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1

Swinging Yo-Yo  

NSDL National Science Digital Library

Learners build a pendulum from a yo-yo, and then design their own experiment to determine what affects the pendulum's period of swing. They can alter the mass of the yo-yo by adding play dough, the length of the yo-yo string, or some other variable of their own choosing. Learners collect data and graph their results. This activity starts on p.17 of the manual. This manual contains 4 activities related to the Spectra's Force comic book published by the American Physical Society.

Thompson, Rebecca; Johnson, Kerry G.; Ellis, David; Bennett-Karasik, Nancy

2011-01-01

2

Recycled Yo-Yo Challenge  

NSDL National Science Digital Library

In this activity, learners are challenged to build their own yo-yo toys using items found in their recycling bins. Learners search for materials to use for each part of the toy: two discs, an axle, and string. Learners then sketch their invention, assemble the parts, and test it out. Learners are encouraged to tweak their yo-yos and make improvements.

History, National M.

2012-06-26

3

Museum of Yo-Yo History  

NSDL National Science Digital Library

Perhaps no toy is as maligned as the yo-yo, despite its long and colorful history. The roots of the yo-yo can be traced back to antiquity, and there is even a Grecian urn in the collection of the Metropolitan Museum of Art that depicts that most well-known of yo-yo maneuvers: walking the dog. Visitors with a penchant for the yo-yo will appreciate the wide range of materials that can be found on the site, particularly the rather compelling online exhibit of highly valuable yo-yos, such as the 1984 Olympics No Jive model. For those who want to continue their exploration of the yo-yo, there is the ÂProfiles & History area, which contains player and company profiles, along with historical photographs of yo-yos in action.

2004-01-01

4

Exploring the Yo-Yo: Filipino Physics Fun  

Microsoft Academic Search

The yo-yo is a scientific toy that has fascinated young and old for thousands of years. According to yo-yo experts, the yo-yo is the second oldest toy in the world, after the doll. Yo-yo activities can be an excellent tool to help students explore many important physics concepts related to energy and motion. The rich history of the yo-yo offers

Brian Murfin

2012-01-01

5

Two-String Yo-Yo  

NSDL National Science Digital Library

Learners build a yo-yo using a piece of wood, PVC pipe, and string. In doing so, learners explore the force of gravity and angular momentum. This activity guide includes step-by-step instructions with images, a video, and focus questions. Drill, hacksaw or jigsaw, and hammer are required.

Workshop, Watsonville E.

2011-01-01

6

Mechanical Study of a Modern Yo-Yo  

ERIC Educational Resources Information Center

|This paper presents the study of a modern yo-yo having a centrifugal clutch allowing the free rolling. First, the mechanical parts of the yo-yo are measured, allowing us to determine analytically its velocity according to its height of fall. Then, we are more particularly interested in the centrifugal device constituted by springs and small…

de Izarra, Charles

2011-01-01

7

The Yo–Yo intermittent recovery test in basketball players  

Microsoft Academic Search

Summary The purpose of this study was to examine the physiological correlates of the Yo—Yo intermittent recovery test level 1 (Yo—Yo IR1) in basketball play- ers. Twenty-two male basketball players (means ± S.D., body mass 72.4 ± 11.4 kg, height 181.7 ± 6.9 cm, age 16.8 ± 2.0 years) were tested for maximal oxygen uptake (VO2max), ventilatory threshold (VT) and

Carlo Castagna; Franco M. Impellizzeri; Ermanno Rampinini; Stefano D’Ottavio; Vincenzo Manzi

2008-01-01

8

?-alanine supplementation improves YoYo intermittent recovery test performance  

PubMed Central

Background ?-alanine supplementation has been shown to improve high-intensity exercise performance and capacity. However, the effects on intermittent exercise are less clear, with no effect shown on repeated sprint activity. The aim of this study was to investigate the effects of ?-alanine supplementation on YoYo Intermittent Recovery Test Level 2 (YoYo IR2) performance. Methods Seventeen amateur footballers were allocated to either a placebo (PLA; N = 8) or ?-alanine (BA; N = 9) supplementation group, and performed the YoYo IR2 on two separate occasions, pre and post 12 weeks of supplementation during a competitive season. Specifically, players were supplemented from early to mid-season (PLA: N = 5; BA: N = 6) or mid- to the end of the season (PLA: N = 3; BA: N = 3). Data were analysed using a two factor ANOVA with Tukey post-hoc analyses. Results Pre supplementation scores were 1185 ± 216 and 1093 ± 148 m for PLA and BA, with no differences between groups (P = 0.41). YoYo performance was significantly improved for BA (+34.3%, P ? 0.001) but not PLA (?7.3%, P = 0.24) following supplementation. 2 of 8 (Early – Mid: 2 of 5; Mid – End: 0 of 3) players improved their YoYo scores in PLA (Range: -37.5 to + 14.7%) and 8 of 9 (Early – Mid: 6 of 6; Mid – End: 2 of 3) improved for BA (Range: +0.0 to +72.7%). Conclusions 12 weeks of ?-alanine supplementation improved YoYo IR2 performance, likely due to an increased muscle buffering capacity resulting in an attenuation of the reduction in intracellular pH during high-intensity intermittent exercise.

2012-01-01

9

Ecological validity of the Yo-Yo SFIE2 test.  

PubMed

The present study investigated the movement pattern of Portuguese top-level futsal referees (n=16) during competitive games and the ecological validity of the new Yo-Yo Sideways-Forwards Intermittent Endurance level 2 test (Yo-Yo SFIE2). Total distance covered (TD), high-intensity running (HIR), sprinting (SPR), and sideways running (Sw) during matches were 5.78±0.24 (±SEM), 0.77±0.08, 0.17±0.02 and 1.61±0.28 km, respectively, with peak 5-min values of 0.50±0.02, 0.12±0.01, 0.05±0.01 and 0.20±0.02 km, respectively. TD, HIR and Sw decreased by 30% (p<0.001), 43% and 60% (p<0.01), respectively from the first to the last 10-min period. Yo-Yo SFIE2 performance was 1205±107 (625-2015) m and showed large correlations with match-values and peak 5-min values for HIR (r=0.58 and 0.68, p<0.01) and SPR (r=0.56 and 0.57, p<0.05). Yo-Yo SFIE2 HR after 4 min [95±1 (87-99) % HRpeak] showed a nearly perfect inverse correlation with Yo-Yo SFIE2 performance (r= -0.90, p<0.001) and large inverse correlations (p<0.05) with match-values and peak 5-min values for HIR (r= -0.55 and -0.71) and SPR (r= -0.57 and -0.55). In conclusion, the Yo-Yo SFIE2 test is movement-specific for top-level futsal referees as high-intensity running and sideways running are important parts of their match activity profile, and maximal and sub-maximal versions of the Yo-Yo SFIE2 test correlates with certain aspects of the physical match performance of top-level futsal referees. PMID:22422308

Krustrup, P; Randers, M; Horton, J; Brito, J; Rebelo, A

2012-03-15

10

The Yo-Yo intermittent recovery test in basketball players.  

PubMed

The purpose of this study was to examine the physiological correlates of the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) in basketball players. Twenty-two male basketball players (means+/-S.D., body mass 72.4+/-11.4kg, height 181.7+/-6.9cm, age 16.8+/-2.0 years) were tested for maximal oxygen uptake (VO(2max)), ventilatory threshold (VT) and running economy (RE) on a motorized treadmill. Lower limb explosive strength and anaerobic-capacity was assessed using vertical jumps (CMJ), 15m shuttle running sprint (15mSR) and line drill (LD), respectively. The same test battery was replicated after an experimental basketball game in order to assess selective effect of fatigue on physical performance. Pre to post-game CMJ (40.3+/-5.7 versus 39.9+/-5.9cm) and 15mSR (5.80+/-0.25 versus 5.77+/-0.22s) performances were not significantly different (p>0.05). LD performance decreased significantly post-game (from 26.7+/-1.3 to 27.7+/-2.7s, p<0.001). Yo-Yo IR1 performances (m) were significantly related to VO(2max) (r=0.77, p=0.0001), speed at VO(2max) (r=0.71, p=0.0001) and %VO(2max) at VT (r=-0.60, p=0.04). Yo-Yo IR1 performance was significantly correlated to post-game LD decrements (r=-0.52, p=0.02). These findings show that Yo-Yo IR1 may be considered as a valid basketball-specific test for the assessment of aerobic fitness and game-related endurance. PMID:17574917

Castagna, Carlo; Impellizzeri, Franco M; Rampinini, Ermanno; D'Ottavio, Stefano; Manzi, Vincenzo

2007-06-15

11

The Yo-Yo Intermittent Recovery Test: Physiological Response, Reliability, and Validity  

Microsoft Academic Search

KRUSTRUP, P., M. MOHR, T. AMSTRUP, T. RYSGAARD, J. JOHANSEN, A. STEENSBERG, P. K. PEDERSEN, and J. BANGSBO. The Yo-Yo Intermittent Recovery Test: Physiological Response, Reliability, and Validity. Med. Sci. Sports Exerc., Vol. 35, No. 4, pp. 697-705, 2003. Purpose: To examine the physiological response and reproducibility of the Yo-Yo intermittent recovery test and its application to elite soccer. Methods:

PETER KRUSTRUP; MAGNI MOHR; TOMMAS AMSTRUP; TORBEN RYSGAARD; JOHNNY JOHANSEN; ADAM STEENSBERG; PREBEN K. PEDERSEN; JENS BANGSBO

2003-01-01

12

Direct validity of the yo-yo intermittent recovery test in young team handball players.  

PubMed

The aim of this study was to examine the possible association between Yo-Yo intermittent recovery test level 1 performance (distance covered, Yo-Yo IR1) and match activities (direct validity) in young male team handball players. Eighteen young male players (age 14.3 +/- 0.5 years, body mass 64 +/- 28.7 kg, height 174 +/- 6 cm, body fat 11.2 +/- 3.9%) took part in this study. Players' match activities were videotaped during an experimental tournament (6 games/player) and analyzed using a computerized system. Games and Yo-Yo IR1 heart rates (HRs) (short-range telemetry, HR) and blood lactate concentrations ([la]b) were assessed throughout and at selected times of the games, respectively. Peak Yo-Yo IR1 HR was assumed as representative of individual maximal HR (HRmax). Mean and peak game HRs were 174 +/- 3 and 198 +/- 2 b.min, which corresponded to 87 and 99% of HRmax, respectively. Yo-Yo IR1 performance (1,831 +/- 373 m) was significantly related (r = 0.88, p < 0.01) to total game distance (1,921 +/- 325 m). Post-game (9.2 +/- 2.3 mmol.L) and Yo-Yo IR1 (8.8 +/- 1.6 mmol.L) [la]b were significantly related (r = 0.51, p < 0.05). These findings demonstrated the direct validity of Yo-Yo IR1. Consequently, Yo-Yo IR1 test may be considered as a team handball test relevant for the assessment of intermittent high-intensity endurance in young male team handball players. PMID:20072052

Souhail, Hermassi; Castagna, Carlo; Mohamed, Haj Yahmed; Younes, Hachana; Chamari, Karim

2010-02-01

13

Kikankei joho tsushin network no koseiho to un'yo kanri hoshiki. 3. Pass kirikae seigyo taisho to shita un'yo kanri system kosei no kento. (Utility broad-band network architecture and its OAM. Part 3. Proposal of OAM system configurations intended to a control method for path re-assignment).  

National Technical Information Service (NTIS)

A number of OAM functions required for Utility's Broad-Band Network was explicitly defined and it was found that the TMN standard system meets to realize a system which can be implemented with a Utility's functional needs. A general idea must be described...

K. Okamura T. Hirozawa T. Otani Y. Inoue

1995-01-01

14

Ureteric diverticula: ureterodiverticular reflux and yo-yo effect. A television study with spot filming.  

PubMed

Two cases of ureteric diverticulum are presented. Repeated infective episodes were the main presenting features in one, whereas intermittent attacks of colicky pain brought the other patient in for clinical assessment. Fluoroscopic evaluation of the latter patient demonstrated free ureterodiverticular reflux and yo-yo phenomenon. Following diverticulectomy the pain completely disappeared. PMID:6775729

Sharma, S K; Subudhi, C L; Kumar, S; Bapna, B C; Suri, S

1980-10-01

15

The Yo-Yo Intermittent Recovery Test (Level 1) to discriminate elite junior Australian football players.  

PubMed

The Yo-Yo Intermittent Recovery (IR) Test is currently used to assess endurance performance in team sport athletes. However, to date, no data has been presented on its application to an elite junior Australian football (AF) playing group. Therefore, the aim of this study was to evaluate the Yo-Yo Intermittent Recovery Test Level 1 (IR1) ability to discriminate between junior AF players at two different playing standards and a group of non-athletic healthy males. Sixty age matched participants (16.6+/-0.5 years) spread over three groups (20 per group): elite junior footballers; sub-elite junior footballers; and non-athletic healthy males participated in this study. Participants undertook a single Yo-Yo test performance on an indoor basketball court for each group. A one-way ANOVA with Scheffe's post hoc analysis revealed the elite junior footballers covered a significantly greater total distance (p<0.001) and completed a significantly greater number of high-intensity efforts (p<0.001) in comparison to their sub-elite counterparts, whilst both AF groups performed significantly better (p<0.001) than the non-athletic healthy males. This study demonstrates the ability of the Yo-Yo IR1 to discriminate endurance performance between elite and sub-elite AF players, whilst further distinguishing AF players from a non-athletic healthy control group. PMID:19451033

Veale, James P; Pearce, Alan J; Carlson, John S

2009-05-17

16

The Yo-yo Oscillator (Analysis of a Nonlinear System using Spice)  

Microsoft Academic Search

Unlike the simplest (Hooke's law spring) oscillator, where the restoring force is in magnitude proportional to the displacement; the yo-yo oscillator has a constant force-magnitude. In other words, its potential energy function is linear, as contrasted to the quadratic (harmonic) potential of the simple harmonic oscillator. The linear potential is responsible for a nonlinear equation of motion which yields many

Randall D. Peters

2005-01-01

17

The Application of the Yo-Yo Intermittent Endurance Level 2 Test to Elite Female Soccer Populations.  

PubMed

The aim of this study was to evaluate the application of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) to elite female soccer populations. Elite senior (n?=?92), youth (n?=?42), domestic (n?=?46) and sub-elite female soccer players (n?=?19) carried out the Yo-Yo IE2 test on numerous occasions across the season. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance in domestic female players was 4.5%. Elite senior female players' Yo-Yo IE2 test performances were better (P?Yo-Yo IE2 test performance (P?Yo-Yo IE2 test performance and the total and high-intensity distance covered (r?=?0.55; P?Yo-Yo IE2 test performance and (r?=?0.68; P?Yo-Yo IE2 test were greater (P?Yo-Yo IE2 test performance increased by 14% (P?Yo-Yo IE2 test is reproducible and is an indicator of the match-specific physical capacity of female soccer players. Furthermore, the Yo-Yo IE2 test illustrates sensitivity by differentiating intermittent exercise performance of female players in various competitive levels, stages of the season and playing positions. PMID:22712498

Bradley, P S; Bendiksen, M; Dellal, A; Mohr, M; Wilkie, A; Datson, N; Orntoft, C; Zebis, M; Gomez-Diaz, A; Bangsbo, J; Krustrup, P

2012-06-19

18

The Yo-yo Oscillator (Analysis of a Nonlinear System using Spice)  

Microsoft Academic Search

Unlike the simplest (Hooke's law spring) oscillator, where the restoring\\u000aforce is in magnitude proportional to the displacement; the yo-yo oscillator\\u000ahas a constant force-magnitude. In other words, its potential energy function\\u000ais linear, as contrasted to the quadratic (harmonic) potential of the simple\\u000aharmonic oscillator. The linear potential is responsible for a nonlinear\\u000aequation of motion which yields many

Randall D. Peters

2005-01-01

19

Validity of the Yo-Yo intermittent endurance test in young soccer players  

Microsoft Academic Search

The Yo-Yo intermittent endurance test is frequently used to assess aerobic endurance performance in young soccer players but only the logical validity of the test has been shown to date. The main ai m of this study was to assess the criterion (i.e. association with maximal aerobic capacity, [Vdot]O2max) and construct validities of the test in young soccer players. A

Pui-Lam Wong; Anis Chaouachi; Carlo Castagna; Patrick W. C. Lau; Karim Chamari; Ulrik Wisløff

2011-01-01

20

Sub-maximal and maximal Yo–Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer  

Microsoft Academic Search

The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo–Yo intermittent\\u000a endurance test level 2 (Yo–Yo IE2 test), (2) assess the relationship between the Yo–Yo IE2 test and match performance and\\u000a (3) quantify the sensitivity of the Yo–Yo IE2 test to detect test–retest changes and discriminate between performance for\\u000a different playing

Paul S. BradleyM; M. Mohr; M. Bendiksen; M. B. Randers; M. Flindt; C. Barnes; P. Hood; A. Gomez; Jesper L. Andersen; M. Di Mascio; J. Bangsbo; P. Krustrup

2011-01-01

21

30-15 Intermittent Fitness Test vs. Yo-Yo Intermittent Recovery Test Level 1: Relationship and Sensitivity to Training.  

PubMed

The aim of the present study was to a) examine the relationship between performance of the Yo-Yo Intermittent Recovery Test Level 1 (Yo-YoIR1) and the 30-15 Intermittent Fitness Test (30-15IFT) and b) compare the sensitivity of both tests to training. Fourteen young soccer players performed both tests before and after an eight-week training intervention, which included six sessions/week: two resistance training sessions, two high-intensity interval training sessions after technical training (four sets of 3:30 min of generic running and small sided games (4v4) during the first and second four-week periods, respectively, [90-95% maximal HR], interspersed with 3 min at 60-70% maximal HR) and two tactical-only training sessions. There was a large correlation between 30-15IFT and Yo-YoIR1 (r = 0.75, 90% confidence limits, CL 0.57;0.86). While within-test % changes suggested a greater sensitivity to training for the Yo-YoIR1 (+35%, 90%CL 24;45) compared with the 30-15IFT (+7%; 4;10), these changes were similarly rated as 'almost certain' (with chances for greater/similar/lower values after training of 100/0/0 for both tests) and moderate, i.e., standardized difference, ES = +1.2 90%CL (0.9;1.5) for Yo-YoIR1 and ES = +1.1 (0.7;1.5) for 30-15IFT. The difference in the change between both tests was clearly trivial (0/100/0, ES = -0.1, 90%CL -0.1;-0.1). Both tests might evaluate slightly different physical capacities, but their sensitivity to training is almost certainly similar. These results also highlight the importance of using standardized differences instead of % changes in performance to assess the actual training effect of an intervention. PMID:23475226

Buchheit, Martin; Rabbani, Alireza

2013-03-01

22

Biochemical Responses to Level-1 Yo-Yo Intermittent Recovery Test in Young Tunisian Football Players  

PubMed Central

Purpose The aim of this work was to investigate the metabolic and muscle damage responses after the level-1 Yo-Yo intermittent recovery test (YYIRT) in young football players. Methods Fifteen male football players (17.42 ± 0.2 yrs, 69.91 ± 4.4 kg, 178.64 ± 3.8 cm; mean ± SD) participated in this study. Fasting blood samples for various biochemical parameters (i.e. lactate (Lac), glucose (GLC), triglycerides (Tri), creatine kinase (CK), uric acid (UA)) collected from a forearm vein after 5-min of seated rest and 3-min after the test. Moreover, rating of perceived exertion (RPE) and maximal heart rate during and after the YYIRT were recorded. Results Mean levels of the selected biochemical markers were raised after the YYIRT exercise (P<0.001 for the other markers). Moreover, lipid parameters increased significantly after the test (P<0.01 for Tri and P<0.001 for HDL). Conclusion These findings confirm the higher metabolic demand of aerobic as well as anaerobic metabolism and reflect a significant mobilization of purine cycle during the YYIRT. The increase of muscle damage markers also reflects the higher anaerobic solicitation. From these findings, we can conclude the importance of aerobic and anaerobic metabolism during soccer-specific endurance performance (i.e. YYIRT, soccer match).

Hammouda, Omar; Chtourou, Hamdi; Chaouachi, Anis; Chahed, Henda; Zarrouk, Nidhal; Miled, Abdelhedi; Chamari, Karim; Souissi, Nizar

2012-01-01

23

40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese yttrium oxide (MnYO3). 721.10009...Chemical Substances § 721.10009 Manganese yttrium oxide (MnYO3 ). (a...The chemical substance identified as manganese yttrium oxide (MnYO3 ) (PMN...

2013-07-01

24

40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Manganese yttrium oxide (Mn2YO5). 721.10013...Chemical Substances § 721.10013 Manganese yttrium oxide (Mn2 YO5 ). ...The chemical substance identified as manganese yttrium oxide (Mn2 YO5 )...

2013-07-01

25

New identifications of YO and CeO in R Cygni  

NASA Astrophysics Data System (ADS)

New molecular features due to YO and CeO are reported present in the spectrum of pure S star R Cyg near minimum light. Of the nearly 60 unidentified features listed in the 4620-6420 A region, 10 with YO and 11 with CeO are identified. Bands of the Delta nu = 0, + or - 1, -2 sequences of the blue-green system (B-X) of YO are identified for the first time in stellar spectra.

Murty, P. S.

26

Reduction in maternal and child mortality in sub-Saharan Africa: the yo-yo effect in delivering on the promises.  

PubMed

Trends in maternal and child mortality (MCM) in sub-Saharan Africa do not follow the patterns seen in developed nations or match the funds and effort invested so far. This paper critically explores trends in MCM, global efforts to reduce MCM, and some of the underlying policies and programmatic issues that have shaped the slow progress or failure in reducing MCM in sub-Saharan Africa. We describe a "yo-yo" effect in policies and funding of Maternal and Child Health, Family Planning, and HIV/AIDS/STI programs in the region, and how this yo-yo effect may limit sustained community level reductions in MCM. We conclude by highlighting how renewed interest in the Alma-Ata declaration, particularly its primary health care concepts with their strong emphasis on horizontally integrated linkage of programs and resources, greater community involvement in program design and implementation, and economic development can contribute to sustainable reductions in MCM in the region. PMID:20168039

Mwalali, Philip; Ngui, Emmanuel

2009-01-01

27

Temperate carbonate debrites and short-lived earliest Miocene yo-yo tectonics, eastern Taranaki Basin margin, New Zealand  

NASA Astrophysics Data System (ADS)

This study examines two unconformity-bound earliest Miocene temperate shallow-marine limestones at remote Gibson Beach, western North Island, on the eastern margin of Taranaki Basin, New Zealand's only producing hydrocarbon province. The local geology comprises an upper limestone of up to 6 m of spectacular conglomeratic limestone (rudstone; Papakura Limestone) whose pebble- to boulder-sized clasts were derived from cannibalisation of the lower skeletal limestone (bryomol grainstone; Otorohanga Limestone). Multiple lines of evidence require the Otorohanga Limestone to have been well indurated before erosion and clast generation. Cementation occurred from pressure dissolution of calcitic skeletons at burial depths of probably 400 m or more. Subsequent uplift led to local subaerial exposure and karstification of a fault-block cliffed coastline where physical erosion sourced talus limestone debris onto adjacent high-energy pocket beaches. Storm and/or seismic events periodically triggered mass flows of the limestone clasts offshore onto the contemporary mixed siliciclastic-carbonate shelf as channelised carbonate debrites. Lithification of these Papakura Limestone debrites occurred via pressure dissolution, and required a second burial episode. Karst pinnacles preserved on the eroded upper surface of the Papakura Limestone demand uplift again and erosion in a subaerial setting, before subsequent deep burial by Early Miocene siliciclastic shelf sand and turbidite deposits. Strontium isotope dating of brachiopod fossils suggests the two postulated burial-uplift cycles, involving movements up to 400 ± 100 m, occurred very rapidly within several 100 kyr. Speculative drivers of the yo-yo tectonic events are earliest Miocene movements on the nearby major Taranaki Fault thrust in association with regional changes in subduction tectonics at the Australian-Pacific plate boundary, along with pulsed emplacement of obducted gravity slide deposits (Northland Allochthon) onto northern North Island. The two limestones record a previously undocumented degree of eastern Taranaki Basin margin tectonic mobility relevant to a fuller appreciation of petroleum system development in that basin.

Hood, Steven D.; Nelson, Campbell S.

2012-03-01

28

AVAST: SOCIAL NETWORKING AND COMPLEX ECONOMIES ON THE HIGH SEAS  

Microsoft Academic Search

This paper examines the activities and economies of YoHoHo! Puzzle Pirates. YoHoHo! Puzzle Pirates is an online role-playing game that draws upon puzzle-orientated gameplay to construct a social world. This paper addresses the important issue of social networking in information systems. It is a theoretical exploration of the deeper issues and implications that social networking has for business models in

Anita Greenhill; Gordon Fletcher

29

Purkinje cell death after uptake of anti-Yo antibodies in cerebellar slice cultures.  

PubMed

Paraneoplastic cerebellar degeneration accompanying gynecological and breast cancers is characteristically accompanied by a serum and cerebrospinal fluid (CSF) antibody response, termed "anti-Yo," which reacts with cytoplasmic proteins of cerebellar Purkinje cells. Because these antibodies interact with cytoplasmic rather than cell surface membrane proteins, their role in causing Purkinje cell death has been questioned. To address this issue, we studied the interaction of anti-Yo antibodies with Purkinje cells in slice (organotypic) cultures of rat cerebellum. We incubated cultures with immunoglobulin G (IgG)-containing anti-Yo antibodies using titers of anti-Yo antibody equivalent to those found in CSF of affected patients. Cultures were then studied in real time and after fixation for potential uptake of antibody and induction of cell death. Anti-Yo antibodies delivered in serum, CSF, or purified IgG were taken up by viable Purkinje cells, accumulated intracellularly, and were associated with cell death. Normal IgG was also taken up by Purkinje cells but did not accumulate and did not affect cell viability. These findings indicate that autoantibodies directed against intracellular Purkinje cell proteins can be taken up to cause cell death and suggest that anti-Yo antibody may be directly involved in the pathogenesis of paraneoplastic cerebellar degeneration. PMID:20838245

Greenlee, John E; Clawson, Susan A; Hill, Kenneth E; Wood, Blair L; Tsunoda, Ikuo; Carlson, Noel G

2010-10-01

30

Reliability, sensitivity and validity of the assistant referee intermittent endurance test (ARIET) - a modified Yo-Yo IE2 test for elite soccer assistant referees.  

PubMed

We examined the reliability and validity of the assistant referee intermittent endurance test (ARIET), a modified Yo-Yo IE2 test including shuttles of sideways running. The ARIET was carried out on 198 Italian (Serie A-B, Lega-Pro and National Level) and 47 Danish elite soccer assistant referees. Reproducibility was tested for 41 assistant referees on four occasions each separated by one week. The ARIET intraclass correlation coefficients and typical error of measurement ranged from 0.96 to 0.99 and 3.1 to 5.7%, respectively. ARIET performance for Serie A and B was 23 and 25% greater than in Lega-Pro (P < 0.001). The lowest cut-off value derived from receiving operator characteristic discriminating Serie A-B from Lega-Pro was 1300 m. The ARIET performance was significantly correlated with VO(2max) (r = 0.78, P < 0.001), %HR(max) after 4 min of ARIET (r = - 0.81, P < 0.001) and Yo-Yo IR1 performance (r = 0.95, P < 0.001), but not sprint performance (r = -0.15; P = 0.58). The results showed that ARIET is a reproducible and valid test that is able to discriminate between assistant referees of different competitive levels. The lack of correlation with sprinting ability and close correlations with aerobic power, intermittent shuttle running and sub-maximal ARIET heart rate loading provide evidence that ARIET is a relevant test for assessment of intermittent endurance capacity of soccer assistant referees. PMID:22435456

Castagna, Carlo; Bendiksen, Mads; Impellizzeri, Franco M; Krustrup, Peter

2012-03-21

31

Toward Autonomy in Love and Work: Situating the Film "Yo, tambien" within the Political Project of Disability Studies  

ERIC Educational Resources Information Center

This essay looks at the representation of disability in the recent Spanish film "Yo, tambien" through the lens of disability studies, understood as a political project. The film's portrayal of a character who is, like the actor who plays him, Europe's first university graduate with Down syndrome, is unique. Moreover, "Yo, tambien" provides the…

Fraser, Benjamin

2011-01-01

32

Evaluation of Hybrid-III 6YO ATD Chest Jacket Shape and Position.  

National Technical Information Service (NTIS)

In previous work, belt fit on the Hybrid-III six-year-old (6YO) anthropomorphic test device (ATD) was found to depend on the positioning of the chest jacket of the ATD. Moreover, differences were noted between jackets manufactured by Denton-ATD and First ...

M. P. Reed S. M. Ebert-Hamilton

2011-01-01

33

Thermodynamic Calculation of the YO1.5-CaO-MgO System.  

National Technical Information Service (NTIS)

The thermodynamic assessment of the YO1.5-CaO and CaO-MgO systems was conducted by the least squares method applied to measured phase diagram data from the literature. The analytic descriptions of above systems were then combined with the previous descrit...

Y. Du Z. P. Jin P. Y. Huang

1995-01-01

34

Networking.  

ERIC Educational Resources Information Center

|This theme issue on the role of networking in improving services for gifted individuals presents two feature articles and several regular columns. "A Network of Scholars" by Jerry Flack describes efforts of a group of professional educators and researchers of gifted persons in Colorado who worked cooperatively to create the Colorado Academy of…

Silverman, Linda Kreger, Ed.

1994-01-01

35

Load conditioner yo daiyoryo lithium niji denchi no kaihatsu. 3. 25Wh kyu lithium/sanka vanadium tandenchi no kairyo. (Research and development of lithium secondary batteries for load conditioner use. 3. Improvement of 25Wh-class lithium/vanadium oxide prototype cells).  

National Technical Information Service (NTIS)

Experiments and researches have been made on 25 Wh-class lithium/vanadium oxide batteries as an improvement of lithium batteries to apply them to the load conditioner use. A thermal characteristics test has discussed heat absorption and generation associa...

K. Takei N. Terada K. Ishihara T. Iwahori T. Tanaka

1993-01-01

36

Load conditioner yo daiyoryo lithium niji denchi no kaihatsu. 2. 25Wh kyu lithium/sanka vanadium denchi no seino hyoka. (Research and development of lithium secondary batteries for load conditioner use. 2. Cycleability and power characteristics of 25Wh-class lithium/vanadium oxide prototype cells).  

National Technical Information Service (NTIS)

Results of evaluation are reported on cycle life/power performance of square lithium/vanadium oxide secondary batteries (25Wh class) trially manufactured as a basic unit for the battery energy storage system which can be installed at home. Experimental re...

N. Terada K. Takei K. Ishihara T. Iwahori T. Tanaka

1992-01-01

37

The existence range and related electrical transport properties of beta-AgxWyV2yO5 bronzes  

Microsoft Academic Search

The existence range of beta-AgxWyV2-yO5 bronzes as a function of x and y has been determined. Cell parameters of the monoclinic unit cell of both beta-AgxWyV2-yO5 (x = y) and beta-AgxV2O5 as a function of x are given. Electrical conductivity measurements were performed on beta-AgxWyV2-yO5 (x = y) as a function of x and temperature. The diffusion coefficient of silver

B. B. Scholtens; M. Winters; J. H. W. de Wit; G. H. J. Broers

1978-01-01

38

The molecular yo-yo method: Live jump detection improves throughput of single-molecule force spectroscopy for out-of-equilibrium transitions.  

PubMed

By monitoring multiple molecular transitions, force-clamp, and trap-position-clamp methods have led to precise determinations of the free energies and free energy landscapes for molecular states populated in equilibrium at the same or similar forces. Here, we present a powerful new elaboration of the force-clamp and force-jump methods, applicable to transitions far from equilibrium. Specifically, we have implemented a live jump detection and force-clamp algorithm that intelligently adjusts and maintains the force on a single molecule in response to the measured state of that molecule. We are able to collect hundreds of individual molecular transitions at different forces, many times faster than previously, permitting us to accurately determine force-dependent lifetime distributions and reaction rates. Application of our method to unwinding and rewinding the nucleosome inner turn, using optical tweezers reveals experimental lifetime distributions that comprise a statistically meaningful number of transitions, and that are accurately single exponential. These measurements significantly reduce the error in the previously measured rates, and demonstrate the existence of a single, dominant free energy barrier at each force studied. A key benefit of the molecular yo-yo method for nucleosomes is that it reduces as far as possible the time spent in the tangentially bound state, which minimizes the loss of nucleosomes by dissociation. PMID:24007119

Mack, A H; Schlingman, D J; Kamenetska, M; Collins, R; Regan, L; Mochrie, S G J

2013-08-01

39

The molecular yo-yo method: Live jump detection improves throughput of single-molecule force spectroscopy for out-of-equilibrium transitions  

NASA Astrophysics Data System (ADS)

By monitoring multiple molecular transitions, force-clamp, and trap-position-clamp methods have led to precise determinations of the free energies and free energy landscapes for molecular states populated in equilibrium at the same or similar forces. Here, we present a powerful new elaboration of the force-clamp and force-jump methods, applicable to transitions far from equilibrium. Specifically, we have implemented a live jump detection and force-clamp algorithm that intelligently adjusts and maintains the force on a single molecule in response to the measured state of that molecule. We are able to collect hundreds of individual molecular transitions at different forces, many times faster than previously, permitting us to accurately determine force-dependent lifetime distributions and reaction rates. Application of our method to unwinding and rewinding the nucleosome inner turn, using optical tweezers reveals experimental lifetime distributions that comprise a statistically meaningful number of transitions, and that are accurately single exponential. These measurements significantly reduce the error in the previously measured rates, and demonstrate the existence of a single, dominant free energy barrier at each force studied. A key benefit of the molecular yo-yo method for nucleosomes is that it reduces as far as possible the time spent in the tangentially bound state, which minimizes the loss of nucleosomes by dissociation.

Mack, A. H.; Schlingman, D. J.; Kamenetska, M.; Collins, R.; Regan, L.; Mochrie, S. G. J.

2013-08-01

40

Fabrication of a Lithium Sensor Based on LiYO 2 by Liquid Phase Processing  

Microsoft Academic Search

A galvanic cell was constructed to measure the activity of lithium in liquid alloys. LiYO2 solid electrolyte tubes were made by slip casting. Y2O3-12.5% MgO was selected as the lid composition due to its inertness to molten lithium and optimum strength. The tube and lid were joined by reaction bonding in which Li2CO3 acts as the bonding agent and also

Jian Wu; Luis Yamarte; Anthony Petric

2002-01-01

41

Preparation of Delafossite-Type CuYO2 Films by Solution Method  

Microsoft Academic Search

The preparation of CuYO2 films on quartz glass substrates was carried out through the solution method using copper and yttrium nitrates as sources. Firstly, dip-coated films on the quartz glass substrates were annealed in air, and then annealed again under nitrogen flow. Continuous films were formed on the substrate surfaces. The films annealed in air at 900-950 °C were almost

Nozomu Tsuboi; Kenichi Tosaka; Satoshi Kobayashi; Keizo Kato; Futao Kaneko

2008-01-01

42

Networks  

Microsoft Academic Search

This paper presents an analytic model for characterizing the traffic in wireless networks using IEEE 802.11 as the MAC protocol. The results of this paper are aimed at filling the existing void created by the ab- sence of any accurate models or understanding of wireless traffic, critical for effective performance evaluation. Our results show that the behavior of wire- less

Omesh Tickoo; Biplab Sikdar

43

Networks  

Microsoft Academic Search

ó This paper presents a new cooperative storage system for sensor networks geared for disconnected opera- tion (where sensor nodes do not have a connected path to a basestation). The goal of the system is to maximize its data storage capacity by appropriately distributing storage utilization and opportunistically ofoading data to external devices when possible. The system is motivated by

Liqian Luo; Chengdu Huang; Tarek Abdelzaher; John Stankovic

44

Yo, Hamlet!  

ERIC Educational Resources Information Center

|This article presents Alan Sitomer, an English teacher at Lynwood High School, and how he teaches his students classic literature through hip-hop. These at-risk students attend a severely overcrowded, low-performing school in East Los Angeles that's surrounded by what Sitomer describes as "gangs, guns, and drugs." Prostitutes work the streets…

Whelan, Debra Lau

2007-01-01

45

Electronic structure and optical properties of CuYO2 nanocrystals  

NASA Astrophysics Data System (ADS)

A unique class of highly stabile, self-saturated and self-charge-compensated delafossite nanocrystals has been identified. The density functional theory (DFT) study of structural and electronic properties of these nano-crystalline CuYO2 will be presented. To have a better estimate of the electronic excitation energies, and consequently the optical gap, time dependent DFT has been employed as well. The goal is to show, first of all, that these unique set of nanocrystals exists, and to study whether the nano-phase can modify the electronic properties for enhanced optical absorption. It has potential application as photocatalysts for H2 production by water splitting.

Huda, Muhammad; Yan, Yanfa; Turner, John A.; Al-Jassim, Mowafak M.

2013-03-01

46

Anti-Yo Associated Paraneoplastic Cerebellar Degeneration in a Man with Large Cell Cancer of the Lung  

PubMed Central

Purkinje cell cytoplasmic antibody type 1 (PCA-1), or anti-Yo, is the most frequently detected autoantibody in paraneoplastic cerebellar degeneration (PCD). The vast majority of cases of anti-Yo PCD, however, occur in females over 60 years old and are associated with gynecologic tumors. Only 10 cases have been reported in males, and only 2 were associated with cancer of the lung. Here we describe the youngest known case of PCA-1 positive PCD in a male, whose lung tumor was undetectable even on FDG-PET.

Lee, James; Wang, Bonnie H.; Yekkirala, Lalitha

2013-01-01

47

Fe1-yO nanoparticles: organometallic synthesis and magnetic properties.  

PubMed

Non-stoichiometric wüstite particles (Fe(1-y)O) are synthesized using the controlled room-temperature hydrolysis of the organometallic precursor {Fe[N(SiMe3)2]2}. Particles stabilized by hexadecylamine with a diameter of approximately 5 nm are obtained. For such small nanoparticles, a distorted crystallographic structure is evidenced by wide-angle X-ray scattering at room temperature and reported for the first time. The study of the magnetic properties indicates that these particles are composed of an antiferromagnetic core surrounded by a ferromagnetic shell. According to the Néel theory, we demonstrate that this shell consists of 1.5 % of Fe3+ ions ferromagnetically coupled with Fe2+ ions. PMID:18348200

Glaria, Arnaud; Kahn, Myrtil L; Lecante, Pierre; Barbara, Bernard; Chaudret, Bruno

2008-04-01

48

Interfacial reaction induced phase separation in La{sub x}Hf{sub y}O films  

SciTech Connect

Amorphous La{sub x}Hf{sub y}O films containing La at concentrations (x) of 50 and 20% were prepared by atomic layer deposition on ultrathin SiO{sub 2} films (1 nm). We examined the electronic structures and microstructures of the La{sub x}Hf{sub y}O films by x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD). Phase separation into La{sub 2}O{sub 3} and HfO{sub 2} was observed in the La{sub x}Hf{sub y}O films subjected to annealing temperatures over 900 deg. C, although the mixture of La{sub 2}O{sub 3} and HfO{sub 2} is thermodynamically stable. The structural changes that occurred as the result of phase separation were dependent on the concentrations of La and Hf in the films. During the annealing treatment, silicate was produced due to interfacial reactions and the interfacial reactions were found to be dependent on the La{sub 2}O{sub 3} content in the La{sub x}Hf{sub y}O films, which has a significant influence on the phase separation process and resulting film structure.

Ma, J. W.; Lee, W. J.; Cho, M.-H. [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, K. M.; Sohn, H. C. [Department of Material Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, C. S. [Korea Research Institute of Standards and Science, Daejeon 305-540 (Korea, Republic of); Cho, H. J. [Process Development Team, Semiconductor R and D Center, Samsung Electronics Co., LTD, Gyeonggi-Do 449-711 (Korea, Republic of)

2011-06-15

49

Toward autonomy in love and work: situating the film "Yo, también" within the political project of disability studies.  

PubMed

This essay looks at the representation of disability in the recent Spanish film "Yo, también" through the lens of disability studies, understood as a political project. The film's portrayal of a character who is, like the actor who plays him, Europe's first university graduate with Down syndrome, is unique. Moreover, "Yo, también" provides the opportunity to assess the state of the struggle for rights for persons with disabilities both in the film's narrative arc and also in the wider Spanish (and global) society. Among other sources, specific articles of the United Nations's recent Convention on the Rights of People with Disabilities are incorporated into the essay. Both essay and film coincide in emphasizing the need to grant disabled populations greater autonomy in the spheres of love and work. PMID:21898936

Fraser, Benjamin

2011-01-01

50

Structure and performance of LiYO[sub 2] methane coupling catalysts: Active phases and decay mechanisms  

SciTech Connect

X-ray diffraction, high-resolution electron microscopy, and microreactor studies have been used to investigate variations in structure and reactivity of a LiYO[sub 2] catalyst during the oxidative coupling of methane. The results indicate that both LiYO[sub 2] and small crystallites of Li[sup +]-doped Y[sub 2]O[sub 3] are active for methane conversion to ethane and ethylene. An amorphous phase appears during transformation of LiYO[sub 2] and Y[sub 2]O[sub 3]; continued loss of lithium accompanied by formation of larger crystallites of Y[sub 2]O[sub 3] gives rise to increased deep oxidation and reduced C[sub 2] production. The deactivation of these catalysts is associated with increase in size and crystallinity of the fluorite-like Y[sub 2]O[sub 3] paracrystals, loss of incorporated Li[sup +], and partial conversion to lithium carbonate. 20 refs., 10 figs., 1 tab.

Zhang, X.; Jefferson, D.A.; Lambert, R.M. (Univ. of Cambridge (United Kingdom))

1993-06-01

51

Reaction dynamics of Y + O2--> YO(X,A',A)+ O(3P(J)) studied by the crossed-beam technique.  

PubMed

The dynamics of the reaction, Y + O2--> YO + O was studied by using the crossed-beam technique at several collision energies from 10.3 to 52.0 kJ mol(-1). The Y atomic beam was generated by laser vaporization and crossed with the O2 beam at a right angle. Among the energetically accessible electronic states of YO, the formation of the A2Pi and A'2Delta states was observed by their chemiluminescence at all collision energies. By analyzing the chemiluminescence spectra of YO(A2Pi(1/2,3/2)-X2Sigma+), vibrational state distributions and relative populations of spin-orbit states were determined for YO(A2Pi(1/2,3/2)). At low collision energies, the vibrational distributions agree quite well with those expected from the statistical energy partitioning, while a little deviation from the statistical expectation was observed at the highest energy, 52.0 kJ mol(-1). The populations of two spin-orbit states are in good agreement with the statistical expectations at all collision energies. The vacuum ultraviolet laser-induced fluorescence (VUV-LIF) technique was employed to determine the distributions of spin-orbit states of the product O(3P(J)) at two collision energies, 20.7 and 52.0 kJ mol(-1). The line shapes of the O atom transitions were analyzed to determine relative branching ratio of the ground state to the excited states of YO, i.e. YO(X2Sigma+)+ O(3P(J))vs. YO(A2Pi and A'2Delta)+ O(3P(J)). The results showed that the electronically excited YO was formed with comparable amount with the ground state which is statistically more favorable, and suggested the occurrence of two mechanisms taking place in the title reaction. PMID:15962033

Higashiyama, T; Ishida, M; Matsumoto, Y; Honma, Kenji

2005-05-13

52

A comparison between a child-size PMHS and the Hybrid III 6 YO in a sled frontal impact  

PubMed Central

As pediatric PMHS data are extremely limited, evidence of kinematic differences between pediatric ATDs and live humans comes from comparison of laboratory data to field crash data. Despite the existence of regulations intended to prevent head injuries, these remain the most common serious injuries sustained by children in crashes. In this study, nine frontal sled tests using a Hybrid III 6YO and three tests performed with a child-size adult PMHS were compared, with focus on the kinematic responses (especially of the head) and the seatbelt forces generated during the impact. Two different restraint systems (a pretensioning, force-limiting seatbelt, and a non pretensioning force-limiting standard belt) and two different impact speeds (29 km/h and 48 km/h) were compared. Data from the PMHS were scaled using the erect sitting height of a 50th percentile 6YO and both scaled and unscaled data are presented. The ATD predicted correctly the peak values of the scaled displacements of the PMHS, but differences in relevant parameters such as torso angle and resultant acceleration at different locations were found between the dummy and the PMHS. The ATD’s stiffer thoracic spine is hypothesized as a major cause of these differences.

Lopez-Valdes, Francisco J.; Forman, Jason; Kent, Richard; Bostrom, Ola; Segui-Gomez, Maria

2009-01-01

53

The use of Yo-Yo intermittent recovery level 1 and Andersen testing for fitness and maximal heart rate assessments of 6- to 10-year-old school children.  

PubMed

We evaluated a submaximal and maximal version of the Yo-Yo intermittent recovery level 1 children's (YYIR1C) test and the Andersen test for fitness and maximal heart rate assessments of children aged 6-10 years. Two repetitions of the YYIR1C and Andersen tests were carried out within 1 week by 6- to 7-year-olds and 8- to 9-year-olds (grade 0, n = 17; grade 2, n = 16) and 6 weeks apart by 9- to 10-year-olds (grade 3, n = 49). Grade 0-2 pupils also performed an incremental treadmill test (ITT). Grade 2 pupils had a better (p < 0.05) YYIR1C (84%; 994 ± 399 m (±SD) vs. 536 ± 218 m) and Andersen test performance (10%; 1,050 ± 71 m vs. 955 ± 56 m) than grade 0 pupils. For grade 0-2 pupils, YYIR1C, Andersen, and ITT peak heart rates were 205 ± 11, 207 ± 9, and 203 ± 7 b·min(-1), respectively (Andersen > ITT, p < 0.05), and for grade 3 pupils, YYIR1C and Andersen peak heart rates were 208 ± 9 and 204 ± 9 b·min(-1), respectively (YYIR1C > Andersen, p < 0.05). Submaximal YYIR1C heart rate (HR) was inversely correlated (p < 0.05) with YYIR1C test performance (r = -0.54 to -0.67) and VO2peak (r = -0.42). The 6-week change in submaximal HR correlated with the change in YYIR1C test performance (r = -0.42 to -0.53, p < 0.05). In conclusion, YYIR1C and Andersen tests are simple and inexpensive intermittent field tests that can detect differences in fitness levels and determine maximal HR of 6- to 10-year-old children. Additionally, submaximal YYIR1C testing can be used for frequent nonexhaustive fitness assessments. PMID:22964860

Bendiksen, Mads; Ahler, Thomas; Clausen, Helle; Wedderkopp, Niels; Krustrup, Peter

2013-06-01

54

Maternal intake of vitamin D during pregnancy and risk of recurrent wheeze in children a t3yo f age1-3  

Microsoft Academic Search

Background: Vitamin D deficiency and asthma are common at higher latitudes. Although vitamin D has important immunologic effects, its relation with asthma is unknown. Objective: We hypothesized that a higher maternal intake of vita- min D during pregnancy is associated with a lower risk of recurrent wheeze in children a t3yo fage. Design: The participants were 1194 mother-child pairs in

Carlos A Camargo Jr; Sheryl L Rifas-Shiman; Augusto A Litonjua; Janet W Rich-Edwards; Scott T Weiss; Diane R Gold; Ken Kleinman; Matthew W Gillman

55

BiSr3(YO)3(BO3)4: a new gaudefroyite-type rare-earth borate with moderate SHG response.  

PubMed

The synthesis, crystal structure, crystal growth, and characterization of a new noncentrosymmetric rare-earth borate BiSr(3)(YO)(3)(BO(3))(4) are reported. BiSr(3)(YO)(3)(BO(3))(4) belongs to gaudefroyite type of structure and crystallizes in the polar hexagonal space group P6(3) (no. 173) with a = 10.6975(16) Å and c = 6.7222(12) Å. In the structure, the YO(7) polyhedra share edges to form an one-dimensional chain along the [001] direction. These chains are interconnected by the BO(3) group to construct a three-dimensional framework, leaving two kinds of channels for Bi atoms and Sr atoms together with BO(3) groups, respectively. On the basis of the powder second-harmonic generation (SHG) measurement, BiSr(3)(YO)(3)(BO(3))(4) belongs to the phase-matchable class with a SHG response of about 3 × KDP. PMID:22168266

Gao, Jianhua; Li, Shuai

2011-12-14

56

Measurements of 4He in metal-poor extragalactic H ii regions: the primordial Helium abundance and the ?Y/?O ratio  

NASA Astrophysics Data System (ADS)

We present a review on the determination of the primordial helium abundance Yp, based on the study of hydrogen and helium recombination lines in extragalactic H ii regions. We also discuss the observational determinations of the increase of helium to the increase of oxygen by mass ?Y/?O, and compare them with predictions based on models of galactic chemical evolution.

Peimbert, Manuel; Peimbert, A.; Carigi, L.; Luridiana, V.

2010-04-01

57

Anion inhibition studies of an ?-carbonic anhydrase from the thermophilic bacterium Sulfurihydrogenibium yellowstonense YO3AOP1.  

PubMed

The newly discovered thermophilic bacterium Sulfurihydrogenibium yellowstonense YO3AOP1 encodes an ?-carbonic anhydrases (CAs, EC 4.2.1.1) which is highly catalytically active and thermostable. Here we report the inhibition of this enzyme, denominated SspCA, with inorganic and complex anions and other molecules interacting with zinc proteins. SspCA was inhibited in the micromolar range by diethyldithiocarbamate, sulfamide, sulfamic acid, phenylboronic and phenylarsonic acid, trithiocarbonate and selenocyanide (K(I)s of 4-70 ?M) and in the submillimolar one by iodide, cyanide, (thio)cyanate, hydrogen sulfide, azide, nitrate, nitrite, many complex anions incorporating heavy metal ions and iminodisulfonate (K(I)s of 0.48-0.86 mM). SspCA was not substantially inhibited by bicarbonate and carbonate, hydrogensulfite and peroxidisulfate (K(I)s in the range of 21.1-84.6mM). The exceptional thermostability and lack of strong affinity for hydrogensulfide, bicarbonate, and carbonate make this enzyme an interesting candidate for biotechnological applications of enzymatic CO(2) fixation. PMID:22835873

De Luca, Viviana; Vullo, Daniela; Scozzafava, Andrea; Carginale, Vincenzo; Rossi, Mosè; Supuran, Claudiu T; Capasso, Clemente

2012-07-09

58

CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: First-principle study of native defects in CuScO2 and CuYO2  

NASA Astrophysics Data System (ADS)

This paper studies the electronic structure and native defects in transparent conducting oxides CuScO2 and CuYO2 using the first-principle calculations. Some typical native copper-related and oxygen-related defects, such as vacancy, interstitials, and antisites in their relevant charge state are considered. The results of calculation show that, CuMO2(M = Sc, Y) is impossible to show n-type conductivity ability. It finds that copper vacancy and oxygen interstitial have relatively low formation energy and they are the relevant defects in CuScO2 and CuYO2. Copper vacancy is the most efficient acceptor, and under O-rich condition oxygen antisite also becomes important acceptor and plays an important role in p-type conductivity.

Fang, Zhi-Jie; Shi, Li-Jie; Liu, Yong-Hui

2008-11-01

59

Improvement of the high temperature properties of the LiYO 2–Si 3N 4 system by removing residual Li  

Microsoft Academic Search

Effects of the vaporization of residual Li on the microstructure, oxidation behavior and high temperature properties of a low-temperature pressureless sintered Si3N4 using LiYO2 additive were investigated. The oxidation and creep resistance of the Si3N4 was improved after an annealing at 1650°C because residual Li, which deteriorated the high temperature properties of the Si3N4, could be mostly removed. The high

Sea-Hoon Lee; Reinhard Mager

2009-01-01

60

Measurement of apoptosis of intact human islets by confocal optical sectioning and stereologic analysis of YO-PRO-1-stained islets.  

PubMed

Apoptosis is an established pathway for islet cell demise. Current protocols for assessment of islet cell apoptosis are time-consuming (as with terminal deoxynucleotide transferase-mediated dUTP nick-end labeling reaction) and involve disruption of the islet architecture (as with flow cytometry) or destruction of cell integrity (as with enzyme-linked immunosorbent assay). The membranes of apoptotic cells, but not those of live cells, are permeant to the DNA-intercalant dye YO-PRO-1. We report a novel methodology for the rapid quantification of apoptosis of human islets: confocal laser optical sectioning and stereologic analysis of intact human islets stained with YO-PRO-1 and Hoechst 33342. The advantages include (1) rapid quantification of apoptosis without disrupting islet architecture and (2) identification of significant heterogeneity in the extent of apoptosis among islets from the same isolate. Confocal laser scanning microscopy microscopic imaging of YO-PRO-1-stained islets may advance investigation of islet cell apoptosis and help develop islet parameters predictive of posttransplant function. PMID:15818328

Boffa, Daniel J; Waka, John; Thomas, Dolca; Suh, Sungwook; Curran, Kevin; Sharma, Vijay K; Besada, Melissa; Muthukumar, Thangamani; Yang, Hua; Suthanthiran, Manikkam; Manova, Katia

2005-04-15

61

Cognitive Networks.  

National Technical Information Service (NTIS)

For complex computer networks with many tunable parameters and network performance objectives, the task of selecting the ideal network operating state is difficult. To improve the performance of these kinds of networks, this research proposes the idea of ...

R. W. Thomas

2007-01-01

62

Programmable Networks  

Microsoft Academic Search

A number of important innovations are creating a paradigm shift in networking leading to higher levels of network programmability. These innovations include the separation between transmission hardware and control software, availability of open programmable network interfaces and the accelerated virtualization of networking infrastructure. The ability to rapidly create, deploy and manage new network services in response to user demands is

Andrew T. Campbell; Michael E. Kounavis; John B. Vicente

2001-01-01

63

Irreversibility line of overdoped Bi2+xSr2-(x+y)Cu1+yO6+/-? at ultralow temperatures and high magnetic fields  

NASA Astrophysics Data System (ADS)

The irreversible magnetization of the layered high-Tc superconductor Bi2+xSr2-(x+y)Cu1+yO6+/-? (Bi-2201) has been measured by means of a capacitive torquemeter up to Ba=28 T and down to T=60 mK. The deduced irreversibility field Birr is in excellent agreement with the analytical form of the melting line of a three-dimensional (3D) anisotropic flux lattice as calculated from the Lindemann criterion. For a comparison, the applicability of alternative models based on quantum melting, 2D melting, and flux-creep models is discussed. Rescaling the magnetic-field dependence of the pinning-force with the irreversibility field reveals a similar magnetic-field dependence for different temperatures.

Morello, A.; Jansen, A. G. M.; Gonnelli, R. S.; Vedeneev, S. I.

2000-04-01

64

Phase evaluation and optical studies of cubic MnxZr1-xO2 and CoyZr1-yO2 nanocrystals  

NASA Astrophysics Data System (ADS)

Nanocrystallites of cubic phase MnxZr1-xO2(0<=x<=0.25) and CoyZr1-yO2(0<=y<=0.20) have been synthesized by co-precipitation technique. The role of dopant concentration and the heat-treatment conditions on the cubic phase stability, crystallite size and optical behavior of these compounds have been discussed. Analysis of the structural data reveals that the cubic-phase is stable up to a critical dopant concentration xc <= 0.25 and yc <= 0.20 beyond which monoclinic phase of ZrO2 emerges. The diffuse-reflectance-spectroscopy of MnxZr1-xO2 exhibits a strong absorption peak at ? = 365 nm associated with ligand to metal charge-transfer transition 3P2(O)-->1S0(Zr) representing the energy band-gap (Eg = 3.39 eV). In addition, a series of absorption bands are observed at 520, 654, and 712 nm associated with the crystal-field transitions of Mn4+ i.e. from 4A2g(F) state to 4T2g(F), 4T1g(P) and 2E states, respectively. However, in CoyZr1-yO2, the main absorption is centered at 211 nm due to the electronic transitions from valance band O2p to conduction band Zr4d together with inter-valence charge transfer transitions occurring at 242, 270, 358 and 757 nm.

Thota, S.; Ansari, A.; Singh, S. K.; Mallick, A.; Kumar, J.

2013-06-01

65

Computer Networks  

NSDL National Science Digital Library

CS4403 is an introduction to computer communications, network architectures, protocol hierarchies, and the open systems interconnection model. Topics covered include modeling, analysis, and specification of protocols, wide area networks, local area networks, and client/server architectures.

Apon, Amy

66

Network Attacks  

Microsoft Academic Search

Network attacks are defined as a set of malicious activities to disrupt, deny, degrade or destroy information and service\\u000a resident in computer networks. A network attack is executed through the data stream on networks and aims to compromise the\\u000a Integrity , Confidentiality or Availability of computer network systems. Network attacks can vary from annoying email directed\\u000a at an individual to

Ali A. Ghorbani; Wei Lu; Mahbod Tavallaee

67

Computer Networks  

NSDL National Science Digital Library

Teachers' Domain presents this interactive lesson on computer networks, which includes three parts: an introduction, network structure, and routers. The concepts covered include various types of networks (local area networks and wide area networks) and the three common components of networks: links, nodes, and routers. Different kinds of network topologies and the basics of how data travels between networks are also covered. The lesson includes 26 screens with reading materials as well as a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

2010-07-11

68

Hierarchical Task-Network Planner Based on Symbolic Model Checking.  

National Technical Information Service (NTIS)

Although several approaches have been developed for planning in non- deterministic domains, solving large planning problems is still quite difficult. In this work, we present a novel algorithm, called YoYo, for planning in non- deterministic domains under...

U. Kuter D. Nau M. Pistore P. Traverso

2005-01-01

69

Industrial networks  

Microsoft Academic Search

Remote control as well as remote supervising systems are the backbone nowadays producing systems. Both are enabled by different kind of computers and especially microcontrollers connected by different data networks. These networks, industrial networks as their common name is, differ from other data networks in at least in the following: (i) shape of traffic, (ii) available processing capabilities for data

Z. Cucej; D. Gleich; M. Kaiser; P. Planinsic

2004-01-01

70

Network Solutions.  

ERIC Educational Resources Information Center

This special section explains the latest developments in networking technologies, profiles school districts benefiting from successful implementations, and reviews new products for building networks. Highlights include ATM (asynchronous transfer mode), cable modems, networking switches, Internet screening software, file servers, network management…

Vietzke, Robert; And Others

1996-01-01

71

Computer Networks As Social Networks  

Microsoft Academic Search

Computer networks are inherently social networks, linking people, organizations, and knowledge. They are social institutions that should not be studied in isolation but as integrated into everyday lives. The proliferation of computer networks has facilitated a deemphasis on group solidarities at work and in the community and afforded a turn to networked societies that are loosely bounded and sparsely knit.

Barry Wellman

2001-01-01

72

Semantic Networks and Social Networks  

ERIC Educational Resources Information Center

|Purpose: To illustrate the need for social network metadata within semantic metadata. Design/methodology/approach: Surveys properties of social networks and the semantic web, suggests that social network analysis applies to semantic content, argues that semantic content is more searchable if social network metadata is merged with semantic web…

Downes, Stephen

2005-01-01

73

Thermochemistry of the mixed molybdenum tungsten oxides, MoyW1-yO3 (0.25 <= y <= 0.69), and their hydrogen insertion compounds, HxMoyW1-yO3 (0.34 <= x <= 0.98)  

NASA Astrophysics Data System (ADS)

The enthalpies of formation of a series of mixed metal oxides, MoyW1-yO3 (y = 0.25, 0.5, 0.64, and 0.69), and hydrogen insertion compounds, H0.54Mo0.25W0.75O3, HxMo0.5W0.5O3 (x = 0.63 and 0.66) and HxMo0.69W0.31O3 (x = 0.34, 0.45, and 0.98) have been determined by solution calorimetry. The enthalpies of hydrogen insertion into the mixed oxides are compared to those for the simple oxides MoO3 and WO3, which have been recalculated. The stability of the insertion compounds toward oxidation is discussed.

Hibble, S. J.; Dickens, P. G.

1986-01-01

74

Networking Computers  

NSDL National Science Digital Library

This tutorial provides a basic overview of the type of networks a computer can be part of. Students will gain an understanding of the different types of computer networks. Flash is required to view this interactive lesson.

2013-07-15

75

Evaluation of the assumption of responsibility of the traumatisms of the locomotors apparatus due to the traffic accidents road in the university hospital – Yalgadogo Ouedraogo (CHU-YO) of Ouagadougou  

Microsoft Academic Search

AimsTo evaluate the assumption of responsibility of the traumatisms of the locomotors apparatus due to the traffic accidents road in the university hospital – Yalgadogo Ouedraogo (CHU-YO) of Ouagadougou.MethodThis study was of transverse futurology type to evaluative aiming. The investigation of ground proceeded 07 August 31, 2009 and concerned 28 agents of health and 162 patients.ResultsThe results to which we

Z Lassane

2010-01-01

76

Early protein intake and later obesity risk: which protein sources at which time points throughout infancy and childhood are important for body mass index and body fat percentage a t7yo fage?1-3  

Microsoft Academic Search

Background: A high early protein intake has been proposed to increase obesity risk. Objective: We examined whether a critical period of protein intake for later obesity may exist early in childhood and investigated the relation between protein intake from different sources and body mass index SD score and body fat percentage (BF%) a t7yo fage. Design:Thestudypopulationincluded203participantsoftheDort- mundNutritionalandLongitudinallyDesignedStudywithinforma- tion on diet

Anke LB; Thomas Remer Gunther; Anja Kroke; Anette E Buyken

77

Protein intake during the period of complementary feeding and early childhood and the association with body mass index and percentage body fat a t7yo f age 1-3  

Microsoft Academic Search

Background: A high protein intake during infancy and early child- hood has been proposed to increase the risk of subsequent obesity. Objective: We analyzed the association of different protein intakes during 6-24 mo with body mass index (BMI; in kg\\/m2) and per- centage body fat (%BF) a t7yo fage. Design: The analyses included 203 participants of the DOrtmund Nutritional and

Anke LB Gunther; Anette E Buyken; Anja Kroke

78

Network science.  

PubMed

Professor Barabási's talk described how the tools of network science can help understand the Web's structure, development and weaknesses. The Web is an information network, in which the nodes are documents (at the time of writing over one trillion of them), connected by links. Other well-known network structures include the Internet, a physical network where the nodes are routers and the links are physical connections, and organizations, where the nodes are people and the links represent communications. PMID:23419844

Barabási, Albert-László

2013-02-18

79

Computer Networks  

NSDL National Science Digital Library

CSC 344. Computer Networks (3) Prerequisite: CSC 242. The theory and application of inter-computer communication. Local-area and wide-area networks; data transmission and error correction; OSI and TCP/IP layering protocols; ethernet, token ring, token bus and other network technologies; network topologies; the client-server model; bridges and multi-protocol routers; the Internet. Applications include electronic funds transfer and distributed databases.

Hudson, Mr T.

2003-04-21

80

Integrated Networks.  

ERIC Educational Resources Information Center

|A strategy for integrated data and voice networks implemented at the University of Michigan is described. These networks often use multi-technologies, multi-vendors, and multi-transmission media that will be fused into a single integrated network. Transmission media include twisted-pair wire, coaxial cable, fiber optics, and microwave.…

Robinovitz, Stewart

1987-01-01

81

Network Stability  

NASA Astrophysics Data System (ADS)

Stability resembles intelligence: easy to imagine and hard to define. Here I will assess network stability at three different levels. First I will describe network perturbations and the concept of local dissipation and global connections. Later a number of different scenarios will be shown, where the perturbation is big or persistent enough to change the stability of the underlying bottom networks, and therefore, the structure of the current network is not preserved. Then stability relationships between the bottom and top networks will be discussed using the example of synchrony. Finally, I will describe the two basic design alternatives: evolution and engineering.

Csermely, Peter

82

Networking computers.  

PubMed

This decade the role of the personal computer has shifted dramatically from a desktop device designed to increase individual productivity and efficiency to an instrument of communication linking people and machines in different places with one another. A computer in one city can communicate with another that may be thousands of miles away. Networking is how this is accomplished. Just like the voice network used by the telephone, computer networks transmit data and other information via modems over these same telephone lines. A network can be created over both short and long distances. Networks can be established within a hospital or medical building or over many hospitals or buildings covering many geographic areas. Those confined to one location are called LANs, local area networks. Those that link computers in one building to those at other locations are known as WANs, or wide area networks. The ultimate wide area network is the one we've all been hearing so much about these days--the Internet, and its World Wide Web. Setting up a network is a process that requires careful planning and commitment. To avoid potential pitfalls and to make certain the network you establish meets your needs today and several years down the road, several steps need to be followed. This article reviews the initial steps involved in getting ready to network. PMID:10166063

McBride, D C

1997-03-01

83

Start Networking!  

NSDL National Science Digital Library

To get a better understanding of complex networks, students create their own, real social network example by interacting with their peers in the classroom and documenting the interactions. They represent the interaction data as a graph, calculate two mathematical quantities associated with the graphâthe degree of each node and the degree distribution of the graphâand analyze how these quantities can be used to infer properties of the social network at hand.

Complex Systems Science Laboratory

84

Visualizing networks.  

PubMed

An interrelated set of genes or proteins can be represented effectively as a network that describes physical interactions, regulatory relationships, or metabolic pathways. Visualizing a network can be a helpful method to extract biological meaning and to generate testable hypotheses about large-scale biological data. This chapter describes some potential rationales for visualizing networks of microarray and other data types, which can be integrated and filtered to show potentially significant relationships. It also presents a practical introduction to Osprey and Cytoscape, two software platforms that are powerful tools for visualizing, integrating, and manipulating networks. PMID:16939803

Bell, George W; Lewitter, Fran

2006-01-01

85

Innovation Networks  

NASA Astrophysics Data System (ADS)

The idea for this book started when we organized a topical workshop entitled "Innovation Networks - New Approaches in Modeling and Analyzing" (held in Augsburg, Germany in October 2005), under the auspices of Exystence, a network of excellence funded in the European Union's Fifth Framework Program. Unlike other conferences on innovation and networks, however, this workshop brought together scientists from economics, sociology, communication science, science and technology studies, and physics. With this book we aim to build further on a bridge connecting the bodies of knowledge on networks in economics, the social sciences and, more recently, statistical physics.

Pyka, Andreas; Scharnhorst, Andrea

86

Networked Assessment  

Microsoft Academic Search

This essay argues that networked thinking represents a logic applicable to writing assessment. Traditionally, assessment at the programmatic or individual levels depends on the circulation of topoi in order to make meaning. These topoi include the circulated points that writers write for multiple media, multiple audiences, multiple genres, and over time. A networked assessment, on the other hand, takes up

Jeff Rice

2011-01-01

87

Traveling Networks  

NSDL National Science Digital Library

In this geometry activity, learners explore networks painted on playgrounds, such as a four square court, and draw their own. Learners walk on every edge until they return to the starting point without walking on any edge more than once. In doing so, learners explore odd and even points (also called nodes), edges, and possible and impossible networks.

Exploratorium

2010-01-01

88

Wavelet networks  

Microsoft Academic Search

A wavelet network concept, which is based on wavelet transform theory, is proposed as an alternative to feedforward neural networks for approximating arbitrary nonlinear functions. The basic idea is to replace the neurons by `wavelons', i.e., computing units obtained by cascading an affine transform and a multidimensional wavelet. Then these affine transforms and the synaptic weights must be identified from

Q. Zhang; A. Benveniste

1992-01-01

89

Network DEA  

Microsoft Academic Search

Most traditional DEA models treat their reference technologies as black boxes. Our network models, developed for the Swedish Institute for Health Economics (IHE), allow us to look into these boxes and to evaluate organizational performance and its component performance. The very general structure of the network model allows us to apply this model to a variety of situations: intermediate products,

Rolf Färe; Shawna Grosskopf

2000-01-01

90

Inter-Network Routing in Ambient Networks  

Microsoft Academic Search

The ambient networks project is developing advanced networking capabilities, such as dynamic multi-access, network mobility, together with availability of ensured service or network context. The Ambient framework offers a \\

C. P. Botham; A. L. Burness; P. L. Eardley; A. Eriksson; M. Jimenez-Abelleira; L. Loyola; J. Rajahalme

2007-01-01

91

Theoretical study on the lithium bond interaction of furan homologues C 4 H 4 Y (Y=O, S) with LiCH 3 via DFT and MP2  

Microsoft Academic Search

The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y (Y=O, S) and CH3Li have been calculated at the B3LYP\\/6-311++G** and MP2\\/6-311++G** levels. Three complexes were obtained. Abnormally, the\\u000a calculations showed that all the C10-Li14 bond lengths increased obviously but the blue-shift of C10-Li14 stretching frequency\\u000a occurred after formed complexes. The calculated binding energy with basis

Kun Yuan; LingLing Lü; YanZhi Liu

2008-01-01

92

Network design for information networks  

Microsoft Academic Search

We define a new class of network design problems motivated by designing information networks. In our model, the cost of transporting flow for a set of users (or servicing them by a facility) depends on the amount of information requested by the set of users. We assume that the aggregation cost follows economies of scale, that is, the incremental cost

Ara Hayrapetyan; Chaitanya Swamy; Éva Tardos

2005-01-01

93

On Networking.  

National Technical Information Service (NTIS)

This paper focuses on the theoretical and practical problems inherent in trying to build, create, develop, enhance, or strengthen networks among persons, groups, or organizations that would be useful in educational change efforts. The concepts of 'social ...

M. B. Miles

1977-01-01

94

Queueing Networks  

Microsoft Academic Search

The purpose of this tutorial is to survey queueing networks, a class of stochastic models extensively applied to represent\\u000a and analyze resource sharing systems such as communication and computer systems. Queueing networks (QNs) have been proved\\u000a to be a powerful and versatile tool for system performance evaluation and prediction. First we briefly survey QNs that consist\\u000a of a single service

Simonetta Balsamo; Andrea Marin

2007-01-01

95

Network specialist  

NSDL National Science Digital Library

Teachers can direct students to this material to help them investigate a career as a network specialist. Having students review this page can be an excellent precursor to a job-shadowing activity. This set of questions and answers can be a helpful resource for an activity in which students produce a number of pertinent questions that should be asked of a network specialist when investigating this field of work.

Project, Iowa P.

2002-01-01

96

Neural Networks  

Microsoft Academic Search

\\u000a Neural networks are networks of nerve cells in the brains of humans and animals. The human brain has about 100 billion nerve\\u000a cells. We humans owe our intelligence and our ability to learn various motor skills and intellectual capabilities to the brain’s\\u000a complex relays and adaptivity. The nerve cells and their connections are responsible for awareness, associations, thoughts,\\u000a consciousness and

Wolfgang Ertel

97

Mobile Networking  

Microsoft Academic Search

\\u000a We point out the different performance problems that need to be addressed when considering mobility in IP networks. We also\\u000a define the reference architecture and present a framework to classify the different solutions for mobility management in IP\\u000a networks. The performance of the major candidate micro-mobility solutions is evaluated for both real-time (UDP) and data (TCP)\\u000a traffic through simulation and

Chris Blondia; Nik Van Den Wijngaert; Gert Willems; Olga Casals; Llorenç Cerdà; Marcelo Bagnulo; Ignacio Soto

2003-01-01

98

Sentient networks  

SciTech Connect

The engineering problems of constructing autonomous networks of sensors and data processors that can provide alerts for dangerous situations provide a new context for debating the question whether man-made systems can emulate the cognitive capabilities of the mammalian brain. In this paper we consider the question whether a distributed network of sensors and data processors can form ``perceptions`` based on sensory data. Because sensory data can have exponentially many explanations, the use of a central data processor to analyze the outputs from a large ensemble of sensors will in general introduce unacceptable latencies for responding to dangerous situations. A better idea is to use a distributed ``Helmholtz machine`` architecture in which the sensors are connected to a network of simple processors, and the collective state of the network as a whole provides an explanation for the sensory data. In general communication within such a network will require time division multiplexing, which opens the door to the possibility that with certain refinements to the Helmholtz machine architecture it may be possible to build sensor networks that exhibit a form of artificial consciousness.

Chapline, G.

1998-03-01

99

Autonomic Networking in Wireless Sensor Networks  

Microsoft Academic Search

In this chapter, we address autonomic networking in termsof wireless sensor networks (WSNs), a typical example of wirelessnetworks\\u000a in pervasive computing. In order to investigate the stateof the art of autonomic networking in sensor networks and its futureprospects,\\u000a we start with a short summary of autonomic networking andSensor networks. It follows the discussion of the appliance ofautonomic\\u000a networking in WSNs

Mengjie Yu; Hala Mokhtar; Madjid Merabti

100

Neural Networks  

SciTech Connect

Physicists use large detectors to measure particles created in high-energy collisions at particle accelerators. These detectors typically produce signals indicating either where ionization occurs along the path of the particle, or where energy is deposited by the particle. The data produced by these signals is fed into pattern recognition programs to try to identify what particles were produced, and to measure the energy and direction of these particles. Ideally, there are many techniques used in this pattern recognition software. One technique, neural networks, is particularly suitable for identifying what type of particle caused by a set of energy deposits. Neural networks can derive meaning from complicated or imprecise data, extract patterns, and detect trends that are too complex to be noticed by either humans or other computer related processes. To assist in the advancement of this technology, Physicists use a tool kit to experiment with several neural network techniques. The goal of this research is interface a neural network tool kit into Java Analysis Studio (JAS3), an application that allows data to be analyzed from any experiment. As the final result, a physicist will have the ability to train, test, and implement a neural network with the desired output while using JAS3 to analyze the results or output. Before an implementation of a neural network can take place, a firm understanding of what a neural network is and how it works is beneficial. A neural network is an artificial representation of the human brain that tries to simulate the learning process [5]. It is also important to think of the word artificial in that definition as computer programs that use calculations during the learning process. In short, a neural network learns by representative examples. Perhaps the easiest way to describe the way neural networks learn is to explain how the human brain functions. The human brain contains billions of neural cells that are responsible for processing information [2]. Each one of these cells acts as a simple processor. When individual cells interact with one another, the complex abilities of the brain are made possible. In neural networks, the input or data are processed by a propagation function that adds up the values of all the incoming data. The ending value is then compared with a threshold or specific value. The resulting value must exceed the activation function value in order to become output. The activation function is a mathematical function that a neuron uses to produce an output referring to its input value. [8] Figure 1 depicts this process. Neural networks usually have three components an input, a hidden, and an output. These layers create the end result of the neural network. A real world example is a child associating the word dog with a picture. The child says dog and simultaneously looks a picture of a dog. The input is the spoken word ''dog'', the hidden is the brain processing, and the output will be the category of the word dog based on the picture. This illustration describes how a neural network functions.

Smith, Patrick I.

2003-09-23

101

Why network? Theoretical perspectives on networking  

Microsoft Academic Search

In recent years, networking and collaboration have become increasingly popular in education. However, there is at present a lack of attention to the theoretical basis of networking, which could illuminate when and when not to network and under what conditions networks are likely to be successful. In this paper, we will attempt to sketch the theoretical background to networking drawing

Daniel Muijs; Mel West; Mel Ainscow

2010-01-01

102

Network localization in partially localizable networks  

Microsoft Academic Search

Knowing the positions of the nodes in a network is essential to many next generation pervasive and sensor network functionalities. Although many network localization systems have recently been proposed and evaluated, there has been no system- atic study of partially localizable networks, i.e., networks in which there exist nodes whose positions cannot be uniquely determined. There is no existing study

David Kiyoshi Goldenberg; Arvind Krishnamurthy; W. C. Maness; Yang Anthony Young; Anthony Young; A. Stephen Morse; A. Savvides

2005-01-01

103

Regulatory networks.  

PubMed

The usefulness of mathematical models for the biological regulatory networks relies on the predictive capability of the models in order to suggest interesting hypotheses and suitable biological experiments. All mathematical frameworks dedicated to biological regulatory networks must manage a large number of abstract parameters, which are not directly measurable in the cell. The cornerstone to establish predictive models is the identification of the possible parameter values. Formal frameworks involve qualitative models with discrete values and computer-aided logic reasoning. They can provide the biologists with an automatic identification of the parameters via a formalization of some biological knowledge into temporal logic formulas. For pedagogical reasons, we focus on gene regulatory networks and develop a qualitative model of the detoxification of benzo[a]pyrene in human cells to illustrate the approach. PMID:23086843

Bernot, Gilles; Comet, Jean-Paul; Faverney, Christine Risso-de

2013-01-01

104

Knowledge Networks  

ERIC Educational Resources Information Center

The blogosphere and the Internet are both examples of complex, self-organizing networks. So too is the world of academic publishing. Some faculty members are prolific article and book writers. Their publications often are hubs, or even superhubs, in the scholarly literature, cited regularly by others. Some scholars might just be nodes, with…

McLeod, Scott

2008-01-01

105

NETWORKING DEMOCRACY?  

Microsoft Academic Search

Early conceptions of digital democracy as a virtual public sphere or civic commons have been replaced by a new technological optimism for democratic renewal based upon the open and collaborative networking characteristics of social media. This article provides an introduction to a special issue of the international journal Information, Communication & Society, which attempts to present a grounded analysis of

Brian D. Loader; Dan Mercea

2011-01-01

106

Network Views  

ERIC Educational Resources Information Center

|The world changed in 2008. The financial crisis brought with it a deepening sense of insecurity, and the desire to be connected to a network increased. Throughout the summer and fall of 2008, events were unfolding with alarming rapidity. The Massachusetts Institute of Technology (MIT) Alumni Association wanted to respond to this change in the…

Alexander, Louis

2010-01-01

107

Secure network coding  

Microsoft Academic Search

Recent work on network coding renders a new view on multicasting in a network. In the paradigm of network coding, the nodes in a network are allowed to encode the information received from the input links. The usual function of switching at a node is a special case of network coding. The advantage of network coding is that the full

Ning Cai; Raymond W. Yeung

2002-01-01

108

Investigation of the chemical composition of (Na 1- xBi x)(Mn yNb 1- y)O 3 ceramics by single particle electron probe X-ray microanalysis with an application of Monte Carlo simulations  

NASA Astrophysics Data System (ADS)

Accurate estimation of the elemental composition of materials that contain both low- and high-Z elements by electron probe X-ray microanalysis is not an easy task. An example of this kind of material is a new family of ceramics with general formula (Na 1- xBi x)(Mn yNb 1- y)O 3. To solve this problem, a method based on Monte Carlo simulations combined with an iterative approximation, which was recently successfully applied to quantitative analysis of the elemental content in aerosol particles, was used. The quantification procedure was evaluated on Bi 2O 3, PbO 2 and NaNbO 3 particles from stoichiometric compounds and applied to check the homogeneity and elemental contents of the selected ceramic after the application of different heat treatments.

Spolnik, Z.; Osán, J.; Klepka, M.; Lawniczak-Jablonska, K.; Van Grieken, R.; Molak, A.; Potgieter, J. H.

2005-04-01

109

Coprecipitation and hydrothermal synthesis of ultrafine 5.5 mol% CeO{sub 2}-2 mol% YO{sub 1.5}-ZrO{sub 2} powders  

SciTech Connect

Ultrafine 5.5 mol% CeO{sub 2}-2 mol% YO{sub 1.5}-ZrO{sub 2} powders with controllable crystallite size were synthesized by two kinds of coprecipitation methods and subsequent crystallization treatment. The amorphous gel produced by ammonia coprecipitation and hydrothermal treatment at 200 C for 3.5 h results in an ultrafine powder with a surface area of 206 m{sup 2}/g and a crystallite size of 4.8 nm. The powder produced by urea hydrolysis and calcination exhibits a purely tetragonal phase. In addition, the powders crystallized by hydrothermal treatment exhibit high packing density and can be sintered at lower temperature (<1,400 C) with nearly 100% tetragonal phase achieved.

Lin, J.D.; Duh, J.G. [National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Materials Science and Engineering

1997-01-01

110

Neuroendocrine Networks  

Microsoft Academic Search

Neuroendocrine networks in the brain are interconnected circuits of neurons, forming the central components of neuroendocrine\\u000a control systems, and, in some cases, extending into the spinal cord. Their activity organizes behaviors and desires, autonomic\\u000a nervous action, and the activity of endocrine systems. Neuroendocrinology is the study of how the brain controls body function by regulating the secretion of hormones, and

John A. Russell; Gareth Leng

111

Sensor network security issues at network layer  

Microsoft Academic Search

This paper presents an overview of the various vulnerabilities in WSN at network layer, and the defensive measures that can be taken against these threats. Resource limitations in the Wireless Sensor networks prevent us to directly apply the security mechanism of normal computer networks, a completely different set of security protocols exist for the sensor networks. Various security protocols for

Asif Habib

2008-01-01

112

Why Network? Theoretical Perspectives on Networking  

ERIC Educational Resources Information Center

|In recent years, networking and collaboration have become increasingly popular in education. However, there is at present a lack of attention to the theoretical basis of networking, which could illuminate when and when not to network and under what conditions networks are likely to be successful. In this paper, we will attempt to sketch the…

Muijs, Daniel; West, Mel; Ainscow, Mel

2010-01-01

113

Network Analysis of US Air Transportation Network  

Microsoft Academic Search

\\u000a There has been a considerable growth in interest in network analysis. Air transportation networks are regarded as complex\\u000a networks which are full of dynamics and complexity. This study focuses on the US air transportation network, which is one\\u000a of the most diverse and dynamic transportation networks in the world. All of the data are drawn from the US Bureau of

Guangying Hua; Yingjie Sun; Dominique Haughton

114

Woodland Network  

NSDL National Science Digital Library

The Woodland Network is "an interactive environmental project for both primary and secondary schools."Available in a variety of different languages, this Web site includes the main project for secondary students, Woodland Research, along with two smaller activities for younger students. The projects are designed to allow students to collect real woodland sample data and make comparisons with data collected from other students around the world. The site includes adequate instructions and reporting forms, as well as a searchable database of submitted results.

Willstedt, Hans.

115

Communications Network  

NASA Astrophysics Data System (ADS)

The Multi-Compatible Network Interface Unit (MCNIU) is intended to connect the space station's communications and tracking, guidance and navigation, life support, electric power, payload data, hand controls, display consoles and other systems, and also communicate with diverse processors. Honeywell is now marketing MCNIU commercially. It has applicability in certain military operations or civil control centers. It has nongovernment utility among large companies, universities and research organizations that transfer large amounts of data among workstations and computers. *This product is no longer commercially available.

1990-01-01

116

Gender and Entrepreneurial Networks  

Microsoft Academic Search

Hanson S. and Blake M. Gender and entrepreneurial networks, Regional Studies. In a recent critical survey in 2003, Peter Nijkamp argued for the importance of networks and networking for successful entrepreneurship and emphasized the strategic advantage that dense urban areas afford to networks. Nijkamp's arguments are extended herein by investigating the impact of an entrepreneur's identity on network formation, use

Susan Hanson; Megan Blake

2009-01-01

117

Queues and Network Computers.  

National Technical Information Service (NTIS)

With the advent of the network computer has come an increasing movement towards developing the necessary analytical tools to properly evaluate and improve these networks. One such tool is system modeling to assist in performance evaluation of networks and...

L. A. Da Rin Mills

1973-01-01

118

Securing Network Servers.  

National Technical Information Service (NTIS)

The development of computer networks has resulted in an important class of computers: network servers. The primary purpose of these machines is to provide services, including both computational and data services, to other computers on the network. Because...

J. Allen K. Kossakowski G. Ford S. Konda D. Simmel

2000-01-01

119

Networks in immunology  

NASA Astrophysics Data System (ADS)

In this note we present a minireview of the idiotypic network in immunology and we study a very simple model for this network. We discuss some of the similarities of this model with spin glasses and neural networks.

Parisi, Giorgio

1989-12-01

120

DARPA Quantum Network Testbed.  

National Technical Information Service (NTIS)

BBN has designed and built the world's first Quantum Network testbed, delivering end-to-end network security via high-speed Quantum Key Distribution (QKD), and testing that Network against sophisticated eavesdropping attacks. BBN has fielded this ultrahig...

C. Elliott H. Yeh

2007-01-01

121

Correlation in business networks  

NASA Astrophysics Data System (ADS)

This paper considers business networks. Through empirical study, we show that business networks display characteristics of small-world networks and scale-free networks. In this paper, we characterize firms as sales and bankruptcy probabilities. A correlation between sales and a correlation between bankruptcy probabilities in business networks are also considered. The results reveal that the correlation between sales depends strongly on the type of network, whereas the correlation between bankruptcy probabilities does so only weakly.

Souma, Wataru; Aoyama, Hideaki; Fujiwara, Yoshi; Ikeda, Yuichi; Iyetomi, Hiroshi; Kaizoji, Taisei

2006-10-01

122

Complex Networks and Graphs  

NSDL National Science Digital Library

Students learn about complex networks and how to represent them using graphs. They also learn that graph theory is a useful mathematical tool for studying complex networks in diverse applications of science and engineering, such as neural networks in the brain, biochemical reaction networks in cells, communication networks, such as the internet, and social networks. Topics covered include set theory, defining a graph, as well as defining the degree of a node and the degree distribution of a graph.

Complex Systems Science Laboratory

123

Unified construction algorithm of network coding in cyclic networks  

Microsoft Academic Search

Network coding in cyclic networks may have better performance than network coding in acyclic networks with regard to the multi-unicast scenarios. Harvey et al. showed that network coding in cyclic networks can be strictly better than fractional routing in conservative networks which have widely practical scenarios such as P2P networks. Hence, we motivated investigating how to achieve that better performance

Jiaqing Huang; Liang Wang; Tiyuan Zhang; Hui Li

2009-01-01

124

Telekom Malaysia Network Feasibility Study: Network Planning.  

National Technical Information Service (NTIS)

The volume is the fourth of a four volume final report submitted to Telekom Malaysia. The report documents the Network Feasibility Study conducted for Telekom Malaysia. The volume discusses the functional and organizational requirements for network planni...

1991-01-01

125

[Military telemedicine: a network of networks].  

PubMed

Military telemedicine is a form of collaborative medicine based on the use of communication and information networks. It is more a network of networks than of independent systems. It comprises electronic medical files, epidemiological networks, and surgical and medical databases. Each system must be able to communicate with the others, thereby enabling the development of remote consultation, expertise and assistance. This requires networking between the army, the navy, and the air force communication networks, especially during special operations conducted abroad. We must also develop interoperability with systems in other countries, and with the French civilian health service. This means respecting the general rules governing these networks. The military health network is unique, in that it focuses on battlefield injuries. In addition, the French military health service operates under a single headquarters, governing nurses, paramedics and physicians. PMID:17001864

Menu, Jean-Pierre; Comtet, Gérald; Di Giusto, Vincent; Colomb, François; de Saint-Julien, Jacques

2006-02-01

126

Psychotherapy Networker  

NSDL National Science Digital Library

The Psychotherapy Networker website is the online presence of the print magazine, which covers "the everyday challenges of clinical practice, while also offering perspective on the social issues, critical ideas, and therapeutic innovations shaping the direction of the [psychotherapy] profession." Visitors to the site will find the full text of the "Current Issue" and the full text of "Recent Issues". Subscribers to the bimonthly magazine have full access to the "Archives". On the left side of any page is a "Popular Topics" link that has over a dozen topics, including "The Business of Therapy", "Challenging Cases", "Ethics", and "Trauma". Visitors should check out the "CE Courses" link at the top of any page as it has many types of continuing education course offerings, such as "Telecourses", "Audio Courses" and "Online Courses". There is even a "Magazine Quiz" to take that will yield two CE credits if 12 questions about designated articles are answered correctly.

127

TVRadio Network  

NSDL National Science Digital Library

This free service offers Webmasters a searchable database of TV and Radio stations that they can place on their site for a 50/50 split on advertising. Visitors can use this resource at partner sites that mirror the database, or simply visit the TVRadio Network homepage. Users can browse the listings by category or location. Each listing includes a link to the homepage and format and speed in which content is offered (RealPlayer or Windows Media Player or both). Selected stations may be added to "My Stations" or emailed to a friend. A keyword search engine is also provided. While a few of the category listings seem a bit sparse -- there are only 22 entries for Jazz, for instance -- the location listings are a very useful resource for those seeking nation-specific audio and video broadcasts.

128

Network Protocols for Networked Control Systems  

Microsoft Academic Search

Control systems with networked communication, called networked control systems (NCSs), provide several advantages over point-to-point wired systems such as improvement in reliability through reduced volume\\u000a of wiring, simpler systems integration, easier troubleshooting and maintenance, and the possibility for distributed processing.\\u000a There are two types of communication networks. Data networks are characterized by large data packets, relatively infrequent bursty transmission, and

Feng-li Lian; James R. Moyne; Dawn M. Tilbury

2005-01-01

129

Computer Networks and Networking: A Primer.  

ERIC Educational Resources Information Center

|Provides a basic introduction to computer networks and networking terminology. Topics addressed include modems; the Internet; TCP/IP (Transmission Control Protocol/Internet Protocol); transmission lines; Internet Protocol numbers; network traffic; Fidonet; file transfer protocol (FTP); TELNET; electronic mail; discussion groups; LISTSERV; USENET;…

Collins, Mauri P.

1993-01-01

130

Twinkle: Network Power Scheduling in Sensor Networks  

Microsoft Academic Search

We present our experience with Twinkle, the first implementation of network-layer power scheduling with real applications. Twinkle uses dynamically created schedules to schedule network flows in sensor networks. The scheduling allows nodes to turn off their radio when idle, thus saving power. Twinkle supports broadcast and partial flows for flexibility, and integrates time synchro- nization to enable scheduling to work

Barbara Hohlt; Eric Brewer

2005-01-01

131

Network Services in Systems Network Architecture  

Microsoft Academic Search

This paper discusses the services provided by a systems network architecture (SNA) network and design aspects related to these services. Both the basic transmission services and higher level network services are discussed. The first section describes the structure of SNA. The second section describes SNA's transmission services and sketches in the other aspects of SNA's structure. The next section describes

J. Gray; B. Wessler; R. Kanodia; J. M. McQuillan; B. P. Cosell; D. C. Walden

1977-01-01

132

Neural Network Trainer through Computer Networks  

Microsoft Academic Search

This paper introduces a neural network training tool through computer networks. The following algorithms, such as neuron by neuron (NBN) , error back propagation (EBP), Levenberg Marquardt (LM) and its improved versions are implemented in two different computing methods, traditional forward-backward computation and newly developed forward-only computation. The training tool can handle not only conventional multilayer perceptron (MLP) networks, but

Nam Pham; Hao Yu; Bogdan M. Wilamowski

2010-01-01

133

Self-optimized cognitive network of networks  

Microsoft Academic Search

Future processing, storage and communication services will be highly pervasive: people, smart objects, machines and the surrounding space (all embedding devices such as with sensors, RFID tags, etc.) will define a highly decentralized cyber environment of resources interconnected by dynamic Networks of Networks. As communications will extend to cover any combination of “people, machines and things”, future networks will be

A. Manzalini; P. H. Deussen; S. Nechifor; M. Mamei; R. Minerva; C. Moiso; A. Salden; T. Wauters; F. Zambonelli

2010-01-01

134

Mesh networks: commodity multihop ad hoc networks  

Microsoft Academic Search

In spite of the massive efforts in researching and developing mobile ad hoc networks in the last decade, this type of network has not yet witnessed mass market deployment. The low commercial penetration of products based on ad hoc networking technology could be explained by noting that the ongoing research is mainly focused on implementing military or specialized civilian applications.

R. Bruno; M. Conti; E. Gregori

2005-01-01

135

Study of Structural, electrical and magnetic properties of Al3+ ions doped Mg0.2Mn0.5Ni0.3AlyFe2-yO4 spinel ferrites for high frequency applications  

NASA Astrophysics Data System (ADS)

Structural, electrical and bulk magnetic properties of spinel system Mg0.2Mn0.5Ni0.3AlyFe2-yO4 with y varying from 0.0-0.3 in step of 0.1, synthesized by citrate precursor technique at 1200 °C, have been investigated. Variations of initial permeability, and RLF (relative loss factor) with frequency, in range of 0.075-20 MHz at different temperatures have been studied. Initial permeability (?i) attains very high value i.e. 59487 and RLF has very low values of 10-6-10-5 which is three orders of magnitude less than the samples prepared by conventional method. There is significant reduction in initial permeability, Curie temperature, RLF and dielectric loss with Al3+ ions. Therefore, very high ?i and very low values of RLF and dielectric loss are attributed to better compositional stoichiometery and uniform microstructure, making these ferrites attractive for use in high frequency applications.

Verma, Satish; Chand, Jagdish; Kumar, Pawan; Singh, M.

2011-12-01

136

H+ diffusion and electrochemical stability of Li1+x+yAlxTi2-xSiyP3-yO12 glass in aqueous Li/air battery electrolytes  

SciTech Connect

It is well known that LATP (Li1+x+y AlxTi2?x SiyP3?yO12) glass is a good lithium ion conductor. However, the interaction between LATP glass and H+ ions (including its diffusion and surface adsorption) needs to be well understood before the long-term application of LATP glass in an aqueous electrolyte based Li-air batteries where H+ always present. In this work, we investigate the H+ ion diffusion properties in LATP glass and their surface interactions using both experimental and modeling approaches. Our analysis indicates that the apparent H+ related current observed in the initial cyclic voltammetry scan should be attributed to the adsorption of H+ ions on the LATP glass rather than the bulk diffusion of H+ ions in the glass. Furthermore, the density functional theory calculations indicate that the H+ ion diffusion energy barrier (3.21 eV) is much higher than that of Li+ ion (0.79 eV) and Na+ ion (0.79 eV) in NASICON type LiTi2(PO4)3 material. As a result, the H+ ion conductivity in LATP glass is negligible at room temperature. However, significant surface corrosion was found after the LATP glass was soaked in strong alkaline electrolyte for extended time. Therefore, appropriate electrolytes have to be developed to prevent the corrosion of LATP glass before its practical application for Li-air batteries using aqueous electrolyte.

Ding, Fei; Xu, Wu; Shao, Yuyan; Chen, Xilin; Wang, Zhiguo; Gao, Fei; Liu, Xingjiang; Zhang, Jiguang

2012-09-15

137

Network Analysis in Marketing  

Microsoft Academic Search

Understanding relationships is fundamental to marketing. Research has moved beyond simple dyadic relations to examine how networks of relations influence behaviour. While network theory is frequently drawn upon in marketing, few researchers apply the formal network analytical techniques developed. The aim here is to make network analysis more accessible. In this paper we discuss the basic data requirements and use

Cynthia M. Webster; Pamela D. Morrison

2004-01-01

138

Seven Questions of Networking  

ERIC Educational Resources Information Center

|What do leaders mean when they talk about networks and whether leadership networks have the power to transform the profession? When it comes to educational leadership networks, there certainly are more than seven important questions. This article focuses on seven key questions about networking in the superintendent ranks by the coordinator of one…

Livingston, David

2007-01-01

139

Differentiated Services Network Simulation  

Microsoft Academic Search

This paper describes the Network Modeler application that helps differentiated services network d esign, planning and configuration testing. This application allows a user to draw a network, configure it, and evaluate its performance through simulation. A simple scenario is presented, showing the potentialities of the Network Modeler, the a dvantages of using differentiated services, and proving that this application is

Paulo Rogério Pereira; Bruno Afonso; Daniel Gomes

2001-01-01

140

Network Telescopes: Technical Report  

Microsoft Academic Search

A network telescope is a portion of routed IP address space in which little or no legitimate traffic exists. Monitoring unexpected traffic arriving at a network telescope provides the opportunity to view remote network security events such as various forms of flooding denial-of-service attacks, infection of hosts by Internet worms, and network scanning. In this paper, we examine the effects

David Moore; Colleen Shannon; Geoffrey M. Voelkery; Stefan Savagey

141

Centrality in affiliation networks  

Microsoft Academic Search

This paper discusses the conceptualization, measurement, and interpretation of centrality in affiliation networks. Although centrality is a well-studied topic in social network analysis, and is one of the most widely used properties for studying affiliation networks, virtually all discussions of centrality and centralization have concerned themselves with one-mode networks. Bonacich's work on simultaneous group and individual centralities is a notable

Katherine Faust

1997-01-01

142

Network MFA tracking architectures  

NASA Astrophysics Data System (ADS)

This work presents some initial steps in the development of a decentralized network centric multiple frame assignment (MFA) class of architecture algorithms that affordably preserves the quality of a centralized architecture across a network of platforms while managing communication loading and achieving a consistent air picture on entities of interest for each platform. In particular, this work discussed four architectures, namely, Centralized, Network MFA Centralized, Network MFA on Local Data and Network Tracks, and Network MFA on All Data and Network Tracks and the results of extensive computations with the architectures.

Lu, Suihua; Poore, Aubrey P.; Suchomel, Brian J.

2001-11-01

143

Economics of Networks  

NSDL National Science Digital Library

Nicholas Economides of the Stern Business School at New York University has assembled a "collection of information on economic issues of networks, such as the internet, telephone and fax communications networks, the railroad network, the airline network, and financial exchange and credit card networks." The site contains a large collection of research papers on networks, compatibility, and related issues; and on financial networks and electronic trading written by Economides in collaboration with other researchers. Visitors to the site can choose to read the abstracts online or download papers (in Adobe Acrobat [.pdf] or Postscript format). In addition, there is also an extensive bibliography.

Economides, Nicholas.

1997-01-01

144

Epidemics on interconnected networks  

NASA Astrophysics Data System (ADS)

Populations are seldom completely isolated from their environment. Individuals in a particular geographic or social region may be considered a distinct network due to strong local ties but will also interact with individuals in other networks. We study the susceptible-infected-recovered process on interconnected network systems and find two distinct regimes. In strongly coupled network systems, epidemics occur simultaneously across the entire system at a critical infection strength ?c, below which the disease does not spread. In contrast, in weakly coupled network systems, a mixed phase exists below ?c of the coupled network system, where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

Dickison, Mark; Havlin, S.; Stanley, H. E.

2012-06-01

145

Mutual influence of ‘3d’ and ‘4f’ atoms in K 2NiF 4-type structure diluted solid solutions Y 1 ? xNd(Ce) xCaCr yAl 1 ? yO 4 (x ? 0.1; y ? 0.1)  

Microsoft Academic Search

Diluted solid solutions of ‘3d’ (chromium) and ‘4f’ (neodymium and cerium) elements in the K2NiF4-type 1\\/1 perovskite rock salt intergrowth structure of mixed aluminates were investigated in order to get evidence of mutual influence phenomena. Crystal chemical data obtained for the solid solution Y1 ? xNdxCaCryAl1 ? yO4 (x ? 0.1; y ? 0.1) point to the existence of an

J. Choisnet; N. Mazéas; I. Zvereva; Yr. Smirnov; E. Ryjova

1997-01-01

146

Declarative Network Verification  

Microsoft Academic Search

In this paper, we present our initial design and implementation of a declarative network verifier (DNV). DNV utilizes theorem proving, a well established verification technique where logic-based axioms that automatically capture network semantics are generated, and a user-driven proof process is used to establish network\\u000a correctness properties. DNV takes as input declarative networking specifications written in the Network Datalog (NDlog)

Anduo Wang; Prithwish Basu; Boon Thau Loo; Oleg Sokolsky

2009-01-01

147

OSEK\\/VDX-Based Dynamic Network Management on Automotive Network  

Microsoft Academic Search

The rapid growth in complexity of the automotive ECU (Electronic Control Unit) networks has posed challenges in real-time network management, which collects network information for fault diagnostic systems. This paper proposes a dynamic network management framework based on the OSEK Network Management protocols, which can automatically adapt to the unstable network load. A method to calculate appropriate network load thresholds

Chengjiong Wei; Min Yao; Pan Lu; Qi Hu; Nenggan Zheng

2009-01-01

148

Network management on Hughes Aircraft's engineering design network  

Microsoft Academic Search

A description is given of the network management on the Ethernet-based engineering design network (EDEN). Past experiences and current network management techniques are presented for the various areas of network management such as protocol-level management, network monitoring, network database, problem reporting, problem diagnosis, and fault isolation. Near-term expectations in network management for EDEN are discussed

P. Ho

1989-01-01

149

Wide area networks for teleradiology.  

PubMed

Teleradiology networks transmit digital radiographic images from one location to another. These networks are wide area networks. Teleradiology networks are used for diagnostic purposes and preview tasks. Wide area networks for teleradiology use public service switching. The use of fiber optics networks provide reduced costs and increased flexibility. An example is presented that compares the cost of teleradiology networks. PMID:2029573

Baxter, K G; Wetzel, L H; Murphey, M D; Rosenthal, S J; Haines, J E; Batnitzky, S; Caresio, J F; Templeton, A W; Dwyer, S J

1991-02-01

150

Network Management of Predictive Mobile Networks  

Microsoft Academic Search

There is a trend toward the use of predictive systems in communications\\u000anetworks. At the systems and network management level predictive capabilities\\u000aare focused on anticipating network faults and performance degradation.\\u000aSimultaneously, mobile communication networks are being developed with\\u000apredictive location and tracking mechanisms. The interactions and synergies\\u000abetween these systems present a new set of problems. A new predictive

Stephen F. Bush; Victor S. Frost; Joseph B. Evans

1999-01-01

151

Improving network utilization over heterogeneous airborne networks  

NASA Astrophysics Data System (ADS)

Existing and future military networks vary widely in bandwidth and other network characteristics, potentially challenging deployment of services and applications across heterogeneous data links. To address this challenge, General Dynamics and Naval Research Laboratory created network services to allow applications to use wireless data links more efficiently. The basis for the network services are hooks into the data links and transport protocols providing status about the airborne networking environment. The network service can monitor heterogeneous data links on a platform and report on link availability and parameters such as latency and bandwidth. The network service then presents the network characteristics to other services and applications. These services and applications are then able to tune parameters and content based on network parameters. The technology has been demonstrated in several live-flight experiments sponsored by the United States Air Force and United States Navy. The technology was housed on several aircraft with a variety of data links ranging from directional, high-bandwidth systems to omnidirectional, medium-bandwidth systems to stable but low-bandwidth satellite systems. In each of these experiments, image and video data was successfully delivered over tactical data links that varied greatly in bandwidth and delay.

Griffin, Peter H.; Rickenbach, Brent L.; Rush, Jason A.

2011-05-01

152

Robustness of Interdependent Networks  

NASA Astrophysics Data System (ADS)

In interdependent networks, when nodes in one network fail, they cause dependent nodes in other networks to also fail. This may happen recursively and can lead to a cascade of failures. In fact, a failure of a very small fraction of nodes in one network may lead to the complete fragmentation of a system of many interdependent networks. We will present a framework for understanding the robustness of interacting networks subject to such cascading failures and provide a basic analytic approach that may be useful in future studies. We present exact analytical solutions for the critical fraction of nodes that upon removal will lead to a failure cascade and to a complete fragmentation of two interdependent networks in a first order transition [1]. Surprisingly, analyzing complex systems as a set of interdependent networks may alter a basic assumption that network theory has relied on: while for a single network a broader degree distribution of the network nodes results in the network being more robust to random failures, for interdependent networks, the broader the distribution is, the more vulnerable the networks become to random failure. We also show [2] that reducing the coupling between the networks leads to a change from a first order percolation phase transition to a second order percolation transition at a critical point. These findings pose a significant challenge to the future design of robust networks that need to consider the unique properties of interdependent networks. [4pt] [1] S. Buldyrev, R. Parshani, G. Paul, H.E. Stanley, S. Havlin, Nature, 465, 0893 (2010)[0pt] [2] R. Parshani, S. Buldyrev, S. Havlin, PRL, 105, 048701 (2010)

Havlin, Shlomo

2011-03-01

153

Human Body Network: Network in the Future?  

Microsoft Academic Search

Based on the analysis of accomplishments and trends of modern technologies (such as the computer, wireless communication, creature science, nanotechnology, medical science, et al.), this paper makes a prediction of the future network, and proposes a new concept - the human body network (HBN), which is formed by people around the world whom are equipped with special micro chip in

Zheng Wu; Debao Xiao; Xi Peng; Hui Xu; Xin Zhuang

2008-01-01

154

Local Area Networking: Ames Centerwide Network.  

National Technical Information Service (NTIS)

A computer network can benefit the user by making his/her work quicker and easier. A computer network is made up of seven different layers with the lowest being the hardware, the top being the user, and the middle being the software. These layers are disc...

E. Price

1988-01-01

155

Network Initialization for Wireless Distributed Beaconing Networks  

Microsoft Academic Search

The unlicensed incumbents must be offered seamless communications on other unused channels in TV white space. It must provide communication processes among competing users through the proper allocation of available resources. It is important to quickly organize a new network connection or to join to a new network rapidly. In this paper, we studied the limitations of the current distributed

Youngmi Baek; Youngil Kim; Byunghwa Lee; Jilong Lee; Jeongbae Yun; Qin Shu; Seungyong Oh; Kijun Han

2010-01-01

156

Network Design for Information Networks (Extended Abstract)  

Microsoft Academic Search

We define a new class of network design problems motivated by designing information networks. In our model, the cost of transporting flow for a set of users (or servicing them by a fac ility) depends on the amount of information requested by the set of users. We assume that the aggregation cost follows economies of scale, that is, the incremental

Ara Hayrapetyan; Chaitanya Swamy; Eva Tardos

157

Networking Issues in Wireless Sensor Networks  

Microsoft Academic Search

The emergence of sensor networks as one of the dominant technology trends in the com- ing decades (1) has posed numerous unique challenges to researchers. These networks are likely to be composed of hundreds, and potentially thousands of tiny sensor nodes, func- tioning autonomously, and in many cases, without access to renewable energy resources. Cost constraints and the need for

Deepak Ganesan; Alberto Cerpa; Yan Yu; Deborah Estrin; Wei Ye; Jerry Zhao

2003-01-01

158

Networking issues in wireless sensor networks  

Microsoft Academic Search

The emergence of sensor networks as one of the dominant technology trends in the com- ing decades (1) has posed numerous unique challenges to researchers. These networks are likely to be composed of hundreds, and potentially thousands of tiny sensor nodes, func- tioning autonomously, and in many cases, without access to renewable energy resources. Cost constraints and the need for

Deepak Ganesan; Alberto Cerpa; Deborah Estrin; Yan Yu; Jerry Zhao

2004-01-01

159

Network Nation Revisited  

NSDL National Science Digital Library

The Network Nation Revisited" is an analysis of the predictions made by Hiltz and Turoff in _The Network Nation_, one of the seminal texts (published in 1978) in the field of Computer Mediated Communications.

160

Geometric Networks Analysis.  

National Technical Information Service (NTIS)

The main goal of the project was to develop and use algorithmic tools with a geometric underpinning to analyze large networks. For example, the Internet, social networks, connectivity properties between genes or proteins in a biological cell, and other ty...

G. Carlsson M. Mahoney

2012-01-01

161

Wavelets and Neural Networks.  

National Technical Information Service (NTIS)

During our previous work, we had established a very dose connection between polynomial approximation and approximation by neural networks. In fact, we had developed a unified theory of the approximation properties of neural networks, radial basis function...

H. N. Mhaskar

1999-01-01

162

Multilayer Optical Learning Networks,  

National Technical Information Service (NTIS)

A new approach to learning in a multilayer optical neural network based on holographically interconnected nonlinear devices is presented. The proposed network can learn the interconnections that form a distributed representation of a desired pattern trans...

K. Wagner D. Psaltis

1987-01-01

163

Networking and Institutional Planning.  

ERIC Educational Resources Information Center

|Explores the impact of networks and shared library resources on the library planning process. Environmental scanning techniques, the need for cooperative planning, and the formulation of strategies to achieve networking goals are discussed. (CLB)|

Riggs, Donald E.

1987-01-01

164

Flexible memory networks.  

PubMed

Networks of neurons in some brain areas are flexible enough to encode new memories quickly. Using a standard firing rate model of recurrent networks, we develop a theory of flexible memory networks. Our main results characterize networks having the maximal number of flexible memory patterns, given a constraint graph on the network's connectivity matrix. Modulo a mild topological condition, we find a close connection between maximally flexible networks and rank 1 matrices. The topological condition is H (1)(X;?)=0, where X is the clique complex associated to the network's constraint graph; this condition is generically satisfied for large random networks that are not overly sparse. In order to prove our main results, we develop some matrix-theoretic tools and present them in a self-contained section independent of the neuroscience context. PMID:21826564

Curto, Carina; Degeratu, Anda; Itskov, Vladimir

2011-08-09

165

Reciprocity of weighted networks  

PubMed Central

In directed networks, reciprocal links have dramatic effects on dynamical processes, network growth, and higher-order structures such as motifs and communities. While the reciprocity of binary networks has been extensively studied, that of weighted networks is still poorly understood, implying an ever-increasing gap between the availability of weighted network data and our understanding of their dyadic properties. Here we introduce a general approach to the reciprocity of weighted networks, and define quantities and null models that consistently capture empirical reciprocity patterns at different structural levels. We show that, counter-intuitively, previous reciprocity measures based on the similarity of mutual weights are uninformative. By contrast, our measures allow to consistently classify different weighted networks according to their reciprocity, track the evolution of a network's reciprocity over time, identify patterns at the level of dyads and vertices, and distinguish the effects of flux (im)balances or other (a)symmetries from a true tendency towards (anti-)reciprocation.

Squartini, Tiziano; Picciolo, Francesco; Ruzzenenti, Franco; Garlaschelli, Diego

2013-01-01

166

Applications of Bayesian Belief Networks in Social Network Analysis  

Microsoft Academic Search

In this paper, we discuss the use of Bayesian belief networks as a tool for enhancing social network analysis. Traditional social network analysis (SNA) primarily uses graph-theoretic algorithms to compute properties of nodes in a network. However, these algorithms assume a degree of completeness and reliability of the social network data, which cannot always be assured. Applying Bayesian belief networks

David Koelle; Jonathan Pfautz; Michael Farry; Zach Cox; Geoffrey Catto; Joseph Campolongo

167

Efficient error recovery with network coding in underwater sensor networks  

Microsoft Academic Search

Wireless sensor networks usually suffer higher error probability and loss rate than wired networks, especially in Underwater Sensor Networks (UWSN). We have noticed that network coding could bring us benefits in both wired and wireless networks, e.g., increasing the throughput. Because of the special conditions of UWSN, we find applying network coding and multi-path routing in UWSN could provide efficient

Zheng Guo; Bing Wang; Peng Xie; Wei Zeng; Jun-hong Cui

2009-01-01

168

Intelligent Social Network Modeling  

Microsoft Academic Search

The recent development of Web 2.0 has provided an enormous increase in human interactions across all corners of the earth. One manifestation of this is the growth of computer mediated social networks. Many notable Web 2.0 applications such as Facebook, Myspace and LinkedIn are social networks. Relational networks are becoming an important technology for modeling these types of social networks

Ronald R. Yager

2009-01-01

169

Securing Personal Network clusters  

Microsoft Academic Search

A Personal Network is a self-organizing, secure and private network of a user’s devices notwithstanding their geographic location. It aims to utilize pervasive computing to provide users with new and improved services. In this paper we propose a model for securing Personal Network clusters. Clusters are ad-hoc networks of co-located personal devices. The ad-hoc makeup of clusters, coupled with the

Assed Jehangir; Sonia M. Heemstra de Groot

2007-01-01

170

Intelligent social network modeling  

Microsoft Academic Search

Summary form only given: Web 2.0 has provided for a rapid growth of computer mediated social networks. Many notable Web 2.0 applications such as Facebook, Myspace and LinkedIn are social networks. Social relational networks are becoming an important technology in human behavioral modeling. Our goal here is to enrich the domain of social network modeling by introducing ideas from fuzzy

R. R. Yager

2009-01-01

171

Centrality and network flow  

Microsoft Academic Search

Centrality measures, or at least popular interpretations of these measures, make implicit assumptions about the manner in which traffic flows through a network. For example, some measures count only geodesic paths, apparently assuming that whatever flows through the network only moves along the shortest possible paths. This paper lays out a typology of network flows based on two dimensions of

Stephen P. Borgatti

2005-01-01

172

Appalachia Community Cancer Network  

Cancer.gov

A multidisciplinary team of collaborators from academic institutions and communities in Appalachian regions of Kentucky, West Virginia, Ohio, Pennsylvania, New York, Maryland, and Virginia are proposing to build on a strong foundation of previous activity of the Appalachia Cancer Network (ACN), an NCI-funded Special Populations Network, and develop the Appalachia Community Cancer Network (ACCN).

173

Dominating Biological Networks  

Microsoft Academic Search

Proteins are essential macromolecules of life that carry out most cellular processes. Since proteins aggregate to perform function, and since protein-protein interaction (PPI) networks model these aggregations, one would expect to uncover new biology from PPI network topology. Hence, using PPI networks to predict protein function and role of protein pathways in disease has received attention. A debate remains open

Tijana Milenkovic; Vesna Memisevic; Anthony Bonato; Natasa Przulj; Franca Fraternali

2011-01-01

174

Dynamic network configuration management  

Microsoft Academic Search

Configuration and traffic management for reconfigurable networks is investigated. Such networks have the potential to adapt well to changing traffic patterns and to failure of physical facilities. The authors define the underlying constrained optimization problem in general, and apply a heuristic technique to a simple case to illustrate the benefit of reconfiguring the logical network. It is found that reconfiguration

G. Gopal; C.-K. Kim; A. Weinrib

1990-01-01

175

Conservative Network Coding  

Microsoft Academic Search

Motivated by practical networking scenarios, we in- troduce a notion of restricted communication called conservative networking. Consider a network of lossless links and a number of independent sources. Each node needs to recover a certain subset of the sources. However, each node is conservative in that all information it receives can only be a function of the sources it will

Nicholas J. A. Harvey; Kamal Jain; Lap Chi; Lau Chandra; Nair Yunnan

176

Business Relationships and Networks  

Microsoft Academic Search

The competitive environment of firms is undergoing a fundamental change. Traditional markets are being rapidly replaced by networks. This poses major managerial challenges for industrial and high technology companies. From a conceptual point of view, this means that we have to look beyond ordinary customer and supplier relationships into intricate webs of firms forming R&D networks, deep supplier networks, and

Kristian K. Möller; Aino Halinen

1999-01-01

177

Networking for Competitiveness  

Microsoft Academic Search

A policy innovation that has achieved widespread diffusion across national and sub-national governments in industrialized countries is the promotion of networks among small manufacturers as a means of promoting competitiveness. However, research and evaluations of formal networks formed in response to policy initiatives tend not account for the informal networks that small manufacturers routinely use in gathering information and business

Gordon Kingsley; Edward J. Malecki

2004-01-01

178

Networks and Economic Behavior  

Microsoft Academic Search

Recent analyses of social networks, both empirical and theoretical, are discussed, with a focus on how social networks influence economic behavior, as well as how social networks form. Some challenges of such research are discussed as are some of the important considerations for the future.

Matthew O. Jackson

2009-01-01

179

The Shared Information Network.  

ERIC Educational Resources Information Center

Discusses the use of shared information networks within organizations to decrease information hoarding and maximize operating efficiencies. Network development issues discussed include choosing the department responsible for development, selecting information to be included in the network, designing the information format, distribution strategies,…

Stanat, Ruth

1990-01-01

180

Government Virtual Service Networks  

Microsoft Academic Search

Governments and their partners have developed sophisticated networks of services to comprehensively reach their common customers. Those networks developed to reach the citizen in the physical world should be extended to reach citizens in the virtual world. Virtual networks should stretch from government agencies to public portals, through public or private service providers and fully leveraging the Internet as a

Mauro Regio

2002-01-01

181

Aeronautical ad hoc networks  

Microsoft Academic Search

There has been an enormous growth in mobile ad hoc networks (MANETs) in land based small to medium size networks with relatively strict power and resources. In this paper the concept of ad hoc networking between aircraft is introduced, which can be considered as a novel approach in increasing the data rate and practicality of future in-flight broadband Internet access.

Ehssan Sakhaee; Abbas Jamalipour; Nei Kato

2006-01-01

182

Taxonomies of Networks  

Microsoft Academic Search

The study of networks has grown into a substantial interdisciplinary endeavour that encompasses myriad disciplines in the natural, social, and information sciences. Here we introduce a framework for constructing taxonomies of networks based on their structural similarities. These networks can arise from any of numerous sources: they can be empirical or synthetic, they can arise from multiple realizations of a

Jukka-Pekka Onnela; Daniel J. Fenn; Stephen Reid; Mason A. Porter; Peter J. Mucha; Mark D. Fricker; Nick S. Jones

2010-01-01

183

Integrated Wireless Optical Networking  

Microsoft Academic Search

The interoperability of wireless and PON topologies is investigated to reduce deployment expenditure by means of centralised network management while providing ubiquitous access connections and mobility. In addition, the application of extended wavelength band overlay has been proposed to enhance scalability in the converged platform with the slightest modification in network hardware. To that extent, network modelling in the physical

M Milosavljevic; P Kourtessis; J M Senior

184

Wireless Network Security  

Microsoft Academic Search

Wireless networking is inherently insecure. From jamming to eavesdropping, from man-in- the middle to spoofing, there are a variety of attack methods that can be used against the users of wireless networks. Modern wireless data networks use a variety of cryptographic techniques such as encryption and authentication to provide barriers to such infiltrations. However, much of the commonly used security

Partha Dasgupta; Tom Boyd

185

Quantifying network heterogeneity  

NASA Astrophysics Data System (ADS)

Despite degree distributions give some insights about how heterogeneous a network is, they fail in giving a unique quantitative characterization of network heterogeneity. This is particularly the case when several different distributions fit for the same network, when the number of data points is very scarce due to network size, or when we have to compare two networks with completely different degree distributions. Here we propose a unique characterization of network heterogeneity based on the difference of functions of node degrees for all pairs of linked nodes. We show that this heterogeneity index can be expressed as a quadratic form of the Laplacian matrix of the network, which allows a spectral representation of network heterogeneity. We give bounds for this index, which is equal to zero for any regular network and equal to one only for star graphs. Using it we study random networks showing that those generated by the Erdös-Rényi algorithm have zero heterogeneity, and those generated by the preferential attachment method of Barabási and Albert display only 11% of the heterogeneity of a star graph. We finally study 52 real-world networks and we found that they display a large variety of heterogeneities. We also show that a classification system based on degree distributions does not reflect the heterogeneity properties of real-world networks.

Estrada, Ernesto

2010-12-01

186

Quantifying network heterogeneity.  

PubMed

Despite degree distributions give some insights about how heterogeneous a network is, they fail in giving a unique quantitative characterization of network heterogeneity. This is particularly the case when several different distributions fit for the same network, when the number of data points is very scarce due to network size, or when we have to compare two networks with completely different degree distributions. Here we propose a unique characterization of network heterogeneity based on the difference of functions of node degrees for all pairs of linked nodes. We show that this heterogeneity index can be expressed as a quadratic form of the Laplacian matrix of the network, which allows a spectral representation of network heterogeneity. We give bounds for this index, which is equal to zero for any regular network and equal to one only for star graphs. Using it we study random networks showing that those generated by the Erdös-Rényi algorithm have zero heterogeneity, and those generated by the preferential attachment method of Barabási and Albert display only 11% of the heterogeneity of a star graph. We finally study 52 real-world networks and we found that they display a large variety of heterogeneities. We also show that a classification system based on degree distributions does not reflect the heterogeneity properties of real-world networks. PMID:21230700

Estrada, Ernesto

2010-12-02

187

Twitter: Network properties analysis  

Microsoft Academic Search

Online Social Networks have had a fast growing since the popularization of Web 2.0. This kind of networks provides the basis to find and maintain social relationships with users having diverse interests as well as a current picture of things happening around them. The analysis of the graph structure is necessary to understand the impact of online social networks among

Abraham Ronel Martínez Teutle

2010-01-01

188

Inequalities in network structures  

Microsoft Academic Search

We use a model of continuous attachments in networks to generate propositions concerning inequalities in network structures, and test the propositions on data from organizational settings. Our network model, inspired by that of [Gould, Roger 2002. The origins of status hierarchies: A formal theory and empirical test. American Journal of Sociology107, 1143–1178], is based on a theoretically informed actor model,

Joseph M. Whitmeyer; Rafael Wittek

2010-01-01

189

Networks in molecular evolution  

Microsoft Academic Search

Networks are a common theme at all levels of molecular evolution: Networks of metastable states and their connecting saddle points determine structure and folding kinetics of biopoly- mers. Neutral networks in sequence space explain the evolvability of both nucleic acids and polypeptides by linking Darwinian selection with neutral drift. Interacting replicators, be they simple molecules or highly complex mammals, form

Peter Schuster; Peter F. Stadler

2002-01-01

190

Secure personal network  

Microsoft Academic Search

Recently, Personal Networks (PNs) have been focused in supporting the user's business and private activities without jeopardizing privacy and security of the users and their data. The support in business and private activities will take place through the user's own personal network consisting of a core Personal Area Network (PAN) extended with clusters of remote devices which could be private,

Puri N. Anggraeni; Neeli R. Prasad; R. Prasad

2008-01-01

191

Detecting a Network Failure  

Microsoft Academic Search

Measuring the properties of a large, unstructured network can be diffi- cult: One may not have full knowledge of the network topology, and detailed global measurements may be infeasible. A valuable approach to such problems is to take mea- surements from selected locations within the network and then aggregate them to infer large-scale properties. One sees this notion applied in

Jon M. Kleinberg

2000-01-01

192

Local Feedback Multilayered Networks  

Microsoft Academic Search

In this paper, we investigate the capabilities of local feedback multilayered networks, a particular class of recurrent networks, in which feedback connections are only allowed from neurons to themselves. In this class, learning can be accomplished by an algorithm that is local in both space and time. We describe the limits and properties of these networks and give some insights

Paolo Frasconi; Marco Gori; Giovanni Soda

1992-01-01

193

Knitted Complex Networks  

Microsoft Academic Search

To a considerable extent, the continuing importance and popularity of complex networks as models of real-world structures has been motivated by scale free degree distributions as well as the respectively implied hubs. Being related to sequential connections of edges in networks, paths represent another important, dual pattern of connectivity (or motif) in complex networks (e.g., paths are related to important

Luciano da Fontoura Costa

2007-01-01

194

Multimedia Networks: Mission Impossible?  

ERIC Educational Resources Information Center

Running multimedia on a network, often difficult because of the memory and processing power required, is becoming easier thanks to new protocols and products. Those developing network design criteria may wish to consider making use of Fast Ethernet, Asynchronous Transfer Method (ATM), switches, "fat pipes", additional network segmentation, and…

Weiss, Andrew M.

1996-01-01

195

Calibrating Distributed Camera Networks  

Microsoft Academic Search

Recent developments in wireless sensor networks have made feasible distributed camera networks, in which cameras and processing nodes may be spread over a wide geographical area, with no centralized processor and limited ability to communicate a large amount of information over long distances. This paper overviews distributed algorithms for the calibration of such camera networks- that is, the automatic estimation

Dhanya Devarajan; Zhaolin Cheng; Richard J. Radke

2008-01-01

196

Public Goods in Networks  

Microsoft Academic Search

Abstract This paper considers incentives to provide goods that are non-excludable along social or geographic links. We find, first, that networks can lead to specialization in public good provision. In every social network there is an equilibrium where some individuals contribute and others free ride. In many networks, this extreme is the only outcome. Second, specialization can benefit society as

Yann Bramoullé; Rachel Kranton

2006-01-01

197

Cognitive Packet Networks  

Microsoft Academic Search

We propose cognitive packet networks (CPN) in which intelligent capabilities for routing and flow control are concentrated in the packets, rather than in the nodes and protocols. Cognitive packets within a CPN route themselves. They are assigned goals before entering the network and pursue these goals adaptively. Cognitive packets learn from their own observations about the network and from the

Erol Gelenbe; Zhiguang Xu; Esin Seref

1999-01-01

198

Technology and Network Participation.  

ERIC Educational Resources Information Center

|Discussion of school library media center automation resulting from network participation provides a brief overview of the literature that mentions automation in conjunction with networks and a review of several model programs in Indiana, New York, and Ohio. Network participation in OCLC is noted. Twenty-three references are included. (EJS)|

Immroth, Barbara

1984-01-01

199

Future Optical Networks  

Microsoft Academic Search

This paper presents views on the future of optical networking. A historical look at the emergence of optical networking is first taken, followed by a discussion on the drivers pushing for a new and pervasive network, which is based on photonics and can satisfy the needs of a broadening base of residential, business, and scientific users. Regional plans and targets

Michael J. O'Mahony; Christina Politi; Dimitrios Klonidis; Reza Nejabati; Dimitra Simeonidou

2006-01-01

200

The NSFNET backbone network  

Microsoft Academic Search

The NSFNET Backbone Network interconnects six supercomputer sites, several regional networks and ARPANET. It supports the DARPA Internet protocol suite and DCN subnet protocols, which provide delay-based routing and very accurate time-synchronization services. This paper describes the design and implementation of this network, with special emphasis on robustness issues and congestion-control mechanisms.

David L. Mills; Hans-Werner Braun

1987-01-01

201

Designing complex networks  

Microsoft Academic Search

We suggest a new perspective of research towards understanding the relations between the structure and dynamics of a complex network: can we design a network, e.g. by modifying the features of its units or interactions, such that it exhibits a desired dynamics? Here we present a case study where we positively answer this question analytically for networks of spiking neural

Raoul-Martin Memmesheimer; Marc Timme

202

Social network visualization in epidemiology  

Microsoft Academic Search

Epidemiological investigations and interventions are increasingly focusing on social networks. Two aspects of social networks are relevant in this regard: the structure of networks and the function of networks. A better understanding of the processes that determine how networks form and how they operate with respect to the spread of behavior holds promise for improving public health. Visualizing social networks

Nicholas A. Christakis; James H. Fowler

2009-01-01

203

Overview of Networks and Control  

Microsoft Academic Search

This paper presents an overview of networks and control in two directions: control of communication networks (CCN) which is studied to improve QoS of networks using control techniques; and networked control systems (NCS) which enhance the control systems capability using the network communications. In the CCN, the focus is on the wireless networks while in the NCS the focus is

Hongnian Yu; Chris Harding; M Shahidul Hasan; T. C. Yang

2005-01-01

204

The Age of Analog Networks  

Microsoft Academic Search

A large class of systems of biological and technological relevance can be described as analog networks, that is, col- lections of dynamic devices interconnected by links of varying strength. Some exam- ples of analog networks are genetic regula- tory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typ- ically complex systems that include non-

Claudio Mattiussi; Daniel Marbach; Peter Dürr; Dario Floreano

2008-01-01

205

Packet transport network in metro  

NASA Astrophysics Data System (ADS)

IP packet based services such as high speed internet, IP voice and IP video will be widely deployed in telecom network, which make transport network evolution to packet transport network. Characteristics of transport network and requirements of packet transport network are analyzed, T-MPLS/MPLS-TP based PTN technology is given and it will be used in metro (access, aggregation and core) network.

Huang, Feng; Yi, Xiaobo; Zhang, Hanzheng; Gong, Ping

2008-11-01

206

Topological generalizations of network motifs  

Microsoft Academic Search

Biological and technological networks contain patterns, termed network motifs, which occur far more often than in randomized networks. Network motifs were suggested to be elementary building blocks that carry out key functions in the network. It is of interest to understand how network motifs combine to form larger structures. To address this, we present a systematic approach to define ``motif

N. Kashtan; S. Itzkovitz; R. Milo; U. Alon

2004-01-01

207

Network Characterization Service (NCS)  

SciTech Connect

Distributed applications require information to effectively utilize the network. Some of the information they require is the current and maximum bandwidth, current and minimum latency, bottlenecks, burst frequency, and congestion extent. This type of information allows applications to determine parameters like optimal TCP buffer size. In this paper, we present a cooperative information-gathering tool called the network characterization service (NCS). NCS runs in user space and is used to acquire network information. Its protocol is designed for scalable and distributed deployment, similar to DNS. Its algorithms provide efficient, speedy and accurate detection of bottlenecks, especially dynamic bottlenecks. On current and future networks, dynamic bottlenecks do and will affect network performance dramatically.

Jin, Guojun; Yang, George; Crowley, Brian; Agarwal, Deborah

2001-06-06

208

Network topology analysis.  

SciTech Connect

Emerging high-bandwidth, low-latency network technology has made network-based architectures both feasible and potentially desirable for use in satellite payload architectures. The selection of network topology is a critical component when developing these multi-node or multi-point architectures. This study examines network topologies and their effect on overall network performance. Numerous topologies were reviewed against a number of performance, reliability, and cost metrics. This document identifies a handful of good network topologies for satellite applications and the metrics used to justify them as such. Since often multiple topologies will meet the requirements of the satellite payload architecture under development, the choice of network topology is not easy, and in the end the choice of topology is influenced by both the design characteristics and requirements of the overall system and the experience of the developer.

Kalb, Jeffrey L.; Lee, David S.

2008-01-01

209

Localizations on complex networks.  

PubMed

We study the structural characteristics of complex networks using the representative eigenvectors of the adjacent matrix. The probability distribution function of the components of the representative eigenvectors are proposed to describe the localization on networks where the Euclidean distance is invalid. Several quantities are used to describe the localization properties of the representative states, such as the participation ratio, the structural entropy, and the probability distribution function of the nearest neighbor level spacings for spectra of complex networks. Whole-cell networks in the real world and the Watts-Strogatz small-world and Barabasi-Albert scale-free networks are considered. The networks have nontrivial localization properties due to the nontrivial topological structures. It is found that the ascending-order-ranked series of the occurrence probabilities at the nodes behave generally multifractally. This characteristic can be used as a structural measure of complex networks. PMID:18643342

Zhu, Guimei; Yang, Huijie; Yin, Chuanyang; Li, Baowen

2008-06-23

210

High-performance networking.  

SciTech Connect

Our research in high-performance networking addresses the communication needs of Grand Challenge applications over a wide range of environments - wide-area network (WAN) in support of grids and local-area network (LAN) and system-area network (SAN) in support of network of workstations and clusters. While the high-performance computing (HPC) community generally groups clusters and grids together as commodity supercomputing infrastructures, the networking aspects of clusters and grids are fundamentally different. In networks of workstations and clusters, the primary communication bottleneck is the host-interface bottleneck whereas in grids, the bottlenecks are adaptation bottlenecks in particular, flow control and congestion control. To address these problems, we offer a set of solutions specifically tailored to each of the aforementioned environments.

Feng, W. C. (Wu-Chun)

2001-01-01

211

Telekom Malaysia Network Feasibility Study: Network Management.  

National Technical Information Service (NTIS)

The document is the second volume of a four volume final report submitted to Malaysia Telekom. The final report documents a Network Feasibility Study conducted for Malaysia Telekom. The volume discusses the functional and organizational requirements for n...

1991-01-01

212

Optical Access Networks  

NASA Astrophysics Data System (ADS)

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Zheng, Jun; Ansari, Nirwan

2005-06-01

213

Optical Access Networks  

NASA Astrophysics Data System (ADS)

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Zheng, Jun; Ansari, Nirwan

2005-05-01

214

Optical Access Networks  

NASA Astrophysics Data System (ADS)

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Zheng, Jun; Ansari, Nirwan; Jersey Inst Ansari, New; Jersey Inst, New

2005-04-01

215

A network security monitor  

SciTech Connect

The study of security in computer networks is a rapidly growing area of interest because of the proliferation of networks and the paucity of security measures in most current networks. Since most networks consist of a collection of inter-connected local area networks (LANs), this paper concentrates on the security-related issues in a single broadcast LAN such as Ethernet. Specifically, we formalize various possible network attacks and outline methods of detecting them. Our basic strategy is to develop profiles of usage of network resources and then compare current usage patterns with the historical profile to determine possible security violations. Thus, our work is similar to the host-based intrusion-detection systems such as SRI's IDES. Different from such systems, however, is our use of a hierarchical model to refine the focus of the intrusion-detection mechanism. We also report on the development of our experimental LAN monitor currently under implementation. Several network attacks have been simulated and results on how the monitor has been able to detect these attacks are also analyzed. Initial results demonstrate that many network attacks are detectable with our monitor, although it can surely be defeated. Current work is focusing on the integration of network monitoring with host-based techniques. 20 refs., 2 figs.

Heberlein, L.T.; Dias, G.V.; Levitt, K.N.; Mukherjee, B.; Wood, J.; Wolber, D. (California Univ., Davis, CA (USA). Dept. of Electrical Engineering and Computer Science)

1989-11-01

216

Collaborative learning in networks  

PubMed Central

Complex problems in science, business, and engineering typically require some tradeoff between exploitation of known solutions and exploration for novel ones, where, in many cases, information about known solutions can also disseminate among individual problem solvers through formal or informal networks. Prior research on complex problem solving by collectives has found the counterintuitive result that inefficient networks, meaning networks that disseminate information relatively slowly, can perform better than efficient networks for problems that require extended exploration. In this paper, we report on a series of 256 Web-based experiments in which groups of 16 individuals collectively solved a complex problem and shared information through different communication networks. As expected, we found that collective exploration improved average success over independent exploration because good solutions could diffuse through the network. In contrast to prior work, however, we found that efficient networks outperformed inefficient networks, even in a problem space with qualitative properties thought to favor inefficient networks. We explain this result in terms of individual-level explore-exploit decisions, which we find were influenced by the network structure as well as by strategic considerations and the relative payoff between maxima. We conclude by discussing implications for real-world problem solving and possible extensions.

Mason, Winter; Watts, Duncan J.

2012-01-01

217

In-Network Monitoring  

NASA Astrophysics Data System (ADS)

Monitoring, i.e., the process of acquiring state information from a network or networked system, is fundamental to system operation. In traditional network and systems management, monitoring is performed on a per-device basis, whereby a centralized management entity polls the devices in its domain for information, which is then analyzed and acted upon. In this chapter, we describe several monitoring algorithms that utilize a new monitoring paradigm called In-network Monitoring. This paradigm is designed to address the above shortcomings, and we demonstrate how it can be applied to managing highly dynamic networked systems. The main idea of In-network Monitoring is to introduce a small management entity inside each network device, which, in addition to monitoring local parameters, can also perform limited management functions and communicate with peering entities in its proximity. The collection of these entities creates a monitoring layer inside the network, which can perform monitoring and control tasks without involving the centralized entity. We demonstrate how In-network monitoring can help building better and more efficient systems. We start with a general description of network monitoring techniques, and then describe two specific cases in which this paradigm generates provably efficient solutions. The first one is in the area of traffic engineering, where there is a need to monitor the aggregated delay of packets along a given network path. The second case deals with the problem of monitoring general aggregated values over the network, with emphasis on computing the values in a distributed way inside the monitoring layer. All together, we believe that this new paradigm presents a promising direction to address the challenges of cost-effective management of future networked systems.

Raz, Danny; Stadler, Rolf; Elster, Constantine; Dam, Mads

218

Wide area networks for teleradiology  

Microsoft Academic Search

Teleradiology networks transmit digital radiographic images from one location to another. These networks are wide area networks.\\u000a Teleradiology networks are used for diagnostic purposes and preview tasks. Wide area networks for teleradiology use public\\u000a service switching. The use of fiber optics networks provide reduced costs and increased flexibility. An example is presented\\u000a that compares the cost of teleradiology networks.

Kirkman G. Baxter; Louis H. Wetzel; Mark D. Murphey; Stanton J. Rosenthal; John E. Haines; Solomon Batnitzky; Joseph F. Caresio; Arch W. Templeton; Samuel J. Dwyer

1991-01-01

219

Integrated Mobile Network Systems for Ubiquitous Network Connectivity  

Microsoft Academic Search

With the advent of various mobile devices with diverse communication capabilities, the interoperability between these networks becomes imperative in order to pro- vide ubiquitous network connectivity with the highest throughput in mobile environments. We focus on the in- teroperability experiments between WiFi computer net- works and Cingular GSM\\/GPRS networks by utilizing these two networks as the transit networks between mo-

Michael Golightly; Lichun Bao

220

Access network architectural issues for future telecommunication networks  

Microsoft Academic Search

This article discusses the evolution of access networks to support future multimedia services, with emphasis on the role of Working Party 3 of ITU-T Study Group 13. An overview of the access network is given, and the interfaces between the access network and other portions of the telecommunications network such as the user-network interface (UNI), service node interface (SNI), and

K. Asatani; Y. Maeda

1998-01-01

221

Fast Network Component Analysis for Gene Regulation Networks  

Microsoft Academic Search

New advancement in microarray technologies has made it possible to reconstruct gene regulation networks from mass gene expression data measured by microarray. Typically, gene regulation networks are sparse networks. This sparse topology knowledge can be exploited to develop algorithms for network reconstruction. In this direction, a method called network component analysis (NCA) has been developed recently. A major disadvantage of

Chunqi Chang; Zhi Ding; Yeung Sam Hung; P. C. W. Fung

2007-01-01

222

Green networks: Energy efficient design for optical networks  

Microsoft Academic Search

In this paper we discuss new energy efficient paradigms for optical networks. With the increasing number of high bandwidth applications, devices used in backbone networks such as optical networks increase. Energy consumption of optical networks is an important issue that has to be addressed. In this work we propose novel routing algorithms for decreasing the energy consumption of optical networks.

Balagangadhar G. Bathula; Jaafar M. H. Elmirghani

2009-01-01

223

Social network analysis of an online dating network  

Microsoft Academic Search

Online social networks can be found everywhere from chatting websites like MSN, blogs such as MySpace to social media such as YouTube and second life. Among them, there is one interesting type of online social networks, online dating network that is growing fast. This paper analyzes an online dating network from social network analysis point of view. Observations are made

Lin Chen; Richi Nayak

2011-01-01

224

Visualizing Evolving Networks: Minimum Spanning Trees versus Pathfinder Networks  

Microsoft Academic Search

Network evolution is a ubiquitous phenomenon in a wide variety of complex systems. In fields such as statistical mechanics, there has been increasingly widespread interest in modeling the growth of complex networks. In this article, we compare two network visualization techniques, minimum spanning trees (MSTs) and Pathfinder networks (PFNETs), and their visualizations of co - citation networks of scientific publications.

Chaomei Chen; Steven Morris

2003-01-01

225

Why social networks are different from other types of networks  

Microsoft Academic Search

We argue that social networks differ from most other types of networks, including technological and biological networks, in two important ways. First, they have nontrivial clustering or network transitivity and second, they show positive correlations, also called assortative mixing, between the degrees of adjacent vertices. Social networks are often divided into groups or communities, and it has recently been suggested

M. E. Newman

2003-01-01

226

The Impact of Active Networks on Established Network Operators  

Microsoft Academic Search

A collaborative case based study has established that Active Networks will have a very significant impact on Network operators. Active Networking appears to be the only route to adding integrated mobility, security, QoS and management services to existing networks. In the short to medium term operators will be keen to use Application Layer Active Networking since the risks are relatively

Arto Juhola; Ian Marshall; Stefan Covaci; Thomas Velte; Mike Donohoe; Seppo Parkkila

1999-01-01

227

Toward secure network coding in wireless networks: Threats and challenges  

Microsoft Academic Search

In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network coding in wireless networks. Although the theoretical foundations of network coding are well understood, a real-world system needs to

Jing Dong; Reza Curtmola; Ruben Sethi; Cristina Nita-Rotaru

2008-01-01

228

Immunization of complex networks  

NASA Astrophysics Data System (ADS)

Complex networks such as the sexual partnership web or the Internet often show a high degree of redundancy and heterogeneity in their connectivity properties. This peculiar connectivity provides an ideal environment for the spreading of infective agents. Here we show that the random uniform immunization of individuals does not lead to the eradication of infections in all complex networks. Namely, networks with scale-free properties do not acquire global immunity from major epidemic outbreaks even in the presence of unrealistically high densities of randomly immunized individuals. The absence of any critical immunization threshold is due to the unbounded connectivity fluctuations of scale-free networks. Successful immunization strategies can be developed only by taking into account the inhomogeneous connectivity properties of scale-free networks. In particular, targeted immunization schemes, based on the nodes' connectivity hierarchy, sharply lower the network's vulnerability to epidemic attacks.

Pastor-Satorras, Romualdo; Vespignani, Alessandro

2002-03-01

229

Reconstructing Regulatory Network Transitions  

PubMed Central

Cellular responses often involve a transition of cells from one state to another. A transition from a stem cell to differentiated cell state, for example, may occur in response to gene expression changes induced by a transcription factor, or signaling cascades triggered by a hormone or pathogen. Regulatory networks are thought to control such cellular transitions. Thus, many researchers are interested in reconstructing regulatory networks, not only to gain a deeper understanding of cellular transitions, but also with the aim of using networks to predict and potentially manipulate cellular transitions and outcomes. In this review, we highlight approaches to the reconstruction of regulatory networks underlying cellular transitions, with special attention to transcriptional regulatory networks. We describe recent regulatory network reconstructions in a variety of organisms and discuss the success they share in identifying new regulatory components as well as shared relationships and phenotypic outcomes.

Petricka, Jalean J.; Benfey, Philip N.

2011-01-01

230

Tomography using neural networks  

SciTech Connect

We have utilized neural networks for fast evaluation of tomographic data on the MT-1M tokamak. The networks have proven useful in providing the parameters of a nonlinear fit to experimental data, producing results in a fraction of the time required for performing the nonlinear fit. Time required for training the networks makes the method worth applying only if a substantial amount of data are to be evaluated. {copyright} {ital 1997 American Institute of Physics.}

Demeter, G. [Department of Plasma Physics, Research Institute for Particle Nuclear Physics of the Hungarian Academy of Sciences, XII. Konkoly Thege Miklos ut 29-33, H-1525 Budapest, P.O. Box 49 (Hungary)

1997-03-01

231

Solving Playground Network Problems  

NSDL National Science Digital Library

In this activity, learners use cooperation and logical thinking to find solutions to network problems on the playground. Learners act both as computer routers, figuring out with each other how to effectively get data to the place it's being sent, and as the actual data, because the learners travel various edges of a network to get to their destination or "home" point. Learners use geometry skills to determine the most efficient routes in the network.

Exploratorium

2010-01-01

232

The INGV tectonomagnetic network  

Microsoft Academic Search

The Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV) tectonomagnetic network was installed in Central Italy since the middle of 1989 to investigate possible magnetic anomalies related to earthquakes. The network is part of the INGV L'Aquila Geomagnetic Observatory and is located in an area extending approximately in latitude range [41.6°-42.8°] N and longitude range [13.0°-14.3°] E. Actually the network

F. Masci; P. Palangio; M. di Persio

2008-01-01

233

Processes on Complex Networks  

NSDL National Science Digital Library

Building on their understanding of graphs, students are introduced to random processes on networks. They walk through an illustrative example to see how a random process can be used to represent the spread of an infectious disease, such as the flu, on a social network of students. This demonstrates how scientists and engineers use mathematics to model and simulate random processes on complex networks. Topics covered include random processes and modeling disease spread, specifically the SIR (susceptible, infectious, resistant) model.

Complex Systems Science Laboratory

234

Physics and technology networks  

NASA Astrophysics Data System (ADS)

Consider a simple network which has physics and technology at its nodes, with parallel connecting branches representing education and technological industry. We describe briefly the historical development of the network, and three new features of it that should be encouraged: (A) small new, science-technology-based enterprises, (B) new connections between the schools and industry, particularly at the secondary level, and (C) recognition of the electronic and print media as major elements of the network.

Granberg, Lawrence

1988-10-01

235

Social networks: looking ahead  

Microsoft Academic Search

By now, online social networks have become an indispensable part of both online and offline lives of human beings. A large fraction of time spent online by a user is directly influence by the social networks to which he\\/she belongs. This calls for a deeper examination of social networks as large-scale dynamic objects that foster efficient person-person interaction. The goal

Ravi Kumar; Alexander Tuzhilin; Christos Faloutsos; David Jensen; Gueorgi Kossinets; Jure Leskovec; Andrew Tomkins

2008-01-01

236

Optoelectronic spiking neural network  

NASA Astrophysics Data System (ADS)

Proposed by the authors compact optoelectronic implementation of a spiking neural network uses a matrix of semiconductor lasers. Also proposed the implementation of neural element on bispin-device, which is able to manage bya range of lasers in the array. Described the principles of the network in the training and operation mode. To modify the connections weights during the training mode used the optically controlled transparant with memory. Network parameters evaluated achievable with current technological capabilities.

Kozemiako, V. P.; Kolesnytskyj, O. K.; Lischenko, T. S.; Wojcik, W.; Sulemenov, A.

2013-01-01

237

Concatenated tensor network states  

Microsoft Academic Search

We introduce the concept of concatenated tensor networks to efficiently describe quantum states. We show that the corresponding concatenated tensor network states can efficiently describe time evolution and possess arbitrary block-wise entanglement and long-ranged correlations. We illustrate the approach for the enhancement of matrix product states, i.e. one-dimensional (1D) tensor networks, where we replace each of the matrices of the

R. Hübener; V. Nebendahl; W. Dür

2010-01-01

238

The Social Network Classroom  

Microsoft Academic Search

\\u000a Online social networking is an important part in the everyday life of college students. Despite the increasing popularity\\u000a of online social networking among students and faculty members, its educational benefits are largely untested. This paper\\u000a presents our experience in using social networking applications and video content distribution websites as a complement of\\u000a traditional classroom education. In particular, the solution has

Peter Bunus

2010-01-01

239

Autonomous Mobile Networks  

Microsoft Academic Search

Summary form only given, as follows. Autonomous mobile networks are distributed ad-hoc networks of nodes that can sense, actuate, compute and communicate with each other using point-to-point multi-hop communication. The nodes in such networks include static sensors, mobile sensors, robots, and humans. Such systems combine the most advanced concepts in perception, communication and control to create computational systems capable of

Daniela Rus

2004-01-01

240

Towards Semantic Social Networks  

Microsoft Academic Search

Computer manipulated social networks are usually built from the explicit assertion by users that they have some relation with\\u000a other users or by the implicit evidence of such relations (e.g., co-authoring). However, since the goal of social network\\u000a analysis is to help users to take advantage of these networks, it would be convenient to take more information into account.\\u000a We

Jason J. Jung; Jérôme Euzenat

2007-01-01

241

Social Network Analysis  

Microsoft Academic Search

{Excerpt} Power no longer resides exclusively (if at all) in states, institutions, or large corporations. It is located in the networks that structure society. Social network analysis seeks to understand networks and their participants and has two main focuses: the actors and the relationships between them in a specific social context.\\u000aThe information revolution has given birth to new economies

Olivier Serrat

2009-01-01

242

An algebraic approach to network coding  

Microsoft Academic Search

We take a new look at the issue of network capacity. It is shown that network coding is an essential ingredient in achieving the capacity of a network. Building on recent work by Li et al., who examined the network capacity of multicast networks, we extend the network coding framework to arbitrary networks and robust networking. For networks which are

Ralf Koetter; Muriel Médard

2003-01-01

243

Directed network modules  

NASA Astrophysics Data System (ADS)

A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos Rényi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs.

Palla, Gergely; Farkas, Illés J.; Pollner, Péter; Derényi, Imre; Vicsek, Tamás

2007-06-01

244

Learn More About Networking  

NSDL National Science Digital Library

These are some interesting sites that will help you to understand networking and how it can benefit you. These sites contain sound so you may want to wear headphones if you are in a classroom. Learn how the internet began and the basics of the www. Learn why a network is useful. Jans network contains the important concepts of networking, Work through section 7 to learn about different types of connections, transmissions, media, and configurations. Then take the quiz at the end to see how ...

Watts, Mrs.

2007-10-12

245

Celestial data routing network  

NASA Astrophysics Data System (ADS)

Imagine that information processing human-machine network is threatened in a particular part of the world. Suppose that an anticipated threat of physical attacks could lead to disruption of telecommunications network management infrastructure and access capabilities for small geographically distributed groups engaged in collaborative operations. Suppose that small group of astronauts are exploring the solar planet and need to quickly configure orbital information network to support their collaborative work and local communications. The critical need in both scenarios would be a set of low-cost means of small team celestial networking. To the geographically distributed mobile collaborating groups such means would allow to maintain collaborative multipoint work, set up orbital local area network, and provide orbital intranet communications. This would be accomplished by dynamically assembling the network enabling infrastructure of the small satellite based router, satellite based Codec, and set of satellite based intelligent management agents. Cooperating single function pico satellites, acting as agents and personal switching devices together would represent self-organizing intelligent orbital network of cooperating mobile management nodes. Cooperative behavior of the pico satellite based agents would be achieved by comprising a small orbital artificial neural network capable of learning and restructing the networking resources in response to the anticipated threat.

Bordetsky, Alex

2000-11-01

246

Future Optical Networks  

NASA Astrophysics Data System (ADS)

This paper presents views on the future of optical networking. A historical look at the emergence of optical networking is first taken, followed by a discussion on the drivers pushing for a new and pervasive network, which is based on photonics and can satisfy the needs of a broadening base of residential, business, and scientific users. Regional plans and targets for optical networking are reviewed to understand which current approaches are judged important. Today, two thrusts are driving separate optical network infrastructure models, namely 1) the need by nations to provide a ubiquitous network infrastructure to support all the future services and telecommunication needs of residential and business users and 2) increasing demands by the scientific community for networks to support their requirements with respect to large-scale data transport and processing. This paper discusses these network models together with the key enabling technologies currently being considered for future implementation, including optical circuit, burst and packet switching, and optical code-division multiplexing. Critical subsystem functionalities are also reviewed. The discussion considers how these separate models might eventually merge to form a global optical network infrastructure.

O'Mahony, Michael J.; Politi, Christina; Klonidis, Dimitrios; Nejabati, Reza; Simeonidou, Dimitra

2006-12-01

247

Exploring complex networks  

NASA Astrophysics Data System (ADS)

The study of networks pervades all of science, from neurobiology to statistical physics. The most basic issues are structural: how does one characterize the wiring diagram of a food web or the Internet or the metabolic network of the bacterium Escherichia coli? Are there any unifying principles underlying their topology? From the perspective of nonlinear dynamics, we would also like to understand how an enormous network of interacting dynamical systems - be they neurons, power stations or lasers - will behave collectively, given their individual dynamics and coupling architecture. Researchers are only now beginning to unravel the structure and dynamics of complex networks.

Strogatz, Steven H.

2001-03-01

248

Composite Random Fiber Networks  

NASA Astrophysics Data System (ADS)

Systems made from fibers are common in the biological and engineering worlds. In many instances, as for example in skin, where elastin and collagen fibers are present, the fiber network is composite, in the sense that it contains fibers of very different properties. The relationship between microstructural parameters and the elastic moduli of random fiber networks containing a single type of fiber is understood. In this work we address a similar target for the composite networks. We show that linear superposition of the contributions to stiffness of individual sub-networks does not apply and interesting non-linear effects are observed. A physical basis of these effects is proposed.

Picu, Catalin; Shahsavari, Ali

2013-03-01

249

Network discovery with DCM  

PubMed Central

This paper is about inferring or discovering the functional architecture of distributed systems using Dynamic Causal Modelling (DCM). We describe a scheme that recovers the (dynamic) Bayesian dependency graph (connections in a network) using observed network activity. This network discovery uses Bayesian model selection to identify the sparsity structure (absence of edges or connections) in a graph that best explains observed time-series. The implicit adjacency matrix specifies the form of the network (e.g., cyclic or acyclic) and its graph-theoretical attributes (e.g., degree distribution). The scheme is illustrated using functional magnetic resonance imaging (fMRI) time series to discover functional brain networks. Crucially, it can be applied to experimentally evoked responses (activation studies) or endogenous activity in task-free (resting state) fMRI studies. Unlike conventional approaches to network discovery, DCM permits the analysis of directed and cyclic graphs. Furthermore, it eschews (implausible) Markovian assumptions about the serial independence of random fluctuations. The scheme furnishes a network description of distributed activity in the brain that is optimal in the sense of having the greatest conditional probability, relative to other networks. The networks are characterised in terms of their connectivity or adjacency matrices and conditional distributions over the directed (and reciprocal) effective connectivity between connected nodes or regions. We envisage that this approach will provide a useful complement to current analyses of functional connectivity for both activation and resting-state studies.

Friston, Karl J.; Li, Baojuan; Daunizeau, Jean; Stephan, Klaas E.

2011-01-01

250

Heterogeneous broadband network  

NASA Astrophysics Data System (ADS)

Although the vision for the future Integrated Broadband Communication Network (IBCN) is an all optical network, it is certain that for a long period to come, the network will remain very heterogeneous, with a mixture of different physical media (fiber, coax and twisted pair), transmission systems (PDH, SDH, ADSL) and transport protocols (TCP/IP, AAL/ATM, frame relay). In the current work towards the IBCN, the ATM concept is considered the generic network protocol for both public and private network, with the ability to use different underlying transmission protocols and, through adaptation protocols, provide the appropriate services (old as well as new) to the customer. One of the major difficulties of heterogeneous network is the restriction that is usually given by the lowest common denominator, e.g. in terms of single channel capacity. A possible way to overcome these limitations is by extending the ATM concept with a multilink capability, that allows us to use separate resources as one common. The improved flexibility obtained by this protocol extension further allows a real time optimization of network and call configuration, without any impact on the quality of service seen from the user. This paper describes an example of an ATM based multilink protocol that has been experimentally implemented within the RACE project 'STRATOSPHERIC'. The paper outlines the complexity of introducing an extra network functionality compared with the added value, such as an improved ability to recover an error due to a malfunctioning network component.

Dittmann, Lars

1995-11-01

251

Communicability in temporal networks  

NASA Astrophysics Data System (ADS)

A first-principles approach to quantify the communicability between pairs of nodes in temporal networks is proposed. It corresponds to the imaginary-time propagator of a quantum random walk in the temporal network, which accounts for unique structural and temporal characteristics of both streaming and nonstreaming temporal networks. The influence of the system's temperature on the perdurability of information and how the communicability identifies patterns of communication hidden in the temporal and topological structure of the networks are also studied for synthetic and real-world systems.

Estrada, Ernesto

2013-10-01

252

Scheduling of networked control systems  

Microsoft Academic Search

The defining characteristic of a networked control system (NCS) is having one or more control loops closed via a serial communication channel. Typically, when the words networking and control are used together, the focus is on the control of networks, but in this article our intent is nearly inverse, not control of networks but control through networks. NCS design objectives

G. C. Walsh; Hong Ye

2001-01-01

253

Internationalisation Network: A Finnish Experience  

ERIC Educational Resources Information Center

|One of the main issues of internationalisation is networking. The network way of action within higher education institutions (HEIs) represents new modes of the information work. Networks are worth evaluating more precisely in the future, and social network analysis (SNA) is a useful tool for this evaluation. This article describes the network of…

Kantola, Mauri; Hautala, Jouni

2008-01-01

254

Privacy in dynamic social networks  

Microsoft Academic Search

Anonymization of social networks before they are published or shared has become an important research question. Recent work on anonymizing social networks has looked at privacy preserving techniques for publishing a single instance of the network. However, social networks evolve and a single instance is inadequate for analyzing the evolution of the social network or for performing any longitudinal data

Smriti Bhagat; Graham Cormode; Balachander Krishnamurthy; Divesh Srivastava

2010-01-01

255

Local Area Networks: Part II.  

ERIC Educational Resources Information Center

Discusses five approaches used by industry/colleges to provide local area network (LAN) capabilities in the analytical laboratory: (1) mixed baseband bus network coupled to a star net; (2) broadband bus network; (3) ring network; (4) star network coupled to broadband net; and (5) simple multiprocessor center. Part I (September issue) focused on…

Dessy, Raymond E., Ed.

1982-01-01

256

A survey of programmable networks  

Microsoft Academic Search

In this paper we present a programmable networking model that provides a common framework for understanding the state-of-the-art in programmable networks. A number of projects are reviewed and discussed against a set of programmable network characteristics. We believe that a number of important innovations are creating a paradigm shift in networking leading to higher levels of network programmability. These innovations

Andrew T. Campbell; Herman G. De Meer; Michael E. Kounavis; Kazuho Miki; John B. Vicente; Daniel A. Villela

1999-01-01

257

A transport network layer based on optical network elements  

Microsoft Academic Search

An approach to the realization of a broadband, flexible, multiwavelength transport network employing an optical network layer. The design methodology for a network demonstrator is presented, and the transmission, switching, line, and management\\/supervisory subsystems and components are described

G. R. Hill; P. J. Chidgey; Frank Kaufhold; Thomas Lynch; Olof Sahlen; Mattias Gustavsson; M. Janson; B. Lagerstrom; G. Grasso; F. Meli; Sonny Johansson; Joakim Ingers; Lars Fernandez; Salvatore Rotolo; Andrea Antonielli; Sergio Tebaldini; Emilio Vezzoni; R. Caddedu; N. Caponio; F. Testa; A. Scavennec; M. J. O'Mahony; J. Zhou; A. Yu; W. Sohler; U. Rust; H. Herrmann

1993-01-01

258

Better sales networks.  

PubMed

Anyone in sales will tell you that social networks are critical. The more contacts you have, the more leads you'll generate, and, ultimately, the more sales you'll make. But that's a vast oversimplification. Different configurations of networks produce different results, and the salesperson who develops a nuanced understanding of social networks will outshine competitors. The salesperson's job changes over the course of the selling process. Different abilities are required in each stage of the sale: identifying prospects, gaining buy-in from potential customers, creating solutions, and closing the deal. Success in the first stage, for instance, depends on the salesperson acquiring precise and timely information about opportunities from contacts in the marketplace. Closing the deal requires the salesperson to mobilize contacts from prior sales to act as references. Managers often view sales networks only in terms of direct contacts. But someone who knows lots of people doesn't necessarily have an effective network because networks often pay off most handsomely through indirect contacts. Moreover, the density of the connections in a network is important. Do a salesperson's contacts know all the same people, or are their associates widely dispersed? Sparse networks are better, for example, at generating unique information. Managers can use three levers--sales force structure, compensation, and skills development--to encourage salespeople to adopt a network-based view and make the best possible use of social webs. For example, the sales force can be restructured to decouple lead generation from other tasks because some people are very good at building diverse ties but not so good at maintaining other kinds of networks. Companies that take steps of this kind to help their sales teams build better networks will reap tremendous advantages. PMID:16846193

Ustüner, Tuba; Godes, David

259

Networked Innovation in Innovation Networks: A Home Appliances Case Study  

NASA Astrophysics Data System (ADS)

Amongst different types of Collaborative Networked Organizations it is possible to highlight those created to develop and market product, process or business model innovation. In this type of innovation network, which has special characteristics, the challenge is to introduce effective networked innovation in the very same innovation network. This paper presents the main features of TALAI-SAREA © methodology that includes a reference model, a set of analysis tools and a method for implementing networked innovation in innovation networks.

Berasategi, Luis; Arana, Joseba; Castellano, Eduardo

260

Network safety evaluation based on Pso-Rbf neural network  

NASA Astrophysics Data System (ADS)

In the study, RBF neural network optimized by particle swarm optimization algorithm is applied to evaluate network safety. In the RBF neural network, the choice of the three parameters including the center of RBF, the width of RBF and the weight have an important influence on the classification performance of RBF neural network. Particle swarm optimization algorithm is used to select the optimal combination of the parameters of the RBF neural network parameters. The experimental results show that the network evaluation model based on PSO-RBF neural network has better evaluation performance than RBF neural network.

Song, Hai-Sheng

2013-03-01

261

Survey of Network Visualization Tools.  

National Technical Information Service (NTIS)

As a first step in determining the way ahead for research and development of network visualisation techniques, a product and literature search of network visualisation technologies was conducted. The contractors developed a taxonomy of network visualisati...

A. Gort J. Gort

2007-01-01

262

On Generalized Feistel Networks  

Microsoft Academic Search

\\u000a We prove beyond-birthday-bound security for most of the well-known types of generalized Feistel networks: (1) unbalanced Feistel\\u000a networks, where the n-bit to m-bit round functions may have n ¹<\\/font\\u000a> mn\\\

Viet Tung Hoang; Phillip Rogaway

2010-01-01

263

GENE EXPRESSION NETWORKS  

EPA Science Inventory

"Gene expression network" is the term used to describe the interplay, simple or complex, between two or more gene products in performing a specific cellular function. Although the delineation of such networks is complicated by the existence of multiple and subtle types of intera...

264

Connecting the Networking Dots.  

ERIC Educational Resources Information Center

|Provides technical recommendations for wiring of college campuses to provide for current and future computer network needs, considering wiring in and between existing and new buildings. The effects of trends in networking costs are discussed. The importance of higher education's involvement and influence in various information technology issues…

Ricart, Glenn

1993-01-01

265

From network to artwork  

Microsoft Academic Search

In this paper a computer program for the construction of a schematic diagram (the artwork) from a net list (the network) is presented. The network-to-artwork generator is composed of a separate placement (Pablo) and a routing part (Eureka). For both parts algorithms, following guidelines traditionally used in manual drawing of schematic diagrams, are used. Several examples are shown and some

L. Stok; G. P. Koster

1989-01-01

266

From Network to Artwork  

Microsoft Academic Search

In this paper a computer program for the construction of a schematic diagram (the artwork) from a net list (the network) is presented. The network-to-artwork generator is composed of a separate placement (Pablo) and a routing part (Eureka). For both parts algorithms, following guidelines traditionally used in manual drawing of schematic diagrams, are used. Several examples are shown and some

L. Stok; G. J. P. Koster

1989-01-01

267

Academe's New Girl Network  

ERIC Educational Resources Information Center

|A "networking" processing pioneered by the Committee for the Concerns of Women in New England Colleges and Universities, which is establishing a New Girl network to compete with and eventually mesh with the Old Boy system, is described. Lobbying and conference efforts of HERS (Higher Education Resource Services) are reported. (LBH)|

Stent, Angela

1978-01-01

268

Networking for marketing advantage  

Microsoft Academic Search

States that networking theories have attracted increasing attention during the 1990s – although the network concept is certainly not new. Looks at the computer industry in Silicone Valley, California and the textile industry in Prato, central Italy. Discusses co-operative behaviour and the relative advantages derived from such arrangements. Examines the slate industry in North Wales and, specifically, the decision by

Cheryl Dennis

2000-01-01

269

Arkansas Cancer Community Network  

Cancer.gov

The Arkansas Cancer Community Network (AR-CCN) at the University of Arkansas for Medical Sciences1 seeks to build upon the accomplishments of the Arkansas Special Populations Access Network (ASPAN) for the continued development and implementation of community-based participatory research and training programs.

270

Intelligent social networks  

Microsoft Academic Search

Personal homepages, blogs or virtual communities have contributed to the birth of the Social Networks. The success of these platforms will continue to increase while they are able to offer tools and services to improve users' social relationships. The rapid evolution of social networks, the growing business opportunities and the possibility to apply new techniques to a relatively unexplored domain,

Miguel; Angel Moreno; Pablo Muñoz; Daniel Díaz; María Dolores Rodríguez-Moreno

2011-01-01

271

Variant Bayesian Networks  

Microsoft Academic Search

The Bayesian networks can express the joint probabilistic distribution compactly between variables and can express the conditionally independence conveniently. The joint probabilistic influence from the parents to their child can be got from the Bayesian network structure however parents are not necessarily have common influence to their child, which are called by the name of causal influence independence other than

Peng Qingsong; Zhang Ming; Wu Weimin; Wang Ronggui

2006-01-01

272

Network vulnerability analysis  

Microsoft Academic Search

The increasing volume of attacks on the Internet has increased the demand for sophisticated tools for vulnerability analysis, intrusion detection, forensic investigations, and possible responses. Current hacker tools and technologies warrant reengineering to address cyber crime and homeland security. The creation of network scanners is necessary to secure the information infrastructure by gathering network topology, intelligence, internal\\/external vulnerability analysis, and

B. Skaggs; B. Blackburn; G. Manes; S. Shenoi

2002-01-01

273

Network Difficulties: Stand By.  

ERIC Educational Resources Information Center

This document traces the development of Federal Communications Commission (FCC) network regulations from their beginning in 1941 with the "Report on Chain Broadcasting." The eight rules defined by the report were aimed at correcting network abuses and were intended to maintain community broadcasting in the public interest. The document discusses…

Oborn, Richard L.

274

Hanford Seismic Network  

SciTech Connect

This report describes the Hanford Seismic Network. The network consists of two instrument arrays: seismometers and strong motion accelerometers. The seismometers determine the location and magnitude of earthquakes, and the strong motion accelerometers determine ground motion. Together these instruments arrays comply with the intent of DOE Order 5480.20, Natural Phenomena Hazards Mitigation.

Reidel, S.P.; Hartshorn, D.C.

1997-05-01

275

PESTICIDE INFORMATION NETWORK  

EPA Science Inventory

The Pesticide Information Network (PIN) is an interactive database containing information about pesticides. PIN is a free service offered by the USEPAs Office of Pesticide Programs which provides contacts on pesticide issues, has a bulletin board network for public and private us...

276

On Heterogeneous Covert Networks  

NASA Astrophysics Data System (ADS)

Covert organizations are constantly faced with a tradeoff between secrecy and operational efficiency. Lindelauf, Borm and Hamers [13] developed a theoretical framework to determine optimal homogeneous networks taking the above mentioned considerations explicitly into account. In this paper this framework is put to the test by applying it to the 2002 Jemaah Islamiyah Bali bombing. It is found that most aspects of this covert network can be explained by the theoretical framework. Some interactions however provide a higher risk to the network than others. The theoretical framework on covert networks is extended to accommodate for such heterogeneous interactions. Given a network structure the optimal location of one risky interaction is established. It is shown that the pair of individuals in the organization that should conduct the interaction that presents the highest risk to the organization, is the pair that is the least connected to the remainder of the network. Furthermore, optimal networks given a single risky interaction are approximated and compared. When choosing among a path, star and ring graph it is found that for low order graphs the path graph is best. When increasing the order of graphs under consideration a transition occurs such that the star graph becomes best. It is found that the higher the risk a single interaction presents to the covert network the later this transition from path to star graph occurs.

Lindelauf, Roy; Borm, Peter; Hamers, Herbert

277

Random Catalytic Reaction Networks  

Microsoft Academic Search

We study networks that are a generalization of replicator (or Lotka-Volterra)equations. They model the dynamics of a population of object types whosebinary interactions determine the specific type of interaction product. We showthat the system always reduces its dimension to a subset that contains productionpathways for all of its members. The network equation can be rewritten at a levelof collectives in

Peter F. Stadler; Walter Fontana; John H. Miller

1993-01-01

278

Broadband network selection issues  

Microsoft Academic Search

Selecting the best network for a given cable or telephone company provider is not as obvious as it appears. The cost and performance trades between Hybrid Fiber Coax (HFC), Fiber to the Curb (FTTC) and Asymmetric Digital Subscriber Line networks lead to very different choices based on the existing plant and the expected interactive subscriber usage model. This paper presents

Michael E. Leimer

1996-01-01

279

A Balanced Memory Network  

Microsoft Academic Search

A fundamental problem in neuroscience is understanding how working memory -- the ability to store information at intermediate timescales, like 10s of seconds -- is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work,

Yasser Roudi; Peter E. Latham

2007-01-01

280

Typologies of attentional networks  

Microsoft Academic Search

Attention is a central theme in cognitive science — it exemplifies the links between the brain and behaviour, and binds psychology to the techniques of neuroscience. A visionary model suggested by Michael Posner described attention as a set of independent control networks. This challenged the previously held view of attention as a uniform concept. The idea that disparate attentional networks

Jason Buhle; Amir Raz

2006-01-01

281

Synchronization in interdependent networks  

NASA Astrophysics Data System (ADS)

We explore the synchronization behavior in interdependent systems, where the one-dimensional (1D) network (the intranetwork coupling strength JI) is ferromagnetically intercoupled (the strength J) to the Watts-Strogatz (WS) small-world network (the intranetwork coupling strength JII). In the absence of the internetwork coupling (J=0), the former network is well known not to exhibit the synchronized phase at any finite coupling strength, whereas the latter displays the mean-field transition. Through an analytic approach based on the mean-field approximation, it is found that for the weakly coupled 1D network (JI<<1) the increase of J suppresses synchrony, because the nonsynchronized 1D network becomes a heavier burden for the synchronization process of the WS network. As the coupling in the 1D network becomes stronger, it is revealed by the renormalization group (RG) argument that the synchronization is enhanced as JI is increased, implying that the more enhanced partial synchronization in the 1D network makes the burden lighter. Extensive numerical simulations confirm these expected behaviors, while exhibiting a reentrant behavior in the intermediate range of JI. The nonmonotonic change of the critical value of JII is also compared with the result from the numerical RG calculation.

Um, Jaegon; Minnhagen, Petter; Kim, Beom Jun

2011-06-01

282

Airline Network Rivalry  

Microsoft Academic Search

In this paper, the effects of the strategic interaction between deregulated airlines on their network choice are analyzed. The authors examine whether switching from a linear to a hub-spoke network confers a strategic advantage because it saves costs and improves service quality. They find that, if hubbing lowers total cost (which includes both airline and passenger inconvenience costs), the pursuit

Tae Hoon Oum; Anming Zhang; Yimin Zhang

1995-01-01

283

The Community Networking Handbook.  

ERIC Educational Resources Information Center

|This publication outlines the complete community networking process: planning, developing partnerships, funding, marketing, content, public access, and evaluation, and discusses the variety of roles that the local public library can play in this process. Chapter One, "The Importance of Community Networking," describes the importance of community…

Bajjaly, Stephen T.

284

Mars Network operations concept  

Microsoft Academic Search

NASA has initiated at the Jet Propulsion Laboratory the design of a Communications and Navigation Network at Mars. It will consist of a constellation of low-altitude orbiting satellites and one or more aerostationary (of synchronous orbit around Mars) satellites. The key Mars Network operations concept is to provide standard services and pave a way for interoperability of future Mars Missions.

Neal R. Kuo

2000-01-01

285

Reconstructing a credit network  

NASA Astrophysics Data System (ADS)

The science of complex networks can be usefully applied in finance, although there is limited data available with which to develop our understanding. All is not lost, however: ideas from statistical physics make it possible to reconstruct details of a financial network from partial sets of information.

Caldarelli, Guido; Chessa, Alessandro; Pammolli, Fabio; Gabrielli, Andrea; Puliga, Michelangelo

2013-03-01

286

Communication Network Analysis Methods.  

ERIC Educational Resources Information Center

This paper reviews a variety of analytic procedures that can be applied to network data, discussing the assumptions and usefulness of each procedure when applied to the complexity of human communication. Special attention is paid to the network properties measured or implied by each procedure. Factor analysis and multidimensional scaling are among…

Farace, Richard V.; Mabee, Timothy

287

Random catalytic reaction networks  

Microsoft Academic Search

We study networks that are a generalization of replicator (or Lotka-Volterra) equations. They model the dynamics of a population of object types whose binary interactions determine the specific type of interaction product. Such a system always reduces its dimension to a subset that contains production pathways for all of its members. The network equation can be rewritten at a level

Peter F. Stadler; Walter Fontana; John H. Miller

1993-01-01

288

Informal Helping Networks.  

ERIC Educational Resources Information Center

|An area probability sample of 200 elderly residents, living in two California cities, were interviewed to determine the nature of informal helping networks enabling them to maintain independence, specifically the relationship between involvement in informal helping networks and utilization of social and health services. Preliminary findings…

Kaplan, Barbara Hade; And Others

289

Secure Mobile Networking.  

National Technical Information Service (NTIS)

This project produced a Secure Mobile Network (SMN) system for secure enclaves or virtual networks among mobile workstations, an integrated Mobile-IP/ IPSEC system in which Mobile Nodes use 2-way tunnels to securely tunnel packets to the Home Agent. A key...

J. R. Binkley J. McHugh

2001-01-01

290

Quantum neural networks  

Microsoft Academic Search

This chapter outlines the research, development and perspectives of quantum neural networks - a burgeoning new field which integrates classical neurocomputing with quantum computation (1). It is argued that the study of quantum neural networks may give us both new undestanding of brain function as well as unprecedented possibilities in creating new systems for information processing, including solving classically intractable

Alexandr A. Ezhov; Dan Ventura

291

The protein folding network  

NASA Astrophysics Data System (ADS)

Networks are everywhere. The conformation space of a 20-residue antiparallel beta-sheet peptide [1], sampled by molecular dynamics simulations, is mapped to a network. Conformations are nodes of the network, and the transitions between them are links. As previously found for the World-Wide Web as well as for social and biological networks , the conformation space contains highly connected hubs like the native state which is the most populated free energy basin. Furthermore, the network shows a hierarchical modularity [2] which is consistent with the funnel mechanism of folding [3] and is not observed for a random heteropolymer lacking a native state. Here we show that the conformation space network describes the free energy landscape without requiring projections into arbitrarily chosen reaction coordinates. The network analysis provides a basis for understanding the heterogeneity of the folding transition state and the existence of multiple pathways. [1] P. Ferrara and A. Caflisch, Folding simulations of a three-stranded antiparallel beta-sheet peptide, PNAS 97, 10780-10785 (2000). [2] Ravasz, E. and Barabási, A. L. Hierarchical organization in complex networks. Phys. Rev. E 67, 026112 (2003). [3] Dill, K. and Chan, H From Levinthal to pathways to funnels. Nature Struct. Biol. 4, 10-19 (1997)

Rao, Francesco; Caflisch, Amedeo

2004-03-01

292

Network Event Recognition  

Microsoft Academic Search

Network protocols can be tested by capturing communication packets, assembling them into the high-level events, and comparing these to a nite state machine that describes the protocol standard. This process, which we call Network Event Recognition (NER), faces a number of challenges only partially addressed by existing systems. These include the ability to provide precise conformance with specications, achieve adequate

Karthikeyan Bhargavan; Carl A. Gunter

2005-01-01

293

Marketing action in networks  

Microsoft Academic Search

Purpose – The aim of this paper is to describe and explain how organizations develop and implement marketing action within their surrounding business networks. Design\\/methodology\\/approach – The paper is an empirical case study research that covered periods 1993 to 1998 and 2002 to 2003 in manufacturer-retailer networks in Germany. A conceptual model is developed and its applicability is illustrated. Findings

Stefanos Mouzas

2006-01-01

294

Survey of Network Reliability.  

National Technical Information Service (NTIS)

We present a brief survey of the current state of the art in network reliability. We survey only exact methods; Monte Carlo methods are not surveyed. Most network reliability problems are, in the worst case, NP-hard and are, in a sense, more difficult tha...

A. Agrawal R. E. Barlow

1983-01-01

295

A Balanced Memory Network  

PubMed Central

A fundamental problem in neuroscience is understanding how working memory—the ability to store information at intermediate timescales, like tens of seconds—is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons.

Roudi, Yasser; Latham, Peter E

2007-01-01

296

A balanced memory network.  

PubMed

A fundamental problem in neuroscience is understanding how working memory--the ability to store information at intermediate timescales, like tens of seconds--is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons. PMID:17845070

Roudi, Yasser; Latham, Peter E

2007-06-05

297

Some Functional Neural Networks.  

National Technical Information Service (NTIS)

Several types of neural networks were constructed using a D. C. pulseless type of neuron model as a basic element. These networks were combined in the construction of a simplified one-dimensional artificial eye to demonstrate a capability for sensing dire...

J. E. Swanekamp

1966-01-01

298

TOXNET (TOXICOLOGY DATA NETWORK)  

EPA Science Inventory

TOXNET (Toxicology Data Network) is a computerized system of files oriented to toxicology and related areas. It is managed by the National Library of Medicines Toxicology and Environmental Health Information Program (TEHIP) and runs on a series of microcomputers in a networked cl...

299

Nanoporous organic polymer networks  

Microsoft Academic Search

Nanoporous organic polymer networks are a class of materials consisting solely of the lighter elements in the periodic table. These materials have potential uses in areas such as storage, separation, and catalysis. Here, we review the different classes of nanoporous polymer networks including covalent organic frameworks, hypercrosslinked polymers, conjugated microporous polymers, and polymers of intrinsic microporosity. The growing variety in

Robert Dawson; Andrew I. Cooper; Dave J. Adams

300

Bilingual Word Association Networks  

Microsoft Academic Search

Bilingual word association networks can be beneficial as a tool in for- eign language education because they show relationships among cognate words of different languages and correspond to structures in the mental lexicon. This paper discusses possible technologies that can be used to generate and represent word association networks. The research for this paper is motivated by a word association

Uta Priss; L. John Old

2007-01-01

301

Networking Systems and Equipment.  

ERIC Educational Resources Information Center

|Describes how high-bandwidth networks are delivering new educational and administrative opportunities for K-12 school districts. Addresses implementing the new network, upgrading to a switched environment, adding intelligent switches, IP telephony, and wireless technology. Describes deployment and benefits of broadband in the Denver public…

Kranz, Maciej

2002-01-01

302

Stop Social Network Pitfalls  

Microsoft Academic Search

Ask a group of teenagers how they spend their spare time and most will mention Facebook, YouTube, World of Warcraft, or Second Life – ‘virtual’ social networks that bring millions of people together online. The benefits of social networks have been touted but what about the pitfalls? Some teens will share everything about themselves to hundreds of online friends, most

K. Michael

2010-01-01

303

Tamper Resistant Network Tracing  

Microsoft Academic Search

Raw network traces can be used to compro- mise the privacy of Internet users. For this reason, many ISPs are reluctant to collect network traces - they often re- gard possession of such traces as a liability. To mitigate th is concern, anonymization techniques have been developed to protect user-identifying information. While most project s anonymize their traces as a

Andrew G. Miklas; Stefan Saroiu; Alec Wolman; Angela Demke Brown

304

Information Network Development.  

ERIC Educational Resources Information Center

|The International Bureau of Education (IBE) and Unesco, together with their member states, are faced with the task of implementing a proposed network--the International Network for Educational Information (INED)--for the better use of information resources for educational development. This review of issues that need to be considered in the…

Mahon, F. V.

305

Social networking sites.  

PubMed

In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools, social networking and social bookmarking sites, virtual worlds, and Web-based teaching and learning programs. This article describes social networking Web sites and techniques to increase their safe use. PMID:20173583

Wink, Diane M

306

Authenticating public access networking  

Microsoft Academic Search

The University of Pittsburgh began offering network connections to residence hall students in 1998. Initially, students were assigned static IP addresses and manual processes were implemented to record the each computer's network card MAC address. This quickly became unwieldy as service was expanded to all of the nearly 6,000 residence hall rooms. In 2000, DHCP was used to provide student

Joseph W. Graham II

2002-01-01

307

Quantum Computational Networks  

Microsoft Academic Search

The theory of quantum computational networks is the quantum generalization of the theory of logic circuits used in classical computing machines. Quantum gates are the generalization of classical logic gates. A single type of gate, the univeral quantum gate, together with quantum 'unit wires', is adequate for constructing networks with any possible quantum computational property.

D. Deutsch

1989-01-01

308

Optical Access Networks  

NASA Astrophysics Data System (ADS)

Call for Papers: Optical Access Networks

Guest Editors Jun Zheng, University of Ottawa Nirwan Ansari, New Jersey Institute of Technology

Submission Deadline: 1 June 2005

Background

With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks.

Scope of Contributions

This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to:
  • Optical access network architectures and protocols
  • Passive optical networks (BPON, EPON, GPON, etc.)
  • Active optical networks
  • Multiple access control
  • Multiservices and QoS provisioning
  • Network survivability
  • Field trials and standards
  • Performance modeling and analysis

Manuscript Submission

To submit to this special issue, follow the normal procedure for submission to JON, indicating ``Optical Access Networks feature' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``Optical Access Networks' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 June 2005

Zheng, Jun; Ansari, Nirwan

2005-01-01

309

Networks in cognitive science.  

PubMed

Networks of interconnected nodes have long played a key role in Cognitive Science, from artificial neural networks to spreading activation models of semantic memory. Recently, however, a new Network Science has been developed, providing insights into the emergence of global, system-scale properties in contexts as diverse as the Internet, metabolic reactions, and collaborations among scientists. Today, the inclusion of network theory into Cognitive Sciences, and the expansion of complex-systems science, promises to significantly change the way in which the organization and dynamics of cognitive and behavioral processes are understood. In this paper, we review recent contributions of network theory at different levels and domains within the Cognitive Sciences. PMID:23726319

Baronchelli, Andrea; Ferrer-i-Cancho, Ramon; Pastor-Satorras, Romualdo; Chater, Nick; Christiansen, Morten H

2013-05-30

310

Controllability of complex networks.  

PubMed

The ultimate proof of our understanding of natural or technological systems is reflected in our ability to control them. Although control theory offers mathematical tools for steering engineered and natural systems towards a desired state, a framework to control complex self-organized systems is lacking. Here we develop analytical tools to study the controllability of an arbitrary complex directed network, identifying the set of driver nodes with time-dependent control that can guide the system's entire dynamics. We apply these tools to several real networks, finding that the number of driver nodes is determined mainly by the network's degree distribution. We show that sparse inhomogeneous networks, which emerge in many real complex systems, are the most difficult to control, but that dense and homogeneous networks can be controlled using a few driver nodes. Counterintuitively, we find that in both model and real systems the driver nodes tend to avoid the high-degree nodes. PMID:21562557

Liu, Yang-Yu; Slotine, Jean-Jacques; Barabási, Albert-László

2011-05-12

311

Decentralized Online Social Networks  

NASA Astrophysics Data System (ADS)

Current Online social networks (OSN) are web services run on logically centralized infrastructure. Large OSN sites use content distribution networks and thus distribute some of the load by caching for performance reasons, nevertheless there is a central repository for user and application data. This centralized nature of OSNs has several drawbacks including scalability, privacy, dependence on a provider, need for being online for every transaction, and a lack of locality. There have thus been several efforts toward decentralizing OSNs while retaining the functionalities offered by centralized OSNs. A decentralized online social network (DOSN) is a distributed system for social networking with no or limited dependency on any dedicated central infrastructure. In this chapter we explore the various motivations of a decentralized approach to online social networking, discuss several concrete proposals and types of DOSN as well as challenges and opportunities associated with decentralization.

Datta, Anwitaman; Buchegger, Sonja; Vu, Le-Hung; Strufe, Thorsten; Rzadca, Krzysztof

312

Categorical Tensor Network States  

NASA Astrophysics Data System (ADS)

We examine the use of string diagrams and the mathematics of category theory in the description of quantum states by tensor networks. This approach lead to a unification of several ideas, as well as several results and methods that have not previously appeared in either side of the literature. Our approach enabled the development of a tensor network framework allowing a solution to the quantum decomposition problem which has several appealing features. Specifically, given an n-body quantum state S, we present a new and general method to factor S into a tensor network of clearly defined building blocks. We use the solution to expose a previously unknown and large class of quantum states which we prove can be sampled efficiently and exactly. This general framework of categorical tensor network states, where a combination of generic and algebraically defined tensors appear, enhances the theory of tensor network states.

Biamonte, Jacob D.; Clark, Stephen R.; Jaksch, Dieter

313

Semaphore network encryption report  

NASA Astrophysics Data System (ADS)

This paper documents the results of a preliminary assessment performed on the commercial off-the-shelf (COTS) Semaphore Communications Corporation (SCC) Network Security System (NSS). The Semaphore NSS is a family of products designed to address important network security concerns, such as network source address authentication and data privacy. The assessment was performed in the INFOSEC Core Integration Laboratory, and its scope was product usability focusing on interoperability and system performance in an existing operational network. Included in this paper are preliminary findings. Fundamental features and functionality of the Semaphore NSS are identified, followed by details of the assessment, including test descriptions and results. A summary of test results and future plans are also included. These findings will be useful to those investigating the use of commercially available solutions to network authentication and data privacy.

Johnson, Karen L.

1994-03-01

314

Network Startup Resource Center (NSRC)  

NSDL National Science Digital Library

The Network Startup Resource Center (NSRC) and PSGnet with partial funding from the National Science Foundation have established a Web server offering a database of information about international networking developments and connectivity providers, with its major emphasis on countries in Asia, Africa, the Middle East, Oceania, and Latin America. Topics include: networking in the developing world, low cost networking tools, general computer networking info, and networking tips and frequently asked questions.

1997-01-01

315

Correlation Dimension of Complex Networks  

NASA Astrophysics Data System (ADS)

We propose a new measure to characterize the dimension of complex networks based on the ergodic theory of dynamical systems. This measure is derived from the correlation sum of a trajectory generated by a random walker navigating the network, and extends the classical Grassberger-Procaccia algorithm to the context of complex networks. The method is validated with reliable results for both synthetic networks and real-world networks such as the world air-transportation network or urban networks, and provides a computationally fast way for estimating the dimensionality of networks which only relies on the local information provided by the walkers.

Lacasa, Lucas; Gómez-Gardeñes, Jesús

2013-04-01

316

Correlation dimension of complex networks.  

PubMed

We propose a new measure to characterize the dimension of complex networks based on the ergodic theory of dynamical systems. This measure is derived from the correlation sum of a trajectory generated by a random walker navigating the network, and extends the classical Grassberger-Procaccia algorithm to the context of complex networks. The method is validated with reliable results for both synthetic networks and real-world networks such as the world air-transportation network or urban networks, and provides a computationally fast way for estimating the dimensionality of networks which only relies on the local information provided by the walkers. PMID:23679650

Lacasa, Lucas; Gómez-Gardeñes, Jesús

2013-04-19

317

Tinnitus: network pathophysiology-network pharmacology  

PubMed Central

Tinnitus, the phantom perception of sound, is a prevalent disorder. One in 10 adults has clinically significant subjective tinnitus, and for one in 100, tinnitus severely affects their quality of life. Despite the significant unmet clinical need for a safe and effective drug targeting tinnitus relief, there is currently not a single Food and Drug Administration (FDA)-approved drug on the market. The search for drugs that target tinnitus is hampered by the lack of a deep knowledge of the underlying neural substrates of this pathology. Recent studies are increasingly demonstrating that, as described for other central nervous system (CNS) disorders, tinnitus is a pathology of brain networks. The application of graph theoretical analysis to brain networks has recently provided new information concerning their topology, their robustness and their vulnerability to attacks. Moreover, the philosophy behind drug design and pharmacotherapy in CNS pathologies is changing from that of “magic bullets” that target individual chemoreceptors or “disease-causing genes” into that of “magic shotguns,” “promiscuous” or “dirty drugs” that target “disease-causing networks,” also known as network pharmacology. In the present work we provide some insight into how this knowledge could be applied to tinnitus pathophysiology and pharmacotherapy.

Elgoyhen, Ana B.; Langguth, Berthold; Vanneste, Sven; De Ridder, Dirk

2012-01-01

318

Optical Network Testbeds Workshop  

SciTech Connect

This is the summary report of the third annual Optical Networking Testbed Workshop (ONT3), which brought together leading members of the international advanced research community to address major challenges in creating next generation communication services and technologies. Networking research and development (R&D) communities throughout the world continue to discover new methods and technologies that are enabling breakthroughs in advanced communications. These discoveries are keystones for building the foundation of the future economy, which requires the sophisticated management of extremely large qualities of digital information through high performance communications. This innovation is made possible by basic research and experiments within laboratories and on specialized testbeds. Initial network research and development initiatives are driven by diverse motives, including attempts to solve existing complex problems, the desire to create powerful new technologies that do not exist using traditional methods, and the need to create tools to address specific challenges, including those mandated by large scale science or government agency mission agendas. Many new discoveries related to communications technologies transition to wide-spread deployment through standards organizations and commercialization. These transition paths allow for new communications capabilities that drive many sectors of the digital economy. In the last few years, networking R&D has increasingly focused on advancing multiple new capabilities enabled by next generation optical networking. Both US Federal networking R&D and other national R&D initiatives, such as those organized by the National Institute of Information and Communications Technology (NICT) of Japan are creating optical networking technologies that allow for new, powerful communication services. Among the most promising services are those based on new types of multi-service or hybrid networks, which use new optical networking technologies. Several years ago, when many of these optical networking research topics were first being investigated, they were the subject of controversial debate. The new techniques challenged many long-held concepts related to architecture and technology. However, today all major networking organizations are transitioning toward infrastructure that incorporates these new concepts. This progress has been assisted through the series of Optical Networking Testbed Workshops (ONT). The first (ONT1) outlined a general framework of key issues and topics and developed a series of recommendations (www.nren.nasa.gov/workshop7). The second (ONT2) developed a common vision of optical network technologies, services, infrastructure, and organizations (www.nren.nasa.gov/workshop8). Processes that allow for a common vision encourage widespread deployment of these types of resources among advanced networking communities. Also, such a shared vision enables key concepts and technologies to migrate from basic research testbeds to wider networking communities. The ONT-3 workshop built on these earlier activities by expanding discussion to include additional considerations of the international interoperability and of greater impact of optical networking technology on networking in general. In accordance with this recognition, the workshop confirmed that future-oriented research and development is indispensable to fundamentally change the current Internet architecture to create a global network incorporating completely new concepts. The workshop also recognized that the first priority to allow for this progress is basic research and development, including international collaborative activities, which are important for the global realization of interoperability of a new generation architecture.

Joe Mambretti

2007-06-01

319

Comparative analysis of collaboration networks  

SciTech Connect

In this paper we carry out a comparative analysis of the word network as the collaboration network based on the novel by M. Bulgakov 'Master and Margarita', the synonym network of the Russian language as well as the Russian movie actor network. We have constructed one-mode projections of these networks, defined degree distributions for them and have calculated main characteristics. In the paper a generation algorithm of collaboration networks has been offered which allows one to generate networks statistically equivalent to the studied ones. It lets us reveal a structural correlation between word network, synonym network and movie actor network. We show that the degree distributions of all analyzable networks are described by the distribution of q-type.

Progulova, Tatiana; Gadjiev, Bahruz [International University for Nature, Society and Man, 19 Universitetskaya Street, Dubna, 141980 (Russian Federation)

2011-03-14

320

Optical storage networking  

NASA Astrophysics Data System (ADS)

For efficient business continuance and backup of mission- critical data an inter-site storage network is required. Where traditional telecommunications costs are prohibitive for all but the largest organizations, there is an opportunity for regional carries to deliver an innovative storage service. This session reveals how a combination of optical networking and protocol-aware SAN gateways can provide an extended storage networking platform with the lowest cost of ownership and the highest possible degree of reliability, security and availability. Companies of every size, with mainframe and open-systems environments, can afford to use this integrated service. Three mayor applications are explained; channel extension, Network Attached Storage (NAS), Storage Area Networks (SAN) and how optical networks address the specific requirements. One advantage of DWDM is the ability for protocols such as ESCON, Fibre Channel, ATM and Gigabit Ethernet, to be transported natively and simultaneously across a single fiber pair, and the ability to multiplex many individual fiber pairs over a single pair, thereby reducing fiber cost and recovering fiber pairs already in use. An optical storage network enables a new class of service providers, Storage Service Providers (SSP) aiming to deliver value to the enterprise by managing storage, backup, replication and restoration as an outsourced service.

Mohr, Ulrich

2001-11-01

321

Simulated Associating Polymer Networks  

NASA Astrophysics Data System (ADS)

Telechelic associating polymer networks consist of polymer chains terminated by endgroups that have a different chemical composition than the polymer backbone. When dissolved in a solution, the endgroups cluster together to form aggregates. At low temperature, a strongly connected reversible network is formed and the system behaves like a gel. Telechelic networks are of interest since they are representative for biopolymer networks (e.g. F-actin) and are widely used in medical applications (e.g. hydrogels for tissue engineering, wound dressings) and consumer products (e.g. contact lenses, paint thickeners). In this thesis such systems are studied by means of a molecular dynamics/Monte Carlo simulation. At first, the system in rest is studied by means of graph theory. The changes in network topology upon cooling to the gel state, are characterized. Hereto an extensive study of the eigenvalue spectrum of the gel network is performed. As a result, an in-depth investigation of the eigenvalue spectra for spatial ER, scale-free, and small-world networks is carried out. Next, the gel under the application of a constant shear is studied, with a focus on shear banding and the changes in topology under shear. Finally, the relation between the gel transition and percolation is discussed.

Billen, Joris

322

Network aware distributed applications  

SciTech Connect

Most distributed applications today manage to utilize only a small percentage of the needed and available network bandwidth. Often application developers are not aware of the potential bandwidth of the network, and therefore do not know what to expect. Even when application developers are aware of the specifications of the machines and network links, they have few resources that can help determine why the expected performance was not achieved. What is needed is a ubiquitous and easy-to-use service that provides reliable, accurate, secure, and timely estimates of dynamic network properties. This service will help advise applications on how to make use of the network's increasing bandwidth and capabilities for traffic shaping and engineering. When fully implemented, this service will make building currently unrealizable levels of network awareness into distributed applications a relatively mundane task. For example, a remote data visualization application could choose between sending a wireframe, a pre-rendered image, or a 3-D representation, based on forecasts of CPU availability and power, compression options, and available bandwidth. The same service will provide on-demand performance information so that applications can compare predicted with actual results, and allow detailed queries about the end-to-end path for application and network tuning and debugging.

Agarwal, Deborah; Tierney, Brian L.; Gunter, Dan; Lee, Jason; Johnston, William

2001-02-04

323

The orphan disease networks.  

PubMed

The low prevalence rate of orphan diseases (OD) requires special combined efforts to improve diagnosis, prevention, and discovery of novel therapeutic strategies. To identify and investigate relationships based on shared genes or shared functional features, we have conducted a bioinformatic-based global analysis of all orphan diseases with known disease-causing mutant genes. Starting with a bipartite network of known OD and OD-causing mutant genes and using the human protein interactome, we first construct and topologically analyze three networks: the orphan disease network, the orphan disease-causing mutant gene network, and the orphan disease-causing mutant gene interactome. Our results demonstrate that in contrast to the common disease-causing mutant genes that are predominantly nonessential, a majority of orphan disease-causing mutant genes are essential. In confirmation of this finding, we found that OD-causing mutant genes are topologically important in the protein interactome and are ubiquitously expressed. Additionally, functional enrichment analysis of those genes in which mutations cause ODs shows that a majority result in premature death or are lethal in the orthologous mouse gene knockout models. To address the limitations of traditional gene-based disease networks, we also construct and analyze OD networks on the basis of shared enriched features (biological processes, cellular components, pathways, phenotypes, and literature citations). Analyzing these functionally-linked OD networks, we identified several additional OD-OD relations that are both phenotypically similar and phenotypically diverse. Surprisingly, we observed that the wiring of the gene-based and other feature-based OD networks are largely different; this suggests that the relationship between ODs cannot be fully captured by the gene-based network alone. PMID:21664998

Zhang, Minlu; Zhu, Cheng; Jacomy, Alexis; Lu, Long J; Jegga, Anil G

2011-06-10

324

The Orphan Disease Networks  

PubMed Central

The low prevalence rate of orphan diseases (OD) requires special combined efforts to improve diagnosis, prevention, and discovery of novel therapeutic strategies. To identify and investigate relationships based on shared genes or shared functional features, we have conducted a bioinformatic-based global analysis of all orphan diseases with known disease-causing mutant genes. Starting with a bipartite network of known OD and OD-causing mutant genes and using the human protein interactome, we first construct and topologically analyze three networks: the orphan disease network, the orphan disease-causing mutant gene network, and the orphan disease-causing mutant gene interactome. Our results demonstrate that in contrast to the common disease-causing mutant genes that are predominantly nonessential, a majority of orphan disease-causing mutant genes are essential. In confirmation of this finding, we found that OD-causing mutant genes are topologically important in the protein interactome and are ubiquitously expressed. Additionally, functional enrichment analysis of those genes in which mutations cause ODs shows that a majority result in premature death or are lethal in the orthologous mouse gene knockout models. To address the limitations of traditional gene-based disease networks, we also construct and analyze OD networks on the basis of shared enriched features (biological processes, cellular components, pathways, phenotypes, and literature citations). Analyzing these functionally-linked OD networks, we identified several additional OD-OD relations that are both phenotypically similar and phenotypically diverse. Surprisingly, we observed that the wiring of the gene-based and other feature-based OD networks are largely different; this suggests that the relationship between ODs cannot be fully captured by the gene-based network alone.

Zhang, Minlu; Zhu, Cheng; Jacomy, Alexis; Lu, Long J.; Jegga, Anil G.

2011-01-01

325

Attractor Metabolic Networks  

PubMed Central

Background The experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a Systemic Metabolic Structure in the cell, characterized by a set of different enzymatic reactions always locked into active states (metabolic core) while the rest of the catalytic processes are only intermittently active. This global metabolic structure was verified for Escherichia coli, Helicobacter pylori and Saccharomyces cerevisiae, and it seems to be a common key feature to all cellular organisms. In concordance with these observations, the cell can be considered a complex metabolic network which mainly integrates a large ensemble of self-organized multienzymatic complexes interconnected by substrate fluxes and regulatory signals, where multiple autonomous oscillatory and quasi-stationary catalytic patterns simultaneously emerge. The network adjusts the internal metabolic activities to the external change by means of flux plasticity and structural plasticity. Methodology/Principal Findings In order to research the systemic mechanisms involved in the regulation of the cellular enzymatic activity we have studied different catalytic activities of a dissipative metabolic network under different external stimuli. The emergent biochemical data have been analysed using statistical mechanic tools, studying some macroscopic properties such as the global information and the energy of the system. We have also obtained an equivalent Hopfield network using a Boltzmann machine. Our main result shows that the dissipative metabolic network can behave as an attractor metabolic network. Conclusions/Significance We have found that the systemic enzymatic activities are governed by attractors with capacity to store functional metabolic patterns which can be correctly recovered from specific input stimuli. The network attractors regulate the catalytic patterns, modify the efficiency in the connection between the multienzymatic complexes, and stably retain these modifications. Here for the first time, we have introduced the general concept of attractor metabolic network, in which this dynamic behavior is observed.

De la Fuente, Ildefonso M.; Cortes, Jesus M.; Pelta, David A.; Veguillas, Juan

2013-01-01

326

Network marketing on a small-world network  

Microsoft Academic Search

We investigate a dynamic model of network marketing in a small-world network structure artificially constructed similarly to the Watts–Strogatz network model. Different from the traditional marketing, consumers can also play the role of the manufacturer's selling agents in network marketing, which is stimulated by the referral fee the manufacturer offers. As the wiring probability ? is increased from zero to

Beom Jun Kim; Tackseung Jun; Jeong-Yoo Kim; M. Y. Choi

2006-01-01

327

Artificial Immune Network based Robot Behavior Coordination Under Wireless Network  

Microsoft Academic Search

Currently the mutually beneficial collaboration between mobile robots and a static sensor network is a hot issue. In this paper two behavior coordination method, behavior network based method and artificial immune network based method, for a robot with simple behaviors and four ultrasonic sensors to achieve complex goals under a wireless mosaic eye network are implemented, especially, the communication strategy

Feng Tian; Qinhua Deng; Zuren Feng; Ping Jiang

2007-01-01

328

A General Neural Network Model for Estimating Telecommunications Network Reliability  

Microsoft Academic Search

This paper puts forth a new encoding method for using neural network models to estimate the reliability of telecom- munications networks with identical link reliabilities. Neural estimation is computationally speedy, and can be used during network design optimization by an iterative algorithm such as tabu search, or simulated annealing. Two significant drawbacks of previous approaches to using neural networks to

Fulya Altiparmak; Berna Dengiz; Alice E. Smith

2009-01-01

329

On applying network coding to underwater sensor networks  

Microsoft Academic Search

High error rates and long propagation delays in underwater sen- sor networks call for efficient error-recovery schemes. We believe network coding is a promising technique for this purpose because of the broadcast nature of acoustic channels and computation ca- pabilities at the sensor nodes. In this paper, we design a network coding scheme for underwater sensor networks and explore its

Zheng Guo; Peng Xie; Jun-hong Cui; Bing Wang

2006-01-01

330

Localization using neural networks in wireless sensor networks  

Microsoft Academic Search

Noisy distance measurements are a pervasive problem in localization in wireless sensor networks. Neural networks are not commonly used in localization, however, our ex- periments in this paper indicate neural networks are a vi- able option for solving localization problems. In this paper we qualitatively compare the performance of three different families of neural networks: Multi-Layer Perceptron (MLP), Radial Basis

Ali Shareef; Yifeng Zhu; Mohamad T. Musavi

2008-01-01

331

Enhancing business networks using social network based virtual communities  

Microsoft Academic Search

Purpose – To enhance an entrepreneur's business network through the integration of the social network concepts and design principles of virtual communities. Design\\/methodology\\/approach – This study documents the design and initial deployment of a virtual community case, Innovation Information Infrastructure, based on social network concepts. Findings – Basic design principles, deployment strategy, and future directions for social network-based virtual communities

Bih-ru Lea; Wen-bin Yu; Nisha Maguluru; Michael Nichols

2006-01-01

332

Social network analysis and the evaluation of leadership networks  

Microsoft Academic Search

Leadership development practitioners are increasingly interested in social networks as a way to strengthen relationships among leaders in fields, communities, and organizations. This paper offers a framework for conceptualizing different types of leadership networks and uses case examples to identify outcomes typically associated with each type of network. Evaluating leadership networks is a challenge for the field of leadership development.

Bruce Hoppe; Claire Reinelt

2010-01-01

333

Networks and learning: communities, practices and the metaphor of networks  

Microsoft Academic Search

This article argues that the use of the network metaphor can link together various different aspects of research into the use of advanced learning technologies based on computer networks. The idea of networked learning has become commonplace as an alternative to e-learning that stresses the interaction of learners, tutors and resources through networks. The arguments put in this article are

Chris Jones

2004-01-01

334

On wireless network scheduling with intersession network coding  

Microsoft Academic Search

Cross-layer optimization including congestion con- trol, routing, and scheduling has shown dramatic throughput improvement over layered designs for wireless networks. In parallel, the paradigm-shifting network coding has empirically demonstrated substantial throughput improvement when coding operations are permitted at intermediate nodes and packets from different sessions are mixed. Designing network codes and the associated flow in network coding presents new challenges

Chih-chun Wang; Ness B. Shroff

2008-01-01

335

Secure Network Coding for Wiretap Networks of Type II  

Microsoft Academic Search

We consider the problem of securing a multicast network against a wiretapper that can intercept the packets on a limited number of arbitrary network edges of its choice. We assume that the network employs the network coding technique to simultaneously deliver the packets available at the source to all the receivers. We show that this problem can be looked at

Salim Y. El Rouayheb; Emina Soljanin; Alexander Sprintson

2009-01-01

336

A Framework for Predictive Network Management of Predictive Mobile Networks  

Microsoft Academic Search

There is a trend toward the use of predictivesystems in communications networks. At the systems andnetwork management level predictive capabilities arefocused on anticipating network faults and performance degradation. Simultaneously, mobilecommunication networks are being developed withpredictive location and tracking mechanisms. Theinteractions and synergies between these systems presenta new set of problems. A new predictive network managementframework is developed and examined. The

Stephen F. Bush; Victor S. Frost

1999-01-01

337

Stochastic Hopfield neural networks  

NASA Astrophysics Data System (ADS)

Hopfield (1984 Proc. Natl Acad. Sci. USA 81 3088-92) showed that the time evolution of a symmetric neural network is a motion in state space that seeks out minima in the system energy (i.e. the limit set of the system). In practice, a neural network is often subject to environmental noise. It is therefore useful and interesting to find out whether the system still approaches some limit set under stochastic perturbation. In this paper, we will give a number of useful bounds for the noise intensity under which the stochastic neural network will approach its limit set.

Hu, Shigeng; Liao, Xiaoxin; Mao, Xuerong

2003-03-01

338

A spin network primer  

NASA Astrophysics Data System (ADS)

Spin networks, essentially labeled graphs, are ``good quantum numbers'' for the quantum theory of geometry. These structures encompass a diverse range of techniques which may be used in the quantum mechanics of finite dimensional systems, gauge theory, and knot theory. Though accessible to undergraduates, spin network techniques are buried in more complicated formulations. In this paper a diagrammatic method, simple but rich, is introduced through an association of 2×2 matrices with diagrams. This spin network diagrammatic method offers new perspectives on the quantum mechanics of angular momentum, group theory, knot theory, and even quantum geometry. Examples in each of these areas are discussed.

Major, Seth A.

1999-11-01

339

Thermal network reduction  

SciTech Connect

A method is presented for reducing the number of elements required in a thermal network representation of a building. The method is based on matching the actual building response at two frequencies, the diurnal response and 3-day response. The procedure provides a straightforward methodology for combining all the various materials inside a discrete building zone into a few nodes while retaining a high degree of accuracy in the dynamic response. An example is given showing a comparison between a large network and the reduced network.

Balcomb, J.D.

1983-01-01

340

Broadband network selection issues  

NASA Astrophysics Data System (ADS)

Selecting the best network for a given cable or telephone company provider is not as obvious as it appears. The cost and performance trades between Hybrid Fiber Coax (HFC), Fiber to the Curb (FTTC) and Asymmetric Digital Subscriber Line networks lead to very different choices based on the existing plant and the expected interactive subscriber usage model. This paper presents some of the issues and trades that drive network selection. The majority of the Interactive Television trials currently underway or planned are based on HFC networks. As a throw away market trial or a short term strategic incursion into a cable market, HFC may make sense. In the long run, if interactive services see high demand, HFC costs per node and an ever shrinking neighborhood node size to service large numbers of subscribers make FTTC appear attractive. For example, thirty-three 64-QAM modulators are required to fill the 550 MHz to 750 MHz spectrum with compressed video streams in 6 MHz channels. This large amount of hardware at each node drives not only initial build-out costs, but operations and maintenance costs as well. FTTC, with its potential for digitally switching large amounts of bandwidth to an given home, offers the potential to grow with the interactive subscriber base with less downstream cost. Integrated telephony on these networks is an issue that appears to be an afterthought for most of the networks being selected at the present time. The major players seem to be videocentric and include telephony as a simple add-on later. This may be a reasonable view point for the telephone companies that plan to leave their existing phone networks untouched. However, a phone company planning a network upgrade or a cable company jumping into the telephony business needs to carefully weigh the cost and performance issues of the various network choices. Each network type provides varying capability in both upstream and downstream bandwidth for voice channels. The noise characteristics vary as well. Cellular quality will not be tolerated by the home or business consumer. The network choices are not simple or obvious. Careful consideration of the cost and performance trades along with cable or telephone company strategic plans is required to ensure selecting the best network.

Leimer, Michael E.

1996-01-01

341

Local area gigabit networking  

SciTech Connect

Computer networks must become faster as the equipment that is being interconnected increases in power and performance. Ethemet, with a 10 Mbit/s speed, seemed awesome a few years ago, but is beginning to show its age as more machines are tied together, and workstations attain the power of yesterdays mainframes. Networks using gigabit speeds are just starting to become available and offer a whole new set of problems and potential. This paper addresses what the higher speeds are being used for, the ''standards'' efforts specifying the higher speed channels, the network architectures being proposed, and some of the open problems requiring extensive further work. 13 refs., 2 figs.

Tolmie, D.E.

1991-01-01

342

Protein structure networks.  

PubMed

The application of the field of network science to the scientific disciplines of structural biology and biochemistry, have yielded important new insights into the nature and determinants of protein structures, function, dynamics and the folding process. Advancements in further understanding protein relationships through network science have also reshaped the way we view the connectivity of proteins in the protein universe. The canonical hierarchical classification can now be visualized for example, as a protein fold continuum. This review will survey several key advances in the expanding area of research being conducted to study protein structures and folding using network approaches. PMID:23042823

Greene, Lesley H

2012-10-04

343

Electro-magnetic earthquake bursts and critical rupture of peroxy bond networks in rocks  

NASA Astrophysics Data System (ADS)

We propose a mechanism for the low frequency electromagnetic emissions and other electromagnetic and electric phenomena which have been associated with earthquakes. The mechanism combines the critical earthquake concept and the concept of crust acting as a charging electric battery under increasing stress. The electric charges are released by activation of dormant charge carriers in the oxygen anion sublattice, called peroxy bonds or positive hole pairs (PHP), where a PHP represents an O3X/OO\\YO3 with X,Y = Si4+,Al3+,…, i.e. O- in a matrix of O2- of silicates. We propose that PHP are activated by plastic deformations during the slow cooperative build-up of stress and the increasingly correlated damage culminating in a large “critical” earthquake. Recent laboratory experiments indeed show that stressed rocks form electric batteries which can release their charge when a conducting path closes the equivalent electric circuit. We conjecture that the intermittent and erratic occurrences of EM signals are a consequence of the progressive build-up of the battery charges in the Earth crust and of their release when crack networks percolate through the stressed rock volumes, providing a conductive pathway for the battery currents to discharge. EM signals are thus expected close to the rupture, either slightly before or after, that is, when percolation is most favored. The proposed mechanism should be relevant for the broader understanding of fractoemissions.

Freund, F.; Sornette, D.

2007-02-01

344

Application of network theory to potential mycorrhizal networks  

Microsoft Academic Search

The concept of a common mycorrhizal network implies that the arrangement of plants and mycorrhizal fungi in a community shares\\u000a properties with other networks. A network is a system of nodes connected by links. Here we apply network theory to mycorrhizas\\u000a to determine whether the architecture of a potential common mycorrhizal network is random or scale-free. We analyzed mycorrhizal\\u000a data

D. Southworth; X.-H. He; W. Swenson; C. S. Bledsoe; W. R. Horwath

2005-01-01

345

Integrated Network Operations for Future Army Tactical Networks  

Microsoft Academic Search

Military Network Operations (NetOps) consist of three main components: network management, network defense (information assurance), and content staging (information dissemination management). NetOps capabilities include organizations, procedures, and technologies required to manage, defend, and utilize a network. Conventionally NetOps components are regarded as functionally orthogonal and operationally independent. However, based on our experience1 with the future Army tactical network that consist

Cho-Yu Jason Chiang; Ritu Chadha; Scott Newman; Richard Lo; Rocio Bauer

2007-01-01

346

Security issues in SCADA networks  

Microsoft Academic Search

The increasing interconnectivity of SCADA (Supervisory Control and Data Acquisition) networks has exposed them to a wide range of network security problems. This paper provides an overview of all the crucial research issues that are involved in strengthening the cyber security of SCADA networks. The paper describes the general architecture of SCADA networks and the properties of some of the

Vinay M. Igure; Sean A. Laughter; Ronald D. Williams

2006-01-01

347

Migration Networks and Immigrant Entrepreneurship  

Microsoft Academic Search

Migration network theory addresses the cumulative causation of migration as a result of reduced social, economic, and emotional costs of migration pursuant to the formation of migration networks. Because it introduces a sociological dimension, network theory improves the mechanical and economistic “push and pull†conceptions that prevailed earlier, including world systems versions thereof. Nonetheless, existing treatments of migration networks overlook

Ivan Light; Parminder Bhachu; Stavros Karageorgis

1989-01-01

348

Distributed computing with parallel networking  

Microsoft Academic Search

For many large scientific applications, computing on a cluster is a viable, economical alternative to a dedicated parallel machine. Application performance on a cluster is largely determined by the speed of the underlying communication network. The authors use a parallel network approach to improve the communication network performance. More specifically, they use multiple networks based on Ethernet to improve the

K. Maly; M. Zubair; S. Kelbar

1993-01-01

349

for Criminal Network Knowledge Discovery  

Microsoft Academic Search

Knowledge about the structure and organization of criminal networks is important for both crime investigation and the development of effective strategies to prevent crimes. However, except for network visualization, criminal network analysis remains primarily a manual process. Existing tools do not provide advanced structural analysis techniques that allow extraction of network knowledge from large volumes of criminal-justice data. To help

JENNIFER J. XU; HSINCHUN CHEN

350

Online social networks in economics  

Microsoft Academic Search

This paper describes how economists study social networks. While economists borrow from other fields like sociology or computer science, their approach of modeling of social networks is distinguished by the emphasis on the role of choices under constraints. Economists investigate how socioeconomic background and economic incentives affect the structure and composition of social networks. The characteristics of social networks are

Adalbert Mayer

2009-01-01

351

Reconfigurable nodes for future networks  

Microsoft Academic Search

Future network architectures aim at solving the shortcomings of the traditional, static Internet architecture. In order to provide optimal service they have to adapt their functionality to different networking situations. This can be achieved by dividing the networking functionality into modular blocks and combining them as required at runtime. While the feasibility and flexibility of novel network architectures have been

Ariane Keller; Bernhard Plattner; Enno Lübbers; Marco Platzner; Christian Plessl

2010-01-01

352

Mapping Networks of Terrorist Cells  

Microsoft Academic Search

This paper looks at the difficulty in mapping covert networks. Analyzing networks afteran event is fairly easy for prosecution purposes. Mapping covert networks to preventcriminal activity is muchmore difficult. Weexamine the network surrounding the tragicevents of September 11th, 2001. Through public data we are able to map a portion of thenetwork centered around the 19 dead hijackers. This map gives

Valdis E. Krebs

2001-01-01

353

Operational principles of neurocognitive networks  

Microsoft Academic Search

Large-scale neural networks are thought to be an essential substrate for the implementation of cognitive function by the brain. If so, then a thorough understanding of cognition is not possible without knowledge of how the large-scale neural networks of cognition (neurocognitive networks) operate. Of necessity, such understanding requires insight into structural, functional, and dynamical aspects of network operation, the intimate

Steven L. Bressler; Emmanuelle Tognoli

2006-01-01

354

Traffic models in broadband networks  

Microsoft Academic Search

Traffic models are at the heart of any performance evaluation of telecommunications networks. An accurate estimation of network performance is critical for the success of broadband networks. Such networks need to guarantee an acceptable quality of service (QoS) level to the users. Therefore, traffic models need to be accurate and able to capture the statistical characteristics of the actual traffic.

A. Adas

1997-01-01

355

A Survey of Opportunistic Networks  

Microsoft Academic Search

We define an opportunistic network as one type of challenged networks where network contacts are intermittent or where link performance is highly variable or extreme. In such a network, there does not exist a complete path from source to destination for most of the time. In addition, the path can be highly unstable and may change or break quickly. Therefore,

Chung-ming Huang; Kun-chan Lan; Chang-zhou Tsai

2008-01-01

356

Seawind: a Wireless Network Emulator  

Microsoft Academic Search

Behavior of current communication protocols as well as current and future networked ap- plications is of fundamental importance for technical and commercial success of Mobile Internet. The forthcoming wireless Wide-Area Networks, such as GPRS and UMTS, are quite complex and network operators have a large set of parameters to tune the transfer performance of these networks. In this situation it

Markku Kojo; Andrei Gurtov; Jukka Manner; Pasi Sarolahti; Timo O. Alanko; Kimmo E. E. Raatikainen

2001-01-01

357

On network coding for security  

Microsoft Academic Search

The use of network coding in military networks opens many interesting issues for security. The mixing of data inherent to network coding may at first appear to pose challenges, but it also enables new security approaches. In this paper, we overview the recent current theoretical understanding and application areas for network-coding based security in the areas of robustness to Byzantine

Keesook Han; Tracey Ho; Ralf Koetter; Muriel M

358

Dynamics in scheduled networks  

NASA Astrophysics Data System (ADS)

When studying real or virtual systems through complex networks theories, usually time restrictions are neglected, and a static structure is defined to characterize which node is connected to which other. However, this approach is oversimplified, as real networks are indeed dynamically modified by external mechanisms. In order to bridge the gap, in this work we present a scheduled network formalism, which takes into account such dynamical modifications by including generic time restrictions in the structure of an extended adjacency matrix. We present some of its properties and apply this formalism to the specific case of the air transportation network in order to analyze its efficiency. Real data are used at this point. We finally discuss on the applicability of this formalism to other complex systems.

Zanin, Massimiliano; Lacasa, Lucas; Cea, Miguel

2009-06-01

359

Hubless Satellite Communications Networks.  

National Technical Information Service (NTIS)

Frequency Comb Multiple Access (FCMA) is a new combined modulation and multiple access method which will allow cheap hubless Very Small Aperture Terminal (VSAT) networks to be constructed. Theoretical results show bandwidth efficiency and power efficiency...

P. A. Robinson

1994-01-01

360

Divers Alert Network  

MedlinePLUS

... Network, the diving industry’s largest association dedicated to scuba diving safety. Serving scuba divers for more than 30 ... to help cover the cost of treatment for scuba diving injuries. DAN fulfilled that need by developing diving’s ...

361

International Rehabilitation Network.  

National Technical Information Service (NTIS)

The International Rehabilitation Network's goal is to improve the quality of services for land mine survivors and other amputees through the dissemination of educational programs and electronic services to rehabilitation professionals. This has been accom...

W. K. Smith

2002-01-01

362

Introduction to Network Security  

NSDL National Science Digital Library

Provided by Internet Security Company Interhack, and written by Matt Curtin, this sixteen-page document is available in HTML, PDF, and Postscript formats. The document includes some history of networking, as well as an introduction to TCP/IP and internetworking. The document then goes on to consider risk management, network threats, firewalls, and more special-purpose secure networking devices. According to the abstract, the author hopes that âÂÂthe reader will have a wider perspective on security in general, and better understand how to reduce and manage risk personally, at home, and in the workplace.â This is a great resource for students and teachers of introductory computer network security and cyber security courses.

Curtin, Matt

2007-09-17

363

Shipboard Wireless Network Applications.  

National Technical Information Service (NTIS)

Recently, the need to leverage technologies for better utilizing valuable personnel resources has become more important Wireless Local Area Networks (WLANs) have been shown to be an enabling technology that allows companies in commercial industry to becom...

T. T. Ly

2001-01-01

364

Communicating Networked Control Systems.  

National Technical Information Service (NTIS)

This report describes research conducted over a twelve month period under support from a multi-university research grant whose focus is the technological foundations of Communicating Networked Control Systems. Coordinated efforts at four participating ins...

J. Baillieul P. R. Kumar P. S. Krishnaprasad R. W. Brockett

2007-01-01

365

Ring Buffered Network Bus.  

National Technical Information Service (NTIS)

This report describes the research effort to demonstrate the integration of a data sharing technology, Ring Buffered Network Bus, in development by Dryden Flight Research Center, with an engine simulation application, the Java Gas Turbine Simulator, in de...

1997-01-01

366

Tools for Network Dynamics  

Microsoft Academic Search

Networks have been studied mainly by statistical methods which em- phasize their topological structure. Here one collects some mathematical tools and results which might be useful to study both the dynamics of

R. VILELA MENDES

2005-01-01

367

Yeast Education Network  

NSDL National Science Digital Library

The Yeast Education Network provides a variety of resources to facilitate use of the budding yeast Saccharomyces cerevisiae in undergraduate science curricula. Laboratory, classroom, and computer-based activities can be used with college and advanced high school students.

368

Trapping in complex networks  

NASA Astrophysics Data System (ADS)

We investigate the trapping problem in Erd?s-Rényi (ER) and scale-free (SF) networks. We calculate the evolution of the particle density ?(t) of random walkers in the presence of one or multiple traps with concentration c. We show using theory and simulations that in ER networks, while for short times ?(t)~exp(-Act), for longer times ?(t) exhibits a more complex behavior, with explicit dependence on both the number of traps and the size of the network. In SF networks we reveal the significant impact of the trap's location: ?(t) is drastically different when a trap is placed on a random node compared to the case of the trap being on the node with the maximum connectivity. For the latter case we find ?(t) propto exp [-At/N?-2/?-1 langlekrangle] for all ?> 2, where ? is the exponent of the degree distribution P(k)~k- ?.

Kittas, A.; Carmi, S.; Havlin, S.; Argyrakis, P.

2008-11-01

369

Local Area Networks.  

National Technical Information Service (NTIS)

A survey of the protocols and literature for the performance analysis of Local Area Networks (LANs) available today is presented. Relevant hardware, in particular the transmission media, is described. The standard reference model is considered. The three ...

A. Dekkers

1990-01-01

370

Biomedical Polyurethane Networks.  

National Technical Information Service (NTIS)

The possibilities of using polyurethanes, especially cross linked ones, as biomaterials are investigated. The preparation, properties, and medical applications of some polyurethane networks are discussed. The design and synthesis of biodegradable lysine d...

P. Bruin

1992-01-01

371

Network Models of Crystals.  

National Technical Information Service (NTIS)

The subject matter of the research on this contract has been two-fold: (1) network models for electrons in solids (2) stochastic models of transport in amorphous materials. A list of publications is included.

E. W. Montroll

1974-01-01

372

Networks: expanding evolutionary thinking.  

PubMed

Networks allow the investigation of evolutionary relationships that do not fit a tree model. They are becoming a leading tool for describing the evolutionary relationships between organisms, given the comparative complexities among genomes. PMID:23764187

Bapteste, Eric; van Iersel, Leo; Janke, Axel; Kelchner, Scot; Kelk, Steven; McInerney, James O; Morrison, David A; Nakhleh, Luay; Steel, Mike; Stougie, Leen; Whitfield, James

2013-06-11

373

Solving Generalized Networks.  

National Technical Information Service (NTIS)

A complete, unified description is given of the design, implementation and use of a family of very fast and efficient large scale minimum-cost (primal simplex) network programs. The class of capacitated generalized transshipment problems solved includes t...

G. G. Brown R. D. McBride

1982-01-01

374

Weakly Secure Network Coding  

Microsoft Academic Search

In this work we consider the problem of secure data transmission on an acyclic multicast network. A new information theoretic model for security is proposed that defines the system as secure if an eavesdropper is unable to get any \\

Kapil Bhattad; Krishna R. Narayanan

2005-01-01

375

Lumped Network Passivity Criteria.  

National Technical Information Service (NTIS)

The classical time-energy definition of passivity is employed to generate workable passivity criteria for lumped networks which are characterizable by standard form state equations. In general, the demonstration of passivity entails the construction of a ...

R. A. Rohrer

1967-01-01

376

Configuring the Networked Citizen  

Microsoft Academic Search

Among legal scholars of technology, it has become commonplace to acknowledge that the design of networked information technologies has regulatory effects. For the most part, that discussion has been structured by the taxonomy developed by Lawrence Lessig, which classifies \\

Julie E. Cohen

2012-01-01

377

Progressive street networks  

NASA Astrophysics Data System (ADS)

The multi-scale representation model and the corresponding generalization method for constructing it are two key issues involved in the progressive transmission of vector map data. In this paper, the characteristics of existing approaches to the generalization of streets are summarized based on an analysis of the literature. A progressive street network representation model is introduced. Information theory has been applied for a better understanding of why and when to generalize. The metric information, topological information and thematic information are quantified for the street network. A progressive generalization algorithm of street network based on information theory is investigated. An experiment is also conducted on an urban street network map from the Compilation specifications for 1:25000 1:50000 topographic maps (GB 12343-90). This paper tries to state that progressive representation needs the support from corresponding progressive generalization algorithm and tries to introduce information theory to solve the problem of "how to generalize".

Tian, J.; Guo, Q. S.; Zhan, T.

2008-10-01

378

Actively Stressed Marginal Networks  

NASA Astrophysics Data System (ADS)

We study the effects of motor-generated stresses in disordered three-dimensional fiber networks using a combination of a mean-field theory, scaling analysis, and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of nonaffine strain fluctuations as a susceptibility to motor stress.

Sheinman, M.; Broedersz, C. P.; MacKintosh, F. C.

2012-12-01

379

The Cooperative Information Network.  

National Technical Information Service (NTIS)

The Library Directors of Santa Clara County in July, 1972, organized the Cooperative Information Network (CIN), funded under the Library Services and Construction Act. The present CIN covers only information and reference services. CIN is composed of 83 l...

S. E. Choi

1973-01-01

380

Social Network Change Detection.  

National Technical Information Service (NTIS)

Changes in observed social networks may signal an underlying change within an organization, and may even predict significant events or behaviors. The breakdown of a team's effectiveness, the emergence of informal leaders, or the preparation of an attack b...

I. A. McCulloh K. M. Carley

2008-01-01

381

International Rehabilitation Network.  

National Technical Information Service (NTIS)

Improving the quality of services for landmine survivors and other- amputees in low-income Countries is the primary goal of the International Rehabilitation network (IRN). This is being accomplished through the dissemination of educational programs and el...

W. K. Smith Y. Wu

2004-01-01

382

CORE Network Background Paper  

Center for Food Safety and Applied Nutrition (CFSAN)

... Response and Evaluation Network, in August 2011, it brought together a full-time team with expertise in medicine, public health and science that is ... More results from www.fda.gov/food/recallsoutbreaksemergencies/outbreaks

383

Broadband Accelerator Control Network.  

National Technical Information Service (NTIS)

A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz...

J. Skelly T. Clifford R. Frankel

1983-01-01

384

Network connectivity entropy and its application on network connectivity reliability  

NASA Astrophysics Data System (ADS)

The network structure entropy has served as one of the index measuring network heterogeneity, but it gives no considerations to the impact of isolated nodes on the network structure. In addition, the all-terminal reliability is zero and is unable to compare it between disconnected networks. Therefore, the concept of network connectivity entropy is suggested to remove the current bottleneck and helps facilitate new index in terms of network connectivity reliability. This study fully proves the rules as follows: when the edges of network are diminishing, the newly-established network connectivity reliability will remain unchanged or become weaker; conversely, when the edges of network are increasing, the network connectivity reliability will remain unchanged or become stronger. Thus, the proposed index of network connectivity reliability is proved reasonable. Furthermore, the impaired metro network of Nanjing city is exemplified to demonstrate the validity and practicability of network connectivity reliability. The result shows that this new approach is in good position to compute network connectivity reliability quickly and effectively, and also to compare it between different networks.

Wu, Liusan; Tan, Qingmei; Zhang, Yuehui

2013-11-01

385

Networking know-how [online networking  

Microsoft Academic Search

This paper discusses the latest trend in online job hunting and hiring, i.e. tapping social and professional networking sites. These sites typically allow you to post a profile, listing information about yourself as well as services and skills you have to offer. Reciprocal connections can also be made between the profiles of different users, allowing for friend-of-a-friend style introductions. These

S. Karlin

2005-01-01

386

Complex networks theory for analyzing metabolic networks  

Microsoft Academic Search

One of the main tasks of post-genomic informatics is to systematically investigate all molecules and their interactions within\\u000a a living cell so as to understand how these molecules and the interactions between them relate to the function of the organism,\\u000a while networks are appropriate abstract description of all kinds of interactions. In the past few years, great achievement\\u000a has been

Jing Zhao; Hong Yu; Jianhua Luo; Z. W. Cao; Yi-Xue Li

2006-01-01

387

High speed networking evolution  

Microsoft Academic Search

The author describes the evolution of computer networks and the impact of the very-high-speed, very-low-bit-error-rate transmission media. Some of the new high-speed switched services that will likely be offered by the communications carriers in the US in the next few years are discussed. The focus is on the wide area network (WAN) environment. The current US communications environment is described.

D. Abensour

1990-01-01

388

Interpenetrating polymer networks  

SciTech Connect

The `Interpenetrating Polymer Networks` symposium was sponsored by the Division of Polymeric Materials: Science and Engineering, of the American Chemical Society in 1991 at New York City, NY. Presented at the symposium were articles related to various aspects of polymer networks including Synthesis and Structure; Miscibility and Morphology; Structure-Property Relationships; Transport and Permeability; and Functionalized Triglyceride Oils. Chemical preparation, structure, environmental and structural applications of a variety of polymers are discussed.

Klempner, D.; Sperling, L.H.; Utracki, L.A. [eds.

1994-12-31

389

Evolution of networks  

Microsoft Academic Search

We review the recent fast progress in statistical physics of evolving\\u000anetworks. Interest has focused mainly on the structural properties of random\\u000acomplex networks in communications, biology, social sciences and economics. A\\u000anumber of giant artificial networks of such a kind came into existence\\u000arecently. This opens a wide field for the study of their topology, evolution,\\u000aand complex processes

S. N. Dorogovtsev; J. F. F. Mendes

2002-01-01

390

Characterizing residential broadband networks  

Microsoft Academic Search

A large and rapidly growing proportion of users connect to the Internet via residential broadband networks such as Dig- ital Subscriber Lines (DSL) and cable. Residential networks are often the bottleneck in the last mile of today's Internet. Their characteristics critically affect Internet applications, including voice-over-IP, online games, and peer-to-peer con- tent sharing\\/delivery systems. However, to date, few studies have

Marcel Dischinger; Andreas Haeberlen; P. Krishna Gummadi; Stefan Saroiu

2007-01-01

391

Trends in Telecommunication Networking  

Microsoft Academic Search

The evolution of telecommunications is rapidly advancing. New technologies foster new applications and vice versa. The up\\u000a to now diverse networks are converging towards an all-IP network. On the other hand, the variety of access technologies is\\u000a even more increasing, and will bring us quicker than expected to the final goal: A world where communication is possible everywhere,\\u000a every time

Jörg Eberspächer

392

A balanced memory network  

Microsoft Academic Search

A fundamental problem in neuroscience is understanding how working memory --\\u000athe ability to store information at intermediate timescales, like 10s of\\u000aseconds -- is implemented in realistic neuronal networks. The most likely\\u000acandidate mechanism is the attractor network, and a great deal of effort has\\u000agone toward investigating it theoretically. Yet, despite almost a quarter\\u000acentury of intense work,

Yasser Roudi; Peter E. Latham

2007-01-01

393

Embedded Sensor Networks  

Microsoft Academic Search

An embedded sensor network is a network of embedded computers placed in the physical world that interacts with the environment. These embedded computers,\\u000a or sensor nodes, are often physically small, relatively inexpensive computers, each with some set of sensors or actuators. These sensor nodes\\u000a are deployed in situ, physically placed in the environment near the objects they are sensing. Sensor

John S. Heidemann; Ramesh Govindan

2005-01-01

394

Visual Digest Networks  

Microsoft Academic Search

Attention, understanding and abstraction are three key elements in our visual communication that we have taken for granted.\\u000a These interconnected elements constitute a Visual Digest Network. In this chapter, we investigate the conceptual design of\\u000a Visual Digest Networks at three visual abstraction levels: gaze, object and word. The goal is to minimize the media footprint\\u000a during visual communication while sustaining

Yang Cai; Guillaume Milcent; Ludmila Marian

395

Decentralized Online Social Networks  

Microsoft Academic Search

\\u000a Current Online social networks (OSN) are web services run on logically centralized infrastructure. Large OSN sites use content\\u000a distribution networks and thus distribute some of the load by caching for performance reasons, nevertheless there is a central\\u000a repository for user and application data. This centralized nature of OSNs has several drawbacks including scalability, privacy,\\u000a dependence on a provider, need for

Anwitaman Datta; Sonja Buchegger; Le-Hung Vu; Thorsten Strufe; Krzysztof Rzadca

2010-01-01

396

Rheothermodynamics of transient networks  

Microsoft Academic Search

The transient network model of Green-Tobolsky [1946], Yamamoto [1956] and\\u000aTanaka-Edwards [1992] is formulated within the frame of thermodynamics of\\u000airreversible processes, using as a fundamental quantity the chemical potential\\u000aassociated to the connection of strands to the network and treating these\\u000aconnections as chemical-like reactions. All thermodynamic quantities are thus\\u000anaturally defined in and out of equilibrium. Constitutive equations

Jean-François Palierne

2000-01-01

397

Rheothermodynamics of transient networks  

Microsoft Academic Search

The transient network model of Green-Tobolsky [1946], Yamamoto [1956] and Tanaka-Edwards [1992] is formulated within the frame of thermodynamics of irreversible processes, using as a fundamental quantity the chemical potential associated to the connection of strands to the network and treating these connections as chemical-like reactions. All thermodynamic quantities are thus naturally defined in and out of equilibrium. Constitutive equations

J. F. Palierne

2000-01-01

398

Global Oscillation Network Group  

NASA Astrophysics Data System (ADS)

The Global Oscillation Network Group (GONG) is an international, community-based project, operated by the NATIONAL SOLAR OBSERVATORY for the US National Science Foundation, to conduct a detailed study of the internal structure and dynamics of the Sun over an 11 year solar cycle using helioseismology. 10 242 velocity images are obtained by a six-station network located at Big Bear Solar Observato...

Murdin, P.

2000-11-01

399

Global Telescope Network Website  

NSDL National Science Digital Library

This Web site contains information for both partners (those with their own telescopes) and associates (those who wish to use a network telescope.) The purpose of the Global Telescope Network (GTN) is to use small telescopes to obtain ground-based observations of high-energy objects of interest to Swift, GLAST (renamed Fermi in 2008) and XMM-Newton missions. It is used both by formal educators working with students and by amateur astronomers.

2005-06-14

400

Categorical Tensor Network States  

Microsoft Academic Search

We examine the use of the mathematics of category theory in the description of quantum states by tensor networks. This approach enables the development of a categorical framework allowing a solution to the quantum decomposition problem. Specifically, given an $n$-body quantum state $\\\\ket{\\\\psi}$, we present a general method to factor $\\\\ket{\\\\psi}$ into a tensor network. Moreover, this decomposition of $\\\\ket{\\\\psi}$

Jacob D. Biamonte; Stephen R. Clark; Dieter Jaksch

2010-01-01

401

Categorical Tensor Network States  

Microsoft Academic Search

We examine the use of the mathematics of category theory in the description\\u000aof quantum states by tensor networks. This approach enables the development of\\u000aa categorical framework allowing a solution to the quantum decomposition\\u000aproblem. Specifically, given an $n$-body quantum state $\\\\ket{\\\\psi}$, we present\\u000aa general method to factor $\\\\ket{\\\\psi}$ into a tensor network. Moreover, this\\u000adecomposition of $\\\\ket{\\\\psi}$

Jacob D. Biamonte; Stephen R. Clark; Dieter Jaksch

2010-01-01

402

Knitted Complex Networks  

Microsoft Academic Search

To a considerable extent, the continuing importance and popularity of complex\\u000anetworks as models of real-world structures has been motivated by scale free\\u000adegree distributions as well as the respectively implied hubs. Being related to\\u000asequential connections of edges in networks, paths represent another important,\\u000adual pattern of connectivity (or motif) in complex networks (e.g., paths are\\u000arelated to important

Luciano da Fontoura Costa

2007-01-01

403

Multicamera Networks: New eyes  

Microsoft Academic Search

According to ancient Greek mythology, Argus, the hundred-eyed guardian of the goddess Hera, alone defeated a whole army of Cyclopes, one-eyed giants. The mythological power of many eyes becomes a reality in this book, after seeing the capabilities of current multi camera networks. The preceding chapters have communi- cated the excitement around this newly formed field. Multi-camera networks are new

Marcel Proust

404

Multicast Overlay Network  

Microsoft Academic Search

Abstract Peer-to-Peer Overlay networks enabling an end-end application level-multicast service have drawn enormous attention. This paper proposes a self- organized -Multicast Overlay Network (-MON) that enables an efficient end-end application level multicast. The -MON is organized into MON- Clusters, where delta is the maximum physical number of hops between any two end-nodes in each MON-Cluster. Thus, end-users accessing from different

Khaled Ragab

2007-01-01

405

Leaf Pack Network  

NSDL National Science Digital Library

The Leaf Pack Network (LPN) is a network of teachers and students investigating their local stream ecosystems by participating in the leaf pack experiment, which involves creating an artificial leaf pack (dry leaves in a mesh bag), immersing it in a stream for 3-4 weeks, and examining it for signs of aquatic insects as indicators of stream health. Participating classrooms share their data through the internet. This activity highlights the connection between streamside forests and the ecology of rivers and streams.

406

Majority Gate Networks  

Microsoft Academic Search

This paper presents methods for realizing simple threshold functions of n arguments by networks of k-input majority gates, where k?n. An optimal network realization of the 5-argument majority function using 3-input majority gates is given, and it is then generalized by steps with realizations for the (2n-l)-argument majority function (where n = 3, 4, ...) using (2n-3)-input majority gates, and

S. Amarel; G. Cooke; R. O. Winder

1964-01-01

407

Neural networks in seismic discrimination  

SciTech Connect

Neural networks are powerful and elegant computational tools that can be used in the analysis of geophysical signals. At Lawrence Livermore National Laboratory, we have developed neural networks to solve problems in seismic discrimination, event classification, and seismic and hydrodynamic yield estimation. Other researchers have used neural networks for seismic phase identification. We are currently developing neural networks to estimate depths of seismic events using regional seismograms. In this paper different types of network architecture and representation techniques are discussed. We address the important problem of designing neural networks with good generalization capabilities. Examples of neural networks for treaty verification applications are also described.

Dowla, F.U.

1995-01-01

408

Network Probe 0.5  

NSDL National Science Digital Library

Network Probe 0.5 is a free network monitor and protocol analyzer that offers users an immediate picture of the current traffic situation on their network. Network Probe 0.5 also gives users the option to identify and isolate traffic problems and congestion throughout their entire network. Adding breadth and depth to the available features is the fact that users may also filter out selected protocols and hosts, along with sorting out network traffic by the amount of bytes sent or received. Network Probe 0.5 is compatible with all systems running Windows NT and higher.

409

DNA Structure and Supercoiling: Ribbons and a Yo-Yo Model  

ERIC Educational Resources Information Center

|The double-helical structure of DNA is a pop cultural icon. Images of the DNA molecule appear in newspapers, popular journals, and advertisements. In addition to scientific instrument sales, the aura surrounding the central molecule of life has been used to sell everything from perfume to beverages and is the inspiration of items ranging from…

Van Horn, J. David

2011-01-01

410

Fuzzy Modeling Using Chaotic Particle Swarm Approaches Applied to a Yo-yo Motion System  

Microsoft Academic Search

A method of nonlinear identification based on the Takagi-Sugeno (TS) fuzzy model and optimization procedure is proposed in this paper. New chaotic particle swarm optimization algorithms based on Zaslavskii chaotic map sequences combined with efficient Gustafson-Kessel (GK) clustering algorithm are proposed here for the design of the premise part of production rules, while the least mean squares technique is utilized

L. dos Santos Coelho; B. M. Herrera

2006-01-01

411

Funnelling Effect in Networks  

NASA Astrophysics Data System (ADS)

Funnelling effect, in the context of searching on networks, precisely indicates that the search takes place through a few specific nodes. We define the funnelling capacity f of a node as the fraction of successful dynamic paths through it with a fixed target. The distribution D(f) of the fraction of nodes with funnelling capacity f shows a power law behaviour in random networks (with power law or stretched exponential degree distribution) for a considerable range of values of the parameters defining the networks. Specifically we study in detail D 1 = D(f = 1), which is the quantity signifying the presence of nodes through which all the dynamical paths pass through. In scale free networks with degree distribution P(k) ? k - ? , D 1 increases linearly with ? initially and then attains a constant value. It shows a power law behaviour, D_1 ? N^{-?}, with the number of nodes N where ? is weakly dependent on ? for ?> 2.2. The latter variation is also independent of the number of searches. On stretched exponential networks with P(k) ? exp{(-k^?)}, ? is strongly dependent on ?. The funnelling distribution for a model social network, where the question of funnelling is most relevant, is also investigated.

Sen, Parongama

412

Subsurface Wireless Sensor Networks  

NASA Astrophysics Data System (ADS)

Conventional thinking holds that underground- and underwater radio communication is not possible, except at very low frequencies employing very long antennas and high transmit power. However, researchers at The University of Iowa have demonstrated that using inexpensive, low-power radios, it is in fact possible to achieve reliable underground radio communication over distances of several meters. This allows for creating underground wireless sensor networks. A proof-of-concept network was established at The University of Iowa, where nodes that measure soil moisture content are buried over a 20×20 m area (up to 1 m deep). The nodes organize themselves into a wireless sensor network, reconfigure routes as radio link quality waxes and wanes, cooperate in routing data packets to a surface base station, and so on. In an agricultural research setting, an advantage of such buried wireless sensor networks is that, if nodes were buried deep enough, they may be left in place during agricultural field work. Power consumption is an important issue in wireless sensor networks. This is especially true in a buried network where battery replacement is a major undertaking. The focus of continuing research is developing methods of inductively recharging buried sensor batteries.

Niemeier, J. J.; Davies, J. L.; Kruger, A.

2008-12-01

413

ONE: The Ohio Network Emulator  

Microsoft Academic Search

Studying network protocols and distributed applications in real networks can bedifficult due to the need for complex topologies, hard to find physical channels (e.g.,satellite channels), and conditions beyond the control of a researcher (e.g., queue sizes).Network emulators can provide a controlled and reproducible environment for networktesting. This paper discusses ONE, a network emulator we have written and tested.1 IntroductionNetwork emulators,

Adam Caldwell; Mark Allman; Shawn Ostermann

1996-01-01

414

Interactome networks and human disease.  

PubMed

Complex biological systems and cellular networks may underlie most genotype to phenotype relationships. Here, we review basic concepts in network biology, discussing different types of interactome networks and the insights that can come from analyzing them. We elaborate on why interactome networks are important to consider in biology, how they can be mapped and integrated with each other, what global properties are starting to emerge from interactome network models, and how these properties may relate to human disease. PMID:21414488

Vidal, Marc; Cusick, Michael E; Barabási, Albert-László

2011-03-18

415

Computing preimages of Boolean networks  

PubMed Central

In this paper we present an algorithm based on the sum-product algorithm that finds elements in the preimage of a feed-forward Boolean networks given an output of the network. Our probabilistic method runs in linear time with respect to the number of nodes in the network. We evaluate our algorithm for randomly constructed Boolean networks and a regulatory network of Escherichia coli and found that it gives a valid solution in most cases.

2013-01-01

416

Introduction to Social Network Analysis  

Microsoft Academic Search

Social Network analysis focuses on patterns of relations between and among people, organizations, states, etc. It aims to\\u000a describe networks of relations as fully as possible, identify prominent patterns in such networks, trace the flow of information\\u000a through them, and discover what effects these relations and networks have on people and organizations. Social network analysis\\u000a offers a very promising potential

Panayiotis Zaphiris; Chee Siang Ang

2009-01-01

417

From photo networks to social networks, creation and use of a social network derived with photos  

Microsoft Academic Search

With the new possibilities in communication and information management, social networks and photos have received plenty of attention in the digital age. In this paper, we show how social photos, captured during family events, representing individuals or groups, can be visualized as a network that reveals social attributes. From this photo network, social network is extracted that can help to

Michel Plantié; Michel Crampes

2010-01-01

418

Network Motifs: Simple Building Blocks of Complex Networks  

NASA Astrophysics Data System (ADS)

Complex networks are studied across many fields of science. To uncover their structural design principles, we defined ``network motifs,'' patterns of interconnections occurring in complex networks at numbers that are significantly higher than those in randomized networks. We found such motifs in networks from biochemistry, neurobiology, ecology, and engineering. The motifs shared by ecological food webs were distinct from the motifs shared by the genetic networks of Escherichia coli and Saccharomyces cerevisiae or from those found in the World Wide Web. Similar motifs were found in networks that perform information processing, even though they describe elements as different as biomolecules within a cell and synaptic connections between neurons in Caenorhabditis elegans. Motifs may thus define universal classes of networks. This approach may uncover the basic building blocks of most networks.

Milo, R.; Shen-Orr, S.; Itzkovitz, S.; Kashtan, N.; Chklovskii, D.; Alon, U.

2002-10-01

419

Synthesis and characterization of a NaSICON series with general formula Na2.8Zr2-ySi1.8-4yP1.2+4yO12 (0?y?0.45)  

NASA Astrophysics Data System (ADS)

In this work, we present the synthesis and the characterization of ionic conducting ceramics of NaSICON-type (Natrium super ionic conductor). The properties of this ceramic make it suitable for use in electrochemical devices. These solid electrolytes can be used as sensors for application in the manufacturing of potentiometric gas sensors, for the detection of pollutant emissions and for environment control. The family of NaSICON that we studied has as a general formula Na2.8Zr2-ySi1.8-4yP1.2+4yO12 with 0?y?0.45. The various compositions were synthesized by produced using the sol-gel method. The electric properties of these compositions were carried out by impedance spectroscopy. The results highlight the good conductivity of the Na2.8Zr1.775Si0.9P2.1O12 composition.

Essoumhi, A.; Favotto, C.; Mansori, M.; Satre, P.

2004-12-01

420

Topological Patterns of Spatial Urban Street Networks  

Microsoft Academic Search

In this paper we analyze the structural properties of four urban street networks in China based on GIS and complex networks theory. We consider the street networks as spatial networks and use the primal approach to turn the GIS data into graph. The urban street networks display similar topological patterns and deviate from random networks and central planned networks, despite

Yihong Hu; Qinmin Wu; Daoli Zhu

2008-01-01

421

Secure Network Coding with a Cost Criterion  

Microsoft Academic Search

Network cost and network security are two of many network parameters that are important to network users. While these two parameters have been separately considered in coded networks (networks that employ network coding), a joint investigation of them both has not been done yet to our knowledge, thus providing the motivation for this work. In this paper, we consider the

Jianlong Tan; M. Medard

2006-01-01

422

Management of coalition sensor networks  

NASA Astrophysics Data System (ADS)

The management of sensor networks in coalition settings has been treated in a piecemeal fashion in the current literature without taking a comprehensive look at the complete life cycle of coalition networks, and determining the different aspects of network management that need to be taken into account for the management of sensor networks in those contexts. In this paper, we provide a holistic approach towards managing sensor networks encountered in the context of coalition operations. We describe how the sensor networks in a coalition ought to be managed at various stages of the life cycle, and the different operations that need to be taken into account for managing various aspects of the networks. In particular, we look at the FCAPS model for network management, and assess the applicability of the FCAPS model to the different aspects of sensor network management in a coalition setting.

Verma, Dinesh Chandra; Brown, Theodore; Ortega, Carolyn

2010-04-01

423

Social Network Visualization in Epidemiology  

PubMed Central

Epidemiological investigations and interventions are increasingly focusing on social networks. Two aspects of social networks are relevant in this regard: the structure of networks and the function of networks. A better understanding of the processes that determine how networks form and how they operate with respect to the spread of behavior holds promise for improving public health. Visualizing social networks is a key to both research and interventions. Network images supplement statistical analyses and allow the identification of groups of people for targeting, the identification of central and peripheral individuals, and the clarification of the macro-structure of the network in a way that should affect public health interventions. People are inter-connected and so their health is inter-connected. Inter-personal health effects in social networks provide a new foundation for public health.

Christakis, Nicholas A.; Fowler, James H.

2010-01-01

424

Networks of Emotion Concepts  

PubMed Central

The aim of this work was to study the similarity network and hierarchical clustering of Finnish emotion concepts. Native speakers of Finnish evaluated similarity between the 50 most frequently used Finnish words describing emotional experiences. We hypothesized that methods developed within network theory, such as identifying clusters and specific local network structures, can reveal structures that would be difficult to discover using traditional methods such as multidimensional scaling (MDS) and ordinary cluster analysis. The concepts divided into three main clusters, which can be described as negative, positive, and surprise. Negative and positive clusters divided further into meaningful sub-clusters, corresponding to those found in previous studies. Importantly, this method allowed the same concept to be a member in more than one cluster. Our results suggest that studying particular network structures that do not fit into a low-dimensional description can shed additional light on why subjects evaluate certain concepts as similar. To encourage the use of network methods in analyzing similarity data, we provide the analysis software for free use (http://www.becs.tkk.fi/similaritynets/).

Toivonen, Riitta; Kivela, Mikko; Saramaki, Jari; Viinikainen, Mikko; Vanhatalo, Maija; Sams, Mikko

2012-01-01

425

Digital graphic network  

NASA Astrophysics Data System (ADS)

The graphic arts industry is increasingly reliant on telecommunications for the transfer of digital data for media production. There are, however, many other aspects of the business process between customers and suppliers that are suited to network-based interaction. The transaction between customer and producer can be separated into four data streams: briefing, content creation and production, and approval. Each of these data streams has specific requirements which lead to a matrix of needs for the different parties in the transaction. These needs are reviewed and proposals made for meeting them through a network service dedicated to the graphic arts. British Telecom, MCI and Scitex are currently beta-testing a service based on these proposals, known as the Digital Graphic Network. Once a managed network service is in place, it is possible to extend it to include a range of other services and third-party interactions, such as automated transfer of media production objects such as high-resolution images, fonts, color profiles, etc. from third-party content providers. The opportunities for users and third-party developers to develop a custom interface between the network and internal production processes and monitoring systems using open systems based on the Java language is described.

Green, Phil

1998-09-01

426

Digital graphic networks  

NASA Astrophysics Data System (ADS)

The graphic arts industry is increasingly reliant on telecommunications for the transfer of digital data for media production. There are, however, many other aspects of the business process between customers and supplies that are suited to network-based interaction. The transaction between customer and producer can be separated into four data streams; briefing, content creation and production, and approval. Each of these data streams has specific requirements which lead to a matrix of needs for the different parties in the transaction. Proposals were made for meeting these needs through a network service dedicated to the graphic arts. British Telecom and Scitex are currently offering a service based on these proposals, known as Vio. A network service of this kind can be extended to include a range of other services and third-party interactions, such as automated transfer of media production objects from third-party content providers. The opportunities for users and third-party developers to develop a custom network applications and interfaces between the network and internal production processes and monitoring systems using open IP-based methods are described.

Green, Phil

1998-12-01

427

The Biomedical Communications Network *  

PubMed Central

The Biomedical Communications Network (BCN) is the embodiment of the plans of the National Library of Medicine to provide improved information, document, and education services to the health community. The BCN also will be the “core” public service network to ensure the most expeditious delivery of health information and education products to a selected public. As such, utilization of communications satellites as well as other more common forms of telecommunications are planned. The library component of the Network will provide decentralized library services to medical libraries, medical schools, hospitals, MEDLARS Centers, local medical centers and individual medical practitioners. These decentralized services will be provided through an information network with its hub at the Bethesda, Maryland site of the NLM. The NLM intends that the library services network be a controlled rather than a permissive system. This simply implies that participation and access to the services of the system will be determined by the NLM. Planning has already progressed to the point where services to be provided can be enumerated.

McCarn, Davis B.

1969-01-01

428

Social Network Infiltration  

NASA Astrophysics Data System (ADS)

Social networks are websites (or software that distributes media online) where users can distribute content to either a list of friends on that site or to anyone who surfs onto their page, and where those friends can interact and discuss the content. By linking to friends online, the users’ personal content (pictures, songs, favorite movies, diaries, websites, and so on) is dynamically distributed, and can "become viral", that is, get spread rapidly as more people see it and spread it themselves. Social networks are immensely popular around the planet, especially with younger users. The biggest social networks are Facebook and MySpace; an IYA2009 user already exists on Facebook, and one will be created for MySpace (in fact, several NASA satellites such as GLAST and Swift already have successful MySpace pages). Twitter is another network where data distribution is more limited; it is more like a mini-blog, but is very popular. IYA2009 already has a Twitter page, and will be updated more often with relevant information. In this talk I will review the existing social networks, show people how and why they are useful, and give them the tools they need to contribute meaningfully to IYA's online reach.

Plait, Philip

2008-05-01

429

Network modularity promotes cooperation.  

PubMed

Cooperation in animals and humans is widely observed even if evolutionary biology theories predict the evolution of selfish individuals. Previous game theory models have shown that cooperation can evolve when the game takes place in a structured population such as a social network because it limits interactions between individuals. Modularity, the natural division of a network into groups, is a key characteristic of all social networks but the influence of this crucial social feature on the evolution of cooperation has never been investigated. Here, we provide novel pieces of evidence that network modularity promotes the evolution of cooperation in 2-person prisoner's dilemma games. By simulating games on social networks of different structures, we show that modularity shapes interactions between individuals favouring the evolution of cooperation. Modularity provides a simple mechanism for the evolution of cooperation without having to invoke complicated mechanisms such as reputation or punishment, or requiring genetic similarity among individuals. Thus, cooperation can evolve over wider social contexts than previously reported. PMID:23261393

Marcoux, Marianne; Lusseau, David

2012-12-19

430

Network design tool for EHF satellite communications networks  

NASA Astrophysics Data System (ADS)

This document describes the design concept of the network design tool. The network design tool (NDT) is a collection of analytical techniques, algorithms and simulation methods that may be used to characterize the performance of a computer communication network. Much work has been done over the past several years in network performance analysis and many techniques have been developed or proposed. Each of these methods applies to a particular aspect of the network design and is based on a particular modeling point of view. We define the computer communication network and then describe the different ways the network may be modeled. Each network model is related to the particular design problem being addressed. The various analytical approaches are briefly described and their relationship to the network models discussed. Chapter 2 is a survey of the major approaches to specific network design problems while chapters 3 and 4 discuss two fairly well defined areas of network analysis: topological design/optimization and protocol validation. Chapter 5 is a survey of network design tools presently available locally or on the advanced research projects agency network (ARPANET). Finally, chapter 6 presents an outline of the NDT specification.

Norvell, S.; Brown, G. J.

1983-06-01

431

Border detection in complex networks  

NASA Astrophysics Data System (ADS)

One important issue implied by the finite nature of real-world networks regards the identification of their more external (border) and internal nodes. The present work proposes a formal and objective definition of these properties, founded on the recently introduced concept of node diversity. It is shown that this feature does not exhibit any relevant correlation with several well-established complex networks measurements. A methodology for the identification of the borders of complex networks is described and illustrated with respect to theoretical (geographical and knitted networks) as well as real-world networks (urban and word association networks), yielding interesting results and insights in both cases.

Travençolo, Bruno A. N.; Viana, Matheus Palhares; Costa, Luciano da Fontoura

2009-06-01

432

High speed optical networks  

NASA Astrophysics Data System (ADS)

This overview will discuss core network technology and cost trade-offs inherent in choosing between "analog" architectures with high optical transparency, and ones heavily dependent on frequent "digital" signal regeneration. The exact balance will be related to the specific technology choices in each area outlined above, as well as the network needs such as node geographic spread, physical connectivity patterns, and demand loading. Over the course of a decade, optical networks have evolved from simple single-channel SONET regenerator-based links to multi-span multi-channel optically amplified ultra-long haul systems, fueled by high demand for bandwidth at reduced cost. In general, the cost of a well-designed high capacity system is dominated by the number of optical to electrical (OE) and electrical to optical (EO) conversions required. As the reach and channel capacity of the transport systems continued to increase, it became necessary to improve the granularity of the demand connections by introducing (optical add/drop multiplexers) OADMs. Thus, if a node requires only small demand connectivity, most of the optical channels are expressed through without regeneration (OEO). The network costs are correspondingly reduced, partially balanced by the increased cost of the OADM nodes. Lately, the industry has been aggressively pursuing a natural extension of this philosophy towards all-optical "analog" core networks, with each demand touching electrical digital circuitry only at the in/egress nodes. This is expected to produce a substantial elimination of OEO costs, increase in network capacity, and a notionally simpler operation and service turn-up. At the same time, such optical "analog" network requires a large amount of complicated hardware and software for monitoring and manipulating high bit rate optical signals. New and more complex modulation formats that provide resiliency to both optical noise and nonlinear propagation effects are important for extended unregenerated reach. More sophisticated optical amplifiers provide lower noise for increased reach and increased spectral bandwidth for higher wavelength count lower wavelength blocking probability. Optical analog networks also require methods for mitigating optical power transients, for controlling optical spectral flatness, and for dynamically managing changes (e.g. in chromatic dispersion and polarization mode dispersion.) Since signals stay in the optical domain, optical performance monitoring techniques are required for fault isolation and correction. Efficient routing of optical signals also requires sophisticated switching nodes with an ability to selectively steer optical signals into several directions with single-channel spectral granularity. Most of these technologies are not modular and require interruption of service if not deployed at the initial system installation, thereby increasing first install costs substantially, even if initial capacity loading is small. Further, validation of systems and software targeting a specific network design is complex. Only a small fraction of the total network may be reasonably reproduced in the lab, and many field configurations are not predictable or even dynamic. Thus, extra system margin has to be allocated to handle the behavior uncertainty. To constrain the complexity of both hardware technology and software algorithms, regions of network transparency can be established with OEO forced at perimeters. Thus, "analog" regions are surrounded by "digital" interfaces. Following are some example tradeoffs that will be discussed. What is a good modulation format choice, and does increased reach and impairment resiliency justify hardware and controls that are more complicated? What are reasonable amplifier choices to make under specific network assumptions? Can high transport system capacity be leveraged to simplify optical switch node design by reducing spectral efficiency?

Frankel, Michael Y.; Livas, Jeff

2005-02-01

433

Gossip in Random Networks  

NASA Astrophysics Data System (ADS)

We consider the average probability X of being informed on a gossip in a given social network. The network is modeled within the random graph theory of Erd{õ}s and Rényi. In this theory, a network is characterized by two parameters: the size N and the link probability p. Our experimental data suggest three levels of social inclusion of friendship. The critical value pc, for which half of agents are informed, scales with the system size as N-gamma with gamma approx 0.68. Computer simulations show that the probability X varies with p as a sigmoidal curve. Influence of the correlations between neighbors is also evaluated: with increasing clustering coefficient C, X decreases.

Malarz, K.; Szvetelszky, Z.; Szekf, B.; Kulakowski, K.

2006-11-01

434

Programmable multimode quantum networks  

PubMed Central

Entanglement between large numbers of quantum modes is the quintessential resource for future technologies such as the quantum internet. Conventionally, the generation of multimode entanglement in optics requires complex layouts of beamsplitters and phase shifters in order to transform the input modes into entangled modes. Here we report the highly versatile and efficient generation of various multimode entangled states with the ability to switch between different linear optics networks in real time. By defining our modes to be combinations of different spatial regions of one beam, we may use just one pair of multi-pixel detectors in order to measure multiple entangled modes. We programme virtual networks that are fully equivalent to the physical linear optics networks they are emulating. We present results for N=2 up to N=8 entangled modes here, including N=2, 3, 4 cluster states. Our approach introduces the highly sought after attributes of flexibility and scalability to multimode entanglement.

Armstrong, Seiji; Morizur, Jean-Francois; Janousek, Jiri; Hage, Boris; Treps, Nicolas; Lam, Ping Koy; Bachor, Hans-A.

2012-01-01

435

Patient Safety Network  

NSDL National Science Digital Library

The Agency for Healthcare Research and Quality (AHRQ) Patient Safety Network (PSNet) website contains recent news and resources to provide those studying to be in the medical profession and for those currently in the medical field. Resources include an extensive glossary as well as a vast supply of articles from various periodicals. The site also contains numerous �Did You Know?� articles that include visual aids and citations. Articles can be sorted or browsed by target audience, resource type, clinical area, error type, safety target, approach to improving safety, and setting of care. Users have the ability to sign up for the weekly AHRQ Patient Safety Network and monthly AHRQ Web Morbidity and Mortality (WEBM&M) newsletters. Users may also sign up for a free account on the AHRQ Patient Safety Network website to receive e-mail alerts that match the users' interests.

2007-02-15

436

Synchronization in complex networks  

SciTech Connect

Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

2007-12-12

437

Semilocal cosmic string networks  

SciTech Connect

We report on a large-scale numerical study of networks of semilocal cosmic strings in flat space in the parameter regime in which they are perturbatively stable. We find a population of segments with an exponential length distribution and indications of a scaling network without significant loop formation. Very deep in the stability regime strings of superhorizon size grow rapidly and ''percolate'' through the box. We believe these should lead at late times to a population of infinite strings similar to topologically stable strings. However, the strings are very light; scalar gradients dominate the energy density, and the network has thus a global texturelike signature. As a result, the observational constraints, at least from the temperature power spectrum of the cosmic microwave background, on models predicting semilocal strings should be closer to those on global textures or monopoles, rather than on topologically stable gauged cosmic strings.

Achucarro, Ana [Instituut-Lorentz, Universiteit Leiden, P. O. Box 9506, 2300 RA, Leiden (Netherlands); Department of Theoretical Physics, University of the Basque Country UPV-EHU, 48080 Bilbao (Spain); Salmi, Petja [Instituut-Lorentz, Universiteit Leiden, P. O. Box 9506, 2300 RA, Leiden (Netherlands); Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Urrestilla, Jon [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

2007-06-15

438

Neighborhood Environmental Watch Network  

SciTech Connect

The Neighborhood Environmental Watch Network (NEWNET) is a regional network of environmental monitoring stations and a data archival center that supports collaboration between communities, industry, and government agencies to solve environmental problems. The stations provide local displays of measurements for the public and transmit measurements via satellite to a central site for archival and analysis. Station managers are selected from the local community and trained to support the stations. Archived data and analysis tools are available to researchers, educational institutions, industrial collaborators, and the public across the nation through a communications network. Los Alamos National Laboratory and the Environmental Protection Agency have developed a NEWNET pilot program for the Department of Energy. The pilot program supports monitoring stations in Nevada, Arizona, Utah, Wyoming, and California. Additional stations are being placed in Colorado and New Mexico. Pilot stations take radiological and meteorological measurements. Other measurements are possible by exchanging sensors.

Sanders, L.D.

1993-10-01

439

Multilayer optical learning networks.  

PubMed

A new approach to learning in a multilayer optical neural network based on holographically interconnected nonlinear devices is presented. The proposed network can learn the interconnections that form a distributed representation of a desired pattern transformation operation. The interconnections are formed in an adaptive and self-aligning fashioias volume holographic gratings in photorefractive crystals. Parallel arrays of globally space-integrated inner products diffracted by the interconnecting hologram illuminate arrays of nonlinear Fabry-Perot etalons for fast thresholding of the transformed patterns. A phase conjugated reference wave interferes with a backward propagating error signal to form holographic interference patterns which are time integrated in the volume of a photorefractive crystal to modify slowly and learn the appropriate self-aligning interconnections. This multilayer system performs an approximate implementation of the backpropagation learning procedure in a massively parallel high-speed nonlinear optical network. PMID:20523485

Wagner, K; Psaltis, D

1987-12-01

440

Universality in network dynamics  

NASA Astrophysics Data System (ADS)

Despite significant advances in characterizing the structural properties of complex networks, a mathematical framework that uncovers the universal properties of the interplay between the topology and the dynamics of complex systems continues to elude us. Here we develop a self-consistent theory of dynamical perturbations in complex systems, allowing us to systematically separate the contribution of the network topology and dynamics. The formalism covers a broad range of steady-state dynamical processes and offers testable predictions regarding the system's response to perturbations and the development of correlations. It predicts several distinct universality classes whose characteristics can be derived directly from the continuum equation governing the system's dynamics and which are validated on several canonical network-based dynamical systems, from biochemical dynamics to epidemic spreading. Finally, we collect experimental data pertaining to social and biological systems, demonstrating that we can accurately uncover their universality class even in the absence of an appropriate continuum theory that governs the system's dynamics.

Barzel, Baruch; Barabási, Albert-László

2013-10-01

441

The Foliage Network  

NSDL National Science Digital Library

Fall brings the transformation of many of the deciduous forests across the eastern half of the United States as the leaves turn a host of shades, ranging from a dark-hued purple to the glory of the shades of red and yellow that also abound. For those many devotees of following these festive foliages, the Foliage Network website is a good way to keep track of these changes. Using a network of "trackers" from locations as diverse as northern Wisconsin to southern Maine, the Foliage Network provides foliage maps which are updated twice a week. The reports also give detailed information on where visitors may go to see the best foliage for that week. The site also offers information about what to see and do in each area, and various potential lodging options and so on.

442

Graphing Your Social Network  

NSDL National Science Digital Library

Students analyze their social networks using graph theory. They gather data on their own social relationships, either from Facebook interactions or the interactions they have throughout the course of a day, recording it in Microsoft Excel and using Cytoscape (a free, downloadable application) to generate social network graphs that visually illustrate the key persons (nodes) and connections between them (edges). The nodes in the Cytoscape graphs are color-coded and sized according to the importance of the node (in this activity, nodes are people in students' social networks). After the analysis, the graphs are further examined to see what can be learned from the visual representation. Students gain practice with graph theory vocabulary, including node, edge, betweeness centrality and degree on interaction, and learn about a range of engineering applications of graph theory.

Impart Ret Program

443

The Social Network Classroom  

NASA Astrophysics Data System (ADS)

Online social networking is an important part in the everyday life of college students. Despite the increasing popularity of online social networking among students and faculty members, its educational benefits are largely untested. This paper presents our experience in using social networking applications and video content distribution websites as a complement of traditional classroom education. In particular, the solution has been based on effective adaptation, extension and integration of Facebook, Twitter, Blogger YouTube and iTunes services for delivering educational material to students on mobile platforms like iPods and 3 rd generation mobile phones. The goals of the proposed educational platform, described in this paper, are to make the learning experience more engaging, to encourage collaborative work and knowledge sharing among students, and to provide an interactive platform for the educators to reach students and deliver lecture material in a totally new way.

Bunus, Peter

444

Network Adaptive Deadband: NCS data flow control for shared networks.  

PubMed

This paper proposes a new middleware solution called Network Adaptive Deadband (NAD) for long time operation of Networked Control Systems (NCS) through the Internet or any shared network based on IP technology. The proposed middleware takes into account the network status and the NCS status, to improve the global system performance and to share more effectively the network by several NCS and sensor/actuator data flows. Relationship between network status and NCS status is solved with a TCP-friendly transport flow control protocol and the deadband concept, relating deadband value and transmission throughput. This creates a deadband-based flow control solution. Simulation and experiments in shared networks show that the implemented network adaptive deadband has better performance than an optimal constant deadband solution in the same circumstances. PMID:23208556

Díaz-Cacho, Miguel; Delgado, Emma; Prieto, José A G; López, Joaquín

2012-12-03

445

Research Libraries Information Network: The Computerized Bibliographic Network.  

ERIC Educational Resources Information Center

|Describes the goals and philosophy of the Research Libraries Group (RLG), and notes the services offered by the Research Libraries Information Network (RLIN), which uses Stanford University's BALLOTS program as the technological base of the bibliographic network. (CWM)|

Kershner, Lois M.

1979-01-01

446

Stability from Structure: Metabolic Networks Are Unlike Other Biological Networks  

PubMed Central

In recent work, attempts have been made to link the structure of biochemical networks to their complex dynamics. It was shown that structurally stable network motifs are enriched in such networks. In this work, we investigate to what extent these findings apply to metabolic networks. To this end, we extend a previously proposed method by changing the null model for determining motif enrichment, by using interaction types directly obtained from structural interaction matrices, by generating a distribution of partial derivatives of reaction rates and by simulating enzymatic regulation on metabolic networks. Our findings suggest that the conclusions drawn in previous work cannot be extended to metabolic networks, that is, structurally stable network motifs are not enriched in metabolic networks.

2009-01-01

447

Energy Efficient Network Protocols for Wireless and Mobile Networks.  

National Technical Information Service (NTIS)

This research project studied the design, analysis and implementation of energy efficient (also called power aware) network protocols for wireless and mobile networks. In particular, we focused on the medium access control, scheduling, reservation signali...

K. M. Sivalingam

2002-01-01

448

Excitable scale free networks  

NASA Astrophysics Data System (ADS)

When a simple excitable system is continuously stimulated by a Poissonian external source, the response function (mean activity versus stimulus rate) generally shows a linear saturating shape. This is experimentally verified in some classes of sensory neurons, which accordingly present a small dynamic range (defined as the interval of stimulus intensity which can be appropriately coded by the mean activity of the excitable element), usually about one or two decades only. The brain, on the other hand, can handle a significantly broader range of stimulus intensity, and a collective phenomenon involving the interaction among excitable neurons has been suggested to account for the enhancement of the dynamic range. Since the role of the pattern of such interactions is still unclear, here we investigate the performance of a scale-free (SF) network topology in this dynamic range problem. Specifically, we study the transfer function of disordered SF networks of excitable Greenberg-Hastings cellular automata. We observe that the dynamic range is maximum when the coupling among the elements is critical, corroborating a general reasoning recently proposed. Although the maximum dynamic range yielded by general SF networks is slightly worse than that of random networks, for special SF networks which lack loops the enhancement of the dynamic range can be dramatic, reaching nearly five decades. In order to understand the role of loops on the transfer function we propose a simple model in which the density of loops in the network can be gradually increased, and show that this is accompanied by a gradual decrease of dynamic range.

Copelli, M.; Campos, P. R. A.

2007-04-01

449

Hyporheic network (Hyporheisches Netzwerk)  

NASA Astrophysics Data System (ADS)

The transition zone between surface waters like streams and rivers and the adjacent aquifers is a zone of paramount ecological importance. Due to the complexity of exchange processes, their temporal variability, and the spatial heterogeneity of the ecotone, the understanding and ability to modell the hydrodynamic, hydrochemical, and (micro-)biological processes is still limited. Therefore, a network of scientists and practitioners involved in research and management of hyporheic zones in German-speaking countries (Germany, Switzerland, Austria) is propsed in analogy to the hyporheic network (www.hyporheic.net) in the UK. The initiators of the network anticipate that an intense scientific exchange of knowledge and methods will improve our understanding of hyporheic processes and in turn our ability to manage them. The network will facilitate the formation of research groups to identify and understand key processes and their interactions. Research will be focused at a few major study sites, to bring together different expertise to allow more detailed, interdisciplinary investigations. Those sites can serve as crystallisation points for new research projects. Exchange within the network will be organized via an internet platform (www.hyporheisches-netzwerk.de), regular workshops, and several working groups dealing with different topics. A fast knowledge transfer is a further aim of the collaboration in order to shorten the time-lag between scientific findings and their implementation into management practice. Water resources management authorities should also be involved in the network to address urgent problems and direct some capacities to answer those questions. For instance, changes in geomorphology, water and temperature regimes as well as other anthropogenic impacts might increase the need for cold water refugia and altered flow regimes to maintain biodiversity. Additional qualitative improvements are required by the EU water framework directive.

Lewandowski, J.; Fleckenstein, J.; Hoehn, E.; Nützmann, G.; Radke, M.; Saenger, N.; Schmidt, C.

2009-04-01

450

Community Seismic Network (CSN)  

NASA Astrophysics Data System (ADS)

The CSN is a network of low-cost accelerometers deployed in the Pasadena, CA region. It is a prototype network with the goal of demonstrating the importance of dense measurements in determining the rapid lateral variations in ground motion due to earthquakes. The main product of the CSN is a map of peak ground produced within seconds of significant local earthquakes that can be used as a proxy for damage. Examples of this are shown using data from a temporary network in Long Beach, CA. Dense measurements in buildings are also being used to determine the state of health of structures. In addition to fixed sensors, portable sensors such as smart phones are also used in the network. The CSN has necessitated several changes in the standard design of a seismic network. The first is that the data collection and processing is done in the "cloud" (Google cloud in this case) for robustness and the ability to handle large impulsive loads (earthquakes). Second, the database is highly de-normalized (i.e. station locations are part of waveform and event-detection meta data) because of the mobile nature of the sensors. Third, since the sensors are hosted and/or owned by individuals, the privacy of the data is very important. The location of fixed sensors is displayed on maps as sensor counts in block-wide cells, and mobile sensors are shown in a similar way, with the additional requirement to inhibit tracking that at least two must be present in a particular cell before any are shown. The raw waveform data are only released to users outside of the network after a felt earthquake.

Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Cheng, M.; Guy, R.; Chandy, M.; Krause, A.; Bunn, J.; Olson, M.; Faulkner, M.

2011-12-01

451

ASP Networking Sessions Summary  

NASA Astrophysics Data System (ADS)

In response to evaluation conducted during the Annual Meeting of the Astronomical Society of the Pacific in 2006, ``Engaging the EPO Community: Best Practices, New Approaches,'' loosely structured networking sessions were added by the program committee in an effort to assist conference attendees in achieving their stated conference goals. The co-chairs of the 2007 conference invited registrants to serve as facilitators for twelve networking sessions. This work aims to summarize the conversations that took place during those sessions, based upon notes and artifacts provided to the author by the session facilitators.

Bartolone, L. M.

2008-06-01

452

Elasticity of biopolymer networks  

NASA Astrophysics Data System (ADS)

This thesis presents a study of the elasticity of three very different cytoskeletal materials, microtubules (MTs), filamentous actin (F-actin) and vimentin, one of the intermediate filaments (IFs). Using bulk rheology, multiple particle tracking, confocal microscopy, and transmission electron microscopy (TEM), we study the microscopic origin of the elasticity of these cytoskeletal networks. In Chapter 1, we briefly introduce the properties of the three components of cytoskeletal filaments as well as the rheology essential to provide the background and motivation of this thesis. In Chapter 2, we describe the materials and experimental techniques involved. In Chapter 3, we study solutions of purified MTs, as well as networks permanently cross-linked with biotin-NeutrAvidin. We show that the mechanical properties of MT solutions cannot be explained by the non-interacting rigid rod model. Instead, they show behavior very similar to the permanently cross-linked networks, suggesting the presence of effective cross-linking even in pure MT solutions. We develop a simple model based on transient cross-linking interactions between MTs to interpret the rheological response. We also calculate a lower bound estimate of the strength of this interaction. In Chapter 4, we investigate the mechanical response of the composite networks of F-actin and MTs. We find that even a small concentration of MTs leads to dramatic and qualitative changes in the elastic properties of F-actin networks. MTs provide a way to regulate the nonlinear stiffening response of F-actin. Theoretically this can be understood in terms of an inhomogeneity in the strain field of the gel. This finding is highly relevant for interpretation of the mechanical behavior of the intracellular cytoskeleton, in which a dilute network of MTs coexists with a denser meshwork of more flexible biopolymers such as F-actin. In Chapter 5, we study the third and final filamentous protein of the cytoskeleton, intermediate filaments (IFs). We find that divalent ions act as cross-linkers in vimentin networks. We demonstrate that the linear and nonlinear elastic responses of vimentin IF networks at intermediate stress can be quantitatively explained by stretching the entropic fluctuations of single semiflexible filaments; at high stress, we propose that enthalpic stretching of the individual filaments contributes to the observed nonlinear response.

Lin, Yi-Chia

453

Social networking and adolescents.  

PubMed

Online social networking is a 21st century innovation increasingly embraced by today's young people. It provides new opportunities for communication that expand an adolescent's world. Yet adults, often suspicious of new trends and technologies initially embraced by youth, often see these new environments as perilous places to visit. These fears have been accentuated by media hype, especially about sexual predators. How dangerous are they? Because the rush to go on these sites is a new phenomenon, research is as yet scant. This review explores current beliefs and knowledge about the dangers of social networking sites. PMID:19492691

Fuld, Gilbert L

2009-04-01

454

Synthetic biological networks.  

PubMed

Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. PMID:24006369

Archer, Eric; Süel, Gürol M

2013-09-04

455

Women's network in Afghanistan.  

PubMed

Violence and discrimination against women have been part of the Afghan culture for thousands of years, but recently this situation has grown worse. In response, Afghan women have recently formed the Afghan Women's Network. The main objective of this organization is to work for peace and human rights in Afghanistan where the Taliban sect has been especially oppressive of women's rights. In a declaration issued late last year, the Network, which includes women in Pakistan as well as Afghanistan, requested international support for their work to guarantee the right of women to work outside the home, as well as their right to education and personal safety. PMID:12179739

1997-01-01

456

Perceptual Network Metaphors: Breaking the Network Transparency Paradigm  

Microsoft Academic Search

\\u000a The design and development of networked applications is based on the principle of network transparency. This premise results\\u000a in the isolation of the users from the network state, independently if such is achieved at the network, transport or the above\\u000a layers of the system. In the case of a Real-Time Interactive Application (RTIA), such as an online game or a

Manuel M. Oliveira; Jon Crowcroft

2003-01-01

457

Telecommunications, local area networks, and computers-integrated network control  

Microsoft Academic Search

The author examines the telecommunications local area network, and computer-integrated network control system (TLC, INC) concept which uses modern network management principles to detect service-affecting problems so that corrective action can be applied to restore service. The information is presented to network managers on a high-resolution color graphic workstation in real time. An operation overview of the TLC, INC is

MICHAEL B. FREEMAN

1988-01-01

458

Generalizing Virtual Network Topologies in OpenFlow-Based Networks  

Microsoft Academic Search

Network Virtualization (NV) is one of the most promising technique to enable innovation in today's network. A recent approach toward NV has been proposed through FlowVisor, whose aim is to leverage on the specific features of an OpenFlow-controlled network to share the same hardware forwarding plane among multiple logical networks. However, FlowVisor lacks some features to enable a full implementation

Elio Salvadori; Roberto Doriguzzi Corin; Attilio Broglio; Matteo Gerola

2011-01-01

459

Interfacing to a virtualized network infrastructure through network service abstractions  

Microsoft Academic Search

Virtualization is the base for a diversified next-generation network architecture design. Much work has been done on virtualization infrastructure, but it is still unclear how to easily instantiate a network slice that meets a high-level description of network functionality. Our work addresses this problem that occurs at the interface between network service providers and virtualized infrastructure providers. The proposed Service-based

Xin Huang; Shashank Shanbhag; Tilman Wolf

2009-01-01

460

Network management of TCP\\/IP networks: present and future  

Microsoft Academic Search

Recent network management activities in the TCP\\/IP community have focused on standardizing two network management protocols-Simple Network Management Protocol (SNMP) and Common Management Information Services and Protocol Over TCP\\/IP (CMOT)-that provide for the exchange of management information. The current SNMP and CMOT approaches to TCP\\/IP network management are compared from several different perspectives; comparisons are based on both theory and

Amatzia Ben-Artzi; Asheem Chandna; Unni Warrier

1990-01-01

461

Optimization of directional antenna network topology in Airborne Networks  

Microsoft Academic Search

Future IP-based Airborne Networks, important components in net-centric military communications, are envisioned to consist of a persistent backbone core network and dynamic tactical edge networks. The backbone would consist of quasi-stable platforms equipped with multiple high-capacity directional wireless links. The tactical edge networks would consist of highly dynamic platforms such as fighter jets equipped with omni-directional wireless links, and these

G. Hadynski; S. B. Lee; G. Rajappan; R. Sundaram; X. Wang; F. Zhou

2010-01-01

462

NetworkBLAST: comparative analysis of protein networks  

Microsoft Academic Search

Summary: The identification of protein complexes is a fundamental challenge in interpreting protein-protein interaction data. Cross- species analysis allows coping with the high levels of noise that are typical to these data. The NetworkBLAST web-server provides a platform for identifying protein complexes in protein-protein interac- tion networks. It can analyze a single network or two networks from different species. In

Maxim Kalaev; Mike Smoot; Trey Ideker; Roded Sharan

2008-01-01

463

Universality in protein residue networks.  

PubMed

Residue networks representing 595 nonhomologous proteins are studied. These networks exhibit universal topological characteristics as they belong to the topological class of modular networks formed by several highly interconnected clusters separated by topological cavities. There are some networks that tend to deviate from this universality. These networks represent small-size proteins having <200 residues. This article explains such differences in terms of the domain structure of these proteins. On the other hand, the topological cavities characterizing proteins residue networks match very well with protein binding sites. This study investigates the effect of the cutoff value used in building the residue network. For small cutoff values, <5 A, the cavities found are very large corresponding almost to the whole protein surface. On the contrary, for large cutoff value, >10.0 A, only very large cavities are detected and the networks look very homogeneous. These findings are useful for practical purposes as well as for identifying protein-like complex networks. Finally, this article shows that the main topological class of residue networks is not reproduced by random networks growing according to Erdös-Rényi model or the preferential attachment method of Barabási-Albert. However, the Watts-Strogatz model reproduces very well the topological class as well as other topological properties of residue network. A more biologically appealing modification of the Watts-Strogatz model to describe residue networks is proposed. PMID:20197043

Estrada, Ernesto

2010-03-01

464

Parsimonious reconstruction of network evolution  

PubMed Central

Background Understanding the evolution of biological networks can provide insight into how their modular structure arises and how they are affected by environmental changes. One approach to studying the evolution of these networks is to reconstruct plausible common ancestors of present-day networks, allowing us to analyze how the topological properties change over time and to posit mechanisms that drive the networks’ evolution. Further, putative ancestral networks can be used to help solve other difficult problems in computational biology, such as network alignment. Results We introduce a combinatorial framework for encoding network histories, and we give a fast procedure that, given a set of gene duplication histories, in practice finds network histories with close to the minimum number of interaction gain or loss events to explain the observed present-day networks. In contrast to previous studies, our method does not require knowing the relative ordering of unrelated duplication events. Results on simulated histories and real biological networks both suggest that common ancestral networks can be accurately reconstructed using this parsimony approach. A software package implementing our method is available under the Apache 2.0 license at http://cbcb.umd.edu/kingsford-group/parana. Conclusions Our parsimony-based approach to ancestral network reconstruction is both efficient and accurate. We show that considering a larger set of potential ancestral interactions by not assuming a relative ordering of unrelated duplication events can lead to improved ancestral network inference.

2012-01-01

465

ASCR Science Network Requirements  

SciTech Connect

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the US Department of Energy Office of Science, the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 20 years. In April 2009 ESnet and the Office of Advanced Scientific Computing Research (ASCR), of the DOE Office of Science, organized a workshop to characterize the networking requirements of the programs funded by ASCR. The ASCR facilities anticipate significant increases in wide area bandwidth utilization, driven largely by the increased capabilities of computational resources and the wide scope of collaboration that is a hallmark of modern science. Many scientists move data sets between facilities for analysis, and in some cases (for example the Earth System Grid and the Open Science Grid), data distribution is an essential component of the use of ASCR facilities by scientists. Due to the projected growth in wide area data transfer needs, the ASCR supercomputer centers all expect to deploy and use 100 Gigabit per second networking technology for wide area connectivity as soon as that deployment is financially feasible. In addition to the network connectivity that ESnet provides, the ESnet Collaboration Services (ECS) are critical to several science communities. ESnet identity and trust services, such as the DOEGrids certificate authority, are widely used both by the supercomputer centers and by collaborations such as Open Science Grid (OSG) and the Earth System Grid (ESG). Ease of use is a key determinant of the scientific utility of network-based services. Therefore, a key enabling aspect for scientists beneficial use of high performance networks is a consistent, widely deployed, well-maintained toolset that is optimized for wide area, high-speed data transfer (e.g. GridFTP) that allows scientists to easily utilize the services and capabilities that the network provides. Network test and measurement is an important part of ensuring that these tools and network services are functioning correctly. One example of a tool in this area is the recently developed perfSONAR, which has already shown its usefulness in fault diagnosis during the recent deployment of high-performance data movers at NERSC and ORNL. On the other hand, it is clear that there is significant work to be done in the area of authentication and access control - there are currently compatibility problems and differing requirements between the authentication systems in use at different facilities, and the policies and mechanisms in use at different facilities are sometimes in conflict. Finally, long-term software maintenance was of concern for many attendees. Scientists rely heavily on a large deployed base of software that does not have secure programmatic funding. Software packages for which this is true include data transfer tools such as GridFTP as well as identity management and other software infrastructure that forms a critical part of the Open Science Grid and the Earth System Grid.

Dart, Eli; Tierney, Brian

2009-08-24

466

Trends in the development of communication networks: Cognitive networks  

Microsoft Academic Search

One of the main challenges already faced by communication networks is the efficient management of increasing complexity. The recently proposed concept of cognitive network appears as a candidate that can address this issue. In this paper, we survey the existing research work on cognitive networks, as well as related and enabling techniques and technologies. We start with identifying the most

Carolina Fortuna; Mihael Mohorcic

2009-01-01

467

Model gene network by semi-fixed Bayesian network  

Microsoft Academic Search

Gene networks describe functional pathways in a given cell or tissue, representing processes such as metabolism, gene expression regulation, and protein or RNA transport. Thus, learning gene network is a crucial problem in the post genome era. Most existing works learn gene networks by assuming one gene provokes the expression of another gene directly leading to an over-simplified model. In

Tie-fei Liu; Wing-kin Sung; Ankush Mittal

2006-01-01

468

Arbutus: Network-Layer Load Balancing for Wireless Sensor Networks  

Microsoft Academic Search

The hot spot problem is a typical byproduct of the many-to-one traffic pattern that characterizes most wireless sensor networks: the nodes with the best channel to the sink are overloaded with traffic from the rest of the network and experience a faster energy depletion rate than their peers. Routing protocols for sensor networks typically use a reliability metric to avoid

Daniele Puccinelli; Martin Haenggi

2008-01-01

469

Network components for market-based network admission and routing  

Microsoft Academic Search

We describe the architecture of a network, in which the trac flow is controlled by a market. The network access is controlled by a trusted access node, that separates trac into best eort and first class trac, adds a source route header, and shapes the trac. The network core consists of rapid forwarding devices, such as label switches, and source

Lars Rasmusson; Gabriel Paues

2002-01-01

470

Employing Bayesian Belief Networks for energy efficient Network Management  

Microsoft Academic Search

Network Management Systems (NMS) are used to monitor the network and along with Operations Support Systems (OSS) maintain the performance with a focus on guaranteeing sustained QoS to the applications and services. One aspect that is given less importance is the energy consumption of the network elements during the off peak periods. This paper looks at a scenario where the

A. Bashar; G. P. Parr; S. I. McClean; B. W. Scotney; M. Subramanian; S. K. Chaudhari; T. A. Gonsalves

2010-01-01

471

Data visualization: From body sensor network to social networks  

Microsoft Academic Search

Sensors can capture very sensitive and valuable information without human intervention and send it to remote location. However, capturing sensory data from a body sensor network (BSN) and sending it to social networks is a challenging task. This is because it requires a number of distributed networks to work together seamlessly. The task becomes more challenging when both the BSN

M. A. Rahman; A. El Saddik; W. Gueaieb

2009-01-01

472

Networked infomechanical systems: a mobile embedded networked sensor platform  

Microsoft Academic Search

Networked Infomechanical Systems (NIMS) introduces a new actuation capability for embedded networked sensing. By exploiting a constrained actuation method based on rapidly deployable infrastructure, NIMS suspends a network of wireless mobile and fixed sensor nodes in three-dimensional space. This permits run-time adaptation with variable sensing location, perspective, and even sensor type. Discoveries in NIMS environmental investigations have raised requirements for

Richard Pon; Maxim A. Batalin; Jason Gordon; Aman Kansal; Duo Liu; Mohammad H. Rahimi; Lisa Shirachi; Yan Yu; Mark M. Hansen; William J. Kaiser; Mani B. Srivastava; Gaurav S. Sukhatme; Deborah Estrin

2005-01-01

473

NetWORKers and their Activity in Intensional Networks  

Microsoft Academic Search

Through ethnographic research, we document the rise of personal social networks in the workplace, which we call intensional networks. Paradoxically, we find that the most fundamental unit of analysis for computer-supported cooperative work is not at the group level for many tasks and settings, but at the individual level as personal social networks come to be more and more important.

Bonnie A. Nardi; Steve Whittaker; Heinrich Schwarz

2002-01-01

474

Do You Lock Your Network Doors? Some Network Management Precautions.  

ERIC Educational Resources Information Center

Discusses security problems and solutions for networked organizations with Internet connections. Topics include access to private networks from electronic mail information; computer viruses; computer software; corporate espionage; firewalls, that is computers that stand between a local network and the Internet; passwords; and physical security.…

Neray, Phil

1997-01-01

475

Social networking and inequality: the role of clustered networks  

Microsoft Academic Search

The paper aims to analyse how income inequality affects social networking in 14 European countries. By using the European Community Household Panel, we introduce new evidence to test the network-inequality nexus and construct inequality indexes directly from the microdata as well their decomposition. We explore how total income inequality is related to three specific levels of social networking; then, we

Emanuela DAngelo; Marco Lilla

2010-01-01

476

New generation network and services management for converged networks  

Microsoft Academic Search

The Internet has changed the manner of thinking and building networks for both service providers and telephony operators. On one hand, service providers need to improve their networks in order to meet current and future customer requirements. Indeed, their applications are increasingly demanding for sophisticated and guaranteed networks services such as mobility, security, quality of services ... On the other

I. Fodil

2006-01-01

477

Do You Lock Your Network Doors? Some Network Management Precautions.  

ERIC Educational Resources Information Center

|Discusses security problems and solutions for networked organizations with Internet connections. Topics include access to private networks from electronic mail information; computer viruses; computer software; corporate espionage; firewalls, that is computers that stand between a local network and the Internet; passwords; and physical security.…

Neray, Phil

1997-01-01

478

A novel fuzzy neural network: the vague neural network  

Microsoft Academic Search

Fuzzy neural network that combines the artificial neural network and fuzzy logic is regarded as one of promising intelligent system. Based on fuzzy theory, fuzzy neural network has its problems: fuzzy membership function is a single value which combines the evidence for and against the pattern without indicating how much there is of which, hence it cannot get the more

Rui Fang; Yibiao Zhao; Wei-sheng Li

2005-01-01

479

Investigating Network Optimization Approaches in Wireless Sensor Networks  

Microsoft Academic Search

More and more wireless mobile sensor networks are employed by robotics to perform harsh tasks such as disaster rescue, emission sources localization or hazardous contaminants localization. There are a lot of network optimization problems to be solved in the protocol design of wireless mobile sensor networks (WMSN), such as rate control, flow control, congestion control, medium access control, queue management,

Hongliang Ren; Max Q.-H. Meng; Xijun Chen

2006-01-01

480

Promoting social network awareness: A social network monitoring system  

Microsoft Academic Search

To increase communication and collaboration opportunities, members of a community must be aware of the social networks that exist within that community. This paper describes a social network monitoring system – the KIWI system – that enables users to register their interactions and visualize their social networks. The system was implemented in a distributed research community and the results have

Rita Cadima; Carlos Ferreira; Josep Maria Monguet; Jordi Ojeda; Joaquin Fernandez

2010-01-01

481

Promoting Social Network Awareness: A Social Network Monitoring System  

ERIC Educational Resources Information Center

|To increase communication and collaboration opportunities, members of a community must be aware of the social networks that exist within that community. This paper describes a social network monitoring system--the KIWI system--that enables users to register their interactions and visualize their social networks. The system was implemented in a…

Cadima, Rita; Ferreira, Carlos; Monguet, Josep; Ojeda, Jordi; Fernandez, Joaquin

2010-01-01

482

Intentional networking: opportunistic exploitation of mobile network diversity  

Microsoft Academic Search

Mobile devices face a diverse and dynamic set of networking o p- tions. Using those options to the fullest requires knowledg e of application intent. This paper describes Intentional Netw orking, a simple but powerful mechanism for handling network divers ity. Applications supply a declarative label for network transm issions, and the system matches transmissions to the most appropriat e

Brett D. Higgins; Azarias Reda; Timur Alperovich; Jason Flinn; Thomas J. Giuli; Brian Noble; David Watson

2010-01-01

483

Hydrologic Behavior of Fracture Networks.  

National Technical Information Service (NTIS)

This paper reviews recent research on the nature of flow and transport in discontinuous fracture networks. The hydrologic behavior of these networks has been examined using two- and three-dimensional numerical models. The numerical models represent random...

J. C. S. Long H. K. Endo K. Karasaki L. Pyrak P. MacLean

1984-01-01

484

High-Performance Neural Networks.  

National Technical Information Service (NTIS)

The new Forth hardware architectures offer an intermediate solution to high-performance neural networks while the theory and programming details of neural networks for synthetic intelligence are developed. This approach has been used successfully to deter...

W. B. Dress

1987-01-01

485

Location on Networks: A Survey.  

National Technical Information Service (NTIS)

A survey of literature on network location theory is provided, with emphasis on theoretical results and on constructive solution approaches which exploit network structure. Each section of the survey is devoted to a particular type of problem, including t...

B. C. Tansel R. L. Francis T. J. Lowe

1981-01-01

486

Implications of Network Centric Warfare.  

National Technical Information Service (NTIS)

This paper will examine Network Centric Warfare the centerpiece of Transformation. This form of warfare depends heavily on computer networks the Internet communications and sensors. These areas of dependence also provide numerous vulnerabilities. This pap...

A. L. Bailey

2004-01-01

487

Exact controllability of complex networks  

NASA Astrophysics Data System (ADS)

Controlling complex networks is of paramount importance in science and engineering. Despite the recent development of structural controllability theory, we continue to lack a framework to control undirected complex networks, especially given link weights. Here we introduce an exact controllability paradigm based on the maximum multiplicity to identify the minimum set of driver nodes required to achieve full control of networks with arbitrary structures and link-weight distributions. The framework reproduces the structural controllability of directed networks characterized by structural matrices. We explore the controllability of a large number of real and model networks, finding that dense networks with identical weights are difficult to be controlled. An efficient and accurate tool is offered to assess the controllability of large sparse and dense networks. The exact controllability framework enables a comprehensive understanding of the impact of network properties on controllability, a fundamental problem towards our ultimate control of complex systems.

Yuan, Zhengzhong; Zhao, Chen; di, Zengru; Wang, Wen-Xu; Lai, Ying-Cheng

2013-09-01

488

Tutorial on Bayesian Belief Networks.  

National Technical Information Service (NTIS)

This tutorial provides an overview of Bayesian belief networks. The subject is introduced through a discussion on probabilistic models that covers probability language, dependency models, graphical representations of models, and belief networks as a parti...

M. L. Krieg

2001-01-01

489

Connectivity and Financial Network Shutdown  

Microsoft Academic Search

Connectivity is a measure of the number of connections in a network. It is applied here to financial network shutdown due to inter-institutional default. Since 1797 when Sir Francis Baring introduced the concept of ``lender of last resort\\

Laurence K. Eisenberg

1995-01-01

490

Network Forensics on Packet Fingerprints  

Microsoft Academic Search

We present an approach to network forensics that makes it feasible to trace the content of all traffic that passed through the network via packet con- tent fingerprints. We develop a new data structure called the \\

Chia Yuan Cho; Sin Yeung Lee; Chung Pheng Tan; Yong Tai Tan

2006-01-01

491

Face Recognition with Neural Networks.  

National Technical Information Service (NTIS)

This study investigated neural networks for face verification and classification. The research concentrated on developing a neural network based feature extractor and/or classifier to perform authorized user verification in a realistic work environment. R...

D. L. Krepp

1992-01-01

492

Network model with structured nodes.  

PubMed

We present a network model in which words over a specific alphabet, called structures, are associated to each node and undirected edges are added depending on some distance measure between different structures. This model shifts the underlying principle of network generation from a purely mathematical one to an information-based one. It is shown how this model differs from the Barábasi-Albert and duplication models and how it can generate networks with topological features similar to biological networks: power law degree distribution, low average path length, clustering coefficient independent from the network size, etc. Two biological networks: S. cerevisiae gene network and E. coli protein-protein interaction network, are replicated using this model. PMID:21929042

Frisco, Pierluigi

2011-08-31

493

Change Detection in Social Networks.  

National Technical Information Service (NTIS)

Social network analysis (SNA) has become an important analytic tool for analyzing terrorist networks, friendly command and control structures, and a wide variety of other applications. This project proposes a new method for detecting change in social netw...

D. B. Horn I. McCulloh J. Graham K. Carley M. Webb

2008-01-01

494

Neural Network Communications Signal Processing.  

National Technical Information Service (NTIS)

This final technical report describes the research and development results of the Neural Network Communications Signal Processing (NNCSP) Program. The objectives of the NNCSP program are to: (1) develop and implement a neural network and communications si...

D. Tebbe J. Doner T. Billhartz

1994-01-01

495

Local Area Networks (The Printout).  

ERIC Educational Resources Information Center

Describes the Local Area Network (LAN), a project in which students used LAN-based word processing and electronic mail software as the center of a writing process approach. Discusses the advantages and disadvantages of networking. (MM)

Aron, Helen; Balajthy, Ernest

1989-01-01

496

Online Advertising in Social Networks  

NASA Astrophysics Data System (ADS)

Online social networks offer opportunities to analyze user behavior and social connectivity and leverage resulting insights for effective online advertising. This chapter focuses on the role of social network information in online display advertising.

Bagherjeiran, Abraham; Bhatt, Rushi P.; Parekh, Rajesh; Chaoji, Vineet

497

Strategizing in investment banking network  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate how network position can influence performance of firms and how firm-specific characteristics can mediate this relation by asking: “Does network position influence performance of its members?” and “How could specialization choices influence this network position-performance relation?” Design\\/methodology\\/approach – These aspects are examined by studying network position and specialization of actors

Vincenzo Farina

2010-01-01

498

Stability of networked control systems  

Microsoft Academic Search

First, we review some previous work on networked control systems (NCSs) and offer some improvements. Then, we summarize the fundamental issues in NCSs and examine them with different underlying network-scheduling protocols. We present NCS models with network-induced delay and analyze their stability using stability regions and a hybrid systems technique. Following that, we discuss methods to compensate network-induced delay and

Wei Zhang; Michael S. Branicky; Stephen M. Phillips

2001-01-01

499

Beyond Space For Spatial Networks  

Microsoft Academic Search

Many complex systems are organized in the form of a network embedded in\\u000aspace. Important examples include the physical Internet infrastucture, road\\u000anetworks, flight connections, brain functional networks and social networks.\\u000aThe effect of space on network topology has recently come under the spotlight\\u000abecause of the emergence of pervasive technologies based on geo-localization,\\u000awhich constantly fill databases with people's

Paul Expert; Tim Evans; Vincent D. Blondel; Renaud Lambiotte

2010-01-01

500

Security for Wireless Sensor Networks  

Microsoft Academic Search

This chapter identifies the vulnerabilities associated with the operational paradigms currently employed by Wireless Sensor\\u000a Networks. A survey of current WSN security research is presented. The security issues of Mobile Ad-Hoc Networks and infrastructure\\u000a supported wireless networks are briefly compared and contrasted to the security concerns of Wireless Sensor Networks. A frame-work\\u000a for implementing security in WSNs, which identifies the

Sasikanth Avancha; Jeffrey Undercoffer; Anupam Joshi; John Pinkston