

    NASA Astrophysics Data System (ADS)

    Biswas, Gautam; Goldman, Susan R.; Fisher, Doug; Bhuva, Bharat; Glewwe, Grant

    1994-03-01

    This chapter characterizes human problem solving in digital circuit design. We analyze protocols of designers with varying degrees of training, identifying problem solving strategies used by these designers, discuss activity patterns that differentiate designers, and propose these as a tentative basis for assessing expertise in digital design. Throughout, we argue that a comprehensive model of human design should integrate a variety of strategies, which heretofore have been proposed as individually sufficient models of human design problem solving. We close by describing an automated tool for design and its assessment.

  13. Networked LQG control over lossy channels with computational/packet-transmission delays and coarsely quantised packets

    NASA Astrophysics Data System (ADS)

    Foo, Yung Kuan; Moayedi, Maryam; Chai Soh, Yeng

    2016-04-01

    This article addresses the linear quadratic Gaussian (LQG) control problem of networked multi-input, multi-output systems where computational delay exists and the measurement and control signals are packetised and transmitted through a network within which random delay and packet loss may occur during transmissions. A transmission control protocol (TCP)-like protocol for the communication network is considered in which acknowledgement is sent from the actuator to the controller if and only if the control packet is received, assuming these acknowledgements always reach the estimator in time and without fail. To minimise the data word-length for transmissions over the network and to maximise control system performance, it is proposed that different quantisation resolutions be used for transmission data encapsulation, and control and output signals A/D-D/A conversions at sensor/actuator. To circumvent the problem of disparity between encapsulation and A/D-D/A quantisation resolutions, a pseudo-stochastic approach via subtractive dither is applied to quantise the transmission packets. This also enables us to model the quantisation errors as uncorrelated independent zero-mean additive white noises and apply standard LQG methodology and separation principle to design the estimator and the controller separately. An example is included to demonstrate the effectiveness of the approach.

  14. The Open Host Network Packet Process Correlator for Windows

    2014-06-17

    The Hone sensors are packet-process correlation engines that log the relationships between applications and the communications they are responsible for. Hone sensors are available for a variety of platforms including Linux, Windows, and MacOSX. Hone sensors are designed to help analysts understand the meaning of communications on a deeper level by associating the origin or destination process to the communication. They do this by tracing communications on a per-packet basis, through the kernel of themore » operating system to determine their ultimate source/destination on the monitored machine.« less

  15. The Open Host Network Packet Process Correlator for Windows

    SciTech Connect

    2014-06-17

    The Hone sensors are packet-process correlation engines that log the relationships between applications and the communications they are responsible for. Hone sensors are available for a variety of platforms including Linux, Windows, and MacOSX. Hone sensors are designed to help analysts understand the meaning of communications on a deeper level by associating the origin or destination process to the communication. They do this by tracing communications on a per-packet basis, through the kernel of the operating system to determine their ultimate source/destination on the monitored machine.

  16. Designing for the Active Classroom

    SciTech Connect

    Wilkerson, Andrea M.; Donohue, Amy; Davis, Robert G.

    2015-02-01

    The article discusses trends in classroom design and then transitions to a discussion of the future of the classroom and how the lighting industry needs to be preparing to meet the needs of the future classroom. The OSU Classroom building as an example throughout, first discussing how trends in classroom design were incorporated into the Classroom Building and then discussing how future lighting systems could enhance the Classroom Building, which is a clear departure from the actual lighting design and current technology.

  17. Cereal Box Design: An Interdisciplinary Graphics Activity

    ERIC Educational Resources Information Center

    Fitzgerald, Mike; Tsosie, Teri

    2004-01-01

    This article describes cereal box design, an interdisciplinary graphics activity. The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. It lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in…

  18. Teen Pregnancy Prevention and Support. An Introductory Packet.

    ERIC Educational Resources Information Center

    California Univ., Los Angeles. Center for Mental Health Schools.

    This introductory packet is designed to help those with an interest in preventing teen pregnancy. It opens with "A Brief Introduction to Teen Pregnancy Prevention and Support," an essay by the Center for Mental Health in Schools of the University of California, Los Angeles, that outlines the dimensions of the problem. "A Quick Overview of Some…

  19. Environmental Education Inservice Training Packet for the Intermediate Level.

    ERIC Educational Resources Information Center

    Upper Mississippi River ECO-Center, Thomson, IL.

    The inservice teacher training packet, developed with help from the environmental education program of the Upper Mississippi River ECO-Center, is designed to help intermediate-level teachers develop teaching skills which will enable them to introduce environmental or outdoor education to their students and develop those concepts, attitudes, and…

  20. Maintaining Inequality: A Background Packet on Tracking and Ability Grouping.

    ERIC Educational Resources Information Center

    National Coalition of Education Activists, Rosendale, NY.

    This document includes a selection of materials from the National Coalition of Education Activists (NCEA) on tracking and ability grouping designed to be a tool for teachers who wish to organize their school or district against tracking. The packet contains a cover letter, a response/feedback form, and reproductions of the following articles: (1)…

  1. Electronic-To-Optical-To-Electronic Packet-Data Conversion

    NASA Technical Reports Server (NTRS)

    Monacos, Steve

    1996-01-01

    Space-time multiplexer (STM) cell-based communication system designed to take advantage of both high throughput attainable in optical transmission links and flexibility and functionality of electronic processing, storage, and switching. Long packets segmented and transmitted optically by wavelength-division multiplexing. Performs optoelectronic and protocol conversion between electronic "store-and-forward" protocols and optical "hot-potato" protocols.

  2. SLIAG Advocacy Packet: A Guide for Community-Based Organizations.

    ERIC Educational Resources Information Center

    National Council of La Raza, Washington, DC.

    This packet of materials is designed as a basic guide for community-based organizations (CBOs) interested in tracking the use of State Legalization Impact Assistance Grants (SLIAG) funds and in advocating that they be used efficiently and effectively. The SLIAG program was created under the Immigration Reform and Control Act of 1986 (IRCA) to…

  3. Alpine Forest. Mount Mitchell State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Bradley, Jack L., Jr.; Beazley, Lea J.; Cook, Carrie

    This curriculum packet was developed to provide environmental education through a series of hands-on activities for the classroom and the outdoor setting of Mount Mitchell State Park, North Carolina. Designed for grades 3 through 6, the packet meets established curriculum objectives of the North Carolina Department of Public Instruction's Standard…

  4. Drug Courts. Technical Assistance Packet.

    ERIC Educational Resources Information Center

    Join Together, Boston, MA.

    Drug courts are designed to stop the abuse of alcohol and other drugs and the related criminal activity by offering individuals, whose criminal activity stems from substance abuse, the choice to participate in treatment. In exchange for successful completion of a treatment program, the court has the option of dismissing the original charge,…

  5. Packet personal radiation monitor

    DOEpatents

    Phelps, James E.

    1989-01-01

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field.

  6. Packet personal radiation monitor

    DOEpatents

    Phelps, J.E.

    1988-03-31

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  7. Designing Instructional Activities for Young Handicapped Children.

    ERIC Educational Resources Information Center

    Kaczmarek, Louise A.; Dell, Amy Glasser

    1981-01-01

    Proposed are several new directions that encourage the variety and flexibility of haphazard teaching and the precision of one objective-one activity teaching in the design of activities for handicapped preschoolers. Journal availability: see EC 133 846. (Author)

  8. Solar Energy Education Packet for Elementary & Secondary Students.

    ERIC Educational Resources Information Center

    Center for Renewable Resources, Washington, DC.

    The arrangement of this packet is essentially evolutionary, with a conscious effort to alternate reading assignments, activities and experiments. It begins with solar energy facts and terminology as background to introduce the reader to basic concepts. It progresses into a discussion of passive solar systems. This is followed by several projects…

  9. Design Concepts. Teacher Edition. Marketing Education LAPs.

    ERIC Educational Resources Information Center

    Hawley, Jana

    This learning activity packet is designed to help prepare students to acquire a competency: how to use design concepts in preparation for a career in the fashion industry. The unit consists of the competency, four objectives, suggested learning activities, transparency masters, and a pretest/posttest with answer keys. Activities include a…

  10. Group-normalized wavelet packet signal processing

    NASA Astrophysics Data System (ADS)

    Shi, Zhuoer; Bao, Zheng

    1997-04-01

    Since the traditional wavelet and wavelet packet coefficients do not exactly represent the strength of signal components at the very time(space)-frequency tilling, group- normalized wavelet packet transform (GNWPT), is presented for nonlinear signal filtering and extraction from the clutter or noise, together with the space(time)-frequency masking technique. The extended F-entropy improves the performance of GNWPT. For perception-based image, soft-logic masking is emphasized to remove the aliasing with edge preserved. Lawton's method for complex valued wavelets construction is extended to generate the complex valued compactly supported wavelet packets for radar signal extraction. This kind of wavelet packets are symmetry and unitary orthogonal. Well-defined wavelet packets are chosen by the analysis remarks on their time-frequency characteristics. For real valued signal processing, such as images and ECG signal, the compactly supported spline or bi- orthogonal wavelet packets are preferred for perfect de- noising and filtering qualities.

  11. A multi-function IEC 61850 packet generator based on FPGA

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Li, Hong-bin; Cheng, Han-miao

    2016-07-01

    An IEC 61850 packet generator is used to produce IEC 61850-9-2 packets by simulating the merging unit and testing the IEC 61850 digital device. While the existing IEC packet generator can produce ideal digital without any noise, it does not take into account the fact that the merging unit output signal packets will be inevitably superimposed with noise. Since the International Electrical Commission standard of the electronic current transformer specifies the minimum output signal-to-noise ratio of the merging unit to be 30 dB, and the signal superimposed with noise will influence the operation performance of the digital device, it is necessary to design a multi-function IEC 61850-9-2 packet generator for a digital device test. Therefore, in this paper, a multi-function IEC 61850 packet generator has been developed, which not only can output various IEC 61850-9-2 packets, but also can add white Gaussian noise to the signal for digital device testing. By testing three digital electricity meters from different manufacturers, we showed that the error of the digital electricity meter is significantly larger when the signal packet is superimposed with noise. Also when the signal-to-noise ration is 30 dB, the error of one of the meters exceeds the allowed range of the accuracy class. This indicates that the noise testing and the noise setting function of the system has an important role in the testing of a digital device.

  12. Cereal Box Design: An Interdisciplinary Graphics Activity

    ERIC Educational Resources Information Center

    Fitzgerald, Mike; Tsosie, Teri

    2012-01-01

    The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. Also, it lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in depth. The activity introduces a wide range of topics. They include graphic…

  13. Ingestion of Laundry Detergent Packets in Children.

    PubMed

    Shah, Lindsey Wilson

    2016-08-01

    Ingestion of laundry detergent packets is an important threat to young children. Because of their developmental stage, toddlers are prone to place these small, colorful packets in their mouths. The packets can easily burst, sending a large volume of viscous, alkaline liquid throughout the oropharynx. Ingestion causes major toxic effects, including depression of the central nervous system, metabolic acidosis, respiratory distress, and dysphagia. Critical care nurses should anticipate these clinical effects and facilitate prompt intervention. Increased understanding of the risks and clinical effects of ingestion of laundry detergent packets will better prepare critical care nurses to provide care for these children. (Critical Care Nurse 2016; 36[4]:70-75).

  14. Ingestion of Laundry Detergent Packets in Children.

    PubMed

    Shah, Lindsey Wilson

    2016-08-01

    Ingestion of laundry detergent packets is an important threat to young children. Because of their developmental stage, toddlers are prone to place these small, colorful packets in their mouths. The packets can easily burst, sending a large volume of viscous, alkaline liquid throughout the oropharynx. Ingestion causes major toxic effects, including depression of the central nervous system, metabolic acidosis, respiratory distress, and dysphagia. Critical care nurses should anticipate these clinical effects and facilitate prompt intervention. Increased understanding of the risks and clinical effects of ingestion of laundry detergent packets will better prepare critical care nurses to provide care for these children. (Critical Care Nurse 2016; 36[4]:70-75). PMID:27481804

  15. Active magnetic bearings for optimum turbomachinery design

    NASA Technical Reports Server (NTRS)

    Hustak, J.; Kirk, R. G.; Schoeneck, K. A.

    1985-01-01

    The design and shop test results are given for a high speed eight stage centrifugal compressor supported by active magnetic bearings. A brief summary of the rotor dynamics analysis is presented with specific attention given to design considerations for optimum rotor stability. The concerns for retrofit of magnetic bearings in existing machinery are discussed with supporting analysis of a four stage centrifugal compressor. Recommendations are given on design and analysis requirements for successful machinery operation of either retrofit or new design turbomachinery.

  16. Designing Physical Activities for Metaphorical Communication.

    ERIC Educational Resources Information Center

    Gillis, H. Lee; Edwards, Marianne

    1987-01-01

    Presents to student affairs professionals a process for designing physical activities that can actively and metaphorically communicate a message and that can be implemented as part of staff inservice, retreats, or orientations. Describes rationale for activities, historical overview, and example of burnout prevention metaphor for resident…

  17. Quality Enhancement of Packet Audio with Time-Scale Modification

    NASA Astrophysics Data System (ADS)

    Liu, Fang; Kuo, C.-C. Jay

    2002-12-01

    In traditional packet voice or the emerging 2.5G and 3G wireless data services, smooth and timely delivery of audio is an essential requirement in Quality of Service (QoS) provision. It has been shown in our previous work that, by adapting time-scale modification to audio signals, an adaptive play-out algorithm can be designed to minimize packet dropping at the receiver end. By stretching the audio frame duration up and down, the proposed algorithm could adapt quickly to accommodate fluctuating delays including delay spikes. In this paper, we will address the packet audio QoS with emphasis on end-to-end delay, packet loss, and delay jitter. The characteristics of delay and loss will be discussed. Adaptive playback will enhance the audio quality by adapting to the transmission delay jitter and delay spike. Coupled with Forward Error Correction (FEC) schemes, the proposed delay and loss concealment algorithm achieves less overall application loss rate without sacrificing on the average end-to-end delay. The optimal solution of such algorithms will be discussed. We also investigate the stretching-ratio transition effect on perceived audio quality by measuring the objective Perceptual Evaluation of Speech Quality (PESQ) Mean Opinion Score (MOS).

  18. Physical Activity Design Guidelines for School Architecture

    PubMed Central

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K.; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children’s physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students’ physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment’s impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards. PMID:26230850

  19. Physical Activity Design Guidelines for School Architecture.

    PubMed

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children's physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students' physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment's impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards. PMID:26230850

  20. Physical Activity Design Guidelines for School Architecture.

    PubMed

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children's physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students' physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment's impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards.

  1. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  2. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS (PRESENTATION)

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  3. IP-over-WDM dynamic link layer: challenges, open issues, and comparison of files-over-lightpaths versus photonic packet switching

    NASA Astrophysics Data System (ADS)

    Izal, Mikel; Aracil Rico, Javier

    2001-08-01

    This paper addresses the suitability of WDM coarse packet switching solutions for IP traffic. Our findings show that the combination of traffic grooming at the higher layers and coarse packet switching at the optical layer provides at least the same performance as more sophisticated and difficult to realize photonic packet switching solutions. We propose a network architecture named files-over-lightpaths that not only simplifies the network optical and electronic design by making use of coarse packet switching, but also serves to the purpose of decreasing the TCP transaction latency in comparison to a flat or split Internet organization with fine grain photonic packet switching.

  4. Oak Ridge Environmental Information System (ORIES) site workstation information packet for OREIS V1. 2

    SciTech Connect

    Voorhees, L.D.; McCord, R.A.; Durfee, R.C.; Land, M.L.; Olson, R.J.; Palmer, M.R.; Thomas, J.K.; Tinnel, E.P.; Zygmunt, B.C.

    1993-02-01

    The OREIS site workstation information packet was developed to accompany the OREIS site workstations, which are being delivered to the Environmental Restoration programs at the five DOE-OR sites. The packet is written specifically for the Site ER program staff at each of the five Sites who have been designated the OREIS contact by their ER program manager, and is not intended for general distribution. The packet provides an overview of the components of OREIS, points to more detailed information provided in the accompanying vendor and OREIS developed manuals, and includes information on training opportunities and user support.

  5. Active Learning through Toy Design and Development

    ERIC Educational Resources Information Center

    Sirinterlikci, Arif; Zane, Linda; Sirinterlikci, Aleea L.

    2009-01-01

    This article presents an initiative that is based on active learning pedagogy by engaging elementary and middle school students in the toy design and development field. The case study presented in this article is about student learning experiences during their participation in the TOYchallenge National Toy Design Competition. Students followed the…

  6. Bad data packet capture device

    DOEpatents

    Chen, Dong; Gara, Alan; Heidelberger, Philip; Vranas, Pavlos

    2010-04-20

    An apparatus and method for capturing data packets for analysis on a network computing system includes a sending node and a receiving node connected by a bi-directional communication link. The sending node sends a data transmission to the receiving node on the bi-directional communication link, and the receiving node receives the data transmission and verifies the data transmission to determine valid data and invalid data and verify retransmissions of invalid data as corresponding valid data. A memory device communicates with the receiving node for storing the invalid data and the corresponding valid data. A computing node communicates with the memory device and receives and performs an analysis of the invalid data and the corresponding valid data received from the memory device.

  7. Karyotype Analysis Activity: A Constructivist Learning Design

    ERIC Educational Resources Information Center

    Ahmed, Noveera T.

    2015-01-01

    This classroom activity is based on a constructivist learning design and engages students in physically constructing a karyotype of three mock patients. Students then diagnose the chromosomal aneuploidy based on the karyotype, list the symptoms associated with the disorder, and discuss the implications of the diagnosis. This activity is targeted…

  8. Three Packets with Which to Evaluate Teacher In-Service Workshops via Participant Evaluation and via Observer Evaluation.

    ERIC Educational Resources Information Center

    Alvir, Howard P.

    Three evaluation packets which can serve as guidelines for evaluation models are illustrated in this document. These packages were designed originally for occupational educators, but editing can make these packets and evaluation forms applicable to any area in which secondary and post-secondary teachers attend an inservice workshop or training…

  9. The Texas Real Estate License Act. Teachers Instructional Packet (TIP), No. 1, Fall 1984. Revised Fall 1985.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Texas Real Estate Research Center.

    Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand the content and complexities of the Real Estate License Act of Texas. The packet has three parts. The first two parts provide an instructor's evaluation form and the instructor's guide to the law,…

  10. Ground equipment for the support of packet telemetry and telecommand

    NASA Technical Reports Server (NTRS)

    Hell, Wolfgang

    1994-01-01

    This paper describes ground equipment for packet telemetry and telecommand which has been recently developed by industry for the European Space Agency. The architectural concept for this type of equipment is outlined and the actual implementation is presented. Focus is put on issues related to cross support and telescience as far as they affect the design of the interfaces to the users of the services provided by the equipment and to the management entities in charge of equipment control and monitoring.

  11. Experiments examining drag in linear droplet packets

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. V.; Dunn-Rankin, D.

    1992-01-01

    This paper presents an experimental study of vertically traveling droplet packets, where the droplets in each packet are aligned linearly, one behind another. The paper describes in detail, an experimental apparatus that produces repeatable, linearly aligned, and isolated droplet packets containing 1 6 droplets per packet. The apparatus is suitable for examining aerodynamic interactions between droplets within each packet. This paper demonstrates the performance of the apparatus by examining the drag reduction and collision of droplets traveling in the wake of a lead droplet. Comparison of a calculated single droplet trajectory with the detailed droplet position versus time data for a droplet packet provides the average drag reduction experienced by the trailing droplets due to the aerodynamic wake of the lead droplet. For the conditions of our experiment (4 droplet packet, 145 μm methanol droplets, 10 m/s initial velocity, initial droplet spacing of 5.2 droplet diameters, Reynolds number approx. 80) the average drag on the first trailing droplet was found to be 75% of the drag on the lead droplet.

  12. Fostering Teachers' Design Expertise in Teacher Design Teams: Conducive Design and Support Activities

    ERIC Educational Resources Information Center

    Huizinga, Tjark; Handelzalts, Adam; Nieveen, Nienke; Voogt, Joke

    2015-01-01

    Supporting Teacher Design Teams (TDTs) during local curriculum development efforts is essential. To be able to provide high-quality support, insights are needed about how TDTs carry out design activities and how support is valued by the members of TDTs and how it affects their design expertise. In this study, the design and support processes of…

  13. Participatory Design Activities and Agile Software Development

    NASA Astrophysics Data System (ADS)

    Kautz, Karlheinz

    This paper contributes to the studies of design activities in information systems development. It provides a case study of a large agile development project and focusses on how customers and users participated in agile development and design activities in practice. The investigated project utilized the agile method eXtreme Programming. Planning games, user stories and story cards, working software, and acceptance tests structured the customer and user involvement. We found genuine customer and user involvement in the design activities in the form of both direct and indirect participation in the agile development project. The involved customer representatives played informative, consultative, and participative roles in the project. This led to their functional empowerment— the users were enabled to carry out their work to their own satisfaction and in an effective, efficient, and economical manner.

  14. Interconnecting network for switching data packets and method for switching data packets

    DOEpatents

    Benner, Alan Frederic; Minkenberg, Cyriel Johan Agnes; Stunkel, Craig Brian

    2010-05-25

    The interconnecting network for switching data packets, having data and flow control information, comprises a local packet switch element (S1) with local input buffers (I(1,1) . . . I(1,y)) for buffering the incoming data packets, a remote packet switch element (S2) with remote input buffers (I(2,1) . . . I(2,y)) for buffering the incoming data packets, and data lines (L) for interconnecting the local and the remote packet switch elements (S1, S2). The interconnecting network further comprises a local and a remote arbiter (A1, A2) which are connected via control lines (CL) to the input buffers (I(1,1) . . . I(1,y), I(2,1) . . . I(2,y)), and which are formed such that they can provide that the flow control information is transmitted via the data lines (L) and the control lines (CL).

  15. A Packet Discarding Method with Two Parametrers

    NASA Astrophysics Data System (ADS)

    Fujii, Atsuro; Inai, Hiroshi

    In order to avoid congestion in the network and to achieve a fair share of the resource among communication flows, the packet discarding method called RED (Random Early Detection) has been proposed. In that method, a router randomly discards arriving packets before its buffer overflows. Although some enhanced methods of RED have been proposed, they employ complicated controls to achieve high throughput and fairness among communication flows. However, many control parameters in the complicated methods would prevent from reaching their practical stages. This paper proposes a simple packet discarding method which reduces the number of parameters and provides better performance than existing ones. Concretely speaking, our method omits the probabilistic packet discard from RED. Via simulation, the proposed method provides higher throughput than existing ones and almost equal fairness.

  16. Individualized Science Packets for Gifted Students.

    ERIC Educational Resources Information Center

    Blurton, Craig

    1983-01-01

    Discusses four problems facing gifted students in elementary science classrooms. Suggests development of teacher-made science packets to resolve these and other problems. A sample lesson on animal classification for grade three is provided. (JN)

  17. Predictive onboard flow control for packet switching satellites

    NASA Technical Reports Server (NTRS)

    Bobinsky, Eric A.

    1992-01-01

    We outline two alternate approaches to predicting the onset of congestion in a packet switching satellite, and argue that predictive, rather than reactive, flow control is necessary for the efficient operation of such a system. The first method discussed is based on standard, statistical techniques which are used to periodically calculate a probability of near-term congestion based on arrival rate statistics. If this probability exceeds a present threshold, the satellite would transmit a rate-reduction signal to all active ground stations. The second method discussed would utilize a neural network to periodically predict the occurrence of buffer overflow based on input data which would include, in addition to arrival rates, the distributions of packet lengths, source addresses, and destination addresses.

  18. Predictive onboard flow control in packet switching satellites

    NASA Technical Reports Server (NTRS)

    Bobinsky, E. A.

    1992-01-01

    We outline two alternate approaches to predicting the onset of congestion in a packet switching satellite, and argue that predictive, rather than reactive, flow control is necessary for the efficient operation of such a system. The first method discussed is based on standard, statistical techniques which are used to periodically calculate a probability of near-term congestion based on arrival rate statistics. If this probability exceeds a present threshold, the satellite would transmit a rate-reduction signal to all active ground stations. The second method discussed would utilize a neural network to periodically predict the occurrence of buffer overflow based on input data which would include, in addition to arrival rates, the distributions of packet lengths, source addresses, and destination addresses.

  19. Comparison of Ring-Buffer-Based Packet Capture Solutions

    SciTech Connect

    Barker, Steven Andrew

    2015-10-01

    Traditional packet-capture solutions using commodity hardware incur a large amount of overhead as packets are copied multiple times by the operating system. This overhead slows sensor systems to a point where they are unable to keep up with high bandwidth traffic, resulting in dropped packets. Incomplete packet capture files hinder network monitoring and incident response efforts. While costly commercial hardware exists to capture high bandwidth traffic, several software-based approaches exist to improve packet capture performance using commodity hardware.

  20. Active array design for FAME: Freeform Active Mirror Experiment

    NASA Astrophysics Data System (ADS)

    Jaskó, Attila; Aitink-Kroes, Gabby; Agócs, Tibor; Venema, Lars; Hugot, Emmanuel; Schnetler, Hermine; Bányai, Evelin

    2014-07-01

    In this paper a status report is given on the development of the FAME (Freeform Active Mirror Experiment) active array. Further information regarding this project can be found in the paper by Venema et al. (this conference). Freeform optics provide the opportunity to drastically reduce the complexity of the future optical instruments. In order to produce these non-axisymmetric freeform optics with up to 1 mm deviation from the best fit sphere, it is necessary to come up with new design and manufacturing methods. The way we would like to create novel freeform optics is by fine tuning a preformed high surface-quality thin mirror using an array which is actively controlled by actuators. In the following we introduce the tools deployed to create and assess the individual designs. The result is an active array having optimal number and lay-out of actuators.

  1. Fast WEP-Key Recovery Attack Using Only Encrypted IP Packets

    NASA Astrophysics Data System (ADS)

    Teramura, Ryoichi; Asakura, Yasuo; Ohigashi, Toshihiro; Kuwakado, Hidenori; Morii, Masakatu

    Conventional efficient key recovery attacks against Wired Equivalent Privacy (WEP) require specific initialization vectors or specific packets. Since it takes much time to collect the packets sufficiently, any active attack should be performed. An Intrusion Detection System (IDS), however, will be able to prevent the attack. Since the attack logs are stored at the servers, it is possible to prevent such an attack. This paper proposes an algorithm for recovering a 104-bit WEP key from any IP packets in a realistic environment. This attack needs about 36, 500 packets with a success probability 0.5, and the complexity of our attack is equivalent to about 220 computations of the RC4 key setups. Since our attack is passive, it is difficult for both WEP users and administrators to detect our attack.

  2. The effect of human rhythm on packet delivery

    NASA Astrophysics Data System (ADS)

    Zhou, Zhao; Huang, Zi-Gang; Yang, Lei; Xue, De-Sheng; Wang, Ying-Hai

    2010-08-01

    In communication networks such as the Internet, the relationship between packet generation rate and time is similar to a rectangle wavefunction due to the rhythm of humans. Thus, we investigate the traffic dynamics on a network with a rectangle wavepacket generation rate. It is found that the critical delivering capacity parameter βc (which separates the congested phase and the free phase) decreases significantly with the duty cycle r of the rectangle wave for package generation. And, in the congested phase, more collective generation of packets (smaller r) is helpful for decreasing the packet aggregation rate. Moreover, it is found that the congested phase can be divided into two regions, i.e., region 1 and region 2, where the distributions of queue lengths are nonlinear and linear, respectively. Also, the linear expression for the distribution of queue lengths in region 2 is obtained analytically. Our work reveals an obvious effect of the rectangle wave on the traffic dynamics and the queue length distribution in the system, which is of essential interest and may provide insights into the designing of work-rest schedules and routing strategies.

  3. Geometrical aspects in optical wave-packet dynamics.

    PubMed

    Onoda, Masaru; Murakami, Shuichi; Nagaosa, Naoto

    2006-12-01

    We construct a semiclassical theory for propagation of an optical wave packet in a nonconducting medium with a periodic structure of dielectric permittivity and magnetic permeability, i.e., a nonconducting photonic crystal. We employ a quantum-mechanical formalism in order to clarify its link to those of electronic systems. It involves the geometrical phase, i.e., Berry's phase, in a natural way, and describes an interplay between orbital motion and internal rotation. Based on the above theory, we discuss the geometrical aspects of the optical Hall effect. We also consider a reduction of the theory to a system without periodic structure and apply it to the transverse shift of an optical beam at an interface reflection or refraction. For a generic incident beam with an arbitrary polarization, an identical result for the transverse shift of each reflected or transmitted beam is given by the following different approaches: (i) analytic evaluation of wave-packet dynamics, (ii) total angular momentum (TAM) conservation for individual photons, and (iii) numerical simulation of wave-packet dynamics. It is consistent with a result by classical electrodynamics. This means that the TAM conservation for individual photons is already taken into account in wave optics, i.e., classical electrodynamics. Finally, we show an application of our theory to a two-dimensional photonic crystal, and propose an optimal design for the enhancement of the optical Hall effect in photonic crystals.

  4. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

  5. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed. PMID:12906279

  6. Health Activities Project (HAP): Breathing Fitness Module.

    ERIC Educational Resources Information Center

    Buller, Dave; And Others

    Contained within this Health Activities Project (HAP) learning packet are activities for children in grades 5-8. Design of the activities centers around the idea that students can control their own health and safety. Within this module are teacher and student folios describing four activities which involve students in learning how to measure their…

  7. Dynamics of Attosecond Electron Wave Packets

    NASA Astrophysics Data System (ADS)

    Mauritsson, Johan

    2005-05-01

    We present results from some of the first experimental studies of attosecond electron wave packets created via the absorption of ultrashort extreme ultraviolet (XUV) light pulses [1]. The pulses, made via high harmonic generation, form an attosecond pulse train (APT) whose properties we can manipulate by a combination of spatial and spectral filtering. For instance, we show that on-target attosecond pulses of 170 as duration, which is close to the single cycle limit, can be produced [2]. The electron wave packets created when such an APT is used to ionize an atom are different from the tunneling wave packets familiar from strong field ionization. We show how to measure the dynamics of these wave packets in a strong infrared (IR) field, where the absorption of energy above the ionization threshold is found to depend strongly on the APT-IR delay [3]. We also demonstrate that altering the properties of the initial electron wave packet by manipulating the APT changes the subsequent continuum electron dynamics. Finally, we show how the phase of a longer, femtosecond electron wave packet can be modulated by a moderately strong IR pulse with duration comparable to or shorter than that of the electron wave packet. This experiment reveals how the normal ponderomotive shift of an XUV ionization event is modified when the IR pulse is shorter than the XUV pulse.[1] The experiments were done at Lund Institute of Technology, Sweden.[2] R. López-Martens, et al., Phys. Rev. Lett. 94, 033001 (2005)[3] P. Johnsson, et al., submitted to Phys. Rev. Lett.

  8. Local encoding of computationally designed enzyme activity

    PubMed Central

    Allert, Malin; Dwyer, Mary A.; Hellinga, Homme W.

    2007-01-01

    One aim of computational protein design is to introduce novel enzyme activity into proteins of known structure by predicting mutations that stabilize transition states. Previously we have shown that it is possible to introduce triose phosphate isomerase activity into the ribose-binding protein of Escherichia coli by constructing 17 mutations in the first two layers of residues that surround the wild-type ligand-binding site. Here we report that these mutations can be “transplanted” into a homologous ribose-binding protein, isolated from the hyperthermophilic bacterium Thermoanaerobacter tengcongensis, with retention of catalytic activity, substrate affinity, and reaction pH dependence. The observed 105–106-fold rate enhancement corresponds to 70% of the maximally known transition-state binding energy. The wild-type sequences in these two homologues are almost perfectly conserved in the vicinity of their ribose-binding sites, but diverge significantly at increasing distance from these sites. The results demonstrate that the computationally designed mutations are sufficient to encode the observed enzyme activity, that all the observed activity is locally encoded within the layer of residues directly in contact with the substrate, and that in this case at least 70% of transition state stabilization energy can be achieved using straightforward considerations of stereochemical complementarity between enzyme and reactants. PMID:17196220

  9. All-optical buffering for DPSK packets

    NASA Astrophysics Data System (ADS)

    Liu, Guodong; Wu, Chongqing; Liu, Lanlan; Wang, Fu; Mao, Yaya; Sun, Zhenchao

    2013-12-01

    Advanced modulation formats, such as DPSK, DQPSK, QAM, have become the mainstream technologies in the optical network over 40Gb/s, the DPSK format is the fundamental of all advanced modulation formats. Optical buffers, as a key element for temporarily storing packets in order to synchronization or contention resolution in optical nodes, must be adapted to this new requirement. Different from other current buffers to store the NRZ or RZ format, an all-optical buffer of storing DPSK packets based on nonlinear polarization rotation in SOA is proposed and demonstrated. In this buffer, a section of PMF is used as fiber delay line to maintain the polarization states unchanged, the driver current of SOA is optimized, and no amplifier is required in the fiber loop. A packet delay resolution of 400ns is obtained and storage for tens rounds is demonstrated without significant signal degradation. Using proposed the new tunable DPSK demodulator, bit error rate has been measured after buffering for tens rounds for 10Gb/s data payload. Configurations for First-in First-out (FIFO) buffer or First-in Last-out (FILO) buffer are proposed based on this buffer. The buffer is easy control and suitable for integration. The terminal contention caused by different clients can be mitigated by managing packets delays in future all-optical network, such as optical packet switching network and WDM switching network.

  10. High Angular Momentum Rydberg Wave Packets

    NASA Astrophysics Data System (ADS)

    Wyker, Brendan

    2011-12-01

    High angular momentum Rydberg wave packets are studied. Application of carefully tailored electric fields to low angular momentum, high- n (n ˜ 300) Rydberg atoms creates coherent superpositions of Stark states with near extreme values of angular momentum, ℓ. Wave packet components orbit the parent nucleus at rates that depend on their energy, leading to periods of localization and delocalization as the components come into and go out of phase with each other. Monitoring survival probability signals in the presence of position dependent probing leads to observation of characteristic oscillations based on the composition of the wave packet. The discrete nature of electron energy levels is observed through the measurement of quantum revivals in the wave packet localization signal. Time-domain spectroscopy of these signals allows determination of both the population and phase of individual superposition components. Precise manipulation of wave packets is achieved through further application of pulsed electric fields. Decoherence effects due to background gas collisions and electrical noise are also detailed. Quantized classical trajectory Monte-Carlo simulations are introduced and agree remarkably well with experimental results.

  11. Early Childhood Motor Skills Information Packet.

    ERIC Educational Resources Information Center

    Juelsgaard, Cheri

    This activity book is designed to assist teachers in enhancing preschool children's motor skills, physical development, and social skills, and to build young children's self-esteem. The activities are designed for both disabled and nondisabled children. The first section of the book suggests specific activities in 13 categories of motor skills:…

  12. Designing an Active Target Test Projection Chamber

    NASA Astrophysics Data System (ADS)

    Koci, James; Tan Ahn Collaboration, Dr.; Nicolas Dixneuf Collaboration

    2015-10-01

    The development of instrumentation in nuclear physics is crucial for advancing our ability to measure the properties of exotic nuclei. One limitation of the use of exotic nuclei in experiment is their very low production intensities. Recently, detectors, called active-target dectectors, have been developed to address this issue. Active-target detectors use a gas medium to image charged-particle tracks that are emitted in nuclear reactions. Last semester, I designed a vacuum chamber to be used in developing Micro-Pattern Gas detectors that will upgrade the capabilities of an active-target detector called the Prototype AT-TPC. With the exterior of the chamber complete, I have now been using an electric field modeling program, Garfield, developed by CERN to design a field cage to be placed within the vacuum chamber. The field cage will be a box-like apparatus consisting of two parallel metal plates connected with a resistor chain and attached to wires wrapped between them. The cage will provide a uniform electric field within the chamber to drift electrons from nuclear reactions down to the detector in the bottom of the chamber. These signals are then amplified by a proportional counter, and the data is sent to a computer. For the long term, we would like to incorporate a Micro-Pattern Gas Detectors in the interior of the chamber and eventually use the AT-TPC to examine various nuclei. Dr. Ahn is my advising professor.

  13. Packet Randomized Experiments for Eliminating Classes of Confounders

    PubMed Central

    Pavela, Greg; Wiener, Howard; Fontaine, Kevin R.; Fields, David A.; Voss, Jameson D.; Allison, David B.

    2014-01-01

    Background Although randomization is considered essential for causal inference, it is often not possible to randomize in nutrition and obesity research. To address this, we develop a framework for an experimental design—packet randomized experiments (PREs), which improves causal inferences when randomization on a single treatment variable is not possible. This situation arises when subjects are randomly assigned to a condition (such as a new roommate) which varies in one characteristic of interest (such as weight), but also varies across many others. There has been no general discussion of this experimental design, including its strengths, limitations, and statistical properties. As such, researchers are left to develop and apply PREs on an ad hoc basis, limiting its potential to improve causal inferences among nutrition and obesity researchers. Methods We introduce PREs as an intermediary design between randomized controlled trials and observational studies. We review previous research that used the PRE design and describe its application in obesity-related research, including random roommate assignments, heterochronic parabiosis, and the quasi-random assignment of subjects to geographic areas. We then provide a statistical framework to control for potential packet-level confounders not accounted for by randomization. Results PREs have successfully been used to improve causal estimates of the effect of roommates, altitude, and breastfeeding on weight outcomes. When certain assumptions are met, PREs can asymptotically control for packet-level characteristics. This has the potential to statistically estimate the effect of a single treatment even when randomization to a single treatment did not occur. Conclusions Applying PREs to obesity-related research will improve decisions about clinical, public health, and policy actions insofar as it offers researchers new insight into cause and effect relationships among variables. PMID:25444088

  14. Packet radar spectrum recovery for physiological signals.

    PubMed

    Yavari, Ehsan; Padasdao, Bryson; Lubecke, Victor; Boric-Lubecke, Olga

    2013-01-01

    Packet Doppler radar is investigated for extracting physiological signals. System on Chip is employed as a signal source in packet mode, and it transmits signals intermittently at 2.405 GHz to save power. Reflected signals are demodulated directly by spectral analysis of received pulses in the baseband. Spectral subtraction, using data from an empty room, is applied to extract the periodic movement. It was experimentally demonstrated that frequency of the periodic motion can be accurately extracted using this technique. Proposed approach reduces the computation complexity of the signal processing part effectively. PMID:24110048

  15. Packet Transport Technologies for Optical Networks

    NASA Astrophysics Data System (ADS)

    Lometti, Alberto; Busi, Italo; Grandi, Pietro; Sestito, Vincenzo; Paparella, Andrea

    The purpose of a transport network is to provide a reliable aggregation and transport infrastructure for any client traffic type, in any scale, at the lowest cost per bit. With the growth of packet services, operators are transforming their network infrastructures while looking at reducing capital expenditures and maximizing operational savings. In that scope, new technologies are emerging such as transport multi-protocol label switching and provider backbone transport. This article outlines the state of the art for packet-based transport technologies, comparing them and highlighting the key factors.

  16. Packet radar spectrum recovery for physiological signals.

    PubMed

    Yavari, Ehsan; Padasdao, Bryson; Lubecke, Victor; Boric-Lubecke, Olga

    2013-01-01

    Packet Doppler radar is investigated for extracting physiological signals. System on Chip is employed as a signal source in packet mode, and it transmits signals intermittently at 2.405 GHz to save power. Reflected signals are demodulated directly by spectral analysis of received pulses in the baseband. Spectral subtraction, using data from an empty room, is applied to extract the periodic movement. It was experimentally demonstrated that frequency of the periodic motion can be accurately extracted using this technique. Proposed approach reduces the computation complexity of the signal processing part effectively.

  17. Optimizing bandwidth utilization in packet based telemetry systems

    SciTech Connect

    Kalibjian, J.R.

    1995-10-17

    A consistent theme in spacecraft telemetry system design is the desire to obtain maximum bandwidth utilization given a fixed transmission capability (usually due to cost/weight criteria). Extensions to basic packetization telemetry architectures are discussed which can facilitate a reduction in the amount of actual data telemetered, without loss of data quality. Central to the extensions are the establishment of an ``intelligent`` telemetry process, which can evaluate pending data to be telemetered, and act to compress, discard, or re-formulate data before actual transmission to ground stations.

  18. A dynamic packet-switching system for satellite broadcast channels

    NASA Technical Reports Server (NTRS)

    Binder, R.

    1975-01-01

    A new satellite multi-access scheme for packet-switching computer communications combines a dynamic allocation technique with conventional time-division multiplexing to minimize delays and maximize traffic thruput. The scheme is designed to give the shortest delays to short-duration interactive or priority traffic, at the expense of longer delays for large data transfers. Simulation results show markedly improved delay-thruput characteristics over conventional time-division multiplexing for a wide range of traffic mixes, with especially significant performance gains as the traffic imbalance among the nodes increases.

  19. Oak Ridge Environmental Information System (ORIES) site workstation information packet for OREIS V1.2. Environmental Restoration Program

    SciTech Connect

    Voorhees, L.D.; McCord, R.A.; Durfee, R.C.; Land, M.L.; Olson, R.J.; Palmer, M.R.; Thomas, J.K.; Tinnel, E.P.; Zygmunt, B.C.

    1993-02-01

    The OREIS site workstation information packet was developed to accompany the OREIS site workstations, which are being delivered to the Environmental Restoration programs at the five DOE-OR sites. The packet is written specifically for the Site ER program staff at each of the five Sites who have been designated the OREIS contact by their ER program manager, and is not intended for general distribution. The packet provides an overview of the components of OREIS, points to more detailed information provided in the accompanying vendor and OREIS developed manuals, and includes information on training opportunities and user support.

  20. Controllably accelerating and decelerating Airy–Bessel–Gaussian wave packets

    NASA Astrophysics Data System (ADS)

    Deng, Fu; Yu, Weihao; Deng, Dongmei

    2016-11-01

    By solving the (3  +  1)D free-space Schrödinger equation in polar coordinates analytically, we have investigated the propagation of 3D controllably accelerating and decelerating Airy–Bessel–Gaussian (CAiBG) wave packets, even CAiBG wave packets, odd CAiBG wave packets and the superposition of several CAiBG wave packets in free space. The CAiBG wave packets are constructed with the Airy pulses with initial velocity in temporal domain and the Bessel–Gaussian beams in space domain. Due to the initial velocity on Airy pulses, we can obtain decelerating and accelerating Airy–Bessel–Gaussian wave packets by selecting different initial velocities. Moreover, by superposing several CAiBG wave packets, we can obtain the rotating wave packets.

  1. The European Space Agency standard for space packet utilisation

    NASA Technical Reports Server (NTRS)

    Kaufeler, J.-F.; Parkes, A.; Pidgeon, A.

    1993-01-01

    This paper presents the ESA concept for the use of CCSDS defined Telemetry and Telecommand Packets at the application level. These Packets are used to monitor and control remotely a space born application. This concept is defined in a Packet Utilisation Standard (PUS) which should become applicable for all ESA missions using Packets. The production of this standard is under the responsibility of an ESA standardization group called 'COES'.

  2. Resource Packet on Disability, Spirituality, and Healing.

    ERIC Educational Resources Information Center

    Lane, Nancy

    This resource packet includes information relating to the inclusion of people with disabilities in the Christian church. The first article, "Changing Attitudes, Creating Awareness," highlights several critical areas where churches can begin to understand the barriers of exclusion to people with disabilities. The following article, "Victim…

  3. The World Around You. Environmental Education Packet.

    ERIC Educational Resources Information Center

    Garden Club of America, New York, NY.

    The Garden Club of America has compiled this environmental education packet of informational materials to help teachers educate their students for survival. The "Study Guide" contains essays by ten authorities on topics of population, soil, air, water, power and energy, solid waste management, open space, public lands, oceans, and wildlife. Each…

  4. Passive analysis technique for packet link performance

    NASA Astrophysics Data System (ADS)

    Fairhurst, G.; Wan, P. S.

    1993-01-01

    The performance of a bearer link is usually assessed by bit error rate (BER) tests or measurement of the error free seconds (EFS). These require exclusive access to the link. An alternative technique is presented that measures performance by passive observation of the frames passing over a packet link. This may be used to estimate the performance of the link.

  5. [Alum Rock Voucher Project. Information Packet.

    ERIC Educational Resources Information Center

    Alum Rock Union Elementary School District, San Jose, CA.

    This packet contains (1) informational booklets for parents in the Alum Rock Union Elementary School District, (2) a booklet on the pros and cons of a voucher system, (3) promotional material, (4) a progress report on the project, (5) the project proposal to OEO, and (6) a sample school and program preferences form. The program, according to the…

  6. Electroencephalography data analysis by using discrete wavelet packet transform

    NASA Astrophysics Data System (ADS)

    Karim, Samsul Ariffin Abdul; Ismail, Mohd Tahir; Hasan, Mohammad Khatim; Sulaiman, Jumat; Muthuvalu, Mohana Sundaram; Janier Josefina, B.

    2015-05-01

    Electroencephalography (EEG) is the electrical activity generated by the movement of neurons in the brain. It is categorized into delta waves, theta, alpha, beta and gamma. These waves exist in a different frequency band. This paper is a continuation of our previous research. EEG data will be decomposed using Discrete Wavelet Packet Transform (DWPT). Daubechies wavelets 10 (D10) will be used as the basic functions for research purposes. From the main results, it is clear that the DWPT able to characterize the EEG signal corresponding to each wave at a specific frequency. Furthermore, the numerical results obtained better than the results using DWT. Statistical analysis support our main findings.

  7. Health Activities Project (HAP): Heart Fitness and Action Module.

    ERIC Educational Resources Information Center

    Buller, Dave; And Others

    Contained within this Health Activities Project (HAP) learning packet are activities for children in grades 5-8. Design of the activities centers around the idea that students can control their own health and safety. Within the Heart Fitness and Action Module are teacher and student folios describing five activities which involve students in…

  8. A Feeling for Clay: Japanese Pottery from Ancient to Pre-Modern Times. A Teacher Workshop on May 8, 1993. Teacher's Packet.

    ERIC Educational Resources Information Center

    Schardt, Molly; And Others

    This packet accompanies a slide series designed to introduce students to the clay pottery works of Japan. The packet includes an essay introduction to the early influences on Japanese pottery, maps of the region, a time line of the chronology of Japan from 2000 B.C. to the present, illustrations of types of kilns, a 18-item bibliography for…

  9. ZooScope. Teacher's Packet.

    ERIC Educational Resources Information Center

    Henrie, Charis

    This curriculum provides background information and activities for teaching inquiry-based science in the classroom and at the Oregon Zoo. The ZooScope program was created to provide students with hands-on and minds-on activities that are crucial to taking theoretical learning into the real world. The hope is that as students begin asking about the…

  10. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented. PMID:11541312

  11. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented.

  12. A Study of the Earth: "Everything Comes from Our Natural Resources." Teacher's Helper Packet.

    ERIC Educational Resources Information Center

    Mineral Information Inst., Denver, CO.

    This instructional information packet had been prepared to help teachers plan lessons and activities related to natural resources. It contains posters, activity sheets, teacher guides, student pages, background and study sheets, video and reading lists, free video offers, and sources for more information. (JRH)

  13. SCDC Spanish Curricula Units. Fine Arts, Unit 4, Grade 2, Supplements & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    The supplement and ditto packet to the unit four fine arts strand for second graders contains visual materials to aid the teacher in carrying out the instructional and assessment activities of this strand. Seatwork for individual students is featured along with materials intended for class participation activities. Illustrations, provided to help…

  14. SCDC Spanish Curricula Units. Language Arts, Unit 6, Grade 2, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    The supplement and ditto packet for the unit six language arts strand for second graders features visual aids to help carry out the activities described in the teacher's guide. Visuals based on the stories are used to help stimulate oral language and conceptual development along with class participation activities and written work. Other materials…

  15. SCDC Spanish Curricula Units. Fine Arts Strand, Unit 9, Grade 3, Supplement & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    The supplement and ditto packet to the fine arts strand of unit nine for third graders contains illustrations, ditto masters, and four songbooks to help the teacher carry out the fine arts activities of this unit. Materials for both group activities and seatwork are included. Kit 33 uses the songbook "Canciones de Aqui y de Alla" and studies the…

  16. Women's History Curriculum Resource Packet.

    ERIC Educational Resources Information Center

    Vermont State Dept. of Education, Montpelier.

    These resources, designed for recognizing Women's History Week in Vermont elementary and secondary classrooms, are suitable for use nationwide. Oral history materials include recommended strategies for conducting oral history projects, a list of general interview questions, sample questionnaires for interviews concerning women's work and immigrant…

  17. Energy-saving scheme based on downstream packet scheduling in ethernet passive optical networks

    NASA Astrophysics Data System (ADS)

    Zhang, Lincong; Liu, Yejun; Guo, Lei; Gong, Xiaoxue

    2013-03-01

    With increasing network sizes, the energy consumption of Passive Optical Networks (PONs) has grown significantly. Therefore, it is important to design effective energy-saving schemes in PONs. Generally, energy-saving schemes have focused on sleeping the low-loaded Optical Network Units (ONUs), which tends to bring large packet delays. Further, the traditional ONU sleep modes are not capable of sleeping the transmitter and receiver independently, though they are not required to transmit or receive packets. Clearly, this approach contributes to wasted energy. Thus, in this paper, we propose an Energy-Saving scheme that is based on downstream Packet Scheduling (ESPS) in Ethernet PON (EPON). First, we design both an algorithm and a rule for downstream packet scheduling at the inter- and intra-ONU levels, respectively, to reduce the downstream packet delay. After that, we propose a hybrid sleep mode that contains not only ONU deep sleep mode but also independent sleep modes for the transmitter and the receiver. This ensures that the energy consumed by the ONUs is minimal. To realize the hybrid sleep mode, a modified GATE control message is designed that involves 10 time points for sleep processes. In ESPS, the 10 time points are calculated according to the allocated bandwidths in both the upstream and the downstream. The simulation results show that ESPS outperforms traditional Upstream Centric Scheduling (UCS) scheme in terms of energy consumption and the average delay for both real-time and non-real-time packets downstream. The simulation results also show that the average energy consumption of each ONU in larger-sized networks is less than that in smaller-sized networks; hence, our ESPS is better suited for larger-sized networks.

  18. On the fly all-optical packet switching based on hybrid WDM/OCDMA labeling scheme

    NASA Astrophysics Data System (ADS)

    Brahmi, Houssem; Giannoulis, Giannis; Menif, Mourad; Katopodis, Vasilis; Kalavrouziotis, Dimitrios; Kouloumentas, Christos; Groumas, Panos; Kanakis, Giannis; Stamatiadis, Christos; Avramopoulos, Hercules; Erasme, Didier

    2014-02-01

    We introduce a novel design of an all-optical packet routing node that allows for the selection and forwarding of optical packets based on the routing information contained in hybrid wavelength division multiplexing/optical code division multiple access (WDM/OCDMA) labels. A stripping paradigm of optical code-label is adopted. The router is built around an optical-code gate that consists in an optical flip-flop controlled by two fiber Bragg grating correlators and is combined with a Mach-Zehnder interferometer (MZI)-based forwarding gate. We experimentally verify the proof-of-principle operation of the proposed self-routing node under NRZ and OCDMA packet traffic conditions. The successful switching of elastic NRZ payload at 40 Gb/s controlled by DS-OCDMA coded labels and the forwarding operation of encoded data using EQC codes are presented. Proper auto-correlation functions are obtained with higher than 8.1 dB contrast ratio, suitable to efficiently trigger the latching device with a contrast ratio of 11.6 dB and switching times below 3.8 ns. Error-free operation is achieved with 1.5 dB penalty for 40 Gb/s NRZ data and with 2.1 dB penalty for DS-OCDMA packets. The scheme can further be applied to large-scale optical packet switching networks by exploiting efficient optical coders allocated at different WDM channels.

  19. A novel timestamp based adaptive clock method for circuit emulation service over packet network

    NASA Astrophysics Data System (ADS)

    Dai, Jin-you; Yu, Shao-hua

    2007-11-01

    It is necessary to transport TDM (time division multiplexing) over packet network such as IP and Ethernet, and synchronization is a problem when carrying TDM over the packet network. Clock methods for TDM over packet network are introduced. A new adaptive clock method is presented. The method is a kind of timestamp based adaptive method, but no timestamp needs transporting over packet network. By using the local oscillator and a counter, the timestamp information (local timestamp) related to the service clock of the remote PE (provide edge) and the near PE can be attained. By using D-EWMA filter algorithm, the noise caused by packet network can be filtered and the useful timestamp can be extracted out. With the timestamp and a voltage-controlled oscillator, clock frequency of near PE can be adjusted the same as clock frequency of the remote PE. A kind of simulation device is designed and a test network topology is set up to test and verify the method. The experiment result shows that synthetical performance of the new method is better than ordinary buffer based method and ordinary timestamp based method.

  20. Effect of Coulomb interaction on multi-electronwave packet dynamics

    SciTech Connect

    Shiokawa, T.; Takada, Y.; Konabe, S.; Hatsugai, Y.; Muraguchi, M.; Endoh, T.; Shiraishi, K.

    2013-12-04

    We have investigated the effect of Coulomb interaction on electron transport in a one-dimensional nanoscale structure using a multi-electron wave packet approach. To study the time evolution, we numerically solve the time-dependent Hartree-Fock equation, finding that the electron wave packet dynamics strongly depends on the Coulomb interaction strength. When the Coulomb interaction is large, each electron wave packet moves separately in the presence of an electric field. With weak Coulomb interaction, however, the electron wave packets overlap, forming and moving as one collective wave packet.

  1. Observer-based H(infinity) control for networked nonlinear systems with random packet losses.

    PubMed

    Li, Jian Guo; Yuan, Jing Qi; Lu, Jun Guo

    2010-01-01

    This paper investigates the observer-based H(infinity) control problem of networked nonlinear systems with global Lipschitz nonlinearities and random communication packet losses. The random packet loss is modelled as a Bernoulli distributed white sequence with a known conditional probability distribution. In the presence of random packet losses, sufficient conditions for the existence of an observer-based feedback controller are derived, such that the closed-loop networked nonlinear system is exponentially stable in the mean-square sense, and a prescribed H(infinity) disturbance-rejection-attenuation performance is also achieved. Then a linear matrix inequality (LMI) approach for designing such an observer-based H(infinity) controller is presented. Finally, a simulation example is used to demonstrate the effectiveness of the proposed method.

  2. A Guide to Microsoft Active Directory (AD) Design

    SciTech Connect

    Dias, J

    2002-04-29

    The goal of this paper is to facilitate the design process for those DOE sites that are currently engaged in designing their Active Directory (AD) network. It is a roadmap to enable analysis of the complicated design tradeoffs associated with Active Directory Design. By providing discussion of Active Directory design elements which are permanent and costly to change once deployed, the hope is to minimize the risks of sponsoring failed designs, or joining existing infrastructures not suitable to programmatic needs. Specifically, most Active Directory structures will fall under one of three common designs: Single Domain, Single Forest with Multiple Domains, or Multiple Forests. Each has benefits and concerns, depending on programmatic and organizational structures. The comparison of these three approaches will facilitate almost any Active Directory design effort. Finally, this paper describes some best practices to consider when designing Active Directory based on three years of research and experience.

  3. Spin Models for Packet Routing Control in Computer Networks

    NASA Astrophysics Data System (ADS)

    Horiguchi, T.

    We investigate packet flow in computer networks within the framework of statistical physics by using numerical simulations. As mathematical models for packet routing, we present a spin model with lattice gas spins and the one with Ising spins. Then we propose dynamic programming for optimal routing control of packet flow by using the two spin models. This is a kind of goal-directed learning for taking into account of time-dependent environment for the packets. Next we investigate a congestion problem by using the model with lattice gas spins when the packets are not sent to nodes at which their buffers are already full up with packets. Since we have found serious congestion in the packet flow, we then propose reinforcement learning for avoiding the congestion and have performed simulations on several networks including small world networks, scale free networks and so on.

  4. Job Discrimination. A Curriculum Packet about Immigration-Related Job Discrimination.

    ERIC Educational Resources Information Center

    Nash, Andrea; Wright, Peggy

    A curriculum packet is presented that is designed to give English-as-a-Second-Language (ESL) teachers the information and tools they need to help students address the issue of job discrimination, especially discrimination based on citizenship status or national origin that may result from the employer verification requirement of the Immigration…

  5. Are the Ideas of Learning Kejar Packet A of Indonesia Still Valid?

    ERIC Educational Resources Information Center

    Napitupulu, Washington P.

    Introduced in Indonesia in 1977, the Learning Kejar Packet A (LKPA) is an educational program for low-literate people and primary school dropouts. The 20-year-old program is still flourishing, but are its ideas still valid and what are the secrets of its longevity? The first reason probably lies in the contents and design of the learning materials…

  6. Ecologia: Spanish Ecology Packet Resource Units and Materials for Intermediate and Advanced Spanish Classes.

    ERIC Educational Resources Information Center

    Bell, Mozelle Sawyer; Arribas, E. Jaime

    This Spanish ecology packet contains resource units and materials for intermediate and advanced Spanish classes. It is designed to be used for individual and small-group instruction in the senior high school to supplement the Spanish language curriculum. Included are articles, pictures, and cartoons from Spanish-language newspapers and magazines…

  7. A Teacher's Ready-to-Use Packet of General Business Subjects Crossword Puzzles.

    ERIC Educational Resources Information Center

    Yacyk, Peter

    Eleven crossword puzzles, designed to give the student practice with the correct spelling and usage of those words needed to indicate his mastery of the concepts and understandings taught in business courses, are contained, with answer keys, in a teacher's packet. Any puzzle can be reproduced by ditto or by transparency for classroom use. There is…

  8. Characteristics of the High Performance Real Estate Salesperson. Teachers Instructional Packet, TIP No. 12, Spring 1987.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Texas Real Estate Research Center.

    Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand the characteristics of Texas real estate salespersons based on a 1983 state survey. First, questions for class discussion are presented, followed by a summary presentation on the survey findings,…

  9. SCDC Spanish Curricula Units. Science/Math Strand, Unit 4, Grade 2, Supplements & Ditto Packet.

    ERIC Educational Resources Information Center

    Spanish Curricula Development Center, Miami Beach, FL.

    Designed for use with unit four of the science/math strand for second graders, the supplement and ditto packet contain visuals, worksheets, and instructional aids referred to in the teacher's guide corresponding to this unit. The brief introductions to kits 13-16 are written in both English and Spanish; all classroom materials for students are in…

  10. Constitutional and Non-Constitutional Governments...Similarities and Differences throughout History. Resource Packet.

    ERIC Educational Resources Information Center

    Pallasch, Brian Thomas

    This civic education resource packet is designed to provide teachers, community leaders, and other civic educators with an understanding of the differences between constitutional and non-constitutional governments. Six papers discussing the topic are included: "The Differences bewteen Constitutional and Non-Constitutional Governments" (John…

  11. Issues and Images: New Yorkers during the Thirties. A Teaching Packet of Historical Documents.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Cultural Education Center.

    Derived from an exhibit produced cooperatively by the New York State Archives and the New York State Museum for the Franklin D. Roosevelt Centennial, and designed to provide secondary students with first-hand exposure to New York during the Great Depression, this packet contains a teacher's guide and 22 facsimile documents, including historic…

  12. Tools and Techniques for Simplifying the Analysis of Captured Packet Data

    ERIC Educational Resources Information Center

    Cavaiani, Thomas P.

    2008-01-01

    Students acquire an understanding of the differences between TCP and UDP (connection-oriented vs. connection-less) data transfers as they analyze network packet data collected during one of a series of labs designed for an introductory network essentials course taught at Boise State University. The learning emphasis of the lab is not on the…

  13. Negotiating an Oil and Gas Lease. Teachers Instructional Packet, TIP No. 6, Spring 1985.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Texas Real Estate Research Center.

    Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand the more common provisions and the legal significance of an oil and gas lease, as well as some provisions landowners may wish to insert for personal benefit and protection. Following an evaluation…

  14. Wavelet packet entropy for heart murmurs classification.

    PubMed

    Safara, Fatemeh; Doraisamy, Shyamala; Azman, Azreen; Jantan, Azrul; Ranga, Sri

    2012-01-01

    Heart murmurs are the first signs of cardiac valve disorders. Several studies have been conducted in recent years to automatically differentiate normal heart sounds, from heart sounds with murmurs using various types of audio features. Entropy was successfully used as a feature to distinguish different heart sounds. In this paper, new entropy was introduced to analyze heart sounds and the feasibility of using this entropy in classification of five types of heart sounds and murmurs was shown. The entropy was previously introduced to analyze mammograms. Four common murmurs were considered including aortic regurgitation, mitral regurgitation, aortic stenosis, and mitral stenosis. Wavelet packet transform was employed for heart sound analysis, and the entropy was calculated for deriving feature vectors. Five types of classification were performed to evaluate the discriminatory power of the generated features. The best results were achieved by BayesNet with 96.94% accuracy. The promising results substantiate the effectiveness of the proposed wavelet packet entropy for heart sounds classification.

  15. A packet switched communications system for GRO

    NASA Astrophysics Data System (ADS)

    Husain, Shabu; Yang, Wen-Hsing; Vadlamudi, Rani; Valenti, Joseph

    1993-11-01

    This paper describes the packet switched Instrumenters Communication System (ICS) that was developed for the Command Management Facility at GSFC to support the Gamma Ray Observatory (GRO) spacecraft. The GRO ICS serves as a vital science data acquisition link to the GRO scientists to initiate commands for their spacecraft instruments. The system is ready to send and receive messages at any time, 24 hours a day and seven days a week. The system is based on X.25 and the International Standard Organization's (ISO) 7-layer Open Systems Interconnection (OSI) protocol model and has client and server components. The components of the GRO ICS are discussed along with how the Communications Subsystem for Interconnection (CSFI) and Network Control Program Packet Switching Interface (NPSI) software are used in the system.

  16. Steering attosecond electron wave packets with light.

    PubMed

    Kienberger, R; Hentschel, M; Uiberacker, M; Spielmann, Ch; Kitzler, M; Scrinzi, A; Wieland, M; Westerwalbesloh, Th; Kleineberg, U; Heinzmann, U; Drescher, M; Krausz, F

    2002-08-16

    Photoelectrons excited by extreme ultraviolet or x-ray photons in the presence of a strong laser field generally suffer a spread of their energies due to the absorption and emission of laser photons. We demonstrate that if the emitted electron wave packet is temporally confined to a small fraction of the oscillation period of the interacting light wave, its energy spectrum can be up- or downshifted by many times the laser photon energy without substantial broadening. The light wave can accelerate or decelerate the electron's drift velocity, i.e., steer the electron wave packet like a classical particle. This capability strictly relies on a sub-femtosecond duration of the ionizing x-ray pulse and on its timing to the phase of the light wave with a similar accuracy, offering a simple and potentially single-shot diagnostic tool for attosecond pump-probe spectroscopy.

  17. Particlelike wave packets in complex scattering systems

    NASA Astrophysics Data System (ADS)

    Gérardin, Benoît; Laurent, Jérôme; Ambichl, Philipp; Prada, Claire; Rotter, Stefan; Aubry, Alexandre

    2016-07-01

    A wave packet undergoes a strong spatial and temporal dispersion while propagating through a complex medium. This wave scattering is often seen as a nightmare in wave physics whether it be for focusing, imaging, or communication purposes. Controlling wave propagation through complex systems is thus of fundamental interest in many areas, ranging from optics or acoustics to medical imaging or telecommunications. Here, we study the propagation of elastic waves in a cavity and a disordered waveguide by means of laser interferometry. From the direct experimental access to the time-delay matrix of these systems, we demonstrate the existence of particlelike wave packets that remain focused in time and space throughout their complex trajectory. Due to their limited dispersion, their selective excitation will be crucially relevant for all applications involving selective wave focusing and efficient information transfer through complex media.

  18. A Packet Loss Concealment Algorithm Robust to Burst Packet Loss Using Multiple Codebooks and Comfort Noise for CELP-Type Speech Coders

    NASA Astrophysics Data System (ADS)

    Park, Nam In; Kim, Hong Kook; Jung, Min A.; Lee, Seong Ro; Choi, Seung Ho

    In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed to improve the quality of decoded speech under burst packet loss. A conventional PLC algorithm is usually based on speech correlation to reconstruct decoded speech of lost frames by using the information on the parameters obtained from the previous frames that are assumed to be correctly received. However, this approach is apt to fail to reconstruct voice onset signals since the parameters such as pitch, LPC coefficient, and adaptive/fixed codebooks of the previous frames are almost related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook based approach which includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm employed in G.729 by means of perceptual evaluation of speech quality (PESQ), a waveform comparison, and an A-B preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC of G.729, especially under burst packet loss and voice onset conditions.

  19. Teleportation of nonclassical wave packets of light.

    PubMed

    Lee, Noriyuki; Benichi, Hugo; Takeno, Yuishi; Takeda, Shuntaro; Webb, James; Huntington, Elanor; Furusawa, Akira

    2011-04-15

    We report on the experimental quantum teleportation of strongly nonclassical wave packets of light. To perform this full quantum operation while preserving and retrieving the fragile nonclassicality of the input state, we have developed a broadband, zero-dispersion teleportation apparatus that works in conjunction with time-resolved state preparation equipment. Our approach brings within experimental reach a whole new set of hybrid protocols involving discrete- and continuous-variable techniques in quantum information processing for optical sciences.

  20. The First Structure–Activity Relationship Studies for Designer Receptors Exclusively Activated by Designer Drugs

    PubMed Central

    2016-01-01

    Over the past decade, two independent technologies have emerged and been widely adopted by the neuroscience community for remotely controlling neuronal activity: optogenetics which utilize engineered channelrhodopsin and other opsins, and chemogenetics which utilize engineered G protein-coupled receptors (Designer Receptors Exclusively Activated by Designer Drugs (DREADDs)) and other orthologous ligand–receptor pairs. Using directed molecular evolution, two types of DREADDs derived from human muscarinic acetylcholine receptors have been developed: hM3Dq which activates neuronal firing, and hM4Di which inhibits neuronal firing. Importantly, these DREADDs were not activated by the native ligand acetylcholine (ACh), but selectively activated by clozapine N-oxide (CNO), a pharmacologically inert ligand. CNO has been used extensively in rodent models to activate DREADDs, and although CNO is not subject to significant metabolic transformation in mice, a small fraction of CNO is apparently metabolized to clozapine in humans and guinea pigs, lessening the translational potential of DREADDs. To effectively translate the DREADD technology, the next generation of DREADD agonists are needed and a thorough understanding of structure–activity relationships (SARs) of DREADDs is required for developing such ligands. We therefore conducted the first SAR studies of hM3Dq. We explored multiple regions of the scaffold represented by CNO, identified interesting SAR trends, and discovered several compounds that are very potent hM3Dq agonists but do not activate the native human M3 receptor (hM3). We also discovered that the approved drug perlapine is a novel hM3Dq agonist with >10 000-fold selectivity for hM3Dq over hM3. PMID:25587888

  1. Packet theory of conditioning and timing.

    PubMed

    Kirkpatrick, Kimberly

    2002-04-28

    Packet theory is based on the assumption that the momentary probability of producing a bout or packet of responding is controlled by the conditional expected time function. Bouts of head entry responses of rats into a food cup appear to have the same characteristics across a range of conditions. The conditional expected time function is the mean expected time remaining until the next food delivery as a function of time since an event such as food or stimulus onset. The conditional expected time function encodes mean interval duration as well as the distribution form so that both the mean response rate and form of responding in time can be predicted. Simulations of Packet theory produced accurate quantitative predictions of: (1) the effect of reinforcement density (mean food-food interval) and distribution form on responding; (2) scalar variance in fixed interval responding; (3) CS-US and intertrial interval effects on the strength of conditioning; and (4) the effect of the ratio of cycle:trial time on the strength of conditioning.

  2. BAG (Continuous Round Robin Packet Capture)

    SciTech Connect

    Wood, C. Philip

    2006-03-10

    Bag is a miniature pcap filter which takes pcap input (or input off the wire) using a bpf filter, if specified, and then writes the output to stdout or a file (in pcap format). It depends for some aspects of its functionality on a libpcap library which uses a shared memory packet capture ring bugger. There are two build in modules: chcksum and session. the build in chcksum modules is used to anonymize the ip addresses and repair any checksums in the stream. % bag -r /tmp/*.pcap -Cchucksum, 128.1 65: 10.10 The session module generates sessions which are defined as a series of packets that have two things in common. the first is a unique five-tuple composed oi an IP protocol, IP source address, IP source port, IP destination address, and IP destination port. The second is that if the originating packet is associated with a bi-directional service such as ftpltcp, characteristics and data will be kept for both flows involved with the service. The only protocols evaluated beyond the IP header are ICMP, TCP and UDP. A session can last for as long as bag is running. However, under normal conditions, sessions are generated every time they appear to have closed down. There is a man page included with the distribution which goes into more detail.

  3. BAG (Continuous Round Robin Packet Capture)

    2006-03-10

    Bag is a miniature pcap filter which takes pcap input (or input off the wire) using a bpf filter, if specified, and then writes the output to stdout or a file (in pcap format). It depends for some aspects of its functionality on a libpcap library which uses a shared memory packet capture ring bugger. There are two build in modules: chcksum and session. the build in chcksum modules is used to anonymize the ipmore » addresses and repair any checksums in the stream. % bag -r /tmp/*.pcap -Cchucksum, 128.1 65: 10.10 The session module generates sessions which are defined as a series of packets that have two things in common. the first is a unique five-tuple composed oi an IP protocol, IP source address, IP source port, IP destination address, and IP destination port. The second is that if the originating packet is associated with a bi-directional service such as ftpltcp, characteristics and data will be kept for both flows involved with the service. The only protocols evaluated beyond the IP header are ICMP, TCP and UDP. A session can last for as long as bag is running. However, under normal conditions, sessions are generated every time they appear to have closed down. There is a man page included with the distribution which goes into more detail.« less

  4. Resilient packet ring media access protocol

    NASA Astrophysics Data System (ADS)

    Thepot, Frederic

    2001-07-01

    The discussion will cover the new initiative to create a new MAC layer standard for resilient packet rings: IEEE 802.17 RPR. The key aspects of the presentation will include a preliminary address of the Metro Area Network today and the current networking technologies such as SONET/SDH which are not optimized to carry IP traffic over Metro MAN. The next segment will cover the options which could change the traditional and expensive layered networking model, and address the real benefits of marrying several technologies like Ethernet, SONET/SDH and IP into one technology. The next part of the discussion will detail the technical advantages a new MAC will bring to the services providers. Lastly a summary of the view and strategy about the acceptance and deployment of this new technology in the next 12 months, specifically, now one defines and develops standards for a Resilient Packet Ring Access Protocol for use in Local, Metropolitan, and Wide Area Networks for transfer of data packets at rates scalable to multiple gigabits per second; specifically address the data transmission requirements of carriers that have present and planned fiber optic physical infrastructure in a ring topology; and, defining and developing detailed specifications for using existing and/or new physical layers at appropriate data rates that will support transmission of this access protocol.

  5. This Is Challenger Center...Changing the Way Teachers Teach and Students Learn. [Information Packet].

    ERIC Educational Resources Information Center

    Challenger Center for Space Science Education, Alexandria, VA.

    The Challenger Center for Space Science Education is a not-for-profit educational organization founded in 1986 following the Challenger 51-L space shuttle tragedy. This packet contains a variety of separate sheets and brochures providing information about the activities of the Challenger Center. Challenger Learning Centers provide hands-on,…

  6. Learning Packet in Social Studies (8th Grade) for ESOL Students.

    ERIC Educational Resources Information Center

    Clemons, Jacquelyn; And Others

    The learning packet is intended to provide the eighth grade social studies teacher with supplemental material for teaching beginning and intermediate students of English as a second language. It contains a variety of activities to assist in developing the student's vocabulary skills, reading comprehension, writing skills, and a working knowledge…

  7. Transitions: Turning Risks into Opportunities for Student Support. An Introductory Packet.

    ERIC Educational Resources Information Center

    California Univ., Los Angeles. Center for Mental Health in Schools.

    This Introductory Packet provides readings and related activities on support for transitions to address barriers to student learning covering both research and best practices. It explores why transitions are dangerous opportunities that can disrupt or promote development. Key transitions and related intervention strategies are presented for…

  8. A GA-based PID active queue management control design for TCP/IP networks

    NASA Astrophysics Data System (ADS)

    Kuo, H.-H.; Chen, C.-K.; Yan, J.-J.; Liao, T.-L.

    2008-02-01

    In this paper, a genetic algorithm-based (GA-based) proportional-integral-derivative (PID) controller as an active queue manager for Internet routers is proposed to reduce packet loss and improve network utilization in TCP/IP networks. Based on the window-based nonlinear dynamics, the TCP network was modeled as a time-delayed system with a saturated input due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks. An improved genetic algorithm is employed to derive optimal or near optimal PID control gains such that a performance index of integrated-absolute error (IAE) in terms of the error between the router queue length and the desired queue length is minimized. The performance of the proposed control scheme was evaluated in various network scenarios via a series of numerical simulations. The simulation results confirm that the proposed scheme outperforms other AQM schemes.

  9. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  10. An RC active filter design handbook

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.

    1977-01-01

    The design of filters is described. Emphasis is placed on simplified procedures that can be used by the reader who has minimum knowledge about circuit design and little acquaintance with filter theory. The handbook has three main parts. The first part is a review of some information that is essential for work with filters. The second part includes design information for specific types of filter circuitry and describes simple procedures for obtaining the component values for a filter that will have a desired set of characteristics. Pertinent information relating to actual performance is given. The third part (appendix) is a review of certain topics in filter theory and is intended to provide some basic understanding of how filters are designed.

  11. Microwave Ionization of an Atomic Electron Wave Packet

    SciTech Connect

    Noel, Michael W.; Ko, Lung; Gallagher, T. F.

    2001-07-23

    A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization.

  12. Lambda network having 2.sup.m-1 nodes in each of m stages with each node coupled to four other nodes for bidirectional routing of data packets between nodes

    DOEpatents

    Napolitano, Jr., Leonard M.

    1995-01-01

    The Lambda network is a single stage, packet-switched interprocessor communication network for a distributed memory, parallel processor computer. Its design arises from the desired network characteristics of minimizing mean and maximum packet transfer time, local routing, expandability, deadlock avoidance, and fault tolerance. The network is based on fixed degree nodes and has mean and maximum packet transfer distances where n is the number of processors. The routing method is detailed, as are methods for expandability, deadlock avoidance, and fault tolerance.

  13. Development of optical packet and circuit integrated ring network testbed.

    PubMed

    Furukawa, Hideaki; Harai, Hiroaki; Miyazawa, Takaya; Shinada, Satoshi; Kawasaki, Wataru; Wada, Naoya

    2011-12-12

    We developed novel integrated optical packet and circuit switch-node equipment. Compared with our previous equipment, a polarization-independent 4 × 4 semiconductor optical amplifier switch subsystem, gain-controlled optical amplifiers, and one 100 Gbps optical packet transponder and seven 10 Gbps optical path transponders with 10 Gigabit Ethernet (10GbE) client-interfaces were newly installed in the present system. The switch and amplifiers can provide more stable operation without equipment adjustments for the frequent polarization-rotations and dynamic packet-rate changes of optical packets. We constructed an optical packet and circuit integrated ring network testbed consisting of two switch nodes for accelerating network development, and we demonstrated 66 km fiber transmission and switching operation of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10GbE frames. Error-free (frame error rate < 1×10(-4)) operation was achieved with optical packets of various packet lengths and packet rates, and stable operation of the network testbed was confirmed. In addition, 4K uncompressed video streaming over OPS links was successfully demonstrated.

  14. Comparison of all optical forwarding packet architectures

    NASA Astrophysics Data System (ADS)

    Farhat, Rim; Farhat, Amel; Menif, Mourad

    2016-04-01

    In this paper two all optical packet forwarding architectures based on non linear effect in semiconductor optical amplifier in Mach-Zehnder configuration SOA-MZI are studied. The first architecture consist in combing flip flop functionality with the AND logic functionality in the same unit. Error free operation at 40 Gbps for two cascaded nodes is achieved. In the second architecture two separated units namely the flip flop and the AND logic gate are used. 100 Gbps bit rate is reached. At 40 Gbps error free operation is achieved for three cascaded nodes.

  15. Audio-Visual/Communications Teaching Aids Packet. Supplementary Materials. Packet P-8.

    ERIC Educational Resources Information Center

    Peace Corps, Washington, DC. Information Collection and Exchange Div.

    This packet contains three handouts on training theory and the use of audiovisual aids, as well as a section on materials and presentation techniques for use by community development workers concerned with exchanging information and working with the people in a community. The first handout, "Communication in Development," briefly discusses the…

  16. Computer Aided Design: Instructional Manual. The North Dakota High Technology Mobile Laboratory Project.

    ERIC Educational Resources Information Center

    Cheng, Wan-Lee

    This instructional manual contains 12 learning activity packets for use in a workshop in computer-aided design and drafting (CADD). The lessons cover the following topics: introduction to computer graphics and computer-aided design/drafting; coordinate systems; advance space graphics hardware configuration and basic features of the IBM PC…

  17. Metamorphic Mountain: Mount Jefferson State Park. An Environmental Education Learning Experience Designed for Grades 5-7.

    ERIC Educational Resources Information Center

    Pittman, George K., II

    This activity packet was designed to introduce students in grades 5-7 to the geology of the Blue Ridge Mountains through hands-on activities for the classroom and the outdoor setting of Mount Jefferson State Park (Jefferson, North Carolina). Previsit activities introduce students to the different rock types: sedimentary, igneous, and metamorphic.…

  18. Designing Technology Activities that Teach Mathematics

    ERIC Educational Resources Information Center

    Silk, Eli M.; Higashi, Ross; Shoop, Robin; Schunn, Christian D.

    2010-01-01

    Over the past three years, the authors have conducted research in middle and high school classrooms in an effort to improve the effectiveness of robotics to teach science, technology, engineering, and mathematics (STEM) education--their focus has been on math. The authors have found that subtle changes in the design and setup of the lesson make a…

  19. Human Spaceflight: Activities for the Intermediate and Junior High Student.

    ERIC Educational Resources Information Center

    Hartsfield, John W.; Hartsfield, Kendra J.

    Since its beginning, space science has created high interest and continues to prod the imagination of students. This activity packet, which has been designed to enhance the curriculum and challenge gifted students, contains background information on spaceflight as well as 24 interdisciplinary classroom activities, 3 crossword puzzles, and 3 word…

  20. Exact Results for `Bouncing' Gaussian Wave Packets

    NASA Astrophysics Data System (ADS)

    Belloni, M.; Doncheski, M. A.; Robinett, R. W.

    2005-01-01

    We consider time-dependent Gaussian wave packet solutions of the Schrödinger equation, with arbitrary initial central position, x0, and momentum, p0, for an otherwise free particle, but with an infinite wall at x = 0, so-called bouncing wave packets. We show how difference or mirror solutions of the form ψ(x,t) - ψ(-x,t) can, in this case, be normalized exactly, allowing for the evaluation of a number of time-dependent expectation values and other quantities in closed form. For example, we calculate langp2rangt explicitly which illustrates how the free-particle kinetic (and hence total energy) is affected by the presence of the distant boundary. We also discuss the time dependence of the expectation values of position, langxrangt, and momentum, langprangt, and their relation to the impulsive force during the `collision' with the wall. Finally, the x0, p0 → 0 limit is shown to reduce a special case of a non-standard free-particle Gaussian solution. The addition of this example to the literature then expands of the relatively small number of Gaussian solutions to quantum mechanical problems with familiar classical analogs (free particle, uniform acceleration, harmonic oscillator, unstable oscillator, and uniform magnetic field) available in closed form.

  1. Per-packet reservation MAC protocols

    NASA Astrophysics Data System (ADS)

    Hrasnica, Halid

    2006-10-01

    Recent and future communications networks have to provide QoS guarantees for a rapidly growing number of various telecommunications services. Therefore, various communications systems, such as wireless and fixed access networks, apply reservation MAC protocols, providing a good network utilization, which is particularly important access networks with typically limited data rates, and ensuring realization of different QoS guarantees for various telecommunications services. This is important because of a hard competition among communications technologies applied in the access area. The considered MAC protocols apply a per-packet reservation method to avoid the transmission gaps caused by per-burst reservation, and accordingly to achieve a better network utilization. However, the per-packet reservation increases the network load caused by the signaling, which calls for an efficient resource sharing strategy in the signaling channel. There are two basic solutions for capacity sharing in the signaling channel: random access, usually using slotted ALOHA, and dedicated access, realized by a polling method. Performance improvement of basic protocols can be carried out in different ways; by protocol extensions, a combination of different protocol solutions, and the application of adaptive protocols providing a change of access parameters according to the current network status. The best network performance is achieved by application of two-step reservation protocol, which combined with additional features, such as appropriate signaling procedure, priority and fairness mechanisms, and combined reservation domains, can fulfill requirements of services with high QoS demands.

  2. Teacher Educators' Design and Implementation of Group Learning Activities

    ERIC Educational Resources Information Center

    De Hei, Miranda S. A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, Jan-Willem

    2016-01-01

    The aim of this study was to describe how teacher educators design and implement group learning activities (GLAs). We used the Group Learning Activities Instructional Design (GLAID) framework to analyse their descriptions. The GLAID framework includes eight components: (1) interaction, (2) learning objectives and outcomes, (3) assessment, (4) task…

  3. Extravehicular activities guidelines and design criteria

    NASA Technical Reports Server (NTRS)

    Brown, N. E.; Dashner, T. R.; Hayes, B. C.

    1973-01-01

    A listing of astronaut EVA support systems and equipment, and the physical, operational, and performance characteristics of each major system are presented. An overview of the major ground based support operations necessary in the development and verification of orbital EVA systems is included. The performance and biomedical characteristics of man in the orbital EV environment are discussed. Major factors affecting astronaut EV work performance are identified and delineated as they relate to EV support systems design. Data concerning the medical and physiological aspects of spaceflight on man are included. The document concludes with an extensive bibliography, and a series of appendices which expand on some of the information presented in the main body.

  4. Responding to Crisis at a School. A Resource Aid Packet.

    ERIC Educational Resources Information Center

    California Univ., Los Angeles. Center for Mental Health Schools.

    Schools are increasingly confronted with crisis events. This resource aid packet provides materials to facilitate planning and implementation of a school-based crisis response and related staff training. The packet is divided into four sections. The first offers a brief overview that can be shared with school staff to raise awareness about the…

  5. Continuing Development of California State Packet Radio Project.

    ERIC Educational Resources Information Center

    Brownrigg, Edwin

    1992-01-01

    Provides background on the California State Library Packet Radio project, which will use packet radios to deploy a wireless, high-speed, wide-area network of 600 nodes, including 100 libraries, in the San Francisco Bay Area. Project goals and objectives, plan of operation, equipment, and evaluation plans are summarized. (MES)

  6. Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Christenson, R. L.; Whitley, M. R.; Knight, K. C.

    2000-01-01

    This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

  7. The ESA standard for telemetry and telecommand packet utilisation: PUS

    NASA Technical Reports Server (NTRS)

    Kaufeler, Jean-Francois

    1994-01-01

    ESA has developed standards for packet telemetry and telecommand, which are derived from the recommendations of the Inter-Agency Consultative Committee for Space Data Systems (CCSDS). These standards are now mandatory for future ESA programs as well as for many programs currently under development. However, while these packet standards address the end-to-end transfer of telemetry and telecommand data between applications on the ground and Application Processes on-board, they leave open the internal structure or content of the packets. This paper presents the ESA Packet Utilization Standard (PUS) which addresses this very subject and, as such, serves to extend and complement the ESA packet standards. The goal of the PUS is to be applicable to future ESA missions in all application areas (Telecommunications, Science, Earth Resources, microgravity, etc.). The production of the PUS falls under the responsibility of the ESA Committee for Operations and EGSE Standards (COES).

  8. Theory for low-frequency modulated Langmuir wave packets

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.; Robinson, P. A.

    1992-01-01

    Langmuir wave packets with low frequency modulations (or beats) observed in the Jovian foreshock are argued to be direct evidence for the Langmuir wave decay L yields L-prime + S. In this decay, 'pump' Langmuir waves L, driven by an electron beam, produce backscattered product Langmuir waves L-prime and ion sound waves S. The L and L-prime waves beat at the frequency and wavevector of the S waves, thereby modulating the wave packets. Beam speeds calculated using the modulated Jovian wave packets (1) are reasonable, at 4-10 times the electron thermal speed, (2) are consistent with theoretical limits on the decay process, and (3) decrease with increasing foreshock depth, as expected theoretically. These results strongly support the theory. The modulation depth of some wave packets suggests saturation by the decay L yields L-prime + S. Applications to modulated Langmuir packets in the Venusian and terrestrial foreshocks and in a type III radio source are proposed.

  9. Design for learning: deconstructing virtual patient activities.

    PubMed

    Ellaway, Rachel H; Davies, David

    2011-01-01

    Digital technologies are used in almost every aspect of contemporary health professional education (HPE) but our understanding of their true potential as instructional tools rather than administrative tools has not significantly advanced in the last decade. One notable exception to this has been the rise of the 'virtual patient' as an educational intervention in HPE. This article attempts to deconstruct the virtual patient concept by developing a model of virtual patients as artifacts with intrinsic encoded properties and emergent constructed properties that build on the core concept of 'activity'.

  10. 40-Gbps optical backbone network deep packet inspection based on FPGA

    NASA Astrophysics Data System (ADS)

    Zuo, Yuan; Huang, Zhiping; Su, Shaojing

    2014-11-01

    In the era of information, the big data, which contains huge information, brings about some problems, such as high speed transmission, storage and real-time analysis and process. As the important media for data transmission, the Internet is the significant part for big data processing research. With the large-scale usage of the Internet, the data streaming of network is increasing rapidly. The speed level in the main fiber optic communication of the present has reached 40Gbps, even 100Gbps, therefore data on the optical backbone network shows some features of massive data. Generally, data services are provided via IP packets on the optical backbone network, which is constituted with SDH (Synchronous Digital Hierarchy). Hence this method that IP packets are directly mapped into SDH payload is named POS (Packet over SDH) technology. Aiming at the problems of real time process of high speed massive data, this paper designs a process system platform based on ATCA for 40Gbps POS signal data stream recognition and packet content capture, which employs the FPGA as the CPU. This platform offers pre-processing of clustering algorithms, service traffic identification and data mining for the following big data storage and analysis with high efficiency. Also, the operational procedure is proposed in this paper. Four channels of 10Gbps POS signal decomposed by the analysis module, which chooses FPGA as the kernel, are inputted to the flow classification module and the pattern matching component based on TCAM. Based on the properties of the length of payload and net flows, buffer management is added to the platform to keep the key flow information. According to data stream analysis, DPI (deep packet inspection) and flow balance distribute, the signal is transmitted to the backend machine through the giga Ethernet ports on back board. Practice shows that the proposed platform is superior to the traditional applications based on ASIC and NP.

  11. Optimal active vibration absorber: Design and experimental results

    NASA Technical Reports Server (NTRS)

    Lee-Glauser, Gina; Juang, Jer-Nan; Sulla, Jeffrey L.

    1992-01-01

    An optimal active vibration absorber can provide guaranteed closed-loop stability and control for large flexible space structures with collocated sensors/actuators. The active vibration absorber is a second-order dynamic system which is designed to suppress any unwanted structural vibration. This can be designed with minimum knowledge of the controlled system. Two methods for optimizing the active vibration absorber parameters are illustrated: minimum resonant amplitude and frequency matched active controllers. The Controls-Structures Interaction Phase-1 Evolutionary Model at NASA LaRC is used to demonstrate the effectiveness of the active vibration absorber for vibration suppression. Performance is compared numerically and experimentally using acceleration feedback.

  12. Nondiffracting accelerating wave packets of Maxwell's equations.

    PubMed

    Kaminer, Ido; Bekenstein, Rivka; Nemirovsky, Jonathan; Segev, Mordechai

    2012-04-20

    We present the nondiffracting spatially accelerating solutions of the Maxwell equations. Such beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams to the full domain of the wave equation. For both TE and TM polarizations, the beams exhibit shape-preserving bending which can have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90°. We show that these accelerating beams are self-healing, analyze their properties, and find the new class of accelerating breathers: self-bending beams of periodically oscillating shapes. Finally, we emphasize that in their scalar form, these beams are the exact solutions for nondispersive accelerating wave packets of the most common wave equation describing time-harmonic waves. As such, this work has profound implications to many linear wave systems in nature, ranging from acoustic and elastic waves to surface waves in fluids and membranes. PMID:22680719

  13. Nondiffracting accelerating wave packets of Maxwell's equations.

    PubMed

    Kaminer, Ido; Bekenstein, Rivka; Nemirovsky, Jonathan; Segev, Mordechai

    2012-04-20

    We present the nondiffracting spatially accelerating solutions of the Maxwell equations. Such beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams to the full domain of the wave equation. For both TE and TM polarizations, the beams exhibit shape-preserving bending which can have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90°. We show that these accelerating beams are self-healing, analyze their properties, and find the new class of accelerating breathers: self-bending beams of periodically oscillating shapes. Finally, we emphasize that in their scalar form, these beams are the exact solutions for nondispersive accelerating wave packets of the most common wave equation describing time-harmonic waves. As such, this work has profound implications to many linear wave systems in nature, ranging from acoustic and elastic waves to surface waves in fluids and membranes.

  14. Active-region designs in quantum cascade lasers

    SciTech Connect

    Zasavitskii, I I

    2012-10-31

    This paper analyses the development of active-region designs in quantum cascade lasers. Active-region designs have been demonstrated to date that employ various radiative transitions (vertical, diagonal, interminiband and interband). The lower laser level is depopulated through nonradiative transitions, such as one- or two-phonon (and even three-phonon) relaxation or bound state {yields} continuum transitions. Advances in active-region designs and energy diagram optimisation in the past few years have led to significant improvements in important characteristics of quantum cascade lasers, such as their output power, emission bandwidth, characteristic temperature and efficiency. (invited paper)

  15. Nuclear design of a very-low-activation fusion reactor

    SciTech Connect

    Cheng, E.T.; Hopkins, G.R.

    1983-06-01

    An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design.

  16. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, Thomas G.; Thacker, Louis H.; Fine, H. Alan

    1993-01-01

    An instrument for the measurement of vacuum within sealed packets 12, the packets 12 having a wall 14 sufficiently thin that it can be deformed by the application of an external vacuum to small area thereof. The instrument has a detector head 18 for placement against the deformable wall 14 of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall 14, with this deformation or lift monitored by the application of light as via a bifurcated light pipe 20. Retro-reflected light through the light pipe is monitored with a photo detector 26. An abrupt change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the vacuum applied through the head 18 to achieve this initiation of movement is equal to the vacuum Within the packet 12. In a preferred embodiment a vacuum reference plate 44 is placed beneath the packet 12 to ensure that no deformation occurs on the reverse surface 16 of the packet. A packet production line model is also described.

  17. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, T.G.; Thacker, L.H.; Fine, H.A.

    1993-10-05

    An instrument is described for the measurement of vacuum within sealed packets, the packets having a wall sufficiently thin that it can be deformed by the application of an external vacuum to small area thereof. The instrument has a detector head for placement against the deformable wall of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall, with this deformation or lift monitored by the application of light as via a bifurcated light pipe. Retro-reflected light through the light pipe is monitored with a photo detector. An abrupt change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the vacuum applied through the head to achieve this initiation of movement is equal to the vacuum within the packet. In a preferred embodiment a vacuum reference plate is placed beneath the packet to ensure that no deformation occurs on the reverse surface of the packet. A packet production line model is also described. 3 figures.

  18. Reinforcement learning for congestion-avoidance in packet flow

    NASA Astrophysics Data System (ADS)

    Horiguchi, Tsuyoshi; Hayashi, Keisuke; Tretiakov, Alexei

    2005-04-01

    Occurrence of congestion of packet flow in computer networks is one of the unfavorable problems in packet communication and hence its avoidance should be investigated. We use a neural network model for packet routing control in a computer network proposed in a previous paper by Horiguchi and Ishioka (Physica A 297 (2001) 521). If we assume that the packets are not sent to nodes whose buffers are already full of packets, then we find that traffic congestion occurs when the number of packets in the computer network is larger than some critical value. In order to avoid the congestion, we introduce reinforcement learning for a control parameter in the neural network model. We find that the congestion is avoided by the reinforcement learning and at the same time we have good performance for the throughput. We investigate the packet flow on computer networks of various types of topology such as a regular network, a network with fractal structure, a small-world network, a scale-free network and so on.

  19. Alpine Forest. Mount Mitchell State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Bradley, Jack L., Jr.

    This curriculum guide was developed to provide environmental education through a series of hands-on activities for the classroom and the outdoor setting of Mount Mitchell State Park, North Carolina. This activity packet, designed for grades 4 through 6, meets established curriculum objectives of the North Carolina Department of Public…

  20. Predators and Prey: Jordan Lake State Recreation Area. An Environmental Education Learning Experience Designed for Grades K-3.

    ERIC Educational Resources Information Center

    Boswell, Henry, III; Stamm, Daniel K.

    This document provides hands-on environmental education activities for the classroom and the outdoor setting of Jordan Lake State Recreation Area. The activity packet, designed for grades K-3, meets curriculum objectives of the standard course of study established by the North Carolina Department of Public Instruction. It includes on-site…

  1. Wetland Wonders. Goose Creek State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Environment, Health, and Natural Resources, Raleigh. Div. of Parks and Recreation.

    This curriculum guide was developed to provide environmental education through a series of hands-on activities for the classroom and the outdoor setting of Goose Creek State Park, North Carolina. This activity packet, designed for the 4th, 5th, and 6th grades, meets established curriculum objectives of the North Carolina Department of Public…

  2. Quasi-active suspension design using magnetorheological dampers

    NASA Astrophysics Data System (ADS)

    Potter, Jack N.; Neild, Simon A.; Wagg, David J.

    2011-05-01

    Quasi-active damping is a method of coupled mechanical and control system design using multiple semi-active dampers. By designing the systems such that the desired control force may always be achieved using a combination of the dampers, quasi-active damping seeks to approach levels of vibration isolation achievable through active damping, whilst retaining the desirable attributes of semi-active systems. In this article a design is proposed for a quasi-active, base-isolating suspension system. Control laws are firstly defined in a generalised form, where semi-active dampers are considered as idealised variable viscous dampers. This system is used to demonstrate in detail the principles of quasi-active damping, in particular the necessary interaction between mechanical and control systems. It is shown how such a system can produce a tunable, quasi-active region in the frequency response of very low displacement transmissibility. Quasi-active control laws are then proposed which are specific for use with magnetorheological dampers. These are validated in simulation using a realistic model of the damper dynamics, again producing a quasi-active region in the frequency response. Finally, the robustness of the magnetorheological, quasi-active suspension system is demonstrated.

  3. Practical Design Activities for Your Technology Education Classes

    ERIC Educational Resources Information Center

    Berkeihiser, Mike

    2006-01-01

    In this article, the author relates how he and his class get involved in doing project designs within their school district every year. The author relates how they have done design projects for local townships and boroughs, non-profit organizations, Eagle Scout projects, and much more. The author relates how these activities have been such…

  4. Bedroom design and decoration: gender differences in preference and activity.

    PubMed

    Jones, Randall M; Taylor, Denise E; Dick, Andrew J; Singh, Archana; Cook, Jerry L

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social institutions. Gender differences were identified for preference, activity, and influence in bedroom design and decoration. Girls and boys differed in the type of items contained in their bedrooms. Girls' rooms contained stuffed animals and pictures of people, including themselves, more frequently than the boys' rooms. In contrast, boys' rooms contained sports-related items, and things for building or that they had built themselves. Although bedroom design activity for both boys and girls was influenced by older teens, friends, media, and popular culture, boys (but not girls) were also influenced by their mothers, fathers, girlfriends, and activities such as sports, Boy or Girl Scouts, and music lessons.

  5. Bedroom design and decoration: gender differences in preference and activity.

    PubMed

    Jones, Randall M; Taylor, Denise E; Dick, Andrew J; Singh, Archana; Cook, Jerry L

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social institutions. Gender differences were identified for preference, activity, and influence in bedroom design and decoration. Girls and boys differed in the type of items contained in their bedrooms. Girls' rooms contained stuffed animals and pictures of people, including themselves, more frequently than the boys' rooms. In contrast, boys' rooms contained sports-related items, and things for building or that they had built themselves. Although bedroom design activity for both boys and girls was influenced by older teens, friends, media, and popular culture, boys (but not girls) were also influenced by their mothers, fathers, girlfriends, and activities such as sports, Boy or Girl Scouts, and music lessons. PMID:18047237

  6. Observation of Quantum Interference between Separated Mechanical Oscillator Wave Packets

    NASA Astrophysics Data System (ADS)

    Kienzler, D.; Flühmann, C.; Negnevitsky, V.; Lo, H.-Y.; Marinelli, M.; Nadlinger, D.; Home, J. P.

    2016-04-01

    We directly observe the quantum interference between two well-separated trapped-ion mechanical oscillator wave packets. The superposed state is created from a spin-motion entangled state using a heralded measurement. Wave packet interference is observed through the energy eigenstate populations. We reconstruct the Wigner function of these states by introducing probe Hamiltonians which measure Fock state populations in displaced and squeezed bases. Squeezed-basis measurements with 8 dB squeezing allow the measurement of interference for Δ α =15.6 , corresponding to a distance of 240 nm between the two superposed wave packets.

  7. Realization of localized Bohr-like wave packets.

    PubMed

    Mestayer, J J; Wyker, B; Lancaster, J C; Dunning, F B; Reinhold, C O; Yoshida, S; Burgdörfer, J

    2008-06-20

    We demonstrate a protocol to create localized wave packets in very-high-n Rydberg states which travel in nearly circular orbits around the nucleus. Although these wave packets slowly dephase and eventually lose their localization, their motion can be monitored over several orbital periods. These wave packets represent the closest analog yet achieved to the original Bohr model of the hydrogen atom, i.e., an electron in a circular classical orbit around the nucleus. The possible extension of the approach to create "planetary atoms" in highly correlated stable multiply excited states is discussed.

  8. Observation of Quantum Interference between Separated Mechanical Oscillator Wave Packets.

    PubMed

    Kienzler, D; Flühmann, C; Negnevitsky, V; Lo, H-Y; Marinelli, M; Nadlinger, D; Home, J P

    2016-04-01

    We directly observe the quantum interference between two well-separated trapped-ion mechanical oscillator wave packets. The superposed state is created from a spin-motion entangled state using a heralded measurement. Wave packet interference is observed through the energy eigenstate populations. We reconstruct the Wigner function of these states by introducing probe Hamiltonians which measure Fock state populations in displaced and squeezed bases. Squeezed-basis measurements with 8 dB squeezing allow the measurement of interference for Δα=15.6, corresponding to a distance of 240 nm between the two superposed wave packets.

  9. Bedroom Design and Decoration: Gender Differences in Preference and Activity

    ERIC Educational Resources Information Center

    Jones, Randall M.; Taylor, Denise E.; Dick, Andrew J.; Singh, Archana; Cook, Jerry L.

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social…

  10. Design of Activities on Numerical Representations Based on Cognitive Research

    ERIC Educational Resources Information Center

    Kalifatidou, Eleftheria R.

    2008-01-01

    The results of the cognitive research on numbers' representations can provide a sound theoretical framework to develop educational activities on representing numbers. A program of such activities for a nursery school was designed in order to enable the children to externalize and strengthen their internal representations about numerosity and link…

  11. Supporting "Learning by Design" Activities Using Group Blogs

    ERIC Educational Resources Information Center

    Fessakis, Georgios; Tatsis, Konstantinos; Dimitracopoulou, Angelique

    2008-01-01

    The paper presents a case study of the educational exploitation of group blogging for the implementation of a "learning by design" activity. More specifically, a group of students used a blog as a communication and information management tool in the University course of ICT-enhanced Geometry learning activities. The analysis of the designed…

  12. The discourse of design-based science classroom activities

    NASA Astrophysics Data System (ADS)

    Azevedo, Flávio S.; Martalock, Peggy L.; Keser, Tugba

    2015-06-01

    This paper is an initial contribution to a general theory in which science classroom activity types and epistemological discourse practices are systematically linked. The idea is that activities and discourse are reflexively related, so that different types of science classroom activities (e.g., scientific argumentation, modeling, and design) recruit characteristically distinct forms of participants' (students and teacher) discourse. Such a general theory would eventually map out the full spectrum of discourse practices (and their patterns of manifestation) across various kinds of science classroom activities, and reveal new relationships between forms of both discourse and activities. Because this defines a complex and long-term project, here our aim is simply to delineate this larger theoretical program and to illustrate it with a detailed case study—namely, that of mapping out and characterizing the discourse practices of design- based science classroom activities. To do so, we draw on data from an activity that is prototypically design-based—i.e., one in which students iteratively design and refine an artifact (in this case, pictorial representations of moving objects)—and examine the structure and dynamics of the whole-class discourse practices that emerge around these representational forms. We then compare and contrast these discourse practices to those of an activity that is prototypical of scientific argumentation (taken from the literature)—i.e., one in which students argue between competing theories and explanations of a phenomenon—and begin to illustrate the kinds of insights our theoretical program might afford.

  13. Engineering Design Activities and Conceptual Change in Middle School Science

    ERIC Educational Resources Information Center

    Schnittka, Christine G.

    2009-01-01

    The purpose of this research was to investigate the impact of engineering design classroom activities on conceptual change in science, and on attitudes toward and knowledge about engineering. Students were given a situated learning context and a rationale for learning science in an active, inquiry-based method, and worked in small collaborative…

  14. Design and Implementation of an Object Oriented Learning Activity System

    ERIC Educational Resources Information Center

    Lin, Huan-Yu; Tseng, Shian-Shyong; Weng, Jui-Feng; Su, Jun-Ming

    2009-01-01

    With the development of e-learning technology, many specifications of instructional design have been proposed to make learning activity sharable and reusable. With the specifications and sufficient learning resources, the researches further focus on how to provide learners more appropriate learning activities to improve their learning performance.…

  15. Structure of the Real Estate Brokerage Industry: Requiem for the Heavyweights? Teachers Instructional Packet (TIP) No. 16, Spring 1987.

    ERIC Educational Resources Information Center

    Harris, Jack C.

    Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand requirements for structure of the Texas real estate brokerage industry. First, information is presented on real estate brokerage, touching upon the industry's growth and the expansion of brokerage…

  16. Activities for Teaching the U.S. Constitution in the Elementary Grades.

    ERIC Educational Resources Information Center

    Corbin, Denee J.

    Designed to work with and be integrated into the existing curriculum, this learning packet contains activities that encourage discussion and critical thinking by students about the U.S. Constitution. The first activity teaches fundamental principles of government while the second asks students to explain how the Constitution was written through…

  17. The EURECA telecommanding chain: Experience with packet telecommand and telemetry systems

    NASA Astrophysics Data System (ADS)

    Mueller, C.; Bater, R.; Sorensen, E. M.

    1993-03-01

    The European Retrieval Carrier (EURECA) was launched on its first flight on the 31st July 1992 by the Space Shuttle Atlantis. EURECA is characterized by several new on-board features, most notable Packet Telemetry and a partial implementation of Packet Telecommanding using an early version of the Command Operation Procedure (COP-1) protocol. EURECA has also very low contact time with its Ground Station, with a consequent high number of out-of-visibility onboard operations. This paper concentrates on the implementation and operational experience with the COP-1 Protocol and the effect the short ground contact time has on the design of the Commanding System. Another interesting feature is that the COP-1 is implemented at the control center rather than at the ground station. The COP-1 protocol also successfully supported the mission during the launch where commands were sent via NASCOM and the Shuttle.

  18. The EURECA telecommanding chain: Experience with packet telecommand and telemetry systems

    NASA Technical Reports Server (NTRS)

    Mueller, C.; Bater, R.; Sorensen, E. M.

    1993-01-01

    The European Retrieval Carrier (EURECA) was launched on its first flight on the 31st July 1992 by the Space Shuttle Atlantis. EURECA is characterized by several new on-board features, most notable Packet Telemetry and a partial implementation of Packet Telecommanding using an early version of the Command Operation Procedure (COP-1) protocol. EURECA has also very low contact time with its Ground Station, with a consequent high number of out-of-visibility onboard operations. This paper concentrates on the implementation and operational experience with the COP-1 Protocol and the effect the short ground contact time has on the design of the Commanding System. Another interesting feature is that the COP-1 is implemented at the control center rather than at the ground station. The COP-1 protocol also successfully supported the mission during the launch where commands were sent via NASCOM and the Shuttle.

  19. Distributed MPC of polytopic uncertain systems: handling quantised communication and packet dropouts

    NASA Astrophysics Data System (ADS)

    Zhang, Langwen; Wang, Jingcheng; Wang, Bohui

    2015-10-01

    In this paper, we study the distributed model predictive control (MPC) of polytopic uncertain systems with quantised communication and packet dropouts. The model of the whole plant is divided into a certain number of incomplete subsystems. Due to the nature of the distributed control structure, there is generally a lack of information about the state of the overall system. Each subsystem shares its information with neighbour subsystems via reliable connection. Distributed MPC controllers are designed for each subsystem by solving the linear matrix inequalities optimisation problem. The distributed state feedback laws are quantised and transmitted via communication network. An iterative algorithm is presented to make coordination among distributed state feedback laws. The communication is assumed to be affected by random packet dropouts in a representation of Bernoulli distributed white sequences with known conditional probabilities. A case study is carried out to demonstrate the effectiveness of the proposed distributed MPC technique.

  20. Initial phase and free-particle wave packet evolution

    NASA Astrophysics Data System (ADS)

    Beach, Theodore L.

    2009-06-01

    The evolution of the free-particle wave function in one dimension is the same as scalar Fresnel diffraction from a one-dimensional structure. Quantum mechanics courses often explore the propagation of Gaussian wave packets, but the diffractionlike mathematics is sufficiently tractable to investigate the propagation of other wave packets, both numerically and analytically. More importantly, the diffraction analogy facilitates the development of an intuitive understanding of the role that the initial phase plays in free-particle wave packet evolution. This article considers some of the effects of the initial phase function on the subsequent evolution of free-particle wave packets in the position representation. These considerations reinforce the idea that the classical mechanics limit embodied in the correspondence principle and formalized in the Ehrenfest theorem is necessarily an incomplete representation of quantum behavior.

  1. Localization of wave packets in one-dimensional random potentials

    NASA Astrophysics Data System (ADS)

    Valdes, Juan Pablo Ramírez; Wellens, Thomas

    2016-06-01

    We study the expansion of an initially strongly confined wave packet in a one-dimensional weak random potential with short correlation length. At long times, the expansion of the wave packet comes to a halt due to destructive interferences leading to Anderson localization. We develop an analytical description for the disorder-averaged localized density profile. For this purpose, we employ the diagrammatic method of Berezinskii which we extend to the case of wave packets, present an analytical expression of the Lyapunov exponent which is valid for small as well as for high energies, and, finally, develop a self-consistent Born approximation in order to analytically calculate the energy distribution of our wave packet. By comparison with numerical simulations, we show that our theory describes well the complete localized density profile, not only in the tails but also in the center.

  2. Analytic approach to the wave packet formalism in oscillation phenomena

    SciTech Connect

    Bernardini, A.E.; Leo, S. de

    2004-09-01

    We introduce an approximation scheme to perform an analytic study of the oscillation phenomena in a pedagogical and comprehensive way. By using Gaussian wave packets, we show that the oscillation is bounded by a time-dependent vanishing function which characterizes the slippage between the mass-eigenstate wave packets. We also demonstrate that the wave packet spreading represents a secondary effect which plays a significant role only in the nonrelativistic limit. In our analysis, we note the presence of a new time-dependent phase and calculate how this additional term modifies the oscillating character of the flavor conversion formula. Finally, by considering box and sine wave packets we study how the choice of different functions to describe the particle localization changes the oscillation probability.

  3. Propagation velocity of Alfven wave packets in a dissipative plasma

    SciTech Connect

    Amagishi, Y.; Nakagawa, H. ); Tanaka, M. )

    1994-09-01

    We have experimentally studied the behavior of Alfven wave packets in a dissipative plasma due to ion--neutral-atom collisions. It is urged that the central frequency of the packet is observed to gradually decrease with traveling distance in the absorption range of frequencies because of a differential damping among the Fourier components, and that the measured average velocity of its peak amplitude is not accounted for by the conventional group velocity, but by the prediction derived by Tanaka, Fujiwara, and Ikegami [Phys. Rev. A 34, 4851 (1986)]. Furthermore, when the initial central frequency is close to the critical frequency in the anomalous dispersion, the wave packet apparently collapses when traveling along the magnetic field; however, we have found that it is decomposed into another two wave packets with the central frequencies being higher or lower than the critical frequency.

  4. Nondispersive wave packets -- control through chaos

    NASA Astrophysics Data System (ADS)

    Buchleitner, Andreas

    2005-05-01

    Nondispersive wave packets were predicted to emerge in periodically driven Rydberg atoms a little more than 10 years ago [1], and have now been observed in the laboratory [2]. I shall illustrate how these robust, generic ``quantum particles'' and their relatives naturally emerge from the theory of chaotic quantum systems [3], and thus open new perspectives for robust quantum control in various experimental settings -- from one and two-electron [4] atoms under periodic or impulsive [5] driving to cold atoms in flashing periodic potentials, possibly amended by harmonic confinement [6]. Besides the fundamental underlying (nonlinear) resonance phenomena also some more subtle properties will be discussed, including open questions within the realm of spectral theory. *[1] A. Buchleitner, thèse de doctorat, Universit'e Paris 6 (1993); I. Bialynicki-Birula, M. Kalinski, and J. H. Eberly, Phys. Rev. Lett. 73, 1777 (1994); D. Delande and A. Buchleitner, Adv. At. Mol. Opt. Phys. 34, 85 (1994). *[2] H. Maeda and T. F. Gallagher, Phys. Rev. Lett. 92, 133004 (2004). *[3] A. Buchleitner, D. Delande, and J. Zakrzewski, Phys. Rep. 386, 409 (2002). *[4] J. Madroñero, PhD thesis, Ludwig-Maximilians-Universität München (2004), http://edoc.ub.uni-muenchen.de/archive/00002187. *[5] D.G. Arb'o et al., Phys. Rev. A 67, 63401 (2003). *[6] A.R.R. de Carvalho and A. Buchleitner, Phys. Rev. Lett. 93, 204101 (2004).

  5. Embedded wavelet packet transform technique for texture compression

    NASA Astrophysics Data System (ADS)

    Li, Jin; Cheng, Po-Yuen; Kuo, C.-C. Jay

    1995-09-01

    A highly efficient texture compression scheme is proposed in this research. With this scheme, energy compaction of texture images is first achieved by the wavelet packet transform, and an embedding approach is then adopted for the coding of the wavelet packet transform coefficients. By comparing the proposed algorithm with the JPEG standard, FBI wavelet/scalar quantization standard and the EZW scheme with extensive experimental results, we observe a significant improvement in the rate-distortion performance and visual quality.

  6. Behavior of a Moist Kelvin Wave Packet with Nonlinear Heating.

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Xue, Yan

    1992-04-01

    The effects of nonlinear (positive only or conditional) heating on moist Kelvin waves are examined with a simple equatorial zonal-plane model describing the gravest baroclinic mode.The unstable perturbation subject to nonlinear beating emerges as a wave packet. A typical amplifying, eastward-moving wave packet is characterized by an asymmetric structure: 1) the ascending branch (wet region) is much narrower than the two descending ones (dry regions); and 2) the circulation cell to the east of the wet region center is smaller and stronger than its counterpart to the west of the center. The wet-dry asymmetry is primarily caused by the nonlinear beating effect, while the east-west asymmetry is a result of the movement of the wave packet relative to mean flow. The existence of Newtonian cooling and Rayleigh friction enhances the structural asymmetries.The unstable wave packet is characterized by two zonal length scales: the ascending branch length (ABL) and total circulation extent (TCE). For a given basic state, the growth rate of a wave packet increases with decreasing ABL or TCE. However, up to a moderate growth rate (order of day1) the energy spectra of all wave packets are dominated by zonal wavenumber one regardless of ABL size. In particular, the slowly growing (low frequency) wave packets normally exhibit TCEs of planetary scale and ABLs of synoptic scale.Observed equatorial intraseasonal disturbances often display a narrow convection region in between two much broader dry regions and a total circulation of planetary scale. These structure and scale characteristics are caused by the effects of nonlinear heating and the cyclic geometry of the equator. It is argued that the unstable disturbance found in numerical experiments (e.g., Lau and Peng; Hayashi and Sumi) is a manifestation of the nonlinear wave packet.

  7. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  8. Aerodynamic Design Study of an Advanced Active Twist Rotor

    NASA Technical Reports Server (NTRS)

    Sekula, Martin K.; Wilbur, Matthew L.; Yeager, William T., Jr.

    2003-01-01

    An Advanced Active Twist Rotor (AATR) is currently being developed by the U.S. Army Vehicle Technology Directorate at NASA Langley Research Center. As a part of this effort, an analytical study was conducted to determine the impact of blade geometry on active-twist performance and, based on those findings, propose a candidate aerodynamic design for the AATR. The process began by creating a baseline design which combined the dynamic design of the original Active Twist Rotor and the aerodynamic design of a high lift rotor concept. The baseline model was used to conduct a series of parametric studies to examine the effect of linear blade twist and blade tip sweep, droop, and taper on active-twist performance. Rotor power requirements and hub vibration were also examined at flight conditions ranging from hover to advance ratio = 0.40. A total of 108 candidate designs were analyzed using the second-generation version of the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II) code. The study concluded that the vibration reduction capabilities of a rotor utilizing controlled, strain-induced twisting are enhanced through the incorporation of blade tip sweep, droop, and taper into the blade design, while they are degraded by increasing the nose-down linear blade twist. Based on the analysis of rotor power, hub vibration, and active-twist response, a candidate aerodynamic design for the AATR consisting of a blade with approximately 10 degrees of linear blade twist and a blade tip design with 30 degree sweep, 10 degree droop, and 2.5:1 taper ratio over the outer five percent of the blade is proposed.

  9. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, T.G.; Thacker, L.H.; Fine, H.A.

    1995-04-18

    An instrument is disclosed for the measurement of vacuum within sealed packets, the packets having a wall that it can be deformed by the application of an external dynamic vacuum to an area thereof. The instrument has a detector head for placement against the deformable wall of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall with this deformation or lift monitored by the application of light as via a bifurcated light pipe. Retro-reflected light through the light pipe is monitored with a photo detector. A change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the dynamic vacuum applied through the head be to achieve this initiation of movement is equal to the vacuum within the packet. In a preferred embodiment a vacuum plate is placed beneath the packet to ensure that no deformation occurs on the reverse surface of the packet. A vacuum can be applied to a recess in this vacuum plate, the value of which can be used to calibrate the vacuum transducer in the detector head. 4 figs.

  10. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, Thomas G.; Thacker, Louis H.; Fine, H. Alan

    1995-01-01

    An instrument for the measurement of vacuum within sealed packets 12, the packets 12 having a wall 14 that it can be deformed by the application of an external dynamic vacuum to an area thereof. The instrument has a detector head 18 for placement against the deformable wall 14 of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall 14, with this deformation or lift monitored by the application of light as via a bifurcated light pipe 20. Retro-reflected light through the light pipe is monitored with a photo detector 26. A change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the dynamic vacuum applied through the head be to achieve this initiation of movement is equal to the vacuum within the packet 12. In a preferred embodiment a vacuum plate 44 is placed beneath the packet 12 to ensure that no deformation occurs on the reverse surface 16 of the packet. A vacuum can be applied to a recess in this vacuum plate, the value of which can be used to calibrate the vacuum transducer in the detector head.

  11. TCP Packet Trace Analysis. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Shepard, Timothy J.

    1991-01-01

    Examination of a trace of packets collected from the network is often the only method available for diagnosing protocol performance problems in computer networks. This thesis explores the use of packet traces to diagnose performance problems of the transport protocol TCP. Unfortunately, manual examination of these traces can be so tedious that effective analysis is not possible. The primary contribution of this thesis is a graphical method of displaying the packet trace which greatly reduce, the tediousness of examining a packet trace. The graphical method is demonstrated by the examination of some packet traces of typical TCP connections. The performance of two different implementations of TCP sending data across a particular network path is compared. Traces many thousands of packets long are used to demonstrate how effectively the graphical method simplifies examination of long complicated traces. In the comparison of the two TCP implementations, the burstiness of the TCP transmitter appeared to be related to the achieved throughput. A method of quantifying this burstiness is presented and its possible relevance to understanding the performance of TCP is discussed.

  12. An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks

    PubMed Central

    Al Ameen, Moshaddique; Hong, Choong Seon

    2015-01-01

    The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime. PMID:26690161

  13. Multidisciplinary design optimization of mechatronic vehicles with active suspensions

    NASA Astrophysics Data System (ADS)

    He, Yuping; McPhee, John

    2005-05-01

    A multidisciplinary optimization method is applied to the design of mechatronic vehicles with active suspensions. The method is implemented in a GA-A'GEM-MATLAB simulation environment in such a way that the linear mechanical vehicle model is designed in a multibody dynamics software package, i.e. A'GEM, the controllers and estimators are constructed using linear quadratic Gaussian (LQG) method, and Kalman filter algorithm in Matlab, then the combined mechanical and control model is optimized simultaneously using a genetic algorithm (GA). The design variables include passive parameters and control parameters. In the numerical optimizations, both random and deterministic road inputs and both perfect measurement of full state variables and estimated limited state variables are considered. Optimization results show that the active suspension systems based on the multidisciplinary optimization method have better overall performance than those derived using conventional design methods with the LQG algorithm.

  14. Layered shielding design for an active neutron interrogation system

    NASA Astrophysics Data System (ADS)

    Whetstone, Zachary D.; Kearfott, Kimberlee J.

    2016-08-01

    The use of source and detector shields in active neutron interrogation can improve detector signal. In simulations, a shielded detector with a source rotated π/3 rad relative to the opening decreased neutron flux roughly three orders of magnitude. Several realistic source and detector shield configurations were simulated. A layered design reduced neutron and secondary photon flux in the detector by approximately one order of magnitude for a deuterium-tritium source. The shield arrangement can be adapted for a portable, modular design.

  15. Wide-band packet radio for multipath environments

    NASA Astrophysics Data System (ADS)

    Fischer, Jeffrey H.; Cafarella, John H.; Bouman, Charles A.; Flynn, Gerard T.; Dolat, Victor S.

    1988-05-01

    A direct-sequence spread-spectrum packet radio is described that has versatile signal-processing and local-control capabilities designed to support the functions required of a robust mobile communications network. Noteworthy capabilities include eleven selectable data rates with accurate range measurements in a fading multipath channel. The radio uses a hybrid analog/digital signal processor and nonrepeating spreading codes for suppression of intersymbol interference and jamming. It incorporates two sets of monolithic surface-acoustic-wave convolvers as programmable matched filters with time-bandwidth products of 64 and 2000. The analog matched filters are coupled with binary postprocessing for the functions of detection, RAKE demodulation, and ranging measurements over a wide multipath spread. The data rate can be varied in response to channel conditions from 1.45 Mb/s down to 44 b/s with an almost ideal tradeoff in signal-processing gain from 18 dB up to 61 dB prior to multipath combining.

  16. Regional-specific Stochastic Simulation of Spatially-distributed Ground-motion Time Histories using Wavelet Packet Analysis

    NASA Astrophysics Data System (ADS)

    Huang, D.; Wang, G.

    2014-12-01

    Stochastic simulation of spatially distributed ground-motion time histories is important for performance-based earthquake design of geographically distributed systems. In this study, we develop a novel technique to stochastically simulate regionalized ground-motion time histories using wavelet packet analysis. First, a transient acceleration time history is characterized by wavelet-packet parameters proposed by Yamamoto and Baker (2013). The wavelet-packet parameters fully characterize ground-motion time histories in terms of energy content, time- frequency-domain characteristics and time-frequency nonstationarity. This study further investigates the spatial cross-correlations of wavelet-packet parameters based on geostatistical analysis of 1500 regionalized ground motion data from eight well-recorded earthquakes in California, Mexico, Japan and Taiwan. The linear model of coregionalization (LMC) is used to develop a permissible spatial cross-correlation model for each parameter group. The geostatistical analysis of ground-motion data from different regions reveals significant dependence of the LMC structure on regional site conditions, which can be characterized by the correlation range of Vs30 in each region. In general, the spatial correlation and cross-correlation of wavelet-packet parameters are stronger if the site condition is more homogeneous. Using the regional-specific spatial cross-correlation model and cokriging technique, wavelet packet parameters at unmeasured locations can be best estimated, and regionalized ground-motion time histories can be synthesized. Case studies and blind tests demonstrated that the simulated ground motions generally agree well with the actual recorded data, if the influence of regional-site conditions is considered. The developed method has great potential to be used in computational-based seismic analysis and loss estimation in a regional scale.

  17. Gearbox design for uncertain load requirements using active robust optimization

    NASA Astrophysics Data System (ADS)

    Salomon, Shaul; Avigad, Gideon; Purshouse, Robin C.; Fleming, Peter J.

    2016-04-01

    Design and optimization of gear transmissions have been intensively studied, but surprisingly the robustness of the resulting optimal design to uncertain loads has never been considered. Active Robust (AR) optimization is a methodology to design products that attain robustness to uncertain or changing environmental conditions through adaptation. In this study the AR methodology is utilized to optimize the number of transmissions, as well as their gearing ratios, for an uncertain load demand. The problem is formulated as a bi-objective optimization problem where the objectives are to satisfy the load demand in the most energy efficient manner and to minimize production cost. The results show that this approach can find a set of robust designs, revealing a trade-off between energy efficiency and production cost. This can serve as a useful decision-making tool for the gearbox design process, as well as for other applications.

  18. Enhancing In-Flight Transoceanic Communications Using Swift-64 Packet Mode Service

    NASA Technical Reports Server (NTRS)

    Slywczak, Richard A.

    2004-01-01

    Current aeronautical communications can be divided into two segments. The first provides state of the art, packet switched technology to the cabin passengers so that they have access to e-mail and web services. The second provides basic circuit switch communication technology to the cockpit, which does not use bandwidth as efficiently as packet switching nor promotes resource sharing. This paper explores the research efforts currently being conducted by the NASA/Glenn Research Center (GRC) for transoceanic communications. The goal is to bring packet mode services to both the cabin and the cockpit of the aircraft and be able to attain benefits by sharing the data link with cabin services. First, this paper will outline the goals of the program and detail the benefits and issues related to this research. We will explain our current laboratory setup and show an architecture implemented in the testbed. Finally, we will present a work plan that will show the progression of research over the next year. This plan will describe a complete cycle from conceptual design and laboratory implementation to the final flight testing.

  19. Use of CCSDS Packets Over SpaceWire to Control Hardware

    NASA Technical Reports Server (NTRS)

    Haddad, Omar; Blau, Michael; Haghani, Noosha; Yuknis, William; Albaijes, Dennis

    2012-01-01

    For the Lunar Reconnaissance Orbiter, the Command and Data Handling subsystem consisted of several electronic hardware assemblies that were connected with SpaceWire serial links. Electronic hardware would be commanded/controlled and telemetry data was obtained using the SpaceWire links. Prior art focused on parallel data buses and other types of serial buses, which were not compatible with the SpaceWire and the core flight executive (CFE) software bus. This innovation applies to anything that utilizes both SpaceWire networks and the CFE software. The CCSDS (Consultative Committee for Space Data Systems) packet contains predetermined values in its payload fields that electronic hardware attached at the terminus of the SpaceWire node would decode, interpret, and execute. The hardware s interpretation of the packet data would enable the hardware to change its state/configuration (command) or generate status (telemetry). The primary purpose is to provide an interface that is compatible with the hardware and the CFE software bus. By specifying the format of the CCSDS packet, it is possible to specify how the resulting hardware is to be built (in terms of digital logic) that results in a hardware design that can be controlled by the CFE software bus in the final application

  20. Optimization of WDM optical packet switches with sparse wavelength converters and nondegenerate fiber delay lines

    NASA Astrophysics Data System (ADS)

    Zhang, Zhizhong; Cheng, Fang; Yuan, Shufang; Zhao, Huandong; Zeng, Qingji; Wang, Jianxin

    2004-05-01

    In this paper, we investigate the somewhat untraditional approach of contention resolution in WDM optical packet switches. The most striking characteristics of the developed switch architecture are that (1) contention resolution is achieved by a combined sharing of fiber delay-lines (FDLs) and tunable optical wavelength converters (TOWCs); (2) FDLs used for contention resolution is in non-degenerate form, i.e., buffers are achieved by non-uniform distribution of the delay lines; (3) TOWCs just can achieve wavelength conversion in partial continuous wavelength channels, i.e., sparse wavelength conversion. We describe and analyze the concrete configuration of FDLs and TOWCs under non-bursty and bursty traffic scenarios. Simulation results demonstrate that for a prefixed packet loss probability constraint, e.g., 10-6, the developed architecture provides a different point of view in the optical packet switching (OPS) design. That is, combined sharing of FDLs and TOWCs can, effectively, obtain a good tradeoff between the switch size and the cost, and TOWCs which are achieved in sparse form can also decrease the implementing complexity.

  1. Fast simulation of packet loss rates in a shared buffer communications switch

    NASA Technical Reports Server (NTRS)

    Chang, Cheng-Shang; Heidelberger, Philip; Shahabuddin, Perwez

    1993-01-01

    This paper describes an efficient technique for estimating, via simulation, the probability of buffer overflows in a queueing model that arises in the analysis of ATM (Asynchronous Transfer Mode) communication switches. There are multiple streams of (autocorrelated) traffic feeding the switch that has a buffer of finite capacity. Each stream is designated as either being of high or low priority. When the queue length reaches a certain threshold, only high priority packets are admitted to the switch's buffer. The problem is to estimate the loss rate of high priority packets. An asymptotically optimal importance sampling approach is developed for this rare event simulation problem. In this approach, the importance sampling is done in two distinct phases. In the first phase, an importance sampling change of measure is used to bring the queue length up to the threshold at which low priority packets get rejected. In the second phase, a different importance sampling change of measure is used to move the queue length from the threshold to the buffer capacity.

  2. Highly survivable communications: Complementary media packet switched networks

    NASA Astrophysics Data System (ADS)

    Yavuz, D.; Eken, F.; Karavassilis, N.

    1994-07-01

    The requirement for highly survivable communications (HSC) for essential command functions in military operations does not need any justification. The ability to communicate under extreme jamming levels and adverse propagation conditions, including high altitude nuclear events, is a very important requirement. There are also many natural disaster related requirements that also need such highly survivable communications. The prevalent and in a sense classical, approach to provide highly assured connectivity can be summarized as follows: Take a particular propagation medium and try to obtain the ultimate performance from it. There are many examples of this philosophy some successful, most not. Our approach, on the other hand, is to use complementary multi-media or mixed-media where communication links utilizing essentially commercial-off-the-shelf (COTS) equipment are integrated using packet radio (PR) techniques. There is also, in our view, an even more fundamental, recently discovered consideration why the expectation of continuous incremental refinement of a system using a given single media may be be achievable. This is derived from the theory of 'deterministic uncertainty' or more popularly known as 'theory of CHAOS', systems whose state space behavior has fractal characteristics. We will elaborate on this novel argument. Complementary multi-media approach has been the focus for all HSC communications activities at STC since 1982. The original STC studies and prototypes were in response to requirements of broadcasting (i.e., one-way transmission) information. A high frequency (HF)/meteorburst (MB) system was developed/prototyped/tested demonstrating the cost effectiveness of the approach. These results are reviewed. More recently, in 1992 STC has completed the development/test of an Open Systems Interconnection (OSI) HF packet radio protocol as no such open or non-proprietary protocol exists. This protocol has been fully tested, documented and made available to

  3. All-Optical Label Swapping Strategies for Spectral Amplitude Code Labels in Packet-Switched Optical Networks

    NASA Astrophysics Data System (ADS)

    Habib, Christian

    There is currently much work focused on developing packet-switched optical networks to overcome the limitations of existing optical networks. Switch design for packet-switched optical networks is particularly challenging, in part due to the lack of a practical optical memory system. As a result, optical labels and all-optical label processing have attracted much attention. This thesis examines a crucial label processing component of an optical packet switch, namely the label swapper. In this thesis, three different tabletop topologies for low-cost all-optical swapping of spectral amplitude code labels for packet-switched networks are examined in a proof-of-concept phase. The first uses cross-absorption modulation in an electro-absorption modulator within a semiconductor fiber ring laser (SFRL), the second uses cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA) within an SFRL, and the third makes use of XGM in a SOA as well as injection locking in a Fabry-Perot laser diode for wavelength conversion. The benefits and limitations of each approach as well as future improvements are discussed. Building on these results, a high-performance integrated version of XGM swapper is designed, simulated, and masks are produced for fabrication using indium phosphide technology.

  4. Design of multitarget activity landscapes that capture hierarchical activity cliff distributions.

    PubMed

    Dimova, Dilyana; Wawer, Mathias; Wassermann, Anne Mai; Bajorath, Jürgen

    2011-02-28

    An activity landscape model of a compound data set can be rationalized as a graphical representation that integrates molecular similarity and potency relationships. Activity landscape representations of different design are utilized to aid in the analysis of structure-activity relationships and the selection of informative compounds. Activity landscape models reported thus far focus on a single target (i.e., a single biological activity) or at most two targets, giving rise to selectivity landscapes. For compounds active against more than two targets, landscapes representing multitarget activities are difficult to conceptualize and have not yet been reported. Herein, we present a first activity landscape design that integrates compound potency relationships across multiple targets in a formally consistent manner. These multitarget activity landscapes are based on a general activity cliff classification scheme and are visualized in graph representations, where activity cliffs are represented as edges. Furthermore, the contributions of individual compounds to structure-activity relationship discontinuity across multiple targets are monitored. The methodology has been applied to derive multitarget activity landscapes for compound data sets active against different target families. The resulting landscapes identify single-, dual-, and triple-target activity cliffs and reveal the presence of hierarchical cliff distributions. From these multitarget activity landscapes, compounds forming complex activity cliffs can be readily selected.

  5. Using Fall to Design Activities: In the Classroom.

    ERIC Educational Resources Information Center

    Grambo, Gregory

    1994-01-01

    Examples of fall activities to bring the natural world into the classroom are offered including conducting a simple chromatography experiment on leaves, correlating number of seeds with the lines on pumpkins, planting colored corn kernels, and designing and making scarecrows. (DB)

  6. Designing the Perfect Plant: Activities to Investigate Plant Ecology

    ERIC Educational Resources Information Center

    Lehnhoff, Erik; Woolbaugh, Walt; Rew, Lisa

    2008-01-01

    Plant ecology is an important subject that often receives little attention in middle school, as more time during science classes is devoted to plant biology. Therefore, the authors have developed a series of activities, including a card game--Designing the Perfect Plant--to introduce student's to plant ecology and the ecological trade offs…

  7. Congestion Control for a Fair Packet Delivery in WSN: From a Complex System Perspective

    PubMed Central

    2014-01-01

    In this work, we propose that packets travelling across a wireless sensor network (WSN) can be seen as the active agents that make up a complex system, just like a bird flock or a fish school, for instance. From this perspective, the tools and models that have been developed to study this kind of systems have been applied. This is in order to create a distributed congestion control based on a set of simple rules programmed at the nodes of the WSN. Our results show that it is possible to adapt the carried traffic to the network capacity, even under stressing conditions. Also, the network performance shows a smooth degradation when the traffic goes beyond a threshold which is settled by the proposed self-organized control. In contrast, without any control, the network collapses before this threshold. The use of the proposed solution provides an effective strategy to address some of the common problems found in WSN deployment by providing a fair packet delivery. In addition, the network congestion is mitigated using adaptive traffic mechanisms based on a satisfaction parameter assessed by each packet which has impact on the global satisfaction of the traffic carried by the WSN. PMID:25177722

  8. Effects of inter-packet spacing on the delivery of multimedia content

    SciTech Connect

    Kapadia, A. C.; Feng, A. C.; Feng, W. C.

    2001-01-01

    Streaming multimedia content with UDP has become increasingly popular over distributed systems such as the Internet. However, because UDP does not possess any congestion-control mechanism and most best-effort trafic is served by the congestion-controlled TCP, UDP flows steal bandwidth from TCP to the point that TCP flows can starve for network resources. Furthermore, such applications may cause the Internet infrastructure to eventually suffer from congestion collapse because UDP trafic does not self-regulate itself. To address this problem, next-generation Internet routers will implement active queue-management schemes to punish malicious traffic, e.g., non-adaptive UDP flows, and to the improve the performance of congestion-controlled traffic, e.g., TCP flows. The arrival of such routers will cripple the performance of today's UDP-based multimedia applications. So, in this paper, we introduce the notion of inter-packet spacing with control feedback to enable these UDP-based applications to perform well in the next-generation Internet while being adaptive and self-regulating. When compared with traditional UDP-based multimedia streaming, we illustrate that our counterintuitive, interpacket-spacing scheme with control feedback can reduce packet loss by 90% without adversely affecting delivered throughput. Keywords: network protocol, multimedia, packet spacing, rate-adjusting congestion control.

  9. Congestion control for a fair packet delivery in WSN: from a complex system perspective.

    PubMed

    Aguirre-Guerrero, Daniela; Marcelín-Jiménez, Ricardo; Rodriguez-Colina, Enrique; Pascoe-Chalke, Michael

    2014-01-01

    In this work, we propose that packets travelling across a wireless sensor network (WSN) can be seen as the active agents that make up a complex system, just like a bird flock or a fish school, for instance. From this perspective, the tools and models that have been developed to study this kind of systems have been applied. This is in order to create a distributed congestion control based on a set of simple rules programmed at the nodes of the WSN. Our results show that it is possible to adapt the carried traffic to the network capacity, even under stressing conditions. Also, the network performance shows a smooth degradation when the traffic goes beyond a threshold which is settled by the proposed self-organized control. In contrast, without any control, the network collapses before this threshold. The use of the proposed solution provides an effective strategy to address some of the common problems found in WSN deployment by providing a fair packet delivery. In addition, the network congestion is mitigated using adaptive traffic mechanisms based on a satisfaction parameter assessed by each packet which has impact on the global satisfaction of the traffic carried by the WSN. PMID:25177722

  10. Active flutter suppression - Control system design and experimental validation

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Srinathkumar, S.

    1991-01-01

    The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind-tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in flutter dynamic pressure and flutter frequency in the mathematical model. The flutter suppression controller was also successfully operated in combination with a roll maneuver controller to perform flutter suppression during rapid rolling maneuvers.

  11. Multi-echo processing by a bottlenose dolphin operating in "packet" transmission mode at long range.

    PubMed

    Finneran, James J; Schroth-Miller, Maddie; Borror, Nancy; Tormey, Megan; Brewer, Arial; Black, Amy; Bakhtiari, Kimberly; Goya, Gavin

    2014-11-01

    Bottlenose dolphins performing echolocation tasks at long ranges may utilize a transmission mode where bursts, or "packets," of echolocation clicks are emitted rather than single clicks. The clicks within each packet are separated by time intervals well below the two-way travel time, while the packets themselves are emitted at intervals greater than the two-way travel time. Packet use has been shown to increase with range; however, the exact function of packets and the advantages gained by their utilization remain unknown. In this study, the capability for dolphins to utilize multi-echo processing within packets of echoes was investigated by manipulating the number of available echoes within each packet as a dolphin performed a long-range echolocation task. The results showed an improvement in detectability with an increase in the number of echoes in each packet and suggest that packet use is an adaptation to allow multi-echo processing at long ranges without introducing range ambiguity.

  12. Optical design and active optics methods in astronomy

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gerard R.

    2013-03-01

    Optical designs for astronomy involve implementation of active optics and adaptive optics from X-ray to the infrared. Developments and results of active optics methods for telescopes, spectrographs and coronagraph planet finders are presented. The high accuracy and remarkable smoothness of surfaces generated by active optics methods also allow elaborating new optical design types with high aspheric and/or non-axisymmetric surfaces. Depending on the goal and performance requested for a deformable optical surface analytical investigations are carried out with one of the various facets of elasticity theory: small deformation thin plate theory, large deformation thin plate theory, shallow spherical shell theory, weakly conical shell theory. The resulting thickness distribution and associated bending force boundaries can be refined further with finite element analysis.

  13. An effective packetization algorithm of LT codes for stable video streaming over wireless network

    NASA Astrophysics Data System (ADS)

    Lee, Dongju; Kim, Wan; Song, Hwangjun

    2011-09-01

    In this work, we propose an effective And-Or tree based packetization algorithm of Luby Transform (LT) codes to provide stable video streaming services by minimizing the deterioration of video streaming service quality caused by lost packets over error-prone wireless network. To accomplish our goal, the proposed packetization algorithm considers the relationships among encoded symbols of LT codes based on an And-Or tree analysis tool, and then puts the these encoded symbols into packets to minimize the packet loss effect during packet transmission and improve the decoding success rate of LT codes by reducing the correlations among packets. We conduct a mathematical analysis to prove performance of our packetization algorithm of LT codes compared with conventional packetization algorithm. Finally, the proposed system is fully implemented in Java and C/C++, and widely tested to show that the proposed packetization algorithm works reasonably well. The experimental results are provided to demonstrate that the proposed packetization algorithm supports more stable video streaming services with higher peak signal-to-nose ratio (PSNR) than the conventional packetization algorithm with various packet loss patterns, including random and burst packet loss patterns.

  14. Rydberg wave packets and half-cycle electromagnetic pulses

    NASA Astrophysics Data System (ADS)

    Raman, Chandra Shekar

    1997-08-01

    This dissertation summarizes an examination of the dynamics of atomic Rydberg wave packets with coherent pulses of THz electromagnetic radiation consisting of less than a single cycle of the electric field. The bulk of the energy is contained in just a half-cycle. Previous work (1, 10) has shown how these half-cycle pulses can be used to ionize the highly excited states of an atom, and that a classical view of electronic motion in the atom explains the ionization mechanism. To further probe the boundary between classical trajectories and quantum mechanics, in this work we investigate dynamical combinations of Rydberg states, or Rydberg wave packets, and how they ionize under the influence of a half-cycle electromagnetic pulse. With time-domain techniques we are able to extract the dynamics of the wave packet from the ionization rate. We then observe wave packet motion in both the electronic radial and angular coordinates, and can view it directly with the half-cycle pulse anywhere on its trajectory. This is the unique feature of half- cycle pulse ionization. Semiclassical ideas of ionization in conjunction with quantum descriptions of the wave packet, are capable of reproducing the main trends in our data, and in the absence of a rigorous model we rely on these. Experiments of this nature provide examples of the ongoing effort to use the coherent properties of radiation to control electronic motion in an atom, as well as to probe the boundaries between quantum and classical mechanics.

  15. Integrated optical buffers for packet-switched networks

    NASA Astrophysics Data System (ADS)

    Burmeister, Emily Frances

    Routers form the backbone of the Internet, directing data to the right locations with huge throughput capacity of terabits/second) and very few errors (1 error allowed in 1012 bits). However, as the Internet continues to grow rapidly, so must the capacity of electronic routers, thereby also growing in footprint and power consumption. The energy bill alone has developers looking for an alternate solution. Today's routers can only operate with electrical signals although Internet data is transmitted optically. This requires the data to be converted from the optical domain to the electrical domain and back again. Optical routers have the potential of saving in power by omitting these conversions, but have been held back in part by the lack of a practical optical memory device. This work presents the first integrated optical buffer for next generation optical packet-switched networks. Buffering is required in a router to move packets of data in order to avoid collisions between packets heading to the same destination at the same time. The device presented here uses an InP-based two-by-two switch with a silica waveguide delay to form a recirculating buffer. Packet storage was shown with 98% packet recovery for 5 circulations. Autonomous contention resolution was demonstrated with two buffered channels to show that the technology is a realistic solution for creating multiple element buffers on multiple router ports. This thesis proposes and demonstrates the first integrated optical random access memory, thereby making a great stride toward high capacity optical routers.

  16. Wireless design of a multisensor system for physical activity monitoring.

    PubMed

    Mo, Lingfei; Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John W; Freedson, Patty S

    2012-11-01

    Real-time monitoring of human physical activity (PA) is important for assessing the intensity of activity and exposure to environmental pollutions. A wireless wearable multisenor integrated measurement system (WIMS) has been designed for real-time measurement of the energy expenditure and breathing volume of human subjects under free-living conditions. To address challenges posted by the limited battery life and data synchronization requirement among multiple sensors in the system, the ZigBee communication platform has been explored for energy-efficient design. Two algorithms have been developed (multiData packaging and slot-data-synchronization) and coded into a microcontroller (MCU)-based sensor circuitry for real-time control of wireless data communication. Experiments have shown that the design enables continued operation of the wearable system for up to 68 h, with the maximum error for data synchronization among the various sensor nodes (SNs) being less than 24 ms. Experiment under free-living conditions have shown that the WIMS is able to correctly recognize the activity intensity level 86% of the time. The results demonstrate the effectiveness of the energy-efficient wireless design for human PA monitoring.

  17. New design deforming controlling system of the active stressed lap

    NASA Astrophysics Data System (ADS)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  18. A New Reactive FMIPv6 Mechanism for Minimizing Packet Loss

    NASA Astrophysics Data System (ADS)

    Kim, Pyungsoo

    This paper considers a new reactive fast handover MIPv6 (FMIPv6) mechanism to minimize packet loss of the existing mechanism. The primary idea of the proposed reactive FMIPv6 mechanism is that the serving access router buffers packets toward the mobile node (MN) as soon as the link layer between MN and serving base station is disconnected. To implement the proposed mechanism, the router discovery message exchanged between MN and serving access router is extended. In addition, the IEEE 802.21 Media Independent Handover Function event service message is defined newly. Through analytic performance evaluation and experiments, the proposed reactive FMIPv6 mechanism can be shown to minimize packet loss much than the existing mechanism.

  19. Semiclassical Dynamics of Electron Wave Packet States with Phase Vortices

    SciTech Connect

    Bliokh, Konstantin Yu.; Bliokh, Yury P.; Savel'ev, Sergey; Nori, Franco

    2007-11-09

    We consider semiclassical higher-order wave packet solutions of the Schroedinger equation with phase vortices. The vortex line is aligned with the propagation direction, and the wave packet carries a well-defined orbital angular momentum (OAM) ({Dirac_h}/2{pi})l (l is the vortex strength) along its main linear momentum. The probability current coils around the momentum in such OAM states of electrons. In an electric field, these states evolve like massless particles with spin l. The magnetic-monopole Berry curvature appears in momentum space, which results in a spin-orbit-type interaction and a Berry/Magnus transverse force acting on the wave packet. This brings about the OAM Hall effect. In a magnetic field, there is a Zeeman interaction, which, can lead to more complicated dynamics.

  20. On-board congestion control for satellite packet switching networks

    NASA Technical Reports Server (NTRS)

    Chu, Pong P.

    1991-01-01

    It is desirable to incorporate packet switching capability on-board for future communication satellites. Because of the statistical nature of packet communication, incoming traffic fluctuates and may cause congestion. Thus, it is necessary to incorporate a congestion control mechanism as part of the on-board processing to smooth and regulate the bursty traffic. Although there are extensive studies on congestion control for both baseband and broadband terrestrial networks, these schemes are not feasible for space based switching networks because of the unique characteristics of satellite link. Here, we propose a new congestion control method for on-board satellite packet switching. This scheme takes into consideration the long propagation delay in satellite link and takes advantage of the the satellite's broadcasting capability. It divides the control between the ground terminals and satellite, but distributes the primary responsibility to ground terminals and only requires minimal hardware resource on-board satellite.

  1. Bufferless Ultra-High Speed All-Optical Packet Routing

    NASA Astrophysics Data System (ADS)

    Muttagi, Shrihari; Prince, Shanthi

    2011-10-01

    All-Optical network is still in adolescence to cope up with steep rise in data traffic at the backbone network. Routing of packets in optical network depends on the processing speed of the All-Optical routers, thus there is a need to enhance optical processing to curb the delay in packet forwarding unit. In the proposed scheme, the header processing takes place on fly, therefore processing delay is at its lower limit. The objective is to propose a framework which establishes high data rate transmission with least latency in data routing from source to destination. The Routing table and optical header pulses are converted into Pulse Position (PP) format, thus reducing the complexity and in turn the processing delay. Optical pulse matching is exercised which results in multi-output transmission. This results in ultra-high speed packet forwarding unit. In addition, this proposed scheme includes dispersion compensation unit, which makes the data reliable.

  2. Chiral wave-packet scattering in Weyl semimetals

    NASA Astrophysics Data System (ADS)

    Jiang, Qing-Dong; Jiang, Hua; Liu, Haiwen; Sun, Qing-Feng; Xie, X. C.

    2016-05-01

    In quantum mechanics, a particle is best described by the wave packet instead of the plane wave. Here, we study the wave-packet scattering problem in Weyl semimetals with the low-energy Weyl fermions of different chiralities. Our results show that the wave packet acquires a chirality-protected shift in the single-impurity scattering process. More importantly, the chirality-protected shift can lead to an anomalous scattering probability, and thus affects the transport properties in Weyl semimetals. We find that the ratio between the transport lifetime and the quantum lifetime increases sharply when the Fermi energy approaches the Weyl nodes, providing an explanation of the experimentally observed ultrahigh mobility in topological (Weyl or Dirac) semimetals.

  3. Wave packet propagation across barriers by semiclassical initial value methods

    NASA Astrophysics Data System (ADS)

    Petersen, Jakob; Kay, Kenneth G.

    2015-07-01

    Semiclassical initial value representation (IVR) formulas for the propagator have difficulty describing tunneling through barriers. A key reason is that these formulas do not automatically reduce, in the classical limit, to the version of the Van Vleck-Gutzwiller (VVG) propagator required to treat barrier tunneling, which involves trajectories that have complex initial conditions and that follow paths in complex time. In this work, a simple IVR expression, that has the correct tunneling form in the classical limit, is derived for the propagator in the case of one-dimensional barrier transmission. Similarly, an IVR formula, that reduces to the Generalized Gaussian Wave Packet Dynamics (GGWPD) expression [D. Huber, E. J. Heller, and R. Littlejohn, J. Chem. Phys. 89, 2003 (1988)] in the classical limit, is derived for the transmitted wave packet. Uniform semiclassical versions of the IVR formulas are presented and simplified expressions in terms of real trajectories and WKB penetration factors are described. Numerical tests show that the uniform IVR treatment gives good results for wave packet transmission through the Eckart and Gaussian barriers in all cases examined. In contrast, even when applied with the proper complex trajectories, the VVG and GGWPD treatments are inaccurate when the mean energy of the wave packet is near the classical transmission threshold. The IVR expressions for the propagator and wave packet are cast as contour integrals in the complex space of initial conditions and these are generalized to potentially allow treatment of a larger variety of systems. A steepest descent analysis of the contour integral formula for the wave packet in the present cases confirms its relationship to the GGWPD method, verifies its semiclassical validity, and explains results of numerical calculations.

  4. Advances in integrated photonic circuits for packet-switched interconnection

    NASA Astrophysics Data System (ADS)

    Williams, Kevin A.; Stabile, Ripalta

    2014-03-01

    Sustained increases in capacity and connectivity are needed to overcome congestion in a range of broadband communication network nodes. Packet routing and switching in the electronic domain are leading to unsustainable energy- and bandwidth-densities, motivating research into hybrid solutions: optical switching engines are introduced for massive-bandwidth data transport while the electronic domain is clocked at more modest GHz rates to manage routing. Commercially-deployed optical switching engines using MEMS technologies are unwieldy and too slow to reconfigure for future packet-based networking. Optoelectronic packet-compliant switch technologies have been demonstrated as laboratory prototypes, but they have so far mostly used discretely pigtailed components, which are impractical for control plane development and product assembly. Integrated photonics has long held the promise of reduced hardware complexity and may be the critical step towards packet-compliant optical switching engines. Recently a number of laboratories world-wide have prototyped optical switching circuits using monolithic integration technology with up to several hundreds of integrated optical components per chip. Our own work has focused on multi-input to multi-output switching matrices. Recently we have demonstrated 8×8×8λ space and wavelength selective switches using gated cyclic routers and 16×16 broadband switching chips using monolithic multi-stage networks. We now operate these advanced circuits with custom control planes implemented with FPGAs to explore real time packet routing in multi-wavelength, multi-port test-beds. We review our contributions in the context of state of the art photonic integrated circuit technology and packet optical switching hardware demonstrations.

  5. Designing an Energy Drink: High School Students Learn Design and Marketing Skills in This Activity

    ERIC Educational Resources Information Center

    Martin, Doug

    2008-01-01

    A decade ago, energy drinks were almost nonexistent in the United States, but in the past five years they've become wildly popular. In fact, the $3.4 billion energy-drink market is expected to double this year alone, and the younger generation is the market targeted by manufacturers. This article presents an energy-drink designing activity. This…

  6. Fashion Design: Designing a Learner-Active, Multi-Level High School Course

    ERIC Educational Resources Information Center

    Nelson, Diane

    2009-01-01

    A high school fashion design teacher has much in common with the ringmaster of a three-ring circus. The challenges of teaching a hands-on course are to facilitate the entire class and to meet the needs of individual students. When teaching family and consumer sciences, the goal is to have a learner-active classroom. Revamping the high school's…

  7. UML activity diagram swimlanes in logic controller design

    NASA Astrophysics Data System (ADS)

    Grobelny, Michał; Grobelna, Iwona

    2015-12-01

    Logic controller behavior can be specified using various techniques, including UML activity diagrams and control Petri nets. Each technique has its advantages and disadvantages. Application of both specification types in one project allows to take benefits from both of them. Additional elements of UML models make it possible to divide a specification into some parts, considered from other point of view (logic controller, user or system). The paper introduces an idea to use UML activity diagrams with swimlanes to increase the understandability of design models.

  8. Engineering design activities and conceptual change in middle school science

    NASA Astrophysics Data System (ADS)

    Schnittka, Christine G.

    The purpose of this research was to investigate the impact of engineering design classroom activities on conceptual change in science, and on attitudes toward and knowledge about engineering. Students were given a situated learning context and a rationale for learning science in an active, inquiry-based method, and worked in small collaborative groups. One eighth-grade physical science teacher and her students participated in a unit on heat transfer and thermal energy. One class served as the control while two others received variations of an engineering design treatment. Data were gathered from teacher and student entrance and exit interviews, audio recordings of student dialog during group work, video recordings and observations of all classes, pre- and posttests on science content and engineering attitudes, and artifacts and all assignments completed by students. Qualitative and quantitative data were collected concurrently, but analysis took place in two phases. Qualitative data were analyzed in an ongoing manner so that the researcher could explore emerging theories and trends as the study progressed. These results were compared to and combined with the results of the quantitative data analysis. Analysis of the data was carried out in the interpretive framework of analytic induction. Findings indicated that students overwhelmingly possessed alternative conceptions about heat transfer, thermal energy, and engineering prior to the interventions. While all three classes made statistically significant gains in their knowledge about heat and energy, students in the engineering design class with the targeted demonstrations made the most significant gains over the other two other classes. Engineering attitudes changed significantly in the two classes that received the engineering design intervention. Implications from this study can inform teachers' use of engineering design activities in science classrooms. These implications are: (1) Alternative conceptions will

  9. Wave packet dynamics under effect of a pulsed electric field

    NASA Astrophysics Data System (ADS)

    da Silva, A. R. C. B.; de Moura, F. A. B. F.; Dias, W. S.

    2016-06-01

    We studied the dynamics of an electron in a crystalline one-dimensional model under effect of a time-dependent Gaussian field. The time evolution of an initially Gaussian wave packet it was obtained through the numerical solution of the time-dependent Schrödinger equation. Our analysis consists of computing the electronic centroid as well as the mean square displacement. We observe that the electrical pulse is able to promote a special kind of displacement along the chain. We demonstrated a direct relation between the group velocity of the wave packet and the applied electrical pulses. We compare those numerical calculations with a semi-classical approach.

  10. Control with a random access protocol and packet dropouts

    NASA Astrophysics Data System (ADS)

    Wang, Liyuan; Guo, Ge

    2016-08-01

    This paper investigates networked control systems whose actuators communicate with the controller via a limited number of unreliable channels. The access to the channels is decided by a so-called group random access protocol, which is modelled as a binary Markov sequence. Data packet dropouts in the channels are modelled as independent Bernoulli processes. For such systems, a systematic characterisation for controller synthesis is established and stated in terms of the transition probabilities of the Markov protocol and the packet dropout probabilities. The results are illustrated via a numerical example.

  11. Gabor Wave Packet Method to Solve Plasma Wave Equations

    SciTech Connect

    A. Pletzer; C.K. Phillips; D.N. Smithe

    2003-06-18

    A numerical method for solving plasma wave equations arising in the context of mode conversion between the fast magnetosonic and the slow (e.g ion Bernstein) wave is presented. The numerical algorithm relies on the expansion of the solution in Gaussian wave packets known as Gabor functions, which have good resolution properties in both real and Fourier space. The wave packets are ideally suited to capture both the large and small wavelength features that characterize mode conversion problems. The accuracy of the scheme is compared with a standard finite element approach.

  12. Symmetry and conservation laws in semiclassical wave packet dynamics

    SciTech Connect

    Ohsawa, Tomoki

    2015-03-15

    We formulate symmetries in semiclassical Gaussian wave packet dynamics and find the corresponding conserved quantities, particularly the semiclassical angular momentum, via Noether’s theorem. We consider two slightly different formulations of Gaussian wave packet dynamics; one is based on earlier works of Heller and Hagedorn and the other based on the symplectic-geometric approach by Lubich and others. In either case, we reveal the symplectic and Hamiltonian nature of the dynamics and formulate natural symmetry group actions in the setting to derive the corresponding conserved quantities (momentum maps). The semiclassical angular momentum inherits the essential properties of the classical angular momentum as well as naturally corresponds to the quantum picture.

  13. Zeno dynamics in wave-packet diffraction spreading

    SciTech Connect

    Porras, Miguel A.; Luis, Alfredo; Gonzalo, Isabel; Sanz, Angel S.

    2011-11-15

    We analyze a simple and feasible practical scheme displaying Zeno, anti-Zeno, and inverse-Zeno effects in the observation of wave-packet spreading caused by free evolution. The scheme is valid both in spatial diffraction of classical optical waves and in time diffraction of a quantum wave packet. In the optical realization, diffraction spreading is observed by placing slits between a light source and a light-power detector. We show that the occurrence of Zeno or anti-Zeno effects depends just on the frequency of observations between the source and detector. These effects are seen to be related to the diffraction mode theory in Fabry-Perot resonators.

  14. Short-time Chebyshev wave packet method for molecular photoionization

    NASA Astrophysics Data System (ADS)

    Sun, Zhaopeng; Zheng, Yujun

    2016-08-01

    In this letter we present the extended usage of short-time Chebyshev wave packet method in the laser induced molecular photoionization dynamics. In our extension, the polynomial expansion of the exponential in the time evolution operator, the Hamiltonian operator can act on the wave packet directly which neatly avoids the matrix diagonalization. This propagation scheme is of obvious advantages when the dynamical system has large Hamiltonian matrix. Computational simulations are performed for the calculation of photoelectronic distributions from intense short pulse ionization of K2 and NaI which represent the Born-Oppenheimer (BO) model and Non-BO one, respectively.

  15. Least cost process design for granular activated carbon adsorbers

    SciTech Connect

    Narbaitz, R.M.; Benedek, A.

    1983-10-01

    Although toxic organics may be removed from industrial effluents by activated carbon adsorbers, the cost of this process is relatively high. Also, adsorber design is complex because of the unsteady-state nature of the process and the numerous operational variables. A package of computer programs has been developed to help to minimise the ultimate cost of 4 types of column configurations. It determines the effect of treatment facility costs of different values for design and operational variables, such as empty bed contact time (EBCT), hydraulic loading, and column configurations. The results of a sample problem indicated that the optimum EBCT for all the column configurations was significantly higher than values typically used by designers.

  16. Spacecraft active thermal control subsystem design and operation considerations

    NASA Technical Reports Server (NTRS)

    Sadunas, J. A.; Lehtinen, A. M.; Nguyen, H. T.; Parish, R.

    1986-01-01

    Future spacecraft missions will be characterized by high electrical power requiring active thermal control subsystems for acquisition, transport, and rejection of waste heat. These systems will be designed to operate with minimum maintenance for up to 10 years, with widely varying externally-imposed environments, as well as the spacecraft waste heat rejection loads. This paper presents the design considerations and idealized performance analysis of a typical thermal control subsystem with emphasis on the temperature control aspects during off-design operation. The selected thermal management subsystem is a cooling loop for a 75-kWe fuel cell subsystem, consisting of a fuel cell heat exchanger, thermal storage, pumps, and radiator. Both pumped-liquid transport and two-phase (liquid/vapor) transport options are presented with examination of similarities and differences of the control requirements for these representative thermal control options.

  17. Wavelet packet transform-based optical orthogonal frequency-division multiplexing transmission using direct detection

    NASA Astrophysics Data System (ADS)

    Zhang, Hongbo; Yi, Xingwen; Chen, Lei; Zhang, Jing; Deng, Mingliang; Qiu, Kun

    2012-10-01

    As an alternate to fast Fourier transform-based orthogonal frequency-division multiplexing (OFDM), wavelet packet transform (WPT)-based OFDM (WPT-OFDM) does not require cyclic prefix to avoid inter-symbol-interference. The wavelet has many varieties and therefore, it can provide more freedom for system design to suit different applications. We propose a real-valued WPT-OFDM that uses intensity modulation/direct detection. We also conduct an experiment to verify its performance through a 75-km standard single-mode fiber.

  18. Alfvénic wave packets collision in a kinetic plasma

    NASA Astrophysics Data System (ADS)

    Pezzi, Oreste; Parashar, Tulasi N.; Servidio, Sergio; Valentini, Francesco; Malara, Francesco; Matthaeus, William H.; Veltri, Pierluigi

    2016-04-01

    The problem of two colliding and counter-propagating Alfvénic wave packets has been investigated in detail since the late Seventies. In particular Moffatt [1] and Parker [2] showed that, in the framework of the incompressible magnetohydrodynamics (MHD), nonlinear interactions can develop only during the overlapping of the two packets. Here we describe a similar problem in the framework of the kinetic physics. The collision of two quasi-Alfvénic packets has been analyzed by means of MHD, Hall-MHD and kinetic simulations performed with two different hybrid codes: a PIC code [3] and a Vlasov-Maxwell code [4]. Due to the huge computational cost, only a 2D-3V phase space is allowed (two dimensions in the physical space, three dimensions in the velocity space). Preliminary results suggest that, as well as in the MHD case, the most relevant nonlinear effects occur during the overlapping of the two packets. For both the PIC and Vlasov cases, strong temperature anisotropies are present during the evolution of the wave packets. Moreover, due to the absence of numerical noise, Vlasov simulations show that the collision of the counter-propagating solitary waves produces a significant beam in the velocity distribution functions [5], which, instead, cannot be appreciated in PIC simulations. We remark that, beyond the interest of studying a well-known MHD problem in the realm of the kinetic physics, our results allows also to compare different numerical codes. [1] H.K. Moffatt, Field generation in electrically conducting fluids (Cambridge University Press, 1978). [2] E.N. Parker, Cosmical magnetic fields: their origin and their activity (Oxford University Press, 1979). [3] T.N. Parashar, M.A. Shay, P.A. Cassak and W.H. Matthaeus, Physics of Plasmas 16, 032310 (2009). [4] F. Valentini, P. Trávníček, F. Califano, P. Hellinger & A. Mangeney, Journal of Computational Physics 225, 753-770 (2007). [5] J. He, C. Tu, E. Marsch, C.H. Chen, L. Wang, Z. Pei, L. Zhang, C.S. Salem and S

  19. Design and analysis of a model predictive controller for active queue management.

    PubMed

    Wang, Ping; Chen, Hong; Yang, Xiaoping; Ma, Yan

    2012-01-01

    Model predictive (MP) control as a novel active queue management (AQM) algorithm in dynamic computer networks is proposed. According to the predicted future queue length in the data buffer, early packets at the router are dropped reasonably by the MPAQM controller so that the queue length reaches the desired value with minimal tracking error. The drop probability is obtained by optimizing the network performance. Further, randomized algorithms are applied to analyze the robustness of MPAQM successfully, and also to provide the stability domain of systems with uncertain network parameters. The performances of MPAQM are evaluated through a series of simulations in NS2. The simulation results show that the MPAQM algorithm outperforms RED, PI, and REM algorithms in terms of stability, disturbance rejection, and robustness.

  20. FEL Design Studies at LBNL: Activities and Plans

    SciTech Connect

    Corlett, John N.; Fawley, W.; Lidia, S.; Padmore, H.; Penn, G.; Pogorelov, I.; Qiang, J.; Sannibale, F.; Staples, J.; Steier, C.; Venturini, M.; Wan, W.; Wilcox, R.; Zholents, A.

    2007-03-01

    LBNL staff are currently pursuing R&D for future x-ray FELs, and participate in two FEL construction projects. Our strategy is to address the most fundamental challenges, which are the cost-drivers and performance limitations of FEL facilities. An internally funded R&D program is aimed at investigating accelerator physics and technologies in three key areas: (1) Theoretical study, modeling, and experimental development of low emittance, high quantum efficiency cathodes; (2) Design studies of electron beam delivery systems, including emittance manipulations, high-resolution modeling of 6-D phase space, and low-emittance beam transport; and (3) Design studies of optical manipulations of electron beams for seeded and SASE FELs, providing short x-ray pulses of variable duration, synchronous with the seed and pump laser sources, and also long transform-limited pulses with a narrow bandwidth. Design studies of means for production of attosecond x-ray pulses at various wavelengths. We are collaborators in the FERMI{at}Elettra seeded FEL facility under construction at Sincrotrone Trieste, Italy, participating in accelerator design and FEL physics studies, and mechanical and electrical engineering. We are participating in the LCLS project at SLAC, implementing our design of stabilized timing and synchronization systems. Here we outline our long-term objectives, and current activities.

  1. Lambda network having 2{sup m{minus}1} nodes in each of m stages with each node coupled to four other nodes for bidirectional routing of data packets between nodes

    DOEpatents

    Napolitano, L.M. Jr.

    1995-11-28

    The Lambda network is a single stage, packet-switched interprocessor communication network for a distributed memory, parallel processor computer. Its design arises from the desired network characteristics of minimizing mean and maximum packet transfer time, local routing, expandability, deadlock avoidance, and fault tolerance. The network is based on fixed degree nodes and has mean and maximum packet transfer distances where n is the number of processors. The routing method is detailed, as are methods for expandability, deadlock avoidance, and fault tolerance. 14 figs.

  2. Active Learning by Design: An Undergraduate Introductory Public Health Course

    PubMed Central

    Yeatts, Karin B.

    2014-01-01

    Principles of active learning were used to design and implement an introductory public health course. Students were introduced to the breadth and practice of public health through team and individual-based activities. Team assignments covered topics in epidemiology, biostatistics, health behavior, nutrition, maternal and child health, environment, and health policy. Students developed an appreciation of the population perspective through an “experience” trip and related intervention project in a public health area of their choice. Students experienced several key critical component elements of a public health undergraduate major; they explored key public health domains, experience public health practice, and integrated concepts with their assignments. In this paper, course assignments, lessons learned, and student successes are described. Given the increased growth in the undergraduate public health major, these active learning assignments may be of interest to undergraduate public health programs at both liberal arts colleges and research universities. PMID:25566526

  3. Joint source coding, transport processing, and error concealment for H.323-based packet video

    NASA Astrophysics Data System (ADS)

    Zhu, Qin-Fan; Kerofsky, Louis

    1998-12-01

    In this paper, we investigate how to adapt different parameters in H.263 source coding, transport processing and error concealment to optimize end-to-end video quality at different bitrates and packet loss rates for H.323-based packet video. First different intra coding patterns are compared and we show that the contiguous rectangle or square block pattern offers the best performance in terms of video quality in the presence of packet loss. Second, the optimal intra coding frequency is found for different bitrates and packet loss rates. The optimal number of GOB headers to be inserted in the source coding is then determined. The effect of transport processing strategies such as packetization and retransmission is also examined. For packetization, the impact of packet size and the effect of macroblock segmentation to picture quality are investigated. Finally, we show that the dejitter buffering delay can be used to the advantage for packet loss recovery with video retransmission without incurring any extra delay.

  4. A multi-ring optical packet and circuit integrated network with optical buffering.

    PubMed

    Furukawa, Hideaki; Shinada, Satoshi; Miyazawa, Takaya; Harai, Hiroaki; Kawasaki, Wataru; Saito, Tatsuhiko; Matsunaga, Koji; Toyozumi, Tatuya; Wada, Naoya

    2012-12-17

    We newly developed a 3 × 3 integrated optical packet and circuit switch-node. Optical buffers and burst-mode erbium-doped fiber amplifiers with the gain flatness are installed in the 3 × 3 switch-node. The optical buffer can prevent packet collisions and decrease packet loss. We constructed a multi-ring optical packet and circuit integrated network testbed connecting two single-ring networks and a client network by the 3 × 3 switch-node. For the first time, we demonstrated 244 km fiber transmission and 5-node hopping of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10 Gigabit Ethernet frames on the testbed. Error-free (frame error rate < 1 × 10(-4)) operation was achieved with optical packets of various packet lengths. In addition, successful avoidance of packet collisions by optical buffers was confirmed.

  5. Activation product safety in the ARIES-I reactor design

    SciTech Connect

    Herring, J.S. ); Sze, D.K. ); Wong, C.; Cheng, E.T. ); Grotz, S.P. )

    1990-01-01

    The ARIES design effort has sought to maximize the environmental and safety advantages of fusion through careful selection of materials and careful design. Three goals are that the reactor achieve inherent or passive safety, that no public evacuation plan be necessary and that the waste be disposable as 10CFR61 Class C waste. The ARIES-I reactor consists of a SiC composite structure for the first wall and blanket, cooled by 10 MPa He. The breeder is Li{sub 2}ZrO{sub 3}, although Li{sub 2}O and Li{sub 4}SiO{sub 4} were also considered. The divertor consists of SiC composite tubes coated with 2 mm of tungsten. Due to the minimal afterheat of this blanket design, LOCA calculations indicate maximum temperatures will not cause damage if the plasma is promptly extinguished. Two primary safety issues are the zirconium in the breeder and tungsten on the divertor. Li{sub 2}ZrO{sub 3} was chosen because of its demonstrated high-temperature stability. The other breeders have lower afterheat and activation. Use of zirconium in the breeder will necessitate isotopic tailoring to remove {sup 90}Zr and {sup 94}Zr. The 5.8 tonnes of W on the divertor would also have to be tailored to remove {sup 186}W and/or to concentrate {sup 183}W. Thus the ARIES-I design achieves the passive safety and low-level waste disposal criteria with respect to activation products. Development of low activation materials to replace zirconium and tungsten is needed to avoid requiring an evacuation plan.

  6. Packet based serial link realized in FPGA dedicated for high resolution infrared image transmission

    NASA Astrophysics Data System (ADS)

    Bieszczad, Grzegorz

    2015-05-01

    In article the external digital interface specially designed for thermographic camera built in Military University of Technology is described. The aim of article is to illustrate challenges encountered during design process of thermal vision camera especially related to infrared data processing and transmission. Article explains main requirements for interface to transfer Infra-Red or Video digital data and describes the solution which we elaborated based on Low Voltage Differential Signaling (LVDS) physical layer and signaling scheme. Elaborated link for image transmission is built using FPGA integrated circuit with built-in high speed serial transceivers achieving up to 2500Gbps throughput. Image transmission is realized using proprietary packet protocol. Transmission protocol engine was described in VHDL language and tested in FPGA hardware. The link is able to transmit 1280x1024@60Hz 24bit video data using one signal pair. Link was tested to transmit thermal-vision camera picture to remote monitor. Construction of dedicated video link allows to reduce power consumption compared to solutions with ASIC based encoders and decoders realizing video links like DVI or packed based Display Port, with simultaneous reduction of wires needed to establish link to one pair. Article describes functions of modules integrated in FPGA design realizing several functions like: synchronization to video source, video stream packeting, interfacing transceiver module and dynamic clock generation for video standard conversion.

  7. Standard services for the capture, processing, and distribution of packetized telemetry data

    NASA Technical Reports Server (NTRS)

    Stallings, William H.

    1989-01-01

    Standard functional services for the capture, processing, and distribution of packetized data are discussed with particular reference to the future implementation of packet processing systems, such as those for the Space Station Freedom. The major functions are listed under the following major categories: input processing, packet processing, and output processing. A functional block diagram of a packet data processing facility is presented, showing the distribution of the various processing functions as well as the primary data flow through the facility.

  8. Compression of echocardiographic scan line data using wavelet packet transform

    NASA Technical Reports Server (NTRS)

    Hang, X.; Greenberg, N. L.; Qin, J.; Thomas, J. D.

    2001-01-01

    An efficient compression strategy is indispensable for digital echocardiography. Previous work has suggested improved results utilizing wavelet transforms in the compression of 2D echocardiographic images. Set partitioning in hierarchical trees (SPIHT) was modified to compress echocardiographic scanline data based on the wavelet packet transform. A compression ratio of at least 94:1 resulted in preserved image quality.

  9. A CURRICULUM FOR ENGLISH, STUDENT PACKET, GRADE 12.

    ERIC Educational Resources Information Center

    Nebraska Univ., Lincoln. Curriculum Development Center.

    THE LITERATURE PROGRAM OF THE GRADE 12 STUDENT PACKET OF THE NEBRASKA ENGLISH CURRICULUM CONSISTS OF A SELECTIVE SURVEY OF ENGLISH LITERATURE FROM THE RENAISSANCE TO THE 20TH CENTURY. IT BEGINS WITH A UNIT ON SHAKESPEAREAN TRAGEDY IN WHICH STUDENTS READ REVENGE TRAGEDIES--SENECA'S "THYESTES" AND KYD'S "THE SPANISH TRAGEDY"--AS PREPARATION FOR THE…

  10. Scattering of wave packets on atoms in the Born approximation

    NASA Astrophysics Data System (ADS)

    Karlovets, D. V.; Kotkin, G. L.; Serbo, V. G.

    2015-11-01

    It has recently been demonstrated experimentally that 200 -300 keV electrons with the unusual spatial profiles can be produced and even focused to a subnanometer scale—namely, electrons carrying nonzero orbital angular momentum and also the so-called Airy beams. Since the wave functions of such electrons do not represent plane waves, the standard Born formula for scattering of them off a potential field is no longer applicable and, hence, needs modification. In the present paper, we address the generic problem of elastic scattering of a wave packet of a fast nonrelativistic particle off a potential field. We obtain simple and convenient formulas for a number of events and an effective cross section in such a scattering, which represent generalization of the Born formula for a case when finite sizes and spatial inhomogeneity of the initial packet should be taken into account. As a benchmark, we consider two simple models corresponding to scattering of a Gaussian wave packet on a Gaussian potential and on a hydrogen atom, and perform a detailed analysis of the effects brought about by the limited sizes of the incident beam and by the finite impact parameter between the potential center and the packet's axis.

  11. Energy Crisis: Libya's and Nigeria's Role. Resource Packet.

    ERIC Educational Resources Information Center

    African-American Inst., New York, NY. School Services Div.

    This resource packet contains practical suggestions and resource materials to help secondary teachers teach about Libya's and Nigeria's roles in the energy crisis. Students become acquainted with the governments and cultures of the two countries, examine their social problems, and learn how the Libyan and Nigerian governments are using money from…

  12. Teaching about the U.S. Constitution. A Resource Packet.

    ERIC Educational Resources Information Center

    Leming, Robert S.; And Others

    The 200th anniversary of the United States Constitution offers an excellent opportunity for encouraging renewed study of the principles and foundations of constitutional government. This resource packet provides a listing of current materials and resources to aid teachers in planning lesson units. The listings include: (1) professional…

  13. 41 CFR 101-39.306 - Operator's packet.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.3-Use and Care of GSA Interagency Fleet Management System Vehicles § 101-39.306 Operator's packet. The GSA Interagency Fleet Management System (IFMS) will provide...

  14. 41 CFR 101-39.306 - Operator's packet.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.3-Use and Care of GSA Interagency Fleet Management System Vehicles § 101-39.306 Operator's packet. The GSA Interagency Fleet Management System (IFMS) will provide...

  15. Using the Internet To Create Primary Source Teaching Packets.

    ERIC Educational Resources Information Center

    VanFossen, Phillip J.; Shiveley, James M.

    2000-01-01

    Describes strategies and guidelines for creating age- and content-appropriate primary source documents using the Internet. Discusses the value of using topic-specific primary source teaching packets, or jackdaws. Provides three Internet generated jackdaws: New Deal/FDR, Home Front during World War II, and the Gilded Age. Addresses fair use issues.…

  16. An Efficient Conflict Detection Algorithm for Packet Filters

    NASA Astrophysics Data System (ADS)

    Lee, Chun-Liang; Lin, Guan-Yu; Chen, Yaw-Chung

    Packet classification is essential for supporting advanced network services such as firewalls, quality-of-service (QoS), virtual private networks (VPN), and policy-based routing. The rules that routers use to classify packets are called packet filters. If two or more filters overlap, a conflict occurs and leads to ambiguity in packet classification. This study proposes an algorithm that can efficiently detect and resolve filter conflicts using tuple based search. The time complexity of the proposed algorithm is O(nW+s), and the space complexity is O(nW), where n is the number of filters, W is the number of bits in a header field, and s is the number of conflicts. This study uses the synthetic filter databases generated by ClassBench to evaluate the proposed algorithm. Simulation results show that the proposed algorithm can achieve better performance than existing conflict detection algorithms both in time and space, particularly for databases with large numbers of conflicts.

  17. A CURRICULUM FOR ENGLISH, STUDENT PACKET, GRADE 7.

    ERIC Educational Resources Information Center

    Nebraska Univ., Lincoln. Curriculum Development Center.

    THE SEVENTH-GRADE STUDENT PACKET, PRODUCED BY THE NEBRASKA CURRICULUM DEVELOPMENT CENTER, BEGINS WITH THE UNIT ENTITLED "THE MAKING OF STORIES" IN WHICH STUDENTS CONSIDER WRITERS' AUDIENCES AND METHODS OF COMPOSITION AND PRESENTATION. SUCH MATERIAL AS "A CHRISTMAS CAROL" AND SELECTIONS FROM "THE ODYSSEY,""BEOWULF,""HYMN TO HERMES," AND GRIMM'S…

  18. Marine and Coastal Resources. Global Issues Education Packet.

    ERIC Educational Resources Information Center

    Holm, Amy E.

    At least 70% of the Earth is covered with water. This packet provides background information on eight areas of concern regarding marine and coastal resources. Considered are: (1) "Coastal Resources"; (2) "Mangroves"; (3) "Coral Reefs"; (4) "Ocean Resources"; (5) "Aquaculture"; (6) "Pollution"; (7) "Marine Debris"; and (8) "The Global Commons."…

  19. Hardware packet pacing using a DMA in a parallel computer

    DOEpatents

    Chen, Dong; Heidelberger, Phillip; Vranas, Pavlos

    2013-08-13

    Method and system for hardware packet pacing using a direct memory access controller in a parallel computer which, in one aspect, keeps track of a total number of bytes put on the network as a result of a remote get operation, using a hardware token counter.

  20. "Macbeth." A Play Packet To Accompany "Elementary, My Dear Shakespeare."

    ERIC Educational Resources Information Center

    Engen, Barbara; Campbell, Joy

    Intended for use by elementary school teachers as a supplement to the book, "Elementary, My Dear Shakespeare," or for use by itself to produce one Shakespeare play, this play packet contains ready-to-reproduce materials for the production of "Macbeth." Materials include: staging suggestions for scenery, props, lighting, and costumes; a short…

  1. A CURRICULUM FOR ENGLISH, TEACHER PACKET, GRADE 11.

    ERIC Educational Resources Information Center

    Nebraska Univ., Lincoln. Curriculum Development Center.

    UNITS IN THE TEACHER PACKET FOR THE 11TH-GRADE NEBRASKA ENGLISH CURRICULUM ARE ORGANIZED AROUND THREE MAJOR THEMES IN AMERICAN LITERATURE--MAN AND NATURE, MAN AND MORAL LAW, AND MAN AND SOCIETY. THE MAN AND NATURE THEME IS EXAMINED IN TWO UNITS--"INDIVIDUALISM AND IDEALISM, SPIRITUAL AUTOBIOGRAPHY" AND "THE SEARCH FOR FORM." THE FORMER UNIT, AN…

  2. Wave packet motion in harmonic potential and computer visualization

    NASA Technical Reports Server (NTRS)

    Tsuru, Hideo; Kobayashi, Takeshi

    1993-01-01

    Wave packet motions of a single electron in harmonic potentials or a magnetic field are obtained analytically. The phase of the wave function which depends on both time and space is also presented explicitly. The probability density of the electron changes its width and central position periodically. These results are visualized using computer animation techniques.

  3. Resonance-assisted decay of nondispersive wave packets.

    PubMed

    Wimberger, Sandro; Schlagheck, Peter; Eltschka, Christopher; Buchleitner, Andreas

    2006-07-28

    We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining resonance-assisted tunneling with subsequent transport across chaotic phase space and a final ionization step.

  4. An integrated circuit/packet switched videoconferencing system

    SciTech Connect

    Kippenhan, H.A. Jr.; Lidinsky, W.P.; Roediger, G.A.; Watts, T.A.

    1995-11-01

    The HEP Network Resource Center (HEPNRC) at Fermilab and the Collider Detector Facility (CDF) collaboration have evolved a flexible, cost-effective, widely accessible videoconferencing system for use by high energy physics collaborations and others wishing to use videoconferencing. No current systems seemed to fully meet the needs of high energy physics collaborations. However, two classes of videoconferencing technology: circuit-switched and packet-switched, if integrated, might encompass most of HEP`s needs. It was also realized that, even with this integration, some additional functions were needed and some of the existing functions were not always wanted. HEPNRC with the help of members of the CDF collaboration set out to develop such an integrated system using as many existing subsystems and components as possible. This system is called VUPAC (Videoconferencing Using PAckets and Circuits). This paper begins with brief descriptions of the circuit-switched and packet-switched videoconferencing systems. Following this, issues and limitations of these systems are considered. Next the VUPAC system is described. Integration is accomplished primarily by a circuit/packet videoconferencing interface. Augmentation is centered in another subsystem called MSB (Multiport multisession Bridge). Finally, there is a discussion of the future work needed in the evolution of this system.

  5. Customized lifting multiwavelet packet information entropy for equipment condition identification

    NASA Astrophysics Data System (ADS)

    Chen, Jinglong; Zuo, Ming J.; Zi, Yanyang; He, Zhengjia; Yuan, Jing; Chen, Xuefeng

    2013-09-01

    Condition identification of mechanical equipment from vibration measurement data is significant to avoid economic loss caused by unscheduled breakdowns and catastrophic accidents. However, this task still faces challenges due to the complexity of equipment and the harsh environment. This paper provides a possibility for equipment condition identification by proposing a method called customized lifting multiwavelet packet information entropy. Benefiting from the properties of multi-resolution analysis and multiple wavelet basis functions, the multiwavelet method has advantages in characterizing non-stationary vibration signals. In order to realize the accurate detection and identification of the condition features, a customized lifting multiwavelet packet is constructed via a multiwavelet lifting scheme. Then the vibration signal from the mechanical equipment is processed by the customized lifting multiwavelet packet transform. The relative energy in each frequency band of the multiwavelet packet transform coefficients that equals a percentage of the whole signal energy is taken as the probability. The normalized information entropy is obtained based on the relative energy to describe the condition of a mechanical system. The proposed method is applied to the condition identification of a rolling mill and a demountable disk-drum aero-engine. The results support the feasibility of the proposed method in equipment condition identification.

  6. The Sphinx and the Pyramids at Giza. Educational Packet.

    ERIC Educational Resources Information Center

    Gagliano, Sara; Rapport, Wendy

    This packet of materials was created to accompany the exhibit "The Sphinx and the Pyramids: 100 Years of American Archaeology at Giza" at the Semitic Museum of Harvard University. The lessons and teacher's guide focus on the following: (1) "The Mystery of the Secret Tomb" where students take on the role of an archaeologist by attempting to solve a…

  7. Application of Cellular Automata to Detection of Malicious Network Packets

    ERIC Educational Resources Information Center

    Brown, Robert L.

    2014-01-01

    A problem in computer security is identification of attack signatures in network packets. An attack signature is a pattern of bits that characterizes a particular attack. Because there are many kinds of attacks, there are potentially many attack signatures. Furthermore, attackers may seek to avoid detection by altering the attack mechanism so that…

  8. Teacher Education Packet for Illinois Core Curriculum in Agriculture.

    ERIC Educational Resources Information Center

    Hemp, Paul; Pepple, Jerry

    Developed for use by teacher educators or state staff, this teaching packet provides preservice or inservice training to teachers and prospective teachers on how to use the Illinois Core Curriculum in Agriculture. (It is recommended that copies of the Illinois core materials be available to the students.) Three problem areas are included:…

  9. Robust H ∞ Filtering for a Class of Complex Networks with Stochastic Packet Dropouts and Time Delays

    PubMed Central

    Lyu, Ming; Guo, Pengfei; Bo, Yuming

    2014-01-01

    The robust H ∞ filtering problem is investigated for a class of complex network systems which has stochastic packet dropouts and time delays, combined with disturbance inputs. The packet dropout phenomenon occurs in a random way and the occurrence probability for each measurement output node is governed by an individual random variable. Besides, the time delay phenomenon is assumed to occur in a nonlinear vector-valued function. We aim to design a filter such that the estimation error converges to zero exponentially in the mean square, while the disturbance rejection attenuation is constrained to a given level by means of the H ∞ performance index. By constructing the proper Lyapunov-Krasovskii functional, we acquire sufficient conditions to guarantee the stability of the state detection observer for the discrete systems, and the observer gain is also derived by solving linear matrix inequalities. Finally, an illustrative example is provided to show the usefulness and effectiveness of the proposed design method. PMID:24987738

  10. Exploring multiple degrees of freedom in Rydberg wave packets

    NASA Astrophysics Data System (ADS)

    Wen, Haidan

    2006-12-01

    Recent advances in the study of Rydberg atoms have focused on the control, manipulation and detection of Rydberg wave packets using novel external fields such as half-cycle pulses. The radial degree of freedom has been controlled and used to process information encoded in Rydberg states. However, these previous experiments make use of only a single degree of freedom, restricting the potential of other degrees of freedom for quantum computing in Rydberg atoms. In this dissertation, we explore the control and detection of other degrees of freedom in an electron wave packet, such as the angular momentum quantum number ℓ, the magnetic quantum number m and the electron spin; so that the full range of quantum numbers can participate in information processing. We first propose an interferometric control of the population of angular momentum states using two time-delayed phase-locked ultrafast laser pulses. The population of arbitrary angular momentum states can be greatly enhanced by optimizing the time delay and the relative phases between two laser pulses. We then qualitatively measure the evolution of angular momentum components in Stark wave packets by a weak half-cycle pulse (HCP). This measurement utilizes a time-delayed HCP and is proved to be effective for detecting various aspects of wave packet dynamics, particularly, the evolution of non-stationary states. The technique relies on the fact that the HCP redistributes the eigenstate populations and induced the population variation which reflects the evolution of eigenstate phases. Finally, we find that the dynamics of m-states could be highly correlated with the internal degree of freedom of the electron, the spin. We study the effect of spin-orbit coupling on the wave packet dynamics and observe the angular precession of a Rydberg wave packet. The population redistribution from p to s states is highly sensitive to the polarization of the HCP and changes with the precession of the electron orbit. We obtain the

  11. Design, test, and evaluation of three active flutter suppression controllers

    NASA Technical Reports Server (NTRS)

    Adams, William M., Jr.; Christhilf, David M.; Waszak, Martin R.; Mukhopadhyay, Vivek; Srinathkumar, S.

    1992-01-01

    Three control law design techniques for flutter suppression are presented. Each technique uses multiple control surfaces and/or sensors. The first method uses traditional tools (such as pole/zero loci and Nyquist diagrams) for producing a controller that has minimal complexity and which is sufficiently robust to handle plant uncertainty. The second procedure uses linear combinations of several accelerometer signals and dynamic compensation to synthesize the model rate of the critical mode for feedback to the distributed control surfaces. The third technique starts with a minimum-energy linear quadratic Gaussian controller, iteratively modifies intensity matrices corresponding to input and output noise, and applies controller order reduction to achieve a low-order, robust controller. The resulting designs were implemented digitally and tested subsonically on the active flexible wing wind-tunnel model in the Langley Transonic Dynamics Tunnel. Only the traditional pole/zero loci design was sufficiently robust to errors in the nominal plant to successfully suppress flutter during the test. The traditional pole/zero loci design provided simultaneous suppression of symmetric and antisymmetric flutter with a 24-percent increase in attainable dynamic pressure. Posttest analyses are shown which illustrate the problems encountered with the other laws.

  12. Design, Synthesis, and Antifungal Activity of New α-Aminophosphonates

    PubMed Central

    Rezaei, Zahra; Khabnadideh, Soghra; Zomorodian, Kamiar; Pakshir, Keyvan; Nadali, Setareh; Mohtashami, Nadia; Faghih Mirzaei, Ehsan

    2011-01-01

    α-Aminophosphonates are bioisosteres of amino acids and have several pharmacological activities. These compounds have been synthesized by various routes from reaction between amine, aldehyde, and phosphite compounds. In order to synthesize α-aminophosphonates, catalytic effect of CuCl2 was compared with FeCl3. Also all designed structures as well as griseofulvin were docked into the active site of microtubule (1JFF), using Autodock program. The results showed that the reactions were carried out in the presence of CuCl2 in lower yields, and also the time of reaction was longer in comparison with FeCl3. The chemical structures of the new compounds were confirmed by spectral analyses. The compounds were investigated for antifungal activity against several fungi in comparison with griseofulvin. An indole-derived bis(α-aminophosphonates) with the best negative ΔG in docking study showed maximum antifungal activity against Microsporum canis, and other investigated compounds did not have a good antifungal activity. PMID:25954522

  13. Design of active orthoses for a robotic gait rehabilitation system

    NASA Astrophysics Data System (ADS)

    Villa-Parra, A. C.; Broche, L.; Delisle-Rodríguez, D.; Sagaró, R.; Bastos, T.; Frizera-Neto, A.

    2015-09-01

    An active orthosis (AO) is a robotic device that assists both human gait and rehabilitation therapy. This work proposes portable AOs, one for the knee joint and another for the ankle joint. Both AOs will be used to complete a robotic system that improves gait rehabilitation. The requirements for actuator selection, the biomechanical considerations during the AO design, the finite element method, and a control approach based on electroencephalographic and surface electromyographic signals are reviewed. This work contributes to the design of AOs for users with foot drop and knee flexion impairment. However, the potential of the proposed AOs to be part of a robotic gait rehabilitation system that improves the quality of life of stroke survivors requires further investigation.

  14. On the modified active region design of interband cascade lasers

    SciTech Connect

    Motyka, M.; Ryczko, K.; Dyksik, M.; Sęk, G.; Misiewicz, J.; Weih, R.; Dallner, M.; Kamp, M.; Höfling, S.

    2015-02-28

    Type II InAs/GaInSb quantum wells (QWs) grown on GaSb or InAs substrates and designed to be integrated in the active region of interband cascade lasers (ICLs) emitting in the mid infrared have been investigated. Optical spectroscopy, combined with band structure calculations, has been used to probe their electronic properties. A design with multiple InAs QWs has been compared with the more common double W-shaped QW and it has been demonstrated that it allows red shifting the emission wavelength and enhancing the transition oscillator strength. This can be beneficial for the improvements of the ICLs performances, especially when considering their long-wavelength operation.

  15. System design for active vibration control of aerospace structures

    NASA Astrophysics Data System (ADS)

    Shankar, V.; Nagaraja, B. V.; Balasubramaniam, R.; Shree S, Amrutha; Muthaiah, Skanda N.

    2003-10-01

    Instrumentation, electronics, digital signal processing and related software form the basic building blocks of a system for implementation of Active Vibration Control (AVC) for smart aerospace structures. This paper essentially deals with the design, development and implementation of a 4 channel analog input sub-system essentially consisting of charge amplifiers, filters, gain amplifiers & Analog to Digital Converters (ADC), the subsequent Digital Signal Processor (DSP) hardware for implementation of the controller and finally a 4 Channel analog output subsystem consisting of Digital to Analog Converters (DAC), reconstruction filters & high voltage amplifiers. This system essentially interfaces to a structure with piezo-ceramic sensors and actuators for implementation of real time AVC on a smart beam. The paper also highlights some of the new ideas that have been incorporated into the system design.

  16. Design of an active magnetic regenerator test apparatus

    NASA Astrophysics Data System (ADS)

    Rowe, A. M.; Barclay, J. A.

    2002-05-01

    The Active Magnetic Regenerator (AMR) has been shown to be a refrigeration technology with high efficiencies. Complex thermodynamic interactions in the regenerator, a shortage of suitable magnetic refrigerants, and difficulty in acquiring accurate experimental data have combined to hamper the development of AMR refrigerators. An apparatus to dynamically characterize the behavior of AMR beds is a valuable tool in furthering the development of the technology. This paper describes the design and construction of an AMR test apparatus. For initial tests, the apparatus has been used to examine the performance of Gd AMR beds operating in 2 T fields.

  17. Shuttle Orbiter Active Thermal Control Subsystem design and flight experience

    NASA Technical Reports Server (NTRS)

    Bond, Timothy A.; Metcalf, Jordan L.; Asuncion, Carmelo

    1991-01-01

    The paper examines the design of the Space Shuttle Orbiter Active Thermal Control Subsystem (ATCS) constructed for providing the vehicle and payload cooling during all phases of a mission and during ground turnaround operations. The operation of the Shuttle ATCS and some of the problems encountered during the first 39 flights of the Shuttle program are described, with special attention given to the major problems encountered with the degradation of the Freon flow rate on the Orbiter Columbia, the Flash Evaporator Subsystem mission anomalies which occurred on STS-26 and STS-34, and problems encountered with the Ammonia Boiler Subsystem. The causes and the resolutions of these problems are discussed.

  18. Design and implementation of a project-based active/cooperative engineering design course for freshmen

    NASA Astrophysics Data System (ADS)

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-08-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long learning, realistic constraints and awareness of current domestic and global challenges. Throughout successive design reports and in-class assignments, the students are required by the end of the semester to communicate, clearly and concisely, the details of their design both orally and in writing through a functional artefact/prototype, a design notebook, an A0 project poster and a final oral presentation. In addition to these direct assessment tools, several indirect measures are used to ensure triangulation. Assignments are based on customer expectations using a detailed checklist. This paper shows the direct and indirect assessment tools that indicated a high level of achievement of course learning outcomes and a high level of student satisfaction.

  19. Design, synthesis and structure-activity relationship of phthalimides endowed with dual antiproliferative and immunomodulatory activities.

    PubMed

    Cardoso, Marcos Veríssimo de Oliveira; Moreira, Diogo Rodrigo Magalhães; Oliveira Filho, Gevanio Bezerra; Cavalcanti, Suellen Melo Tiburcio; Coelho, Lucas Cunha Duarte; Espíndola, José Wanderlan Pontes; Gonzalez, Laura Rubio; Rabello, Marcelo Montenegro; Hernandes, Marcelo Zaldini; Ferreira, Paulo Michel Pinheiro; Pessoa, Cláudia; Alberto de Simone, Carlos; Guimarães, Elisalva Teixeira; Soares, Milena Botelho Pereira; Leite, Ana Cristina Lima

    2015-01-01

    The present work reports the synthesis and evaluation of the antitumour and immunomodulatory properties of new phthalimides derivatives designed to explore molecular hybridization and bioisosterism approaches between thalidomide, thiosemicarbazone, thiazolidinone and thiazole series. Twenty-seven new molecules were assessed for their immunosuppressive effect toward TNFα, IFNγ, IL-2 and IL-6 production and antiproliferative activity. The best activity profile was observed for the (6a-f) series, which presents phthalyl and thiazolidinone groups.

  20. People on Parade. An Idea Packet.

    ERIC Educational Resources Information Center

    Kahn, Lois

    This unit is designed to introduce students to individuals who have been important in U.S. history and who contributed to society. Students are asked to research, study, and portray an important person from one of the following fields: leaders, sports figures, humanitarians/philanthropists, industrialist/business figures, entertainment,…

  1. Health Occupations: Clinical Rotations and Learning Packets.

    ERIC Educational Resources Information Center

    Perrine, Patricia

    A one-year introductory course covering twelve different health occupations is presented in this curriculum guide designed for use at the secondary education level. Following a list of course objectives and suggested time allotments for each unit, the health occupations course outline is provided. Unit titles are the following: orientation and…

  2. Food Stamps. Learning Packet No. 2.

    ERIC Educational Resources Information Center

    American Bar Association, Washington, DC. Clearinghouse for Offender Literacy Programs.

    This package of instructional materials is designed to aid adults in prison to perform the functional skill of applying for food stamps. The materials consist of instructions for teachers, a sample application for food stamps, a student's work sheet and answer sheet, vocabulary flash cards, and resource materials on food stamps. (MKM)

  3. MMPP Traffic Generator for the Testing of the SCAR 2 Fast Packet Switch

    NASA Technical Reports Server (NTRS)

    Chren, William A., Jr.

    1995-01-01

    A prototype MWP Traffic Generator (TG) has been designed for testing of the COMSAT-supplied SCAR II Fast Packet Switch. By generating packets distributed according to a Markov-Modulated Poisson Process (MMPP) model. it allows the assessment of the switch performance under traffic conditions that are more realistic than could be generated using the COMSAT-supplied Traffic Generator Module. The MMPP model is widely believed to model accurately real-world superimposed voice and data communications traffic. The TG was designed to be as much as possible of a "drop-in" replacement for the COMSAT Traffic Generator Module. The latter fit on two Altera EPM7256EGC 192-pin CPLDs and produced traffic for one switch input port. No board changes are necessary because it has been partitioned to use the existing board traces. The TG, consisting of parts "TGDATPROC" and "TGRAMCTL" must merely be reprogrammed into the Altera devices of the same name. However, the 040 controller software must be modified to provide TG initialization data. This data will be given in Section II.

  4. Array CGH data modeling and smoothing in Stationary Wavelet Packet Transform domain

    PubMed Central

    Huang, Heng; Nguyen, Nha; Oraintara, Soontorn; Vo, An

    2008-01-01

    Background Array-based comparative genomic hybridization (array CGH) is a highly efficient technique, allowing the simultaneous measurement of genomic DNA copy number at hundreds or thousands of loci and the reliable detection of local one-copy-level variations. Characterization of these DNA copy number changes is important for both the basic understanding of cancer and its diagnosis. In order to develop effective methods to identify aberration regions from array CGH data, many recent research work focus on both smoothing-based and segmentation-based data processing. In this paper, we propose stationary packet wavelet transform based approach to smooth array CGH data. Our purpose is to remove CGH noise in whole frequency while keeping true signal by using bivariate model. Results In both synthetic and real CGH data, Stationary Wavelet Packet Transform (SWPT) is the best wavelet transform to analyze CGH signal in whole frequency. We also introduce a new bivariate shrinkage model which shows the relationship of CGH noisy coefficients of two scales in SWPT. Before smoothing, the symmetric extension is considered as a preprocessing step to save information at the border. Conclusion We have designed the SWTP and the SWPT-Bi which are using the stationary wavelet packet transform with the hard thresholding and the new bivariate shrinkage estimator respectively to smooth the array CGH data. We demonstrate the effectiveness of our approach through theoretical and experimental exploration of a set of array CGH data, including both synthetic data and real data. The comparison results show that our method outperforms the previous approaches. PMID:18831782

  5. Fiber Fabry-Perot tunable filter for high-speed optical packet switching

    SciTech Connect

    Taranenko, N.L.; Tenbrink, S.C.; Hsu, K.; Miller, C.M.

    1997-01-01

    Tunable optical filters are important building blocks for All-Optical systems and networks. Fast optical tuning in several microseconds is necessary to perform high-speed optical packet switching. Multi- Gigabit/sec packet-switching will provide flexibility and higher network throughput when large numbers of users communicate simultaneously. One approach to achieve fast wavelength tuning is to use high-speed piezoelectrically-driven Fiber Fabry-Perot tunable filters (FFP-TFs). The requirement for tuning in microseconds raises a whole new set of challenges, such as ringing, thermostability and mechanical inertia control. It was shown that correlation between the mechanical resonance and optical response of the filter is important for the filter`s speed and for mounting hardware and control circuitry optimization. These features together with the FFP-TF`s high capacitance (approximately 0.25-0.5 microfarad) are being folded into building a special controller to substantially improve the shape of the driving signal and the response of the filter. The resultant controller enables tuning the high-speed FFP-TF three-orders-of- magnitude faster than that possible with standard commercial FFP-TFS. The fastest switching time achieved is 2.5 microseconds. As the result, a new packet-switched media access control protocol is being designed to minimize the searching time. The filter scans only once through the entire optical region and then tunes to all the required channels one after another in a few microseconds. It can help update Rainbow-2 Broadcast-and-Select High-Speed Wavelength Division Multiplexing All-Optical network that currently has a circuit- switched protocol using standard FFP-TFS.

  6. Design Strategies for Redox Active Metalloenzymes: Applications in Hydrogen Production.

    PubMed

    Alcala-Torano, R; Sommer, D J; Bahrami Dizicheh, Z; Ghirlanda, G

    2016-01-01

    The last decades have seen an increased interest in finding alternative means to produce renewable fuels in order to satisfy the growing energy demands and to minimize environmental impact. Nature can serve as an inspiration for development of these methodologies, as enzymes are able to carry out a wide variety of redox processes at high efficiency, employing a wide array of earth-abundant transition metals to do so. While it is well recognized that the protein environment plays an important role in tuning the properties of the different metal centers, the structure/function relationships between amino acids and catalytic centers are not well resolved. One specific approach to study the role of proteins in both electron and proton transfer is the biomimetic design of redox active peptides, binding organometallic clusters in well-understood protein environments. Here we discuss different strategies for the design of peptides incorporating redox active FeS clusters, [FeFe]-hydrogenase organometallic mimics, and porphyrin centers into different peptide and protein environments in order to understand natural redox enzymes. PMID:27586342

  7. Design and test of three active flutter suppression controllers

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.; Waszak, Martin R.; Adams, William M.; Srinathkumar, S.; Mukhopadhyay, Vivek

    1991-01-01

    Three flutter suppression control law design techniques are presented. Each uses multiple control surfaces and/or sensors. The first uses linear combinations of several accelerometer signals together with dynamic compensation to synthesize the modal rate of the critical mode for feedback to distributed control surfaces. The second uses traditional tools (pole/zero loci and Nyquist diagrams) to develop a good understanding of the flutter mechanism and produce a controller with minimal complexity and good robustness to plant uncertainty. The third starts with a minimum energy Linear Quadratic Gaussian controller, applies controller order reduction, and then modifies weight and noise covariance matrices to improve multi-variable robustness. The resulting designs were implemented digitally and tested subsonically on the Active Flexible Wing (AFW) wind tunnel model. Test results presented here include plant characteristics, maximum attained closed-loop dynamic pressure, and Root Mean Square control surface activity. A key result is that simultaneous symmetric and antisymmetric flutter suppression was achieved by the second control law, with a 24 percent increase in attainable dynamic pressure.

  8. Sensitivity method for integrated structure/active control law design

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.

    1987-01-01

    The development is described of an integrated structure/active control law design methodology for aeroelastic aircraft applications. A short motivating introduction to aeroservoelasticity is given along with the need for integrated structures/controls design algorithms. Three alternative approaches to development of an integrated design method are briefly discussed with regards to complexity, coordination and tradeoff strategies, and the nature of the resulting solutions. This leads to the formulation of the proposed approach which is based on the concepts of sensitivity of optimum solutions and multi-level decompositions. The concept of sensitivity of optimum is explained in more detail and compared with traditional sensitivity concepts of classical control theory. The analytical sensitivity expressions for the solution of the linear, quadratic cost, Gaussian (LQG) control problem are summarized in terms of the linear regulator solution and the Kalman Filter solution. Numerical results for a state space aeroelastic model of the DAST ARW-II vehicle are given, showing the changes in aircraft responses to variations of a structural parameter, in this case first wing bending natural frequency.

  9. On-board B-ISDN fast packet switching architectures. Phase 1: Study

    NASA Technical Reports Server (NTRS)

    Faris, Faris; Inukai, Thomas; Lee, Fred; Paul, Dilip; Shyy, Dong-Jye

    1993-01-01

    The broadband integrate services digital network (B-ISDN) is an emerging telecommunications technology that will meet most of the telecommunications networking needs in the mid-1990's to early next century. The satellite-based system is well positioned for providing B-ISDN service with its inherent capabilities of point-to-multipoint and broadcast transmission, virtually unlimited connectivity between any two points within a beam coverage, short deployment time of communications facility, flexible and dynamic reallocation of space segment capacity, and distance insensitive cost. On-board processing satellites, particularly in a multiple spot beam environment, will provide enhanced connectivity, better performance, optimized access and transmission link design, and lower user service cost. The following are described: the user and network aspects of broadband services; the current development status in broadband services; various satellite network architectures including system design issues; and various fast packet switch architectures and their detail designs.

  10. Jump state estimation with multiple sensors with packet dropping and delaying channels

    NASA Astrophysics Data System (ADS)

    Dolz, Daniel; Peñarrocha, Ignacio; Sanchis, Roberto

    2016-03-01

    This work addresses the design of a state observer for systems whose outputs are measured through a communication network. The measurements from each sensor node are assumed to arrive randomly, scarcely and with a time-varying delay. The proposed model of the plant and the network measurement scenarios cover the cases of multiple sensors, out-of-sequence measurements, buffered measurements on a single packet and multirate sensor measurements. A jump observer is proposed that selects a different gain depending on the number of periods elapsed between successfully received measurements and on the available data. A finite set of gains is pre-calculated offline with a tractable optimisation problem, where the complexity of the observer implementation is a design parameter. The computational cost of the observer implementation is much lower than in the Kalman filter, whilst the performance is similar. Several examples illustrate the observer design for different measurement scenarios and observer complexity and show the achievable performance.

  11. Resistive wall mode active control physics design for KSTAR

    NASA Astrophysics Data System (ADS)

    Park, Y. S.; Sabbagh, S. A.; Bak, J. G.; Bialek, J. M.; Berkery, J. W.; Lee, S. G.; Oh, Y. K.

    2014-01-01

    As KSTAR H-mode operation approaches the region where the resistive wall mode (RWM) can be unstable, an important issue for future long pulse, high beta plasma operation is to evaluate RWM active feedback control performance using a planned active/passive RWM stabilization system on the device. In particular, an optimal design of feedback sensors allows mode stabilization up to the highest achievable βN close to the ideal with-wall limit, βNwall, with reduced control power requirements. The computed ideal n = 1 mode structure from the DCON code has been input to the VALEN-3D code to calculate the projected performance of an active RWM control system in the KSTAR three-dimensional conducting structure device geometry. Control performance with the midplane locked mode detection sensors, off-midplane saddle loops, and magnetic pickup coils is examined. The midplane sensors measuring the radial component of the mode perturbation is found to be strongly affected by the wall eddy current. The off-axis saddle loops with proper compensation of the prompt applied field are computed to provide stabilization at βN up to 86% of βNwall but the low RWM amplitude computed in the off-axis regions near the sensors can produce a low signal-to-noise ratio. The required control power and bandwidth are also estimated with varied noise levels in the feedback sensors. Further improvements have been explored by examining a new RWM sensor design motivated by the off-midplane poloidal magnetic field sensors in NSTX. The new sensors mounted off of the copper passive stabilizer plates near the device midplane show a clear advantage in control performance corresponding to achieving 99% of βNwall without the need of compensation of the prompt field. The result shows a significant improvement of RWM feedback stabilization using the new sensor set which motivates a future feedback sensor upgrade.

  12. Observer-based H∞ fuzzy control for discrete-time Takagi-Sugeno fuzzy mixed delay systems with random packet losses and multiplicative noises

    NASA Astrophysics Data System (ADS)

    Wen, Shiping; Zeng, Zhigang; Huang, Tingwen

    2015-01-01

    This paper investigates the observer-based H∞ fuzzy control problem for a class of discrete-time fuzzy mixed delay systems with random communication packet losses and multiplicative noises, where the mixed delays comprise both discrete time-varying and distributed delays. The random packet losses are described by a Bernoulli distributed white sequence that obeys a conditional probability distribution, and the multiplicative disturbances are in the form of a scalar Gaussian white noise with unit variance. In the presence of mixed delays, random packet losses and multiplicative noises, sufficient conditions for the existence of an observer-based fuzzy feedback controller are derived, such that the closed-loop control system is asymptotically mean-square stable and preserves a guaranteed H∞ performance. Then a linear matrix inequality approach for designing such an observer-based H∞ fuzzy controller is presented. Finally, a numerical example is provided to illustrate the effectiveness of the developed theoretical results.

  13. Design and Implementation of Alkali Activated Cement For Sustainable Development

    NASA Astrophysics Data System (ADS)

    Moseson, Alexander James

    Herein, progress is presented on the design and implementation of technology for sustainable development in general and international development in particular. Necessarily interdisciplinary, the work draws upon the tools and techniques of Mechanical, Materials, and Civil Engineering; and History & Politics. The work was conducted along two paths, the first being the theory and methodology of sustainable development. A flexible design and dissemination framework was developed, Technology Seeding, defined as: development by the transfer and participatory adaptation of appropriate proven conceptual designs. The methodology was developed in part through two case studies which implemented, respectively, wood-turning lathes in Tanzania and upland rice planters in Thailand. The second path is the design and investigation of alkali-activated cements (AACs) for practical use. Those developed herein, for US markets, comprise ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68 wt.% granular limestone. Mixture Design of Experiment (DOE) was utilized to guide empirical and theoretical analysis of performance (e.g. compressive strength), economic & ecological aspects (e.g. cost, CO2 production, energy consumption), and chemistry (e.g. Rietveld analysis of x-ray diffractograms). Models were derived to understand the impact of mix design on performance and for optimization. Successful formulations are hydraulic and cure at room temperature, with strengths as high as 41 MPa at 3 days and 65 MPa at 28 days. Some of these formulations, compared to OPC, are competitive in performance, reduce cost by up to 40%, and reduce both CO2 production and energy consumption by up to 97%. Major chemical products include calcium silicate hydrates / calcium aluminum silicate hydrates (C-(A)-S-H), gaylussite, and calcite (both newly formed and remaining from limestone). Calcite/dolomite and C-(A)-S-H both contribute to strength. A fraction of the limestone is consumed

  14. Teaching with Data: Resources for Designing Effective Activities

    NASA Astrophysics Data System (ADS)

    Manduca, C. A.; Mogk, D. W.

    2004-12-01

    Faculty and teachers understand the power of engaging students directly with data and are tremendously enthusiastic about the possibilities of incorporating data-rich activities in their teaching. This enthusiasm reflects the desire to empower students to solve problems, to place learning in an exciting and authentic real world context that motivates learning, and to illuminate students' understanding of the nature of science. Data-rich activities provide abundant opportunities to motivate students to engage in learning, to integrate learning of facts and skills, and to build on prior knowledge. These are all factors that are identified by research as fundamental to the learning process (How People Learn, 1999, NRC). Data-rich activities can place learning in a context that enhances students' ability to use information in new situations. Seismological data offer many opportunities due to students' familiarity with and interest in earthquakes, and its use to probe the internal structure of the Earth. Three of the most challenging aspects of teaching with data are 1) presenting data with analysis tools that can be quickly mastered, 2) designing learning activities to match the level of student expertise with data analysis and critical thinking, and 3) creating assessments that capture learning beyond factual recall. The Using Data in the Classroom website (serc.carleton.edu/usingdata) helps faculty excel at teaching with data by providing easy access to a wide range of data, discussion of the ways in which data can be effectively used in the classroom, examples of data-rich activities at a variety of educational levels across a range of geoscience topics, and references to pedagogic information. The Earth Exploration Toolbook (serc.Carleton.edu/eet) supports teachers' use of particular datasets and tools by providing step-by-step instructions in the context of an example. The Investigating Earthquakes chapter focuses specifically on use of GIS to analyze USGS

  15. Resolving Behavioral Output via Chemogenetic Designer Receptors Exclusively Activated by Designer Drugs.

    PubMed

    Burnett, C Joseph; Krashes, Michael J

    2016-09-01

    Designer receptors exclusively activated by designer drugs (DREADDs) have proven to be highly effective neuromodulatory tools for the investigation of neural circuits underlying behavioral outputs. They exhibit a number of advantages: they rely on cell-specific manipulations through canonical intracellular signaling pathways, they are easy and cost-effective to implement in a laboratory setting, and they are easily scalable for single-region or full-brain manipulations. On the other hand, DREADDs rely on ligand-G-protein-coupled receptor interactions, leading to coarse temporal dynamics. In this review we will provide a brief overview of DREADDs, their implementation, and the advantages and disadvantages of their use in animal systems. We also will provide numerous examples of their use across a broad variety of biomedical research fields. PMID:27605603

  16. The Transfer Achievement Program (TAP): Information Packet.

    ERIC Educational Resources Information Center

    Segura, Armando; Noseworthy, Victoria

    Santa Barbara City College (California) created the Transfer Achievement Program (TAP) to deliver an integrated and cohesive set of services to underrepresented students to help increase their transfer rate to four-year institutions. TAP provides students with a developmental map of transfer-related activities through the use of the Transfer Task…

  17. Investigation into the formation of charge packets in polyethylene: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Chen, G.; Lewin, P. L.

    2012-08-01

    The phenomenon of charge packet has been reported in polymeric insulation materials under the application of dc electric fields in recent decades. It is noted that such charge packets could lead to substantial modification of local electric stress, which increases the possibility of failure of insulating materials. The physics of charge packets has not yet been revealed clearly. In this paper, the dynamics of positive charge packets in polyethylene is observed using the pulsed electro-acoustic technique. Negative differential mobility of positive charge carrier is found, which is believed to be crucial to the formation of charge packets. This negative differential mobility is introduced into a bipolar charge transport model to simulate the packet-like space charge in polymers. Simulation results show that not only the negative differential mobility but also weaker trapping characteristic are required to generate a positive charge packet in polyethylene under dc stress.

  18. Alternative packet switch architectures for a 30/20 GHz FDMA/TDMA geostationary communication satellite network

    NASA Technical Reports Server (NTRS)

    Stehle, Roy; Ogier, Richard G.

    1995-01-01

    This study has investigated alternatives for realizing a packet-based network switch for deployment on a communication satellite. The emphasis was on the avoidance of contention problems that can occur due to the simultaneous arrival of an excessive number of packets destined for the same downlink dwell. The study was to look ahead, beyond the current Advanced Communications Technology Satellite (ACTS) capability, to the next generation of satellites. The study has not been limited by currently available technology, but has used university and commercial research efforts as a basis for designs that can be readily constructed and launched within the next five years. Tradeoffs in memory requirement, power requirement, and architecture have been considered as a part of our study.

  19. Leisure Activities for Retarded Children. A Task Analysis Approach. Integrating Trainable Mentally Retarded Children Through Community Education. ESEA Title IV, Part C.

    ERIC Educational Resources Information Center

    Minneapolis Public Schools, Minn.

    Designed to meet the need of trainable mentally retarded persons for recreation skill training and for opportunities to experience leisure/social skill development in a community setting, the packet provides task analysis information on 114 activities. Information is provided on behavioral objectives, basic skills required, materials and…

  20. Learning about Science Graphs and Word Games. Superific Science Book V. A Good Apple Science Activity Book for Grades 5-8+.

    ERIC Educational Resources Information Center

    Conway, Lorraine

    This packet of student materials contains a variety of worksheet activities dealing with science graphs and science word games. These reproducible materials deal with: (1) bar graphs; (2) line graphs; (3) circle graphs; (4) pictographs; (5) histograms; (6) artgraphs; (7) designing your own graphs; (8) medical prefixes; (9) color prefixes; (10)…

  1. Second Harmonic Generation of Nanoscale Phonon Wave Packets

    NASA Astrophysics Data System (ADS)

    Bojahr, A.; Gohlke, M.; Leitenberger, W.; Pudell, J.; Reinhardt, M.; von Reppert, A.; Roessle, M.; Sander, M.; Gaal, P.; Bargheer, M.

    2015-11-01

    Phonons are often regarded as delocalized quasiparticles with certain energy and momentum. The anharmonic interaction of phonons determines macroscopic properties of the solid, such as thermal expansion or thermal conductivity, and a detailed understanding becomes increasingly important for functional nanostructures. Although phonon-phonon scattering processes depicted in simple wave-vector diagrams are the basis of theories describing these macroscopic phenomena, experiments directly accessing these coupling channels are scarce. We synthesize monochromatic acoustic phonon wave packets with only a few cycles to introduce nonlinear phononics as the acoustic counterpart to nonlinear optics. Control of the wave vector, bandwidth, and consequently spatial extent of the phonon wave packets allows us to observe nonlinear phonon interaction, in particular, second harmonic generation, in real time by wave-vector-sensitive Brillouin scattering with x-rays and optical photons.

  2. Wave packet dynamics in the optimal superadiabatic approximation

    NASA Astrophysics Data System (ADS)

    Betz, V.; Goddard, B. D.; Manthe, U.

    2016-06-01

    We explain the concept of superadiabatic representations and show how in the context of electronically non-adiabatic transitions they lead to an explicit formula that can be used to predict transitions at avoided crossings. Based on this formula, we present a simple method for computing wave packet dynamics across avoided crossings. Only knowledge of the adiabatic potential energy surfaces near the avoided crossing is required for the computation. In particular, this means that no diabatization procedure is necessary, the adiabatic electronic energies can be computed on the fly, and they only need to be computed to higher accuracy when an avoided crossing is detected. We test the quality of our method on the paradigmatic example of photo-dissociation of NaI, finding very good agreement with results of exact wave packet calculations.

  3. Probing surface states with many-body wave packet scattering

    NASA Astrophysics Data System (ADS)

    Damon, F.; Georgeot, B.; Guéry-Odelin, D.

    2016-07-01

    The scattering of 1D matter wave bright solitons on attractive potentials enables one to populate bound states, a feature impossible with noninteracting wave packets. Compared to noninteracting states, the populated states are renormalized by the attractive interactions between atoms and keep the same topology. This renormalization can even transform a virtual state into a bound state. By switching off adiabatically the interactions, the trapped wave packets converge towards the true noninteracting bound states. Our numerical studies show how such scattering experiments can reveal and characterize the surface states of a periodic structure whose translational invariance has been broken. We provide evidence that the corresponding 3D regime should be accessible with current techniques.

  4. Exciton-polariton localized wave packets in a microcavity

    NASA Astrophysics Data System (ADS)

    Voronych, Oksana; Buraczewski, Adam; Matuszewski, MichałÂ; Stobińska, Magdalena

    2016-06-01

    We investigate the possibility of creating X waves, or localized wave packets, in resonantly excited exciton-polariton superfluids. We demonstrate the existence of X-wave traveling solutions in the coupled exciton-photon system past the inflection point, where the effective mass of lower polaritons is negative in the direction perpendicular to the wave vector of the pumping beam. Contrary to the case of bright solitons, X waves do not require nonlinearity for sustaining their shape. Nevertheless, we show that nonlinearity is important for their dynamics, as it allows for their spontaneous formation from an initial Gaussian wave packet. Unique properties of exciton-polaritons may lead to applications of their X waves in long-distance signal propagation inside novel integrated optoelectronic circuits based on excitons.

  5. Very low bit rate voice for packetized mobile applications

    SciTech Connect

    Knittle, C.D.; Malone, K.T.

    1991-01-01

    Transmitting digital voice via packetized mobile communications systems that employ relatively short packet lengths and narrow bandwidths often necessitates very low bit rate coding of the voice data. Sandia National Laboratories is currently developing an efficient voice coding system operating at 800 bits per second (bps). The coding scheme is a modified version of the 2400 bps NSA LPC-10e standard. The most significant modification to the LPC-10e scheme is the vector quantization of the line spectrum frequencies associated with the synthesis filters. An outline of a hardware implementation for the 800 bps coder is presented. The speech quality of the coder is generally good, although speaker recognition is not possible. Further research is being conducted to reduce the memory requirements and complexity of the vector quantizer, and to increase the quality of the reconstructed speech. 4 refs., 2 figs., 3 tabs.

  6. Very low bit rate voice for packetized mobile applications

    SciTech Connect

    Knittle, C.D.; Malone, K.T. )

    1991-01-01

    This paper reports that transmitting digital voice via packetized mobile communications systems that employ relatively short packet lengths and narrow bandwidths often necessitates very low bit rate coding of the voice data. Sandia National Laboratories is currently developing an efficient voice coding system operating at 800 bits per second (bps). The coding scheme is a modified version of the 2400 bps NSA LPC-10e standard. The most significant modification to the LPC-10e scheme is the vector quantization of the line spectrum frequencies associated with the synthesis filters. An outline of a hardware implementation for the 800 bps coder is presented. The speech quality of the coder is generally good, although speaker recognition is not possible. Further research is being conducted to reduce the memory requirements and complexity of the vector quantizer, and to increase the quality of the reconstructed speech. This work may be of use dealing with nuclear materials.

  7. Wave packet dynamics in the optimal superadiabatic approximation.

    PubMed

    Betz, V; Goddard, B D; Manthe, U

    2016-06-14

    We explain the concept of superadiabatic representations and show how in the context of electronically non-adiabatic transitions they lead to an explicit formula that can be used to predict transitions at avoided crossings. Based on this formula, we present a simple method for computing wave packet dynamics across avoided crossings. Only knowledge of the adiabatic potential energy surfaces near the avoided crossing is required for the computation. In particular, this means that no diabatization procedure is necessary, the adiabatic electronic energies can be computed on the fly, and they only need to be computed to higher accuracy when an avoided crossing is detected. We test the quality of our method on the paradigmatic example of photo-dissociation of NaI, finding very good agreement with results of exact wave packet calculations. PMID:27305998

  8. Stochastic acceleration of ions driven by Pc1 wave packets

    SciTech Connect

    Khazanov, G. V. Sibeck, D. G.; Tel'nikhin, A. A.; Kronberg, T. K.

    2015-07-15

    The stochastic motion of protons and He{sup +} ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10{sup −4} nT{sup 2}/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with the electrostatic component of wave packets can also accelerate ions. The main effect of this interaction is to accelerate thermal protons to the local Alfven speed. The dependencies of observable quantities on the wave power and plasma parameters are determined, and estimates for the heating extent and rate of particle heating in these wave-particle interactions are shown to be in reasonable agreement with known empirical data.

  9. Future directions in packet radio architectures and protocols

    NASA Astrophysics Data System (ADS)

    Shacham, Nachum; Westcott, Jil

    1987-01-01

    The technology of packet switching over multihop, multiple-access channels has evolved to the point at which its protocols can now support internetwork operation of medium-size networks whose nodes possess some degree of mobility. As regards the needs and challenges of the future operating environment, it is clear that these can be met only by enhancing the packet radio architecture and its protocols. Several enhancements that allow the organization of large, dynamic networks that can operate over multiple channels, adapt to varying conditions, and possess self-monitoring and self-control capabilities are discussed. As these areas are examined, the attendant issues and tradeoffs are discussed; in addition, some protocols and information regarding their performance are presented.

  10. Two-dimensional attosecond electron wave-packet interferometry.

    PubMed

    Xie, Xinhua

    2015-05-01

    We propose a two-dimensional interferometry based on the electron wave-packet interference by using a cycle-shaped orthogonally polarized two-color laser field. With such a method, the subcycle and intercycle interferences can be disentangled into different directions in the measured photoelectron momentum spectra. The Coulomb influence can be minimized and the overlapping of interference fringes with the complicated low-energy structures can be avoided as well. The contributions of the excitation effect and the long-range Coulomb potential can be traced in the Fourier domain of the photoelectron distribution. Because of these advantages, precise information on valence electron dynamics of atoms or molecules with attosecond temporal resolution and additional spatial information with angstrom resolution can be obtained with the two-dimensional electron wave-packet interferometry.

  11. The Interference of the Dynamically Squeezed Vibrational Wave Packets

    NASA Technical Reports Server (NTRS)

    Vinogradov, An. V.; Janszky, J.; Kobayashi, T.

    1996-01-01

    An electronic excitation of a molecule by a sequence of two femtosecond phase-locked laser pulses is considered. In this case the interference between the vibrational wave packets induced by each of the subpulses within a single molecule takes place. It is shown that due to the dynamical squeezing effect of a molecular vibrational state the interference of the vibrational wave packets allows one to measure the duration of a femtosecond laser pulse. This can be achieved experimentally by measuring the dependence of the integral fluorescence of the excited molecule on the delay time between the subpulses. The interference can lead to a sharp peak (or to a down-fall) in that dependence, the width of which is equal to the duration of the laser pulse. It is shown that finite temperature of the medium is favorable for such an experiment.

  12. Two-Dimensional Attosecond Electron Wave-Packet Interferometry

    NASA Astrophysics Data System (ADS)

    Xie, Xinhua

    2015-05-01

    We propose a two-dimensional interferometry based on the electron wave-packet interference by using a cycle-shaped orthogonally polarized two-color laser field. With such a method, the subcycle and intercycle interferences can be disentangled into different directions in the measured photoelectron momentum spectra. The Coulomb influence can be minimized and the overlapping of interference fringes with the complicated low-energy structures can be avoided as well. The contributions of the excitation effect and the long-range Coulomb potential can be traced in the Fourier domain of the photoelectron distribution. Because of these advantages, precise information on valence electron dynamics of atoms or molecules with attosecond temporal resolution and additional spatial information with angstrom resolution can be obtained with the two-dimensional electron wave-packet interferometry.

  13. Formation of wave packets in electron diffraction on crystals

    NASA Astrophysics Data System (ADS)

    Lanning, Robert; Bahrim, Cristian

    2012-02-01

    Measurements of electron diffraction typically reveal the atomic structure of crystals and allow finding the length of chemical bonds. The effective electronic charge of each atom in the crystal acts upon the incident electron beam as a netting of narrow pinholes, and Fourier transforms the unique deBroglie wavelength of the projectile electron accelerated at fixed voltage into a wave packet. Using the uncertainty principle one can understand the mechanism that makes an incident electron to become a wave packet travelling inside the crystal at a group velocity identical with the initial speed of the projectile electron. Furthermore, the Pauli Exclusion Principle allows us to understand the fast passage of the projectile electron through the crystal and also, it allows the evaluation of the characteristic time for electron transmission. The project was sponsored by the STAIRSTEP program under the NSF-DUE grant# 0757057.

  14. Design of a novel chimeric tissue plasminogen activator with favorable Vampire bat plasminogen activator properties.

    PubMed

    Kazemali, MohammadReza; Majidzadeh-A, Keivan; Sardari, Soroush; Saadatirad, Amir Hossein; Khalaj, Vahid; Zarei, Najmeh; Barkhordari, Farzaneh; Adeli, Ahmad; Mahboudi, Fereidoun

    2014-12-01

    Fibrinolytic agents are widely used in treatment of the thromboembolic disorders. The new generations like recombinant tissue plasminogen activator (t-PA, alteplase) are not showing promising results in clinical practice in spite of displaying specific binding to fibrin in vitro. Vampire bat plasminogen activator (b-PA) is a plasminogen activator with higher fibrin affinity and specificity in comparison to t-PA resulting in reduced probability of hemorrhage. b-PA is also resistant to plasminogen activator inhibitor-1 (PAI-1) showing higher half-life compared to other variants of t-PA. However, its non-human origin was a driving force to design a human t-PA with favorable properties of b-PA. In the present study, we designed a chimeric t-PA with desirable b-PA properties and this new molecule was called as CT-b. The construct was prepared through kringle 2 domain removal and replacement of t-PA finger domain with b-PA one. In addition, the KHRR sequence at the initial part of protease domain was replaced by four alanine residues. The novel construct was integrated in Pichia pastoris genome by electroporation. Catalytic activity was investigated in the presence and absence of fibrin. The purified protein was analyzed by western blot. Fibrin binding and PAI resistance assays were also conducted. The activity of the recombinant protein in the presence of fibrin was 1560 times more than its activity in the absence of fibrin, showing its higher specificity to fibrin. The fibrin binding of CT-b was 1.2 fold more than t-PA. In addition, it was inhibited by PAI enzyme 44% less than t-PA. Although the presented data demonstrate a promising in vitro activity, more in vivo studies are needed to confirm the therapeutic advantage of this novel plasminogen activator.

  15. Design of a novel chimeric tissue plasminogen activator with favorable Vampire bat plasminogen activator properties.

    PubMed

    Kazemali, MohammadReza; Majidzadeh-A, Keivan; Sardari, Soroush; Saadatirad, Amir Hossein; Khalaj, Vahid; Zarei, Najmeh; Barkhordari, Farzaneh; Adeli, Ahmad; Mahboudi, Fereidoun

    2014-12-01

    Fibrinolytic agents are widely used in treatment of the thromboembolic disorders. The new generations like recombinant tissue plasminogen activator (t-PA, alteplase) are not showing promising results in clinical practice in spite of displaying specific binding to fibrin in vitro. Vampire bat plasminogen activator (b-PA) is a plasminogen activator with higher fibrin affinity and specificity in comparison to t-PA resulting in reduced probability of hemorrhage. b-PA is also resistant to plasminogen activator inhibitor-1 (PAI-1) showing higher half-life compared to other variants of t-PA. However, its non-human origin was a driving force to design a human t-PA with favorable properties of b-PA. In the present study, we designed a chimeric t-PA with desirable b-PA properties and this new molecule was called as CT-b. The construct was prepared through kringle 2 domain removal and replacement of t-PA finger domain with b-PA one. In addition, the KHRR sequence at the initial part of protease domain was replaced by four alanine residues. The novel construct was integrated in Pichia pastoris genome by electroporation. Catalytic activity was investigated in the presence and absence of fibrin. The purified protein was analyzed by western blot. Fibrin binding and PAI resistance assays were also conducted. The activity of the recombinant protein in the presence of fibrin was 1560 times more than its activity in the absence of fibrin, showing its higher specificity to fibrin. The fibrin binding of CT-b was 1.2 fold more than t-PA. In addition, it was inhibited by PAI enzyme 44% less than t-PA. Although the presented data demonstrate a promising in vitro activity, more in vivo studies are needed to confirm the therapeutic advantage of this novel plasminogen activator. PMID:25442953

  16. Active noise control: A tutorial for HVAC designers

    SciTech Connect

    Gelin, L.J.

    1997-08-01

    This article will identify the capabilities and limitations of ANC in its application to HVAC noise control. ANC can be used in ducted HVAC systems to cancel ductborne, low-frequency fan noise by injecting sound waves of equal amplitude and opposite phase into an air duct, as close as possible to the source of the unwanted noise. Destructive interference of the fan noise and injected noise results in sound cancellation. The noise problems that it solves are typically described as rumble, roar or throb, all of which are difficult to address using traditional noise control methods. This article will also contrast the use of active against passive noise control techniques. The main differences between the two noise control measures are acoustic performance, energy consumption, and design flexibility. The article will first present the fundamentals and basic physics of ANC. The application to real HVAC systems will follow.

  17. Module Design, Materials, and Packaging Research Team: Activities and Capabilities

    SciTech Connect

    McMahon, T. J.; del Cueto, J.; Glick, S.; Jorgensen, G.; Kempe, M.; Kennedy, C.; Pern, J.; Terwilliger, K

    2005-01-01

    Our team activities are directed at improving PV module reliability by incorporating new, more effective, and less expensive packaging materials and techniques. New and existing materials or designs are evaluated before and during accelerated environmental exposure for the following properties: (1) Adhesion and cohesion: peel strength and lap shear. (2) Electrical conductivity: surface, bulk, interface and transients. (3) Water vapor transmission: solubility and diffusivity. (4) Accelerated weathering: ultraviolet, temperature, and damp heat tests. (5) Module and cell failure diagnostics: infrared imaging, individual cell shunt characterization, coring. (6) Fabrication improvements: SiOxNy barrier coatings and enhanced wet adhesion. (7) Numerical modeling: Moisture ingress/egress, module and cell performance, and cell-to-frame leakage current. (8) Rheological properties of polymer encapsulant and sheeting materials. Specific examples will be described.

  18. Atomic hydrogen maser active oscillator cavity and bulb design optimization

    NASA Technical Reports Server (NTRS)

    Peters, H. E.; Washburn, P. J.

    1984-01-01

    The performance characteristics and reliability of the active oscillator atomic hydrogen maser depend upon oscillation parameters which characterize the interaction region of the maser, the resonant cavity and atom storage bulb assembly. With particular attention to use of the cavity frequency switching servo (1) to reduce cavity pulling, it is important to maintain high oscillation level, high atomic beam flux utilization efficiency, small spin exchange parameter and high cavity quality factor. It is also desirable to have a small and rigid cavity and bulb structure and to minimize the cavity temperature sensitivity. Curves for a novel hydrogen maser cavity configuration which is partially loaded with a quartz dielectric cylinder and show the relationships between cavity length, cavity diameter, bulb size, dielectric thickness, cavity quality factor, filling factor and cavity frequency temperature coefficient are presented. The results are discussed in terms of improvement in maser performance resulting from particular design choices.

  19. IP- -: A Reduced Internet Protocol for Optical Packet Networking

    NASA Astrophysics Data System (ADS)

    Ohta, Masataka; Fujikawa, Kenji

    IP- - is proposed as an Internet Protocol suitable for optical packet networking. As optical routers require much faster control than electric ones and lack of optical buffers other than those by fiber delay lines requires fixed time control, Internet Protocols must be at least as simple as IPv4 and much simpler than IPv6. IP- - also addresses issues of IP address space exhaustion and IP routing table explosion.

  20. Spin-orbit states of neutron wave packets

    NASA Astrophysics Data System (ADS)

    Nsofini, Joachim; Sarenac, Dusan; Wood, Christopher J.; Cory, David G.; Arif, Muhammad; Clark, Charles W.; Huber, Michael G.; Pushin, Dmitry A.

    2016-07-01

    We propose a method to prepare an entangled spin-orbit state between the spin and the orbital angular momenta of a neutron wave packet. This spin-orbit state is created by passing neutrons through the center of a quadrupole magnetic field, which provides a coupling between the spin and orbital degrees of freedom. A Ramsey-fringe-type measurement is suggested as a means of verifying the spin-orbit correlations.

  1. Lossless Compression of Data into Fixed-Length Packets

    NASA Technical Reports Server (NTRS)

    Kiely, Aaron B.; Klimesh, Matthew A.

    2009-01-01

    A computer program effects lossless compression of data samples from a one-dimensional source into fixed-length data packets. The software makes use of adaptive prediction: it exploits the data structure in such a way as to increase the efficiency of compression beyond that otherwise achievable. Adaptive linear filtering is used to predict each sample value based on past sample values. The difference between predicted and actual sample values is encoded using a Golomb code.

  2. Software For Management Of A Packet-Radio Network

    NASA Technical Reports Server (NTRS)

    Smyth, Patrick J.; Chauvin, Todd H.; Oliver, Gordon P.; Statman, Joseph I.

    1994-01-01

    Network-management software assists in planning, monitoring, and controlling resources of Datalink network. Packet-message network featuring time-division multiple access, frequency and spatial diversity, and dynamic tree-structured routing scheme. Developed for communication between central control station on ground and instrumented aircraft flying over test range. Aircraft derives navigational data from satellites of Global Positioning System, and primary function of Datalink network feeding GPS position data from participating aircraft into control center in real time.

  3. Attosecond Electron Wave-Packet Interference Observed by Transient Absorption

    SciTech Connect

    Holler, M.; Schapper, F.; Gallmann, L.; Keller, U.

    2011-03-25

    We perform attosecond time-resolved transient absorption spectroscopy around the first ionization threshold of helium and observe rapid oscillations of the absorption of the individual harmonics as a function of time delay with respect to a superimposed, moderately strong infrared laser field. The phase relation between the absorption modulation of individual harmonics gives direct evidence for the interference of transiently bound electronic wave packets as the mechanism behind the absorption modulation.

  4. Attosecond electron wave-packet interference observed by transient absorption.

    PubMed

    Holler, M; Schapper, F; Gallmann, L; Keller, U

    2011-03-25

    We perform attosecond time-resolved transient absorption spectroscopy around the first ionization threshold of helium and observe rapid oscillations of the absorption of the individual harmonics as a function of time delay with respect to a superimposed, moderately strong infrared laser field. The phase relation between the absorption modulation of individual harmonics gives direct evidence for the interference of transiently bound electronic wave packets as the mechanism behind the absorption modulation.

  5. Accelerating Airy-Gauss-Kummer localized wave packets

    NASA Astrophysics Data System (ADS)

    Zhong, Wei-Ping; Belić, Milivoj; Zhang, Yiqi; Huang, Tingwen

    2014-01-01

    A general approach to generating three-dimensional nondiffracting spatiotemporal solutions of the linear Schrödinger equation with an Airy-beam time-dependence is reported. A class of accelerating optical pulses with the structure of Airy-Gauss-Kummer vortex beams is obtained. Our results demonstrate that the optical field contributions to the Airy-Gauss-Kummer accelerating optical wave packets of the cylindrical symmetry can be characterized by the radial and angular mode numbers.

  6. SDN architecture for optical packet and circuit integrated networks

    NASA Astrophysics Data System (ADS)

    Furukawa, Hideaki; Miyazawa, Takaya

    2016-02-01

    We have been developing an optical packet and circuit integrated (OPCI) network, which realizes dynamic optical path, high-density packet multiplexing, and flexible wavelength resource allocation. In the OPCI networks, a best-effort service and a QoS-guaranteed service are provided by employing optical packet switching (OPS) and optical circuit switching (OCS) respectively, and users can select these services. Different wavelength resources are assigned for OPS and OCS links, and the amount of their wavelength resources are dynamically changed in accordance with the service usage conditions. To apply OPCI networks into wide-area (core/metro) networks, we have developed an OPCI node with a distributed control mechanism. Moreover, our OPCI node works with a centralized control mechanism as well as a distributed one. It is therefore possible to realize SDN-based OPCI networks, where resource requests and a centralized configuration are carried out. In this paper, we show our SDN architecture for an OPS system that configures mapping tables between IP addresses and optical packet addresses and switching tables according to the requests from multiple users via a web interface. While OpenFlow-based centralized control protocol is coming into widespread use especially for single-administrative, small-area (LAN/data-center) networks. Here, we also show an interworking mechanism between OpenFlow-based networks (OFNs) and the OPCI network for constructing a wide-area network, and a control method of wavelength resource selection to automatically transfer diversified flows from OFNs to the OPCI network.

  7. Design of Responsive and Active (Soft) Materials Using Liquid Crystals.

    PubMed

    Bukusoglu, Emre; Bedolla Pantoja, Marco; Mushenheim, Peter C; Wang, Xiaoguang; Abbott, Nicholas L

    2016-06-01

    Liquid crystals (LCs) are widely known for their use in liquid crystal displays (LCDs). Indeed, LCDs represent one of the most successful technologies developed to date using a responsive soft material: An electric field is used to induce a change in ordering of the LC and thus a change in optical appearance. Over the past decade, however, research has revealed the fundamental underpinnings of potentially far broader and more pervasive uses of LCs for the design of responsive soft material systems. These systems involve a delicate interplay of the effects of surface-induced ordering, elastic strain of LCs, and formation of topological defects and are characterized by a chemical complexity and diversity of nano- and micrometer-scale geometry that goes well beyond that previously investigated. As a reflection of this evolution, the community investigating LC-based materials now relies heavily on concepts from colloid and interface science. In this context, this review describes recent advances in colloidal and interfacial phenomena involving LCs that are enabling the design of new classes of soft matter that respond to stimuli as broad as light, airborne pollutants, bacterial toxins in water, mechanical interactions with living cells, molecular chirality, and more. Ongoing efforts hint also that the collective properties of LCs (e.g., LC-dispersed colloids) will, over the coming decade, yield exciting new classes of driven or active soft material systems in which organization (and useful properties) emerges during the dissipation of energy. PMID:26979412

  8. Design of Responsive and Active (Soft) Materials Using Liquid Crystals.

    PubMed

    Bukusoglu, Emre; Bedolla Pantoja, Marco; Mushenheim, Peter C; Wang, Xiaoguang; Abbott, Nicholas L

    2016-06-01

    Liquid crystals (LCs) are widely known for their use in liquid crystal displays (LCDs). Indeed, LCDs represent one of the most successful technologies developed to date using a responsive soft material: An electric field is used to induce a change in ordering of the LC and thus a change in optical appearance. Over the past decade, however, research has revealed the fundamental underpinnings of potentially far broader and more pervasive uses of LCs for the design of responsive soft material systems. These systems involve a delicate interplay of the effects of surface-induced ordering, elastic strain of LCs, and formation of topological defects and are characterized by a chemical complexity and diversity of nano- and micrometer-scale geometry that goes well beyond that previously investigated. As a reflection of this evolution, the community investigating LC-based materials now relies heavily on concepts from colloid and interface science. In this context, this review describes recent advances in colloidal and interfacial phenomena involving LCs that are enabling the design of new classes of soft matter that respond to stimuli as broad as light, airborne pollutants, bacterial toxins in water, mechanical interactions with living cells, molecular chirality, and more. Ongoing efforts hint also that the collective properties of LCs (e.g., LC-dispersed colloids) will, over the coming decade, yield exciting new classes of driven or active soft material systems in which organization (and useful properties) emerges during the dissipation of energy.

  9. Generalized Gaussian wave packet dynamics: Integrable and chaotic systems

    NASA Astrophysics Data System (ADS)

    Pal, Harinder; Vyas, Manan; Tomsovic, Steven

    2016-01-01

    The ultimate semiclassical wave packet propagation technique is a complex, time-dependent Wentzel-Kramers-Brillouin method known as generalized Gaussian wave packet dynamics (GGWPD). It requires overcoming many technical difficulties in order to be carried out fully in practice. In its place roughly twenty years ago, linearized wave packet dynamics was generalized to methods that include sets of off-center, real trajectories for both classically integrable and chaotic dynamical systems that completely capture the dynamical transport. The connections between those methods and GGWPD are developed in a way that enables a far more practical implementation of GGWPD. The generally complex saddle-point trajectories at its foundation are found using a multidimensional Newton-Raphson root search method that begins with the set of off-center, real trajectories. This is possible because there is a one-to-one correspondence. The neighboring trajectories associated with each off-center, real trajectory form a path that crosses a unique saddle; there are exceptions that are straightforward to identify. The method is applied to the kicked rotor to demonstrate the accuracy improvement as a function of ℏ that comes with using the saddle-point trajectories.

  10. Electronically nonadiabatic wave packet propagation using frozen Gaussian scattering

    NASA Astrophysics Data System (ADS)

    Kondorskiy, Alexey D.; Nanbu, Shinkoh

    2015-09-01

    We present an approach, which allows to employ the adiabatic wave packet propagation technique and semiclassical theory to treat the nonadiabatic processes by using trajectory hopping. The approach developed generates a bunch of hopping trajectories and gives all additional information to incorporate the effect of nonadiabatic coupling into the wave packet dynamics. This provides an interface between a general adiabatic frozen Gaussian wave packet propagation method and the trajectory surface hopping technique. The basic idea suggested in [A. D. Kondorskiy and H. Nakamura, J. Chem. Phys. 120, 8937 (2004)] is revisited and complemented in the present work by the elaboration of efficient numerical algorithms. We combine our approach with the adiabatic Herman-Kluk frozen Gaussian approximation. The efficiency and accuracy of the resulting method is demonstrated by applying it to popular benchmark model systems including three Tully's models and 24D model of pyrazine. It is shown that photoabsorption spectrum is successfully reproduced by using a few hundreds of trajectories. We employ the compact finite difference Hessian update scheme to consider feasibility of the ab initio "on-the-fly" simulations. It is found that this technique allows us to obtain the reliable final results using several Hessian matrix calculations per trajectory.

  11. Wave packet spreading and localization in electron-nuclear scattering

    NASA Astrophysics Data System (ADS)

    Grabowski, Paul E.; Markmann, Andreas; Morozov, Igor V.; Valuev, Ilya A.; Fichtl, Christopher A.; Richards, David F.; Batista, Victor S.; Graziani, Frank R.; Murillo, Michael S.

    2013-06-01

    The wave packet molecular dynamics (WPMD) method provides a variational approximation to the solution of the time-dependent Schrödinger equation. Its application in the field of high-temperature dense plasmas has yielded diverging electron width (spreading), which results in diminishing electron-nuclear interactions. Electron spreading has previously been ascribed to a shortcoming of the WPMD method and has been counteracted by various heuristic additions to the models used. We employ more accurate methods to determine if spreading continues to be predicted by them and how WPMD can be improved. A scattering process involving a single dynamic electron interacting with a periodic array of statically screened protons is used as a model problem for comparison. We compare the numerically exact split operator Fourier transform method, the Wigner trajectory method, and the time-dependent variational principle (TDVP). Within the framework of the TDVP, we use the standard variational form of WPMD, the single Gaussian wave packet (WP), as well as a sum of Gaussian WPs, as in the split WP method. Wave packet spreading is predicted by all methods, so it is not the source of the unphysical diminishing of electron-nuclear interactions in WPMD at high temperatures. Instead, the Gaussian WP's inability to correctly reproduce breakup of the electron's probability density into localized density near the protons is responsible for the deviation from more accurate predictions. Extensions of WPMD must include a mechanism for breakup to occur in order to yield dynamics that lead to accurate electron densities.

  12. Generalized Gaussian wave packet dynamics: Integrable and chaotic systems.

    PubMed

    Pal, Harinder; Vyas, Manan; Tomsovic, Steven

    2016-01-01

    The ultimate semiclassical wave packet propagation technique is a complex, time-dependent Wentzel-Kramers-Brillouin method known as generalized Gaussian wave packet dynamics (GGWPD). It requires overcoming many technical difficulties in order to be carried out fully in practice. In its place roughly twenty years ago, linearized wave packet dynamics was generalized to methods that include sets of off-center, real trajectories for both classically integrable and chaotic dynamical systems that completely capture the dynamical transport. The connections between those methods and GGWPD are developed in a way that enables a far more practical implementation of GGWPD. The generally complex saddle-point trajectories at its foundation are found using a multidimensional Newton-Raphson root search method that begins with the set of off-center, real trajectories. This is possible because there is a one-to-one correspondence. The neighboring trajectories associated with each off-center, real trajectory form a path that crosses a unique saddle; there are exceptions that are straightforward to identify. The method is applied to the kicked rotor to demonstrate the accuracy improvement as a function of ℏ that comes with using the saddle-point trajectories.

  13. The performance analysis of linux networking - packet receiving

    SciTech Connect

    Wu, Wenji; Crawford, Matt; Bowden, Mark; /Fermilab

    2006-11-01

    The computing models for High-Energy Physics experiments are becoming ever more globally distributed and grid-based, both for technical reasons (e.g., to place computational and data resources near each other and the demand) and for strategic reasons (e.g., to leverage equipment investments). To support such computing models, the network and end systems, computing and storage, face unprecedented challenges. One of the biggest challenges is to transfer scientific data sets--now in the multi-petabyte (10{sup 15} bytes) range and expected to grow to exabytes within a decade--reliably and efficiently among facilities and computation centers scattered around the world. Both the network and end systems should be able to provide the capabilities to support high bandwidth, sustained, end-to-end data transmission. Recent trends in technology are showing that although the raw transmission speeds used in networks are increasing rapidly, the rate of advancement of microprocessor technology has slowed down. Therefore, network protocol-processing overheads have risen sharply in comparison with the time spent in packet transmission, resulting in degraded throughput for networked applications. More and more, it is the network end system, instead of the network, that is responsible for degraded performance of network applications. In this paper, the Linux system's packet receive process is studied from NIC to application. We develop a mathematical model to characterize the Linux packet receiving process. Key factors that affect Linux systems network performance are analyzed.

  14. Electronically nonadiabatic wave packet propagation using frozen Gaussian scattering

    SciTech Connect

    Kondorskiy, Alexey D.; Nanbu, Shinkoh

    2015-09-21

    We present an approach, which allows to employ the adiabatic wave packet propagation technique and semiclassical theory to treat the nonadiabatic processes by using trajectory hopping. The approach developed generates a bunch of hopping trajectories and gives all additional information to incorporate the effect of nonadiabatic coupling into the wave packet dynamics. This provides an interface between a general adiabatic frozen Gaussian wave packet propagation method and the trajectory surface hopping technique. The basic idea suggested in [A. D. Kondorskiy and H. Nakamura, J. Chem. Phys. 120, 8937 (2004)] is revisited and complemented in the present work by the elaboration of efficient numerical algorithms. We combine our approach with the adiabatic Herman-Kluk frozen Gaussian approximation. The efficiency and accuracy of the resulting method is demonstrated by applying it to popular benchmark model systems including three Tully’s models and 24D model of pyrazine. It is shown that photoabsorption spectrum is successfully reproduced by using a few hundreds of trajectories. We employ the compact finite difference Hessian update scheme to consider feasibility of the ab initio “on-the-fly” simulations. It is found that this technique allows us to obtain the reliable final results using several Hessian matrix calculations per trajectory.

  15. On the Performance of Video Quality Assessment Metrics under Different Compression and Packet Loss Scenarios

    PubMed Central

    Martínez-Rach, Miguel O.; Piñol, Pablo; López, Otoniel M.; Perez Malumbres, Manuel; Oliver, José; Calafate, Carlos Tavares

    2014-01-01

    When comparing the performance of video coding approaches, evaluating different commercial video encoders, or measuring the perceived video quality in a wireless environment, Rate/distortion analysis is commonly used, where distortion is usually measured in terms of PSNR values. However, PSNR does not always capture the distortion perceived by a human being. As a consequence, significant efforts have focused on defining an objective video quality metric that is able to assess quality in the same way as a human does. We perform a study of some available objective quality assessment metrics in order to evaluate their behavior in two different scenarios. First, we deal with video sequences compressed by different encoders at different bitrates in order to properly measure the video quality degradation associated with the encoding system. In addition, we evaluate the behavior of the quality metrics when measuring video distortions produced by packet losses in mobile ad hoc network scenarios with variable degrees of network congestion and node mobility. Our purpose is to determine if the analyzed metrics can replace the PSNR while comparing, designing, and evaluating video codec proposals, and, in particular, under video delivery scenarios characterized by bursty and frequent packet losses, such as wireless multihop environments. PMID:24982988

  16. On the performance of video quality assessment metrics under different compression and packet loss scenarios.

    PubMed

    Martínez-Rach, Miguel O; Piñol, Pablo; López, Otoniel M; Perez Malumbres, Manuel; Oliver, José; Calafate, Carlos Tavares

    2014-01-01

    When comparing the performance of video coding approaches, evaluating different commercial video encoders, or measuring the perceived video quality in a wireless environment, Rate/distortion analysis is commonly used, where distortion is usually measured in terms of PSNR values. However, PSNR does not always capture the distortion perceived by a human being. As a consequence, significant efforts have focused on defining an objective video quality metric that is able to assess quality in the same way as a human does. We perform a study of some available objective quality assessment metrics in order to evaluate their behavior in two different scenarios. First, we deal with video sequences compressed by different encoders at different bitrates in order to properly measure the video quality degradation associated with the encoding system. In addition, we evaluate the behavior of the quality metrics when measuring video distortions produced by packet losses in mobile ad hoc network scenarios with variable degrees of network congestion and node mobility. Our purpose is to determine if the analyzed metrics can replace the PSNR while comparing, designing, and evaluating video codec proposals, and, in particular, under video delivery scenarios characterized by bursty and frequent packet losses, such as wireless multihop environments.

  17. All-optical multiplexing schemes for multiple access networks based on wavelet packet filter banks

    NASA Astrophysics Data System (ADS)

    Cincotti, Gabriella; Svaluto Moreolo, Michela; Neri, Alessandro

    2004-08-01

    All optical architectures for Wavelet Packet Division Multiplexing (WPDM) are presented, that can be used in multiple access networks to increase the number of simultaneous users. Wavelet waveform coding spreads data signals both in time and frequency domains, with a large capacity improvement with respect to standard Optical-Code Division Multiple Access (O-CDMA) systems. In addition, the orthogonal property of the wavelet atoms ensures low InterSymbol Interference (ISI) and Multiple Access Interference (MAI) noises. To exploit the large bandwidth capacity of optical fibres, the Optical-Electrical-Optical (O-E-O) conversion is completely avoided, and we designed an all optical system that realizes the WPDM fully in the optical domain. A single Planar Lightwave Circuit (PLC) device multiplies/demultiplies N different users and a diffractive or an integrated optical device performs the waveform coding/decoding. The Wavelet Packet (WP) encoder/decoder is realized as a tree of lattice-form delay-line filters, and can be integrated on a single device along with the optical waveform modulator, resulting in a compact planar optical system. In addition, we show that different choices of WP encoders/decoders are possible to further enhance the system performances.

  18. Design and comparative anticonvulsant activity assessment of CNS-active alkyl-carbamoyl imidazole derivatives.

    PubMed

    Mawasi, Hafiz; Bibi, David; Bialer, Meir

    2016-09-15

    A novel series of carbamoyl derivatives of alkylimidazole has been designed and their anticonvulsant activity was comparatively evaluated in the mice- and rats-maximal-electroshock (MES), subcutaneous-metrazol (scMet) seizure tests and the mice-6Hz psychomotor (6Hz) models. The ten new designed molecules contain in their chemical structure imidazole, alkyl side-chain and carbamate as three potential active moieties. In spite of the close structural features of the carbamoyl imidazole derivatives only compounds 7, 8, 13 and 16 were active at the MES test with ED50 values ranging from 12 to 20mg/kg coupled with high protective index (PI=TD50/ED50) values of 4.1-7.3 after ip administration to rats. A similar phenomenon was observed in mice where compounds 7, 8, 9, 12 had MES-ED50 values of 14-26mg/kg. Compounds 7 and 13 also demonstrated anticonvulsant activity in the 6Hz model with ED50 values of 32 and 44mg/kg, respectively. As the most active entities, compounds 7, 8 followed by 13 and 16, thus offer an optimal efficacy-safety profile and consequently, might be promising candidates for development as new antiepileptics. PMID:27469980

  19. Resistive wall mode active control physics design for KSTAR

    SciTech Connect

    Park, Y. S. Sabbagh, S. A.; Bialek, J. M.; Berkery, J. W.; Bak, J. G.; Lee, S. G.; Oh, Y. K.

    2014-01-15

    As KSTAR H-mode operation approaches the region where the resistive wall mode (RWM) can be unstable, an important issue for future long pulse, high beta plasma operation is to evaluate RWM active feedback control performance using a planned active/passive RWM stabilization system on the device. In particular, an optimal design of feedback sensors allows mode stabilization up to the highest achievable β{sub N} close to the ideal with-wall limit, β{sub N}{sup wall}, with reduced control power requirements. The computed ideal n = 1 mode structure from the DCON code has been input to the VALEN-3D code to calculate the projected performance of an active RWM control system in the KSTAR three-dimensional conducting structure device geometry. Control performance with the midplane locked mode detection sensors, off-midplane saddle loops, and magnetic pickup coils is examined. The midplane sensors measuring the radial component of the mode perturbation is found to be strongly affected by the wall eddy current. The off-axis saddle loops with proper compensation of the prompt applied field are computed to provide stabilization at β{sub N} up to 86% of β{sub N}{sup wall} but the low RWM amplitude computed in the off-axis regions near the sensors can produce a low signal-to-noise ratio. The required control power and bandwidth are also estimated with varied noise levels in the feedback sensors. Further improvements have been explored by examining a new RWM sensor design motivated by the off-midplane poloidal magnetic field sensors in NSTX. The new sensors mounted off of the copper passive stabilizer plates near the device midplane show a clear advantage in control performance corresponding to achieving 99% of β{sub N}{sup wall} without the need of compensation of the prompt field. The result shows a significant improvement of RWM feedback stabilization using the new sensor set which motivates a future feedback sensor upgrade.

  20. Multirate Flutter Suppression System Design for the Benchmark Active Controls Technology Wing. Part 1; Theory and Design Procedure

    NASA Technical Reports Server (NTRS)

    Mason, Gregory S.; Berg, Martin C.; Mukhopadhyay, Vivek

    2002-01-01

    To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies were applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing. This report describes a project at the University of Washington to design a multirate suppression system for the BACT wing. The objective of the project was two fold. First, to develop a methodology for designing robust multirate compensators, and second, to demonstrate the methodology by applying it to the design of a multirate flutter suppression system for the BACT wing.

  1. Rydberg Wave Packets and Half-Cycle Electromagnetic Pulses

    NASA Astrophysics Data System (ADS)

    Raman, Chandra S.

    1998-05-01

    This dissertation summarizes an examination of the dynamics of atomic Rydberg wave packets with coherent pulses of THz electromagnetic radiation consisting of less than a single cycle of the electric field. The bulk of the energy is contained in just a half-cycle. Previous work ( R. Jones, D. You, and P. Bucksbaum, ``Ionization of Rydberg atoms by subpicosecond half-cycle electromagnetic pulses,'' Phys. Rev. Lett.), vol. 70, 1993. had shown how these half-cycle pulses can be used to ionize the highly excited states of an atom, and that a classical view of electronic motion in the atom explains the ionization mechanism. To further probe the boundary between classical trajectories and quantum mechanics, in this work I investigate dynamical combinations of Rydberg states, or Rydberg wave packets, and how they ionize under the influence of a half-cycle electromagnetic pulse. With time-domain techniques I am able to extract the dynamics of the wave packet from the ionization rate, and to observe wave packet motion in both the electronic radial ( C. Raman, C. Conover, C. Sukenik, and P. Bucksbaum, ``Ionization of Rydberg wavepackets by sub-picosecond half-cycle electromagnetic pulses,'' Phys. Rev. Lett.), vol. 76, 1996.and angular ( C. Raman, T. Weinacht, and P. Bucksbaum, ``Stark wavepackets viewed with half cycle pulses.'' Phys. Rev. A), vol. 55, No. 6, 1997. coordinates. This is the first time a wavepacket technique has been used to view electron motion everywhere on its trajectory, and not just at the nucleus. This is the principal feature of half-cycle pulse ionization. Semiclassical ideas of ionization in conjunction with quantum descriptions of the wave packet, are capable of reproducing the main trends in the data, and in the absence of a rigorous model I rely on these. Experiments of this nature provide examples of the ongoing effort to use the coherent properties of radiation to control electronic motion in an atom, as well as to probe the boundaries between

  2. Optimal design of active and semi-active suspensions including time delays and preview

    NASA Astrophysics Data System (ADS)

    Hac', A.; Youn, I.

    1993-10-01

    Several control laws for active and semi-active suspension based on a linear half car model are derived and investigated. The strategies proposed take full advantage of the fact that the road input to the rear wheels is a delayed version of that to the front wheels, which in turn can be obtained either from the measurements of the front wheels and body motions or by direct preview of road irregularities if preview sensors are available. The suspension systems are optimized with respect to ride comfort, road holding and suspension rattle space as expressed by the mean-square-values of body acceleration (including effects of heave and pitch), tire deflections and front and rear suspension travels. The optimal control laws that minimize the given performance index and include passivity constraints in the semi-active case are derived using calculus of variation. The optimal semi-active suspension becomes piecewise linear, varying between passive and fully active systems and combinations of them. The performances of active and semi-active systems with and without preview were evaluated by numerical simulation in the time and frequency domains. The results show that incorporation of time delay between the front and rear axles in controller design improves the dynamic behavior of the rear axle and control of body pitch motion, while additional preview improves front wheel dynamics and body heave.

  3. America's Hero to the World, George C. Marshall. Teacher's Guide. Second Edition [and] Resource Packet [and] George C. Marshall: An American Leader. A Teacher's Notebook.

    ERIC Educational Resources Information Center

    Thompson, Rachel Yarnell; Sittig, Linda H.

    This teaching unit about George C. Marshall contains a teacher's guide, a resource packet, and a teacher's notebook. The teacher's guide includes ten introductory, overarching, and culminating activities: (1) About this Guide; (2) Getting to Know Him; (3) Marshal on Video; (4) Share a Space with a Hero; (5) On a Global Stage--Links; (6) A Picture…

  4. Art Image Preschool: Introducing 3-to-5-Year-Old Children to Art and Artists. [Packet] 4: Animals in the Wild. Teacher's Guide.

    ERIC Educational Resources Information Center

    Thompson, Christine

    This teacher's guide accompanies a packet of five art reproductions based on animals as a theme. The guide offers suggestions for engaging children's attention and curiosity about art and artists, and encourages exploration of the issues these works present through art activities, discussions, learning centers, field trips, and other experiences…

  5. Art Image Preschool: Introducing 3-to-5-Year-Old Children to Art and Artists. [Packet] 2: Pets Are Part of Our Lives. Teacher's Guide.

    ERIC Educational Resources Information Center

    Thompson, Christine

    This teacher's guide accompanies a packet of five art reproductions based on pets as a theme. The guide offers suggestions for engaging children's attention and curiosity about art and artists, and encourages exploration of the issues these works present through art activities, discussions, learning centers, field trips, and other experiences…

  6. Art Image Preschool: Introducing 3-to-5-Year-Old Children to Art and Artists. [Packet] 3: Portraits Are Images of People. Teacher's Guide.

    ERIC Educational Resources Information Center

    Thompson, Christine

    This teacher's guide accompanies a packet of five art reproductions based on portraits as a theme. The guide offers suggestions for engaging children's attention and curiosity about art and artists, and encourages exploration of the issues these works present through art activities, discussions, learning centers, field trips, and other experiences…

  7. Art Image Preschool: Introducing 3-to-5-Year-Old Children to Art and Artists. [Packet] 1: Shapes, Colors, and Stories. Teacher's Guide.

    ERIC Educational Resources Information Center

    Thompson, Christine

    This teacher's guide accompanies a packet of five art reproductions based on the theme: shapes, colors, and stories. The guide offers suggestions for engaging children's attention and curiosity about art and artists, and encourages exploration of the issues these works present through art activities, discussions, learning centers, field trip, and…

  8. Burst Packet Loss Concealment Using Multiple Codebooks and Comfort Noise for CELP-Type Speech Coders in Wireless Sensor Networks

    PubMed Central

    Park, Nam In; Kim, Hong Kook; Jung, Min A; Lee, Seong Ro; Choi, Seung Ho

    2011-01-01

    In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed in order to improve the quality of decoded speech under burst packet loss conditions in a wireless sensor network. Conventional receiver-based PLC algorithms in the G.729 speech codec are usually based on speech correlation to reconstruct the decoded speech of lost frames by using parameter information obtained from the previous correctly received frames. However, this approach has difficulty in reconstructing voice onset signals since the parameters such as pitch, linear predictive coding coefficient, and adaptive/fixed codebooks of the previous frames are mostly related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook-based approach that includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm currently employed in G.729 via a perceptual evaluation of speech quality, a waveform comparison, and a preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC algorithm employed in G.729 under all the test conditions. PMID:22163902

  9. Design of electro-active polymer gels as actuator materials

    NASA Astrophysics Data System (ADS)

    Popovic, Suzana

    Smart materials, alternatively called active or adaptive, differ from passive materials in their sensing and activation capability. These materials can sense changes in environment such as: electric field, magnetic field, UV light, pH, temperature. They are capable of responding in numerous ways. Some change their stiffness properties (electro-rheological fluids), other deform (piezos, shape memory alloys, electrostrictive materials) or change optic properties (electrochromic polymers). Polymer gels are one of such materials which can change the shape, volume and even optical properties upon different applied stimuli. Due to their low stiffness property they are capable of having up to 100% of strain in a short time, order of seconds. Their motion resembles the one of biosystems, and they are often seen as possible artificial muscle materials. Despite their delicate nature, appropriate design can make them being used as actuator materials which can form controllable surfaces and mechanical switches. In this study several different groups of polymer gel material were investigated: (a) acrylamide based gels are sensitive to pH and electric field and respond in volume change, (b) polyacrylonitrile (PAN) gel is sensitive to pH and electric field and responds in axial strain and bending, (c) polyvinylalcohol (PVA) gel is sensitive to electric field and responds in axial strain and bending and (d) perfluorinated sulfonic acid membrane, Nafion RTM, is sensitive to electric field and responds in bending. Electro-mechanical and chemo-mechanical behavior of these materials is a function of a variety of phenomena: polymer structure, affinity of polymer to the solvent, charge distribution within material, type of solvent, elasticity of polymer matrix, etc. Modeling of this behavior is a task aimed to identify what is driving mechanism for activation and express it in a quantitative way in terms of deformation of material. In this work behavior of the most promising material as

  10. Implementation of a Data Packet Generator Using Pattern Matching for Wearable ECG Monitoring Systems

    PubMed Central

    Noh, Yun Hong; Jeong, Do Un

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  11. Implementation of a data packet generator using pattern matching for wearable ECG monitoring systems.

    PubMed

    Noh, Yun Hong; Jeong, Do Un

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  12. Observation of ICRF (ion cyclotron range of frequencies) wave-packet propagation in a tokamak plasma

    SciTech Connect

    Greene, G.J.; Gould, R.W.

    1987-11-01

    Experimental observation of ICRF wave-packet propagation in a tokamak plasma is reported. Studies were carried out in the Caltech Research Tokamak in a pure hydrogen plasma and in a regime where fast-wave damping was sufficiently small to permit multiple toroidal transits of the wave-packet. Waves were launched by exciting a small loop antenna with a short burst of rf current and were detected with shielded magnetic probes. Probe scans revealed a large increase in wave-packet amplitude at smaller minor radii, and the packet velocity was found to be independent of radial position. Measurement of the packet transit time yielded direct information about the wave group velocity. Packet velocity was investigated as a function of the fundamental excitation frequency, plasma density, and toroidal magnetic field. Results are compared with the predictions of a cold plasma model which includes a vacuum layer at the edge. 24 refs., 8 figs.

  13. PacketLib: A C++ Library for Scientific Satellite Telemetry Applications

    NASA Astrophysics Data System (ADS)

    Bulgarelli, A.; Gianotti, F.; Trifoglio, M.

    PacketLib is a C++ open-source software library for writing applications which deal with satellite telemetry source packets, provided that the packets are compliant with the CCSDS Telemetry and Telecommand Standards. The library is being used within the Italian Space Agency (ASI) mission AGILE for simulation, graphical display, processing and decoding of the telemetry generated by the Test Equipment (TE) of two AGILE detectors. From an input stream of bytes, the library is able to recognize automatically the source packets (described by a simple configuration file), and provides a simple access to each packet field by means of an object oriented interface. In the same way the library writes source packets to output stream. Various types of input and output streams are abstracted by a software layer.

  14. Encoding and Decoding Information in High-n Circular Wave Packets

    SciTech Connect

    Yoshida, S.; Reinhold, Carlos O; Burgdorfer, J.; Wyker, B.; Dunning, F. B.

    2010-01-01

    We demonstrate theoretically and experimentally the extraction of detailed information on the density matrix of very-high-n(> 300) near-circular Rydberg wave packets through Fourier analysis of the quantum beat and quantum revival signal. The remarkably long coherence times associated with circular wave packets facilitate the preservation and read-out of information encoded in this matrix. We illustrate the power of the method by determining the angular localization of the components of a wave packet.

  15. Time delay of wave packets during their tunnelling through a quantum diode

    SciTech Connect

    Ivanov, N A; Skalozub, V V

    2014-04-28

    A modified saddle-point method is used to investigate the process of propagation of a wave packet through a quantum diode. A scattering matrix is constructed for the structure in question. The case of tunnelling of a packet with a Gaussian envelope through the diode is considered in detail. The time delay and the shape of the wave packet transmitted are calculated. The dependence of the delay time on the characteristics of the input packet and the internal characteristics of the quantum diode is studied. Possible applications of the results obtained are discussed. (laser applications and other topics in quantum electronics)

  16. Wave-packet dynamics on Chern-band lattices in a trap

    NASA Astrophysics Data System (ADS)

    Roy, Sthitadhi; Grushin, Adolfo G.; Moessner, Roderich; Haque, Masudul

    2015-12-01

    The experimental realization of lattices with Chern bands in ultracold-atom and photonic systems has motivated the study of time-dependent phenomena, such as spatial propagation, in lattices with nontrivial topology. We study the dynamics of Gaussian wave packets on the Haldane honeycomb Chern-band lattice model, in the presence of a harmonic trap. We focus on the transverse response to a force, which is due partly to the Berry curvature and partly to the transverse component of the energy band curvature. We evaluate the accuracy of a semiclassical description, which treats the wave packet as a point particle in both real and momentum space, in reproducing the motion of a realistic wave packet with finite extent. We find that, in order to accurately capture the wave-packet dynamics, the extent of the wave packet in momentum space needs to be taken into account: The dynamics is sensitive to the interplay of band dispersion and Berry curvature over the finite region of momentum (reciprocal) space where the wave packet has support. Moreover, if the wave packet is prepared with a finite initial momentum, the semiclassical analysis reproduces its motion as long as it has a large overlap with the eigenstates of a single band. The semiclassical description generally improves with increasing real-space size of the wave packet, as long as the external conditions (e.g., external force) remain uniform throughout the spatial extent of the wave packet.

  17. Time behavior of a Gaussian wave packet accompanying the generalized coherent state for the inverted oscillator

    NASA Astrophysics Data System (ADS)

    Maamache, Mustapha; Bouguerra, Yacine; Choi, Jeong Ryeol

    2016-06-01

    A Gaussian wave packet of the inverted oscillator is investigated using the invariant operator method together with the unitary transformation method. A simple wave packet directly derived from the eigenstates of the invariant operator of the system corresponds to a plane wave that is fully delocalized. However, we can construct a weighted wave packet in terms of such plane waves, which corresponds to a Gaussian wave. This wave packet is associated with the generalized coherent state, which can be crucially utilized for investigating the classical limit of quantum wave mechanics. Various quantum properties of the system, such as fluctuations of the canonical variables, the uncertainty product, and the motion of the wave packet or quantum particle, are analyzed by means of this wave packet. We have confirmed that the time behavior of such a wave packet is very similar to the counterpart classical state. The wave packet runs away from the origin in the positive or negative direction in the 1D coordinate depending on the condition of the initial state. We have confirmed that this wave packet not only moves acceleratively but also spreads out during its propagation.

  18. Real-time video transmission over a fast packet-switched network

    NASA Astrophysics Data System (ADS)

    Moorhead, Robert J.; Ma, Joong S.; Gonzales, Cesar A.

    1989-04-01

    Realtime transmission of packetized video is a relatively new but important area of research since tomorrow's networks will likely be based on a common fast packet-switching technology, replacing today's heterogeneous networks which are mixtures of circuit-switched and packet-switched networks dedicated for synchronous and asynchronous applications respectively. Unlike fixed bandwidth transmission channels, packet-switched networks can accommodate the bursty and highly variable rate of compressed motion video yet keep a constant level of image quality. Potential applications include motion video databases, video teleconferencing, and broadcasting over private networks. Unfortunately, traditional video-compression techniques which are applicable to synchronous, fixed bandwidth channels--cannot be applied in this new environment without substantial revisions that take into account the statistical nature of packet data transmission. Independent of their topology, fast packet-switched networks present unique challenges to the coding of motion video; one cannot simply divorce the coding of the source from the characteristics of the channel. The potential for loss of data integrity due to packet losses and transmission errors must be taken into account. The problem of re-synchronization must also be addressed since packet-switched networks are asynchronous by nature. In this paper, we evaluate image coding techniques for motion video in view of the constraints imposed by the packetized medium.

  19. The application study of wavelet packet transformation in the de-noising of dynamic EEG data.

    PubMed

    Li, Yifeng; Zhang, Lihui; Li, Baohui; Wei, Xiaoyang; Yan, Guiding; Geng, Xichen; Jin, Zhao; Xu, Yan; Wang, Haixia; Liu, Xiaoyan; Lin, Rong; Wang, Quan

    2015-01-01

    This paper briefly describes the basic principle of wavelet packet analysis, and on this basis introduces the general principle of wavelet packet transformation for signal den-noising. The dynamic EEG data under +Gz acceleration is made a de-noising treatment by using wavelet packet transformation, and the de-noising effects with different thresholds are made a comparison. The study verifies the validity and application value of wavelet packet threshold method for the de-noising of dynamic EEG data under +Gz acceleration. PMID:26405863

  20. Field structure of collapsing wave packets in 3D strong Langmuir turbulence

    NASA Technical Reports Server (NTRS)

    Newman, D. L.; Robinson, P. A.; Goldman, M. V.

    1989-01-01

    A simple model is constructed for the electric fields in the collapsing wave packets found in 3D simulations of driven and damped isotropic strong Langmuir turbulence. This model, based on a spherical-harmonic decomposition of the electrostatic potential, accounts for the distribution of wave-packet shapes observed in the simulations, particularly the predominance of oblate wave packets. In contrast with predictions for undamped and undriven subsonic collapse of scalar fields, oblate vector-field wave packets do not flatten during collapse but, instead, remain approximately self-similar and rigid.

  1. Nonlinear single Compton scattering of an electron wave packet

    NASA Astrophysics Data System (ADS)

    Angioi, A.; Mackenroth, F.; Di Piazza, A.

    2016-05-01

    Nonlinear single Compton scattering has been thoroughly investigated in the literature under the assumption that the electron initially has a definite momentum. Here, we study a more general initial state and consider the electron as a wave packet. In particular, we investigate the energy spectrum of the emitted radiation and show that, in typical experimental situations, some features of the spectra shown in previous works are almost completely washed out. Moreover, we show that, at comparable relative uncertainties, the one in the momentum of the incoming electron has a larger impact on the photon spectra at a fixed observation direction than the one on the laser frequency.

  2. Engineering biphoton wave packets with an electromagnetically induced grating

    SciTech Connect

    Wen Jianming; Xiao Min; Zhai Yanhua; Du Shengwang

    2010-10-15

    We propose to shape biphoton wave packets with an electromagnetically induced grating in a four-level double-{Lambda} cold atomic system. We show that the induced hybrid grating plays an essential role in directing the new fields into different angular positions, especially for the zeroth-order diffraction. A number of interesting features appears in the shaped two-photon wave forms. For example, broadening or narrowing the spectrum would be possible in the proposed scheme even without the use of a cavity.

  3. A Wavelet Packets Approach to Electrocardiograph Baseline Drift Cancellation

    PubMed Central

    Mozaffary, Behzad

    2006-01-01

    Baseline wander elimination is considered a classical problem. In electrocardiography (ECG) signals, baseline drift can influence the accurate diagnosis of heart disease such as ischemia and arrhythmia. We present a wavelet-transform- (WT-) based search algorithm using the energy of the signal in different scales to isolate baseline wander from the ECG signal. The algorithm computes wavelet packet coefficients and then in each scale the energy of the signal is calculated. Comparison is made and the branch of the wavelet binary tree corresponding to higher energy wavelet spaces is chosen. This algorithm is tested using the data record from MIT/BIH database and excellent results are obtained. PMID:23165064

  4. Wave-packet evolution in non-Hermitian quantum systems

    SciTech Connect

    Graefe, Eva-Maria; Schubert, Roman

    2011-06-15

    The quantum evolution of the Wigner function for Gaussian wave packets generated by a non-Hermitian Hamiltonian is investigated. In the semiclassical limit ({h_bar}/2{pi}){yields}0 this yields the non-Hermitian analog of the Ehrenfest theorem for the dynamics of observable expectation values. The lack of Hermiticity reveals the importance of the complex structure on the classical phase space: The resulting equations of motion are coupled to an equation of motion for the phase-space metric - a phenomenon having no analog in Hermitian theories.

  5. Simulation of the collapse and dissipation of Langmuir wave packets

    NASA Technical Reports Server (NTRS)

    Newman, D. L.; Winglee, R. M.; Robinson, P. A.; Glanz, J.; Goldman, M. V.

    1990-01-01

    Particle-in-cell (PIC) simulations and Zakharov's partial differential equations (PDEs) are used to investigate the collapse of isolated Langmuir wave packets in two dimensions. Collapse thresholds are determined numerically, and the roles of enhanced Langmuir wave damping and nonlinearities not included in the standard Zakharov equations are discussed. The Langmuir wave and ion dynamics in PIC simulations are compared with the predictions of PDE simulations incorporating enhanced Langmuir damping. Electron heating and coherent acceleration in the PIC simulations are discussed and compared with predictions of the transit-time theory.

  6. Packet communication system for a multi-beam beam switched satellite repeater

    NASA Technical Reports Server (NTRS)

    Bose, S. K.

    1982-01-01

    This paper presents the design of a packet-switched communication system using a multi-beam, beam switched satellite repeater. The protocol provides a combination of random access via Slotted ALOHA techniques and demand assigned access using collision requests. This allows efficient bandwidth usage and low average delays. Minimization of earth station cost was a major objective. This was achieved by transferring the bulk of the system complexity to the satellite repeater and the (ground) network controller. This centrally controlled protocol would allow greater system stability and would permit system reconfiguration in response to changes in traffic intensity. Sufficient signalling is also incorporated to allow both rate diversity to combat fading and timing corrections to account for satellite drift.

  7. DDE-MITR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; J.D. Wiest; J.W. Nielsen; G.A. Roth; S.D. Snow

    2012-09-01

    The Design Demonstration Experiment for the Massachusetts Institute of Technology Reactor (DDE-MITR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MITR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MITR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MITR.

  8. DDE-MURR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; M.H. Sprenger; G.K. Housley

    2012-09-01

    The Design Demonstration Experiment for the University of Missouri Research Reactor (DDE-MURR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MURR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in a 200mm channel at the Belgium Reactor 2. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MURR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MURR.

  9. DDE-NBSR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; B.P. Durtschi; C.R. Glass; G.A. Roth; D.T. Clark

    2012-09-01

    The Design Demonstration Experiment for the National Bureau of Standard Reactor (DDE-NBSR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the NBSR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-NBSR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the NBSR.

  10. NASA/USRA advanced design program activity, 1991-1992

    NASA Technical Reports Server (NTRS)

    Dorrity, J. Lewis; Patel, Suneer

    1992-01-01

    The School of Textile and Fiber Engineering continued to pursue design projects with the Mechanical Engineering School giving the students an outstanding opportunity to interact with students from another discipline. Four problems were defined which had aspects which would be reasonably assigned to an interdisciplinary team. The design problems are described. The projects included lunar preform manufacturing, dust control for Enabler, an industrial sewing machine variable speed controllor, Enabler operation station, and design for producing fiberglass fabric in a lunar environment.

  11. Design, structure activity relationship, cytotoxicity and evaluation of antioxidant activity of curcumin derivatives/analogues.

    PubMed

    Sahu, Pramod K

    2016-10-01

    New fourteen 3,4-dihydropyrimidine derivatives/analogues of curcumin (2a-2n) were designed, synthesized and biologically evaluated for their cytotoxicity and antioxidant activity. Cytotoxicity effect has been evaluated against three cell lines HeLa, HCT-116 and QG-56 by MTT assay method. From SAR study, it has been revealed that particularly, compound 2e and 2j (IC50 value 12.5 μM) have shown better cytotoxicity effect against three cell lines. According to results of SAR study, it was found that 3,4-dihydropyrimidines of curcumin, 2c, 2d, 2j and 2n exhibited better antioxidant activity than curcumin. A correlation of structure and activities relationship of these compounds with respect to drug score profiles and other physico-chemical properties of drugs are described and verified experimentally. Therefore, we conclude that physico-chemical analyses may prove structural features of curcumin analogues with their promising combined cytotoxicity/antioxidant activity and it is also concluded from virtual and practical screening that the compounds were varied to possess a broad range of lipophilic character, revealed by Log P values. PMID:27318975

  12. Using iPads to Help Teens Design Their Own Activities

    ERIC Educational Resources Information Center

    Underwood, Joshua

    2014-01-01

    This paper reports on action research aimed at helping teenage English language learners become more aware of ways they might use technology to support their learning. Over nine-months we used iPads to support a wide variety of teacher-designed learning activities and then used design thinking to help students co-design their own activities.…

  13. Students' Interest and Expectancy for Success while Engaged in Analysis- and Creative Design Activities

    ERIC Educational Resources Information Center

    Lawanto, Oenardi; Stewardson, Gary

    2013-01-01

    Inasmuch as design is a central activity in K-12 engineering education, understanding the students' motivation during engaging in engineering design activities will help educators to develop and evaluate strategies for engineering design challenges, and improve curriculum. The objective of this study is to better understand the relationship…

  14. Modeling the Benchmark Active Control Technology Wind-Tunnel Model for Active Control Design Applications

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    1998-01-01

    This report describes the formulation of a model of the dynamic behavior of the Benchmark Active Controls Technology (BACT) wind tunnel model for active control design and analysis applications. The model is formed by combining the equations of motion for the BACT wind tunnel model with actuator models and a model of wind tunnel turbulence. The primary focus of this report is the development of the equations of motion from first principles by using Lagrange's equations and the principle of virtual work. A numerical form of the model is generated by making use of parameters obtained from both experiment and analysis. Comparisons between experimental and analytical data obtained from the numerical model show excellent agreement and suggest that simple coefficient-based aerodynamics are sufficient to accurately characterize the aeroelastic response of the BACT wind tunnel model. The equations of motion developed herein have been used to aid in the design and analysis of a number of flutter suppression controllers that have been successfully implemented.

  15. Using Critical Incidents of Instructional Design and Multimedia Production Activities to Investigate Instructional Designers' Current Practices and Roles

    ERIC Educational Resources Information Center

    Sugar, William A.; Luterbach, Kenneth J.

    2016-01-01

    Through consideration of critical incidents, this study analyzed 106 effective, ineffective and extraordinary instructional design and multimedia production (MP) activities discussed by 36 instructional design professionals. This evaluation provided insights into these professionals' best and not so best practices during the past 6 months.…

  16. Thermal design for areas of interference heating on actively cooled hypersonic aircraft

    NASA Technical Reports Server (NTRS)

    Herring, R. L.; Stone, J. E.

    1978-01-01

    Numerous actively cooled panel design alternatives for application in regions on high speed aircraft that are subject to interference heating effects were studied. Candidate design concepts were evaluated using mass, producibility, reliability and inspectability/maintainability as figures of merit. Three design approaches were identified as superior within certain regimes of the matrix of design heating conditions considered. Only minor modifications to basic actively cooled panel design are required to withstand minor interference heating effects. Designs incorporating internally finned coolant tubes to augment heat transfer are recommended for moderate design heating conditions. At severe heating conditions, an insulated panel concept is required.

  17. Orchestrating Learning Activities Using the CADMOS Learning Design Tool

    ERIC Educational Resources Information Center

    Katsamani, Maria; Retalis, Symeon

    2013-01-01

    This paper gives an overview of CADMOS (CoursewAre Development Methodology for Open instructional Systems), a graphical IMS-LD Level A & B compliant learning design (LD) tool, which promotes the concept of "separation of concerns" during the design process, via the creation of two models: the conceptual model, which describes the…

  18. Position paper - peer review and design verification of selected activities

    SciTech Connect

    Stine, M.D.

    1994-09-01

    Position Paper to develop and document a position on the performance of independent peer reviews on selected design and analysis components of the Title I (preliminary) and Title II (detailed) design phases of the Multi-Function Waste Tank Facility project.

  19. Non-Hermitian wave packet approximation of Bloch optical equations

    SciTech Connect

    Charron, Eric; Sukharev, Maxim

    2013-01-14

    We introduce a non-Hermitian approximation of Bloch optical equations. This approximation provides a complete description of the excitation, relaxation, and decoherence dynamics of ensembles of coupled quantum systems in weak laser fields, taking into account collective effects and dephasing. In the proposed method, one propagates the wave function of the system instead of a complete density matrix. Relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. As an application, we compute the numerical wave packet solution of a time-dependent non-Hermitian Schroedinger equation describing the interaction of electromagnetic radiation with a quantum nano-structure, and compare the calculated transmission, reflection, and absorption spectra with those obtained from the numerical solution of the Liouville-von Neumann equation. It is shown that the proposed wave packet scheme is significantly faster than the propagation of the full density matrix while maintaining small error. We provide the key ingredients for easy-to-use implementation of the proposed scheme and identify the limits and error scaling of this approximation.

  20. Application of wavelet packet transform to compressing Raman spectra data

    NASA Astrophysics Data System (ADS)

    Chen, Chen; Peng, Fei; Cheng, Qinghua; Xu, Dahai

    2008-12-01

    Abstract The Wavelet transform has been established with the Fourier transform as a data-processing method in analytical fields. The main fields of application are related to de-noising, compression, variable reduction, and signal suppression. Raman spectroscopy (RS) is characterized by the frequency excursion that can show the information of molecule. Every substance has its own feature Raman spectroscopy, which can analyze the structure, components, concentrations and some other properties of samples easily. RS is a powerful analytical tool for detection and identification. There are many databases of RS. But the data of Raman spectrum needs large space to storing and long time to searching. In this paper, Wavelet packet is chosen to compress Raman spectra data of some benzene series. The obtained results show that the energy retained is as high as 99.9% after compression, while the percentage for number of zeros is 87.50%. It was concluded that the Wavelet packet has significance in compressing the RS data.