Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson's Disease.

Science.gov (United States)

Koshimori, Yuko; Cho, Sang-Soo; Criaud, Marion; Christopher, Leigh; Jacobs, Mark; Ghadery, Christine; Coakeley, Sarah; Harris, Madeleine; Mizrahi, Romina; Hamani, Clement; Lang, Anthony E; Houle, Sylvain; Strafella, Antonio P

2016-01-01

The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson's disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD.

Virtual Campus Hub technology

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

Matrix logistics indicators assessment of distributed transport hub

Directory of Open Access Journals (Sweden)

Igor Arefyev

2014-06-01

Full Text Available Background: The paper is devoted to the distributed transport hub substantiation and assessment. The paper  was an example of the technique and form an array of logistical factors as variables that determine this condition. Experience in organizing multimodal transport showed that the "bottleneck" of transport logistics are items of cargo handling ports, terminals, freight stations and warehouses. At the core of the solution of these problems is the problem of estimating the variables determine the Multi-purpose Hubs. The aim is to develop a method of forming the system of logistical multiplying factors determine the role of each of the types in the technologiacal process of distributed Multi-purpose Hubs. Methods: The assessment model for the formation of Distributed Transport Units  can be based on formal methods to predict the behavior of complex systems engineering complexes. Then one of the approaches to the solution of the problem may be the matrix method of technological factors. Results and conclusions: The proposed methodology of the selection and validation of logistic coefficients has the practical importance in the models development for assessing the condition and behavior of Distributed Transport.

Transition Process from Diffuser Stall to Stage Stall in a Centrifugal Compressor with a Vaned Diffuser

Directory of Open Access Journals (Sweden)

Nobumichi Fujisawa

2017-01-01

Full Text Available The transition process from a diffuser rotating stall to a stage stall in a centrifugal compressor with a vaned diffuser was investigated by experimental and numerical analyses. From the velocity measurements, it was found that the rotating stall existed on the shroud side of the diffuser passage in the off-design flow condition. The numerical results revealed the typical vortical structure of the diffuser stall. The diffuser stall cell was caused by the systematic vortical structure which consisted of the tornado-type vortex, the longitudinal vortex at the shroud/suction surface corner (i.e., leading edge vortex (LEV, and the vortex in the throat area of the diffuser passages. Furthermore, the stage stall, which rotated within both the impeller and diffuser passages, occurred instead of the diffuser stall as the mass flow rate was decreased. According to the velocity measurements at the diffuser inlet, the diffuser stall which rotated on the shroud side was shifted to the hub side. Then, the diffuser stall moved into the impeller passages and formed the stage stall. Therefore, the stage stall was caused by the development of the diffuser stall, which transferred from the shroud side to the hub side in the vaneless space and expanded to the impeller passages.

Structures and short linear motif of disordered transcription factor regions provide clues to the interactome of the cellular hub radical-induced cell death1

DEFF Research Database (Denmark)

O'Shea, Charlotte; Staby, Lasse; Bendsen, Sidsel Krogh

2017-01-01

Intrinsically disordered protein regions (IDRs) lack a well-defined three-dimensional structure, but often facilitate key protein functions. Some interactions between IDRs and folded protein domains rely on short linear motifs (SLiMs). These motifs are challenging to identify, but once found can...... point to larger networks of interactions, such as with proteins that serve as hubs for essential cellular functions. The stress-associated plant protein Radical-Induced Cell Death1 (RCD1) is one such hub, interacting with many transcription factors via their flexible IDRs. To identify the SLiM bound......046 formed different structures or were fuzzy in the complexes. These findings allow us to present a model of the stress-associated RCD1-transcription factor interactome and to contribute to the emerging understanding of the interactions between folded hubs and their intrinsically disordered partners....

Disrupted nodal and hub organization account for brain network abnormalities in Parkinson’s disease

Directory of Open Access Journals (Sweden)

Yuko Koshimori

2016-11-01

Full Text Available The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson’s disease. This study aimed to investigate functional changes in sensorimotor and cognitive networks in parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the healthy control and patient groups. We found nodal and hub changes in patients compared with healthy controls, including the right pre-supplementary motor area, left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex, and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e. right pre-supplementary motor area and right mid-insula displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral dorsolateral prefrontal cortex possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of Parkinson’s disease.

Natural Gas Market Hubs

Data.gov (United States)

Department of Homeland Security — A hub is a physical transfer point for natural gas where several pipelines are connected. A market center is a hub where the operator offers services that facilitate...

Permasalahan P-Hub Median Dengan Lintasan Terpendek

OpenAIRE

Pasaribu, Raja David

2013-01-01

Hub are facilities that serve as sorting, switching, and transhipment in a transportation network. P-hub median problem is a discrete case location allocation problem which all hub is fully connected. In this paper will be intoduced Mixed Integrer Linear Programming (MILP) formulation models of cost for p-hub median problem allocation for uncapacitaced single allocation p-hub median(USApHMP). In this paper also introduced Floyd-Warshall shortest path algorithm to solve p-hub median problems a...

Abnormal hubs of white matter networks in the frontal-parieto circuit contribute to depression discrimination via pattern classification.

Science.gov (United States)

Qin, Jiaolong; Wei, Maobin; Liu, Haiyan; Chen, Jianhuai; Yan, Rui; Hua, Lingling; Zhao, Ke; Yao, Zhijian; Lu, Qing

2014-12-01

Previous studies had explored the diagnostic and prognostic value of the structural neuroimaging data of MDD and treated the whole brain voxels, the fractional anisotropy and the structural connectivity as classification features. To our best knowledge, no study examined the potential diagnostic value of the hubs of anatomical brain networks in MDD. The purpose of the current study was to provide an exploratory examination of the potential diagnostic and prognostic values of hubs of white matter brain networks in MDD discrimination and the corresponding impaired hub pattern via a multi-pattern analysis. We constructed white matter brain networks from 29 depressions and 30 healthy controls based on diffusion tensor imaging data, calculated nodal measures and identified hubs. Using these measures as features, two types of feature architectures were established, one only included hubs (HUB) and the other contained both hubs and non hubs. The support vector machine classifiers with Gaussian radial basis kernel were used after the feature selection. Moreover, the relative contribution of the features was estimated by means of the consensus features. Our results presented that the hubs (including the bilateral dorsolateral part of superior frontal gyrus, the left middle frontal gyrus, the bilateral middle temporal gyrus, and the bilateral inferior temporal gyrus) played an important role in distinguishing the depressions from healthy controls with the best accuracy of 83.05%. Moreover, most of the HUB consensus features located in the frontal-parieto circuit. These findings provided evidence that the hubs could be served as valuable potential diagnostic measure for MDD, and the hub-concentrated lesion distribution of MDD was primarily anchored within the frontal-parieto circuit. Copyright © 2014 Elsevier Inc. All rights reserved.

Fixed-axis electric sail deployment dynamics analysis using hub-mounted momentum control

Science.gov (United States)

Fulton, JoAnna; Schaub, Hanspeter

2018-03-01

The deployment dynamics of a spin stabilized electric sail (E-sail) with a hub-mounted control actuator are investigated. Both radial and tangential deployment mechanisms are considered to take the electric sail from a post-launch stowed configuration to a fully deployed configuration. The tangential configuration assumes the multi-kilometer tethers are wound up on the exterior of the spacecraft hub, similar to yo-yo despinner configurations. The deployment speed is controlled through the hub rate. The radial deployment configuration assumes each tether is on its own spool. Here both the hub and spool rate are control variables. The sensitivity of the deployment behavior to E-sail length, maximum rate and tension parameters is investigated. A constant hub rate deployment is compared to a time varying hub rate that maintains a constant tether tension condition. The deployment time can be reduced by a factor of 2 or more by using a tension controlled deployment configuration.

Using the Contextual Hub Analysis Tool (CHAT) in Cytoscape to Identify Contextually Relevant Network Hubs.

Science.gov (United States)

Muetze, Tanja; Lynn, David J

2017-09-13

Highly connected nodes in biological networks are called network hubs. Hubs are topologically important to the structure of the network and have been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we provide a step-by-step protocol for using the Contextual Hub Analysis Tool (CHAT), an application within Cytoscape 3, which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene or protein expression data, and identify hub nodes that are more highly connected to contextual nodes than expected by chance. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Contextual Hub Analysis Tool (CHAT): A Cytoscape app for identifying contextually relevant hubs in biological networks.

Science.gov (United States)

Muetze, Tanja; Goenawan, Ivan H; Wiencko, Heather L; Bernal-Llinares, Manuel; Bryan, Kenneth; Lynn, David J

2016-01-01

Highly connected nodes (hubs) in biological networks are topologically important to the structure of the network and have also been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we report a Cytoscape app, the Contextual Hub Analysis Tool (CHAT), which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene expression or mass spectrometry data, and identify hub nodes that are more highly connected to contextual nodes (e.g. genes or proteins that are differentially expressed) than expected by chance. In a case study, we use CHAT to construct a network of genes that are differentially expressed in Dengue fever, a viral infection. CHAT was used to identify and compare contextual and degree-based hubs in this network. The top 20 degree-based hubs were enriched in pathways related to the cell cycle and cancer, which is likely due to the fact that proteins involved in these processes tend to be highly connected in general. In comparison, the top 20 contextual hubs were enriched in pathways commonly observed in a viral infection including pathways related to the immune response to viral infection. This analysis shows that such contextual hubs are considerably more biologically relevant than degree-based hubs and that analyses which rely on the identification of hubs solely based on their connectivity may be biased towards nodes that are highly connected in general rather than in the specific context of interest. CHAT is available for Cytoscape 3.0+ and can be installed via the Cytoscape App Store ( http://apps.cytoscape.org/apps/chat).

Optimal hub location in pipeline networks

Energy Technology Data Exchange (ETDEWEB)

Dott, D.R.; Wirasinghe, S.C.; Chakma, A. [Univ. of Calgary, Alberta (Canada)

1996-12-31

This paper discusses optimization strategies and techniques for the location of natural gas marketing hubs in the North American gas pipeline network. A hub is a facility at which inbound and outbound network links meet and freight is redirected towards their destinations. Common examples of hubs used in the gas pipeline industry include gas plants, interconnects and market centers. Characteristics of the gas pipeline industry which are relevant to the optimization of transportation costs using hubs are presented. Allocation techniques for solving location-allocation problems are discussed. An outline of the research in process by the authors in the field of optimal gas hub location concludes the paper.

Joint Hub Network Development

NARCIS (Netherlands)

Cruijssen, F.C.A.M.; Borm, P.E.M.; Dullaert, W.; Hamers, H.J.M.

2007-01-01

This paper introduces a framework for joint hub network development. Building a joint physical hub for transhipment of goods is expensive and therefore involves considerable risks for the cooperating companies. In a practical setting, it is unlikely that an entire network will be built at once.

Southwest Regional Climate Hub and California Subsidiary Hub assessment of climate change vulnerability and adaptation and mitigation strategies

Science.gov (United States)

Emile Elias; Caiti Steele; Kris Havstad; Kerri Steenwerth; Jeanne Chambers; Helena Deswood; Amber Kerr; Albert Rango; Mark Schwartz; Peter Stine; Rachel Steele

2015-01-01

This report is a joint effort of the Southwest Regional Climate Hub and the California Subsidiary Hub (Sub Hub). The Southwest Regional Climate Hub covers Arizona, California, Hawai‘i and the U.S. affiliated Pacific Islands, Nevada, New Mexico, and Utah and contains vast areas of western rangeland, forests, and high-value specialty crops (Figure 1). The California Sub...

PolarHub: A Global Hub for Polar Data Discovery

Science.gov (United States)

Li, W.

2014-12-01

This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

Experimental Investigation of a Helicopter Rotor Hub Wake

Science.gov (United States)

Reich, David; Elbing, Brian; Schmitz, Sven

2013-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The main objectives of the experiment were to understand the spatial- and temporal content of the unsteady wake downstream of a rotor hub up to a distance corresponding to the empennage. Primary measurements were the total hub drag and velocity measurements at three nominal downstream locations. Various flow structures were identified and linked to geometric features of the hub model. The most prominent structures were two-per-revolution (hub component: scissors) and four-per-revolution (hub component: main hub arms) vortices shed by the hub. Both the two-per-revolution and four-per-revolution structures persisted far downstream of the hub, but the rate of dissipation was greater for the four-per-rev structures. This work provides a dataset for enhanced understanding of the fundamental physics underlying rotor hub flows and serves as validation data for future CFD analyses.

Analysis of Food Hub Commerce and Participation Using Agent-Based Modeling: Integrating Financial and Social Drivers.

Science.gov (United States)

Krejci, Caroline C; Stone, Richard T; Dorneich, Michael C; Gilbert, Stephen B

2016-02-01

Factors influencing long-term viability of an intermediated regional food supply network (food hub) were modeled using agent-based modeling techniques informed by interview data gathered from food hub participants. Previous analyses of food hub dynamics focused primarily on financial drivers rather than social factors and have not used mathematical models. Based on qualitative and quantitative data gathered from 22 customers and 11 vendors at a midwestern food hub, an agent-based model (ABM) was created with distinct consumer personas characterizing the range of consumer priorities. A comparison study determined if the ABM behaved differently than a model based on traditional economic assumptions. Further simulation studies assessed the effect of changes in parameters, such as producer reliability and the consumer profiles, on long-term food hub sustainability. The persona-based ABM model produced different and more resilient results than the more traditional way of modeling consumers. Reduced producer reliability significantly reduced trade; in some instances, a modest reduction in reliability threatened the sustainability of the system. Finally, a modest increase in price-driven consumers at the outset of the simulation quickly resulted in those consumers becoming a majority of the overall customer base. Results suggest that social factors, such as desire to support the community, can be more important than financial factors. An ABM of food hub dynamics, based on human factors data gathered from the field, can be a useful tool for policy decisions. Similar approaches can be used for modeling customer dynamics with other sustainable organizations. © 2015, Human Factors and Ergonomics Society.

Hub exchange operations in intermodal hub-and spoke networks: A performance comparison of rail-rail exchange facilities

OpenAIRE

Bontekoning, Y.M.

2006-01-01

The implementation of hub-and-spoke networks in intermodal transport is suggested as one of the potential solutions for helping to increase the intermodal market share. Traditionally, trains are shunted at hubs; this is a time-consuming process. Since the early 1990s a new type of intermodal terminal, specifically designed for fast tran-shipment at nodes in hub-and-spoke networks, has been introduced in Europe. These hub terminals could replace this time-consuming shunting. Studies on the new...

Composite hub/metal blade compressor rotor

Science.gov (United States)

Yao, S.

1978-01-01

A low cost compressor rotor was designed and fabricated for a small jet engine. The rotor hub and blade keepers were compression molded with graphite epoxy. Each pair of metallic blades was held in the hub by a keeper. All keepers were locked in the hub with circumferential windings. Feasibility of fabrication was demonstrated in this program.

Wave Augmented Diffusers for Centrifugal Compressors

Science.gov (United States)

Paxson, Daniel E.; Skoch, Gary J.

1998-01-01

A conceptual device is introduced which would utilize unsteady wave motion to slow and turn flows in the diffuser section of a centrifugal compressor. The envisioned device would substantially reduce the size of conventional centrifugal diffusers by eliminating the relatively large ninety degree bend needed to turn the flow from the radial/tangential to the axial direction. The bend would be replaced by a wall and the flow would instead exit through a series of rotating ports located on a disk, adjacent to the diffuser hub, and fixed to the impeller shaft. The ports would generate both expansion and compression waves which would rapidly transition from the hub/shroud (axial) direction to the radial/tangential direction. The waves would in turn induce radial/tangential and axial flow. This paper presents a detailed description of the device. Simplified cycle analysis and performance results are presented which were obtained using a time accurate, quasi-one-dimensional CFD code with models for turning, port flow conditions, and losses due to wall shear stress. The results indicate that a periodic wave system can be established which yields diffuser performance comparable to a conventional diffuser. Discussion concerning feasibility, accuracy, and integration follow.

Data Collection and Management with ENSITE HUB: ENSITE HUB Version 1.0

Science.gov (United States)

2017-08-01

ER D C/ CE RL S R- 17 -1 4 Engineer Site Identification for the Tactical Environment (ENSITE) Data Collection and Management with ENSITE...and Management with ENSITE HUB ENSITE HUB Version 1.0 Juliana M. Wilhoit, Natalie R. Myers, and George W. Calfas Construction Engineering Research...and standardized manner. With such a tool, CB planners (as well as designers, operators, and manag - ers) can rapidly assess possible current and

Experimental Investigation of a Helicopter Rotor Hub Flow

Science.gov (United States)

Reich, David

The rotor hub system is by far the largest contributor to helicopter parasite drag and a barrier to increasing helicopter forward-flight speed and range. Additionally, the hub sheds undesirable vibration- and instability-inducing unsteady flow over the empennage. The challenges associated with rotor hub flows are discussed, including bluff body drag, interactional aerodynamics, and the effect of the turbulent hub wake on the helicopter empennage. This study was conducted in three phases to quantify model-scale rotor hub flows in water tunnels at The Pennsylvania State University Applied research lab. The first phase investigated scaling and component interaction effects on a 1:17 scale rotor hub model in the 12-inch diameter water tunnel. Effects of Reynolds number, advance ratio, and hub geometry configuration on the drag and wake shed from the rotor hub were quantified using load cell measurements and particle-image velocimetry (PIV). The second phase focused on flow visualization and measurement on a rotor hub and rotor hub/pylon geometry in the 12-inch diameter water tunnel. Stereo PIV was conducted in a cross plane downstream of the hub and flow visualization was conducted using oil paint and fluorescent dye. The third phase concentrated on high accuracy load measurement and prediction up to full-scale Reynolds number on a 1:4.25 scale model in the 48-inch diameter water tunnel. Measurements include 6 degree of freedom loads on the hub and two-component laser-Doppler velocimetry in the wake. Finally, results and conclusions are discussed, followed by recommendations for future investigations.

Public Transportation Hub Location with Stochastic Demand: An Improved Approach Based on Multiple Attribute Group Decision-Making

Directory of Open Access Journals (Sweden)

Sen Liu

2015-01-01

Full Text Available Urban public transportation hubs are the key nodes of the public transportation system. The location of such hubs is a combinatorial problem. Many factors can affect the decision-making of location, including both quantitative and qualitative factors; however, most current research focuses solely on either the quantitative or the qualitative factors. Little has been done to combine these two approaches. To fulfill this gap in the research, this paper proposes a novel approach to the public transportation hub location problem, which takes both quantitative and qualitative factors into account. In this paper, an improved multiple attribute group decision-making (MAGDM method based on TOPSIS (Technique for Order Preference by Similarity to Ideal Solution and deviation is proposed to convert the qualitative factors of each hub into quantitative evaluation values. A location model with stochastic passenger flows is then established based on the above evaluation values. Finally, stochastic programming theory is applied to solve the model and to determine the location result. A numerical study shows that this approach is applicable and effective.

The impact of network characteristics on the diffusion of innovations

Science.gov (United States)

Peres, Renana

2014-05-01

This paper studies the influence of network topology on the speed and reach of new product diffusion. While previous research has focused on comparing network types, this paper explores explicitly the relationship between topology and measurements of diffusion effectiveness. We study simultaneously the effect of three network metrics: the average degree, the relative degree of social hubs (i.e., the ratio of the average degree of highly-connected individuals to the average degree of the entire population), and the clustering coefficient. A novel network-generation procedure based on random graphs with a planted partition is used to generate 160 networks with a wide range of values for these topological metrics. Using an agent-based model, we simulate diffusion on these networks and check the dependence of the net present value (NPV) of the number of adopters over time on the network metrics. We find that the average degree and the relative degree of social hubs have a positive influence on diffusion. This result emphasizes the importance of high network connectivity and strong hubs. The clustering coefficient has a negative impact on diffusion, a finding that contributes to the ongoing controversy on the benefits and disadvantages of transitivity. These results hold for both monopolistic and duopolistic markets, and were also tested on a sample of 12 real networks.

Soft hub for bearingless rotors

Science.gov (United States)

Dixon, Peter G. C.

1991-01-01

Soft hub concepts which allow the direct replacement of articulated rotor systems by bearingless types without any change in controllability or need for reinforcement to the drive shaft and/or transmission/fuselage attachments of the helicopter were studied. Two concepts were analyzed and confirmed for functional and structural feasibility against a design criteria and specifications established for this effort. Both systems are gimballed about a thrust carrying universal elastomeric bearing. One concept includes a set of composite flexures for drive torque transmittal from the shaft to the rotor, and another set (which is changeable) to impart hub tilting stiffness to the rotor system as required to meet the helicopter application. The second concept uses a composite bellows flexure to drive the rotor and to augment the hub stiffness provided by the elastomeric bearing. Each concept was assessed for weight, drag, ROM cost, and number of parts and compared with the production BO-105 hub.

Supervised hub-detection for brain connectivity

DEFF Research Database (Denmark)

Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde

2016-01-01

, but can smooth discriminative signals in the population, degrading predictive performance. We present a novel hub-detection optimized for supervised learning that both clusters network nodes based on population level variation in connectivity and also takes the learning problem into account. The found......A structural brain network consists of physical connections between brain regions. Brain network analysis aims to find features associated with a parameter of interest through supervised prediction models such as regression. Unsupervised preprocessing steps like clustering are often applied...... hubs are a low-dimensional representation of the network and are chosen based on predictive performance as features for a linear regression. We apply our method to the problem of finding age-related changes in structural connectivity. We compare our supervised hub-detection (SHD) to an unsupervised hub...

Capacitated Bounded Cardinality Hub Routing Problem: Model and Solution Algorithm

OpenAIRE

Gelareha, Shahin; Monemic, Rahimeh Neamatian; Semetd, Frederic

2017-01-01

In this paper, we address the Bounded Cardinality Hub Location Routing with Route Capacity wherein each hub acts as a transshipment node for one directed route. The number of hubs lies between a minimum and a maximum and the hub-level network is a complete subgraph. The transshipment operations take place at the hub nodes and flow transfer time from a hub-level transporter to a spoke-level vehicle influences spoke- to-hub allocations. We propose a mathematical model and a branch-and-cut algor...

THE ROLE OF AUTOMOBILE TRANSPORT IN HUBS SERVICE

Directory of Open Access Journals (Sweden)

Kirill Iurievich Bely

2015-09-01

Full Text Available Article contains approaches to development and functioning of transport-logistic nodes – hubs – in modern conditions. There is hub classification and examples of them on different transport modes. An important component in providing reliability of hub work is automobile transport.

Contextual Hub Analysis Tool (CHAT: A Cytoscape app for identifying contextually relevant hubs in biological networks [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Tanja Muetze

2016-08-01

Full Text Available Highly connected nodes (hubs in biological networks are topologically important to the structure of the network and have also been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we report a Cytoscape app, the Contextual Hub Analysis Tool (CHAT, which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene expression or mass spectrometry data, and identify hub nodes that are more highly connected to contextual nodes (e.g. genes or proteins that are differentially expressed than expected by chance. In a case study, we use CHAT to construct a network of genes that are differentially expressed in Dengue fever, a viral infection. CHAT was used to identify and compare contextual and degree-based hubs in this network. The top 20 degree-based hubs were enriched in pathways related to the cell cycle and cancer, which is likely due to the fact that proteins involved in these processes tend to be highly connected in general. In comparison, the top 20 contextual hubs were enriched in pathways commonly observed in a viral infection including pathways related to the immune response to viral infection. This analysis shows that such contextual hubs are considerably more biologically relevant than degree-based hubs and that analyses which rely on the identification of hubs solely based on their connectivity may be biased towards nodes that are highly connected in general rather than in the specific context of interest.   Availability: CHAT is available for Cytoscape 3.0+ and can be installed via the Cytoscape App Store (http://apps.cytoscape.org/apps/chat.

Virtual Campus Hub technical evaluation report

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future.......This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future....

HIV protein sequence hotspots for crosstalk with host hub proteins.

Directory of Open Access Journals (Sweden)

Mahdi Sarmady

Full Text Available HIV proteins target host hub proteins for transient binding interactions. The presence of viral proteins in the infected cell results in out-competition of host proteins in their interaction with hub proteins, drastically affecting cell physiology. Functional genomics and interactome datasets can be used to quantify the sequence hotspots on the HIV proteome mediating interactions with host hub proteins. In this study, we used the HIV and human interactome databases to identify HIV targeted host hub proteins and their host binding partners (H2. We developed a high throughput computational procedure utilizing motif discovery algorithms on sets of protein sequences, including sequences of HIV and H2 proteins. We identified as HIV sequence hotspots those linear motifs that are highly conserved on HIV sequences and at the same time have a statistically enriched presence on the sequences of H2 proteins. The HIV protein motifs discovered in this study are expressed by subsets of H2 host proteins potentially outcompeted by HIV proteins. A large subset of these motifs is involved in cleavage, nuclear localization, phosphorylation, and transcription factor binding events. Many such motifs are clustered on an HIV sequence in the form of hotspots. The sequential positions of these hotspots are consistent with the curated literature on phenotype altering residue mutations, as well as with existing binding site data. The hotspot map produced in this study is the first global portrayal of HIV motifs involved in altering the host protein network at highly connected hub nodes.

The Bass diffusion model on networks with correlations and inhomogeneous advertising

Science.gov (United States)

Bertotti, M. L.; Brunner, J.; Modanese, G.

2016-09-01

The Bass model, which is an effective forecasting tool for innovation diffusion based on large collections of empirical data, assumes an homogeneous diffusion process. We introduce a network structure into this model and we investigate numerically the dynamics in the case of networks with link density $P(k)=c/k^\\gamma$, where $k=1, \\ldots , N$. The resulting curve of the total adoptions in time is qualitatively similar to the homogeneous Bass curve corresponding to a case with the same average number of connections. The peak of the adoptions, however, tends to occur earlier, particularly when $\\gamma$ and $N$ are large (i.e., when there are few hubs with a large maximum number of connections). Most interestingly, the adoption curve of the hubs anticipates the total adoption curve in a predictable way, with peak times which can be, for instance when $N=100$, between 10% and 60% of the total adoptions peak. This may allow to monitor the hubs for forecasting purposes. We also consider the case of networks with assortative and disassortative correlations and a case of inhomogeneous advertising where the publicity terms are "targeted" on the hubs while maintaining their total cost constant.

Integration of transcriptomic and metabolic data reveals hub transcription factors involved in drought stress response in sunflower (Helianthus annuus L.).

Science.gov (United States)

Moschen, Sebastián; Di Rienzo, Julio A; Higgins, Janet; Tohge, Takayuki; Watanabe, Mutsumi; González, Sergio; Rivarola, Máximo; García-García, Francisco; Dopazo, Joaquin; Hopp, H Esteban; Hoefgen, Rainer; Fernie, Alisdair R; Paniego, Norma; Fernández, Paula; Heinz, Ruth A

2017-07-01

By integration of transcriptional and metabolic profiles we identified pathways and hubs transcription factors regulated during drought conditions in sunflower, useful for applications in molecular and/or biotechnological breeding. Drought is one of the most important environmental stresses that effects crop productivity in many agricultural regions. Sunflower is tolerant to drought conditions but the mechanisms involved in this tolerance remain unclear at the molecular level. The aim of this study was to characterize and integrate transcriptional and metabolic pathways related to drought stress in sunflower plants, by using a system biology approach. Our results showed a delay in plant senescence with an increase in the expression level of photosynthesis related genes as well as higher levels of sugars, osmoprotectant amino acids and ionic nutrients under drought conditions. In addition, we identified transcription factors that were upregulated during drought conditions and that may act as hubs in the transcriptional network. Many of these transcription factors belong to families implicated in the drought response in model species. The integration of transcriptomic and metabolomic data in this study, together with physiological measurements, has improved our understanding of the biological responses during droughts and contributes to elucidate the molecular mechanisms involved under this environmental condition. These findings will provide useful biotechnological tools to improve stress tolerance while maintaining crop yield under restricted water availability.

Hub location proplems under polyhedral demand uncertainty

OpenAIRE

Meraklı, Merve

2015-01-01

Cataloged from PDF version of thesis. Includes bibliographical references (leaves 69-74). Thesis (M.S.): Bilkent University, Department of Industrial Engineering, İhsan Doğramacı Bilkent University, 2015. Hubs are points of consolidation and transshipment in many-to-many distribution systems that bene t from economies of scale. In hub location problems, the aim is to locate hub facilities such that each pairwise demand is satis ed and the total cost is minimized. The problem...

Numerical study of hub taper angle on podded propeller performance

International Nuclear Information System (INIS)

Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

2005-01-01

Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

Flow Structures within a Helicopter Rotor Hub Wake

Science.gov (United States)

Elbing, Brian; Reich, David; Schmitz, Sven

2015-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

Logistics hubs: an integration of transport infrastructure

CSIR Research Space (South Africa)

Botha, M

2008-07-01

Full Text Available " that have jumped on the band wagon pushing for logistics hubs to be established in their regions or within their areas of jurisdiction. The feasibility of a logistics hub is dependent on a number of criteria with access to ideally more than two...

Transaction hubs: can tame energy market communications

Energy Technology Data Exchange (ETDEWEB)

Hamilos, C.

2002-07-01

The nature and function of transaction hubs is described in view of their growing usefulness as electric industry deregulation takes hold and with it the urgent requirement for trading partners to exchange information quickly and efficiently. The paper stresses the many difficulties involved in communications between trading partners since each partner operates under a different set of business rules, with the result that there are 'language differences' to overcome, not to mention the sheer volume of data that must be handled. To make it all work, companies turn increasingly to products like communication hubs. They are able to overcome the fact that different companies have different systems, different data formats and different business rules, and are able to help companies to package, transmit, receive and process information. The principal advantage of a hub is that no one has to learn anyone else's interface. Everyone can continue to use their own data format and transaction models. The hub supplies the protocols and processing rules needed to work with any of the partners connected to the hub. In order to achieve the level of efficiency and reliability required in a hub, certain design principles must be satisfied. These are : scalability, facilities for load balancing, availability of standard routine services, ability to recognize a process as consisting of various transactions, and a transaction as belonging to a specific process, ability to allow the user to configure expiration times around the business processes according to market rules, facility to easily configure validation rules, ability to handle exceptions, ability to interoperate with many middle-ware products, and to manage work flow in a manner that is transparent to operating personnel.

Modelagem para localização de hubs no transporte de encomendas expressas Modelling for location hubs in the express cargo transport

Directory of Open Access Journals (Sweden)

Javier Antonio Timaná Alamo

2006-12-01

Full Text Available Na presente pesquisa se propõe um modelo matemático de programação linear com variáveis binárias 0/1, para projetar a configuração de uma rede de distribuição de encomendas expressas, visando minimizar os custos e garantindo um bom nível de serviço. O modelo, que é uma modificação da formulação proposta por O’Kelly, define as posições dos hubs, a alocação deles às demais instalações físicas e a construção de roteiros com apenas uma parada intermediária, o que confere mais agilidade ao atendimento da demanda de transporte de carga. Considera-se a instalação de um único hub maior (Hub Principal, que serve como ponto de transbordo para os fluxos de carga entre as distintas regiões de um território, e um conjunto de terminais regionais (mini-hubs, servindo como ponto de conexão, unicamente, para os fluxos de carga existentes em um determinado raio de cobertura. Foram propostas extensões que incluem uma restrição da capacidade operacional do Hub Principal, para evitar seu congestionamento, e duas diferentes estratégias de induzir o aumento de fluxo de carga manipulado pelos mini-hubs. O modelo proposto e suas extensões foram aplicados ao estudo de um caso real, obtendo-se resultados consistentes e uma redução significativa no custo total da rede de distribuição da empresa analisada.This study proposes a mathematical model of linear programming with binary variables 0/1 to project the configuration of a distribution network for express cargo which aims to minimize costs and guarantee a high level of service. The model, which is a modification of the formulation proposed by O’Kelly, defines the position of the hubs, their allocation regarding the other physical installations, and the building of itineraries with only one intermediate stop, which increases agility in meeting the demand of cargo transport. It assumes the installation of a single, major hub (Main Hub, which serves as the transfer point for

An Endosymbiotic Evolutionary Algorithm for the Hub Location-Routing Problem

Directory of Open Access Journals (Sweden)

Ji Ung Sun

2015-01-01

Full Text Available We consider a capacitated hub location-routing problem (HLRP which combines the hub location problem and multihub vehicle routing decisions. The HLRP not only determines the locations of the capacitated p-hubs within a set of potential hubs but also deals with the routes of the vehicles to meet the demands of customers. This problem is formulated as a 0-1 mixed integer programming model with the objective of the minimum total cost including routing cost, fixed hub cost, and fixed vehicle cost. As the HLRP has impractically demanding for the large sized problems, we develop a solution method based on the endosymbiotic evolutionary algorithm (EEA which solves hub location and vehicle routing problem simultaneously. The performance of the proposed algorithm is examined through a comparative study. The experimental results show that the proposed EEA can be a viable solution method for the supply chain network planning.

Learning Graphical Models With Hubs.

Science.gov (United States)

Tan, Kean Ming; London, Palma; Mohan, Karthik; Lee, Su-In; Fazel, Maryam; Witten, Daniela

2014-10-01

We consider the problem of learning a high-dimensional graphical model in which there are a few hub nodes that are densely-connected to many other nodes. Many authors have studied the use of an ℓ 1 penalty in order to learn a sparse graph in the high-dimensional setting. However, the ℓ 1 penalty implicitly assumes that each edge is equally likely and independent of all other edges. We propose a general framework to accommodate more realistic networks with hub nodes, using a convex formulation that involves a row-column overlap norm penalty. We apply this general framework to three widely-used probabilistic graphical models: the Gaussian graphical model, the covariance graph model, and the binary Ising model. An alternating direction method of multipliers algorithm is used to solve the corresponding convex optimization problems. On synthetic data, we demonstrate that our proposed framework outperforms competitors that do not explicitly model hub nodes. We illustrate our proposal on a webpage data set and a gene expression data set.

Lean GHTorrent : GitHub data on demand

NARCIS (Netherlands)

Gousios, G.; Vasilescu, B.N.; Serebrenik, A.; Zaidman, A.

2014-01-01

In recent years, GitHub has become the largest code host in the world, with more than 5M developers collaborating across 10M repositories. Numerous popular open source projects (such as Ruby on Rails, Homebrew, Bootstrap, Django or jQuery) have chosen GitHub as their host and have migrated their

Identification of promising Twin Hub networks : Report of Work Package 1 of the Intermodal rail freight Twin hub Network Northwest Europe - project (final report)

NARCIS (Netherlands)

Kreutzberger, E.D.; Konings, J.W.; Meijer, S.; Witteveen, C.; Meijers, B.M.; Pekin, E.; Macharis, C.; Kiel, J.; Kawabata, Y.; Vos, W.

2014-01-01

This report is the first deliverable of the project Intermodal Rail Freight Twin Hub Network Northwest Europe. We call its subject Twin hub network and the organisational entity to carry out the actions the Twin hub project. The project is funded by INTERREG NWE (programme IVb). Its work started in

Turbine exhaust diffuser with region of reduced flow area and outer boundary gas flow

Science.gov (United States)

Orosa, John

2014-03-11

An exhaust diffuser system and method for a turbine engine. The outer boundary may include a region in which the outer boundary extends radially inwardly toward the hub structure and may direct at least a portion of an exhaust flow in the diffuser toward the hub structure. At least one gas jet is provided including a jet exit located on the outer boundary. The jet exit may discharge a flow of gas downstream substantially parallel to an inner surface of the outer boundary to direct a portion of the exhaust flow in the diffuser toward the outer boundary to effect a radially outward flow of at least a portion of the exhaust gas flow toward the outer boundary to balance an aerodynamic load between the outer and inner boundaries.

Location of Urban Logistic Terminals as Hub Location Problem

Directory of Open Access Journals (Sweden)

Jasmina Pašagić Škrinjar

2012-09-01

Full Text Available In this paper the problems of locating urban logistic terminals are studied as hub location problems that due to a large number of potential nodes in big cities belong to hard non-polynomial problems, the so-called NP-problems. The hub location problems have found wide application in physical planning of transport and telecommunication systems, especially systems of fast delivery, networks of logistic and distribution centres and cargo traffic terminals of the big cities, etc. The paper defines single and multiple allocations and studies the numerical examples. The capacitated single allocation hub location problems have been studied, with the provision of a mathematical model of selecting the location for the hubs on the network. The paper also presents the differences in the possibilities of implementing the exact and heuristic methods to solve the actual location problems of big dimensions i.e. hub problems of the big cities.

Altered cortical hubs in functional brain networks in amyotrophic lateral sclerosis.

Science.gov (United States)

Ma, Xujing; Zhang, Jiuquan; Zhang, Youxue; Chen, Heng; Li, Rong; Wang, Jian; Chen, Huafu

2015-11-01

Cortical hubs are highly connected nodes in functional brain networks that play vital roles in the efficient transfer of information across brain regions. Although altered functional connectivity has been found in amyotrophic lateral sclerosis (ALS), the changing pattern in functional network hubs in ALS remains unknown. In this study, we applied a voxel-wise method to investigate the changing pattern of cortical hubs in ALS. Through resting-state fMRI, we constructed whole-brain voxel-wise functional networks by measuring the temporal correlations of each pair of brain voxels and identified hubs using the graph theory method. Specifically, a functional connectivity strength (FCS) map was derived from the data on 20 patients with ALS and 20 healthy controls. The brain regions with high FCS values were regarded as functional network hubs. Functional hubs were found mainly in the bilateral precuneus, parietal cortex, medial prefrontal cortex, and in several visual regions and temporal areas in both groups. Within the hub regions, the ALS patients exhibited higher FCS in the prefrontal cortex compared with the healthy controls. The FCS value in the significantly abnormal hub regions was correlated with clinical variables. Results indicated the presence of altered cortical hubs in the ALS patients and could therefore shed light on the pathophysiology mechanisms underlying ALS.

Optimum hub height of a wind turbine for maximizing annual net profit

International Nuclear Information System (INIS)

Lee, Jaehwan; Kim, Dong Rip; Lee, Kwan-Soo

2015-01-01

Highlights: • Annual Net Profit was proposed to optimize the hub height of a wind turbine. • Procedures of the hub height optimization method were introduced. • Effect of local wind speed characteristics on optimum hub height was illustrated. • Effect of rated power on optimum hub height was negligible in the range 0.75–3 MW. • Rated speed and cut-out speed had great effects on optimum hub height. - Abstract: The optimization method of the hub height, which can ensure the economic feasibility of the wind turbine, is proposed in this study. Annual Net Profit is suggested as an objective function and the optimization procedure is developed. The effects of local wind speed and wind turbine power characteristics on the optimum hub height are investigated. The optimum hub height decreased as the mean wind speed and wind shear exponent increased. Rated power had little effect on optimum hub height; it follows that the economies of scale are negligible in the rated power range of 0.75–3 MW. Among the wind turbine power characteristics, rated speed and cut-out speed most strongly affected the optimum hub height

Report on survey on international hub

International Nuclear Information System (INIS)

Ebisawa, Hirobumi; Hoshino, Junko; Hashimoto, Kazuichiro; Okada, Sohei

2011-06-01

Japan Atomic Energy Agency (JAEA) is promoting initiative to form an international hub in line with its aim to accept more researchers/engineers from all over the world. Establishment of 'the Committee for JAEA Internationalization Initiative' was planned in 2010 so as to intensify this initiative, and in February, 2010, we visited research institutions in Europe, which include European Organization for Nuclear Research (CERN), the construction site of ITER in Cadarache, and Rutherford Appleton Laboratory (RAL), with the intention to survey and learn their advanced activities and systems in regard to the International Hub, so that the committee will be able to make fruitful discussion. This report describes strategy taken in each institution for an International Hub, and the state of each institution regarding acceptance and management of overseas researchers and engineers, research environment, living environment/health and welfare, and PR activities/coexistence with the local community. (author)

Numerical investigation of hub clearance flow in a Kaplan turbine

Science.gov (United States)

Wu, H.; Feng, J. J.; Wu, G. K.; Luo, X. Q.

2012-11-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

Numerical investigation of hub clearance flow in a Kaplan turbine

International Nuclear Information System (INIS)

Wu, H; Feng, J J; Wu, G K; Luo, X Q

2012-01-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

The factors impacted to local contractor from Foreign Direct Investment in advancing economic hub development in Iskandar Malaysia

Science.gov (United States)

Syafiq Salim, Muhamad; Zakaria, Rozana; Aminuddin, Eeydzah; Hamid, Abdul Rahim Abdul; Abdullah, Redzuan; Shahzaib Khan, Jam

2018-04-01

Iskandar Malaysia is an advanced economic hub which is rapidly growing in the State of Johor. It has been an attractive place for Foreign Direct Investment (FDI) to invest. Many sectors are affected by the presence of FDI including the construction sector. This paper highlights the investigation on the effects of FDI to the local contractor in the Iskandar Malaysia Development. In this study, a questionnaire survey was carried out to gain the information on problems from internal factors and external factors that caused the limitation on involvement in FDI project by local contractors. 73 numbers of local contractor registered under CIDB in class G5, G6 and G7 are the respondents. Frequency analysis and Average Index Analysis are used for the results. This study provides the factors that impacted local construction players in Iskandar Malaysia Development. This study has portrayed that FDI plays a vital and significant role in spearheading the active involvement of local contractors in an urban sustainable development.

A versatile framework for cooperative hub network development

NARCIS (Netherlands)

Cruijssen, F.C.A.M.; Borm, P.; Dullaert, W.; Hamers, H.

2010-01-01

This paper introduces a framework for cooperative hub network development. Building a joint physical hub for the transshipment of goods is expensive and, therefore, involves considerable risks for cooperating companies. In a practical setting, it is unlikely that an entire network will be built at

A versatile framework for cooperative hub network development

NARCIS (Netherlands)

Cruijssen, Frans; Borm, Peter; Dullaert, Wout; Hamers, Herbert

This paper introduces a framework for cooperative hub network development. Building a joint physical hub for the transshipment of goods is expensive and, therefore, involves considerable risks for cooperating companies. In a practical setting, it is unlikely that an entire network will be built at

Static pressure recovery analysis in the vane island diffuser of a centrifugal pump

Energy Technology Data Exchange (ETDEWEB)

Si, Qiaorui [National Research Center of Pumps, Jiangsu University, Zhenjiang (China); Dupont, Patrick; Bayeul-Laine, Annie-Claude; Dazin, Antoine; Roussette, Olivier; Bois, Gerard [LML, UMR CNRS 8107 Ecole Centrale de Lille, Lille (France)

2016-02-15

The overall performance of a vane-island type diffuser of a centrifugal pump model was obtained by means of directional probe traverses. These measurements were performed in an air model of a real hydraulic pump for five volume flow rates. Directional probe traverses are performed with a classical three-hole probe to cover most of the complete inlet section of the diffuser from hub to shroud and from pressure to suction side. Existing Particle image velocimetry (PIV) measurement results are also used to compare probe measurement results between the inlet and outlet throats of vane island diffuser at mid-span. Some assistance from already existing unsteady calculation, including leakage effects, is used to evaluate the numerical approach capability and to correctly define the mean initial conditions at impeller's outlet section. Pressure recovery and the measured total pressure loss levels inside this particular vane diffuser geometry are then calculated. Detailed analysis of the flow structure at the inlet section of the vane island diffuser is presented to focus on pressure evolution inside the entire diffuser section for different flow rates. The combined effects of incidence angle and blockage distributions along hub to shroud direction are found to play an important role on loss distribution in such a diffuser.

International Education Hubs: Collaboration for Competitiveness and Sustainability

Science.gov (United States)

Knight, Jane

2014-01-01

This chapter focuses on the development of education hubs, a recent phenomenon in international higher education. Three models of hubs are examined in relation to the forces, risks, and opportunities of globalization and how local and international collaborations are essential for both global competitiveness and sustainability.

Development of an improved low profile hub seal refurbishment tool

International Nuclear Information System (INIS)

Wagg, L.

1997-01-01

The hub seal area of a fuel channel feeder coupling can be exposed to oxygen in the atmosphere if protective measures are not taken during maintenance outages. Exposure to oxygen can lead to pitting of the hub seal area. Although this is a rare occurrence, the resulting possibility of the feeder coupling leakage led to the development of a feeder hub refurbishment tool. To reduce time and man-rem exposure during feeder hub seal refurbishment, an improved low profile hub seat refurbishing tool has been developed. The improved tool design will allow for quick and controlled removal of material, and the restoration of a roll-burnished finish equivalent to the original requirements. The new tool can be used in maintenance operations, with the end fitting present, as well as under retube-type circumstances, with the end fitting removed. (author)

Integrated technology rotor/flight research rotor hub concept definition

Science.gov (United States)

Dixon, P. G. C.

1983-01-01

Two variations of the helicopter bearingless main rotor hub concept are proposed as bases for further development in the preliminary design phase of the Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) program. This selection was the result of an evaluation of three bearingless hub concepts and two articulated hub concepts with elastomeric bearings. The characteristics of each concept were evaluated by means of simplified methodology. These characteristics included the assessment of stability, vulnerability, weight, drag, cost, stiffness, fatigue life, maintainability, and reliability.

E-hubs: the new B2B (business-to-business) marketplaces.

Science.gov (United States)

Kaplan, S; Sawhney, M

2000-01-01

Electronic hubs--Internet-based intermediaries that host electronic marketplaces and mediate transactions among businesses--are generating a lot of interest. Companies like Ariba, Chemdex, and Commerce One have already attained breathtaking stock market capitalizations. Venture capitalists are pouring money into more business-to-business start-ups. Even industrial stalwarts like GM and Ford are making plans to set up their own Web markets. As new entrants with new business models pour into the business-to-business space, it's increasingly difficult to make sense of the landscape. This article provides a blueprint of the e-hub arena. The authors start by looking at the two dimensions of purchasing: what businesses buy--manufacturing inputs or operating inputs--and how they buy--through systematic sourcing or spot sourcing. They classify B2B e-hubs into four categories: MRO hubs, yield managers, exchanges, and catalog hubs, and they discuss each type in detail. Drilling deeper into this B2B matrix, the authors look at how e-hubs create value--through aggregation and matching--and explain when each mechanism works best. They also examine the biases of e-hubs. Although many e-hubs are neutral--they're operated by independent third parties--some favor the buyers or sellers. The authors explain the differences and discuss the pros and cons of each position. The B2B marketplace is changing rapidly. This framework helps buyers, sellers, and market makers navigate the landscape by explaining what the different hubs do and how they add the most value.

Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing.

Science.gov (United States)

Huang, Jing; Deng, Furong; Wu, Shaowei; Zhao, Yan; Shima, Masayuki; Guo, Bin; Liu, Qichen; Guo, Xinbiao

2016-09-01

Transport hub is an important part of urban comprehensive transportation system. Traffic-related air pollution can reach high level because of difficulty of diffusion and increase of emission in transport hub. However, whether exposure in this semi-closed traffic micro-environment causes acute changes in pulmonary function of commuters still needs to be explored. Forty young healthy adults participated in this randomized, crossover study. Each participant underwent 2 h exposure in a designated transport hub and, on a separate occasion, in an appointed park. Personal exposures to fine particulate matter (PM 2.5 ), black carbon (BC) and carbon monoxide (CO) were measured. Forced expiratory volume in 1 s (FEV 1 ) and peak expiratory flow (PEF) were assessed pre-, during and post-exposure. Mixed linear models were used to analyze the pulmonary effects of traffic-related air pollutants. Participants had significantly higher exposures to PM 2.5 , BC and CO in the transport hub than in the park. Exposure in transport hub induced significant reductions in FEV 1 and PEF compared with the park during exposure 1 and 2 h. The reductions were significant associated with traffic-related air pollutants. For instance, per 10 μg/m 3 increment in PM 2.5 was associated with -0.15 % (95 % CI -0.28, -0.02 %) reduction in FEV 1 during exposure 2 h. However, effects became attenuate after 2 h exposure. Short-term exposure in transport hub had acute reduction effects on pulmonary function. More attention should be paid to the health effects of exposure in the semi-closed traffic micro-environment.

Sci-Hub provides access to nearly all scholarly literature.

Science.gov (United States)

Himmelstein, Daniel S; Romero, Ariel Rodriguez; Levernier, Jacob G; Munro, Thomas Anthony; McLaughlin, Stephen Reid; Greshake Tzovaras, Bastian; Greene, Casey S

2018-03-01

The website Sci-Hub enables users to download PDF versions of scholarly articles, including many articles that are paywalled at their journal's site. Sci-Hub has grown rapidly since its creation in 2011, but the extent of its coverage has been unclear. Here we report that, as of March 2017, Sci-Hub's database contains 68.9% of the 81.6 million scholarly articles registered with Crossref and 85.1% of articles published in toll access journals. We find that coverage varies by discipline and publisher, and that Sci-Hub preferentially covers popular, paywalled content. For toll access articles, we find that Sci-Hub provides greater coverage than the University of Pennsylvania, a major research university in the United States. Green open access to toll access articles via licit services, on the other hand, remains quite limited. Our interactive browser at https://greenelab.github.io/scihub allows users to explore these findings in more detail. For the first time, nearly all scholarly literature is available gratis to anyone with an Internet connection, suggesting the toll access business model may become unsustainable. © 2018, Himmelstein et al.

Liner Shipping Hub Network Design in a Competitive Environment

DEFF Research Database (Denmark)

Gelareh, Shahin; Nickel, Stefan; Pisinger, David

A new mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses competition between a newcomer liner service provider and an alliance, both operating on hub-and-spoke networks. The newcomer company maximizes its market share...... — proportional to service time and transportation cost —by locating a predefined number of hubs at candidate ports and designing its network. While general-purpose solvers do not solve instances of even small size, an accelerated lagrangian method coupled with a primal heuristic obtains very good bounds. Our...

Variable Eddington factors and flux-limiting diffusion coefficients

International Nuclear Information System (INIS)

Whalen, P.P.

1982-01-01

Variable Eddington factors and flux limiting diffusion coefficients arise in two common techniques of closing the moment equations of transport. The first two moment equations of the full transport equation are still frequently used to solve many problems of radiative or particle transport. An approximate analysis, developed by Levermore, exhibits the relation between the coefficients of the two different techniques. This analysis is described and then used to test the validity of several commonly used flux limiters and Eddington factors. All of the ad-hoc flux limiters have limited validity. All of the variable Eddington factors derived from some underlying description of the angular distribution function are generally valid. The use of coefficients from Minerbo's elegant maximum entropy Eddington factor analysis is suggested for use in either flux limited diffusion or variable Eddington factor equations

Multi-Item Distribution Policies with Supply Hub and Lateral Transshipment

OpenAIRE

Zhong Jin-Hong; Jiang Rui-Xuan; Zheng Gui

2015-01-01

Supply Hub is defined as the horizontal coordination among the suppliers while lateral transshipment is a horizontal coordination policy among the retailers. By considering the Supply Hub and lateral transshipment simultaneously, ones can reduce the total cost of the supply chain system and improve the response to customer requirement and the customers’ satisfaction. We investigate the distribution policies for the supply chain which consists of multisuppliers, single Supply Hub, and multidis...

Revisiting date and party hubs: novel approaches to role assignment in protein interaction networks.

Directory of Open Access Journals (Sweden)

Sumeet Agarwal

2010-06-01

Full Text Available The idea of "date" and "party" hubs has been influential in the study of protein-protein interaction networks. Date hubs display low co-expression with their partners, whilst party hubs have high co-expression. It was proposed that party hubs are local coordinators whereas date hubs are global connectors. Here, we show that the reported importance of date hubs to network connectivity can in fact be attributed to a tiny subset of them. Crucially, these few, extremely central, hubs do not display particularly low expression correlation, undermining the idea of a link between this quantity and hub function. The date/party distinction was originally motivated by an approximately bimodal distribution of hub co-expression; we show that this feature is not always robust to methodological changes. Additionally, topological properties of hubs do not in general correlate with co-expression. However, we find significant correlations between interaction centrality and the functional similarity of the interacting proteins. We suggest that thinking in terms of a date/party dichotomy for hubs in protein interaction networks is not meaningful, and it might be more useful to conceive of roles for protein-protein interactions rather than for individual proteins.

Classification of gene expression data: A hubness-aware semi-supervised approach.

Science.gov (United States)

Buza, Krisztian

2016-04-01

Classification of gene expression data is the common denominator of various biomedical recognition tasks. However, obtaining class labels for large training samples may be difficult or even impossible in many cases. Therefore, semi-supervised classification techniques are required as semi-supervised classifiers take advantage of unlabeled data. Gene expression data is high-dimensional which gives rise to the phenomena known under the umbrella of the curse of dimensionality, one of its recently explored aspects being the presence of hubs or hubness for short. Therefore, hubness-aware classifiers have been developed recently, such as Naive Hubness-Bayesian k-Nearest Neighbor (NHBNN). In this paper, we propose a semi-supervised extension of NHBNN which follows the self-training schema. As one of the core components of self-training is the certainty score, we propose a new hubness-aware certainty score. We performed experiments on publicly available gene expression data. These experiments show that the proposed classifier outperforms its competitors. We investigated the impact of each of the components (classification algorithm, semi-supervised technique, hubness-aware certainty score) separately and showed that each of these components are relevant to the performance of the proposed approach. Our results imply that our approach may increase classification accuracy and reduce computational costs (i.e., runtime). Based on the promising results presented in the paper, we envision that hubness-aware techniques will be used in various other biomedical machine learning tasks. In order to accelerate this process, we made an implementation of hubness-aware machine learning techniques publicly available in the PyHubs software package (http://www.biointelligence.hu/pyhubs) implemented in Python, one of the most popular programming languages of data science. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Liner shipping hub network design in a competitive environment

DEFF Research Database (Denmark)

Gelareh, Shahin; Nickel, Stefan; Pisinger, David

2010-01-01

A mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses the competition between a newcomer liner service provider and an existing dominating operator, both operating on hub-and-spoke networks. The newcomer company maximizes i...

Flow Merging and Hub Route Optimization in Collaborative Transportation

Directory of Open Access Journals (Sweden)

Kerui Weng

2014-01-01

Full Text Available This paper studies the optimal hub routing problem of merged tasks in collaborative transportation. This problem allows all carriers’ transportation tasks to reach the destinations optionally passing through 0, 1, or 2 hubs within limited distance, while a cost discount on arcs in the hub route could be acquired after paying fixed charges. The problem arises in the application of logistics, postal services, airline transportation, and so forth. We formulate the problem as a mixed-integer programming model, and provide two heuristic approaches, respectively, based on Lagrangian relaxation and Benders decomposition. Computational experiments show that the algorithms work well.

Predicting the binding patterns of hub proteins: a study using yeast protein interaction networks.

Directory of Open Access Journals (Sweden)

Carson M Andorf

Full Text Available Protein-protein interactions are critical to elucidating the role played by individual proteins in important biological pathways. Of particular interest are hub proteins that can interact with large numbers of partners and often play essential roles in cellular control. Depending on the number of binding sites, protein hubs can be classified at a structural level as singlish-interface hubs (SIH with one or two binding sites, or multiple-interface hubs (MIH with three or more binding sites. In terms of kinetics, hub proteins can be classified as date hubs (i.e., interact with different partners at different times or locations or party hubs (i.e., simultaneously interact with multiple partners.Our approach works in 3 phases: Phase I classifies if a protein is likely to bind with another protein. Phase II determines if a protein-binding (PB protein is a hub. Phase III classifies PB proteins as singlish-interface versus multiple-interface hubs and date versus party hubs. At each stage, we use sequence-based predictors trained using several standard machine learning techniques.Our method is able to predict whether a protein is a protein-binding protein with an accuracy of 94% and a correlation coefficient of 0.87; identify hubs from non-hubs with 100% accuracy for 30% of the data; distinguish date hubs/party hubs with 69% accuracy and area under ROC curve of 0.68; and SIH/MIH with 89% accuracy and area under ROC curve of 0.84. Because our method is based on sequence information alone, it can be used even in settings where reliable protein-protein interaction data or structures of protein-protein complexes are unavailable to obtain useful insights into the functional and evolutionary characteristics of proteins and their interactions.We provide a web server for our three-phase approach: http://hybsvm.gdcb.iastate.edu.

Climate programs update: USDA Southwest Regional Climate Hub update

Science.gov (United States)

PROGRAM OVERVIEW: The overarching goal of the USDA SW Climate Hub is to assist farmers, ranchers and foresters in addressing the effects of climate change including prolonged drought, increased insect outbreaks and severe wildfires. In the first year of operations, the SW Climate Hub (est. Februa...

Wave Transformation for International Hub Port Planning (Transformasi Gelombang untuk Perencanaan Pelabuhan Hub Internasional

Directory of Open Access Journals (Sweden)

Denny Nugroho Sugianto

2015-02-01

archipelagic countries in the world, therefore port has vital role in economic development. Port is not just as a complement to the infrastructure, but it must be planned and managed properly and attention to the dynamics of marine phenomena such as ocean wave patterns. Ocean wave data become important factors in planning coastal building, since it is influenced by wave height, tides and waves transformation. The purpose of this study was to analyse characteristic and forms wave transformations for planning of international hub port at Kuala Tanjung, Baru Bara District North Sumatra. This port is one of two Indonesian government's plan in the development of international hub port. Quantitative method was used in this study by statistical calculations and mathematical modeling with hydrodinamic modules and spectral wave to determine the direction of wave propagation and transformation. Results show that based on ECMWF data during 1999-June 2014, known significant wave height (Hs maximum of 1.69 m and maximum period (Ts of 8 secs. The classification wave characteristics iswave transition (d.L-1: 0.27–0.48 and by the period are classified as gravitational waves. Wave transformation occurs due to the soaling, withKs 0.93–0.98 and the wave refraction Kr 0.97–0.99. Whereas Hb of 1.24 meters anddb 1.82 meters. The effectiveness of the design of the terminal building at the Port of Kuala Tanjung overall for the season amounted to 79.8%, which is quite effective in reducing the wave. Keywords: wave transformation, wave height and period, Port of Kuala Tanjung

Hub Status and Indexation of Container Ports

Directory of Open Access Journals (Sweden)

Yong-An Park

2015-06-01

This study develops two sub-indexes of port classification and capacity, and combines cases of these two sub-indexes into various types in order to find a proper port hub index. The paper demonstrates how different types of port hub index are useful measurements for evaluating outputs and inputs of container ports. In a case analysis we show that the indexes of period variables and lagged variables have more explanatory power with regard to changes of port throughputs and high correlation with inputs.

Rigid-flexible coupling dynamics of three-dimensional hub-beams system

International Nuclear Information System (INIS)

Liu Jinyang; Lu Hao

2007-01-01

In the previous research of the coupling dynamics of a hub-beam system, coupling between the rotational motion of hub and the torsion deformation of beam is not taken into account since the system undergoes planar motion. Due to the small longitudinal deformation, coupling between the rotational motion of hub and the longitudinal deformation of beam is also neglected. In this paper, rigid-flexible coupling dynamics is extended to a hub-beams system with three-dimensional large overall motion. Not only coupling between the large overall motion and the bending deformation, but also coupling between the large overall motion and the torsional deformation are taken into account. In case of temperature increase, the longitudinal deformation caused by the thermal expansion is significant, such that coupling between the large overall motion and the longitudinal deformation is also investigated. Combining the characteristics of the hybrid coordinate formulation and the absolute nodal coordinate formulation, the system generalized coordinates include the relative nodal displacement and the slope of each beam element with respect to the body-fixed frame of the hub, and the variables related to the spatial large overall motion of the hub and beams. Based on precise strain-displacement relation, the geometric stiffening effect is taken into account, and the rigid-flexible coupling dynamic equations are derived using velocity variational principle. Finite element method is employed for discretization. Simulation of a hub-beams system is used to show the coupling effect between the large overall motion and the torsional deformation as well as the longitudinal deformation. Furthermore, conservation of energy in case of free motion is shown to verify the formulation

Nonlinear analysis of the GFRP material wheel hub

Directory of Open Access Journals (Sweden)

Dong Yun-Feng

2015-01-01

Full Text Available In this paper, the current bicycle wheel was replaced by the ones which composed by the wheel hub with Glassfiber Reinforced Plastic (alkali free thin-walled cylinder material, hereinafter referred to as GFRP material and the protective components made up of rubber outer pneumatic pad. With the help of the basic theory of elastic-plastic mechanics, the finite element “Nonlinear buckling” analysis of the wheel was carried out. The results show that the maximum elastic deformation of the wheel hub and the critical value of buckling failure load were restricted by the elasticity under the condition of external loads. Considering with the tensile strength and elastic modulus of the GFRP value of the material, it is demonstrated that the material is feasible to be used for wheel hub.

Managing effective and efficient hub operations : a study of ground time management

NARCIS (Netherlands)

Yunita, Theresia

2009-01-01

This Logistics Design Project was carried out at KLM Aircraft Services (AS), from February 2008 - April 2009. The project focuses on ideal description of KLM operational controls for daily executions at the hub and within the AS processes. The daily execution at the hub is managed by the Hub Control

Virtual Replication of IoT Hubs in the Cloud: A Flexible Approach to Smart Object Management

Directory of Open Access Journals (Sweden)

Simone Cirani

2018-03-01

Full Text Available In future years, the Internet of Things is expected to interconnect billions of highly heterogeneous devices, denoted as “smart objects”, enabling the development of innovative distributed applications. Smart objects are constrained sensor/actuator-equipped devices, in terms of computational power and available memory. In order to cope with the diverse physical connectivity technologies of smart objects, the Internet Protocol is foreseen as the common “language” for full interoperability and as a unifying factor for integration with the Internet. Large-scale platforms for interconnected devices are required to effectively manage resources provided by smart objects. In this work, we present a novel architecture for the management of large numbers of resources in a scalable, seamless, and secure way. The proposed architecture is based on a network element, denoted as IoT Hub, placed at the border of the constrained network, which implements the following functions: service discovery; border router; HTTP/Constrained Application Protocol (CoAP and CoAP/CoAP proxy; cache; and resource directory. In order to protect smart objects (which cannot, because of their constrained nature, serve a large number of concurrent requests and the IoT Hub (which serves as a gateway to the constrained network, we introduce the concept of virtual IoT Hub replica: a Cloud-based “entity” replicating all the functions of a physical IoT Hub, which external clients will query to access resources. IoT Hub replicas are constantly synchronized with the physical IoT Hub through a low-overhead protocol based on Message Queue Telemetry Transport (MQTT. An experimental evaluation, proving the feasibility and advantages of the proposed architecture, is presented.

FROM PRE-OIL SETTLEMENT TO POST-OIL HUB: The Urban Transformation of Doha

Directory of Open Access Journals (Sweden)

Florian Wiedmann

2013-07-01

Full Text Available Since oil production commenced in the middle of the 20th century Qatar's capital Doha witnessed a rapid urbanisation period. Today, new development strategies, which have been implemented to diversify Qatar's economy, have led to a new urban transformation process with the vision to establish Doha as hub within global networks. Economic transformation processes in Qatar have always caused new structures within its society, which in turn affected urban developments. After decades of urbanisation based on the export of oil, the introduction of a hub vision at the end of the 1990s marked a new process that has been rethinking urbanism in Qatar. Although current developments have attracted worldwide attention, there has been rather little scientific reflection as to how current urbanism in the Gulf should be understood in relation to its past and projected future. Therefore, this paper seeks to investigate the various factors impacting Doha's urban environment during economic transformation processes. Each economc transformation has had a large impact  on the structure of the city’s society as well as its built environment. The curren transformation process can still be considered at its beginning. In order to understand the impact of contemporary economic diversification strategies, the city’s past urbanisation stages and their spatial development factors had to be analysed. All in all four distinct phases of urbanism can be distinguished in the case of Doha: The pre-oil settlement, the modernisation period, the oil city and the globalised hub.

Mechanical Design, Analysis, and Testing of a Two-Bladed Wind Turbine Hub

Energy Technology Data Exchange (ETDEWEB)

Cotrell, J.

2002-06-01

Researchers at the National Wind Technology Center (NWTC) in Golden, Colorado, began performing the Unsteady Aerodynamics Experiment in 1993 to better understand the unsteady aerodynamics and structural responses of horizontal-axis wind turbines. The experiment consists of an extensively instrumented, downwind, three-bladed, 20-kilowatt wind turbine. In May 1995, I received a request from the NWTC to design a two-bladed hub for the experiment. For my thesis, I present the results of the mechanical design, analysis, and testing of the hub. The hub I designed is unique because it runs in rigid, teetering, or independent blade-flapping modes. In addition, the design is unusual because it uses two servomotors to pitch the blades independently. These features are used to investigate new load reduction, noise reduction, blade pitch optimization, and yaw control techniques for two-bladed turbines. I used a methodology by G. Phal and W. Bietz to design the hub. The hub meets all the performance specifications except that it achieves only 90% of the specified teeter range. In my thesis, I focus on the analysis and testing of the hub body. I performed solid-mechanics calculations, ran a finite-element analysis simulation, and experimentally investigated the structural integrity of the hub body.

SUN HUB – ENERGY HUB FOR OUTDOOR TABLES

DEFF Research Database (Denmark)

Poulsen, Peter Behrensdorff; Benatto, Gisele Alves dos Reis; Riedel, Nicholas

2017-01-01

connections, providing opportunity to stream music via Bluetooth and play it from a handheld device to the table and lastly to provide LED lighting on the table during the dark hours. 3 prototypes of the system was built and tested at the Roskilde Festival 2017. Electrical logger units were built into the 3...... on festivals where people camps for several days it can be hard to have your portable units charged. In this this work we report a solar powered hub, as an add-on to a table in the urban environment for charging mobile phones and tablets and other handheld devices through USBs, charging laptops through AC...

Multiple Hub Network Choice in the Liberalized European Market

Science.gov (United States)

Berechman, Joseph; deWit, Jaap

1997-01-01

A key question that so far has received relatively little attention in the germane literature is that of the changes at various airports as a result of the EU liberalization policies. That is, presently, most major European airports still benefit from the so-called home-carrier phenomenon where the country's publicly or semi-publicly owned carrier uses the country's main airport as its gateway hub and, consequently, the home-carrier is also the principal user of this airport (in terms of proportion of total aircraft movements, number of passengers transported, connections, slots ownership, etc.). The country's main airport has substantially benefited from these monopoly conditions of airline captivity, strongly determined by the bilateral system of international air transport regulation. Therefore, European major airports were used to operate in essentially different markets, compared to the increasingly competitive markets of their home based carriers. This partly explains relative stability of transport volumes and financial results of European major airports compared to the relatively volatile financial results of most European national airlines. However, the liberalization of European aviation is likely to change this situation. Market access is open now to all community carriers, i.e. carriers with majority ownership and effective control in the hands of EU citizens. Ticket prices are free, governments can only intervene in case of dumping or excessive pricing. A community airline can choose its seat in any of the 15 member states. Licensing procedures are harmonized between member states. In the last few months community carriers have had unrestricted route access within the EU. Most probably this development will be extended to countries inside and outside Europe. Last year the European Commission got the mandate to start negotiations with 10 other European countries. In the meantime the EC has also started negotiations with the USA on so-called soft rights

Predicting highly-connected hubs in protein interaction networks by QSAR and biological data descriptors

Science.gov (United States)

Hsing, Michael; Byler, Kendall; Cherkasov, Artem

2009-01-01

Hub proteins (those engaged in most physical interactions in a protein interaction network (PIN) have recently gained much research interest due to their essential role in mediating cellular processes and their potential therapeutic value. It is straightforward to identify hubs if the underlying PIN is experimentally determined; however, theoretical hub prediction remains a very challenging task, as physicochemical properties that differentiate hubs from less connected proteins remain mostly uncharacterized. To adequately distinguish hubs from non-hub proteins we have utilized over 1300 protein descriptors, some of which represent QSAR (quantitative structure-activity relationship) parameters, and some reflect sequence-derived characteristics of proteins including domain composition and functional annotations. Those protein descriptors, together with available protein interaction data have been processed by a machine learning method (boosting trees) and resulted in the development of hub classifiers that are capable of predicting highly interacting proteins for four model organisms: Escherichia coli, Saccharomyces cerevisiae, Drosophila melanogaster and Homo sapiens. More importantly, through the analyses of the most relevant protein descriptors, we are able to demonstrate that hub proteins not only share certain common physicochemical and structural characteristics that make them different from non-hub counterparts, but they also exhibit species-specific characteristics that should be taken into account when analyzing different PINs. The developed prediction models can be used for determining highly interacting proteins in the four studied species to assist future proteomics experiments and PIN analyses. Availability The source code and executable program of the hub classifier are available for download at: http://www.cnbi2.ca/hub-analysis/ PMID:20198194

Microfluidic hubs, systems, and methods for interface fluidic modules

Science.gov (United States)

Bartsch, Michael S; Claudnic, Mark R; Kim, Hanyoup; Patel, Kamlesh D; Renzi, Ronald F; Van De Vreugde, James L

2015-01-27

Embodiments of microfluidic hubs and systems are described that may be used to connect fluidic modules. A space between surfaces may be set by fixtures described herein. In some examples a fixture may set substrate-to-substrate spacing based on a distance between registration surfaces on which the respective substrates rest. Fluidic interfaces are described, including examples where fluid conduits (e.g. capillaries) extend into the fixture to the space between surfaces. Droplets of fluid may be introduced to and/or removed from microfluidic hubs described herein, and fluid actuators may be used to move droplets within the space between surfaces. Continuous flow modules may be integrated with the hubs in some examples.

North West Surrey's locality hubs - delivering integrated care

OpenAIRE

Compton, Lisa; Wilkinson, Peter; Lawn, Liz

2017-01-01

Introduction: North West Surrey CCG (NWSCCG) is establishing Locality Hubs – physical buildings offering a fully integrated GP-led, multi-disciplinary ‘one-stop-shop’ services in the community for a defined cohort of frail elderly patients with multiple core morbidities. Hubs will ultimately deliver proactive and reactive care, available 24 hours a day, 365 days a year.The key drivers are;Ageing population, people living longer & more people living with chronic conditionsCost & demand...

A protein interaction atlas for the nuclear receptors: properties and quality of a hub-based dimerisation network

Directory of Open Access Journals (Sweden)

De Graaf David

2007-07-01

Full Text Available Abstract Background The nuclear receptors are a large family of eukaryotic transcription factors that constitute major pharmacological targets. They exert their combinatorial control through homotypic heterodimerisation. Elucidation of this dimerisation network is vital in order to understand the complex dynamics and potential cross-talk involved. Results Phylogeny, protein-protein interactions, protein-DNA interactions and gene expression data have been integrated to provide a comprehensive and up-to-date description of the topology and properties of the nuclear receptor interaction network in humans. We discriminate between DNA-binding and non-DNA-binding dimers, and provide a comprehensive interaction map, that identifies potential cross-talk between the various pathways of nuclear receptors. Conclusion We infer that the topology of this network is hub-based, and much more connected than previously thought. The hub-based topology of the network and the wide tissue expression pattern of NRs create a highly competitive environment for the common heterodimerising partners. Furthermore, a significant number of negative feedback loops is present, with the hub protein SHP [NR0B2] playing a major role. We also compare the evolution, topology and properties of the nuclear receptor network with the hub-based dimerisation network of the bHLH transcription factors in order to identify both unique themes and ubiquitous properties in gene regulation. In terms of methodology, we conclude that such a comprehensive picture can only be assembled by semi-automated text-mining, manual curation and integration of data from various sources.

DigitalHub: A Repository Focused on the Future.

Science.gov (United States)

Ilik, Violeta; Hebal, Piotr; Olson, Anton; Wishnetsky, Susan; Pastva, Joelen; Kubilius, Ramune; Shank, Jonathan; Gutzman, Karen; Chung, Margarita; Holmes, Kristi

2018-01-01

The DigitalHub scholarly repository was developed and launched at the Galter Health Sciences Library for the Feinberg School of Medicine and the greater Northwestern Medicine community. The repository was designed to allow scholars the ability to create, share, and preserve a range of citable digital outputs. This article traces the evolution of DigitalHub's development and engagement activities, highlighting project challenges, innovations, success stories, and the team-based approach that was employed to successfully achieve project goals.

Incremental Optimization of Hub and Spoke Network for the Spokes’ Numbers and Flow

Directory of Open Access Journals (Sweden)

Yanfeng Wang

2015-01-01

Full Text Available Hub and spoke network problem is solved as part of a strategic decision making process which may have a profound effect on the future of enterprises. In view of the existing network structure, as time goes on, the number of spokes and the flow change because of different sources of uncertainty. Hence, the incremental optimization of hub and spoke network problem is considered in this paper, and the policy makers should adopt a series of strategies to cope with the change, such as setting up new hubs, adjusting the capacity level of original hubs, or closing some original hubs. The objective is to minimize the total cost, which includes the setup costs for the new hubs, the closure costs, and the adjustment costs for the original hubs as well as the flow routing costs. Two mixed-integer linear programming formulations are proposed and analyzed for this problem. China Deppon Logistics as an example is performed to present computational analysis, and we analyze the changes in the solutions driven by the number of spokes and the flow. The tests also allow an analysis to consider the effect of variation in parameters on network.

Sci-Hub: What Librarians Should Know and Do about Article Piracy.

Science.gov (United States)

Hoy, Matthew B

2017-01-01

The high cost of journal articles has driven many researchers to turn to a new way of getting access: "pirate" article sites. Sci-Hub, the largest and best known of these sites, currently offers instant access to more than 58 million journal articles. Users attracted by the ease of use and breadth of the collection may not realize that these articles are often obtained using stolen credentials and downloading them may be illegal. This article will briefly describe Sci-Hub and how it works, the legal and ethical issues it raises, and the problems it may cause for librarians. Librarians should be aware of Sci-Hub and the ways it may change their patrons' expectations. They should also understand the risks Sci-Hub can pose to their patrons and their institutions.

Zoning Districts - Volusia County HUB Zones

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — Historically Underutilized Business (HUB) Zones in Volusia County. Go to http://www.sba.gov/hubzone or contact the Department of Economic Development (386) 248-8048...

City Hub : a cloud based IoT platform for Smart Cities

OpenAIRE

Lea, Rodger; Blackstock, Michael

2014-01-01

Cloud based Smart City hubs are an attractive approach to addressing some of the complex issues faced when deploying PaaS infrastructure for Smart Cities. In this paper we introduce the general notion of IoT hubs and then discusses our work to generalize our IoT hub as a Smart City PaaS. Two key issues are identified, support for hybrid public/private cloud and interoperability. We briefly describe our approach to these issues and discuss our experiences deploying two cloud-based Smart City h...

Interface discontinuity factors in the modal Eigenspace of the multigroup diffusion matrix

International Nuclear Information System (INIS)

Garcia-Herranz, N.; Herrero, J.J.; Cuervo, D.; Ahnert, C.

2011-01-01

Interface discontinuity factors based on the Generalized Equivalence Theory are commonly used in nodal homogenized diffusion calculations so that diffusion average values approximate heterogeneous higher order solutions. In this paper, an additional form of interface correction factors is presented in the frame of the Analytic Coarse Mesh Finite Difference Method (ACMFD), based on a correction of the modal fluxes instead of the physical fluxes. In the ACMFD formulation, implemented in COBAYA3 code, the coupled multigroup diffusion equations inside a homogenized region are reduced to a set of uncoupled modal equations through diagonalization of the multigroup diffusion matrix. Then, physical fluxes are transformed into modal fluxes in the Eigenspace of the diffusion matrix. It is possible to introduce interface flux discontinuity jumps as the difference of heterogeneous and homogeneous modal fluxes instead of introducing interface discontinuity factors as the ratio of heterogeneous and homogeneous physical fluxes. The formulation in the modal space has been implemented in COBAYA3 code and assessed by comparison with solutions using classical interface discontinuity factors in the physical space. (author)

Idea Hubs as Nexus of Collective Creativity in Digital Innovation

DEFF Research Database (Denmark)

Ciriello, Raffaele; Richter, Alexander

2015-01-01

Digital innovation radically transforms the nature of corporate innovation practices, implying a growing need for deeper understanding its origins and outcomes. In this paper, we conceptualize the focal points of social networking in digital innovation as idea hubs. We focus our analysis...... on instances of idea hubs in two multinational European software companies, where we conducted a case study over a two-year period, and collected data in form of interviews, digital documents, and participant observations. In doing so, we identify a set of social networking practices in which idea hubs serve...... of digital artifacts individuals can choose from, offline interaction still plays a major role in facilitating digital innovation....

Introducing serendipity in a social network model of knowledge diffusion

International Nuclear Information System (INIS)

Cremonini, Marco

2016-01-01

Highlights: • Serendipity as a control mechanism for knowledge diffusion in social network. • Local communication enhanced in the periphery of a network. • Prevalence of hub nodes in the network core mitigated. • Potential disruptive effect on network formation of uncontrolled serendipity. - Abstract: In this paper, we study serendipity as a possible strategy to control the behavior of an agent-based network model of knowledge diffusion. The idea of considering serendipity in a strategic way has been first explored in Network Learning and Information Seeking studies. After presenting the major contributions of serendipity studies to digital environments, we discuss the extension to our model: Agents are enriched with random topics for establishing new communication according to different strategies. The results show how important network properties could be influenced, like reducing the prevalence of hubs in the network’s core and increasing local communication in the periphery, similar to the effects of more traditional self-organization methods. Therefore, from this initial study, when serendipity is opportunistically directed, it appears to behave as an effective and applicable approach to social network control.

Connectome hubs at resting state in children and adolescents: Reproducibility and psychopathological correlation

Directory of Open Access Journals (Sweden)

João Ricardo Sato

2016-08-01

Full Text Available Functional brain hubs are key integrative regions in brain networks. Recently, brain hubs identified through resting-state fMRI have emerged as interesting targets to increase understanding of the relationships between large-scale functional networks and psychopathology. However, few studies have directly addressed the replicability and consistency of the hub regions identified and their association with symptoms. Here, we used the eigenvector centrality (EVC measure obtained from graph analysis of two large, independent population-based samples of children and adolescents (7–15 years old; total N = 652; 341 subjects for site 1 and 311 for site 2 to evaluate the replicability of hub identification. Subsequently, we tested the association between replicable hub regions and psychiatric symptoms. We identified a set of hubs consisting of the anterior medial prefrontal cortex and inferior parietal lobule/intraparietal sulcus (IPL/IPS. Moreover, lower EVC values in the right IPS were associated with psychiatric symptoms in both samples. Thus, low centrality of the IPS was a replicable sign of potential vulnerability to mental disorders in children. The identification of critical and replicable hubs in functional cortical networks in children and adolescents can foster understanding of the mechanisms underlying mental disorders.

Factors affecting the diffusion of online end user literature searching.

Science.gov (United States)

Ash, J S

1999-01-01

The aim of this study was to identify factors that affect diffusion of usage of online end user literature searching. Fifteen factors clustered into three attribute sets (innovation attributes, organizational attributes, and marketing attributes) were measured to study their effect on the diffusion of online searching within institutions. A random sample of sixty-seven academic health sciences centers was selected and then 1,335 library and informatics staff members at those institutions were surveyed by mail with electronic mail follow-up. Multiple regression analysis was performed. The survey yielded a 41% response rate with electronic mail follow-up being particularly effective. Two dependent variables, internal diffusion (spread of diffusion) and infusion (depth of diffusion), were measured. There was little correlation between them, indicating they measured different things. Fifteen independent variables clustered into three attribute sets were measured. The innovation attributes set was significant for both internal diffusion and infusion. Significant individual variables were visibility for internal diffusion and image enhancement effects (negative relation) as well as visibility for infusion (depth of diffusion). Organizational attributes were also significant predictors for both dependent variables. No individual variables were significant for internal diffusion. Communication, management support (negative relation), rewards, and existence of champions were significant for infusion. Marketing attributes were not significant predictors. Successful diffusion of online end user literature searching is dependent on the visibility of the systems, communication among, rewards to, and peers of possible users who promote use (champions). Personal image enhancement effects have a negative relation to infusion, possibly because the use of intermediaries is still seen as the more luxurious way to have searches done. Management support also has a negative relation to

On the geometrical factor in the off-centre diffusion

International Nuclear Information System (INIS)

Despa, F.; Apostol, M.

1995-07-01

The geometrical factor of the off-centre diffusion coefficient is computed for certain two- and three-dimensional cubic lattice, and a method is indicated for estimating this factor in more general cases. (author). 7 refs, 4 figs

A Hub Matrix Theory and Applications to Wireless Communications

Directory of Open Access Journals (Sweden)

Kung HT

2007-01-01

Full Text Available This paper considers communications and network systems whose properties are characterized by the gaps of the leading eigenvalues of for a matrix . It is shown that a sufficient and necessary condition for a large eigen-gap is that is a "hub" matrix in the sense that it has dominant columns. Some applications of this hub theory in multiple-input and multiple-output (MIMO wireless systems are presented.

The Virtual Campus Hub Concept

DEFF Research Database (Denmark)

Badger, Merete; Prag, Sidsel-Marie Winther; Monaco, Lucio

of Technology in Sweden, Politecnico di Torino in Italy, and Eindhoven University of Technology in the Netherlands. The project is partially funded by the European Commission under the 7th Framework Programme (project no. RI-283746). This report describes the final concept of Virtual Campus Hub. It gives...

MyGeoHub: A Collaborative Geospatial Research and Education Platform

Science.gov (United States)

Kalyanam, R.; Zhao, L.; Biehl, L. L.; Song, C. X.; Merwade, V.; Villoria, N.

2017-12-01

Scientific research is increasingly collaborative and globally distributed; research groups now rely on web-based scientific tools and data management systems to simplify their day-to-day collaborative workflows. However, such tools often lack seamless interfaces, requiring researchers to contend with manual data transfers, annotation and sharing. MyGeoHub is a web platform that supports out-of-the-box, seamless workflows involving data ingestion, metadata extraction, analysis, sharing and publication. MyGeoHub is built on the HUBzero cyberinfrastructure platform and adds general-purpose software building blocks (GABBs), for geospatial data management, visualization and analysis. A data management building block iData, processes geospatial files, extracting metadata for keyword and map-based search while enabling quick previews. iData is pervasive, allowing access through a web interface, scientific tools on MyGeoHub or even mobile field devices via a data service API. GABBs includes a Python map library as well as map widgets that in a few lines of code, generate complete geospatial visualization web interfaces for scientific tools. GABBs also includes powerful tools that can be used with no programming effort. The GeoBuilder tool provides an intuitive wizard for importing multi-variable, geo-located time series data (typical of sensor readings, GPS trackers) to build visualizations supporting data filtering and plotting. MyGeoHub has been used in tutorials at scientific conferences and educational activities for K-12 students. MyGeoHub is also constantly evolving; the recent addition of Jupyter and R Shiny notebook environments enable reproducible, richly interactive geospatial analyses and applications ranging from simple pre-processing to published tools. MyGeoHub is not a monolithic geospatial science gateway, instead it supports diverse needs ranging from just a feature-rich data management system, to complex scientific tools and workflows.

Soft Power and Cultural Diplomacy: Emerging Education Hubs in Asia

Science.gov (United States)

Lee, Jack T.

2015-01-01

Several education hubs have emerged in Asia and the Middle East in recent years with a specific focus on cross-border higher education. Through considerable efforts in policy planning and generous funding, these hubs aim to transform a country or city into an eminent destination for education, research, and training. The inherent design of these…

Study of the factors affecting radon diffusion through building materials

International Nuclear Information System (INIS)

Chauhan, R.P.

2011-01-01

Radon appears mainly by diffusion processes from the point of origin following - decay of 226 Ra in underground soil and building materials used, in the construction of floors, walls, and ceilings. The diffusion of radon in dwellings is a process determined by the radon concentration gradient across the building material structure and can be a significant contributor to indoor radon inflow. Radon can originate from the deeply buried deposit beneath homes and can migrate to the surface of earth. Radon diffusion and transport through different media is a complex process and is affected by several factors. It is well known that for building construction materials the porosity, permeability and the diffusion coefficient are the parameters, which can quantify the materials capability to hinder the flow of radon soil gas. An increase in porosity will provide more air space within the material for radon to travel, thus reducing its resistance to radon transport. The permeability of material describes its ability to act as a barrier to gas movement when a pressure gradient exists across it and is closely related to the porosity of material. The radon diffusion coefficient of a material quantifies the ability of radon gas to move through it when a concentration gradient is the driving force. This parameter depends upon the porosity and permeability of the medium. As diffusion process is the major contributor to indoor levels, therefore, the factors affecting the diffusion process need to be kept in consideration. Keeping this in mind the experimental arrangements have been made for control study of radon diffusion through some building materials to observe the effects of different factors viz.; compaction, grain size, temperature, humidity and the mixing of these materials etc. For the present study alpha sensitive LR-115 type II solid-state nuclear track detectors (SSNTDs) have been used for the recording of alpha tracks caused by radon gas after its diffusion through the

Alterations of brain network hubs in reflex syncope: Evidence from a graph theoretical analysis based on DTI.

Science.gov (United States)

Park, Bong Soo; Lee, Yoo Jin; Park, Jin-Han; Kim, Il Hwan; Park, Si Hyung; Lee, Ho-Joon; Park, Kang Min

2018-06-01

We evaluated global topology and organization of regional hubs in the brain networks and microstructural abnormalities in the white matter of patients with reflex syncope. Twenty patients with reflex syncope and thirty healthy subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on extracted DTI data, using DSI Studio. We then investigated differences in the network measures between the patients with reflex syncope and the healthy subjects. We also analyzed microstructural abnormalities of white matter using tract-based spatial statistics analysis (TBSS). Measures of global topology were not different between patients with reflex syncope and healthy subjects. However, in reflex syncope patients, the strength measures of the right angular, left inferior frontal, left middle orbitofrontal, left superior medial frontal, and left middle temporal gyrus were lower than in healthy subjects. The betweenness centrality measures of the left middle orbitofrontal, left fusiform, and left lingual gyrus in patients were lower than those in healthy subjects. The PageRank centrality measures of the right angular, left middle orbitofrontal, and left superior medial frontal gyrus in patients were lower than those in healthy subjects. Regarding the analysis of the white matter microstructure, there were no differences in the fractional anisotropy and mean diffusivity values between the two groups. We have identified a reorganization of network hubs in the brain network of patients with reflex syncope. These alterations in brain network may play a role in the pathophysiologic mechanism underlying reflex syncope. © 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

Analysis of Sci-Hub downloads of computer science papers

Directory of Open Access Journals (Sweden)

Andročec Darko

2017-07-01

Full Text Available The scientific knowledge is disseminated by research papers. Most of the research literature is copyrighted by publishers and avail- able only through paywalls. Recently, some websites offer most of the recent content for free. One of them is the controversial website Sci-Hub that enables access to more than 47 million pirated research papers. In April 2016, Science Magazine published an article on Sci-Hub activity over the period of six months and publicly released the Sci-Hub’s server log data. The mentioned paper aggregates the view that relies on all downloads and for all fields of study, but these findings might be hiding interesting patterns within computer science. The mentioned Sci-Hub log data was used in this paper to analyse downloads of computer science papers based on DBLP’s list of computer science publications. The top downloads of computer science papers were analysed, together with the geographical location of Sci-Hub users, the most downloaded publishers, types of papers downloaded, and downloads of computer science papers per publication year. The results of this research can be used to improve legal access to the most relevant scientific repositories or journals for the computer science field.

Using hybrid latent class model for city-HUBs´users behaviour analysis

OpenAIRE

Di Ciommo, Floridea; Monzón de Cáceres, Andrés; Oña, Rocío de; Oña López, Juan de; Hernández del Olmo, Sara

2014-01-01

Data from an attitudinal survey and stated preference ranking experiment conducted in two urban European interchanges (i.e. City-HUBs) in Madrid (Spain) and Thessaloniki (Greece) show that the importance that City-HUBs users attach to the intermodal infrastructure varies strongly as a function of their perceptions of time spent in the interchange (i.e.intermodal transfer and waiting time). A principal components analysis allocates respondents (i.e. city-HUB users) to two classes with substant...

The BioHub Knowledge Base: Ontology and Repository for Sustainable Biosourcing.

Science.gov (United States)

Read, Warren J; Demetriou, George; Nenadic, Goran; Ruddock, Noel; Stevens, Robert; Winter, Jerry

2016-06-01

The motivation for the BioHub project is to create an Integrated Knowledge Management System (IKMS) that will enable chemists to source ingredients from bio-renewables, rather than from non-sustainable sources such as fossil oil and its derivatives. The BioHubKB is the data repository of the IKMS; it employs Semantic Web technologies, especially OWL, to host data about chemical transformations, bio-renewable feedstocks, co-product streams and their chemical components. Access to this knowledge base is provided to other modules within the IKMS through a set of RESTful web services, driven by SPARQL queries to a Sesame back-end. The BioHubKB re-uses several bio-ontologies and bespoke extensions, primarily for chemical feedstocks and products, to form its knowledge organisation schema. Parts of plants form feedstocks, while various processes generate co-product streams that contain certain chemicals. Both chemicals and transformations are associated with certain qualities, which the BioHubKB also attempts to capture. Of immediate commercial and industrial importance is to estimate the cost of particular sets of chemical transformations (leading to candidate surfactants) performed in sequence, and these costs too are captured. Data are sourced from companies' internal knowledge and document stores, and from the publicly available literature. Both text analytics and manual curation play their part in populating the ontology. We describe the prototype IKMS, the BioHubKB and the services that it supports for the IKMS. The BioHubKB can be found via http://biohub.cs.manchester.ac.uk/ontology/biohub-kb.owl .

Features analysis for identification of date and party hubs in protein interaction network of Saccharomyces Cerevisiae

Directory of Open Access Journals (Sweden)

Araabi Babak N

2010-12-01

Full Text Available Abstract Background It has been understood that biological networks have modular organizations which are the sources of their observed complexity. Analysis of networks and motifs has shown that two types of hubs, party hubs and date hubs, are responsible for this complexity. Party hubs are local coordinators because of their high co-expressions with their partners, whereas date hubs display low co-expressions and are assumed as global connectors. However there is no mutual agreement on these concepts in related literature with different studies reporting their results on different data sets. We investigated whether there is a relation between the biological features of Saccharomyces Cerevisiae's proteins and their roles as non-hubs, intermediately connected, party hubs, and date hubs. We propose a classifier that separates these four classes. Results We extracted different biological characteristics including amino acid sequences, domain contents, repeated domains, functional categories, biological processes, cellular compartments, disordered regions, and position specific scoring matrix from various sources. Several classifiers are examined and the best feature-sets based on average correct classification rate and correlation coefficients of the results are selected. We show that fusion of five feature-sets including domains, Position Specific Scoring Matrix-400, cellular compartments level one, and composition pairs with two and one gaps provide the best discrimination with an average correct classification rate of 77%. Conclusions We study a variety of known biological feature-sets of the proteins and show that there is a relation between domains, Position Specific Scoring Matrix-400, cellular compartments level one, composition pairs with two and one gaps of Saccharomyces Cerevisiae's proteins, and their roles in the protein interaction network as non-hubs, intermediately connected, party hubs and date hubs. This study also confirms the

Functional Hubs in Mild Cognitive Impairment

Science.gov (United States)

Navas, Adrián; Papo, David; Boccaletti, Stefano; Del-Pozo, F.; Bajo, Ricardo; Maestú, Fernando; Martínez, J. H.; Gil, Pablo; Sendiña-Nadal, Irene; Buldú, Javier M.

We investigate how hubs of functional brain networks are modified as a result of mild cognitive impairment (MCI), a condition causing a slight but noticeable decline in cognitive abilities, which sometimes precedes the onset of Alzheimer's disease. We used magnetoencephalography (MEG) to investigate the functional brain networks of a group of patients suffering from MCI and a control group of healthy subjects, during the execution of a short-term memory task. Couplings between brain sites were evaluated using synchronization likelihood, from which a network of functional interdependencies was constructed and the centrality, i.e. importance, of their nodes was quantified. The results showed that, with respect to healthy controls, MCI patients were associated with decreases and increases in hub centrality respectively in occipital and central scalp regions, supporting the hypothesis that MCI modifies functional brain network topology, leading to more random structures.

MODELS AND METHODS FOR LOGISTICS HUB LOCATION: A REVIEW TOWARDS TRANSPORTATION NETWORKS DESIGN

Directory of Open Access Journals (Sweden)

Carolina Luisa dos Santos Vieira

Full Text Available ABSTRACT Logistics hubs affect the distribution patterns in transportation networks since they are flow-concentrating structures. Indeed, the efficient moving of goods throughout supply chains depends on the design of such networks. This paper presents a literature review on the logistics hub location problem, providing an outline of modeling approaches, solving techniques, and their applicability to such context. Two categories of models were identified. While multi-criteria models may seem best suited to find optimal locations, they do not allow an assessment of the impact of new hubs on goods flow and on the transportation network. On the other hand, single-criterion models, which provide location and flow allocation information, adopt network simplifications that hinder an accurate representation of the relationshipbetween origins, destinations, and hubs. In view of these limitations we propose future research directions for addressing real challenges of logistics hubs location regarding transportation networks design.

Epidemics in Complex Networks: The Diversity of Hubs

Science.gov (United States)

Kitsak, Maksim; Gallos, Lazaros K.; Havlin, Shlomo; Stanley, H. Eugene; Makse, Hernan A.

2009-03-01

Many complex systems are believed to be vulnerable to spread of viruses and information owing to their high level of interconnectivity. Even viruses of low contagiousness easily proliferate the Internet. Rumors, fads, and innovation ideas are prone to efficient spreading in various social systems. Another commonly accepted standpoint is the importance of the most connected elements (hubs) in the spreading processes. We address following questions. Do all hubs conduct epidemics in the same manner? How does the epidemics spread depend on the structure of the network? What is the most efficient way to spread information over the system? We analyze several large-scale systems in the framework of of the susceptible/infective/removed (SIR) disease spread model which can also be mapped to the problem of rumor or fad spreading. We show that hubs are often ineffective in the transmission of virus or information owing to the highly heterogeneous topology of most networks. We also propose a new tool to evaluate the efficiency of nodes in spreading virus or information.

Looking Into Pandora's Box: The Content Of Sci-Hub And Its Usage

OpenAIRE

Greshake, Bastian

2017-01-01

Despite the growth of Open Access, potentially illegally circumventing paywalls to access scholarly publications is becoming a more mainstream phenomenon. The web service Sci-Hub is amongst the biggest facilitators of this, offering free access to around 62 million publications. So far it is not well studied how and why its users are accessing publications through Sci-Hub. By utilizing the recently released corpus of Sci-Hub and comparing it to the data of  ~28 million downloads done through ...

Influence of Hub Parameters on Joining Forces and Torque Transmission Output of Plastically-Joined Shaft-Hub-Connections with a Knurled Contact Surface

Directory of Open Access Journals (Sweden)

Lukáš Suchý

2018-04-01

Full Text Available A knurled interference fit is a machine part connection made by a plastic joining, which includes the advantages of commonly-used shaft-hub-connections. The combination of the friction and form fit, which are responsible for torque transmission, results in a higher power density than conventional connections. In this paper, parameter gaps are bridged with the aim of enhance the design calculation of the knurled interference fit. Experimental investigations on the shaft chamfer angle (100Cr6 and hub-diameter-ratio (AlSi1MgMn were performed. The analytical approaches are developed for calculating the joining force and maximal torque capacity by accounting for experimentally investigated loss of load transmission at high hub-diameter-ratios and high shaft chamfer angles. The presented calculation approach is an accurate tool for the assessment of early machine designs of the knurled interference fit and helps to save from having to perform time-extensive tests.

Economic Impact of the Dutch Gas Hub Strategy on the Netherlands

International Nuclear Information System (INIS)

Harris, D.; Bazelon, C.; Humphreys, B.; Dickson, P.

2010-09-01

Since the discovery of the Groningen gas field in 1959, the Netherlands has been a key player in the European gas market. The Netherlands has built up a large onshore and offshore Exploration and Production sector, it has a highly developed gas transmission and distribution network, and is a major exporter of gas to other EU Member States. The Netherlands has considerable expertise in all parts of the gas supply chain, and is a world centre for Research and development in natural gas supply and use. More recently construction has begun on terminals to allow the import of Liquid Natural Gas to the Netherlands. However, Dutch gas reserves are now in decline, and the Netherlands will become a net importer of gas around 2025. The Dutch government wishes to capitalise on the existing industry and skills and sustain the Netherlands' place in the European gas industry beyond the life of the existing gas fields. In November 2009 the Minister of Economic Affairs published a paper describing the strategy of turning the Netherlands into a 'Gas Hub' or 'gas roundabout' for north-west Europe. The Dutch government intends that the gas hub would capitalise on the existing skills and industry, increase competition and security of supply in the Dutch gas market, create employment and make a significant contribution to the Dutch economy. The Dutch Ministry of Economic Affairs, Agriculture and Innovation has commissioned The Brattle Group to perform an analysis of the economic impact of the gas hub concept. The study has several aims including: To analyse the current contribution of the Dutch gas sector to the economy; To assess the Strengths, Weaknesses, Opportunities and Threats associated with the gas hub strategy; To quantify the benefits of the gas hub strategy to the Dutch economy. Note that the aim of the study is to define in more detail what a successful Dutch gas hub strategy would look like, to assess the strengths and weakness of the Dutch gas sector in achieving a

The Banana Genome Hub

Science.gov (United States)

Droc, Gaëtan; Larivière, Delphine; Guignon, Valentin; Yahiaoui, Nabila; This, Dominique; Garsmeur, Olivier; Dereeper, Alexis; Hamelin, Chantal; Argout, Xavier; Dufayard, Jean-François; Lengelle, Juliette; Baurens, Franc-Christophe; Cenci, Alberto; Pitollat, Bertrand; D’Hont, Angélique; Ruiz, Manuel; Rouard, Mathieu; Bocs, Stéphanie

2013-01-01

Banana is one of the world’s favorite fruits and one of the most important crops for developing countries. The banana reference genome sequence (Musa acuminata) was recently released. Given the taxonomic position of Musa, the completed genomic sequence has particular comparative value to provide fresh insights about the evolution of the monocotyledons. The study of the banana genome has been enhanced by a number of tools and resources that allows harnessing its sequence. First, we set up essential tools such as a Community Annotation System, phylogenomics resources and metabolic pathways. Then, to support post-genomic efforts, we improved banana existing systems (e.g. web front end, query builder), we integrated available Musa data into generic systems (e.g. markers and genetic maps, synteny blocks), we have made interoperable with the banana hub, other existing systems containing Musa data (e.g. transcriptomics, rice reference genome, workflow manager) and finally, we generated new results from sequence analyses (e.g. SNP and polymorphism analysis). Several uses cases illustrate how the Banana Genome Hub can be used to study gene families. Overall, with this collaborative effort, we discuss the importance of the interoperability toward data integration between existing information systems. Database URL: http://banana-genome.cirad.fr/ PMID:23707967

Location of an intermediate hub for port activities

Science.gov (United States)

Burciu, Ş.; Ştefănică, C.; Roşca, E.; Dragu, V.; Ruscă, F.

2015-11-01

An intermediate hub might increase the accessibility level of ports but also hinterland and so it can be considered more than a facility with a transhipment role. These hubs might lead to the development of other transport services and enhance their role in gathering and covering economic centres within hinterlands and also getting the part of logistic facility for the ports, with effects on port utilization and its connectivity to global economy. A new location for a hub terminal leads to reduced transport distances within hinterland, with decreased transport costs and external effects, so with gains in people's life quality. Because the production and distribution systems are relatively fixed on short and medium term and the location decisions are strategic and on long term, the logistic chains activities location models have to consider the uncertainties regarding the possible future situations. In most models, production costs are considered equal, the location problem reducing itself to a problem that aims to minimize the total transport costs, meaning the transport problem. The main objective of the paper is to locate a hub terminal that links the producers of cereals that are going to be exported by naval transportation with the Romanian fluvial-maritime ports (Galaţi, Brăila). GIS environment can be used to integrate and analyse a great amount of data and has the ability of using functions as location - allocation models necessary both to private and public sector, being able to determine the optimal location for services like factories, warehouses, logistic platforms and other public services.

Maritime Domain Awareness Architecture Management Hub Strategy

National Research Council Canada - National Science Library

2008-01-01

This document provides an initial high level strategy for carrying out the responsibilities of the national Maritime Domain Awareness Architecture Management Hub to deliver a standards based service...

Factorized Estimation of Partially Shared Parameters in Diffusion Networks

Czech Academy of Sciences Publication Activity Database

Dedecius, Kamil; Sečkárová, Vladimíra

2017-01-01

Roč. 65, č. 19 (2017), s. 5153-5163 ISSN 1053-587X R&D Projects: GA ČR(CZ) GP14-06678P; GA ČR GA16-09848S Institutional support: RVO:67985556 Keywords : Diffusion network * Diffusion estimation * Heterogeneous parameters * Multitask networks Subject RIV: BD - Theory of Information OBOR OECD: Applied mathematics Impact factor: 4.300, year: 2016 http://library.utia.cas.cz/separaty/2017/AS/dedecius-0477044.pdf

Left Frontal Hub Connectivity during Memory Performance Supports Reserve in Aging and Mild Cognitive Impairment.

Science.gov (United States)

Franzmeier, Nicolai; Hartmann, Julia C; Taylor, Alexander N W; Araque Caballero, Miguel Á; Simon-Vermot, Lee; Buerger, Katharina; Kambeitz-Ilankovic, Lana M; Ertl-Wagner, Birgit; Mueller, Claudia; Catak, Cihan; Janowitz, Daniel; Stahl, Robert; Dichgans, Martin; Duering, Marco; Ewers, Michael

2017-01-01

Reserve in aging and Alzheimer's disease (AD) is defined as maintaining cognition at a relatively high level in the presence of neurodegeneration, an ability often associated with higher education among other life factors. Recent evidence suggests that higher resting-state functional connectivity within the frontoparietal control network, specifically the left frontal cortex (LFC) hub, contributes to higher reserve. Following up these previous resting-state fMRI findings, we probed memory-task related functional connectivity of the LFC hub as a neural substrate of reserve. In elderly controls (CN, n = 37) and patients with mild cognitive impairment (MCI, n = 17), we assessed global connectivity of the LFC hub during successful face-name association learning, using generalized psychophysiological interaction analyses. Reserve was quantified as residualized memory performance, accounted for gender and proxies of neurodegeneration (age, hippocampus atrophy, and APOE genotype). We found that greater education was associated with higher LFC-connectivity in both CN and MCI during successful memory. Furthermore, higher LFC-connectivity predicted higher residualized memory (i.e., reserve). These results suggest that higher LFC-connectivity contributes to reserve in both healthy and pathological aging.

Global Search of a Three-dimensional Low Solidity Circular Cascade Diffuser for Centrifugal Blowers by Meta-model Assisted Optimization

Science.gov (United States)

Sakaguchi, Daisaku; Sakue, Daiki; Tun, Min Thaw

2018-04-01

A three-dimensional blade of a low solidity circular cascade diffuser in centrifugal blowers is designed by means of a multi-point optimization technique. The optimization aims at improving static pressure coefficient at a design point and at a small flow rate condition. Moreover, a clear definition of secondary flow expressed by positive radial velocity at hub side is taken into consideration in constraints. The number of design parameters for three-dimensional blade reaches to 10 in this study, such as a radial gap, a radial chord length and mean camber angle distribution of the LSD blade with five control points, control point between hub and shroud with two design freedom. Optimization results show clear Pareto front and selected optimum design shows good improvement of pressure rise in diffuser at small flow rate conditions. It is found that three-dimensional blade has advantage to stabilize the secondary flow effect with improving pressure recovery of the low solidity circular cascade diffuser.

Development and validation of a new kind of coupling element for wheel-hub motors

Science.gov (United States)

Perekopskiy, Sergey; Kasper, Roland

2018-05-01

For the automotive industry, electric powered vehicles are becoming an increasingly relevant factor in the competition against climate change. Application of one special example - a wheel-hub motor, for electric powered vehicle can support this challenge. Patented slotless air gap winding invented at the chair of mechatronics of the Otto von Guericke University Magdeburg has great application potential in constantly growing e-mobility field, especially for wheel-hub motors based on this technology due to its advantages, such as a high gravimetric power density and high efficiency. However, advantages of this technology are decreased by its sensibility to the loads out of driving maneuvers by dimensional variations of air gap consistency. This article describes the development and validation of a coupling element for the designed wheel-hub motor. To find a suitable coupling concept first the assembly structure of the motor was analyzed and developed design of the coupling element was checked. Based on the geometry of the motor and wheel a detailed design of the coupling element was generated. The analytical approach for coupling element describes a potential of the possible loads on the coupling element. The FEM simulation of critical load cases for the coupling element validated results of the analytical approach.

Energy flow modeling and optimal operation analysis of the micro energy grid based on energy hub

International Nuclear Information System (INIS)

Ma, Tengfei; Wu, Junyong; Hao, Liangliang

2017-01-01

Highlights: • Design a novel architecture for energy hub integrating power hub, cooling hub and heating hub. • The micro energy grid based on energy hub is introduced and its advantages are discussed. • Propose a generic modeling method for the energy flow of micro energy grid. • Propose an optimal operation model for micro energy grid with considering demand response. • The roles of renewable energy, energy storage devices and demand response are discussed separately. - Abstract: The energy security and environmental problems impel people to explore a more efficient, environment friendly and economical energy utilization pattern. In this paper, the coordinated operation and optimal dispatch strategies for multiple energy system are studied at the whole Micro Energy Grid level. To augment the operation flexibility of energy hub, the innovation sub-energy hub structure including power hub, heating hub and cooling hub is put forward. Basing on it, a generic energy hub architecture integrating renewable energy, combined cooling heating and power, and energy storage devices is developed. Moreover, a generic modeling method for the energy flow of micro energy grid is proposed. To minimize the daily operation cost, a day-ahead dynamic optimal operation model is formulated as a mixed integer linear programming optimization problem with considering the demand response. Case studies are undertaken on a community Micro Energy Grid in four different scenarios on a typical summer day and the roles of renewable energy, energy storage devices and demand response are discussed separately. Numerical simulation results indicate that the proposed energy flow modeling and optimal operation method are universal and effective over the entire energy dispatching horizon.

Report on survey on international Hub

International Nuclear Information System (INIS)

Ebisawa, Hirobumi; Hoshino, Junko; Hashimoto, Kazuichiro; Okada, Sohei

2011-03-01

Japan Atomic Energy Agency (JAEA) is promoting initiative to form an international Center of Excellence in line with its aim to accept more researchers/engineers from all over the world. Establishment of 'the Committee for JAEA Internationalization Initiative' was planned in 2010 so as to intensify this initiative, and in February, 2010, we visited research institutions in Europe, which include European Organization for Nuclear Research (CERN), the construction site of ITER in Cadarache, and Rutherford Appleton Laboratory (RAL), with the intention to survey and learn their advanced activities and systems in regard to the International Hub, so that the committee will be able to make fruitful discussion. This report describes strategy taken in each institution for an International Hub, and the state of each institution regarding acceptance and management of overseas researchers and engineers, research environment, living environment/health and welfare, and PR activities/coexistence with the local community. (author)

Modeling and optimization of a network of energy hubs to improve economic and emission considerations

International Nuclear Information System (INIS)

Maroufmashat, Azadeh; Elkamel, Ali; Fowler, Michael; Sattari, Sourena; Roshandel, Ramin; Hajimiragha, Amir; Walker, Sean; Entchev, Evgueniy

2015-01-01

Energy hubs that incorporate a variety of energy generation and energy transformation technologies can be used to provide the energy storage needed to enable the efficient operation of a ‘smart energy network’. When these hubs are combined as a network and allowed to exchange energy, they create efficiency advantages in both financial and environmental performance. Further, the interconnectedness of the energy network design provides an added layer of reliability. In this paper, a complex network of energy hubs is modeled and optimized under different scenarios to examine both the financial viability and potential reduction of greenhouse gas emissions. Two case studies consisting of two and three energy hubs within a network are considered. The modeling Scenarios vary according to the consideration of distributed energy systems and energy interaction between energy hubs. In the case of a network of two energy hubs, there is no significant economic or emissions benefit with only a 0.5% reduction in total cost and 3% reduction in CO_2 emission. In the case of a network of three energy hubs, there is a significant economic benefit ranging from 11% to 29%, and 11% emission reduction benefit, as well as a 13% reduction in natural gas consumption. - Highlights: • The generic form of the modified energy hub concept with network model is presented. • Two case studies are presented to demonstrate the benefits of energy hub network. • Distributed energy is shown to provide economic and environmental advantages. • Multi criteria optimization of the economic and environmental performance is done.

A collaborative scheduling model for the supply-hub with multiple suppliers and multiple manufacturers.

Science.gov (United States)

Li, Guo; Lv, Fei; Guan, Xu

2014-01-01

This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment.

Fatigue based design and analysis of wheel hub for Student formula car by Simulation Approach

Science.gov (United States)

Gowtham, V.; Ranganathan, A. S.; Satish, S.; Alexis, S. John; Siva kumar, S.

2016-09-01

In the existing design of Wheel hub used for Student formula cars, the brake discs cannot be removed easily since the disc is mounted in between the knuckle and hub. In case of bend or any other damage to the disc, the replacement of the disc becomes difficult. Further using OEM hub and knuckle that are used for commercial vehicles will result in increase of unsprung mass, which should be avoided in Student formula cars for improving the performance. In this design the above mentioned difficulties have been overcome by redesigning the hub in such a way that the brake disc could be removed easily by just removing the wheel and the caliper and also it will have reduced weight when compared to existing OEM hub. A CAD Model was developed based on the required fatigue life cycles. The forces acting on the hub were calculated and linear static structural analysis was performed on the wheel hub for three different materials using ANSYS Finite Element code V 16.2. The theoretical fatigue strength was compared with the stress obtained from the structural analysis for each material.

Strategies for contracting gas storage and hub services

International Nuclear Information System (INIS)

Auld, J.

1996-01-01

The many efficiencies that can be gained by the natural gas industry in effectively using storage, were demonstrated. The circumstances under which the natural gas industry uses storage and how Market Centres or Hub Services can be strategically used in offering companies the highest flexibility in a tough marketplace, were explained. For example, in North America, storage played an important role during the winter of 95/96, which will be remembered for its extreme cold. That year provided the first true opportunity to test the natural gas delivery system since deregulation in 1985. The fact that natural gas supplies continued to be delivered throughout the entire winter was attributed to the use of stored gas held in reserves to meet the severe demand. The companies that did well, relied on storage and also on the services offered by Hub Services which increased margins for all players in the natural gas industry. Using storage, companies can ensure that field deliveries of gas are kept constant by having storage facilities absorb the swings in market demand. The companies that learn to use storage effectively can create competitive edges over their competition and provide more value to their customers. The three main categories of hub services were also described. These are parking (interruptible storage), gas loans (stored gas can be offered to customers on a term basis for low daily rates), and title exchange (the transfer of gas between buyer and seller). The strategic use of parking, loaned gas, title exchange, direct connections, and InterHub Services can provide customers even greater benefits than are provided by storage-based services. 6 figs

SPARK: Sparsity-based analysis of reliable k-hubness and overlapping network structure in brain functional connectivity.

Science.gov (United States)

Lee, Kangjoo; Lina, Jean-Marc; Gotman, Jean; Grova, Christophe

2016-07-01

Functional hubs are defined as the specific brain regions with dense connections to other regions in a functional brain network. Among them, connector hubs are of great interests, as they are assumed to promote global and hierarchical communications between functionally specialized networks. Damage to connector hubs may have a more crucial effect on the system than does damage to other hubs. Hubs in graph theory are often identified from a correlation matrix, and classified as connector hubs when the hubs are more connected to regions in other networks than within the networks to which they belong. However, the identification of hubs from functional data is more complex than that from structural data, notably because of the inherent problem of multicollinearity between temporal dynamics within a functional network. In this context, we developed and validated a method to reliably identify connectors and corresponding overlapping network structure from resting-state fMRI. This new method is actually handling the multicollinearity issue, since it does not rely on counting the number of connections from a thresholded correlation matrix. The novelty of the proposed method is that besides counting the number of networks involved in each voxel, it allows us to identify which networks are actually involved in each voxel, using a data-driven sparse general linear model in order to identify brain regions involved in more than one network. Moreover, we added a bootstrap resampling strategy to assess statistically the reproducibility of our results at the single subject level. The unified framework is called SPARK, i.e. SParsity-based Analysis of Reliable k-hubness, where k-hubness denotes the number of networks overlapping in each voxel. The accuracy and robustness of SPARK were evaluated using two dimensional box simulations and realistic simulations that examined detection of artificial hubs generated on real data. Then, test/retest reliability of the method was assessed

Enhancement of crop photosynthesis by diffuse light: quantifying the contributing factors

NARCIS (Netherlands)

Li, T.; Heuvelink, E.; Dueck, T.A.; Janse, J.; Gort, G.; Marcelis, L.F.M.

2014-01-01

Plants use diffuse light more efficiently than direct light. However, experimental comparisons between diffuse and direct light have been obscured by co-occurring differences in environmental conditions (e.g. light intensity). This study aims to analyse the factors that contribute to an increase in

Surface-micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.; Krygowski, Thomas W.

2003-11-18

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

Surface--micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.

2002-01-01

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

A Collaborative Scheduling Model for the Supply-Hub with Multiple Suppliers and Multiple Manufacturers

Directory of Open Access Journals (Sweden)

Guo Li

2014-01-01

Full Text Available This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment.

A Collaborative Scheduling Model for the Supply-Hub with Multiple Suppliers and Multiple Manufacturers

Science.gov (United States)

Lv, Fei; Guan, Xu

2014-01-01

This paper investigates a collaborative scheduling model in the assembly system, wherein multiple suppliers have to deliver their components to the multiple manufacturers under the operation of Supply-Hub. We first develop two different scenarios to examine the impact of Supply-Hub. One is that suppliers and manufacturers make their decisions separately, and the other is that the Supply-Hub makes joint decisions with collaborative scheduling. The results show that our scheduling model with the Supply-Hub is a NP-complete problem, therefore, we propose an auto-adapted differential evolution algorithm to solve this problem. Moreover, we illustrate that the performance of collaborative scheduling by the Supply-Hub is superior to separate decision made by each manufacturer and supplier. Furthermore, we also show that the algorithm proposed has good convergence and reliability, which can be applicable to more complicated supply chain environment. PMID:24892104

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

N.K. Olver (Neil)

2016-01-01

textabstractRobust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

Olver, Neil

2016-01-01

Robust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to terminals

Correlation factor, velocity autocorrelation function and frequency-dependent tracer diffusion coefficient

NARCIS (Netherlands)

Beijeren, H. van; Kehr, K.W.

1986-01-01

The correlation factor, defined as the ratio between the tracer diffusion coefficient in lattice gases and the diffusion coefficient for a corresponding uncorrelated random walk, is known to assume a very simple form under certain conditions. A simple derivation of this is given with the aid of

Robust Energy Hub Management Using Information Gap Decision Theory

DEFF Research Database (Denmark)

Javadi, Mohammad Sadegh; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2017-01-01

This paper proposes a robust optimization framework for energy hub management. It is well known that the operation of energy systems can be negatively affected by uncertain parameters, such as stochastic load demand or generation. In this regard, it is of high significance to propose efficient...... tools in order to deal with uncertainties and to provide reliable operating conditions. On a broader scale, an energy hub includes diverse energy sources for supplying both electrical load and heating/cooling demands with stochastic behaviors. Therefore, this paper utilizes the Information Decision Gap...

Innovation Hub How-To

DEFF Research Database (Denmark)

Berger, Andreas; Brem, Alexander

2016-01-01

in establishing an innovative environment: carefully considering the decision to set up such a center, hiring the right people, designing a framework for effective output, creating a buffer from bureaucratic distractions, securing a leader to champion the effort, focusing on business outcomes, fostering...... disruptive over incremental innovation, and being patient. Regardless of where an innovation hub is established, the key to success lies in hiring creative, intrinsically motivated staff and then giving them the freedom to do what they do best....

Exploring hubness in Regional Trade Agreements

NARCIS (Netherlands)

Vaal, A. de

2016-01-01

In the plethora of Regional Trade Agreements (RTAs) some countries take in a more central position than others in the sense that some countries are much more engaged with other countries through RTAs. Furthermore, the position of some countries is that of a hub: they have (many) trade

Gas and LNG pricing and trading hub in East Asia: An introduction

Directory of Open Access Journals (Sweden)

Xunpeng Shi

2016-10-01

Full Text Available This paper summarizes the four papers in the special issues on ‘Gas and LNG pricing and trading hub in East Asia’. The papers examine lessons and experience from European hub development, other commodity, the Japanese history on developing of futures markets and inter-fuel substitution in East Asia. The papers finds that liquid futures market is the key to formulate benchmark prices while a well-developed spot market is the foundation; political will and strong leadership are required to overcome the power of incumbents and to restructure the gas market that impede the the development of competitive markets; and East Asia needs to develop its indigenous gas or LNG trading hubs even in low oil prices period and its developing market allows easier changes in new contracts than in existing ones. This hub development requires governments to go through tough domestic market reforms, including liberalization and cooperation with each other and with gas exporters.

Medium-term energy hub management subject to electricity price and wind uncertainty

International Nuclear Information System (INIS)

Najafi, Arsalan; Falaghi, Hamid; Contreras, Javier; Ramezani, Maryam

2016-01-01

Highlights: • A new model for medium-term energy hub management is proposed. • Risk aversion is considered in medium-term energy hub management. • Stochastic programing is used to solve the medium-term energy hub management problem. • Electricity price and wind uncertainty are considered. - Abstract: Energy hubs play an important role in implementing multi-carrier energy systems. More studies are required in both their modeling and operating aspects. In this regard, this paper attempts to develop medium-term management of an energy hub in restructured power systems. A model is presented to manage an energy hub which has electrical energy and natural gas as inputs and electrical and heat energy as outputs. Electricity is procured in various ways, either purchasing it from a pool-based market and bilateral contracts, or producing it from a Combined Heat and Power (CHP) unit, a diesel generator unit and Wind Turbine Generators (WTGs). Pool prices and wind turbine production are subject to uncertainty, which makes energy management a complex puzzle. Heat demand is also procured by a furnace and a CHP unit. Energy hub managers should make decisions whether to purchase electricity from the electricity market and gas from the gas network or to produce electricity using a set of generators to meet the electrical and heat demands in the presence of uncertainties. The energy management objective is to minimize the total cost subject to several technical constraints using stochastic programming. Conditional Value at Risk (CVaR), a well-known risk measure, is used to reduce the unfavorable risk of costs. In doing so, the proposed model is illustrated using a sample test case with actual prices, load and wind speed data. The results show that the minimum cost is obtained by the best decisions involving the electricity market and purchasing natural gas for gas facilities. Considering risk also increases the total expected cost and decreases the CVaR.

Hub network design for sparse travel demand within the African aviation industry

CSIR Research Space (South Africa)

Ssamula, B

2007-07-01

Full Text Available and analysed to reveal that the best option for a hub network is the so-called geo-political network. A geo-political network is where hubs are created in the North, South, East and West of Africa, at airports with strong political influence, high passenger...

Design and Analysis of Wind Turbine Blade Hub using Aluminium Alloy AA 6061-T6

Science.gov (United States)

Ravikumar, S.; Jaswanthvenkatram, V.; Sai kumar, Y. J. N. V.; Sohaib, S. Md.

2017-05-01

This work presents the design and analysis of horizontal axis wind turbine blade hub using different material. The hub is very crucial part of the wind turbine, which experience the loads from the blades and the loads were transmitted to the main shaft. At present wind turbine is more expensive and weights more than a million pounds, with the nacelle, rotor hub and blades accounting for most of the weight. In this work Spheroidal graphite cast iron GGG 40.3 is replaced by aluminium alloy 6061-T6 to enhance the casting properties and also to improve the strength-weight ratio. This transition of material leads to reduction in weight of the wind turbine. All the loads caused by wind and extreme loads on the blades are transferred to the hub. Considering the IEC 61400-1 standard for defining extreme loads on the hub the stress and deflection were calculated on the hub by using Finite element Analysis. Result obtained from ANSYS is compared and discussed with the existing design.

Enhancement of crop photosynthesis by diffuse light: quantifying the contributing factors.

Science.gov (United States)

Li, T; Heuvelink, E; Dueck, T A; Janse, J; Gort, G; Marcelis, L F M

2014-07-01

Plants use diffuse light more efficiently than direct light. However, experimental comparisons between diffuse and direct light have been obscured by co-occurring differences in environmental conditions (e.g. light intensity). This study aims to analyse the factors that contribute to an increase in crop photosynthesis in diffuse light and to quantify their relative contribution under different levels of diffuseness at similar light intensities. The hypothesis is that the enhancement of crop photosynthesis in diffuse light results not only from the direct effects of more uniform vertical and horizontal light distribution in the crop canopy, but also from crop physiological and morphological acclimation. Tomato (Solanum lycopersicum) crops were grown in three greenhouse compartments that were covered by glass with different degrees of light diffuseness (0, 45 and 71 % of the direct light being converted into diffuse light) while maintaining similar light transmission. Measurements of horizontal and vertical photosynthetic photon flux density (PPFD) distribution in the crop, leaf photosynthesis light response curves and leaf area index (LAI) were used to quantify each factor's contribution to an increase in crop photosynthesis in diffuse light. In addition, leaf temperature, photoinhibition, and leaf biochemical and anatomical properties were studied. The highest degree of light diffuseness (71 %) increased the calculated crop photosynthesis by 7·2 %. This effect was mainly attributed to a more uniform horizontal (33 % of the total effect) and vertical PPFD distribution (21 %) in the crop. In addition, plants acclimated to the high level of diffuseness by gaining a higher photosynthetic capacity of leaves in the middle of the crop and a higher LAI, which contributed 23 and 13 %, respectively, to the total increase in crop photosynthesis in diffuse light. Moreover, diffuse light resulted in lower leaf temperatures and less photoinhibition at the top of the canopy when

KINEMATIC ANALYSES OF THE GOLF SWING HUB PATH AND ITS ROLE IN GOLFER/CLUB KINETIC TRANSFERS

Directory of Open Access Journals (Sweden)

Steven M. Nesbit

2009-06-01

Full Text Available This study analyzed the fundamental geometric and kinematic characteristics of the swing hub path of the golf shot for four diverse subjects. In addition, the role of the hub path geometry in transferring the kinetic quantities from the golfer to the club were investigated. The hub path was found to have a complex geometry with significantly changing radii, and a constantly moving center-of-curvature during the downswing for all subjects. While the size and shape of the hub path differed considerably among the subjects, a three phase radius-based pattern was revealed that aligned with distinct stages of the downswing. Artificially controlling and optimizing the hub path of the better golfer in the group indicated that a non-circular hub path was superior to a constant radius path in minimizing the kinetic loading while generating the highest possible club head velocity. The shape and purpose of the hub path geometry appears to result from a complex combination of achieving equilibrium between the golfer and the club, and a purposeful configuring of the path to control the outward movement of the club while minimizing the kinetic loading on the golfer yet transferring the maximum kinetic quantities to the club. Describing the downswing relative to the hub path phasing is presented and was found to be informative since the phases align with significant swing, kinetic and kinematic markers. These findings challenge golf swing modeling methodologies which fix the center-of-curvature of the hub path thus constraining it to constant radius motion

TYPE PROJECTS HUB - AN INTERNATIONAL MODEL OF DEVELOPMENT OF THE ENTREPRENEURIAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

Rozalia Nistor

2014-06-01

Full Text Available Impact Hub is a global network of local spaces and communities designed to facilitate sustainable impact through collaboration. Local Impact Hubs are autonomous companies that offer co-working spaces, programming, events platforms, and communities of individuals and organizations with ideas to build a better world. Hub was established in 2005 in London with the aim of creating a space dedicated to inspire, connect and enable people to achieve a sustainable entrepreneurial idea. The idea was simple: There are a lot of people with good ideas for a "better world". What seem to be missing are places to help these people to move from intent to action and to find like-minded for a greater impact. In Romania about four years ago, first opened in Bucharest office space hubs in Romania (for entrepreneurs in technology and business where teams from different companies could collaborate. The idea to open a hub in Bucharest focused on social innovation and entrepreneurship appeared some time ago in the context in which part of the team now has worked since 2010 at the initiation and growth of a community to support social entrepreneurship. In all this diversity, there is a common mission: “we can create if we put all our innovation capacity in the common goal to create a positive impact through our work?”

Analysis and Modeling of Ground Operations at Hub Airports

Science.gov (United States)

Atkins, Stephen (Technical Monitor); Andersson, Kari; Carr, Francis; Feron, Eric; Hall, William D.

2000-01-01

Building simple and accurate models of hub airports can considerably help one understand airport dynamics, and may provide quantitative estimates of operational airport improvements. In this paper, three models are proposed to capture the dynamics of busy hub airport operations. Two simple queuing models are introduced to capture the taxi-out and taxi-in processes. An integer programming model aimed at representing airline decision-making attempts to capture the dynamics of the aircraft turnaround process. These models can be applied for predictive purposes. They may also be used to evaluate control strategies for improving overall airport efficiency.

Application of hydraulically assembled shaft coupling hubs to large agitators

International Nuclear Information System (INIS)

Murray, W.E.; Anderson, T.D.; Bethmann, H.K.

1991-01-01

This paper describes the basis for and implementation of hydraulically assembled shaft coupling hubs for large tank-mounted agitators. This modification to the original design was intended to minimize maintenance personnel exposure to ionizing radiation and also provide for disassembly capability without damage to shafts or hubs. In addition to realizing these objectives, test confirmed that the modified couplings reduced agitator shaft end runouts approximately 65%, thereby reducing bearing loads and increasing service life, a significant enhancement for a nuclear facility. 5 refs

Why do European companies have Innovation Hubs in Silicon Valley

DEFF Research Database (Denmark)

Berger, Andreas; Brem, Alexander

2017-01-01

Innovation hubs are gaining high attention in recent years, especially from European companies. Silicon Valley has been deemed as one of the most attractive and successful environments for establishing innovation hubs. This article highlights examples of companies from Europe that made the step...... to California—namely, Volkswagen, Swisscom, BMW, Axel Springer, Munich Re, and Innogy SE (RWE Group). Based on these companies’ experiences, recommendations are given on how companies might approach a setup in Silicon Valley for long-term success....

Biaxial wheel/hub test facility. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Fischer, G.; Grubisic, V. [eds.

2000-07-01

The 4{sup th} meeting aims to exchange the experience and knowledge of engineers during several presentations and discussions about new developments required for a reliable, time and cost reducing validation of the wheel/hub assembly. Tremendous development of the wheel performance, described by the ratio of the rated load (kg) versus the wheel weight (kg) had taken place during the last 5000 years. Starting from the ratio of 3 for wooden 2-piece-disc-wheels in Mesopotamia it needed nearly 1000 years to increase the ratio to approx 5 at light-weight spoke wheels for fighting carriages, found in the grave of king Tutenchamon in Egypt. Modern light alloy wheels of commercial vehicles reach values up to 160 kg/kg. Additionally the comlex design of the modern systems for cars and commercial vehicles comprising wheel, brake, hub, bearing, spindle and hub carrier, including different materials and their treatment, fasteners, press-fits, require an appropriate testing procedure. The variable loading conditions, caused by operational wheel forces, brake and torque moments including heating, may result in changing tolerances and press-fits during operation and consequently in different damage mechanisms. This can be simulated in the Biaxial Wheel Test Machine, whereby corresponding load programs are necessary. An overview about all biaxial test machines in usage at the end of 1999 is shown in the introduction. The total number is 17 for cars, 7 for commercial vehicles and 1 for trains. The six presentations of this meeting were consequently concentrated on: (a) recommendations for a standardization of load programs of the German Wheel Committee, (b) the simulation of brake and torque events and (c) the possibility for a numerical stress analyses and fatigue life assessment. (orig./AKF)

Comparative efficiency of wind turbines with different heights of rotor hubs: performance evaluation for Latvia

International Nuclear Information System (INIS)

Bezrukovs, V P; Zacepins, A J; Bezrukovs, V V

2014-01-01

Performance evaluation of wind turbines (WT) for different heights of the rotor hub is made based on the wind speed and direction data obtained in 2009–2013 on-shore in the north of Latvia using a LOGGER 9200 Symphonie measurement system mounted on a 60 m mast. Based on the measurement analysis results, wind speed distribution curves have been modelled for heights of up to 200 m using power and logarithmic (log) law approximation methods. The curves for the modelled Weibull's parameters are plotted in dependence on height. The efficiency comparison is made for different WT types taking into account the distribution of the wind energy potential in height in the Latvian territory. The annual electric energy production was calculated for the WTs with different heights of rotor hubs. In the calculations the technical data on the following WT types were used: E-3120 (50 kW, hub height 20.5/30.5/36.5/42.7 m), E-33 (330 kW, hub height 37/44/49/50 m), E-48 (800 kW, hub height 50/60/75 m) and E-82 (2.3 MW, hub height of 78/85/98/108/138 m)

Puertos, espacio y globalización: el desarrollo de hubs en México

Directory of Open Access Journals (Sweden)

Carlos Daniel Martner Peyrelongue

2010-01-01

Full Text Available Los puertos hubs se presentan como el nuevo paradigma de desarrollo del transporte y el comercio marítimo internacional en la globalización. Prácticamente todos los países latinoamericanos anuncian megaproyectos para el desarrollo de puertos hubs en sus litorales, generando grandes expectativas de desarrollo regional, con un débil sustento tanto teórico como empírico. En este sentido, el presente trabajo busca contribuir a la caracterización del modelo de puertos hubs en países periféricos dentro de la economíamundo capitalista, aludiendo, en especial, al caso mexicano. Se trata de aportar elementos de análisis para reconocer, a grandes rasgos, las posibilidades del desarrollo de hubs en los litorales mexicanos, desde la perspectiva de los estudios regionales y la geografía del transporte.

Evaluation of the Thermodynamic Models for the Thermal Diffusion Factor

DEFF Research Database (Denmark)

Gonzalez-Bagnoli, Mariana G.; Shapiro, Alexander; Stenby, Erling Halfdan

2003-01-01

Over the years, several thermodynamic models for the thermal diffusion factors for binary mixtures have been proposed. The goal of this paper is to test some of these models in combination with different equations of state. We tested the following models: those proposed by Rutherford and Drickamer...... we applied different thermodynamic models, such as the Soave-Redlich-Kwong and the Peng-Robinson equations of state. The necessity to try different thermo-dynamic models is caused by the high sensitivity of the thermal diffusion factors to the values of the partial molar properties. Two different...... corrections for the determination of the partial molar volumes have been implemented; the Peneloux correction and the correction based on the principle of corresponding states....

Portable Desktop Apps with GitHub Electron

CERN Multimedia

CERN. Geneva

2016-01-01

Wouldn't it be nice if you could develop applications that work everywhere, regardless of Operating System or Platform? Even better, what if you could employ the same front-end technologies you use for your web/mobile apps? Meet GitHub Electron.

A novel method to identify hub pathways of rheumatoid arthritis based on differential pathway networks.

Science.gov (United States)

Wei, Shi-Tong; Sun, Yong-Hua; Zong, Shi-Hua

2017-09-01

The aim of the current study was to identify hub pathways of rheumatoid arthritis (RA) using a novel method based on differential pathway network (DPN) analysis. The present study proposed a DPN where protein‑protein interaction (PPI) network was integrated with pathway‑pathway interactions. Pathway data was obtained from background PPI network and the Reactome pathway database. Subsequently, pathway interactions were extracted from the pathway data by building randomized gene‑gene interactions and a weight value was assigned to each pathway interaction using Spearman correlation coefficient (SCC) to identify differential pathway interactions. Differential pathway interactions were visualized using Cytoscape to construct a DPN. Topological analysis was conducted to identify hub pathways that possessed the top 5% degree distribution of DPN. Modules of DPN were mined according to ClusterONE. A total of 855 pathways were selected to build pathway interactions. By filtrating pathway interactions of weight values >0.7, a DPN with 312 nodes and 791 edges was obtained. Topological degree analysis revealed 15 hub pathways, such as heparan sulfate/heparin‑glycosaminoglycan (HS‑GAG) degradation, HS‑GAG metabolism and keratan sulfate degradation for RA based on DPN. Furthermore, hub pathways were also important in modules, which validated the significance of hub pathways. In conclusion, the proposed method is a computationally efficient way to identify hub pathways of RA, which identified 15 hub pathways that may be potential biomarkers and provide insight to future investigation and treatment of RA.

Hub location problems in transportation networks

DEFF Research Database (Denmark)

Gelareh, Shahin; Nickel, Stefan

2011-01-01

In this paper we propose a 4-index formulation for the uncapacitated multiple allocation hub location problem tailored for urban transport and liner shipping network design. This formulation is very tight and most of the tractable instances for MIP solvers are optimally solvable at the root node....... also introduce fixed cost values for Australian Post (AP) dataset....

Role of governance in creating a commodity hub: A comparative analysis

Directory of Open Access Journals (Sweden)

M.P. Haris

2016-10-01

Full Text Available The body of work on natural gas hubs has been expanding rapidly in recent years, with most of the current work examining the creation of gas hubs focusing on either the European experience or the North American experience. In this paper, we adopt a different perspective and place the focus on experience of hub building from other international commodities. We analyse three commodities - crude oil, iron ore and coal, and draw experience on the role of governance in development of hub based prices. In particular, we propose that the role of governance is different at different stages of the pricing transition to market based pricing. Governance could play an important role at the initial stage, building the relevant soft and physical infrastructure which facilitates the reaping of first mover advantage. As the market develops, private sector players may prefer less involvement of governance, which may distort markets. With market stabilization, governance should be focused on maintaining stable rules and regulation for private sector development, as well as monitoring for further changes in global trends. To facilitate the building of a benchmark price, the public sector should adopt a long-term and overarching view on industry growth.

Excitatory Neuronal Hubs Configure Multisensory Integration of Slow Waves in Association Cortex

Directory of Open Access Journals (Sweden)

Satoshi Kuroki

2018-03-01

Full Text Available Summary: Multisensory integration (MSI is a fundamental emergent property of the mammalian brain. During MSI, perceptual information encoded in patterned activity is processed in multimodal association cortex. The systems-level neuronal dynamics that coordinate MSI, however, are unknown. Here, we demonstrate intrinsic hub-like network activity in the association cortex that regulates MSI. We engineered calcium reporter mouse lines based on the fluorescence resonance energy transfer sensor yellow cameleon (YC2.60 expressed in excitatory or inhibitory neurons. In medial and parietal association cortex, we observed spontaneous slow waves that self-organized into hubs defined by long-range excitatory and local inhibitory circuits. Unlike directional source/sink-like flows in sensory areas, medial/parietal excitatory and inhibitory hubs had net-zero balanced inputs. Remarkably, multisensory stimulation triggered rapid phase-locking mainly of excitatory hub activity persisting for seconds after the stimulus offset. Therefore, association cortex tends to form balanced excitatory networks that configure slow-wave phase-locking for MSI. Video Abstract: : Kuroki et al. performed cell-type-specific, wide-field FRET-based calcium imaging to visualize cortical network activity induced by multisensory inputs. They observed phase-locking of cortical slow waves in excitatory neuronal hubs in association cortical areas that may underlie multisensory integration. Keywords: wide-field calcium imaging, multisensory integration, cortical slow waves, association cortex, phase locking, fluorescence resonance energy transfer, spontaneous activity, excitatory neuron, inhibitory neuron, mouse

Extraversion modulates functional connectivity hubs of resting-state brain networks.

Science.gov (United States)

Pang, Yajing; Cui, Qian; Duan, Xujun; Chen, Heng; Zeng, Ling; Zhang, Zhiqiang; Lu, Guangming; Chen, Huafu

2017-09-01

Personality dimension extraversion describes individual differences in social behaviour and socio-emotional functioning. The intrinsic functional connectivity patterns of the brain are reportedly associated with extraversion. However, whether or not extraversion is associated with functional hubs warrants clarification. Functional hubs are involved in the rapid integration of neural processing, and their dysfunction contributes to the development of neuropsychiatric disorders. In this study, we employed the functional connectivity density (FCD) method for the first time to distinguish the energy-efficient hubs associated with extraversion. The resting-state functional magnetic resonance imaging data of 71 healthy subjects were used in the analysis. Short-range FCD was positively correlated with extraversion in the left cuneus, revealing a link between the local functional activity of this region and extraversion in risk-taking. Long-range FCD was negatively correlated with extraversion in the right superior frontal gyrus and the inferior frontal gyrus. Seed-based resting-state functional connectivity (RSFC) analyses revealed that a decreased long-range FCD in individuals with high extraversion scores showed a low long-range functional connectivity pattern between the medial and dorsolateral prefrontal cortex, middle temporal gyrus, and anterior cingulate cortex. This result suggests that decreased RSFC patterns are responsible for self-esteem, self-evaluation, and inhibitory behaviour system that account for the modulation and shaping of extraversion. Overall, our results emphasize specific brain hubs, and reveal long-range functional connections in relation to extraversion, thereby providing a neurobiological basis of extraversion. © 2015 The British Psychological Society.

PERSEUS-HUB: Interactive and Collective Exploration of Large-Scale Graphs

Directory of Open Access Journals (Sweden)

Di Jin

2017-07-01

Full Text Available Graphs emerge naturally in many domains, such as social science, neuroscience, transportation engineering, and more. In many cases, such graphs have millions or billions of nodes and edges, and their sizes increase daily at a fast pace. How can researchers from various domains explore large graphs interactively and efficiently to find out what is ‘important’? How can multiple researchers explore a new graph dataset collectively and “help” each other with their findings? In this article, we present Perseus-Hub, a large-scale graph mining tool that computes a set of graph properties in a distributed manner, performs ensemble, multi-view anomaly detection to highlight regions that are worth investigating, and provides users with uncluttered visualization and easy interaction with complex graph statistics. Perseus-Hub uses a Spark cluster to calculate various statistics of large-scale graphs efficiently, and aggregates the results in a summary on the master node to support interactive user exploration. In Perseus-Hub, the visualized distributions of graph statistics provide preliminary analysis to understand a graph. To perform a deeper analysis, users with little prior knowledge can leverage patterns (e.g., spikes in the power-law degree distribution marked by other users or experts. Moreover, Perseus-Hub guides users to regions of interest by highlighting anomalous nodes and helps users establish a more comprehensive understanding about the graph at hand. We demonstrate our system through the case study on real, large-scale networks.

The evolution of the MasAgro hubs

NARCIS (Netherlands)

Camacho-Villa, Tania Carolina; Almekinders, Conny; Hellin, Jon; Martinez-Cruz, Tania Eulalia; Rendon-Medel, Roberto; Guevara-Hernández, Francisco; Beuchelt, Tina D.; Govaerts, Bram

2016-01-01

Purpose: Little is known about effective ways to operationalize agricultural innovation processes. We use the MasAgro program in Mexico (which aims to increase maize and wheat productivity, profitability and sustainability), and the experiences of middle level ‘hub managers’, to understand how

76 FR 10328 - Grant of Authority for Subzone Status; Vestas Nacelles America, Inc. (Wind Turbine Nacelles, Hubs...

Science.gov (United States)

2011-02-24

... Status; Vestas Nacelles America, Inc. (Wind Turbine Nacelles, Hubs, Blades and Towers), Brighton, Denver...-purpose subzone at the wind turbine nacelle, hub, blade and tower manufacturing and warehousing facilities... status for activity related to the manufacturing and warehousing of wind turbine nacelles, hubs, blades...

78 FR 20314 - Jefferson Island Storage & Hub, L.L.C.; Notice of Filing

Science.gov (United States)

2013-04-04

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR13-44-000] Jefferson Island Storage & Hub, L.L.C.; Notice of Filing Take notice that on March 28, 2013, Jefferson Island Storage & Hub, L.L.C. filed to revise its Statement of Operating Conditions to among others, update...

When Is Hub Gene Selection Better than Standard Meta-Analysis?

Science.gov (United States)

Langfelder, Peter; Mischel, Paul S.; Horvath, Steve

2013-01-01

Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when) hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data). Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis) and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility) in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA) in three comprehensive and unbiased empirical studies: (1) Finding genes predictive of lung cancer survival, (2) finding methylation markers related to age, and (3) finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1). However, standard meta-analysis methods perform as good as (if not better than) a consensus network approach in terms of validation success (criterion 2). The article also reports a comparison of meta-analysis techniques applied to

When is hub gene selection better than standard meta-analysis?

Directory of Open Access Journals (Sweden)

Peter Langfelder

Full Text Available Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data. Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA in three comprehensive and unbiased empirical studies: (1 Finding genes predictive of lung cancer survival, (2 finding methylation markers related to age, and (3 finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1. However, standard meta-analysis methods perform as good as (if not better than a consensus network approach in terms of validation success (criterion 2. The article also reports a comparison of meta-analysis techniques

When is hub gene selection better than standard meta-analysis?

Science.gov (United States)

Langfelder, Peter; Mischel, Paul S; Horvath, Steve

2013-01-01

Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when) hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data). Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis) and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility) in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA) in three comprehensive and unbiased empirical studies: (1) Finding genes predictive of lung cancer survival, (2) finding methylation markers related to age, and (3) finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1). However, standard meta-analysis methods perform as good as (if not better than) a consensus network approach in terms of validation success (criterion 2). The article also reports a comparison of meta-analysis techniques applied to

Factors affecting the adoption and diffusion of Internet in higher ...

African Journals Online (AJOL)

Journal of Language, Technology & Entrepreneurship in Africa ... Factors affecting the adoption and diffusion of Internet in higher educational institutions in Kenya ... communication Technologies (ICTs) such as the Internet, Learning ...

The East African Resilience Innovation Hub | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

Project leadership The Resilience Innovation Hub will be housed within a ... Region at the Levy Mwanawasa Regional Centre, Lusaka -Conflict Early Warning and ... Authority on Development, Addis Ababa This initiative will support innovative ...

PASSENGER FLOWS PREDICTION IN MAJOR TRANSPORTATION HUBS

Directory of Open Access Journals (Sweden)

O. O. Ozerova

2013-11-01

Full Text Available Purpose. An effective organization of passenger traffic, due to the reliability prediction of traffic flow in passenger transport hubs. In order to determine the parameters of prospective passenger transport areas it is essential to analyze the impact of various factors and determine the most influential ones. Methodology. The article presents the method of paired linear correlation for a more influential factors on passengers in intercity and commuter and possible use in predicting the linear regression equations. Passenger transport vessel areas and branches of industry are interconnected and are in the ratio of passengers and production. Findings. It is found that the coefficient of correlation is in complex dependence on the duration of the period of retrospective analysis. Evaluation of reliability correlation coefficients and coefficients of predictive models led to the conclusion that the population gives the most accurate prediction of passenger flows, providing account of changes in Ukraine during the period of transformation. Originality. Equations of dependence on the impact of macroeconomic indicators were obtained and the evaluation of the reliability results was received. Practical value. The results of analysis and calculations will make short-term forecasting of traffic flow.

Virtual Hubs for facilitating access to Open Data

Science.gov (United States)

Mazzetti, Paolo; Latre, Miguel Á.; Ernst, Julia; Brumana, Raffaella; Brauman, Stefan; Nativi, Stefano

2015-04-01

In October 2014 the ENERGIC-OD (European NEtwork for Redistributing Geospatial Information to user Communities - Open Data) project, funded by the European Union under the Competitiveness and Innovation framework Programme (CIP), has started. In response to the EU call, the general objective of the project is to "facilitate the use of open (freely available) geographic data from different sources for the creation of innovative applications and services through the creation of Virtual Hubs". In ENERGIC-OD, Virtual Hubs are conceived as information systems supporting the full life cycle of Open Data: publishing, discovery and access. They facilitate the use of Open Data by lowering and possibly removing the main barriers which hampers geo-information (GI) usage by end-users and application developers. Data and data services heterogeneity is recognized as one of the major barriers to Open Data (re-)use. It imposes end-users and developers to spend a lot of effort in accessing different infrastructures and harmonizing datasets. Such heterogeneity cannot be completely removed through the adoption of standard specifications for service interfaces, metadata and data models, since different infrastructures adopt different standards to answer to specific challenges and to address specific use-cases. Thus, beyond a certain extent, heterogeneity is irreducible especially in interdisciplinary contexts. ENERGIC-OD Virtual Hubs address heterogeneity adopting a mediation and brokering approach: specific components (brokers) are dedicated to harmonize service interfaces, metadata and data models, enabling seamless discovery and access to heterogeneous infrastructures and datasets. As an innovation project, ENERGIC-OD will integrate several existing technologies to implement Virtual Hubs as single points of access to geospatial datasets provided by new or existing platforms and infrastructures, including INSPIRE-compliant systems and Copernicus services. ENERGIC OD will deploy a

Emerging Education Hubs: The Case of Singapore

Science.gov (United States)

Sidhu, Ravinder; Ho, K.-C.; Yeoh, Brenda

2011-01-01

In anticipation of a globalising post-Fordist political economy, countries and universities are increasingly pursuing strategic transnational education and research alliances. This article analyses the Global Schoolhouse, a key education policy platform that aims to transform Singapore into a knowledge and innovation hub by establishing networks…

Waves, currents and sediment transport modelling at the Wave Hub site

OpenAIRE

Gonzalez-Santamaria, Raul

2013-01-01

Primary supervisory team: Qingping Zou and Shunqi Pan This research project uses an integrated modelling system to investigate the effects of a wave farm on nearshore sediment transport at the Wave Hub site. The Wave Hub project is a large scale demonstration site for the development of the operation of arrays of wave energy generation devices located at the southwest coast of the UK where multiple field measurements took place. Particular attention of this study was paid to th...

Hubs and spokes in Regional Trade Agreements

NARCIS (Netherlands)

Vaal, A. de

2017-01-01

In the plethora of Regional Trade Agreements (RTAs) some countries are involved in much more RTAs than others. Furthermore, some countries take in a position as a hub: they have trade agreements with many other countries, while their partner countries are much less involved in RTA relations. Even

Publishing and sharing of hydrologic models through WaterHUB

Science.gov (United States)

Merwade, V.; Ruddell, B. L.; Song, C.; Zhao, L.; Kim, J.; Assi, A.

2011-12-01

Most hydrologists use hydrologic models to simulate the hydrologic processes to understand hydrologic pathways and fluxes for research, decision making and engineering design. Once these tasks are complete including publication of results, the models generally are not published or made available to the public for further use and improvement. Although publication or sharing of models is not required for journal publications, sharing of models may open doors for new collaborations, and avoids duplication of efforts if other researchers are interested in simulating a particular watershed for which a model already exists. For researchers, who are interested in sharing models, there are limited avenues to publishing their models to the wider community. Towards filling this gap, a prototype cyberinfrastructure (CI), called WaterHUB, is developed for sharing hydrologic data and modeling tools in an interactive environment. To test the utility of WaterHUB for sharing hydrologic models, a system to publish and share SWAT (Soil Water Assessment Tool) is developed. Users can utilize WaterHUB to search and download existing SWAT models, and also upload new SWAT models. Metadata such as the name of the watershed, name of the person or agency who developed the model, simulation period, time step, and list of calibrated parameters also published with individual model.

Resolution-limiting factors in 2-deoxyglucose autoradiography. I. Factors other than diffusion

Energy Technology Data Exchange (ETDEWEB)

Gallistel, C.R.; Nichols, S. (Pennsylvania Univ., Philadelphia, PA (USA). Dept. of Psychology)

1983-05-16

The authors measured the extent to which factors other than the diffusion of the radioactive label during tissue preparation limits the spatial resolving power of 2-deoxyglucose (2-DG) autoradiography. Radioactive swept frequency gratings were created using microcircuit lithography. The gratings consisted of alternating equal width radioactive and non-radioactive bars in groups of narrowing bar width (effective range 500-20 ..mu..m). The vertical thickness of the gratings ranged from 2.25 to 20 ..mu..m. The isotope in the radioactive bars was either /sup 14/C or /sup 3/H. A variety of X-ray films were exposed to these gratings and the resulting images scanned with microdensitometers or video digitizers to determine the fall off in image contrast (dark-bar values minus light-bar values) as a function of the number of dark bars (lines) per millimeter. The power of the isotope was the resolution limiting factor. Grating thickness and type of film made little difference. The limit of resolution with /sup 14/C was 10 lines/mm: with /sup 3/H it was 25 lines/mm. The microdensitometer itself is apt to be a resolution limiting factor; the resolving power of those commonly used in autoradiography is unlikely to exceed 10 lines/mm. From measurements of the steepness of gray-matter to white-matter transitions in the image from a tissue section, they conclude that the resolution in the image was no worse than 1.6-3.2 lines/mm. Either the isotope or diffusion of the 2-DG during tissue preparation must be the factor that limits resolution.

Mapping the changed hubs and corresponding functional connectivity in idiopathic restless legs syndrome.

Science.gov (United States)

Liu, Chunyan; Wang, Jiaojian; Hou, Yue; Qi, Zhigang; Wang, Li; Zhan, Shuqin; Wang, Rong; Wang, Yuping

2018-05-01

The hubs of the brain network play a key role in integrating and transferring information between different functional modules. However, whether the changed pattern in functional network hubs contributes to the onset of leg discomfort symptoms in restless legs syndrome (RLS) patients remains unclear. Using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory methods, we investigated whether alterations of hubs can be detected in RLS. First, we constructed the whole-brain voxelwise functional connectivity and calculated a functional connectivity strength (FCS) map in each of 16 drug-naive idiopathic RLS patients and 26 gender- and age-matched healthy control (HC) subjects. Next, a two-sample t test was applied to compare the FCS maps between HC and RLS patients, and to identify significant changes in FCS in RLS patients. To further elucidate the corresponding changes in the functional connectivity patterns of the aberrant hubs in RLS patients, whole-brain resting-state functional connectivity analyses for the hub areas were performed. The hub analysis revealed decreased FCS in the cuneus, fusiform gyrus, paracentral lobe, and precuneus, and increased FCS in the superior frontal gyrus and thalamus in idiopathic drug-naive RLS patients. Subsequent functional connectivity analyses revealed decreased functional connectivity in sensorimotor and visual processing networks and increased functional connectivity in the affective cognitive network and cerebellar-thalamic circuit. Furthermore, the mean FCS value in the superior frontal gyrus was significantly correlated with Hamilton Anxiety Rating Scale scores in RLS patients, and the mean FCS value in the fusiform gyrus was significantly correlated with Hamilton Depression Rating Scale scores. These findings may provide novel insight into the pathophysiology of RLS. Copyright © 2018 Elsevier B.V. All rights reserved.

Altered network hub connectivity after acute LSD administration

Directory of Open Access Journals (Sweden)

Felix Müller

Full Text Available LSD is an ambiguous substance, said to mimic psychosis and to improve mental health in people suffering from anxiety and depression. Little is known about the neuronal correlates of altered states of consciousness induced by this substance. Limited previous studies indicated profound changes in functional connectivity of resting state networks after the administration of LSD. The current investigation attempts to replicate and extend those findings in an independent sample. In a double-blind, randomized, cross-over study, 100 μg LSD and placebo were orally administered to 20 healthy participants. Resting state brain activity was assessed by functional magnetic resonance imaging. Within-network and between-network connectivity measures of ten established resting state networks were compared between drug conditions. Complementary analysis were conducted using resting state networks as sources in seed-to-voxel analyses. Acute LSD administration significantly decreased functional connectivity within visual, sensorimotor and auditory networks and the default mode network. While between-network connectivity was widely increased and all investigated networks were affected to some extent, seed-to-voxel analyses consistently indicated increased connectivity between networks and subcortical (thalamus, striatum and cortical (precuneus, anterior cingulate cortex hub structures. These latter observations are consistent with findings on the importance of hubs in psychopathological states, especially in psychosis, and could underlay therapeutic effects of hallucinogens as proposed by a recent model. Keywords: LSD, fMRI, Functional connectivity, Networks, Hubs

Pinoy Nutrition Hub: The Philippine Experience in Addressing Moderate Malnutrition

International Nuclear Information System (INIS)

Ramos, Arlo; Fuentes, Eureka; Duque, Yvonette; Soriano, Nezer; Gomez, Marijo

2014-01-01

Full text: • Objective: Malnutrition is a persistent problem in the Philippines. The 2011 survey of the Food and Nutrition Research Institute reported that 3 out of 10 children are malnourished. Data shows 20.2% of children 0-47 months are underweight while 33.6% are stunted. This rate is higher in depressed areas in the country. PD Hearth is a time and tested effective program model to address malnutrition. But the PDH has minimum standards that need to be followed in the program implementation. However, a developing country like the Philippines has limitations in its resources and implementations. This paper aims to share the Philippine experience in addressing moderate malnutrition through a contextualized and modified PD Hearth approach. The specific objectives of this paper are: - to describe the challenges in implementing PD Hearth in the context of the Philippines; - to describe the innovations and modifications in the PD Hearth; - and, to illustrate the successful intervention of the PNH program against malnourished children in the community. • Methods: The Pinoy Nutrition Hub model is an innovation of PD Hearth approach. The first step was the participatory approach evaluation of existing programs on MNCHN in the communities. The next step was for the stakeholders to identify the gaps and address them. This was followed by gathering lessons learned and good practices that arose from implementing PD Hearth. Innovations were adopted to address restrictions and maximize learning in its implementation. The contextualized approach was called Pinoy Nutrition Hub (PNH). • Outcomes: - The PNH was piloted in three Area Development Programs (ADP) that represent the three island groups of the Philippines. All three ADPs reported improvement in the weight of the malnourished children enrolled in the program. Below is an illustration of the how the actual weight of children in the Visayas ADP increased. Figure 1 (Display Omitted). Average Weight of Malnourished

A State Cyber Hub Operations Framework

Science.gov (United States)

2016-06-01

current and future decision support. Finally, the Hub operations team must track and report key performance indictors ( KPIs ) (established by the state...Region); then mutually agreed-upon core KPIs should be identified and reported at this time. The goal of the Act Element is to implement the decision...Force Headquarters Page 58 JIE Joint Information Environment JMC JIE Management Construct KPI Key Performance Indicator LEA Law Enforcement

The deep-sea hub of the ANTARES neutrino telescope

Energy Technology Data Exchange (ETDEWEB)

Anghinolfi, M. [INFN Sezione di Genova, Via Dodecaneso 33, I-16146 Genova (Italy); Calzas, A. [Centre de Physique des Particules de Marseille (CNRS/IN2P3), Universite de la Mediterranee, 13288 Marseille (France); Dinkespiler, B. [Centre de Physique des Particules de Marseille (CNRS/IN2P3), Universite de la Mediterranee, 13288 Marseille (France); Cuneo, S. [INFN Laboratori Nazionali del Sud, Via S. Sofia 44, I-95123 Catania (Italy); Favard, S. [Centre de Physique des Particules de Marseille (CNRS/IN2P3), Universite de la Mediterranee, 13288 Marseille (France); Hallewell, G. [Centre de Physique des Particules de Marseille (CNRS/IN2P3), Universite de la Mediterranee, 13288 Marseille (France)]. E-mail: gregh@cppm.in2p3.fr; Jaquet, M. [Centre de Physique des Particules de Marseille (CNRS/IN2P3), Universite de la Mediterranee, 13288 Marseille (France); Musumeci, M. [INFN Laboratori Nazionali del Sud, Via S. Sofia 44, I-95123 Catania (Italy); Papaleo, R. [INFN Laboratori Nazionali del Sud, Via S. Sofia 44, I-95123 Catania (Italy); Raia, G. [INFN Laboratori Nazionali del Sud, Via S. Sofia 44, I-95123 Catania (Italy); Valdy, P. [IFREMER - Institut francais de recherche pour l' exploitation de la mer, Centre de La Seyne, 83500 La Seyne sur mer (France); Vernin, P. [DSM-DAPNIA, CEA SACLAY, 91191 Gif sur Yvette Cedex (France)

2006-11-15

The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub.

The deep-sea hub of the ANTARES neutrino telescope

International Nuclear Information System (INIS)

Anghinolfi, M.; Calzas, A.; Dinkespiler, B.; Cuneo, S.; Favard, S.; Hallewell, G.; Jaquet, M.; Musumeci, M.; Papaleo, R.; Raia, G.; Valdy, P.; Vernin, P.

2006-01-01

The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub

The application of design criteria for locating a hub configured supply chain for a restaurant cluster in the Stellenbosch area

Directory of Open Access Journals (Sweden)

Claudia B. Struwig

2013-06-01

Full Text Available Restaurants, in general, utilise numerous suppliers. Normally they deliver on different days in the week and at different times during the day, logistically not an optimum approach. Not only does the current practice cause frequent interruptions, but by segregating the food supply chain unnecessary traffic is generated. This article investigated the need for developing a third party supplier hub, the best positioning of that hub and the most economical routes to the customers. With the aim of providing non-franchised restaurants with the necessary leverage to become market leaders, the hub is planned to only service the restaurants within the vicinity of the Stellenbosch area. In such a hub-configured supply chain, the suppliers would be delivering to the proposed hub, from where once-off deliveries to all the restaurants may be made on days and/or times determined by them. In order to investigate the benefits of providing such a hub structure, a systematic implementation approach was used. The first step was to do market research in order to establish the need for such a hub. That is, the viability of the hub from a restaurant’s perspective was established. The next step entailed the investigation of the design criteria needed in determining a favourable hub location. Four possible hub locations were identified. The Clark and Wright’s savings algorithm was then used to determine the optimal hub location and the feasibility of the results was verified with the aid of a global positioning system (GPS device. The last steps followed involved the determination of an effective hub floor plan that may be utilised, possible products that can be supplied to the restaurants and the necessary assets needed to provide the hub’s service. Finally, by incorporating all these facets, a cost analysis was done to determine the hub’s profitability.

Gravity drives the evolution of infrared dark hubs: JVLA observations of SDC13

Science.gov (United States)

Williams, G. M.; Peretto, N.; Avison, A.; Duarte-Cabral, A.; Fuller, G. A.

2018-05-01

Context. Converging networks of interstellar filaments, that is hubs, have been recently linked to the formation of stellar clusters and massive stars. Understanding the relationship between the evolution of these systems and the formation of cores and stars inside them is at the heart of current star formation research. Aims: The goal is to study the kinematic and density structure of the SDC13 prototypical hub at high angular resolution to determine what drives its evolution and fragmentation. Methods: We have mapped SDC13, a 1000 M⊙ infrared dark hub, in NH3(1,1) and NH3(2,2) emission lines, with both the Jansky Very Large Array and Green Bank Telescope. The high angular resolution achieved in the combined dataset allowed us to probe scales down to 0.07 pc. After fitting the ammonia lines, we computed the integrated intensities, centroid velocities and line widths, along with gas temperatures and H2 column densities. Results: The mass-per-unit-lengths of all four hub filaments are thermally super-critical, consistent with the presence of tens of gravitationally bound cores identified along them. These cores exhibit a regular separation of 0.37 ± 0.16 pc suggesting gravitational instabilities running along these super-critical filaments are responsible for their fragmentation. The observed local increase of the dense gas velocity dispersion towards starless cores is believed to be a consequence of such fragmentation process. Using energy conservation arguments, we estimate that the gravitational to kinetic energy conversion efficiency in the SDC13 cores is 35%. We see velocity gradient peaks towards 63% of cores as expected during the early stages of filament fragmentation. Another clear observational signature is the presence of the most massive cores at the filaments' junction, where the velocity dispersion is largest. We interpret this as the result of the hub morphology generating the largest acceleration gradients near the hub centre. Conclusions: We

Strategic analysis on establishing a natural gas trading hub in China

Directory of Open Access Journals (Sweden)

Xiaoguang Tong

2014-12-01

Full Text Available Since 2010, the LNG importing price premium in the Asia–Pacific markets has become increasingly high, generating great effects on the economic development in China. In addition, the natural gas dependence degree is expanding continuously, making it extremely urgent to establish a natural gas trading hub in China, with the aim to ensure national energy security, to gain the pricing power, and to build the regional benchmark prices. Through a comparative analysis of internal strength/weakness and external competitiveness, we concluded that with intensively-issued supporting policies on the natural gas sector, the initiation of spot and futures markets, the rapid growth of gas production and highly-improved infrastructures, as well as Shanghai's advantageous location, China has more advantages in establishing an Asian Natural Gas Trading Hub than other counties like Singapore, Japan and Malaysia. Moreover, based on the SWOT (strength, weakness, opportunity and threat and the marketization process analysis, the following strategies were presented: to impel the establishment of a natural gas trading hub depending on the gas supply condition, to follow the policies to complete the gas storage system, to form regional communities by taking comparative advantages, and to reinforce the marketization reform and regulation system establishment with foreign experiences for reference. This study rationalized the necessity and practicality of establishing a natural gas trading hub in China and will help China make a proper decision and find a periodical strategic path in this sector.

nanoHUB.org: Experiences and Challenges in Software Sustainability for a Large Scientific Community

Directory of Open Access Journals (Sweden)

Lynn Zentner

2014-07-01

Full Text Available The science gateway nanoHUB.org, funded by the National Science Foundation (NSF, serves a large scientific community dedicated to research and education in nanotechnology with community-contributed simulation codes as well as a vast repository of other materials such as recorded presentations, teaching materials, and workshops and courses. Nearly 330,000 users annually access over 4400 items of content on nanoHUB, including 343 simulation tools. Arguably the largest nanotechnology facility in the world, nanoHUB has led the way not only in providing open access to scientific code in the nanotechnology community, but also in lowering barriers to the use of that code, by providing a platform where developers are able to easily and quickly deploy code written in a variety of languages with user-friendly graphical user interfaces and where users can run the latest versions of codes transparently on the grid or other powerful resources without ever having to download or update code. Being a leader in open access code deployment provides nanoHUB with opportunities and challenges as it meets the current and future needs of its community. This paper discusses the experiences of nanoHUB in addressing and adapting to the changing landscape of scientific software in ways that best serve its community and meet the needs of the largest portion of its user base.

Googling Service Boundaries for Endovascular Clot Retrieval Hub Hospitals in a Metropolitan Setting: Proof-of-Concept Study.

Science.gov (United States)

Phan, Thanh G; Beare, Richard; Chen, Jian; Clissold, Benjamin; Ly, John; Singhal, Shaloo; Ma, Henry; Srikanth, Velandai

2017-05-01

There is great interest in how endovascular clot retrieval hubs provide services to a population. We applied a computational method to objectively generate service boundaries for such endovascular clot retrieval hubs, defined by traveling time to hub. Stroke incidence data merged with population census to estimate numbers of stroke in metropolitan Melbourne, Australia. Traveling time from randomly generated addresses to 4 endovascular clot retrieval-capable hubs (Royal Melbourne Hospital [RMH], Monash Medical Center [MMC], Alfred Hospital [ALF], and Austin Hospital [AUS]) estimated using Google Map application program interface. Boundary maps generated based on traveling time at various times of day for combinations of hubs. In a 2-hub model, catchment was best distributed when RMH was paired with MMC (model 1a, RMH 1765 km 2 and MMC 1164 km 2 ) or with AUS (model 1c, RMH 1244 km 2 and AUS 1685 km 2 ), with no statistical difference between models ( P =0.20). Catchment was poorly distributed when RMH was paired with ALF (model 1b, RMH 2252 km 2 and ALF 676 km 2 ), significantly different from both models 1a and 1c (both P AUS was superior to that of RMH, MMC, and ALF in catchment distribution and travel time. The method was also successfully applied to the city of Adelaide demonstrating wider applicability. We provide proof of concept for a novel computational method to objectively designate service boundaries for endovascular clot retrieval hubs. © 2017 American Heart Association, Inc.

Electricity consumption in Morocco: Stochastic Gompertz diffusion analysis with exogenous factors

International Nuclear Information System (INIS)

Gutierrez, R.; Gutierrez-Sanchez, R.; Nafidi, A.

2006-01-01

This paper proposes a means of using stochastic diffusion processes to model the total consumption of electrical power (including distribution and transport losses) in Morocco, as recorded by the official data for total sales published by Office Nationale de l'Electricite (ONE), the Moroccan electricity authority. Two models of univariate stochastic diffusion were used: the time-homogeneous Gompertz Diffusion Process (HGDP) and the time-non-homogeneous Gompertz Diffusion Process (NHGDP). The methodology proposed is based on the analysis of the trend function; this requires the analyst to obtain fits and forecasts for the consumption of electrical power by means of the estimated trend function (conditioned and non-conditioned). This latter function is obtained from the mean value of the process and the maximum likelihood estimators (MLE) of the parameters of the model. This estimation and the subsequent statistical inference are based on the discretised observation of the variable 'electricity consumption in Morocco', using annual data for the period 1980-2001. The fit and forecast are improved by using macroeconomic exogenous factors such as the gross domestic product per inhabitant (GDP/inhab), the final domestic consumption (FDC) and the gross fixed capital formation (GFCF). The results obtained show that NHGDP (with the above three exogenous factors) provides an adequate fit and medium-term forecast of electricity consumption in Morocco

Hub River: A private power prototype

International Nuclear Information System (INIS)

Sachs, J.L.

1992-01-01

This article examines the challenges of financing an independent power project in a developing country. The oil-fired plant is to be located on the Hub River in Baluchistan on the Arabian Sea coast. The topics of the article include a description of the team that put the project together, the financing plans, the risk in the face of political unrest and change of governments, and the beginning of construction of the project

Addressing congestion on single allocation hub-and-spoke networks

Directory of Open Access Journals (Sweden)

Ricardo Saraiva de Camargo

2012-12-01

Full Text Available When considering hub-and-spoke networks with single allocation, the absence of alternative routes makes this kind of systems specially vulnerable to congestion effects. In order to improve the design of such networks, congestion costs must be addressed. This article deploys two different techniques for addressing congestion on single allocation hub-and-spoke networks: the Generalized Benders Decomposition and the Outer Approximation method. Both methods are able to solve large scale instances. Computational experiments show how the adoption of advanced solution strategies, such as Pareto-optimal cut generation on the Master Problem branch-and-bound tree, may be decisive. They also demonstrate that the solution effort is not only associated with the size of the instances, but also with their combination of the installation and congestion costs.

Development of passive-controlled HUB (teetered brake & damper mechanism) of horizontal axis wind turbine

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Yukimaru; Kamada, Yasunari; Maeda, Takao [Mie Univ. (Japan)

1997-12-31

For the purpose of the improvement of reliability of the Mega-Watt wind turbine, this paper indicates the development of an original mechanism for the passive-controlled hub, which has the effects of braking and damping on aerodynamic forces. This mechanism is useful for variable speed control of the large wind turbine. The passive-controlled hub is the combination of two mechanisms. One is the passive-teetered and damping mechanism, and the other is the passive-variable-pitch mechanism. These mechanism are carried out by the combination of the teetering and feathering motions. When the wind speed exceeds the rated wind speed, the blade is passively teetered in a downwind direction and, simultaneously, a feathering mechanism, which is linked to the teetering mechanism through a connecting rods, is activated. Testing of the model horizontal axis wind turbine in a wind tunnel showed that the passive-controlled hub mechanism can suppress the over-rotational speed of the rotor. By the application of the passive-controlled hub mechanism, the maximum rotor speed is reduced to about 60%.

Gas and LNG pricing and trading hub in East Asia: An introduction

OpenAIRE

Shi, Xunpeng

2017-01-01

This paper summarizes the four papers in the special issues on ‘Gas and LNG pricing and trading hub in East Asia’. The papers examine lessons and experience from European hub development, other commodity, the Japanese history on developing of futures markets and inter-fuel substitution in East Asia. The papers finds that liquid futures market is the key to formulate benchmark prices while a well-developed spot market is the foundation; political will and strong leadership are required to over...

FEM analysis of hollow hub forming in rolling extrusion process

Directory of Open Access Journals (Sweden)

J. Bartnicki

2014-10-01

Full Text Available In this paper are presented the results of numerical calculations of rolling extrusion process of a hollow hub. As the flanges manufacturing at both sides of the product is required, in the analyzed process of rolling extrusion, a rear bumper was implemented as additional tool limiting axial metal flow. Numerical calculations of the hub forming process were conducted basing on finite element method, applying software Deform3D and Simufact in conditions of three dimensional state of strain. The obtained satisfactory results show that it is possible to conduct the further research works of experimental character, with the application of a modernized aggregate for the rolling extrusion process PO-2.

Continuous Integration for Concurrent MOOSE Framework and Application Development on GitHub

Directory of Open Access Journals (Sweden)

Andrew E. Slaughter

2015-11-01

Full Text Available For the past several years, Idaho National Laboratory’s MOOSE framework team has employed modern software engineering techniques (continuous integration, joint application/framework source code repos- itories, automated regression testing, etc. in developing closed-source multiphysics simulation software (Gaston et al., 'Journal of Open Research Software' vol. 2, article e10, 2014. In March 2014, the MOOSE framework was released under an open source license on GitHub, significantly expanding and diversifying the pool of current active and potential future contributors on the project. Despite this recent growth, the same philosophy of concurrent framework and application development continues to guide the project’s development roadmap. Several specific practices, including techniques for managing multiple repositories, conducting automated regression testing, and implementing a cascading build process are discussed in this short paper. Special attention is given to describing the manner in which these practices naturally synergize with the GitHub API and GitHub-specific features such as issue tracking, Pull Requests, and project forks.

Characteristics of steady vibration in a rotating hub-beam system

Science.gov (United States)

Zhao, Zhen; Liu, Caishan; Ma, Wei

2016-02-01

A rotating beam features a puzzling character in which its frequencies and modal shapes may vary with the hub's inertia and its rotating speed. To highlight the essential nature behind the vibration phenomena, we analyze the steady vibration of a rotating Euler-Bernoulli beam with a quasi-steady-state stretch. Newton's law is used to derive the equations governing the beam's elastic motion and the hub's rotation. A combination of these equations results in a nonlinear partial differential equation (PDE) that fully reflects the mutual interaction between the two kinds of motion. Via the Fourier series expansion within a finite interval of time, we reduce the PDE into an infinite system of a nonlinear ordinary differential equation (ODE) in spatial domain. We further nondimensionalize the ODE and discretize it via a difference method. The frequencies and modal shapes of a general rotating beam are then determined numerically. For a low-speed beam where the ignorance of geometric stiffening is feasible, the beam's vibration characteristics are solved analytically. We validate our numerical method and the analytical solutions by comparing with either the past experiments or the past numerical findings reported in existing literature. Finally, systematic simulations are performed to demonstrate how the beam's eigenfrequencies vary with the hub's inertia and rotating speed.

Coffee Shops, Classrooms and Conversations: public engagement and outreach in a large interdisciplinary research Hub

Science.gov (United States)

Holden, Jennifer A.

2014-05-01

Public engagement and outreach activities are increasingly using specialist staff for co-ordination, training and support for researchers, they are also becoming expected for large investments. Here, the experience of public engagement and outreach a large, interdisciplinary Research Hub is described. dot.rural, based at the University of Aberdeen UK, is a £11.8 million Research Councils UK Rural Digital Economy Hub, funded as part of the RCUK Digital Economy Theme (2009-2015). Digital Economy research aims to realise the transformational impact of digital technologies on aspects of the environment, community life, cultural experiences, future society, and the economy. The dot.rural Hub involves 92 researchers from 12 different disciplines, including Geography, Hydrology and Ecology. Public Engagement and Outreach is embedded in the dot.rural Digital Economy Hub via an Outreach Officer. Alongside this position, public engagement and outreach activities are compulsory part of PhD student contracts. Public Engagement and Outreach activities at the dot.rural Hub involve individuals and groups in both formal and informal settings organised by dot.rural and other organisations. Activities in the realms of Education, Public Engagement, Traditional and Social Media are determined by a set of Underlying Principles designed for the Hub by the Outreach Officer. The underlying Engagement and Outreach principles match funding agency requirements and expectations alongside researcher demands and the user-led nature of Digital Economy Research. All activities include researchers alongside the Outreach Officer are research informed and embedded into specific projects that form the Hub. Successful public engagement activities have included participation in Café Scientifique series, workshops in primary and secondary schools, and online activities such as I'm a Scientist Get Me Out of Here. From how to engage 8 year olds with making hydrographs more understandable to members of

Calculation of the power factor using the neutron diffusion hybrid equation

International Nuclear Information System (INIS)

Costa da Silva, Adilson; Carvalho da Silva, Fernando; Senra Martinez, Aquilino

2013-01-01

Highlights: ► A neutron diffusion hybrid equation with an external neutron source was used. ► Nodal expansion method to obtain the neutron flux was used. ► Nuclear power factors in each fuel element in the reactor core were calculated. ► The results obtained were very accurate. -- Abstract: In this paper, we used a neutron diffusion hybrid equation with an external neutron source to calculate nuclear power factors in each fuel element in the reactor core. We used the nodal expansion method to obtain the neutron flux for a given control rods bank position. The results were compared with results obtained for eigenvalue problem near criticality condition and fixed source problem during the start-up of the reactor, where external neutron sources are extremely important for the stabilization of external neutron detectors.

Network performance, hub connectivity potential, and competitive position of primary airports in Asia/Pacific region

NARCIS (Netherlands)

Matsumoto, H.; Veldhuis, J.; de Wit, J.; Burghouwt, G.

2008-01-01

Recently, hub-and-spoke network configurations are more and more developed in the Asia/Pacific region. In this paper, it is argued that the measurement of network performance in hub-and-spoke systems should take into account the quantity and quality of both direct and indirect connections. The

Review of research on AFPM hub motor

Directory of Open Access Journals (Sweden)

Jianguo DAI

2018-02-01

Full Text Available The industrialization of new energy vehicles is an important way to promote the sustainable development of automobile industry, and it is also the key measure to solve the problems of energy and environment. As an important type of new energy vehicles, electric vehicles will play an important role in the future competition in the automotive industry, especially in the field of electric vehicle driven by wheel. With the advantages of compact structure, high power density, low working noise and good heat dissipation performance, the AFPM motor has gradually become the preferred object of the hub driving device. Based on the statement of the technical development and research status about AFPM motor, this paper mainly analyzes the engineering application and technical problems of AFPM motor in hub drive, especially the matching of AFPM motor with other systems and the problem of heat dissipation at high load conditions, and looks forward to the key role in the future development of the automotive industry. This paper will play a certain reference and guiding role in the application of AFPM motor in the field of new energy vehicles.

Sharing environmental models: An Approach using GitHub repositories and Web Processing Services

Science.gov (United States)

Stasch, Christoph; Nuest, Daniel; Pross, Benjamin

2016-04-01

The GLUES (Global Assessment of Land Use Dynamics, Greenhouse Gas Emissions and Ecosystem Services) project established a spatial data infrastructure for scientific geospatial data and metadata (http://geoportal-glues.ufz.de), where different regional collaborative projects researching the impacts of climate and socio-economic changes on sustainable land management can share their underlying base scenarios and datasets. One goal of the project is to ease the sharing of computational models between institutions and to make them easily executable in Web-based infrastructures. In this work, we present such an approach for sharing computational models relying on GitHub repositories (http://github.com) and Web Processing Services. At first, model providers upload their model implementations to GitHub repositories in order to share them with others. The GitHub platform allows users to submit changes to the model code. The changes can be discussed and reviewed before merging them. However, while GitHub allows sharing and collaborating of model source code, it does not actually allow running these models, which requires efforts to transfer the implementation to a model execution framework. We thus have extended an existing implementation of the OGC Web Processing Service standard (http://www.opengeospatial.org/standards/wps), the 52°North Web Processing Service (http://52north.org/wps) platform to retrieve all model implementations from a git (http://git-scm.com) repository and add them to the collection of published geoprocesses. The current implementation is restricted to models implemented as R scripts using WPS4R annotations (Hinz et al.) and to Java algorithms using the 52°North WPS Java API. The models hence become executable through a standardized Web API by multiple clients such as desktop or browser GIS and modelling frameworks. If the model code is changed on the GitHub platform, the changes are retrieved by the service and the processes will be updated

GeoTrust Hub: A Platform For Sharing And Reproducing Geoscience Applications

Science.gov (United States)

Malik, T.; Tarboton, D. G.; Goodall, J. L.; Choi, E.; Bhatt, A.; Peckham, S. D.; Foster, I.; Ton That, D. H.; Essawy, B.; Yuan, Z.; Dash, P. K.; Fils, G.; Gan, T.; Fadugba, O. I.; Saxena, A.; Valentic, T. A.

2017-12-01

Recent requirements of scholarly communication emphasize the reproducibility of scientific claims. Text-based research papers are considered poor mediums to establish reproducibility. Papers must be accompanied by "research objects", aggregation of digital artifacts that together with the paper provide an authoritative record of a piece of research. We will present GeoTrust Hub (http://geotrusthub.org), a platform for creating, sharing, and reproducing reusable research objects. GeoTrust Hub provides tools for scientists to create `geounits'--reusable research objects. Geounits are self-contained, annotated, and versioned containers that describe and package computational experiments in an efficient and light-weight manner. Geounits can be shared on public repositories such as HydroShare and FigShare, and also using their respective APIs reproduced on provisioned clouds. The latter feature enables science applications to have a lifetime beyond sharing, wherein they can be independently verified and trust be established as they are repeatedly reused. Through research use cases from several geoscience laboratories across the United States, we will demonstrate how tools provided from GeoTrust Hub along with Hydroshare as its public repository for geounits is advancing the state of reproducible research in the geosciences. For each use case, we will address different computational reproducibility requirements. Our first use case will be an example of setup reproducibility which enables a scientist to set up and reproduce an output from a model with complex configuration and development environments. Our second use case will be an example of algorithm/data reproducibility, where in a shared data science model/dataset can be substituted with an alternate one to verify model output results, and finally an example of interactive reproducibility, in which an experiment is dependent on specific versions of data to produce the result. Toward this we will use software and data

Human projected area factors for detailed direct and diffuse solar radiation analysis

DEFF Research Database (Denmark)

Kubaha, K.; Fiala, D.; Toftum, Jørn

2004-01-01

Projected area factors for individual segments of the standing and sedentary human body were modelled for both direct and diffuse solar radiation using detailed 3D geometry and radiation models. The local projected area factors with respect to direct short-wave radiation are a function of the solar...

Stochastic optimization of energy hub operation with consideration of thermal energy market and demand response

International Nuclear Information System (INIS)

Vahid-Pakdel, M.J.; Nojavan, Sayyad; Mohammadi-ivatloo, B.; Zare, Kazem

2017-01-01

Highlights: • Studying heating market impact on energy hub operation considering price uncertainty. • Investigating impact of implementation of heat demand response on hub operation. • Presenting stochastic method to consider wind generation and prices uncertainties. - Abstract: Multi carrier energy systems or energy hubs has provided more flexibility for energy management systems. On the other hand, due to mutual impact of different energy carriers in energy hubs, energy management studies become more challengeable. The initial patterns of energy demands from grids point of view can be modified by optimal scheduling of energy hubs. In this work, optimal operation of multi carrier energy system has been studied in the presence of wind farm, electrical and thermal storage systems, electrical and thermal demand response programs, electricity market and thermal energy market. Stochastic programming is implemented for modeling the system uncertainties such as demands, market prices and wind speed. It is shown that adding new source of heat energy for providing demand of consumers with market mechanism changes the optimal operation point of multi carrier energy system. Presented mixed integer linear formulation for the problem has been solved by executing CPLEX solver of GAMS optimization software. Simulation results shows that hub’s operation cost reduces up to 4.8% by enabling the option of using thermal energy market for meeting heat demand.

Penentuan Pelabuhan Hub untuk Crude Palm Oil (CPO Ekspor di Indonesia

Directory of Open Access Journals (Sweden)

Eko Andi Haranto

2013-03-01

Full Text Available CPO (Crude Palm Oil merupakan salah satu komoditi ekspor terbesar di Indonesia. Moda angkut darat dan sungai menjadi pilihan untuk didistribusikan menuju calon pelabuhan hub. Tugas Akhir ini bertujuan untuk merencanakan pola operasi armada pengangkut CPO, dan penentuan pelabuhan hub untuk ekspor CPO. Metode Transportasi digunakan untuk memilih pabrik pengolahan CPO sebagai pemasok utama. Dari hasil analisis didapatkan bahwa penggunaan moda darat menggunakan truk lebih optimal dibandingkan menggunakan tongkang hal ini dikarenakan kondisi sungai di Kalimantan Tengah yang dangkal. Dengan menggunakan metode transportasi didapatkan empat lokasi pabrik pengolahan minyak kelapa sawit. Pelabuhan hub yang terpilih berlokasi di Bagendang dan Bumi Harjo. Kedua titik tersebut dipilih karena sudah memiliki tangki timbun dan dermaga untuk ekspor CPO, selain itu pemilihan berdasarkan hasil analisa didapatkan biaya dari Pabrik PT. ATLANTIS ke Pelabuhan Bagendang dengan truk berukuran 10 ton memerlukan biaya sebesar Rp. 333.016,25/TRIP/TRUK. Pabrik PT. ATLANTIS II ke Pelabuhan Bagendang Rp. 237.868,75/TRIP/TRUK. Pabrik PT. TIGER ke Pelabuhan Bumi Harjo Rp. 475.737,50/TRIP/TRUK. PT. TIGER II merupakan pabrik yang dapat melakukan pengiriman langsung menggunakan tongkang berukuran 1800 DWT melewati sungai Barito, dengan biaya Rp.123.007.828,27,- /voyage.

DAVINC3I: moving towards responsive hub network designs

NARCIS (Netherlands)

Ossevoort, R.; Keizer, de M.; Vorst, van der J.G.A.J.; Wenink, E.

2013-01-01

The Dutch floricultural sector is generally appreciated for its world leadership; the Netherlands is the flower trading hub for the European market. There are two trends affecting this position. First, virtualisation makes trade flows relatively footloose and flexible. Moreover, it enables the use

Research dedusting efficiency of the inertial hub with adjustable parameters

Directory of Open Access Journals (Sweden)

Sharapov Rashid

2016-01-01

Full Text Available Production of construction materials every year production increases, thus increasing emissions pollutants into the atmosphere subjected to cleaning. At the enterprises of building materials production equipment becoming outdated both morally and physically exhausted their useful life. Technological design standards in the operation of purification equipment has undergone a number of changes. There are a large number of works devoted to the theory of cyclone separation. They examined calculation method and to determine the minimum size of particles is separated completely from the air stream in a cyclone. In theory, the high efficiency cyclones are relatively small separation of particles from the air stream. The experiments show that certain fractions of full capture occurs from the cyclones and out relatively large particles. Designed dust device hubs. They capture dust particles with low specific density and smaller than 5–10 microns. Rational use of hubs is achieved in the aspiration systems high performance. They are placed in front of or between the filter and the cyclone filter. Hub much reduces the amount of dust-laden air directed onto a thin cleaning. This reduces energy consumption for manufacturing as a whole, as well as, due to a possible decrease in performance fine filters, reducing their initial cost, metal consumption, maintenance costs and reduce the area occupied by them.

Real-Time Monitoring and Fault Diagnosis of a Low Power Hub Motor Using Feedforward Neural Network

Directory of Open Access Journals (Sweden)

Mehmet Şimşir

2016-01-01

Full Text Available Low power hub motors are widely used in electromechanical systems such as electrical bicycles and solar vehicles due to their robustness and compact structure. Such systems driven by hub motors (in wheel motors encounter previously defined and undefined faults under operation. It may inevitably lead to the interruption of the electromechanical system operation; hence, economic losses take place at certain times. Therefore, in order to maintain system operation sustainability, the motor should be precisely monitored and the faults are diagnosed considering various significant motor parameters. In this study, the artificial feedforward backpropagation neural network approach is proposed to real-time monitor and diagnose the faults of the hub motor by measuring seven main system parameters. So as to construct a necessary model, we trained the model, using a data set consisting of 4160 samples where each has 7 parameters, by the MATLAB environment until the best model is obtained. The results are encouraging and meaningful for the specific motor and the developed model may be applicable to other types of hub motors. The prosperous model of the whole system was embedded into Arduino Due microcontroller card and the mobile real-time monitoring and fault diagnosis system prototype for hub motor was designed and manufactured.

The influence of hubs in the structure of a neuronal network during an epileptic seizure

Science.gov (United States)

Rodrigues, Abner Cardoso; Cerdeira, Hilda A.; Machado, Birajara Soares

2016-02-01

In this work, we propose changes in the structure of a neuronal network with the intention to provoke strong synchronization to simulate episodes of epileptic seizure. Starting with a network of Izhikevich neurons we slowly increase the number of connections in selected nodes in a controlled way, to produce (or not) hubs. We study how these structures alter the synchronization on the spike firings interval, on individual neurons as well as on mean values, as a function of the concentration of connections for random and non-random (hubs) distribution. We also analyze how the post-ictal signal varies for the different distributions. We conclude that a network with hubs is more appropriate to represent an epileptic state.

Progression of diffuse esophageal spasm to achalasia: incidence and predictive factors.

Science.gov (United States)

Fontes, L H S; Herbella, F A M; Rodriguez, T N; Trivino, T; Farah, J F M

2013-07-01

The progression of certain primary esophageal motor disorders to achalasia has been documented; however, the true incidence of this decay is still elusive. This study aims to evaluate: (i) the incidence of the progression of diffuse esophageal spasm to achalasia, and (ii) predictive factors to this progression. Thirty-five patients (mean age 53 years, 80% females) with a manometric picture of diffuse esophageal spasm were followed for at least 1 year. Patients with gastroesophageal reflux disease confirmed by pH monitoring or systemic diseases that may affect esophageal motility were excluded. Esophageal manometry was repeated in all patients. Five (14%) of the patients progressed to achalasia at a mean follow-up of 2.1 (range 1-4) years. Demographic characteristics were not predictive of transition to achalasia, while dysphagia (P= 0.005) as the main symptom and the wave amplitude of simultaneous waves less than 50 mmHg (P= 0.003) were statistically significant. In conclusion, the transition of diffuse esophageal spasm to achalasia is not frequent at a 2-year follow-up. Dysphagia and simultaneous waves with low amplitude are predictive factors for this degeneration. © 2012 Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Diffusion piecewise homogenization via flux discontinuity factors

International Nuclear Information System (INIS)

Sanchez, Richard; Zmijarevic, Igor

2011-01-01

We analyze the calculation of flux discontinuity factors (FDFs) for use with piecewise subdomain assembly homogenization. These coefficients depend on the numerical mesh used to compute the diffusion problem. When the mesh has a single degree of freedom on subdomain interfaces the solution is unique and can be computed independently per subdomain. For all other cases we have implemented an iterative calculation for the FDFs. Our numerical results show that there is no solution to this nonlinear problem but that the iterative algorithm converges towards FDFs values that reproduce subdomains reaction rates with a relatively high precision. In our test we have included both the GET and black-box FDFs. (author)

The development of gas hubs in Europe

International Nuclear Information System (INIS)

Miriello, Caterina; Polo, Michele

2015-01-01

This paper investigates the development of wholesale markets for natural gas at the different stages of market liberalization. We identify three steps in the process: wholesale trade initially develops to cope with balancing needs when the shippers and suppliers segments become more fragmented; once the market becomes more liquid, it turns out to be a second source of gas procurement in alternative to long term contracts; finally, to manage price risk financial instruments are traded. We review in detail the different regulatory measures that must be introduced to create an efficient and functioning wholesale gas market. Finally, we analyze the evolution of gas hubs in the UK, the Netherlands, Germany and Italy in terms of market rules and market liquidity. We argue that each of these country cases can be easily located into the evolutionary path we have highlighted at the beginning, with the UK and the Netherlands leading the process, Germany and Italy constrained by limited supply; Italy is also showing an interesting counterfactual. -- Highlights: •The paper illustrates development paths for natural gas hubs in Europe. •Wholesale trade increases with competition. •The regulatory settings of UK, Netherlands, Germany and Italy are reviewed. •Each country is located into the evolutionary path highlighted in the analytical framework

Optimal integrated sizing and planning of hubs with midsize/large CHP units considering reliability of supply

International Nuclear Information System (INIS)

Moradi, Saeed; Ghaffarpour, Reza; Ranjbar, Ali Mohammad; Mozaffari, Babak

2017-01-01

Highlights: • New hub planning formulation is proposed to exploit assets of midsize/large CHPs. • Linearization approaches are proposed for two-variable nonlinear CHP fuel function. • Efficient operation of addressed CHPs & hub devices at contingencies are considered. • Reliability-embedded integrated planning & sizing is formulated as one single MILP. • Noticeable results for costs & reliability-embedded planning due to mid/large CHPs. - Abstract: Use of multi-carrier energy systems and the energy hub concept has recently been a widespread trend worldwide. However, most of the related researches specialize in CHP systems with constant electricity/heat ratios and linear operating characteristics. In this paper, integrated energy hub planning and sizing is developed for the energy systems with mid-scale and large-scale CHP units, by taking their wide operating range into consideration. The proposed formulation is aimed at taking the best use of the beneficial degrees of freedom associated with these units for decreasing total costs and increasing reliability. High-accuracy piecewise linearization techniques with approximation errors of about 1% are introduced for the nonlinear two-dimensional CHP input-output function, making it possible to successfully integrate the CHP sizing. Efficient operation of CHP and the hub at contingencies is extracted via a new formulation, which is developed to be incorporated to the planning and sizing problem. Optimal operation, planning, sizing and contingency operation of hub components are integrated and formulated as a single comprehensive MILP problem. Results on a case study with midsize CHPs reveal a 33% reduction in total costs, and it is demonstrated that the proposed formulation ceases the need for additional components/capacities for increasing reliability of supply.

Optimal Scheduling of a Multi-Carrier Energy Hub Supplemented By Battery Energy Storage Systems

DEFF Research Database (Denmark)

Javadi, Mohammad Sadegh; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2017-01-01

This paper introduces a management model for optimal scheduling of a multi-carrier energy hub. In the proposed hub, three types of assets are considered: dispersed generating systems (DGs) such as micro-combined heat and power (mCHP) units, storage devices such as battery-based electrical storage...... systems (ESSs), and heating/cooling devices such as electrical heater, heat-pumps and absorption chillers. The optimal scheduling and management of the examined energy hub assets in line with electrical transactions with distribution network is modeled as a mixed-integer non-linear optimization problem....... In this regard, optimal operating points of DG units as well as ESSs are calculated based on a cost-effective strategy. Degradation cost of ESSs is also taken into consideration for short-term scheduling. Simulation results demonstrate that including well-planned energy storage options together with optimal...

WHAT IS CONTROLLING THE FRAGMENTATION IN THE INFRARED DARK CLOUD G14.225–0.506?: DIFFERENT LEVELS OF FRAGMENTATION IN TWIN HUBS

Energy Technology Data Exchange (ETDEWEB)

Busquet, Gemma; Girart, Josep Miquel [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193, Cerdanyola del Vallès, Catalunya (Spain); Estalella, Robert [Departament d’Astronomia i Meteorologia, Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Martí i Franquès, 1, E-08028 Barcelona, Catalunya (Spain); Palau, Aina [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090 Morelia, Michoacán, México (Mexico); Liu, Hauyu Baobab; Ho, Paul T. P. [Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); De Gregorio-Monsalvo, Itziar [European Southern Observatory (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Pillai, Thushara [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Anglada, Guillem, E-mail: busquet@ice.cat [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía, s/n, E-18008, Granada (Spain)

2016-03-20

We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225–0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 μm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clump elongated in the direction of the associated filament. At small scales, the SMA images reveal that both hubs fragment into several dust condensations. The fragmentation level was assessed under the same conditions and we found that hub-N presents 4 fragments while hub-S is more fragmented, with 13 fragments identified. We studied the density structure by means of a simultaneous fit of the radial intensity profile at 870 and 350 μm and the spectral energy distribution adopting a Plummer-like function to describe the density structure. The parameters inferred from the model are remarkably similar in both hubs, suggesting that density structure could not be responsible for determining the fragmentation level. We estimated several physical parameters, such as the level of turbulence and the magnetic field strength, and we found no significant differences between these hubs. The Jeans analysis indicates that the observed fragmentation is more consistent with thermal Jeans fragmentation compared with a scenario in which turbulent support is included. The lower fragmentation level observed in hub-N could be explained in terms of stronger UV radiation effects from a nearby H ii region, evolutionary effects, and/or stronger magnetic fields at small scales, a scenario that should be further investigated.

WHAT IS CONTROLLING THE FRAGMENTATION IN THE INFRARED DARK CLOUD G14.225–0.506?: DIFFERENT LEVELS OF FRAGMENTATION IN TWIN HUBS

International Nuclear Information System (INIS)

Busquet, Gemma; Girart, Josep Miquel; Estalella, Robert; Palau, Aina; Liu, Hauyu Baobab; Ho, Paul T. P.; Zhang, Qizhou; De Gregorio-Monsalvo, Itziar; Pillai, Thushara; Anglada, Guillem

2016-01-01

We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225–0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 μm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clump elongated in the direction of the associated filament. At small scales, the SMA images reveal that both hubs fragment into several dust condensations. The fragmentation level was assessed under the same conditions and we found that hub-N presents 4 fragments while hub-S is more fragmented, with 13 fragments identified. We studied the density structure by means of a simultaneous fit of the radial intensity profile at 870 and 350 μm and the spectral energy distribution adopting a Plummer-like function to describe the density structure. The parameters inferred from the model are remarkably similar in both hubs, suggesting that density structure could not be responsible for determining the fragmentation level. We estimated several physical parameters, such as the level of turbulence and the magnetic field strength, and we found no significant differences between these hubs. The Jeans analysis indicates that the observed fragmentation is more consistent with thermal Jeans fragmentation compared with a scenario in which turbulent support is included. The lower fragmentation level observed in hub-N could be explained in terms of stronger UV radiation effects from a nearby H ii region, evolutionary effects, and/or stronger magnetic fields at small scales, a scenario that should be further investigated

Dynamically Allocated Hub in Task-Evoked Network Predicts the Vulnerable Prefrontal Locus for Contextual Memory Retrieval in Macaques.

Directory of Open Access Journals (Sweden)

Takahiro Osada

2015-06-01

Full Text Available Neuroimaging and neurophysiology have revealed that multiple areas in the prefrontal cortex (PFC are activated in a specific memory task, but severity of impairment after PFC lesions is largely different depending on which activated area is damaged. The critical relationship between lesion sites and impairments has not yet been given a clear mechanistic explanation. Although recent works proposed that a whole-brain network contains hubs that play integrative roles in cortical information processing, this framework relying on an anatomy-based structural network cannot account for the vulnerable locus for a specific task, lesioning of which would bring impairment. Here, we hypothesized that (i activated PFC areas dynamically form an ordered network centered at a task-specific "functional hub" and (ii the lesion-effective site corresponds to the "functional hub," but not to a task-invariant "structural hub." To test these hypotheses, we conducted functional magnetic resonance imaging experiments in macaques performing a temporal contextual memory task. We found that the activated areas formed a hierarchical hub-centric network based on task-evoked directed connectivity, differently from the anatomical network reflecting axonal projection patterns. Using a novel simulated-lesion method based on support vector machine, we estimated severity of impairment after lesioning of each area, which accorded well with a known dissociation in contextual memory impairment in macaques (impairment after lesioning in area 9/46d, but not in area 8Ad. The predicted severity of impairment was proportional to the network "hubness" of the virtually lesioned area in the task-evoked directed connectivity network, rather than in the anatomical network known from tracer studies. Our results suggest that PFC areas dynamically and cooperatively shape a functional hub-centric network to reallocate the lesion-effective site depending on the cognitive processes, apart from

The East African Resilience Innovation Hub | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

The hub will explore several research streams to examine why interventions succeed or fail, and how individuals, communities, and states can cope with and overcome conflict and violence. Researchers will also look at how to support peacemaking processes and increase disaster prevention efforts. Their work will respond ...

Assessment of Effective Factor of Hydrogen Diffusion Equation Using FE Analysis

International Nuclear Information System (INIS)

Kim, Nak Hyun; Oh, Chang Sik; Kim, Yun Jae

2010-01-01

The coupled model with hydrogen transport and elasto-plasticity behavior was introduced. In this paper, the effective factor of the hydrogen diffusion equation has been described. To assess the effective factor, finite element (FE) analyses including hydrogen transport and mechanical loading for boundary layer specimens with low-strength steel properties are carried out. The results of the FE analyses are compared with those from previous studies conducted by Taha and Sofronis (2001)

Brokered virtual hubs for facilitating access and use of geospatial Open Data

Science.gov (United States)

Mazzetti, Paolo; Latre, Miguel; Kamali, Nargess; Brumana, Raffaella; Braumann, Stefan; Nativi, Stefano

2016-04-01

Open Data is a major trend in current information technology scenario and it is often publicised as one of the pillars of the information society in the near future. In particular, geospatial Open Data have a huge potential also for Earth Sciences, through the enablement of innovative applications and services integrating heterogeneous information. However, open does not mean usable. As it was recognized at the very beginning of the Web revolution, many different degrees of openness exist: from simple sharing in a proprietary format to advanced sharing in standard formats and including semantic information. Therefore, to fully unleash the potential of geospatial Open Data, advanced infrastructures are needed to increase the data openness degree, enhancing their usability. In October 2014, the ENERGIC OD (European NEtwork for Redistributing Geospatial Information to user Communities - Open Data) project, funded by the European Union under the Competitiveness and Innovation framework Programme (CIP), has started. In response to the EU call, the general objective of the project is to "facilitate the use of open (freely available) geographic data from different sources for the creation of innovative applications and services through the creation of Virtual Hubs". The ENERGIC OD Virtual Hubs aim to facilitate the use of geospatial Open Data by lowering and possibly removing the main barriers which hampers geo-information (GI) usage by end-users and application developers. Data and services heterogeneity is recognized as one of the major barriers to Open Data (re-)use. It imposes end-users and developers to spend a lot of effort in accessing different infrastructures and harmonizing datasets. Such heterogeneity cannot be completely removed through the adoption of standard specifications for service interfaces, metadata and data models, since different infrastructures adopt different standards to answer to specific challenges and to address specific use-cases. Thus

EXPANSION OF UNIVERSITY EDUCATION, GRADUATE UNEMPLOYMENT AND THE KNOWLEDGE HUB IN SRI LANKA

Directory of Open Access Journals (Sweden)

Gamini Samaranayake

2016-04-01

Full Text Available The main objective of this paper is to examine the nexus between the existing university education system and graduate unemployment, and to explore the responses of successive governments to address this issue. It also examines the viability and potential of the knowledge hub as a solution to graduate unemployment. Towards this end, it argues that the solution to graduate employment lies in implementing structural changes that are concurrent to changes that are taking place at the international level in higher education. It illustrates, with the use of relevant sources, the pressing issue of graduate un- and underemployment, and identifies the mismatch between skills and requirements as a major factor contributing to intensify the crisis. It observes that strategies such as training unemployed graduates to enable them to acquire the competencies needed for the modern work place, developing systems to link them to the world of work, re-structuring the university system such that it is more concerned with quality and relevance rather than the width of knowledge imparted, and introducing job-oriented programmes could partially address this issue. It also identifies the proposal to establish a knowledge hub in Sri Lanka as constituting a long term and sustainable strategy not only to mitigate the effects of graduate un- and underemployment, but also to facilitate a lucrative source of revenue for the country.

A Genome-Wide Association Study and Complex Network Identify Four Core Hub Genes in Bipolar Disorder

Directory of Open Access Journals (Sweden)

Zengyan Xie

2017-12-01

Full Text Available Bipolar disorder is a common and severe mental illness with unsolved pathophysiology. A genome-wide association study (GWAS has been used to find a number of risk genes, but it is difficult for a GWAS to find genes indirectly associated with a disease. To find core hub genes, we introduce a network analysis after the GWAS was conducted. Six thousand four hundred fifty eight single nucleotide polymorphisms (SNPs with p < 0.01 were sifted out from Wellcome Trust Case Control Consortium (WTCCC dataset and mapped to 2045 genes, which are then compared with the protein–protein network. One hundred twelve genes with a degree >17 were chosen as hub genes from which five significant modules and four core hub genes (FBXL13, WDFY2, bFGF, and MTHFD1L were found. These core hub genes have not been reported to be directly associated with BD but may function by interacting with genes directly related to BD. Our method engenders new thoughts on finding genes indirectly associated with, but important for, complex diseases.

Nonlinear model of a rotating hub-beams structure: Equations of motion

Science.gov (United States)

Warminski, Jerzy

2018-01-01

Dynamics of a rotating structure composed of a rigid hub and flexible beams is presented in the paper. A nonlinear model of a beam takes into account bending, extension and nonlinear curvature. The influence of geometric nonlinearity and nonconstant angular velocity on dynamics of the rotating structure is presented. The exact equations of motion and associated boundary conditions are derived on the basis of the Hamilton's principle. The simplification of the exact nonlinear mathematical model is proposed taking into account the second order approximation. The reduced partial differential equations of motion together with associated boundary conditions can be used to study natural or forced vibrations of a rotating structure considering constant or nonconstant angular speed of a rigid hub and an arbitrary number of flexible blades.

Diffusion trajectory of self-propagating innovations interacting with institutions-incorporation of multi-factors learning function to model PV diffusion in Japan

International Nuclear Information System (INIS)

Nagamatsu, Akira; Watanabe, Chihiro; Shum, Kwok L.

2006-01-01

This paper first proposes a modeling framework to study diffusion of innovations which exhibit strong interaction with the institution systems across which they diffuse. A unique character of such generic innovation is that specific applications are continually developed during its diffusion. This self-propagation in continual applications generation, which is dependent upon the cumulative installed base of the technological innovation, can be modeled to lead to a dynamic changing carrying capacity in an otherwise simple logistic diffusion curve. The cumulative installed base is dependent upon the price of technology and the cost learning dynamics. This paper utilizes a multi-factors learning function to represent such learning dynamics. Empirical estimates from our model are compared with those from other logistics curve formulations and are shown to better fit the annual PV production data during the past quarter century in the case of Japan. The very fact that the potential of this class of innovation can be leveraged only if it interacts closely with the institution highlights the importance of institutional determinants of adoption and diffusion of such innovations like PV. We therefore attempt to put forward an institutional framework, based on viewing PV as a technology platform, to consider PV diffusion beyond mathematical and empirical modeling. Some future research directions are also proposed. (author)

Evaluating neighborhood structures for modeling intercity diffusion of large-scale dengue epidemics.

Science.gov (United States)

Wen, Tzai-Hung; Hsu, Ching-Shun; Hu, Ming-Che

2018-05-03

Dengue fever is a vector-borne infectious disease that is transmitted by contact between vector mosquitoes and susceptible hosts. The literature has addressed the issue on quantifying the effect of individual mobility on dengue transmission. However, there are methodological concerns in the spatial regression model configuration for examining the effect of intercity-scale human mobility on dengue diffusion. The purposes of the study are to investigate the influence of neighborhood structures on intercity epidemic progression from pre-epidemic to epidemic periods and to compare definitions of different neighborhood structures for interpreting the spread of dengue epidemics. We proposed a framework for assessing the effect of model configurations on dengue incidence in 2014 and 2015, which were the most severe outbreaks in 70 years in Taiwan. Compared with the conventional model configuration in spatial regression analysis, our proposed model used a radiation model, which reflects population flow between townships, as a spatial weight to capture the structure of human mobility. The results of our model demonstrate better model fitting performance, indicating that the structure of human mobility has better explanatory power in dengue diffusion than the geometric structure of administration boundaries and geographic distance between centroids of cities. We also identified spatial-temporal hierarchy of dengue diffusion: dengue incidence would be influenced by its immediate neighboring townships during pre-epidemic and epidemic periods, and also with more distant neighbors (based on mobility) in pre-epidemic periods. Our findings suggest that the structure of population mobility could more reasonably capture urban-to-urban interactions, which implies that the hub cities could be a "bridge" for large-scale transmission and make townships that immediately connect to hub cities more vulnerable to dengue epidemics.

Electric wheel hub motor; Elektrischer Radnabenmotor

Energy Technology Data Exchange (ETDEWEB)

Groeninger, Michael; Kock, Alexander [IFAM Bremen (Germany); Horch, Felix [IFAM Bremen (Germany). Komponentenentwicklung; Pleteit, Hermann [IFAM Bremen (Germany). Abt. Giessereitechnologie und Komponentenentwicklung

2012-02-15

The bundled competences of the participating Fraunhofer Institutes have made it possible to develop a wheel hub motor that has essentially overcome currently existing technical hurdles, enabling its use in a vehicle. In addition to direct technical challenges such as sealing against external influences, high bearing stiffness requirements, necessary high torque densities and simple integration in the chassis, the safety aspects required by modern vehicles were also taken into account. A drive system that guarantees safe driving states, even in the case of malfunction, was developed through the combination of recuperative braking with a classic mechanical braking system and redundant motor design. (orig.)

Using hub technology to facilitate information system integration in a health-care enterprise.

Science.gov (United States)

Gendler, S M; Friedman, B A; Henricks, W H

1996-04-01

The deployment and maintenance of multiple point-to-point interfaces between a clinical information system, such as a laboratory information system, and other systems within a healthcare enterprise is expensive and time consuming. Moreover, the demand for such interfaces is increasing as hospitals consolidate and clinical laboratories participate in the development of regional laboratory networks and create host-to-host links with laboratory outreach clients. An interface engine, also called a hub, is an evolving technology that could replace multiple point-to-point interfaces from a laboratory information system with a single interface to the hub, preferably HL7 based. The hub then routes and translates laboratory information to other systems within the enterprise. Changes in application systems in an enterprise where a centralized interface engine has been implemented then amount to thorough analysis, an update of the enterprise's data dictionary, purchase of a single new vendor-supported interface, and table-based parameter changes on the hub. Two other features of an interface engine, support for structured query language and information store-and-forward, will facilitate the development of clinical data repositories and provide flexibility when interacting with other host systems. This article describes the advantages and disadvantages of an interface engine and lists some problems not solved by the technology. Finally, early developmental experience with an interface engine at the University of Michigan Medical Center and the benefits of the project on system integration efforts are described, not the least of which has been the enthusiastic adoption of the HL7 standard for all future interface projects.

Spectral Analysis of the Wake behind a Helicopter Rotor Hub

Science.gov (United States)

Petrin, Christopher; Reich, David; Schmitz, Sven; Elbing, Brian

2016-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48" Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. LDV and PIV measurements in the far-wake consistently showed a six-per-revolution flow structure, in addition to stronger two- and four-per-revolution structures. These six-per-revolution structures persisted into the far-field, and have no direct geometric counterpart on the hub model. The current study will examine the Reynolds number dependence of these structures and present higher-order statistics of the turbulence within the wake. In addition, current activity using the EFPL Large Water Tunnel at Oklahoma State University will be presented. This effort uses a more canonical configuration to identify the source for these six-per-revolution structures, which are assumed to be a non-linear interaction between the two- and four-per-revolution structures.

[What is "normal"? Maternal parenting behavior as risk and protective factor for psychopathology and identity diffusion].

Science.gov (United States)

Seiffge-Krenke, Inge; Escher, Fabian J

2018-06-01

What is "normal"? Maternal parenting behavior as risk and protective factor for psychopathology and identity diffusion Objectives: This study analyzes the implications of today's highly altered maternal parenting behaviors on children's development and psychological health. The relationship between maternal parenting behaviors (support, psychological control, and anxious monitoring) and delayed identity development or identity diffusion as well as internalizing or externalizing symptomatology was investigated in a sample of 732 youths (301 adolescents, 351 young adults, and 80 patients). Cluster analysis identified two types of maternal parenting behaviors: authoritative maternal behavior and dysfunctionalmaternal behavior. As expected, patients exhibited a high degree of dysfunctional maternal parenting behavior (low support, high psychological control), delayed identity development as well as elevated identity diffusion and symptomatology.Authoritative maternal parenting emerged as a protective factor in the prediction of identity diffusion and symptomatology.All three groups described a high degree of anxious maternal monitoring. The implications of changed maternal parenting behaviors on identity diffusion and symptomatology are discussed in light of societal changes and changing criteria of personality disorders in the new DSM-5.

On the interconnection of stable protein complexes: inter-complex hubs and their conservation in Saccharomyces cerevisiae and Homo sapiens networks.

Science.gov (United States)

Guerra, Concettina

2015-01-01

Protein complexes are key molecular entities that perform a variety of essential cellular functions. The connectivity of proteins within a complex has been widely investigated with both experimental and computational techniques. We developed a computational approach to identify and characterise proteins that play a role in interconnecting complexes. We computed a measure of inter-complex centrality, the crossroad index, based on disjoint paths connecting proteins in distinct complexes and identified inter-complex hubs as proteins with a high value of the crossroad index. We applied the approach to a set of stable complexes in Saccharomyces cerevisiae and in Homo sapiens. Just as done for hubs, we evaluated the topological and biological properties of inter-complex hubs addressing the following questions. Do inter-complex hubs tend to be evolutionary conserved? What is the relation between crossroad index and essentiality? We found a good correlation between inter-complex hubs and both evolutionary conservation and essentiality.

Modelling energy demand for a fleet of hydrogen-electric vehicles interacting with a clean energy hub

International Nuclear Information System (INIS)

Syed, F.; Fowler, M.; Wan, D.; Maniyali, Y.

2009-01-01

This paper details the development of an energy demand model for a hydrogen-electric vehicle fleet and the modelling of the fleet interactions with a clean energy hub. The approach taken is to model the architecture and daily operation of every individual vehicle in the fleet. A generic architecture was developed based on understanding gained from existing detailed models used in vehicle powertrain design, with daily operation divided into two periods: charging and travelling. During the charging period, the vehicle charges its Electricity Storage System (ESS) and refills its Hydrogen Storage System (HSS), and during the travelling period, the vehicle depletes the ESS and HSS based on distance travelled. Daily travel distance is generated by a stochastic model and is considered an input to the fleet model. The modelling of a clean energy hub is also presented. The clean energy hub functions as an interface between electricity supply and the energy demand (i.e. hydrogen and electricity) of the vehicle fleet. Finally, a sample case is presented to demonstrate the use of the fleet model and its implications on clean energy hub sizing. (author)

Factors Associated with Diffusely Increased Splenic F-18 FDG Uptake in Patients with Cholangiocarcinoma

Energy Technology Data Exchange (ETDEWEB)

Kim, Keunyoung; Kim, Seongjang; Kim, Injoo; Kim, Dong Uk; Kim, Heeyoung; Kim, Sojung; Ahn, Sang Hyun [Pusan National Univ. Hospital, Busan (Korea, Republic of)

2014-06-15

Although diffuse splenic {sup 18}F-fluorodeoxyglucose (F-18 FDG) uptake exceeding hepatic activity, is considered abnormal, its clinical significance is rarely discussed in the literature. The aim of this study was to determine the contributing factors causing diffusely increased splenic FDG uptake in patients with cholangiocarcinoma. From January 2010 to March 2013, 140 patients (84 men, 56 women) were enrolled in this study. All patients had been diagnosed with cholangiocarcinoma and underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) for the pretreatment staging work up. Clinical records were reviewed retrospectively. Various hematological parameters, C-reactive protein (CRP) level, CEA, CA19-9, pancreatic enzymes and liver function tests were conducted within 2 days after the F-18 FDG PET/CT study. Diffuse splenic uptake was observed in 23 patients (16.4%). Of those, 19 patients (82.6%) underwent endoscopic retrograde cholangiopancreastography (ERCP) 7 days before F-18 FDG PET/CT. The CRP level (p <0.001) and white blood cell count (p =0.023) were significantly higher in the group of patients with diffuse splenic FDG uptake. The hemoglobin (p <0.001) and the hematocrit (p <0.001) were significantly lower in patients with diffuse splenic FDG uptake. Pancreatic enzymes, liver function test results, and tumor markers were not significantly different between the patients who did or did not have diffusely increased splenic FDG uptake. The significant factors for diffuse splenic F-18 FDG uptake exceeding hepatic F-18 FDG uptake on multivariate analysis included: performing ERCP before F-18 FDG PET-CT (odds ratio [OR], 77.510; 95% CI, 7.624-132.105), and the presence of leukocytosis (OR, 12.436; 95% CI, 2.438-63.445) or anemia (OR, 1.211; 95% CI, 1.051-1.871). In conclusion, our study demonstrated that concurrent inflammation could be associated with diffusely increased splenic FDG uptake. We suggest that performing ERCP before F-18 FDG PET

Factors Associated with Diffusely Increased Splenic F-18 FDG Uptake in Patients with Cholangiocarcinoma

International Nuclear Information System (INIS)

Kim, Keunyoung; Kim, Seongjang; Kim, Injoo; Kim, Dong Uk; Kim, Heeyoung; Kim, Sojung; Ahn, Sang Hyun

2014-01-01

Although diffuse splenic 18 F-fluorodeoxyglucose (F-18 FDG) uptake exceeding hepatic activity, is considered abnormal, its clinical significance is rarely discussed in the literature. The aim of this study was to determine the contributing factors causing diffusely increased splenic FDG uptake in patients with cholangiocarcinoma. From January 2010 to March 2013, 140 patients (84 men, 56 women) were enrolled in this study. All patients had been diagnosed with cholangiocarcinoma and underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) for the pretreatment staging work up. Clinical records were reviewed retrospectively. Various hematological parameters, C-reactive protein (CRP) level, CEA, CA19-9, pancreatic enzymes and liver function tests were conducted within 2 days after the F-18 FDG PET/CT study. Diffuse splenic uptake was observed in 23 patients (16.4%). Of those, 19 patients (82.6%) underwent endoscopic retrograde cholangiopancreastography (ERCP) 7 days before F-18 FDG PET/CT. The CRP level (p <0.001) and white blood cell count (p =0.023) were significantly higher in the group of patients with diffuse splenic FDG uptake. The hemoglobin (p <0.001) and the hematocrit (p <0.001) were significantly lower in patients with diffuse splenic FDG uptake. Pancreatic enzymes, liver function test results, and tumor markers were not significantly different between the patients who did or did not have diffusely increased splenic FDG uptake. The significant factors for diffuse splenic F-18 FDG uptake exceeding hepatic F-18 FDG uptake on multivariate analysis included: performing ERCP before F-18 FDG PET-CT (odds ratio [OR], 77.510; 95% CI, 7.624-132.105), and the presence of leukocytosis (OR, 12.436; 95% CI, 2.438-63.445) or anemia (OR, 1.211; 95% CI, 1.051-1.871). In conclusion, our study demonstrated that concurrent inflammation could be associated with diffusely increased splenic FDG uptake. We suggest that performing ERCP before F-18 FDG PET

Visioning for secondary palliative care service hubs in rural communities: a qualitative case study from British Columbia's interior

Directory of Open Access Journals (Sweden)

Hanlon Neil

2009-10-01

Full Text Available Abstract Background As the populations of many developed nations continue to age at rapid rates it is becoming increasingly important to enhance palliative care service delivery in order to meet anticipated demand. Rural areas face a number of challenges in doing this, and thus dedicated attention must be given to determining how to best enhance service delivery in ways that are sensitive to their particular needs. The purposes of this article are to determine the vision for establishing secondary palliative care service hubs (SPCH in rural communities through undertaking a case study, and to ascertain the criteria that need to be considered when siting such hubs. Methods A rural region of British Columbia, Canada was selected for primary data collection, which took place over a five-month period in 2008. Formal and informal palliative care providers (n = 31 were interviewed. A purposeful recruitment strategy was used to maximize occupational and practice diversity. Interviews were conducted by phone using a semi-structured guide. Interviews were audio recorded and transcribed verbatim. Data were managed using NVivo8™ software and analyzed thematically, using investigator triangulation to strengthen interpretation. Results Four themes emerged from the dataset: (1 main SPCH features; (2 determining a location; (3 value-added outcomes; and (4 key considerations. It was found that participants generally supported implementing a SPCH in the rural region of focus. Several consistent messages emerged, including that: (1 SPCHs must create opportunities for two-way information exchange between specialists and generalists and communities; (2 SPCHs should diffuse information and ideas throughout the region, thus serving as a locus for education and a means of enhancing training opportunities; and (3 hubs need not be physical sites in the community (e.g., an office in a hospice or hospital, but may be virtual or take other forms based upon local needs

Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

Directory of Open Access Journals (Sweden)

Yi-Chang Wu

2013-01-01

Full Text Available The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.

A framework for creating an ICT knowledge hub in Zimbabwe: A holistic approach in fostering economic growth

Directory of Open Access Journals (Sweden)

Gilbert Mahlangu

2018-01-01

Full Text Available ICT knowledge hubs are important resources for a country to grow towards an innovative economy. Their growth has been viewed as a node point for techno-prenuership development and economic sustainability by many countries. The purpose of this study was to establish how Zimbabwe as a developing country should move towards the creation of an ICT knowledge hub that will promote economic growth in line with the Zimbabwe Agenda for Sustainable Socio-Economic Transformation (ZimAsset economic blueprint crafted in 2013. A qualitative research design was used whereby literature was conducted to establish models for ICT Knowledge hub creation while two focus group discussions were held with academia, research agents and software developers to achieve face validity and in-depth interviews were held with officials from The Ministry of ICT Postal and Courier services. The consensus was reached on the need for creating a focal point which will act as a cyber-port where ICT driven solutions can be obtained based on the industry needs. The focus group discussions settled for four components in creating an ICT knowledge hub. These are planning function, development function, management function and co-ordinating function. The research also established that the Ministry of ICT and Courier services in Zimbabwe has set up an innovation fund to encourage and reward innovation and craftsmanship in Zimbabwe mainly targeted at the youths. The government acquired the high-performance computing facility which is stationed at the University of Zimbabwe. The ICT hub should be used to facilitate access and use of this resource. Every country should therefore strive to create its own centre of innovation which enables it to gain maximum utility from its indigenous people in order to fully utilise ICTs for industry development and spearhead economic growth. The study recommends that there is need for establishing an ICT Knowledge hub in the country.

Channel Bonding in Linux Ethernet Environment using Regular Switching Hub

Directory of Open Access Journals (Sweden)

Chih-wen Hsueh

2004-06-01

Full Text Available Bandwidth plays an important role for quality of service in most network systems. There are many technologies developed to increase host bandwidth in a LAN environment. Most of them need special hardware support, such as switching hub that supports IEEE Link Aggregation standard. In this paper, we propose a Linux solution to increase the bandwidth between hosts with multiple network adapters connected to a regular switching hub. The approach is implemented as two Linux kernel modules in a LAN environment without modification to the hardware and operating systems on host machines. Packets are dispatched to bonding network adapters for transmission. The proposed approach is backward compatible, flexible and transparent to users and only one IP address is needed for multiple bonding network adapters. Evaluation experiments in TCP and UDP transmission are shown with bandwidth gain proportionally to the number of network adapters. It is suitable for large-scale LAN systems with high bandwidth requirement, such as clustering systems.

An Airlift Hub-and-Spoke Location-Routing Model with Time Windows: Case Study of the CONUS-to-Korea Airlift Problem

National Research Council Canada - National Science Library

Cox, David

1998-01-01

.... This study develops an alternative hub-and-spoke combined location-routing integer linear programming prototype model, and uses this model to determine what advantages a hub-and-spoke system offers...

Managing the cellular redox hub in photosynthetic organisms.

Science.gov (United States)

Foyer, Christine H; Noctor, Graham

2012-02-01

Light-driven redox chemistry is a powerful source of redox signals that has a decisive input into transcriptional control within the cell nucleus. Like photosynthetic electron transport pathways, the respiratory electron transport chain exerts a profound control over gene function, in order to balance energy (reductant and ATP) supply with demand, while preventing excessive over-reduction or over-oxidation that would be adversely affect metabolism. Photosynthetic and respiratory redox chemistries are not merely housekeeping processes but they exert a controlling influence over every aspect of plant biology, participating in the control of gene transcription and translation, post-translational modifications and the regulation of assimilatory reactions, assimilate partitioning and export. The number of processes influenced by redox controls and signals continues to increase as do the components that are recognized participants in the associated signalling pathways. A step change in our understanding of the overall importance of the cellular redox hub to plant cells has occurred in recent years as the complexity of the management of the cellular redox hub in relation to metabolic triggers and environmental cues has been elucidated. This special issue describes aspects of redox regulation and signalling at the cutting edge of current research in this dynamic and rapidly expanding field. © 2011 Blackwell Publishing Ltd.

Performance of high-area-ratio annular dump diffuser using suction-stabilized-vortex flow control

Science.gov (United States)

Juhasz, A. J.; Smith, J. M.

1977-01-01

A short annular dump diffuser having a geometry conductive to formation of suction stabilized toroidal vortices in the region of abrupt area change was tested. The overall diffuser area ratio was 4.0 and the length to inlet height ratio was 2.0. Performance data were obtained at near ambient temperature and pressure for inlet Mach numbers of 0.18 and 0.30 with suction rates ranging from 0 to 18 percent of total inlet mass flowrate. Results show that the exit velocity profile could be readily biased toward either wall by adjustment of inner and outer wall suction rates. Symmetric exit velocity profiles were inherently unstable with a tendency to revert to a hub or tip bias. Diffuser effectiveness was increased from about 38 percent without suction to over 85 percent at a total suction rate of 10 to 12 percent. At the same time diffuser total pressure loss was reduced from 3.1 percent to 1.1 percent at an inlet Mach number of 0.3.

Factors That Influence the Diffusion Process of Mobile Devices in Higher Education in Botswana and Namibia

Science.gov (United States)

Asino, Tutaleni I.

2015-01-01

This comparative study uses the Diffusion of Innovation (DoI) theoretical framework to explore factors that influence diffusion of mobile devices in higher education in Botswana and Namibia. The five attributes (Relative Avantage, Compatability, Complexity, Trialability, and Observability) of the persuasion stage, which have been found in previous…

A new transport hub

CERN Multimedia

Corinne Pralavorio

2016-01-01

CERN’s new Mobility Centre, allowing you to switch easily from one mode of transport to another, has just been officially opened.   Inauguration of the CERN Mobility Centre by Martin Steinacher, Director for Finance and Human Resources, and Lluis Miralles, Head of the SMB department. CERN’s new Mobility Centre, on the car park next to the Globe of Science and Innovation was officially opened on Tuesday, 22 March. The centre brings together all of CERN’s transport options in a single location. "Our aim is to create an intermodal hub where CERN users and personnel can switch from one mode of transport to another, and from CERN transport to public transport," explains Lluis Miralles, head of the Site Management and Buildings (SMB) department. The Mobility Centre incorporates the CERN bike and car rental services, the self-service car- and bike-sharing schemes, and SIXT car rental facilities (for long-distance journeys). It is located right ne...

Deconstructing Hub Drag. Part 2. Computational Development and Anaysis

Science.gov (United States)

2013-09-30

leveraged a Vertical Lift Consortium ( VLC )-funded hub drag scaling research effort. To confirm this objective, correlations are performed with the...Technology™ Demonstrator aircraft using an unstructured computational solver. These simpler faired elliptical geome- tries can prove to be challenging ...possible. However, additional funding was obtained from the Vertical Lift Consortium ( VLC ) to perform this study. This analysis is documented in

Characterization of a diffusible signaling factor from Xylella fastidiosa.

Science.gov (United States)

Beaulieu, Ellen D; Ionescu, Michael; Chatterjee, Subhadeep; Yokota, Kenji; Trauner, Dirk; Lindow, Steven

2013-01-08

Cell-cell signaling in Xylella fastidiosa has been implicated in the coordination of traits enabling colonization in plant hosts as well as insect vectors. This cell density-dependent signaling has been attributed to a diffusible signaling factor (DSF) produced by the DSF synthase RpfF. DSF produced by related bacterial species are unsaturated fatty acids, but that of X. fastidiosa was thought to be different from those of other taxa. We describe here the isolation and characterization of an X. fastidiosa DSF (XfDSF) as 2(Z)-tetradecenoic acid. This compound was isolated both from recombinant Erwinia herbicola expressing X. fastidiosa rpfF and from an X. fastidiosa rpfC deletion mutant that overproduces DSF. Since an rpfF mutant is impaired in biofilm formation and underexpresses the hemagglutinin-like protein-encoding genes hxfA and hxfB, we demonstrate that these traits can be restored by ca. 0.5 µM XfDSF but not by myristic acid, the fully saturated tetradecenoic acid. A phoA-based X. fastidiosa biosensor that assesses DSF-dependent expression of hxfA or hxfB revealed a high level of molecular specificity of DSF signaling. X. fastidiosa causes diseases in many important plants, including grape, where it incites Pierce's disease. Virulence of X. fastidiosa for grape is coordinated by cell-cell signaling molecules, designated DSF (Diffusible Signaling Factor). Mutants blocked in DSF production are hypervirulent for grape, suggesting that virulence is suppressed upon DSF accumulation and that disease could be controlled by artificial elevation of the DSF level in plants. In this work, we describe the isolation of the DSF produced by X. fastidiosa and the verification of its biological activity as an antivirulence factor. We also have developed X. fastidiosa DSF biosensors to evaluate the specificity of cell-cell signaling to be investigated.

Modelling and predicting electricity consumption in Spain using the stochastic Gamma diffusion process with exogenous factors

International Nuclear Information System (INIS)

Nafidi, A.; Gutiérrez, R.; Gutiérrez-Sánchez, R.; Ramos-Ábalos, E.; El Hachimi, S.

2016-01-01

The aim of this study is to model electric power consumption during a period of economic crisis, characterised by declining gross domestic product. A novel aspect of this study is its use of a Gamma-type diffusion process for short and medium-term forecasting – other techniques that have been used to describe such consumption patterns are not valid in this situation. In this study, we consider a new extension of the stochastic Gamma diffusion process by introducing time functions (exogenous factors) that affect its trend. This extension is defined in terms of Kolmogorov backward and forward equations. After obtaining the transition probability density function and the moments (specifically, the trend function), the inference on the process parameters is obtained by discrete sampling of the sample paths. Finally, this stochastic process is applied to model total net electricity consumption in Spain, when affected by the following set of exogenous factors: Gross Domestic Product (GDP), Gross Fixed Capital Formation (GFCF) and Final Domestic Consumption (FDC). - Highlights: • The aim is modelling and predicting electricity consumption in Spain. • We propose a Gamma-type diffusion process for short and medium-term forecasting. • We compared the fit using diffusion processes with different exogenous factors.

Dimensional consistency achieved in high-performance synchronizing hubs

International Nuclear Information System (INIS)

Garcia, P.; Campos, M.; Torralba, M.

2013-01-01

The tolerances of parts produced for the automotive industry are so tight that any small process variation may mean that the product does not fulfill them. As dimensional tolerances decrease, the material properties of parts are expected to be improved. Depending on the dimensional and material requirements of a part, different production routes are available to find robust processes, minimizing cost and maximizing process capability. Dimensional tolerances have been reduced in recent years, and as a result, the double pressing-double sintering production via ( 2 P2S ) has again become an accurate way to meet these increasingly narrow tolerances. In this paper, it is shown that the process parameters of the first sintering have great influence on the following production steps and the dimensions of the final parts. The roles of factors other than density and the second sintering process in defining the final dimensions of product are probed. All trials were done in a production line that produces synchronizer hubs for manual transmissions, allowing the maintenance of stable conditions and control of those parameters that are relevant for the product and process. (Author) 21 refs.

Cortical hubs form a module for multisensory integration on top of the hierarchy of cortical networks

Directory of Open Access Journals (Sweden)

Gorka Zamora-López

2010-03-01

Full Text Available Sensory stimuli entering the nervous system follow particular paths of processing, typically separated (segregated from the paths of other modal information. However, sensory perception, awareness and cognition emerge from the combination of information (integration. The corticocortical networks of cats and macaque monkeys display three prominent characteristics: (i modular organisation (facilitating the segregation, (ii abundant alternative processing paths and (iii the presence of highly connected hubs. Here, we study in detail the organisation and potential function of the cortical hubs by graph analysis and information theoretical methods. We find that the cortical hubs form a spatially delocalised, but topologically central module with the capacity to integrate multisensory information in a collaborative manner. With this, we resolve the underlying anatomical substrate that supports the simultaneous capacity of the cortex to segregate and to integrate multisensory information.

Determination of the separation factor of uranium isotopes by gaseous diffusion

International Nuclear Information System (INIS)

Bilous, O.; Counas, G.

1958-01-01

A 12-stage pilot separation cascade with a low output has been constructed to measure the separation factor of uranium isotopes by gaseous diffusion. The report describes some of the separation results obtained, and also provides information on the time necessary for equilibrium to be established and on the influence of various perturbations on the pressure profile in the cascade. (author) [fr

Assessing inspection sensitivity as it relates to damage tolerance in composite rotor hubs

Science.gov (United States)

Roach, Dennis P.; Rackow, Kirk

2001-08-01

Increasing niche applications, growing international markets, and the emergence of advanced rotorcraft technology are expected to greatly increase the population of helicopters over the next decade. In terms of fuselage fatigue, helicopters show similar trends as fixed-wing aircraft. The highly unsteady loads experienced by rotating wings not only directly affect components in the dynamic systems but are also transferred to the fixed airframe structure. Expanded use of rotorcraft has focused attention on the use of new materials and the optimization of maintenance practices. The FAA's Airworthiness Assurance Center (AANC) at Sandia National Labs has joined with Bell Helicopter andother agencies in the rotorcraft industry to evaluate nondestructive inspection (NDI) capabilities in light of the damage tolerance of assorted rotorcraft structure components. Currently, the program's emphasis is on composite rotor hubs. The rotorcraft industry is constantly evaluating new types of lightweight composite materials that not only enhance the safety and reliability of rotor components but also improve performance and extended operating life as well. Composite rotor hubs have led to the use of bearingless rotor systems that are less complex and require less maintenance than their predecessors. The test facility described in this paper allows the structural stability and damage tolerance of composite hubs to be evaluated using realistic flight load spectrums of centrifugal force and bending loads. NDI was integrated into the life-cycle fatigue tests in order to evaluate flaw detection sensitivity simultaneously wiht residual strength and general rotor hub peformance. This paper will describe the evolving use of damage tolerance analysis (DTA) to direct and improve rotorcraft maintenance along with the related use of nondestructive inspections to manage helicopter safety. OVeralll, the data from this project will provide information to improve the producibility, inspectability

The WaterHub at Emory University: Campus Resiliency through Decentralized Reuse.

Science.gov (United States)

Allison, Daniel; Lohan, Eric; Baldwin, Tim

2018-02-01

  In the spring of 2015, Emory University in Atlanta, GA, commissioned an innovative campuswide water reclamation and reuse system known as the WaterHub®. Treating up to 400,000 gallons each day, the system can recycle the equivalent of two-thirds of the University's wastewater production and reduce the campus water footprint by up to 40 percent.One of the first district-scale water reuse systems in North America, the WaterHub mines wastewater from the campus sewer system and repurposes it for beneficial reuse on campus. In its first year of operation, the facility has treated more than 80 million gallons of campus wastewater and is expected to save millions of dollars in utility costs for the University over the next 20 years. The system represents a new age in commercial-scale water management in which onsite, urban water reclamation facilities may be a new norm.

Giant hub Src and Syk tyrosine kinase thermodynamic profiles recapitulate evolution

Science.gov (United States)

Phillips, J. C.

2017-10-01

Thermodynamic scaling theory, previously applied mainly to small proteins, here analyzes quantitative evolution of the titled functional network giant hub enzymes. The broad domain structure identified homologically is confirmed hydropathically using amino acid sequences only. The most surprising results concern the evolution of the tyrosine kinase globular surface roughness from avians to mammals, which is first order, compared to the evolution within mammals from rodents to humans, which is second order. The mystery of the unique amide terminal region of proto oncogene tyrosine protein kinase is resolved by the discovery there of a rare hydroneutral septad targeting cluster, which is paralleled by an equally rare octad catalytic cluster in tyrosine kinase in humans and a few other species (cat and dog). These results, which go far towards explaining why these proteins are among the largest giant hubs in protein interaction networks, use no adjustable parameters.

Electrical hubs: An effective way to integrate non-dispatchable renewable energy sources with minimum impact to the grid

International Nuclear Information System (INIS)

Perera, A.T.D.; Nik, Vahid M.; Mauree, Dasaraden; Scartezzini, Jean-Louis

2017-01-01

Highlights: • A novel method introduced to optimize Electrical Hubs. • Novel dispatch based on fuzzy control and finite state machines. • Evaluating sensitivity of three performance indices for system autonomy. • Multi objective optimization considering system autonomy-cost. • Electrical Hubs can cover above 60% of the demand using wind and Solar PV. - Abstract: A paradigm change in energy system design tools, energy market, and energy policy is required to attain the target levels in renewable energy integration and in minimizing pollutant emissions in power generation. Integrating non-dispatchable renewable energy sources such as solar and wind energy is vital in this context. Distributed generation has been identified as a promising method to integrate Solar PV (SPV) and wind energy into grid in recent literature. Distributed generation using grid-tied electrical hubs, which consist of Internal Combustion Generator (ICG), non-dispatchable energy sources (i.e., wind turbines and SPV panels) and energy storage for providing the electricity demand in Sri Lanka is considered in this study. A novel dispatch strategy is introduced to address the limitations in the existing methods in optimizing grid-integrated electrical hubs considering real time pricing of the electricity grid and curtailments in grid integration. Multi-objective optimization is conducted for the system design considering grid integration level and Levelized Energy Cost (LEC) as objective functions to evaluate the potential of electrical hubs to integrate SPV and wind energy. The sensitivity of grid curtailments, energy market, price of wind turbines and SPV panels on Pareto front is evaluated subsequently. Results from the Pareto analysis demonstrate the potential of electrical hubs to cover more than 60% of the annual electricity demand from SPV and wind energy considering stringent grid curtailments. Such a share from SPV and wind energy is quite significant when compared to direct grid

CER Hub: An informatics platform for conducting comparative effectiveness research using multi-institutional, heterogeneous, electronic clinical data.

Science.gov (United States)

Hazlehurst, Brian L; Kurtz, Stephen E; Masica, Andrew; Stevens, Victor J; McBurnie, Mary Ann; Puro, Jon E; Vijayadeva, Vinutha; Au, David H; Brannon, Elissa D; Sittig, Dean F

2015-10-01

Comparative effectiveness research (CER) requires the capture and analysis of data from disparate sources, often from a variety of institutions with diverse electronic health record (EHR) implementations. In this paper we describe the CER Hub, a web-based informatics platform for developing and conducting research studies that combine comprehensive electronic clinical data from multiple health care organizations. The CER Hub platform implements a data processing pipeline that employs informatics standards for data representation and web-based tools for developing study-specific data processing applications, providing standardized access to the patient-centric electronic health record (EHR) across organizations. The CER Hub is being used to conduct two CER studies utilizing data from six geographically distributed and demographically diverse health systems. These foundational studies address the effectiveness of medications for controlling asthma and the effectiveness of smoking cessation services delivered in primary care. The CER Hub includes four key capabilities: the ability to process and analyze both free-text and coded clinical data in the EHR; a data processing environment supported by distributed data and study governance processes; a clinical data-interchange format for facilitating standardized extraction of clinical data from EHRs; and a library of shareable clinical data processing applications. CER requires coordinated and scalable methods for extracting, aggregating, and analyzing complex, multi-institutional clinical data. By offering a range of informatics tools integrated into a framework for conducting studies using EHR data, the CER Hub provides a solution to the challenges of multi-institutional research using electronic medical record data. Copyright © 2015. Published by Elsevier Ireland Ltd.

Diffusion in the presence of a local attracting factor: Theory and interdisciplinary applications

Science.gov (United States)

Veermäe, Hardi; Patriarca, Marco

2017-06-01

In many complex diffusion processes the drift of random walkers is not caused by an external force, as in the case of Brownian motion, but by local variations of fitness perceived by the random walkers. In this paper, a simple but general framework is presented that describes such a type of random motion and may be of relevance in different problems, such as opinion dynamics, cultural spreading, and animal movement. To this aim, we study the problem of a random walker in d dimensions moving in the presence of a local heterogeneous attracting factor expressed in terms of an assigned position-dependent "attractiveness function." At variance with standard Brownian motion, the attractiveness function introduced here regulates both the advection and diffusion of the random walker, thus providing testable predictions for a specific form of fluctuation-relations. We discuss the relation between the drift-diffusion equation based on the attractiveness function and that describing standard Brownian motion, and we provide some explicit examples illustrating its relevance in different fields, such as animal movement, chemotactic diffusion, and social dynamics.

Improved vascularization of planar membrane diffusion devices following continuous infusion of vascular endothelial growth factor.

Science.gov (United States)

Trivedi, N; Steil, G M; Colton, C K; Bonner-Weir, S; Weir, G C

2000-01-01

Improving blood vessel formation around an immunobarrier device should improve the survival of the encapsulated tissue. In the present study we investigated the formation of new blood vessels around a planar membrane diffusion device (the Baxter Theracyte System) undergoing a continuous infusion of vascular endothelial growth factor through the membranes and into the surrounding tissue. Each device (20 microl) had both an inner immunoisolation membrane and an outer vascularizing membrane. Human recombinant vascular endothelial growth factor-165 was infused at 100 ng/day (low dose: n = 6) and 500 ng/day (high dose: n = 7) for 10 days into devices implanted s.c. in Sprague-Dawley rats; noninfused devices transplanted for an identical period were used as controls (n = 5). Two days following the termination of VEGF infusion, devices were loaded with 20 microl of Lispro insulin (1 U/kg) and the kinetics of insulin release from the lumen of the device was assessed. Devices were then explanted and the number of blood vessels (capillary and noncapillary) was quantified using morphometry. High-dose vascular endothelial growth factor infusion resulted in two- to threefold more blood vessels around the device than that obtained with the noninfused devices and devices infused with low-dose vascular endothelial growth factor. This increase in the number of blood vessels was accompanied by a modest increase in insulin diffusion from the device in the high-dose vascular endothelial growth factor infusion group. We conclude that vascular endothelial growth factor can be used to improve blood vessel formation adjacent to planar membrane diffusion devices.

Changed hub and corresponding functional connectivity of subgenual anterior cingulate cortex in major depressive disorder

Directory of Open Access Journals (Sweden)

Huawang Wu

2016-12-01

Full Text Available Major depressive disorder (MDD is one of the most prevalent mental disorders. In the brain, the hubs of the brain network play a key role in integrating and transferring information between different functional modules. However, whether the changed pattern in functional network hubs contributes to the onset of MDD remains unclear. Using resting-state functional magnetic resonance imaging and graph theory methods, we investigated whether alterations of hubs can be detected in MDD. First, we constructed the whole-brain voxel-wise functional networks and calculated a functional connectivity strength (FCS map in each subject in 34 MDD patients and 34 gender-, age-, and education level-matched healthy controls (HC. Next, the two-sample t-test was applied to compare the FCS maps between HC and MDD patients and identified significant decreased FCS in subgenual anterior cingulate cortex (sgACC in MDD patients. Subsequent functional connectivity analyses of sgACC showed disruptions in functional connectivity with posterior insula, middle and inferior temporal gyrus, lingual gyrus, and cerebellum in MDD patients. Furthermore, the changed FCS of sgACC and functional connections to sgACC were significantly correlated with the Hamilton Depression Rating Scale (HDRS scores in MDD patients. The results of the present study revealed the abnormal hub of sgACC and its corresponding disrupted frontal-limbic-visual cognitive-cerebellum functional networks in MDD. These findings may provide a new insight for the diagnosis and treatment of MDD.

Using the CER Hub to ensure data quality in a multi-institution smoking cessation study.

Science.gov (United States)

Walker, Kari L; Kirillova, Olga; Gillespie, Suzanne E; Hsiao, David; Pishchalenko, Valentyna; Pai, Akshatha Kalsanka; Puro, Jon E; Plumley, Robert; Kudyakov, Rustam; Hu, Weiming; Allisany, Art; McBurnie, MaryAnn; Kurtz, Stephen E; Hazlehurst, Brian L

2014-01-01

Comparative effectiveness research (CER) studies involving multiple institutions with diverse electronic health records (EHRs) depend on high quality data. To ensure uniformity of data derived from different EHR systems and implementations, the CER Hub informatics platform developed a quality assurance (QA) process using tools and data formats available through the CER Hub. The QA process, implemented here in a study of smoking cessation services in primary care, used the 'emrAdapter' tool programmed with a set of quality checks to query large samples of primary care encounter records extracted in accord with the CER Hub common data framework. The tool, deployed to each study site, generated error reports indicating data problems to be fixed locally and aggregate data sharable with the central site for quality review. Across the CER Hub network of six health systems, data completeness and correctness issues were prevalent in the first iteration and were considerably improved after three iterations of the QA process. A common issue encountered was incomplete mapping of local EHR data values to those defined by the common data framework. A highly automated and distributed QA process helped to ensure the correctness and completeness of patient care data extracted from EHRs for a multi-institution CER study in smoking cessation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Comparing the demographic factors of patient with limited and diffuse type of alopecia areata

Directory of Open Access Journals (Sweden)

Mina Daliri

2010-09-01

Full Text Available Background: Alopecia areata is a chronic inflammatory disease that involves the hair follicle. Clinically, patients with alopecia areata may have patchy or confluent hair loss on the scalp or body so we conduct a study to compare the demographic aspects of patient with limited and diffuse type of alopecia areata.Materials and Method: We conducted a descriptive-analyzing study in which 306 patient were chosen. The patients were divided into two groups of diffuse and limited Alopecia. Demographic factors including age, gender, disease onset were compared in two groups. Results: Out of 306 patients, 58.8 % were male and 41.2 % were female. 247 patients (80.7% suffered from limited type and 59 patients (19.2% suffered from diffuse type. The mean age of the onset of involvement in limited group was 21.9±12 yr and 15.8±12 yr in diffuse group. The mean duration of involvement in limited group was 18.7 months and 71 months in diffuse group. Conclusion: Diffuse type alopecia areata starts at lower age and has longer duration. Our study results were similar to the others. Like other studies, thyroid disorders and atopic dermatitis are positively correlative to the severity of disease

From hub proteins to hub modules: the relationship between essentiality and centrality in the yeast interactome at different scales of organization.

Directory of Open Access Journals (Sweden)

Jimin Song

Full Text Available Numerous studies have suggested that hub proteins in the S. cerevisiae physical interaction network are more likely to be essential than other proteins. The proposed reasons underlying this observed relationship between topology and functioning have been subject to some controversy, with recent work suggesting that it arises due to the participation of hub proteins in essential complexes and processes. However, do these essential modules themselves have distinct network characteristics, and how do their essential proteins differ in their topological properties from their non-essential proteins? We aimed to advance our understanding of protein essentiality by analyzing proteins, complexes and processes within their broader functional context and by considering physical interactions both within and across complexes and biological processes. In agreement with the view that essentiality is a modular property, we found that the number of intracomplex or intraprocess interactions that a protein has is a better indicator of its essentiality than its overall number of interactions. Moreover, we found that within an essential complex, its essential proteins have on average more interactions, especially intracomplex interactions, than its non-essential proteins. Finally, we built a module-level interaction network and found that essential complexes and processes tend to have higher interaction degrees in this network than non-essential complexes and processes; that is, they exhibit a larger amount of functional cross-talk than their non-essential counterparts.

From “Comprehensive Transportation Hub” to “City New Sitting Room”---Overall the design about Jinan East district comprehensive transportation hub

Science.gov (United States)

Lv, Jie; Guo, Jianmin; Li, Jin

2017-08-01

integrated transport hub or high-speed rail station often talked about, often known as the “city portal” and the title of “city window”, so the comprehensive transportation hub or the high-speed rail station of a city is very important to a region or a provincial. At the same time, it reflects that the managers and users of a city only focus on the comprehensive transportation hub of transportation service function and ignore her cities attributes and functions. Jinan east district comprehensive transportation hub in the beginning of design is given a feature that it has to serve both the traffic and city. We are trying to build a new center for Jinan east new town, the window to welcome people, the city hall of hospitality.

National Geothermal Data System Hub Deployment Timeline (Appendix E-1-d)

Energy Technology Data Exchange (ETDEWEB)

Caudill, Christy [Executive Office of the State of Arizona (Arizona Geological Survey)

2015-12-20

Excel spreadsheet describing activity, spending, and development for the four data hubs (Arizona Geoloical Survey, Kentucky Geological Survey, Illinois Geological Survey, and Nevada Bureau of Mines and Geology) serving data for the National Geothermal Data System under the State Contributions to the National Geothermal Data System Project.

Fleet deployment, network design and hub location of liner shipping companies

DEFF Research Database (Denmark)

Gelareh, Shahin; Pisinger, David

2011-01-01

A mixed integer linear programming formulation is proposed for the simultaneous design of network and fleet deployment of a deep-sea liner service provider. The underlying network design problem is based on a 4-index (5-index by considering capacity type) formulation of the hub location problem...

Analysis of 2D Torus and Hub Topologies of 100Mb/s Ethernet for the Whitney Commodity Computing Testbed

Science.gov (United States)

Pedretti, Kevin T.; Fineberg, Samuel A.; Kutler, Paul (Technical Monitor)

1997-01-01

A variety of different network technologies and topologies are currently being evaluated as part of the Whitney Project. This paper reports on the implementation and performance of a Fast Ethernet network configured in a 4x4 2D torus topology in a testbed cluster of 'commodity' Pentium Pro PCs. Several benchmarks were used for performance evaluation: an MPI point to point message passing benchmark, an MPI collective communication benchmark, and the NAS Parallel Benchmarks version 2.2 (NPB2). Our results show that for point to point communication on an unloaded network, the hub and 1 hop routes on the torus have about the same bandwidth and latency. However, the bandwidth decreases and the latency increases on the torus for each additional route hop. Collective communication benchmarks show that the torus provides roughly four times more aggregate bandwidth and eight times faster MPI barrier synchronizations than a hub based network for 16 processor systems. Finally, the SOAPBOX benchmarks, which simulate real-world CFD applications, generally demonstrated substantially better performance on the torus than on the hub. In the few cases the hub was faster, the difference was negligible. In total, our experimental results lead to the conclusion that for Fast Ethernet networks, the torus topology has better performance and scales better than a hub based network.

Turbulence measurements in the inlet plane of a centrifugal compressor vaneless diffuser

International Nuclear Information System (INIS)

Pinarbasi, Ali

2009-01-01

Detailed flow measurements at the inlet of a centrifugal compressor vaneless diffuser are presented. The mean 3-d velocities and six Reynolds stress components tensor are used to determine the turbulence production terms which lead to total pressure loss. High levels of turbulence kinetic energy were observed in both the blade and passage wakes, but these were only associated with high Reynolds stresses in the blade wakes. For this reason the blade wakes mixed out rapidly, whereas the passage wake maintained its size, but was redistributed across the full length of the shroud wall. Peak levels of Reynolds stress occurred in regions of high velocity shear and streamline curvature which would tend to destabilize the shear gradient. Four regions in the flow are identified as potential sources of loss - the blade wake, the shear layers between passage wake and jet, the thickened hub boundary layer and the interaction region between the secondary flow within the blade wake and the passage vortex. The blade wakes generate most turbulence, with smaller contributions from the hub boundary layer and secondary flows, but no significant contribution is apparent from the passage wake shear layers.

Evaluating a European knowledge hub on climate change in agriculture: Are we building a better connected community?

Science.gov (United States)

Saetnan, Eli Rudinow; Kipling, Richard Philip

In order to maintain food security and sustainability of production under climate change, interdisciplinary and international collaboration in research is essential. In the EU, knowledge hubs are important funding instruments for the development of an interconnected European Research Area. Here, network analysis was used to assess whether the pilot knowledge hub MACSUR has affected interdisciplinary collaboration, using co-authorship of peer reviewed articles as a measure of collaboration. The broad community of all authors identified as active in the field of agriculture and climate change was increasingly well connected over the period studied. Between knowledge hub members, changes in network parameters suggest an increase in collaborative interaction beyond that expected due to network growth, and greater than that found in the broader community. Given that interdisciplinary networks often take several years to have an impact on research outputs, these changes within the relatively new MACSUR community provide evidence that the knowledge hub structure has been effective in stimulating collaboration. However, analysis showed that knowledge hub partners were initially well-connected, suggesting that the initiative may have gathered together researchers with particular resources or inclinations towards collaborative working. Long term, consistent funding and ongoing reflection to improve networking structures may be necessary to sustain the early positive signs from MACSUR, to extend its success to a wider community of researchers, or to repeat it in less connected fields of science. Tackling complex challenges such as climate change will require research structures that can effectively support and utilise the diversity of talents beyond the already well-connected core of scientists at major research institutes. But network research shows that this core, well-connected group are vital brokers in achieving wider integration.

Sustaining the Higher Education Hub Model: The Challenge of Adequate Academic and Social Support Structures for International Students

Directory of Open Access Journals (Sweden)

Cameron Richards

2011-11-01

Full Text Available In recent years, the Education Hub (EH concept has perhaps become the single most important focus of higher education policy in most Asian countries. A particular Asian Education Hub model (e.g. Cheng, 2010 is now globally influential with its emphasis on how governments can harness direct as well as indirect economic benefits of a higher education system. Such a model aims to prepare students for employment in an emerging global economy and also to attract fee-paying international students in terms of education as not just a public good but a key and increasingly important area of national investment and economic development. In a related paper which focused on a comparison between distinct Malaysian and Singaporean versions of Asian EH l models developed over the last two decades (Richards, 2011c, we investigated the dangers as well as opportunities at stake. In this paper, we investigate the linked idea that sufficient academic and social support structures for supporting international as well as local students provide the crucial key to the factors of sustainability needed to support the various versions of the general strategy of Higher Education internationalisation.

Virtual Campus Hub: A single sign-on system for cross-border collaboration

DEFF Research Database (Denmark)

Badger, Merete; Vercoulen, F.; Monaco, L.

2013-01-01

laboratory exercises, examination tools, courses, collaboration tools, and tools to support the incubation of new small or medium size enterprises (SMEs). All of the applications serve as use cases for the demonstration of how the technology behind Virtual Campus Hub works. They can be accessed via...... in connection with joint educational programs and courses. These experiences are gained through a series of virtual events where users from the partners are invited to test each other’s applications. So far, testing of remote laboratory exercises, examination tools and an online course in wind energy has shown......Four technical universities in Europe work together in the EU-funded project Virtual Campus Hub (FP7 RI-283746, www.virtualcampushub.eu) to lower the technical barriers for cross-border collaboration. Universities have many connections to the outside world (e.g. to other universities, to joint...

Control networks and hubs.

Science.gov (United States)

Gratton, Caterina; Sun, Haoxin; Petersen, Steven E

2018-03-01

Executive control functions are associated with frontal, parietal, cingulate, and insular brain regions that interact through distributed large-scale networks. Here, we discuss how fMRI functional connectivity can shed light on the organization of control networks and how they interact with other parts of the brain. In the first section of our review, we present convergent evidence from fMRI functional connectivity, activation, and lesion studies that there are multiple dissociable control networks in the brain with distinct functional properties. In the second section, we discuss how graph theoretical concepts can help illuminate the mechanisms by which control networks interact with other brain regions to carry out goal-directed functions, focusing on the role of specialized hub regions for mediating cross-network interactions. Again, we use a combination of functional connectivity, lesion, and task activation studies to bolster this claim. We conclude that a large-scale network perspective provides important neurobiological constraints on the neural underpinnings of executive control, which will guide future basic and translational research into executive function and its disruption in disease. © 2017 Society for Psychophysiological Research.

Application of atmospheric diffusion factor in the bay of east Liaoning

International Nuclear Information System (INIS)

Yang Hongbin; Liu Wanjun; Ma Yanjun; Zhao Guozhen

1999-01-01

The characteristics of atmospheric diffusion factor in the Bay of East Liaoning are studied using the data obtained from meteorological tower-based sensors at the site located about 800 m from the coast. The results show that the nuclear power station emits pollutants as a high source during its operation. Furthermore, it is found that the lifting level of plume is lower than 30 m when wind speed is greater

Additional Value of Diffusion-Weighted Imaging to Evaluate Prognostic Factors of Breast Cancer: Correlation with the Apparent Diffusion Coefficient

International Nuclear Information System (INIS)

Park, Eun Kyung; Cho, Kyu Ran; Seo, Bo Kyoung; Woo, Ok Hee; Cho, Sung Bum; Bae, Jeoung Won

2016-01-01

Breast cancer is a heterogeneous disease with diverse prognoses. The main prognostic determinants are lymph node status, tumor size, histological grade, and biological factors, such as hormone receptors, human epidermal growth factor receptor 2 (HER2), Ki-67 protein levels, and p53 expression. Diffusion-weighted imaging (DWI) can be used to measure the apparent diffusion coefficient (ADC) that provides information related to tumor cellularity and the integrity of the cell membranes. The goal of this study was to evaluate whether ADC measurements could provide information on the prognostic factors of breast cancer. A total of 71 women with invasive breast cancer, treated consecutively, who underwent preoperative breast MRIs with DWI at 3.0 Tesla and subsequent surgery, were prospectively included in this study. Each DWI was acquired with b values of 0 and 1000 s/mm 2 . The mean ADC values of the lesions were measured, including the entire lesion on the three largest sections. We performed histopathological analyses for the tumor size, lymph node status, histological grade, hormone receptors, human epidermal growth factor receptor 2 (HER2), Ki-67, p53, and molecular subtypes. The associations with the ADC values and prognostic factors of breast cancer were evaluated using the independent-samples t test and the one-way analysis of variance (ANOVA). A low ADC value was associated with lymph node metastasis (P < 0.01) and with high Ki-67 protein levels (P = 0.03). There were no significant differences in the ADC values among the histological grade (P = 0.48), molecular subtype (P = 0.51), tumor size (P = 0.46), and p53 protein level (P = 0.62). The pre-operative use of the 3.0 Tesla DWI could provide information about the lymph node status and tumor proliferation for breast cancer patients, and could help determine the optimal treatment plan

Perceptions of Quality Life in Hamilton's Neighbourhood Hubs: A Qualitative Analysis

Science.gov (United States)

Eby, Jeanette; Kitchen, Peter; Williams, Allison

2012-01-01

This paper examines perceptions of quality of life in Hamilton, Ontario, Canada from the perspective of residents and key community stakeholders. A series of eight focus groups were conducted. Six sessions were held with residents of neighbourhood "hubs", areas characterized by high levels of poverty. The following themes were…

Schools as Community Hubs: Policy Contexts, Educational Rationales, and Design Challenges

Science.gov (United States)

McShane, Ian; Watkins, Jerry; Meredyth, Denise

2012-01-01

There is increasing interest in making more effective use of schools as community hubs, both in Australia and internationally. Investment in shared facilities aims to engage parents and local communities in schooling, encourage civic participation, co-ordinate educational and community services and overcome disadvantages of location or service…

Design and Development of an Integrated Workstation Automation Hub

Energy Technology Data Exchange (ETDEWEB)

Weber, Andrew; Ghatikar, Girish; Sartor, Dale; Lanzisera, Steven

2015-03-30

Miscellaneous Electronic Loads (MELs) account for one third of all electricity consumption in U.S. commercial buildings, and are drivers for a significant energy use in India. Many of the MEL-specific plug-load devices are concentrated at workstations in offices. The use of intelligence, and integrated controls and communications at the workstation for an Office Automation Hub – offers the opportunity to improve both energy efficiency and occupant comfort, along with services for Smart Grid operations. Software and hardware solutions are available from a wide array of vendors for the different components, but an integrated system with interoperable communications is yet to be developed and deployed. In this study, we propose system- and component-level specifications for the Office Automation Hub, their functions, and a prioritized list for the design of a proof-of-concept system. Leveraging the strength of both the U.S. and India technology sectors, this specification serves as a guide for researchers and industry in both countries to support the development, testing, and evaluation of a prototype product. Further evaluation of such integrated technologies for performance and cost is necessary to identify the potential to reduce energy consumptions in MELs and to improve occupant comfort.

Regional Hub port development : the case of Montevideo, Uruguay

OpenAIRE

Wilmsmeier, Gordon; Martínez Zarzoso, Inmaculada; Fiess, Norbert

2011-01-01

This paper reflects on port development in Uruguay in an environment of trilateral interport competition. The regional characteristics of port development in terms of their geographical, functional and operational characteristics are discussed by analysing the port system’s evolution. The case of Montevideo as the success or failure of a regional hub port development strategy is analysed in detail. Particular attention is given to the evolution and impact of the liner shipping service network...

Environmental and self-sufficiency assessment of the energy metabolism of tourist hubs on Mediterranean Islands: The case of Menorca (Spain)

International Nuclear Information System (INIS)

Sanyé-Mengual, Esther; Romanos, Héctor; Molina, Catalina; Oliver, M. Antònia; Ruiz, Núria; Pérez, Marta; Carreras, David; Boada, Martí; Garcia-Orellana, Jordi; Duch, Jordi; Rieradevall, Joan

2014-01-01

Energy performance of island tourism has been analyzed in the literature. However, tourist services tend to concentrate in tourist hubs, especially where mass tourism predominates (e.g., Mediterranean), and the energy metabolism of these systems has not yet been assessed. The present paper models and estimates the energy metabolism of tourist hubs in the Menorca Island (Spain) by integrating social, geographical and environmental methods. Mobility (both external and internal) and consumption of lodging services were characterized through surveys to users (tourists) and business managers. An environmental assessment evaluated CO 2 emissions, and energy self-sufficiency potential was estimated via GIS data. The results indicate that, on average, a tourist consumes 4756 MJ with associated emissions of 277 kg of CO 2 per stay (20 days on average). Of all the energy flows, external mobility contributes the most to total emissions (77%). For every day spent in a tourist hub, a tourist consumes between 29 MJ and 93 MJ in lodging services, consumption that could be 100% satisfied by photovoltaic systems, and these systems would result in positive effects for the island. Sustainable tourism management might focus on promoting environmentally friendly transportation, energy efficient practices, and environmental communication through ecolabeling. - Highlights: • We modeled the entire energy metabolism of tourist hubs in islands. • Results showed that a tourist in Menorca consumes from 4000 to 6000 MJ per trip. • External mobility (trip to the island) accounts for 77% of the total CO 2 emissions. • Photovoltaic systems could provide enough power to achieve self-sufficiency. • Tourists at hotel hubs have higher energy consumption than other types of hubs

Graph theory reveals dysconnected hubs in 22q11DS and altered nodal efficiency in patients with hallucinations

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Marie-Christine eOttet

2013-09-01

Full Text Available Schizophrenia is postulated to be the prototypical dysconnection disorder, in which hallucinations are the core symptom. Due to high heterogeneity in methodology across studies and the clinical phenotype, it remains unclear whether the structural brain dysconnection is global or focal and if clinical symptoms result from this dysconnection. In the present work, we attempt to clarify this issue by studying a population considered as a homogeneous genetic sub-type of schizophrenia, namely the 22q11.2 deletion syndrome (22q11.2DS. Cerebral MRIs were acquired for 46 patients and 48 age and gender matched controls (aged 6 to 26, respectively mean age = 15.20 ± 4.53 and 15.28 ± 4.35 years old. Using the Connectome mapper pipeline (connectomics.org that combines structural and diffusion MRI, we created a whole brain network for each individual. The graph theory was used to quantify the global and local properties in the brain network organization for each participant. A global degree loss of 6% was found in patients’ network along with an increased Characteristic Path Length. After identifying and comparing hubs, a significant loss of degree in patients’ hubs was found in 58% of them. Based on Allen’s brain network model for hallucinations, we explored the association between local efficiency and symptom severity. Negative correlations were found in the Broca’s area (p<0.004, the Wernicke area (p<0.023 and a positive correlation was found in the dorsolateral prefrontal cortex (DLPFC (p<0.014. In line with the dysconnection findings in schizophrenia, our results provide preliminary evidence for a targeted alteration in the brain network hubs’organisation in individuals with a genetic risk for schizophrenia. The study of specific disorganization in language, speech and thought regulation networks sharing similar network properties may help to understand their role in the hallucination mechanism.

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

N.K. Olver (Neil)

2014-01-01

htmlabstractRobust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. The notion of "hierarchical hubbing" was introduced (in the narrow context of a specific robust network design question), by Olver and Shepherd

A note on hierarchical hubbing for a generalization of the VPN problem

NARCIS (Netherlands)

Olver, N.K.

2014-01-01

Robust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. The notion of "hierarchical hubbing" was introduced (in the narrow context of a specific robust network design question), by Olver and Shepherd [2010].

Dipy, a library for the analysis of diffusion MRI data.

Science.gov (United States)

Garyfallidis, Eleftherios; Brett, Matthew; Amirbekian, Bagrat; Rokem, Ariel; van der Walt, Stefan; Descoteaux, Maxime; Nimmo-Smith, Ian

2014-01-01

Diffusion Imaging in Python (Dipy) is a free and open source software project for the analysis of data from diffusion magnetic resonance imaging (dMRI) experiments. dMRI is an application of MRI that can be used to measure structural features of brain white matter. Many methods have been developed to use dMRI data to model the local configuration of white matter nerve fiber bundles and infer the trajectory of bundles connecting different parts of the brain. Dipy gathers implementations of many different methods in dMRI, including: diffusion signal pre-processing; reconstruction of diffusion distributions in individual voxels; fiber tractography and fiber track post-processing, analysis and visualization. Dipy aims to provide transparent implementations for all the different steps of dMRI analysis with a uniform programming interface. We have implemented classical signal reconstruction techniques, such as the diffusion tensor model and deterministic fiber tractography. In addition, cutting edge novel reconstruction techniques are implemented, such as constrained spherical deconvolution and diffusion spectrum imaging (DSI) with deconvolution, as well as methods for probabilistic tracking and original methods for tractography clustering. Many additional utility functions are provided to calculate various statistics, informative visualizations, as well as file-handling routines to assist in the development and use of novel techniques. In contrast to many other scientific software projects, Dipy is not being developed by a single research group. Rather, it is an open project that encourages contributions from any scientist/developer through GitHub and open discussions on the project mailing list. Consequently, Dipy today has an international team of contributors, spanning seven different academic institutions in five countries and three continents, which is still growing.

The hub-and-spoke organization design revisited: a lifeline for rural hospitals.

Science.gov (United States)

Elrod, James K; Fortenberry, John L

2017-12-13

Characterized by declining populations, high poverty, reduced employment opportunities, and high numbers of uninsured residents, rural communities pose significant challenges for healthcare providers desirous of addressing these medically underserved areas. Such difficult environments, in fact, have forced the closure of many rural hospitals across America, with scores facing the same threat, compelling intensive efforts to identify pathways which will yield an improved future. Collaborations with stronger urban or suburban healthcare institutions offer a prudent avenue for rural hospitals to continue serving their patients. Such relationships can be structured in many different ways, but Willis-Knighton Health System found that its use of the hub-and-spoke organization design set the stage for the institution to cast a vital lifeline to neighboring rural hospitals, affording the relatively seamless integration and assimilation of partner facilities into its network, ensuring continuity of services in remote regions. This article supplies an overview of the hub-and-spoke network and discusses Willis-Knighton Health System's use of it to facilitate the establishment of productive partnerships with rural hospitals. The delivery of healthcare services in rural environments is essential, but with small community hospitals increasingly being under threat, the outlook is not particularly attractive. Partnerships with better positioned healthcare entities offer significant hope, but care must be taken to structure these arrangements optimally. Willis-Knighton Health System found utility and value in its hub-and-spoke organization design, with the insights presented in this account potentially offering a pathway for others to follow as they go about addressing the healthcare needs of rural populations.

Dipy, a library for the analysis of diffusion MRI data

Directory of Open Access Journals (Sweden)

Eleftherios eGaryfallidis

2014-02-01

Full Text Available Diffusion Imaging in Python (Dipy is a free and open source software projectfor the analysis of data from diffusion magnetic resonance imaging (dMRIexperiments. dMRI is an application of MRI that can be used to measurestructural features of brain white matter. Many methods have been developed touse dMRI data to model the local configuration of white matter nerve fiberbundles and infer the trajectory of bundles connecting different parts of thebrain.Dipy gathers implementations of many different methods in dMRI, including:diffusion signal pre-processing; reconstruction of diffusion distributions inindividual voxels; fiber tractography and fiber track post-processing, analysisand visualization. Dipy aims to provide transparent implementations forall the different steps of dMRI analysis with a uniform programming interface.We have implemented classical signal reconstruction techniques, such as thediffusion tensor model and deterministic fiber tractography. In addition,cutting edge novel reconstruction techniques are implemented, such asconstrained spherical deconvolution and diffusion spectrum imaging withdeconvolution, as well as methods for probabilistic tracking and originalmethods for tractography clustering. Many additional utility functions areprovided to calculate various statistics, informative visualizations, as wellas file-handling routines to assist in the development and use of noveltechniques.In contrast to many other scientific software projects, Dipy is not beingdeveloped by a single research group. Rather, it is an open project thatencourages contributions from any scientist/developer through GitHub and opendiscussions on the project mailing list. Consequently, Dipy today has aninternational team of contributors, spanning seven different academic institutionsin five countries and three continents, which is still growing.

Active Flow Control in a Radial Vaned Diffuser for Surge Margin Improvement: A Multislot Suction Strategy

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Aurélien Marsan

2017-01-01

Full Text Available This work is the final step of a research project that aims at evaluating the possibility of delaying the surge of a centrifugal compressor stage using a boundary-layer suction technique. It is based on Reynolds-Averaged Navier-Stokes numerical simulations. Boundary-layer suction is applied within the radial vaned diffuser. Previous work has shown the necessity to take into account the unsteady behavior of the flow when designing the active flow control technique. In this paper, a multislot strategy is designed according to the characteristics of the unsteady pressure field. Its implementation results in a significant increase of the stable operating range predicted by the unsteady RANS numerical model. A hub-corner separation still exists further downstream in the diffuser passage but does not compromise the stability of the compressor stage.

Efficiency analysis of diffusion on T-fractals in the sense of random walks.

Science.gov (United States)

Peng, Junhao; Xu, Guoai

2014-04-07

Efficiently controlling the diffusion process is crucial in the study of diffusion problem in complex systems. In the sense of random walks with a single trap, mean trapping time (MTT) and mean diffusing time (MDT) are good measures of trapping efficiency and diffusion efficiency, respectively. They both vary with the location of the node. In this paper, we analyze the effects of node's location on trapping efficiency and diffusion efficiency of T-fractals measured by MTT and MDT. First, we provide methods to calculate the MTT for any target node and the MDT for any source node of T-fractals. The methods can also be used to calculate the mean first-passage time between any pair of nodes. Then, using the MTT and the MDT as the measure of trapping efficiency and diffusion efficiency, respectively, we compare the trapping efficiency and diffusion efficiency among all nodes of T-fractal and find the best (or worst) trapping sites and the best (or worst) diffusing sites. Our results show that the hub node of T-fractal is the best trapping site, but it is also the worst diffusing site; and that the three boundary nodes are the worst trapping sites, but they are also the best diffusing sites. Comparing the maximum of MTT and MDT with their minimums, we find that the maximum of MTT is almost 6 times of the minimum of MTT and the maximum of MDT is almost equal to the minimum for MDT. Thus, the location of target node has large effect on the trapping efficiency, but the location of source node almost has no effect on diffusion efficiency. We also simulate random walks on T-fractals, whose results are consistent with the derived results.

Beyond the Gatekeeper State : African Infrastructure Hubs as Sites of Experimentation

NARCIS (Netherlands)

Hönke, Jana

2018-01-01

While Africa has often been portrayed as peripheral to major global economic flows, the copper mines in the South of the DRC as much as the port of Dar es Salaam are hubs of extraction and trade at the heart of the global economy. This article departs from the notion of the gatekeeper state that

Improving Healthcare in Pediatric Oncology: Development and Testing of Multiple Indicators to Evaluate a Hub-And-Spoke Model.

Science.gov (United States)

Zucchetti, Giulia; Bertorello, Nicoletta; Angelastro, Angela; Gianino, Paola; Bona, Gianni; Barbara, Affif; Besenzon, Luigi; Brach Del Prever, Adalberto; Pesce, Fernando; Nangeroni, Marco; Fagioli, Franca

2017-06-01

Purpose The hub-and-spoke is a new innovation model in healthcare that has been adopted in some countries to manage rare pathologies. We developed a set of indicators to assess current quality practices of the hub-and-spoke model adopted in the Interregional Pediatric Oncology Network in Northwest Italy and to promote patient, family, and professional healthcare empowerment. Methods Literature and evidence-based clinical guidelines were reviewed and multiprofessional team workshops were carried out to highlight some important issues on healthcare in pediatric oncology and to translate them into a set of multiple indicators. For each indicator, specific questions were formulated and tested through a series of questionnaires completed by 80 healthcare professionals and 50 pediatric patients and their parents. Results The results highlighted a positive perception of healthcare delivered by the hub-and-spoke model (M HP = 156, M Pat = 93, M Par = 104). Based on the participants' suggestions, some quality improvements have been implemented. Conclusions This study represents the first attempt to examine this new model of pediatric oncology care through the active involvement of patients, families, and healthcare professionals. Suggestions for adopting a hub-and-spoke model in pediatric oncology in other regions and countries are also highlighted.

Multiperiod Hierarchical Location Problem of Transit Hub in Urban Agglomeration Area

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Ting-ting Li

2017-01-01

Full Text Available With the rapid urbanization in developing countries, urban agglomeration area (UAA forms. Also, transportation demand in UAA grows rapidly and presents hierarchical feature. Therefore, it is imperative to develop models for transit hubs to guide the development of UAA and better meet the time-varying and hierarchical transportation demand. In this paper, the multiperiod hierarchical location problem of transit hub in urban agglomeration area (THUAA is studied. A hierarchical service network of THUAA with a multiflow, nested, and noncoherent structure is described. Then a multiperiod hierarchical mathematical programming model is proposed, aiming at minimizing the total demand weighted travel time. Moreover, an improved adaptive clonal selection algorithm is presented to solve the model. Both the model and algorithm are verified by the application to a real-life problem of Beijing-Tianjin-Hebei Region in China. The results of different scenarios in the case show that urban population migration has a great impact on the THUAA location scheme. Sustained and appropriate urban population migration helps to reduce travel time for urban residents.

Joint Optimization of Star P-hub Median Problem and Seat Inventory Control Decisions Considering a Hybrid Routing Transportation System

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Hamid Tikani

2016-11-01

Full Text Available In this paper, we study the problem of integrated capacitated hub location problem and seat inventory control considering concept and techniques of revenue management. We consider an airline company maximizes its revenue by utilizing the best network topology and providing proper booking limits for all itineraries and fare classes. The transportation system arises in the form of a star/star network and includes both hub-stop and non-stop flights. This problem is formulated as a two-stage stochastic integer program with mixed-integer recourse. We solve various instances carried out from the Turkish network data set. Due to the NP-hardness of the problem, we propose a hybrid optimization method, consisting of an evolutionary algorithm based on genetic algorithm and exact solution. The quality of the solutions found by the proposed meta-heuristic is compared with the original version of GA and the mathematical programming model. The results obtained by the proposed model imply that integrating hub location and seat inventory control problem would help to increase the total revenue of airline companies. Also, in the case of serving non-stop flights, the model can provide more profit by employing less number of hubs.

Diffusion of Botulinum Toxins

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Matthew A. Brodsky

2012-08-01

Full Text Available Background: It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion.Methods: This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method. It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB.Results: Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others.Discussion: Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

FDG-PET/CT and diffusion-weighted imaging for resected lung cancer: correlation of maximum standardized uptake value and apparent diffusion coefficient value with prognostic factors.

Science.gov (United States)

Usuda, Katsuo; Funasaki, Aika; Sekimura, Atsushi; Motono, Nozomu; Matoba, Munetaka; Doai, Mariko; Yamada, Sohsuke; Ueda, Yoshimichi; Uramoto, Hidetaka

2018-04-09

Diffusion-weighted magnetic resonance imaging (DWI) is useful for detecting malignant tumors and the assessment of lymph nodes, as FDG-PET/CT is. But it is not clear how DWI influences the prognosis of lung cancer patients. The focus of this study is to evaluate the correlations between maximum standardized uptake value (SUVmax) of FDG-PET/CT and apparent diffusion coefficient (ADC) value of DWI with known prognostic factors in resected lung cancer. A total of 227 patients with resected lung cancers were enrolled in this study. FEG-PET/CT and DWI were performed in each patient before surgery. There were 168 patients with adenocarcinoma, 44 patients with squamous cell carcinoma, and 15 patients with other cell types. SUVmax was a factor that was correlated to T factor, N factor, or cell differentiation. ADC of lung cancer was a factor that was not correlated to T factor, or N factor. There was a significantly weak inverse relationship between SUVmax and ADC (Correlation coefficient r = - 0.227). In analysis of survival, there were significant differences between the categories of sex, age, pT factor, pN factor, cell differentiation, cell type, and SUVmax. Univariate analysis revealed that SUVmax, pN factor, age, cell differentiation, cell type, sex, and pT factor were significant factors. Multivariate analysis revealed that SUVmax and pN factor were independent significant prognostic factors. SUVmax was a significant prognostic factor that is correlated to T factor, N factor, or cell differentiation, but ADC was not. SUVmax may be more useful for predicting the prognosis of lung cancer than ADC values.

A factor analysis of Functional Independence and Functional Assessment Measure scores among focal and diffuse brain injury patients: The importance of bi-factor models.

Science.gov (United States)

Gunn, Sarah; Burgess, Gerald H; Maltby, John

2018-04-28

To explore the factor structure of the UK Functional Independence Measure and Functional Assessment Measure (FIM+FAM) among focal and diffuse acquired brain injury patients. Criterion standard. An NHS acute acquired brain injury inpatient rehabilitation hospital. Referred sample of 447 adults (835 cases after exclusions) admitted for inpatient treatment following an acquired brain injury significant enough to justify intensive inpatient neurorehabilitation. Not applicable. Functional Independence Measure and Functional Assessment Measure. Exploratory Factor Analysis suggested a two-factor structure to FIM+FAM scores, among both focal-proximate and diffuse-proximate acquired brain injury aetiologies. Confirmatory Factor Analysis suggested a three-factor bi-factor structure presented the best fit of the FIM+FAM score data across both aetiologies. However, across both analyses, a convergence was found towards a general factor, demonstrated by high correlations between factors in the Exploratory Factor Analysis, and by a general factor explaining the majority of the variance in scores on Confirmatory Factor Analysis. Our findings suggested that although factors describing specific functional domains can be derived from FIM+FAM item scores, there is a convergence towards a single factor describing overall functioning. This single factor informs the specific group factors (e.g. motor, psychosocial and communication function) following brain injury. Further research into the comparative value of the general and group factors as evaluative/prognostic measures is indicated. Copyright © 2018. Published by Elsevier Inc.

The FUTUREVOLC Supersite's e-Infrastructure - A multidisciplinary data hub and data service for Icelandic Volcanoes

Science.gov (United States)

Vogfjörd, Kristín S.; Sigmundsson, Freysteinn; Sverrisson, Sverrir Th.; Sigurdsson, Sigurdur F.; Ófeigsson, Benedikt G.; Arnarsson, Ólafur S.; Kristinsson, Ingvar; Ilyinskaya, Evgenia; Oddsdóttir, Thorarna Ýr; Bergsveinsson, Sölvi Th.; Hjartansson, Kristján R.

2014-05-01

The FUTUREVOLC volanological supersite will establish a data hub and dataservice, where researchers, hazard managers and other stake holders can freely obtain access to multidisciplinary data and products on activity, unrest and eruptions at Icelandic volcanoes. The supersite is firmly founded on close interaction between the main Icelandic volcanological research and monitoring institutions, in coordination with expertise from European researchers participating in FUTUREVOLC. The hub is located at the Icelandic Meteorological Office (IMO), an institution responsible for monitoring and archiving data on all natural hazards in Iceland and, which also has a mandate as the state volcano observatory. This association will ensure a long-term sustainable data service. The data accessible at the hub include in-situ and space-based observations, products and models from all the relevant disciplines contributing to volcanological research and local as well as cross-border hazard management, i.e. Earth sciences, atmospheric science, hydrology, remote sensing and space science. Access to the data will be in compliance with the access policy of the GEO (Group on Earth Observations), providing registered users with easy and timely access to data and products of documented quality. This commitment has already led to the acceptance of FUTUREVOLC as a permanent geohazard supersite by CEOS (Committee on Earth Observation Satellites), which will ensure access to additional satellite data and products on Icelandic volcanoes. To facilitate services to seismological data at the supersite hub, the IMO is reconstructing its existing data base and utilizing the SeisComp3 software to manage waveform and parameter data. The accompanying ArcLink component will be used to provide access to event data and waveforms. Access to GPS data will be provided by the GSAC web service which has been installed at the IMO through collaboration with UNAVCO. If appropriate, the format and data base

Idea Exchange Music Hub Hits the Right Note in Community

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Greg Bester

2014-06-01

Full Text Available The Cambridge Libraries and Galleries has made many changes over the last two years, rebranding as Idea Exchange and adding 3D printers, creative spaces and many on-site events. This article focuses on one of the organization’s newest innovations, the addition of a Music Hub, and the challenges of creating a space where members can learn and collaborate musically without disturbing those around them.

Continuous integration in a social-coding world : empirical evidence from GitHub

NARCIS (Netherlands)

Vasilescu, B.N.; van Schuylenburg, S.B.; Wulms, Jules; Serebrenik, A.; Brand, van den M.G.J.

2014-01-01

Continuous integration is a software engineering practice of frequently merging all developer working copies with a shared main branch, e.g., several times a day. With the advent of GitHub, a platform well known for its "social coding" features that aid collaboration and sharing, and currently the

Diffusion in solids

International Nuclear Information System (INIS)

Tiwari, G.P.; Kale, G.B.; Patil, R.V.

1999-01-01

The article presents a brief survey of process of diffusion in solids. It is emphasised that the essence of diffusion is the mass transfer through the atomic jumps. To begin with formal equations for diffusion coefficient are presented. This is followed by discussions on mechanisms of diffusion. Except for solutes which form interstitial solid solution, diffusion in majority of cases is mediated through exchange of sites between an atom and its neighbouring vacancy. Various vacancy parameters such as activation volume, correlation factor, mass effect etc are discussed and their role in establishing the mode of diffusion is delineated. The contribution of dislocations and grain boundaries in diffusion process is brought out. The experimental determination of different types of diffusion coefficients are described. Finally, the pervasive nature of diffusion process in number of commercial processes is outlined to show the importance of diffusion studies in materials science and technology. (author)

A Futile Search for Values and Pedagogy? A Discursive Analysis of the Marketing Messages of Branch-Campuses in Higher Education Hubs

Science.gov (United States)

Karram, Grace

2014-01-01

Higher education has become a key strategy for the economic development of certain city-states that are positioning themselves as higher education hubs, recruiting both students and foreign providers. This article presents the findings of a research study that examined the online messages of foreign branch-campuses in education hubs (Dubai, Hong…

Factors related to the implementation and diffusion of new technologies: a pilot study

Energy Technology Data Exchange (ETDEWEB)

1979-06-01

In order to develop an understanding of how government intervention affects the processes of implementation and diffusion of new technologies, case studies of 14 technologies were carried out: automobiles; broadcast radio; frozen foods; black and white TV; color TV; polio vaccine; supersonic transport; fluoridation of water supplies; computer-aided instruction; basic oxygen process for steel; numerical control in manufacturing; digital computers; lasers; and integrated circuit. The key factors, their motivations for implementing/adopting the technology (or not doing so), the interactions among the key factors, and how these affected implementation/adoption are examined.

Study and Control of a Radial Vaned Diffuser Stall

Directory of Open Access Journals (Sweden)

Aurélien Marsan

2012-01-01

Full Text Available The aim of the present study is to evaluate the efficiency of a boundary layer suction technique in case of a centrifugal compressor stage in order to extend its stable operating range. First, an analysis of the flow pattern within the radial vaned diffuser is presented. It highlights the stall of the diffuser vanes when reaching a low massflow. A boundary layer separation in the hub-suction side corner grows when decreasing the massflow from the nominal operating point to the surge and finally leads to a massive stall. An aspiration strategy is investigated in order to control the stall. The suction slot is put in the vicinity of the saddle that originates the main separating skin-friction line, identified thanks to the analysis of the skin-friction pattern. Several aspiration massflow rates are tested, and two different modelings of the aspiration are evaluated. Finally, an efficient control is reached with a removal of only 0,1% of the global massflow and leads—from a steady-state calculations point of view—to an increase by 40% of the compressor operating range extent.

Comparison of the effectiveness of analytical wake models for wind farm with constant and variable hub heights

International Nuclear Information System (INIS)

Wang, Longyan; Tan, Andy C.C.; Cholette, Michael; Gu, Yuantong

2016-01-01

Highlights: • The effectiveness of three analytical wake models is studied. • The results of the analytical wake models are compared with the CFD simulations. • The results of CFD simulation are verified by comparison to the offshore wind farm observation data. • The onshore wind farm with both constant and different hub height turbines are analyzed. • PARK model is able to predict the total wind farm power production well with tuned surface roughness value. - Abstract: Extensive power losses of wind farm have been witnessed due to the wake interactions between wind turbines. By applying analytical wake models which describe the wind speed deficits in the wake quantitatively, the power losses can be regained to a large extent through wind farm layout optimization, and this has been extensively reported in literature. Nevertheless, the effectiveness of the analytical wake models in predicting the wind farm power production have rarely been studied and compared for wind farm with both constant and variable wind turbine hub heights. In this study, the effectiveness of three different analytical wake models (PARK model, Larsen model and B-P model) is thoroughly compared over a wide range of wake properties. After the validation with the observation data from offshore wind farm, CFD simulations are used to verify the effectiveness of the analytical wake models for an onshore wind farm. The results show that when using the PARK model the surface roughness value (z 0 ) must be carefully tuned to achieve good performance in predicting the wind farm power production. For the other two analytical wake models, their effectiveness varies depending on the situation of wind farm (offshore or onshore) and the wind turbine hub heights (constant or variable). It was found that the results of B-P model agree well with the CFD simulations for offshore wind farm, but not for the onshore wind farm. The Larsen model is more accurate for the wind farm with variable wind turbine

Abnormal functional connectivity of brain network hubs associated with symptom severity in treatment-naive patients with obsessive-compulsive disorder: A resting-state functional MRI study.

Science.gov (United States)

Tian, Lin; Meng, Chun; Jiang, Ying; Tang, Qunfeng; Wang, Shuai; Xie, Xiyao; Fu, Xiangshuai; Jin, Chunhui; Zhang, Fuquan; Wang, Jidong

2016-04-03

Abnormal brain networks have been observed in patients with obsessive-compulsive disorder (OCD). However, detailed network hub and connectivity changes remained unclear in treatment-naive patients with OCD. Here, we sought to determine whether patients show hub-related connectivity changes in their whole-brain functional networks. We used resting-state functional magnetic resonance imaging data and voxel-based graph-theoretic analysis to investigate functional connectivity strength and hubs of whole-brain networks in 29 treatment-naive patients with OCD and 29 age- and gender-matched healthy controls. Correlation analysis was applied for potential associations with OCD symptom severity. OCD selectively targeted brain regions of higher functional connectivity strength than the average including brain network hubs, mainly distributed in the cortico-striato-thalamo-cortical (CSTC) circuits and additionally parietal, occipital, temporal and cerebellar regions. Moreover, affected functional connectivity strength in the cerebellum, the medial orbitofrontal cortex and superior occipital cortex was significantly associated with global OCD symptom severity. Our results provide the evidence about OCD-related brain network hub changes, not only in the CSTC circuits but more distributed in whole brain networks. Data suggest that whole brain network hub analysis is useful for understanding the pathophysiology of OCD. Copyright © 2015 Elsevier Inc. All rights reserved.

Form of multicomponent Fickian diffusion coefficients matrix

International Nuclear Information System (INIS)

Wambui Mutoru, J.; Firoozabadi, Abbas

2011-01-01

Highlights: → Irreversible thermodynamics establishes form of multicomponent diffusion coefficients. → Phenomenological coefficients and thermodynamic factors affect sign of diffusion coefficients. → Negative diagonal elements of diffusion coefficients matrix can occur in non-ideal mixtures. → Eigenvalues of the matrix of Fickian diffusion coefficients may not be all real. - Abstract: The form of multicomponent Fickian diffusion coefficients matrix in thermodynamically stable mixtures is established based on the form of phenomenological coefficients and thermodynamic factors. While phenomenological coefficients form a symmetric positive definite matrix, the determinant of thermodynamic factors matrix is positive. As a result, the Fickian diffusion coefficients matrix has a positive determinant, but its elements - including diagonal elements - can be negative. Comprehensive survey of reported diffusion coefficients data for ternary and quaternary mixtures, confirms that invariably the determinant of the Fickian diffusion coefficients matrix is positive.

The effect of spherical hub-nose position on pressure drop in an oscillating water column system for wave energy conversion

Energy Technology Data Exchange (ETDEWEB)

Taha, Z.; Ahmad, N.; Ghazilla, R.A.R.; Yap, H.J.; Ya, T.Y.T.; Passarella, R.; Hasanuddin, I.; Yunus, M. [Malaya Univ. (Malaysia). Centre for Product Design and Manufacturing; Sugiyono [Malaya Univ., (Malaysia). Centre for Product Design and Manufacturing; Gadjah Mada Univ. (Indonesia). Dept. of Mechanical and Industrial Engineering

2009-07-01

The use of renewable energy sources as an alternative to conventional fuels was discussed with particular reference to ocean wave energy and its potential to contribute to the energy requirements of coastal nations. Ocean wave energy has been harnessed and converted into electricity using processes and technologies that are environmentally sound. The oscillating water column (OWC) system is considered to be among the most promising technology for harnessing wave energy. This paper presented the results of a study that investigated the pressure drop in an OWC system and the effect of spherical hub-nose position in an annular duct. Computational fluid dynamics (CFD) analysis was used under steady flow conditions for several hub-nose positions to determine the characteristic of pressure drop. The study showed that the hub-nose position influenced the pressure drop in the OWC system. The highest value of the pressure drop in this study occurred when the hub-nose was at the position of 0.0 m relative to the end of the converging cone. The pressure drop decreased when the hub-nose position moved away from the end of converging cone. The lowest value occurred at the position of -0.5 m. It was concluded that despite the numerically small change in pressure drop, this phenomenon should be considered in the design process of the OWC system because of the operational condition of the system at low-pressure pneumatic power. The pressure drop actually reduces the amount of energy that will be converted by the air turbine. 9 refs., 2 tabs., 6 figs.

Network Competition - the Coexistence of Hub-and-Spoke and Point-to-Point Systems

NARCIS (Netherlands)

Alderighi, M.; Cento, A.; Nijkamp, P.; Rietveld, P.

2005-01-01

The paper identifies conditions under which asymmetric equilibria may exist when carriers compete in designing their network configurations in a game-theoretical framework. Two carriers are assumed here, which are allowed to play three different strategies: Point-to-point (PP), hub-and-spoke (HS) or

Mass transfer rate through liquid membranes: interfacial chemical reactions and diffusion as simultaneous permeability controlling factors

International Nuclear Information System (INIS)

Danesi, P.R.; Horwitz, E.P.; Vandegrift, G.F.; Chiarizia, R.

1981-01-01

Equations describing the permeability of a liquid membrane to metal cations have been derived taking into account aqueous diffusion, membrane diffusion, and interfacial chemical reactions as simultaneous permeability controlling factors. Diffusion and chemical reactions have been coupled by a simple model analogous to the one previously described by us to represent liquid-liquid extraction kinetics. The derived equations, which make use of experimentally determined interfacial reaction mechanisms, qualitatively fit unexplained literature data regarding Cu 2+ transfer through liquid membranes. Their use to predict and optimize membrane permeability in practical separation processes by setting the appropriate concentration of the membrane carrier [LIX 64 (General Mills), a commercial β-hydroxy-oxime] and the pH of the aqueous copper feed solution is briefly discussed. 4 figures

A proposed parameterization of interface discontinuity factors depending on neighborhood for pin-by-pin diffusion computations for LWR

International Nuclear Information System (INIS)

Herrero, Jose Javier; Garcia-Herranz, Nuria; Ahnert, Carol

2011-01-01

There exists an interest in performing full core pin-by-pin computations for present nuclear reactors. In such type of problems the use of a transport approximation like the diffusion equation requires the introduction of correction parameters. Interface discontinuity factors can improve the diffusion solution to nearly reproduce a transport solution. Nevertheless, calculating accurate pin-by-pin IDF requires the knowledge of the heterogeneous neutron flux distribution, which depends on the boundary conditions of the pin-cell as well as the local variables along the nuclear reactor operation. As a consequence, it is impractical to compute them for each possible configuration. An alternative to generate accurate pin-by-pin interface discontinuity factors is to calculate reference values using zero-net-current boundary conditions and to synthesize afterwards their dependencies on the main neighborhood variables. In such way the factors can be accurately computed during fine-mesh diffusion calculations by correcting the reference values as a function of the actual environment of the pin-cell in the core. In this paper we propose a parameterization of the pin-by-pin interface discontinuity factors allowing the implementation of a cross sections library able to treat the neighborhood effect. First results are presented for typical PWR configurations. (author)

A proposed parameterization of interface discontinuity factors depending on neighborhood for pin-by-pin diffusion computations for LWR

Energy Technology Data Exchange (ETDEWEB)

Herrero, Jose Javier; Garcia-Herranz, Nuria; Ahnert, Carol, E-mail: herrero@din.upm.es, E-mail: nuria@din.upm.es, E-mail: carol@din.upm.es [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid (Spain)

2011-07-01

There exists an interest in performing full core pin-by-pin computations for present nuclear reactors. In such type of problems the use of a transport approximation like the diffusion equation requires the introduction of correction parameters. Interface discontinuity factors can improve the diffusion solution to nearly reproduce a transport solution. Nevertheless, calculating accurate pin-by-pin IDF requires the knowledge of the heterogeneous neutron flux distribution, which depends on the boundary conditions of the pin-cell as well as the local variables along the nuclear reactor operation. As a consequence, it is impractical to compute them for each possible configuration. An alternative to generate accurate pin-by-pin interface discontinuity factors is to calculate reference values using zero-net-current boundary conditions and to synthesize afterwards their dependencies on the main neighborhood variables. In such way the factors can be accurately computed during fine-mesh diffusion calculations by correcting the reference values as a function of the actual environment of the pin-cell in the core. In this paper we propose a parameterization of the pin-by-pin interface discontinuity factors allowing the implementation of a cross sections library able to treat the neighborhood effect. First results are presented for typical PWR configurations. (author)

HuB (elavl2 mRNA is restricted to the germ cells by post-transcriptional mechanisms including stabilisation of the message by DAZL.

Directory of Open Access Journals (Sweden)

Sophie E Wiszniak

Full Text Available The ability of germ cells to carry out a gene regulatory program distinct from the surrounding somatic tissue, and their capacity to specify an entire new organism has made them a focus of many studies that seek to understand how specific regulatory mechanisms, particularly post-transcriptional mechanisms, contribute to cell fate. In zebrafish, germ cells are specified through the inheritance of cytoplasmic determinants, termed the germ plasm, which contains a number of maternal mRNAs and proteins. Investigation of several of these messages has revealed that the restricted localisation of these mRNAs to the germ plasm and subsequent germ cells is due to cis-acting sequence elements present in their 3'UTRs. Here we show that a member of the Hu family of RNA-binding proteins, HuB, is maternally provided in the zebrafish embryo and exhibits germ cell specific expression during embryogenesis. Restriction of HuB mRNA to the germ cells is dependent on a number of sequence elements in its 3'UTR, which act to degrade the mRNA in the soma and stabilise it in the germ cells. In addition, we show that the germ cell specific RNA-binding protein DAZL is able to promote HuB mRNA stability and translation in germ cells, and further demonstrate that these activities require a 30 nucleotide element in the 3'UTR. Our study suggests that DAZL specifically binds the HuB 3'UTR and protects the message from degradation and/or enhances HuB translation, leading to the germ cell specific expression of HuB protein.

Of Hubs and Hinterlands: Cyprus as an Insular Space of Overlapping Diasporas

Directory of Open Access Journals (Sweden)

Russell King

2012-05-01

Full Text Available This paper uses the metaphor of diasporic hubs and hinterlands to document and analyse the various diasporic formations that overlap and encounter each other on the divided island of Cyprus. After a review of the various ways that islands interface with migration processes and some essential historical and statistical background on Cyprus and its population, the paper considers a number of migrations/diasporas that are based on or affect the island. They include the emigration from the diasporic hub of Cyprus during the 1950s-1970s; return migration, both of the original emigrants and their descendants; the British military/colonial settlement of Cyprus; retirees and ‘lifestyle migrants’; and various categories of recent immigrants, for whom Cyprus is a diasporic hinterland. We draw both similarities and differences between migratory dynamics in the northern, Turkish Cypriot part of the island and the southern, Greek Cypriot part. In the final part of the paper we describe recent fieldwork on various spaces of inter-diasporic encounter in Cyprus.

Determining Domestic Container Shipping as an Enforcement of Indonesian International Hub Port

Science.gov (United States)

Nur, H. I.; Lazuardi, S. D.; Hadi, F.; Hapis, M.

2018-03-01

According to Presidential Regulation Number 26 year of 2012 about the National Logistics System Development Blueprint, the Indonesian government proposed to build two international hub ports, which were in Port of Kuala Tanjung for the western region and Port of Bitung for eastern region. Therefore, the optimum routes and fleet size are required to support the enforcement of Indonesian International Hub Port. The optimization model is used to obtain the optimum route and fleet by minimizing the total shipping costs, while considering the container demand. The result of analysis obtained that the optimum route and fleet size for the western region of Indonesia were: (1) Kuala Tanjung-Belawan required 15 ships of 1,000 TEU; (2) Kuala Tanjung-Tanjung Priok required 73 ships of 2,500 TEU; (3) Kuala Tanjung- Tanjung Perak required 44 ships of 2,500 TEU. Meanwhile, the optimum route and fleet size for the eastern region of Indonesia consisted of: (1) Bitung-Sorong required 1 ship of 500 TEU; (2) Bitung-Banjarmasin required 3 ships of 500 TEU; and (3) Bitung-Makassar required 1 ship of 1,500 TEU.

Finding p-Hub Median Locations: An Empirical Study on Problems and Solution Techniques

Directory of Open Access Journals (Sweden)

Xiaoqian Sun

2017-01-01

Full Text Available Hub location problems have been studied by many researchers for almost 30 years, and, accordingly, various solution methods have been proposed. In this paper, we implement and evaluate several widely used methods for solving five standard hub location problems. To assess the scalability and solution qualities of these methods, three well-known datasets are used as case studies: Turkish Postal System, Australia Post, and Civil Aeronautics Board. Classical problems in small networks can be solved efficiently using CPLEX because of their low complexity. Genetic algorithms perform well for solving three types of single allocation problems, since the problem formulations can be neatly encoded with chromosomes of reasonable size. Lagrangian relaxation is the only technique that solves reliable multiple allocation problems in large networks. We believe that our work helps other researchers to get an overview on the best solution techniques for the problems investigated in our study and also stipulates further interest on cross-comparing solution techniques for more expressive problem formulations.

A modified derivation of the correlation factor in tracer diffusion via vacancy mechanism

International Nuclear Information System (INIS)

Koiwa, Masahiro

1978-01-01

The average number of site exchanges made by a particular atom-vacancy pair has been calculated. It is found that the number of exchanges is equal to the number of visits to the origin of a random walker; for an infinite fcc lattice the number of exchanges is about 1.345, including the first exchange. This result seems invalidate the assumption of an infinite number of exchanges, which is usually made in the derivation of the correlation factor in diffusion via the vacancy mechanism. A modified derivation of the correlation factor, which takes into account the number of exchanges explicitly, is presented. (author)

Anomalous diffusion in niobium. Study of solute diffusion mechanism of iron in niobium

International Nuclear Information System (INIS)

Ablitzer, D.

1977-01-01

In order to explain anomalously high diffusion velocities observed for iron diffusion in niobium, the following parameters were measured: isotope effect, b factor (which expresses the effect of iron on niobium self-diffusion), self-diffusion coefficient of niobium, solute diffusion coefficient of iron in niobium. The results obtained show that neither pure vacancy models, nor diffusion in the lattice defects (dislocations, sub-boundaries, grain boundaries), nor pure interstitialy mechanisms, nor simple or cyclic exchange mechanisms agree with experiments. A mechanism is proposed which considers an equilibrium between substitution iron atoms and interstitial iron atoms. The diffusion of iron then occurs through interstitial vancancy pairs [fr

Helminth-infected patients with malaria: a low profile transmission hub?

Science.gov (United States)

Nacher, Mathieu

2012-11-15

Eclipsed by the debates about malaria incidence and severity in individual patients, malaria transmission in helminth-infected persons has so far received very little attention. Studies in humans have shown increased malaria incidence and prevalence, and a trend for a reduction of symptoms in patients with malaria. This suggests that such patients could possibly be less likely to seek treatment thus carrying malaria parasites and their gametocytes for longer durations, therefore, being a greater potential source of transmission. In addition, in humans, a study showed increased gametocyte carriage, and in an animal model of helminth-malaria co-infection, there was increased malaria transmission. These elements converge towards the hypothesis that patients co-infected with worms and malaria may represent a hub of malaria transmission. The test of this hypothesis requires verifying, in different epidemiological settings, that helminth-infected patients have more gametocytes, that they have less symptomatic malaria and longer-lasting infections, and that they are more attractive for the vectors. The negative outcome in one setting of one of the above aspects does not necessarily mean that the other two aspects may suffice to increase transmission. If it is verified that patients co-infected by worms and malaria could be a transmission hub, this would be an interesting piece of strategic information in the context of the spread of anti-malarial resistance and the malaria eradication attempts.

A review study of the current research on energy hub for energy positive neighborhoods

NARCIS (Netherlands)

Walker, S.W.W.; Labeodan, T.; Maassen, W.H.; Zeiler, W.

2017-01-01

Energy positive neighborhoods and cities are emerging concepts aimed at addressing the current energy and environmental sustainability challenges. In this paper, the concept and current research on energy hubs relating to energy positive neighborhoods are presented. In addition to discussing

Guiding Principles for Data Architecture to Support the Pathways Community HUB Model.

Science.gov (United States)

Zeigler, Bernard P; Redding, Sarah; Leath, Brenda A; Carter, Ernest L; Russell, Cynthia

2016-01-01

The Pathways Community HUB Model provides a unique strategy to effectively supplement health care services with social services needed to overcome barriers for those most at risk of poor health outcomes. Pathways are standardized measurement tools used to define and track health and social issues from identification through to a measurable completion point. The HUB use Pathways to coordinate agencies and service providers in the community to eliminate the inefficiencies and duplication that exist among them. Experience with the Model has brought out the need for better information technology solutions to support implementation of the Pathways themselves through decision-support tools for care coordinators and other users to track activities and outcomes, and to facilitate reporting. Here we provide a basis for discussing recommendations for such a data infrastructure by developing a conceptual model that formalizes the Pathway concept underlying current implementations. The main contribution is a set of core recommendations as a framework for developing and implementing a data architecture to support implementation of the Pathways Community HUB Model. The objective is to present a tool for communities interested in adopting the Model to learn from and to adapt in their own development and implementation efforts. Experience with the Community Health Access Project (CHAP) data base system (the core implementation of the Model) has identified several issues and remedies that have been developed to address these issues. Based on analysis of issues and remedies, we present several key features for a data architecture meeting the just mentioned recommendations. Presentation of features is followed by a practical guide to their implementation allowing an organization to consider either tailoring off-the-shelf generic systems to meet the requirements or offerings that are specialized for community-based care coordination. Looking to future extensions, we discuss the

A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison

Science.gov (United States)

2017-03-01

computed at various pitch angles through changes in actuator length. The linear spring stiffness was estimated by using the internal volume of the...Vehicle Technology Directorate Mechanics Division (ATTN: RDRL-VTM) Aberdeen Proving Ground, MD 21005-5066 8. PERFORMING ORGANIZATION REPORT NUMBER...Finally, the balance loads are not only induced by the rotor hub loads, but also by loads transmitted via the pitch links to the swashplate. Thus

The home hemodialysis hub: physical infrastructure and integrated governance structure.

Science.gov (United States)

Marshall, Mark R; Young, Bessie A; Fox, Sally J; Cleland, Calli J; Walker, Robert J; Masakane, Ikuto; Herold, Aaron M

2015-04-01

An effective home hemodialysis program critically depends on adequate hub facilities and support functions and on transparent and accountable organizational processes. The likelihood of optimal service delivery and patient care will be enhanced by fit-for-purpose facilities and implementation of a well-considered governance structure. In this article, we describe the required accommodation and infrastructure for a home hemodialysis program and a generic organizational structure that will support both patient-facing clinical activities and business processes. © 2015 International Society for Hemodialysis.

Evaluation of total and partial structure factors, self-diffusion coefficients, and compressibilities of the cadmium-gallium melt

International Nuclear Information System (INIS)

Gopala Rao, R.V.; Das, R.

1988-01-01

The three partial structure factors S/sub 11/(K), S/sub 22/(K), and S/sub 12/(K) defined by Ashcroft and Langreth are computed with a square-well potential as a perturbation over a hard-sphere potential for different atomic fractions or concentrations of cadmium for Cd-Ga melt at 296 0 C. Also, the number-number, concentration-concentration, and the cross-term number-concentration structure factors due to Bhatia-Thornton have been calculated for the seven concentrations of Cd-Ga melt at that temperature. From these partial structure factors total structure factors are computed and are compared with the experimental results. The total structure factors so computed are found to be in excellent agreement with the measured values except in the long-wavelength limit of S(0). Using the partial structure factors in the long-wavelength limit the isothermal compressibilities have been calculated. From these partial structure factors and by using the linear-trajectory approximation of Helfand, the self-diffusion coefficients D/sub i/'s have also been calculated for various atomic fractions of Cd for Cd-Ga alloy at 296 0 C. From these D/sub i/'s, an estimate of the mutual diffusion coefficients has been made to a good approximation

Left frontal hub connectivity delays cognitive impairment in autosomal-dominant and sporadic Alzheimer’s disease

Science.gov (United States)

Franzmeier, Nicolai; Düzel, Emrah; Jessen, Frank; Buerger, Katharina; Levin, Johannes; Duering, Marco; Dichgans, Martin; Haass, Christian; Suárez-Calvet, Marc; Fagan, Anne M; Paumier, Katrina; Benzinger, Tammie; Masters, Colin L; Morris, John C; Perneczky, Robert; Janowitz, Daniel; Catak, Cihan; Wolfsgruber, Steffen; Wagner, Michael; Teipel, Stefan; Kilimann, Ingo; Ramirez, Alfredo; Rossor, Martin; Jucker, Mathias; Chhatwal, Jasmeer; Spottke, Annika; Boecker, Henning; Brosseron, Frederic; Falkai, Peter; Fliessbach, Klaus; Heneka, Michael T; Laske, Christoph; Nestor, Peter; Peters, Oliver; Fuentes, Manuel; Menne, Felix; Priller, Josef; Spruth, Eike J; Franke, Christiana; Schneider, Anja; Kofler, Barbara; Westerteicher, Christine; Speck, Oliver; Wiltfang, Jens; Bartels, Claudia; Araque Caballero, Miguel Ángel; Metzger, Coraline; Bittner, Daniel; Weiner, Michael; Lee, Jae-Hong; Salloway, Stephen; Danek, Adrian; Goate, Alison; Schofield, Peter R; Bateman, Randall J; Ewers, Michael

2018-01-01

Abstract Patients with Alzheimer’s disease vary in their ability to sustain cognitive abilities in the presence of brain pathology. A major open question is which brain mechanisms may support higher reserve capacity, i.e. relatively high cognitive performance at a given level of Alzheimer’s pathology. Higher functional MRI-assessed functional connectivity of a hub in the left frontal cortex is a core candidate brain mechanism underlying reserve as it is associated with education (i.e. a protective factor often associated with higher reserve) and attenuated cognitive impairment in prodromal Alzheimer’s disease. However, no study has yet assessed whether such hub connectivity of the left frontal cortex supports reserve throughout the evolution of pathological brain changes in Alzheimer’s disease, including the presymptomatic stage when cognitive decline is subtle. To address this research gap, we obtained cross-sectional resting state functional MRI in 74 participants with autosomal dominant Alzheimer’s disease, 55 controls from the Dominantly Inherited Alzheimer’s Network and 75 amyloid-positive elderly participants, as well as 41 amyloid-negative cognitively normal elderly subjects from the German Center of Neurodegenerative Diseases multicentre study on biomarkers in sporadic Alzheimer’s disease. For each participant, global left frontal cortex connectivity was computed as the average resting state functional connectivity between the left frontal cortex (seed) and each voxel in the grey matter. As a marker of disease stage, we applied estimated years from symptom onset in autosomal dominantly inherited Alzheimer’s disease and cerebrospinal fluid tau levels in sporadic Alzheimer’s disease cases. In both autosomal dominant and sporadic Alzheimer’s disease patients, higher levels of left frontal cortex connectivity were correlated with greater education. For autosomal dominant Alzheimer’s disease, a significant left frontal cortex connectivity �

An Airlift Hub-and-Spoke Location-Routing Model with Time Windows: Case Study of the CONUS-to-Korea Airlift Problem

Science.gov (United States)

1998-03-01

a point of embarkation to a point of debarkation. This study develops an alternative hub-and-spoke combined location-routing integer linear...programming prototype model, and uses this model to determine what advantages a hub-and-spoke system offers, and in which scenarios it is better-suited than the...extension on the following works: the hierarchical model of Perl and Daskin (1983), time windows features of Chan (1991), combining subtour-breaking and range

Omni directional mobile robot capable of variable foot printing based on hub type drive module

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyo Joong; Cho, Chang Nho; Kim, Hwi Su; Song, Jae Bok [Korea Univ., Seoul (Korea, Republic of)

2012-03-15

In recent years, an increased amount of research has been carried out on mobile robots to improve the performance of service robots. Mobile robots maximize the mobility of service robots, thus allowing them to work in different areas. However, conventional service robots have their center of mass placed high above the ground, which may cause them to fall when moving at high speed. Furthermore, hub type actuators, which are often used for mobile robots, are large and expensive. In this study, we propose a mobile robot with a hub type actuator unit and a variable footprint mechanism. The proposed variable footprint mechanism greatly improves the stability and mobility of the robot, allowing it to move freely in a narrow space and carry out various tasks. The performance of the proposed robot is verified experimentally.

Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 2: Project planning data

Science.gov (United States)

1980-01-01

Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.

Lazy Updating of hubs can enable more realistic models by speeding up stochastic simulations

International Nuclear Information System (INIS)

Ehlert, Kurt; Loewe, Laurence

2014-01-01

To respect the nature of discrete parts in a system, stochastic simulation algorithms (SSAs) must update for each action (i) all part counts and (ii) each action's probability of occurring next and its timing. This makes it expensive to simulate biological networks with well-connected “hubs” such as ATP that affect many actions. Temperature and volume also affect many actions and may be changed significantly in small steps by the network itself during fever and cell growth, respectively. Such trends matter for evolutionary questions, as cell volume determines doubling times and fever may affect survival, both key traits for biological evolution. Yet simulations often ignore such trends and assume constant environments to avoid many costly probability updates. Such computational convenience precludes analyses of important aspects of evolution. Here we present “Lazy Updating,” an add-on for SSAs designed to reduce the cost of simulating hubs. When a hub changes, Lazy Updating postpones all probability updates for reactions depending on this hub, until a threshold is crossed. Speedup is substantial if most computing time is spent on such updates. We implemented Lazy Updating for the Sorting Direct Method and it is easily integrated into other SSAs such as Gillespie's Direct Method or the Next Reaction Method. Testing on several toy models and a cellular metabolism model showed >10× faster simulations for its use-cases—with a small loss of accuracy. Thus we see Lazy Updating as a valuable tool for some special but important simulation problems that are difficult to address efficiently otherwise

Positioning Mauritius as a Knowledge Hub in the Context of Globalisation

OpenAIRE

Deepa Gokulsing

2014-01-01

Knowledge is the most valued commodity in the global economy. Since 2005, it has been proposed to develop Mauritius into a knowledge hub and a centre of higher learning, thus meeting the needs of an increasingly competitive, knowledge-based and globalised economy. Therefore, this paper provides an understanding of the higher education system in Mauritius. Secondly, it explores the interconnection between globalisation and higher education in Mauritius. Thirdly, it also focuses the challenges ...

Variable forgetting factor mechanisms for diffusion recursive least squares algorithm in sensor networks

Science.gov (United States)

Zhang, Ling; Cai, Yunlong; Li, Chunguang; de Lamare, Rodrigo C.

2017-12-01

In this work, we present low-complexity variable forgetting factor (VFF) techniques for diffusion recursive least squares (DRLS) algorithms. Particularly, we propose low-complexity VFF-DRLS algorithms for distributed parameter and spectrum estimation in sensor networks. For the proposed algorithms, they can adjust the forgetting factor automatically according to the posteriori error signal. We develop detailed analyses in terms of mean and mean square performance for the proposed algorithms and derive mathematical expressions for the mean square deviation (MSD) and the excess mean square error (EMSE). The simulation results show that the proposed low-complexity VFF-DRLS algorithms achieve superior performance to the existing DRLS algorithm with fixed forgetting factor when applied to scenarios of distributed parameter and spectrum estimation. Besides, the simulation results also demonstrate a good match for our proposed analytical expressions.

Determination of the separation factor of uranium isotopes by gaseous diffusion; Determination des facteurs de separation des isotopes de l'uranium par diffusion gazeuse

Energy Technology Data Exchange (ETDEWEB)

Bilous, O; Counas, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

A 12-stage pilot separation cascade with a low output has been constructed to measure the separation factor of uranium isotopes by gaseous diffusion. The report describes some of the separation results obtained, and also provides information on the time necessary for equilibrium to be established and on the influence of various perturbations on the pressure profile in the cascade. (author) [French] Une cascade pilote de 12 etages de separation a faible debit a ete construite pour mesurer le facteur de separation des isotopes de l'uranium par diffusion gazeuse. Le rapport decrit certains des resultats de separation obtenus et fournit egalement des donnees sur les temps de mise en equilibre et l'influence de diverses perturbations sur le profil des pressions dans la cascade. (auteur)

Orbital Hub: a concept for human spaceflight beyond ISS operations

Science.gov (United States)

Jahnke, Stephan S.; Maiwald, Volker; Philpot, Claudia; Quantius, Dominik; Romberg, Oliver; Seboldt, Wolfgang; Vrakking, Vincent; Zeidler, Conrad

2018-04-01

The International Space Station (ISS) is the greatest endeavour in low-Earth orbit since the beginning of the space age and the culmination of human outposts like Skylab and Mir. While a clear schedule has yet to be drafted, it is expected that ISS will cease operation in the 2020s. What could be the layout for a human outpost in LEO with lessons learnt from ISS? What are the use cases and applications of such an outpost in the future? The System Analysis Space Segment group of the German Aerospace Center investigated these and other questions and developed the Orbital Hub concept. In this paper an overview is presented of how the overall concept has been derived and its properties and layouts are described. Starting with a workshop involving the science community, the scientific requirements have been derived and Strawman payloads have been defined for use in further design activities. These design activities focused on Concurrent Engineering studies, where besides DLR employees participants from the industry and astronauts were involved. The result is an expandable concept that is composed of two main parts, the Base Platform, home for a permanent crew of up to three astronauts, and the Free Flyer, an uncrewed autonomous research platform. This modular approach provides one major advantage: the decoupling of the habitat and payload leading to increased quality of the micro-gravity environment. The former provides an environment for human physiology experiments, while the latter allows science without the perturbations caused by a crew, e.g. material experiments or Earth observation. The Free Flyer is designed to operate for up to 3 months on its own, but can dock with the space station for maintenance and experiment servicing. It also has a hybrid propulsion system, chemical and electrical, for different applications. The hub's design allows launch with just three launches, as the total mass of all the hub parts is about 60,000 kg. The main focus of the design is

Helminth-infected patients with malaria: a low profile transmission hub?

Directory of Open Access Journals (Sweden)

Nacher Mathieu

2012-11-01

Full Text Available Abstract Eclipsed by the debates about malaria incidence and severity in individual patients, malaria transmission in helminth-infected persons has so far received very little attention. Studies in humans have shown increased malaria incidence and prevalence, and a trend for a reduction of symptoms in patients with malaria. This suggests that such patients could possibly be less likely to seek treatment thus carrying malaria parasites and their gametocytes for longer durations, therefore, being a greater potential source of transmission. In addition, in humans, a study showed increased gametocyte carriage, and in an animal model of helminth-malaria co-infection, there was increased malaria transmission. These elements converge towards the hypothesis that patients co-infected with worms and malaria may represent a hub of malaria transmission. The test of this hypothesis requires verifying, in different epidemiological settings, that helminth-infected patients have more gametocytes, that they have less symptomatic malaria and longer-lasting infections, and that they are more attractive for the vectors. The negative outcome in one setting of one of the above aspects does not necessarily mean that the other two aspects may suffice to increase transmission. If it is verified that patients co-infected by worms and malaria could be a transmission hub, this would be an interesting piece of strategic information in the context of the spread of anti-malarial resistance and the malaria eradication attempts.

On the Predictability of Hub Height Winds

DEFF Research Database (Denmark)

Draxl, Caroline

Wind energy is a major source of power in over 70 countries across the world, and the worldwide share of wind energy in electricity consumption is growing. The introduction of signicant amounts of wind energy into power systems makes accurate wind forecasting a crucial element of modern electrical...... grids. These systems require forecasts with temporal scales of tens of minutes to a few days in advance at wind farm locations. Traditionally these forecasts predict the wind at turbine hub heights; this information is then converted by transmission system operators and energy companies into predictions...... of power output at wind farms. Since the power available in the wind is proportional to the wind speed cubed, even small wind forecast errors result in large power prediction errors. Accurate wind forecasts are worth billions of dollars annually; forecast improvements will result in reduced costs...

Numerical and Experimental Investigation of Heat Flow in Permanent Magnet Brushless DC Hub Motor

DEFF Research Database (Denmark)

Fasil, Muhammed; Plesner, Daniel; Walther, Jens Honore

2014-01-01

This paper investigates the heat dissipation in the hub motor of an electric two-wheeler using lumped parameter (LP), finite element (FE) and computational fluid dynamic (CFD) models. The motor uses external rotor permanent magnet brushless DC topology and nearly all of its losses are generated...

Identifying hubs and spokes in global supply chains using redirected trade in value added

NARCIS (Netherlands)

Lejour, Arjan; Rojas-Romagosa, Hugo; Veenendaal, Paul

2017-01-01

The increasing importance of global supply chains has prompted the use of analytical tools based on trade in value added - instead of traditional measures in gross value. We use this analytical framework to develop indicators that identify production hubs and supply spokes in global supply chains.

Partial synchronization in networks of non-linearly coupled oscillators: The Deserter Hubs Model

Energy Technology Data Exchange (ETDEWEB)

Freitas, Celso, E-mail: cbnfreitas@gmail.com; Macau, Elbert, E-mail: elbert.macau@inpe.br [Associate Laboratory for Computing and Applied Mathematics - LAC, Brazilian National Institute for Space Research - INPE (Brazil); Pikovsky, Arkady, E-mail: pikovsky@uni-potsdam.de [Department of Physics and Astronomy, University of Potsdam, Germany and Department of Control Theory, Nizhni Novgorod State University, Gagarin Av. 23, 606950, Nizhni Novgorod (Russian Federation)

2015-04-15

We study the Deserter Hubs Model: a Kuramoto-like model of coupled identical phase oscillators on a network, where attractive and repulsive couplings are balanced dynamically due to nonlinearity of interactions. Under weak force, an oscillator tends to follow the phase of its neighbors, but if an oscillator is compelled to follow its peers by a sufficient large number of cohesive neighbors, then it actually starts to act in the opposite manner, i.e., in anti-phase with the majority. Analytic results yield that if the repulsion parameter is small enough in comparison with the degree of the maximum hub, then the full synchronization state is locally stable. Numerical experiments are performed to explore the model beyond this threshold, where the overall cohesion is lost. We report in detail partially synchronous dynamical regimes, like stationary phase-locking, multistability, periodic and chaotic states. Via statistical analysis of different network organizations like tree, scale-free, and random ones, we found a measure allowing one to predict relative abundance of partially synchronous stationary states in comparison to time-dependent ones.

Diffusion tensor tractography of the brainstem pyramidal tract; A study on the optimal reduction factor in parallel imaging

Energy Technology Data Exchange (ETDEWEB)

Bae, Yun Jung; Park, Jong Bin; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheol Kyu [Dept. of of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2016-08-15

Parallel imaging mitigates susceptibility artifacts that can adversely affect diffusion tensor tractography (DTT) of the pons depending on the reduction (R) factor. We aimed to find the optimal R factor for DTT of the pons that would allow us to visualize the largest possible number of pyramidal tract fibers. Diffusion tensor imaging was performed on 10 healthy subjects at 3 Tesla based on single-shot echo-planar imaging using the following parameters: b value, 1000 s/mm{sup 2}; gradient direction, 15; voxel size, 2 × 2 × 2 mm{sup 3}; and R factors, 1, 2, 3, 4, and 5. DTT of the right and left pyramidal tracts in the pons was conducted in all subjects. Signal-to-noise ratio (SNR), image distortion, and the number of fibers in the tracts were compared across R factors. SNR, image distortion, and fiber number were significantly different according to R factor. Maximal SNR was achieved with an R factor of 2. Image distortion was minimal with an R factor of 5. The number of visible fibers was greatest with an R factor of 3. R factor 3 is optimal for DTT of the pontine pyramidal tract. A balanced consideration of SNR and image distortion, which do not have the same dependence on the R factor, is necessary for DTT of the pons.

Analysis of Wheel Hub Motor Drive Application in Electric Vehicles

Directory of Open Access Journals (Sweden)

Sun Yuechao

2017-01-01

Full Text Available Based on the comparative analysis of the performance characteristics of centralized and distributed drive electric vehicles, we found that the wheel hub motor drive mode of the electric vehicles with distributed drive have compact structure, high utilization ratio of interior vehicle space, lower center of vehicle gravity, good driving stability, easy intelligent control and many other advantages, hence in line with the new requirements for the development of drive performance of electric vehicles, and distributed drive will be the ultimate mode of electric vehicles in the future.

Abnormal intrinsic functional hubs in alcohol dependence: evidence from a voxelwise degree centrality analysis

Directory of Open Access Journals (Sweden)

Luo X

2017-07-01

Full Text Available Xiaoping Luo,1,2 Linghong Guo,1 Xi-Jian Dai,3 Qinglai Wang,2 Wenzhong Zhu,2 Xinjun Miao,2 Honghan Gong1 1Department of Radiology, The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China; 2Department of Radiology, Wenzhou Chinese Medicine Hospital, Wenzhou, Zhejiang, People’s Republic of China; 3Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, People’s Republic of China Objective: To explore the abnormal intrinsic functional hubs in alcohol dependence using voxelwise degree centrality analysis approach, and their relationships with clinical features.Materials and methods: Twenty-four male alcohol dependence subjects free of medicine (mean age, 50.21±9.62 years and 24 age- and education-matched male healthy controls (mean age, 50.29±8.92 years were recruited. The alcohol use disorders identification test and the severity of alcohol dependence questionnaire (SADQ were administered to assess the severity of alcohol craving. Voxelwise degree centrality approach was used to assess the abnormal intrinsic functional hubs features in alcohol dependence. Simple linear regression analysis was performed to investigate the relationships between the clinical features and abnormal intrinsic functional hubs.Results: Compared with healthy controls, alcohol dependence subjects exhibited significantly different degree centrality values in widespread left lateralization brain areas, including higher degree centrality values in the left precentral gyrus (BA 6, right hippocampus (BA 35, 36, and left orbitofrontal cortex (BA 11 and lower degree centrality values in the left cerebellum posterior lobe, bilateral secondary visual network (BA 18, and left precuneus (BA 7, 19. SADQ revealed a negative linear correlation with the degree centrality value in the left precentral gyrus (R2=0.296, P=0.006.Conclusion: The specific abnormal intrinsic functional hubs appear

Continuous Integration for Concurrent MOOSE Framework and Application Development on GitHub

OpenAIRE

Slaughter, Andrew E.; Peterson, John W.; Gaston, Derek R.; Permann, Cody J.; Andrš, David; Miller, Jason M.

2015-01-01

For the past several years, Idaho National Laboratory’s MOOSE framework team has employed modern software engineering techniques (continuous integration, joint application/framework source code repos- itories, automated regression testing, etc.) in developing closed-source multiphysics simulation software (Gaston et al., 'Journal of Open Research Software' vol. 2, article e10, 2014). In March 2014, the MOOSE framework was released under an open source license on GitHub, significantly expandin...

Trade-off between multiple constraints enables simultaneous formation of modules and hubs in neural systems.

Directory of Open Access Journals (Sweden)

Yuhan Chen

Full Text Available The formation of the complex network architecture of neural systems is subject to multiple structural and functional constraints. Two obvious but apparently contradictory constraints are low wiring cost and high processing efficiency, characterized by short overall wiring length and a small average number of processing steps, respectively. Growing evidence shows that neural networks are results from a trade-off between physical cost and functional value of the topology. However, the relationship between these competing constraints and complex topology is not well understood quantitatively. We explored this relationship systematically by reconstructing two known neural networks, Macaque cortical connectivity and C. elegans neuronal connections, from combinatory optimization of wiring cost and processing efficiency constraints, using a control parameter α, and comparing the reconstructed networks to the real networks. We found that in both neural systems, the reconstructed networks derived from the two constraints can reveal some important relations between the spatial layout of nodes and the topological connectivity, and match several properties of the real networks. The reconstructed and real networks had a similar modular organization in a broad range of α, resulting from spatial clustering of network nodes. Hubs emerged due to the competition of the two constraints, and their positions were close to, and partly coincided, with the real hubs in a range of α values. The degree of nodes was correlated with the density of nodes in their spatial neighborhood in both reconstructed and real networks. Generally, the rebuilt network matched a significant portion of real links, especially short-distant ones. These findings provide clear evidence to support the hypothesis of trade-off between multiple constraints on brain networks. The two constraints of wiring cost and processing efficiency, however, cannot explain all salient features in the real

A Hypercat-enabled Semantic Internet of Things Data Hub: Technical Report

OpenAIRE

Tachmazidis, Ilias; Batsakis, Sotiris; Davies, John; Duke, Alistair; Vallati, Mauro; Antoniou, Grigoris; Clarke, Sandra Stincic

2017-01-01

An increasing amount of information is generated from the rapidly increasing number of sensor networks and smart devices. A wide variety of sources generate and publish information in different formats, thus highlighting interoperability as one of the key prerequisites for the success of Internet of Things (IoT). The BT Hypercat Data Hub provides a focal point for the sharing and consumption of available datasets from a wide range of sources. In this work, we propose a semantic enrichment of ...

Promiscuous Diffusible Signal Factor Production and Responsiveness of the Xylella fastidiosa Rpf System

OpenAIRE

Ionescu, Michael; Yokota, Kenji; Antonova, Elena; Garcia, Angelica; Beaulieu, Ellen; Hayes, Terry; Iavarone, Anthony T.; Lindow, Steven E.

2016-01-01

© 2016 Ionescu et al. Cell density-dependent regulation of gene expression in Xylella fastidiosa that is crucial to its switching between plant hosts and insect vectors is dependent on RpfF and its production of 2-enoic acids known as diffusible signal factor (DSF). We show that X. fastidiosa produces a particularly large variety of similar, relatively long-chain-length 2-enoic acids that are active in modulating gene expression. Both X. fastidiosa itself and a Pantoea agglomerans surrogate h...

Measurement of acoustic properties of the composite materials constituting the main rotor hub of the Agusta-Westland helicopter EH-101 (civil version)

Science.gov (United States)

Tenti, L.; Denis, R.; Lakestani, F.

1991-10-01

The acoustic properties of the EH-101 helicopter rotor hub are tested by characterizing the ultrasonic propagation phenomena in the main directions of the composite materials. The carbon fiber and epoxy resin that make up the rotor hub are measured to determine the attenuation coefficient, phase propagation at normal incidence, and phase propagation as a function of angle of incidence. The speeds are measured for external box and filler samples, and strap samples are discussed separately because of their anisotropic nature and structural importance. Deviations angles of 5 deg cause refraction angles of 10 deg in the deviation of the phase propagation; therefore planar defects with an angle of 10 deg relative to the fiber direction can be easily detected. The method presented is useful in characterizing and locating defects in the composite materials that make up the main rotor hub of helicopters.

Effects of MR parameter changes on the quantification of diffusion anisotropy and apparent diffusion coefficient in diffusion tensor imaging: Evaluation using a diffusional anisotropic phantom

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Joon; Choi, Choong Gon; Kim, Jeong Kon [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yun, Sung Cheol [Dept. of Biostatistics, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Jeong, Ha Kyu [Dept. of Radiology, East-West Neomedical Center, Kyung Hee University College of Medicine, Seoul (Korea, Republic of); Kim, Eun Ju [Clinical Scientist, MR, Philips Healthcare, Seoul (Korea, Republic of)

2015-04-15

To validate the usefulness of a diffusional anisotropic capillary array phantom and to investigate the effects of diffusion tensor imaging (DTI) parameter changes on diffusion fractional anisotropy (FA) and apparent diffusion coefficient (ADC) using the phantom. Diffusion tensor imaging of a capillary array phantom was performed with imaging parameter changes, including voxel size, number of sensitivity encoding (SENSE) factor, echo time (TE), number of signal acquisitions, b-value, and number of diffusion gradient directions (NDGD), one-at-a-time in a stepwise-incremental fashion. We repeated the entire series of DTI scans thrice. The coefficients of variation (CoV) were evaluated for FA and ADC, and the correlation between each MR imaging parameter and the corresponding FA and ADC was evaluated using Spearman's correlation analysis. The capillary array phantom CoVs of FA and ADC were 7.1% and 2.4%, respectively. There were significant correlations between FA and SENSE factor, TE, b-value, and NDGD, as well as significant correlations between ADC and SENSE factor, TE, and b-value. A capillary array phantom enables repeated measurements of FA and ADC. Both FA and ADC can vary when certain parameters are changed during diffusion experiments. We suggest that the capillary array phantom can be used for quality control in longitudinal or multicenter clinical studies.

Determination of diffusion coefficients and diffusion characteristics for chlorferon and diethylthiophosphate in Ca-alginate gel beads.

Science.gov (United States)

Ha, Jiyeon; Engler, Cady R; Lee, Seung Jae

2008-07-01

Diffusion characteristics of chlorferon and diethylthiophosphate (DETP) in Ca-alginate gel beads were studied to assist in designing and operating bioreactor systems. Diffusion coefficients for chlorferon and DETP in Ca-alginate gel beads determined at conditions suitable for biodegradation studies were 2.70 x 10(-11) m(2)/s and 4.28 x 10(-11) m(2)/s, respectively. Diffusivities of chlorferon and DETP were influenced by several factors, including viscosity of the bulk solution, agitation speed, and the concentrations of diffusing substrate and immobilized cells. Diffusion coefficients increased with increasing agitation speed, probably due to poor mixing at low speed and some attrition of beads at high speeds. Diffusion coefficients also increased with decreasing substrate concentration. Increased cell concentration in the gel beads caused lower diffusivity. Theoretical models to predict diffusivities as a function of cell weight fraction overestimated the effective diffusivities for both chlorferon and DETP, but linear relations between effective diffusivity and cell weight fraction were derived from experimental data. Calcium-alginate gel beads with radii of 1.65-1.70 mm used in this study were not subject to diffusional limitations: external mass transfer resistances were negligible based on Biot number calculations and effectiveness factors indicated that internal mass transfer resistance was negligible. Therefore, the degradation rates of chlorferon and DETP inside Ca-alginate gel beads were reaction-limited. (c) 2007 Wiley Periodicals, Inc.

Analysis of risk factor of unfavorable outcome in patients with diffuse brain injury from clinical, CT and magnetic resonance imaging findings

International Nuclear Information System (INIS)

Ishizaka, Hideo; Goto, Tadateru; Osada, Takahiro; Shiramizu, Hideki; Shibata, Masayoshi; Matsumae, Mitsunori

2010-01-01

We performed a statistical investigation of poor outcome factors for diffuse brain injury using the state of consciousness, age, gender, pupil abnormality, CT, and MRI findings upon arrival of diffuse brain injury patients to the hospital. We studied 93 diffuse brain injury patients but excluded those with multiple trauma of AIS 3 or above, those who tested positive for alcohol at the time of arrival at the hospital, and those who also exhibited a focal brain injury. Based on clinical findings made at the time patients arrived at the hospital, being older than 65 years of age, Glasgow coma scale (GCS) 7 and below, and having abnormal light reflexes were poor outcome factors. Regarding CT findings, being unable to see the suprasellar cistern, poor visualization of the ambient cistern, and subarachnoid hemorrhage (SAH) on the brain surface were poor outcome factors. Regarding MRI findings, the presence of basal ganglia injury and brainstem injury were poor outcome factors. Based on a stepwise logistic regression analysis of all poor outcome factors, it was revealed that being older than 65 years of age, having light reflex abnormalities, and the existence of brainstem injuries are all poor outcome factors, independent of each other. In addition, regarding injuries to the brain stem, midbrain injuries were the most prevalent and lateral injuries of the midbrain was the most prevalent poor outcome factor. However, in cases of injury to the brainstem only, recovery was good. (author)

Abnormal Intrinsic Functional Hubs in Severe Male Obstructive Sleep Apnea: Evidence from a Voxel-Wise Degree Centrality Analysis.

Science.gov (United States)

Li, Haijun; Li, Lan; Shao, Yi; Gong, Honghan; Zhang, Wei; Zeng, Xianjun; Ye, Chenglong; Nie, Si; Chen, Liting; Peng, Dechang

2016-01-01

Obstructive sleep apnea (OSA) has been associated with changes in brain structure and regional function in certain brain areas. However, the functional features of network organization in the whole brain remain largely uncertain. The purpose of this study was to identify the OSA-related spatial centrality distribution of the whole brain functional network and to investigate the potential altered intrinsic functional hubs. Forty male patients with newly confirmed severe OSA on polysomnography, and well-matched good sleepers, participated in this study. All participants underwent a resting-state functional MRI scan and clinical and cognitive evaluation. Voxel-wise degree centrality (DC) was measured across the whole brain, and group difference in DC was compared. The relationship between the abnormal DC value and clinical variables was assessed using a linear correlation analysis. Remarkably similar spatial distributions of the functional hubs (high DC) were found in both groups. However, OSA patients exhibited a pattern of significantly reduced regional DC in the left middle occipital gyrus, posterior cingulate cortex, left superior frontal gyrus, and bilateral inferior parietal lobule, and DC was increased in the right orbital frontal cortex, bilateral cerebellum posterior lobes, and bilateral lentiform nucleus, including the putamen, extending to the hippocampus, and the inferior temporal gyrus, which overlapped with the functional hubs. Furthermore, a linear correlation analysis revealed that the DC value in the posterior cingulate cortex and left superior frontal gyrus were positively correlated with Montreal cognitive assessment scores, The DC value in the left middle occipital gyrus and bilateral inferior parietal lobule were negatively correlated with apnea-hypopnea index and arousal index in OSA patients. Our findings suggest that OSA patients exhibited specific abnormal intrinsic functional hubs including relatively reduced and increased DC. This expands

Communication and logging hub for rapid prototyping of environmental sensors: presenting the Smartphone.

Science.gov (United States)

Hut, R.

2017-12-01

When desiging prototype sensors for environmental variables a critical step is a comparison campaign where the new sensor is compared to current state of the art sensors. In this step one of the headaches for researchers can be connecting their sensor to a logging or communication device. I present a simple solution: to use smartphone that scans for Bluetooth Low Energy transmissions and uploads any measurement to a data server. In this way the prototype sensor only has to transmit its measurement values over BLE, which can be done using off-the-shelf components. The sensors don't have to be physically connected to the phone, allowing for very rapid deployment of sensors in locations that have a communication hub (ie. phone) installed. The communication and logging hub consists of nothing more than a low cost Android smartphone running a dedicated app. The phone is encased in a waterproof box with a large powerbank and a solar panel. I will demonstrate this live at the Fall Meeting. By installing these phones along permanent WMO certified station locations, comparisons campaigns can use the "golden standard" from the WMO without much problems.

A operação das companhias aéreas nos aeroportos hub & spoke e nas bases operacionais

Directory of Open Access Journals (Sweden)

Cláudia Ribeiro de Almeida

2014-01-01

Full Text Available The process of deregulation of air transportation and all changes that have arisen in the air transport market led to the emergence of new airport concepts, not always clear and easy to understand. Airports Hub & Spoke and operational bases, has specific characteristics to be exploited in this article through case studies that aim to highlight the differences and emphasize its importance for the airlines involved. In this article we are going to evaluate the operation of two airlines that are members of a Strategic Alliance, which operate under a Hub & Spoke network, as well as an example of a low cost airline operating to more than 50 operational bases all over Europe.

TravisTorrent : Synthesizing Travis CI and GitHub for Full-Stack Research on Continuous Integration

NARCIS (Netherlands)

Beller, M.M.; Gousios, Giorgos; Zaidman, A.E.

2017-01-01

Continuous Integration (CI) has become a best practice of modern software development. Thanks in part to its tight integration with GitHub, Travis CI has emerged as arguably the most widely used CI platform for Open-Source Software (OSS) development. However, despite its prominent role in Software

Solar systems diffusion in local markets

International Nuclear Information System (INIS)

Sidiras, D.K.; Koukios, E.G.

2004-01-01

This paper reports on a study of the driving forces and barriers of the spectacular diffusion of solar energy use for domestic hot-water production in Greece. Through the various kinds of questionnaires used in this work, the main diffusion actors have been requested to grade the various diffusion factors identified by desk and preliminary field research. Households identify a number of economic (available family income), technical (new technologies), political (new incentives), and socio-cultural (sensitivity in energy matters) factors as dominant. According to the solar industry, advertising, distribution and quality control standards have to be added to the list of critical factors. Technical experts contribute with identifying, besides R and D, public awareness on energy matters. Solar collector diffusion, despite the fact that it has followed a market-driven mechanism, was revealed to be a multi-actor, multi-dimensional and multi-parametric phenomenon. Presently, the phenomenon is constrained by the available family income, with technology-related factors, i.e., research, and standardization quality control, playing increasing roles

Basic consideration of diffusion/perfusion imaging

International Nuclear Information System (INIS)

Tamagawa, Yoichi; Kimura, Hirohiko; Matsuda, Tsuyoshi; Kawamura, Yasutaka; Nakatsugawa, Shigekazu; Ishii, Yasushi; Sakuma, Hajime; Tsukamoto, Tetsuji.

1990-01-01

In magnetic resonance imaging (MRI), microscopic motion of biological system such as molecular diffusion of water and microcirculation of blood in the capillary network (perfusion) has been proposed to cause signal attenuation as an intravoxel incoherent motion (IVIM). Quantitative imaging of the IVIM phenomenon was attempted to generate from a set of spin-echo (SE) sequences with or without sensitization by motion probing gradient (MPG). The IVIM imaging is characterized by a parameter, apparent diffusion coefficient (ADC), which is an integration of both the diffusion and the perfusion factor on voxel-by-voxel basis. Hard ware was adjusted to avoid image artifact mainly produced by eddy current. Feasibility of the method was tested using bottle phantom filled with water at different temperature and acetone, and the calculated ADC values of these media corresponded well with accepted values of diffusion. The method was then applied to biological system to investigate mutual participation of diffusion/perfusion on the ADC value. The result of tumor model born on nude mouse suggested considerable participation of perfusion factor which immediately disappeared after sacrificing the animal. Meanwhile, lower value of sacrificed tissue without microcirculation was suggested to have some restriction of diffusion factor by biological tissue. To substantiate the restriction effect on the diffusion, a series of observation have made on a fiber phantom, stalk of celory with botanical fibers and human brain with nerve fibers, in applying unidirectional MPG along the course of these banch of fiber system. The directional restriction effect of diffusion along the course of fiber (diffusion anisotrophy) was clearly visualized as directional change of ADC value. The present method for tissue characterization by diffusion/perfusion on microscopic level will provide a new insight for evaluation of functional derangement in human brain and other organs. (author)

Diffusion through statically compacted clay

International Nuclear Information System (INIS)

Ho, C.L.; Shebl, M.A.A.

1994-01-01

This paper presents experimental work on the effect of compaction on contaminant flow through clay liners. The experimental program included evaluation of soil properties, compaction, permeability and solute diffusion. A permeameter was built of non reactive materials to test samples compacted at different water contents and compactive efforts. The flow of a permeating solute, LiCl, was monitored. Effluent samples were collected for solute concentration measurements. The concentrations were measured by performing atomic adsorption tests. The analyzed results showed different diffusion characteristics when compaction conditions changed. At each compactive effort, permeability decreased as molding water content increased. Consequently, transit time (measured at relative concentration 50%) increased and diffusivity decreased. As compactive effort increased for soils compacted dry of optimum, permeability and diffusion decreased. On the other hand, as compactive effort increased for soils compacted wet of optimum, permeability and diffusivity increased. Tortuosity factor was indirectly measured from the diffusion and retardation rate. Tortuosity factor also decreased as placement water content was increased from dry of optimum to wet of optimum. Then decreases were more pronounced for low compactive effort tests. 27 refs., 7 figs., 5 tabs

Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 1: Engineering studies

Science.gov (United States)

Alexander, H. R.; Smith, K. E.; Mcveigh, M. A.; Dixon, P. G.; Mcmanus, B. L.

1979-01-01

Composite structures technology is applied in a preliminary design study of advanced technology blades and hubs for the XV-15 tilt rotor research demonstrator aircraft. Significant improvements in XV-15 hover and cruise performance are available using blades designed for compatibility with the existing aircraft, i.e., blade installation would not require modification of the airframe, hub or upper controls. Provision of a low risk nonmechanical control system was also studied, and a development specification is given.

Final Report for Project: Impacts of stratification and non-equilibrium winds and waves on hub-height winds

Energy Technology Data Exchange (ETDEWEB)

Patton, Edward G. [Univ. Corporation for Atmospheric Research, Boulder, CO (United States)

2015-07-14

wind plant scale. Overall project conclusions include; In the presence of fast-moving swell (significant wave height Hs = 6.4 m, and phase speed cp = 18 ms^-1), the atmospheric boundary layer grows more rapidly when waves propagate opposite to the winds compared to when winds and waves are aligned. Pressure drag increases by nearly a factor of 2 relative to the turbulent stress for the extreme case where waves propagate at 180° compared to the pressure gradient forcing. Net wind speed reduces by nearly 15% at hub-height for the 180°-case compared to the 0°-case, and turbulence intensities increase by nearly a factor of 2. These impacts diminish with decreasing wave age; Stratification increases hub height wind speeds and increases the vertical shear of the mean wind across the rotor plane. Fortuitously, this stability-induced enhanced shear does not influence turbulence intensity at hub height, but does increase (decrease) turbulence intensity below (above) hub height. Increased stability also increases the wave-induced pressure stress by ~ 10%; Off the East Coast of the United States during Coupled Boundary Layers Air-Sea Transfer - Low Wind (CBLAST-Low), cases with short fetch include thin stable boundary layers with depths of only a few tens of meters. In the coastal zone, the relationship between the mean wind and the surface fiction velocity (u*(V )) is significantly related to wind direction for weak winds but is not systematically related to the air sea difference of virtual potential temperature, δθv; since waves generally propagate from the south at the Air-Sea Interaction Tower (ASIT) tower, these results suggest that under weak wind conditions waves likely influence surface stress more than stratification does; and Winds and waves are frequently misaligned in the coastal zone. Stability conditions persist for long duration. Over a four year period, the Forschungsplattformen in Nord- und Ostsee Nr. 1 (FINO1) tower (a site with long fetch

Establishment of a Hub for the Light Water Reactor Sustainability Online Monitoring Community

International Nuclear Information System (INIS)

Lybeck, Nancy J.; Tawfik, Magdy S.; Pham, Binh T.

2011-01-01

Implementation of online monitoring and prognostics in existing U.S. nuclear power plants will involve coordinating the efforts of national laboratories, utilities, universities, and private companies. Internet-based collaborative work environments provide necessary communication tools to facilitate interaction between geographically diverse participants. Available technologies were considered, and a collaborative workspace was established at INL as a hub for the light water reactor sustainability online monitoring community.

Effect on the annual atmospheric dispersion factor of different diffusion parameters and meteorological data at nuclear power plant

International Nuclear Information System (INIS)

Hu Erbang; Yan Jiangyu; Wang Han; Xin Cuntian

2003-01-01

Based on the hourly metrological observing data of 100 m high tower during 1997-1999 at Tianwan Nuclear Power Plant (NPP) site and 1995-1997 in Fujian Huian NPP site, the effect on the annual atmospheric dispersion factor (AADF) of four different diffusion parameters (on-site measuring values, IAEA's, Briggs's and Pasquill's) are estimated. The analysis shows that the deviation between the results from IAEA's, Briggs's and on-site measured diffusion parameters is less than 20%. The effect on the AADF from different years' meteorological data also is estimated. (authors)

Reviewing the Justice and Security Hub Modality as Piloted in Liberia

Directory of Open Access Journals (Sweden)

Rory Keane

2012-11-01

Full Text Available ‘The Republic of Bangui’ or ‘the Republic of Monrovia’ are phrases we sometimes hear from practitioners to describe post conflict countries where very few services exist outside the capital city. This is especially the case for security – the critical public good in post conflict countries. In response to the need to bring security services closer to the citizens who often need them most, the Government of Liberia and the United Nations are piloting a new approach financed by the UN Peacebuilding Fund (PBF – the so-called ‘Justice and Security Hubs’. The donor community and the United Nations are watching closely. If this works, there is indication from UN officials that the model could potentially be replicated in other settings such as the East of the Democratic Republic of the Congo (DRC, Haiti and the northern states of South Sudan. If the hub concept is capable of being adapted and successful elsewhere, the United Nations will not only have added a new instrument to its peacekeeping toolkit but will also firmly demonstrate how the UN Peacebuilding Fund can in essence be catalytic in fostering long-term and comprehensive approaches to peacebuilding. This practice note outlines the process of developing and constructing the first hub in Liberia, which is due to be partly operational by the end of 2012, and provides a prognosis on its chances for success.

Diffusing Best Practices

DEFF Research Database (Denmark)

Pries-Heje, Jan; Baskerville, Richard

2014-01-01

approach. The study context is a design case in which an organization desires to diffuse its best practices across different groups. The design goal is embodied in organizational mechanisms to achieve this diffusion. The study used Theory of Planned Behavior (TPB) as a kernel theory. The artifacts...... resulting from the design were two-day training workshops conceptually anchored to TBP. The design theory was evaluated through execution of eight diffusion workshops involving three different groups in the same company. The findings indicate that the match between the practice and the context materialized...... that the behavior will be effective). These two factors were especially critical if the source context of the best practice is qualitatively different from the target context into which the organization is seeking to diffuse the best practice....

Interpatch foraging in honeybees-rational decision making at secondary hubs based upon time and motivation.

Science.gov (United States)

Najera, Daniel A; McCullough, Erin L; Jander, Rudolf

2012-11-01

For honeybees, Apis mellifera, the hive has been well known to function as a primary decision-making hub, a place from which foragers decide among various directions, distances, and times of day to forage efficiently. Whether foraging honeybees can make similarly complex navigational decisions from locations away from the hive is unknown. To examine whether or not such secondary decision-making hubs exist, we trained bees to forage at four different locations. Specifically, we trained honeybees to first forage to a distal site "CT" 100 m away from the hive; if food was present, they fed and then chose to go home. If food was not present, the honeybees were trained to forage to three auxiliary sites, each at a different time of the day: A in the morning, B at noon, and C in the afternoon. The foragers learned to check site CT for food first and then efficiently depart to the correct location based upon the time of day if there was no food at site CT. Thus, the honeybees were able to cognitively map motivation, time, and five different locations (Hive, CT, A, B, and C) in two spatial dimensions; these are the contents of the cognitive map used by the honeybees here. While at site CT, we verified that the honeybees could choose between 4 different directions (to A, B, C, and the Hive) and thus label it as a secondary decision-making hub. The observed decision making uncovered here is inferred to constitute genuine logical operations, involving a branched structure, based upon the premises of motivational state, and spatiotemporal knowledge.

Diffusion in substitutionally disordered B2 intermetallics

International Nuclear Information System (INIS)

Belova, I.V.; Murch, G.E.

2002-01-01

In this paper, a comprehensive diffusion kinetics theory is formulated to describe seamlessly tracer and chemical diffusion in antistructurally disordered B2 intermetallics showing positive and negative deviations from stoichiometry. The theory is based around unit processes consisting of six-jump cycles that can be assisted by intrinsic and extrinsic antistructural atoms of either atomic species. The Ising alloy model is used to illustrate the formalism, but the formalism can be adapted to other models. Expressions are developed for the tracer diffusion coefficients, the phenomenological coefficients, the intrinsic diffusion coefficients, the interdiffusion coefficient and the various correlation factor components. Results for the tracer and collective correlation factors and the vacancy wind factor (in interdiffusion) are in excellent agreement with results from Monte Carlo computer simulations based around single vacancy jumps. (author)

Determination of neutron buildup factor using analytical solution of one-dimensional neutron diffusion equation in cylindrical geometry

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Julio Cesar L.; Vilhena, Marco Tullio, E-mail: julio.lombaldo@ufrgs.b, E-mail: vilhena@pq.cnpq.b [Universidade Federal do Rio Grande do Sul (DMPA/UFRGS), Porto Alegre, RS (Brazil). Dept. de Matematica Pura e Aplicada. Programa de Pos Graduacao em Matematica Aplicada; Borges, Volnei; Bodmann, Bardo Ernest, E-mail: bardo.bodmann@ufrgs.b, E-mail: borges@ufrgs.b [Universidade Federal do Rio Grande do Sul (PROMEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica

2011-07-01

The principal idea of this work, consist on formulate an analytical method to solved problems for diffusion of neutrons with isotropic scattering in one-dimensional cylindrical geometry. In this area were develop many works that study the same problem in different system of coordinates as well as cartesian system, nevertheless using numerical methods to solve the shielding problem. In view of good results in this works, we starting with the idea that we can represent a source in the origin of the cylindrical system by a Delta Dirac distribution, we describe the physical modeling and solved the neutron diffusion equation inside of cylinder of radius R. For the case of transport equation, the formulation of discrete ordinates S{sub N} consists in discretize the angular variables in N directions and in using a quadrature angular set for approximate the sources of scattering, where the Diffusion equation consist on S{sub 2} approximated transport equation in discrete ordinates. We solved the neutron diffusion equation with an analytical form by the finite Hankel transform. Was presented also the build-up factor for the case that we have neutron flux inside the cylinder. (author)

Determination of neutron buildup factor using analytical solution of one-dimensional neutron diffusion equation in cylindrical geometry

International Nuclear Information System (INIS)

Fernandes, Julio Cesar L.; Vilhena, Marco Tullio; Borges, Volnei; Bodmann, Bardo Ernest

2011-01-01

The principal idea of this work, consist on formulate an analytical method to solved problems for diffusion of neutrons with isotropic scattering in one-dimensional cylindrical geometry. In this area were develop many works that study the same problem in different system of coordinates as well as cartesian system, nevertheless using numerical methods to solve the shielding problem. In view of good results in this works, we starting with the idea that we can represent a source in the origin of the cylindrical system by a Delta Dirac distribution, we describe the physical modeling and solved the neutron diffusion equation inside of cylinder of radius R. For the case of transport equation, the formulation of discrete ordinates S N consists in discretize the angular variables in N directions and in using a quadrature angular set for approximate the sources of scattering, where the Diffusion equation consist on S 2 approximated transport equation in discrete ordinates. We solved the neutron diffusion equation with an analytical form by the finite Hankel transform. Was presented also the build-up factor for the case that we have neutron flux inside the cylinder. (author)

Confusion with Diffusion? Unravelling IS Diffusion and Innovation Literature with a Focus on SME'S

Directory of Open Access Journals (Sweden)

Jeanette Van Akkeren

1999-11-01

Full Text Available The aim of this paper is to contribute to understanding of the various models used in research for the adoption and diffusion of information technology in small and medium sized enterprises (SMEs. Starting with Rogers' diffusion theory and behavioural models, technology adoption models used in IS research are discussed. Empirical research has shown that the reasons why firms choose to adopt or not adopt technology is dependent on a number of factors. These factors can be categorised as owner/manager characteristics, firm characteristics, and other characteristics. The existing models explaining IS diffusion and adoption by SMEs overlap and complement each other. This paper reviews the existing literature and proposes a comprehensive model which includes the whole array of variables from earlier models.

Unveiling Exception Handling Bug Hazards in Android Based on GitHub and Google Code Issues

NARCIS (Netherlands)

Coelho, R.; Almeida, L.; Gousios, G.; Van Deursen, A.

2015-01-01

This paper reports on a study mining the exception stack traces included in 159,048 issues reported on Android projects hosted in GitHub (482 projects) and Google Code (157 projects). The goal of this study is to investigate whether stack trace information can reveal bug hazards related to exception

Hypocretin as a Hub for Arousal and Motivation

Directory of Open Access Journals (Sweden)

Susan M. Tyree

2018-06-01

Full Text Available The lateral hypothalamus is comprised of a heterogeneous mix of neurons that serve to integrate and regulate sleep, feeding, stress, energy balance, reward, and motivated behavior. Within these populations, the hypocretin/orexin neurons are among the most well studied. Here, we provide an overview on how these neurons act as a central hub integrating sensory and physiological information to tune arousal and motivated behavior accordingly. We give special attention to their role in sleep-wake states and conditions of hyper-arousal, as is the case with stress-induced anxiety. We further discuss their roles in feeding, drug-seeking, and sexual behavior, which are all dependent on the motivational state of the animal. We further emphasize the application of powerful techniques, such as optogenetics, chemogenetics, and fiber photometry, to delineate the role these neurons play in lateral hypothalamic functions.

Global Dynamics and International Cooperation Needs of RT Development and Utilization for the Establishment of the Northeast Asia RT Hub in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. K.; Oh, G. B.; Yun, S. W.; Yang, M. H.; Ryu, J. S.; Choi, S. J.; Choi, S. G

2005-11-15

In an effort to achieve the objectives, the following scopes were categorized for in-depth study. First, analysis framework was developed for RT capacity development and international technology cooperation strategy. RT survey checklist and international technology cooperation was analyzed with interviewing and reports of domestic participants recently. Second, RT strategic environment was analyze for East-Asia hub competition/cooperation and developing nations using analysis framework. Korean RT was analyzed using SWOT analysis for establishment of RT hub in Korea. Third, East-Asian nations were classified analyzed by RT categories in standpoint of our country. Technology status and future cooperation plan were discussed about RT application for bio-medicine. Products/technology seminar related to an export was hold about support plan of admission/sales for functional food HemoHIM. This study can be utilized in the establishment of RT hub and development strategy. And it can be also utilized in promotion devising of domestic RT and planning setup for obtaing the international competitive power.

Global Dynamics and International Cooperation Needs of RT Development and Utilization for the Establishment of the Northeast Asia RT Hub in Korea

International Nuclear Information System (INIS)

Kim, Y. K.; Oh, G. B.; Yun, S. W.; Yang, M. H.; Ryu, J. S.; Choi, S. J.; Choi, S. G.

2005-11-01

In an effort to achieve the objectives, the following scopes were categorized for in-depth study. First, analysis framework was developed for RT capacity development and international technology cooperation strategy. RT survey checklist and international technology cooperation was analyzed with interviewing and reports of domestic participants recently. Second, RT strategic environment was analyze for East-Asia hub competition/cooperation and developing nations using analysis framework. Korean RT was analyzed using SWOT analysis for establishment of RT hub in Korea. Third, East-Asian nations were classified analyzed by RT categories in standpoint of our country. Technology status and future cooperation plan were discussed about RT application for bio-medicine. Products/technology seminar related to an export was hold about support plan of admission/sales for functional food HemoHIM. This study can be utilized in the establishment of RT hub and development strategy. And it can be also utilized in promotion devising of domestic RT and planning setup for obtaing the international competitive power

Tracer diffusion in ternary alloys

International Nuclear Information System (INIS)

Tahir-Kheli, R.A.

1985-07-01

An intuitive extension of the theory for diffusion in dynamic binary alloys given in the preceding paper is presented. This theory has also received an independent derivation, based on more formal procedures, by Holdsworth and Elliott. We present Monte Carlo estimates for diffusion correlation factors, fsup(A), fsup(B), and fsup(C) and compare them with the theory. The agreement between the theoretical results and the Monte Carlo estimates for the correlation factors of the slow particles, i.e., fsup(C) and fsup(B), is found to be generally good. In contrast, for the correlation factor, fsup(A), referring to the diffusion coefficient of fast particles in the system, the theoretical results are found to be systematically lower by a small but resolvable margin. It is suggested that this is occasioned by the neglect of spatial constraints on the scattering of coupled tracer-background particle field pairs. (author)

Consequences of Diffusion of Innovations.

Science.gov (United States)

Goss, Kevin F.

1979-01-01

The article traces evolution of diffusion theory; illustrates undesirable consequences in a cross-cultural setting, reviews criticisms of several scholars; considers distributional effects and unanticipated consequences for potential ameliorative impact on diffusion theory; and codifies these factors into a framework for research into consequences…

Dynamic Migration Intentions and the Impact of Socio-Institutional Environments: A Transit Migration Hub in Turkey

NARCIS (Netherlands)

Wissink, M.J.; Düvell, F.; van Eerdewijk, A.

2013-01-01

Transit migration is generally defined by migrants having the intention to move onwards to a third country. Based on an empirical investigation in Izmir, a transit migration hub in Turkey, this paper critically discusses intentionality as a valid dimension in conceptualisations of transit migration.

Systems biology approach to transplant tolerance: proof of concept experiments using RNA interference (RNAi) to knock down hub genes in Jurkat and HeLa cells in vitro.

Science.gov (United States)

Lwin, Wint Wah; Park, Ken; Wauson, Matthew; Gao, Qin; Finn, Patricia W; Perkins, David; Khanna, Ajai

2012-07-01

Systems biology is gaining importance in studying complex systems such as the functional interconnections of human genes [1]. To investigate the molecular interactions involved in T cell immune responses, we used databases of physical gene-gene interactions to constructed molecular interaction networks (interconnections) with R language algorithms. This helped to identify highly interconnected "hub" genes AT(1)P5C1, IL6ST, PRKCZ, MYC, FOS, JUN, and MAPK1. We hypothesized that suppression of these hub genes in the gene network would result in significant phenotypic effects on T cells and examined this in vitro. The molecular interaction networks were then analyzed and visualized with Cytoscape. Jurkat and HeLa cells were transfected with siRNA for the selected hub genes. Cell proliferation was measured using ATP luminescence and BrdU labeling, which were measured 36, 72, and 96 h after activation. Following T cell stimulation, we found a significant decrease in ATP production (P cells. However, HeLa cells showed a significant (P cell proliferation when the genes MAPK1, IL6ST, ATP5C1, JUN, and FOS were knocked down. In both Jurkat and HeLa cells, targeted gene knockdown using siRNA showed decreased cell proliferation and ATP production in both Jurkat and HeLa cells. However, Jurkat T cells and HELA cells use different hub genes to regulate activation responses. This experiment provides proof of principle of applying siRNA knockdown of T cell hub genes to evaluate their proliferative capacity and ATP production. This novel concept outlines a systems biology approach to identify hub genes for targeted therapeutics. Published by Elsevier Inc.

Client and event driven data hub system at CDF

International Nuclear Information System (INIS)

Kilminster, Ben; McFarland, Kevin; Vaiciulis, Tony; Matsunaga, Hiroyuki; Shimojima, Makoto

2001-01-01

The Consumer-Server Logger (CSL) system at the Collider Detector at Fermilab is a client and event driven data hub capable of receiving physics events from multiple connections, and logging them to multiple streams while distributing them to multiple online analysis programs (consumers). Its multiple-partitioned design allows data flowing through different paths of the detector sub-systems to be processed separately. The CSL system, using a set of internal memory buffers and message queues mapped to the location of events within its programs, and running on an SGI 2200 Server, is able to process at least the required 20 MB/s of constant event logging (75 Hz of 250 KB events) while also filtering up to 10 MB/s to consumers requesting specific types of events

Reducing Time to Science: Unidata and JupyterHub Technology Using the Jetstream Cloud

Science.gov (United States)

Chastang, J.; Signell, R. P.; Fischer, J. L.

2017-12-01

Cloud computing can accelerate scientific workflows, discovery, and collaborations by reducing research and data friction. We describe the deployment of Unidata and JupyterHub technologies on the NSF-funded XSEDE Jetstream cloud. With the aid of virtual machines and Docker technology, we deploy a Unidata JupyterHub server co-located with a Local Data Manager (LDM), THREDDS data server (TDS), and RAMADDA geoscience content management system. We provide Jupyter Notebooks and the pre-built Python environments needed to run them. The notebooks can be used for instruction and as templates for scientific experimentation and discovery. We also supply a large quantity of NCEP forecast model results to allow data-proximate analysis and visualization. In addition, users can transfer data using Globus command line tools, and perform their own data-proximate analysis and visualization with Notebook technology. These data can be shared with others via a dedicated TDS server for scientific distribution and collaboration. There are many benefits of this approach. Not only is the cloud computing environment fast, reliable and scalable, but scientists can analyze, visualize, and share data using only their web browser. No local specialized desktop software or a fast internet connection is required. This environment will enable scientists to spend less time managing their software and more time doing science.

Branding by Proxy? : How hubs market (or not) higher education systems globally: the example of Qatar

NARCIS (Netherlands)

Cremonini, Leon; Taylor, John; Papadimitriou, Antigoni

2017-01-01

This chapter proposes a framework to understand if and how hubs contribute to stronger positioning of higher education system in global competition, and uses the case of Qatar to draw conclusions. Increasingly, governments around the world invest in so-called “education hubs”, which host excellent

Comparison of radon diffusion coefficients measured by transient-diffusion and steady-state laboratory methods

International Nuclear Information System (INIS)

Kalwarf, D.R.; Nielson, K.K.; Rich, D.C.; Rogers, V.C.

1982-11-01

A method was developed and used to determine radon diffusion coefficients in compacted soils by transient-diffusion measurements. A relative standard deviation of 12% was observed in repeated measurements with a dry soil by the transient-diffusion method, and a 40% uncertainty was determined for moistures exceeding 50% of saturation. Excellent agreement was also obtained between values of the diffusion coefficient for radon in air, as measured by the transient-diffusion method, and those in the published literature. Good agreement was also obtained with diffusion coefficients measured by a steady-state method on the same soils. The agreement was best at low moistures, averaging less than ten percent difference, but differences of up to a factor of two were observed at high moistures. The comparison of the transient-diffusion and steady-state methods at low moistures provides an excellent verification of the theoretical validity and technical accuracy of these approaches, which are based on completely independent experimental conditions, measurement methods and mathematical interpretations

Researching Higher Education in "Asia's Global Education Hub": Trends and Issues in Singapore

Science.gov (United States)

Lee, Michael H.

2016-01-01

Higher education studies as a field of academic research has become more developed and important in Singapore since the 1980s when the city-state placed more emphasis on reforming and restructuring its higher education sector to achieve the status of "Asia's global education hub". The past few decades witnessed a more significant growth…

Diffusion coefficients of paracetamol in aqueous solutions

International Nuclear Information System (INIS)

Ribeiro, Ana C.F.; Barros, Marisa C.F.; Veríssimo, Luís M.P.; Santos, Cecilia I.A.V.; Cabral, Ana M.T.D.P.V.; Gaspar, Gualter D.; Esteso, Miguel A.

2012-01-01

Highlights: ► Mutual diffusion coefficients of paracetamol in aqueous dilute solutions. ► Influence of the thermodynamic factors on the variation of their mutual diffusion coefficients. ► Estimation of the mutual limiting diffusion coefficients of the molecular, D m 0 , and ionized forms, D ± 0 , of this drug. - Abstract: Binary mutual diffusion coefficients measured by the Taylor dispersion method, for aqueous solutions of paracetamol (PA) at concentrations from (0.001 to 0.050) mol·dm −3 at T = 298.15 K, are reported. From the Nernst–Hartley equation and our experimental results, the limiting diffusion coefficient of this drug and its thermodynamic factors are estimated, thereby contributing in this way to a better understanding of the structure of such systems and of their thermodynamic behaviour in aqueous solution at different concentrations.

Design and optimizing factors of PACS network architecture

International Nuclear Information System (INIS)

Tao Yonghao; Miao Jingtao

2001-01-01

Objective: Exploring the design and optimizing factors of picture archiving and communication system (PACS) network architecture. Methods: Based on the PACS of shanghai first hospital to performed the measurements and tests on the requirements of network bandwidth and transmitting rate for different PACS functions and procedures respectively in static and dynamic network traffic situation, utilizing the network monitoring tools which built-in workstations and provided by Windows NT. Results: No obvious difference between switch equipment and HUB when measurements and tests implemented in static situation except route which slow down the rate markedly. In dynamic environment Switch is able to provide higher bandwidth utilizing than HUB and local system scope communication achieved faster transmitting rate than global system. Conclusion: The primary optimizing factors of PACS network architecture design include concise network topology and disassemble tremendous global traffic to multiple distributed local scope network communication to reduce the traffic of network backbone. The most important issue is guarantee essential bandwidth for diagnosis procedure of medical imaging

Benefits of Two Turbine Rotor Diameters and Hub Heights in the Same Wind Farm

Energy Technology Data Exchange (ETDEWEB)

Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stanley, Andrew P. J. [Brigham Young University; Ning, Andrew [Brigham Young University

2018-01-12

Significant turbine-wake interactions greatly reduce power output in a wind farm. If different turbine hub heights and rotor diameters are included in the same wind farm, the wake interference in the farm will be reduced, resulting in a lower cost of energy (COE) than a farm with identical turbines. In this paper, we present a method to model wind farm COE in farms with hub heights and rotor diameters that vary across the wind farm. We also demonstrate how to optimize these wind farms to minimize COE. The results show that COE can be greatly reduced in wind farms with non-homogeneous turbines, especially when the turbines are spaced close together. For a unidirectional wind rose, including different turbine design in the wind farm has a similar decrease in COE to spreading the wind turbines farther apart. When the rotor diameter and hub height of the wind turbines in a farm are optimized uniformly, a COE decrease of 4% to 13% (depending on the grid spacing and wind shear exponent) is achieved compared to the baseline. When the rotor diameter and turbine heights are optimized non-uniformly, with two different diameters and heights throughout the farm, there is a COE decrease of 22% to 41% compared to the baseline. For a more spread wind rose with a dominant probability from the west, there is a COE decrease between 3% and 10% for uniformly optimized rotor diameter and height compared to the baseline. With two optimized rotor diameters and heights through the farm, a COE decrease of 3% to 19% is achieved. For a similar wind rose shifted such that the dominant wind direction is from the northwest, a COE decrease between 3% and 10% results from uniformly optimized wind turbines compared to the baseline. A COE decrease of 3% to 17% compared to the baseline occurs with two different turbines are optimized throughout the wind farm.

A preliminary assessment of the potential for 'team science' in DOE Energy Innovation Hubs and Energy Frontier Research Centers

International Nuclear Information System (INIS)

Boardman, Craig; Ponomariov, Branco

2011-01-01

President Obama has called for the development of new energy technologies to address our national energy needs and restore US economic competitiveness. In response, the Department of Energy has established new R and D modalities for energy research and development designed to facilitate collaboration across disciplinary, institutional, and sectoral boundaries. In this research note, we provide a preliminary assessment of the potential for essential mechanisms for coordinated problem solving among diverse actors within two new modalities at the DOE: Energy Innovation Hubs and Energy Frontier Research Centers. - Highlights: → Energy Frontier Research Centers may lack the basic mechanisms for coordinating diverse actors. → Divergent goals across diverse actors may hinder coordination in Energy Innovation Hubs. → The implementation of these and similar energy policies require further investigation.

Diffusion of Messages from an Electronic Cigarette Brand to Potential Users through Twitter.

Directory of Open Access Journals (Sweden)

Kar-Hai Chu

Full Text Available This study explores the presence and actions of an electronic cigarette (e-cigarette brand, Blu, on Twitter to observe how marketing messages are sent and diffused through the retweet (i.e., message forwarding functionality. Retweet networks enable messages to reach additional Twitter users beyond the sender's local network. We follow messages from their origin through multiple retweets to identify which messages have more reach, and the different users who are exposed.We collected three months of publicly available data from Twitter. A combination of techniques in social network analysis and content analysis were applied to determine the various networks of users who are exposed to e-cigarette messages and how the retweet network can affect which messages spread.The Blu retweet network expanded during the study period. Analysis of user profiles combined with network cluster analysis showed that messages of certain topics were only circulated within a community of e-cigarette supporters, while other topics spread further, reaching more general Twitter users who may not support or use e-cigarettes.Retweet networks can serve as proxy filters for marketing messages, as Twitter users decide which messages they will continue to diffuse among their followers. As certain e-cigarette messages extend beyond their point of origin, the audience being exposed expands beyond the e-cigarette community. Potential implications for health education campaigns include utilizing Twitter and targeting important gatekeepers or hubs that would maximize message diffusion.

Why primary care practices should become digital health information hubs for their patients.

Science.gov (United States)

Baird, Aaron; Nowak, Samantha

2014-11-25

Two interesting health care trends are currently occurring: 1) patient-facing technologies, such as personal health records, patient portals, and mobile health apps, are being adopted at rapid rates, and 2) primary care, which includes family practice, is being promoted as essential to reducing health care costs and improving health care outcomes. While these trends are notable and commendable, both remain subject to significant fragmentation and incentive misalignments, which has resulted in significant data coordination and value generation challenges. In particular, patient-facing technologies designed to increase care coordination, often fall prey to the very digital fragmentation issues they are supposed to overcome. Additionally, primary care providers are treating patients that may have considerable health information histories, but generating a single view of such multi-source data is nearly impossible. We contribute to this debate by proposing that primary care practices become digital health information hubs for their patients. Such hubs would offer health data coordination in a medically professional setting with the benefits of expert, trustworthy advice coupled with active patient engagement. We acknowledge challenges including: costs, information quality and provenance, willingness-to-share information and records, willingness-to-use (by both providers and patients), primary care scope creep, and determinations of technical and process effectiveness. Even with such potential challenges, we strongly believe that more debate is needed on this topic prior to full implementation of various health information technology incentives and reform programs currently being designed and enacted throughout the world. Ultimately, if we do not provide a meaningful way for the full spectrum of health information to be used by both providers and patients, especially early in the health care continuum, effectively improving health outcomes may remain elusive. We view

WetDATA Hub: Democratizing Access to Water Data to Accelerate Innovation through Data Visualization, Predictive Analytics and Artificial Intelligence Applications

Science.gov (United States)

Sarni, W.

2017-12-01

Water scarcity and poor quality impacts economic development, business growth, and social well-being. Water has become, in our generation, the foremost critical local, regional, and global issue of our time. Despite these needs, there is no water hub or water technology accelerator solely dedicated to water data and tools. There is a need by the public and private sectors for vastly improved data management and visualization tools. This is the WetDATA opportunity - to develop a water data tech hub dedicated to water data acquisition, analytics, and visualization tools for informed policy and business decisions. WetDATA's tools will help incubate disruptive water data technologies and accelerate adoption of current water data solutions. WetDATA is a Colorado-based (501c3), global hub for water data analytics and technology innovation. WetDATA's vision is to be a global leader in water information, data technology innovation and collaborate with other US and global water technology hubs. ROADMAP * Portal (www.wetdata.org) to provide stakeholders with tools/resources to understand related water risks. * The initial activities will provide education, awareness and tools to stakeholders to support the implementation of the Colorado State Water Plan. * Leverage the Western States Water Council Water Data Exchange database. * Development of visualization, predictive analytics and AI tools to engage with stakeholders and provide actionable data and information. TOOLS Education: Provide information on water issues and risks at the local, state, national and global scale. Visualizations: Development of data analytics and visualization tools based upon the 2030 Water Resources Group methodology to support the implementation of the Colorado State Water Plan. Predictive Analytics: Accessing publically available water databases and using machine learning to develop water availability forecasting tools, and time lapse images to support city / urban planning.

Impact of Tidal Level Variations on Wave Energy Absorption at Wave Hub

Directory of Open Access Journals (Sweden)

Valeria Castellucci

2016-10-01

Full Text Available The energy absorption of the wave energy converters (WEC characterized by a limited stroke length —like the point absorbers developed at Uppsala University—depends on the sea level variation at the deployment site. In coastal areas characterized by high tidal ranges, the daily energy production of the generators is not optimal. The study presented in this paper quantifies the effects of the changing sea level at the Wave Hub test site, located at the south-west coast of England. This area is strongly affected by tides: the tidal height calculated as the difference between the Mean High Water Spring and the Mean Low Water Spring in 2014 was about 6.6 m. The results are obtained from a hydro-mechanic model that analyzes the behaviour of the point absorber at the Wave Hub, taking into account the sea state occurrence scatter diagram and the tidal time series at the site. It turns out that the impact of the tide decreases the energy absorption by 53%. For this reason, the need for a tidal compensation system to be included in the design of the WEC becomes compelling. The economic advantages are evaluated for different scenarios: the economic analysis proposed within the paper allows an educated guess to be made on the profits. The alternative of extending the stroke length of the WEC is investigated, and the gain in energy absorption is estimated.

Hubs of Anticorrelation in High-Resolution Resting-State Functional Connectivity Network Architecture.

Science.gov (United States)

Gopinath, Kaundinya; Krishnamurthy, Venkatagiri; Cabanban, Romeo; Crosson, Bruce A

2015-06-01

A major focus of brain research recently has been to map the resting-state functional connectivity (rsFC) network architecture of the normal brain and pathology through functional magnetic resonance imaging. However, the phenomenon of anticorrelations in resting-state signals between different brain regions has not been adequately examined. The preponderance of studies on resting-state fMRI (rsFMRI) have either ignored anticorrelations in rsFC networks or adopted methods in data analysis, which have rendered anticorrelations in rsFC networks uninterpretable. The few studies that have examined anticorrelations in rsFC networks using conventional methods have found anticorrelations to be weak in strength and not very reproducible across subjects. Anticorrelations in rsFC network architecture could reflect mechanisms that subserve a number of important brain processes. In this preliminary study, we examined the properties of anticorrelated rsFC networks by systematically focusing on negative cross-correlation coefficients (CCs) among rsFMRI voxel time series across the brain with graph theory-based network analysis. A number of methods were implemented to enhance the neuronal specificity of resting-state functional connections that yield negative CCs, although at the cost of decreased sensitivity. Hubs of anticorrelation were seen in a number of cortical and subcortical brain regions. Examination of the anticorrelation maps of these hubs indicated that negative CCs in rsFC network architecture highlight a number of regulatory interactions between brain networks and regions, including reciprocal modulations, suppression, inhibition, and neurofeedback.

HIV and AIDS Data Hub for Asia Pacific: a regional tool to support strategic information needs

Directory of Open Access Journals (Sweden)

Ye Yu Shwe

2012-09-01

Full Text Available The 2011 global commitments towards controlling HIV made by Asia-Pacific countries require considerable improvement in strategic information and response tracking. The HIV and AIDS Data Hub can serve as an important tool for stakeholders with its regional database of subnational indicators, web site and data synthesis capacity.

ABACUS and AQME: Semiconductor Device and Quantum Mechanics Education on nanoHUB.org

OpenAIRE

Klimeck, Gerhard; Vasileska, Dragica

2009-01-01

The ABACUS and AQME on-line tools and their associated wiki pages form one-stop shops for educators and students of existing university courses. They are geared towards courses like "introduction to Semiconductor Devices" and "Quantum Mechanics for Engineers". The service is free to anyone and no software installation is required on the user's computer. All simulations, including advanced visualization are performed at a remote computer. The tools have been deployed on nanoHUB.org in August 2...

Performance improvement of centrifugal compressor stage with pinched geometry or vaned diffuser

Energy Technology Data Exchange (ETDEWEB)

Jaatinen, A.

2009-07-01

Centrifugal compressors are widely used for example in refrigeration processes, the oil and gas industry, superchargers, and waste water treatment. In this work, five different vaneless diffusers and six different vaned diffusers are investigated numerically. The vaneless diffusers vary only by their diffuser width, so that four of the geometries have pinch implemented to them. Pinch means a decrease in the diffuser width. Four of the vaned diffusers have the same vane turning angle and a different number of vanes, and two have different vane turning angles. The flow solver used to solve the flow fields is Finfo, which is a Navier-Stokes solver. All the cases are modeled Chien's k-epsilon turbulence model. All five vaneless diffusers and three vaned diffusers are investigated also experimentally. For each construction, the compressor operating map is measured according to relevant standards. In addition to this, the flow fields before and after the diffuser are measured with static and total pressure, flow angle and total temperature measurements k-omega SST turbulence model. The simulation results indicate that it is possible to improve the efficiency with the pinch, and according to the numerical results, the two best geometries are the ones with most pinch at the shroud. These geometries have approximately 4 percentage points higher effciency than the unpinched vaneless diffusers. The hub pinch does not seem to have any major benefits. In general, the pinches make the flow fields before and after the diffuser more uniform. The pinch also seems to improve the impeller effciency. This is down to two reasons. The major reason is that the pinch decreases the size of slow flow and possible backflow region located near the shroud after the impeller. Secondly, the pinches decrease the flow velocity in the tip clearance, leading to a smaller tip leakage flow and therefore slightly better impeller efficiency. Also some of the vaned diffusers improve the efficiency

Matrix diffusion in crystalline rocks: coupling of anion exclusion, surface diffusion and surface complexation

International Nuclear Information System (INIS)

Olin, M.; Valkiainen, M.; Aalto, H.

1997-12-01

This report includes both experimental and modelling parts. Also, a novel approach to the diffusion experiments is introduced, where ions of the same electric charge diffuse in opposite directions through the same rock sample. Six rock-types from Olkiluoto radioactive waste disposal investigation site were used in the experiments: granite, weathered granite, mica gneiss, weathered mica gneiss, tonalite and altered mica gneiss/migmatite. The experiments consisted of the determination of the effective diffusion coefficient and the rock capacity factor for tritium, chloride (Cl-36) and sodium (Na-22). The modelling consisted of a chemical model for small pores (< 100 nm), a model for counter ion diffusion and models for the laboratory experiments

Matrix diffusion in crystalline rocks: coupling of anion exclusion, surface diffusion and surface complexation

Energy Technology Data Exchange (ETDEWEB)

Olin, M.; Valkiainen, M.; Aalto, H. [VTT Chemical Technology, Espoo (Finland)

1997-12-01

This report includes both experimental and modelling parts. Also, a novel approach to the diffusion experiments is introduced, where ions of the same electric charge diffuse in opposite directions through the same rock sample. Six rock-types from Olkiluoto radioactive waste disposal investigation site were used in the experiments: granite, weathered granite, mica gneiss, weathered mica gneiss, tonalite and altered mica gneiss/migmatite. The experiments consisted of the determination of the effective diffusion coefficient and the rock capacity factor for tritium, chloride (Cl-36) and sodium (Na-22). The modelling consisted of a chemical model for small pores (< 100 nm), a model for counter ion diffusion and models for the laboratory experiments. 21 refs.

The Host Plant Metabolite Glucose Is the Precursor of Diffusible Signal Factor (DSF) Family Signals in Xanthomonas campestris

OpenAIRE

Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

2015-01-01

Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous ad...

Particle image velocimetry measurement of complex flow structures in the diffuser and spherical casing of a reactor coolant pump

Directory of Open Access Journals (Sweden)

Yongchao Zhang

2018-04-01

Full Text Available Understanding of turbulent flow in the reactor coolant pump (RCP is a premise of the optimal design of the RCP. Flow structures in the RCP, in view of the specially devised spherical casing, are more complicated than those associated with conventional pumps. Hitherto, knowledge of the flow characteristics of the RCP has been far from sufficient. Research into the nonintrusive measurement of the internal flow of the RCP has rarely been reported. In the present study, flow measurement using particle image velocimetry is implemented to reveal flow features of the RCP model. Velocity and vorticity distributions in the diffuser and spherical casing are obtained. The results illuminate the complexity of the flows in the RCP. Near the lower end of the discharge nozzle, three-dimensional swirling flows and flow separation are evident. In the diffuser, the imparity of the velocity profile with respect to different axial cross sections is verified, and the velocity increases gradually from the shroud to the hub. In the casing, velocity distribution is nonuniform over the circumferential direction. Vortices shed consistently from the diffuser blade trailing edge. The experimental results lend sound support for the optimal design of the RCP and provide validation of relevant numerical algorithms. Keywords: Diffuser, Flow Structures, Particle Image Velocimetry, Reactor Coolant Pump, Spherical Casing, Velocity Distribution

Formulation of Low Peclet Number Based Grid Expansion Factor for the Solution of the Convection Diffusion Equation

Directory of Open Access Journals (Sweden)

A. Abdullah

2018-04-01

Full Text Available Convection-diffusion problems, due to its fundamental nature, are found in various science and engineering applications. In this research, the importance of the relationship between grid structure and flow parameters in such problems is emphasized. In particular, we propose a systematic technique in the selection of the grid expansion factor based on its logarithmic relationship with low Peclet number. Such linear mathematical connection between the two non-dimensional parameters serves as a guideline for more structured decision-making and improves the heuristic process in the determination of the computational domain grid for the numerical solution of convection-diffusion equations especially in the prediction of the concentration of the scalar. Results confirm the effectiveness of the new approach.

Diffusion of 51Cr along high-diffusivity paths in Ni-Fe alloys

International Nuclear Information System (INIS)

Cermak, J.

1990-01-01

Penetration profiles of 51 Cr in polycrystalline alloys Ni-xFe (x = 0, 20, 40, and 60 wt.% Fe) after diffusion anneals at temperatures between 693 and 1473 K are studied. Sectioning of diffusion zones of samples annealed above 858 K is carried out by grinding, at lower temperatures by DC glow discharge sputtering. The concentration of 51 Cr in depth x is assumed to be proportional to relative radioactivity of individual sections. With help of volume and pipe self-diffusion data taken from literature, the temperature dependence of product P = δD g (δ and D g are grain boundary width and grain boundary diffusion coefficient, respectively) is obtained: P = (2.68 - 0.88 +1.3 ) x 10 -11 exp [-(221.3 ± 3.0) kJ/mol/RT]m 3 /s. This result agrees well with the previous measurements of 51 Cr diffusivity in Fe-18 Cr-12 Ni and Fe-21 Cr-31 Ni. It indicates that the mean chemical composition of Fe-Cr-Ni ternary alloys is not a dominant factor affecting the grain boundary diffusivity of Cr in these alloys. (author)

Hexcrete Tower for Harvesting Wind Energy at Taller Hub Heights - Budget Period 2

Energy Technology Data Exchange (ETDEWEB)

Sritharan, Sri [Iowa State Univ., Ames, IA (United States)

2017-05-01

Interest in designing taller towers for wind energy production in the United States (U.S.) has been steadily growing. In May 2015, it was revealed that taller towers will make wind energy production a reality in all 50 states, including some states that have nearly zero renewables in their energy portfolio. Facilitating wind energy production feasibility in all 50 states will no doubt contribute to increasing the electricity produced by wind from 4.5% in 2013 to a targeted scenario of 35% by 2050 in the Wind Vision report. This project focuses on the Hexcrete tower concept developed for tall towers using High Strength Concrete (HSC) and/or Ultra-High Performance Concrete (UHPC). Among other benefits, the Hexcrete concept overcomes transportation and logistical challenges, thus facilitating construction of towers with hub heights of 100-m (328-ft) and higher. The goal of this project is to facilitate widespread deployment of Hexcrete towers for harvesting wind energy at 120 to 140-m (394 to 459-ft) hub heights and reduce the Levelized Cost of Energy (LCOE) of wind energy production in the U.S. The technical scope of the project includes detailed design and optimization of at least three wind turbine towers using the Hexcrete concept together with experimental validation and LCOE analyses and development of a commercialization plan.

Mammalian transcriptional hotspots are enriched for tissue specific enhancers near cell type specific highly expressed genes and are predicted to act as transcriptional activator hubs.

Science.gov (United States)

Joshi, Anagha

2014-12-30

Transcriptional hotspots are defined as genomic regions bound by multiple factors. They have been identified recently as cell type specific enhancers regulating developmentally essential genes in many species such as worm, fly and humans. The in-depth analysis of hotspots across multiple cell types in same species still remains to be explored and can bring new biological insights. We therefore collected 108 transcription-related factor (TF) ChIP sequencing data sets in ten murine cell types and classified the peaks in each cell type in three groups according to binding occupancy as singletons (low-occupancy), combinatorials (mid-occupancy) and hotspots (high-occupancy). The peaks in the three groups clustered largely according to the occupancy, suggesting priming of genomic loci for mid occupancy irrespective of cell type. We then characterized hotspots for diverse structural functional properties. The genes neighbouring hotspots had a small overlap with hotspot genes in other cell types and were highly enriched for cell type specific function. Hotspots were enriched for sequence motifs of key TFs in that cell type and more than 90% of hotspots were occupied by pioneering factors. Though we did not find any sequence signature in the three groups, the H3K4me1 binding profile had bimodal peaks at hotspots, distinguishing hotspots from mono-modal H3K4me1 singletons. In ES cells, differentially expressed genes after perturbation of activators were enriched for hotspot genes suggesting hotspots primarily act as transcriptional activator hubs. Finally, we proposed that ES hotspots might be under control of SetDB1 and not DNMT for silencing. Transcriptional hotspots are enriched for tissue specific enhancers near cell type specific highly expressed genes. In ES cells, they are predicted to act as transcriptional activator hubs and might be under SetDB1 control for silencing.

Hepatic hemangioma: Correlation of enhancement types with diffusion-weighted MR findings and apparent diffusion coefficients

Energy Technology Data Exchange (ETDEWEB)

Goshima, Satoshi [Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan)], E-mail: gossy@par.odn.ne.jp; Kanematsu, Masayuki [Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan); Department of Radiology Services, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan); Kondo, Hiroshi [Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan); Yokoyama, Ryujiro; Kajita, Kimihiro [Department of Radiology Services, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan); Tsuge, Yusuke [Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194 (Japan); Shiratori, Yoshimune [Department of Medical Informatics, Gifu University School of Medicine, Gifu (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka (Japan); Moriyama, Noriyuki [Research Center for Cancer Prevention and Screening, National Cancer Center Hospital, Tsukiji (Japan)

2009-05-15

Purpose: To correlate hepatic hemangioma enhancement types in gadolinium-enhanced magnetic resonance (MR) images with diffusion-weighted MR findings and apparent diffusion coefficients (ADCs). Materials and methods: Respiratory-triggered diffusion-weighted MR images (TR/TE, 2422/46 ms; parallel imaging factor, 2; b factor, 500 s/mm{sup 2}; number of averaging, 6) obtained in 35 patients with 44 hepatic hemangiomas diagnosed by gadolinium-enhanced MR and by follow-up imaging were retrospectively evaluated. Hemangiomas were classified into three enhancement types based on gadolinium-enhanced MR imaging findings: type I, early-enhancement type; type II, peripheral nodular enhancement type; type III, delayed enhancement type. Two blinded readers qualitatively assessed lesion sizes and signal intensities on T2-weighted turbo spin-echo and diffusion-weighted images. The ADCs of hemangiomas were also measured. Results: No significant difference was observed between the three enhancement types in terms of signal intensities on T2-weighted images. Signal intensities on diffusion-weighted images were lower in the order type I to III (P < .01), and mean ADCs were 2.18 x 10{sup -3}, 1.86 x 10{sup -3}, and 1.71 x 10{sup -3} mm{sup 2}/s for types I, II, and III, respectively (P < .01). No correlation was found between lesion sizes and ADCs. Conclusion: Hepatic hemangiomas were found to have enhancement type dependent signal intensities and ADCs on diffusion-weighted MR images. Further studies will have to substantiate that these diffusion patterns might reflect intratumoral blood flow or perfusion.

Research of Innovation Diffusion on Industrial Networks

Directory of Open Access Journals (Sweden)

Yongtai Chen

2014-01-01

Full Text Available The real value of innovation consists in its diffusion on industrial network. The factors which affect the diffusion of innovation on industrial network are the topology of industrial network and rules of diffusion. Industrial network is a complex network which has scale-free and small-world characters; its structure has some affection on threshold, length of path, enterprise’s status, and information share of innovation diffusion. Based on the cost and attitude to risk of technical innovation, we present the “avalanche” diffusing model of technical innovation on industrial network.

Integrative Analysis of Transcription Factor Combinatorial Interactions Using a Bayesian Tensor Factorization Approach

Science.gov (United States)

Ye, Yusen; Gao, Lin; Zhang, Shihua

2017-01-01

Transcription factors play a key role in transcriptional regulation of genes and determination of cellular identity through combinatorial interactions. However, current studies about combinatorial regulation is deficient due to lack of experimental data in the same cellular environment and extensive existence of data noise. Here, we adopt a Bayesian CANDECOMP/PARAFAC (CP) factorization approach (BCPF) to integrate multiple datasets in a network paradigm for determining precise TF interaction landscapes. In our first application, we apply BCPF to integrate three networks built based on diverse datasets of multiple cell lines from ENCODE respectively to predict a global and precise TF interaction network. This network gives 38 novel TF interactions with distinct biological functions. In our second application, we apply BCPF to seven types of cell type TF regulatory networks and predict seven cell lineage TF interaction networks, respectively. By further exploring the dynamics and modularity of them, we find cell lineage-specific hub TFs participate in cell type or lineage-specific regulation by interacting with non-specific TFs. Furthermore, we illustrate the biological function of hub TFs by taking those of cancer lineage and blood lineage as examples. Taken together, our integrative analysis can reveal more precise and extensive description about human TF combinatorial interactions. PMID:29033978

75 FR 76003 - Tricor Ten Section Hub LLC; Notice of Availability of the Environmental Assessment for the...

Science.gov (United States)

2010-12-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP09-432-000] Tricor Ten Section Hub LLC; Notice of Availability of the Environmental Assessment for the Proposed Ten Section Gas... Commission) has prepared an environmental assessment (EA) for the Ten Section Gas Storage Project, in Kern...

Studies of ionic diffusion in crystalline rock

International Nuclear Information System (INIS)

Ohlsson, Yvonne

2001-01-01

Matrix diffusion is of great importance in delaying radionuclides escaping from a deep geologic repository, on their way to the biosphere. There are, however, poorly understood mechanisms related to transport in pores with charged pore surfaces. Ions are affected by this charge and may be repelled or attracted by it. The rate of transport may be reduced, or even enhanced, as a result of this. Transport of ions is studied by traditional diffusion experiments, but mainly by a faster electrical conductivity method. With this method the pore connectivity, the formation factor variability and its relation to the porosity, as well as the surface conductivity are investigated. The method is compared. with traditional diffusion experiments, and an in-situ application is suggested and qualitatively tested. Furthermore, surface diffusion is studied by evaluating literature data and recently developed diffusion models. The pore connectivity reached to a depth of at least 15 cm in the rocks studied. The formation factor did not generally decrease with increasing sample length. It was also found that not only cations in the free pore water add to the electrical conductivity, but also at least part of those sorbed to the pore surfaces of the minerals. This surface conductivity influences the determination of the formation factor in low ionic strength pore waters, and was also found to be a function of the formation factor. It was furthermore dependent on the type of ion at the surface, giving for example a higher conductivity for Na + than for Cs + . It is not fully understood which part of the sorbed ions that are mobile. A simple model was developed assigning the mobile ions to the diffuse layer, and this model explained experimental data for diffusion of Cs + in clay well. This is contradicted by surface conductivity measurements that have shown that most mobile ions are found behind the Stern layer. The in-situ formation factor determination method seems promising. The most

ABACUS and AQME: Semiconducor Device and Quantum Mechanics Education on nanoHUB.org

OpenAIRE

Klimeck, Gerhard; Vasileska, Dragica

2009-01-01

The ABACUS and AQME on-line tools and their associated wiki pages form one-stop shops for educators and students of existing university courses. They are geared towards courses like “introduction to Semiconductor Devices” and “Quantum Mechanics for Engineers”. The service is free to anyone and no software installation is required on the user’s computer. All simulations, including advanced visualization are performed at a remote computer. The tools have been deployed on nanoHUB.org in August 2...

Spatial diffusion of influenza outbreak-related climate factors in Chiang Mai Province, Thailand.

Science.gov (United States)

Nakapan, Supachai; Tripathi, Nitin Kumar; Tipdecho, Taravudh; Souris, Marc

2012-10-24

Influenza is one of the most important leading causes of respiratory illness in the countries located in the tropical areas of South East Asia and Thailand. In this study the climate factors associated with influenza incidence in Chiang Mai Province, Northern Thailand, were investigated. Identification of factors responsible for influenza outbreaks and the mapping of potential risk areas in Chiang Mai are long overdue. This work examines the association between yearly climate patterns between 2001 and 2008 and influenza outbreaks in the Chiang Mai Province. The climatic factors included the amount of rainfall, percent of rainy days, relative humidity, maximum, minimum temperatures and temperature difference. The study develops a statistical analysis to quantitatively assess the relationship between climate and influenza outbreaks and then evaluate its suitability for predicting influenza outbreaks. A multiple linear regression technique was used to fit the statistical model. The Inverse Distance Weighted (IDW) interpolation and Geographic Information System (GIS) techniques were used in mapping the spatial diffusion of influenza risk zones. The results show that there is a significance correlation between influenza outbreaks and climate factors for the majority of the studied area. A statistical analysis was conducted to assess the validity of the model comparing model outputs and actual outbreaks.

Spatial Diffusion of Influenza Outbreak-Related Climate Factors in Chiang Mai Province, Thailand

Directory of Open Access Journals (Sweden)

Marc Souris

2012-10-01

Full Text Available Influenza is one of the most important leading causes of respiratory illness in the countries located in the tropical areas of South East Asia and Thailand. In this study the climate factors associated with influenza incidence in Chiang Mai Province, Northern Thailand, were investigated. Identification of factors responsible for influenza outbreaks and the mapping of potential risk areas in Chiang Mai are long overdue. This work examines the association between yearly climate patterns between 2001 and 2008 and influenza outbreaks in the Chiang Mai Province. The climatic factors included the amount of rainfall, percent of rainy days, relative humidity, maximum, minimum temperatures and temperature difference. The study develops a statistical analysis to quantitatively assess the relationship between climate and influenza outbreaks and then evaluate its suitability for predicting influenza outbreaks. A multiple linear regression technique was used to fit the statistical model. The Inverse Distance Weighted (IDW interpolation and Geographic Information System (GIS techniques were used in mapping the spatial diffusion of influenza risk zones. The results show that there is a significance correlation between influenza outbreaks and climate factors for the majority of the studied area. A statistical analysis was conducted to assess the validity of the model comparing model outputs and actual outbreaks.

A genome-wide screen identifies conserved protein hubs required for cadherin-mediated cell–cell adhesion

Science.gov (United States)

Toret, Christopher P.; D’Ambrosio, Michael V.; Vale, Ronald D.; Simon, Michael A.

2014-01-01

Cadherins and associated catenins provide an important structural interface between neighboring cells, the actin cytoskeleton, and intracellular signaling pathways in a variety of cell types throughout the Metazoa. However, the full inventory of the proteins and pathways required for cadherin-mediated adhesion has not been established. To this end, we completed a genome-wide (∼14,000 genes) ribonucleic acid interference (RNAi) screen that targeted Ca2+-dependent adhesion in DE-cadherin–expressing Drosophila melanogaster S2 cells in suspension culture. This novel screen eliminated Ca2+-independent cell–cell adhesion, integrin-based adhesion, cell spreading, and cell migration. We identified 17 interconnected regulatory hubs, based on protein functions and protein–protein interactions that regulate the levels of the core cadherin–catenin complex and coordinate cadherin-mediated cell–cell adhesion. Representative proteins from these hubs were analyzed further in Drosophila oogenesis, using targeted germline RNAi, and adhesion was analyzed in Madin–Darby canine kidney mammalian epithelial cell–cell adhesion. These experiments reveal roles for a diversity of cellular pathways that are required for cadherin function in Metazoa, including cytoskeleton organization, cell–substrate interactions, and nuclear and cytoplasmic signaling. PMID:24446484

Air network performance and hub competitive position: evaluation of primary airports in East and South-East Asia

NARCIS (Netherlands)

Burghouwt, G.; de Wit, J.; Veldhuis, J.; Matsumoto, H.

2009-01-01

The growth of hub-and-spoke operations has changed the structure of competition among airlines and airports, meaning that airlines now compete both directly (air services from A to B) as well as indirectly (services from A to B via H). Traditional measures of airport performance, such as passenger

Contrast-enhanced CT and diffusion-weighted MR imaging: Performance as a prognostic factor in patients with pancreatic ductal adenocarcinoma

Energy Technology Data Exchange (ETDEWEB)

Fukukura, Yoshihiko, E-mail: fukukura@m.kufm.kagoshima-u.ac.jp [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan); Takumi, Koji [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan); Higashi, Michiyo [Department of Human Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan); Shinchi, Hiroyuki [Department of Surgical Oncology and Digestive Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan); Kamimura, Kiyohisa; Yoneyama, Tomohide; Tateyama, Akihiro [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan)

2014-04-15

Objective: To determine whether contrast enhancement of CT and apparent diffusion coefficient on diffusion-weighted MR imaging are important parameters that can predict outcomes for patients with pancreatic ductal adenocarcinoma. Materials and methods: Ninety-two patients with histologically confirmed pancreatic ductal adenocarcinoma who underwent quadriphasic CT (including unenhanced, pancreatic parenchymal, portal venous and delayed phases) and fat-suppressed single-shot echo-planar diffusion-weighted MR imaging at 3.0 T were retrospectively analyzed to investigate prognostic factors. Overall survival curves were drawn using the Kaplan–Meier method. Effects on survival of variables including age, sex, tumor location, tumor size, TNM stage, carbohydrate antigen 19-9, carcinoembryonic antigen, treatment, tumor contrast enhancement and apparent diffusion coefficient values were analyzed in univariate analysis using the log-rank test. Variables were analyzed in multivariate analyses using the Cox proportional hazards regression model. Results: Median survival for the entire patient population was 18.2 months. Higher contrast enhancement during all phases was associated with significantly longer overall survival (P < 0.001 for all phases). The difference in overall survival between groups divided by median apparent diffusion coefficient value was not significant (P = 0.672). TNM stage (P = 0.026) and tumor contrast enhancement on CT (P = 0.027) were significantly related to survival in multivariate analysis. Conclusions: Poor enhancement of pancreatic adenocarcinomas on enhanced CT is associated with reduced patient survival.

Contrast-enhanced CT and diffusion-weighted MR imaging: Performance as a prognostic factor in patients with pancreatic ductal adenocarcinoma

International Nuclear Information System (INIS)

Fukukura, Yoshihiko; Takumi, Koji; Higashi, Michiyo; Shinchi, Hiroyuki; Kamimura, Kiyohisa; Yoneyama, Tomohide; Tateyama, Akihiro

2014-01-01

Objective: To determine whether contrast enhancement of CT and apparent diffusion coefficient on diffusion-weighted MR imaging are important parameters that can predict outcomes for patients with pancreatic ductal adenocarcinoma. Materials and methods: Ninety-two patients with histologically confirmed pancreatic ductal adenocarcinoma who underwent quadriphasic CT (including unenhanced, pancreatic parenchymal, portal venous and delayed phases) and fat-suppressed single-shot echo-planar diffusion-weighted MR imaging at 3.0 T were retrospectively analyzed to investigate prognostic factors. Overall survival curves were drawn using the Kaplan–Meier method. Effects on survival of variables including age, sex, tumor location, tumor size, TNM stage, carbohydrate antigen 19-9, carcinoembryonic antigen, treatment, tumor contrast enhancement and apparent diffusion coefficient values were analyzed in univariate analysis using the log-rank test. Variables were analyzed in multivariate analyses using the Cox proportional hazards regression model. Results: Median survival for the entire patient population was 18.2 months. Higher contrast enhancement during all phases was associated with significantly longer overall survival (P < 0.001 for all phases). The difference in overall survival between groups divided by median apparent diffusion coefficient value was not significant (P = 0.672). TNM stage (P = 0.026) and tumor contrast enhancement on CT (P = 0.027) were significantly related to survival in multivariate analysis. Conclusions: Poor enhancement of pancreatic adenocarcinomas on enhanced CT is associated with reduced patient survival

Self-Interest in Innovation Diffusion Decision Process

DEFF Research Database (Denmark)

Williams, Idongesit; Gyaase, Patrick Ohemeng Kwadwo

2013-01-01

This paper assesses the factors that would facilitate the diffusion and adoption of broadband internet services in rural areas using the internet café business model. The rural areas of developing countries are predominantly ignored or underserved with broadband Internet connectivity. However...... in the cities, the internet café business model has been a major driver in the diffusion of the internet services. This paper adopts an exploratory approach to investigate why Internet café entrepreneurs do not supply internet services to rural areas. It also explores the factors that would stimulate...... diffusion and adoption in the rural areas using the internet café business model....

Diffusion of condenser water discharge

International Nuclear Information System (INIS)

Iwakiri, Toshio

1977-01-01

Thermal and nuclear power stations in Japan are mostly located in coastal area, and the cooling water is discharged into sea as warm water. Recently, large interest is taken in this matter, and it is desirable to predict the diffusion of warm discharge accurately and to take effective measures for lowering the temperature. As for the methods of predicting the diffusion of warm discharge, simplified estimation, mathematical analysis and hydrographical model experiment are used corresponding to objects and conditions. As for the measures to lower temperature, the method of discharging warm water into deep sea bottom was confirmed to be very effective. In this paper, the phenomena of diffusion of warm discharge in sea, the methods of predicting the diffusion of warm discharge, and the deep sea discharge as the measure for lowering temperature are outlined. The factors concerning the diffusion of warm discharge in sea are the conditions of discharge, topography and sea state, and the diffusion is roughly divided into mixing diffusion in the vicinity of warm water outlet and eddy diffusion in distant region. It is difficult to change artificially the conditions of diffusion in distant region, and the measures of raising the rate of dilution in near region are effective, therefore the deep sea discharge is adopted. (Kako, I.)

Diffusion of helium and estimated diffusion coefficients of hydrogen dissolved in water-saturated, compacted Ca-montmorillonite

International Nuclear Information System (INIS)

Higashihara, Tomohiro; Sato, Seichi; Ohashi, Hiroshi; Otsuka, Teppei

2001-01-01

The diffusion coefficients of hydrogen gas dissolved in water-saturated, compacted montmorillonite are required to estimate the performance of bentonite buffer materials for geological disposal of nuclear waste. As part of the effort to determine the diffusion coefficients, the diffusion coefficients of helium in water-saturated, compacted calcium montmorillonite (Ca-montmorillonite) were determined as a function of dry density, 0.78 to 1.37x10 3 kg m -3 , by a transient diffusion method. The diffusion coefficients were from 8.3x10 -10 m 2 s -1 at 0.78x10 3 kgm -3 to 2.8x10 -10 m 2 s -1 at 1.37x10 3 kgm -3 . The data obtained by this diffusion experiment of helium were highly reproducible. The diffusion coefficients of helium in Ca-montmorillonite were somewhat larger than those previously obtained for helium in sodium montmorillonite (Na-montmorillonite). The diffusion coefficients of hydrogen gas in the montmorillonites were roughly estimated using the diffusion coefficients of helium. These estimates were based on assumptions that both helium and hydrogen molecules are non-adsorptive and that the geometric factors in the compacted montmorillonites are approximately the same for diffusion of helium and diffusion of hydrogen. (author)

Convergence of surface diffusion parameters with model crystal size

Science.gov (United States)

Cohen, Jennifer M.; Voter, Arthur F.

1994-07-01

A study of the variation in the calculated quantities for adatom diffusion with respect to the size of the model crystal is presented. The reported quantities include surface diffusion barrier heights, pre-exponential factors, and dynamical correction factors. Embedded atom method (EAM) potentials were used throughout this effort. Both the layer size and the depth of the crystal were found to influence the values of the Arrhenius factors significantly. In particular, exchange type mechanisms required a significantly larger model than standard hopping mechanisms to determine adatom diffusion barriers of equivalent accuracy. The dynamical events that govern the corrections to transition state theory (TST) did not appear to be as sensitive to crystal depth. Suitable criteria for the convergence of the diffusion parameters with regard to the rate properties are illustrated.

Linking the Diffusion of Water in Compacted Clays at Two Different Time Scales: Tracer Through-Diffusion and QENS

International Nuclear Information System (INIS)

Juranyi, Fanni; Gonzalez Sanchez, Fatima; Gimmi, Thomas; Bestel, Martina; Van Loon, Luc; Diamond, Larryn W.

2013-01-01

Observable water diffusion processes in clays and their parameters depend on the spatial- and time-scale of the measurement. Comparing the diffusion coefficients of quasielastic neutron scattering and tracer through-diffusion, 'chemical' and 'geometrical' effects can be distinguished and quantified. Results for montmorillonite and illite in the Na- and Ca- form illustrate this very well. Swelling clays such as montmorillonite are especially interesting because of the interlayer water. This water is confined in form of few layers such that the diffusion occurs essentially in 2D. Furthermore the ratio of interlayer- and external- (macro-pore) water changes as a function of bulk dry density and degree of water saturation. Therefore it is of interest to describe the diffusion process using these parameters. Finally, the activation energy of the diffusion should be equal for both methods assuming that the geometrical factor does not depend on temperature. For the montmorillonites this was not the case, which might also indicate that the main processes on the two scales are different. We conclude that the geometrical factor and the electrostatic constraint can be determined from a comparison of the diffusion coefficients measured by the two different techniques: quasielastic neutron scattering and tracer through diffusion. Furthermore, activation energies obtained at the two scales are similar for clays having no interlayer water. For montmorillonite the activation energy values are different. Further investigations are required to clarify the reason. (authors)

Diffusion of Convenience Stores and the Change in Locational Factors in Fukui City, Fukui Prefecture

OpenAIRE

田中, 和子; 甚佐, 直樹

2000-01-01

In Fukui City ,the first convenience store was opened in the beginning of the 1980's. Now , convenience stores spread over the central-built up and suburban areas. Recently, new stores are founded mostly in the suburbs. Many of the stores are distributed within a radius of four kilometers of the urban center. At the beginning of the diffusion of convenience stores, the amount of transportation was the most important factor when a new store was decided to be set up . Most old stores are locate...

Beta cell 5'-shifted isomiRs are candidate regulatory hubs in type 2 diabetes.

Directory of Open Access Journals (Sweden)

Jeanette Baran-Gale

Full Text Available Next-generation deep sequencing of small RNAs has unveiled the complexity of the microRNA (miRNA transcriptome, which is in large part due to the diversity of miRNA sequence variants ("isomiRs". Changes to a miRNA's seed sequence (nucleotides 2-8, including shifted start positions, can redirect targeting to a dramatically different set of RNAs and alter biological function. We performed deep sequencing of small RNA from mouse insulinoma (MIN6 cells (widely used as a surrogate for the study of pancreatic beta cells and developed a bioinformatic analysis pipeline to profile isomiR diversity. Additionally, we applied the pipeline to recently published small RNA-seq data from primary human beta cells and whole islets and compared the miRNA profiles with that of MIN6. We found that: (1 the miRNA expression profile in MIN6 cells is highly correlated with those of primary human beta cells and whole islets; (2 miRNA loci can generate multiple highly expressed isomiRs with different 5'-start positions (5'-isomiRs; (3 isomiRs with shifted start positions (5'-shifted isomiRs are highly expressed, and can be as abundant as their unshifted counterparts (5'-reference miRNAs. Finally, we identified 10 beta cell miRNA families as candidate regulatory hubs in a type 2 diabetes (T2D gene network. The most significant candidate hub was miR-29, which we demonstrated regulates the mRNA levels of several genes critical to beta cell function and implicated in T2D. Three of the candidate miRNA hubs were novel 5'-shifted isomiRs: miR-375+1, miR-375-1 and miR-183-5p+1. We showed by in silico target prediction and in vitro transfection studies that both miR-375+1 and miR-375-1 are likely to target an overlapping, but distinct suite of beta cell genes compared to canonical miR-375. In summary, this study characterizes the isomiR profile in beta cells for the first time, and also highlights the potential functional relevance of 5'-shifted isomiRs to T2D.

Mechanisms of component diffusion in mercury cadmium telluride

International Nuclear Information System (INIS)

Tang, M.S.; Stevenson, D.A.

1989-01-01

The component diffusion coefficients for the Hg/sub 0.8/Cd/sub 0.2/Te (MCT) system are measured using radioactive tracers. Multiple branches are observed in the tracer diffusion profiles which are related to fast and slow-diffusing components. Diffusion models for each component are proposed based on the defect chemistry of MCT, a calculation of the thermodynamic factor, and the relationship between component diffusion coefficients and the interdiffusion coefficients for pseudobinary systems. The model provides insight into the thermodynamic properties of the system, the mechanisms for diffusion, and the practical application of tracer diffusion data to interdiffusion and p-to-n conversion by Hg annealing

Diffusion of Fission Product Elements in Compacted Bentonite

International Nuclear Information System (INIS)

Pratomo-Budiman-Sastrowardoyo; Dewi-Susilowati; Dadang-Suganda

2000-01-01

Study on diffusion of fission product in compacted bentonite has been conducted. The information about mobilities of these elements have been obtained from the studies resulted in many countries. It is presented that the diffusion coefficient was varied by the function of solution phase condition as well as the nature of bentonite. It is also showed that the diffusion coefficient decreased by the increasing of density, as well as the increasing of montmorillonite content in bentonite. The ratio of bentonite/silica-sand used, was related to the increasing of elements mobility. In many case variation of diffusion coefficient was related to the variation of pH, redox condition, and the presence of complex ant in solution phase. The lower diffusion coefficient could give the higher retardation factor, which is a favorable factor to retard the radionuclides release from a disposal facility to geosphere. (author)

Simulation of diffusion in concentrated lattice gases

International Nuclear Information System (INIS)

Kehr, K.W.

1986-01-01

Recently the diffusion of particles in lattice gases was studied extensively by theoretical methods and numerical simulations. This paper reviews work on collective and, in particular, on tracer diffusion. The diffusion of tagged particles is characterized by a correlation factor whose behavior as a function of concentration is now well understood. Also the detailed kinetics of the tracer transitions was investigated. A special case is the one-dimensional lattice gas where the tracer diffusion coefficient vanishes. An interesting extension is the case of tagged atoms with a different transition rate. This model allows to study various physical situations, including impurity diffusion, percolation, and diffusion in partially blocked lattices. Finally some recent work on diffusion in lattice gases under the influence of a drift field will be reported. (author)

Environment as a home to architecture. The Cremona City Hub project

Directory of Open Access Journals (Sweden)

Emilio Faroldi

2014-10-01

Full Text Available The urban regeneration pro- ject of the former Marketplace area promoted by the Local Administration in Cremona through a two-step international contest which ended in May 2012, relies on the willingness to guarantee new and high standards of welcoming and liveability within a logic of “smart city” to be meant as an healthy, dynamic and economically sustainable city. The promotion of energy policies, the close connection between the urban and the architectural project, a new dimension of welcoming and residentiality, the environmental quality, and the fruition of culture, represent questions to which new project development capabilities intend to ensure adequate answers. The experimental research of the Cremona City Hub project targets these very values.

Enrichment by diffusion

International Nuclear Information System (INIS)

Mezin, M.

1976-01-01

The report presents an introduction to general basic principles of the gaseous diffusion process for the separation of uranium isotopes. Dealt with are: a) theoretical background and basic considerations of separation work and production costs, b) construction of a single separation stage and a multistage plant, c) the components of a plant and the optimization factors, d) cost factors. The text is illustrated by instructive diagrammes and flow charts. (RB) [de

Single Allocation Hub-and-spoke Networks Design Based on Ant Colony Optimization Algorithm

Directory of Open Access Journals (Sweden)

Yang Pingle

2014-10-01

Full Text Available Capacitated single allocation hub-and-spoke networks can be abstracted as a mixed integer linear programming model equation with three variables. Introducing an improved ant colony algorithm, which has six local search operators. Meanwhile, introducing the "Solution Pair" concept to decompose and optimize the composition of the problem, the problem can become more specific and effectively meet the premise and advantages of using ant colony algorithm. Finally, location simulation experiment is made according to Australia Post data to demonstrate this algorithm has good efficiency and stability for solving this problem.

Explaining subsidiaries' knowledge-diffusion behaviours within MNEs

NARCIS (Netherlands)

Ho, H.C.

2007-01-01

This study explores how subsidiaries can contribute their advantages for the whole MNE in knowledge diffusion processes. The research model includes both organisational factors and local resources in a host country to explain subsidiaries' diffusion behaviours. We carried out an online survey for

DisasterHub: A mobile application for enabling crowd generated data fusion in Earth Observation disaster management services

Science.gov (United States)

Tsironis, Vassilis; Herekakis, Themistocles; Tsouni, Alexia; Kontoes, Charalampos Haris

2016-04-01

by DisasterHub, an application proposal that won the MYGEOSS Second Call for Innovative Apps (http://beyond-eocenter.eu/index.php/ann-blog/197-disasterhub-mygeoss). DisasterHub will fill the gap by introducing a mobile application that will act as a middleware between mobile users and BEYOND services, building on the concept of citizen observatories in support of Copernicus, GEO, GEOSS, and UN-SPIDER. In this context the roadmap for generating beneficial EO services through DisasterHub is sketched in two main branches: (i) ingestion, processing and fusion of big multimodal data with additional spatiotemporal evidences (originated from Core Copernicus, GEO, GEOSS) for deriving higher value DRR and EMS products, (ii) interlinking the web and mobile platforms for the exchange and ease access of the societies to open EO/crowd generated data. The benefited communities will be effectively enlarged through DisasterHub mobile app. Mutually the BEYOND ecosystem will profit from the large amount of tagged information returned from the field, forming a unique input to the production chains and assimilation of predictive modeling. In conclusion DisasterHub will showcase in the EO community an enhanced EO services ecosystem with a software infrastructure for easy access of mobile users to the real-time monitoring and early-warning systems of BEYOND and tools for incorporating crowd-sourced data with open geospatial and socioeconomic data via open/linked data ingestion mechanisms (APIs), retrieved from the GEOSS Data-CORE, Copernicus and other EU portals.

Study on mutual diffusion and phase diagram in the Ni-Ta system

International Nuclear Information System (INIS)

Pimenov, V.N.; Ugaste, Yu.Eh.; Akkushkarova, K.A.

1977-01-01

The mutual diffusion in the Ni-Ta system has been investigated with a view of refining the constitutional diagram. The mutual diffusion factors and their effective values in the various phases and the diffusion activation energies are calculated. Given are the dependences of the phase growth constants and the mutual diffusion factors upon the temperature. The existence of five new phases Ta 2 Ni, TaNi, TaNi 2 , TaNi 3 , TaNi 8 has been discovered in the range of temperatures between 1150 and 1300 deg C. It is established that all the phases have a small concentration range of existence. It is noted that the diffusion characteristics in the phases (mutual diffusion factor and activation energy) differ widely, but fail to correlate with their melting points

Tracer diffusion in compacted, water-saturated bentonite

International Nuclear Information System (INIS)

Bourg, Ian C.; Sposito, Garrison; Bourg, Alain C.M.

2005-01-01

Compacted Na-bentonite clay barriers, widely used in the isolation of solid-waste landfills and other contaminated sites, have been proposed for a similar use in the disposal of high-level radioactive waste. Molecular diffusion through the pore space in these barriers plays a key role in their performance, thus motivating recent measurements of the apparent diffusion coefficient tensor of water tracers in compacted, water-saturated Na-bentonites. In the present study, we introduce a conceptual model in which the pore space of water-saturated bentonite is divided into 'macropore' and 'interlayer nanopore' compartments. With this model we determine quantitatively the relative contributions of pore-network geometry (expressed as a geometric factor) and of the diffusive behavior of water molecules near montmorillonite basal surfaces(expressed as a contrastivity factor) to the apparent diffusion coefficient tensor. Our model predicts, in agreement with experiment, that the mean principal value of the apparent diffusion coefficient tensor follows a single relationship when plotted against the partial montmorillonite dry density (mass of montmorillonite per combined volume of montmorillonite and pore space). Using a single fitted parameter, the mean principal geometric factor, our model successfully describes this relationship for a broad range of bentonite-water system, from dilute gel to highly-compacted bentonite with 80 percent of its pore water in interlayer nanopores

A preliminary assessment of the potential for 'team science' in DOE Energy Innovation Hubs and Energy Frontier Research Centers

Energy Technology Data Exchange (ETDEWEB)

Boardman, Craig, E-mail: boardman.10@osu.edu [John Glenn School of Public Affairs, Ohio State University (United States); Ponomariov, Branco, E-mail: branco.ponomariov@utsa.edu [Department of Public Administration, University of Texas at San Antonio (United States)

2011-06-15

President Obama has called for the development of new energy technologies to address our national energy needs and restore US economic competitiveness. In response, the Department of Energy has established new R and D modalities for energy research and development designed to facilitate collaboration across disciplinary, institutional, and sectoral boundaries. In this research note, we provide a preliminary assessment of the potential for essential mechanisms for coordinated problem solving among diverse actors within two new modalities at the DOE: Energy Innovation Hubs and Energy Frontier Research Centers. - Highlights: > Energy Frontier Research Centers may lack the basic mechanisms for coordinating diverse actors. > Divergent goals across diverse actors may hinder coordination in Energy Innovation Hubs. > The implementation of these and similar energy policies require further investigation.

Connectivity and tissue microstructural alterations in right and left temporal lobe epilepsy revealed by diffusion spectrum imaging.

Science.gov (United States)

Lemkaddem, Alia; Daducci, Alessandro; Kunz, Nicolas; Lazeyras, François; Seeck, Margitta; Thiran, Jean-Philippe; Vulliémoz, Serge

2014-01-01

Focal epilepsy is increasingly recognized as the result of an altered brain network, both on the structural and functional levels and the characterization of these widespread brain alterations is crucial for our understanding of the clinical manifestation of seizure and cognitive deficits as well as for the management of candidates to epilepsy surgery. Tractography based on Diffusion Tensor Imaging allows non-invasive mapping of white matter tracts in vivo. Recently, diffusion spectrum imaging (DSI), based on an increased number of diffusion directions and intensities, has improved the sensitivity of tractography, notably with respect to the problem of fiber crossing and recent developments allow acquisition times compatible with clinical application. We used DSI and parcellation of the gray matter in regions of interest to build whole-brain connectivity matrices describing the mutual connections between cortical and subcortical regions in patients with focal epilepsy and healthy controls. In addition, the high angular and radial resolution of DSI allowed us to evaluate also some of the biophysical compartment models, to better understand the cause of the changes in diffusion anisotropy. Global connectivity, hub architecture and regional connectivity patterns were altered in TLE patients and showed different characteristics in RTLE vs LTLE with stronger abnormalities in RTLE. The microstructural analysis suggested that disturbed axonal density contributed more than fiber orientation to the connectivity changes affecting the temporal lobes whereas fiber orientation changes were more involved in extratemporal lobe changes. Our study provides further structural evidence that RTLE and LTLE are not symmetrical entities and DSI-based imaging could help investigate the microstructural correlate of these imaging abnormalities.

International environmental and occupational health: From individual scientists to networked science Hubs.

Science.gov (United States)

Rosenthal, Joshua; Jessup, Christine; Felknor, Sarah; Humble, Michael; Bader, Farah; Bridbord, Kenneth

2012-12-01

For the past 16 years, the International Training and Research in Environmental and Occupational Health program (ITREOH) has supported projects that link U.S. academic scientists with scientists from low- and middle-income countries in diverse research and research training activities. Twenty-two projects of varied duration have conducted training to enhance the research capabilities of scientists at 75 institutions in 43 countries in Asia, Africa, Eastern Europe, and Latin America, and have built productive research relationships between these scientists and their U.S. partners. ITREOH investigators and their trainees have produced publications that have advanced basic sciences, developed methods, informed policy outcomes, and built institutional capacity. Today, the changing nature of the health sciences calls for a more strategic approach. Data-rich team science requires greater capacity for information technology and knowledge synthesis at the local institution. More robust systems for ethical review and administrative support are necessary to advance population-based research. Sustainability of institutional research capability depends on linkages to multiple national and international partners. In this context, the Fogarty International Center, the National Institute of Environmental Sciences and the National Institute for Occupational Safety and Health, have reengineered the ITREOH program to support and catalyze a multi-national network of regional hubs for Global Environmental and Occupational Health Sciences (GEOHealth). We anticipate that these networked science hubs will build upon previous investments by the ITREOH program and will serve to advance locally and internationally important health science, train and attract first-class scientists, and provide critical evidence to guide policy discussions. Published in 2012. This article is a U.S. Government work and is in the public domain in the USA.

A Study of Influential Factors in the Adoption and Diffusion of B2C E-Commerce

OpenAIRE

Rayed Al Ghamdi; Ann Nguyen; Vicki Jones

2013-01-01

This paper looks at the present standing of ecommerce in Saudi Arabia, as well as the challenges and strengths of Business to Customers (B2C) electronic commerce. Many studies have been conducted around the world in order to gain a better understanding of the demands, needs and effectiveness of online commerce. A study was undertaken to review the literature identifying the factors influencing the adoption and diffusion of B2C e-commerce. It found four distinct categories: businesses, custome...

Fractional Diffusion Equations and Anomalous Diffusion

Science.gov (United States)

Evangelista, Luiz Roberto; Kaminski Lenzi, Ervin

2018-01-01

Preface; 1. Mathematical preliminaries; 2. A survey of the fractional calculus; 3. From normal to anomalous diffusion; 4. Fractional diffusion equations: elementary applications; 5. Fractional diffusion equations: surface effects; 6. Fractional nonlinear diffusion equation; 7. Anomalous diffusion: anisotropic case; 8. Fractional Schrödinger equations; 9. Anomalous diffusion and impedance spectroscopy; 10. The Poisson–Nernst–Planck anomalous (PNPA) models; References; Index.

Midwest gas and power markets, hubs, pipelines, and interconnects

International Nuclear Information System (INIS)

Wirick, J.

2001-01-01

The existing interstate pipelines and proposed pipeline projects for the Chicago hub area were illustrated. The presentation explained why energy suppliers in the current competitive market need to balance and manage energy and transportation services for gas-fired power generators in terms of hourly winter and summer peaking services. The new infrastructure of the energy market will include new pipelines, storage and balancing to meet the ever increasing power demand. One of the options to meet power demand is to increase natural gas supply, transportation, storage, and hourly balancing capabilities. Other options are to build nuclear or coal-fired power generating facilities, or to go with renewables such as solar and wind power. Energy conservation and the reduction of natural gas usage per capita is another option to eliminate blackouts. This presentation also addressed the role that local distribution companies (LDC) and unbundling will play in the choice of these options. tabs., figs

Comparison of the diagnostic performances of diffusion parameters in diffusion weighted imaging and diffusion tensor imaging of breast lesions

International Nuclear Information System (INIS)

Cakir, Ozgur; Arslan, Arzu; Inan, Nagihan; Anık, Yonca; Sarısoy, Tahsin; Gumustas, Sevtap; Akansel, Gur

2013-01-01

Purpose: To evaluate the diagnostic efficiency of the diffusion parameters measured by conventional diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) for discrimination of malignant breast lesions from benign lesions and the normal breast. Materials and methods: The study included 52 women with 55 breast lesions (30 malignant, 25 benign). DTI and DWI were performed complementary to dynamic contrast MRI at 3T. Apparent diffusion coefficient (ADC) of DWI, mean diffusivity (MD) and fractional anisotropy (FA) values of DTI were measured for lesions and contralateral breast parenchyma in each patient. We used b factors of 0, 50, 850, 1000 and 1500 s/mm 2 for DWI and b 0 and 1000 s/mm 2 for DTI. ADC, MD and FA values were compared between malignant and benign lesions, and the normal parenchyma by univariate and multivariate analyses. Results: Diffusion parameters showed no difference according to menopausal status in the normal breast. ADC and MD values of the malignant lesions were significantly lower than benign lesions and normal parenchyma (p = 0.001). The FA showed no statistical significance. With the cut-off values of ≤1.23 × 10 −3 mm 2 /s (b 0–1000 s/mm 2 ) and ≤1.12 × 10 −3 mm 2 /s (b 0–1500 s/mm 2 ), ADC showed 92.85% and 96.15% sensitivity; 72.22% and 73.52% PPV, respectively. With a cut-off value of ≤1.27 × 10 −3 mm 2 /s (b 1000 s/mm 2 ), MD was 100% sensitive with a PPV of 65.90%. Comparing the diagnostic performance of the parameters in DTI with DWI, we obtained similar efficiency of ADC with b values of 0,1000 and 0,1500 s/mm 2 and MD with a b value of 0, 1000 s/mm 2 (AUC = 0.82 ± 0.07). Conclusion: ADC of DWI and MD of DTI values provide significant discriminative factors for benign and malignant breast lesions. FA measurement was not discriminative. Supported with clinical and dynamic contrast MRI findings, DWI and DTI findings provide significant contribution to the final radiologic decision

Comparison of the diagnostic performances of diffusion parameters in diffusion weighted imaging and diffusion tensor imaging of breast lesions

Energy Technology Data Exchange (ETDEWEB)

Cakir, Ozgur, E-mail: cakirozgur@hotmail.com; Arslan, Arzu, E-mail: arzu.s.arslan@gmail.com; Inan, Nagihan, E-mail: nagihaninan@yahoo.com.tr; Anık, Yonca, E-mail: yoncaanik@yahoo.com; Sarısoy, Tahsin, E-mail: htsarisoy@yahoo.com; Gumustas, Sevtap, E-mail: svtgumustas@yahoo.com; Akansel, Gur, E-mail: gakansel@gmail.com

2013-12-01

Purpose: To evaluate the diagnostic efficiency of the diffusion parameters measured by conventional diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) for discrimination of malignant breast lesions from benign lesions and the normal breast. Materials and methods: The study included 52 women with 55 breast lesions (30 malignant, 25 benign). DTI and DWI were performed complementary to dynamic contrast MRI at 3T. Apparent diffusion coefficient (ADC) of DWI, mean diffusivity (MD) and fractional anisotropy (FA) values of DTI were measured for lesions and contralateral breast parenchyma in each patient. We used b factors of 0, 50, 850, 1000 and 1500 s/mm{sup 2} for DWI and b 0 and 1000 s/mm{sup 2} for DTI. ADC, MD and FA values were compared between malignant and benign lesions, and the normal parenchyma by univariate and multivariate analyses. Results: Diffusion parameters showed no difference according to menopausal status in the normal breast. ADC and MD values of the malignant lesions were significantly lower than benign lesions and normal parenchyma (p = 0.001). The FA showed no statistical significance. With the cut-off values of ≤1.23 × 10{sup −3} mm{sup 2}/s (b 0–1000 s/mm{sup 2}) and ≤1.12 × 10{sup −3} mm{sup 2}/s (b 0–1500 s/mm{sup 2}), ADC showed 92.85% and 96.15% sensitivity; 72.22% and 73.52% PPV, respectively. With a cut-off value of ≤1.27 × 10{sup −3} mm{sup 2}/s (b 1000 s/mm{sup 2}), MD was 100% sensitive with a PPV of 65.90%. Comparing the diagnostic performance of the parameters in DTI with DWI, we obtained similar efficiency of ADC with b values of 0,1000 and 0,1500 s/mm{sup 2} and MD with a b value of 0, 1000 s/mm{sup 2} (AUC = 0.82 ± 0.07). Conclusion: ADC of DWI and MD of DTI values provide significant discriminative factors for benign and malignant breast lesions. FA measurement was not discriminative. Supported with clinical and dynamic contrast MRI findings, DWI and DTI findings provide significant

Tellurium self-diffusion and point defects in lead telluride

International Nuclear Information System (INIS)

Simirskij, Yu.N.; Firsova, L.P.

1982-01-01

Method of radioactive indicators was used to determine factors of tellurium self-diffusion in lead telluride with different deviation of the composition from stoichiometric in the range of enrichment by tellurium. It was found that at 973 K factors of tellurium self-diffusion in lead telluride depend slightly on the vapor pressure of tellurium equilibrium with solid phase

The relevance of light diffusion profiles for interstitial PDT using light-diffusing optical fibers

Science.gov (United States)

Stringasci, Mirian D.; Fortunato, Thereza C.; Moriyama, Lilian T.; Vollet Filho, José Dirceu; Bagnato, Vanderlei S.; Kurachi, Cristina

2017-02-01

Photodynamic therapy (PDT) is a technique used for several tumor types treatment. Light penetration on biological tissue is one limiting factor for PDT applied to large tumors. An alternative is using interstitial PDT, in which optical fibers are inserted into tumors. Cylindrical diffusers have been used in interstitial PDT. Light emission of different diffusers depends on the manufacturing process, size and optical properties of fibers, which make difficult to establish an adequate light dosimetry, since usually light profile is not designed for direct tissue-fiber contact. This study discusses the relevance of light distribution by a cylindrical diffuser into a turbid lipid emulsion solution, and how parts of a single diffuser contribute to illumination. A 2 cm-long cylindrical diffuser optical fiber was connected to a diode laser (630 nm), and the light spatial distribution was measured by scanning the solution with a collection probe. From the light field profile generated by a 1 mm-long intermediary element of a 20 mm-long cylindrical diffuser, recovery of light distribution for the entire diffuser was obtained. PDT was performed in rat healthy liver for a real treatment outcome analysis. By using computational tools, a typical necrosis profile generated by the irradiation with such a diffuser fiber was reconstructed. The results showed that it was possible predicting theoretically the shape of a necrosis profile in a healthy, homogeneous tissue with reasonable accuracy. The ability to predict the necrosis profile obtained from an interstitial illumination by optical diffusers has the potential improve light dosimetry for interstitial PDT.

Evaluation of diffusion parameters of radon in porous material by flow-through diffusion experiment

International Nuclear Information System (INIS)

Chunnan Hsu; Shihchin Tsai; Shihming Liang

1994-01-01

The effectiveness of a material in reducing the fluence rate of Rn from soil was assessed in this study by using a flow-through diffusion experiment to evaluate the diffusion parameters -apparent diffusion coefficient and capacity factor - of radon (Rn) in a porous material. An improved method based on the nonlinear least-squares and Marquardt's method (NLSM method) was proposed to provide more reliable analyses of experimental data than the graphical method. The NLSM method was confirmed by the experimental results to be capable of estimating the diffusion parameters, even if the process was transient. This method was also demonstrated to correlate sufficiently with the results by the conventional method while the process had already reached steady-state. Natural mordenite was employed in this study as a testing material because it has more effective sorption for noble gas than any other earthen material. (author)

Factors influencing pharmacists' adoption of prescribing: qualitative application of the diffusion of innovations theory.

Science.gov (United States)

Makowsky, Mark J; Guirguis, Lisa M; Hughes, Christine A; Sadowski, Cheryl A; Yuksel, Nese

2013-09-14

In 2007, Alberta became the first Canadian jurisdiction to grant pharmacists a wide range of prescribing privileges. Our objective was to understand what factors influence pharmacists' adoption of prescribing using a model for the Diffusion of Innovations in healthcare services. Pharmacists participated in semi-structured telephone interviews to discuss their prescribing practices and explore the facilitators and barriers to implementation. Pharmacists working in community, hospital, PCN, or other settings were selected using a mix of random and purposive sampling. Two investigators independently analyzed each transcript using an Interpretive Description approach to identify themes. Analyses were informed by a model explaining the Diffusion of Innovations in health service organizations. Thirty-eight participants were interviewed. Prescribing behaviours varied from non-adoption through to product, disease, and patient focused use of prescribing. Pharmacists' adoption of prescribing was dependent on the innovation itself, adopter, system readiness, and communication and influence. Adopting pharmacists viewed prescribing as a legitimization of previous practice and advantageous to instrumental daily tasks. The complexity of knowledge required for prescribing increased respectively in product, disease and patient focused prescribing scenarios. Individual adopters had higher levels of self-efficacy toward prescribing skills. At a system level, pharmacists who were in practice settings that were patient focused were more likely to adopt advanced prescribing practices, over those in product-focused settings. All pharmacists stated that physician relationships impacted their prescribing behaviours and individual pharmacists' decisions to apply for independent prescribing privileges. Diffusion of Innovations theory was helpful in understanding the multifaceted nature of pharmacists' adoption of prescribing. The characteristics of the prescribing model itself which

Information Technology Diffusion: A Comparative Case Study of Intranet Adoption

OpenAIRE

Zolla, George A., Jr.

1999-01-01

This exploratory study identifies factors that influence the adoption and diffusion of intranet technology. A comparative case study of bipolar organizations is used to identify crucial implementation factors and create an innovation adoption model. A strategic approach for the adoption and diffusion of intranet technology is then presented.

Multicomponent diffusion in molten salt LiF-BeF{sub 2}: Dynamical correlations and Maxwell–Stefan diffusivities

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Brahmananda, E-mail: brahma@barc.gov.in; Ramaniah, Lavanya M. [High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

2015-06-24

Applying Green–Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied the dynamic correlation, Onsager coeeficients and Maxwell–Stefan (MS) Diffusivities of molten salt LiF-BeF{sub 2}, which is used as coolant in high temperature reactor. All the diffusive flux correlations show back-scattering or cage dynamics which becomes pronouced at higher temperature. Although the MS diffusivities are expected to depend very lightly on the composition due to decoupling of thermodynamic factor, the diffusivity Đ{sub Li-F} and Đ{sub Be-F} decreases sharply for higher concentration of LiF and BeF{sub 2} respectively. Interestingly, all three MS diffusivities have highest magnitude for eutectic mixture at 1000K (except Đ{sub Be-F} at lower LiF mole fraction) which is desirable from coolant point of view. Although the diffusivity for positive-positive ion pair is negative it is not in violation of the second law of thermodynamics as it satisfies the non-negative entropic constraints.

Gene expression patterns combined with network analysis identify hub genes associated with bladder cancer.

Science.gov (United States)

Bi, Dongbin; Ning, Hao; Liu, Shuai; Que, Xinxiang; Ding, Kejia

2015-06-01

To explore molecular mechanisms of bladder cancer (BC), network strategy was used to find biomarkers for early detection and diagnosis. The differentially expressed genes (DEGs) between bladder carcinoma patients and normal subjects were screened using empirical Bayes method of the linear models for microarray data package. Co-expression networks were constructed by differentially co-expressed genes and links. Regulatory impact factors (RIF) metric was used to identify critical transcription factors (TFs). The protein-protein interaction (PPI) networks were constructed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and clusters were obtained through molecular complex detection (MCODE) algorithm. Centralities analyses for complex networks were performed based on degree, stress and betweenness. Enrichment analyses were performed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Co-expression networks and TFs (based on expression data of global DEGs and DEGs in different stages and grades) were identified. Hub genes of complex networks, such as UBE2C, ACTA2, FABP4, CKS2, FN1 and TOP2A, were also obtained according to analysis of degree. In gene enrichment analyses of global DEGs, cell adhesion, proteinaceous extracellular matrix and extracellular matrix structural constituent were top three GO terms. ECM-receptor interaction, focal adhesion, and cell cycle were significant pathways. Our results provide some potential underlying biomarkers of BC. However, further validation is required and deep studies are needed to elucidate the pathogenesis of BC. Copyright © 2015 Elsevier Ltd. All rights reserved.

Multicomponent diffusion in molten salt NaF-ZrF{sub 4}: Dynamical correlations and Maxwell–Stefan diffusivities

Energy Technology Data Exchange (ETDEWEB)

Baig, Mohammad Saad, E-mail: saad110baig@gmail.com; Chakraborty, Brahmananda; Ramaniah, Lavanya M. [High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-85 (India)

2016-05-23

NaF-ZrF{sub 4} is used as a waste incinerator and as a coolant in Generation IV reactors.Structural and dynamical properties of molten NaF-ZrF{sub 4} system were studied along with Onsagercoefficients and Maxwell–Stefan (MS) Diffusivities applying Green–Kubo formalism and molecular dynamics (MD) simulations. The zirconium ions are found to be 8 fold coordinated with fluoride ions for all temperatures and concentrations. All the diffusive flux correlations show back-scattering. Even though the MS diffusivities are expected to depend very lightly on the composition because of decoupling of thermodynamic factor, the diffusivity Đ{sub Na-F} shows interesting behavior with the increase in concentration of ZrF{sub 4}. This is because of network formation in NaF-ZrF{sub 4}. Positive entropy constraints have been plotted to authenticate negative diffusivities observed.

The solubility and diffusion coefficient of helium in uranium dioxide

International Nuclear Information System (INIS)

Nakajima, Kunihisa; Serizawa, Hiroyuki; Shirasu, Noriko; Haga, Yoshinori; Arai, Yasuo

2011-01-01

Highlights: ► The solubility and diffusivity of He in single-crystal UO 2 were determined. ► The determined He solubility lay within the scatter of the available data. ► The determined He diffusivity was in good agreement with recent experimental data. ► The He behavior was analyzed in terms of a simple interstitial diffusion mechanism. ► The experimental diffusivity was much lower than that analyzed theoretically. - Abstract: The solubility and diffusion coefficient of helium in the single-crystal UO 2 samples were determined by a Knudsen-effusion mass-spectrometric method. The measured helium solubilities were found to lie within the scatter of the available data, but to be much lower than those for the polycrystalline samples. The diffusion analysis was conducted based on a hypothetical equivalent sphere model and the simple Fick’s law. The helium diffusion coefficient was determined by using the pre-exponential factor and activation energy as the fitting parameters for the measured and calculated fractional releases of helium. The optimized diffusion coefficients were in good agreement with those obtained by a nuclear reaction method reported in the past. It was also found that the pre-exponential factors of the determined diffusion coefficients were much lower than those analyzed in terms of a simple interstitial diffusion mechanism.

An agent-based evacuation model with social contagion mechanisms and cultural factors

NARCIS (Netherlands)

van der Wal, C. Natalie; Formolo, Daniel; Bosse, Tibor

2017-01-01

© Springer International Publishing AG 2017. A fire incident at a transport hub can cost many lives. To save lives, effective crisis management and prevention measures need to be taken. In this project, the effect of cultural factors in managing and preventing emergencies in public transport systems

Contribution to the study of the interfacial diffusion

International Nuclear Information System (INIS)

Perinet, Francois.

1975-07-01

The diffusion behaviour of matrix-precipitate boundaries is the same as that of interphase boundaries prepared by welding. Therefore the latter can be used to measure diffusivity along interphase boundaries. Diffusion rates of silver along copper-silver interfaces prepared by welding single crystals have been measured. The interfacial diffusion coefficients deduced through different analytical solutions of the diffusion equations, yield for the activation energy and the frequency factor values close to: Q(i)=65kcal/mole Dsub(i)sup(o) delta=100cm 3 .s -1 . These results seem to indicate that, in agreement with Bondy's and Job's previous results, the activation energies for interfacial diffusion are high. Furthermore it is shown that the misorientation between the two phases building the interface has an influence on the measured diffusion coefficients [fr

Carrier illumination measurement of dopant lateral diffusion

International Nuclear Information System (INIS)

Budiarto, E.; Segovia, M.; Borden, P.; Felch, S.

2005-01-01

This paper describes the application of the carrier illumination technique to non-destructively measure the lateral diffusion of implanted dopants after annealing. Experiments to validate the feasibility of this method employed test structures with a constant line width of 300 nm and varying undoped spaces of 100-5000 nm. The test patterns were implanted with a p-type dopant and annealed in a 3 x 3 matrix. For each implant condition, the measured lateral diffusion was found to increase with annealing temperature, as expected. More interestingly, the lateral diffusion was not observed to relate to the vertical diffusion by a fixed proportionality factor, as is usually assumed. The ratio of lateral to vertical diffusion varies with annealing temperature, with a trend that depends on the implant condition

Self-diffusion in MgO--a density functional study.

Science.gov (United States)

Runevall, Odd; Sandberg, Nils

2011-08-31

Density functional theory calculations have been performed to study self-diffusion in magnesium oxide, a model material for a wide range of ionic compounds. Formation energies and entropies of Schottky defects and divacancies were obtained by means of total energy and phonon calculations in supercell configurations. Transition state theory was used to estimate defect migration rates, with migration energies taken from static calculations, and the corresponding frequency factors estimated from the phonon spectrum. In all static calculations we corrected for image effects using either a multipole expansion or an extrapolation to the low concentration limit. It is shown that both methods give similar results. The results for self-diffusion of Mg and O confirm the previously established picture, namely that in materials of nominal purity, Mg diffuses extrinsically by a single vacancy mechanism, while O diffuses intrinsically by a divacancy mechanism. Quantitatively, the current results are in very good agreement with experiments concerning O diffusion, while for Mg the absolute diffusion rate is generally underestimated by a factor of 5-10. The reason for this discrepancy is discussed.

Diffusion of anions and cations in compacted sodium bentonite

International Nuclear Information System (INIS)

Muurinen, A.

1994-02-01

The thesis presents the results of studies on the diffusion mechanisms of anions and cations in compacted sodium bentonite, which is planned to be used as a buffer material in nuclear waste disposal in Finland. The diffusivities and sorption factors were determined by tracer experiments. The pore volume accessible to chloride, here defined as effective porosity, was determined as a function of bentonite density and electrolyte concentration in water, and the Stern-Gouy double-layer model was used to explain the observed anion exclusion. The sorption of Cs + and Sr 2+ was studied in loose and compacted bentonite samples as a function of the electrolyte concentration in solution. In order to obtain evidence of the diffusion of exchangeable cations, defined as surface diffusion, the diffusivities of Cs + and Sr 2+ in compacted bentonite were studied as a function of the sorption factor, which was varied by electrolyte concentration in solution. The measurements were performed both by a non-steady state method and by a through-diffusion method. (89 refs., 35 fig., 4 tab.)

Unraveling the WRKY transcription factors network in Arabidopsis Thaliana by integrative approach

Directory of Open Access Journals (Sweden)

Mouna Choura

2015-06-01

Full Text Available The WRKY transcription factors superfamily are involved in diverse biological processes in plants including response to biotic and abiotic stresses and plant immunity. Protein-protein interaction network is a useful approach for understanding these complex processes. The availability of Arabidopsis Thaliana interactome offers a good opportunity to do get a global view of protein network. In this work, we have constructed the WRKY transcription factor network by combining different sources of evidence and we characterized its topological features using computational tools. We found that WRKY network is a hub-based network involving multifunctional proteins denoted as hubs such as WRKY 70, WRKY40, WRKY 53, WRKY 60, WRKY 33 and WRKY 51. Functional annotation showed seven functional modules particularly involved in biotic stress and defense responses. Furthermore, the gene ontology and pathway enrichment analysis revealed that WRKY proteins are mainly involved in plant-pathogen interaction pathways and their functions are directly related to the stress response and immune system process.

Diffusion in inhomogeneous polymer membranes

Science.gov (United States)

Kasargod, Sameer S.; Adib, Farhad; Neogi, P.

1995-10-01

The dual mode sorption solubility isotherms assume, and in instances Zimm-Lundberg analysis of the solubilities show, that glassy polymers are heterogeneous and that the distribution of the solute in the polymer is also inhomogeneous. Under some conditions, the heterogeneities cannot be represented as holes. A mathematical model describing diffusion in inhomogeneous polymer membranes is presented using Cahn and Hilliard's gradient theory. The fractional mass uptake is found to be proportional to the fourth root of time rather than the square root, predicted by Fickian diffusion. This type of diffusion is classified as pseudo-Fickian. The model is compared with one experimental result available. A negative value of the persistence factor is obtained and the results are interpreted.

Optimal factors of diffusion tensor imaging predicting cortico spinal tract injury in patients with brain tumors

Energy Technology Data Exchange (ETDEWEB)

Min, Zhi Gang; Niu, Chen; Zhang, Qiu Li; Zhang, Ming [Dept. of Radiology, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an (China); Qian, Yu Cheng [Dept. of Medical Imaging, School of Medicine, Jiangsu University, Zhenjiang (China)

2017-09-15

To identify the optimal factors in diffusion tensor imaging for predicting corticospinal tract (CST) injury caused by brain tumors. This prospective study included 33 patients with motor weakness and 64 patients with normal motor function. The movement of the CST, minimum distance between the CST and the tumor, and relative fractional anisotropy (rFA) of the CST on diffusion tensor imaging, were compared between patients with motor weakness and normal function. Logistic regression analysis was used to obtain the optimal factor predicting motor weakness. In patients with motor weakness, the displacement (8.44 ± 6.64 mm) of the CST (p = 0.009), minimum distance (3.98 ± 7.49 mm) between the CST and tumor (p < 0.001), and rFA (0.83 ± 0.11) of the CST (p < 0.001) were significantly different from those of the normal group (4.64 ± 6.65 mm, 14.87 ± 12.04 mm, and 0.98 ± 0.05, respectively) (p = 0.009, p < 0.001, and p < 0.001). The frequencies of patients with the CST passing through the tumor (6%, p = 0.002), CST close to the tumor (23%, p < 0.001), CST close to a malignant tumor (high grade glioma, metastasis, or lymphoma) (19%, p < 0.001), and CST passing through infiltrating edema (19%, p < 0.001) in the motor weakness group, were significantly different from those of the patients with normal motor function (0, 8, 1, and 10%, respectively). Logistic regression analysis showed that decreased rFA and CST close to a malignant tumor were effective variables related to motor weakness. Decreased fractional anisotropy, combined with closeness of a malignant tumor to the CST, is the optimal factor in predicting CST injury caused by a brain tumor.

A Three-Legged Stool or Race? Governance Models for NOAA RISAs, DOI CSCs, and USDA Climate Hubs

Science.gov (United States)

Foster, J. G.

2014-12-01

NOAAs Regional Integrated Sciences and Assessments (RISA) Teams, DOIs Climate Science Centers (CSCs), and USDAs Regional Climate Hubs (RCHs) have common missions of integrating climate and related knowledge across scientific disciplines and regions to create "actionable" information that decision-makes can use to manage climate risks and impacts at state and local scales. However, the sponsoring agency programs, university investigators, and local federal officials govern each differently. The three models of program and center governance are 1) exclusively university (RISAs), 2) a hybrid of Federal government and (host) university (CSCs,), and 3) exclusively Federal (Hubs). Each model has it's advantages and disadvantages in terms of legal definition and authority, scientific mission requirements and strategies, flexibility and legitimacy to conduct research and to collaborate regionally with constituencies, leadership and governance approach and "friction points,", staff capacity and ability to engage stakeholders, necessity to deliver products and services, bureaucratic oversight, performance evaluation, and political support at Congressional, state, and local levels. Using available sources of information and data, this paper will compare and contrast the strengths and weakness of these three regional applied climate science center governance models.

A Three-Legged Stool or Race? Governance Models for NOAA RISAs, DOI CSCs, and USDA Climate Hub

Science.gov (United States)

Foster, J. G.

2014-12-01

NOAAs Regional Integrated Sciences and Assessments (RISA) Teams, DOIs Climate Science Centers (CSCs), and USDAs Regional Climate Hubs (RCHs) have common missions of integrating climate and related knowledge across scientific disciplines and regions to create "actionable" information that decision-makes can use to manage climate risks and impacts at state and local scales. However, the sponsoring agency programs, university investigators, and local federal officials govern each differently. The three models of program and center governance are 1) exclusively university (RISAs), 2) a hybrid of Federal government and (host) university (CSCs,), and 3) exclusively Federal (Hubs). Each model has it's advantages and disadvantages in terms of legal definition and authority, scientific mission requirements and strategies, flexibility and legitimacy to conduct research and to collaborate regionally with constituencies, leadership and governance approach and "friction points,", staff capacity and ability to engage stakeholders, necessity to deliver products and services, bureaucratic oversight, performance evaluation, and political support at Congressional, state, and local levels. Using available sources of information and data, this paper will compare and contrast the strengths and weakness of these three regional applied climate science center governance models.

Identifying the Functional Requirements for an Arizona Astronomy Data Hub (AADH)

Science.gov (United States)

Stahlman, G.; Heidorn, P. B.

2015-12-01

Astronomy data represent a curation challenge for information managers, as well as for astronomers. Extracting knowledge from these heterogeneous and complex datasets is particularly complicated and requires both interdisciplinary and domain expertise to accomplish true curation, with an overall goal of facilitating reproducible science through discoverability and persistence. A group of researchers and professional staff at the University of Arizona held several meetings during the spring of 2015 about astronomy data and the role of the university in curation of that data. The group decided that it was critical to obtain a broader consensus on the needs of the community. With assistance from a Start for Success grant provided by the University of Arizona Office of Research and Discovery and funding from the American Astronomical Society (AAS), a workshop was held in early July 2015, with 28 participants plus 4 organizers in attendance. Representing University researchers as well as astronomical facilities and a scholarly society, the group verified that indeed there is a problem with the long-term curation of some astronomical data not associated with major facilities, and that a repository or "data hub" with the correct functionality could facilitate research and the preservation and use of astronomy data. The workshop members also identified a set of next steps, including the identification of possible data and metadata to be included in the Hub. The participants further helped to identify additional information that must be gathered before construction of the AADH could begin, including identifying significant datasets that do not currently have sufficient preservation and dissemination infrastructure, as well as some data associated with journal publications and the broader context of the data beyond that directly published in the journals. Workshop participants recommended that a set of grant proposal should be developed that ensures community buy-in and

Mutual diffusion of sodium hyaluranate in aqueous solutions

International Nuclear Information System (INIS)

Veríssimo, Luís M.P.; Valada, Teresa I.C.; Sobral, Abilio J.F.N.; Azevedo, Eduarda E.F.G.; Azevedo, Maria L.G.; Ribeiro, Ana C.F.

2014-01-01

Highlights: • Binary diffusion coefficients for the systems containing sodium hyaluronate. • Influence of the aggregation on diffusion of the sodium hyaluronate in the aqueous media. • Estimation of the thermodynamic and mobility factors from mutual diffusion. -- Abstract: The Taylor dispersion technique has been used for measuring mutual diffusion coefficients of sodium hyaluronate in aqueous solutions at T = 298.15 K, and concentrations ranging from (0.00 to 0.50) g · dm −3 . The results are interpreted on the basis of Nernst, and Onsager and Fuoss theoretical equations. From the diffusion coefficient at infinitesimal concentration, the limiting ionic conductivity and the tracer diffusion coefficient of hyaluronate ion were estimated. These studies have been complemented by molecular mechanics calculations

Diffusible signal factor-dependent quorum sensing in pathogenic bacteria and its exploitation for disease control.

Science.gov (United States)

Dow, J M

2017-01-01

Cell-to-cell signals of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids of differing chain length and branching pattern. DSF signalling has been described in diverse bacteria to include plant and human pathogens where it acts to regulate functions such as biofilm formation, antibiotic tolerance and the production of virulence factors. DSF family signals can also participate in interspecies signalling with other bacteria and interkingdom signalling such as with the yeast Candida albicans. Interference with DSF signalling may afford new opportunities for the control of bacterial disease. Such strategies will depend in part on detailed knowledge of the molecular mechanisms underlying the processes of signal synthesis, perception and turnover. Here, I review both recent progress in understanding DSF signalling at the molecular level and prospects for translating this knowledge into approaches for disease control. © 2016 The Society for Applied Microbiology.

Diffusion mechanisms of strontium, cesium and cobalt in compacted sodium bentonite

International Nuclear Information System (INIS)

Muurinen, A.; Rantanen, J.; Penttilae-Hiltunen, P.

1986-01-01

For a porous water-saturated material where diffusion in the porewater, sorption on the solid material and diffusion of the sorbed ions (surface diffusion) occur, a diffusion equation can be derived where the apparent diffusivity includes two terms. One represents diffusion in the pore-water, the other surface diffusion. In this research diffusion mechanisms were studied. The apparent diffusivities of strontium, cesium and cobalt in compacted sodium bentonite were measured by a non-steady state method. The sorption factors were adjusted using different sodium chloride solutions, groundwater and addition of EDTA for saturation of the bentonite samples. The corresponding sorption factors were measured by a batch method. The results suggest that cations diffuse also while being sorbed. A combined pore diffusion-surface diffusion model has been used to explain the transport and the corresponding diffusivities have been evaluated. The surface diffusivities (D/sub s/) of Sr and Cs were 8-9 x 10 -12 m 2 /s and 4-7 x 10 -13 m 2 /s respectively. The pore diffusivity epsilon D/sub p/ of Cs was 3.5 x 10 -11 m 2 /s which has been used also for Sr. The sorption mechanisms of Co seems to be different from that of Sr or Cs and the results allow no specific conclusions of the diffusion mechanisms of Co. The apparent diffusivity of Co ranged from 2 x 10 -14 to 7 x 10 -14 m 2 /s. The anionic Co-EDTA seems to follow some other diffusion mechanism than the cations

Systematic homogenization and self-consistent flux and pin power reconstruction for nodal diffusion methods. 1: Diffusion equation-based theory

International Nuclear Information System (INIS)

Zhang, H.; Rizwan-uddin; Dorning, J.J.

1995-01-01

A diffusion equation-based systematic homogenization theory and a self-consistent dehomogenization theory for fuel assemblies have been developed for use with coarse-mesh nodal diffusion calculations of light water reactors. The theoretical development is based on a multiple-scales asymptotic expansion carried out through second order in a small parameter, the ratio of the average diffusion length to the reactor characteristic dimension. By starting from the neutron diffusion equation for a three-dimensional heterogeneous medium and introducing two spatial scales, the development systematically yields an assembly-homogenized global diffusion equation with self-consistent expressions for the assembly-homogenized diffusion tensor elements and cross sections and assembly-surface-flux discontinuity factors. The rector eigenvalue 1/k eff is shown to be obtained to the second order in the small parameter, and the heterogeneous diffusion theory flux is shown to be obtained to leading order in that parameter. The latter of these two results provides a natural procedure for the reconstruction of the local fluxes and the determination of pin powers, even though homogenized assemblies are used in the global nodal diffusion calculation

Diffusion

International Nuclear Information System (INIS)

Kubaschewski, O.

1983-01-01

The diffusion rate values of titanium, its compounds and alloys are summarized and tabulated. The individual chemical diffusion coefficients and self-diffusion coefficients of certain isotopes are given. Experimental methods are listed which were used for the determination of diffusion coefficients. Some values have been taken over from other studies. Also given are graphs showing the temperature dependences of diffusion and changes in the diffusion coefficient with concentration changes

Synergizing two NWP models to improve hub-height wind speed forecasts

Energy Technology Data Exchange (ETDEWEB)

Liu, H. [Ortech International, Mississauga, ON (Canada); Taylor, P. [York Univ., Toronto, ON (Canada)

2010-07-01

This PowerPoint presentation discussed some of the methods used to optimize hub-height wind speed forecasts. Statistical and physical forecast paradigms were considered. Forecast errors are often dictated by phase error, while refined NWP modelling is limited by data availability. A nested meso-scale NWP model was combined with a physical model to predict wind and power forecasts. Maps of data sources were included as well as equations used to derive predictions. Data from meteorological masts located near the Great Lakes were used to demonstrate the model. The results were compared with other modelling prediction methods. Forecasts obtained using the modelling approach can help operators in scheduling and trading procedures. Further research is being conducted to determine if the model can be used to improve ramp forecasts. tabs., figs.

Replacement of Chromium Electroplating on C-2, E-2, P-3 and C-130 Propeller Hub Components Using HVOF Thermal Spray Coatings

National Research Council Canada - National Science Library

Sartwell, Bruce

2004-01-01

.... This document constitutes the final report on a project to qualify high-velocity oxygen-fuel (HVOF) thermal spray coatings as a replacement for hard chrome plating on propeller hub components from various military aircraft...

Understanding Cultural Geography as a Pseudo-Diffusion Process: The Case of the Veneto Region

Directory of Open Access Journals (Sweden)

Guido Ferilli

2015-06-01

Full Text Available In this paper, we study the cultural geography of the Veneto Region on the basis of a pseudo-diffusion approach to the analysis of the inherent semantic spatial data. We find somewhat surprising results, and, in particular, that Venice, indisputably the Region’s cultural hub in terms of concentration of activities and facilities, global visibility and attraction of resources, plays a marginal role in determining the momentum of cultural initiative at the regional level as of 2007 data. The areas with the greater momentum are relatively marginal ones but characterized by a strong presence of design-oriented companies that are actively engaging in culture-driven innovation in a context of gradually horizontally-integrated clusters. Our findings call for a revision of the traditional policy approaches that identify centralities in terms of concentration of activities and facilities based on past dynamics, and to design policies accordingly. We argue in favour of a more forward-looking, evidence-based approach.

Research and development of groundwater dating (Part 3). A proposal of determination method for diffusion coefficients of dissolved helium in rock and applicability of estimation of diffusion coefficients using anions

International Nuclear Information System (INIS)

Higashihara, Tomohiro; Nakata, Kotaro; Hasegawa, Takuma

2006-01-01

Dissolved helium in groundwater is one of the most suitable tracers for the groundwater dating. The diffusion coefficients in aquitard and aquifer were important to estimate an accumulation of the helium in groundwater. However, few papers have been reported about the diffusion of helium in rocks. In this study, effective diffusion coefficients of the helium in sandstones and mudstone were determined using a through-diffusion method. The effective diffusion coefficients of helium were in the range of 1.5 x 10 -10 to 1.1 x 10 -9 m 2 s -1 and larger than those of Br - ions. Geometrical factors for the diffusion of helium were also larger than those for the diffusion of Br - ions. This fact suggests that diffusion path of helium in the rocks is not more restricted than that of Br - ions. The diffusion coefficients of helium were also estimated using the diffusion coefficient of helium in bulk water and formation factors for diffusion of Br - ions. The estimated diffusion coefficients of helium were larger than the effective diffusion coefficients. It is clarified that the effective diffusion coefficients of helium are underestimated by the estimation method using anions. (author)