WorldWideScience

Sample records for hoc co-located collaboration

  1. Building collaboration? Co-location and territoriality in a railway control center

    NARCIS (Netherlands)

    Willems, T.A.H.; van Marrewijk, A.H.

    2017-01-01

    This paper studies the design of co-located spaces and how organizational actors experience such spaces. The literature on co-location is ambiguous about how reduced physical distance increases collaboration. To address this problem, we draw on an ethnographic study of a co-located railway control

  2. Look together : Using gaze for assisting co-located collaborative search

    NARCIS (Netherlands)

    Zhang, Y.; Pfeuffer, Ken; Chong, Ming Ki; Alexander, Jason; Bulling, Andreas; Gellersen, Hans

    2017-01-01

    Gaze information provides indication of users focus which complements remote collaboration tasks, as distant users can see their partner’s focus. In this paper, we apply gaze for co-located collaboration, where users’ gaze locations are presented on the same display, to help collaboration between

  3. Co-location as a Driver for Cross-Sectoral Collaboration with General Practitioners as Coordinators

    DEFF Research Database (Denmark)

    Scheele, Christian Elling; Vrangbæk, Karsten

    2016-01-01

    The issue of integrated care and inter-sectoral collaboration is on the health policy agenda in many countries. Yet, there is limited knowledge about the effects of the different policy instruments used to achieve this. This paper studies co-location as a driver for cross-sectoral collaboration...... with general practitioners (GPs) acting as coordinators in a municipal health centre. The purpose of the health centre, which is staffed by health professionals from municipal, regional and private sectors, is to provide primary health services to the citizens of the municipality. Co......-locating these professionals is supposed to benefit e.g., elder citizens and patients with chronic diseases who frequently require services from health professionals across administrative sectors. Methodologically, the analysis is based on qualitative data in the form of semi-structured interviews with the health...

  4. Synchronous gesture manipulation for collaboration and coordination of co-located Business Process Modelling

    Directory of Open Access Journals (Sweden)

    Brenda Scholtz

    2015-12-01

    Full Text Available The purpose of this study was to investigate approaches (techniques and technologies for the coordination of collaborative tasks using synchronous gesture manipulation. Business Process Modelling (BPM tasks are often performed in teams of modellers who need to collaborate with each other in order to coordinate and integrate their individual contributions into the various process models in a co-located environment. These collaborative BPM tasks were used as a case study in order to develop the artifact (the BPM-Touch approach as a proof of concept. The BPM-Touch approach allows for the coordination and collaboration of BPM tasks in co-located modelling teams using synchronous gesture manipulation approaches. The Design Science Research (DSR methodology was used and several cycles of developing and evaluating the artifact took place. This paper reports on the last cycle and set of evaluations. The proposed approach was implemented in a BPM software package in order to provide empirical validation. Usability evaluations of the software were undertaken with both students and BPM professionals as participants. The empirical results of the evaluations revealed that the participants found the approach to be effective and rated the usability and satisfaction of the collaboration and gesture manipulation aspects of the software positively.

  5. Mental health measurement among women veterans receiving co-located, collaborative care services.

    Science.gov (United States)

    Lilienthal, Kaitlin R; Buchholz, Laura J; King, Paul R; Vair, Christina L; Funderburk, Jennifer S; Beehler, Gregory P

    2017-12-01

    Routine use of measurement to identify patient concerns and track treatment progress is critical to high quality patient care. This is particularly relevant to the Primary Care Behavioral Health model, where rapid symptom assessment and effective referral management are critical to sustaining population-based care. However, research suggests that women who receive treatment in co-located collaborative care settings utilizing the PCBH model are less likely to be assessed with standard measures than men in these settings. The current study utilized regional retrospective data obtained from the Veterans Health Administration's electronic medical record system to: (1) explore rates of mental health measurement for women receiving co-located collaborative care services (N = 1008); and (2) to identify predictors of mental health measurement in women veterans in these settings. Overall, only 8% of women had documentation of standard mental health measures. Measurement was predicted by diagnosis, facility size, length of care episode and care setting. Specifically, women diagnosed with depression were less likely than those with anxiety disorders to have standard mental health measurement documented. Several suggestions are offered to increase the quality of mental health care for women through regular use of measurement in integrated care settings.

  6. Supporting Dynamic Ad hoc Collaboration Capabilities

    CERN Document Server

    Agarwal, D

    2003-01-01

    Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.

  7. Supporting Dynamic Ad hoc Collaboration Capabilities

    International Nuclear Information System (INIS)

    Agarwal, Deborah A.; Berket, Karlo

    2003-01-01

    Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment

  8. Study of Co-Located and Distant Collaboration with Symbolic Support via a Haptics-Enhanced Virtual Reality Task

    Science.gov (United States)

    Yeh, Shih-Ching; Hwang, Wu-Yuin; Wang, Jin-Liang; Zhan, Shi-Yi

    2013-01-01

    This study intends to investigate how multi-symbolic representations (text, digits, and colors) could effectively enhance the completion of co-located/distant collaborative work in a virtual reality context. Participants' perceptions and behaviors were also studied. A haptics-enhanced virtual reality task was developed to conduct…

  9. Co-Located Single Display Collaborative Learning for Early Childhood Education

    Science.gov (United States)

    Gomez, Florencia; Nussbaum, Miguel; Weitz, Juan F.; Lopez, Ximena; Mena, Javiera; Torres, Alex

    2013-01-01

    The benefits of collaborative learning are well documented. However, most of the research has been done with children beyond the ages of early childhood. This could be due to the common and erroneous belief that young children have not developed the capacity to work collaboratively toward a given aim. In this paper we show how small group…

  10. Assured Resource Sharing in Ad-Hoc Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Gail-Joon [Arizona State Univ., Tempe, AZ (United States)

    2015-12-19

    The project seeks an innovative framework to enable users to access and selectively share resources in distributed environments, enhancing the scalability of information sharing. We have investigated secure sharing & assurance approaches for ad-hoc collaboration, focused on Grids, Clouds, and ad-hoc network environments.

  11. Collaboration Layer for Robots in Mobile Ad-hoc Networks

    DEFF Research Database (Denmark)

    Borch, Ole; Madsen, Per Printz; Broberg, Jacob Honor´e

    2009-01-01

    In many applications multiple robots in Mobile Ad-hoc Networks are required to collaborate in order to solve a task. This paper shows by proof of concept that a Collaboration Layer can be modelled and designed to handle the collaborative communication, which enables robots in small to medium size...

  12. Optimal channel choice for collaborative ad-hoc dissemination

    DEFF Research Database (Denmark)

    Hu, Liang; Boudec, J-Y. L.; Vojnovic, M.

    2010-01-01

    Collaborative ad-hoc dissemination of information has been proposed as an efficient means to disseminate information among devices in a wireless ad-hoc network. Devices help in forwarding the information channels to the entire network, by disseminating the channels they subscribe to, plus others...... by a Metropolis-Hastings sampling algorithm. We also give a variant that accounts for battery level. This leads to a practical channel selection and re-selection algorithm that can be implemented without any central control....

  13. Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

    Directory of Open Access Journals (Sweden)

    Simeone O

    2007-01-01

    Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

  14. Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

    Directory of Open Access Journals (Sweden)

    O. Simeone

    2007-03-01

    Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

  15. Collaboration Layer for Robots in Mobile Ad-hoc Networks

    DEFF Research Database (Denmark)

    Borch, Ole; Madsen, Per Printz; Broberg, Jacob Honor´e

    2009-01-01

    networks to solve tasks collaboratively. In this proposal the Collaboration Layer is modelled to handle service and position discovery, group management, and synchronisation among robots, but the layer is also designed to be extendable. Based on this model of the Collaboration Layer, generic services...... are provided to the application running on the robot. The services are generic because they can be used by many different applications, independent of the task to be solved. Likewise, specific services are requested from the underlying Virtual Machine, such as broadcast, multicast, and reliable unicast....... A prototype of the Collaboration Layer has been developed to run in a simulated environment and tested in an evaluation scenario. In the scenario five robots solve the tasks of vacuum cleaning and entrance guarding, which involves the ability to discover potential co-workers, form groups, shift from one group...

  16. Trust Evolution Policies for Security in Collaborative Ad Hoc Applications

    DEFF Research Database (Denmark)

    Gray, Elizabeth; Jensen, Christian D.; Connell, Paul O

    2006-01-01

    The vision of pervasive computing has introduced the notion of a vast, networked infrastructure of heterogeneous entities interact through collaborative applications, e.g., playing a multi-player online game on the way to work. This will require interactions between users who may be marginally...... admission policies in a manner similar to what would be expected from human trust assessment. This indicates that trust evolution policies can replace explicit human intervention in application scenarios that are similar to the evaluated prototype....

  17. Selecting optimum locations for co-located wave and wind energy farms. Part I: The Co-Location Feasibility index

    International Nuclear Information System (INIS)

    Astariz, S.; Iglesias, G.

    2016-01-01

    Highlights: • New approach to identifying suitable sites for co-located wave and wind farms. • A new tool, the Co-Location Feasibility (CLF) index, is defined. • Its application is analysed by means of a case study off the Danish coast. • Hindcast and measured wave and wind data from 2005 to 2015 are used. • Third-generation models of winds and waves (WAsP and SWAN) are used. - Abstract: Marine energy is poised to play a fundamental role in meeting renewable energy and carbon emission targets thanks to the abundant, and still largely untapped, wave and tidal resources. However, it is often considered difficult and uneconomical – as is usually the case of nascent technologies. Combining various renewables, such as wave and offshore wind energy, has emerged as a solution to improve their competitiveness and in the process overcome other challenges that hinder their development. The objective of this paper is to develop a new approach to identifying suitable sites for co-located wave and wind farms based on the assessment of the available resources and technical constraints, and to illustrate its application by means of a case study off the Danish coast – an area of interest for combining wave and wind energy. The method is based on an ad hoc tool, the Co-Location Feasibility (CLF) index, and is based on a joint characterisation of the wave and wind resources, which takes into account not only the available power but also the correlation between both resources and the power variability. The analysis is carried out based on hindcast data and observations from 2005 to 2015, and using third-generation models of winds and waves – WAsP and SWAN, respectively. Upon selection and ranking, it is found that a number of sites in the study region are indeed suited to realising the synergies between wave and offshore wind energy. The approach developed in this work can be applied elsewhere.

  18. Demand Externalities from Co-Location

    OpenAIRE

    Boudhayan Sen; Jiwoong Shin; K. Sudhir

    2012-01-01

    We illustrate an approach to measure demand externalities from co-location by estimating household level changes in grocery spending at a supermarket among households that also buy gas at a co-located gas station, relative to those who do not. Controlling for observable and unobserved selection in the use of gas station, we find significant demand externalities; on average a household that buys gas has 7.7% to 9.3% increase in spending on groceries. Accounting for differences in gross margins...

  19. Design and implementation of Ad-Hoc collaborative proxying scheme for reducing network energy waste

    Directory of Open Access Journals (Sweden)

    Rafiullah Khan

    2017-05-01

    Full Text Available Network devices are equipped with low power states but they are rarely activated due to their inability of maintaining network connectivity. Recently, Network Connectivity Proxy (NCP concept has been proposed in literature as an effective mechanism to exploit full potential of low power features on network devices by impersonating their virtual presence. However, the NCP concept faces several open issues and challenges especially related to proxying of TCP connections and majority of daily used proprietary closed-source applications. This paper presents a new approach for reducing network energy waste through intelligent collaboration among daily used devices (e.g., desktop computers, laptops, tablets, smartphones, etc. It guarantees to run applications on only and only one user device that is under active use at that specific moment. To reduce energy waste and allow idle devices to sleep, our approach also takes benefit from a light-weight home gateway proxy with very basic practically realizable functionalities. The proposed system not just reduces energy waste of fixed devices but also enables mobile devices to significantly improve their battery life. Our developed software prototypes allow devices to autonomously and seamlessly collaborate with each other without requiring any configuration or user input. Further, this paper also presents the basic performance evaluation of developed prototypes in real networking environments.

  20. Designing for social play in co-located mobile games

    DEFF Research Database (Denmark)

    Goddard, William; Garner, Jayden; Jensen, Mads Møller

    2016-01-01

    In this paper we explore how mobile devices and co-location in mobile contexts contribute social play in game design, addressing the limited understanding of social interactivity in mobile games. Using the Mechanics-Dynamics-Aesthetics (MDA) framework, we code four games illustrating effective use...... of mobile, social, and colocated elements. Subsequently, we analyse and discuss this data to identify generalisability in these games. In our discussion we identify how these findings address game design problems of designing collaborative games. Furthermore, we contribute to theory of designing for social...

  1. Exploring the Definitions and Discourse of Co-Location

    Science.gov (United States)

    Griffiths, Eve

    2015-01-01

    The phenomenon of co-location is not new, but there is very little research that focuses specifically on co-located schools and the teaching and learning that takes place therein. This article focuses on the term "co-location" and considers the sometimes vague discourse and definitions surrounding the term. The article recommends that…

  2. Co-location synergies : specialized versus diverse logistics concentration areas

    OpenAIRE

    Heuvel, van den, F.P.; Langen, de, P.W.; Donselaar, van, K.H.; Fransoo, J.C.

    2012-01-01

    Purpose: The purpose of this paper is to contribute to the understanding of spatial concentration of logistics firms by empirically analyzing synergies through co-location and investigating whether co-location of logistics establishments in specialized logistics concentration areas results in benefits compared to co-location in diverse logistics concentration areas. Methodology: A survey among managers of 128 logistics establishments located in logistics concentration areas was used to test f...

  3. Proximity matters : synergies through co-location of logistics establishments

    OpenAIRE

    Heuvel, van den, F.P.; Langen, de, P.W.; Donselaar, van, K.H.; Fransoo, J.C.

    2012-01-01

    Although anecdotic evidence suggests that co-location of logistics activities can bring several benefits to the co-located logistics companies and hence, can be important to incorporate in the location decisions of these companies, this is the first paper to empirically research these benefits. This paper contributes to the understanding of spatial concentration of logistics firms by empirically analyzing synergies through co-location and investigates whether spatial concentration of logistic...

  4. 75 FR 33198 - Co-Location/Proximity Hosting Services

    Science.gov (United States)

    2010-06-11

    ... computing hardware closer to the trading market's matching engine. Along with space, co-location and... identified by the Securities and Exchange Commission (``SEC''). On January 13, 2010, the SEC issued a concept... things, co-location and high frequency trading. See SEC, Concept Release on Equity Market Structure...

  5. Proximity matters : synergies through co-location of logistics establishments

    NARCIS (Netherlands)

    Heuvel, van den F.P.; Langen, de P.W.; Donselaar, van K.H.; Fransoo, J.C.

    2012-01-01

    Although anecdotic evidence suggests that co-location of logistics activities can bring several benefits to the co-located logistics companies and hence, can be important to incorporate in the location decisions of these companies, this is the first paper to empirically research these benefits. This

  6. Co-location synergies : specialised versus diverse logistics concentration areas

    NARCIS (Netherlands)

    van den Heuvel, F.P.; van Donselaar, K.H.; de Langen, P.W.; Fransoo, J.C.

    Although anecdotal evidence suggests that co-location can bring about several benefits for co-located logistics companies, implying the need to incorporate such considerations in location decisions, these benefits have hardly been analysed empirically. This paper provides detailed insights for

  7. Co-location synergies : specialized versus diverse logistics concentration areas

    NARCIS (Netherlands)

    Heuvel, van den F.P.; Langen, de P.W.; Donselaar, van K.H.; Fransoo, J.C.

    2012-01-01

    Purpose: The purpose of this paper is to contribute to the understanding of spatial concentration of logistics firms by empirically analyzing synergies through co-location and investigating whether co-location of logistics establishments in specialized logistics concentration areas results in

  8. The benefits of co-location in primary care practices: the perspectives of general practitioners and patients in 34 countries.

    Science.gov (United States)

    Bonciani, M; Schäfer, W; Barsanti, S; Heinemann, S; Groenewegen, P P

    2018-02-21

    There is no clear evidence as to whether the co-location of primary care professionals in the same facility positively influences their way of working and the quality of healthcare as perceived by patients. The aim of this study was to identify the relationships between general practitioner (GP) co-location with other GPs and/or other professionals and the GP outcomes and patients' experiences. We wanted to test whether GP co-location is related to a broader range of services provided, the use of clinical governance tools and inter-professional collaboration, and whether the patients of co-located GPs perceive a better quality of care in terms of accessibility, comprehensiveness and continuity of care with their GPs. The source of data was the QUALICOPC study (Quality and Costs of Primary Care in Europe), which involved surveys of GPs and their patients in 34 countries, mostly in Europe. In order to study the relationships between GP co-location and both GPs' outcomes and patients' experience, multilevel linear regression analysis was carried out. The GP questionnaire was filled in by 7183 GPs and the patient experience questionnaire by 61,931 patients. Being co-located with at least one other professional is the most common situation of the GPs involved in the study. Compared with single-handed GP practices, GP co-location are positively associated with the GP outcomes. Considering the patients' perspective, comprehensiveness of care has the strongest negative relationship of GP co-location of all the dimensions of patient experiences analysed. The paper highlights that GP mono- and multi-disciplinary co-location is related to positive outcomes at a GP level, such as a broader provision of technical procedures, increased collaboration among different providers and wider coordination with secondary care. However, GP co-location, particularly in a multidisciplinary setting, is related to less positive patient experiences, especially in countries with health systems

  9. Enabling Co-located Learning over Mobile Ad Hoc P2P with LightPeers

    DEFF Research Database (Denmark)

    Christensen, Bent Guldbjerg; Kristensen, Mads Darø; Hansen, Frank Allan

    2008-01-01

    This paper presents LightPeers – a new mobile P2P framework specifically tailored for use in a nomadic learning environment. A set of key requirements for the framework is identified based on nomadic learning, and these requirements are used as outset for designing and implementing the architectu...

  10. Small Aperture Telescope Observations of Co-located Geostationary Satellites

    Science.gov (United States)

    Scott, R.; Wallace, B.

    As geostationary orbit (GEO) continues to be populated, satellite operators are increasing usage of co-location techniques to maximize usage of fewer GEO longitude slots. Co-location is an orbital formation strategy where two or more geostationary satellites reside within one GEO stationkeeping box. The separation strategy used to prevent collision between the co-located satellites generally uses eccentricity (radial separation) and inclination (latitude separation) vector offsets. This causes the satellites to move in relative motion ellipses about each other as the relative longitude drift between the satellites is near zero. Typical separations between the satellites varies from 1 to 100 kilometers. When co-located satellites are observed by optical ground based space surveillance sensors the participants appear to be separated by a few minutes of arc or less in angular extent. Under certain viewing geometries, these satellites appear to visually conjunct even though the satellites are, in fact, well separated spatially. In situations where one of the co-located satellites is more optically reflective than the other, the reflected sunglint from the more reflective satellite can overwhelm the other. This less frequently encountered issue causes the less reflective satellite to be glint masked in the glare of the other. This paper focuses on space surveillance observations on co-located Canadian satellites using a small optical telescope operated by Defence R&D Canada - Ottawa. The two above mentioned problems (cross tagging and glint masking) are investigated and we quantify the results for Canadian operated geostationary satellites. The performance of two line element sets when making in-frame CCD image correlation between the co-located satellites is also examined. Relative visual magnitudes between the co-located members are also inspected and quantified to determine the susceptibility of automated telescopes to glint masking of co-located satellite members.

  11. TinCan: User-Defined P2P Virtual Network Overlays for Ad-hoc Collaboration

    Directory of Open Access Journals (Sweden)

    Pierre St Juste

    2014-10-01

    Full Text Available Virtual private networking (VPN has become an increasingly important component of a collaboration environment because it ensures private, authenticated communication among participants, using existing collaboration tools, where users are distributed across multiple institutions and can be mobile. The majority of current VPN solutions are based on a centralized VPN model, where all IP traffic is tunneled through a VPN gateway. Nonetheless, there are several use case scenarios that require a model where end-to-end VPN links are tunneled upon existing Internet infrastructure in a peer-to-peer (P2P fashion, removing the bottleneck of a centralized VPN gateway. We propose a novel virtual network — TinCan — based on peerto-peer private network tunnels. It reuses existing standards and implementations of services for discovery notification (XMPP, reflection (STUN and relaying (TURN, facilitating configuration. In this approach, trust relationships maintained by centralized (or federated services are automatically mapped to TinCan links. In one use scenario, TinCan allows unstructured P2P overlays connecting trusted end-user devices — while only requiring VPN software on user devices and leveraging online social network (OSN infrastructure already widely deployed. This paper describes the architecture and design of TinCan and presents an experimental evaluation of a prototype supporting Windows, Linux, and Android mobile devices. Results quantify the overhead introduced by the network virtualization layer, and the resource requirements imposed on services needed to bootstrap TinCan links.

  12. Delay-sensitive content distribution via peer-to-peer collaboration in public safety vehicular ad-hoc networks

    KAUST Repository

    Atat, Rachad; Yaacoub, Elias E.; Alouini, Mohamed-Slim; Filali, Fethi; Abu-Dayya, Adnan A.

    2014-01-01

    Delay-sensitive content distribution with peer-to-peer (P2P) cooperation in public safety vehicular networks is investigated. Two cooperative schemes are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range (LR) communications with the base station (BS) and IEEE 802.11p is considered for inter-vehicle collaboration on the short range (SR). The first scheme is shown to outperform non-cooperative unicasting and multicasting, while the second scheme outperforms non-cooperative unicasting beyond a specific number of cooperating vehicles, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2014 Elsevier B.V. All rights reserved.

  13. Delay-sensitive content distribution via peer-to-peer collaboration in public safety vehicular ad-hoc networks

    KAUST Repository

    Atat, Rachad

    2014-05-01

    Delay-sensitive content distribution with peer-to-peer (P2P) cooperation in public safety vehicular networks is investigated. Two cooperative schemes are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range (LR) communications with the base station (BS) and IEEE 802.11p is considered for inter-vehicle collaboration on the short range (SR). The first scheme is shown to outperform non-cooperative unicasting and multicasting, while the second scheme outperforms non-cooperative unicasting beyond a specific number of cooperating vehicles, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2014 Elsevier B.V. All rights reserved.

  14. Proximity matters : synergies through co-location of logistics establishments

    NARCIS (Netherlands)

    Heuvel, van den F.P.; Langen, de P.W.; Donselaar, van K.H.; Fransoo, J.C.

    2012-01-01

    Purpose: The purpose of this paper is to contribute to the understanding of spatial concentration of logistics firms by empirically analyzing synergies through co-location and investigating whether spatial concentration of logistics activities indeed results in classical agglomeration economies as

  15. Assessment of local GNSS baselines at co-location sites

    Science.gov (United States)

    Herrera Pinzón, Iván; Rothacher, Markus

    2018-01-01

    As one of the major contributors to the realisation of the International Terrestrial Reference System (ITRS), the Global Navigation Satellite Systems (GNSS) are prone to suffer from irregularities and discontinuities in time series. While often associated with hardware/software changes and the influence of the local environment, these discrepancies constitute a major threat for ITRS realisations. Co-located GNSS at fundamental sites, with two or more available instruments, provide the opportunity to mitigate their influence while improving the accuracy of estimated positions by examining data breaks, local biases, deformations, time-dependent variations and the comparison of GNSS baselines with existing local tie measurements. With the use of co-located GNSS data from a subset sites of the International GNSS Service network, this paper discusses a global multi-year analysis with the aim of delivering homogeneous time series of coordinates to analyse system-specific error sources in the local baselines. Results based on the comparison of different GNSS-based solutions with the local survey ties show discrepancies of up to 10 mm despite GNSS coordinate repeatabilities at the sub-mm level. The discrepancies are especially large for the solutions using the ionosphere-free linear combination and estimating tropospheric zenith delays, thus corresponding to the processing strategy used for global solutions. Snow on the antennas causes further problems and seasonal variations of the station coordinates. These demonstrate the need for a permanent high-quality monitoring of the effects present in the short GNSS baselines at fundamental sites.

  16. Ubiquitous computing to support co-located clinical teams: using the semiotics of physical objects in system design.

    Science.gov (United States)

    Bang, Magnus; Timpka, Toomas

    2007-06-01

    Co-located teams often use material objects to communicate messages in collaboration. Modern desktop computing systems with abstract graphical user interface (GUIs) fail to support this material dimension of inter-personal communication. The aim of this study is to investigate how tangible user interfaces can be used in computer systems to better support collaborative routines among co-located clinical teams. The semiotics of physical objects used in team collaboration was analyzed from data collected during 1 month of observations at an emergency room. The resulting set of communication patterns was used as a framework when designing an experimental system. Following the principles of augmented reality, physical objects were mapped into a physical user interface with the goal of maintaining the symbolic value of those objects. NOSTOS is an experimental ubiquitous computing environment that takes advantage of interaction devices integrated into the traditional clinical environment, including digital pens, walk-up displays, and a digital desk. The design uses familiar workplace tools to function as user interfaces to the computer in order to exploit established cognitive and collaborative routines. Paper-based tangible user interfaces and digital desks are promising technologies for co-located clinical teams. A key issue that needs to be solved before employing such solutions in practice is associated with limited feedback from the passive paper interfaces.

  17. An Isometric Mapping Based Co-Location Decision Tree Algorithm

    Science.gov (United States)

    Zhou, G.; Wei, J.; Zhou, X.; Zhang, R.; Huang, W.; Sha, H.; Chen, J.

    2018-05-01

    Decision tree (DT) induction has been widely used in different pattern classification. However, most traditional DTs have the disadvantage that they consider only non-spatial attributes (ie, spectral information) as a result of classifying pixels, which can result in objects being misclassified. Therefore, some researchers have proposed a co-location decision tree (Cl-DT) method, which combines co-location and decision tree to solve the above the above-mentioned traditional decision tree problems. Cl-DT overcomes the shortcomings of the existing DT algorithms, which create a node for each value of a given attribute, which has a higher accuracy than the existing decision tree approach. However, for non-linearly distributed data instances, the euclidean distance between instances does not reflect the true positional relationship between them. In order to overcome these shortcomings, this paper proposes an isometric mapping method based on Cl-DT (called, (Isomap-based Cl-DT), which is a method that combines heterogeneous and Cl-DT together. Because isometric mapping methods use geodetic distances instead of Euclidean distances between non-linearly distributed instances, the true distance between instances can be reflected. The experimental results and several comparative analyzes show that: (1) The extraction method of exposed carbonate rocks is of high accuracy. (2) The proposed method has many advantages, because the total number of nodes, the number of leaf nodes and the number of nodes are greatly reduced compared to Cl-DT. Therefore, the Isomap -based Cl-DT algorithm can construct a more accurate and faster decision tree.

  18. AN ISOMETRIC MAPPING BASED CO-LOCATION DECISION TREE ALGORITHM

    Directory of Open Access Journals (Sweden)

    G. Zhou

    2018-05-01

    Full Text Available Decision tree (DT induction has been widely used in different pattern classification. However, most traditional DTs have the disadvantage that they consider only non-spatial attributes (ie, spectral information as a result of classifying pixels, which can result in objects being misclassified. Therefore, some researchers have proposed a co-location decision tree (Cl-DT method, which combines co-location and decision tree to solve the above the above-mentioned traditional decision tree problems. Cl-DT overcomes the shortcomings of the existing DT algorithms, which create a node for each value of a given attribute, which has a higher accuracy than the existing decision tree approach. However, for non-linearly distributed data instances, the euclidean distance between instances does not reflect the true positional relationship between them. In order to overcome these shortcomings, this paper proposes an isometric mapping method based on Cl-DT (called, (Isomap-based Cl-DT, which is a method that combines heterogeneous and Cl-DT together. Because isometric mapping methods use geodetic distances instead of Euclidean distances between non-linearly distributed instances, the true distance between instances can be reflected. The experimental results and several comparative analyzes show that: (1 The extraction method of exposed carbonate rocks is of high accuracy. (2 The proposed method has many advantages, because the total number of nodes, the number of leaf nodes and the number of nodes are greatly reduced compared to Cl-DT. Therefore, the Isomap -based Cl-DT algorithm can construct a more accurate and faster decision tree.

  19. A Qualitative Exploration of Co-location as an Intervention to Strengthen Home Visiting Implementation in Addressing Maternal Child Health.

    Science.gov (United States)

    Kellom, Katherine S; Matone, Meredith; Adejare, Aderinola; Barg, Frances K; Rubin, David M; Cronholm, Peter F

    2018-06-01

    Objectives The aim of this paper is to explore the process and impact of co-locating evidence-based maternal and child service models to inform future implementation efforts. Methods As part of a state-wide evaluation of maternal and child home visiting programs, we conducted semi-structured interviews with administrators and home visitors from home visiting agencies across Pennsylvania. We collected 33 interviews from 4 co-located agencies. We used the Consolidated Framework for Implementation Research (CFIR) to describe the key elements mitigating implementation of multiple home visiting models. Results A primary advantage of co-location described by participants was the ability to increase the agency's base of eligible clients through the implementation of a model with different program eligibility (e.g. income, child age) than the existing agency offering. Model differences related to curriculum (e.g. content or intensity/meeting frequency) enabled programs to more selectively match clients to models. To recruit eligible clients, new models were able to build upon the existing service networks of the initial program. Co-location provided organizational opportunities for shared trainings, enabling administrative efficiencies and collaborative staff learning. Programs implemented strategies to build synergies with complementary model features, for instance using the additional program option to serve waitlisted clients and to transition services after one model is completed. Conclusions for Practice Considerable benefits are experienced when home visiting models co-locate. This research builds on literature encouraging collaboration among community agencies and provides insight on a specific facilitative approach. This implementation strategy informs policy across the social services spectrum and competitive funding contexts.

  20. General practitioners: Between integration and co-location. The case of primary care centers in Tuscany, Italy.

    Science.gov (United States)

    Barsanti, Sara; Bonciani, Manila

    2018-01-01

    Healthcare systems have followed several strategies aimed at integrating primary care services and professionals. Medical homes in the USA and Canada, and primary care centres across Europe have collocated general practitioners and other health and social professionals in the same building in order to boost coordination among services and the continuity of care for patients. However, in the literature, the impact of co-location on primary care has led to controversial results. This article analyses the possible benefits of the co-location of services in primary care focusing on the Italian model of primary care centres (Case della Salute) in terms of general practitioners' perception. We used the results of a web survey of general practitioners in Tuscany to compare the experiences and satisfaction of those general practitioners involved and not involved in a primary care centre, performed a MONAVA and ANOVA analysis. Our case study highlights the positive impact of co-location on the integration of professionals, especially with nurses and social workers, and on organizational integration, in terms of frequency of meeting to discuss about quality of care. Conversely, no significant differences were found in terms of either clinical or system integration. Furthermore, the collaboration with specialists is still weak. Considering the general practitioners' perspective in terms of experience and satisfaction towards primary care, co-location strategies is a necessary step in order to facilitate the collaboration among professionals and to prevent unintended consequences in terms of an even possible isolation of primary care as an involuntary 'disintegration of the integration'.

  1. Clinical response to eliglustat in treatment-naïve patients with Gaucher disease type 1: Post-hoc comparison to imiglucerase-treated patients enrolled in the International Collaborative Gaucher Group Gaucher Registry

    Directory of Open Access Journals (Sweden)

    Jennifer Ibrahim

    2016-09-01

    Full Text Available Eliglustat is a recently approved oral therapy in the United States and Europe for adults with Gaucher disease type 1 who are CYP2D6 extensive, intermediate, or poor metabolizers (>90% of patients that has been shown to decrease spleen and liver volume and increase hemoglobin concentrations and platelet counts in untreated adults with Gaucher disease type 1 and maintain these parameters in patients previously stabilized on enzyme replacement therapy. In a post-hoc analysis, we compared the results of eliglustat treatment in treatment-naïve patients in two clinical studies with the results of imiglucerase treatment among a cohort of treatment-naïve patients with comparable baseline hematologic and visceral parameters in the International Collaborative Gaucher Group Gaucher Registry. Organ volumes and hematologic parameters improved from baseline in both treatment groups, with a time course and degree of improvement in eliglustat-treated patients similar to imiglucerase-treated patients.

  2. Clinical response to eliglustat in treatment-naïve patients with Gaucher disease type 1: Post-hoc comparison to imiglucerase-treated patients enrolled in the International Collaborative Gaucher Group Gaucher Registry.

    Science.gov (United States)

    Ibrahim, Jennifer; Underhill, Lisa H; Taylor, John S; Angell, Jennifer; Peterschmitt, M Judith

    2016-09-01

    Eliglustat is a recently approved oral therapy in the United States and Europe for adults with Gaucher disease type 1 who are CYP2D6 extensive, intermediate, or poor metabolizers (> 90% of patients) that has been shown to decrease spleen and liver volume and increase hemoglobin concentrations and platelet counts in untreated adults with Gaucher disease type 1 and maintain these parameters in patients previously stabilized on enzyme replacement therapy. In a post-hoc analysis, we compared the results of eliglustat treatment in treatment-naïve patients in two clinical studies with the results of imiglucerase treatment among a cohort of treatment-naïve patients with comparable baseline hematologic and visceral parameters in the International Collaborative Gaucher Group Gaucher Registry. Organ volumes and hematologic parameters improved from baseline in both treatment groups, with a time course and degree of improvement in eliglustat-treated patients similar to imiglucerase-treated patients.

  3. VISTILES: Coordinating and Combining Co-located Mobile Devices for Visual Data Exploration.

    Science.gov (United States)

    Langner, Ricardo; Horak, Tom; Dachselt, Raimund

    2017-08-29

    We present VISTILES, a conceptual framework that uses a set of mobile devices to distribute and coordinate visualization views for the exploration of multivariate data. In contrast to desktop-based interfaces for information visualization, mobile devices offer the potential to provide a dynamic and user-defined interface supporting co-located collaborative data exploration with different individual workflows. As part of our framework, we contribute concepts that enable users to interact with coordinated & multiple views (CMV) that are distributed across several mobile devices. The major components of the framework are: (i) dynamic and flexible layouts for CMV focusing on the distribution of views and (ii) an interaction concept for smart adaptations and combinations of visualizations utilizing explicit side-by-side arrangements of devices. As a result, users can benefit from the possibility to combine devices and organize them in meaningful spatial layouts. Furthermore, we present a web-based prototype implementation as a specific instance of our concepts. This implementation provides a practical application case enabling users to explore a multivariate data collection. We also illustrate the design process including feedback from a preliminary user study, which informed the design of both the concepts and the final prototype.

  4. Mining Co-Location Patterns with Clustering Items from Spatial Data Sets

    Science.gov (United States)

    Zhou, G.; Li, Q.; Deng, G.; Yue, T.; Zhou, X.

    2018-05-01

    The explosive growth of spatial data and widespread use of spatial databases emphasize the need for the spatial data mining. Co-location patterns discovery is an important branch in spatial data mining. Spatial co-locations represent the subsets of features which are frequently located together in geographic space. However, the appearance of a spatial feature C is often not determined by a single spatial feature A or B but by the two spatial features A and B, that is to say where A and B appear together, C often appears. We note that this co-location pattern is different from the traditional co-location pattern. Thus, this paper presents a new concept called clustering terms, and this co-location pattern is called co-location patterns with clustering items. And the traditional algorithm cannot mine this co-location pattern, so we introduce the related concept in detail and propose a novel algorithm. This algorithm is extended by join-based approach proposed by Huang. Finally, we evaluate the performance of this algorithm.

  5. Collaboration

    Science.gov (United States)

    King, Michelle L.

    2010-01-01

    This article explores collaboration between library media educators and regular classroom teachers. The article focuses on the context of the issue, positions on the issue, the impact of collaboration, and how to implement effective collaboration into the school system. Various books and professional journals are used to support conclusions…

  6. A Partial Join Approach for Mining Co-Location Patterns: A Summary of Results

    National Research Council Canada - National Science Library

    Yoo, Jin S; Shekhar, Shashi

    2005-01-01

    .... They propose a novel partial-join approach for mining co-location patterns efficiently. It transactionizes continuous spatial data while keeping track of the spatial information not modeled by transactions...

  7. Mobile ad hoc networking

    CERN Document Server

    John Wiley & Sons

    2004-01-01

    "Assimilating the most up-to-date information on research and development activities in this rapidly growing area, Mobile Ad Hoc Networking covers physical, data link, network, and transport layers, as well as application, security, simulation, and power management issues in sensor, local area, personal, and mobile ad hoc networks. Each of the book's sixteen chapters has been written by a top expert and discusses in-depth the most important topics in the field. Mobile Ad Hoc Networking is an excellent reference and guide for professionals seeking an in-depth examination of topics that also provides a comprehensive overview of the current state-of-the-art."--Jacket.

  8. The Ex hoc Architecture

    DEFF Research Database (Denmark)

    2006-01-01

    Developed in the LIWAS project which develops technology for measuring road surfaces and communicating this data in an ad hoc environment. The communication part is built upon OOVM Resilient technology....

  9. Better Together: Co-Location of Dental and Primary Care Provides Opportunities to Improve Oral Health.

    Science.gov (United States)

    Pourat, Nadereh; Martinez, Ana E; Crall, James J

    2015-09-01

    Community Health Centers (CHCs) are one of the principal safety-net providers of health care for low-income and uninsured populations. Co-locating dental services in primary care settings provides an opportunity to improve access to dental care. Yet this study of California CHCs that provide primary care services shows that only about one-third of them co-located primary and dental care services on-site. An additional one-third were members of multisite organizations in which at least one other site provided dental care. The remaining one-third of CHC sites had no dental care capacity. Policy options to promote co-location include requiring on-site availability of dental services, providing infrastructure funding to build and equip dental facilities, and offering financial incentives to provide dental care and recruit dental providers.

  10. Dynamic ad hoc networks

    CERN Document Server

    Rashvand, Habib

    2013-01-01

    Motivated by the exciting new application paradigm of using amalgamated technologies of the Internet and wireless, the next generation communication networks (also called 'ubiquitous', 'complex' and 'unstructured' networking) are changing the way we develop and apply our future systems and services at home and on local, national and global scales. Whatever the interconnection - a WiMAX enabled networked mobile vehicle, MEMS or nanotechnology enabled distributed sensor systems, Vehicular Ad hoc Networking (VANET) or Mobile Ad hoc Networking (MANET) - all can be classified under new networking s

  11. Co-Location versus Disintegration of Manufacturing and R&D in Emerging Markets

    DEFF Research Database (Denmark)

    Søberg, Peder Veng; Wæhrens, Brian Vejrum

    2012-01-01

    The paper investigates what makes it more or less relevant to co-locate manufacturing activities and R&D activities in emerging markets within multinational companies. A framework to this end is developed and illustrated in relation to four cases from multinational companies, which have established...

  12. Progress in SLR-GPS co-location at San Juan (Argentina) station

    Science.gov (United States)

    Luis, Hernan; Rojas, Alvis; Adarvez, Sonia; Quinteros, Johana; Cobos, Pablo; Aracena, Andrés; Pacheco, Ana M.; Podestá, Ricardo; Actis, Eloy V.; Li, Jinzeng; Yin, Zhiqiang; Wang, Rui; Huang, Dongping; Márquez, Raúl

    2012-08-01

    From February, 2006, performing a Cooperation Agreement with National Astronomical Observatories of China (NAOC) of the Chinese Academy of Sciences (CAS), Observatorio Astronómico Félix Aguilar (OAFA) of Universidad Nacional de San Juan (UNSJ) is operating a SLR System (ILRS 7406 Station). From the beginning of 2012 a GPS Aztech - Micro Z CGRS is operative at the same place, which made the SLR - GPS co - location possible. The prior objective is to reach co - location between both techniques, so the Station became of 1st order in ITRF net. For that we study and adopt an appropriate strategy to select and place Survey Control Points that ensures higher precision in determination of 3D vectors between the selected reference point s. Afterwards we perform translocation tasks of receptor and antenna checking that the GPS verifies builder standards. Then we design and compensate survey control network, by means of software of our own draught. We expect to obtain definitive local ties with precision better than 3 mm, as suggested by IERS for co - located stations. There are very few stations with co - located spatial techniques in the Southern Hemisphere, so it is of great importance to have one in Argentina for improve our participation in IERS on the new realizations of ITRF from now on.

  13. Overview of Opportunities for Co-Location of Solar Energy Technologies and Vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beatty, Brenda [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hill, Graham [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    Large-scale solar facilities have the potential to contribute significantly to national electricity production. Many solar installations are large-scale or utility-scale, with a capacity over 1 MW and connected directly to the electric grid. Large-scale solar facilities offer an opportunity to achieve economies of scale in solar deployment, yet there have been concerns about the amount of land required for solar projects and the impact of solar projects on local habitat. During the site preparation phase for utility-scale solar facilities, developers often grade land and remove all vegetation to minimize installation and operational costs, prevent plants from shading panels, and minimize potential fire or wildlife risks. However, the common site preparation practice of removing vegetation can be avoided in certain circumstances, and there have been successful examples where solar facilities have been co-located with agricultural operations or have native vegetation growing beneath the panels. In this study we outline some of the impacts that large-scale solar facilities can have on the local environment, provide examples of installations where impacts have been minimized through co-location with vegetation, characterize the types of co-location, and give an overview of the potential benefits from co-location of solar energy projects and vegetation. The varieties of co-location can be replicated or modified for site-specific use at other solar energy installations around the world. We conclude with opportunities to improve upon our understanding of ways to reduce the environmental impacts of large-scale solar installations.

  14. The role of co-located storage for wind power producers in conventional electricity markets

    KAUST Repository

    Bitar, E.

    2011-06-01

    In this paper we study the problem of optimizing contract offerings for an independent wind power producer (WPP) participating in conventional day-ahead forward electricity markets for energy. As wind power is an inherently variable source of energy and is difficult to predict, we explore the extent to which co-located energy storage can be used to improve expected profit and mitigate the the financial risk associated with shorting on the offered contracts. Using a simple stochastic model for wind power production and a model for the electricity market, we show that the problem of determining optimal contract offerings for a WPP with co-located energy storage can be solved using convex programming.

  15. Squeeze: designing for playful experiences among co-located people in homes. (received first prize people's choice award)

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves

    2007-01-01

    Squeeze is a multi-person, flexible and interactive furniture that allows for collective and playful exploration of the family history among co-located people in homes. It is designed to explore how we can use digital technology to create settings where co-located family members can collectively ...

  16. Fuel from Wastewater - Harnessing a Potential Energy Source in Canada through the Co-location of Algae Biofuel Production to Sources of Effluent, Heat and CO2

    Science.gov (United States)

    Klise, G. T.; Roach, J. D.; Passell, H. D.; Moreland, B. D.; O'Leary, S. J.; Pienkos, P. T.; Whalen, J.

    2010-12-01

    Sandia National Laboratories is collaborating with the National Research Council (NRC) Canada and the National Renewable Energy Laboratory (NREL) to develop a decision-support model that will evaluate the tradeoffs associated with high-latitude algae biofuel production co-located with wastewater, CO2, and waste heat. This project helps Canada meet its goal of diversifying fuel sources with algae-based biofuels. The biofuel production will provide a wide range of benefits including wastewater treatment, CO2 reuse and reduction of demand for fossil-based fuels. The higher energy density in algae-based fuels gives them an advantage over crop-based biofuels as the “production” footprint required is much less, resulting in less water consumed and little, if any conversion of agricultural land from food to fuel production. Besides being a potential source for liquid fuel, algae have the potential to be used to generate electricity through the burning of dried biomass, or anaerobically digested to generate methane for electricity production. Co-locating algae production with waste streams may be crucial for making algae an economically valuable fuel source, and will certainly improve its overall ecological sustainability. The modeling process will address these questions, and others that are important to the use of water for energy production: What are the locations where all resources are co-located, and what volumes of algal biomass and oil can be produced there? In locations where co-location does not occur, what resources should be transported, and how far, while maintaining economic viability? This work is being funded through the U.S. Department of Energy (DOE) Biomass Program Office of Energy Efficiency and Renewable Energy, and is part of a larger collaborative effort that includes sampling, strain isolation, strain characterization and cultivation being performed by the NREL and Canada’s NRC. Results from the NREL / NRC collaboration including specific

  17. GNSS-SLR satellite co-location for the estimate of local ties

    Science.gov (United States)

    Bruni, Sara; Zerbini, Susanna; Errico, Maddalena; Santi, Efisio

    2013-04-01

    The current realization of the International Terrestrial Reference Frame (ITRF) is based on four different space-geodetic techniques, so that the benefits brought by each observing system to the definition of the frame can compensate for the drawbacks of the others and technique-specific systematic errors might be identified. The strategy used to combine the observations from the different techniques is then of prominent importance for the realization of a precise and stable reference frame. This study concentrates, in particular, on the combination of Satellite Laser Ranging (SLR) and Global Navigation Satellite System (GNSS) observations by exploiting satellite co-locations. This innovative approach is based on the fact that laser tracking of GNSS satellites, carrying on board laser reflector arrays, allows for the combination of optical and microwave signals in the determination of the spacecraft orbit. Besides, the use of satellite co-locations differs quite significantly from the traditional combination method in which each single technique solution is carried out autonomously and is interrelated in a second step. One of the benefits of the approach adopted in this study is that it allows for an independent validation of the local tie, i.e. of the vector connecting the SLR and GNSS reference points in a multi-techniques station. Typically, local ties are expressed by a single value, measured with ground-based geodetic techniques and taken as constant. In principle, however, local ties might show time variations likely caused by the different monumentation characteristics of the GNSS antennas with respect to those of a SLR system. This study evaluates the possibility of using the satellite co-location approach to generate local-ties time series by means of observations available for a selected network of ILRS stations. The data analyzed in this study were acquired as part of the NASA's Earth Science Data Systems and are archived and distributed by the Crustal

  18. Searching for Stochastic Gravitational Waves Using Data from the Two Co-Located LIGO Hanford Detectors

    Science.gov (United States)

    Aasi, J.; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Accadia, T.; Acernese, F.; Adams, C.; Adams, T.; hide

    2014-01-01

    Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a co-located detector pair is more sensitive to a gravitational-wave background than a nonco- located detector pair. However, co-located detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the potential increase in sensitivity of co-located detectors. Here we report on the first SGWB analysis using the two LIGO Hanford detectors and address the complications arising from correlated environmental noise. We apply correlated noise identification and mitigation techniques to data taken by the two LIGO Hanford detectors, H1 and H2, during LIGO's fifth science run. At low frequencies, 40-460Hz, we are unable to sufficiently mitigate the correlated noise to a level where we may confidently measure or bound the stochastic gravitational-wave signal. However, at high frequencies, 460 - 1000Hz, these techniques are sufficient to set a 95% confidence level (C.L.) upper limit on the gravitational-wave energy density of Omega(f) < 7.7 × 10(exp -4)(f/900Hz)(sup 3), which improves on the previous upper limit by a factor of approx. 180. In doing so, we demonstrate techniques that will be useful for future searches using advanced detectors, where correlated noise (e.g., from global magnetic fields) may affect even widely separated detectors.

  19. Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Hong-Chuan Yang

    2007-01-01

    Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.

  20. Sustainable use of marine resources through offshore wind and mussel farm co-location

    DEFF Research Database (Denmark)

    Di Tullio, Giacomo R.; Mariani, Patrizio; Benassai, Guido

    2018-01-01

    wind farms and open-water mussel cultivation. An index of co-location sustainability (SI) was developed based on the application of MCE technique constructed with physical and biological parameters on the basis of remote-sensing data. The relevant physical factors considered were wind velocity, depth...... range, concerning the site location for energy production, and sea surface temperature anomaly. The biological variables used were Chlorofill-a (as a measurement of the productivity) and Particle Organic Carbon(POC) concentration, in order to assess their influence on the probable benefits and complete...

  1. Precise Haptic Device Co-Location for Visuo-Haptic Augmented Reality.

    Science.gov (United States)

    Eck, Ulrich; Pankratz, Frieder; Sandor, Christian; Klinker, Gudrun; Laga, Hamid

    2015-12-01

    Visuo-haptic augmented reality systems enable users to see and touch digital information that is embedded in the real world. PHANToM haptic devices are often employed to provide haptic feedback. Precise co-location of computer-generated graphics and the haptic stylus is necessary to provide a realistic user experience. Previous work has focused on calibration procedures that compensate the non-linear position error caused by inaccuracies in the joint angle sensors. In this article we present a more complete procedure that additionally compensates for errors in the gimbal sensors and improves position calibration. The proposed procedure further includes software-based temporal alignment of sensor data and a method for the estimation of a reference for position calibration, resulting in increased robustness against haptic device initialization and external tracker noise. We designed our procedure to require minimal user input to maximize usability. We conducted an extensive evaluation with two different PHANToMs, two different optical trackers, and a mechanical tracker. Compared to state-of-the-art calibration procedures, our approach significantly improves the co-location of the haptic stylus. This results in higher fidelity visual and haptic augmentations, which are crucial for fine-motor tasks in areas such as medical training simulators, assembly planning tools, or rapid prototyping applications.

  2. Intrasite motions and monument instabilities at Medicina ITRF co-location site

    Science.gov (United States)

    Sarti, Pierguido; Abbondanza, Claudio; Legrand, Juliette; Bruyninx, Carine; Vittuari, Luca; Ray, Jim

    2013-03-01

    We process the total-station surveys performed at the ITRF co-location site Medicina (Northern Italy) over the decade (2001-2010) with the purpose of determining the extent of local intrasite motions and relating them to local geophysical processes, the geological setting and the design of the ground pillars. In addition, continuous observations acquired by two co-located GPS stations (MEDI and MSEL separated by ≈27 m) are analysed and their relative motion is cross-checked with the total-station results. The local ground control network extends over a small area (<100 × 100 m) but the results demonstrate significant anisotropic deformations with rates up to 1.6 mm a-1, primarily horizontal, a value comparable to intraplate tectonic deformations. The results derived from GPS and total-station observations are consistent and point to the presence of horizontal intrasite motions over very short distances possibly associated with varying environmental conditions in a very unfavourable local geological setting and unsuitable monument design, these latter being crucial aspects of the realization and maintenance of global permanent geodetic networks and the global terrestrial reference frame.

  3. Ground Motion Analysis of Co-Located DAS and Seismometer Sensors

    Science.gov (United States)

    Wang, H. F.; Fratta, D.; Lord, N. E.; Lancelle, C.; Thurber, C. H.; Zeng, X.; Parker, L.; Chalari, A.; Miller, D.; Feigl, K. L.; Team, P.

    2016-12-01

    The PoroTomo research team deployed 8700-meters of Distributed Acoustic Sensing (DAS) cable in a shallow trench and 400-meters in a borehole at Brady Hot Springs, Nevada in March 2016 together with an array of 246, three-component geophones. The seismic sensors occupied a natural laboratory 1500 x 500 x 400 meters overlying the Brady geothermal field. The DAS cable was laid out in three parallel zig-zag lines with line segments approximately 100-meters in length and geophones were spaced at approximately 50-m intervals. In several line segments, geophones were co-located within one meter of the DAS cable. Both DAS and the conventional geophones recorded continuously over 15 days. A large Vibroseis truck (T-Rex) provided the seismic source at approximately 250 locations outside and within the array. The Vibroseis protocol called for excitation in one vertical and two orthogonal horizontal directions at each location. For each mode, three, 5-to-80-Hz upsweeps were made over 20 seconds. In addition, a moderate-sized earthquake with a local magnitude of 4.3 was recorded on March 21, 2016. Its epicenter was approximately 150-km away. Several DAS line segments with co-located geophone stations were used to test relationships between the strain rate recorded by DAS and ground velocity recorded by the geophones.

  4. Situational Awareness Support to Enhance Teamwork in Collaborative Working Environments

    NARCIS (Netherlands)

    Kulyk, Olga Anatoliyivna; van Dijk, Elisabeth M.A.G.; van der Vet, P.E.; Nijholt, Antinus; van der Veer, Gerrit C.; Whitworth, B.; de Moor, A.

    This chapter addresses awareness support to enhance teamwork in co-located collaborative environments. In particular, we focus on the concept of situational awareness which is essential for successful team collaboration. Mutual situational awareness leads to informal social interactions, development

  5. Co-located wind-wave farm synergies (Operation and Maintenance): A case study

    International Nuclear Information System (INIS)

    Astariz, S.; Perez-Collazo, C.; Abanades, J.; Iglesias, G.

    2015-01-01

    Highlights: • The shielding effect of WECs located around the wind farm is analysed. • The height wave reductions achieved by 15 different layouts are compared. • The increase in the accessibility to the wind turbines is quantified. • Alpha Ventus offshore wind farm is considered as baseline scenario. • High-resolution numerical modelling (SWAN) and real sea conditions are used. - Abstract: Operation and maintenance can jeopardise the financial viability of an offshore wind energy project due to the cost of downtime, repairs and, above all, the inevitable uncertainties. The variability of wave climate can impede or hinder emergency repairs when a failure occurs, and the resulting delays imply additional costs which ultimately reduce the competitiveness of offshore wind energy as an alternative to fossil fuels. Co-located wind turbines and Wave Energy Converters (WECs) are proposed in this paper as a novel solution: the reduction of the significant wave height brought about by the WECs along the periphery of the wind farm results in a milder wave climate within the farm. This reduction, also called shadow effect, enlarges weather windows for Operation and Maintenance (O and M). The objective of this paper is to investigate the increase in the accessibility time to the turbines and to optimise the layout for the co-located wind-wave farm in order to maximise this time. The investigation is carried out through a case study: Alpha Ventus, an operating offshore wind farm. To maximise the reduction of wave height in the turbine area no fewer than 15 layouts are tested using high-resolution numerical modelling, and a sensitivity analysis is conducted. The results show that, thanks to the wave energy extraction by the WECs, weather windows (access time) can increase very significantly – over 80%. This substantial effect, together with other benefits from the combination of wave and offshore wind power in a co-located farm (common electrical infrastructures

  6. Co-location satellite GPS and SLR geodetic techniques at the Felix Aguilar Astronomical Observatory of San Juan, Argentina

    Science.gov (United States)

    Podestá, R.; Pacheco, A. M.; Alvis Rojas, H.; Quinteros, J.; Podestá, F.; Albornoz, E.; Navarro, A.; Luna, M.

    2018-01-01

    This work shows the strategy followed for the co-location of the Satellite Laser Ranging (SLR) ILRS 7406 telescope and the antenna of the permanent Global Positioning System (GPS) station, located at the Félix Aguilar Astronomical Observatory (OAFA) in San Juan, Argentina. The accomplishment of the co-location consisted in the design, construction, measurement, adjustment and compensation of a geodesic net between the stations SLR and GPS, securing support points solidly built in the soil. The co-location allows the coordinates of the station to be obtained by combining the data of both SLR and GPS techniques, achieving a greater degree of accuracy than individually. The International Earth Rotation and Reference Systems Service (IERS) considers the co-located stations as the most valuable and important points for the maintenance of terrestrial reference systems and their connection with the celestial ones. The 3 mm precision required by the IERS has been successfully achieved.

  7. Feasibility Study for Bioethanol Co-Location with a Coal Fired Power Plant: 29 November 2001--28 July 2002

    Energy Technology Data Exchange (ETDEWEB)

    2002-12-01

    This study looks at the feasibility of co-locating 30, 50, and 70 million gallon per year bioethanol facilities with coal fired power plants in Indiana and Nebraska. Corn stover is the feedstock for ethanol production in both cases.

  8. Feasibility study for co-locating and integrating ethanol production plants from corn starch and lignocellulosic feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibsen, Kelly [National Renewable Energy Lab. (NREL), Golden, CO (United States); McAloon, Andrew [U.S. Department of Agriculture, Washington, D.C. (United States); Yee, Winnie [U.S. Department of Agriculture, Washington, D.C. (United States)

    2005-01-01

    Analysis of the feasibility of co-locating corn-grain-to-ethanol and lignocellulosic ethanol plants and potential savings from combining utilities, ethanol purification, product processing, and fermentation.

  9. Collaboration in Augmented Reality

    NARCIS (Netherlands)

    Lukosch, S.; Billinghurst, M.; Alem, L.; Kiyokawa, K.

    2015-01-01

    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they

  10. Persistent Social Networks: Civil War Veterans Who Fought Together Co-Locate in Later Life.

    Science.gov (United States)

    Costa, Dora L; Kahn, Matthew E; Roudiez, Christopher; Wilson, Sven

    2018-05-01

    We demonstrate the long reach of early social ties in the location decision of individuals and in their older age mortality risk using data on Union Army veterans of the US Civil War (1861-5). We estimate discrete choice migration models to quantify the trade-offs across locations faced by veterans. Veterans were more likely to move to a neighborhood or county where men from their same war company lived and were more likely to move to such areas than to areas where other veterans were located. Veterans also were less likely to move far from their origin and avoided urban immigrant areas and high mortality risk areas. They also avoided areas that opposed the Civil War. This co-location evidence highlights the existence of persistent social networks. Such social networks had long-term consequences: veterans living close to war-time comrades had a 6% lower probability of dying.

  11. A Sustainability Index of potential co-location of offshore wind farms and open water aquaculture

    DEFF Research Database (Denmark)

    Bennassai, G.; Mariani, Patrizio; Stenberg, Claus

    2014-01-01

    This paper presents the definition of a Sustainability Index for the co-location in marine areas of offshore wind farms and aquaculture plans. The development of the index is focused on the application of MCE technique based on physical constraints and biological parameters that are directly linked...... to the primary production. The relevant physical factors considered are wind velocity and depth range (which directly governs the choice of the site for energy production and for offshore technology), the relevant biological parameters are SST, SST anomaly and CHL-a concentration (as a measurement...... the computation of the Sustainability Index (SI) was identified in the Danish portion of the Baltic Sea and in the western part of the Danish North Sea. Results on the spatial distribution of the SI underline different responses as a function of the physical and biological main influencing parameters...

  12. Advantages of co-located spent fuel reprocessing, repository and underground reactor facilities

    International Nuclear Information System (INIS)

    Mahar, James M.; Kunze, Jay F.; Wes Myers, Carl; Loveland, Ryan

    2007-01-01

    The purpose of this work is to extend the discussion of potential advantages of the underground nuclear park (UNP) concept by making specific concept design and cost estimate comparisons for both present Generation III types of reactors and for some of the modular Gen IV or the GNEP modular concept. For the present Gen III types, we propose co-locating reprocessing and (re)fabrication facilities along with disposal facilities in the underground park. The goal is to determine the site costs and facility construction costs of such a complex which incorporates the advantages of a closed fuel cycle, nuclear waste repository, and ultimate decommissioning activities all within the UNP. Modular power generation units are also well-suited for placement underground and have the added advantage of construction using current and future tunnel boring machine technology. (authors)

  13. Market floors strategy and fixed pricing model for co-location under the traditional leaseback framework

    DEFF Research Database (Denmark)

    Osei-Owusu, Alexander

    2016-01-01

    Towers make up a substantial proportion of capital investments for telecoms operators and, in emerging markets, most of their operating costs. Mobile operators are opting to share towers, renting them from other tower companies instead of making ongoing and a single financial investments...... on the same towers. The higher the co-location ratio the better for the towers companies (and their financiers), as this drives up revenues from the same base costs. Traditional towers are often designed for a specific number of spaces or tenants’ and finding ways to get these “perishable” spaces filled up...... by infrastructure operators may help drive the needed revenues and investments. The research will also investigate whether the adoption of the fixed pricing strategy is primed on a business sense rather than institutional arrangement or influences. The implication of the pricing regime on expansion of telecom...

  14. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO)

    Science.gov (United States)

    Sim, Victor S.T.; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y.; Fane, Anthony G.; Krantz, William B.

    2013-01-01

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination. PMID:24956940

  15. Simulations of VLBI observations of a geodetic satellite providing co-location in space

    Science.gov (United States)

    Anderson, James M.; Beyerle, Georg; Glaser, Susanne; Liu, Li; Männel, Benjamin; Nilsson, Tobias; Heinkelmann, Robert; Schuh, Harald

    2018-02-01

    We performed Monte Carlo simulations of very-long-baseline interferometry (VLBI) observations of Earth-orbiting satellites incorporating co-located space-geodetic instruments in order to study how well the VLBI frame and the spacecraft frame can be tied using such measurements. We simulated observations of spacecraft by VLBI observations, time-of-flight (TOF) measurements using a time-encoded signal in the spacecraft transmission, similar in concept to precise point positioning, and differential VLBI (D-VLBI) observations using angularly nearby quasar calibrators to compare their relative performance. We used the proposed European Geodetic Reference Antenna in Space (E-GRASP) mission as an initial test case for our software. We found that the standard VLBI technique is limited, in part, by the present lack of knowledge of the absolute offset of VLBI time to Coordinated Universal Time at the level of microseconds. TOF measurements are better able to overcome this problem and provide frame ties with uncertainties in translation and scale nearly a factor of three smaller than those yielded from VLBI measurements. If the absolute time offset issue can be resolved by external means, the VLBI results can be significantly improved and can come close to providing 1 mm accuracy in the frame tie parameters. D-VLBI observations with optimum performance assumptions provide roughly a factor of two higher uncertainties for the E-GRASP orbit. We additionally simulated how station and spacecraft position offsets affect the frame tie performance.

  16. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO

    Directory of Open Access Journals (Sweden)

    William B. Krantz

    2013-07-01

    Full Text Available This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.

  17. Experience with procuring, deploying and maintaining hardware at remote co-location centre

    International Nuclear Information System (INIS)

    Bärring, O; Bonfillou, E; Clement, B; Santos, M Coelho Dos; Dore, V; Gentit, A; Grossir, A; Salter, W; Valsan, L; Xafi, A

    2014-01-01

    In May 2012 CERN signed a contract with the Wigner Data Centre in Budapest for an extension to CERN's central computing facility beyond its current boundaries set by electrical power and cooling available for computing. The centre is operated as a remote co-location site providing rack-space, electrical power and cooling for server, storage and networking equipment acquired by CERN. The contract includes a 'remote-hands' services for physical handling of hardware (rack mounting, cabling, pushing power buttons, ...) and maintenance repairs (swapping disks, memory modules, ...). However, only CERN personnel have network and console access to the equipment for system administration. This report gives an insight to adaptations of hardware architecture, procurement and delivery procedures undertaken enabling remote physical handling of the hardware. We will also describe tools and procedures developed for automating the registration, burn-in testing, acceptance and maintenance of the equipment as well as an independent but important change to the IT assets management (ITAM) developed in parallel as part of the CERN IT Agile Infrastructure project. Finally, we will report on experience from the first large delivery of 400 servers and 80 SAS JBOD expansion units (24 drive bays) to Wigner in March 2013. Changes were made to the abstract file on 13/06/2014 to correct errors, the pdf file was unchanged.

  18. Using Team Communication to Understand Team Cognition in Distributed vs. Co-Located Mission Environments

    National Research Council Canada - National Science Library

    Cooke, Nancy J; Gorman, Jamie C; Kiekel, Preston A; Foltz, Peter; Martin, Melanie

    2005-01-01

    This report documents a 30-month effort sponsored by the Office of Naval Research that refined, applied and evaluated methods for analyzing the communication flow and content surrounding collaboration...

  19. Space Geodetic Technique Co-location in Space: Simulation Results for the GRASP Mission

    Science.gov (United States)

    Kuzmicz-Cieslak, M.; Pavlis, E. C.

    2011-12-01

    The Global Geodetic Observing System-GGOS, places very stringent requirements in the accuracy and stability of future realizations of the International Terrestrial Reference Frame (ITRF): an origin definition at 1 mm or better at epoch and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale (0.1 ppb) and orientation components. These goals were derived from the requirements of Earth science problems that are currently the international community's highest priority. None of the geodetic positioning techniques can achieve this goal alone. This is due in part to the non-observability of certain attributes from a single technique. Another limitation is imposed from the extent and uniformity of the tracking network and the schedule of observational availability and number of suitable targets. The final limitation derives from the difficulty to "tie" the reference points of each technique at the same site, to an accuracy that will support the GGOS goals. The future GGOS network will address decisively the ground segment and to certain extent the space segment requirements. The JPL-proposed multi-technique mission GRASP (Geodetic Reference Antenna in Space) attempts to resolve the accurate tie between techniques, using their co-location in space, onboard a well-designed spacecraft equipped with GNSS receivers, a SLR retroreflector array, a VLBI beacon and a DORIS system. Using the anticipated system performance for all four techniques at the time the GGOS network is completed (ca 2020), we generated a number of simulated data sets for the development of a TRF. Our simulation studies examine the degree to which GRASP can improve the inter-technique "tie" issue compared to the classical approach, and the likely modus operandi for such a mission. The success of the examined scenarios is judged by the quality of the origin and scale definition of the resulting TRF.

  20. Analysis of co-located MODIS and CALIPSO observations near clouds

    Directory of Open Access Journals (Sweden)

    T. Várnai

    2012-02-01

    Full Text Available This paper aims at helping synergistic studies in combining data from different satellites for gaining new insights into two critical yet poorly understood aspects of anthropogenic climate change, aerosol-cloud interactions and aerosol radiative effects. In particular, the paper examines the way cloud information from the MODIS (MODerate resolution Imaging Spectroradiometer imager can refine our perceptions based on CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization lidar measurements about the systematic aerosol changes that occur near clouds.

    The statistical analysis of a yearlong dataset of co-located global maritime observations from the Aqua and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellites reveals that MODIS's multispectral imaging ability can greatly help the interpretation of CALIOP observations. The results show that imagers on Aqua and CALIPSO yield very similar pictures, and that the discrepancies – due mainly to wind drift and differences in view angle – do not significantly hinder aerosol measurements near clouds. By detecting clouds outside the CALIOP track, MODIS reveals that clouds are usually closer to clear areas than CALIOP data alone would suggest. The paper finds statistical relationships between the distances to clouds in MODIS and CALIOP data, and proposes a rescaling approach to statistically account for the impact of clouds outside the CALIOP track even when MODIS cannot reliably detect low clouds, for example at night or over sea ice. Finally, the results show that the typical distance to clouds depends on both cloud coverage and cloud type, and accordingly varies with location and season. In maritime areas perceived cloud free, the global median distance to clouds below 3 km altitude is in the 4–5 km range.

  1. The Impact of Co-Locating American Job Centers on Community College Campuses in North Carolina. A CAPSEE Working Paper

    Science.gov (United States)

    Van Noy, Michelle

    2015-01-01

    Relationships between community colleges and the public workforce system might have an important role in promoting students' success in the labor market and in college. In particular, the co-location of American Job Centers (AJC) on community college campuses is a particularly strong form of relationship that might benefit students. Yet little is…

  2. Feasibility Study for Co-Locating and Integrating Ethanol Production Plants from Corn Starch and Lignocellulosic Feedstocks (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.; Ibsen, K.; McAloon, A.; Yee, W.

    2005-01-01

    Analysis of the feasibility of co-locating corn-grain-to-ethanol and lignocellulosic ethanol plants and potential savings from combining utilities, ethanol purification, product processing, and fermentation. Although none of the scenarios identified could produce ethanol at lower cost than a straight grain ethanol plant, several were lower cost than a straight cellulosic ethanol plant.

  3. MPL-Net Measurements of Aerosol and Cloud Vertical Distributions at Co-Located AERONET Sites

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Tsay, Si-Chee; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    In the early 1990s, the first small, eye-safe, and autonomous lidar system was developed, the Micropulse Lidar (MPL). The MPL acquires signal profiles of backscattered laser light from aerosols and clouds. The signals are analyzed to yield multiple layer heights, optical depths of each layer, average extinction-to-backscatter ratios for each layer, and profiles of extinction in each layer. In 2000, several MPL sites were organized into a coordinated network, called MPL-Net, by the Cloud and Aerosol Lidar Group at NASA Goddard Space Flight Center (GSFC) using funding provided by the NASA Earth Observing System. tn addition to the funding provided by NASA EOS, the NASA CERES Ground Validation Group supplied four MPL systems to the project, and the NASA TOMS group contributed their MPL for work at GSFC. The Atmospheric Radiation Measurement Program (ARM) also agreed to make their data available to the MPL-Net project for processing. In addition to the initial NASA and ARM operated sites, several other independent research groups have also expressed interest in joining the network using their own instruments. Finally, a limited amount of EOS funding was set aside to participate in various field experiments each year. The NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) project also provides funds to deploy their MPL during ocean research cruises. All together, the MPL-Net project has participated in four major field experiments since 2000. Most MPL-Net sites and field experiment locations are also co-located with sunphotometers in the NASA Aerosol Robotic Network. (AERONET). Therefore, at these locations data is collected on both aerosol and cloud vertical structure as well as column optical depth and sky radiance. Real-time data products are now available from most MPL-Net sites. Our real-time products are generated at times of AERONET aerosol optical depth (AOD) measurements. The AERONET AOD is used as input to our

  4. agradecimento aos consultores ad hoc

    Directory of Open Access Journals (Sweden)

    REA Editor

    2012-02-01

    Full Text Available Agradecemos aos professores Nildo Viana (UFG e Flavio Sofiati (UFG, organizadores do DOSSIÊ JUVENTUDE & SOCIEDADE, e aos Consultores Ad hoc pela leitura e apreciação crítica dos artigos submetidos e publicados nesta edição.

  5. Ocean zoning for conservation, fisheries and marine renewable energy: assessing trade-offs and co-location opportunities.

    Science.gov (United States)

    Yates, Katherine L; Schoeman, David S; Klein, Carissa J

    2015-04-01

    Oceans, particularly coastal areas, are getting busier and within this increasingly human-dominated seascape, marine biodiversity continues to decline. Attempts to maintain and restore marine biodiversity are becoming more spatial, principally through the designation of marine protected areas (MPAs). MPAs compete for space with other uses, and the emergence of new industries, such as marine renewable energy generation, will increase competition for space. Decision makers require guidance on how to zone the ocean to conserve biodiversity, mitigate conflict and accommodate multiple uses. Here we used empirical data and freely available planning software to identified priority areas for multiple ocean zones, which incorporate goals for biodiversity conservation, two types of renewable energy, and three types of fishing. We developed an approached to evaluate trade-offs between industries and we investigated the impacts of co-locating some fishing activities within renewable energy sites. We observed non-linear trade-offs between industries. We also found that different subsectors within those industries experienced very different trade-off curves. Incorporating co-location resulted in significant reductions in cost to the fishing industry, including fisheries that were not co-located. Co-location also altered the optimal location of renewable energy zones with planning solutions. Our findings have broad implications for ocean zoning and marine spatial planning. In particular, they highlight the need to include industry subsectors when assessing trade-offs and they stress the importance of considering co-location opportunities from the outset. Our research reinforces the need for multi-industry ocean-zoning and demonstrates how it can be undertaken within the framework of strategic conservation planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Remote Collaboration With Mixed Reality Displays

    DEFF Research Database (Denmark)

    Müller, Jens; Rädle, Roman; Reiterer, Harald

    2017-01-01

    HCI research has demonstrated Mixed Reality (MR) as being beneficial for co-located collaborative work. For remote collaboration, however, the collaborators' visual contexts do not coincide due to their individual physical environments. The problem becomes apparent when collaborators refer...... to physical landmarks in their individual environments to guide each other's attention. In an experimental study with 16 dyads, we investigated how the provisioning of shared virtual landmarks (SVLs) influences communication behavior and user experience. A quantitative analysis revealed that participants used...

  7. Impact of co-located general practitioner (GP) clinics and patient choice on duration of wait in the emergency department.

    Science.gov (United States)

    Sharma, Anurag; Inder, Brett

    2011-08-01

    To empirically model the determinants of duration of wait of emergency (triage category 2) patients in an emergency department (ED) focusing on two questions: (i) What is the effect of enhancing the degree of choice for non-urgent (triage category 5) patients on duration of wait for emergency (category 2) patients in EDs; and (ii) What is the effect of co-located GP clinics on duration of wait for emergency patients in EDs? The answers to these questions will help in understanding the effectiveness of demand management strategies, which are identified as one of the solutions to ED crowding. The duration of wait for each patient (difference between arrival time and time first seen by treating doctor) was modelled as a function of input factors (degree of choice, patient characteristics, weekend admission, metro/regional hospital, concentration of emergency (category 2) patients in hospital service area), throughput factors (availability of doctors and nurses) and output factor (hospital bed capacity). The unit of analysis was a patient episode and the model was estimated using a survival regression technique. The degree of choice for non-urgent (category 5) patients has a non-linear effect: more choice for non-urgent patients is associated with longer waits for emergency patients at lower values and shorter waits at higher values of degree of choice. Thus more choice of EDs for non-urgent patients is related to a longer wait for emergency (category 2) patients in EDs. The waiting time for emergency patients in hospital campuses with co-located GP clinics was 19% lower (1.5 min less) on average than for those waiting in campuses without co-located GP clinics. These findings suggest that diverting non-urgent (category 5) patients to an alternative model of care (co-located GP clinics) is a more effective demand management strategy and will reduce ED crowding.

  8. Half a Year of Co-located Gaseous Elemental Mercury Measurements: Investigation of Temporal Changes in Measurement Differences

    Czech Academy of Sciences Publication Activity Database

    Veselík, P.; Dvorská, Alice; Michálek, J.

    2017-01-01

    Roč. 26, č. 5 (2017), s. 3128-3137 ISSN 1018-4619 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : gaseous elemental mercury * Tekran 2537B * co-located measurement * capability indices * regression * cluster analysis Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 0.425, year: 2016

  9. Designing for Co-located Social Media Use in the Home - Using the CASOME Infrastructure

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Ludvigsen, Martin; Grønbæk, Kaj

    2007-01-01

    A range of research has pointed to empirical studies of the use of domestic materials as a useful insight when designing future interactive systems for homes. In this paper we describe how we designed a system from the basis of lessons from such studies. Our system applies the CASOME infrastructure...... (context-aware interactive media platform for social computing in the home) to construct a system supporting distributed and collaborative handling of digital materials in a domestic context. It contains a collective platform for handling digital materials in the home and also contains a range of connected...... interactive surfaces supporting the flow of digital materials around the physical home. We discuss applications and use scenarios of the system, and finally, we present experiences from lab and field tests of the system. The main contribution of the paper is that it illustrates how insights from empirical...

  10. Performance Analysis of Hierarchical Group Key Management Integrated with Adaptive Intrusion Detection in Mobile ad hoc Networks

    Science.gov (United States)

    2016-04-05

    applications in wireless networks such as military battlefields, emergency response, mobile commerce , online gaming, and collaborative work are based on the...www.elsevier.com/locate/peva Performance analysis of hierarchical group key management integrated with adaptive intrusion detection in mobile ad hoc...Accepted 19 September 2010 Available online 26 September 2010 Keywords: Mobile ad hoc networks Intrusion detection Group communication systems Group

  11. Ad-hoc networking towards seamless communications

    CERN Document Server

    Gavrilovska, Liljana

    2006-01-01

    Ad-Hoc Networking Towards Seamless Communications is dedicated to an area that attracts growing interest in academia and industry and concentrates on wireless ad hoc networking paradigm. The persistent efforts to acquire the ability to establish dynamic wireless connections from anywhere to anyone with any device without prerequisite imbedded infrastructure move the communications boundaries towards ad-hoc networks. Recently, ad hoc networking has attracted growing interest due to advances in wireless communications, and developed framework for running IP based protocols. The expected degree of penetration of these networks will depend on the successful resolution of the key features. Ad-hoc networks pose many complex and open problems for researchers. Ad-Hoc Networking Towards Seamless Communications reveals the state-of-the-art in wireless ad-hoc networking and discusses some of the key research topics that are expected to promote and accelerate the commercial applications of these networks (e.g., MAC, rout...

  12. Selecting optimum locations for co-located wave and wind energy farms. Part II: A case study

    International Nuclear Information System (INIS)

    Astariz, S.; Iglesias, G.

    2016-01-01

    Highlights: • The benefits of wave and wind combined systems relative to independent farms are analysed. • This purpose is carried out through a case study off the Danish coast. • The power production, power smoothing and shadow effect are analysed. • Hindcast and measured wave and wind data from 2005 to 2015 are used. • Third-generation models of winds and waves (WAsP and SWAN) are used. - Abstract: Combined energy systems present an opportunity to enhance the competitiveness of renewables and overcome other challenges of these novel renewables by realising the synergies between them. Among the different possibilities for combined systems, this work focuses on wave and wind co-located farms with the aim of assessing their benefits relative to standalone wind farms. To this end we estimate the energy production, investigate the power smoothing and shadow effect, and quantify the reduction in downtime achieved by the co-located farm through a case study off the Danish coast – a promising area for co-located farms based on the available resource and other considerations including technical constraints. The analysis is carried out based on hindcast data and observations extending from 2005 to 2015, and by means of state-of-the-art numerical models of the wind and wave fields – WAsP and SWAN, respectively. It is found that the energy yield per unit area with the combined wave-wind farm increases by 3.4% relative to a standalone wind farm, the downtime periods decrease by 58% and the power output variability reduces by 12.5%. Moreover, the capital and operational expenditures (CAPEX and OPEX, respectively) would also be significantly reduced thanks to the synergies realised through the combination of wind and wave power.

  13. Information Sharing Modalities for Mobile Ad-Hoc Networks

    Science.gov (United States)

    de Spindler, Alexandre; Grossniklaus, Michael; Lins, Christoph; Norrie, Moira C.

    Current mobile phone technologies have fostered the emergence of a new generation of mobile applications. Such applications allow users to interact and share information opportunistically when their mobile devices are in physical proximity or close to fixed installations. It has been shown how mobile applications such as collaborative filtering and location-based services can take advantage of ad-hoc connectivity to use physical proximity as a filter mechanism inherent to the application logic. We discuss the different modes of information sharing that arise in such settings based on the models of persistence and synchronisation. We present a platform that supports the development of applications that can exploit these modes of ad-hoc information sharing and, by means of an example, show how such an application can be realised based on the supported event model.

  14. Spontaneous ad hoc mobile cloud computing network.

    Science.gov (United States)

    Lacuesta, Raquel; Lloret, Jaime; Sendra, Sandra; Peñalver, Lourdes

    2014-01-01

    Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

  15. Enhancing Wave Energy Competitiveness through Co-Located Wind and Wave Energy Farms. A Review on the Shadow Effect

    Directory of Open Access Journals (Sweden)

    Sharay Astariz

    2015-07-01

    Full Text Available Wave energy is one of the most promising alternatives to fossil fuels due to the enormous available resource; however, its development may be slowed as it is often regarded as uneconomical. The largest cost reductions are expected to be obtained through economies of scale and technological progress. In this sense, the incorporation of wave energy systems into offshore wind energy farms is an opportunity to foster the development of wave energy. The synergies between both renewables can be realised through these co-located energy farms and, thus, some challenges of offshore wind energy can be met. Among them, this paper focuses on the longer non-operational periods of offshore wind turbines—relative to their onshore counterparts—typically caused by delays in maintenance due to the harsh marine conditions. Co-located wave energy converters would act as a barrier extracting energy from the waves and resulting in a shielding effect over the wind farm. On this basis, the aim of this paper is to analyse wave energy economics in a holistic way, as well as the synergies between wave and offshore wind energy, focusing on the shadow effect and the associated increase in the accessibility to the wind turbines.

  16. Queueing Models for Mobile Ad Hoc Networks

    NARCIS (Netherlands)

    de Haan, Roland

    2009-01-01

    This thesis presents models for the performance analysis of a recent communication paradigm: \\emph{mobile ad hoc networking}. The objective of mobile ad hoc networking is to provide wireless connectivity between stations in a highly dynamic environment. These dynamics are driven by the mobility of

  17. Context discovery in ad-hoc networks

    NARCIS (Netherlands)

    Liu, F.

    2011-01-01

    With the rapid development of wireless technology and portable devices, mobile ad-hoc networks (MANETs) are more and more present in our daily life. Ad-hoc networks are often composed of mobile and battery-supplied devices, like laptops, mobile phones, and PDAs. With no requirement for

  18. LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA

    Science.gov (United States)

    Abbondanza, C.; Sarti, P.; Legrand, J.

    2009-12-01

    ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra

  19. An Active-Radio-Frequency-Identification system capable of identifying co-locations and social-structure: validation with a wild free-ranging animal

    OpenAIRE

    Ellwood, SA; Newman, C; Montgomery, RA; Nicosia, V; Buesching, CD; Markham, A; Mascolo, C; Trigoni, N; Pasztor, B; Dyo, V; Latora, V; Baker, SE; Macdonald, DW

    2017-01-01

    Behavioural events that are important for understanding sociobiology and movement ecology are often rare, transient and localised, but can occur at spatially distant sites e.g. territorial incursions and co-locating individuals. Existing animal tracking technologies, capable of detecting such events, are limited by one or more of: battery life; data resolution; location accuracy; data security; ability to co-locate individuals both spatially and temporally. Technology that at least partly res...

  20. Whither voluntary communities of co-located patients in Vietnam? Empirical evidence from a 2016 medical survey dataset

    Directory of Open Access Journals (Sweden)

    Quan-Hoang Vuong

    2016-12-01

    Full Text Available Background: Empirical evidence on quality of life of poor patients falls short for policy-making in Vietnam. Financial burdens and isolation give rise to Vietnamese voluntary co-location clusters where patients seek to rely on each other. These communities, although important, have been under-researched. Increasingly, there are questions about their sustainability. Aim & Objectives: This study aims to identify factors that affect sustainability of such co-location clusters, seeking to measure the community prospect through critical determinants as seen by member patients. An in-depth analysis is expected to yield insights that help shape future policies contributing to improvement of healthcare systems.  Material & Method: A dataset containing responses from 336 patients living in four clusters in Hanoi was obtained from a survey during 2015Q4-2016Q1. The processing of data is performed using R 3.2.3, employing baseline category logit models (BCL. Coefficients are estimated to compute empirical probabilities. Results: 1 There is a 50% probability that a patient seeing his/her benefits as unsatisfactory views the community prospect as dim; 2 The more a patient contributes time/effort, the less he/she believes in future growth; 3 There is a 80.8% probability that a patient who makes a significant financial contribution and receives back in-kind benefits predicts no growth. Conclusion: Patients predict community growth when receiving what they need/expect. There exists a kind of “liquidity preference”. Only 14% and 32% make significant financial and labor contributions, respectively. There exists a “risk aversion” attitude, viewing contribution as certain while future benefits to be uncertain.

  1. Research of Ad Hoc Networks Access Algorithm

    Science.gov (United States)

    Xiang, Ma

    With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. When the ad hoc network is the access network of the internet, the gateway discovery protocol is very important to choose the most appropriate gateway to guarantee the connectivity between ad hoc network and IP based fixed networks. The paper proposes a QoS gateway discovery protocol which uses the time delay and stable route to the gateway selection conditions. And according to the gateway discovery protocol, it also proposes a fast handover scheme which can decrease the handover time and improve the handover efficiency.

  2. Model checking mobile ad hoc networks

    NARCIS (Netherlands)

    Ghassemi, Fatemeh; Fokkink, Wan

    2016-01-01

    Modeling arbitrary connectivity changes within mobile ad hoc networks (MANETs) makes application of automated formal verification challenging. We use constrained labeled transition systems as a semantic model to represent mobility. To model check MANET protocols with respect to the underlying

  3. Preliminary safety analysis of a PBMR supplying process heat to a co-located ethylene production plant

    International Nuclear Information System (INIS)

    Scarlat, Raluca O.; Cisneros, Anselmo T.; Koutchesfahani, Tawni; Hong, Rada; Peterson, Per F.

    2012-01-01

    This paper considers the safety analysis and licensing approach for co-locating a pebble bed modular reactor (PBMR) to provide process heat to an ethylene production unit. The PBMR is an advanced nuclear reactor design that provides 400 MW of thermal energy. Ethylene production is an energy intensive process that utilizes large gas furnaces to provide the heat for the process. Coupling a PBMR with an ethylene production plant would open a new market for nuclear power, and would provide the chemical industry with a cleaner power source, helping to achieve the Clean Air Act standards, and eliminating the 0.5 ton of CO 2 emissions per ton of produced ethylene. Our analysis uses the Chevron Phillips chemical plant in Sweeney, TX as a prototypical site. The plant has four ethylene production trains, with a total power consumption of 2.4 GW, for an ethylene output of 3.7 million tons per year, 4% of the global ethylene production capacity. This paper proposes replacement of the gas furnaces by low-emission PBMR modules, and presents the safety concerns and risk mitigation and management options for this coupled system. Two coupling design options are proposed, and the necessary changes to the design basis events and severe accidents for the PBMR licensing application are discussed. A joint effort between the chemical and the nuclear entities to optimize the coupling design, establish preventive maintenance procedures, and develop emergency response plans for both of the units is recommended.

  4. Estimation of 557.7 nm Emission Altitude using Co-located Lidars and Photometers over Arecibo

    Science.gov (United States)

    Franco, E.; Raizada, S.; Lautenbach, J.; Brum, C. G. M.

    2017-12-01

    Airglow at 557.7 nm (green line emission) is generated through the Barth mechanism in the E-region altitude and is sometimes associated with red line (630.0 nm) originating at F-region altitudes. Photons at 557.7 nm are produced through the quenching of excited atomic oxygen atoms, O(1S), while 630.0 nm results through the de-excitation of O(1D) atoms. Even though, the contribution of the green line from F-region is negligible and the significant component comes from the mesosphere, this uncertainty gives rise to a question related to its precise altitude. Previous studies have shown that perturbations generated by atmospheric gravity Waves (GWs) alter the airglow intensity and can be used for studying dynamics of the region where it originates. The uncertainty in the emission altitude of green line can be resolved by using co-located lidars, which provide altitude resolved metal densities. At Arecibo, the resonance lidars tuned to Na and K resonance wavelengths at 589 nm and 770 nm can be used in conjunction with simultaneous measurements from green line photometer to resolve this issue. Both photometer and lidars have narrow field of view as compared to airglow imagers, and hence provide an added advantage that these instruments sample same GW spectrum. Hence, correlation between density perturbations inferred from lidars and airglow intensity perturbations can shed light on the exact altitude of green line emission.

  5. Preliminary safety analysis of a PBMR supplying process heat to a co-located ethylene production plant

    Energy Technology Data Exchange (ETDEWEB)

    Scarlat, Raluca O., E-mail: rscarlat@nuc.berkeley.edu [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Cisneros, Anselmo T. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Koutchesfahani, Tawni [University of California, Chemical and Biomolecular Engineering, 201 Gilman Hall, Berkeley, CA 94720 (United States); Hong, Rada; Peterson, Per F. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States)

    2012-10-15

    This paper considers the safety analysis and licensing approach for co-locating a pebble bed modular reactor (PBMR) to provide process heat to an ethylene production unit. The PBMR is an advanced nuclear reactor design that provides 400 MW of thermal energy. Ethylene production is an energy intensive process that utilizes large gas furnaces to provide the heat for the process. Coupling a PBMR with an ethylene production plant would open a new market for nuclear power, and would provide the chemical industry with a cleaner power source, helping to achieve the Clean Air Act standards, and eliminating the 0.5 ton of CO{sub 2} emissions per ton of produced ethylene. Our analysis uses the Chevron Phillips chemical plant in Sweeney, TX as a prototypical site. The plant has four ethylene production trains, with a total power consumption of 2.4 GW, for an ethylene output of 3.7 million tons per year, 4% of the global ethylene production capacity. This paper proposes replacement of the gas furnaces by low-emission PBMR modules, and presents the safety concerns and risk mitigation and management options for this coupled system. Two coupling design options are proposed, and the necessary changes to the design basis events and severe accidents for the PBMR licensing application are discussed. A joint effort between the chemical and the nuclear entities to optimize the coupling design, establish preventive maintenance procedures, and develop emergency response plans for both of the units is recommended.

  6. When students from different professions are co-located: the importance of interprofessional rapport for learning to work together.

    Science.gov (United States)

    Croker, Anne; Fisher, Karin; Smith, Tony

    2015-01-01

    With increasing interest and research into interprofessional learning, there is scope to more deeply understand what happens when students from different professions live and study in the same location. This study aimed to explore the issue of co-location and its effects on how students learn to work with other professions. The setting for this study was a rural health education facility in Australia with close links to local health care and community services. Philosophical hermeneutics informed the research method. Interviews were undertaken with 29 participants, including students, academic educators and clinical supervisors in diagnostic radiography, medicine, nursing, nutrition and dietetics, pharmacy, physiotherapy, occupational therapy, and speech pathology. Photo-elicitation was used to facilitate participant engagement with the topic. The findings foreground the value of interprofessional rapport building opportunities for students learning to work together. Enabled by the proximity of different professions in shared educational, clinical and social spaces, interprofessional rapport building was contingent on contextual conditions (balance of professions, shared spaces and adequate time) and individual's interpersonal capabilities (being interested, being inclusive, developing interpersonal bonds, giving and receiving respect, bringing a sense of own profession and being patient-centred). In the absence of these conditions and capabilities, negative professional stereotypes may be inadvertently re-enforced. From these findings suggestions are made for nurturing interprofessional rapport building opportunities to enable students of different professions to learn to work together.

  7. Breaching barriers to collaboration in public spaces

    DEFF Research Database (Denmark)

    Heinemann, Trine; Mitchell, Robb

    2014-01-01

    Technology provoking disparate individuals to collaborate or share experiences in the public space faces a difficult barrier, namely the ordinary social order of urban places. We employed the notion of the breaching experiment to explore how this barrier might be overcome. We analyse responses...... of life in public spaces. Arising from this, we argue for the importance of qualities such as availability, facilitation, perspicuous settings, and perspicuous participants to encourage and support co-located strangers to collaborate and share experiences....

  8. Using remote participation tools to improve collaborations

    International Nuclear Information System (INIS)

    Balme, S.; How, J.; Theis, J.M.; Utzel, N.

    2005-01-01

    Research on fusion requires effective collaboration between members who are not co-located in time and space. In order that distance should not restrict collaboration, this paper gives ideas and solutions to encourage and improve remote participation. This includes techniques for:1.'On-line' discussions with internet via instant messaging (IM). 2.Sharing a publication space, using a collaborative web workspace. 3.Equipping dedicated meeting rooms with flexible communication and collaboration tools, hardware and software for multi-standard videoconferences. 4.Sharing presentations and supervision screens. 5.Participating remotely to experiments

  9. Opportunities for co-location of solar PV with agriculture for cost reductions and carbon, water, and energy footprint mitigation in the tropics

    Science.gov (United States)

    Choi, C. S.; Macknick, J.; Ravi, S.

    2017-12-01

    Recently, co-locating the production of agricultural crops or biofuels with solar photovoltaics (PV) installations has been studied as a possible strategy to mitigate the environmental impacts and the high cost of solar PV in arid and semi-arid regions. Co-located PV and agricultural systems can provide multiple benefits in these areas related to water savings, erosion control, energy access, and rural economic development. However, such studies have been rare for water-rich, land-limited tropical countries, where ideal agricultural growing conditions can be substantially different from those in arid regions. We consider a case study in Indonesia to address this research gap. As the fourth most populous nation with an ever-growing energy demand and high vulnerability to the effects of climate change, Indonesia is being prompted to develop means to electrify approximately one-fifth of its population that still lacks access to the grid without incurring increases in its carbon footprint. We address the following questions to explore the feasibility and the benefits of co-location of solar PV with patchouli cultivation and essential oil production: i) How do the lifetime carbon, water, and energy footprints per unit land area of co-located solar PV/patchouli compare to those of standalone diesel microgrid, solar PV or patchouli cultivation? ii) Does energy production from standalone solar PV, diesel/solar PV microgrid, or co-located solar PV/patchouli systems satisfy energy demands of a typical rural Indonesian village? iii) How does the net economic return of the co-located system compare to each standalone land use? iv) How can surplus energy from the co-located system benefit rural socioeconomics? To answer these questions, life cycle assessment and economic analysis are performed for each of the standalone and the co-located land uses utilizing known values and data collected from a field visit to the island of Java in Indonesia. Then, sensitivity analyses and

  10. MRS/IS facility co-located with a repository: preconceptual design and life-cycle cost estimates

    International Nuclear Information System (INIS)

    Smith, R.I.; Nesbitt, J.F.

    1982-11-01

    A program is described to examine the various alternatives for monitored retrievable storage (MRS) and interim storage (IS) of spent nuclear fuel, solidified high-level waste (HLW), and transuranic (TRU) waste until appropriate geologic repository/repositories are available. The objectives of this study are: (1) to develop a preconceptual design for an MRS/IS facility that would become the principal surface facility for a deep geologic repository when the repository is opened, (2) to examine various issues such as transportation of wastes, licensing of the facility, and environmental concerns associated with operation of such a facility, and (3) to estimate the life cycle costs of the facility when operated in response to a set of scenarios which define the quantities and types of waste requiring storage in specific time periods, which generally span the years from 1990 until 2016. The life cycle costs estimated in this study include: the capital expenditures for structures, casks and/or drywells, storage areas and pads, and transfer equipment; the cost of staff labor, supplies, and services; and the incremental cost of transporting the waste materials from the site of origin to the MRS/IS facility. Three scenarios are examined to develop estimates of life cycle costs of the MRS/IS facility. In the first scenario, HLW canisters are stored, starting in 1990, until the co-located repository is opened in the year 1998. Additional reprocessing plants and repositories are placed in service at various intervals. In the second scenario, spent fuel is stored, starting in 1990, because the reprocessing plants are delayed in starting operations by 10 years, but no HLW is stored because the repositories open on schedule. In the third scenario, HLW is stored, starting in 1990, because the repositories are delayed 10 years, but the reprocessing plants open on schedule

  11. Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

    Science.gov (United States)

    Hagan, David H.; Isaacman-VanWertz, Gabriel; Franklin, Jonathan P.; Wallace, Lisa M. M.; Kocar, Benjamin D.; Heald, Colette L.; Kroll, Jesse H.

    2018-01-01

    The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2) levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors) was found to have excellent performance (RMSE 0.997) across a wide dynamic range in SO2 ( 2 ppm). However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear-nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (pollutant species in other areas (e.g., polluted urban regions), the calibration and validation approaches described here should be widely applicable to a range of pollutants, sensors, and environments.

  12. Ad Hoc Access Gateway Selection Algorithm

    Science.gov (United States)

    Jie, Liu

    With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. For mobile nodes in Ad Hoc network to internet, internet communications in the peer nodes must be achieved through the gateway. Therefore, the key Ad Hoc Access Networks will focus on the discovery gateway, as well as gateway selection in the case of multi-gateway and handover problems between different gateways. This paper considers the mobile node and the gateway, based on the average number of hops from an average access time and the stability of routes, improved gateway selection algorithm were proposed. An improved gateway selection algorithm, which mainly considers the algorithm can improve the access time of Ad Hoc nodes and the continuity of communication between the gateways, were proposed. This can improve the quality of communication across the network.

  13. The 11th Annual Mediterranean Ad Hoc Networking Workshop (Med-Hoc-Net 2012)

    NARCIS (Netherlands)

    Pitsillides, A.; Douligeris, C.; Vassiliou, V.; Heijenk, Geert; Cavalcante de Oliveira, J.

    Message from the General Chairs Welcome to the 2012 Mediterranean Ad Hoc Networking Workshop in Ayia Napa, Cyprus. We are excited to host Med-Hoc-Net. As a major annual international workshop, following recent successful workshops in Sicily (2006), Corfu (2007), Palma de Mallorca (2008), Haifa

  14. Co-located monogenetic eruptions similar to 200 kyr apart driven by tapping vertically separated mantle source regions, Chagwido, Jeju Island, Republic of Korea

    NARCIS (Netherlands)

    Brenna, M.; Nemeth, K.; Cronin, S.J.; Sohn, Y.K.; Smith, I.E.M.; Wijbrans, J.R.

    2015-01-01

    New eruptions in monogenetic volcanic fields conceptually occur independently of previous ones. In some instances, however, younger volcanic structures and vents may overlap with older edifices. The genetic links between such co-located eruptions remain unclear. We mapped and analysed the

  15. A Spontaneous Ad Hoc Network to Share WWW Access

    Directory of Open Access Journals (Sweden)

    Lloret Jaime

    2010-01-01

    Full Text Available In this paper, we propose a secure spontaneous ad-hoc network, based on direct peer-to-peer interaction, to grant a quick, easy, and secure access to the users to surf the Web. The paper shows the description of our proposal, the procedure of the nodes involved in the system, the security algorithms implemented, and the designed messages. We have taken into account the security and its performance. Although some people have defined and described the main features of spontaneous ad-hoc networks, nobody has published any design and simulation until today. Spontaneous networking will enable a more natural form of wireless computing when people physically meet in the real world. We also validate the success of our proposal through several simulations and comparisons with a regular architecture, taking into account the optimization of the resources of the devices. Finally, we compare our proposal with other caching techniques published in the related literature. The proposal has been developed with the main objective of improving the communication and integration between different study centers of low-resource communities. That is, it lets communicate spontaneous networks, which are working collaboratively and which have been created on different physical places.

  16. Ad hoc networks telecommunications and game theory

    CERN Document Server

    Benslama, Malek; Batatia, Hadj

    2015-01-01

    Random SALOHA and CSMA protocols that are used to access MAC in ad hoc networks are very small compared to the multiple and spontaneous use of the transmission channel. So they have low immunity to the problems of packet collisions. Indeed, the transmission time is the critical factor in the operation of such networks. The simulations demonstrate the positive impact of erasure codes on the throughput of the transmission in ad hoc networks. However, the network still suffers from the intermittency and volatility of its efficiency throughout its operation, and it switches quickly to the satura

  17. Vehicular ad hoc network security and privacy

    CERN Document Server

    Lin, X

    2015-01-01

    Unlike any other book in this area, this book provides innovative solutions to security issues, making this book a must read for anyone working with or studying security measures. Vehicular Ad Hoc Network Security and Privacy mainly focuses on security and privacy issues related to vehicular communication systems. It begins with a comprehensive introduction to vehicular ad hoc network and its unique security threats and privacy concerns and then illustrates how to address those challenges in highly dynamic and large size wireless network environments from multiple perspectives. This book is richly illustrated with detailed designs and results for approaching security and privacy threats.

  18. Ground motion response to an ML 4.3 earthquake using co-located distributed acoustic sensing and seismometer arrays

    Science.gov (United States)

    Wang, Herbert F.; Zeng, Xiangfang; Miller, Douglas E.; Fratta, Dante; Feigl, Kurt L.; Thurber, Clifford H.; Mellors, Robert J.

    2018-06-01

    The PoroTomo research team deployed two arrays of seismic sensors in a natural laboratory at Brady Hot Springs, Nevada in March 2016. The 1500 m (length) × 500 m (width) × 400 m (depth) volume of the laboratory overlies a geothermal reservoir. The distributed acoustic sensing (DAS) array consisted of about 8400 m of fiber-optic cable in a shallow trench and 360 m in a well. The conventional seismometer array consisted of 238 shallowly buried three-component geophones. The DAS cable was laid out in three parallel zig-zag lines with line segments approximately 100 m in length and geophones were spaced at approximately 60 m intervals. Both DAS and conventional geophones recorded continuously over 15 d during which a moderate-sized earthquake with a local magnitude of 4.3 was recorded on 2016 March 21. Its epicentre was approximately 150 km south-southeast of the laboratory. Several DAS line segments with co-located geophone stations were used to compare signal-to-noise ratios (SNRs) in both time and frequency domains and to test relationships between DAS and geophone data. The ratios were typically within a factor of five of each other with DAS SNR often greater for P-wave but smaller for S-wave relative to geophone SNR. The SNRs measured for an earthquake can be better than for active sources because the earthquake signal contains more low-frequency energy and the noise level is also lower at those lower frequencies. Amplitudes of the sum of several DAS strain-rate waveforms matched the finite difference of two geophone waveforms reasonably well, as did the amplitudes of DAS strain waveforms with particle-velocity waveforms recorded by geophones. Similar agreement was found between DAS and geophone observations and synthetic strain seismograms. The combination of good SNR in the seismic frequency band, high-spatial density, large N and highly accurate time control among individual sensors suggests that DAS arrays have potential to assume a role in earthquake

  19. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Directory of Open Access Journals (Sweden)

    T. Verhoelst

    2015-12-01

    Full Text Available Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs, named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC comparisons between GOME-type direct fitting (GODFITv3 satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith–sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC. The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only

  20. Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

    Directory of Open Access Journals (Sweden)

    D. H. Hagan

    2018-01-01

    Full Text Available The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2 levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors was found to have excellent performance (RMSE < 7 ppb, MAE < 4 ppb, r2 > 0.997 across a wide dynamic range in SO2 (< 1 ppb, > 2 ppm. However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear–nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (< 25 ppb, for which they exhibit an error of less than 2.5 ppb. While some specific results of this study (calibration accuracy, performance of the various algorithms, etc. may differ for measurements of other pollutant species in other areas (e.g., polluted urban regions, the calibration and validation approaches described here should be widely applicable

  1. The impact of HIV status and antiretroviral treatment on TB treatment outcomes of new tuberculosis patients attending co-located TB and ART services in South Africa: a retrospective cohort study.

    Science.gov (United States)

    Nglazi, Mweete D; Bekker, Linda-Gail; Wood, Robin; Kaplan, Richard

    2015-11-19

    The implementation of collaborative TB-HIV services is challenging. We, therefore, assessed TB treatment outcomes in relation to HIV infection and antiretroviral therapy (ART) among TB patients attending a primary care service with co-located ART and TB clinics in Cape Town, South Africa. In this retrospective cohort study, all new TB patients aged ≥ 15 years who registered and initiated TB treatment between 1 October 2009 and 30 June 2011 were identified from an electronic database. The effects of HIV-infection and ART on TB treatment outcomes were analysed using a multinomial logistic regression model, in which treatment success was the reference outcome. The 797 new TB patients included in the analysis were categorized as follows: HIV- negative, in 325 patients (40.8 %); HIV-positive on ART, in 339 patients (42.5 %) and HIV-positive not on ART, in 133 patients (16.7 %). Overall, bivariate analyses showed no significant difference in death and default rates between HIV-positive TB patients on ART and HIV-negative patients. Statistically significant higher mortality rates were found among HIV-positive patients not on ART compared to HIV-negative patients (unadjusted odds ratio (OR) 3.25; 95 % confidence interval (CI) 1.53-6.91). When multivariate analyses were conducted, the only significant difference between the patient categories on TB treatment outcomes was that HIV-positive TB patients not on ART had significantly higher mortality rates than HIV-negative patients (adjusted OR 4.12; 95 % CI 1.76-9.66). Among HIV-positive TB patients (n = 472), 28.2 % deemed eligible did not initiate ART in spite of the co-location of TB and ART services. When multivariate analyses were restricted to HIV-positive patients in the cohort, we found that being HIV-positive not on ART was associated with higher mortality (adjusted OR 7.12; 95 % CI 2.95-18.47) and higher default rates (adjusted OR 2.27; 95 % CI 1.15-4.47). There was no significant difference in death and

  2. A multi-protocol framework for ad-hoc service discovery

    OpenAIRE

    Flores-Cortes, C.; Blair, Gordon S.; Grace, P.

    2006-01-01

    Discovering the appropriate services in ad-hoc computing environments where a great number of devices and software components collaborate discreetly and provide numerous services is an important challenge. Service discovery protocols make it possible for participating nodes in a network to locate and advertise services with minimum user intervention. However, because it is not possible to predict at design time which protocols will be used to advertise services in a given context/environment,...

  3. Clinician's perspectives of the relocation of a regional child and adolescent mental health service from co-located to stand alone premises.

    Science.gov (United States)

    Francis, K J; Boyd, C P; Sewell, J; Nurse, S

    2008-01-01

    Australia's National Mental Health Strategy's statement of rights and responsibilities states that children and adolescents admitted to a mental health facility or community program have the right to be separated from adult patients and provided with programs suited to their developmental needs. However, in rural Australia, where a lack of healthcare services, financial constraints, greater service delivery areas and fewer mental healthcare specialists represent the norm, Child and Adolescent Mental Health Services (CAMHS) are sometimes co-located with adult mental health services. The aim of the present study was to evaluate the impact of a recent relocation of a regional CAMHS in Victoria from co-located to stand alone premises. Six CAMHS clinicians who had experienced service delivery at a co-located setting and the current stand-alone CAMHS setting were interviewed about their perceptions of the impact of the relocation on service delivery. An exploratory interviewing methodology was utilized due to the lack of previous research in this area. Interview data were transcribed and analysed according to interpretative phenomenological analysis techniques. Findings indicated a perception that the relocation was positive for clients due to the family-friendly environment at the new setting and separation of CAMHS from adult psychiatric services. However, the impact of the relocation on clinicians was marked by a perceived loss of social capital from adult psychiatric service clinicians. These results provide increased understanding of the effects of service relocation and the influence of co-located versus stand-alone settings on mental health service delivery - an area where little prior research exists.

  4. Evolutionary algorithms for mobile ad hoc networks

    CERN Document Server

    Dorronsoro, Bernabé; Danoy, Grégoire; Pigné, Yoann; Bouvry, Pascal

    2014-01-01

    Describes how evolutionary algorithms (EAs) can be used to identify, model, and minimize day-to-day problems that arise for researchers in optimization and mobile networking. Mobile ad hoc networks (MANETs), vehicular networks (VANETs), sensor networks (SNs), and hybrid networks—each of these require a designer’s keen sense and knowledge of evolutionary algorithms in order to help with the common issues that plague professionals involved in optimization and mobile networking. This book introduces readers to both mobile ad hoc networks and evolutionary algorithms, presenting basic concepts as well as detailed descriptions of each. It demonstrates how metaheuristics and evolutionary algorithms (EAs) can be used to help provide low-cost operations in the optimization process—allowing designers to put some “intelligence” or sophistication into the design. It also offers efficient and accurate information on dissemination algorithms topology management, and mobility models to address challenges in the ...

  5. Quantum load balancing in ad hoc networks

    Science.gov (United States)

    Hasanpour, M.; Shariat, S.; Barnaghi, P.; Hoseinitabatabaei, S. A.; Vahid, S.; Tafazolli, R.

    2017-06-01

    This paper presents a novel approach in targeting load balancing in ad hoc networks utilizing the properties of quantum game theory. This approach benefits from the instantaneous and information-less capability of entangled particles to synchronize the load balancing strategies in ad hoc networks. The quantum load balancing (QLB) algorithm proposed by this work is implemented on top of OLSR as the baseline routing protocol; its performance is analyzed against the baseline OLSR, and considerable gain is reported regarding some of the main QoS metrics such as delay and jitter. Furthermore, it is shown that QLB algorithm supports a solid stability gain in terms of throughput which stands a proof of concept for the load balancing properties of the proposed theory.

  6. Three Case Studies on Business Collaboration and Process Management

    Science.gov (United States)

    Fan, Shaokun

    2012-01-01

    The importance of collaboration has been recognized for more than 2000 years. While recent improvement in technology creates vast opportunities for collaboration, effective collaboration remains challenging as ad hoc teams work across time, geographical, language, and technical boundaries, and suffer from process inefficiency. My dissertation…

  7. AD HOC Networks for the Autonomous Car

    Science.gov (United States)

    Ron, Davidescu; Negrus, Eugen

    2017-10-01

    The future of the vehicle is made of cars, roads and infrastructures connected in a two way automated communication in a holistic system. It is a mandatory to use Encryption to maintain Confidentiality, Integrity and Availability in an ad hoc vehicle network. Vehicle to Vehicle communication, requires multichannel interaction between mobile, moving and changing parties to insure the full benefit from data sharing and real time decision making, a network of such users referred as mobile ad hoc network (MANET), however as ad hoc networks were not implemented in such a scale, it is not clear what is the best method and protocol to apply. Furthermore the visibility of secure preferred asymmetric encrypted ad hoc networks in a real time environment of dense moving autonomous vehicles has to be demonstrated, In order to evaluate the performance of Ad Hoc networks in changing conditions a simulation of multiple protocols was performed on large number of mobile nodes. The following common routing protocols were tested, DSDV is a proactive protocol, every mobile station maintains a routing table with all available destinations, DSR is a reactive routing protocol which allows nodes in the MANET to dynamically discover a source route across multiple network hops, AODV is a reactive routing protocol Instead of being proactive. It minimizes the number of broadcasts by creating routes based on demand, SAODV is a secure version of AODV, requires heavyweight asymmetric cryptographic, ARIANDE is a routing protocol that relies on highly efficient symmetric cryptography the concept is primarily based on DSR. A methodical evolution was performed in a various density of transportation, based on known communication bench mark parameters including, Throughput Vs. time, Routing Load per packets and bytes. Out of the none encrypted protocols, It is clear that in terms of performance of throughput and routing load DSR protocol has a clear advantage the high node number mode. The encrypted

  8. Collaboration 'Engineerability'

    NARCIS (Netherlands)

    Kolfschoten, Gwendolyn L.; de Vreede, Gert-Jan; Briggs, Robert O.; Sol, Henk G.

    Collaboration Engineering is an approach to create sustained collaboration support by designing collaborative work practices for high-value recurring tasks, and transferring those designs to practitioners to execute for themselves without ongoing support from collaboration professionals. A key

  9. On knowledge transfer management as a learning process for ad hoc teams

    Science.gov (United States)

    Iliescu, D.

    2017-08-01

    Knowledge management represents an emerging domain becoming more and more important. Concepts like knowledge codification and personalisation, knowledge life-cycle, social and technological dimensions, knowledge transfer and learning management are integral parts. Focus goes here in the process of knowledge transfer for the case of ad hoc teams. The social dimension of knowledge transfer plays an important role. No single individual actors involved in the process, but a collective one, representing the organisation. It is critically important for knowledge to be managed from the life-cycle point of view. A complex communication network needs to be in place to supports the process of knowledge transfer. Two particular concepts, the bridge tie and transactive memory, would eventually enhance the communication. The paper focuses on an informational communication platform supporting the collaborative work on knowledge transfer. The platform facilitates the creation of a topic language to be used in knowledge modelling, storage and reuse, by the ad hoc teams.

  10. Game Theory in Wireless Ad-Hoc Opportunistic Radios

    OpenAIRE

    Mumtaz, Shahid; Gameiro, Atilio

    2010-01-01

    Emerging research in game theory based power control applied to ad hoc opportunist networks shows much promise to help understand the complex interactions between OR nodes in this highly dynamic and distributed environment. Also, the employment of game theory in modeling dynamic situations for opportunist ad hoc networks where OR nodes have incomplete information has led to the application of largely unexplored games such as games of imperfect monitoring. Ad hoc security using game theory is ...

  11. Ad hoc mobile wireless networks principles, protocols and applications

    CERN Document Server

    Sarkar, Subir Kumar; Puttamadappa, C

    2007-01-01

    Ad hoc mobile wireless networks have seen increased adaptation in a variety of disciplines because they can be deployed with simple infrastructures and virtually no central administration. In particular, the development of ad hoc wireless and sensor networks provides tremendous opportunities in areas including disaster recovery, defense, health care, and industrial environments. Ad Hoc Mobile Wireless Networks: Principles, Protocols and Applications explains the concepts, mechanisms, design, and performance of these systems. It presents in-depth explanations of the latest wireless technologies

  12. Ad hoc mobile wireless networks principles, protocols, and applications

    CERN Document Server

    Sarkar, Subir Kumar

    2013-01-01

    The military, the research community, emergency services, and industrial environments all rely on ad hoc mobile wireless networks because of their simple infrastructure and minimal central administration. Now in its second edition, Ad Hoc Mobile Wireless Networks: Principles, Protocols, and Applications explains the concepts, mechanism, design, and performance of these highly valued systems. Following an overview of wireless network fundamentals, the book explores MAC layer, routing, multicast, and transport layer protocols for ad hoc mobile wireless networks. Next, it examines quality of serv

  13. Worm epidemics in wireless ad hoc networks

    Energy Technology Data Exchange (ETDEWEB)

    Nekovee, Maziar [BT Research, Polaris 134, Adastral Park, Martlesham, Suffolk IP5 3RE (United Kingdom); Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2007-06-15

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  14. Worm epidemics in wireless ad hoc networks

    Science.gov (United States)

    Nekovee, Maziar

    2007-06-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  15. Worm epidemics in wireless ad hoc networks

    International Nuclear Information System (INIS)

    Nekovee, Maziar

    2007-01-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet

  16. Intrusion detection in wireless ad-hoc networks

    CERN Document Server

    Chaki, Nabendu

    2014-01-01

    Presenting cutting-edge research, Intrusion Detection in Wireless Ad-Hoc Networks explores the security aspects of the basic categories of wireless ad-hoc networks and related application areas. Focusing on intrusion detection systems (IDSs), it explains how to establish security solutions for the range of wireless networks, including mobile ad-hoc networks, hybrid wireless networks, and sensor networks.This edited volume reviews and analyzes state-of-the-art IDSs for various wireless ad-hoc networks. It includes case studies on honesty-based intrusion detection systems, cluster oriented-based

  17. Identification and characterization of pleiotropic and co-located resistance loci to leaf rust and stripe rust in bread wheat cultivar Sujata.

    Science.gov (United States)

    Lan, Caixia; Zhang, Yelun; Herrera-Foessel, Sybil A; Basnet, Bhoja R; Huerta-Espino, Julio; Lagudah, Evans S; Singh, Ravi P

    2015-03-01

    Two new co-located resistance loci, QLr.cim - 1AS/QYr.cim - 1AS and QLr.cim - 7BL/YrSuj , in combination with Lr46 / Yr29 and Lr67/Yr46 , and a new leaf rust resistance quantitative trait loci, conferred high resistance to rusts in adult plant stage. The tall Indian bread wheat cultivar Sujata displays high and low infection types to leaf rust and stripe rust, respectively, at the seedling stage in greenhouse tests. It was also highly resistant to both rusts at adult plant stage in field trials in Mexico. The genetic basis of this resistance was investigated in a population of 148 F5 recombinant inbred lines (RILs) derived from the cross Avocet × Sujata. The parents and RIL population were characterized in field trials for resistance to leaf rust during 2011 at El Batán, and 2012 and 2013 at Ciudad Obregón, Mexico, and for stripe rust during 2011 and 2012 at Toluca, Mexico; they were also characterized three times for stripe rust at seedling stage in the greenhouse. The RILs were genotyped with diversity arrays technology and simple sequence repeat markers. The final genetic map was constructed with 673 polymorphic markers. Inclusive composite interval mapping analysis detected two new significant co-located resistance loci, QLr.cim-1AS/QYr.cim-1AS and QLr.cim-7BL/YrSuj, on chromosomes 1AS and 7BL, respectively. The chromosomal position of QLr.cim-7BL overlapped with the seedling stripe rust resistance gene, temporarily designated as YrSuj. Two previously reported pleiotropic adult plant resistance genes, Lr46/Yr29 and Lr67/Yr46, and a new leaf rust resistance quantitative trait loci derived from Avocet were also mapped in the population. The two new co-located resistance loci are expected to contribute to breeding durable rust resistance in wheat. Closely linked molecular markers can be used to transfer all four resistance loci simultaneously to modern wheat varieties.

  18. Flexible Access Control for Dynamic Collaborative Environments

    NARCIS (Netherlands)

    Dekker, M.A.C.

    2009-01-01

    Access control is used in computer systems to control access to confidential data. In this thesis we focus on access control for dynamic collaborative environments where multiple users and systems access and exchange data in an ad hoc manner. In such environments it is difficult to protect

  19. Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.

    Science.gov (United States)

    Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

    2016-01-01

    Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV.

  20. Co-located hAT transposable element and 5S rDNA in an interstitial telomeric sequence suggest the formation of Robertsonian fusion in armored catfish.

    Science.gov (United States)

    Glugoski, Larissa; Giuliano-Caetano, Lucia; Moreira-Filho, Orlando; Vicari, Marcelo R; Nogaroto, Viviane

    2018-04-15

    Co-located 5S rDNA genes and interstitial telomeric sites (ITS) revealed the involvement of multiple 5S rDNA clusters in chromosome rearrangements of Loricariidae. Interstitial (TTAGGG)n vestiges, in addition to telomeric sites, can coincide with locations of chromosomal rearrangements, and they are considered to be hotspots for chromosome breaks. This study aimed the molecular characterization of 5S rDNA in two Rineloricaria latirostris populations and examination of roles of 5S rDNA in breakpoint sites and its in situ localization. Rineloricaria latirostris from Brazil's Das Pedras river (2n = 46 chromosomes) presented five pairs identified using a 5S rDNA probe, in addition to a pair bearing a co-located ITS/5S rDNA. Rineloricaria latirostris from the Piumhi river (2n = 48 chromosomes) revealed two pairs containing 5S rDNA, without ITS. A 702-bp amplified sequence, using 5S rDNA primers, revealed an insertion of the hAT transposable element (TE), referred to as a degenerate 5S rDNA. Double-FISH (fluorescence in situ hybridization) demonstrated co-localization of 5S rDNA/degenerate 5S rDNA, 5S rDNA/hAT and ITS/5S rDNA from the Das Pedras river population. Piumhi river isolates possessed only 5S rDNA sites. We suggest that the degenerate 5S rDNA was generated by unequal crossing over, which was driven by invasion of hAT, establishing a breakpoint region susceptible to chromosome breakage, non-homologous recombination and Robertsonian (Rb) fusion. Furthermore, the presence of clusters of 5S rDNA at fusion points in other armored catfish species suggests its re-use and that these regions represent hotspots for evolutionary rearrangements within Loricariidae genomes. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Decentralized position verification in geographic ad hoc routing

    NARCIS (Netherlands)

    Leinmüller, Tim; Schoch, Elmar; Kargl, Frank; Maihöfer, Christian

    Inter-vehicle communication is regarded as one of the major applications of mobile ad hoc networks (MANETs). Compared to MANETs or wireless sensor networks (WSNs), these so-called vehicular ad hoc networks (VANETs) have unique requirements on network protocols. The requirements result mainly from

  2. AD HOC TEAMWORK BEHAVIORS FOR INFLUENCING A FLOCK

    Directory of Open Access Journals (Sweden)

    Katie Genter

    2016-02-01

    Full Text Available Ad hoc teamwork refers to the challenge of designing agents that can influence the behavior of a team, without prior coordination with its teammates. This paper considers influencing a flock of simple robotic agents to adopt a desired behavior within the context of ad hoc teamwork. Specifically, we examine how the ad hoc agents should behave in order to orient a flock towards a target heading as quickly as possible when given knowledge of, but no direct control over, the behavior of the flock. We introduce three algorithms which the ad hoc agents can use to influence the flock, and we examine the relative importance of coordinating the ad hoc agents versus planning farther ahead when given fixed computational resources. We present detailed experimental results for each of these algorithms, concluding that in this setting, inter-agent coordination and deeper lookahead planning are no more beneficial than short-term lookahead planning.

  3. Ad hoc committee on reactor physics benchmarks

    International Nuclear Information System (INIS)

    Diamond, D.J.; Mosteller, R.D.; Gehin, J.C.

    1996-01-01

    In the spring of 1994, an ad hoc committee on reactor physics benchmarks was formed under the leadership of two American Nuclear Society (ANS) organizations. The ANS-19 Standards Subcommittee of the Reactor Physics Division and the Computational Benchmark Problem Committee of the Mathematics and Computation Division had both seen a need for additional benchmarks to help validate computer codes used for light water reactor (LWR) neutronics calculations. Although individual organizations had employed various means to validate the reactor physics methods that they used for fuel management, operations, and safety, additional work in code development and refinement is under way, and to increase accuracy, there is a need for a corresponding increase in validation. Both organizations thought that there was a need to promulgate benchmarks based on measured data to supplement the LWR computational benchmarks that have been published in the past. By having an organized benchmark activity, the participants also gain by being able to discuss their problems and achievements with others traveling the same route

  4. Broadcast design in cognitive radio ad hoc networks

    CERN Document Server

    Song, Yi

    2014-01-01

    This SpringerBrief investigates the special challenges of broadcast design in cognitive radio (CR) ad hoc networks. It introduces two broadcast protocols in CR ad hoc networks: a quality-of-service based broadcast protocol under blind information and a fully-distributed broadcast protocol with collision avoidance. A novel unified analytical model is also presented to analyze the performance of the broadcast protocols. This is the first book dedicated to the unique broadcast design challenges in CR ad hoc networks. The authors also discuss the recent research on the performance analysis of broa

  5. Ad hoc laser networks component technology for modular spacecraft

    Science.gov (United States)

    Huang, Xiujun; Shi, Dele; Shen, Jingshi

    2017-10-01

    Distributed reconfigurable satellite is a new kind of spacecraft system, which is based on a flexible platform of modularization and standardization. Based on the module data flow analysis of the spacecraft, this paper proposes a network component of ad hoc Laser networks architecture. Low speed control network with high speed load network of Microwave-Laser communication mode, no mesh network mode, to improve the flexibility of the network. Ad hoc Laser networks component technology was developed, and carried out the related performance testing and experiment. The results showed that ad hoc Laser networks components can meet the demand of future networking between the module of spacecraft.

  6. Collaborative Economy

    DEFF Research Database (Denmark)

    collaborative economy and tourism Dianne Dredge and Szilvia Gyimóthy PART I - Theoretical explorations 2.Definitions and mapping the landscape in the collaborative economy Szilvia Gyimóthy and Dianne Dredge 3.Business models of the collaborative economy Szilvia Gyimóthy 4.Responsibility and care...... in the collaborative economy Dianne Dredge 5.Networked cultures in the collaborative economy Szilvia Gyimóthy 6.Policy and regulatory perspectives in the collaborative economy Dianne Dredge PART II - Disruptions, innovations and transformations 7.Regulating innovation in the collaborative economy: An examination...... localities of tourism Greg Richards 11.Collaborative economy and destination marketing organizations: A systems approach Jonathan Day 12.Working within the Collaborative Tourist Economy: The complex crafting of work and meaning Jane Widtfeldt Meged and Mathilde Dissing Christensen PART - III Encounters...

  7. Direction-of-arrival estimation for co-located multiple-input multiple-output radar using structural sparsity Bayesian learning

    International Nuclear Information System (INIS)

    Wen Fang-Qing; Zhang Gong; Ben De

    2015-01-01

    This paper addresses the direction of arrival (DOA) estimation problem for the co-located multiple-input multiple-output (MIMO) radar with random arrays. The spatially distributed sparsity of the targets in the background makes compressive sensing (CS) desirable for DOA estimation. A spatial CS framework is presented, which links the DOA estimation problem to support recovery from a known over-complete dictionary. A modified statistical model is developed to accurately represent the intra-block correlation of the received signal. A structural sparsity Bayesian learning algorithm is proposed for the sparse recovery problem. The proposed algorithm, which exploits intra-signal correlation, is capable being applied to limited data support and low signal-to-noise ratio (SNR) scene. Furthermore, the proposed algorithm has less computation load compared to the classical Bayesian algorithm. Simulation results show that the proposed algorithm has a more accurate DOA estimation than the traditional multiple signal classification (MUSIC) algorithm and other CS recovery algorithms. (paper)

  8. Observations on Stratospheric-Mesospheric-Thermospheric temperatures using Indian MST radar and co-located LIDAR during Leonid Meteor Shower (LMS

    Directory of Open Access Journals (Sweden)

    R. Selvamurugan

    2002-11-01

    Full Text Available The temporal and height statistics of the occurrence of meteor trails during the Leonid meteor shower revealed the capability of the Indian MST radar to record large numbers of meteor trails. The distribution of radio meteor trails due to a Leonid meteor shower in space and time provided a unique opportunity to construct the height profiles of lower thermospheric temperatures and winds, with good time and height resolution. There was a four-fold increase in the meteor trails observed during the LMS compared to a typical non-shower day. The temperatures were found to be in excellent continuity with the temperature profiles below the radio meteor region derived from the co-located Nd-Yag LIDAR and the maximum height of the temperature profile was extended from the LIDAR to ~110 km. There are, how-ever, some significant differences between the observed profiles and the CIRA-86 model profiles. The first results on the meteor statistics and neutral temperature are presented and discussed below.  Key words. Atmospheric composition and structure (pres-sure, density, and temperature History of geophysics (at-mospheric sciences Meteorology and atmospheric dynamics (middle atmosphere dynamics

  9. Direction-of-arrival estimation for co-located multiple-input multiple-output radar using structural sparsity Bayesian learning

    Science.gov (United States)

    Wen, Fang-Qing; Zhang, Gong; Ben, De

    2015-11-01

    This paper addresses the direction of arrival (DOA) estimation problem for the co-located multiple-input multiple-output (MIMO) radar with random arrays. The spatially distributed sparsity of the targets in the background makes compressive sensing (CS) desirable for DOA estimation. A spatial CS framework is presented, which links the DOA estimation problem to support recovery from a known over-complete dictionary. A modified statistical model is developed to accurately represent the intra-block correlation of the received signal. A structural sparsity Bayesian learning algorithm is proposed for the sparse recovery problem. The proposed algorithm, which exploits intra-signal correlation, is capable being applied to limited data support and low signal-to-noise ratio (SNR) scene. Furthermore, the proposed algorithm has less computation load compared to the classical Bayesian algorithm. Simulation results show that the proposed algorithm has a more accurate DOA estimation than the traditional multiple signal classification (MUSIC) algorithm and other CS recovery algorithms. Project supported by the National Natural Science Foundation of China (Grant Nos. 61071163, 61271327, and 61471191), the Funding for Outstanding Doctoral Dissertation in Nanjing University of Aeronautics and Astronautics, China (Grant No. BCXJ14-08), the Funding of Innovation Program for Graduate Education of Jiangsu Province, China (Grant No. KYLX 0277), the Fundamental Research Funds for the Central Universities, China (Grant No. 3082015NP2015504), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PADA), China.

  10. Interference in wireless ad hoc networks with smart antennas

    KAUST Repository

    Alabdulmohsin, Ibrahim

    2014-01-01

    In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical

  11. Source Authentication for Multicast in Mobile Ad Hoc Networks

    National Research Council Canada - National Science Library

    Ramachandran, Prabha

    2003-01-01

    Recent emergence and popularity of mobile ad hoc networks in a host of current-day applications has instigated a suite of research challenges, primarily in routing and security issues for such networks...

  12. Internet-Based Mobile Ad Hoc Networking (Preprint)

    National Research Council Canada - National Science Library

    Corson, M. S; Macker, Joseph P; Cirincione, Gregory H

    1999-01-01

    Internet-based Mobile Ad Hoc Networking is an emerging technology that supports self-organizing, mobile networking infrastructures, and is one which appears well-suited for use in future commercial...

  13. Ad Hoc Human Information Nets for Asymmetric Threat Surveillance

    National Research Council Canada - National Science Library

    Thiruvathukal, George

    2003-01-01

    ...: Hybrid-Hierarchical Micro-Databases, Query Optimization, and XML for Embedded Systems. After meeting with the program manager, Tom Armour, in Washington, DC, we were able to get a better perspective on the ad hoc nature of the solicitation...

  14. A New Hybrid Channel Access Scheme for Ad Hoc Networks

    National Research Council Canada - National Science Library

    Wang, Yu; Garcia-Luna-Aceves, J. J

    2002-01-01

    Many contention-based channel access schemes have been proposed for multi-hop ad hoc networks in the recent past, and they can be divided into two categories, sender-initiated and receiver-initiated...

  15. Sensor and ad-hoc networks theoretical and algorithmic aspects

    CERN Document Server

    Makki, S Kami; Pissinou, Niki; Makki, Shamila; Karimi, Masoumeh; Makki, Kia

    2008-01-01

    This book brings together leading researchers and developers in the field of wireless sensor networks to explain the special problems and challenges of the algorithmic aspects of sensor and ad-hoc networks. The book also fosters communication not only between the different sensor and ad-hoc communities, but also between those communities and the distributed systems and information systems communities. The topics addressed pertain to the sensors and mobile environment.

  16. Collaborative Economy

    DEFF Research Database (Denmark)

    that are emerging from them, and how governments are responding to these new challenges. In doing so, the book provides both theoretical and practical insights into the future of tourism in a world that is, paradoxically, becoming both increasingly collaborative and individualized. Table of Contents Preface 1.The...... collaborative economy and tourism Dianne Dredge and Szilvia Gyimóthy PART I - Theoretical explorations 2.Definitions and mapping the landscape in the collaborative economy Szilvia Gyimóthy and Dianne Dredge 3.Business models of the collaborative economy Szilvia Gyimóthy 4.Responsibility and care...... in the collaborative economy Dianne Dredge 5.Networked cultures in the collaborative economy Szilvia Gyimóthy 6.Policy and regulatory perspectives in the collaborative economy Dianne Dredge PART II - Disruptions, innovations and transformations 7.Regulating innovation in the collaborative economy: An examination...

  17. Working Collaboratively

    DEFF Research Database (Denmark)

    Holder, Anna; Lovett, George

    2009-01-01

    identified as a transformative global force of the last decade, most notably in knowledge and information publishing, communication and creation. This paper presents a structured conversation on changing understandings of collaboration, and the realities of collaborative methodology in architectural work...

  18. Coal-fired Power Plants with Flexible Amine-based CCS and Co-located Wind Power: Environmental, Economic and Reliability Outcomes

    Science.gov (United States)

    Bandyopadhyay, Rubenka

    Carbon Capture and Storage (CCS) technologies provide a means to significantly reduce carbon emissions from the existing fleet of fossil-fired plants, and hence can facilitate a gradual transition from conventional to more sustainable sources of electric power. This is especially relevant for coal plants that have a CO2 emission rate that is roughly two times higher than that of natural gas plants. Of the different kinds of CCS technology available, post-combustion amine based CCS is the best developed and hence more suitable for retrofitting an existing coal plant. The high costs from operating CCS could be reduced by enabling flexible operation through amine storage or allowing partial capture of CO2 during high electricity prices. This flexibility is also found to improve the power plant's ramp capability, enabling it to offset the intermittency of renewable power sources. This thesis proposes a solution to problems associated with two promising technologies for decarbonizing the electric power system: the high costs of the energy penalty of CCS, and the intermittency and non-dispatchability of wind power. It explores the economic and technical feasibility of a hybrid system consisting of a coal plant retrofitted with a post-combustion-amine based CCS system equipped with the option to perform partial capture or amine storage, and a co-located wind farm. A techno-economic assessment of the performance of the hybrid system is carried out both from the perspective of the stakeholders (utility owners, investors, etc.) as well as that of the power system operator. (Abstract shortened by ProQuest.).

  19. CMS Collaboration

    International Nuclear Information System (INIS)

    Faridah Mohammad Idris; Wan Ahmad Tajuddin Wan Abdullah; Zainol Abidin Ibrahim

    2013-01-01

    Full-text: CMS Collaboration is an international scientific collaboration located at European Organization for Nuclear Research (CERN), Switzerland, dedicated in carried out research on experimental particle physics. Consisting of 179 institutions from 41 countries from all around the word, CMS Collaboration host a general purpose detector for example the Compact Muon Solenoid (CMS) for members in CMS Collaboration to conduct experiment from the collision of two proton beams accelerated to a speed of 8 TeV in the LHC ring. In this paper, we described how the CMS detector is used by the scientist in CMS Collaboration to reconstruct the most basic building of matter. (author)

  20. Collaborative Economy

    DEFF Research Database (Denmark)

    collaborative economy and tourism Dianne Dredge and Szilvia Gyimóthy PART I - Theoretical explorations 2.Definitions and mapping the landscape in the collaborative economy Szilvia Gyimóthy and Dianne Dredge 3.Business models of the collaborative economy Szilvia Gyimóthy 4.Responsibility and care...... and similar phenomena are among these collective innovations in tourism that are shaking the very bedrock of an industrial system that has been traditionally sustained along commercial value chains. To date there has been very little investigation of these trends, which have been inspired by, amongst other...... in the collaborative economy Dianne Dredge 5.Networked cultures in the collaborative economy Szilvia Gyimóthy 6.Policy and regulatory perspectives in the collaborative economy Dianne Dredge PART II - Disruptions, innovations and transformations 7.Regulating innovation in the collaborative economy: An examination...

  1. Innovative research of AD HOC network mobility model

    Science.gov (United States)

    Chen, Xin

    2017-08-01

    It is difficult for researchers of AD HOC network to conduct actual deployment during experimental stage as the network topology is changeable and location of nodes is unfixed. Thus simulation still remains the main research method of the network. Mobility model is an important component of AD HOC network simulation. It is used to describe the movement pattern of nodes in AD HOC network (including location and velocity, etc.) and decides the movement trail of nodes, playing as the abstraction of the movement modes of nodes. Therefore, mobility model which simulates node movement is an important foundation for simulation research. In AD HOC network research, mobility model shall reflect the movement law of nodes as truly as possible. In this paper, node generally refers to the wireless equipment people carry. The main research contents include how nodes avoid obstacles during movement process and the impacts of obstacles on the mutual relation among nodes, based on which a Node Self Avoiding Obstacle, i.e. NASO model is established in AD HOC network.

  2. Routing Protocol for Mobile Ad-hoc Wireless Networks

    Directory of Open Access Journals (Sweden)

    I. M. B. Nogales

    2007-09-01

    Full Text Available Bluetooth is a cutting-edge technology used for implementing wireless ad hoc networks. In order to provide an overall scheme for mobile ad hoc networks, this paper deals with scatternet topology formation and routing algorithm to form larger ad hoc wireless Networks. Scatternet topology starts by forming a robust network, which is less susceptible to the problems posed by node mobility. Mobile topology relies on the presence of free nodes that create multiple connections with the network and on their subsequently rejoining the network. Our routing protocol is a proactive routing protocol, which is tailor made for the Bluetooth ad hoc network. The connection establishment connects nodes in a structure that simplifies packet routing and scheduling. The design allows nodes to arrive and leave arbitrarily, incrementally building the topology and healing partitions when they occur. We present simulation results that show that the algorithm presents low formation latency and also generates an efficient topology for forwarding packets along ad-hoc wireless networks.

  3. Collaboration and E-collaboration

    DEFF Research Database (Denmark)

    Razmerita, Liana; Kirchner, Kathrin

    2015-01-01

    Understanding student’s perception of collaboration and how collaboration is supported by ICT is important for its efficient use in the classroom. This article aims to investigate how students perceive collaboration and how they use new technologies in collaborative group work. Furthermore......, it tries to measure the impact of technology on students’ satisfaction with collaboration outcomes. In particular, the study aims to address the following research questions: Which demographic information (e.g. gender and place of origin) is significant for collaboration and ecollaboration? and Which...... are the perceived factors that influence the students’ group performance? The findings of this study emphasize that there are gender and cultural differences with respect to the perception of e-collaboration. Furthermore, the article summarizes in a model the most significant factors influencing group performance....

  4. Co-location of space geodetic techniques carried out at the Geodetic Observatory Wettzell using a closure in time and a multi-technique reference target

    Science.gov (United States)

    Kodet, J.; Schreiber, K. U.; Eckl, J.; Plötz, C.; Mähler, S.; Schüler, T.; Klügel, T.; Riepl, S.

    2018-01-01

    The quality of the links between the different space geodetic techniques (VLBI, SLR, GNSS and DORIS) is still one of the major limiting factors for the realization of a unique global terrestrial reference frame that is accurate enough to allow the monitoring of the Earth system, i.e., of processes like sea level change, postglacial rebound and silent earthquakes. According to the specifications of the global geodetic observing system of the International Association of Geodesy, such a reference frame should be accurate to 1 mm over decades, with rates of change stable at the level of 0.1 mm/year. The deficiencies arise from inaccurate or incomplete local ties at many fundamental sites as well as from systematic instrumental biases in the individual space geodetic techniques. Frequently repeated surveys, the continuous monitoring of antenna heights and the geometrical mount stability (Lösler et al. in J Geod 90:467-486, 2016. https://doi.org/10.1007/s00190-016-0887-8) have not provided evidence for insufficient antenna stability. Therefore, we have investigated variations in the respective system delays caused by electronic circuits, which is not adequately captured by the calibration process, either because of subtle differences in the circuitry between geodetic measurement and calibration, high temporal variability or because of lacking resolving bandwidth. The measured system delay variations in the electric chain of both VLBI- and SLR systems reach the order of 100 ps, which is equivalent to 3 cm of path length. Most of this variability is usually removed by the calibrations but by far not all. This paper focuses on the development of new technologies and procedures for co-located geodetic instrumentation in order to identify and remove systematic measurement biases within and between the individual measurement techniques. A closed-loop optical time and frequency distribution system and a common inter-technique reference target provide the possibility to remove

  5. Collaborative experience

    DEFF Research Database (Denmark)

    Mortensen, Thomas Bøtker

    -Doerr, 1996) and has been shown to have a positive effect to the outcome of collaborative R&D (Sampson, 2005). Anand & Khanna (2000), furthermore, hypothesized that research joint ventures are more ambiguous than marketing joint ventures and even more the licensing and showed that the effect of collaborative......Literature review: Collaborative experience has been shown to have a positive effect on the collaborative outcome in general (Anand & Khanna, 2000; Kale, Dyer & Singh, 2002). Furthermore, it has been linked to the ability to exploit the network of the firm for learning (Powell, Koput and Smith...... experience was largest the higher the hypothesized ambiguity. Theoretically contribution: This research project aims at contributing to existing literature by arguing, that collaborative experience is a moderating variable which moderates the effects on collaborative outcome from the level of complexity...

  6. A Framework for Speech Enhancement with Ad Hoc Microphone Arrays

    DEFF Research Database (Denmark)

    Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2016-01-01

    Speech enhancement is vital for improved listening practices. Ad hoc microphone arrays are promising assets for this purpose. Most well-established enhancement techniques with conventional arrays can be adapted into ad hoc scenarios. Despite recent efforts to introduce various ad hoc speech...... enhancement apparatus, a common framework for integration of conventional methods into this new scheme is still missing. This paper establishes such an abstraction based on inter and intra sub-array speech coherencies. Along with measures for signal quality at the input of sub-arrays, a measure of coherency...... is proposed both for sub-array selection in local enhancement approaches, and also for selecting a proper global reference when more than one sub-array are used. Proposed methods within this framework are evaluated with regard to quantitative and qualitative measures, including array gains, the speech...

  7. A Clustering Routing Protocol for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Jinke Huang

    2016-01-01

    Full Text Available The dynamic topology of a mobile ad hoc network poses a real challenge in the design of hierarchical routing protocol, which combines proactive with reactive routing protocols and takes advantages of both. And as an essential technique of hierarchical routing protocol, clustering of nodes provides an efficient method of establishing a hierarchical structure in mobile ad hoc networks. In this paper, we designed a novel clustering algorithm and a corresponding hierarchical routing protocol for large-scale mobile ad hoc networks. Each cluster is composed of a cluster head, several cluster gateway nodes, several cluster guest nodes, and other cluster members. The proposed routing protocol uses proactive protocol between nodes within individual clusters and reactive protocol between clusters. Simulation results show that the proposed clustering algorithm and hierarchical routing protocol provide superior performance with several advantages over existing clustering algorithm and routing protocol, respectively.

  8. Multiagent Based Information Dissemination in Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    S.S. Manvi

    2009-01-01

    Full Text Available Vehicular Ad hoc Networks (VANETs are a compelling application of ad hoc networks, because of the potential to access specific context information (e.g. traffic conditions, service updates, route planning and deliver multimedia services (Voice over IP, in-car entertainment, instant messaging, etc.. This paper proposes an agent based information dissemination model for VANETs. A two-tier agent architecture is employed comprising of the following: 1 'lightweight', network-facing, mobile agents; 2 'heavyweight', application-facing, norm-aware agents. The limitations of VANETs lead us to consider a hybrid wireless network architecture that includes Wireless LAN/Cellular and ad hoc networking for analyzing the proposed model. The proposed model provides flexibility, adaptability and maintainability for traffic information dissemination in VANETs as well as supports robust and agile network management. The proposed model has been simulated in various network scenarios to evaluate the effectiveness of the approach.

  9. Auto-configuration protocols in mobile ad hoc networks.

    Science.gov (United States)

    Villalba, Luis Javier García; Matesanz, Julián García; Orozco, Ana Lucila Sandoval; Díaz, José Duván Márquez

    2011-01-01

    The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity.

  10. Effects of Data Replication on Data Exfiltration in Mobile Ad Hoc Networks Utilizing Reactive Protocols

    Science.gov (United States)

    2015-03-01

    aerial vehicle VANET vehicular ad hoc network VoIP Voice over Internet Protocol VRR Virtual Ring Routing xiii EFFECTS OF DATA REPLICATION ON DATA...ad hoc networks in mobile ad hoc networks (MANETs), vehicular ad hoc networks (VANETs), and flying ad hoc net- works (FANETs). Much of the research...metric, such as capacity, congestion , power, or combinations thereof. Caro refers to two different types of ants, FANTs and BANTs which are analogous to

  11. Intelligent Networks Data Fusion Web-based Services for Ad-hoc Integrated WSNs-RFID

    Directory of Open Access Journals (Sweden)

    Falah Alshahrany

    2016-01-01

    Full Text Available The use of variety of data fusion tools and techniques for big data processing poses the problem of the data and information integration called data fusion having objectives which can differ from one application to another. The design of network data fusion systems aimed at meeting these objectives, need to take into account of the necessary synergy that can result from distributed data processing within the data networks and data centres, involving increased computation and communication. This papers reports on how this processing distribution is functionally structured as configurable integrated web-based support services, in the context of an ad-hoc wireless sensor network used for sensing and tracking, in the context of distributed detection based on complete observations to support real rime decision making. The interrelated functional and hardware RFID-WSN integration is an essential aspect of the data fusion framework that focuses on multi-sensor collaboration as an innovative approach to extend the heterogeneity of the devices and sensor nodes of ad-hoc networks generating a huge amount of heterogeneous soft and hard raw data. The deployment and configuration of these networks require data fusion processing that includes network and service management and enhances the performance and reliability of networks data fusion support systems providing intelligent capabilities for real-time control access and fire detection.

  12. Multichannel MAC Layer In Mobile Ad—Hoc Network

    Science.gov (United States)

    Logesh, K.; Rao, Samba Siva

    2010-11-01

    This paper we presented the design objectives and technical challenges in Multichannel MAC protocols in Mobile Ad-hoc Network. In IEEE 802.11 a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. Even though complex environments in ad hoc networks require a combined control of physical (PHY) and medium access control (MAC) layers resources in order to optimize performance. And also we discuss the characteristics of cross-layer frame and give a multichannel MAC approach.

  13. Collaborative Hierarchy.

    Science.gov (United States)

    Maris, Mariann

    The University of Wisconsin-Milwaukee writing program is collaborative, not divisionary, as some, such as Jeanne Gunner, have suggested. Three terms are useful in understanding the relationships and ethics governing operations at Wisconsin-Milwaukee: (1) authority and collaboration; (2) hierarchical difference; (3) professional respect.…

  14. Collaborative Prototyping

    DEFF Research Database (Denmark)

    Bogers, Marcel; Horst, Willem

    2014-01-01

    of the prototyping process, the actual prototype was used as a tool for communication or development, thus serving as a platform for the cross-fertilization of knowledge. In this way, collaborative prototyping leads to a better balance between functionality and usability; it translates usability problems into design......This paper presents an inductive study that shows how collaborative prototyping across functional, hierarchical, and organizational boundaries can improve the overall prototyping process. Our combined action research and case study approach provides new insights into how collaborative prototyping...... can provide a platform for prototype-driven problem solving in early new product development (NPD). Our findings have important implications for how to facilitate multistakeholder collaboration in prototyping and problem solving, and more generally for how to organize collaborative and open innovation...

  15. Ad Hoc Transient Groups: Instruments for Awareness in Learning Networks

    NARCIS (Netherlands)

    Fetter, Sibren; Rajagopal, Kamakshi; Berlanga, Adriana; Sloep, Peter

    2011-01-01

    Fetter, S., Rajagopal, K., Berlanga, A. J., & Sloep, P. B. (2011). Ad Hoc Transient Groups: Instruments for Awareness in Learning Networks. In W. Reinhardt, T. D. Ullmann, P. Scott, V. Pammer, O. Conlan, & A. J. Berlanga (Eds.), Proceedings of the 1st European Workshop on Awareness and Reflection in

  16. Verification of mobile ad hoc networks : an algebraic approach

    NARCIS (Netherlands)

    Ghassemi, F.; Fokkink, W.J.; Movaghar, A.

    2011-01-01

    We introduced Computed Network Process Theory to reason about protocols for mobile ad hoc networks (MANETs). Here we explore the applicability of our framework in two regards: model checking and equational reasoning. The operational semantics of our framework is based on constrained labeled

  17. What Is the Problem of Ad Hoc Hypotheses?

    Science.gov (United States)

    Bamford, Greg

    1999-01-01

    Philosophers' attempts to convincingly explicate the received view of an ad hoc hypothesis--that it accounts for only the observations it was designed to account for--have been unsuccessful. Familiar and firmer criteria for evaluating the hypotheses or modified theories so classified are characteristically available. Contains 41 references.…

  18. Securing DSR with mobile agents in wireless ad hoc networks

    Directory of Open Access Journals (Sweden)

    Ahmed Abosamra

    2011-03-01

    Full Text Available Ad hoc wireless network consists of a set of wireless nodes communicating with each other without a pre-defined infrastructure. They communicate by forwarding packets which can reach wireless nodes that do not exist in the range of the direct radio transmission. Designing ad hoc network routing protocols is a challenging task because of its decentralized infrastructure which makes securing ad hoc networks more and more challenging. Dynamic Source Routing (DSR protocol is a popular routing protocol designed for use in wireless ad hoc networks. Mobile agent is a promising technology used in diverse fields of network applications. In this paper, we try to implement DSR using mobile agents for securing this type of wireless network. Hybrid encryption technique (symmetric key encryption/public key encryption is used to improve performance; where symmetric keys are used to encrypt routing data to authenticate and authorize node sending data, while, public keys are used for the exchange of symmetric keys between nodes. We found that DSR may be secured using mobile agents with competitive performance.

  19. ON SECURE FULL DUPLEX COMMUNICATION IN MOBILE AD HOC NETWORK

    OpenAIRE

    S. C. Dutta; Sudha Singh; D. K. Singh

    2013-01-01

    This paper is to establish Ad Hoc network in mobile phones and start fully secured full duplex communication in any situation. This type of communication will be cost effective and it will be fastest way of communication in case of any server failure or server error.

  20. The accuracy of interpreting key psychiatric terms by ad hoc ...

    African Journals Online (AJOL)

    MacFarlane et al.15 note that a greater number of people have a preference for working with ad hoc interpreters in comparison to professional interpreters ... As part of a larger study, a cross-sectional qualitative interview design was used to ..... obstacle they would face if they would receive training. They had concerns over ...

  1. Authentication and consensus overhead in vehicular ad hoc networks

    NARCIS (Netherlands)

    Petit, Jonathan; Mammeri, Zoubir

    Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages between vehicles wirelessly. A main challenge is to resist to various malicious abuses and security attacks. However, any security mechanism comes with overhead. We analyze how the authentication algorithm

  2. Challenges of evidence acquisition in wireless ad-hoc networks

    CSIR Research Space (South Africa)

    Mutanga, MB

    2010-05-01

    Full Text Available a big challenge. Thus, the aim of this paper is to explore the challenges of acquiring live evidence in wireless ad-hoc networks. We also give some legal requirements of evidence admissibility as outlined in the Communications and Transactions Act...

  3. Analysis of Pervasive Mobile Ad Hoc Routing Protocols

    Science.gov (United States)

    Qadri, Nadia N.; Liotta, Antonio

    Mobile ad hoc networks (MANETs) are a fundamental element of pervasive networks and therefore, of pervasive systems that truly support pervasive computing, where user can communicate anywhere, anytime and on-the-fly. In fact, future advances in pervasive computing rely on advancements in mobile communication, which includes both infrastructure-based wireless networks and non-infrastructure-based MANETs. MANETs introduce a new communication paradigm, which does not require a fixed infrastructure - they rely on wireless terminals for routing and transport services. Due to highly dynamic topology, absence of established infrastructure for centralized administration, bandwidth constrained wireless links, and limited resources in MANETs, it is challenging to design an efficient and reliable routing protocol. This chapter reviews the key studies carried out so far on the performance of mobile ad hoc routing protocols. We discuss performance issues and metrics required for the evaluation of ad hoc routing protocols. This leads to a survey of existing work, which captures the performance of ad hoc routing algorithms and their behaviour from different perspectives and highlights avenues for future research.

  4. VMQL: A Visual Language for Ad-Hoc Model Querying

    DEFF Research Database (Denmark)

    Störrle, Harald

    2011-01-01

    In large scale model based development, analysis level models are more like knowledge bases than engineering artifacts. Their effectiveness depends, to a large degree, on the ability of domain experts to retrieve information from them ad hoc. For large scale models, however, existing query...

  5. Ad Hoc Physical Hilbert Spaces in Quantum Mechanics

    Czech Academy of Sciences Publication Activity Database

    Fernandez, F. M.; Garcia, J.; Semorádová, Iveta; Znojil, Miloslav

    2015-01-01

    Roč. 54, č. 12 (2015), s. 4187-4203 ISSN 0020-7748 Institutional support: RVO:61389005 Keywords : quantum mechanics * physical Hilbert spaces * ad hoc inner product * singular potentials regularized * low lying energies Subject RIV: BE - Theoretical Physics Impact factor: 1.041, year: 2015

  6. TMAP ad hoc Working Group Fish Progress report 2007

    NARCIS (Netherlands)

    Bolle, L.J.; Damm, U.; Diederichs, B.; Jager, Z.; Overzee, van H.M.J.

    2007-01-01

    Building on previous work done by the TMAP ad hoc Working Group Fish, a meeting and a workshop were held in Hamburg in June and October 2007. The most important aim of both was to come to an agreement on how to proceed with the data preparations and analyses, and to facilitate the exchange of data

  7. Node counting in wireless ad-hoc networks

    NARCIS (Netherlands)

    Evers, J.H.M.; Kiss, D.; Kowalczyk, W.; Navilarekallu, T.; Renger, D.R.M.; Sella, L.; Timperio, V.; Viorel, A.; Wijk, van A.C.C.; Yzelman, A.J.; Planqué, B.; Bhulai, S.; Hulshof, J.; Kager, W.; Rot, T.

    2012-01-01

    We study wireless ad-hoc networks consisting of small microprocessors with limited memory, where the wireless communication between the processors can be highly unreliable. For this setting, we propose a number of algorithms to estimate the number of nodes in the network, and the number of direct

  8. Capacity, delay and mobility in wireless ad-hoc networks

    NARCIS (Netherlands)

    Bansal, N.; Liu, Z.

    2003-01-01

    Network throughput and packet delay are two important parameters in the design and the evaluation of routing protocols for ad-hoc networks. While mobility has been shown to increase the capacity of a network, it is not clear whether the delay can be kept low without trading off the throughput. We

  9. Access Point Security Service for wireless ad-hoc communication

    NARCIS (Netherlands)

    Scholten, Johan; Nijdam, M.

    2006-01-01

    This paper describes the design and implementation of a security solution for ad-hoc peer-to-peer communication. The security solution is based on a scenario where two wireless devices require secure communication, but share no security relationship a priori. The necessary requirements for the

  10. Modelling Mobility in Mobile AD-HOC Network Environments ...

    African Journals Online (AJOL)

    In the simulation of mobile ad-hoc networks (MANETs), the probability distribution governing the movement of nodes typically varies over time and converges to a steady state distribution, known as the stationary distribution. This paper presents and evaluates the stationary distribution for location, speed and pause time of a ...

  11. Dynamic Mobile IP routers in ad hoc networks

    NARCIS (Netherlands)

    Kock, B.A.; Schmidt, J.R.

    2005-01-01

    This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

  12. Infrastructure Support for Collaborative Pervasive Computing Systems

    DEFF Research Database (Denmark)

    Vestergaard Mogensen, Martin

    Collaborative Pervasive Computing Systems (CPCS) are currently being deployed to support areas such as clinical work, emergency situations, education, ad-hoc meetings, and other areas involving information sharing and collaboration.These systems allow the users to work together synchronously......, but from different places, by sharing information and coordinating activities. Several researchers have shown the value of such distributed collaborative systems. However, building these systems is by no means a trivial task and introduces a lot of yet unanswered questions. The aforementioned areas......, are all characterized by unstable, volatile environments, either due to the underlying components changing or the nomadic work habits of users. A major challenge, for the creators of collaborative pervasive computing systems, is the construction of infrastructures supporting the system. The complexity...

  13. Collaborative Consumption

    DEFF Research Database (Denmark)

    Gjerdrum Pedersen, Esben Rahbek; Netter, Sarah

    2015-01-01

    Purpose – The purpose of this paper is to explore barriers and opportunities for business models based on the ideas of collaborative consumption within the fashion industry. Design/methodology/approach – The analysis is based on a multiple-case study of Scandinavian fashion libraries – a new...... to the new phenomenon of fashion libraries and does not cover other types of collaborative consumption within the fashion industry (Swap-parties, etc.). Originality/value – The paper is one of the first attempts to examine new business models of collaborative consumption in general and the fashion library...... concept in particular. The study contributes to the discussions of whether and how fashion sharing and collaboration holds promise as a viable business model and as a means to promote sustainability....

  14. Collaborative Consumption

    DEFF Research Database (Denmark)

    Gjerdrum Pedersen, Esben Rahbek; Netter, Sarah

    Purpose: The purpose of this paper is to explore barriers and opportunities for business models based on the ideas of collaborative consumption within the fashion industry. Design/methodology/approach: The analysis is based on a multiple-­‐‑case study of Scandinavian fashion libraries – a new...... to the new phenomenon of fashion libraries and does not cover other types of collaborative consumption within the fashion industry (Swap-­‐‑parties, etc.). Originality/value: The paper is one of the first attempts to examine new business models of collaborative consumption in general and the fashion library...... concept in particular. The study contributes to the discussions of whether and how fashion sharing and collaboration holds promise as a viable business model and as a means to promote sustainability....

  15. Stakeholder Engagement: Ensuring Confidence in the Regulatory Decision of a Possible Co-Located Low Level Waste (LLW) Disposal and Intermediate Level Waste (ILW) Storage Facility in Australia

    International Nuclear Information System (INIS)

    Murray, Julie

    2016-01-01

    Stakeholder Engagement Strategy and Plan: 1. Explicitly state your OBJECTIVE! I.“Strengthen and sustain stakeholder trust …..”; II.Independence, capability and evidence-based approach. 2. Important to get the tone and preferred mode of engagement right … from the start. I. Collaboration mode: I. Person-to-Person; II. One-to-One; III. Small Groups. 3. Executed and managed over a sustained period of time; I.The plan MUST be amenable! 4. The 6 Pillars strategy (1. Position APANSA as the peoples' expert; 2. Engage all Tier One stakeholders person-to-person; 3. Generate content that is understood readily; 4. Provide information openly; 5. Create awareness; 6. Involve stateholders) of the engagement and plan and engagement activities.

  16. Proposal of interference reduction routing for ad-hoc networks

    Directory of Open Access Journals (Sweden)

    Katsuhiro Naito

    2010-10-01

    Full Text Available In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

  17. Energy management in wireless cellular and ad-hoc networks

    CERN Document Server

    Imran, Muhammad; Qaraqe, Khalid; Alouini, Mohamed-Slim; Vasilakos, Athanasios

    2016-01-01

    This book investigates energy management approaches for energy efficient or energy-centric system design and architecture and presents end-to-end energy management in the recent heterogeneous-type wireless network medium. It also considers energy management in wireless sensor and mesh networks by exploiting energy efficient transmission techniques and protocols. and explores energy management in emerging applications, services and engineering to be facilitated with 5G networks such as WBANs, VANETS and Cognitive networks. A special focus of the book is on the examination of the energy management practices in emerging wireless cellular and ad hoc networks. Considering the broad scope of energy management in wireless cellular and ad hoc networks, this book is organized into six sections covering range of Energy efficient systems and architectures; Energy efficient transmission and techniques; Energy efficient applications and services. .

  18. Secure Geographic Routing in Ad Hoc and Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zahariadis Theodore

    2010-01-01

    Full Text Available Security in sensor networks is one of the most relevant research topics in resource constrained wireless devices and networks. Several attacks can be suffered in ad hoc and wireless sensor networks (WSN, which are highly susceptible to attacks, due to the limited resources of the nodes. In this paper, we propose innovative and lightweight localization techniques that allow for intrusion identification and isolation schemes and provide accurate location information. This information is used by our routing protocol which additionally incorporates a distributed trust model to prevent several routing attacks to the network. We finally evaluate our algorithms for accurate localization and for secure routing which have been implemented and tested in real ad hoc and wireless sensor networks.

  19. Cognitive radio application for vehicular ad hoc networks (VANETS

    Directory of Open Access Journals (Sweden)

    Miladić Suzana D.

    2016-01-01

    Full Text Available This paper presents the application of cognitive radio technology in vehicular ad-hoc networks aimed to improve the communications between vehicles themselves as well as between vehicles and roadside infrastructure. Due to dynamic approach of spectrum access, cognitive radio is a technology that enables more efficient usage of radio-frequency spectrum. We review actual approaches and discuss research challenges related to the use of cognitive radio technology in vehicular ad hoc networks with emphasis on architecture, spectrum management as well as QoS optimization. The researching on cognitive radio application in vehicular networks is still developing and there are not many experimental platforms due to their complex setups. Some related research projects and cognitive radio realizations are provided in this paper.

  20. A framework for reactive optimization in mobile ad hoc networks

    DEFF Research Database (Denmark)

    McClary, Dan; Syrotiuk, Violet; Kulahci, Murat

    2008-01-01

    We present a framework to optimize the performance of a mobile ad hoc network over a wide range of operating conditions. It includes screening experiments to quantify the parameters and interactions among parameters influential to throughput. Profile-driven regression is applied to obtain a model....... The predictive accuracy of the model is monitored and used to update the model dynamically. The results indicate the framework may be useful for the optimization of dynamic systems of high dimension....

  1. Power control algorithms for mobile ad hoc networks

    Directory of Open Access Journals (Sweden)

    Nuraj L. Pradhan

    2011-07-01

    We will also focus on an adaptive distributed power management (DISPOW algorithm as an example of the multi-parameter optimization approach which manages the transmit power of nodes in a wireless ad hoc network to preserve network connectivity and cooperatively reduce interference. We will show that the algorithm in a distributed manner builds a unique stable network topology tailored to its surrounding node density and propagation environment over random topologies in a dynamic mobile wireless channel.

  2. A Survey on Trust Management for Mobile Ad Hoc Networks

    Science.gov (United States)

    2011-11-01

    expects, trust is dangerous implying the possible betrayal of trust. In his comments on Lagerspetz’s book titled Trust: The Tacit Demand, Lahno [24...AODV Zouridaki et al. (2005 ) [79] (2006) [80] Secure routing Direct observation [79][80] Reputation by secondhand information [80] Packet dropping...areas of signal processing, wireless communications, sensor and mobile ad hoc networks. He is co-editor of the book Wireless Sensor Networks: Signal

  3. Decentralized session initiation protocol solution in ad hoc networks

    Science.gov (United States)

    Han, Lu; Jin, Zhigang; Shu, Yantai; Dong, Linfang

    2006-10-01

    With the fast development of ad hoc networks, SIP has attracted more and more attention in multimedia service. This paper proposes a new architecture to provide SIP service for ad hoc users, although there is no centralized SIP server deployed. In this solution, we provide the SIP service by the introduction of two nodes: Designated SIP Server (DS) and its Backup Server (BDS). The nodes of ad hoc network designate DS and BDS when they join the session nodes set and when some pre-defined events occur. A new sip message type called REGISTRAR is presented so nodes can send others REGISTRAR message to declare they want to be DS. According to the IP information taken in the message, an algorithm works like the election of DR and BDR in OSPF protocol is used to vote DS and BDS SIP servers. Naturally, the DS will be replaced by BDS when the DS is down for predicable or unpredictable reasons. To facilitate this, the DS should register to the BDS and transfer a backup of the SIP users' database. Considering the possibility DS or BDS may abruptly go down, a special policy is given. When there is no DS and BDS, a new election procedure is triggered just like the startup phase. The paper also describes how SIP works normally in the decentralized model as well as the evaluation of its performance. All sessions based on SIP in ad hoc such as DS voting have been tested in the real experiments within a 500m*500m square area where about 30 random nodes are placed.

  4. Ad hoc Sensor Networks to Support Maritime Interdiction Operations

    OpenAIRE

    Osmundson, John; Bordetsky, Alex

    2014-01-01

    Networking sensors, decision centers, and boarding parties supports success in Maritime Interdiction Operations. Led by a team from Naval Post-graduate School (NPS), experiments were conducted in 2012 to test the use of ad-hoc, self-forming communication networks to link sensors, people, and decision centers. The experiments involved international participants and successfully shared valuable biometric and radiological sensor data between boarding parties and decis...

  5. Interference in wireless ad hoc networks with smart antennas

    KAUST Repository

    Alabdulmohsin, Ibrahim

    2014-08-01

    In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical and virtual carrier sense networks, which reveals counter-intuitively that receivers in large dense networks with directional antennas can experience larger interference than in omnidirectional networks unless the beamwidth is sufficiently small. Validity of mathematical analysis is confirmed using simulations.

  6. Report of the Ad Hoc Committee on SSC physics

    International Nuclear Information System (INIS)

    1990-04-01

    The Ad Hoc Committee on SSC Physics has reexamined the relationship between beam energy, machine luminosity, and physics capability. In the next section, the physics motivation for the SSC is reviewed in general terms. This is followed by a discussion of the ability to detect a number of specific processes as a function of the SSC energy and luminosity. The viability of various detector technologies is then assessed as a function of luminosity. The report ends with a brief summary and some conclusions

  7. MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

    Science.gov (United States)

    Elizarraras, Omar; Panduro, Marco; Méndez, Aldo L.

    2014-01-01

    The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput. PMID:25140339

  8. MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Omar Elizarraras

    2014-01-01

    Full Text Available The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15% compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput.

  9. Recent development in wireless sensor and ad-hoc networks

    CERN Document Server

    Li, Xiaolong; Yang, Yeon-Mo

    2015-01-01

    Wireless Sensor Network (WSN) consists of numerous physically distributed autonomous devices used for sensing and monitoring the physical and/or environmental conditions. A WSN uses a gateway that provides wireless connectivity to the wired world as well as distributed networks. There are many open problems related to Ad-Hoc networks and its applications. Looking at the expansion of the cellular infrastructure, Ad-Hoc network may be acting as the basis of the 4th generation wireless technology with the new paradigm of ‘anytime, anywhere communications’. To realize this, the real challenge would be the security, authorization and management issues of the large scale WSNs. This book is an edited volume in the broad area of WSNs. The book covers various chapters like Multi-Channel Wireless Sensor Networks, its Coverage, Connectivity as well as Deployment. It covers comparison of various communication protocols and algorithms such as MANNET, ODMRP and ADMR Protocols for Ad hoc Multicasting, Location Based C...

  10. Auto-Configuration Protocols in Mobile Ad Hoc Networks

    Science.gov (United States)

    Villalba, Luis Javier García; Matesanz, Julián García; Orozco, Ana Lucila Sandoval; Díaz, José Duván Márquez

    2011-01-01

    The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity. PMID:22163814

  11. MWAHCA: a multimedia wireless ad hoc cluster architecture.

    Science.gov (United States)

    Diaz, Juan R; Lloret, Jaime; Jimenez, Jose M; Sendra, Sandra

    2014-01-01

    Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node's capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss). The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.

  12. MWAHCA: A Multimedia Wireless Ad Hoc Cluster Architecture

    Directory of Open Access Journals (Sweden)

    Juan R. Diaz

    2014-01-01

    Full Text Available Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node’s capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss. The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.

  13. Collaborative Economy

    DEFF Research Database (Denmark)

    things, de-industrialization processes and post-capitalist forms of production and consumption, postmaterialism, the rise of the third sector and collaborative governance. Addressing that gap, this book explores the character, depth and breadth of these disruptions, the creative opportunities for tourism...... that are emerging from them, and how governments are responding to these new challenges. In doing so, the book provides both theoretical and practical insights into the future of tourism in a world that is, paradoxically, becoming both increasingly collaborative and individualized. Table of Contents Preface 1.The......This book employs an interdisciplinary, cross-sectoral lens to explore the collaborative dynamics that are currently disrupting, re-creating and transforming the production and consumption of tourism. House swapping, ridesharing, voluntourism, couchsurfing, dinner hosting, social enterprise...

  14. Collaborative Improvement

    DEFF Research Database (Denmark)

    Kaltoft, Rasmus

    The thesis data have been collected in the EU-sponsored project: Collaborative Improvement Tool for the Extended Manufacturing Enterprise, CO-IMPROVE. In this project four universities (Denmark, Ireland, Italy, and The Netherlands), two software vendors (Greece and Sweden) and three companies...... (Denmark, Italy and The Netherlands) each with three to five suppliers were involved. The CO-IMPROVE project and the thesis is based on “action research” and “action learning”. The main aim of the whole project is through actual involvement and actions make the researchers, companies and selected suppliers...... learn how to improve operations in (hopefully) a win-win like manner through collaboration....

  15. Collaborative Improvement

    DEFF Research Database (Denmark)

    Kaltoft, Rasmus

    -organisational continuous improvement of their performance, relative to that of other EMEs. Developing a collaborative improvement relationship between companies is a protracted and complex process and, according to some surveys, the failure rate is as low as one to three. This failure rate is affected by a whole range...... of factors. The research presented in this thesis was aimed at identifying these factors and investigating their interplay and influence on the progress and success of the development of the collaborative improvement. This thesis presents our findings regarding the factors found, their interplay...

  16. Contested collaboration

    DEFF Research Database (Denmark)

    Sonnenwald, Diane H.

    1995-01-01

    . The model describes design phases, roles, themes, and intergroup communication networks as they evolve throughout the design process and characterizes design as a process of "contested collaboration". It is a first step towards a predictive design model that suggests strategies which may help participants...

  17. Timeline Collaboration

    DEFF Research Database (Denmark)

    Bohøj, Morten; Borchorst, Nikolaj Gandrup; Bouvin, Niels Olof

    2010-01-01

    This paper explores timelines as a web-based tool for collaboration between citizens and municipal caseworkers. The paper takes its outset in a case study of planning and control of parental leave; a process that may involve surprisingly many actors. As part of the case study, a web-based timeline...

  18. Collaborative Appropriation

    DEFF Research Database (Denmark)

    Muller, Michael; Neureiter, Katja; Verdezoto, Nervo

    2016-01-01

    Previous workshops and papers have examined how individual users adopt and adapt technologies to meet their own local needs, by “completing design through use.” However, there has been little systematic study of how groups of people engage collaboratively in these activities. This workshop opens ...

  19. Collaborative Design

    Science.gov (United States)

    Broderick, Debora

    2014-01-01

    This practitioner research study investigates the power of multimodal texts within a real-world context and argues that a participatory culture focused on literary arts offers marginalized high school students opportunities for collaborative design and authoring. Additionally, this article invites educators to rethink the at-risk label. This…

  20. Implementation of a geological disposal facility (GDF) in the UK by the NDA Radioactive Waste Management Directorate (RWMD): the potential for interaction between the co-located ILW/LLW and HLW/SF components of a GDF - 16306

    International Nuclear Information System (INIS)

    Towler, George; Hicks, Tim; Watson, Sarah; Norris, Simon

    2009-01-01

    In June 2008 the UK government published a 'White Paper' as part of the 'Managing Radioactive Waste Safety' (MRWS) programme to provide a framework for managing higher activity radioactive wastes in the long-term through geological disposal. The White Paper identifies that there are benefits to disposing all of the UK's higher activity wastes (Low and Intermediate Level Waste (LLW and ILW), High Level Waste (HLW), Spent Fuel (SF), Uranium (U) and Plutonium (Pu)) at the same site, and this is currently the preferred option. It also notes that research will be required to support the detailed design and safety assessment in relation to any potentially detrimental interactions between the different modules. Different disposal system designs and associated Engineered Barrier Systems (EBS) will be required for these different waste types, i.e. ILW/LLW and HLW/SF. If declared as waste U would be disposed as ILW and Pu as HLW/SF. The Geological Disposal Facility (GDF) would therefore comprise two co-located modules (respectively for ILW/LLW and HLW/SF). This paper presents an overview of a study undertaken to assess the implications of co-location by identifying the key Thermo-Hydro-Mechanical-Chemical (THMC) interactions that might occur during both the operational and post-closure phases, and their consequences for GDF design, performance and safety. The MRWS programme is currently seeking expressions of interest from communities to host a GDF. Therefore, the study was required to consider a wide range of potential GDF host rocks and consistent, conceptual disposal system designs. Two example disposal concepts (i.e. combinations of host rock, GDF design including wasteform and layout, etc.) were carried forward for detailed assessment and a third for qualitative analysis. Dimensional and 1D analyses were used to identify the key interactions, and 3D models were used to investigate selected interactions in more detail. The results of this study show that it is possible

  1. Digital Hive Project: Prototyping a Collaborative Web Portal for the Explosive Ordnance Disposal Community

    Science.gov (United States)

    2014-06-01

    25 Ibid. 26 Mark Tovey, “Mass Collaboration, Open Source, and Social Entrepreneurship ,” in Collective Intelligence: Creating a Prosperous World at...Eduardo Salas and Stephen M. Fiore (Washington, DC: American Psychological Association, 2004), 108. 48 Alex Pukinskis, “Co-located Teams,” in Agile...dominated media where only consumption is possible. As a naturally occurring byproduct of human psychology , people have always held a desire to

  2. Distributed optimization of a multisubchannel Ad Hoc cognitive radio network

    KAUST Repository

    Leith, Alex

    2012-05-01

    In this paper, we study the distributed-duality-based optimization of a multisubchannel ad hoc cognitive radio network (CRN) that coexists with a multicell primary radio network (PRN). For radio resource allocation in multiuser orthogonal frequency-division multiplexing (MU-OFDM) systems, the orthogonal-access-based exclusive subchannel assignment (ESA) technique has been a popular method, but it is suboptimal in ad hoc networks, because nonorthogonal access between multiple secondary-user links by using shared subchannel assignment (SSA) can bring a higher weighted sum rate. We utilize the Lagrangian dual composition tool and design low-complexity near-optimal SSA resource allocation methods, assuming practical discrete-rate modulation and that the CRN-to-PRN interference constraint has to strictly be satisfied. However, available SSA methods for CRNs are either suboptimal or involve high complexity and suffer from slow convergence. To address this problem, we design fast-convergence SSA duality schemes and introduce several novel methods to increase the speed of convergence and to satisfy various system constraints with low complexity. For practical implementation in ad hoc CRNs, we design distributed-duality schemes that involve only a small number of CRN local information exchanges for dual update. The effects of many system parameters are presented through simulation results, which show that the near-optimal SSA duality scheme can perform significantly better than the suboptimal ESA duality and SSA-iterative waterfilling schemes and that the performance loss of the distributed schemes is small, compared with their centralized counterparts. © 2012 IEEE.

  3. Studies on urban vehicular ad-hoc networks

    CERN Document Server

    Zhu, Hongzi

    2013-01-01

    With the advancement of wireless technology, vehicular ad hoc networks (VANETs) are emerging as a promising approach to realizing 'smart cities' and addressing many important transportation problems such as road safety, efficiency, and convenience.This brief provides an introduction to the large trace data set collected from thousands of taxis and buses in Shanghai, the largest metropolis in China. It also presents the challenges, design issues, performance modeling and evaluation of a wide spectrum of VANET research topics, ranging from realistic vehicular mobility models and opportunistic ro

  4. Throughput Capacity of Ad Hoc Networks with Route Discovery

    Directory of Open Access Journals (Sweden)

    Blum Rick S

    2007-01-01

    Full Text Available Throughput capacity of large ad hoc networks has been shown to scale adversely with the size of network . However the need for the nodes to find or repair routes has not been analyzed in this context. In this paper, we explicitly take route discovery into account and obtain the scaling law for the throughput capacity under general assumptions on the network environment, node behavior, and the quality of route discovery algorithms. We also discuss a number of possible scenarios and show that the need for route discovery may change the scaling for the throughput capacity.

  5. Wireless ad hoc and sensor networks management, performance, and applications

    CERN Document Server

    He, Jing

    2013-01-01

    Although wireless sensor networks (WSNs) have been employed across a wide range of applications, there are very few books that emphasize the algorithm description, performance analysis, and applications of network management techniques in WSNs. Filling this need, Wireless Ad Hoc and Sensor Networks: Management, Performance, and Applications summarizes not only traditional and classical network management techniques, but also state-of-the-art techniques in this area. The articles presented are expository, but scholarly in nature, including the appropriate history background, a review of current

  6. Power-Aware Intrusion Detection in Mobile Ad Hoc Networks

    Science.gov (United States)

    Şen, Sevil; Clark, John A.; Tapiador, Juan E.

    Mobile ad hoc networks (MANETs) are a highly promising new form of networking. However they are more vulnerable to attacks than wired networks. In addition, conventional intrusion detection systems (IDS) are ineffective and inefficient for highly dynamic and resource-constrained environments. Achieving an effective operational MANET requires tradeoffs to be made between functional and non-functional criteria. In this paper we show how Genetic Programming (GP) together with a Multi-Objective Evolutionary Algorithm (MOEA) can be used to synthesise intrusion detection programs that make optimal tradeoffs between security criteria and the power they consume.

  7. Mobile ad hoc networking the cutting edge directions

    CERN Document Server

    Basagni, Stefano; Giordano, Silvia; Stojmenovic, Ivan

    2013-01-01

    ""An excellent book for those who are interested in learning the current status of research and development . . . [and] who want to get a comprehensive overview of the current state-of-the-art.""-E-Streams This book provides up-to-date information on research and development in the rapidly growing area of networks based on the multihop ad hoc networking paradigm. It reviews all classes of networks that have successfully adopted this paradigm, pointing out how they penetrated the mass market and sparked breakthrough research. Covering both physical issues and applica

  8. Ad-Hoc vs. Standardized and Optimized Arthropod Diversity Sampling

    Directory of Open Access Journals (Sweden)

    Pedro Cardoso

    2009-09-01

    Full Text Available The use of standardized and optimized protocols has been recently advocated for different arthropod taxa instead of ad-hoc sampling or sampling with protocols defined on a case-by-case basis. We present a comparison of both sampling approaches applied for spiders in a natural area of Portugal. Tests were made to their efficiency, over-collection of common species, singletons proportions, species abundance distributions, average specimen size, average taxonomic distinctness and behavior of richness estimators. The standardized protocol revealed three main advantages: (1 higher efficiency; (2 more reliable estimations of true richness; and (3 meaningful comparisons between undersampled areas.

  9. Mobile agents affect worm spreading in wireless ad hoc networks

    International Nuclear Information System (INIS)

    Huang, Zi-Gang; Sun, Jin-Tu; Wang, Ying-Hai; Wang, Sheng-Jun; Xu, Xin-Jian

    2009-01-01

    Considering the dynamic nature of portable computing devices with wireless communication capability, an extended model is introduced for worm spreading in the wireless ad hoc network, with a population of mobile agents in a planar distribution, starting from an initial infected seed. The effect of agents' mobility on worm spreading is investigated via extensive Monte Carlo simulations. The threshold behavior and the dynamics of worm epidemics in the wireless networks are greatly affected by both agents' mobility and spatial and temporal correlations. The medium access control mechanism for the wireless communication promotes the sensitivity of the spreading dynamics to agents' mobility

  10. Collaborative Consumption

    OpenAIRE

    Rahbek Gjerdrum Pedersen, Esben; Netter, Sarah

    2013-01-01

    Purpose: The purpose of this paper is to explore barriers and opportunities for business models based on the ideas of collaborative consumption within the fashion industry. Design/methodology/approach: The analysis is based on a multiple-­‐‑case study of Scandinavian fashion libraries – a new, clothes-­‐‑sharing concept that has emerged as a fashion niche within the last decade. Findings: It is concluded that fashion libraries offers interesting perspectives, e.g. by allow...

  11. Collaborative sketching

    DEFF Research Database (Denmark)

    Johansson, Martin Wetterstrand

    2006-01-01

    Sketching is a most central activity with in most design projects. But what happens if we adopt the ideas of collaborative design and invite participants that are not trained to sketch in to the design process, how can they participate in this central activity? This paper offers an introduction to...... the design material has been used to co- author possible futures within the scope of design sessions....

  12. Energy Efficient Probabilistic Broadcasting for Mobile Ad-Hoc Network

    Science.gov (United States)

    Kumar, Sumit; Mehfuz, Shabana

    2017-06-01

    In mobile ad-hoc network (MANETs) flooding method is used for broadcasting route request (RREQ) packet from one node to another node for route discovery. This is the simplest method of broadcasting of RREQ packets but it often results in broadcast storm problem, originating collisions and congestion of packets in the network. A probabilistic broadcasting is one of the widely used broadcasting scheme for route discovery in MANETs and provides solution for broadcasting storm problem. But it does not consider limited energy of the battery of the nodes. In this paper, a new energy efficient probabilistic broadcasting (EEPB) is proposed in which probability of broadcasting RREQs is calculated with respect to remaining energy of nodes. The analysis of simulation results clearly indicate that an EEPB route discovery scheme in ad-hoc on demand distance vector (AODV) can increase the network lifetime with a decrease in the average power consumption and RREQ packet overhead. It also decreases the number of dropped packets in the network, in comparison to other EEPB schemes like energy constraint gossip (ECG), energy aware gossip (EAG), energy based gossip (EBG) and network lifetime through energy efficient broadcast gossip (NEBG).

  13. Taxonomic and ad hoc categorization within the two cerebral hemispheres.

    Science.gov (United States)

    Shen, Yeshayahu; Aharoni, Bat-El; Mashal, Nira

    2015-01-01

    A typicality effect refers to categorization which is performed more quickly or more accurately for typical than for atypical members of a given category. Previous studies reported a typicality effect for category members presented in the left visual field/right hemisphere (RH), suggesting that the RH applies a similarity-based categorization strategy. However, findings regarding the typicality effect within the left hemisphere (LH) are less conclusive. The current study tested the pattern of typicality effects within each hemisphere for both taxonomic and ad hoc categories, using words presented to the left or right visual fields. Experiment 1 tested typical and atypical members of taxonomic categories as well as non-members, and Experiment 2 tested typical and atypical members of ad hoc categories as well as non-members. The results revealed a typicality effect in both hemispheres and in both types of categories. Furthermore, the RH categorized atypical stimuli more accurately than did the LH. Our findings suggest that both hemispheres rely on a similarity-based categorization strategy, but the coarse semantic coding of the RH seems to facilitate the categorization of atypical members.

  14. A Novel Routing Algorithm for Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Raúl Aquino Santos

    2008-01-01

    Full Text Available Este trabajo examina la importancia de las redes inalámbricas ad hoc y el algoritmo de enrutamiento con inundación basada en grupos (LORA-CBF para la comunicación inter-vehicular con la finalidad de optimizar el flujo de tráfico e incrementar la seguridad en las autopistas. Se discute el algoritmo de enrutamiento LORA-CBF y se presentan los resultados de simulaciones realizadas en OPNET de una autopista con alta movilidad vehicular. Primero, el modelo de simulación propuesto se valida a pequeña escala con resultados experimentales. Posteriormente, se emplean simulaciones de nuestro modelo comparándolos con Ad Hoc On-Demand Distance Vector (AODV y Dynamic Source Routing (DSR. Finalmente, se emplea un modelo de tráfico microscópico desarrollado en OPNET para simular la movilidad de 250 vehículos en una autopista y se aplica el algoritmo de enrutamiento LORA-CBF en un escenario vehicular.

  15. Minimizing Broadcast Expenses in Clustered Ad-hoc Networks

    Directory of Open Access Journals (Sweden)

    S. Zeeshan Hussain

    2018-01-01

    Full Text Available One way to minimize the broadcast expenses of routing protocols is to cluster the network. In clustered ad-hoc networks, all resources can be managed easily by resolving scalability issues. However, blind query broadcast is a major issue that leads to the broadcast storm problem in clustered ad-hoc networks. This query broadcast is done to carry out the route-search task that leads to the unnecessary propagation of route-query even after route has been found. Hence, this query propagation poses the problem of congestion in the network. In particular this motivates us to propose a query-control technique in such networks which works based on broadcast repealing. A huge amount of work has been devoted to propose the query control broadcasting techniques. However, such techniques used in traditional broadcasting mechanisms need to be properly extended for use in the cluster based routing architecture. In this paper, query-control technique is proposed for cluster based routing technique to reduce the broadcast expenses. Finally, we report some experiments which compare the proposed technique to other commonly used techniques including standard one-class AODV that follows TTL-sequence based broadcasting technique.

  16. LAMAN: Load Adaptable MAC for Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Realp Marc

    2005-01-01

    Full Text Available In mobile ad hoc radio networks, mechanisms on how to access the radio channel are extremely important in order to improve network efficiency. In this paper, the load adaptable medium access control for ad hoc networks (LAMAN protocol is described. LAMAN is a novel decentralized multipacket MAC protocol designed following a cross-layer approach. Basically, this protocol is a hybrid CDMA-TDMA-based protocol that aims at throughput maximization in multipacket communication environments by efficiently combining contention and conflict-free protocol components. Such combination of components is used to adapt the nodes' access priority to changes on the traffic load while, at the same time, accounting for the multipacket reception (MPR capability of the receivers. A theoretical analysis of the system is developed presenting closed expressions of network throughput and packet delay. By simulations the validity of our analysis is shown and the performances of a LAMAN-based system and an Aloha-CDMA-based one are compared.

  17. Autonomous Power Control MAC Protocol for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Battery energy limitation has become a performance bottleneck for mobile ad hoc networks. IEEE 802.11 has been adopted as the current standard MAC protocol for ad hoc networks. However, it was developed without considering energy efficiency. To solve this problem, many modifications on IEEE 802.11 to incorporate power control have been proposed in the literature. The main idea of these power control schemes is to use a maximum possible power level for transmitting RTS/CTS and the lowest acceptable power for sending DATA/ACK. However, these schemes may degrade network throughput and reduce the overall energy efficiency of the network. This paper proposes autonomous power control MAC protocol (APCMP, which allows mobile nodes dynamically adjusting power level for transmitting DATA/ACK according to the distances between the transmitter and its neighbors. In addition, the power level for transmitting RTS/CTS is also adjustable according to the power level for DATA/ACK packets. In this paper, the performance of APCMP protocol is evaluated by simulation and is compared with that of other protocols.

  18. Collaborative Care

    OpenAIRE

    Schuyler, Dean

    2005-01-01

    本書を著したHornbyは英国のソーシャルワーカーである。彼女は1983年に「Collaboration in social work(Journal of social work practice,1.1)」を発表し、ソーシャルワークでの職種間の連携の重要性について報告している。さらに1993年に発刊した本書では、同一機関内の人間関係 ...

  19. Intelligent routing protocol for ad hoc wireless network

    Science.gov (United States)

    Peng, Chaorong; Chen, Chang Wen

    2006-05-01

    A novel routing scheme for mobile ad hoc networks (MANETs), which combines hybrid and multi-inter-routing path properties with a distributed topology discovery route mechanism using control agents is proposed in this paper. In recent years, a variety of hybrid routing protocols for Mobile Ad hoc wireless networks (MANETs) have been developed. Which is proactively maintains routing information for a local neighborhood, while reactively acquiring routes to destinations beyond the global. The hybrid protocol reduces routing discovery latency and the end-to-end delay by providing high connectivity without requiring much of the scarce network capacity. On the other side the hybrid routing protocols in MANETs likes Zone Routing Protocol still need route "re-discover" time when a route between zones link break. Sine the topology update information needs to be broadcast routing request on local zone. Due to this delay, the routing protocol may not be applicable for real-time data and multimedia communication. We utilize the advantages of a clustering organization and multi-routing path in routing protocol to achieve several goals at the same time. Firstly, IRP efficiently saves network bandwidth and reduces route reconstruction time when a routing path fails. The IRP protocol does not require global periodic routing advertisements, local control agents will automatically monitor and repair broke links. Secondly, it efficiently reduces congestion and traffic "bottlenecks" for ClusterHeads in clustering network. Thirdly, it reduces significant overheads associated with maintaining clusters. Fourthly, it improves clusters stability due to dynamic topology changing frequently. In this paper, we present the Intelligent Routing Protocol. First, we discuss the problem of routing in ad hoc networks and the motivation of IRP. We describe the hierarchical architecture of IRP. We describe the routing process and illustrate it with an example. Further, we describe the control manage

  20. Extending Service Area of IEEE 802.11 Ad Hoc Networks

    Science.gov (United States)

    Choi, Woo-Yong

    2012-06-01

    According to the current IEEE 802.11 wireless LAN standards, IEEE 802.11 ad hoc networks have the limitation that all STAs (Stations) are in the one-hop transmission range of each other. In this paper, to alleviate the limitation of IEEE 802.11 ad hoc networks we propose the efficient method for selecting the most appropriate pseudo AP (Access Point) from among the set of ad hoc STAs and extending the service area of IEEE 802.11 ad hoc networks by the pseudo AP's relaying the internal traffic of IEEE 802.11 ad hoc networks. Numerical examples show that the proposed method significantly extends the service area of IEEE 802.11 ad hoc networks.

  1. Les Protocoles de routage dans les réseaux mobiles Ad Hoc ...

    African Journals Online (AJOL)

    Dans cet article nous présentons un état de l'art sur les protocoles de routage dans les réseaux mobiles Ad hoc. Mots clés : Réseaux mobiles ad hoc/, Protocoles de routage. Routing protocols in wireless mobile ad hoc networks. Abstract:The communication between users with handheld computers interconnected through ...

  2. Topology for efficient information dissemination in ad-hoc networking

    Science.gov (United States)

    Jennings, E.; Okino, C. M.

    2002-01-01

    In this paper, we explore the information dissemination problem in ad-hoc wirless networks. First, we analyze the probability of successful broadcast, assuming: the nodes are uniformly distributed, the available area has a lower bould relative to the total number of nodes, and there is zero knowledge of the overall topology of the network. By showing that the probability of such events is small, we are motivated to extract good graph topologies to minimize the overall transmissions. Three algorithms are used to generate topologies of the network with guaranteed connectivity. These are the minimum radius graph, the relative neighborhood graph and the minimum spanning tree. Our simulation shows that the relative neighborhood graph has certain good graph properties, which makes it suitable for efficient information dissemination.

  3. Undilatable Stent Neoatherosclerosis Treated with Ad Hoc Rotational Atherectomy

    Directory of Open Access Journals (Sweden)

    Michael Koutouzis

    2017-01-01

    Full Text Available A middle age woman with known ischemic heart disease and old stents in proximal left anterior descending coronary artery (LAD was admitted to Coronary Care Unit with acute coronary syndrome. The coronary angiography showed one vessel disease with significant restenosis within the previously implanted stents. The lesion was tough and remained undilatable despite high pressure balloon inflation. Eventually, the balloon ruptured creating a massive dissection of the LAD beginning immediately after the distal part of the undilatable lesion. We proceeded with a challenging ad hoc rotational atherectomy of the lesion and finally stenting of the lesion. In-stent restenosis many years after stent implantation is considered to be mainly due to neoatheromatosis compared to intimal hyperplasia, making lesion treatment more difficult and unpredictable.

  4. Optimum Combining for Rapidly Fading Channels in Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Sonia Furman

    2003-10-01

    Full Text Available Research and technology in wireless communication systems such as radar and cellular networks have successfully implemented alternative design approaches that utilize antenna array techniques such as optimum combining, to mitigate the degradation effects of multipath in rapid fading channels. In ad hoc networks, these methods have not yet been exploited primarily due to the complexity inherent in the network's architecture. With the high demand for improved signal link quality, devices configured with omnidirectional antennas can no longer meet the growing need for link quality and spectrum efficiency. This study takes an empirical approach to determine an optimum combining antenna array based on 3 variants of interelement spacing. For rapid fading channels, the simulation results show that the performance in the network of devices retrofitted with our antenna arrays consistently exceeded those with an omnidirectional antenna. Further, with the optimum combiner, the performance increased by over 60% compared to that of an omnidirectional antenna in a rapid fading channel.

  5. Vehicular ad hoc networks standards, solutions, and research

    CERN Document Server

    Molinaro, Antonella; Scopigno, Riccardo

    2015-01-01

    This book presents vehicular ad-hoc networks (VANETs) from the their onset, gradually going into technical details, providing a clear understanding of both theoretical foundations and more practical investigation. The editors gathered top-ranking authors to provide comprehensiveness and timely content; the invited authors were carefully selected from a list of who’s who in the respective field of interest: there are as many from Academia as from Standardization and Industry sectors from around the world. The covered topics are organized around five Parts starting from an historical overview of vehicular communications and standardization/harmonization activities (Part I), then progressing to the theoretical foundations of VANETs and a description of the day-one standard-compliant solutions (Part II), hence going into details of vehicular networking and security (Part III) and to the tools to study VANETs, from mobility and channel models, to network simulators and field trial methodologies (Part IV), and fi...

  6. Making friends on the fly advances in ad hoc teamwork

    CERN Document Server

    Barrett, Samuel

    2015-01-01

    This book is devoted to the encounter and interaction of agents such as robots with other agents and describes how they cooperate with their previously unknown teammates, forming an Ad Hoc team. It presents a new algorithm, PLASTIC, that allows agents to quickly adapt to new teammates by reusing knowledge learned from previous teammates.  PLASTIC is instantiated in both a model-based approach, PLASTIC-Model, and a policy-based approach, PLASTIC-Policy.  In addition to reusing knowledge learned from previous teammates, PLASTIC also allows users to provide expert-knowledge and can use transfer learning (such as the new TwoStageTransfer algorithm) to quickly create models of new teammates when it has some information about its new teammates. The effectiveness of the algorithm is demonstrated on three domains, ranging from multi-armed bandits to simulated robot soccer games.

  7. A Hybrid Energy Efficient Protocol for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Niranjan Kumar Ray

    2016-01-01

    Full Text Available We proposed an energy conservation technique called Location Based Topology Control with Sleep Scheduling for ad hoc networks. It uses the feature of both topology control approach and power management approach. Like the topology control approach, it attempts to reduce the transmission power of a node, which is determined from its neighborhood location information. A node goes to sleep state based on the traffic condition as that of power management approach. In the proposed scheme, a node goes to sleep state only when its absence does not create local partition in its neighborhood. We preformed extensive simulation to compare the proposed scheme with existing ones. Simulation results show that the energy consumption is lower with increase in the network lifetime and higher throughput in the proposed scheme.

  8. Adaptive Probabilistic Broadcasting over Dense Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Victor Gau

    2010-01-01

    Full Text Available We propose an idle probability-based broadcasting method, iPro, which employs an adaptive probabilistic mechanism to improve performance of data broadcasting over dense wireless ad hoc networks. In multisource one-hop broadcast scenarios, the modeling and simulation results of the proposed iPro are shown to significantly outperform the standard IEEE 802.11 under saturated condition. Moreover, the results also show that without estimating the number of competing nodes and changing the contention window size, the performance of the proposed iPro can still approach the theoretical bound. We further apply iPro to multihop broadcasting scenarios, and the experiment results show that within the same elapsed time after the broadcasting, the proposed iPro has significantly higher Packet-Delivery Ratios (PDR than traditional methods.

  9. Collaborative Environments. Considerations Concerning Some Collaborative Systems

    Directory of Open Access Journals (Sweden)

    Mihaela I. MUNTEAN

    2009-01-01

    Full Text Available It is obvious, that all collaborative environments (workgroups, communities of practice, collaborative enterprises are based on knowledge and between collaboration and knowledge management there is a strong interdependence. The evolution of information systems in these collaborative environments led to the sudden necessity to adopt, for maintaining the virtual activities and processes, the latest technologies/systems, which are capable to support integrated collaboration in business services. In these environments, portal-based IT platforms will integrate multi-agent collaborative systems, collaborative tools, different enterprise applications and other useful information systems.

  10. Increased longevity of wireless Ad hoc network through fuzzy system

    Directory of Open Access Journals (Sweden)

    Fawzia Abdali Larki

    2014-06-01

    Full Text Available The Ad hoc network is one of the multistep-based self-organizing networks, which are dynamically changing and are taken more into account as the ways of connecting the terminals through the development of wireless communication terminals. We are faced with numerous challenges in designing a wireless network such as the dynamic topology, common and limited bandwidth, and the limited energy. The nodes are moving according to the continuous changes in the topology and the source-to-destination paths are completely broken. Therefore, the repeated route discovery enhances the delay and overload of routing. Thus, it is essential to consider the link stability while designing the path in order to choose the routing protocol. Providing the multiple paths may lead to the better performance than a path. The transmission energy control in the wireless Ad hoc networks is the option for the level of transmission energy in order to transmit each node packet in this system. Therefore, transmission energy control affects the wireless medium interface. Because of choosing the appropriate protocol, the routing operation can be improved and the energy consumption can be controlled properly as well as enhancing the durability and longevity of network. The main objective of this study is to enhance the network longevity. The proposed algorithm in this research considers the combination of 2 parameters including the rate of node energy and number of steps in Fuzzy System applied on AOMDV Protocol, which is a Multipath Routing Protocol. The results of simulation also indicate the improved performance of proposed algorithm (AOMDV-F compared to AODV and AOMDV Protocols in NS2 simulator.

  11. Collaborative innovation

    DEFF Research Database (Denmark)

    Torfing, Jacob; Sørensen, Eva; Hartley, Jean

    2013-01-01

    , which emphasizes market competition; the neo-Weberian state, which emphasizes organizational entrepreneurship; and collaborative governance, which emphasizes multiactor engagement across organizations in the private, public, and nonprofit sectors. The authors conclude that the choice of strategies......-driven private sector is more innovative than the public sector by showing that both sectors have a number of drivers of as well as barriers to innovation, some of which are similar, while others are sector specific. The article then systematically analyzes three strategies for innovation: New Public Management......There are growing pressures for the public sector to be more innovative but considerable disagreement about how to achieve it. This article uses institutional and organizational analysis to compare three major public innovation strategies. The article confronts the myth that the market...

  12. Cytoarchitecture of the human lateral occipital cortex: mapping of two extrastriate areas hOc4la and hOc4lp.

    Science.gov (United States)

    Malikovic, Aleksandar; Amunts, Katrin; Schleicher, Axel; Mohlberg, Hartmut; Kujovic, Milenko; Palomero-Gallagher, Nicola; Eickhoff, Simon B; Zilles, Karl

    2016-05-01

    The microstructural correlates of the functional segregation of the human lateral occipital cortex are largely unknown. Therefore, we analyzed the cytoarchitecture of this region in ten human post-mortem brains using an observer-independent and statistically testable parcellation method to define the position and extent of areas in the lateral occipital cortex. Two new cytoarchitectonic areas were found: an anterior area hOc4la and a posterior area hOc4lp. hOc4la was located behind the anterior occipital sulcus in rostral and ventral portions of this region where it occupies the anterior third of the middle and inferior lateral occipital gyri. hOc4lp was found in caudal and dorsal portions of this region where it extends along the superior and middle lateral occipital gyri. The cytoarchitectonic areas were registered to 3D reconstructions of the corresponding brains, which were subsequently spatially normalized to the Montreal Neurological Institute reference space. Continuous probabilistic maps of both areas based on the analysis of ten brains were generated to characterize their inter-subject variability in location and size. The maps of hOc4la and hOc4lp were then used as seeds for meta-analytic connectivity modeling and quantitative functional decoding to identify their co-activation patterns and assignment to functional domains. Convergent evidence from their location, topography, size, functional domains and connectivity indicates that hOc4la and hOc4lp are the potential anatomical correlates of the functionally defined lateral occipital areas LO-1 and LO-2.

  13. Science friction: data, metadata, and collaboration.

    Science.gov (United States)

    Edwards, Paul N; Mayernik, Matthew S; Batcheller, Archer L; Bowker, Geoffrey C; Borgman, Christine L

    2011-10-01

    When scientists from two or more disciplines work together on related problems, they often face what we call 'science friction'. As science becomes more data-driven, collaborative, and interdisciplinary, demand increases for interoperability among data, tools, and services. Metadata--usually viewed simply as 'data about data', describing objects such as books, journal articles, or datasets--serve key roles in interoperability. Yet we find that metadata may be a source of friction between scientific collaborators, impeding data sharing. We propose an alternative view of metadata, focusing on its role in an ephemeral process of scientific communication, rather than as an enduring outcome or product. We report examples of highly useful, yet ad hoc, incomplete, loosely structured, and mutable, descriptions of data found in our ethnographic studies of several large projects in the environmental sciences. Based on this evidence, we argue that while metadata products can be powerful resources, usually they must be supplemented with metadata processes. Metadata-as-process suggests the very large role of the ad hoc, the incomplete, and the unfinished in everyday scientific work.

  14. Ad-Hoc Business Processes in Web Services

    NARCIS (Netherlands)

    Wombacher, Andreas; Mahleko, Bendick

    Web service technologies promise to facilitate collaboration among business partners by helping potential business partners find one another and integrate their business processes to do business. Daunting challenges however exist before the full potential of Web services can be realized. Indexing

  15. Collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2008-01-01

    Since common ground is pivotal to collaboration, this paper proposes to define collaborative information seeking as the combined activity of information seeking and collaborative grounding. While information-seeking activities are necessary for collaborating actors to acquire new information......, the activities involved in information seeking are often performed by varying subgroups of actors. Consequently, collaborative grounding is necessary to share information among collaborating actors and, thereby, establish and maintain the common ground necessary for their collaborative work. By focusing...... on the collaborative level, collaborative information seeking aims to avoid both individual reductionism and group reductionism, while at the same time recognizing that only some information and understanding need be shared....

  16. Building Realistic Mobility Models for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Adrian Pullin

    2018-04-01

    Full Text Available A mobile ad hoc network (MANET is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR, destination-sequenced distance-vector routing (DSDV, and ad hoc n-demand distance vector routing (AODV. The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To

  17. Typicality Mediates Performance during Category Verification in Both Ad-Hoc and Well-Defined Categories

    Science.gov (United States)

    Sandberg, Chaleece; Sebastian, Rajani; Kiran, Swathi

    2012-01-01

    Background: The typicality effect is present in neurologically intact populations for natural, ad-hoc, and well-defined categories. Although sparse, there is evidence of typicality effects in persons with chronic stroke aphasia for natural and ad-hoc categories. However, it is unknown exactly what influences the typicality effect in this…

  18. Ad Hoc Categories and False Memories: Memory Illusions for Categories Created On-The-Spot

    Science.gov (United States)

    Soro, Jerônimo C.; Ferreira, Mário B.; Semin, Gün R.; Mata, André; Carneiro, Paula

    2017-01-01

    Three experiments were designed to test whether experimentally created ad hoc associative networks evoke false memories. We used the DRM (Deese, Roediger, McDermott) paradigm with lists of ad hoc categories composed of exemplars aggregated toward specific goals (e.g., going for a picnic) that do not share any consistent set of features. Experiment…

  19. A peer-to-peer file search and download protocol for wireless ad-hoc networks

    NARCIS (Netherlands)

    Sözer, Hasan; Tekkalmaz, M.; Korpeoglu, I.

    Deployment of traditional peer-to-peer file sharing systems on a wireless ad-hoc network introduces several challenges. Information and workload distribution as well as routing are major problems for members of a wireless ad-hoc network, which are only aware of their immediate neighborhood. In this

  20. A flow level model for wireless multihop ad hoc network throughput

    NARCIS (Netherlands)

    Coenen, Tom Johannes Maria; van den Berg, Hans Leo; Boucherie, Richardus J.

    2005-01-01

    A flow level model for multihop wireless ad hoc networks is presented in this paper. Using a flow level view, we show the main properties and modeling challenges for ad hoc networks. Considering different scenarios, a multihop WLAN and a serial network with a TCP-like flow control protocol, we

  1. On the impact of network dynamics on a discovery protocol for ad-hoc networks

    NARCIS (Netherlands)

    Liu, F.; Heijenk, Geert

    A very promising approach to discovering services and context information in ad-hoc networks is based on the use of Attenuated Bloom filters. In this paper we analyze the impact of changes in the connectivity of an ad-hoc network on this approach. We evaluate the performance of the discovery

  2. Twenty-One at TREC-7: ad-hoc and cross-language track

    NARCIS (Netherlands)

    Hiemstra, Djoerd; Kraaij, Wessel; Voorhees, E.M; Harman, D.K.

    1999-01-01

    This paper describes the official runs of the Twenty-One group for TREC-7. The Twenty-One group participated in the ad-hoc and the cross-language track and made the following accomplishments: We developed a new weighting algorithm, which outperforms the popular Cornell version of BM25 on the ad-hoc

  3. Collaboration and decision making tools for mobile groups

    International Nuclear Information System (INIS)

    Abrahamyan, S.; Balyan, S.; Degtyarev, A.; Ter-Minasyan, H.

    2017-01-01

    Nowadays the use of distributed collaboration tools is widespread in many areas of people activity. But lack of mobility and certain equipment dependence create difficulties and decelerate development and integration of such technologies. Also, mobile technologies allow individuals to interact with each other without need of traditional office spaces and regardless of location. Hence, realization of special infrastructures on mobile platforms with the help of ad hoc wireless local networks could eliminate hardware attachment and be also useful in terms of scientific approach. Solutions from basic internet messengers to complex software for online collaboration equipment in large-scale workgroups are implementations of tools based on mobile infrastructures. Despite growth of mobile infrastructures, applied distributed solutions in group decision-making and e-collaboration are not common. In this article we propose software complex for real-time collaboration and decision-making based on mobile devices, describe its architecture and evaluate performance.

  4. Collaboration and decision making tools for mobile groups

    Science.gov (United States)

    Abrahamyan, Suren; Balyan, Serob; Ter-Minasyan, Harutyun; Degtyarev, Alexander

    2017-12-01

    Nowadays the use of distributed collaboration tools is widespread in many areas of people activity. But lack of mobility and certain equipment-dependency creates difficulties and decelerates development and integration of such technologies. Also mobile technologies allow individuals to interact with each other without need of traditional office spaces and regardless of location. Hence, realization of special infrastructures on mobile platforms with help of ad-hoc wireless local networks could eliminate hardware-attachment and be useful also in terms of scientific approach. Solutions from basic internet-messengers to complex software for online collaboration equipment in large-scale workgroups are implementations of tools based on mobile infrastructures. Despite growth of mobile infrastructures, applied distributed solutions in group decisionmaking and e-collaboration are not common. In this article we propose software complex for real-time collaboration and decision-making based on mobile devices, describe its architecture and evaluate performance.

  5. Collaboration rules.

    Science.gov (United States)

    Evans, Philip; Wolf, Bob

    2005-01-01

    Corporate leaders seeking to boost growth, learning, and innovation may find the answer in a surprising place: the Linux open-source software community. Linux is developed by an essentially volunteer, self-organizing community of thousands of programmers. Most leaders would sell their grandmothers for workforces that collaborate as efficiently, frictionlessly, and creatively as the self-styled Linux hackers. But Linux is software, and software is hardly a model for mainstream business. The authors have, nonetheless, found surprising parallels between the anarchistic, caffeinated, hirsute world of Linux hackers and the disciplined, tea-sipping, clean-cut world of Toyota engineering. Specifically, Toyota and Linux operate by rules that blend the self-organizing advantages of markets with the low transaction costs of hierarchies. In place of markets' cash and contracts and hierarchies' authority are rules about how individuals and groups work together (with rigorous discipline); how they communicate (widely and with granularity); and how leaders guide them toward a common goal (through example). Those rules, augmented by simple communication technologies and a lack of legal barriers to sharing information, create rich common knowledge, the ability to organize teams modularly, extraordinary motivation, and high levels of trust, which radically lowers transaction costs. Low transaction costs, in turn, make it profitable for organizations to perform more and smaller transactions--and so increase the pace and flexibility typical of high-performance organizations. Once the system achieves critical mass, it feeds on itself. The larger the system, the more broadly shared the knowledge, language, and work style. The greater individuals' reputational capital, the louder the applause and the stronger the motivation. The success of Linux is evidence of the power of that virtuous circle. Toyota's success is evidence that it is also powerful in conventional companies.

  6. Reliability analysis of cluster-based ad-hoc networks

    International Nuclear Information System (INIS)

    Cook, Jason L.; Ramirez-Marquez, Jose Emmanuel

    2008-01-01

    The mobile ad-hoc wireless network (MAWN) is a new and emerging network scheme that is being employed in a variety of applications. The MAWN varies from traditional networks because it is a self-forming and dynamic network. The MAWN is free of infrastructure and, as such, only the mobile nodes comprise the network. Pairs of nodes communicate either directly or through other nodes. To do so, each node acts, in turn, as a source, destination, and relay of messages. The virtue of a MAWN is the flexibility this provides; however, the challenge for reliability analyses is also brought about by this unique feature. The variability and volatility of the MAWN configuration makes typical reliability methods (e.g. reliability block diagram) inappropriate because no single structure or configuration represents all manifestations of a MAWN. For this reason, new methods are being developed to analyze the reliability of this new networking technology. New published methods adapt to this feature by treating the configuration probabilistically or by inclusion of embedded mobility models. This paper joins both methods together and expands upon these works by modifying the problem formulation to address the reliability analysis of a cluster-based MAWN. The cluster-based MAWN is deployed in applications with constraints on networking resources such as bandwidth and energy. This paper presents the problem's formulation, a discussion of applicable reliability metrics for the MAWN, and illustration of a Monte Carlo simulation method through the analysis of several example networks

  7. An ad hoc wireless sensor network for tele medicine applications

    International Nuclear Information System (INIS)

    Sheltami, Tarek R.; Mahmoud, Ashraf S.; Abu-Amara, Marwan H.

    2007-01-01

    Recent advances in embedded computing systems have led to the emergence of wireless sensor networks (SNETs), consisting of small, battery-powered motes with limited computation and radio communication capabilities. SNETs permit data gathering and computation to be deeply embedded in the physical environment. Large scale ad hoc sensor networks (ASNET), when deployed among mobile patients, can provide dynamic data query architecture to allow medical specialists to monitor patients at any place via the web or cellular network. In case of an emergency, doctors and/or nurses will be contacted automatically through their handheld personal digital assistants (PDAs) or cellular phones. In specific, the proposed network consists of sensor nodes at the first layer whose responsibility is to measure, collect and communicate, via wired or wireless interface, readings to a microcontroller presenting the second layer of architecture. Deployed microcontrollers process incoming readings and report to a central system via a wireless interface. The implemented network distinguishes between periodic sensor readings and critical or event driven readings where higher priorities is given for the latter. In this paper we implement 3 special cases for tracking and monitoring patients and doctors using SNETs. In addition, the performance of a large scale of our implementation has been tested by means of mathematical analysis. (author)

  8. Resistivity tomography of Pointe du Hoc cliffs for stability assessment

    Science.gov (United States)

    Udphuay, S.; Everett, M. E.; Warden, R.

    2008-12-01

    Pointe du Hoc WWII battlefield overlooking the English Channel in western Normandy, France, is an important cultural resource, being an integral component of the June 6 1944 D-Day invasion. Two major buildings, the forward observation post (OP) and Col. Rudder's command post (RCP), are now perched perilously close to the cliff's edge owing to six decades of cliff retreat. Geophysical surveys were carried out in March 2008 to investigate the risk of cliff failure and to inform possible geotechnical remediation strategies with a final goal toward re-opening the observation post that is now closed to visitors. The geophysical surveying is accomplished by high-resolution resistivity tomography, conducted in extreme topography and in the midst of dense cultural clutter. The results of the OP tomography indicate that the highest mass movement hazard is associated with the marine caverns at the base of the cliff at the point of strongest wave attack. These caverns occupy the future site of a sea arch which will threaten the OP building. There is a high probability of a soil wedge failure on the east facing cliff edge close to the OP building. Such a failure could damage or destroy the building. The possibility of a sudden catastrophic failure along any one of these fractures cannot be ruled out. The greatest risk at the RCP site, which is under less immediate threat, is associated with soil wedge failures at the top of the cliffs.

  9. Post hoc subgroups in clinical trials: Anathema or analytics?

    Science.gov (United States)

    Weisberg, Herbert I; Pontes, Victor P

    2015-08-01

    There is currently much interest in generating more individualized estimates of treatment effects. However, traditional statistical methods are not well suited to this task. Post hoc subgroup analyses of clinical trials are fraught with methodological problems. We suggest that the alternative research paradigm of predictive analytics, widely used in many business contexts, can be adapted to help. We compare the statistical and analytics perspectives and suggest that predictive modeling should often replace subgroup analysis. We then introduce a new approach, cadit modeling, that can be useful to identify and test individualized causal effects. The cadit technique is particularly useful in the context of selecting from among a large number of potential predictors. We describe a new variable-selection algorithm that has been applied in conjunction with cadit. The cadit approach is illustrated through a reanalysis of data from the Randomized Aldactone Evaluation Study trial, which studied the efficacy of spironolactone in heart-failure patients. The trial was successful, but a serious adverse effect (hyperkalemia) was subsequently discovered. Our reanalysis suggests that it may be possible to predict the degree of hyperkalemia based on a logistic model and to identify a subgroup in which the effect is negligible. Cadit modeling is a promising alternative to subgroup analyses. Cadit regression is relatively straightforward to implement, generates results that are easy to present and explain, and can mesh straightforwardly with many variable-selection algorithms. © The Author(s) 2015.

  10. A Dynamic Reputation Management System for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Eric Chiejina

    2015-04-01

    Full Text Available Nodes in mobile ad hoc networks (MANETs are mandated to utilize their limited energy resources in forwarding routing control and data packets for other nodes. Since a MANET lacks a centralized administration and control, a node may decide to act selfishly, either by refusing to respond to route requests from other nodes or deceitfully by responding to some route requests, but dropping the corresponding data packets that are presented for forwarding. A significant increase in the presence of these misbehaving nodes in a MANET can subsequently degrade network performance. In this paper, we propose a dynamic reputation management system for detecting and isolating misbehaving nodes in MANETs. Our model employs a novel direct monitoring technique to evaluate the reputation of a node in the network, which ensures that nodes that expend their energy in transmitting data and routing control packets for others are allowed to carry out their network activities while the misbehaving nodes are detected and isolated from the network. Simulation results show that our model is effective at curbing and mitigating the effects of misbehaving nodes in the network.

  11. Data management issues in mobile ad hoc networks.

    Science.gov (United States)

    Hara, Takahiro

    2017-01-01

    Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990's. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000's have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research.

  12. Managing collaborative design

    NARCIS (Netherlands)

    Sebastian, R.

    2007-01-01

    Collaborative design has been emerging in building projects everywhere. The more complex a building project becomes, the closer and more intensive collaboration between the design actors is required. This research focuses on collaborative design in the conceptual architecture design phase,

  13. Collaborative networks: Reference modeling

    NARCIS (Netherlands)

    Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Collaborative Networks: Reference Modeling works to establish a theoretical foundation for Collaborative Networks. Particular emphasis is put on modeling multiple facets of collaborative networks and establishing a comprehensive modeling framework that captures and structures diverse perspectives of

  14. DISCOVERY OF PULSED γ-RAYS FROM PSR J0034-0534 WITH THE FERMI LARGE AREA TELESCOPE: A CASE FOR CO-LOCATED RADIO AND γ-RAY EMISSION REGIONS

    International Nuclear Information System (INIS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.

    2010-01-01

    Millisecond pulsars (MSPs) have been firmly established as a class of γ-ray emitters via the detection of pulsations above 0.1 GeV from eight MSPs by the Fermi Large Area Telescope (LAT). Using 13 months of LAT data, significant γ-ray pulsations at the radio period have been detected from the MSP PSR J0034-0534, making it the ninth clear MSP detection by the LAT. The γ-ray light curve shows two peaks separated by 0.274 ± 0.015 in phase which are very nearly aligned with the radio peaks, a phenomenon seen only in the Crab pulsar until now. The ≥0.1 GeV spectrum of this pulsar is well fit by an exponentially cutoff power law with a cutoff energy of 1.8 ± 0.6 ± 0.1 GeV and a photon index of 1.5 ± 0.2 ± 0.1, first errors are statistical and second are systematic. The near-alignment of the radio and γ-ray peaks strongly suggests that the radio and γ-ray emission regions are co-located and both are the result of caustic formation.

  15. Does Ad Hoc Coronary Intervention Reduce Radiation Exposure? – Analysis of 568 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Truffa, Márcio A. M., E-mail: marciotruffa@yahoo.com.br; Alves, Gustavo M.P.; Bernardi, Fernando; Esteves Filho, Antonio; Ribeiro, Expedito; Galon, Micheli Z.; Spadaro, André; Kajita, Luiz J.; Arrieta, Raul; Lemos, Pedro A. [Instituto do Coração - Hospital das Clínicas - Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil)

    2015-11-15

    Advantages and disadvantages of ad hoc percutaneous coronary intervention have been described. However little is known about the radiation exposure of that procedure as compared with the staged intervention. To compare the radiation dose of the ad hoc percutaneous coronary intervention with that of the staged procedure The dose-area product and total Kerma were measured, and the doses of the diagnostic and therapeutic procedures were added. In addition, total fluoroscopic time and number of acquisitions were evaluated. A total of 568 consecutive patients were treated with ad hoc percutaneous coronary intervention (n = 320) or staged percutaneous coronary intervention (n = 248). On admission, the ad hoc group had less hypertension (74.1% vs 81.9%; p = 0.035), dyslipidemia (57.8% vs. 67.7%; p = 0.02) and three-vessel disease (38.8% vs. 50.4%; p = 0.015). The ad hoc group was exposed to significantly lower radiation doses, even after baseline characteristic adjustment between both groups. The ad hoc group was exposed to a total dose-area product of 119.7 ± 70.7 Gycm{sup 2}, while the staged group, to 139.2 ± 75.3 Gycm{sup 2} (p < 0.001). Ad hoc percutaneous coronary intervention reduced radiation exposure as compared with diagnostic and therapeutic procedures performed at two separate times.

  16. Does Ad Hoc Coronary Intervention Reduce Radiation Exposure? – Analysis of 568 Patients

    International Nuclear Information System (INIS)

    Truffa, Márcio A. M.; Alves, Gustavo M.P.; Bernardi, Fernando; Esteves Filho, Antonio; Ribeiro, Expedito; Galon, Micheli Z.; Spadaro, André; Kajita, Luiz J.; Arrieta, Raul; Lemos, Pedro A.

    2015-01-01

    Advantages and disadvantages of ad hoc percutaneous coronary intervention have been described. However little is known about the radiation exposure of that procedure as compared with the staged intervention. To compare the radiation dose of the ad hoc percutaneous coronary intervention with that of the staged procedure The dose-area product and total Kerma were measured, and the doses of the diagnostic and therapeutic procedures were added. In addition, total fluoroscopic time and number of acquisitions were evaluated. A total of 568 consecutive patients were treated with ad hoc percutaneous coronary intervention (n = 320) or staged percutaneous coronary intervention (n = 248). On admission, the ad hoc group had less hypertension (74.1% vs 81.9%; p = 0.035), dyslipidemia (57.8% vs. 67.7%; p = 0.02) and three-vessel disease (38.8% vs. 50.4%; p = 0.015). The ad hoc group was exposed to significantly lower radiation doses, even after baseline characteristic adjustment between both groups. The ad hoc group was exposed to a total dose-area product of 119.7 ± 70.7 Gycm 2 , while the staged group, to 139.2 ± 75.3 Gycm 2 (p < 0.001). Ad hoc percutaneous coronary intervention reduced radiation exposure as compared with diagnostic and therapeutic procedures performed at two separate times

  17. Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

    OpenAIRE

    Tripp Barba, Carolina

    2013-01-01

    The constant mobility of people, the growing need to be always connected, the large number of vehicles that nowadays can be found in the roads and the advances in technology make Vehicular Ad hoc Networks (VANETs) be a major area of research. Vehicular Ad hoc Networks are a special type of wireless Mobile Ad hoc Networks (MANETs), which allow a group of mobile nodes configure a temporary network and maintain it without the need of a fixed infrastructure. A vehicular network presents some spec...

  18. Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

    OpenAIRE

    Tripp Barba, Carolina

    2013-01-01

    La movilidad constante de las personas y la creciente necesidad de estar conectados en todo momento ha hecho de las redes vehiculares un área cuyo interés ha ido en aumento. La gran cantidad de vehículos que hay en la actualidad, y los avances tecnológicos han hecho de las redes vehiculares (VANETS, Vehicular Ad hoc Networks) un gran campo de investigación. Las redes vehiculares son un tipo especial de redes móviles ad hoc inalámbricas, las cuales, al igual que las redes MANET (Mobile Ad hoc ...

  19. History of the research ad hoc committee on 'dissemination of information' and the special ad hoc committee on 'dissemination of information' of the Atomic Energy Society of Japan

    Energy Technology Data Exchange (ETDEWEB)

    Itabashi, Keizo [Japan Atomic Energy Agency, Intellectual Resources Department, Tokai, Ibaraki (Japan)

    2010-06-15

    The Research ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 15 times from Oct. 1970 to Mar 1973. After that, The Special ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 115 times from Apr. 1973 to Mar 2009. The history of these two committees is described. Activity report is arranged including the information on change of the member and topics of the meeting, and the minutes. Furthermore, the document list on International Nuclear Information System (INIS) from Japan is included. (author)

  20. History of the research ad hoc committee on 'dissemination of information' and the special ad hoc committee on 'dissemination of information' of the Atomic Energy Society of Japan

    International Nuclear Information System (INIS)

    Itabashi, Keizo

    2010-06-01

    The Research ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 15 times from Oct. 1970 to Mar 1973. After that, The Special ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 115 times from Apr. 1973 to Mar 2009. The history of these two committees is described. Activity report is arranged including the information on change of the member and topics of the meeting, and the minutes. Furthermore, the document list on International Nuclear Information System (INIS) from Japan is included. (author)

  1. The effect of DAD timeout period on address autoconfiguration in wireless ad-hoc networks

    CSIR Research Space (South Africa)

    Mutanga, MB

    2011-09-01

    Full Text Available Lack of manual management mechanisms in wireless ad-hoc networks means that automatic configuration of IP addresses and other related network parameters are very crucial. Many IP address autoconfiguration mechanisms have been proposed in literature...

  2. A Tool for Visualizing Mobile Ad-Hoc Network Topology Definitions Files

    National Research Council Canada - National Science Library

    Nguyen, Binh Q

    2006-01-01

    This report documents a research and development effort that the U.S. Army Research Laboratory conducted in FY05 in support of the building of an emulated tactical mobile ad hoc network (MANET) research test bed...

  3. Accurate 3D Localization Method for Public Safety Applications in Vehicular Ad-hoc Networks

    KAUST Repository

    Ansari, Abdul Rahim; Saeed, Nasir; Haq, Mian Imtiaz Ul; Cho, Sunghyun

    2018-01-01

    Vehicular ad hoc networks (VANETs) represent a very promising research area because of their ever increasing demand, especially for public safety applications. In VANETs vehicles communicate with each other to exchange road maps and traffic

  4. DESAIN ALGORITMA DAN SIMULASI ROUTING UNTUK GATEWAY AD HOC WIRELESS NETWORKS

    Directory of Open Access Journals (Sweden)

    Nixson Meok

    2009-12-01

    Full Text Available   Routing protocol to the wireless ad hoc networks is very needed in the communication process between some terminals, to send the data packet through one or several node(s to the destination address where the network typology is always changing. Many previous works that discussed about routing ad hoc both for manet (mobile ad hoc networks and wireless networks, but the emphasis have more focus on comparing the performance of several routing ad hoc. While in this work, there is a bulding of routing algorithm model to gateway in land to the nodes that analogized as a boat that move on the sea. With the assumption that the communication inter terminals to radio band of Very High Frequency, thus algorithm that built in the simulation based on the range gap of the HF frequency. The result of this simulation will be developed as the platform to implement the service development of multiuser communication

  5. Analysis for Ad Hoc Network Attack-Defense Based on Stochastic Game Model

    Directory of Open Access Journals (Sweden)

    Yuanjie LI

    2014-06-01

    Full Text Available The attack actions analysis for Ad Hoc networks can provide a reference for the design security mechanisms. This paper presents an analysis method of security of Ad Hoc networks based on Stochastic Game Nets (SGN. This method can establish a SGN model of Ad Hoc networks and calculate to get the Nash equilibrium strategy. After transforming the SGN model into a continuous-time Markov Chain (CTMC, the security of Ad Hoc networks can be evaluated and analyzed quantitatively by calculating the stationary probability of CTMC. Finally, the Matlab simulation results show that the probability of successful attack is related to the attack intensity and expected payoffs, but not attack rate.

  6. SURVEI TEKNIK CLUSTERING ROUTING BERDASARKAN MOBILITAS PADA WIRELESS AD-HOC NETWORK

    Directory of Open Access Journals (Sweden)

    I Nyoman Trisna Wirawan

    2016-01-01

    Full Text Available Wireless ad-hoc merupakan sebuah skema jaringan yang didesain supaya mampu beroperasi tanpa membutuhkan infrastruktur tetap serta bersifat otonom. Teknik flooding pada proses path discovery dalam kasus wireless ad-hoc network dapat menimbulkan masalah beban jaringan yang berlebihan. Oleh karena itu, sebuah skema clustering diusulkan untuk mengurangi adanya flooding paket yang berlebihan dengan membagi node-node dalam jaringan menjadi beberapa bagian berdasarkan parameter tertentu. Teknik ini efektifuntuk mengurangi paket yang harus dilewatkan dalam jaringan. Namun masalah muncul ketika sebuah jaringan wireless ad-hoc harus membentuk sebuah cluster dengan mempertimbangkan beberapa parameter khusus. Parameter tersebut harus disesuaikan dengan kasus yang dihadapi. Pada tulisan ini akan dibahas secara khusus mengenai penerapan skema clustering dalam lingkungan wireless ad-hoc network, baik pada MANETdan penyesuaian skema clustering yang harus dilakukan pada VANET berdasarkan mobilitasnya.

  7. An Ad-Hoc Opportunistic Dissemination Protocol for Smartphone-based Participatory Traffic Monitoring

    NARCIS (Netherlands)

    Türkes, Okan; Seraj, Fatjon; Scholten, Johan; Meratnia, Nirvana; Havinga, Paul J.M.

    2015-01-01

    This study introduces an ad-hoc opportunistic data dissemination protocol, called VADISS, that facilitates participatory traffic monitoring applications with smartphones. As a ubiquitous alternative to existing vehicular networking methods, VADISS uses the default WiFi interfaces universally adopted

  8. Energy-Aware Broadcasting and Multicasting in Wireless Ad Hoc Networks: A Cross-Layering Approach

    National Research Council Canada - National Science Library

    Wieselthier, Jeffrey E; Nguyen, Gam D; Ephremides, Anthony

    2004-01-01

    ...) problems, especially when energy-aware operation is required. To address the specific problem of energy-aware tree construction in wireless ad hoc networks, we have developed the Broadcast Incremental Power (BIP...

  9. A Group Based Key Sharing and Management Algorithm for Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Zeeshan Shafi Khan

    2014-01-01

    Full Text Available Vehicular ad hoc networks (VANETs are one special type of ad hoc networks that involves vehicles on roads. Typically like ad hoc networks, broadcast approach is used for data dissemination. Blind broadcast to each and every node results in exchange of useless and irrelevant messages and hence creates an overhead. Unicasting is not preferred in ad-hoc networks due to the dynamic topology and the resource requirements as compared to broadcasting. Simple broadcasting techniques create several problems on privacy, disturbance, and resource utilization. In this paper, we propose media mixing algorithm to decide what information should be provided to each user and how to provide such information. Results obtained through simulation show that fewer number of keys are needed to share compared to simple broadcasting. Privacy is also enhanced through this approach.

  10. On-Demand Routing in Multi-hop Wireless Mobile Ad Hoc Networks

    National Research Council Canada - National Science Library

    Maltz, David A

    2001-01-01

    .... Routing protocols used in ad hoc networks must automatically adjust to environments that can vary between the extremes of high mobility with low bandwidth, and low mobility with high bandwidth...

  11. Ad-hoc Content-based Queries and Data Analysis for Virtual Observatories, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Aquilent, Inc. proposes to support ad-hoc, content-based query and data retrieval from virtual observatories (VxO) by developing 1) Higher Order Query Services that...

  12. Voice Communications over 802.11 Ad Hoc Networks: Modeling, Optimization and Call Admission Control

    Science.gov (United States)

    Xu, Changchun; Xu, Yanyi; Liu, Gan; Liu, Kezhong

    Supporting quality-of-service (QoS) of multimedia communications over IEEE 802.11 based ad hoc networks is a challenging task. This paper develops a simple 3-D Markov chain model for queuing analysis of IEEE 802.11 MAC layer. The model is applied for performance analysis of voice communications over IEEE 802.11 single-hop ad hoc networks. By using the model, we finish the performance optimization of IEEE MAC layer and obtain the maximum number of voice calls in IEEE 802.11 ad hoc networks as well as the statistical performance bounds. Furthermore, we design a fully distributed call admission control (CAC) algorithm which can provide strict statistical QoS guarantee for voice communications over IEEE 802.11 ad hoc networks. Extensive simulations indicate the accuracy of the analytical model and the CAC scheme.

  13. Throughput and Fairness of Collision Avoidance Protocols in Ad Hoc Networks

    National Research Council Canada - National Science Library

    Garcia-Luna-Aceves, J. J; Wang, Yu

    2004-01-01

    .... In Section 1, The authors present an analytical modeling to derive the saturation throughput of these sender-initiated collision avoidance protocols in multi-hop ad hoc networks with nodes randomly...

  14. Key Success Factors and Guidance for International Collaborative Design Projects

    Directory of Open Access Journals (Sweden)

    Robby Soetanto

    2015-11-01

    Full Text Available In the built environment (BE sector, the co-creation process of design demands understanding of requirements (as viewed by parties involved, mobilisation of tacit knowledge, negotiation, and complex exchange of information. The need to collaborate over distance has further exacerbated the complexity of the process, and, in itself, represents a significant challenge for BE professionals who are increasingly expected to undertake this process within globally distributed virtual teams. The research aims to identify key success factors and develop guidance for international collaborative design projects, via the implementation of collaborative design courses in UK and Canadian universities over three academic years. Questionnaire surveys, focus groups, observation of online meetings, personal reflections provided data for the analysis. The findings reveal the significance of the perceived risk of collaboration and a difference in preferred communication mode between architects and civil/structural engineers. These findings suggest the impact of training in the subject discipline, and that the opportunity for co-located working has helped the development of trust. The guidance is aimed at BE educators who wish to implement this activity in their courses.

  15. Analysis and Enhancements of Leader Elections algorithms in Mobile Ad Hoc Networks

    OpenAIRE

    Shayeji, Mohammad H. Al; Al-Azmi, AbdulRahman R.; Al-Azmi, AbdulAziz R.; Samrajesh, M. D.

    2012-01-01

    Mobile Ad Hoc networks (MANET), distinct from traditional distributed systems, are dynamic and self-organizing networks. MANET requires a leader to coordinate and organize tasks. The challenge is to have the right election algorithm that chooses the right leader based on various factors in MANET. In this paper, we analyze four leader election algorithms used in mobile Ad Hoc Networks. Factors considered in our analysis are time complexity, message complexity, assumptions considered, fault tol...

  16. Algorithmic, LOCS and HOCS (chemistry) exam questions: performance and attitudes of college students

    Science.gov (United States)

    Zoller, Uri

    2002-02-01

    The performance of freshmen biology and physics-mathematics majors and chemistry majors as well as pre- and in-service chemistry teachers in two Israeli universities on algorithmic (ALG), lower-order cognitive skills (LOCS), and higher-order cognitive skills (HOCS) chemistry exam questions were studied. The driving force for the study was an interest in moving science and chemistry instruction from an algorithmic and factual recall orientation dominated by LOCS, to a decision-making, problem-solving and critical system thinking approach, dominated by HOCS. College students' responses to the specially designed ALG, LOCS and HOCS chemistry exam questions were scored and analysed for differences and correlation between the performance means within and across universities by the questions' category. This was followed by a combined student interview - 'speaking aloud' problem solving session for assessing the thinking processes involved in solving these types of questions and the students' attitudes towards them. The main findings were: (1) students in both universities performed consistently in each of the three categories in the order of ALG > LOCS > HOCS; their 'ideological' preference, was HOCS > algorithmic/LOCS, - referred to as 'computational questions', but their pragmatic preference was the reverse; (2) success on algorithmic/LOCS does not imply success on HOCS questions; algorithmic questions constitute a category on its own as far as students success in solving them is concerned. Our study and its results support the effort being made, worldwide, to integrate HOCS-fostering teaching and assessment strategies and, to develop HOCS-oriented science-technology-environment-society (STES)-type curricula within science and chemistry education.

  17. simulate_CAT: A Computer Program for Post-Hoc Simulation for Computerized Adaptive Testing

    Directory of Open Access Journals (Sweden)

    İlker Kalender

    2015-06-01

    Full Text Available This paper presents a computer software developed by the author. The software conducts post-hoc simulations for computerized adaptive testing based on real responses of examinees to paper and pencil tests under different parameters that can be defined by user. In this paper, short information is given about post-hoc simulations. After that, the working principle of the software is provided and a sample simulation with required input files is shown. And last, output files are described

  18. User-centred and context-aware identity management in mobile ad-hoc networks

    CERN Document Server

    Arabo, Abdullahi

    2013-01-01

    The emergent notion of ubiquitous computing makes it possible for mobile devices to communicate and provide services via networks connected in an ad-hoc manner. These have resulted in the proliferation of wireless technologies such as Mobile Ad-hoc Networks (MANets), which offer attractive solutions for services that need flexible setup as well as dynamic and low cost wireless connectivity. However, the growing trend outlined above also raises serious concerns over Identity Management (IM) du...

  19. The Ex Hoc Infrastructure - Enhancing Traffic Safety through LIfe WArning Systems

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Kristensen, Lars Michael; Eskildsen, Toke

    2004-01-01

    New pervasive computing technologies for sensing and communication open up novel possibilities for enhancing traffic safety. We are currently designing and implementing the Ex Hoc infrastructure framework for communication among mobile and stationary units including vehicles. The infrastructure...... will connect sensing devices on vehicles with sensing devices on other vehicles and with stationary communication units placed alongside roads. The current application of Ex Hoc is to enable the collection and dissemination of information on road condition through LIfe Warning Systems (LIWAS) units....

  20. Handbook on theoretical and algorithmic aspects of sensor, ad hoc wireless, and peer-to-peer networks

    CERN Document Server

    Wu, Jie

    2005-01-01

    PrefaceAD HOC WIRELESS NETWORKSA Modular Cross Layer Architecture for Ad Hoc Networks, M. Conti, J. Crowcroft, G. Maselli, and G. TuriRouting Scalability in MANETs, J. Eriksson, S. Krishnamurthy and M. FaloutsosUniformly Distributed Algorithm for Virtual Backbone Routing in Ad Hoc Wireless Networks, D.S. KimMaximum Necessary Hop Count for Packet Routing in MANET, X. Chen and J. ShenEfficient Strategyproof Multicast in Selfish Wireless Networks, X.-Yang LiGeocasting in Ad Hoc and Sensor Networks, I. StojmenovicTopology Control for Ad hoc Networks: Present Solutions and Open Issues, C.-C. Shen a

  1. Collaborative In-Network Processing for Target Tracking

    Directory of Open Access Journals (Sweden)

    Juan Liu

    2003-03-01

    Full Text Available This paper presents a class of signal processing techniques for collaborative signal processing in ad hoc sensor networks, focusing on a vehicle tracking application. In particular, we study two types of commonly used sensors—acoustic-amplitude sensors for target distance estimation and direction-of-arrival sensors for bearing estimation—and investigate how networks of such sensors can collaborate to extract useful information with minimal resource usage. The information-driven sensor collaboration has several advantages: tracking is distributed, and the network is energy-efficient, activated only on a when-needed basis. We demonstrate the effectiveness of the approach to target tracking using both simulation and field data.

  2. Insight: Exploring Hidden Roles in Collaborative Play

    Directory of Open Access Journals (Sweden)

    Tricia Shi

    2015-06-01

    Full Text Available This paper looks into interaction modes between players in co-located, collaborative games. In particular, hidden traitor games, in which one or more players is secretly working against the group mission, has the effect of increasing paranoia and distrust between players, so this paper looks into the opposite of a hidden traitor – a hidden benefactor. Rather than sabotaging the group mission, the hidden benefactor would help the group achieve the end goal while still having a reason to stay hidden. The paper explores what games with such a role can look like and how the role changes player interactions. Finally, the paper addresses the divide between video game and board game interaction modes; hidden roles are not common within video games, but they are of growing prevalence in board games. This fact, combined with the exploration of hidden benefactors, reveals that hidden roles is a mechanic that video games should develop into in order to match board games’ complexity of player interaction modes.

  3. Collaborative Contracting in Projects

    NARCIS (Netherlands)

    Suprapto, M.

    2016-01-01

    Project practitioners have increasingly recognized the importance of collaborative relationships to ensure successful executions of projects. However, the ability to sustain and consistenly drive real collaborative attitudes and behavior for achieving the desired outcomes remains of enduring

  4. Global Collaborative STEM Education

    Science.gov (United States)

    Meabh Kelly, Susan; Smith, Walter

    2016-04-01

    Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

  5. Experiences of Collaborative Research

    Science.gov (United States)

    Kahneman, Daniel

    2003-01-01

    The author's personal history of the research that led to his recognition in economics is described, focusing on the process of collaboration and on the experience of controversy. The author's collaboration with Amos Tversky dealt with 3 major topics: judgment under uncertainty, decision making, and framing effects. A subsequent collaboration,…

  6. An implementation of traffic light system using multi-hop Ad hoc networks

    KAUST Repository

    Ansari, Imran Shafique

    2009-08-01

    In ad hoc networks nodes cooperate with each other to form a temporary network without the aid of any centralized administration. No wired base station or infrastructure is supported, and each host communicates via radio packets. Each host must act as a router, since routes are mostly multi-hop, due to the limited power transmission set by government agencies, (e.g. the Federal Communication Commission (FCC), which is 1 Watt in Industrial Scientific and Medical (ISM) band. The natures of wireless mobile ad hoc networks depend on batteries or other fatiguing means for their energy. A limited energy capacity may be the most significant performance constraint. Therefore, radio resource and power management is an important issue of any wireless network. In this paper, a design for traffic light system employing ad hoc networks is proposed. The traffic light system runs automatically based on signals sent through a multi-hop ad hoc network of \\'n\\' number of nodes utilizing the Token Ring protocol, which is efficient for this application from the energy prospective. The experiment consists of a graphical user interface that simulates the traffic lights and laptops (which have wireless network adapters) are used to run the graphical user interface and are responsible for setting up the ad hoc network between them. The traffic light system has been implemented utilizing A Mesh Driver (which allows for more than one wireless device to be connected simultaneously) and Java-based client-server programs. © 2009 IEEE.

  7. Trust repertoires for collaboration

    DEFF Research Database (Denmark)

    Fuglsang, Lars

    This case study analyses the role of trust in a public private innovation network that involved a private consultancy company as a facilitator. We know that collaboration is a important for innovation, and that collaboration across organizational boundaries is not a trivial issue. But we know very...... little about how such processes develop and how trust, understood as “confident positive expectations” (Lewicki et al. 1998) to collaborative activities, arises out of collaboration. The paper contributes by showing how trust and collaboration are intertwined. The main finding is that a facilitator can...

  8. Collaborative Data Mining

    Science.gov (United States)

    Moyle, Steve

    Collaborative Data Mining is a setting where the Data Mining effort is distributed to multiple collaborating agents - human or software. The objective of the collaborative Data Mining effort is to produce solutions to the tackled Data Mining problem which are considered better by some metric, with respect to those solutions that would have been achieved by individual, non-collaborating agents. The solutions require evaluation, comparison, and approaches for combination. Collaboration requires communication, and implies some form of community. The human form of collaboration is a social task. Organizing communities in an effective manner is non-trivial and often requires well defined roles and processes. Data Mining, too, benefits from a standard process. This chapter explores the standard Data Mining process CRISP-DM utilized in a collaborative setting.

  9. Packets Distributing Evolutionary Algorithm Based on PSO for Ad Hoc Network

    Science.gov (United States)

    Xu, Xiao-Feng

    2018-03-01

    Wireless communication network has such features as limited bandwidth, changeful channel and dynamic topology, etc. Ad hoc network has lots of difficulties in accessing control, bandwidth distribution, resource assign and congestion control. Therefore, a wireless packets distributing Evolutionary algorithm based on PSO (DPSO)for Ad Hoc Network is proposed. Firstly, parameters impact on performance of network are analyzed and researched to obtain network performance effective function. Secondly, the improved PSO Evolutionary Algorithm is used to solve the optimization problem from local to global in the process of network packets distributing. The simulation results show that the algorithm can ensure fairness and timeliness of network transmission, as well as improve ad hoc network resource integrated utilization efficiency.

  10. Service for fault tolerance in the Ad Hoc Networks based on Multi Agent Systems

    Directory of Open Access Journals (Sweden)

    Ghalem Belalem

    2011-02-01

    Full Text Available The Ad hoc networks are distributed networks, self-organized and does not require infrastructure. In such network, mobile infrastructures are subject of disconnections. This situation may concern a voluntary or involuntary disconnection of nodes caused by the high mobility in the Ad hoc network. In these problems we are trying through this work to contribute to solving these problems in order to ensure continuous service by proposing our service for faults tolerance based on Multi Agent Systems (MAS, which predict a problem and decision making in relation to critical nodes. Our work contributes to study the prediction of voluntary and involuntary disconnections in the Ad hoc network; therefore we propose our service for faults tolerance that allows for effective distribution of information in the Network by selecting some objects of the network to be duplicates of information.

  11. Energy-Aware Routing Protocol for Ad Hoc Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mann Raminder P

    2005-01-01

    Full Text Available Wireless ad hoc sensor networks differ from wireless ad hoc networks from the following perspectives: low energy, lightweight routing protocols, and adaptive communication patterns. This paper proposes an energy-aware routing protocol (EARP suitable for ad hoc wireless sensor networks and presents an analysis for its energy consumption in various phases of route discovery and maintenance. Based on the energy consumption associated with route request processing, EARP advocates the minimization of route requests by allocating dynamic route expiry times. This paper introduces a unique mechanism for estimation of route expiry time based on the probability of route validity, which is a function of time, number of hops, and mobility parameters. In contrast to AODV, EARP reduces the repeated flooding of route requests by maintaining valid routes for longer durations.

  12. Analysis of DDoS Attack Effect and Protection Scheme in Wireless Mobile Ad-hoc Network

    OpenAIRE

    Ramratan Ahirwal; Leeladhar Mahour

    2012-01-01

    In Wireless mobile Ad Hoc Networks (MANET) every node functions as transmitter, router and data sink is network without infrastructure. Detecting malicious nodes in an open ad-hoc network in whichparticipating nodes have no previous security associations presents a number of challenges not faced by traditional wired networks. Traffic monitoring in wired networks is usually performed at switches,routers and gateways, but an ad-hoc network does not have these types of network elements where the...

  13. Collaborative research: Accomplishments & potential

    Science.gov (United States)

    Katsouyanni, Klea

    2008-01-01

    Although a substantial part of scientific research is collaborative and increasing globalization will probably lead to its increase, very few studies actually investigate the advantages, disadvantages, experiences and lessons learned from collaboration. In environmental epidemiology interdisciplinary collaboration is essential and the contrasting geographical patterns in exposure and disease make multi-location projects essential. This paper is based on a presentation given at the Annual Conference of the International Society for Environmental Epidemiology, Paris 2006, and is attempting to initiate a discussion on a framework for studying collaborative research. A review of the relevant literature showed that indeed collaborative research is rising, in some countries with impressive rates. However, there are substantial differences between countries in their outlook, need and respect for collaboration. In many situations collaborative publications receive more citations than those based on national authorship. The European Union is the most important host of collaborative research, mainly driven by the European Commission through the Framework Programmes. A critical assessment of the tools and trends of collaborative networks under FP6, showed that there was a need for a critical revision, which led to changes in FP7. In conclusion, it is useful to study the characteristics of collaborative research and set targets for the future. The added value for science and for the researchers involved may be assessed. The motivation for collaboration could be increased in the more developed countries. Particular ways to increase the efficiency and interaction in interdisciplinary and intercultural collaboration may be developed. We can work towards "the principles of collaborative research" in Environmental Epidemiology. PMID:18208596

  14. Ad Hoc Wireless Networking and Shared Computation for Autonomous Multirobot Systems

    OpenAIRE

    Bevilacqua, Riccardo; Hall, Jason S.; Horning, James; Romano, Marcello

    2009-01-01

    The article of record as published may be located at http://dx.doi.org/10.2514/1.40734 A wireless ad hoc network is introduced that enables inter-robot communication and shared computation among multiple robots with PC/104-based single board computers running the real-time application interface patched Linux operating system. Through the use of IEEE 802.11 ad hoc technology and User Datagram Protocol, each robot is able to exchange data without the need of a centralized router ...

  15. A-priori and post-hoc segmentation in the design of healthy eating campaigns

    DEFF Research Database (Denmark)

    Kazbare, Laura; van Trijp, Hans C. M.; Eskildsen, Jacob Kjær

    2010-01-01

    . Although such practice may be justifiable from the practical point of view, it is unclear how effective these implicit segmentations are. In this study the authors argue that  it is important to transcend demographic boundaries and to further segment demographic groups. A study with 13-15-year-old...... and a post-hoc segmentation. The results of the study show that it is useful and also ethical to differentiate people using segmentation methods, since it facilitates reaching more vulnerable segments of society that in general resist change. It also demonstrates that post-hoc segmentation is more helpful...

  16. Mitigate DoS and DDoS attacks in Mobile Ad Hoc Networks

    DEFF Research Database (Denmark)

    Michalas, Antonis; Komninos, Nikos; Prasad, Neeli R.

    2011-01-01

    This paper proposes a technique to defeat Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks in Ad Hoc Networks. The technique is divided into two main parts and with game theory and cryptographic puzzles. Introduced first is a new client puzzle to prevent DoS attacks...... in DoS and DDoS attacks. Experimental results show the effectiveness of the approach for devices with limited resources and for environments like ad hoc networks where nodes must exchange information quickly....

  17. Multiplayer Game for DDoS Attacks Resilience in Ad Hoc Networks

    DEFF Research Database (Denmark)

    Mikalas, Antonis; Komninos, Nikos; Prasad, Neeli R.

    2011-01-01

    This paper proposes a multiplayer game to prevent Distributed Denial of Service attack (DDoS) in ad hoc networks. The multiplayer game is based on game theory and cryptographic puzzles. We divide requests from nodes into separate groups which decreases the ability of malicious nodes to cooperate...... with one another in order to effectively make a DDoS attack. Finally, through our experiments we have shown that the total overhead of the multiplayer game as well as the the total time that each node needs to be served is affordable for devices that have limited resources and for environments like ad hoc...

  18. Deny-by-Default Distributed Security Policy Enforcement in Mobile Ad Hoc Networks

    Science.gov (United States)

    Alicherry, Mansoor; Keromytis, Angelos D.; Stavrou, Angelos

    Mobile Ad-hoc Networks (MANETs) are increasingly employed in tactical military and civil rapid-deployment networks, including emergency rescue operations and ad hoc disaster-relief networks. However, this flexibility of MANETs comes at a price, when compared to wired and base station-based wireless networks: MANETs are susceptible to both insider and outsider attacks. This is mainly because of the lack of a well-defined defense perimeter preventing the effective use of wired defenses including firewalls and intrusion detection systems.

  19. Multicasting in Wireless Communications (Ad-Hoc Networks): Comparison against a Tree-Based Approach

    Science.gov (United States)

    Rizos, G. E.; Vasiliadis, D. C.

    2007-12-01

    We examine on-demand multicasting in ad hoc networks. The Core Assisted Mesh Protocol (CAMP) is a well-known protocol for multicast routing in ad-hoc networks, generalizing the notion of core-based trees employed for internet multicasting into multicast meshes that have much richer connectivity than trees. On the other hand, wireless tree-based multicast routing protocols use much simpler structures for determining route paths, using only parent-child relationships. In this work, we compare the performance of the CAMP protocol against the performance of wireless tree-based multicast routing protocols, in terms of two important factors, namely packet delay and ratio of dropped packets.

  20. Centralized cooperative spectrum sensing for ad-hoc disaster relief network clusters

    DEFF Research Database (Denmark)

    Pratas, Nuno; Marchetti, Nicola; Prasad, Neeli R.

    2010-01-01

    Disaster relief networks have to be highly adaptable and resilient. Cognitive radio enhanced ad-hoc architecture have been put forward as a candidate to enable such networks. Spectrum sensing is the cornerstone of the cognitive radio paradigm, and it has been the target of intensive research....... The main common conclusion was that the achievable spectrum sensing accuracy can be greatly enhanced through the use of cooperative sensing schemes. When considering applying Cognitive Radio to ad-hoc disaster relief networks, spectrum sensing cooperative schemes are paramount. A centralized cluster...

  1. Collaboration across the Arctic

    DEFF Research Database (Denmark)

    Huppert, Verena Gisela; Chuffart, Romain François R.

    2017-01-01

    The Arctic is witnessing the rise of a new paradigm caused by an increase in pan-Arctic collaborations which co-exist with the region’s traditional linkages with the South. Using an analysis of concrete examples of regional collaborations in the Arctic today in the fields of education, health...... and infrastructure, this paper questions whether pan-Arctic collaborations in the Arctic are more viable than North-South collaborations, and explores the reasons behind and the foreseeable consequences of such collaborations. It shows that the newly emerging East-West paradigm operates at the same time...... as the traditional North-South paradigm, with no signs of the East-West paradigm being more viable in the foreseeable future. However, pan-Arctic collaboration, both due to pragmatic reasons and an increased awareness of similarities, is likely to increase in the future. The increased regionalization process...

  2. Professional Learning and Collaboration

    OpenAIRE

    Greer, Janet Agnes

    2012-01-01

    The American education system must utilize collaboration to meet the challenges and demands our culture poses for schools. Deeply rooted processes and structures favor teaching and learning in isolation and hinder the shift to a more collaborative paradigm. Professional learning communities (PLCs) support continuous teacher learning, improved efficacy, and program implementation. The PLC provides the framework for the development and enhancement of teacher collaboration and teacher collaborat...

  3. Managing collaborative design

    OpenAIRE

    Sebastian, R.

    2007-01-01

    Collaborative design has been emerging in building projects everywhere. The more complex a building project becomes, the closer and more intensive collaboration between the design actors is required. This research focuses on collaborative design in the conceptual architecture design phase, especially during the elaboration of the masterplan and the development of the preliminary building designs. This research is descriptive and has two aims. First, it aims at describing the characteristics a...

  4. Opposing incentives for collaboration

    DEFF Research Database (Denmark)

    Dorch, Bertil F.; Wien, Charlotte; Larsen, Asger Væring

    , and gives a bonus for publications done through inter-institutionary collaboration. Credits given to universities are fractionalized between the participating universities. So far credits are not assigned to the individual authors but only to their institutions. However, it turns out that research...... collaboration is associated with a higher number of citations than single authorship which may present the author with two opposing incentives for research collaboration....

  5. The Collaborative Future

    Directory of Open Access Journals (Sweden)

    Thomas Marlowe

    2011-10-01

    Full Text Available Collaboration has become an important goal in modern ventures, across the spectrum of commercial, social, and intellectual activities, sometimes as a mediating factor, and sometimes as a driving, foundational principle. Research, development, social programs, and ongoing ventures of all sorts benefit from interactions between teams, groups, and organizations, across intellectual disciplines and across facets and features of the inquiry, product, entity, or activity under consideration. We present a survey of the state of collaboration and collaborative enterprise, in the context of papers and presentations at the International Symposium on Collaborative Enterprises 2011 (CENT 2011, and the extended papers appearing in this special issue.

  6. Commemorating Misadventures, Celebrating Collaborations

    Centers for Disease Control (CDC) Podcasts

    Byron Breedlove, Managing Editor of Emerging Infectious Diseases journal, reads his February 2018 cover essay, "Commemorating Misadventures, Celebrating Collaborations" and discusses a sketch by Picasso and zoonoses.

  7. Collaborative Service Arrangements

    DEFF Research Database (Denmark)

    J. May, Peter; Winter, Søren

    While much of prior research on collaboration addresses the service delivery network as a whole, we address collaborative relationships between one type of organization—municipal employment services—and a range of governmental and non-governmental partners for employment services in Denmark....... Municipalities differ in the type, degree, and character of collaboration with these partners. As others have found in prior research, we find that organizational benefits, trust, and a variety of contextual factors help shape the extent of collaboration. But, the relevance of these and problem-solving benefits...

  8. Educators' Interprofessional Collaborative Relationships: Helping Pharmacy Students Learn to Work with Other Professions.

    Science.gov (United States)

    Croker, Anne; Smith, Tony; Fisher, Karin; Littlejohns, Sonja

    2016-03-30

    Similar to other professions, pharmacy educators use workplace learning opportunities to prepare students for collaborative practice. Thus, collaborative relationships between educators of different professions are important for planning, implementing and evaluating interprofessional learning strategies and role modelling interprofessional collaboration within and across university and workplace settings. However, there is a paucity of research exploring educators' interprofessional relationships. Using collaborative dialogical inquiry we explored the nature of educators' interprofessional relationships in a co-located setting. Data from interprofessional focus groups and semi-structured interviews were interpreted to identify themes that transcended the participants' professional affiliations. Educators' interprofessional collaborative relationships involved the development and interweaving of five interpersonal behaviours: being inclusive of other professions; developing interpersonal connections with colleagues from other professions; bringing a sense of own profession in relation to other professions; giving and receiving respect to other professions; and being learner-centred for students' collaborative practice . Pharmacy educators, like other educators, need to ensure that interprofessional relationships are founded on positive experiences rather than vested in professional interests.

  9. New grid based test bed environment for carrying out ad-hoc networking experiments

    CSIR Research Space (South Africa)

    Johnson, D

    2006-09-01

    Full Text Available and the third is to do analysis on a real test bed network which has implemented the ad-hoc networking protocol. This paper concerns the third option. Most researchers who have done work on test bed environments have used either indoor Wifi inter-office links...

  10. Correctness-by-construction and post-hoc verification : a marriage of convenience?

    NARCIS (Netherlands)

    Watson, B.W.; Kourie, D.G.; Schaefer, I.; Cleophas, L.G.W.A.; Margaria, T.; Steffen, B.

    2016-01-01

    Correctness-by-construction (CbC), traditionally based on weakest precondition semantics, and post-hoc verification (PhV) aspire to ensure functional correctness. We argue for a lightweight approach to CbC where lack of formal rigour increases productivity. In order to mitigate the risk of

  11. Peer-to-peer over mobile ad hoc networks (Chapter 11)

    NARCIS (Netherlands)

    Qadri, N.N.; Liotta, A.; Pierre, S.

    2010-01-01

    In this chapter we review various approaches for the convergence of Peer-to-Peer (P2P) and Mobile Ad hoc Networks (MANETs), identifying strengths and weaknesses, and putting things in perspective. P2P and MANETs are among the most active research topics in pervasive computing. The convergence of P2P

  12. Specification and Validation of an Edge Router Discovery Protocol for Mobile Ad Hoc Networks

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Jensen, Kurt

    2004-01-01

    We present an industrial project at Ericsson Telebit A/S where Coloured Petri Nets (CP-nets or CPNs) have been used for the design and specification of an edge router discovery protocol for mobile ad-hoc networks. The Edge Router Discovery Protocol (ERDP) supports an edge router in a stationary...

  13. An Economic Framework for Resource Allocation in Ad-hoc Grids

    NARCIS (Netherlands)

    Pourebrahimi, B.

    2009-01-01

    In this dissertation, we present an economic framework to study and develop different market-based mechanisms for resource allocation in an ad-hoc Grid. Such an economic framework helps to understand the impact of certain choices and explores what are the suitable mechanisms from Grid user/owner

  14. NDN-CRAHNs: Named Data Networking for Cognitive Radio Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Rana Asif Rehman

    2015-01-01

    Full Text Available Named data networking (NDN is a newly proposed paradigm for future Internet, in which communication among nodes is based on data names, decoupling from their locations. In dynamic and self-organized cognitive radio ad hoc networks (CRAHNs, it is difficult to maintain end-to-end connectivity between ad hoc nodes especially in the presence of licensed users and intermittent wireless channels. Moreover, IP-based CRAHNs have several issues like scalability, inefficient-mapping, poor resource utilization, and location dependence. By leveraging the advantages of NDN, in this paper, we propose a new cross layer fine-grained architecture called named data networking for cognitive radio ad hoc networks (NDN-CRAHNs. The proposed architecture provides distinct features such as in-networking caching, security, scalability, and multipath routing. The performances of the proposed scheme are evaluated comparing to IP-based scheme in terms of average end-to-end delay and packet delivery ratio. Simulation results show that the proposed scheme is effective in terms of average contents download time and packet delivery ratios comparing to conventional cognitive radio ad hoc networks.

  15. Conflict Management in "Ad Hoc" Problem-Solving Groups: A Preliminary Investigation.

    Science.gov (United States)

    Wallace, Les; Baxter, Leslie

    Full study of small group communication must include consideration of task and socio-emotional dimensions, especially in relation to group problem solving. Thirty small groups were tested for their reactions in various "ad hoc" conflict resolution situations. Instructions to the groups were (1) no problem-solving instructions (control),…

  16. Performance analysis of differentiated resource-sharing in a wireless ad-hoc network

    NARCIS (Netherlands)

    Roijers, F.; van den Berg, H.; Mandjes, M.

    2010-01-01

    In this paper we model and analyze a relay node in a wireless ad-hoc network; the capacity available at this node is used to both transmit traffic from the source nodes (towards the relay node), and to serve traffic at the relay node (so that it can be forwarded to successor nodes). Clearly, a

  17. On the Geometrical Characteristics of Three-Dimensional Wireless Ad Hoc Networks and Their Applications

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available In a wireless ad hoc network, messages are transmitted, received, and forwarded in a finite geometrical region and the transmission of messages is highly dependent on the locations of the nodes. Therefore the study of geometrical relationship between nodes in wireless ad hoc networks is of fundamental importance in the network architecture design and performance evaluation. However, most previous works concentrated on the networks deployed in the two-dimensional region or in the infinite three-dimensional space, while in many cases wireless ad hoc networks are deployed in the finite three-dimensional space. In this paper, we analyze the geometrical characteristics of the three-dimensional wireless ad hoc network in a finite space in the framework of random graph and deduce an expression to calculate the distance probability distribution between network nodes that are independently and uniformly distributed in a finite cuboid space. Based on the theoretical result, we present some meaningful results on the finite three-dimensional network performance, including the node degree and the max-flow capacity. Furthermore, we investigate some approximation properties of the distance probability distribution function derived in the paper.

  18. Built-In Device Orientation Sensors for Ad-Hoc Pairing and Spatial Awareness

    DEFF Research Database (Denmark)

    Grønbæk, Jens Emil; O'Hara, Kenton

    Mobile devices are equipped with multiple sensors. The ubiquity of these sensors is key in their ability to support in-the-wild application and use. Building on the ubiquity we look at how we can use this existing sensing infrastructure combined with user mediation to support ad-hoc sharing with ...

  19. Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

    OpenAIRE

    Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

    2007-01-01

    Sloep, P.B., Kester, L. Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007) Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. In V. Uskov (Ed.) The Sixth IASTED International Conference on Web-based Education WBE 2007, March 14-16, Chamonix, France (pp. 549-554). Calgary, Canada: Acta Press.

  20. Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

    NARCIS (Netherlands)

    Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

    2007-01-01

    Sloep, P.B., Kester, L. Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007) Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. In V. Uskov (Ed.) The Sixth IASTED International Conference on Web-based Education WBE 2007, March 14-16,

  1. Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

    NARCIS (Netherlands)

    Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

    2007-01-01

    Sloep, P.B., Kester, L., Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007). Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. Presentation given at the Sixth IASTED International Conference on Web-based Education, 14-16 March,

  2. Neuroprotection as initial therapy in acute stroke - Third report of an Ad Hoc Consensus Group Meeting

    NARCIS (Netherlands)

    Bogousslavsky, J; De Keyser, J; Diener, HC; Fieschi, C; Hacke, W; Kaste, M; Orgogozo, JM; Pulsinelli, W; Wahlgren, NG

    1998-01-01

    Although a considerable body of scientific data is now available on neuroprotection in acute ischaemic stroke, this field is not yet established in clinical practice. At its third meeting, the European Ad Hoc Consensus Group considered the potential for neuroprotection in acute stroke and the

  3. Model-based prototyping of an interoperability protocol for mobile ad-hoc networks

    NARCIS (Netherlands)

    Kristensen, L.M.; Westergaard, M.; Norgaard, P.C.; Romijn, J.; Smith, G.; Pol, van de J.

    2005-01-01

    We present an industrial project conducted at Ericsson Danmark A/S, Telebit where formal methods in the form of Coloured Petri Nets (CP-nets or CPNs) have been used for the specification of an interoperability protocol for routing packets between fixed core networks and mobile ad-hoc networks. The

  4. BLESSED with Opportunistic Beacons: A Lightweight Data Dissemination Model for Smart Mobile Ad-Hoc Networks

    NARCIS (Netherlands)

    Türkes, Okan; Scholten, Johan; Havinga, Paul J.M.

    2015-01-01

    This paper introduces BLESSED, a universal opportunistic ad hoc networking model intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the complementary utilization of the IEEE 802.11 and Bluetooth Low Energy standards. As a

  5. Integrated Social and Quality of Service Trust Management of Mobile Groups in Ad Hoc Networks

    Science.gov (United States)

    2013-01-01

    high resiliency to malicious attacks and misbehaving nodes. Keywords—trust management; mobile ad hoc networks; QoS trust; social trust; trust...paper we address an importance issue of trust management protocol design for MANETs: trust bias minimization despite misbehaving nodes performing

  6. Ad hoc public disclosure obligations of public companies on the capital market

    Directory of Open Access Journals (Sweden)

    Marjanski Vladimir

    2012-01-01

    Full Text Available The author gives a comprehensive analysis of the obligations of public companies regarding the provision of periodical (ad hoc information to the public on the capital market. Ad hoc disclosure is to achieve a number of aims. It is one of the devices to secure the market's functional abilities. By means of regularly fulfilling this obligation, the market is provided with all the relevant information necessary to form adequate prices of market materials - i.e. securities and other financial instruments (the function of market protection. Investors are thus being able to aptly respond to modified circumstances and deliver investment decisions whether to buy or sell market materials the price of which are being changed (the function of investor protection. Due to the fact that the duty of ad hoc disclosure encompasses the obligation to reveal insider information directly affecting the emitter, ad hoc disclosure serves as a preventive measure, i.e. as a protection against illicit trade with insider information (the function of prevention against the abuse of insider information.

  7. Student Self-Assessment in HOCS Science Examinations: Is There a Problem?

    Science.gov (United States)

    Zoller, Uri; Ben-Chaim, David

    1998-06-01

    A specially-designed self-assessment questionnaire (SAQHOCS), containing higher-order cognitive skills (HOCS)-type questions, was administered to 71 biology majors, enrolled in a four-year college program. The gap between students' self-assessment marking, and that of their HOCS-biased teachers (the authors), is accounted for by the prevailing LOCS-orientation and the "testing culture"—a total separation between testing and learning—in contemporary science teaching. The majority of the students in the study evaluated themselves as capable of self-assessment, and felt reasonably confident in doing so. They were quite reserved as far as the applicability of the self-assessment method to nonalgorithmic ("correct/incorrect") questions is concerned. The results of this study suggest that the potential for student self-assessment within college science teaching and learning exists. However, still a great purposed effort in HOCS-oriented teaching and learning is required in order for the student self-assessment practice to become a routine integral component of HOCS science examinations.

  8. PUCA: A Pseudonym Scheme with User-Controlled Anonymity for Vehicular Ad-Hoc Networks (VANET)

    NARCIS (Netherlands)

    Förster, David; Kargl, Frank; Löhr, Hans

    2014-01-01

    Envisioned vehicular ad-hoc networks (VANET) standards use pseudonym certificates to provide secure and privacy-friendly message authentication. Revocation of long-term credentials is required to remove participants from the system, e.g. in case of vehicle theft. However, the current approach to

  9. A tandem queueing model for delay analysis in disconnected ad hoc networks

    NARCIS (Netherlands)

    Al Hanbali, Ahmad; de Haan, Roland; Boucherie, Richardus J.; van Ommeren, Jan C.W.

    2007-01-01

    Ad hoc network routing protocols may fail to operate in the absence of an end-to-end connection from source to destination. This deficiency can be resolved by so-called opportunistic networking which exploits the mobility of the nodes by letting them operate as relays according to the

  10. Improving the Usability of OCL as an Ad-hoc Model Querying Language

    DEFF Research Database (Denmark)

    Störrle, Harald

    2013-01-01

    from our research and make it accessible to the OCL community, we propose the OCL Query API (OQAPI), a library of query-predicates to improve the user-friendliness of OCL for ad-hoc querying. The usability of OQAPI is studied using controlled experiments. We nd considerable evidence to support our...

  11. RAILWAY INFRASTRUCTURE CAPACITY MANAGEMENT FOR AD-HOC TRAINS ON THE SŽDC NETWORK

    Directory of Open Access Journals (Sweden)

    Petr Nachtigall

    2016-09-01

    Full Text Available The paper describes basic principles of ad-hoc routes assignment. Each carrier has its own interface called information system KADR with SŽDC for capacity requests management. The paper describes all steps which must be done before train departure.

  12. Impact of mobility on the performance of relaying in ad hoc networks (Extended version)

    NARCIS (Netherlands)

    Al Hanbali, A.; Kherani, A.A.; Groenevelt, R.; Nain, P.; Altman, E.

    2007-01-01

    We consider a mobile ad hoc network consisting of three types of nodes: source, destination, and relay nodes. All the nodes are moving over a bounded region with possibly different mobility patterns. We introduce and study the notion of relay throughput, i.e. the maximum rate at which a node can

  13. Impact of Mobility on the Performance of Relaying in Ad Hoc Networks

    NARCIS (Netherlands)

    Al Hanbali, Ahmad; Kherani, A.A.; Groenevelt, R.; Nain, P.; Altman, E

    2006-01-01

    We consider a mobile ad hoc network consisting of three types of nodes: source, destination, and relay nodes. All the nodes are moving over a bounded region with possibly different mobility patterns. We introduce and study the notion of relay throughput, i.e. the maximum rate at which a node can

  14. Impact of mobility on the performance7 of relaying in ad hoc networks – Extended version

    NARCIS (Netherlands)

    Al Hanbali, Ahmad; Kherani, A.A.; Groenevelt, R.; Nain, P.; Altman, E

    2007-01-01

    We consider a mobile ad hoc network consisting of three types of nodes: source, destination, and relay nodes. All the nodes are moving over a bounded region with possibly different mobility patterns. We introduce and study the notion of relay throughput, i.e. the maximum rate at which a node can

  15. Adjusting Sensing Range to Maximize Throughput on Ad-Hoc Multi-Hop Wireless Networks

    National Research Council Canada - National Science Library

    Roberts, Christopher

    2003-01-01

    .... Such a network is referred to as a multi-hop ad-hoc network, or simply a multi-hop network. Most multi-hop network protocols use some form of carrier sensing to determine if the wireless channel is in use...

  16. Adaptive Demand-Driven Multicast Routing in Multi-Hop Wireless Ad Hoc Networks

    National Research Council Canada - National Science Library

    Jetcheva, Jorjeta G

    2004-01-01

    ...) nodes that wish to communicate. Each node in the ad hoc network acts as a router and forwards packets on behalf of other nodes, allowing nodes that are not within wireless range of each other to communicate over multi-hop paths...

  17. System optimization for peer-to-peer multi hop video broadcasting in wireless ad hoc networks

    NARCIS (Netherlands)

    Dedeoglu, V.; Atici, C.; Salman, F.S.; Sunay, M.O.

    2008-01-01

    We consider peer-to-peer video broadcasting using cooperation among peers in an ad hoc wireless network. As opposed to the traditional single hop broadcasting, multiple hops cause an increase in broadcast video quality while creating interference and increasing transmission delay. We develop

  18. Collaboration in teacher teams

    NARCIS (Netherlands)

    Brouwer, P.

    2011-01-01

    In order to deal with innovations and the associated complexity of work, ongoing collaboration between teachers has become more important in secondary education. Teacher collaboration is one of the factors that contribute to the successful implementation of innovations in secondary schools. However,

  19. Enabling distributed collaborative science

    DEFF Research Database (Denmark)

    Hudson, T.; Sonnenwald, Diane H.; Maglaughlin, K.

    2000-01-01

    To enable collaboration over distance, a collaborative environment that uses a specialized scientific instrument called a nanoManipulator is evaluated. The nanoManipulator incorporates visualization and force feedback technology to allow scientists to see, feel, and modify biological samples bein...

  20. Solo Librarians Working Collaboratively

    Science.gov (United States)

    Nickel, Robbie

    2011-01-01

    The Elko County School District in Nevada has elementary school librarians that are "solo" librarians. Over the last several years they have worked to collaborate on meeting monthly--even though the district covers 17,100 square miles--and on providing professional development face to face and online. Sharing and collaboration help them…

  1. Collaborating with Rising Stars

    DEFF Research Database (Denmark)

    Andersen, Kristina Vaarst; Mors, Marie Louise; Jeppesen, Jacob

    2018-01-01

    Status provides preferential access to resources, as well as favorable judgment, which in turn may lead to increases in performance. Prior work has established that such benefits even spill over between collaboration partners, thus allowing collaboration partners of high status individuals to bas...

  2. Negotiating Collaborative Governance Designs

    DEFF Research Database (Denmark)

    Plotnikof, Mie

    2017-01-01

    This chapter addresses the design and implementation issues of collaborative governance, a public management practice aimed at involving stakeholders in problem-solving and public innovation.......This chapter addresses the design and implementation issues of collaborative governance, a public management practice aimed at involving stakeholders in problem-solving and public innovation....

  3. Enhancing performance through collaboration

    International Nuclear Information System (INIS)

    Froats, J.

    2010-01-01

    This presentation examines how co-operation and collaboration are keys to high performing organizations and attempts to provoke some thinking about how one can improve the game to meet the challenges of today. The presentation discusses the origins of the belief system and gives examples of the benefits of collaborative approaches.

  4. Collaborative Car Pooling System

    OpenAIRE

    João Ferreira; Paulo Trigo; Porfírio Filipe

    2009-01-01

    This paper describes the architecture for a collaborative Car Pooling System based on a credits mechanism to motivate the cooperation among users. Users can spend the accumulated credits on parking facilities. For this, we propose a business model to support the collaboration between a car pooling system and parking facilities. The Portuguese Lisbon-s Metropolitan area is used as application scenario.

  5. Emergent Collaboration on Twitter

    DEFF Research Database (Denmark)

    Lundgaard, Daniel; Razmerita, Liana; Tan, Chee-Wee

    2018-01-01

    This paper explores the organizing elements that foster emergent collaboration within large-scale communities on online social platforms like Twitter. This study is based on a case study of the #BlackLivesMatter social movement and draws on organizing dynamics and online social network literature...... foster emergent collaboration in social movements using Twitter....

  6. Protocols for Detection and Removal of Wormholes for Secure Routing and Neighborhood Creation in Wireless Ad Hoc Networks

    Science.gov (United States)

    Hayajneh, Thaier Saleh

    2009-01-01

    Wireless ad hoc networks are suitable and sometimes the only solution for several applications. Many applications, particularly those in military and critical civilian domains (such as battlefield surveillance and emergency rescue) require that ad hoc networks be secure and stable. In fact, security is one of the main barriers to the extensive use…

  7. Collaborative Policy Innovation

    DEFF Research Database (Denmark)

    Sørensen, Eva; Boch Waldorff, Susanne

    2014-01-01

    Governments all over the Western world currently face wicked problems that call for policy innovation. A new strand of research in public innovation points to collaboration between public authorities and relevant and affected stakeholders as an important driver of public innovation. A case study...... of collaborative policy innovation in the area of mental health care in Denmark indicates that collaboration can contribute to qualify the politicians’ understanding of wicked policy problems, and to fostering new creative policy solutions. The study also shows, however, that the new problem understandings...... and policy ideas produced in collaborative governance arenas are not diffused to the formal political institutions of representative democracy because the participating politicians only to a limited extent function as boundary spanners between the collaborative governance arena and the decision making arenas...

  8. Nurse-patient collaboration

    DEFF Research Database (Denmark)

    Sørensen, Dorthe; Frederiksen, Kirsten; Groefte, Thorbjoern

    2013-01-01

    Objectives: This paper provides a theoretical account of nurses’ collaboration with patients with chronic obstructive pulmonary disease during non-invasive ventilation treatment in hospital. Background: Despite strong evidence for the effect of non-invasive ventilation treatment, success remains...... a huge challenge. Nurse-patient collaboration may be vital for treatment tolerance and success. A better understanding of how nurses and patients collaborate during non-invasive ventilation may therefore contribute to improvement in treatment success. Design: A constant comparative classical grounded...... at three intensive care units and one general respiratory ward in Denmark. Results: Succeeding emerged as the nurses’ main concern in the nurse-patient collaboration during non-invasive ventilation treatment. Four collaborative typologies emerged as processing their main concern: (1) twofold oriented...

  9. Electronic Collaboration Logbook

    International Nuclear Information System (INIS)

    Gysin, Suzanne; Mandrichenko, Igor; Podstavkov, Vladimir; Vittone, Margherita

    2012-01-01

    In HEP, scientific research is performed by large collaborations of organizations and individuals. The logbook of a scientific collaboration is an important part of the collaboration record. Often it contains experimental data. At Fermi National Accelerator Laboratory (FNAL), we developed an Electronic Collaboration Logbook (ECL) application, which is used by about 20 different collaborations, experiments and groups at FNAL. The ECL is the latest iteration of the project formerly known as the Control Room Logbook (CRL). We have been working on mobile (IOS and Android) clients for the ECL. We will present the history, current status and future plans of the project, as well as design, implementation and support solutions made by the project.

  10. Writing as collaborative inquiry

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth; Pedersen, Christina Hee; Novak, Martin

    2015-01-01

    involved in collaborative knowledge production across difference (including age, professional position, life situation, nation). We tell about our experiences with how collaboration can lead toward re-invention of our research practices and methods, as well as our own subjectivities, through involvement......In our presentation we strive to disturb and unravel the romantic discourses of collaboration, dialogue and empowerment in relation to qualitative inquiry. For more than two years we (five Danish and Czech researchers) have been exploring the complex obstructions, difficulties and potentials...... in the not-yet-known. Over the years, we have shared and analyzed personal stories about our collaborative experiences in an on-going reflective learning process. We draw on writing methodologies, including memory-work (Haug, Davies) and collaborative writing such as by Wyatt, Gale, Gannon & Davies. Our...

  11. INDEPENDENSI HAKIM AD-HOC PADA LINGKUNGAN PERADILAN HUBUNGAN INDUSTRIAL / THE JUDICIAL INDEPENDENCE OF AD-HOC JUDGES IN INDUSTRIAL RELATION COURT

    Directory of Open Access Journals (Sweden)

    Muhammad Ishar Helmi

    2017-08-01

    Full Text Available Undang-Undang PPHI mengatur asas penyelesaian perselisihan hubungan industrial dilakukan secara musyawarah mufakat, dengan berprinsip jika terjadi perselisihan antara pekerja/buruh dan pengusaha maka tahap pertama penyelesaian perselisihan tersebut diserahkan pada pihak yang berselisih (bipartit. Ketentuan Pasal 63 ayat (2 dan Pasal 67 ayat (1 huruf f Undang-Undang tersebut mengakibatkan hakim ad-hoc Pengadilan Hubungan Industrial, dalam menjalankan tugas dan tanggung jawabnya memeriksa dan memutus suatu perkara harus mandiri dan lepas dari segala bentuk intervensi lembaga/instansi manapun menjadi terbatasi dan tidak optimal. Hakim ad-hoc Peradilan Hubungan Industrial merupakan hakim yang diusulkan oleh serikat pekerja/serikat buruh, organisasi pengusaha, juga diberhentikan secara hormat oleh serikat pekerja/serikat buruh, organisasi pengusaha tersebut. Hal ini tentunya akan menciderai sistem peradilan yang bebas, tidak memihak dan bersih yang diimpikan karena para hakim akan dikuasai oleh para pihak yang berperkara, karena keberadaan hakim diangkat dan diberhentikan oleh pihak yang akan disidangkan di peradilan hubungan industrial tersebut. PPHI (Industrial Relations Disputes Settlement Act regulates the principle of settlement of industrial relations disputes by consensus, if there is a dispute between employee/workers and employers, the first stage of dispute settlement shall be submitted to disputing party (bipartite settlement. The provisions of Article 63 paragraph (2 and Article 67 paragraph (1 sub-paragraph f of the Act shall result in the ad-hoc judges of the Industrial Relations Court, in carrying out their duties and responsibilities to examine and decide a case shall be independent and kept away from any intervention of any institution. The ad-hoc judges of the Industrial Relations Court is a judge proposed by a trade union, employers organization, also dismissed respectfully by the trade union and the employers organization. This

  12. Theoretical foundations for collaboration engineering

    NARCIS (Netherlands)

    Kolfschoten, G.L.

    2007-01-01

    Collaboration is often presented as the solution to numerous problems in business and society. However, collaboration is challenging, and collaboration support is not an off-the-shelf-product. This research offers theoretical foundations for Collaboration Engineering. Collaboration Engineering is an

  13. Enhanced WWTP effluent organic matter removal in hybrid ozonation-coagulation (HOC) process catalyzed by Al-based coagulant

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Jin, Pengkang, E-mail: pkjin@hotmail.com [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Hou, Rui [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Yang, Lei [Department of Materials Science and Engineering, Monash University, Clayton, VIC, 3800 (Australia); Wang, Xiaochang C., E-mail: xcwang@xauat.edu.cn [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China)

    2017-04-05

    Highlights: • A novel HOC process was firstly put forward to apply in wastewater reclamation. • Interactions between ozone and Al-based coagulants was found in the HOC process. • Ozonation can be catalyzed and enhanced by Al-based coagulants in the HOC process. • HOC process showed better organics removal than pre-ozonation-coagulation process. - Abstract: A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1 mgO{sub 3}/mg DOC at each pH value (pH 5, 7 and 9). In order to interpret the mechanism of the HOC process, ozone decomposition was monitored. The results indicated that ozone decomposed much faster in the HOC process. Moreover, by using the reagent of O{sub 3}-resistant hydroxyl radical (·OH) probe compound, para-chlorobenzoic acid (pCBA), and electron paramagnetic resonance (EPR) analysis, it was observed that the HOC process generated higher content of ·OH compared with pre-ozonation process. This indicates that the ·OH oxidation reaction as the key step can be catalyzed and enhanced by Al-based coagulants and their hydrolyzed products in this developed process. Thus, based on the catalytic effects of Al-based coagulants on ozonation, the HOC process provides a promising alternative to the conventional technology for wastewater reclamation in terms of higher efficiency.

  14. Virtual laboratories: Collaborative environments and facilities-on-line

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E. Jr. [Oak Ridge National Lab., TN (United States). I and C Div.; Cavallini, J.S.; Seweryniak, G.R.; Kitchens, T.A.; Hitchcock, D.A.; Scott, M.A.; Welch, L.C. [Dept. of Energy, Germantown, MD (United States). Mathematical Information, and Computational Sciences Div.; Aiken, R.J. [Dept. of Energy, Germantown, MD (United States). Mathematical Information, and Computational Sciences Div.]|[Lawrence Livermore National Lab., CA (United States); Stevens, R.L. [Argonne National Lab., IL (United States). Mathematics and Computer Sciences Div.

    1995-07-01

    The Department of Energy (DOE) has major research laboratories in a number of locations in the US, typically co-located with large research instruments or research facilities valued at tens of millions to even billions of dollars. Present budget exigencies facing the entire nation are felt very deeply at DOE, just as elsewhere. Advances over the last few years in networking and computing technologies make virtual collaborative environments and conduct of experiments over the internetwork structure a possibility. The authors believe that development of these collaborative environments and facilities-on-line could lead to a ``virtual laboratory`` with tremendous potential for decreasing the costs of research and increasing the productivity of their capital investment in research facilities. The majority of these cost savings would be due to increased productivity of their research efforts, better utilization of resources and facilities, and avoiding duplication of expensive facilities. A vision of how this might all fit together and a discussion of the infrastructure necessary to enable these developments is presented.

  15. Energy Efficiency Collaboratives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Michael [US Department of Energy, Washington, DC (United States); Bryson, Joe [US Environmental Protection Agency, Washington, DC (United States)

    2015-09-01

    Collaboratives for energy efficiency have a long and successful history and are currently used, in some form, in more than half of the states. Historically, many state utility commissions have used some form of collaborative group process to resolve complex issues that emerge during a rate proceeding. Rather than debate the issues through the formality of a commission proceeding, disagreeing parties are sent to discuss issues in a less-formal setting and bring back resolutions to the commission. Energy efficiency collaboratives take this concept and apply it specifically to energy efficiency programs—often in anticipation of future issues as opposed to reacting to a present disagreement. Energy efficiency collaboratives can operate long term and can address the full suite of issues associated with designing, implementing, and improving energy efficiency programs. Collaboratives can be useful to gather stakeholder input on changing program budgets and program changes in response to performance or market shifts, as well as to provide continuity while regulators come and go, identify additional energy efficiency opportunities and innovations, assess the role of energy efficiency in new regulatory contexts, and draw on lessons learned and best practices from a diverse group. Details about specific collaboratives in the United States are in the appendix to this guide. Collectively, they demonstrate the value of collaborative stakeholder processes in producing successful energy efficiency programs.

  16. Assessing Online Collaborative Discourse.

    Science.gov (United States)

    Breen, Henny

    2015-01-01

    This qualitative study using transcript analysis was undertaken to clarify the value of Harasim's Online Collaborative Learning Theory as a way to assess the collaborative process within nursing education. The theory incorporated three phases: (a) idea generating; (b) idea organizing; and (c) intellectual convergence. The transcripts of asynchronous discussions from a 2-week module about disaster nursing using a virtual community were analyzed and formed the data for this study. This study supports the use of Online Collaborative Learning Theory as a framework for assessing online collaborative discourse. Individual or group outcomes were required for the students to move through all three phases of the theory. The phases of the Online Collaborative Learning Theory could be used to evaluate the student's ability to collaborate. It is recommended that group process skills, which have more to do with interpersonal skills, be evaluated separately from collaborative learning, which has more to do with cognitive skills. Both are required for practicing nurses. When evaluated separately, the student learning needs are more clearly delineated. © 2014 Wiley Periodicals, Inc.

  17. Collaborative quality improvement.

    Science.gov (United States)

    Luckenbaugh, Amy N; Miller, David C; Ghani, Khurshid R

    2017-07-01

    Quality improvement collaboratives were developed in many medical and surgical disciplines with the goal of measuring and improving the quality of care provided to patients. The aim of this review is to provide an overview of surgical quality improvement collaboratives, and in particular those aimed at improving urological care. Quality improvement collaboratives collect high-quality data using standardized methodologies, and use the data to provide feedback to physicians and practices, and then implement processes to improve patient outcomes. The largest regional collaborative in urology is the Michigan Urological Surgery Improvement Collaborative (MUSIC). Recent efforts by this group have been focused at understanding variation in care, improving patient selection for treatment, reducing treatment morbidity and measuring and optimizing technical skill. The American Urological Association has also recently launched a national quality registry (AQUA), with an initial focus on prostate cancer care. By understanding factors that result in exemplary performance, quality improvement collaboratives are able to develop best practices around areas of care with high variation that have the potential to improve outcomes and reduce costs. These developments have been made possible by the unique model offered by the collaborative structure with the goal of improving patient care at a population level.

  18. What is needed to deliver collaborative care to address comorbidity more effectively for adults with a severe mental illness?

    Science.gov (United States)

    Lee, Stuart J; Crowther, Elizabeth; Keating, Charlotte; Kulkarni, Jayashri

    2013-04-01

    Innovative models of care for people with a severe mental illness have been developed across Australia to more effectively address comorbidity and disability by enhancing the collaboration between clinical and non-clinical services. In particular, this review paper focuses on collaboration that has occurred to address comorbidities affecting the following domains: homelessness; substance addiction; physical ill-health; unemployment; and forensic issues. The identification of relevant collaborative care models was facilitated by carrying out a review of the published peer-reviewed literature and policy or other published reports available on the Internet. Contact was also made with representatives of the mental health branches of each Australian state and territory health department to assist in identifying examples of innovative collaborative care models established within their jurisdiction. A number of nationally implemented and local examples of collaborative care models were identified that have successfully delivered enhanced integration of care between clinical and non-clinical services. Several key principles for effective collaboration were also identified. Governmental and organisational promotion of and incentives for cross-sector collaboration is needed along with education for staff about comorbidity and the capacity of cross-sector agencies to work in collaboration to support shared clients. Enhanced communication has been achieved through mechanisms such as the co-location of staff from different agencies to enhance sharing of expertise and interagency continuity of care, shared treatment plans and client records, and shared case review meetings. Promoting a 'housing first approach' with cross-sector services collaborating to stabilise housing as the basis for sustained clinical engagement has also been successful. Cross-sector collaboration is achievable and can result in significant benefits for mental health consumers and staff of collaborating

  19. Designing collaborative policy innovation

    DEFF Research Database (Denmark)

    Agger, Annika; Sørensen, Eva

    2014-01-01

    Recent approaches to enhancing public innovation suffer from two shortcomings: They overemphasize competition as a driver of innovation and overlook the fact that public sector innovation involves policy innovation as well as service innovation. Drawing on governance research and innovation theory......, the chapter investigates the extent to which and how collaboration between politicians and relevant stakeholders can spur the formulation, implementation and diffusion of new innovative policies. A case study of a process of collaborative policy innovation in a Danish municipality shows that collaborative...... policy arenas do contribute to policy innovation but also that the degree to which they do so depends on the institutional design of these arenas....

  20. Comprehensive multiplatform collaboration

    Science.gov (United States)

    Singh, Kundan; Wu, Xiaotao; Lennox, Jonathan; Schulzrinne, Henning G.

    2003-12-01

    We describe the architecture and implementation of our comprehensive multi-platform collaboration framework known as Columbia InterNet Extensible Multimedia Architecture (CINEMA). It provides a distributed architecture for collaboration using synchronous communications like multimedia conferencing, instant messaging, shared web-browsing, and asynchronous communications like discussion forums, shared files, voice and video mails. It allows seamless integration with various communication means like telephones, IP phones, web and electronic mail. In addition, it provides value-added services such as call handling based on location information and presence status. The paper discusses the media services needed for collaborative environment, the components provided by CINEMA and the interaction among those components.

  1. Collaboration in experiential therapy.

    Science.gov (United States)

    Berdondini, Lucia; Elliott, Robert; Shearer, Joan

    2012-02-01

    We offer a view of the nature and role of client-therapist collaboration in experiential psychotherapy, focusing on Gestalt and emotion-focused therapy (EFT). We distinguish between the necessary condition of mutual trust (the emotional bond between client and therapist) and effective collaboration (regarding the goals and tasks of therapy). Using a case study of experiential therapy for social anxiety, we illustrate how the development of collaboration can be both complex and pivotal for therapeutic success, and how it can involve client and therapist encountering one another through taking risks by openly and nonjudgementally disclosing difficult experiences in order to enrich and advance the work. © 2012 Wiley Periodicals, Inc.

  2. Collaborative Video Sketching

    DEFF Research Database (Denmark)

    Henningsen, Birgitte; Gundersen, Peter Bukovica; Hautopp, Heidi

    2017-01-01

    This paper introduces to what we define as a collaborative video sketching process. This process links various sketching techniques with digital storytelling approaches and creative reflection processes in video productions. Traditionally, sketching has been used by designers across various...... findings: 1) They are based on a collaborative approach. 2) The sketches act as a mean to externalizing hypotheses and assumptions among the participants. Based on our analysis we present an overview of factors involved in collaborative video sketching and shows how the factors relate to steps, where...... the participants: shape, record, review and edit their work, leading the participants to new insights about their work....

  3. Sensemaking in collaborative networks

    DEFF Research Database (Denmark)

    Peronard, Jean-Paul; Brix, Jacob

    2018-01-01

    be redesigned to strengthen the collaboration between companies. To enable this discussion we delve into the sensemaking literature and theory from loosely coupled systems. Our discussion leads to the development of the Balanced Activity System (BAS) model. The paper’s key contribution is the prescriptive BAS......The purpose of the study is to advance research on open business models as activity systems (Zott and Amit, 2010) in collaborative networks. We utilize Bradley’s (1995) theory of exchange behavior to discuss how new joint activities can be explored as well as how existing activities can...... model that can be used strategically in collaborative networks to redesign or create new joint activities....

  4. Collaborative Learning in the Cloud

    DEFF Research Database (Denmark)

    Kirchner, Kathrin; Razmerita, Liana

    2015-01-01

    This present study aims to investigate how students perceive collaboration and identifies associated technologies used to collaborate. In particular we aim to address the following research questions: What are the factors that impact satisfaction with collaboration? How do these factors differ in...... in different collaborative settings? Based on data from 75 students from Denmark and Germany, the article identifies collaborative practices and factors that impact positively and negatively satisfaction with collaboration....

  5. Collaborative engagement experiment

    Science.gov (United States)

    Mullens, Katherine; Troyer, Bradley; Wade, Robert; Skibba, Brian; Dunn, Michael

    2006-05-01

    Unmanned ground and air systems operating in collaboration have the potential to provide future Joint Forces a significant capability for operations in complex terrain. Collaborative Engagement Experiment (CEE) is a consolidation of separate Air Force, Army and Navy collaborative efforts within the Joint Robotics Program (JRP) to provide a picture of the future of unmanned warfare. The Air Force Research Laboratory (AFRL), Material and Manufacturing Directorate, Aerospace Expeditionary Force Division, Force Protection Branch (AFRL/MLQF), The Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) Joint Technology Center (JTC)/Systems Integration Laboratory (SIL), and the Space and Naval Warfare Systems Center - San Diego (SSC San Diego) are conducting technical research and proof of principle experiments for an envisioned operational concept for extended range, three dimensional, collaborative operations between unmanned systems, with enhanced situational awareness for lethal operations in complex terrain. This paper describes the work by these organizations to date and outlines some of the plans for future work.

  6. Collaborative Learning through Teletutorials.

    Science.gov (United States)

    Idrus, Rozhan

    1993-01-01

    Describes the use of audiographic teleconferencing for distance education courses for adult higher education at the Universiti Sains Malaysia. Telecommunications is discussed, and a collaborative learning strategy is explained that emphasizes the student-teacher relationship. (Contains 18 references.) (LRW)

  7. Collaborative Knowledge Management

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... collaboration of knowledge. The organizational structures and ... enables organizations to see the collective knowledge as a base element of ..... requirements for communication across different equipment and applications by ...

  8. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    2011-01-01

    and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...... is an organizational model called the collaborative community of firms. This chapter addresses an important organizational role in a collaborative community, that of the shared services provider. The shared services provider acts as a facilitator in the community, helping member firms collaborate with one another...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed....

  9. Drivers of Collaborative Advantage

    DEFF Research Database (Denmark)

    Weihe, Gudrid

    processes and behavioural dimensions is practically non-existent. This article tries to remedy the current gap in the literature by reviewing research findings on interfirm collaboration (alliances). On that basis a conceptual framework for analyzing partnership processes is developed. Finally......, the antecedents of collaborative advantage are theoretically examined, and the organizational competences contributing to collaborative success are identified. The conclusion is that operational processes and social dynamics are vital drivers of collaborative advantage. Another significant conclusion...... is that public management research can benefit from drawing upon existing alliance research. Alliance scholars have during the past couple of decades accumulated an impressive amount of knowledge on different aspects of inter-firm cooperation, and therefore the learning potential for public management scholars...

  10. Collaboration in scientific practice

    DEFF Research Database (Denmark)

    Wagenknecht, Susann

    2014-01-01

    This monograph investigates the collaborative creation of scientific knowledge in research groups. To do so, I combine philosophical analysis with a first-hand comparative case study of two research groups in experimental science. Qualitative data are gained through observation and interviews......, and I combine empirical insights with existing approaches to knowledge creation in philosophy of science and social epistemology. On the basis of my empirically-grounded analysis I make several conceptual contributions. I study scientific collaboration as the interaction of scientists within research...... to their publication. Specifically, I suggest epistemic difference and the porosity of social structure as two conceptual leitmotifs in the study of group collaboration. With epistemic difference, I emphasize the value of socio-cognitive heterogeneity in group collaboration. With porosity, I underline the fact...

  11. EPA Collaboration with Israel

    Science.gov (United States)

    The United States and Israel focus on scientific and technical collaboration to protect the environment, by exchanging scientific and technical information, arranging visits of scientific personnel, cooperating in scientific symposia and workshops, etc.

  12. Providers’ perspectives on collaboration

    Directory of Open Access Journals (Sweden)

    Patricia Bruner

    2011-08-01

    Full Text Available Objective: Changes in models of health care are required to better meet the needs of diverse, underserved patient populations. Collaboration among providers is one way to promote accessible, comprehensive and continuous care in healthcare organizations. This paper describes the quantitative findings from two time points that examined providers' views of collaboration among a sample of diverse personnel (e.g. clinical nurses, social workers, dental providers, mental health providers, clerical staff, medical assistants, public health staff, and administrators within a federally qualified nurse managed health care centre in the United States. Methods: The quantitative arm of a mixed-method study is presented in this paper. Two instruments, the Collaboration and Satisfaction About Care Decisions Scale and the University of the West of England Interprofessional Questionnaire (comprised of 4 subscales-Communication and Teamwork Scale, Interprofessional Learning Scale, Interprofessional Interaction Scale, and Interprofessional Relationships Scale were administered to providers at baseline and three to eight months following six same discipline focus group discussions on collaboration, in order to evaluate whether participating in the focus group discussions changed providers' views of collaboration. A summary of the focus group data which were published elsewhere is additionally summarized to help provide insight to the quantitative findings. Thirty-nine staff participated. Results: Paired t-tests revealed that only one scale out of the five, Collaboration and Satisfaction About Care Decisions Scale (33.97 at time one and 37.45 at time two, significantly and positively changed after the focus group discussion (p=0.046. Providers' views on collaboration ranged from positive to moderate views of collaboration; most measures revealed a non-significant improvement after the focus group discussions. Staff with some graduate school reported the greatest

  13. Providers’ perspectives on collaboration

    Directory of Open Access Journals (Sweden)

    Patricia Bruner

    2011-08-01

    Full Text Available Objective: Changes in models of health care are required to better meet the needs of diverse, underserved patient populations. Collaboration among providers is one way to promote accessible, comprehensive and continuous care in healthcare organizations. This paper describes the quantitative findings from two time points that examined providers' views of collaboration among a sample of diverse personnel (e.g. clinical nurses, social workers, dental providers, mental health providers, clerical staff, medical assistants, public health staff, and administrators within a federally qualified nurse managed health care centre in the United States.Methods: The quantitative arm of a mixed-method study is presented in this paper. Two instruments, the Collaboration and Satisfaction About Care Decisions Scale and the University of the West of England Interprofessional Questionnaire (comprised of 4 subscales-Communication and Teamwork Scale, Interprofessional Learning Scale, Interprofessional Interaction Scale, and Interprofessional Relationships Scale were administered to providers at baseline and three to eight months following six same discipline focus group discussions on collaboration, in order to evaluate whether participating in the focus group discussions changed providers' views of collaboration. A summary of the focus group data which were published elsewhere is additionally summarized to help provide insight to the quantitative findings. Thirty-nine staff participated.Results: Paired t-tests revealed that only one scale out of the five, Collaboration and Satisfaction About Care Decisions Scale (33.97 at time one and 37.45 at time two, significantly and positively changed after the focus group discussion (p=0.046. Providers' views on collaboration ranged from positive to moderate views of collaboration; most measures revealed a non-significant improvement after the focus group discussions. Staff with some graduate school reported the greatest

  14. Silence in Intercultural Collaboration

    NARCIS (Netherlands)

    Verouden, Nick W.; Sanden, Van der Maarten C.A.; Aarts, Noelle

    2018-01-01

    China is widely recognized as a significant scientific partner for Western universities. Given that many Western universities are now operating in the Chinese context, this study investigates the everyday conversations in which international partnerships are collaboratively developed and

  15. Indico: CERN Collaboration Hub

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Indico development is also moving towards a broader collaboration where other institutes, hosting their own Indico instance, can contribute to the project in order make it a better and more complete tool.

  16. PNNI routing support for ad hoc mobile networking: The multilevel case

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, L.; Sholander, P.; Tolendino, L.

    1998-01-01

    This contribution extends the Outside Nodal Hierarchy List (ONHL) procedures described in ATM Forum Contributions 97-0766 and 97-0933. These extensions allow multiple mobile networks to form either an ad hoc network or an extension of a fixed PNNI infrastructure. A previous contribution (97-1073) covered the simplest case where the top-most Logical Group Nodes (LGNs), in those mobile networks, all resided at the same level in a PNNI hierarchy. This contribution covers the more general case wherein those top-most LGNs may reside at different PNNI hierarchy levels. Both of the SNL contributions consider flat ad hoc network architectures in the sense that each mobile network always participates in the PNNI hierarchy at the pre-configured level of its top-most LGN.

  17. The Ad Hoc process to strengthen the framework convention on climate change

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishna, K.; Deutz, A.M.; Jacobsen, L.A. [eds.

    1995-11-01

    The Woods Hole Research Center convened an International Conference on The Ad Hoc Process to Strengthen the Framework Convention on Climate Change in Woods Hole, MA, on October 7-9, 1995. The conference was conducted to examine the prospects for successful adoption of a protocol to the Framework Convention on Climate Change by 1997. In preparation for the Second session of the Ad Hoc Group on the Berlin Mandate, several governmental and nongovernmental representatives met in Woods Hole to discuss the process and possible outcome of the Berlin Mandate negotiations for a protocol or other legal instrument to strengthen the Convention. The conference was by invitation and all participants attended in their personal capacities.

  18. Regressive research: The pitfalls of post hoc data selection in the study of unconscious mental processes.

    Science.gov (United States)

    Shanks, David R

    2017-06-01

    Many studies of unconscious processing involve comparing a performance measure (e.g., some assessment of perception or memory) with an awareness measure (such as a verbal report or a forced-choice response) taken either concurrently or separately. Unconscious processing is inferred when above-chance performance is combined with null awareness. Often, however, aggregate awareness is better than chance, and data analysis therefore employs a form of extreme group analysis focusing post hoc on participants, trials, or items where awareness is absent or at chance. The pitfalls of this analytic approach are described with particular reference to recent research on implicit learning and subliminal perception. Because of regression to the mean, the approach can mislead researchers into erroneous conclusions concerning unconscious influences on behavior. Recommendations are made about future use of post hoc selection in research on unconscious cognition.

  19. Forming an ad-hoc nearby storage, based on IKAROS and social networking services

    International Nuclear Information System (INIS)

    Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

    2014-01-01

    We present an ad-hoc 'nearby' storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

  20. Design of free patterns of nanocrystals with ad hoc features via templated dewetting

    Energy Technology Data Exchange (ETDEWEB)

    Aouassa, M.; Berbezier, I.; Favre, L.; Ronda, A. [IM2NP, CNRS, AMU, Marseille (France); Bollani, M.; Sordan, R. [LNES, Como (Italy); Delobbe, A.; Sudraud, P. [Orsay Physics, Fuveau (France)

    2012-07-02

    Design of monodisperse ultra-small nanocrystals (NCs) into large scale patterns with ad hoc features is demonstrated. The process makes use of solid state dewetting of a thin film templated through alloy liquid metal ion source focused ion beam (LMIS-FIB) nanopatterning. The solid state dewetting initiated at the edges of the patterns controllably creates the ordering of NCs with ad hoc placement and periodicity. The NC size is tuned by varying the nominal thickness of the film while their position results from the association of film retraction from the edges of the lay out and Rayleigh-like instability. The use of ultra-high resolution LMIS-FIB enables to produce monocrystalline NCs with size, periodicity, and placement tunable as well. It provides routes for the free design of nanostructures for generic applications in nanoelectronics.

  1. An Ad-Hoc Adaptive Pilot Model for Pitch Axis Gross Acquisition Tasks

    Science.gov (United States)

    Hanson, Curtis E.

    2012-01-01

    An ad-hoc algorithm is presented for real-time adaptation of the well-known crossover pilot model and applied to pitch axis gross acquisition tasks in a generic fighter aircraft. Off-line tuning of the crossover model to human pilot data gathered in a fixed-based high fidelity simulation is first accomplished for a series of changes in aircraft dynamics to provide expected values for model parameters. It is shown that in most cases, for this application, the traditional crossover model can be reduced to a gain and a time delay. The ad-hoc adaptive pilot gain algorithm is shown to have desirable convergence properties for most types of changes in aircraft dynamics.

  2. Cross-layer model design in wireless ad hoc networks for the Internet of Things.

    Directory of Open Access Journals (Sweden)

    Xin Yang

    Full Text Available Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

  3. Cross-layer model design in wireless ad hoc networks for the Internet of Things.

    Science.gov (United States)

    Yang, Xin; Wang, Ling; Xie, Jian; Zhang, Zhaolin

    2018-01-01

    Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

  4. Cross-Layer Design Approach for Power Control in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    A. Sarfaraz Ahmed

    2015-03-01

    Full Text Available In mobile ad hoc networks, communication among mobile nodes occurs through wireless medium The design of ad hoc network protocol, generally based on a traditional “layered approach”, has been found ineffective to deal with receiving signal strength (RSS-related problems, affecting the physical layer, the network layer and transport layer. This paper proposes a design approach, deviating from the traditional network design, toward enhancing the cross-layer interaction among different layers, namely physical, MAC and network. The Cross-Layer design approach for Power control (CLPC would help to enhance the transmission power by averaging the RSS values and to find an effective route between the source and the destination. This cross-layer design approach was tested by simulation (NS2 simulator and its performance over AODV was found to be better.

  5. FRAMEWORK FOR AD HOC NETWORK COMMUNICATION IN MULTI-ROBOT SYSTEMS

    Directory of Open Access Journals (Sweden)

    Khilda Slyusar

    2016-11-01

    Full Text Available Assume a team of mobile robots operating in environments where no communication infrastructure like routers or access points is available. The robots have to create a mobile ad hoc network, in that case, it provides communication on peer-to-peer basis. The paper gives an overview of existing solutions how to route messages in such ad hoc networks between robots that are not directly connected and introduces a design of a software framework for realization of such communication. Feasibility of the proposed framework is shown on the example of distributed multi-robot exploration of an a priori unknown environment. Testing of developed functionality in an exploration scenario is based on results of several experiments with various input conditions of the exploration process and various sizes of a team and is described herein.

  6. Level of literacy and dementia: A secondary post-hoc analysis from North-West India

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Raina

    2014-01-01

    Full Text Available Introduction: A relation between literacy and dementia has been studied in past and an association has been documented. This is in spite of some studies pointing to the contrary. The current study was aimed at investigating the influence of level of literacy on dementia in a sample stratified by geography (Migrant, Urban, Rural and Tribal areas of sub-Himalayan state of Himachal Pradesh, India. Materials and Methods: The study was based on post-hoc analysis of data obtained from a study conducted on elderly population (60 years and above from selected geographical areas (Migrant, Urban, Rural and Tribal of Himachal Pradesh state in North-west India. Results: Analysis of variance revealed an effect of education on cognitive scores [F = 2.823, P =0.01], however, post-hoc Tukey′s HSD test did not reveal any significant pairwise comparisons. Discussion: The possibility that education effects dementia needs further evaluation, more so in Indian context.

  7. PERFORMANCE ANALYSIS OF DSR ROUTING PROTOCOL UNDER ENERGY BASED SELFISH ATTACK IN MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    T.V.P.Sundararajan

    2010-06-01

    Full Text Available Mobile Ad hoc Networks (MANETs rely on the cooperation of all participating nodes to provide the fundamental operations such as routing and data forwarding. However, due to the open structure and scarcely available battery-based energy, node misbehaviors may exist.[1]. One such routing misbehavior is that some selfish nodes will participate in the route discovery and maintenance processes but refuse to forward data packets. This paper pointed out Energy based selfish nodes (EBSN where these selfish nodes tend to use the network but do not cooperate, saving battery life for their own communications [2],[3]. We present a simulation study of the effects of Energy based selfish nodes (EBSN on DSR routing protocol and its impact over network performance in terms of throughput and delay of a mobile ad hoc network where a defined percentage of nodes were misbehaving.

  8. Performance Analysis of Mobile Ad Hoc Unmanned Aerial Vehicle Communication Networks with Directional Antennas

    Directory of Open Access Journals (Sweden)

    Abdel Ilah Alshbatat

    2010-01-01

    Full Text Available Unmanned aerial vehicles (UAVs have the potential of creating an ad hoc communication network in the air. Most UAVs used in communication networks are equipped with wireless transceivers using omnidirectional antennas. In this paper, we consider a collection of UAVs that communicate through wireless links as a mobile ad-hoc network using directional antennas. The network design goal is to maximize the throughput and minimize the end-to-end delay. In this respect, we propose a new medium access control protocol for a network of UAVs with directional antennas. We analyze the communication channel between the UAVs and the effect of aircraft attitude on the network performance. Using the optimized network engineering tool (OPNET, we compare our protocol with the IEEE 802.11 protocol for omnidirectional antennas. The simulation results show performance improvement in end-to-end delay as well as throughput.

  9. A LOOP-BASED APPROACH IN CLUSTERING AND ROUTING IN MOBILE AD HOC NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Li Yanping; Wang Xin; Xue Xiangyang; C.K. Toh

    2006-01-01

    Although clustering is a convenient framework to enable traffic control and service support in Mobile Ad hoc NETworks (MANETs), it is seldom adopted in practice due to the additional traffic overhead it leads to for the resource limited ad hoc network. In order to address this problem, we proposed a loop-based approach to combine clustering and routing. By employing loop topologies, topology information is disseminated with a loop instead of a single node, which provides better robustness, and the nature of a loop that there are two paths between each pair of nodes within a loop suggests smart route recovery strategy. Our approach is composed of setup procedure, regular procedure and recovery procedure to achieve clustering, routing and emergent route recovering.

  10. Enhanced Secure Trusted AODV (ESTA Protocol to Mitigate Blackhole Attack in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Dilraj Singh

    2015-09-01

    Full Text Available The self-organizing nature of the Mobile Ad hoc Networks (MANETs provide a communication channel anywhere, anytime without any pre-existing network infrastructure. However, it is exposed to various vulnerabilities that may be exploited by the malicious nodes. One such malicious behavior is introduced by blackhole nodes, which can be easily introduced in the network and, in turn, such nodes try to crumble the working of the network by dropping the maximum data under transmission. In this paper, a new protocol is proposed which is based on the widely used Ad hoc On-Demand Distance Vector (AODV protocol, Enhanced Secure Trusted AODV (ESTA, which makes use of multiple paths along with use of trust and asymmetric cryptography to ensure data security. The results, based on NS-3 simulation, reveal that the proposed protocol is effectively able to counter the blackhole nodes in three different scenarios.

  11. Enhancing On-Demand Multicast Routing Protocols using Mobility Prediction in Mobile Ad-hoc Network

    Directory of Open Access Journals (Sweden)

    Nermin Makhlouf

    2014-08-01

    Full Text Available A Mobile Ad hoc Network (MANET is a self-organizing wireless communication network in which mobile devices are based on no infrastructure like base stations or access points. Minimal configuration and quick deployment make ad hoc networks suitable for emergency situations like disaster recovery or military conflict. Since node mobility may cause links to be broken frequently, a very important issue for routing in MANETs is how to set reliable paths which can last as long as possible. To solve this problem, non-random behaviors for the mobility patterns that mobile users exhibit are exploited. This paper introduces a scheme to improve On-Demand Multicast Routing Protocol (ODMRP performances by using mobility prediction. 

  12. The post hoc use of randomised controlled trials to explore drug associated cancer outcomes

    DEFF Research Database (Denmark)

    Stefansdottir, Gudrun; Zoungas, Sophia; Chalmers, John

    2013-01-01

    on public health before proper regulatory action can be taken. This paper aims to discuss challenges of exploring drug-associated cancer outcomes by post-hoc analyses of Randomised controlled trials (RCTs) designed for other purposes. METHODOLOGICAL CHALLENGES TO CONSIDER: We set out to perform a post......-hoc nested case-control analysis in the ADVANCE trial in order to examine the association between insulin use and cancer. We encountered several methodological challenges that made the results difficult to interpret, including short duration of exposure of interest, lack of power, and correlation between...... exposure and potential confounders. Considering these challenges, we concluded that using the data would not enlighten the discussion about insulin use and cancer risk and only serve to further complicate any understanding. Therefore, we decided to use our experience to illustrate methodological challenges...

  13. Formal reconstruction of attack scenarios in mobile ad hoc and sensor networks

    Directory of Open Access Journals (Sweden)

    Rekhis Slim

    2011-01-01

    Full Text Available Abstract Several techniques of theoretical digital investigation are presented in the literature but most of them are unsuitable to cope with attacks in wireless networks, especially in Mobile Ad hoc and Sensor Networks (MASNets. In this article, we propose a formal approach for digital investigation of security attacks in wireless networks. We provide a model for describing attack scenarios in a wireless environment, and system and network evidence generated consequently. The use of formal approaches is motivated by the need to avoid ad hoc generation of results that impedes the accuracy of analysis and integrity of investigation. We develop an inference system that integrates the two types of evidence, handles incompleteness and duplication of information in them, and allows possible and provable actions and attack scenarios to be generated. To illustrate the proposal, we consider a case study dealing with the investigation of a remote buffer overflow attack.

  14. Adhoc: an R package to calculate ad hoc distance thresholds for DNA barcoding identification

    Directory of Open Access Journals (Sweden)

    Gontran Sonet

    2013-12-01

    Full Text Available Identification by DNA barcoding is more likely to be erroneous when it is based on a large distance between the query (the barcode sequence of the specimen to identify and its best match in a reference barcode library. The number of such false positive identifications can be decreased by setting a distance threshold above which identification has to be rejected. To this end, we proposed recently to use an ad hoc distance threshold producing identifications with an estimated relative error probability that can be fixed by the user (e.g. 5%. Here we introduce two R functions that automate the calculation of ad hoc distance thresholds for reference libraries of DNA barcodes. The scripts of both functions, a user manual and an example file are available on the JEMU website (http://jemu.myspecies.info/computer-programs as well as on the comprehensive R archive network (CRAN, http://cran.r-project.org.

  15. Illustration, detection and prevention of sleep deprivation anomaly in mobile ad hoc networks

    International Nuclear Information System (INIS)

    Nadeem, A.; Ahsan, K.; Sarim, M.

    2017-01-01

    MANETs (Mobile Ad Hoc Networks) have applications in various walks of life from rescue operations to battle field operations, personal and commercial. However, routing operations in MANETs are still vulnerable to anomalies and DoS (Denial of Service) attacks such as sleep deprivation. In SD (Sleep Deprivation) attack malicious node exploits the vulnerability in the route discovery function of the reactive routing protocol for example AODV (Ad Hoc On-Demand Distance Vector). In this paper, we first illustrate the SD anomaly in MANETs and then propose a SD detection and prevention algorithm which efficiently deals with this attack. We assess the performance of our proposed approach through simulation, evaluating its successfulness using different network scenarios. (author)

  16. Forming an ad-hoc nearby storage, based on IKAROS and social networking services

    Science.gov (United States)

    Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

    2014-06-01

    We present an ad-hoc "nearby" storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

  17. Selective epidemic broadcast algorithm to suppress broadcast storm in vehicular ad hoc networks

    Directory of Open Access Journals (Sweden)

    M. Chitra

    2018-03-01

    Full Text Available Broadcasting in Vehicular Ad Hoc Networks is the best way to spread emergency messages all over the network. With the dynamic nature of vehicular ad hoc networks, simple broadcast or flooding faces the problem called as Broadcast Storm Problem (BSP. The issue of the BSP will degrade the performance of a message broadcasting process like increased overhead, collision and dissemination delay. The paper is motivated to solve the problems in the existing Broadcast Strom Suppression Algorithms (BSSAs like p-Persistence, TLO, VSPB, G-SAB and SIR. This paper proposes to suppress the Broadcast Storm Problem and to improve the Emergency Safety message dissemination rate through a new BSSA based on Selective Epidemic Broadcast Algorithm (SEB. The simulation results clearly show that the SEB outperforms the existing algorithms in terms of ESM Delivery Ratio, Message Overhead, Collision Ratio, Broadcast Storm Ratio and Redundant Rebroadcast Ratio with decreased Dissemination Delay.

  18. Electronic Collaboration Logbook

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    At FNAL, we developed an Electronic Collaboration Logbook (ECL) application which is used by about 20 different collaborations, experiments and groups at FNAL. ECL is the latest iteration of the project formerly known as Control Room Logbook (CRL). We have been working on mobile (IOS and Android) clients for ECL. We will present history, current status and future plans of the project, as well as design, implementation and support solutions made by the project.

  19. Embarrassing To Collaborate

    DEFF Research Database (Denmark)

    Mitchell, Robb

    This position paper briefly outlines my interest in embarrassment– principally in relation to experiments provoking collaborative encounters in contexts that range from urban spaces to art galleries, and from music events to industrial innovation workshops.......This position paper briefly outlines my interest in embarrassment– principally in relation to experiments provoking collaborative encounters in contexts that range from urban spaces to art galleries, and from music events to industrial innovation workshops....

  20. Collaboration Between Multistakeholder Standards

    DEFF Research Database (Denmark)

    Rasche, Andreas; Maclean, Camilla

    Public interest in corporate social responsibility (CSR) has resulted in a wide variety of multistakeholder CSR standards in which companies can choose to participate. While such standards reflect collaborative governance arrangements between public and private actors, the market for corporate...... responsibility is unlikely to support a great variety of partly competing and overlapping standards. Increased collaboration between these standards would enhance both their impact and their adoption by firms. This report examines the nature, benefits, and shortcomings of existing multistakeholder standards...

  1. Intelligent Security Auditing Based on Access Control of Devices in Ad Hoc Network

    Institute of Scientific and Technical Information of China (English)

    XU Guang-wei; SHI You-qun; ZHU Ming; WU Guo-wen; CAO Qi-ying

    2006-01-01

    Security in Ad Hoc network is an important issue under the opening circumstance of application service. Some protocols and models of security auditing have been proposed to ensure rationality of contracting strategy and operating regulation and used to identify abnormal operation. Model of security auditing based on access control of devices will be advanced to register sign of devices and property of event of access control and to audit those actions. In the end, the model is analyzed and simulated.

  2. Position-Based Packet Forwarding for Vehicular Ad-Hoc Networks

    OpenAIRE

    Füßler, Holger

    2007-01-01

    Mobile Ad-Hoc Networks, or MANETs, are data communication networks between (potentially) mobile computer systems equipped with wireless communication devices and — in their purest form — in complete absence of communication infrastructure. Usage scenarios for these systems include communication during disaster recovery or battlefield communications. One of the great research challenges concerning MANETs is the Packet Forwarding Problem, i.e., the question to which neighbor node a data packet ...

  3. Ad Hoc Microphone Array Beamforming Using the Primal-Dual Method of Multipliers

    DEFF Research Database (Denmark)

    Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Heusdens, Richard

    2016-01-01

    In the recent years, there have been increasing amount of researches aiming at optimal beamforming with ad hoc microphone arrays, mostly with fusion-based schemes. However, huge amount of computational complexity and communication overhead impede many of these algorithms from being useful in prac...... the distributed linearly-constrained minimum variance beamformer using the the state of the art primal-dual method of multipliers. We study the proposed algorithm with an experiment....

  4. Secure and Usable Out-Of-Band Channels for Ad Hoc Mobile Device Interactions

    OpenAIRE

    Kainda , Ronald; Flechais , Ivan; Roscoe , A. W.

    2010-01-01

    International audience; Protocols for bootstrapping security in ad hoc mobile device interactions rely on users' ability to perform specific tasks such as transferring or comparing fingerprints of information between devices. The size of fingerprints depends on the level of technical security required by a given application but, at the same time, is limited by users' inability to deal with large amounts of data with high levels of accuracy. Large fingerprints provide high technical security b...

  5. Recreating the seawater mixture composition of HOCs in toxicity tests with Artemia franciscana by passive dosing

    Energy Technology Data Exchange (ETDEWEB)

    Rojo-Nieto, E., E-mail: elisa.rojo@uca.es [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Smith, K.E.C. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark); Perales, J.A. [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Mayer, P. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark)

    2012-09-15

    The toxicity testing of hydrophobic organic compounds (HOCs) in aquatic media is generally challenging, and this is even more problematic for mixtures. The hydrophobic properties of these compounds make them difficult to dissolve, and subsequently to maintain constant exposure concentrations. Evaporative and sorptive losses are highly compound-specific, which can alter not only total concentrations, but also the proportions between the compounds in the mixture. Therefore, the general aim of this study was to explore the potential of passive dosing for testing the toxicity of a PAH mixture that recreates the mixture composition found in seawater from a coastal area of Spain, the Bay of Algeciras. First, solvent spiking and passive dosing were compared for their suitability to determine the acute toxicity to Artemia franciscana nauplii of several PAHs at their respective solubility limits. Second, passive dosing was applied to recreate the seawater mixture composition of PAHs measured in a Spanish monitoring program, to test the toxicity of this mixture at different levels. HPLC analysis was used to confirm the reproducibility of the dissolved exposure concentrations for the individual PAHs and mixtures. This study shows that passive dosing has some important benefits in comparison with solvent spiking for testing HOCs in aquatic media. These include maintaining constant exposure concentrations, leading to higher reproducibility and a relative increase in toxicity. Passive dosing is also able to faithfully reproduce real mixtures of HOCs such as PAHs, in toxicity tests, reproducing both the levels and proportions of the different compounds. This provides a useful approach for studying the toxicity of environmental mixtures of HOCs, both with a view to investigating their toxicity but also for determining safety factors before such mixtures result in detrimental effects.

  6. Optimal design of cluster-based ad-hoc networks using probabilistic solution discovery

    International Nuclear Information System (INIS)

    Cook, Jason L.; Ramirez-Marquez, Jose Emmanuel

    2009-01-01

    The reliability of ad-hoc networks is gaining popularity in two areas: as a topic of academic interest and as a key performance parameter for defense systems employing this type of network. The ad-hoc network is dynamic and scalable and these descriptions are what attract its users. However, these descriptions are also synonymous for undefined and unpredictable when considering the impacts to the reliability of the system. The configuration of an ad-hoc network changes continuously and this fact implies that no single mathematical expression or graphical depiction can describe the system reliability-wise. Previous research has used mobility and stochastic models to address this challenge successfully. In this paper, the authors leverage the stochastic approach and build upon it a probabilistic solution discovery (PSD) algorithm to optimize the topology for a cluster-based mobile ad-hoc wireless network (MAWN). Specifically, the membership of nodes within the back-bone network or networks will be assigned in such as way as to maximize reliability subject to a constraint on cost. The constraint may also be considered as a non-monetary cost, such as weight, volume, power, or the like. When a cost is assigned to each component, a maximum cost threshold is assigned to the network, and the method is run; the result is an optimized allocation of the radios enabling back-bone network(s) to provide the most reliable network possible without exceeding the allowable cost. The method is intended for use directly as part of the architectural design process of a cluster-based MAWN to efficiently determine an optimal or near-optimal design solution. It is capable of optimizing the topology based upon all-terminal reliability (ATR), all-operating terminal reliability (AoTR), or two-terminal reliability (2TR)

  7. Reducing Congestion in Obstructed Highways with Traffic Data Dissemination Using Ad hoc Vehicular Networks

    OpenAIRE

    Thomas D. Hewer; Maziar Nekovee; Peter V. Coveney

    2010-01-01

    Vehicle-to-vehicle communications can be used effectively for intelligent transport systems (ITSs) and location-aware services. The ability to disseminate information in an ad hoc fashion allows pertinent information to propagate faster through a network. In the realm of ITS, the ability to spread warning information faster and further is of great advantage to receivers. In this paper we propose and present a message-dissemination procedure that uses vehicular wireless protocols to influence...

  8. Performance Analysis of Routing Protocols in Ad-hoc and Sensor Networking Environments

    Directory of Open Access Journals (Sweden)

    L. Gavrilovska

    2009-06-01

    Full Text Available Ad-hoc and sensor networks are becoming an increasingly popular wireless networking concepts lately. This paper analyzes and compares prominent routing schemes in these networking environments. The knowledge obtained can serve users to better understand short range wireless network solutions thus leading to options for implementation in various scenarios. In addition, it should aid researchers develop protocol improvements reliable for the technologies of interest.

  9. On Throughput Improvement of Wireless Ad Hoc Networks with Hidden Nodes

    Science.gov (United States)

    Choi, Hong-Seok; Lim, Jong-Tae

    In this letter, we present the throughput analysis of the wireless ad hoc networks based on the IEEE 802.11 MAC (Medium Access Control). Especially, our analysis includes the case with the hidden node problem so that it can be applied to the multi-hop networks. In addition, we suggest a new channel access control algorithm to maximize the network throughput and show the usefulness of the proposed algorithm through simulations.

  10. ARSENAL: A Cross Layer Architecture for Secure Resilient Tactical Mobile AdHoc Networks

    Science.gov (United States)

    2016-01-21

    stations separated by 0.5 to 1 km can be coherently measured to a single mobile subscriber using LTE signaling. These are the first measurements of...undertake three parallel but inter-coupled tasks geared towards a) performing measurements via real deployments and enhancing our understanding of layer...dependencies and vulnerabilities in mobile ad hoc networks; these measurements will be on existing testbeds at The views, opinions and/or findings

  11. Energy-Efficient Cluster Based Routing Protocol in Mobile Ad Hoc Networks Using Network Coding

    OpenAIRE

    Srinivas Kanakala; Venugopal Reddy Ananthula; Prashanthi Vempaty

    2014-01-01

    In mobile ad hoc networks, all nodes are energy constrained. In such situations, it is important to reduce energy consumption. In this paper, we consider the issues of energy efficient communication in MANETs using network coding. Network coding is an effective method to improve the performance of wireless networks. COPE protocol implements network coding concept to reduce number of transmissions by mixing the packets at intermediate nodes. We incorporate COPE into cluster based routing proto...

  12. Clustering of Mobile Ad Hoc Networks: An Adaptive Broadcast Period Approach

    OpenAIRE

    Gavalas, Damianos; Pantziou, Grammati; Konstantopoulos, Charalampos; Mamalis, Basilis

    2011-01-01

    Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering algorithm that uses both location and energy metrics for cluster formation. Our proposed solution mainly addresses cluster stability, manageability and energy efficiency i...

  13. Staging Collaborative Innovation Processes

    DEFF Research Database (Denmark)

    Pedersen, Signe; Clausen, Christian

    Organisations are currently challenged by demands for increased collaborative innovation internally as well as with external and new entities - e.g. across the value chain. The authors seek to develop new approaches to managing collaborative innovative processes in the context of open innovation ...... the diverse matters of concern into a coherent product or service concept, and 2) in the same process move these diverse holders of the matters of concern into a translated actor network which carry or support the concept.......Organisations are currently challenged by demands for increased collaborative innovation internally as well as with external and new entities - e.g. across the value chain. The authors seek to develop new approaches to managing collaborative innovative processes in the context of open innovation...... and public private innovation partnerships. Based on a case study of a collaborative design process in a large electronics company the paper points to the key importance of staging and navigation of collaborative innovation process. Staging and navigation is presented as a combined activity: 1) to translate...

  14. Collaborations in fusion research

    International Nuclear Information System (INIS)

    Barnes, D.; Davis, S.; Roney, P.

    1995-01-01

    This paper reviews current experimental collaborative efforts in the fusion community and extrapolates to operational scenarios for the Tokamak Physics Experiment (TPX) and the International Thermonuclear Experimental Reactor (ITER). Current requirements, available technologies and tools, and problems, issues and concerns are discussed. This paper specifically focuses on the issues that apply to experimental operational collaborations. Special requirements for other types of collaborations, such as theoretical or design and construction efforts, will not be addressed. Our current collaborative efforts have been highly successful, even though the tools in use will be viewed as primitive by tomorrow's standards. An overview of the tools and technologies in today's collaborations can be found in the first section of this paper. The next generation of fusion devices will not be primarily institutionally based, but will be national (TPX) and international (ITER) in funding, management, operation and in ownership of scientific results. The TPX will present the initial challenge of real-time remotely distributed experimental data analysis for a steady state device. The ITER will present new challenges with the possibility of several remote control rooms all participating in the real-time operation of the experimental device. A view to the future of remote collaborations is provided in the second section of this paper

  15. Distributed generation of shared RSA keys in mobile ad hoc networks

    Science.gov (United States)

    Liu, Yi-Liang; Huang, Qin; Shen, Ying

    2005-12-01

    Mobile Ad Hoc Networks is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner, independent of fixed physical infrastructure and centralized administrative infrastructure. However, the nature of Ad Hoc Networks makes them very vulnerable to security threats. Generation and distribution of shared keys for CA (Certification Authority) is challenging for security solution based on distributed PKI(Public-Key Infrastructure)/CA. The solutions that have been proposed in the literature and some related issues are discussed in this paper. The solution of a distributed generation of shared threshold RSA keys for CA is proposed in the present paper. During the process of creating an RSA private key share, every CA node only has its own private security. Distributed arithmetic is used to create the CA's private share locally, and that the requirement of centralized management institution is eliminated. Based on fully considering the Mobile Ad Hoc network's characteristic of self-organization, it avoids the security hidden trouble that comes by holding an all private security share of CA, with which the security and robustness of system is enhanced.

  16. Fault Tolerant Mechanism for Multimedia Flows in Wireless Ad Hoc Networks Based on Fast Switching Paths

    Directory of Open Access Journals (Sweden)

    Juan R. Diaz

    2014-01-01

    Full Text Available Multimedia traffic can be forwarded through a wireless ad hoc network using the available resources of the nodes. Several models and protocols have been designed in order to organize and arrange the nodes to improve transmissions along the network. We use a cluster-based framework, called MWAHCA architecture, which optimizes multimedia transmissions over a wireless ad hoc network. It was proposed by us in a previous research work. This architecture is focused on decreasing quality of service (QoS parameters like latency, jitter, and packet loss, but other network features were not developed, like load balance or fault tolerance. In this paper, we propose a new fault tolerance mechanism, using as a base the MWAHCA architecture, in order to recover any multimedia flow crossing the wireless ad hoc network when there is a node failure. The algorithm can run independently for each multimedia flow. The main objective is to keep the QoS parameters as low as possible. To achieve this goal, the convergence time must be controlled and reduced. This paper provides the designed protocol, the analytical model of the algorithm, and a software application developed to test its performance in a real laboratory.

  17. Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    M. Isabel Vara

    2015-07-01

    Full Text Available Service discovery plays an important role in mobile ad hoc networks (MANETs. The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2. In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1. In order to advertise services, we have added a new type-length-value structure (TLV to the OLSRv2 protocol, called service discovery message (SDM, according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV protocol, in terms of service discovery ratio, service latency and network overhead.

  18. ENERGY EFFICIENT ROUTING PROTOCOLS FOR WIRELESS AD HOC NETWORKS – A SURVEY

    Directory of Open Access Journals (Sweden)

    K. Sankar

    2012-06-01

    Full Text Available Reducing energy consumption, primarily with the goal of extending the lifetime of battery-powered devices, has emerged as a fundamental challenge in wireless communication. The performance of the medium access control (MAC scheme not only has a fairly significant end-result on the behaviour of the routing approach employed, but also on the energy consumption of the wireless network interface card (NIC. We investigate the inadequacies of the MAC schemes designed for ad hoc wireless networks in the context of power awareness herein. The topology changes due to uncontrollable factors such as node mobility, weather, interference, noise, as well as on controllable parameters such as transmission power and antenna direction results in significant amount of energy loss. Controlling rapid topology changes by minimizing the maximum transmission power used in ad hoc wireless networks, while still maintaining networks connectivity can prolong battery life and hence network lifetime considerably. In addition, we systematically explore the potential energy consumption pitfalls of non–power-based and power based routing schemes. We suggest a thorough energy-based performance survey of energy aware routing protocols for wireless mobile ad-hoc networks. We also present the statistical performance metrics measured by our simulations.

  19. Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN

    Directory of Open Access Journals (Sweden)

    Yuan Hai-Feng

    2006-01-01

    Full Text Available As an important complement to infrastructured wireless networks, mobile ad hoc networks (MANET are more flexible in providing wireless access services, but more difficult in meeting different quality of service (QoS requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks (WLAN, which can offer high data-rate wireless multimedia services to the mobile stations (MSs in a limited geographical area. For those out-of-coverage MSs, how to effectively connect them to the access point (AP and provide QoS support is a challenging issue. By mixing the infrastructure and the ad hoc modes in WLAN, we propose in this paper a new coverage improvement scheme that can identify suitable idle MSs in good service zones as traffic agents (TAs to relay traffic from those out-of-coverage MSs to the AP. The service coverage area of WLAN is then expanded. The QoS requirements (e.g., bandwidth of those MSs are considered in the selection process of corresponding TAs. Mathematical analysis, verified by computer simulations, shows that the proposed TA scheme can effectively reduce blocking probability when traffic load is light.

  20. Maximization of Energy Efficiency in Wireless ad hoc and Sensor Networks With SERENA

    Directory of Open Access Journals (Sweden)

    Saoucene Mahfoudh

    2009-01-01

    Full Text Available In wireless ad hoc and sensor networks, an analysis of the node energy consumption distribution shows that the largest part is due to the time spent in the idle state. This result is at the origin of SERENA, an algorithm to SchEdule RoutEr Nodes Activity. SERENA allows router nodes to sleep, while ensuring end-to-end communication in the wireless network. It is a localized and decentralized algorithm assigning time slots to nodes. Any node stays awake only during its slot and the slots assigned to its neighbors, it sleeps the remaining time. Simulation results show that SERENA enables us to maximize network lifetime while increasing the number of user messages delivered. SERENA is based on a two-hop coloring algorithm, whose complexity in terms of colors and rounds is evaluated. We then quantify the slot reuse. Finally, we show how SERENA improves the node energy consumption distribution and maximizes the energy efficiency of wireless ad hoc and sensor networks. We compare SERENA with classical TDMA and optimized variants such as USAP in wireless ad hoc and sensor networks.

  1. Research on Propagation Model of Malicious Programs in Ad Hoc Wireless Network

    Directory of Open Access Journals (Sweden)

    Weimin GAO

    2014-01-01

    Full Text Available Ad Hoc wireless network faces more security threats than traditional network due to its P2P system structure and the limited node resources. In recent years, malicious program has become one of the most important researches on international network security and information security. The research of malicious programs on wireless network has become a new research hotspot in the field of malicious programs. This paper first analyzed the Ad Hoc network system structure, security threats, the common classification of malicious programs and the bionic propagation model. Then starting from the differential equations of the SEIR virus propagation model, the question caused by introducing the SEIR virus propagation model in Ad Hoc wireless network was analyzed. This paper improved the malicious program propagation model through introducing the network topology features and concepts such as immunization delay, and designed an improved algorithm combined with the dynamic evolution of malware propagation process. Considering of the network virus propagation characteristics, network characteristics and immunization strategy to improve simulation model experiment analysis, the experimental results show that both the immunization strategy and the degrees of node can affect the propagation of malicious program.

  2. An Effective Approach for Mobile ad hoc Network via I-Watchdog Protocol

    Directory of Open Access Journals (Sweden)

    Nidhi Lal

    2014-12-01

    Full Text Available Mobile ad hoc network (MANET is now days become very famous due to their fixed infrastructure-less quality and dynamic nature. They contain a large number of nodes which are connected and communicated to each other in wireless nature. Mobile ad hoc network is a wireless technology that contains high mobility of nodes and does not depend on the background administrator for central authority, because they do not contain any infrastructure. Nodes of the MANET use radio wave for communication and having limited resources and limited computational power. The Topology of this network is changing very frequently because they are distributed in nature and self-configurable. Due to its wireless nature and lack of any central authority in the background, Mobile ad hoc networks are always vulnerable to some security issues and performance issues. The security imposes a huge impact on the performance of any network. Some of the security issues are black hole attack, flooding, wormhole attack etc. In this paper, we will discuss issues regarding low performance of Watchdog protocol used in the MANET and proposed an improved Watchdog mechanism, which is called by I-Watchdog protocol that overcomes the limitations of Watchdog protocol and gives high performance in terms of throughput, delay.

  3. Intelligent Stale-Frame Discards for Real-Time Video Streaming over Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Sheu Tsang-Ling

    2009-01-01

    Full Text Available Abstract This paper presents intelligent early packet discards (I-EPD for real-time video streaming over a multihop wireless ad hoc network. In a multihop wireless ad hoc network, the quality of transferring real-time video streams could be seriously degraded, since every intermediate node (IN functionally like relay device does not possess large buffer and sufficient bandwidth. Even worse, a selected relay node could leave or power off unexpectedly, which breaks the route to destination. Thus, a stale video frame is useless even if it can reach destination after network traffic becomes smooth or failed route is reconfigured. In the proposed I-EPD, an IN can intelligently determine whether a buffered video packet should be early discarded. For the purpose of validation, we implement the I-EPD on Linux-based embedded systems. Via the comparisons of performance metrics (packet/frame discards ratios, PSNR, etc., we demonstrate that video quality over a wireless ad hoc network can be substantially improved and unnecessary bandwidth wastage is greatly reduced.

  4. Power-Controlled MAC Protocols with Dynamic Neighbor Prediction for Ad hoc Networks

    Institute of Scientific and Technical Information of China (English)

    LI Meng; ZHANG Lin; XIAO Yong-kang; SHAN Xiu-ming

    2004-01-01

    Energy and bandwidth are the scarce resources in ad hoc networks because most of the mobile nodes are battery-supplied and share the exclusive wireless medium. Integrating the power control into MAC protocol is a promising technique to fully exploit these precious resources of ad hoc wireless networks. In this paper, a new intelligent power-controlled Medium Access Control (MAC) (iMAC) protocol with dynamic neighbor prediction is proposed. Through the elaborate design of the distributed transmit-receive strategy of mobile nodes, iMAC greatly outperforms the prevailing IEEE 802.11 MAC protocols in not only energy conservation but also network throughput. Using the Dynamic Neighbor Prediction (DNP), iMAC performs well in mobile scenes. To the best of our knowledge, iMAC is the first protocol that considers the performance deterioration of power-controlled MAC protocols in mobile scenes and then proposes a solution. Simulation results indicate that DNP is important and necessary for power-controlled MAC protocols in mobile ad hoc networks.

  5. Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks.

    Science.gov (United States)

    Vara, M Isabel; Campo, Celeste

    2015-07-20

    Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.

  6. UMDR: Multi-Path Routing Protocol for Underwater Ad Hoc Networks with Directional Antenna

    Science.gov (United States)

    Yang, Jianmin; Liu, Songzuo; Liu, Qipei; Qiao, Gang

    2018-01-01

    This paper presents a new routing scheme for underwater ad hoc networks based on directional antennas. Ad hoc networks with directional antennas have become a hot research topic because of space reuse may increase networks capacity. At present, researchers have applied traditional self-organizing routing protocols (such as DSR, AODV) [1] [2] on this type of networks, and the routing scheme is based on the shortest path metric. However, such routing schemes often suffer from long transmission delays and frequent link fragmentation along the intermediate nodes of the selected route. This is caused by a unique feature of directional transmission, often called as “deafness”. In this paper, we take a different approach to explore the advantages of space reuse through multipath routing. This paper introduces the validity of the conventional routing scheme in underwater ad hoc networks with directional antennas, and presents a special design of multipath routing algorithm for directional transmission. The experimental results show a significant performance improvement in throughput and latency.

  7. QoS Routing in Ad-Hoc Networks Using GA and Multi-Objective Optimization

    Directory of Open Access Journals (Sweden)

    Admir Barolli

    2011-01-01

    Full Text Available Much work has been done on routing in Ad-hoc networks, but the proposed routing solutions only deal with the best effort data traffic. Connections with Quality of Service (QoS requirements, such as voice channels with delay and bandwidth constraints, are not supported. The QoS routing has been receiving increasingly intensive attention, but searching for the shortest path with many metrics is an NP-complete problem. For this reason, approximated solutions and heuristic algorithms should be developed for multi-path constraints QoS routing. Also, the routing methods should be adaptive, flexible, and intelligent. In this paper, we use Genetic Algorithms (GAs and multi-objective optimization for QoS routing in Ad-hoc Networks. In order to reduce the search space of GA, we implemented a search space reduction algorithm, which reduces the search space for GAMAN (GA-based routing algorithm for Mobile Ad-hoc Networks to find a new route. We evaluate the performance of GAMAN by computer simulations and show that GAMAN has better behaviour than GLBR (Genetic Load Balancing Routing.

  8. Exploiting Mobile Ad Hoc Networking and Knowledge Generation to Achieve Ambient Intelligence

    Directory of Open Access Journals (Sweden)

    Anna Lekova

    2012-01-01

    Full Text Available Ambient Intelligence (AmI joins together the fields of ubiquitous computing and communications, context awareness, and intelligent user interfaces. Energy, fault-tolerance, and mobility are newly added dimensions of AmI. Within the context of AmI the concept of mobile ad hoc networks (MANETs for “anytime and anywhere” is likely to play larger roles in the future in which people are surrounded and supported by small context-aware, cooperative, and nonobtrusive devices that will aid our everyday life. The connection between knowledge generation and communication ad hoc networking is symbiotic—knowledge generation utilizes ad hoc networking to perform their communication needs, and MANETs will utilize the knowledge generation to enhance their network services. The contribution of the present study is a distributed evolving fuzzy modeling framework (EFMF to observe and categorize relationships and activities in the user and application level and based on that social context to take intelligent decisions about MANETs service management. EFMF employs unsupervised online one-pass fuzzy clustering method to recognize nodes' mobility context from social scenario traces and ubiquitously learn “friends” and “strangers” indirectly and anonymously.

  9. Signaling-Free Max-Min Airtime Fairness in IEEE 802.11 Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Youngsoo Lee

    2016-01-01

    Full Text Available We propose a novel media access control (MAC protocol, referred to as signaling-free max-min airtime fair (SMAF MAC, to improve fairness and channel utilization in ad hoc networks based on IEEE 802.11 wireless local area networks (WLANs. We introduce busy time ratio (BTR as a measure for max-min airtime fairness. Each node estimates its BTR and adjusts the transmission duration by means of frame aggregation and fragmentation, so that it can implicitly announce the BTR to neighbor nodes. Based on the announced BTR, each of the neighbor nodes controls its contention window. In this way, the SMAF MAC works in a distributed manner without the need to know the max-min fair share of airtime, and it does not require exchanging explicit control messages among nodes to attain fairness. Moreover, we successfully incorporate the hidden node detection and resolution mechanisms into the SMAF MAC to deal with the hidden node problem in ad hoc networks. The simulation results confirm that the SMAF MAC enhances airtime fairness without degrading channel utilization, and it effectively resolves several serious problems in ad hoc networks such as the starvation, performance anomaly, and hidden node problems.

  10. Improving VANETs Connectivity with a Totally Ad Hoc Living Mobile Backbone

    Directory of Open Access Journals (Sweden)

    Joilson Alves Junior

    2015-01-01

    Full Text Available The vehicular ad hoc network (VANET for intelligent transportation systems is an emerging concept to improve transportation security, reliability, and management. The network behavior can be totally different in topological aspects because of the mobility of vehicular nodes. The topology can be fully connected when the flow of vehicles is high and may have low connectivity or be invalid when the flow of vehicles is low or unbalanced. In big cities, the metropolitan buses that travel on exclusive lanes may be used to set up a metropolitan vehicular data network (backbone, raising the connectivity among the vehicles. Therefore, this paper proposes the implementation of a living mobile backbone, totally ad hoc (MOB-NET, which will provide infrastructure and raise the network connectivity. In order to show the viability of MOB-NET, statistical analyses were made with real data of express buses that travel through exclusive lanes, besides evaluations through simulations and analytic models. The statistic, analytic, and simulation results prove that the buses that travel through exclusive lanes can be used to build a communication network totally ad hoc and provide connectivity in more than 99% of the time, besides raising the delivery rate up to 95%.

  11. Collaborative engagement experiment (CEE)

    Science.gov (United States)

    Wade, Robert L.; Reames, Joseph M.

    2005-05-01

    Unmanned ground and air systems operating in collaboration have the potential to provide future Joint Forces a significant capability for operations in complex terrain. Ground and air collaborative engagements potentially offer force conservation, perform timely acquisition and dissemination of essential combat information, and can eliminate high value and time critical targets. These engagements can also add considerably to force survivability by reducing soldier and equipment exposure during critical operations. The Office of the Secretary of Defense, Joint Robotics Program (JRP) sponsored Collaborative Engagement Experiment (CEE) is a consolidation of separate Air Force, Army and Navy collaborative efforts to provide a Joint capability. The Air Force Research Laboratory (AFRL), Material and Manufacturing Directorate, Aerospace Expeditionary Force Division, Force Protection Branch (AFRLMLQF), The Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) Joint Technology Center (JTC)/Systems Integration Laboratory (SIL), and the Space and Naval Warfare Systems Center-San Diego (SSC San Diego) are conducting technical research and proof of principle for an envisioned operational concept for extended range, three dimensional, collaborative operations between unmanned systems, with enhanced situational awareness for lethal operations in complex terrain. This program will assess information requirements and conduct experiments to identify and resolve technical risks for collaborative engagements using Unmanned Ground Vehicles (UGVs) and Unmanned Aerial Vehicles (UAVs). It will research, develop and physically integrate multiple unmanned systems and conduct live collaborative experiments. Modeling and Simulation systems will be upgraded to reflect engineering fidelity levels to greater understand technical challenges to operate as a team. This paper will provide an update of a multi-year program and will concentrate primarily on the JTC

  12. Reputational Information and Strategic Collaboration

    DEFF Research Database (Denmark)

    Andersen, Poul Houman; Bendix, Henrik B.

    1998-01-01

    What types of information do decision-makers use when deciding on collaboration? What are the role of reputational information in relation to decisions on collaboration......What types of information do decision-makers use when deciding on collaboration? What are the role of reputational information in relation to decisions on collaboration...

  13. Distance collaborations with industry

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, A.; Swyler, K.

    1998-06-01

    The college industry relationship has been identified as a key policy issue in Engineering Education. Collaborations between academic institutions and the industrial sector have a long history and a bright future. For Engineering and Engineering Technology programs in particular, industry has played a crucial role in many areas including advisement, financial support, and practical training of both faculty and students. Among the most important and intimate interactions are collaborative projects and formal cooperative education arrangements. Most recently, such collaborations have taken on a new dimension, as advances in technology have made possible meaningful technical collaboration at a distance. There are several obvious technology areas that have contributed significantly to this trend. Foremost is the ubiquitous presence of the Internet. Perhaps almost as important are advances in computer based imaging. Because visual images offer a compelling user experience, it affords greater knowledge transfer efficiency than other modes of delivery. Furthermore, the quality of the image appears to have a strongly correlated effect on insight. A good visualization facility offers both a means for communication and a shared information space for the subjects, which are among the essential features of both peer collaboration and distance learning.

  14. COLLABORATION BOARD (CB55)

    CERN Multimedia

    B. Cousins

    Open Access Publication Policy ATLAS had recently issued a short statement in support of open access publishing. The mood of the discussions in the December CMS Collaboration Board had appeared to be in favour and so it was being proposed that CMS issue the same statement as that made by ATLAS (the statement is attached to the agenda of this meeting). The Collaboration Board agreed. Election of the Chair of the Collaboration Board Following the agreement to shorten the terms of both the Spokesperson and the Collaboration Board Chair, and to introduce a longer overlap period between the election and the start of the term, the election for the next Collaboration Board Chair was due in December 2007. If the old standard schedule specified in the Constitution were adapted to this date, then the Board should be informed at the present meeting that the election was being prepared. However, it was felt that the experience of the previous year's election of the Spokesperson had shown that it would be desirable to...

  15. A collaborative chain out of phase

    Directory of Open Access Journals (Sweden)

    Bård Paulsen

    2013-03-01

    Full Text Available Introduction: The aim of this study is to explore the obstacles to collaborations between nurses in hospital and municipal care in the discharge of hospital patients who need continuing care. Methods: First, we conducted in-depth interviews of nurses in hospitals and nurses in municipal care. Second, we developed questionnaires and distributed them to a representative sample of Norwegian municipalities to study the representativeness of the most important findings from the interviews. Results: Municipal care nurses reported that the information they receive from hospital departments usually is insufficient for a complete understanding of a patient's needs. Formal discharge reports from hospital serve as a post factum formalization and authorization of information collected by municipal nurses in an ad hoc fashion and via oral communication.  Typically, formal information routines are out of phase with the information needed by municipal care professionals. Conclusions: Hospital information provided at discharge is neither sufficient nor timely with respect to the information needs of nurses in municipal care. Organizational efforts and the use of information technology might ease some obstacles, but several problems will remain because of differences in professional orientation and the contexts of care delivery.

  16. An Automated Tool for the Creation of Desired Emulated Topologies of a Mobile Ad-Hoc Network

    National Research Council Canada - National Science Library

    Nguyen, Binh Q

    2006-01-01

    This report documents a research effort that the U.S. Army Research Laboratory conducted in FY 2005 in support of the development of advanced technologies for tactical mobile ad hoc networks (MANET...

  17. The impact of brief team communication, leadership and team behavior training on ad hoc team performance in trauma care settings.

    Science.gov (United States)

    Roberts, Nicole K; Williams, Reed G; Schwind, Cathy J; Sutyak, John A; McDowell, Christopher; Griffen, David; Wall, Jarrod; Sanfey, Hilary; Chestnut, Audra; Meier, Andreas H; Wohltmann, Christopher; Clark, Ted R; Wetter, Nathan

    2014-02-01

    Communication breakdowns and care coordination problems often cause preventable adverse patient care events, which can be especially acute in the trauma setting, in which ad hoc teams have little time for advanced planning. Existing teamwork curricula do not address the particular issues associated with ad hoc emergency teams providing trauma care. Ad hoc trauma teams completed a preinstruction simulated trauma encounter and were provided with instruction on appropriate team behaviors and team communication. Teams completed a postinstruction simulated trauma encounter immediately afterward and 3 weeks later, then completed a questionnaire. Blinded raters rated videotapes of the simulations. Participants expressed high levels of satisfaction and intent to change practice after the intervention. Participants changed teamwork and communication behavior on the posttest, and changes were sustained after a 3-week interval, though there was some loss of retention. Brief training exercises can change teamwork and communication behaviors on ad hoc trauma teams. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Managing collaborative innovation networks

    DEFF Research Database (Denmark)

    Stevens, Vidar; Agger, Annika

    2017-01-01

    Collaborative innovation networks are increasingly used as vehicles for fostering innovative policy solutions. However, scholars have noted that the extent to which collaborative networks can actually contribute to the development of innovative policy solutions depends on how they are managed...... a Flemish administrative network to develop a radical new Spatial Planning Policy Plan. This study shows that the best way to manage collaborative innovation networks is not to press directly for results, but take the time to invest in relationship-building and together agree on a planning and clear process...... steps. Such a management approach allows actors to get to know each other and from thereon expand, with more background and appreciation for the others’ goals, behaviors, and intentions, their group activities concerning the formulation of a radical and innovative policy plan....

  19. Innovation and network collaboration

    DEFF Research Database (Denmark)

    Kesting, Peter; Müller, Sabine; Jørgensen, Frances

    2011-01-01

    Research suggests that small and medium-sized enterprises (SMEs) can benefit from network collaboration by enhancing opportunities for innovation. Managing the necessary collaboration to benefit from network participation may however be particularly challenging for SMEs due to their size...... and their inherent shortage of resources. In this paper, we propose that human resource management (HRM) practices may provide a means by which SMEs can increase their innovation capacity through network collaboration. Following a brief presentation of the relevant literature on networks, and innovation in networks...... in particular, and HRM, we analyse and evaluate the potential applicability of existing models for supporting innovation in SMEs participating in networks. Finally, we propose several lines of inquiry arising from our analysis that provide directions for future research....

  20. Securing collaborative environments

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Deborah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jackson, Keith [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Thompson, Mary [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2002-05-16

    The diverse set of organizations and software components involved in a typical collaboratory make providing a seamless security solution difficult. In addition, the users need support for a broad range of frequency and locations for access to the collaboratory. A collaboratory security solution needs to be robust enough to ensure that valid participants are not denied access because of its failure. There are many tools that can be applied to the task of securing collaborative environments and these include public key infrastructure, secure sockets layer, Kerberos, virtual and real private networks, grid security infrastructure, and username/password. A combination of these mechanisms can provide effective secure collaboration capabilities. In this paper, we discuss the requirements of typical collaboratories and some proposals for applying various security mechanisms to collaborative environments.

  1. Intercultural Collaboration Stories

    DEFF Research Database (Denmark)

    Gertsen, Martine Cardel; Søderberg, Anne-Marie

    2011-01-01

    The objective of this article is to show how narrative methods provide useful tools for international business research. We do this by presenting a study of stories told about the collaboration between a Danish expatriate manager and his Chinese CEO in the Shanghai subsidiary of an MNE. First, we...... to elucidate intercultural collaboration processes by analyzing how each member of a dyad of interacting managers narrates the same chain of events. We show how the narratological concepts of peripeteia and anagnorisis are well suited to identifying focal points in their stories: situations where change...... follows their recognizing new dimensions of their conflicts, eventually furthering their collaboration. We explain how Greimas's actantial model is valuable when mapping differences between and changes in the narrators’ projects, alliances and oppositions in the course of their interaction. Thus, we make...

  2. Playful Collaboration (or Not)

    DEFF Research Database (Denmark)

    Bogers, Marcel

    2011-01-01

    This paper explores how games and play, which are deeply rooted in human beings as a way to learn and interact, can be used to teach certain concepts and practices related to open collaborative innovation. We discuss how playing games can be a source of creativity, imagination and fun, while it can...... also be conducive to deep learning. As such, a game can engage different dimensions of learning and embed elements of active, collaborative, cooperative and problem-based learning. Building on this logic, we present an exploratory case study of the use of a particular board game in a class of a course...... collaboration at the cost of individual performance and possible long-term collective performance as well....

  3. Collaborative Economy and Tourism

    DEFF Research Database (Denmark)

    Dredge, Dianne; Gyimóthy, Szilvia

    2017-01-01

    The digital collaborative economy is one of the most fascinating developments to have claimed our attention in the last decade. Not only does it defy clear definition, but its historical links back to non-monetised sharing and gift economies and its contemporary foundations in monetising idling...... or spare capacity make it difficult to theorise. In this chapter, we lay the foundation for a social science approach to the exploration of the collaborative economy and its relationship with tourism. We argue that “collaborative” and “economy” should be conceptualised in a broad and inclusive manner...... in order to avoid narrow theorisations and blinkered accounts that focus only on digitally-mediated, monetised transactions. A balance between individual and collective dimensions of the collaborative economy is also necessary if we are to understand its societal implications....

  4. The collaboration imperative.

    Science.gov (United States)

    Nidumolu, Ram; Ellison, Jib; Whalen, John; Billman, Erin

    2014-04-01

    Addressing global sustainability challenges--including climate change, resource depletion, and ecosystem loss--is beyond the individual capabilities of even the largest companies. To tackle these threats, and unleash new value, companies and other stakeholders must collaborate in new ways that treat fragile and complex ecosystems as a whole. In this article, the authors draw on cases including the Latin American Water Funds Partnership, the Sustainable Apparel Coalition (led by Nike, Patagonia, and Walmart), and Action to Accelerate Recycling (a partnership between Alcoa, consumer packaged goods companies, and local governments, among others) to describe four new collaboration models that create shared value and address environmental protection across the value stream. Optimal collaborations focus on improving either business processes or outcomes. They start with a small group of key organizations, bring in project management expertise, link self-interest to shared interest, encourage productive competition, create quick wins, and, above all, build and maintain trust.

  5. A Cross Layer Solution to Address TCP Intra-flow Performance Degradation in Multihop Ad hoc Networks

    OpenAIRE

    Rakocevic, V.; Hamadani, E.

    2008-01-01

    Incorporating the concept of TCP end-to-end congestion control for wireless networks is one of the primary concerns in designing ad hoc networks since TCP was primarily designed and optimized based on the assumptions for wired networks. In this study, our interest lies on tackling the TCP instability and in particular intra-flow instability problem since due to the nature of applications in multihop ad hoc networks, connection instability or starvation even for a short period of time can have...

  6. Communication and collaboration technologies.

    Science.gov (United States)

    Cheeseman, Susan E

    2012-01-01

    This is the third in a series of columns exploring health information technology (HIT) in the neonatal intensive care unit (NICU). The first column provided background information on the implementation of information technology throughout the health care delivery system, as well as the requisite informatics competencies needed for nurses to fully engage in the digital era of health care. The second column focused on information and resources to master basic computer competencies described by the TIGER initiative (Technology Informatics Guiding Education Reform) as learning about computers, computer networks, and the transfer of data.1 This column will provide additional information related to basic computer competencies, focusing on communication and collaboration technologies. Computers and the Internet have transformed the way we communicate and collaborate. Electronic communication is the ability to exchange information through the use of computer equipment and software.2 Broadly defined, any technology that facilitates linking one or more individuals together is a collaborative tool. Collaboration using technology encompasses an extensive range of applications that enable groups of individuals to work together including e-mail, instant messaging (IM ), and several web applications collectively referred to as Web 2.0 technologies. The term Web 2.0 refers to web applications where users interact and collaborate with each other in a collective exchange of ideas generating content in a virtual community. Examples of Web 2.0 technologies include social networking sites, blogs, wikis, video sharing sites, and mashups. Many organizations are developing collaborative strategies and tools for employees to connect and interact using web-based social media technologies.3.

  7. Playful Collaboration (Or Not)

    DEFF Research Database (Denmark)

    Bogers, Marcel; Sproedt, Henrik

    2012-01-01

    This article explores how playing games can be used to teach intangible social interaction across boundaries, in particular within open collaborative innovation. We present an exploratory case study of how students learned from playing a board game in a graduate course of the international...... and interdisciplinary Innovation and Business master's program in Denmark. We identify several important themes related to the process of learning through playing and the social dynamics of open collaborative innovation, while we also highlight possible caveats of “playing” and practicing open innovation. Our findings...

  8. Organizing for Asymmetric Collaboration

    DEFF Research Database (Denmark)

    Nielsen, Jørn Flohr; Sørensen, Henrik B.

      The vision of new organizational forms consists of less-organized networks and alliances between organizations, in which collaborative capabilities are assumed to be crucial (Miles et al., 2005). The path to such new forms may go through fragile cooperative efforts. Despite the good will of many...... complexity to already complex models, we claim that our approach has practical implications: it offers rather simple diagnostic cues to change agents that are coping with the barriers to management and collaboration among loosely coupled units....

  9. Collaboratively Constructed Contradictory Accounts

    DEFF Research Database (Denmark)

    Tunby Gulbrandsen, Ib; Just, Sine Nørholm

    2013-01-01

    Based on a mixed-method case study of online communication about the Danish pharmaceutical company Novo Nordisk, this article argues that online communication plays out as a centrifugal narration process with centripetal consequences. Through a content analysis of communication about Novo Nordisk...... the theoretical and methodological implications of the empirical findings. It is argued that although the findings are not in themselves surprising, they adequately reflect that online meaning formation is, indeed, a collaborative process in which centrifugal forces have centripetal consequences. Furthermore......, the findings suggest that the chosen mixed-method case study successfully navigates the dilemma of studying online collaborative processes through the traces they leave behind....

  10. Report of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. Result evaluation in fiscal year 2000

    International Nuclear Information System (INIS)

    2001-06-01

    The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Nuclear Safety Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Reactor Safety Research, Department of Fuel Cycle Safety Research, Department of Environmental Safety Research and Department of Safety Research Technical Support in Tokai Research Establishment at JAERI. The Ad Hoc Review Committee consisted of 11 specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to February 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 11, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. (author)

  11. Report of the evaluation by the Ad Hoc Review Committee on Health Physics. Result evaluation in fiscal year 2000

    International Nuclear Information System (INIS)

    2001-06-01

    The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Health Physics in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Health Physics in Tokai Research Establishment and at related departments in other Establishments of JAERI. The Ad Hoc Review Committee consisted of six specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from October 2000 to January 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on October 10, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Health Physics. (author)

  12. Report of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. Result evaluation in fiscal year 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Nuclear Safety Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Reactor Safety Research, Department of Fuel Cycle Safety Research, Department of Environmental Safety Research and Department of Safety Research Technical Support in Tokai Research Establishment at JAERI. The Ad Hoc Review Committee consisted of 11 specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to February 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 11, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. (author)

  13. Dynamic fair node spectrum allocation for ad hoc networks using random matrices

    Science.gov (United States)

    Rahmes, Mark; Lemieux, George; Chester, Dave; Sonnenberg, Jerry

    2015-05-01

    Dynamic Spectrum Access (DSA) is widely seen as a solution to the problem of limited spectrum, because of its ability to adapt the operating frequency of a radio. Mobile Ad Hoc Networks (MANETs) can extend high-capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact, cognitive radio employs spectrum sensing to facilitate the identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, while secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate fair path use of the DSA-discovered links. Utilization of high-resolution geospatial data layers in RF propagation analysis is directly applicable. Random matrix theory (RMT) is useful in simulating network layer usage in nodes by a Wishart adjacency matrix. We use the Dijkstra algorithm for discovering ad hoc network node connection patterns. We present a method for analysts to dynamically allocate node-node path and link resources using fair division. User allocation of limited resources as a function of time must be dynamic and based on system fairness policies. The context of fair means that first available request for an asset is not envied as long as it is not yet allocated or tasked in order to prevent cycling of the system. This solution may also save money by offering a Pareto efficient repeatable process. We use a water fill queue algorithm to include Shapley value marginal contributions for allocation.

  14. A hardware and software architecture to deal with multimodal and collaborative interactions in multiuser virtual reality environments

    Science.gov (United States)

    Martin, P.; Tseu, A.; Férey, N.; Touraine, D.; Bourdot, P.

    2014-02-01

    Most advanced immersive devices provide collaborative environment within several users have their distinct head-tracked stereoscopic point of view. Combining with common used interactive features such as voice and gesture recognition, 3D mouse, haptic feedback, and spatialized audio rendering, these environments should faithfully reproduce a real context. However, even if many studies have been carried out on multimodal systems, we are far to definitively solve the issue of multimodal fusion, which consists in merging multimodal events coming from users and devices, into interpretable commands performed by the application. Multimodality and collaboration was often studied separately, despite of the fact that these two aspects share interesting similarities. We discuss how we address this problem, thought the design and implementation of a supervisor that is able to deal with both multimodal fusion and collaborative aspects. The aim of this supervisor is to ensure the merge of user's input from virtual reality devices in order to control immersive multi-user applications. We deal with this problem according to a practical point of view, because the main requirements of this supervisor was defined according to a industrial task proposed by our automotive partner, that as to be performed with multimodal and collaborative interactions in a co-located multi-user environment. In this task, two co-located workers of a virtual assembly chain has to cooperate to insert a seat into the bodywork of a car, using haptic devices to feel collision and to manipulate objects, combining speech recognition and two hands gesture recognition as multimodal instructions. Besides the architectural aspect of this supervisor, we described how we ensure the modularity of our solution that could apply on different virtual reality platforms, interactive contexts and virtual contents. A virtual context observer included in this supervisor in was especially designed to be independent to the

  15. The Cochrane collaboration

    NARCIS (Netherlands)

    Scholten, R. J. P. M.; Clarke, M.; Hetherington, J.

    2005-01-01

    The Cochrane Collaboration is an international, not-for-profit organisation that aims to help people make well-informed decisions about health care by preparing, maintaining and promoting the accessibility of systematic reviews of the effects of health-care interventions. Cochrane systematic reviews

  16. Strategic importance of collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K.A. [NB Power, Fredericton, New Brunswick (Canada)

    2015-07-01

    In the nuclear industry there is a need to collaborate because of aging equipment, aging people that contribute to dilution of expertise, obsolesce and advances in codes and standards. In the longer term there is a need to focus on operational issues, sustain our suppliers and expertise as well as improve and sustain performance.

  17. Strategic importance of collaboration

    International Nuclear Information System (INIS)

    Miller, K.A.

    2015-01-01

    In the nuclear industry there is a need to collaborate because of aging equipment, aging people that contribute to dilution of expertise, obsolesce and advances in codes and standards. In the longer term there is a need to focus on operational issues, sustain our suppliers and expertise as well as improve and sustain performance.

  18. When industry & academia collaborate

    NARCIS (Netherlands)

    Kopczak, L.R.; Fransoo, J.C.

    1999-01-01

    Innovative "project-based courses" are bringing the business and academic worlds together to advance global supply chain management. By collaborating with universities to solve specific supply chain problems, companies not only benefit from the infusion of new ideas, but also gain access to a pool

  19. INTERNATIONAL COLLABORATION: Panelling

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    At the meeting of the International Committee for Future Accelerators (ICFA), in Geneva in July, Chairman A.N. Skrinsky of Novosibirsk reviewed ICFA progress, particularly the activities of the specialist Panels which pursue specific Committee objectives in guiding worldwide collaboration in high energy physics

  20. Preparing for Collaborative Working.

    Science.gov (United States)

    David, Rachel; Smith, Beryl

    1987-01-01

    Interdisciplinary collaboration with other professionals was the theme of a preservice training activity in England in which 18 students enrolled in a teacher training program for learning difficulties were paired with students of speech and language pathology to observe, discuss, and assess a severely disabled child in the school setting. (JW)

  1. Beyond Collaborative Services

    DEFF Research Database (Denmark)

    Seravalli, Anna; Agger Eriksen, Mette

    2017-01-01

    between the designer and various other stakeholders. To navigate this rich complexity, we propose the two notions of commons and infrastructuring, and we do that by re ecting on the case of designing a makerspace, Fabriken, a sharing-based collaborative service. We use the notion of commons as a framework...

  2. INTERNATIONAL COLLABORATION: Panelling

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1991-10-15

    At the meeting of the International Committee for Future Accelerators (ICFA), in Geneva in July, Chairman A.N. Skrinsky of Novosibirsk reviewed ICFA progress, particularly the activities of the specialist Panels which pursue specific Committee objectives in guiding worldwide collaboration in high energy physics.

  3. Understanding collaborative design

    NARCIS (Netherlands)

    Kleinsmann, M.S.

    2006-01-01

    Fast product follow-ups and increasing customer demands have changed product design from a rather unstructured process, into a systematic activity. Nowadays, both companies and researchers have developed the organizational aspects of integrated product design. However, attention to the collaborative

  4. Collaboration and Networking

    NARCIS (Netherlands)

    Husson, O.; Manten-Horst, E.; Graaf, W.T.A. van der

    2016-01-01

    Awareness of the need for collaboration across pediatric and adult cancer to care for adolescents and young adults (AYAs) arose from the recognition of the unique characteristics of AYAs with cancer. Neither pediatric nor adult oncology hospital departments are able to provide age-appropriate care

  5. Collaborative engineering experiences

    NARCIS (Netherlands)

    Ir. Peter van Kollenburg; Dr. Ir. P. Mulders; Ir. Dick van Schenk Brill; Dr. Ir. G. Schouten; Dr. J. Ochs

    2000-01-01

    In the fall of 1999, an international integrated product development pilot project based on collaborative engineering was started with team members in two international teams from the United States, The Netherlands and Germany. Team members interacted using various Internet capabilities, including,

  6. Collaboration in Print

    DEFF Research Database (Denmark)

    Lund, Joachim

    2012-01-01

    During the Second World War, Germany's National Socialist regime mobilized German universities in order to support the war efforts through academic collaboration and a number of publications that were meant to legitimize Germany's territorial ambitions. The rector of the University of Kiel, Dr Paul...

  7. Collaborating for Impact

    Science.gov (United States)

    Dobrzeniecki, Aimee; Poole, Ken; Troppe, Mark

    2006-01-01

    Collaborating to define clear roles, responsibilities, and expectations can help a college and its partners avoid misunderstandings and "turf" problems. In this article, the authors describe vital partnerships between community colleges and economic development organizations to foster economic growth. The authors also share some lessons…

  8. The Promise of Collaboration

    Science.gov (United States)

    Bauml, Michelle

    2016-01-01

    Whether a teacher loves it or dreads it, lesson planning is a crucial step in the teaching process. Done effectively, collaborative lesson planning--in which teachers work together to design lessons--leads to increased professional learning, higher job satisfaction for teachers, and better lesson plans. The process poses challenges for both…

  9. Pseudo-Coherence-Based MVDR Beamformer for Speech Enhancement with Ad Hoc Microphone Arrays

    DEFF Research Database (Denmark)

    Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2015-01-01

    Speech enhancement with distributed arrays has been met with various methods. On the one hand, data independent methods require information about the position of sensors, so they are not suitable for dynamic geometries. On the other hand, Wiener-based methods cannot assure a distortionless output....... This paper proposes minimum variance distortionless response filtering based on multichannel pseudo-coherence for speech enhancement with ad hoc microphone arrays. This method requires neither position information nor control of the trade-off used in the distortion weighted methods. Furthermore, certain...

  10. Reputation-Based Internet Protocol Security: A Multilayer Security Framework for Mobile Ad Hoc Networks

    Science.gov (United States)

    2010-09-01

    motivated research in behavior grading systems [56]. Peer-to-peer eCommerce appli- cations such as eBay, Amazon, uBid, and Yahoo have performed research that...Security in Mobile Ad Hoc Networks”. IEEE Security & Privacy , 72–75, 2008. 15. Chakeres, ID and EM Belding-Royer. “AODV Routing Protocol Implementa...Detection System”. Proceedings of IEEE Computer Society Symposium on Research in Security and Privacy , 240–250. 1992. 21. Devore, J.L. and N.R. Farnum

  11. An Economic Framework for Resource Allocation in Ad-hoc Grids

    OpenAIRE

    Pourebrahimi, B.

    2009-01-01

    In this dissertation, we present an economic framework to study and develop different market-based mechanisms for resource allocation in an ad-hoc Grid. Such an economic framework helps to understand the impact of certain choices and explores what are the suitable mechanisms from Grid user/owner perspectives under given circumstances. We focus on resource allocation in a Grid-based environment in the case where some resources are lying idle and could be linked with overloaded nodes in a netwo...

  12. Optimalization of Beacon Selection for Localization in Wireless AD-HOC Networks

    Directory of Open Access Journals (Sweden)

    Martin Matula

    2008-01-01

    Full Text Available In this paper we engage in optimalization of convenient beacons for localization position of a node in the ad-hoc network. An algorithm designed by us localizes position of moving or static node by RSS (Received Signal Strength method and trilateration. At first, localization of unknown node runs by combination of all beacons. Than optimalizating algorithmreduces the number of beacons (and repeats localization, while only three left. Its reduction is based on highest levels of received signal strength. It is only when signals are from the nearest beacons. Position localizating exactness is statistically interpreted from all localization by beacons combination and its repeating.

  13. Comunicaciones seguras sobre redes móviles ad hoc

    OpenAIRE

    Rocabado Moreno, Sergio Hernán; Arias Figueroa, Daniel; Sánchez, Ernesto

    2011-01-01

    En este proyecto se ha planteado investigar diferentes mecanismos para realizar comunicaciones seguras utilizando redes móviles ad-hoc, esto permitirá aprovechar las características inherentes de este tipo de redes, para llevar información crítica de forma segura a lugares donde no se disponga de acceso a redes de infraestructura. El resultado final será una propuesta que servirá de base para el desarrollo e implementación de sistemas móviles para emergencias médicas y también como material d...

  14. Improvement over the OLSR Routing Protocol in Mobile Ad Hoc Networks by Eliminating the Unnecessary Loops

    OpenAIRE

    Shahram Behzad; Reza Fotohi; Shahram Jamali

    2013-01-01

    Mobile ad hoc networks are type of wireless networks in which any kind of infrastructure is not used, i.e. there are no infrastructures such as routers or switches or anything else on the network that can be used to support the network structure and the nodes has mobility. The purpose of this paper is to provide a better quality of the package delivery rate and the throughput, that is in need of powerful routing protocol standards, which can guarantee delivering of the packages to destination...

  15. A Game Theory Based Approach for Power Efficient Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Kun Hua

    2017-01-01

    Full Text Available Green communications are playing critical roles in vehicular ad hoc networks (VANETs, while the deployment of a power efficient VANET is quite challenging in practice. To add more greens into such kind of complicated and time-varying mobile network, we specifically investigate the throughput and transmission delay performances for real-time and delay sensitive services through a repeated game theoretic solution. This paper has employed Nash Equilibrium in the noncooperative game model and analyzes its efficiency. Simulation results have shown an obvious improvement on power efficiency through such efforts.

  16. A time-based admission control mechanism for IEEE 802.11 ad Hoc networks

    OpenAIRE

    Costa, Luís Henrique M. K.; Cerveira, Carlos Rodrigo

    2006-01-01

    This paper presents a time-based admission control mechanism (TAC) for IEEE 802.11 ad hoc networks. The proposed mechanism was adapted to the QoS AODV routing protocol, which takes the quality of service requirements of the data flow into account in the route discovery process. TAC-AODV estimates the idle time of the physical medium based on the frames listened. The incoming traffic is admitted according to the offered load as well as the intra-flow interference, calculated based on the numbe...

  17. An Incentivized Approach for Fair Participation in Wireless Ad hoc Networks

    OpenAIRE

    Choudhuri, Arka Rai; S, Kalyanasundaram; Sridhar, Shriyak; B, Annappa

    2015-01-01

    In Wireless Ad hoc networks (WANETs), nodes separated by considerable distance communicate with each other by relaying their messages through other nodes. However, it might not be in the best interests of a node to forward the message of another node due to power constraints. In addition, all nodes being rational, some nodes may be selfish, i.e. they might not relay data from other nodes so as to increase their lifetime. In this paper, we present a fair and incentivized approach for participa...

  18. Energy-aware architecture for multi-rate ad hoc networks

    Directory of Open Access Journals (Sweden)

    Ahmed Yahya

    2010-06-01

    Full Text Available The backbone of ad hoc network design is energy performance and bandwidth resources limitations. Multi-rate adaptation architectures have been proposed to reduce the control overhead and to increase bandwidth utilization efficiency. In this paper, we propose a multi-rate protocol to provide the highest network performance under very low control overhead. The efficiency of the proposed auto multi-rate protocol is validated extensive simulations using QualNet network simulator. The simulation results demonstrate that our solution significantly improves the overall network performance.

  19. Novel store–carry–forward scheme for message dissemination in vehicular ad-hoc networks

    Directory of Open Access Journals (Sweden)

    Truc D.T. Nguyen

    2017-12-01

    Full Text Available To improve traffic safety in intelligent transportation systems, vehicles formed by vehicular ad-hoc networks (VANETs conventionally disseminate warning messages to their nearby vehicles as soon as a dangerous situation occurs. In this paper, we propose a novel scheme employing a novel story–carry–forward (SCF mechanism to tackle the network partition and broadcast storm problems, which are two major challenges in VANETs. The experimental result in the Veins simulation framework shows that the proposed SCF scheme significantly mitigates broadcast storms relative to other schemes, and maintains good coverage across various traffic densities.

  20. A Partitioned Approach to Signal Separation with Microphone Ad Hoc Arrays

    DEFF Research Database (Denmark)

    Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Benesty, Jacob

    2016-01-01

    In this paper, a blind algorithm is proposed for speech enhancement in multi-speaker scenarios, in which interference rejection is the main objective. Here, the ad hoc array is broken into microphone duples which are used to partition the array into local sub-arrays. The core algorithm takes...... advantage of differences in signal structure in each duple. A geometric mean filter is then used to merge the output signals obtained with different duples, and to form a global broadband maximum signal-to-interference ratio (SIR) enhancement apparatus. The resulting filter outputs are enhanced acoustic...