Sample records for multi-user cooperative diversity

  1. Energy Efficiency of D2D Multi-User Cooperation.

    PubMed

    Zhang, Zufan; Wang, Lu; Zhang, Jie

    2017-03-28

    The Device-to-Device (D2D) communication system is an important part of heterogeneous networks. It has great potential to improve spectrum efficiency, throughput and energy efficiency cooperation of multiple D2D users with the advantage of direct communication. When cooperating, D2D users expend extraordinary energy to relay data to other D2D users. Hence, the remaining energy of D2D users determines the life of the system. This paper proposes a cooperation scheme for multiple D2D users who reuse the orthogonal spectrum and are interested in the same data by aiming to solve the energy problem of D2D users. Considering both energy availability and the Signal to Noise Ratio (SNR) of each D2D user, the Kuhn-Munkres algorithm is introduced in the cooperation scheme to solve relay selection problems. Thus, the cooperation issue is transformed into a maximum weighted matching (MWM) problem. In order to enhance energy efficiency without the deterioration of Quality of Service (QoS), the link outage probability is derived according to the Shannon Equation by considering the data rate and delay. The simulation studies the relationships among the number of cooperative users, the length of shared data, the number of data packets and energy efficiency.

  2. Performance Analysis of Diversity-Controlled Multi-User Superposition Transmission for 5G Wireless Networks.

    PubMed

    Yeom, Jeong Seon; Chu, Eunmi; Jung, Bang Chul; Jin, Hu

    2018-02-10

    In this paper, we propose a novel low-complexity multi-user superposition transmission (MUST) technique for 5G downlink networks, which allows multiple cell-edge users to be multiplexed with a single cell-center user. We call the proposed technique diversity-controlled MUST technique since the cell-center user enjoys the frequency diversity effect via signal repetition over multiple orthogonal frequency division multiplexing (OFDM) sub-carriers. We assume that a base station is equipped with a single antenna but users are equipped with multiple antennas. In addition, we assume that the quadrature phase shift keying (QPSK) modulation is used for users. We mathematically analyze the bit error rate (BER) of both cell-edge users and cell-center users, which is the first theoretical result in the literature to the best of our knowledge. The mathematical analysis is validated through extensive link-level simulations.

  3. Performance Analysis of Diversity-Controlled Multi-User Superposition Transmission for 5G Wireless Networks

    PubMed Central

    Yeom, Jeong Seon; Jung, Bang Chul; Jin, Hu

    2018-01-01

    In this paper, we propose a novel low-complexity multi-user superposition transmission (MUST) technique for 5G downlink networks, which allows multiple cell-edge users to be multiplexed with a single cell-center user. We call the proposed technique diversity-controlled MUST technique since the cell-center user enjoys the frequency diversity effect via signal repetition over multiple orthogonal frequency division multiplexing (OFDM) sub-carriers. We assume that a base station is equipped with a single antenna but users are equipped with multiple antennas. In addition, we assume that the quadrature phase shift keying (QPSK) modulation is used for users. We mathematically analyze the bit error rate (BER) of both cell-edge users and cell-center users, which is the first theoretical result in the literature to the best of our knowledge. The mathematical analysis is validated through extensive link-level simulations. PMID:29439413

  4. Managing a Safe and Successful Multi-User Spaceport

    NASA Technical Reports Server (NTRS)

    Dacko, Taylor; Ketterer, Kirk; Meade, Phillip

    2016-01-01

    Encouraged by the creation of the Office of Commercial Space Transportation within the U.S. Federal Aviation Administration (FAA) in 1984 and the Commercial Space Act of 1998, the National Aeronautics and Space Administration (NASA) now relies on an extensive network of support from commercial companies and organizations. At NASA's Kennedy Space Center (KSC), this collaboration opens competitive opportunities for launch providers, including repurposing underutilized Shuttle Program resources, constructing new facilities, and utilizing center services and laboratories. The resulting multi-user spaceport fosters diverse activity, though it engenders risk from hazards associated with various spaceflight processing activities. The KSC Safety & Mission Assurance (S&MA) Directorate, in coordination with the center's Spaceport Integration and Center Planning & Development organizations, has developed a novel approach to protect NASA's workforce, critical assets, and the public from hazardous, space-related activity associated with KSC's multi-user spaceport. For NASA KSC S&MA, the transformation to a multi-user spaceport required implementing methods to foster safe and successful commercial activity while resolving challenges involving: Retirement of the Space Shuttle program; Co-location of multiple NASA programs; Relationships between the NASA programs; Complex relationships between NASA programs and commercial partner operations in exclusive-use facilities; Complex relationships between NASA programs and commercial partner operations in shared-use facilities. NASA KSC S&MA challenges were met with long-term planning and solutions involving cooperation with the Spaceport Integration and Services Directorate. This directorate is responsible for managing active commercial partnerships with customer advocacy and services management, providing a dedicated and consistent level of support to a wide array of commercial operations. This paper explores these solutions, their

  5. Social diversity promotes cooperation in spatial multigames

    NASA Astrophysics Data System (ADS)

    Qin, Jiahu; Chen, Yaming; Kang, Yu; Perc, Matjaž

    2017-04-01

    Social diversity is omnipresent in the modern world. Here we introduce this diversity into spatial multigames and study its impact on the evolution of cooperation. Multigames are characterized by two or more different social dilemmas being contested among players in the population. When a fraction of players plays the prisoner's dilemma game while the remainder plays the snowdrift game cooperation becomes a difficult proposition. We show that social diversity, determined by the payoff scaling factors from the uniform, exponential or power-law distribution, significantly promotes cooperation. In particular, the stronger the social diversity, the more widespread cooperative behavior becomes. Monte Carlo simulations on the square lattice reveal that a power-law distribution of social diversity is in fact optimal for socially favorable states, thus resonating with findings previously reported for single social dilemmas. We also show that the same promotion mechanism works in time-varying environments, thus further generalizing the important role of social diversity for cooperation in social dilemmas.

  6. Coevolutionary dynamics of phenotypic diversity and contingent cooperation

    PubMed Central

    Wang, Long

    2017-01-01

    Phenotypic diversity is considered beneficial to the evolution of contingent cooperation, in which cooperators channel their help preferentially towards others of similar phenotypes. However, it remains largely unclear how phenotypic variation arises in the first place and thus leads to the construction of phenotypic complexity. Here we propose a mathematical model to study the coevolutionary dynamics of phenotypic diversity and contingent cooperation. Unlike previous models, our model does not assume any prescribed level of phenotypic diversity, but rather lets it be an evolvable trait. Each individual expresses one phenotype at a time and only the phenotypes expressed are visible to others. Moreover, individuals can differ in their potential of phenotypic variation, which is characterized by the number of distinct phenotypes they can randomly switch to. Each individual incurs a cost proportional to the number of potentially expressible phenotypes so as to retain phenotypic variation and expression. Our results show that phenotypic diversity coevolves with contingent cooperation under a wide range of conditions and that there exists an optimal level of phenotypic diversity best promoting contingent cooperation. It pays for contingent cooperators to elevate their potential of phenotypic variation, thereby increasing their opportunities of establishing cooperation via novel phenotypes, as these new phenotypes serve as secret tags that are difficult for defector to discover and chase after. We also find that evolved high levels of phenotypic diversity can occasionally collapse due to the invasion of defector mutants, suggesting that cooperation and phenotypic diversity can mutually reinforce each other. Thus, our results provide new insights into better understanding the coevolution of cooperation and phenotypic diversity. PMID:28141806

  7. Relational diversity promotes cooperation in prisoner's dilemma games.

    PubMed

    Xu, Bo; Wang, Jianwei; Deng, Ruipu; Li, Miao

    2014-01-01

    Relational diversity can be characterized by heterogeneous distributions of tie strengths in social networks and this diversity is present not only among humans, but throughout the animal world. We account for this observation by analyzing two network datasets from Facebook. We measure the strength of a tie by calculating the extent of overlap of friends between the two individuals. Based on the previous findings in human experiments, we argue that it is very unlikely that players will allocate their investments equally to their neighbors. There is a tendency that players prefer to donate more to their intimate friends. We find that if players preferentially allocate their investments to their good friends, cooperation will be promoted in PDG. We proved that the facilitation of the cooperative strategy relies mostly on the cooperative allies between best friends, resulting in the formation of cooperative clusters which are able to prevail against the defectors even when there is a large cost to cooperate. Moreover, we discover that the effect of relational diversity cannot be analyzed by adopting classical complex networks models, because neither of the artificial networks is able to produce networks with diverse distributions of tie strengths. It is of vital importance to introduce real social networks to study the influence of diverse relations especially when it comes to humans. This research proposes a brand new perspective to understand the influence of social relations on the emergence of cooperation in evolutionary prisoner's dilemma games.

  8. Cooperative processing user interfaces for AdaNET

    NASA Technical Reports Server (NTRS)

    Gutzmann, Kurt M.

    1991-01-01

    A cooperative processing user interface (CUI) system shares the task of graphical display generation and presentation between the user's computer and a remote host. The communications link between the two computers is typically a modem or Ethernet. The two main purposes of a CUI are reduction of the amount of data transmitted between user and host machines, and provision of a graphical user interface system to make the system easier to use.

  9. Interactive diversity promotes the evolution of cooperation in structured populations

    NASA Astrophysics Data System (ADS)

    Su, Qi; Li, Aming; Zhou, Lei; Wang, Long

    2016-10-01

    Evolutionary games on networks traditionally assume that each individual adopts an identical strategy to interact with all its neighbors in each generation. Considering the prevalent diversity of individual interactions in the real society, here we propose the concept of interactive diversity, which allows individuals to adopt different strategies against different neighbors in each generation. We investigate the evolution of cooperation based on the edge dynamics rather than the traditional nodal dynamics in networked systems. The results show that, without invoking any other mechanisms, interactive diversity drives the frequency of cooperation to a high level for a wide range of parameters in both well-mixed and structured populations. Even in highly connected populations, cooperation still thrives. When interactive diversity and large topological heterogeneity are combined together, however, in the relaxed social dilemma, cooperation level is lower than that with just one of them, implying that the combination of many promotive factors may make a worse outcome. By an analytical approximation, we get the condition under which interactive diversity provides more advantages for cooperation than traditional evolutionary dynamics does. Numerical simulations validating the approximation are also presented. Our work provides a new line to explore the latent relation between the ubiquitous cooperation and individuals’ distinct responses in different interactions. The presented results suggest that interactive diversity should receive more attention in pursuing mechanisms fostering cooperation.

  10. Popularity and user diversity of online objects

    NASA Astrophysics Data System (ADS)

    Wang, Jia-Hua; Guo, Qiang; Yang, Kai; Zhang, Yi-Lu; Han, Jingti; Liu, Jian-Guo

    2016-11-01

    The popularity has been widely used to describe the object property of online user-object bipartite networks regardless of the user characteristics. In this paper, we introduce a measurement namely user diversity to measure diversity of users who select or rate one type of objects by using the information entropy. We empirically calculate the user diversity of objects with specific degree for both MovieLens and Diggs data sets. The results indicate that more types of users select normal-degree objects than those who select large-degree and small-degree objects. Furthermore, small-degree objects are usually selected by large-degree users while large-degree objects are usually selected by small-degree users. Moreover, we define 15% objects of smallest degrees as unpopular objects and 10% ones of largest degrees as popular objects. The timestamp is introduced to help further analyze the evolution of user diversity of popular objects and unpopular objects. The dynamic analysis shows that as objects become popular gradually, they are more likely accepted by small-degree users but lose attention among the large-degree users.

  11. Diversity of rationality affects the evolution of cooperation

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Zhong; Huang, Zi-Gang; Wang, Sheng-Jun; Zhang, Yan; Wang, Ying-Hai

    2009-05-01

    By modifying the Fermi updating rule, we present the diversity of individual rationality to the evolutionary prisoner’s dilemma game, and our results shows that this diversity heavily influences the evolution of cooperation. Cluster-forming mechanism of cooperators can either be highly enhanced or severely deteriorated by different distributions of rationality. Slight change in the rationality distribution may transfer the whole system from the global absorbing state of cooperators to that of defectors. Based on mean-field argument, quantitative analysis of the stability of cooperative clusters reveals the critical role played by agents with moderate degree values in the evolution of the whole system. The inspiration from our work may provide us a deeper comprehension toward some social phenomena.

  12. Relational Diversity Promotes Cooperation in Prisoner’s Dilemma Games

    PubMed Central

    Xu, Bo; Wang, Jianwei; Deng, Ruipu; Li, Miao

    2014-01-01

    Relational diversity can be characterized by heterogeneous distributions of tie strengths in social networks and this diversity is present not only among humans, but throughout the animal world. We account for this observation by analyzing two network datasets from Facebook. We measure the strength of a tie by calculating the extent of overlap of friends between the two individuals. Based on the previous findings in human experiments, we argue that it is very unlikely that players will allocate their investments equally to their neighbors. There is a tendency that players prefer to donate more to their intimate friends. We find that if players preferentially allocate their investments to their good friends, cooperation will be promoted in PDG. We proved that the facilitation of the cooperative strategy relies mostly on the cooperative allies between best friends, resulting in the formation of cooperative clusters which are able to prevail against the defectors even when there is a large cost to cooperate. Moreover, we discover that the effect of relational diversity cannot be analyzed by adopting classical complex networks models, because neither of the artificial networks is able to produce networks with diverse distributions of tie strengths. It is of vital importance to introduce real social networks to study the influence of diverse relations especially when it comes to humans. This research proposes a brand new perspective to understand the influence of social relations on the emergence of cooperation in evolutionary prisoner’s dilemma games. PMID:25474354

  13. Efficient cooperative compressive spectrum sensing by identifying multi-candidate and exploiting deterministic matrix

    NASA Astrophysics Data System (ADS)

    Li, Jia; Wang, Qiang; Yan, Wenjie; Shen, Yi

    2015-12-01

    Cooperative spectrum sensing exploits the spatial diversity to improve the detection of occupied channels in cognitive radio networks (CRNs). Cooperative compressive spectrum sensing (CCSS) utilizing the sparsity of channel occupancy further improves the efficiency by reducing the number of reports without degrading detection performance. In this paper, we firstly and mainly propose the referred multi-candidate orthogonal matrix matching pursuit (MOMMP) algorithms to efficiently and effectively detect occupied channels at fusion center (FC), where multi-candidate identification and orthogonal projection are utilized to respectively reduce the number of required iterations and improve the probability of exact identification. Secondly, two common but different approaches based on threshold and Gaussian distribution are introduced to realize the multi-candidate identification. Moreover, to improve the detection accuracy and energy efficiency, we propose the matrix construction based on shrinkage and gradient descent (MCSGD) algorithm to provide a deterministic filter coefficient matrix of low t-average coherence. Finally, several numerical simulations validate that our proposals provide satisfactory performance with higher probability of detection, lower probability of false alarm and less detection time.

  14. Evolution properties of online user preference diversity

    NASA Astrophysics Data System (ADS)

    Guo, Qiang; Ji, Lei; Liu, Jian-Guo; Han, Jingti

    2017-02-01

    Detecting the evolution properties of online user preference diversity is of significance for deeply understanding online collective behaviors. In this paper, we empirically explore the evolution patterns of online user rating preference, where the preference diversity is measured by the variation coefficient of the user rating sequence. The statistical results for four real systems show that, for movies and reviews, the user rating preference would become diverse and then get centralized finally. By introducing the empirical variation coefficient, we present a Markov model, which could regenerate the evolution properties of two online systems regarding to the stable variation coefficients. In addition, we investigate the evolution of the correlation between the user ratings and the object qualities, and find that the correlation would keep increasing as the user degree increases. This work could be helpful for understanding the anchoring bias and memory effects of the online user collective behaviors.

  15. The interplay between cooperativity and diversity in model threshold ensembles

    PubMed Central

    Cervera, Javier; Manzanares, José A.; Mafe, Salvador

    2014-01-01

    The interplay between cooperativity and diversity is crucial for biological ensembles because single molecule experiments show a significant degree of heterogeneity and also for artificial nanostructures because of the high individual variability characteristic of nanoscale units. We study the cross-effects between cooperativity and diversity in model threshold ensembles composed of individually different units that show a cooperative behaviour. The units are modelled as statistical distributions of parameters (the individual threshold potentials here) characterized by central and width distribution values. The simulations show that the interplay between cooperativity and diversity results in ensemble-averaged responses of interest for the understanding of electrical transduction in cell membranes, the experimental characterization of heterogeneous groups of biomolecules and the development of biologically inspired engineering designs with individually different building blocks. PMID:25142516

  16. Molecular Cooperativity Governs Diverse and Monoallelic Olfactory Receptor Expression

    NASA Astrophysics Data System (ADS)

    Xing, Jianhua; Tian, Xiaojun; Zhang, Hang; Sannerud, Jens

    Multiple-objective optimization is common in biological systems. In the mammalian olfactory system, each sensory neuron stochastically expresses only one out of up to thousands of olfactory receptor (OR) gene alleles; at organism level the types of expressed ORs need to be maximized. The molecular mechanism of this Nobel-Prize winning puzzle remains unresolved after decades of extensive studies. Existing models focus only on monoallele activation, and cannot explain recent observations in mutants, especially the reduced global diversity of expressed ORs in G9a/GLP knockouts. In this work we integrated existing information on OR expression, and proposed an evolutionarily optimized three-layer regulation mechanism, which includes zonal segregation, epigenetic and enhancer competition coupled to a negative feedback loop. This model not only recapitulates monoallelic OR expression, but also elucidates how the olfactory system maximizes and maintains the diversity of OR expression. The model is validated by several experimental results, and particularly underscores cooperativity and synergy as a general design principle of multi-objective optimization in biology. The work is supported by the NIGMS/DMS Mathematical Biology program.

  17. The interplay between cooperativity and diversity in model threshold ensembles.

    PubMed

    Cervera, Javier; Manzanares, José A; Mafe, Salvador

    2014-10-06

    The interplay between cooperativity and diversity is crucial for biological ensembles because single molecule experiments show a significant degree of heterogeneity and also for artificial nanostructures because of the high individual variability characteristic of nanoscale units. We study the cross-effects between cooperativity and diversity in model threshold ensembles composed of individually different units that show a cooperative behaviour. The units are modelled as statistical distributions of parameters (the individual threshold potentials here) characterized by central and width distribution values. The simulations show that the interplay between cooperativity and diversity results in ensemble-averaged responses of interest for the understanding of electrical transduction in cell membranes, the experimental characterization of heterogeneous groups of biomolecules and the development of biologically inspired engineering designs with individually different building blocks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  18. Social diversity promotes the emergence of cooperation in public goods games.

    PubMed

    Santos, Francisco C; Santos, Marta D; Pacheco, Jorge M

    2008-07-10

    Humans often cooperate in public goods games and situations ranging from family issues to global warming. However, evolutionary game theory predicts that the temptation to forgo the public good mostly wins over collective cooperative action, and this is often also seen in economic experiments. Here we show how social diversity provides an escape from this apparent paradox. Up to now, individuals have been treated as equivalent in all respects, in sharp contrast with real-life situations, where diversity is ubiquitous. We introduce social diversity by means of heterogeneous graphs and show that cooperation is promoted by the diversity associated with the number and size of the public goods game in which each individual participates and with the individual contribution to each such game. When social ties follow a scale-free distribution, cooperation is enhanced whenever all individuals are expected to contribute a fixed amount irrespective of the plethora of public goods games in which they engage. Our results may help to explain the emergence of cooperation in the absence of mechanisms based on individual reputation and punishment. Combining social diversity with reputation and punishment will provide instrumental clues on the self-organization of social communities and their economical implications.

  19. Modeling Misbehavior in Cooperative Diversity: A Dynamic Game Approach

    NASA Astrophysics Data System (ADS)

    Dehnie, Sintayehu; Memon, Nasir

    2009-12-01

    Cooperative diversity protocols are designed with the assumption that terminals always help each other in a socially efficient manner. This assumption may not be valid in commercial wireless networks where terminals may misbehave for selfish or malicious intentions. The presence of misbehaving terminals creates a social-dilemma where terminals exhibit uncertainty about the cooperative behavior of other terminals in the network. Cooperation in social-dilemma is characterized by a suboptimal Nash equilibrium where wireless terminals opt out of cooperation. Hence, without establishing a mechanism to detect and mitigate effects of misbehavior, it is difficult to maintain a socially optimal cooperation. In this paper, we first examine effects of misbehavior assuming static game model and show that cooperation under existing cooperative protocols is characterized by a noncooperative Nash equilibrium. Using evolutionary game dynamics we show that a small number of mutants can successfully invade a population of cooperators, which indicates that misbehavior is an evolutionary stable strategy (ESS). Our main goal is to design a mechanism that would enable wireless terminals to select reliable partners in the presence of uncertainty. To this end, we formulate cooperative diversity as a dynamic game with incomplete information. We show that the proposed dynamic game formulation satisfied the conditions for the existence of perfect Bayesian equilibrium.

  20. University multi-user facility survey-2010.

    PubMed

    Riley, Melissa B

    2011-12-01

    Multi-user facilities serve as a resource for many universities. In 2010, a survey was conducted investigating possible changes and successful characteristics of multi-user facilities, as well as identifying problems in facilities. Over 300 surveys were e-mailed to persons identified from university websites as being involved with multi-user facilities. Complete responses were received from 36 facilities with an average of 20 years of operation. Facilities were associated with specific departments (22%), colleges (22%), and university research centers (8.3%) or were not affiliated with any department or college within the university (47%). The five most important factors to succeed as a multi-user facility were: 1) maintaining an experienced, professional staff in an open atmosphere; 2) university-level support providing partial funding; 3) broad client base; 4) instrument training programs; and 5) an effective leader and engaged strategic advisory group. The most significant problems were: 1) inadequate university financial support and commitment; 2) problems recovering full service costs from university subsidies and user fees; 3) availability of funds to repair and upgrade equipment; 4) inability to retain highly qualified staff; and 5) unqualified users dirtying/damaging equipment. Further information related to these issues and to fee structure was solicited. Overall, there appeared to be a decline in university support for facilities and more emphasis on securing income by serving clients outside of the institution and by obtaining grants from entities outside of the university.

  1. Multi-agent cooperation rescue algorithm based on influence degree and state prediction

    NASA Astrophysics Data System (ADS)

    Zheng, Yanbin; Ma, Guangfu; Wang, Linlin; Xi, Pengxue

    2018-04-01

    Aiming at the multi-agent cooperative rescue in disaster, a multi-agent cooperative rescue algorithm based on impact degree and state prediction is proposed. Firstly, based on the influence of the information in the scene on the collaborative task, the influence degree function is used to filter the information. Secondly, using the selected information to predict the state of the system and Agent behavior. Finally, according to the result of the forecast, the cooperative behavior of Agent is guided and improved the efficiency of individual collaboration. The simulation results show that this algorithm can effectively solve the cooperative rescue problem of multi-agent and ensure the efficient completion of the task.

  2. Cooperative path planning for multi-USV based on improved artificial bee colony algorithm

    NASA Astrophysics Data System (ADS)

    Cao, Lu; Chen, Qiwei

    2018-03-01

    Due to the complex constraints, more uncertain factors and critical real-time demand of path planning for multiple unmanned surface vehicle (multi-USV), an improved artificial bee colony (I-ABC) algorithm were proposed to solve the model of cooperative path planning for multi-USV. First the Voronoi diagram of battle field space is conceived to generate the optimal area of USVs paths. Then the chaotic searching algorithm is used to initialize the collection of paths, which is regard as foods of the ABC algorithm. With the limited data, the initial collection can search the optimal area of paths perfectly. Finally simulations of the multi-USV path planning under various threats have been carried out. Simulation results verify that the I-ABC algorithm can improve the diversity of nectar source and the convergence rate of algorithm. It can increase the adaptability of dynamic battlefield and unexpected threats for USV.

  3. Presence of a loner strain maintains cooperation and diversity in well-mixed bacterial communities.

    PubMed

    Inglis, R F; Biernaskie, J M; Gardner, A; Kümmerli, R

    2016-01-13

    Cooperation and diversity abound in nature despite cooperators risking exploitation from defectors and superior competitors displacing weaker ones. Understanding the persistence of cooperation and diversity is therefore a major problem for evolutionary ecology, especially in the context of well-mixed populations, where the potential for exploitation and displacement is greatest. Here, we demonstrate that a 'loner effect', described by economic game theorists, can maintain cooperation and diversity in real-world biological settings. We use mathematical models of public-good-producing bacteria to show that the presence of a loner strain, which produces an independent but relatively inefficient good, can lead to rock-paper-scissor dynamics, whereby cooperators outcompete loners, defectors outcompete cooperators and loners outcompete defectors. These model predictions are supported by our observations of evolutionary dynamics in well-mixed experimental communities of the bacterium Pseudomonas aeruginosa. We find that the coexistence of cooperators and defectors that produce and exploit, respectively, the iron-scavenging siderophore pyoverdine, is stabilized by the presence of loners with an independent iron-uptake mechanism. Our results establish the loner effect as a simple and general driver of cooperation and diversity in environments that would otherwise favour defection and the erosion of diversity. © 2016 The Authors.

  4. Single-Trial Classification of Multi-User P300-Based Brain-Computer Interface Using Riemannian Geometry.

    PubMed

    Korczowski, L; Congedo, M; Jutten, C

    2015-08-01

    The classification of electroencephalographic (EEG) data recorded from multiple users simultaneously is an important challenge in the field of Brain-Computer Interface (BCI). In this paper we compare different approaches for classification of single-trials Event-Related Potential (ERP) on two subjects playing a collaborative BCI game. The minimum distance to mean (MDM) classifier in a Riemannian framework is extended to use the diversity of the inter-subjects spatio-temporal statistics (MDM-hyper) or to merge multiple classifiers (MDM-multi). We show that both these classifiers outperform significantly the mean performance of the two users and analogous classifiers based on the step-wise linear discriminant analysis. More importantly, the MDM-multi outperforms the performance of the best player within the pair.

  5. Contribution diversity and incremental learning promote cooperation in public goods games

    NASA Astrophysics Data System (ADS)

    Liu, Penghui; Liu, Jing

    2017-11-01

    Understanding the evolution of cooperation in nature has long been a challenge and how to promote cooperation in public goods games (PGG) has attracted lots of attention recently. Social diversity has been found helpful to explain the emergence of cooperation in the absence of reputation and punishment. However, further refinement on how individuals reallocate their contribution to each PGG remains an open question. Moreover, individuals in existing works mostly teach or learn from neighbors according to their payoff in the last generation only. However, individuals in reality are preferred to learn from others with a long-term good performance. Therefore, in this paper, a new contribution diversity (CD) is designed and incremental learning (IL) is introduced. We investigate how these two may influence the evolution of cooperation in PGG. Based on the simulation results, we found that both the CD and IL can promote the cooperation in PGGs. Moreover, when cooperators are shaken in their strategy, CD may fail in reallocating contribution of individuals properly. However, IL is found effective to stabilize faith of cooperators and cooperators under IL reflect a long-term advantage over defectors in terms of benefits. Therefore, we further find IL and CD can mutually benefit each other in promoting cooperation, as CD can reasonably adjust the investment of cooperators while IL can provide more information to CD.

  6. Multi-Agent Cooperative Target Search

    PubMed Central

    Hu, Jinwen; Xie, Lihua; Xu, Jun; Xu, Zhao

    2014-01-01

    This paper addresses a vision-based cooperative search for multiple mobile ground targets by a group of unmanned aerial vehicles (UAVs) with limited sensing and communication capabilities. The airborne camera on each UAV has a limited field of view and its target discriminability varies as a function of altitude. First, by dividing the whole surveillance region into cells, a probability map can be formed for each UAV indicating the probability of target existence within each cell. Then, we propose a distributed probability map updating model which includes the fusion of measurement information, information sharing among neighboring agents, information decay and transmission due to environmental changes such as the target movement. Furthermore, we formulate the target search problem as a multi-agent cooperative coverage control problem by optimizing the collective coverage area and the detection performance. The proposed map updating model and the cooperative control scheme are distributed, i.e., assuming that each agent only communicates with its neighbors within its communication range. Finally, the effectiveness of the proposed algorithms is illustrated by simulation. PMID:24865884

  7. [Osteoporosis Liaison Service and multi medical staff cooperation.

    PubMed

    Ikeda, Satoshi

    A place of the activity of Osteoporosis Liaison Service (OLS) is classified into the in-hospital and the out-hospital. "Kotsu-Kotsu approach" is performed in our hospital for fracture inpatients as OLS. "Kotsu-Kotsu approach" can be able to performed the various and comprehensive assessment for the patients by multi medical staff, especially Osteoporosis managers. The construction of the cooperation with other facilities is propelled for activity of out-hospital. Ministry of Health, Labour and Welfare impel to establish community-based integrated care systems. Importance adds to OLS under the multi medical staff cooperation that I included the care in the community in more and more from now on. To that end, the leadership of the doctor is required.

  8. Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity

    PubMed Central

    Hegyi, Barnabás; Levendovszky, János

    2010-01-01

    Battery-operated medical implants—such as pacemakers or cardioverter-defibrillators—have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading—hence to improve system performance—in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability. PMID:20379346

  9. Can Dissimilar Users Contribute to Accuracy and Diversity of Personalized Recommendation?

    NASA Astrophysics Data System (ADS)

    Zeng, Wei; Shang, Ming-Sheng; Zhang, Qian-Ming; Lü, Linyuan; Zhou, Tao

    Recommender systems are becoming a popular and important set of personalization techniques that assist individual users with navigating through the rapidly growing amount of information. A good recommender system should be able to not only find out the objects preferred by users, but also help users in discovering their personalized tastes. The former corresponds to high accuracy of the recommendation, while the latter to high diversity. A big challenge is to design an algorithm that provides both highly accurate and diverse recommendation. Traditional recommendation algorithms only take into account the contributions of similar users, thus, they tend to recommend popular items for users ignoring the diversity of recommendations. In this paper, we propose a recommendation algorithm by considering both the effects of similar and dissimilar users under the framework of collaborative filtering. Extensive analyses on three datasets, namely MovieLens, Netflix and Amazon, show that our method performs much better than the standard collaborative filtering algorithm for both accuracy and diversity.

  10. From user needs to system specifications: multi-disciplinary thematic seminars as a collaborative design method for development of health information systems.

    PubMed

    Scandurra, I; Hägglund, M; Koch, S

    2008-08-01

    This paper presents a new multi-disciplinary method for user needs analysis and requirements specification in the context of health information systems based on established theories from the fields of participatory design and computer supported cooperative work (CSCW). Whereas conventional methods imply a separate, sequential needs analysis for each profession, the "multi-disciplinary thematic seminar" (MdTS) method uses a collaborative design process. Application of the method in elderly homecare resulted in prototypes that were well adapted to the intended user groups. Vital information in the points of intersection between different care professions was elicited and a holistic view of the entire care process was obtained. Health informatics-usability specialists and clinical domain experts are necessary to apply the method. Although user needs acquisition can be time-consuming, MdTS was perceived to efficiently identify in-context user needs, and transformed these directly into requirements specifications. Consequently the method was perceived to expedite the entire ICT implementation process.

  11. A Case Study in User Support for Managing OpenSim Based Multi User Learning Environments

    ERIC Educational Resources Information Center

    Perera, Indika; Miller, Alan; Allison, Colin

    2017-01-01

    Immersive 3D Multi User Learning Environments (MULE) have shown sufficient success to warrant their consideration as a mainstream educational paradigm. These are based on 3D Multi User Virtual Environment platforms (MUVE), and although they have been used for various innovative educational projects their complex permission systems and large…

  12. Community Identity and User Engagement in a Multi-Community Landscape.

    PubMed

    Zhang, Justine; Hamilton, William L; Danescu-Niculescu-Mizil, Cristian; Jurafsky, Dan; Leskovec, Jure

    2017-05-01

    A community's identity defines and shapes its internal dynamics. Our current understanding of this interplay is mostly limited to glimpses gathered from isolated studies of individual communities. In this work we provide a systematic exploration of the nature of this relation across a wide variety of online communities. To this end we introduce a quantitative, language-based typology reflecting two key aspects of a community's identity: how distinctive , and how temporally dynamic it is. By mapping almost 300 Reddit communities into the landscape induced by this typology, we reveal regularities in how patterns of user engagement vary with the characteristics of a community. Our results suggest that the way new and existing users engage with a community depends strongly and systematically on the nature of the collective identity it fosters, in ways that are highly consequential to community maintainers. For example, communities with distinctive and highly dynamic identities are more likely to retain their users. However, such niche communities also exhibit much larger acculturation gaps between existing users and newcomers, which potentially hinder the integration of the latter. More generally, our methodology reveals differences in how various social phenomena manifest across communities, and shows that structuring the multi-community landscape can lead to a better understanding of the systematic nature of this diversity.

  13. Usability testing of a prototype multi-user telehealth kiosk.

    PubMed

    Courtney, Karen L; Matthews, Judith T; McMillan, Julie M; Person Mecca, Laurel; Smailagic, Asim; Siewiorek, Daniel

    2015-01-01

    The overall purpose of this study was to learn how community-dwelling older adults would interact with our prototype multi-user telehealth kiosk and their views about its usability. Seven subjects participated in laboratory-based usability sessions to evaluate the physical design, appearance, functionality and perceived ease of use of a multi-user telehealth kiosk prototype. During usability testing participants recommended 18 new features (29% of comments), identified 15 software errors (23% of comments) and 29 user interface errors (47% of comments).

  14. Sensor-Based Human Activity Recognition in a Multi-user Scenario

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Gu, Tao; Tao, Xianping; Lu, Jian

    Existing work on sensor-based activity recognition focuses mainly on single-user activities. However, in real life, activities are often performed by multiple users involving interactions between them. In this paper, we propose Coupled Hidden Markov Models (CHMMs) to recognize multi-user activities from sensor readings in a smart home environment. We develop a multimodal sensing platform and present a theoretical framework to recognize both single-user and multi-user activities. We conduct our trace collection done in a smart home, and evaluate our framework through experimental studies. Our experimental result shows that we achieve an average accuracy of 85.46% with CHMMs.

  15. MULTI: a shared memory approach to cooperative molecular modeling.

    PubMed

    Darden, T; Johnson, P; Smith, H

    1991-03-01

    A general purpose molecular modeling system, MULTI, based on the UNIX shared memory and semaphore facilities for interprocess communication is described. In addition to the normal querying or monitoring of geometric data, MULTI also provides processes for manipulating conformations, and for displaying peptide or nucleic acid ribbons, Connolly surfaces, close nonbonded contacts, crystal-symmetry related images, least-squares superpositions, and so forth. This paper outlines the basic techniques used in MULTI to ensure cooperation among these specialized processes, and then describes how they can work together to provide a flexible modeling environment.

  16. Mobile user environment and satellite diversity for NGSO S-PCN's

    NASA Technical Reports Server (NTRS)

    Werner, Markus; Bischl, Hermann; Lutz, Erich

    1995-01-01

    The performance of satellite diversity under the influence of the mobile user environment is analyzed. To this end, a digital channel model is presented which takes into account the elevation angle as well as the user mobility in a given environment. For different LEO and MEO systems and for varying mobile user environments, some crucial benefits and drawbacks of satellite diversity are discussed. Specifically, the important GW service area concept is introduced. The conclusions are validated by numerical results from computer simulations. Globalstar (LEO) and Inmarsat (MEO) are compared in terms of visibility, service availability and equivalent handover complexity for different environments and user mobility.

  17. Multi-Hop Link Capacity of Multi-Route Multi-Hop MRC Diversity for a Virtual Cellular Network

    NASA Astrophysics Data System (ADS)

    Daou, Imane; Kudoh, Eisuke; Adachi, Fumiyuki

    In virtual cellular network (VCN), proposed for high-speed mobile communications, the signal transmitted from a mobile terminal is received by some wireless ports distributed in each virtual cell and relayed to the central port that acts as a gateway to the core network. In this paper, we apply the multi-route MHMRC diversity in order to decrease the transmit power and increase the multi-hop link capacity. The transmit power, the interference power and the link capacity are evaluated for DS-CDMA multi-hop VCN by computer simulation. The multi-route MHMRC diversity can be applied to not only DS-CDMA but also other access schemes (i. e. MC-CDMA, OFDM, etc.).

  18. A Stigmergic Cooperative Multi-Robot Control Architecture

    NASA Technical Reports Server (NTRS)

    Howsman, Thomas G.; O'Neil, Daniel; Craft, Michael A.

    2004-01-01

    In nature, there are numerous examples of complex architectures constructed by relatively simple insects, such as termites and wasps, which cooperatively assemble their nests. A prototype cooperative multi-robot control architecture which may be suitable for the eventual construction of large space structures has been developed which emulates this biological model. Actions of each of the autonomous robotic construction agents are only indirectly coordinated, thus mimicking the distributed construction processes of various social insects. The robotic construction agents perform their primary duties stigmergically, i.e., without direct inter-agent communication and without a preprogrammed global blueprint of the final design. Communication and coordination between individual agents occurs indirectly through the sensed modifications that each agent makes to the structure. The global stigmergic building algorithm prototyped during the initial research assumes that the robotic builders only perceive the current state of the structure under construction. Simulation studies have established that an idealized form of the proposed architecture was indeed capable of producing representative large space structures with autonomous robots. This paper will explore the construction simulations in order to illustrate the multi-robot control architecture.

  19. Achieving Common Expectations for Overall Goals amid Diversity among Cooperative Extension Faculty.

    ERIC Educational Resources Information Center

    Taylor, Barbara

    As a part of the initial phase of a strategic planning effort for the development of Florida's 1988 through 1991 long-range cooperative extension program, an effort was initiated to achieve common expectations for overall organizational mission and purpose among diverse cooperative extension faculty. The unification effort included the following…

  20. Multi-Vehicle Cooperative Control Research at the NASA Armstrong Flight Research Center, 2000-2014

    NASA Technical Reports Server (NTRS)

    Hanson, Curt

    2014-01-01

    A brief introductory overview of multi-vehicle cooperative control research conducted at the NASA Armstrong Flight Research Center from 2000 - 2014. Both flight research projects and paper studies are included. Since 2000, AFRC has been almost continuously pursuing research in the areas of formation flight for drag reduction and automated cooperative trajectories. An overview of results is given, including flight experiments done on the FA-18 and with the C-17. Other multi-vehicle cooperative research is discussed, including small UAV swarming projects and automated aerial refueling.

  1. Our Deming Users' Group.

    ERIC Educational Resources Information Center

    Dinklocker, Christina

    1992-01-01

    After training in the Total Quality Management concept, a suburban Ohio school district created a Deming Users' Group to link agencies, individuals, and ideas. The group has facilitated ongoing school/business collaboration, networking among individuals from diverse school systems, mentoring and cooperative learning activities, and resource…

  2. Secure Cooperative Data Access in Multi-Cloud Environment

    ERIC Educational Resources Information Center

    Le, Meixing

    2013-01-01

    In this dissertation, we discuss the problem of enabling cooperative query execution in a multi-cloud environment where the data is owned and managed by multiple enterprises. Each enterprise maintains its own relational database using a private cloud. In order to implement desired business services, parties need to share selected portion of their…

  3. Users matter : multi-agent systems model of high performance computing cluster users.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    North, M. J.; Hood, C. S.; Decision and Information Sciences

    2005-01-01

    High performance computing clusters have been a critical resource for computational science for over a decade and have more recently become integral to large-scale industrial analysis. Despite their well-specified components, the aggregate behavior of clusters is poorly understood. The difficulties arise from complicated interactions between cluster components during operation. These interactions have been studied by many researchers, some of whom have identified the need for holistic multi-scale modeling that simultaneously includes network level, operating system level, process level, and user level behaviors. Each of these levels presents its own modeling challenges, but the user level is the most complex duemore » to the adaptability of human beings. In this vein, there are several major user modeling goals, namely descriptive modeling, predictive modeling and automated weakness discovery. This study shows how multi-agent techniques were used to simulate a large-scale computing cluster at each of these levels.« less

  4. Cooperative dry-electrode sensors for multi-lead biopotential and bioimpedance monitoring.

    PubMed

    Rapin, M; Proença, M; Braun, F; Meier, C; Solà, J; Ferrario, D; Grossenbacher, O; Porchet, J-A; Chételat, O

    2015-04-01

    Cooperative sensors is a novel measurement architecture that allows the acquiring of biopotential signals on patients in a comfortable and easy-to-integrate manner. The novel sensors are defined as cooperative in the sense that at least two of them work in concert to measure a target physiological signal, such as a multi-lead electrocardiogram or a thoracic bioimpedance.This paper starts by analysing the state-of-the-art methods to simultaneously measure biopotential and bioimpedance signals, and justifies why currently (1) passive electrodes require the use of shielded or double-shielded cables, and (2) active electrodes require the use of multi-wired cabled technologies, when aiming at high quality physiological measurements.In order to overcome the limitations of the state-of-the-art, a new method for biopotential and bioimpedance measurement using the cooperative sensor is then presented. The novel architecture allows the acquisition of the aforementioned biosignals without the need of shielded or multi-wire cables by splitting the electronics into separate electronic sensors comprising each of two electrodes, one for voltage measurement and one for current injection. The sensors are directly in contact with the skin and connected together by only one unshielded wire. This new configuration requires one power supply per sensor and all sensors need to be synchronized together to allow them to work in concert.After presenting the working principle of the cooperative sensor architecture, this paper reports first experimental results on the use of the technology when applied to measuring multi-lead ECG signals on patients. Measurements performed on a healthy patient demonstrate the feasibility of using this novel cooperative sensor architecture to measure biopotential signals and compliance with common mode rejection specification accordingly to international standard (IEC 60601-2-47) has also been assessed.By reducing the need of using complex wiring setups, and

  5. Polar Cooperative Navigation Algorithm for Multi-Unmanned Underwater Vehicles Considering Communication Delays.

    PubMed

    Yan, Zheping; Wang, Lu; Wang, Tongda; Yang, Zewen; Chen, Tao; Xu, Jian

    2018-03-30

    To solve the navigation accuracy problems of multi-Unmanned Underwater Vehicles (multi-UUVs) in the polar region, a polar cooperative navigation algorithm for multi-UUVs considering communication delays is proposed in this paper. UUVs are important pieces of equipment in ocean engineering for marine development. For UUVs to complete missions, precise navigation is necessary. It is difficult for UUVs to establish true headings because of the rapid convergence of Earth meridians and the severe polar environment. Based on the polar grid navigation algorithm, UUV navigation in the polar region can be accomplished with the Strapdown Inertial Navigation System (SINS) in the grid frame. To save costs, a leader-follower type of system is introduced in this paper. The leader UUV helps the follower UUVs to achieve high navigation accuracy. Follower UUVs correct their own states based on the information sent by the leader UUV and the relative position measured by ultra-short baseline (USBL) acoustic positioning. The underwater acoustic communication delay is quantized by the model. In this paper, considering underwater acoustic communication delay, the conventional adaptive Kalman filter (AKF) is modified to adapt to polar cooperative navigation. The results demonstrate that the polar cooperative navigation algorithm for multi-UUVs that considers communication delays can effectively navigate the sailing of multi-UUVs in the polar region.

  6. Polar Cooperative Navigation Algorithm for Multi-Unmanned Underwater Vehicles Considering Communication Delays

    PubMed Central

    Yan, Zheping; Wang, Lu; Wang, Tongda; Yang, Zewen; Chen, Tao; Xu, Jian

    2018-01-01

    To solve the navigation accuracy problems of multi-Unmanned Underwater Vehicles (multi-UUVs) in the polar region, a polar cooperative navigation algorithm for multi-UUVs considering communication delays is proposed in this paper. UUVs are important pieces of equipment in ocean engineering for marine development. For UUVs to complete missions, precise navigation is necessary. It is difficult for UUVs to establish true headings because of the rapid convergence of Earth meridians and the severe polar environment. Based on the polar grid navigation algorithm, UUV navigation in the polar region can be accomplished with the Strapdown Inertial Navigation System (SINS) in the grid frame. To save costs, a leader-follower type of system is introduced in this paper. The leader UUV helps the follower UUVs to achieve high navigation accuracy. Follower UUVs correct their own states based on the information sent by the leader UUV and the relative position measured by ultra-short baseline (USBL) acoustic positioning. The underwater acoustic communication delay is quantized by the model. In this paper, considering underwater acoustic communication delay, the conventional adaptive Kalman filter (AKF) is modified to adapt to polar cooperative navigation. The results demonstrate that the polar cooperative navigation algorithm for multi-UUVs that considers communication delays can effectively navigate the sailing of multi-UUVs in the polar region. PMID:29601537

  7. Constructing Robust Cooperative Networks using a Multi-Objective Evolutionary Algorithm

    PubMed Central

    Wang, Shuai; Liu, Jing

    2017-01-01

    The design and construction of network structures oriented towards different applications has attracted much attention recently. The existing studies indicated that structural heterogeneity plays different roles in promoting cooperation and robustness. Compared with rewiring a predefined network, it is more flexible and practical to construct new networks that satisfy the desired properties. Therefore, in this paper, we study a method for constructing robust cooperative networks where the only constraint is that the number of nodes and links is predefined. We model this network construction problem as a multi-objective optimization problem and propose a multi-objective evolutionary algorithm, named MOEA-Netrc, to generate the desired networks from arbitrary initializations. The performance of MOEA-Netrc is validated on several synthetic and real-world networks. The results show that MOEA-Netrc can construct balanced candidates and is insensitive to the initializations. MOEA-Netrc can find the Pareto fronts for networks with different levels of cooperation and robustness. In addition, further investigation of the robustness of the constructed networks revealed the impact on other aspects of robustness during the construction process. PMID:28134314

  8. Multi-User Hardware Solutions to Combustion Science ISS Research

    NASA Technical Reports Server (NTRS)

    Otero, Angel M.

    2001-01-01

    In response to the budget environment and to expand on the International Space Station (ISS) Fluids and Combustion Facility (FCF) Combustion Integrated Rack (CIR), common hardware approach, the NASA Combustion Science Program shifted focus in 1999 from single investigator PI (Principal Investigator)-specific hardware to multi-user 'Minifacilities'. These mini-facilities would take the CIR common hardware philosophy to the next level. The approach that was developed re-arranged all the investigations in the program into sub-fields of research. Then common requirements within these subfields were used to develop a common system that would then be complemented by a few PI-specific components. The sub-fields of research selected were droplet combustion, solids and fire safety, and gaseous fuels. From these research areas three mini-facilities have sprung: the Multi-user Droplet Combustion Apparatus (MDCA) for droplet research, Flow Enclosure for Novel Investigations in Combustion of Solids (FEANICS) for solids and fire safety, and the Multi-user Gaseous Fuels Apparatus (MGFA) for gaseous fuels. These mini-facilities will develop common Chamber Insert Assemblies (CIA) and diagnostics for the respective investigators complementing the capability provided by CIR. Presently there are four investigators for MDCA, six for FEANICS, and four for MGFA. The goal of these multi-user facilities is to drive the cost per PI down after the initial development investment is made. Each of these mini-facilities will become a fixture of future Combustion Science NASA Research Announcements (NRAs), enabling investigators to propose against an existing capability. Additionally, an investigation is provided the opportunity to enhance the existing capability to bridge the gap between the capability and their specific science requirements. This multi-user development approach will enable the Combustion Science Program to drive cost per investigation down while drastically reducing the time

  9. Research on multi-user encrypted search scheme in cloud environment

    NASA Astrophysics Data System (ADS)

    Yu, Zonghua; Lin, Sui

    2017-05-01

    Aiming at the existing problems of multi-user encrypted search scheme in cloud computing environment, a basic multi-user encrypted scheme is proposed firstly, and then the basic scheme is extended to an anonymous hierarchical management authority. Compared with most of the existing schemes, the scheme not only to achieve the protection of keyword information, but also to achieve the protection of user identity privacy; the same time, data owners can directly control the user query permissions, rather than the cloud server. In addition, through the use of a special query key generation rules, to achieve the hierarchical management of the user's query permissions. The safety analysis shows that the scheme is safe and that the performance analysis and experimental data show that the scheme is practicable.

  10. Multi-Touch Tabletop System Using Infrared Image Recognition for User Position Identification.

    PubMed

    Suto, Shota; Watanabe, Toshiya; Shibusawa, Susumu; Kamada, Masaru

    2018-05-14

    A tabletop system can facilitate multi-user collaboration in a variety of settings, including small meetings, group work, and education and training exercises. The ability to identify the users touching the table and their positions can promote collaborative work among participants, so methods have been studied that involve attaching sensors to the table, chairs, or to the users themselves. An effective method of recognizing user actions without placing a burden on the user would be some type of visual process, so the development of a method that processes multi-touch gestures by visual means is desired. This paper describes the development of a multi-touch tabletop system using infrared image recognition for user position identification and presents the results of touch-gesture recognition experiments and a system-usability evaluation. Using an inexpensive FTIR touch panel and infrared light, this system picks up the touch areas and the shadow area of the user's hand by an infrared camera to establish an association between the hand and table touch points and estimate the position of the user touching the table. The multi-touch gestures prepared for this system include an operation to change the direction of an object to face the user and a copy operation in which two users generate duplicates of an object. The system-usability evaluation revealed that prior learning was easy and that system operations could be easily performed.

  11. The Relationship between Cultural Diversity and User Needs in Virtual Reference Services

    ERIC Educational Resources Information Center

    Shachaf, Pnina; Snyder, Mary

    2007-01-01

    While the racial diversity of academic library users continues to grow, research on the effects of this diversity remains scarce. This study looks at similarities and differences between non-traditional Caucasian and African American library users through content analysis of ninety-four virtual reference transactions.

  12. Multi-way multi-group segregation and diversity indices.

    PubMed

    Gorelick, Root; Bertram, Susan M

    2010-06-01

    How can we compute a segregation or diversity index from a three-way or multi-way contingency table, where each variable can take on an arbitrary finite number of values and where the index takes values between zero and one? Previous methods only exist for two-way contingency tables or dichotomous variables. A prototypical three-way case is the segregation index of a set of industries or departments given multiple explanatory variables of both sex and race. This can be further extended to other variables, such as disability, number of years of education, and former military service. We extend existing segregation indices based on Euclidean distance (square of coefficient of variation) and Boltzmann/Shannon/Theil index from two-way to multi-way contingency tables by including multiple summations. We provide several biological applications, such as indices for age polyethism and linkage disequilibrium. We also provide a new heuristic conceptualization of entropy-based indices. Higher order association measures are often independent of lower order ones, hence an overall segregation or diversity index should be the arithmetic mean of the normalized association measures at all orders. These methods are applicable when individuals self-identify as multiple races or even multiple sexes and when individuals work part-time in multiple industries. The policy implications of this work are enormous, allowing people to rigorously test whether employment or biological diversity has changed.

  13. A cooperative transponder system for improved traffic safety, localizing road users in the 5 GHz band

    NASA Astrophysics Data System (ADS)

    Schaffer, B.; Kalverkamp, G.; Chaabane, M.; Biebl, E. M.

    2012-09-01

    We present a multi-user cooperative mobile transponder system which enables cars to localize pedestrians, bicyclists and other road users in order to improve traffic safety. The system operates at a center frequency of 5.768 GHz, offering the ability to test precision localization technology at frequencies close to the newly designated automotive safety related bands around 5.9 GHz. By carrying out a roundtrip time of flight measurement, the sensor can determine the distance from the onboard localization unit of a car to a road user who is equipped with an active transponder, employing the idea of a secondary radar and pulse compression. The onboard unit sends out a pseudo noise coded interrogation pulse, which is answered by one or more transponders after a short waiting time. Each transponder uses a different waiting time in order to allow for time division multiple access. We present the system setup as well as range measurement results, achieving an accuracy up to centimeters for the distance measurement and a range in the order of hundred meters. We also discuss the effect of clock drift and offset on distance accuracy for different waiting times and show how the system can be improved to further increase precision in a multiuser environment.

  14. Cooperation based dynamic team formation in multi-agent auctions

    NASA Astrophysics Data System (ADS)

    Pippin, Charles E.; Christensen, Henrik

    2012-06-01

    Auction based methods are often used to perform distributed task allocation on multi-agent teams. Many existing approaches to auctions assume fully cooperative team members. On in-situ and dynamically formed teams, reciprocal collaboration may not always be a valid assumption. This paper presents an approach for dynamically selecting auction partners based on observed team member performance and shared reputation. In addition, we present the use of a shared reputation authority mechanism. Finally, experiments are performed in simulation on multiple UAV platforms to highlight situations in which it is better to enforce cooperation in auctions using this approach.

  15. A Biologically Inspired Cooperative Multi-Robot Control Architecture

    NASA Technical Reports Server (NTRS)

    Howsman, Tom; Craft, Mike; ONeil, Daniel; Howell, Joe T. (Technical Monitor)

    2002-01-01

    A prototype cooperative multi-robot control architecture suitable for the eventual construction of large space structures has been developed. In nature, there are numerous examples of complex architectures constructed by relatively simple insects, such as termites and wasps, which cooperatively assemble their nests. The prototype control architecture emulates this biological model. Actions of each of the autonomous robotic construction agents are only indirectly coordinated, thus mimicking the distributed construction processes of various social insects. The robotic construction agents perform their primary duties stigmergically i.e., without direct inter-agent communication and without a preprogrammed global blueprint of the final design. Communication and coordination between individual agents occurs indirectly through the sensed modifications that each agent makes to the structure. The global stigmergic building algorithm prototyped during the initial research assumes that the robotic builders only perceive the current state of the structure under construction. Simulation studies have established that an idealized form of the proposed architecture was indeed capable of producing representative large space structures with autonomous robots. This paper will explore the construction simulations in order to illustrate the multi-robot control architecture.

  16. Flexibility, Diversity, and Cooperativity: Pillars of Enzyme Catalysis

    PubMed Central

    Hammes, Gordon G.; Benkovic, Stephen J.; Hammes-Schiffer, Sharon

    2011-01-01

    This brief review discusses our current understanding of the molecular basis of enzyme catalysis. A historical development is presented, beginning with steady state kinetics and progressing through modern fast reaction methods, NMR, and single molecule fluorescence techniques. Experimental results are summarized for ribonuclease, aspartate aminotransferase, and especially dihydrofolate reductase (DHFR). Multiple intermediates, multiple conformations, and cooperative conformational changes are shown to be an essential part of virtually all enzyme mechanisms. In the case of DHFR, theoretical investigations have provided detailed information about the movement of atoms within the enzyme-substrate complex as the reaction proceeds along the collective reaction coordinate for hydride transfer. A general mechanism is presented for enzyme catalysis that includes multiple intermediates and a complex, multidimensional standard free energy surface. Protein flexibility, diverse protein conformations, and cooperative conformational changes are important features of this model. PMID:22029278

  17. Multi-Touch Tabletop System Using Infrared Image Recognition for User Position Identification

    PubMed Central

    Suto, Shota; Watanabe, Toshiya; Shibusawa, Susumu; Kamada, Masaru

    2018-01-01

    A tabletop system can facilitate multi-user collaboration in a variety of settings, including small meetings, group work, and education and training exercises. The ability to identify the users touching the table and their positions can promote collaborative work among participants, so methods have been studied that involve attaching sensors to the table, chairs, or to the users themselves. An effective method of recognizing user actions without placing a burden on the user would be some type of visual process, so the development of a method that processes multi-touch gestures by visual means is desired. This paper describes the development of a multi-touch tabletop system using infrared image recognition for user position identification and presents the results of touch-gesture recognition experiments and a system-usability evaluation. Using an inexpensive FTIR touch panel and infrared light, this system picks up the touch areas and the shadow area of the user’s hand by an infrared camera to establish an association between the hand and table touch points and estimate the position of the user touching the table. The multi-touch gestures prepared for this system include an operation to change the direction of an object to face the user and a copy operation in which two users generate duplicates of an object. The system-usability evaluation revealed that prior learning was easy and that system operations could be easily performed. PMID:29758006

  18. The Fluids And Combustion Facility Combustion Integrated Rack And The Multi-User Droplet Combustion Apparatus: Microgravity Combustion Science Using Modular Multi-User Hardware

    NASA Technical Reports Server (NTRS)

    OMalley, Terence F.; Myhre, Craig A.

    2000-01-01

    The Fluids and Combustion Facility (FCF) is a multi-rack payload planned for the International Space Station (ISS) that will enable the study of fluid physics and combustion science in a microgravity environment. The Combustion Integrated Rack (CIR) is one of two International Standard Payload Racks of the FCF and is being designed primarily to support combustion science experiments. The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user apparatus designed to accommodate four different droplet combustion science experiments and is the first payload for CIR. The CIR will function independently until the later launch of the Fluids Integrated Rack component of the FCF. This paper provides an overview of the capabilities and the development status of the CIR and MDCA.

  19. Possibility of Cooper-pair formation controlled by multi-terminal spin injection

    NASA Astrophysics Data System (ADS)

    Ohnishi, K.; Sakamoto, M.; Ishitaki, M.; Kimura, T.

    2018-03-01

    A multi-terminal lateral spin valve consisting of three ferromagnetic nanopillars on a Cu/Nb bilayer has been fabricated. We investigated the influence of the spin injection on the superconducting properties at the Cu/Nb interface. The non-local spin valve signal exhibits a clear spin insulation signature due to the superconducting gap of the Nb. The magnitude of the spin signal is found to show the probe configuration dependence. From the careful analysis of the bias current dependence, we found the suppression of the superconductivity due to the exchange interaction between the Cooper pair and accumulated spin plays an important role in the multi-terminal spin injections. We also discuss about the possibility of the Cooper-pair formation due to the spin injection from the two injectors with the anti-parallel alignment.

  20. Experiments in cooperative manipulation: A system perspective

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Cannon, Robert H., Jr.

    1989-01-01

    In addition to cooperative dynamic control, the system incorporates real time vision feedback, a novel programming technique, and a graphical high level user interface. By focusing on the vertical integration problem, not only these subsystems are examined, but also their interfaces and interactions. The control system implements a multi-level hierarchical structure; the techniques developed for operator input, strategic command, and cooperative dynamic control are presented. At the highest level, a mouse-based graphical user interface allows an operator to direct the activities of the system. Strategic command is provided by a table-driven finite state machine; this methodology provides a powerful yet flexible technique for managing the concurrent system interactions. The dynamic controller implements object impedance control; an extension of Nevill Hogan's impedance control concept to cooperative arm manipulation of a single object. Experimental results are presented, showing the system locating and identifying a moving object catching it, and performing a simple cooperative assembly. Results from dynamic control experiments are also presented, showing the controller's excellent dynamic trajectory tracking performance, while also permitting control of environmental contact force.

  1. Proposal for Implementing Multi-User Database (MUD) Technology in an Academic Library.

    ERIC Educational Resources Information Center

    Filby, A. M. Iliana

    1996-01-01

    Explores the use of MOO (multi-user object oriented) virtual environments in academic libraries to enhance reference services. Highlights include the development of multi-user database (MUD) technology from gaming to non-recreational settings; programming issues; collaborative MOOs; MOOs as distinguished from other types of virtual reality; audio…

  2. Testing Universal Design of a Public Media Website with Diverse Users.

    PubMed

    Chen, Weiqin; Kessel, Siri; Sanderson, Norun C; Tatara, Naoe

    2016-01-01

    Testing with users can identify more issues than other testing methods. Many researchers have argued for the importance of user testing in Universal Design. However, testing Universal Design with diverse users poses many challenges. In this paper we will share our experience with testing the Universal Design of a public media website with real users. We discuss the challenges faced and lessons learned in the process.

  3. Multi-user Droplet Combustion Apparatus (MDCA) Hardware Replacement

    NASA Image and Video Library

    2013-10-02

    ISS037-E-004956 (2 Oct. 2013) --- NASA astronaut Karen Nyberg, Expedition 37 flight engineer, performs the Multi-user Droplet Combustion Apparatus (MDCA) hardware replacement in the Harmony node of the International Space Station.

  4. Multi-user Droplet Combustion Apparatus (MDCA) Hardware Replacement

    NASA Image and Video Library

    2013-10-02

    ISS037-E-004959 (2 Oct. 2013) --- NASA astronaut Karen Nyberg, Expedition 37 flight engineer, performs the Multi-user Droplet Combustion Apparatus (MDCA) hardware replacement in the Harmony node of the International Space Station.

  5. The ATLAS multi-user upgrade and potential applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mustapha, B.; Nolen, J. A.; Savard, G.

    With the recent integration of the CARIBU-EBIS charge breeder into the ATLAS accelerator system to provide for more pure and efficient charge breeding of radioactive beams, a multi-user upgrade of the ATLAS facility is being proposed to serve multiple users simultaneously. ATLAS was the first superconducting ion linac in the world and is the US DOE low-energy Nuclear Physics National User Facility. The proposed upgrade will take advantage of the continuous-wave nature of ATLAS and the pulsed nature of the EBIS charge breeder in order to simultaneously accelerate two beams with very close mass-to-charge ratios; one stable from the existingmore » ECR ion source and one radioactive from the newly commissioned EBIS charge breeder. In addition to enhancing the nuclear physics program, beam extraction at different points along the linac will open up the opportunity for other potential applications; for instance, material irradiation studies at ~ 1 MeV/u and isotope production at ~ 6 MeV/u or at the full ATLAS energy of ~ 15 MeV/u. The concept and proposed implementation of the ATLAS multi-user upgrade will be presented. Future plans to enhance the flexibility of this upgrade will also be presented.« less

  6. The ATLAS multi-user upgrade and potential applications

    NASA Astrophysics Data System (ADS)

    Mustapha, B.; Nolen, J. A.; Savard, G.; Ostroumov, P. N.

    2017-12-01

    With the recent integration of the CARIBU-EBIS charge breeder into the ATLAS accelerator system to provide for more pure and efficient charge breeding of radioactive beams, a multi-user upgrade of the ATLAS facility is being proposed to serve multiple users simultaneously. ATLAS was the first superconducting ion linac in the world and is the US DOE low-energy Nuclear Physics National User Facility. The proposed upgrade will take advantage of the continuous-wave nature of ATLAS and the pulsed nature of the EBIS charge breeder in order to simultaneously accelerate two beams with very close mass-to-charge ratios; one stable from the existing ECR ion source and one radioactive from the newly commissioned EBIS charge breeder. In addition to enhancing the nuclear physics program, beam extraction at different points along the linac will open up the opportunity for other potential applications; for instance, material irradiation studies at ~1 MeV/u, isotope production and radiobiological studies at ~6 MeV/u and at the full ATLAS energy of ~15 MeV/u. The concept and proposed implementation of the ATLAS multi-user upgrade will be discussed. Future plans to enhance the flexibility of this upgrade will be presented.

  7. What Do Our Users Want? Perspectives on Understanding and Meeting User Needs for Multi-Mission Data Services

    NASA Technical Reports Server (NTRS)

    McGuire, Robert E.; Candey, Robert M.; Bilitza, D.

    2006-01-01

    The Sun-Earth Connection Active Archive (SECAA) project of NASA's Space Physics Data Facility operates a range of unique and heavily used multi-mission data services in support of the large-scale science objectives of the Great Observatory, including services such as CDAWeb, the CDAWeb Plus client, SSCWeb, OMNIweb and the CDF data format. In developing and operating these services, we have encountered and continue to struggle with a wide range of issues such as balancing scope and functionality with simplicity and ease of use, understanding the effectiveness of our choices and identifying areas most important for further improvement. In this paper, we will review our key services and then discuss some of our observations and new approaches to understanding and meeting user data service requirements. Some observations are obvious but may still have substantial implications; e.g. functionality without information content is of little user interest, which has led to our recent emphasis on development of web services interfaces, so the content and functionality we already serve is readily and fully available as a building block for new services. Some observations require careful design and tradeoffs; e.g. users will complain when they are offered interfaces with limited options but users are also easily intimidated and become lost when offered extensive options for customization. Some observations remain highly challenging; e.g. a comprehensive multi-mission, multi-source view of all data and services available easily produces a daunting list, but a more selective view can easily lead users to overlook available and relevant data. It is often difficult to obtain and meaningfully interpret measures of true productive usage and overall user satisfaction, even with a variety of techniques including statistics, citations, case studies, user feedback and advisory committees. Most of these issues will apply to and may even be more acute for distributed implementation

  8. Multi-cooperation of Cultural Heritage Conservation: The Cangdong Project of Guangdong Province

    NASA Astrophysics Data System (ADS)

    Tan, J.

    2015-09-01

    In recent years, some workshops and research cases have arisen in China to seek for suitable ways for heritage conservation and development of historic villages. However, the issue of multi-cooperation has not been much mentioned in research works. The case of Cangdong Project in Guangdong Province is a social enterprise. It is a center focusing on heritage education. It organizes tailor-made workshops for interested people from all over China and Hong Kong, Macao and overseas, including university courses for credits, summer/winter camps for primary and middle school students, as well as common people who are interested in heritage conservation. The purpose of the education center is to enhance heritage/cultural interest of the younger generations and common people, and try to work with local villagers to build a wealthy community. Nowadays, more and more villagers moved out for work and the countryside population in China is decreasing, this project also aims to create work opportunities for villagers through heritage conservation projects, so that the villagers can be willing to stay. The project focuses more in a sustainable way for community development. It has been five years since the project was set up in Cangdong Village. The project team worked with villagers, city people, students, scholars, different levels of local governments, investors, Medias, charitable organizations, as well as the market of tourism. As such, a platform of multi-cooperation for the above parties has formed during the past five years. This paper takes the Project experience from 2010-2015 as the case to study multi-cooperation in the field of heritage conservation in China, as well as to discuss how to co-operate the subjective initiatives of different stokeholds.

  9. Cooperation, but not competition, improves 4-year-old children's reasoning about others' diverse desires.

    PubMed

    Jin, Xinyi; Li, Pengchao; He, Jie; Shen, Mowei

    2017-05-01

    Three experiments examined whether cooperation or competition affects 4-year-old children's reasoning about other people's desires-which differed from their own-in a gift selection task. Experiment 1 (N=72) found that children's performance in selecting an adult-preferred gift for an adult experimenter was enhanced by a short period of preceding cooperative, but not competitive or individualistic, play with the experimenter. Experiment 2 (N=24) ruled out the alternative explanation that children resisted satisfying their opponent after competition. Experiment 3 (N=48) replicated the cooperation advantage in selecting a gift for someone else, indicating that children's understanding of diverse desires was generally improved by cooperation but not competition. These findings support the constructivist view of social development and highlight the advantage of cooperation. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Privacy and Security in Multi-User Health Kiosks

    PubMed Central

    TAKYI, HAROLD; WATZLAF, VALERIE; MATTHEWS, JUDITH TABOLT; ZHOU, LEMING; DEALMEIDA, DILHARI

    2017-01-01

    Enforcement of the Health Insurance Portability and Accountability Act (HIPAA) and the Health Information Technology for Economic and Clinical Health Act (HITECH) has gotten stricter and penalties have become more severe in response to a significant increase in computer-related information breaches in recent years. With health information said to be worth twice as much as other forms of information on the underground market, making preservation of privacy and security an integral part of health technology development, rather than an afterthought, not only mitigates risks but also helps to ensure HIPAA and HITECH compliance. This paper provides a guide, based on the Office for Civil Rights (OCR) audit protocol, for creating and maintaining an audit checklist for multi-user health kiosks. Implementation of selected audit elements for a multi-user health kiosk designed for use by community-residing older adults illustrates how the guide can be applied. PMID:28814990

  11. Distributed Multi-Cell Resource Allocation with Price Based ICI Coordination in Downlink OFDMA Networks

    NASA Astrophysics Data System (ADS)

    Lv, Gangming; Zhu, Shihua; Hui, Hui

    Multi-cell resource allocation under minimum rate request for each user in OFDMA networks is addressed in this paper. Based on Lagrange dual decomposition theory, the joint multi-cell resource allocation problem is decomposed and modeled as a limited-cooperative game, and a distributed multi-cell resource allocation algorithm is thus proposed. Analysis and simulation results show that, compared with non-cooperative iterative water-filling algorithm, the proposed algorithm can remarkably reduce the ICI level and improve overall system performances.

  12. Dynamic instability of cooperation due to diverse activity patterns in evolutionary social dilemmas

    NASA Astrophysics Data System (ADS)

    Xia, Cheng-Yi; Meloni, Sandro; Perc, Matjaž; Moreno, Yamir

    2015-03-01

    Individuals might abstain from participating in an instance of an evolutionary game for various reasons, ranging from lack of interest to risk aversion. In order to understand the consequences of such diverse activity patterns on the evolution of cooperation, we study a weak prisoner's dilemma where each player's participation is probabilistic rather than certain. Players that do not participate get a null payoff and are unable to replicate. We show that inactivity introduces cascading failures of cooperation, which are particularly severe on scale-free networks with frequently inactive hubs. The drops in the fraction of cooperators are sudden, while the spatiotemporal reorganization of compact cooperative clusters, and thus the recovery, takes time. Nevertheless, if the activity of players is directly proportional to their degree, or if the interaction network is not strongly heterogeneous, the overall evolution of cooperation is not impaired. This is because inactivity negatively affects the potency of low-degree defectors, who are hence unable to utilize on their inherent evolutionary advantage. Between cascading failures, the fraction of cooperators is therefore higher than usual, which lastly balances out the asymmetric dynamic instabilities that emerge due to intermittent blackouts of cooperative hubs.

  13. A joint precoding scheme for indoor downlink multi-user MIMO VLC systems

    NASA Astrophysics Data System (ADS)

    Zhao, Qiong; Fan, Yangyu; Kang, Bochao

    2017-11-01

    In this study, we aim to improve the system performance and reduce the implementation complexity of precoding scheme for visible light communication (VLC) systems. By incorporating the power-method algorithm and the block diagonalization (BD) algorithm, we propose a joint precoding scheme for indoor downlink multi-user multi-input-multi-output (MU-MIMO) VLC systems. In this scheme, we apply the BD algorithm to eliminate the co-channel interference (CCI) among users firstly. Secondly, the power-method algorithm is used to search the precoding weight for each user based on the optimal criterion of signal to interference plus noise ratio (SINR) maximization. Finally, the optical power restrictions of VLC systems are taken into account to constrain the precoding weight matrix. Comprehensive computer simulations in two scenarios indicate that the proposed scheme always has better bit error rate (BER) performance and lower computation complexity than that of the traditional scheme.

  14. Assessment of a cooperative workstation.

    PubMed Central

    Beuscart, R. J.; Molenda, S.; Souf, N.; Foucher, C.; Beuscart-Zephir, M. C.

    1996-01-01

    Groupware and new Information Technologies have now made it possible for people in different places to work together in synchronous cooperation. Very often, designers of this new type of software are not provided with a model of the common workspace, which is prejudicial to software development and its acceptance by potential users. The authors take the example of a task of medical co-diagnosis, using a multi-media communication workstation. Synchronous cooperative work is made possible by using local ETHERNET or public ISDN Networks. A detailed ergonomic task analysis studies the cognitive functioning of the physicians involved, compares their behaviour in the normal and the mediatized situations, and leads to an interpretation of the likely causes for success or failure of CSCW tools. PMID:8947764

  15. Cooperative Learning: A Response to Linguistic and Cultural Diversity. Language in Education: Theory and Practice 81.

    ERIC Educational Resources Information Center

    Holt, Daniel D., Ed.

    Essays on cooperative learning focus on the use of this strategy to address the special needs of linguistically and culturally diverse student groups in elementary and secondary education. The volume contains several essays on theory, principles, and techniques of cooperative learning and a series of model instructional units for a variety of…

  16. A Multi-User Microcomputer System for Small Libraries.

    ERIC Educational Resources Information Center

    Leggate, Peter

    1988-01-01

    Describes the development of Bookshelf, a multi-user microcomputer system for small libraries that uses an integrated software package. The discussion covers the design parameters of the package, which were based on a survey of seven small libraries, and some characteristics of the software. (three notes with references) (CLB)

  17. Promotion of cooperation induced by discriminators in the spatial multi-player donor-recipient game

    NASA Astrophysics Data System (ADS)

    Cui, Guang-Hai; Wang, Zhen; Ren, Jian-Kang; Lu, Kun; Li, Ming-Chu

    2016-11-01

    Although the two-player donor-recipient game has been used extensively in studying cooperation in social dilemmas, the scenario in which a donor can simultaneously donate resources to multiple recipients is also common in human societies, economic systems, and social networks. This paper formulates a model of the multi-player donor-recipient game considering a multi-recipient scenario. The promotion of cooperation is also studied by introducing a discriminative cooperation strategy into the game, which donates resources to recipients in proportion to their previous donations with a cost for the collection of information. The evolutionary dynamics of individual strategies are explored in homogeneous and heterogeneous scenarios by leveraging spatial evolutionary game theory. The results show that in a homogeneous scenario, defectors can dominate the network at the equilibrium state only when the cost-to-benefit ratio (R) of donated resources is large. In a heterogeneous scenario, three strategies can coexist all the time within the range of R that was studied, and the promotion of cooperation is more effective when the values of R are smaller. Results from a single node evolution and the formation of local patterns of interaction are provided, and it is analytically shown that discriminators can maintain fairness in resource donation and guarantee long-term cooperation when R is not too large.

  18. Distributed cooperative H∞ optimal tracking control of MIMO nonlinear multi-agent systems in strict-feedback form via adaptive dynamic programming

    NASA Astrophysics Data System (ADS)

    Luy, N. T.

    2018-04-01

    The design of distributed cooperative H∞ optimal controllers for multi-agent systems is a major challenge when the agents' models are uncertain multi-input and multi-output nonlinear systems in strict-feedback form in the presence of external disturbances. In this paper, first, the distributed cooperative H∞ optimal tracking problem is transformed into controlling the cooperative tracking error dynamics in affine form. Second, control schemes and online algorithms are proposed via adaptive dynamic programming (ADP) and the theory of zero-sum differential graphical games. The schemes use only one neural network (NN) for each agent instead of three from ADP to reduce computational complexity as well as avoid choosing initial NN weights for stabilising controllers. It is shown that despite not using knowledge of cooperative internal dynamics, the proposed algorithms not only approximate values to Nash equilibrium but also guarantee all signals, such as the NN weight approximation errors and the cooperative tracking errors in the closed-loop system, to be uniformly ultimately bounded. Finally, the effectiveness of the proposed method is shown by simulation results of an application to wheeled mobile multi-robot systems.

  19. MDCA (Multi-user Drop Combustion Apparatus) operations

    NASA Image and Video Library

    2009-05-12

    ISS019-E-015912 (12 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, works on the Combustion Integrated Rack (CIR) Multi-user Drop Combustion Apparatus (MDCA) in the Destiny laboratory of the International Space Station. Wakata removed and replaced one fuel reservoir, which required temporary opening the front end cap and removing the fuel supply bypass Quick Disconnect (QD).

  20. MDCA (Multi-user Drop Combustion Apparatus) operations

    NASA Image and Video Library

    2009-05-12

    ISS019-E-015906 (12 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, works on the Combustion Integrated Rack (CIR) Multi-user Drop Combustion Apparatus (MDCA) in the Destiny laboratory of the International Space Station. Wakata removed and replaced one fuel reservoir, which required temporary opening the front end cap and removing the fuel supply bypass Quick Disconnect (QD).

  1. MDCA (Multi-user Drop Combustion Apparatus) operations

    NASA Image and Video Library

    2009-05-12

    ISS019-E-015910(12 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, works on the Combustion Integrated Rack (CIR) Multi-user Drop Combustion Apparatus (MDCA) in the Destiny laboratory of the International Space Station. Wakata removed and replaced one fuel reservoir, which required temporary opening the front end cap and removing the fuel supply bypass Quick Disconnect (QD).

  2. User-centered design of multi-gene sequencing panel reports for clinicians.

    PubMed

    Cutting, Elizabeth; Banchero, Meghan; Beitelshees, Amber L; Cimino, James J; Fiol, Guilherme Del; Gurses, Ayse P; Hoffman, Mark A; Jeng, Linda Jo Bone; Kawamoto, Kensaku; Kelemen, Mark; Pincus, Harold Alan; Shuldiner, Alan R; Williams, Marc S; Pollin, Toni I; Overby, Casey Lynnette

    2016-10-01

    The objective of this study was to develop a high-fidelity prototype for delivering multi-gene sequencing panel (GS) reports to clinicians that simulates the user experience of a final application. The delivery and use of GS reports can occur within complex and high-paced healthcare environments. We employ a user-centered software design approach in a focus group setting in order to facilitate gathering rich contextual information from a diverse group of stakeholders potentially impacted by the delivery of GS reports relevant to two precision medicine programs at the University of Maryland Medical Center. Responses from focus group sessions were transcribed, coded and analyzed by two team members. Notification mechanisms and information resources preferred by participants from our first phase of focus groups were incorporated into scenarios and the design of a software prototype for delivering GS reports. The goal of our second phase of focus group, to gain input on the prototype software design, was accomplished through conducting task walkthroughs with GS reporting scenarios. Preferences for notification, content and consultation from genetics specialists appeared to depend upon familiarity with scenarios for ordering and delivering GS reports. Despite familiarity with some aspects of the scenarios we proposed, many of our participants agreed that they would likely seek consultation from a genetics specialist after viewing the test reports. In addition, participants offered design and content recommendations. Findings illustrated a need to support customized notification approaches, user-specific information, and access to genetics specialists with GS reports. These design principles can be incorporated into software applications that deliver GS reports. Our user-centered approach to conduct this assessment and the specific input we received from clinicians may also be relevant to others working on similar projects. Copyright © 2016 Elsevier Inc. All rights

  3. A Novel Optimal Joint Resource Allocation Method in Cooperative Multicarrier Networks: Theory and Practice

    PubMed Central

    Gao, Yuan; Zhou, Weigui; Ao, Hong; Chu, Jian; Zhou, Quan; Zhou, Bo; Wang, Kang; Li, Yi; Xue, Peng

    2016-01-01

    With the increasing demands for better transmission speed and robust quality of service (QoS), the capacity constrained backhaul gradually becomes a bottleneck in cooperative wireless networks, e.g., in the Internet of Things (IoT) scenario in joint processing mode of LTE-Advanced Pro. This paper focuses on resource allocation within capacity constrained backhaul in uplink cooperative wireless networks, where two base stations (BSs) equipped with single antennae serve multiple single-antennae users via multi-carrier transmission mode. In this work, we propose a novel cooperative transmission scheme based on compress-and-forward with user pairing to solve the joint mixed integer programming problem. To maximize the system capacity under the limited backhaul, we formulate the joint optimization problem of user sorting, subcarrier mapping and backhaul resource sharing among different pairs (subcarriers for users). A novel robust and efficient centralized algorithm based on alternating optimization strategy and perfect mapping is proposed. Simulations show that our novel method can improve the system capacity significantly under the constraint of the backhaul resource compared with the blind alternatives. PMID:27077865

  4. Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

    PubMed

    Shaban, Heba; Abou El-Nasr, Mohamad

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

  5. Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

    PubMed Central

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

  6. Multi-Source Cooperative Data Collection with a Mobile Sink for the Wireless Sensor Network.

    PubMed

    Han, Changcai; Yang, Jinsheng

    2017-10-30

    The multi-source cooperation integrating distributed low-density parity-check codes is investigated to jointly collect data from multiple sensor nodes to the mobile sink in the wireless sensor network. The one-round and two-round cooperative data collection schemes are proposed according to the moving trajectories of the sink node. Specifically, two sparse cooperation models are firstly formed based on geographical locations of sensor source nodes, the impairment of inter-node wireless channels and moving trajectories of the mobile sink. Then, distributed low-density parity-check codes are devised to match the directed graphs and cooperation matrices related with the cooperation models. In the proposed schemes, each source node has quite low complexity attributed to the sparse cooperation and the distributed processing. Simulation results reveal that the proposed cooperative data collection schemes obtain significant bit error rate performance and the two-round cooperation exhibits better performance compared with the one-round scheme. The performance can be further improved when more source nodes participate in the sparse cooperation. For the two-round data collection schemes, the performance is evaluated for the wireless sensor networks with different moving trajectories and the variant data sizes.

  7. Multi-Source Cooperative Data Collection with a Mobile Sink for the Wireless Sensor Network

    PubMed Central

    Han, Changcai; Yang, Jinsheng

    2017-01-01

    The multi-source cooperation integrating distributed low-density parity-check codes is investigated to jointly collect data from multiple sensor nodes to the mobile sink in the wireless sensor network. The one-round and two-round cooperative data collection schemes are proposed according to the moving trajectories of the sink node. Specifically, two sparse cooperation models are firstly formed based on geographical locations of sensor source nodes, the impairment of inter-node wireless channels and moving trajectories of the mobile sink. Then, distributed low-density parity-check codes are devised to match the directed graphs and cooperation matrices related with the cooperation models. In the proposed schemes, each source node has quite low complexity attributed to the sparse cooperation and the distributed processing. Simulation results reveal that the proposed cooperative data collection schemes obtain significant bit error rate performance and the two-round cooperation exhibits better performance compared with the one-round scheme. The performance can be further improved when more source nodes participate in the sparse cooperation. For the two-round data collection schemes, the performance is evaluated for the wireless sensor networks with different moving trajectories and the variant data sizes. PMID:29084155

  8. Multi-dimensional classification of biomedical text: Toward automated, practical provision of high-utility text to diverse users

    PubMed Central

    Shatkay, Hagit; Pan, Fengxia; Rzhetsky, Andrey; Wilbur, W. John

    2008-01-01

    Motivation: Much current research in biomedical text mining is concerned with serving biologists by extracting certain information from scientific text. We note that there is no ‘average biologist’ client; different users have distinct needs. For instance, as noted in past evaluation efforts (BioCreative, TREC, KDD) database curators are often interested in sentences showing experimental evidence and methods. Conversely, lab scientists searching for known information about a protein may seek facts, typically stated with high confidence. Text-mining systems can target specific end-users and become more effective, if the system can first identify text regions rich in the type of scientific content that is of interest to the user, retrieve documents that have many such regions, and focus on fact extraction from these regions. Here, we study the ability to characterize and classify such text automatically. We have recently introduced a multi-dimensional categorization and annotation scheme, developed to be applicable to a wide variety of biomedical documents and scientific statements, while intended to support specific biomedical retrieval and extraction tasks. Results: The annotation scheme was applied to a large corpus in a controlled effort by eight independent annotators, where three individual annotators independently tagged each sentence. We then trained and tested machine learning classifiers to automatically categorize sentence fragments based on the annotation. We discuss here the issues involved in this task, and present an overview of the results. The latter strongly suggest that automatic annotation along most of the dimensions is highly feasible, and that this new framework for scientific sentence categorization is applicable in practice. Contact: shatkay@cs.queensu.ca PMID:18718948

  9. Fault-tolerant cooperative output regulation for multi-vehicle systems with sensor faults

    NASA Astrophysics Data System (ADS)

    Qin, Liguo; He, Xiao; Zhou, D. H.

    2017-10-01

    This paper presents a unified framework of fault diagnosis and fault-tolerant cooperative output regulation (FTCOR) for a linear discrete-time multi-vehicle system with sensor faults. The FTCOR control law is designed through three steps. A cooperative output regulation (COR) controller is designed based on the internal mode principle when there are no sensor faults. A sufficient condition on the existence of the COR controller is given based on the discrete-time algebraic Riccati equation (DARE). Then, a decentralised fault diagnosis scheme is designed to cope with sensor faults occurring in followers. A residual generator is developed to detect sensor faults of each follower, and a bank of fault-matching estimators are proposed to isolate and estimate sensor faults of each follower. Unlike the current distributed fault diagnosis for multi-vehicle systems, the presented decentralised fault diagnosis scheme in each vehicle reduces the communication and computation load by only using the information of the vehicle. By combing the sensor fault estimation and the COR control law, an FTCOR controller is proposed. Finally, the simulation results demonstrate the effectiveness of the FTCOR controller.

  10. Multi-Sector Sustainability Browser (MSSB) User Manual: A ...

    EPA Pesticide Factsheets

    EPA’s Sustainable and Healthy Communities (SHC) Research Program is developing methodologies, resources, and tools to assist community members and local decision makers in implementing policy choices that facilitate sustainable approaches in managing their resources affecting the built environment, natural environment, and human health. In order to assist communities and decision makers in implementing sustainable practices, EPA is developing computer-based systems including models, databases, web tools, and web browsers to help communities decide upon approaches that support their desired outcomes. Communities need access to resources that will allow them to achieve their sustainability objectives through intelligent decisions in four key sustainability areas: • Land Use • Buildings and Infrastructure • Transportation • Materials Management (i.e., Municipal Solid Waste [MSW] processing and disposal) The Multi-Sector Sustainability Browser (MSSB) is designed to support sustainable decision-making for communities, local and regional planners, and policy and decision makers. Document is an EPA Technical Report, which is the user manual for the Multi-Sector Sustainability Browser (MSSB) tool. The purpose of the document is to provide basic guidance on use of the tool for users

  11. Introducing ORACLE: Library Processing in a Multi-User Environment.

    ERIC Educational Resources Information Center

    Queensland Library Board, Brisbane (Australia).

    Currently being developed by the State Library of Queensland, Australia, ORACLE (On-Line Retrieval of Acquisitions, Cataloguing, and Circulation Details for Library Enquiries) is a computerized library system designed to provide rapid processing of library materials in a multi-user environment. It is based on the Australian MARC format and fully…

  12. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Kennedy Space Center Director Bob Cabana speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  13. Cooperative multi-user detection and ranging based on pseudo-random codes

    NASA Astrophysics Data System (ADS)

    Morhart, C.; Biebl, E. M.

    2009-05-01

    We present an improved approach for a Round Trip Time of Flight distance measurement system. The system is intended for the usage in a cooperative localisation system for automotive applications. Therefore, it is designed to address a large number of communication partners per measurement cycle. By using coded signals in a time divison multiple access order, we can detect a large number of pedestrian sensors with just one car sensor. We achieve this by using very short transmit bursts in combination with a real time correlation algorithm. Futhermore, the correlation approach offers real time data, concerning the time of arrival, that can serve as a trigger impulse for other comunication systems. The distance accuracy of the correlation result was further increased by adding a fourier interpolation filter. The system performance was checked with a prototype at 2.4 GHz. We reached a distance measurement accuracy of 12 cm at a range up to 450 m.

  14. Cooperation and Coordination Between Fuzzy Reinforcement Learning Agents in Continuous State Partially Observable Markov Decision Processes

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.; Vengerov, David

    1999-01-01

    Successful operations of future multi-agent intelligent systems require efficient cooperation schemes between agents sharing learning experiences. We consider a pseudo-realistic world in which one or more opportunities appear and disappear in random locations. Agents use fuzzy reinforcement learning to learn which opportunities are most worthy of pursuing based on their promise rewards, expected lifetimes, path lengths and expected path costs. We show that this world is partially observable because the history of an agent influences the distribution of its future states. We consider a cooperation mechanism in which agents share experience by using and-updating one joint behavior policy. We also implement a coordination mechanism for allocating opportunities to different agents in the same world. Our results demonstrate that K cooperative agents each learning in a separate world over N time steps outperform K independent agents each learning in a separate world over K*N time steps, with this result becoming more pronounced as the degree of partial observability in the environment increases. We also show that cooperation between agents learning in the same world decreases performance with respect to independent agents. Since cooperation reduces diversity between agents, we conclude that diversity is a key parameter in the trade off between maximizing utility from cooperation when diversity is low and maximizing utility from competitive coordination when diversity is high.

  15. Center Planning and Development: Multi-User Spaceport Initiatives

    NASA Technical Reports Server (NTRS)

    Kennedy, Christopher John

    2015-01-01

    The Vehicle Assembly building at NASAs Kennedy Space Center has been used since 1966 to vertically assemble every launch vehicle, since the Apollo Program, launched from Launch Complex 39 (LC-39). After the cancellation of the Constellation Program in 2010 and the retirement of the Space Shuttle Program in 2011, the VAB faced an uncertain future. As the Space Launch System (SLS) gained a foothold as the future of American spaceflight to deep space, NASA was only using a portion of the VABs initial potential. With three high bays connected to the Crawler Way transportation system, the potential exists for up to three rockets to be simultaneously processed for launch. The Kennedy Space Center (KSC) Master plan, supported by the Center Planning and Development (CPD) Directorate, is guiding Kennedy toward a 21st century multi-user spaceport. This concept will maintain Kennedy as the United States premier gateway to space and provide multi-user operations through partnerships with the commercial aerospace industry. Commercial aerospace companies, now tasked with transporting cargo and, in the future, astronauts to the International Space Station (ISS) via the Commercial Resupply Service (CRS) and Commercial Crew Program (CCP), are a rapidly growing industry with increasing capabilities to make launch operations more economical for both private companies and the government. Commercial operations to Low Earth Orbit allow the government to focus on travel to farther destinations through the SLS Program. With LC-39B designated as a multi-use launch pad, companies seeking to use it will require an integration facility to assemble, integrate, and test their launch vehicle. An Announcement for Proposals (AFP) was released in June, beginning the process of finding a non-NASA user for High Bay 2 (HB2) and the Mobile Launcher Platforms (MLPs). An Industry Day, a business meeting and tour for interested companies and organizations, was also arranged to identify and answer any

  16. DEEP SPACE: High Resolution VR Platform for Multi-user Interactive Narratives

    NASA Astrophysics Data System (ADS)

    Kuka, Daniela; Elias, Oliver; Martins, Ronald; Lindinger, Christopher; Pramböck, Andreas; Jalsovec, Andreas; Maresch, Pascal; Hörtner, Horst; Brandl, Peter

    DEEP SPACE is a large-scale platform for interactive, stereoscopic and high resolution content. The spatial and the system design of DEEP SPACE are facing constraints of CAVETM-like systems in respect to multi-user interactive storytelling. To be used as research platform and as public exhibition space for many people, DEEP SPACE is capable to process interactive, stereoscopic applications on two projection walls with a size of 16 by 9 meters and a resolution of four times 1080p (4K) each. The processed applications are ranging from Virtual Reality (VR)-environments to 3D-movies to computationally intensive 2D-productions. In this paper, we are describing DEEP SPACE as an experimental VR platform for multi-user interactive storytelling. We are focusing on the system design relevant for the platform, including the integration of the Apple iPod Touch technology as VR control, and a special case study that is demonstrating the research efforts in the field of multi-user interactive storytelling. The described case study, entitled "Papyrate's Island", provides a prototypical scenario of how physical drawings may impact on digital narratives. In this special case, DEEP SPACE helps us to explore the hypothesis that drawing, a primordial human creative skill, gives us access to entirely new creative possibilities in the domain of interactive storytelling.

  17. OpenGL in Multi-User Web-Based Applications

    NASA Astrophysics Data System (ADS)

    Szostek, K.; Piórkowski, A.

    In this article construction and potential of OpenGL multi-user web-based application are presented. The most common technologies like: .NET ASP, Java and Mono were used with specific OpenGL libraries to visualize tree-dimensional medical data. The most important conclusion of this work is that server side applications can easily take advantage of fast GPU and produce efficient results of advanced computation just like the visualization.

  18. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Nancy Bray, director of Spaceport Integration and Services at NASA's Kennedy Space Center, speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  19. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Tom Engler, director of Center Planning and Development at NASA's Kennedy Space Center, speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  20. Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA)

    NASA Image and Video Library

    2013-07-24

    ISS036-E-024569 (24 July 2013) --- European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, works on the Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA) at a maintenance work station in the Harmony node of the International Space Station.

  1. Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA)

    NASA Image and Video Library

    2013-07-24

    ISS036-E-024605 (24 July 2013) --- European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, works on the Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA) at a maintenance work station in the Harmony node of the International Space Station.

  2. Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA)

    NASA Image and Video Library

    2013-07-24

    ISS036-E-024637 (24 July 2013) --- European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, works on the Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA) at a maintenance work station in the Harmony node of the International Space Station.

  3. Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design

    PubMed Central

    Cheng, Yi-Chang; Hsu, Yung-Chi

    2010-01-01

    In this paper, a TSK-type neuro-fuzzy system with multi groups cooperation based symbiotic evolution method (TNFS-MGCSE) is proposed. The TNFS-MGCSE is developed from symbiotic evolution. The symbiotic evolution is different from traditional GAs (genetic algorithms) that each chromosome in symbiotic evolution represents a rule of fuzzy model. The MGCSE is different from the traditional symbiotic evolution; with a population in MGCSE is divided to several groups. Each group formed by a set of chromosomes represents a fuzzy rule and cooperate with other groups to generate the better chromosomes by using the proposed cooperation based crossover strategy (CCS). In this paper, the proposed TNFS-MGCSE is used to evaluate by numerical examples (Mackey-Glass chaotic time series and sunspot number forecasting). The performance of the TNFS-MGCSE achieves excellently with other existing models in the simulations. PMID:21709856

  4. Multi-Level Adaptation in End-User Development of 3D Virtual Chemistry Experiments

    ERIC Educational Resources Information Center

    Liu, Chang; Zhong, Ying

    2014-01-01

    Multi-level adaptation in end-user development (EUD) is an effective way to enable non-technical end users such as educators to gradually introduce more functionality with increasing complexity to 3D virtual learning environments developed by themselves using EUD approaches. Parameterization, integration, and extension are three levels of…

  5. Context-based user grouping for multi-casting in heterogeneous radio networks

    NASA Astrophysics Data System (ADS)

    Mannweiler, C.; Klein, A.; Schneider, J.; Schotten, H. D.

    2011-08-01

    Along with the rise of sophisticated smartphones and smart spaces, the availability of both static and dynamic context information has steadily been increasing in recent years. Due to the popularity of social networks, these data are complemented by profile information about individual users. Making use of this information by classifying users in wireless networks enables targeted content and advertisement delivery as well as optimizing network resources, in particular bandwidth utilization, by facilitating group-based multi-casting. In this paper, we present the design and implementation of a web service for advanced user classification based on user, network, and environmental context information. The service employs simple and advanced clustering algorithms for forming classes of users. Available service functionalities include group formation, context-aware adaptation, and deletion as well as the exposure of group characteristics. Moreover, the results of a performance evaluation, where the service has been integrated in a simulator modeling user behavior in heterogeneous wireless systems, are presented.

  6. Multi-year Content Analysis of User Facility Related Publications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patton, Robert M; Stahl, Christopher G; Hines, Jayson

    2013-01-01

    Scientific user facilities provide resources and support that enable scientists to conduct experiments or simulations pertinent to their respective research. Consequently, it is critical to have an informed understanding of the impact and contributions that these facilities have on scientific discoveries. Leveraging insight into scientific publications that acknowledge the use of these facilities enables more informed decisions by facility management and sponsors in regard to policy, resource allocation, and influencing the direction of science as well as more effectively understand the impact of a scientific user facility. This work discusses preliminary results of mining scientific publications that utilized resources atmore » the Oak Ridge Leadership Computing Facility (OLCF) at Oak Ridge National Laboratory (ORNL). These results show promise in identifying and leveraging multi-year trends and providing a higher resolution view of the impact that a scientific user facility may have on scientific discoveries.« less

  7. Hybrid position/force control of multi-arm cooperating robots

    NASA Technical Reports Server (NTRS)

    Hayati, Samad

    1986-01-01

    This paper extends the theory of hybrid position/force control to the case of multi-arm cooperating robots. Cooperation between n robot arms is achieved by controlling each arm such that the burden of actuation is shared between the arms in a nonconflicting way as they control the position of and force on a designated point on an object. The object, which may or may not be in contact with a rigid environment, is assumed to be held rigidly by n robot end-effectors. Natural and artificial position and force constraints are defined for a point on the object and two selection matrices are obtained to control the arms. The position control loops are designed based on each manipulator's Cartesian space dynamic equations. In the position control subspace, a feature is provided which allows the robot arms to exert additional forces/torques to achieve compression, tension, or torsion in the object without affecting the execution of the motion trajectories. In the force control subspace, a method is introduced to minimize the total force/torque magnitude square while realizing the net desired force/torque on the environment.

  8. Authenticated multi-user quantum key distribution with single particles

    NASA Astrophysics Data System (ADS)

    Lin, Song; Wang, Hui; Guo, Gong-De; Ye, Guo-Hua; Du, Hong-Zhen; Liu, Xiao-Fen

    2016-03-01

    Quantum key distribution (QKD) has been growing rapidly in recent years and becomes one of the hottest issues in quantum information science. During the implementation of QKD on a network, identity authentication has been one main problem. In this paper, an efficient authenticated multi-user quantum key distribution (MQKD) protocol with single particles is proposed. In this protocol, any two users on a quantum network can perform mutual authentication and share a secure session key with the assistance of a semi-honest center. Meanwhile, the particles, which are used as quantum information carriers, are not required to be stored, therefore the proposed protocol is feasible with current technology. Finally, security analysis shows that this protocol is secure in theory.

  9. Cooperative answers in database systems

    NASA Technical Reports Server (NTRS)

    Gaasterland, Terry; Godfrey, Parke; Minker, Jack; Novik, Lev

    1993-01-01

    A major concern of researchers who seek to improve human-computer communication involves how to move beyond literal interpretations of queries to a level of responsiveness that takes the user's misconceptions, expectations, desires, and interests into consideration. At Maryland, we are investigating how to better meet a user's needs within the framework of the cooperative answering system of Gal and Minker. We have been exploring how to use semantic information about the database to formulate coherent and informative answers. The work has two main thrusts: (1) the construction of a logic formula which embodies the content of a cooperative answer; and (2) the presentation of the logic formula to the user in a natural language form. The information that is available in a deductive database system for building cooperative answers includes integrity constraints, user constraints, the search tree for answers to the query, and false presuppositions that are present in the query. The basic cooperative answering theory of Gal and Minker forms the foundation of a cooperative answering system that integrates the new construction and presentation methods. This paper provides an overview of the cooperative answering strategies used in the CARMIN cooperative answering system, an ongoing research effort at Maryland. Section 2 gives some useful background definitions. Section 3 describes techniques for collecting cooperative logical formulae. Section 4 discusses which natural language generation techniques are useful for presenting the logic formula in natural language text. Section 5 presents a diagram of the system.

  10. International Microgravity Plasma Facility IMPF: A Multi-User Modular Research Facility for Complex Plasma Research on ISS

    NASA Astrophysics Data System (ADS)

    Seurig, R.; Burfeindt, J.; Castegini, R.; Griethe, W.; Hofmann, P.

    2002-01-01

    On March 03, 2001, the PKE-Nefedov plasma experiment was successfully put into operation on board ISS. This complex plasma experiment is the predecessor for the semi-autonomous multi-user facility IMPF (International Microgravity Plasma Facility) to be flown in 2006 with an expected operational lifetime of 10 years. IMPF is envisioned to be an international research facility for investigators in the field of multi-component plasmas containing ions, electrons, and charged microparticles. This research filed is often referred to as "complex plasmas". The actual location of IMPF on ISS is not decided yet; potential infrastructure under consideration are EXPRESS Rack, Standard Interface Rack SIR, European Drawer Rack EDR, or a to be designed custom rack infrastructure on the Russian Segment. The actual development status of the DLR funded Pre-phase B Study for IMPF will be presented. For this phase, IMPF was assumed to be integrated in an EXPRESS Rack requiring four middeck lockers with two 4-PU ISIS drawers for accommodation. Technical and operational challenges, like a 240 Mbytes/sec continuous experimental data stream for 60 minutes, will be addressed. The project was funded by the German Space Agency (DLR) and was performed in close cooperation with scientists from the Max-Planck-Institute for Extraterrestical Physics in Munich, Germany.

  11. Staff regard towards working with substance users: a European multi-centre study.

    PubMed

    Gilchrist, Gail; Moskalewicz, Jacek; Slezakova, Silvia; Okruhlica, Lubomir; Torrens, Marta; Vajd, Rajko; Baldacchino, Alex

    2011-06-01

    To compare regard for working with different patient groups (including substance users) among different professional groups in different health-care settings in eight European countries. A multi-centre, cross-sectional comparative study. Primary care, general psychiatry and specialist addiction services in Bulgaria, Greece, Italy, Poland, Scotland, Slovakia, Slovenia and Spain. A multi-disciplinary convenience sample of 866 professionals (physicians, psychiatrists, psychologists, nurses and social workers) from 253 services. The Medical Condition Regard Scale measured regard for working with different patient groups. Multi-factor between-subjects analysis of variance determined the factors associated with regard for each condition by country and all countries. Regard for working with alcohol (mean score alcohol: 45.35, 95% CI 44.76, 45.95) and drug users (mean score drugs: 43.67, 95% CI 42.98, 44.36) was consistently lower than for other patient groups (mean score diabetes: 50.19, 95% CI 49.71, 50.66; mean score depression: 51.34, 95% CI 50.89, 51.79) across all countries participating in the study, particularly among staff from primary care compared to general psychiatry or specialist addiction services (P<0.001). After controlling for sex of staff, profession and duration of time working in profession, treatment entry point and country remained the only statistically significant variables associated with regard for working with alcohol and drug users. Health professionals appear to ascribe lower status to working with substance users than helping other patient groups, particularly in primary care; the effect is larger in some countries than others. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

  12. Distributed Compressive CSIT Estimation and Feedback for FDD Multi-User Massive MIMO Systems

    NASA Astrophysics Data System (ADS)

    Rao, Xiongbin; Lau, Vincent K. N.

    2014-06-01

    To fully utilize the spatial multiplexing gains or array gains of massive MIMO, the channel state information must be obtained at the transmitter side (CSIT). However, conventional CSIT estimation approaches are not suitable for FDD massive MIMO systems because of the overwhelming training and feedback overhead. In this paper, we consider multi-user massive MIMO systems and deploy the compressive sensing (CS) technique to reduce the training as well as the feedback overhead in the CSIT estimation. The multi-user massive MIMO systems exhibits a hidden joint sparsity structure in the user channel matrices due to the shared local scatterers in the physical propagation environment. As such, instead of naively applying the conventional CS to the CSIT estimation, we propose a distributed compressive CSIT estimation scheme so that the compressed measurements are observed at the users locally, while the CSIT recovery is performed at the base station jointly. A joint orthogonal matching pursuit recovery algorithm is proposed to perform the CSIT recovery, with the capability of exploiting the hidden joint sparsity in the user channel matrices. We analyze the obtained CSIT quality in terms of the normalized mean absolute error, and through the closed-form expressions, we obtain simple insights into how the joint channel sparsity can be exploited to improve the CSIT recovery performance.

  13. The Self-Organized Archive: SPASE, PDS and Archive Cooperatives

    NASA Astrophysics Data System (ADS)

    King, T. A.; Hughes, J. S.; Roberts, D. A.; Walker, R. J.; Joy, S. P.

    2005-05-01

    Information systems with high quality metadata enable uses and services which often go beyond the original purpose. There are two types of metadata: annotations which are items that comment on or describe the content of a resource and identification attributes which describe the external properties of the resource itself. For example, annotations may indicate which columns are present in a table of data, whereas an identification attribute would indicate source of the table, such as the observatory, instrument, organization, and data type. When the identification attributes are collected and used as the basis of a search engine, a user can constrain on an attribute, the archive can then self-organize around the constraint, presenting the user with a particular view of the archive. In an archive cooperative where each participating data system or archive may have its own metadata standards, providing a multi-system search engine requires that individual archive metadata be mapped to a broad based standard. To explore how cooperative archives can form a larger self-organized archive we will show how the Space Physics Archive Search and Extract (SPASE) data model will allow different systems to create a cooperative and will use Planetary Data System (PDS) plus existing space physics activities as a demonstration.

  14. Impact of user influence on information multi-step communication in a micro-blog

    NASA Astrophysics Data System (ADS)

    Wu, Yue; Hu, Yong; He, Xiao-Hai; Deng, Ken

    2014-06-01

    User influence is generally considered as one of the most critical factors that affect information cascading spreading. Based on this common assumption, this paper proposes a theoretical model to examine user influence on the information multi-step communication in a micro-blog. The multi-steps of information communication are divided into first-step and non-first-step, and user influence is classified into five dimensions. Actual data from the Sina micro-blog is collected to construct the model by means of an approach based on structural equations that uses the Partial Least Squares (PLS) technique. Our experimental results indicate that the dimensions of the number of fans and their authority significantly impact the information of first-step communication. Leader rank has a positive impact on both first-step and non-first-step communication. Moreover, global centrality and weight of friends are positively related to the information non-first-step communication, but authority is found to have much less relation to it.

  15. Diverse ontogenies of reciprocal and prosocial behavior: cooperative development in Fiji and the United States.

    PubMed

    House, Bailey R

    2017-11-01

    Contingent reciprocity is an important foundation of human cooperation, but we know little about how reciprocal behavior develops across diverse societies, nor about how the development of reciprocal behavior is related to the development of prosocial behavior more broadly. Three- to 16-year-old children were presented with the opportunity to control the allocation of real food rewards in a binary-choice cooperative dilemma. Within dyads children alternated making choices across multiple trials, and reciprocal behavior emerged in three diverse populations (rural Fijian villages, and urban communities in both Fiji and the United States) by age 7-8. There was more societal variation in prosocial behavior than in reciprocal behavior, and there were more substantial differences between Fijians and Americans than between rural and urban populations. This suggests that the development of prosocial behavior is not driven entirely by the development of reciprocity, and differences in prosocial behavior across rural Fijians and urban Americans may not be due only to differences across rural and urban populations. © 2016 John Wiley & Sons Ltd.

  16. Considering Decision Variable Diversity in Multi-Objective Optimization: Application in Hydrologic Model Calibration

    NASA Astrophysics Data System (ADS)

    Sahraei, S.; Asadzadeh, M.

    2017-12-01

    Any modern multi-objective global optimization algorithm should be able to archive a well-distributed set of solutions. While the solution diversity in the objective space has been explored extensively in the literature, little attention has been given to the solution diversity in the decision space. Selection metrics such as the hypervolume contribution and crowding distance calculated in the objective space would guide the search toward solutions that are well-distributed across the objective space. In this study, the diversity of solutions in the decision-space is used as the main selection criteria beside the dominance check in multi-objective optimization. To this end, currently archived solutions are clustered in the decision space and the ones in less crowded clusters are given more chance to be selected for generating new solution. The proposed approach is first tested on benchmark mathematical test problems. Second, it is applied to a hydrologic model calibration problem with more than three objective functions. Results show that the chance of finding more sparse set of high-quality solutions increases, and therefore the analyst would receive a well-diverse set of options with maximum amount of information. Pareto Archived-Dynamically Dimensioned Search, which is an efficient and parsimonious multi-objective optimization algorithm for model calibration, is utilized in this study.

  17. Application of the multi-disciplinary thematic seminar method in two homecare cases - a comparative study.

    PubMed

    Scandurra, Isabella; Hägglund, Maria; Koch, Sabine

    2008-01-01

    A significant problem with current health information technologies is that they poorly support collaborative work of healthcare professionals, sometimes leading to a fragmentation of workflow and disruption of healthcare processes. This paper presents two homecare cases, both applying multi-disciplinary thematic seminars (MdTS) as a collaborative method for user needs elicitation and requirements specification. This study describes the MdTS application to elicit user needs from different perspectives to coincide with collaborative professions' work practices in two cases. Despite different objectives, the two cases validated that MdTS emphasized the "points of intersection" in cooperative work. Different user groups with similar, yet distinct needs reached a common understanding of the entire work process, agreed upon requirements and participated in the design of prototypes supporting cooperative work. MdTS was applicable in both exploratory and normative studies aiming to elicit the specific requirements in a cooperative environment.

  18. Interactions between carbon sequestration and shade tree diversity in a smallholder coffee cooperative in El Salvador.

    PubMed

    Richards, Meryl Breton; Méndez, V Ernesto

    2014-04-01

    Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration. We measured changes in shade-tree diversity and shade-tree carbon stocks in 14 plots of a 35-ha coffee cooperative over 9 years and analyzed relations between species diversity and carbon sequestration. Carbon sequestration was positively correlated with initial species richness of shade trees. Species diversity of shade trees did not change significantly over the study period, but carbon stocks increased due to tree growth. Our results show a potential for carbon sequestration and long-term biodiversity conservation in smallholder coffee agroforestry systems and illustrate the opportunity for synergies between biodiversity conservation and climate change mitigation. © 2013 Society for Conservation Biology.

  19. Navigating to the Future: Understanding Common Tasks in a Multi-Campus Environment in the Dramatically Changing Acquisition World

    ERIC Educational Resources Information Center

    Bock, Julia; Burgos-Mira, Rosemary

    2010-01-01

    In the context of a diverse, multi-campus university, this study discusses historical factors and recent changes in scholarly communication and the economic impact of these changes as we seek to forge stronger cooperation among our campuses. After consulting literature, the authors found that issues relating to acquisitions of multi-campus…

  20. Diverse applications of advanced man-telerobot interfaces

    NASA Technical Reports Server (NTRS)

    Mcaffee, Douglas A.

    1991-01-01

    Advancements in man-machine interfaces and control technologies used in space telerobotics and teleoperators have potential application wherever human operators need to manipulate multi-dimensional spatial relationships. Bilateral six degree-of-freedom position and force cues exchanged between the user and a complex system can broaden and improve the effectiveness of several diverse man-machine interfaces.

  1. Cooperative learning neural network output feedback control of uncertain nonlinear multi-agent systems under directed topologies

    NASA Astrophysics Data System (ADS)

    Wang, W.; Wang, D.; Peng, Z. H.

    2017-09-01

    Without assuming that the communication topologies among the neural network (NN) weights are to be undirected and the states of each agent are measurable, the cooperative learning NN output feedback control is addressed for uncertain nonlinear multi-agent systems with identical structures in strict-feedback form. By establishing directed communication topologies among NN weights to share their learned knowledge, NNs with cooperative learning laws are employed to identify the uncertainties. By designing NN-based κ-filter observers to estimate the unmeasurable states, a new cooperative learning output feedback control scheme is proposed to guarantee that the system outputs can track nonidentical reference signals with bounded tracking errors. A simulation example is given to demonstrate the effectiveness of the theoretical results.

  2. Cooperative global optimal preview tracking control of linear multi-agent systems: an internal model approach

    NASA Astrophysics Data System (ADS)

    Lu, Yanrong; Liao, Fucheng; Deng, Jiamei; Liu, Huiyang

    2017-09-01

    This paper investigates the cooperative global optimal preview tracking problem of linear multi-agent systems under the assumption that the output of a leader is a previewable periodic signal and the topology graph contains a directed spanning tree. First, a type of distributed internal model is introduced, and the cooperative preview tracking problem is converted to a global optimal regulation problem of an augmented system. Second, an optimal controller, which can guarantee the asymptotic stability of the augmented system, is obtained by means of the standard linear quadratic optimal preview control theory. Third, on the basis of proving the existence conditions of the controller, sufficient conditions are given for the original problem to be solvable, meanwhile a cooperative global optimal controller with error integral and preview compensation is derived. Finally, the validity of theoretical results is demonstrated by a numerical simulation.

  3. A software for managing chemical processes in a multi-user laboratory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Camino, Fernando E.

    Here, we report a software for logging chemical processes in a multi-user laboratory, which implements a work flow designed to reduce hazardous situations associated with the disposal of chemicals in incompatible waste containers. The software allows users to perform only those processes displayed in their list of authorized chemical processes and provides the location and label code of waste containers, among other useful information. The software has been used for six years in the cleanroom of the Center for Functional Nanomaterials at Brookhaven National Laboratory and has been an important factor for the excellent safety record of the Center.

  4. A software for managing chemical processes in a multi-user laboratory

    DOE PAGES

    Camino, Fernando E.

    2016-10-26

    Here, we report a software for logging chemical processes in a multi-user laboratory, which implements a work flow designed to reduce hazardous situations associated with the disposal of chemicals in incompatible waste containers. The software allows users to perform only those processes displayed in their list of authorized chemical processes and provides the location and label code of waste containers, among other useful information. The software has been used for six years in the cleanroom of the Center for Functional Nanomaterials at Brookhaven National Laboratory and has been an important factor for the excellent safety record of the Center.

  5. Hormonal mechanisms of cooperative behaviour

    PubMed Central

    Soares, Marta C.; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F.

    2010-01-01

    Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation. PMID:20679116

  6. Changing drug users' risk environments: peer health advocates as multi-level community change agents.

    PubMed

    Weeks, Margaret R; Convey, Mark; Dickson-Gomez, Julia; Li, Jianghong; Radda, Kim; Martinez, Maria; Robles, Eduardo

    2009-06-01

    Peer delivered, social oriented HIV prevention intervention designs are increasingly popular for addressing broader contexts of health risk beyond a focus on individual factors. Such interventions have the potential to affect multiple social levels of risk and change, including at the individual, network, and community levels, and reflect social ecological principles of interaction across social levels over time. The iterative and feedback dynamic generated by this multi-level effect increases the likelihood for sustained health improvement initiated by those trained to deliver the peer intervention. The Risk Avoidance Partnership (RAP), conducted with heroin and cocaine/crack users in Hartford, Connecticut, exemplified this intervention design and illustrated the multi-level effect on drug users' risk and harm reduction at the individual level, the social network level, and the larger community level. Implications of the RAP program for designing effective prevention programs and for analyzing long-term change to reduce HIV transmission among high-risk groups are discussed from this ecological and multi-level intervention perspective.

  7. Connecting Satellite-Based Precipitation Estimates to Users

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Bolvin, David T.; Nelkin, Eric

    2018-01-01

    Beginning in 1997, the Merged Precipitation Group at NASA Goddard has distributed gridded global precipitation products built by combining satellite and surface gauge data. This started with the Global Precipitation Climatology Project (GPCP), then the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), and recently the Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG). This 20+-year (and on-going) activity has yielded an important set of insights and lessons learned for making state-of-the-art precipitation data accessible to the diverse communities of users. Merged-data products critically depend on the input sensors and the retrieval algorithms providing accurate, reliable estimates, but it is also important to provide ancillary information that helps users determine suitability for their application. We typically provide fields of estimated random error, and recently reintroduced the quality index concept at user request. Also at user request we have added a (diagnostic) field of estimated precipitation phase. Over time, increasingly more ancillary fields have been introduced for intermediate products that give expert users insight into the detailed performance of the combination algorithm, such as individual merged microwave and microwave-calibrated infrared estimates, the contributing microwave sensor types, and the relative influence of the infrared estimate.

  8. Boosting Female Ambition: How College Diversity Impacts Graduate Degree Aspirations of Women. ASHE Annual Meeting Paper.

    ERIC Educational Resources Information Center

    Tsui, Lisa

    In seeking to expand research on the actual effects of diversity on college students, this study investigated whether various multi-cultural and feminism-related variables at the individual, peer, and institutional levels significantly influenced educational degree ambitions among women. The study used data from the Cooperative Institutional…

  9. Heterogeneous Multi-Robot Cooperation

    DTIC Science & Technology

    1994-02-01

    1992a) Maja Mataric. Designing emergent behaviors: From local interac- tions to collective intelligence. In J. Meyer, H. Roitblat , and S. Wilson, editors...1992] Lynne E. Parker. Adaptive action selection for cooperative agent teams. In Jean-Arcady Meyer, Herbert Roitblat . and Stewart Wilson. editors

  10. Leveling up: enabling diverse users to locate and effectively use unfamiliar data sets through NCAR's Research Data Archive

    NASA Astrophysics Data System (ADS)

    Peng, G. S.

    2016-12-01

    Research necessarily expands upon the volume and variety of data used in prior work. Increasingly, investigators look outside their primary areas of expertise for data to incorporate into their research. Locating and using the data that they need, which may be described in terminology from other fields of science or be encoded in unfamiliar data formats, present often insurmountable barriers for potential users. As a data provider of a diverse collection of over 600 atmospheric and oceanic data sets (DS) (http://rda.ucar.edu), we seek to reduce or remove those barriers. Serving a broadening and increasing user base with fixed and finite resources requires automation. Our software harvests metadata descriptors about the data from the data files themselves. Data curators/subject matter experts augment the machine-generated metadata as needed. Metadata powers our data search tools. Users may search for data in a myriad of ways ranging from free text queries to GCMD keywords to faceted searches capable of narrowing down selections by specific criteria. Users are offered customized lists of DSs fitting their criteria with links to DS main information pages that provide detailed information about each DS. Where appropriate, they link to the NCAR Climate Data Guide for expert guidance about strengths and weaknesses of that particular DS. Once users find the data sets they need, we provide modular lessons for common data tasks. The lessons may be data tool install guides, data recipes, blog posts, or short YouTube videos. Rather than overloading users with reams of information, we provide targeted lessons when the user is most receptive, e.g. when they want to use data in an unfamiliar format. We add new material when we discover common points of confusion. Each educational resource is tagged with DS ID numbers so that they are automatically linked with the relevant DSs. How can data providers leverage the work of other data providers? Can a common tagging scheme for data

  11. Multi-user distribution of polarization entangled photon pairs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trapateau, J.; Orieux, A.; Diamanti, E.

    We experimentally demonstrate multi-user distribution of polarization entanglement using commercial telecom wavelength division demultiplexers. The entangled photon pairs are generated from a broadband source based on spontaneous parametric down conversion in a periodically poled lithium niobate crystal using a double path setup employing a Michelson interferometer and active phase stabilisation. We test and compare demultiplexers based on various technologies and analyze the effect of their characteristics, such as losses and polarization dependence, on the quality of the distributed entanglement for three channel pairs of each demultiplexer. In all cases, we obtain a Bell inequality violation, whose value depends on themore » demultiplexer features. This demonstrates that entanglement can be distributed to at least three user pairs of a network from a single source. Additionally, we verify for the best demultiplexer that the violation is maintained when the pairs are distributed over a total channel attenuation corresponding to 20 km of optical fiber. These techniques are therefore suitable for resource-efficient practical implementations of entanglement-based quantum key distribution and other quantum communication network applications.« less

  12. Action tagging in a multi-user indoor environment for behavioural analysis purposes.

    PubMed

    Guerra, Claudio; Bianchi, Valentina; De Munari, Ilaria; Ciampolini, Paolo

    2015-01-01

    EU population is getting older, so that ICT-based solutions are expected to provide support in the challenges implied by the demographic change. At the University of Parma an AAL (Ambient Assisted Living) system, named CARDEA, has been developed. In this paper a new feature of the system is introduced, in which environmental and personal (i.e., wearable) sensors coexist, providing an accurate picture of the user's activity and needs. Environmental devices may greatly help in performing activity recognition and behavioral analysis tasks. However, in a multi-user environment, this implies the need of attributing environmental sensors outcome to a specific user, i.e., identifying the user when he performs a task detected by an environmental device. We implemented such an "action tagging" feature, based on information fusion, within the CARDEA environment, as an inexpensive, alternative solution to the problematic issue of indoor locationing.

  13. Preservice Teachers Experience Reading Response Pedagogy in a Multi-User Virtual Environment

    ERIC Educational Resources Information Center

    Dooley, Caitlin McMunn; Calandra, Brendan; Harmon, Stephen

    2014-01-01

    This qualitative case study describes how 18 preservice teachers learned to nurture literary meaning-making via activities based on Louise Rosenblatt's Reader Response Theory within a multi-user virtual environment (MUVE). Participants re-created and responded to scenes from selected works of children's literature in Second Life as a way to…

  14. Interference Information Based Power Control for Cognitive Radio with Multi-Hop Cooperative Sensing

    NASA Astrophysics Data System (ADS)

    Yu, Youngjin; Murata, Hidekazu; Yamamoto, Koji; Yoshida, Susumu

    Reliable detection of other radio systems is crucial for systems that share the same frequency band. In wireless communication channels, there is uncertainty in the received signal level due to multipath fading and shadowing. Cooperative sensing techniques in which radio stations share their sensing information can improve the detection probability of other systems. In this paper, a new cooperative sensing scheme that reduces the false detection probability while maintaining the outage probability of other systems is investigated. In the proposed system, sensing information is collected using multi-hop transmission from all sensing stations that detect other systems, and transmission decisions are based on the received sensing information. The proposed system also controls the transmit power based on the received CINRs from the sensing stations. Simulation results reveal that the proposed system can reduce the outage probability of other systems, or improve its link success probability.

  15. The right view from the wrong location: depth perception in stereoscopic multi-user virtual environments.

    PubMed

    Pollock, Brice; Burton, Melissa; Kelly, Jonathan W; Gilbert, Stephen; Winer, Eliot

    2012-04-01

    Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.

  16. Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage

    PubMed Central

    Wang, Shangping; Zhang, Xiaoxue; Zhang, Yaling

    2016-01-01

    Cipher-policy attribute-based encryption (CP-ABE) focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH) assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA). And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA) in the random oracle model. PMID:27898703

  17. Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage.

    PubMed

    Wang, Shangping; Zhang, Xiaoxue; Zhang, Yaling

    2016-01-01

    Cipher-policy attribute-based encryption (CP-ABE) focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH) assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA). And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA) in the random oracle model.

  18. Silviculture in cooperation with hunters: The Kinzua Quality Deer Cooperative

    Treesearch

    Scott Reitz; Andrea Hille; Susan Stout

    2004-01-01

    The long history of deer overabundance in Pennsylvania is associated with very high reforestation costs and substantial threats to diversity and sustainability. In response to this legacy, several landowners and agency personnel formed the Kinzua Quality Deer Cooperative (KQDC) in partnership with the Sand County Foundation. This Cooperative focuses on about 74,000...

  19. Diverse Planning for UAV Control and Remote Sensing

    PubMed Central

    Tožička, Jan; Komenda, Antonín

    2016-01-01

    Unmanned aerial vehicles (UAVs) are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands) to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well) together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs. PMID:28009831

  20. Diverse Planning for UAV Control and Remote Sensing.

    PubMed

    Tožička, Jan; Komenda, Antonín

    2016-12-21

    Unmanned aerial vehicles (UAVs) are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands) to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well) together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs.

  1. Orbitofrontal and caudate volumes in cannabis users: a multi-site mega-analysis comparing dependent versus non-dependent users.

    PubMed

    Chye, Yann; Solowij, Nadia; Suo, Chao; Batalla, Albert; Cousijn, Janna; Goudriaan, Anna E; Martin-Santos, Rocio; Whittle, Sarah; Lorenzetti, Valentina; Yücel, Murat

    2017-07-01

    Cannabis (CB) use and dependence are associated with regionally specific alterations to brain circuitry and substantial psychosocial impairment. The objective of this study was to investigate the association between CB use and dependence, and the volumes of brain regions critically involved in goal-directed learning and behaviour-the orbitofrontal cortex (OFC) and caudate. In the largest multi-site structural imaging study of CB users vs healthy controls (HC), 140 CB users and 121 HC were recruited from four research sites. Group differences in OFC and caudate volumes were investigated between HC and CB users and between 70 dependent (CB-dep) and 50 non-dependent (CB-nondep) users. The relationship between quantity of CB use and age of onset of use and caudate and OFC volumes was explored. CB users (consisting of CB-dep and CB-nondep) did not significantly differ from HC in OFC or caudate volume. CB-dep compared to CB-nondep users exhibited significantly smaller volume in the medial and the lateral OFC. Lateral OFC volume was particularly smaller in CB-dep females, and reduced volume in the CB-dep group was associated with higher monthly cannabis dosage. Smaller medial OFC volume may be driven by CB dependence-related mechanisms, while smaller lateral OFC volume may be due to ongoing exposure to cannabinoid compounds. The results highlight a distinction between cannabis use and dependence and warrant examination of gender-specific effects in studies of CB dependence.

  2. A joint swarm intelligence algorithm for multi-user detection in MIMO-OFDM system

    NASA Astrophysics Data System (ADS)

    Hu, Fengye; Du, Dakun; Zhang, Peng; Wang, Zhijun

    2014-11-01

    In the multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) system, traditional multi-user detection (MUD) algorithms that usually used to suppress multiple access interference are difficult to balance system detection performance and the complexity of the algorithm. To solve this problem, this paper proposes a joint swarm intelligence algorithm called Ant Colony and Particle Swarm Optimisation (AC-PSO) by integrating particle swarm optimisation (PSO) and ant colony optimisation (ACO) algorithms. According to simulation results, it has been shown that, with low computational complexity, the MUD for the MIMO-OFDM system based on AC-PSO algorithm gains comparable MUD performance with maximum likelihood algorithm. Thus, the proposed AC-PSO algorithm provides a satisfactory trade-off between computational complexity and detection performance.

  3. Civic Participation among Seventh-Grade Social Studies Students in Multi-User Virtual Environments

    ERIC Educational Resources Information Center

    Zieger, Laura; Farber, Matthew

    2012-01-01

    Technological advances on the Internet now enable students to develop participation skills in virtual worlds. Similar to controlling a character in a video game, multi-user virtual environments, or MUVEs, allow participants to interact with others in synchronous, online settings. The authors of this study created a link between MUVEs and…

  4. Advancing MEMS Technology Usage through the MUMPS (Multi-User MEMS Processes) Program

    NASA Technical Reports Server (NTRS)

    Koester, D. A.; Markus, K. W.; Dhuler, V.; Mahadevan, R.; Cowen, A.

    1995-01-01

    In order to help provide access to advanced micro-electro-mechanical systems (MEMS) technologies and lower the barriers for both industry and academia, the Microelectronic Center of North Carolina (MCNC) and ARPA have developed a program which provides users with access to both MEMS processes and advanced electronic integration techniques. The four distinct aspects of this program, the multi-user MEMS processes (MUMP's), the consolidated micro-mechanical element library, smart MEMS, and the MEMS technology network are described in this paper. MUMP's is an ARPA-supported program created to provide inexpensive access to MEMS technology in a multi-user environment. It is both a proof-of-concept and educational tool that aids in the development of MEMS in the domestic community. MUMP's technologies currently include a 3-layer poly-silicon surface micromachining process and LIGA (lithography, electroforming, and injection molding) processes that provide reasonable design flexibility within set guidelines. The consolidated micromechanical element library (CaMEL) is a library of active and passive MEMS structures that can be downloaded by the MEMS community via the internet. Smart MEMS is the development of advanced electronics integration techniques for MEMS through the application of flip chip technology. The MEMS technology network (TechNet) is a menu of standard substrates and MEMS fabrication processes that can be purchased and combined to create unique process flows. TechNet provides the MEMS community greater flexibility and enhanced technology accessibility.

  5. A Robotic Coach Architecture for Elder Care (ROCARE) Based on Multi-User Engagement Models.

    PubMed

    Fan, Jing; Bian, Dayi; Zheng, Zhi; Beuscher, Linda; Newhouse, Paul A; Mion, Lorraine C; Sarkar, Nilanjan

    2017-08-01

    The aging population with its concomitant medical conditions, physical and cognitive impairments, at a time of strained resources, establishes the urgent need to explore advanced technologies that may enhance function and quality of life. Recently, robotic technology, especially socially assistive robotics has been investigated to address the physical, cognitive, and social needs of older adults. Most system to date have predominantly focused on one-on-one human robot interaction (HRI). In this paper, we present a multi-user engagement-based robotic coach system architecture (ROCARE). ROCARE is capable of administering both one-on-one and multi-user HRI, providing implicit and explicit channels of communication, and individualized activity management for long-term engagement. Two preliminary feasibility studies, a one-on-one interaction and a triadic interaction with two humans and a robot, were conducted and the results indicated potential usefulness and acceptance by older adults, with and without cognitive impairment.

  6. Prescription opioid use, misuse, and diversion among street drug users in New York City.

    PubMed

    Davis, W Rees; Johnson, Bruce D

    2008-01-01

    The use of heroin, cocaine, and other drugs is well researched in New York City, but prescription opioids (POs) have been overlooked. This study documents patterns of PO use, misuse, and diversion among street drug users, and begins to indicate how drug culture practices interact with the legitimate therapeutic goals of PO prescriptions (e.g. pain management). Staff completed interviews inquiring about the reasons for use of POs and illicit drugs with 586 street drug users. Ethnographers wrote extensive field notes about subjects' complex patterns of PO use. Methadone was used (71.9%) and sold (64.7%) at a higher level than OxyContin, Vicodin, and Percocet, used by between 34% and 38% of the users and sold by between 28% and 41% of the sellers. Recent PO use is associated with the recency of using heroin and cocaine (p<.001). Half of the heroin/cocaine sellers sold POs, and one quarter of the PO sellers only sold POs. Subjects were classified into four groups by whether they diverted POs or used POs to relieve pain or withdrawal rather than for euphoria. This classification was associated with frequency of PO use, whether POs were obtained from doctors/pharmacies or from drug dealers and family members, and those mostly likely to use POs for pain and withdrawal. POs are an important component of street drug users' drug-taking regimes, especially those who are Physically Ill Chemical Abusers (PICA). Future research is needed to model PO use, misuse, and diversion among this population.

  7. Cooperation of return-to-work professionals: the challenges of multi-actor work disability management.

    PubMed

    Liukko, Jyri; Kuuva, Niina

    2017-07-01

    This article explores which concrete factors hinder or facilitate the cooperation of return-to-work (RTW) professionals in a complex system of multiple stakeholders. The empirical material consists of in-depth interviews with 24 RTW professionals from various organizations involved in work disability management in Finland. The interviews were analyzed using thematic content analysis. The study revealed several kinds of challenges in the cooperation of the professionals. These were related to two partly interrelated themes: communication and distribution of responsibility. The most difficult problems were connected to the cooperation between public employment offices and other stakeholders. However, the study distinguished notable regional differences depending primarily on the scale of the local network. The main areas of improvement proposed by the interviewees were related to better networking of case managers and expansion of expertise. The article argues for the importance of systematic networking and stresses the role of public employment services in the multi-actor management of work disabilities. The article contributes to existing work disability case management models by suggesting the employment administration system as an important component in addition to health care, workplace and insurance systems. The study also highlights the need for expansion of expertise in the field. Implications for Rehabilitation Cooperation between RTW professionals in public employment offices and other organizations involved in work disability management was considered inadequate. In order to improve the cooperation of RTW professionals, the stakeholders need to create more systematic ways of communication and networking with professionals in other organizations. There is a need to expand the expertise in work disability management and rehabilitation, partly by increasing the role of other professionals than physicians.

  8. EPANET Multi-Species Extension Software and User's Manual ...

    EPA Pesticide Factsheets

    Software and User's Manual EPANET is used in homeland security research to model contamination threats to water systems. Historically, EPANET has been limited to tracking the dynamics of a single chemical transported through a network of pipes and storage tanks, such as a fluoride used in a tracer study or free chlorine used in a disinfection decay study. Recently, the NHSRC released a new extension to EPANET called EPANET-MSX (Multi-Species eXtension) that allows for the consideration of multiple interacting species in the bulk flow and on the pipe walls. This capability has been incorporated into both a stand-alone executable program as well as a toolkit library of functions that programmers can use to build customized applications.

  9. Multi-User Spaceport Update News Conference

    NASA Image and Video Library

    2014-01-23

    CAPE CANAVERAL, Fla. – Larry Price, Lockheed Martin Space Systems deputy program manager for NASA's Orion spacecraft, joins Sierra Nevada Corporation, or SNC, Space Systems, as the company announces the steps it will take to prepare for a November 2016 orbital flight of its Dream Chaser spacecraft from Florida’s Space Coast. The steps are considered substantial for SNC and important to plans by NASA and Space Florida for Kennedy Space Center’s transformation into a multi-user spaceport for both commercial and government customers. SNC said it plans to work with United Launch Alliance, or ULA, to launch the Dream Chaser spacecraft into orbit atop an Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station intends to land the winged spacecraft at Kennedy’s 3.5-mile long runway at the Shuttle Landing Facility lease office space at Exploration Park, right outside Kennedy’s gates and process the spacecraft in the high bay of the Operations and Checkout Building at Kennedy, with Lockheed Martin performing the work. Photo credit: NASA/Kim Shiflett

  10. Multi-User Spaceport Update News Conference

    NASA Image and Video Library

    2014-01-23

    CAPE CANAVERAL, Fla. – Frank DiBello, right, president and CEO of Space Florida, joins Sierra Nevada Corporation, or SNC, Space Systems, as the company announces the steps it will take to prepare for a November 2016 orbital flight of its Dream Chaser spacecraft from Florida’s Space Coast. The steps are considered substantial for SNC and important to plans by NASA and Space Florida for Kennedy Space Center’s transformation into a multi-user spaceport for both commercial and government customers. SNC said it plans to work with United Launch Alliance, or ULA, to launch the Dream Chaser spacecraft into orbit atop an Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station intends to land the winged spacecraft at Kennedy’s 3.5-mile long runway at the Shuttle Landing Facility lease office space at Exploration Park, right outside Kennedy’s gates and process the spacecraft in the high bay of the Operations and Checkout Building at Kennedy, with Lockheed Martin performing the work. Photo credit: NASA/Kim Shiflett

  11. Managing Cognitive Load in Educational Multi-User Virtual Environments: Reflection on Design Practice

    ERIC Educational Resources Information Center

    Nelson, Brian C.; Erlandson, Benjamin E.

    2008-01-01

    In this paper, we explore how the application of multimedia design principles may inform the development of educational multi-user virtual environments (MUVEs). We look at design principles that have been shown to help learners manage cognitive load within multimedia environments and conduct a conjectural analysis of the extent to which such…

  12. Inspiring Equal Contribution and Opportunity in a 3D Multi-User Virtual Environment: Bringing Together Men Gamers and Women Non-Gamers in Second Life[R

    ERIC Educational Resources Information Center

    deNoyelles, Aimee; Seo, Kay Kyeong-Ju

    2012-01-01

    A 3D multi-user virtual environment holds promise to support and enhance student online learning communities due to its ability to promote global synchronous interaction and collaboration, rich multisensory experience and expression, and elaborate design capabilities. Second Life[R], a multi-user virtual environment intended for adult users 18 and…

  13. Supporting Shared Resource Usage for a Diverse User Community: the OSG Experience and Lessons Learned

    NASA Astrophysics Data System (ADS)

    Garzoglio, Gabriele; Levshina, Tanya; Rynge, Mats; Sehgal, Chander; Slyz, Marko

    2012-12-01

    The Open Science Grid (OSG) supports a diverse community of new and existing users in adopting and making effective use of the Distributed High Throughput Computing (DHTC) model. The LHC user community has deep local support within the experiments. For other smaller communities and individual users the OSG provides consulting and technical services through the User Support area. We describe these sometimes successful and sometimes not so successful experiences and analyze lessons learned that are helping us improve our services. The services offered include forums to enable shared learning and mutual support, tutorials and documentation for new technology, and troubleshooting of problematic or systemic failure modes. For new communities and users, we bootstrap their use of the distributed high throughput computing technologies and resources available on the OSG by following a phased approach. We first adapt the application and run a small production campaign on a subset of “friendly” sites. Only then do we move the user to run full production campaigns across the many remote sites on the OSG, adding to the community resources up to hundreds of thousands of CPU hours per day. This scaling up generates new challenges - like no determinism in the time to job completion, and diverse errors due to the heterogeneity of the configurations and environments - so some attention is needed to get good results. We cover recent experiences with image simulation for the Large Synoptic Survey Telescope (LSST), small-file large volume data movement for the Dark Energy Survey (DES), civil engineering simulation with the Network for Earthquake Engineering Simulation (NEES), and accelerator modeling with the Electron Ion Collider group at BNL. We will categorize and analyze the use cases and describe how our processes are evolving based on lessons learned.

  14. Advanced graphical user interface for multi-physics simulations using AMST

    NASA Astrophysics Data System (ADS)

    Hoffmann, Florian; Vogel, Frank

    2017-07-01

    Numerical modelling of particulate matter has gained much popularity in recent decades. Advanced Multi-physics Simulation Technology (AMST) is a state-of-the-art three dimensional numerical modelling technique combining the eX-tended Discrete Element Method (XDEM) with Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) [1]. One major limitation of this code is the lack of a graphical user interface (GUI) meaning that all pre-processing has to be made directly in a HDF5-file. This contribution presents the first graphical pre-processor developed for AMST.

  15. Memorandum : feasibility assessment, bicycle or bicycle/pedestrian (multi-user) facility at Appomattox Court house NHP

    DOT National Transportation Integrated Search

    2007-10-12

    This memorandum provides a preliminary feasibility assessment for a bicycle or combined bicycle/pedestrian (i.e., multi-user) facility at Appomattox Court House National Historical Park (NHP). This assessment is based on discussions with park staff, ...

  16. Helping solve Georgia's water problems - the USGS Cooperative Water Program

    USGS Publications Warehouse

    Clarke, John S.

    2006-01-01

    The U.S. Geological Survey (USGS) addresses a wide variety of water issues in the State of Georgia through the Cooperative Water Program (CWP). As the primary Federal science agency for water-resource information, the USGS monitors the quantity and quality of water in the Nation's rivers and aquifers, assesses the sources and fate of contaminants in aquatic systems, collects and analyzes data on aquatic ecosystems, develops tools to improve the application of hydrologic information, and ensures that its information and tools are available to all potential users. This broad, diverse mission cannot be accomplished effectively without the contributions of the CWP.

  17. Controlling the transmitted information of a multi-photon interacting with a single-Cooper pair box

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kadry, Heba, E-mail: hkadry1@yahoo.com; Abdel-Aty, Abdel-Haleem, E-mail: hkadry1@yahoo.com; Zakaria, Nordin, E-mail: hkadry1@yahoo.com

    2014-10-24

    We study a model of a multi-photon interaction of a single Cooper pair box with a cavity field. The exchange of the information using this system is studied. We quantify the fidelity of the transmitted information. The effect of the system parameters (detuning parameter, field photons, state density and mean photon number) in the fidelity of the transmitted information is investigated. We found that the fidelity of the transmitted information can be controlled using the system parameters.

  18. MultiMetEval: Comparative and Multi-Objective Analysis of Genome-Scale Metabolic Models

    PubMed Central

    Gevorgyan, Albert; Kierzek, Andrzej M.; Breitling, Rainer; Takano, Eriko

    2012-01-01

    Comparative metabolic modelling is emerging as a novel field, supported by the development of reliable and standardized approaches for constructing genome-scale metabolic models in high throughput. New software solutions are needed to allow efficient comparative analysis of multiple models in the context of multiple cellular objectives. Here, we present the user-friendly software framework Multi-Metabolic Evaluator (MultiMetEval), built upon SurreyFBA, which allows the user to compose collections of metabolic models that together can be subjected to flux balance analysis. Additionally, MultiMetEval implements functionalities for multi-objective analysis by calculating the Pareto front between two cellular objectives. Using a previously generated dataset of 38 actinobacterial genome-scale metabolic models, we show how these approaches can lead to exciting novel insights. Firstly, after incorporating several pathways for the biosynthesis of natural products into each of these models, comparative flux balance analysis predicted that species like Streptomyces that harbour the highest diversity of secondary metabolite biosynthetic gene clusters in their genomes do not necessarily have the metabolic network topology most suitable for compound overproduction. Secondly, multi-objective analysis of biomass production and natural product biosynthesis in these actinobacteria shows that the well-studied occurrence of discrete metabolic switches during the change of cellular objectives is inherent to their metabolic network architecture. Comparative and multi-objective modelling can lead to insights that could not be obtained by normal flux balance analyses. MultiMetEval provides a powerful platform that makes these analyses straightforward for biologists. Sources and binaries of MultiMetEval are freely available from https://github.com/PiotrZakrzewski/MetEval/downloads. PMID:23272111

  19. Cooperative institutions for sustainable common pool resource management: Application to groundwater

    NASA Astrophysics Data System (ADS)

    Madani, Kaveh; Dinar, Ariel

    2012-09-01

    Beneficiaries of common pool resources (CPRs) may select available noncooperative and regulatory exogenous institutions for managing the resource, as well as cooperative management institutions. All these institutions may increase the long-term gains, prolong the life of the resource, and help to escape the tragedy of the commons trap. Cooperative game theory approaches can serve as the backbone of cooperative CPR management institutions. This paper formulates and applies several commonly used cooperative game theoretic solution concepts, namely, the core, Nash-Harsanyi, Shapley, and nucleolus. Through a numerical groundwater example, we show how CPR users can share the gains obtained from cooperation in a fair and efficient manner based on these cooperative solution concepts (management institutions). Although, based on their fairness rationales, various cooperative management institutions may suggest different allocations that are potentially acceptable to the users, these allocation solutions may not be stable as some users may find them unfair. This paper discusses how different methods, such as application of the plurality rule and power index, stability index, and propensity to disrupt concepts, can help identify the most stable and likely solutions for enforcing cooperation among the CPR beneficiaries. Furthermore, how the noncooperative managerial characteristics of the CPR users can affect the stability and acceptability of the different cooperative CPR management institutions is discussed, providing valuable policy insights for cooperative CPR management at community levels.

  20. A Robotic Coach Architecture for Elder Care (ROCARE) Based on Multi-user Engagement Models

    PubMed Central

    Fan, Jing; Bian, Dayi; Zheng, Zhi; Beuscher, Linda; Newhouse, Paul A.; Mion, Lorraine C.; Sarkar, Nilanjan

    2017-01-01

    The aging population with its concomitant medical conditions, physical and cognitive impairments, at a time of strained resources, establishes the urgent need to explore advanced technologies that may enhance function and quality of life. Recently, robotic technology, especially socially assistive robotics has been investigated to address the physical, cognitive, and social needs of older adults. Most system to date have predominantly focused on one-on-one human robot interaction (HRI). In this paper, we present a multi-user engagement-based robotic coach system architecture (ROCARE). ROCARE is capable of administering both one-on-one and multi-user HRI, providing implicit and explicit channels of communication, and individualized activity management for long-term engagement. Two preliminary feasibility studies, a one-on-one interaction and a triadic interaction with two humans and a robot, were conducted and the results indicated potential usefulness and acceptance by older adults, with and without cognitive impairment. PMID:28113672

  1. Global cooperation among diverse organizations to reduce illegal fishing in the Southern Ocean.

    PubMed

    Osterblom, Henrik; Bodin, Orjan

    2012-08-01

    Illegal, unreported, and unregulated (IUU) fishing is prevalent globally and has detrimental effects on commercial fish stocks and nontarget species. Effective monitoring and enforcement aimed at reducing the level of IUU fishing in extensive, remote ocean fisheries requires international collaboration. Changes in trade and vessel activities further complicate enforcement. We used a web-based survey of governmental and nongovernmental organizations engaged in reducing IUU fishing in the Southern Ocean to collect information on interorganizational collaborations. We used social-network analyses to examine the nature of collaborations among the identified 117 organizations engaged in reducing IUU fishing. International collaboration improved the ability to control and manage harvest of commercially important toothfish (Dissostichus spp.) stocks and reduced bycatch of albatrosses (Diomedeidae) and petrels (Procellariidae) in longlines of IUU fishing vessels. The diverse group of surveyed organizations cooperated frequently, thereby making a wide range of resources available for improved detection of suspected IUU vessels and trade flows, cooperation aimed at prosecuting suspected offenders or developing new policy measures. Our results suggest the importance of a central agency for coordination and for maintaining commonly agreed-upon protocols for communication that facilities collaboration. Despite their differences, the surveyed organizations have developed common perceptions about key problems associated with IUU fishing. This has likely contributed to a sustained willingness to invest in collaborations. Our results show that successful international environmental governance can be accomplished through interorganizational collaborations. Such cooperation requires trust, continuous funding, and incentives for actors to participate. ©2012 Society for Conservation Biology.

  2. Identifying Service Delivery Strategies for Ethnically Diverse Users of a Wildland-Urban Recreation Site

    Treesearch

    John M. Baas

    1992-01-01

    Service delivery has become an increasingly important part of managing public lands for recreation. The range of preferences held by ethnically diverse users of recreation sites may warrant the development of more than one service delivery strategy. Two questions were examined: (1) Are there differences in site perceptions that can be identified on the basis on...

  3. Harsh environments and the evolution of multi-player cooperation.

    PubMed

    De Jaegher, Kris

    2017-02-01

    The game-theoretic model in this paper provides micro-foundations for the effect a harsher environment on the probability of cooperation among multiple players. The harshness of the environment is alternatively measured by the degree of complementarity between the players' cooperative efforts in producing a public good, and by the number of attacks on an existing public good that the players can collectively defend, where it is shown that these two measures of the degree of adversity facing the players operate in a similar fashion. We show that the effect of the degree of adversity on the probability of cooperation is monotonous, and has an opposite sign for smaller and for larger cooperation costs. For intermediate cooperation costs, we show that the effect of a harsher environment on the probability of cooperation is hill-shaped. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Multi-diversity combining and selection for relay-assisted mixed RF/FSO system

    NASA Astrophysics Data System (ADS)

    Chen, Li; Wang, Weidong

    2017-12-01

    We propose and analyze multi-diversity combining and selection to enhance the performance of relay-assisted mixed radio frequency/free-space optics (RF/FSO) system. We focus on a practical scenario for cellular network where a single-antenna source is communicating to a multi-apertures destination through a relay equipped with multiple receive antennas and multiple transmit apertures. The RF single input multiple output (SIMO) links employ either maximal-ratio combining (MRC) or receive antenna selection (RAS), and the FSO multiple input multiple output (MIMO) links adopt either repetition coding (RC) or transmit laser selection (TLS). The performance is evaluated via an outage probability analysis over Rayleigh fading RF links and Gamma-Gamma atmospheric turbulence FSO links with pointing errors where channel state information (CSI) assisted amplify-and-forward (AF) scheme is considered. Asymptotic closed-form expressions at high signal-to-noise ratio (SNR) are also derived. Coding gain and diversity order for different combining and selection schemes are further discussed. Numerical results are provided to verify and illustrate the analytical results.

  5. Multi-EMR Structured Data Entry Form: User-Acceptance Testing of a Prototype.

    PubMed

    Zavar, Abbas; Keshavjee, Karim

    2017-01-01

    Capturing standardized data from multiple EMRs at the point of care is highly desirable for a variety of uses, including quality improvement programs, multi-centered clinical trials and clinical decision support. In this paper, we describe the design, development and user acceptance testing of a prototype web-based form (the Form) that can integrate with multiple EMRs. We used the validated UTAUT questionnaire to assess the likelihood of uptake of the Form into clinical practice. The Form was found to be easy to use, elicits low anxiety, supports productivity and is perceived to have good support. Users would benefit from training and from better social signaling about the importance of using the Form in their practice. Making the Form more fun and interesting could help increase uptake.

  6. A multi-user real time inventorying system for radioactive materials: a networking approach.

    PubMed

    Mehta, S; Bandyopadhyay, D; Hoory, S

    1998-01-01

    A computerized system for radioisotope management and real time inventory coordinated across a large organization is reported. It handles hundreds of individual users and their separate inventory records. Use of highly efficient computer network and database technologies makes it possible to accept, maintain, and furnish all records related to receipt, usage, and disposal of the radioactive materials for the users separately and collectively. The system's central processor is an HP-9000/800 G60 RISC server and users from across the organization use their personal computers to login to this server using the TCP/IP networking protocol, which makes distributed use of the system possible. Radioisotope decay is automatically calculated by the program, so that it can make the up-to-date radioisotope inventory data of an entire institution available immediately. The system is specifically designed to allow use by large numbers of users (about 300) and accommodates high volumes of data input and retrieval without compromising simplicity and accuracy. Overall, it is an example of a true multi-user, on-line, relational database information system that makes the functioning of a radiation safety department efficient.

  7. Socialisation for Learning at a Distance in a 3-D Multi-User Virtual Environment

    ERIC Educational Resources Information Center

    Edirisingha, Palitha; Nie, Ming; Pluciennik, Mark; Young, Ruth

    2009-01-01

    This paper reports findings of a pilot study that examined the pedagogical potential of "Second Life" (SL), a popular three-dimensional multi-user virtual environment (3-D MUVE) developed by the Linden Lab. The study is part of a 1-year research and development project titled "Modelling of Secondlife Environments"…

  8. Marky: a tool supporting annotation consistency in multi-user and iterative document annotation projects.

    PubMed

    Pérez-Pérez, Martín; Glez-Peña, Daniel; Fdez-Riverola, Florentino; Lourenço, Anália

    2015-02-01

    Document annotation is a key task in the development of Text Mining methods and applications. High quality annotated corpora are invaluable, but their preparation requires a considerable amount of resources and time. Although the existing annotation tools offer good user interaction interfaces to domain experts, project management and quality control abilities are still limited. Therefore, the current work introduces Marky, a new Web-based document annotation tool equipped to manage multi-user and iterative projects, and to evaluate annotation quality throughout the project life cycle. At the core, Marky is a Web application based on the open source CakePHP framework. User interface relies on HTML5 and CSS3 technologies. Rangy library assists in browser-independent implementation of common DOM range and selection tasks, and Ajax and JQuery technologies are used to enhance user-system interaction. Marky grants solid management of inter- and intra-annotator work. Most notably, its annotation tracking system supports systematic and on-demand agreement analysis and annotation amendment. Each annotator may work over documents as usual, but all the annotations made are saved by the tracking system and may be further compared. So, the project administrator is able to evaluate annotation consistency among annotators and across rounds of annotation, while annotators are able to reject or amend subsets of annotations made in previous rounds. As a side effect, the tracking system minimises resource and time consumption. Marky is a novel environment for managing multi-user and iterative document annotation projects. Compared to other tools, Marky offers a similar visually intuitive annotation experience while providing unique means to minimise annotation effort and enforce annotation quality, and therefore corpus consistency. Marky is freely available for non-commercial use at http://sing.ei.uvigo.es/marky. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Cooperative Solutions in Multi-Person Quadratic Decision Problems: Finite-Horizon and State-Feedback Cost-Cumulant Control Paradigm

    DTIC Science & Technology

    2007-01-01

    CONTRACT NUMBER Problems: Finite -Horizon and State-Feedback Cost-Cumulant Control Paradigm (PREPRINT) 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...cooperative cost-cumulant control regime for the class of multi-person single-objective decision problems characterized by quadratic random costs and... finite -horizon integral quadratic cost associated with a linear stochastic system . Since this problem formation is parameterized by the number of cost

  10. ISS Expedition 18 Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA) in Node 2

    NASA Image and Video Library

    2008-12-06

    ISS018-E-010645 (6 Dec. 2008) --- Astronaut Michael Fincke, Expedition 18 commander, works on the Multi-User Droplet Combustion Apparatus (MDCA) Chamber Insert Assembly (CIA) in the Harmony node of the International Space Station.

  11. McMAC: Towards a MAC Protocol with Multi-Constrained QoS Provisioning for Diverse Traffic in Wireless Body Area Networks

    PubMed Central

    Monowar, Muhammad Mostafa; Hassan, Mohammad Mehedi; Bajaber, Fuad; Al-Hussein, Musaed; Alamri, Atif

    2012-01-01

    The emergence of heterogeneous applications with diverse requirements for resource-constrained Wireless Body Area Networks (WBANs) poses significant challenges for provisioning Quality of Service (QoS) with multi-constraints (delay and reliability) while preserving energy efficiency. To address such challenges, this paper proposes McMAC, a MAC protocol with multi-constrained QoS provisioning for diverse traffic classes in WBANs. McMAC classifies traffic based on their multi-constrained QoS demands and introduces a novel superframe structure based on the “transmit-whenever-appropriate” principle, which allows diverse periods for diverse traffic classes according to their respective QoS requirements. Furthermore, a novel emergency packet handling mechanism is proposed to ensure packet delivery with the least possible delay and the highest reliability. McMAC is also modeled analytically, and extensive simulations were performed to evaluate its performance. The results reveal that McMAC achieves the desired delay and reliability guarantee according to the requirements of a particular traffic class while achieving energy efficiency. PMID:23202224

  12. Multi-agent Water Resources Management

    NASA Astrophysics Data System (ADS)

    Castelletti, A.; Giuliani, M.

    2011-12-01

    Increasing environmental awareness and emerging trends such as water trading, energy market, deregulation and democratization of water-related services are challenging integrated water resources planning and management worldwide. The traditional approach to water management design based on sector-by-sector optimization has to be reshaped to account for multiple interrelated decision-makers and many stakeholders with increasing decision power. Centralized management, though interesting from a conceptual point of view, is unfeasible in most of the modern social and institutional contexts, and often economically inefficient. Coordinated management, where different actors interact within a full open trust exchange paradigm under some institutional supervision is a promising alternative to the ideal centralized solution and the actual uncoordinated practices. This is a significant issue in most of the Southern Alps regulated lakes, where upstream hydropower reservoirs maximize their benefit independently form downstream users; it becomes even more relevant in the case of transboundary systems, where water management upstream affects water availability downstream (e.g. the River Zambesi flowing through Zambia, Zimbabwe and Mozambique or the Red River flowing from South-Western China through Northern Vietnam. In this study we apply Multi-Agent Systems (MAS) theory to design an optimal management in a decentralized way, considering a set of multiple autonomous agents acting in the same environment and taking into account the pay-off of individual water users, which are inherently distributed along the river and need to coordinate to jointly reach their objectives. In this way each real-world actor, representing the decision-making entity (e.g. the operator of a reservoir or a diversion dam) can be represented one-to-one by a computer agent, defined as a computer system that is situated in some environment and that is capable of autonomous action in this environment in

  13. Supporting Multi-view User Ontology to Understand Company Value Chains

    NASA Astrophysics Data System (ADS)

    Zuo, Landong; Salvadores, Manuel; Imtiaz, Sm Hazzaz; Darlington, John; Gibbins, Nicholas; Shadbolt, Nigel R.; Dobree, James

    The objective of the Market Blended Insight (MBI) project is to develop web based techniques to improve the performance of UK Business to Business (B2B) marketing activities. The analysis of company value chains is a fundamental task within MBI because it is an important model for understanding the market place and the company interactions within it. The project has aggregated rich data profiles of 3.7 million companies that form the active UK business community. The profiles are augmented by Web extractions from heterogeneous sources to provide unparalleled business insight. Advances by the Semantic Web in knowledge representation and logic reasoning allow flexible integration of data from heterogeneous sources, transformation between different representations and reasoning about their meaning. The MBI project has identified that the market insight and analysis interests of different types of users are difficult to maintain using a single domain ontology. Therefore, the project has developed a technique to undertake a plurality of analyses of value chains by deploying a distributed multi-view ontology to capture different user views over the classification of companies and their various relationships.

  14. Cooperative vehicle routing problem: an opportunity for cost saving

    NASA Astrophysics Data System (ADS)

    Zibaei, Sedighe; Hafezalkotob, Ashkan; Ghashami, Seyed Sajad

    2016-09-01

    In this paper, a novel methodology is proposed to solve a cooperative multi-depot vehicle routing problem. We establish a mathematical model for multi-owner VRP in which each owner (i.e. player) manages single or multiple depots. The basic idea consists of offering an option that owners cooperatively manage the VRP to save their costs. We present cooperative game theory techniques for cost saving allocations which are obtained from various coalitions of owners. The methodology is illustrated with a numerical example in which different coalitions of the players are evaluated along with the results of cooperation and cost saving allocation methods.

  15. Single-user MIMO versus multi-user MIMO in distributed antenna systems with limited feedback

    NASA Astrophysics Data System (ADS)

    Schwarz, Stefan; Heath, Robert W.; Rupp, Markus

    2013-12-01

    This article investigates the performance of cellular networks employing distributed antennas in addition to the central antennas of the base station. Distributed antennas are likely to be implemented using remote radio units, which is enabled by a low latency and high bandwidth dedicated link to the base station. This facilitates coherent transmission from potentially all available antennas at the same time. Such distributed antenna system (DAS) is an effective way to deal with path loss and large-scale fading in cellular systems. DAS can apply precoding across multiple transmission points to implement single-user MIMO (SU-MIMO) and multi-user MIMO (MU-MIMO) transmission. The throughput performance of various SU-MIMO and MU-MIMO transmission strategies is investigated in this article, employing a Long-Term evolution (LTE) standard compliant simulation framework. The previously theoretically established cell-capacity improvement of MU-MIMO in comparison to SU-MIMO in DASs is confirmed under the practical constraints imposed by the LTE standard, even under the assumption of imperfect channel state information (CSI) at the base station. Because practical systems will use quantized feedback, the performance of different CSI feedback algorithms for DASs is investigated. It is shown that significant gains in the CSI quantization accuracy and in the throughput of especially MU-MIMO systems can be achieved with relatively simple quantization codebook constructions that exploit the available temporal correlation and channel gain differences.

  16. Evolutionary dynamics under interactive diversity

    NASA Astrophysics Data System (ADS)

    Su, Qi; Li, Aming; Wang, Long

    2017-10-01

    As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

  17. Comparison of two underwater acoustic communications techniques for multi-user access

    NASA Astrophysics Data System (ADS)

    Hursky, Paul; Siderius, T. Martin; Kauaiex Group

    2004-05-01

    Frequency hopped frequency shift keying (FHFSK) and code division multiple access (CDMA) are two different modulation techniques for multiple users to communicate with a single receiver simultaneously. In July 2003, these two techniques were tested alongside each other in a shallow water coastal environment off the coast of Kauai. A variety of instruments were used to measure the prevailing oceanography, enabling detailed modeling of the channel. The channel was acoustically probed using LFM waveforms and m-sequences as well. We will present the results of demodulating the FHFSK and CDMA waveforms and discuss modeling the channel for the purpose of predicting multi-user communications performance. a)Michael B. Porter, Paul Hursky, Martin Siderius (SAIC), Mohsen Badiey (UD), Jerald Caruthers (USM), William S. Hodgkiss, Kaustubha Raghukumar (SIO), Dan Rouseff, Warren Fox (APL-UW), Christian de Moustier, Brian Calder, Barbara J. Kraft (UNH), Keyko McDonald (SPAWARSSC), Peter Stein, James K. Lewis, and Subramaniam Rajan (SSI).

  18. Prescription Opioid Use, Misuse, and Diversion among Street Drug Users in New York City

    PubMed Central

    Rees Davis, W.; Johnson, Bruce D.

    2008-01-01

    Objective The use of heroin, cocaine, and other drugs is well researched in New York City, but prescription opioids (POs) have been overlooked. This study documents patterns of PO use, misuse, and diversion among street drug users, and begins to indicate how drug culture practices interact with the legitimate therapeutic goals of PO prescriptions (e.g. pain management). Methods Staff completed interviews inquiring about the reasons for use of POs and illicit drugs with 586 street drug users. Ethnographers wrote extensive field notes about subjects’ complex patterns of PO use. Results Methadone was used (71.9%) and sold (64.7%) at a higher level than OxyContin, Vicodin, and Percocet, used by between 34% and 38% of the users and sold by between 28% and 41% of the sellers. Recent PO use is associated with the recency of using heroin and cocaine (p<.001). Half of the heroin/cocaine sellers sold POs, and one quarter of the PO sellers only sold POs. Subjects were classified into four groups by whether they diverted POs or used POs to relieve pain or withdrawal rather than for euphoria. This classification was associated with frequency of PO use, whether POs were obtained from doctors/pharmacies or from drug dealers and family members, and those mostly likely to use POs for pain and withdrawal. Conclusions POs are an important component of street drug users’ drug-taking regimes, especially those who are Physically III Chemical Abusers (PICA). Future research is needed to model PO use, misuse, and diversion among this population. PMID:17913395

  19. Multi-User Space Link Extension (SLE) System

    NASA Technical Reports Server (NTRS)

    Perkins, Toby

    2013-01-01

    The Multi-User Space (MUS) Link Extension system, a software and data system, provides Space Link Extension (SLE) users with three space data transfer services in timely, complete, and offline modes as applicable according to standards defined by the Consultative Committee for Space Data Systems (CCSDS). MUS radically reduces the schedule, cost, and risk of implementing a new SLE user system, minimizes operating costs with a lights-out approach to SLE, and is designed to require no sustaining engineering expense during its lifetime unless changes in the CCSDS SLE standards, combined with new provider implementations, force changes. No software modification to MUS needs to be made to support a new mission. Any systems engineer with Linux experience can begin testing SLE user service instances with MUS starting from a personal computer (PC) within five days. For flight operators, MUS provides a familiar-looking Web page for entering SLE configuration data received from SLE. Operators can also use the Web page to back up a space mission's entire set of up to approximately 500 SLE service instances in less than five seconds, or to restore or transfer from another system the same amount of data from a MUS backup file in about the same amount of time. Missions operate each MUS SLE service instance independently by sending it MUS directives, which are legible, plain ASCII strings. MUS directives are usually (but not necessarily) sent through a TCP-IP (Transmission Control Protocol Internet Protocol) socket from a MOC (Mission Operations Center) or POCC (Payload Operations Control Center) system, under scripted control, during "lights-out" spacecraft operation. MUS permits the flight operations team to configure independently each of its data interfaces; not only commands and telemetry, but also MUS status messages to the MOC. Interfaces can use single- or multiple-client TCP/IP server sockets, TCP/IP client sockets, temporary disk files, the system log, or standard in

  20. Issues in educating health professionals to meet the diverse needs of patients and other service users from ethnic minority groups.

    PubMed

    Chevannes, Mel

    2002-08-01

    The main aim of the study was to undertake training needs analysis among a multi-professional group for the purpose of improving care for ethnic minority patients and other service users. Evidence from the literature identifies that some of the explanations advanced for the failure of health professionals to meet the needs of ethnic minorities include lack of understanding of cultural diversities, racism, racial stereotyping, lack of knowledge, exclusivity, and ethnocentrism. While these issues have been addressed in different countries, little work has been carried out to examine these from the perspective of health professionals caring for ethnic minorities. This study is therefore an attempt to find out what health professionals know about caring for patients and other service users from minority ethnic groups and their perception of training needs in this area of work. A pre- and post-training design phase structured the qualitative approach. A purposive sample of individuals working across five health service organizations located in a multi-racial city yielded a multi-professional group of participants. Views of 22 participants were obtained by semi-structured interviews at a pretraining phase. Training needs of health professionals drew on Walklin's (1992) six stages used to structure data collection, data analysis and delivery of training. The post-training phase used questionnaires to evaluate immediate learning that based on a 4-week period of reflection and applied to practice. The questionnaires were complemented by a facilitator-lead focus group. The majority of the participants confirmed that no attention was given in their initial education to the health care needs of minority ethnic groups. Instead, participants engaged in self-initiated learning to improve their knowledge and understanding. The issue of communication was viewed with dissatisfaction and seen as affecting the sufficiency of caring for these patients. All participants rated meeting

  1. Cooperative mission execution and planning

    NASA Astrophysics Data System (ADS)

    Flann, Nicholas S.; Saunders, Kevin S.; Pells, Larry

    1998-08-01

    Utilizing multiple cooperating autonomous vehicles to perform tasks enhances robustness and efficiency over the use of a single vehicle. Furthermore, because autonomous vehicles can be controlled precisely and their status known accurately in real time, new types of cooperative behaviors are possible. This paper presents a working system called MEPS that plans and executes missions for multiple autonomous vehicles in large structured environments. Two generic spatial tasks are supported, to sweep an area and to visit a location while activating on-board equipment. Tasks can be entered both initially by the user and dynamically during mission execution by both users and vehicles. Sensor data and task achievement data is shared among the vehicles enabling them to cooperatively adapt to changing environmental, vehicle and tasks conditions. The system has been successfully applied to control ATV and micro-robotic vehicles in precision agriculture and waste-site characterization environments.

  2. A framework for service enterprise workflow simulation with multi-agents cooperation

    NASA Astrophysics Data System (ADS)

    Tan, Wenan; Xu, Wei; Yang, Fujun; Xu, Lida; Jiang, Chuanqun

    2013-11-01

    Process dynamic modelling for service business is the key technique for Service-Oriented information systems and service business management, and the workflow model of business processes is the core part of service systems. Service business workflow simulation is the prevalent approach to be used for analysis of service business process dynamically. Generic method for service business workflow simulation is based on the discrete event queuing theory, which is lack of flexibility and scalability. In this paper, we propose a service workflow-oriented framework for the process simulation of service businesses using multi-agent cooperation to address the above issues. Social rationality of agent is introduced into the proposed framework. Adopting rationality as one social factor for decision-making strategies, a flexible scheduling for activity instances has been implemented. A system prototype has been developed to validate the proposed simulation framework through a business case study.

  3. A Multi-User Virtual Environment for Building and Assessing Higher Order Inquiry Skills in Science

    ERIC Educational Resources Information Center

    Ketelhut, Diane Jass; Nelson, Brian C.; Clarke, Jody; Dede, Chris

    2010-01-01

    This study investigated novel pedagogies for helping teachers infuse inquiry into a standards-based science curriculum. Using a multi-user virtual environment (MUVE) as a pedagogical vehicle, teams of middle-school students collaboratively solved problems around disease in a virtual town called River City. The students interacted with "avatars" of…

  4. Multi-agent cooperation pursuit based on an extension of AALAADIN organisational model

    NASA Astrophysics Data System (ADS)

    Souidi, Mohammed El Habib; Songhao, Piao; Guo, Li; Lin, Chang

    2016-11-01

    An approach of cooperative pursuit for multiple mobile targets based on multi-agents system is discussed. In this kind of problem the pursuit process is divided into two kinds of tasks. The first one (coalition problem) is designed to solve the problem of the pursuit team formation. To achieve this mission, we used an innovative method based on a dynamic organisation and reorganisation of the pursuers' groups. We introduce our coalition strategy extended from the organisational agent, group, role model by assigning an access mechanism to the groups inspired by fuzzy logic principles. The second task (motion problem) is the treatment of the pursuers' motion strategy. To manage this problem we applied the principles of the Markov decision process. Simulation results show the feasibility and validity of the given proposal.

  5. Image Re-Ranking Based on Topic Diversity.

    PubMed

    Qian, Xueming; Lu, Dan; Wang, Yaxiong; Zhu, Li; Tang, Yuan Yan; Wang, Meng

    2017-08-01

    Social media sharing Websites allow users to annotate images with free tags, which significantly contribute to the development of the web image retrieval. Tag-based image search is an important method to find images shared by users in social networks. However, how to make the top ranked result relevant and with diversity is challenging. In this paper, we propose a topic diverse ranking approach for tag-based image retrieval with the consideration of promoting the topic coverage performance. First, we construct a tag graph based on the similarity between each tag. Then, the community detection method is conducted to mine the topic community of each tag. After that, inter-community and intra-community ranking are introduced to obtain the final retrieved results. In the inter-community ranking process, an adaptive random walk model is employed to rank the community based on the multi-information of each topic community. Besides, we build an inverted index structure for images to accelerate the searching process. Experimental results on Flickr data set and NUS-Wide data sets show the effectiveness of the proposed approach.

  6. Design and Implementation of a 3D Multi-User Virtual World for Language Learning

    ERIC Educational Resources Information Center

    Ibanez, Maria Blanca; Garcia, Jose Jesus; Galan, Sergio; Maroto, David; Morillo, Diego; Kloos, Carlos Delgado

    2011-01-01

    The best way to learn is by having a good teacher and the best language learning takes place when the learner is immersed in an environment where the language is natively spoken. 3D multi-user virtual worlds have been claimed to be useful for learning, and the field of exploiting them for education is becoming more and more active thanks to the…

  7. Building a Generic Virtual Research Environment Framework for Multiple Earth and Space Science Domains and a Diversity of Users.

    NASA Astrophysics Data System (ADS)

    Wyborn, L. A.; Fraser, R.; Evans, B. J. K.; Friedrich, C.; Klump, J. F.; Lescinsky, D. T.

    2017-12-01

    Virtual Research Environments (VREs) are now part of academic infrastructures. Online research workflows can be orchestrated whereby data can be accessed from multiple external repositories with processing taking place on public or private clouds, and centralised supercomputers using a mixture of user codes, and well-used community software and libraries. VREs enable distributed members of research teams to actively work together to share data, models, tools, software, workflows, best practices, infrastructures, etc. These environments and their components are increasingly able to support the needs of undergraduate teaching. External to the research sector, they can also be reused by citizen scientists, and be repurposed for industry users to help accelerate the diffusion and hence enable the translation of research innovations. The Virtual Geophysics Laboratory (VGL) in Australia was started in 2012, built using a collaboration between CSIRO, the National Computational Infrastructure (NCI) and Geoscience Australia, with support funding from the Australian Government Department of Education. VGL comprises three main modules that provide an interface to enable users to first select their required data; to choose a tool to process that data; and then access compute infrastructure for execution. VGL was initially built to enable a specific set of researchers in government agencies access to specific data sets and a limited number of tools. Over the years it has evolved into a multi-purpose Earth science platform with access to an increased variety of data (e.g., Natural Hazards, Geochemistry), a broader range of software packages, and an increasing diversity of compute infrastructures. This expansion has been possible because of the approach to loosely couple data, tools and compute resources via interfaces that are built on international standards and accessed as network-enabled services wherever possible. Built originally for researchers that were not fussy about

  8. Development and implementation of an integrated, multi-modality, user-centered interactive dietary change program

    PubMed Central

    Glasgow, Russell E.; Christiansen, Steve; Smith, K. Sabina; Stevens, Victor J.; Toobert, Deborah J.

    2009-01-01

    Computer-tailored behavior change programs offer the potential for reaching large populations at a much lower cost than individual or group-based programs. However, few of these programs to date appear to integrate behavioral theory with user choice, or combine different electronic modalities. We describe the development of an integrated CD-ROM and interactive voice response dietary change intervention that combines behavioral problem-solving theory with a high degree of user choice. The program, WISE CHOICES, is being evaluated as part of an ongoing trial. This paper describes the program development, emphasizing how user preferences are accommodated, and presents implementation and user satisfaction data. The program was successfully implemented; the linkages among the central database, the CD-ROM and the automated telephone components were robust, and participants liked the program almost as well as a counselor-delivered dietary change condition. Multi-modality programs that emphasize the strengths of each approach appear to be feasible. Future research is needed to determine the program impact and cost-effectiveness compared with counselor-delivered intervention. PMID:18711204

  9. Cooperation stimulation strategies for peer-to-peer wireless live video-sharing social networks.

    PubMed

    Lin, W Sabrina; Zhao, H Vicky; Liu, K J Ray

    2010-07-01

    Human behavior analysis in video sharing social networks is an emerging research area, which analyzes the behavior of users who share multimedia content and investigates the impact of human dynamics on video sharing systems. Users watching live streaming in the same wireless network share the same limited bandwidth of backbone connection to the Internet, thus, they might want to cooperate with each other to obtain better video quality. These users form a wireless live-streaming social network. Every user wishes to watch video with high quality while paying as little as possible cost to help others. This paper focuses on providing incentives for user cooperation. We propose a game-theoretic framework to model user behavior and to analyze the optimal strategies for user cooperation simulation in wireless live streaming. We first analyze the Pareto optimality and the time-sensitive bargaining equilibrium of the two-person game. We then extend the solution to the multiuser scenario. We also consider potential selfish users' cheating behavior and malicious users' attacking behavior and analyze the performance of the proposed strategies with the existence of cheating users and malicious attackers. Both our analytical and simulation results show that the proposed strategies can effectively stimulate user cooperation, achieve cheat free and attack resistance, and help provide reliable services for wireless live streaming applications.

  10. Hybrid Augmented Reality for Participatory Learning: The Hidden Efficacy of Multi-User Game-Based Simulation

    ERIC Educational Resources Information Center

    Oh, Seungjae; So, Hyo-Jeong; Gaydos, Matthew

    2018-01-01

    The goal for this research is to articulate and test a new hybrid Augmented Reality (AR) environment for conceptual understanding. From the theoretical lens of embodied interaction, we have designed a multi-user participatory simulation called ARfract where visitors in a science museum can learn about complex scientific concepts on the refraction…

  11. Cultural safety, diversity and the servicer user and carer movement in mental health research.

    PubMed

    Cox, Leonie G; Simpson, Alan

    2015-12-01

    This study will be of interest to anyone concerned with a critical appraisal of mental health service users' and carers' participation in research collaboration and with the potential of the postcolonial paradigm of cultural safety to contribute to the service user research (SUR) movement. The history and nature of the mental health field and its relationship to colonial processes provokes a consideration of whether cultural safety could focus attention on diversity, power imbalance, cultural dominance and structural inequality, identified as barriers and tensions in SUR. We consider these issues in the context of state-driven approaches towards SUR in planning and evaluation and the concurrent rise of the SUR movement in the UK and Australia, societies with an intimate involvement in processes of colonisation. We consider the principles and motivations underlying cultural safety and SUR in the context of the policy agenda informing SUR. We conclude that while both cultural safety and SUR are underpinned by social constructionism constituting similarities in principles and intent, cultural safety has additional dimensions. Hence, we call on researchers to use the explicitly political and self-reflective process of cultural safety to think about and address issues of diversity, power and social justice in research collaboration. © 2015 John Wiley & Sons Ltd.

  12. Robots, multi-user virtual environments and healthcare: synergies for future directions.

    PubMed

    Moon, Ajung; Grajales, Francisco J; Van der Loos, H F Machiel

    2011-01-01

    The adoption of technology in healthcare over the last twenty years has steadily increased, particularly as it relates to medical robotics and Multi-User Virtual Environments (MUVEs) such as Second Life. Both disciplines have been shown to improve the quality of care and have evolved, for the most part, in isolation from each other. In this paper, we present four synergies between medical robotics and MUVEs that have the potential to decrease resource utilization and improve the quality of healthcare delivery. We conclude with some foreseeable barriers and future research directions for researchers in these fields.

  13. Data Aggregation in Multi-Agent Systems in the Presence of Hybrid Faults

    ERIC Educational Resources Information Center

    Srinivasan, Satish Mahadevan

    2010-01-01

    Data Aggregation (DA) is a set of functions that provide components of a distributed system access to global information for purposes of network management and user services. With the diverse new capabilities that networks can provide, applicability of DA is growing. DA is useful in dealing with multi-value domain information and often requires…

  14. Assessing group differences in biodiversity by simultaneously testing a user-defined selection of diversity indices.

    PubMed

    Pallmann, Philip; Schaarschmidt, Frank; Hothorn, Ludwig A; Fischer, Christiane; Nacke, Heiko; Priesnitz, Kai U; Schork, Nicholas J

    2012-11-01

    Comparing diversities between groups is a task biologists are frequently faced with, for example in ecological field trials or when dealing with metagenomics data. However, researchers often waver about which measure of diversity to choose as there is a multitude of approaches available. As Jost (2008, Molecular Ecology, 17, 4015) has pointed out, widely used measures such as the Shannon or Simpson index have undesirable properties which make them hard to compare and interpret. Many of the problems associated with the use of these 'raw' indices can be corrected by transforming them into 'true' diversity measures. We introduce a technique that allows the comparison of two or more groups of observations and simultaneously tests a user-defined selection of a number of 'true' diversity measures. This procedure yields multiplicity-adjusted P-values according to the method of Westfall and Young (1993, Resampling-Based Multiple Testing: Examples and Methods for p-Value Adjustment, 49, 941), which ensures that the rate of false positives (type I error) does not rise when the number of groups and/or diversity indices is extended. Software is available in the R package 'simboot'. © 2012 Blackwell Publishing Ltd.

  15. Integrating care for frequent users of emergency departments: implementation evaluation of a brief multi-organizational intensive case management intervention.

    PubMed

    Kahan, Deborah; Leszcz, Molyn; O'Campo, Patricia; Hwang, Stephen W; Wasylenki, Donald A; Kurdyak, Paul; Wise Harris, Deborah; Gozdzik, Agnes; Stergiopoulos, Vicky

    2016-04-27

    Addressing the needs of frequent users of emergency departments (EDs) is a health system priority in many jurisdictions. This study describes stakeholder perspectives on the implementation of a multi-organizational brief intervention designed to support integration and continuity of care for frequent ED users with mental health and addictions problems, focusing on perceived barriers and facilitators to early implementation in a large urban centre. Coordinating Access to Care from Hospital Emergency Departments (CATCH-ED) is a brief case management intervention bridging hospital, primary and community care for frequent ED users experiencing mental illness and addictions. To examine barriers and facilitators to early implementation of this multi-organizational intervention, between July and October 2012, 47 stakeholders, including direct service providers, managers and administrators participated in 32 semi-structured qualitative interviews and one focus group exploring their experience with the intervention and factors that helped or hindered successful early implementation. Qualitative data were analyzed using thematic analysis. Stakeholders valued the intervention and its potential to support continuity of care for this population. Service delivery system factors, including organizational capacity and a history of collaborative relationships across the healthcare continuum, and support system factors, such as training and supervision, emerged as key facilitators of program implementation. Operational challenges included early low program referral rates, management of a multi-organizational initiative, variable adherence to the model among participating organizations, and scant access to specialty psychiatric resources. Factors contributing to these challenges included lack of dedicated staff in the ED and limited local system capacity to support this population, and insufficient training and technical assistance available to participating organizations. A multi

  16. Multi-User Domain Object Oriented (MOO) as a High School Procedure for Foreign Language Acquisition.

    ERIC Educational Resources Information Center

    Backer, James A.

    Foreign language students experience added difficulty when they are isolated from native speakers and from the culture of the target language. It has been posited that MOO (Multi-User Domain Object Oriented) may help overcome the geographical isolation of these students. MOOs are Internet-based virtual worlds in which people from all over the real…

  17. Five rules for the evolution of cooperation

    PubMed Central

    Nowak, Martin A.

    2011-01-01

    Cooperation is needed for evolution to construct new levels of organization. The emergence of genomes, cells, multi-cellular organisms, social insects and human society are all based on cooperation. Cooperation means that selfish replicators forgo some of their reproductive potential to help one another. But natural selection implies competition and therefore opposes cooperation unless a specific mechanism is at work. Here I discuss five mechanisms for the evolution of cooperation: kin selection, direct reciprocity, indirect reciprocity, network reciprocity and group selection. For each mechanism, a simple rule is derived which specifies whether natural selection can lead to cooperation. PMID:17158317

  18. Looking for unity in diversity: human cooperative childcare in comparative perspective.

    PubMed

    Burkart, Judith M; van Schaik, Carel; Griesser, Michael

    2017-12-20

    Humans engage in cooperative childcare, which includes some elements not found in other animals, such as the presence of post-reproductive helpers, extensive food sharing among adults and a pervasive sexual division of labour. In animals, cooperative offspring care has typically been studied in two different contexts. The first mainly involves helpers contributing care in cooperatively breeding family groups; the second context is allomaternal care in species usually not categorized as cooperative breeders (e.g. plural and communal breeders, often without male care). Comparative analyses suggest that cooperative breeding and allomaternal care in plural and communal breeders have distinct evolutionary origins, with humans fitting neither pathway entirely. Nevertheless, some critical proximate mechanisms of helping, including hormonal regulators, are likely to be shared across species. Other mechanisms may vary among species, such as social tolerance, proactive prosociality or conditional mother-infant bonding. These are presumably associated with specific details of the care system, such as whether all group members contribute, or whether mothers can potentially raise offspring alone. Thus, cooperative offspring care is seen in different contexts across animal lineages, but may nonetheless share several important psychological characteristics. We end by discussing how work on humans may play a unifying role in studying cooperative offspring care. © 2017 The Author(s).

  19. Looking for unity in diversity: human cooperative childcare in comparative perspective

    PubMed Central

    van Schaik, Carel

    2017-01-01

    Humans engage in cooperative childcare, which includes some elements not found in other animals, such as the presence of post-reproductive helpers, extensive food sharing among adults and a pervasive sexual division of labour. In animals, cooperative offspring care has typically been studied in two different contexts. The first mainly involves helpers contributing care in cooperatively breeding family groups; the second context is allomaternal care in species usually not categorized as cooperative breeders (e.g. plural and communal breeders, often without male care). Comparative analyses suggest that cooperative breeding and allomaternal care in plural and communal breeders have distinct evolutionary origins, with humans fitting neither pathway entirely. Nevertheless, some critical proximate mechanisms of helping, including hormonal regulators, are likely to be shared across species. Other mechanisms may vary among species, such as social tolerance, proactive prosociality or conditional mother–infant bonding. These are presumably associated with specific details of the care system, such as whether all group members contribute, or whether mothers can potentially raise offspring alone. Thus, cooperative offspring care is seen in different contexts across animal lineages, but may nonetheless share several important psychological characteristics. We end by discussing how work on humans may play a unifying role in studying cooperative offspring care. PMID:29237848

  20. DS-CDMA satellite diversity reception for personal satellite communication: Downlink performance analysis

    NASA Technical Reports Server (NTRS)

    DeGaudenzi, Riccardo; Giannetti, Filippo

    1995-01-01

    The downlink of a satellite-mobile personal communication system employing power-controlled Direct Sequence Code Division Multiple Access (DS-CDMA) and exploiting satellite-diversity is analyzed and its performance compared with a more traditional communication system utilizing single satellite reception. The analytical model developed has been thoroughly validated by means of extensive Monte Carlo computer simulations. It is shown how the capacity gain provided by diversity reception shrinks considerably in the presence of increasing traffic or in the case of light shadowing conditions. Moreover, the quantitative results tend to indicate that to combat system capacity reduction due to intra-system interference, no more than two satellites shall be active over the same region. To achieve higher system capacity, differently from terrestrial cellular systems, Multi-User Detection (MUD) techniques are likely to be required in the mobile user terminal, thus considerably increasing its complexity.

  1. A workout for virtual bodybuilders (design issues for embodiment in multi-actor virtual environments)

    NASA Technical Reports Server (NTRS)

    Benford, Steve; Bowers, John; Fahlen, Lennart E.; Greenhalgh, Chris; Snowdon, Dave

    1994-01-01

    This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which support cooperative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative systems). The main part of the paper identifies a list of embodiment design issues including: presence, location, identity, activity, availability, history of activity, viewpoint, action point, gesture, facial expression, voluntary versus involuntary expression, degree of presence, reflecting capabilities, manipulating the user's view of others, representation across multiple media, autonomous and distributed body parts, truthfulness and efficiency. Following this, we show how these issues are reflected in our own DIVE and MASSIVE prototype collaborative virtual environments.

  2. Exploring the Integration of Technology into Jewish Education: Multi-User Virtual Environments and Supplementary School Settings

    ERIC Educational Resources Information Center

    Sohn, Johannah Eve

    2014-01-01

    This descriptive case study explores the implementation of a multi-user virtual environment (MUVE) in a Jewish supplemental school setting. The research was conducted to present the recollections and reflections of three constituent populations of a new technology exploring constructivist education in the context of supplemental and online…

  3. Coded Cooperation for Multiway Relaying in Wireless Sensor Networks.

    PubMed

    Si, Zhongwei; Ma, Junyang; Thobaben, Ragnar

    2015-06-29

    Wireless sensor networks have been considered as an enabling technology for constructing smart cities. One important feature of wireless sensor networks is that the sensor nodes collaborate in some manner for communications. In this manuscript, we focus on the model of multiway relaying with full data exchange where each user wants to transmit and receive data to and from all other users in the network. We derive the capacity region for this specific model and propose a coding strategy through coset encoding. To obtain good performance with practical codes, we choose spatially-coupled LDPC (SC-LDPC) codes for the coded cooperation. In particular, for the message broadcasting from the relay, we construct multi-edge-type (MET) SC-LDPC codes by repeatedly applying coset encoding. Due to the capacity-achieving property of the SC-LDPC codes, we prove that the capacity region can theoretically be achieved by the proposed MET SC-LDPC codes. Numerical results with finite node degrees are provided, which show that the achievable rates approach the boundary of the capacity region in both binary erasure channels and additive white Gaussian channels.

  4. A power-efficient ZF precoding scheme for multi-user indoor visible light communication systems

    NASA Astrophysics Data System (ADS)

    Zhao, Qiong; Fan, Yangyu; Deng, Lijun; Kang, Bochao

    2017-02-01

    In this study, we propose a power-efficient ZF precoding scheme for visible light communication (VLC) downlink multi-user multiple-input-single-output (MU-MISO) systems, which incorporates the zero-forcing (ZF) and the characteristics of VLC systems. The main idea of this scheme is that the channel matrix used to perform pseudoinverse comes from the set of optical Access Points (APs) shared by more than one user, instead of the set of all involved serving APs as the existing ZF precoding schemes often used. By doing this, the waste of power, which is caused by the transmission of one user's data in the un-serving APs, can be avoided. In addition, the size of the channel matrix needs to perform pseudoinverse becomes smaller, which helps to reduce the computation complexity. Simulation results in two scenarios show that the proposed ZF precoding scheme has higher power efficiency, better bit error rate (BER) performance and lower computation complexity compared with traditional ZF precoding schemes.

  5. Meteorological Data Visualization in Multi-User Virtual Reality

    NASA Astrophysics Data System (ADS)

    Appleton, R.; van Maanen, P. P.; Fisher, W. I.; Krijnen, R.

    2017-12-01

    Due to their complexity and size, visualization of meteorological data is important. It enables the precise examining and reviewing of meteorological details and is used as a communication tool for reporting, education and to demonstrate the importance of the data to policy makers. Specifically for the UCAR community it is important to explore all of such possibilities.Virtual Reality (VR) technology enhances the visualization of volumetric and dynamical data in a more natural way as compared to a standard desktop, keyboard mouse setup. The use of VR for data visualization is not new but recent developments has made expensive hardware and complex setups unnecessary. The availability of consumer of the shelf VR hardware enabled us to create a very intuitive and low cost way to visualize meteorological data. A VR viewer has been implemented using multiple HTC Vive head sets and allows visualization and analysis of meteorological data in NetCDF format (e.g. of NCEP North America Model (NAM), see figure). Sources of atmospheric/meteorological data include radar and satellite as well as traditional weather stations. The data includes typical meteorological information such as temperature, humidity, air pressure, as well as those data described by the climate forecast (CF) model conventions (http://cfconventions.org). Other data such as lightning-strike data and ultra-high-resolution satellite data are also becoming available. The users can navigate freely around the data which is presented in a virtual room at a scale of up to 3.5 X 3.5 meters. The multiple users can manipulate the model simultaneously. Possible mutations include scaling/translating, filtering by value and using a slicing tool to cut-off specific sections of the data to get a closer look. The slicing can be done in any direction using the concept of a `virtual knife' in real-time. The users can also scoop out parts of the data and walk though successive states of the model. Future plans are (a.o.) to

  6. Multi-factor authentication using quantum communication

    DOEpatents

    Hughes, Richard John; Peterson, Charles Glen; Thrasher, James T.; Nordholt, Jane E.; Yard, Jon T.; Newell, Raymond Thorson; Somma, Rolando D.

    2018-02-06

    Multi-factor authentication using quantum communication ("QC") includes stages for enrollment and identification. For example, a user enrolls for multi-factor authentication that uses QC with a trusted authority. The trusted authority transmits device factor information associated with a user device (such as a hash function) and user factor information associated with the user (such as an encrypted version of a user password). The user device receives and stores the device factor information and user factor information. For multi-factor authentication that uses QC, the user device retrieves its stored device factor information and user factor information, then transmits the user factor information to the trusted authority, which also retrieves its stored device factor information. The user device and trusted authority use the device factor information and user factor information (more specifically, information such as a user password that is the basis of the user factor information) in multi-factor authentication that uses QC.

  7. "Less Clicking, More Watching": Results from the User-Centered Design of a Multi-Institutional Web Site for Art and Culture.

    ERIC Educational Resources Information Center

    Vergo, John; Karat, Clare-Marie; Karat, John; Pinhanez, Claudio; Arora, Renee; Cofino, Thomas; Riecken, Doug; Podlaseck, Mark

    This paper summarizes a 10-month long research project conducted at the IBM T.J. Watson Research Center aimed at developing the design concept of a multi-institutional art and culture web site. The work followed a user-centered design (UCD) approach, where interaction with prototypes and feedback from potential users of the web site were sought…

  8. Diverse and abundant multi-drug resistant E. coli in Matang mangrove estuaries, Malaysia

    PubMed Central

    Ghaderpour, Aziz; Ho, Wing Sze; Chew, Li-Lee; Bong, Chui Wei; Chong, Ving Ching; Thong, Kwai-Lin; Chai, Lay Ching

    2015-01-01

    E.coli, an important vector distributing antimicrobial resistance in the environment, was found to be multi-drug resistant, abundant, and genetically diverse in the Matang mangrove estuaries, Malaysia. One-third (34%) of the estuarine E. coli was multi-drug resistant. The highest antibiotic resistance prevalence was observed for aminoglycosides (83%) and beta-lactams (37%). Phylogenetic groups A and B1, being the most predominant E. coli, demonstrated the highest antibiotic resistant level and prevalence of integrons (integron I, 21%; integron II, 3%). Detection of phylogenetic group B23 downstream of fishing villages indicates human fecal contamination as a source of E. coli pollution. Enteroaggregative E. coli (1%) were also detected immediately downstream of the fishing village. The results indicated multi-drug resistance among E. coli circulating in Matang estuaries, which could be reflective of anthropogenic activities and aggravated by bacterial and antibiotic discharges from village lack of a sewerage system, aquaculture farms and upstream animal husbandry. PMID:26483759

  9. Cooperative Monocular-Based SLAM for Multi-UAV Systems in GPS-Denied Environments.

    PubMed

    Trujillo, Juan-Carlos; Munguia, Rodrigo; Guerra, Edmundo; Grau, Antoni

    2018-04-26

    This work presents a cooperative monocular-based SLAM approach for multi-UAV systems that can operate in GPS-denied environments. The main contribution of the work is to show that, using visual information obtained from monocular cameras mounted onboard aerial vehicles flying in formation, the observability properties of the whole system are improved. This fact is especially notorious when compared with other related visual SLAM configurations. In order to improve the observability properties, some measurements of the relative distance between the UAVs are included in the system. These relative distances are also obtained from visual information. The proposed approach is theoretically validated by means of a nonlinear observability analysis. Furthermore, an extensive set of computer simulations is presented in order to validate the proposed approach. The numerical simulation results show that the proposed system is able to provide a good position and orientation estimation of the aerial vehicles flying in formation.

  10. Web-based multi-channel analyzer

    DOEpatents

    Gritzo, Russ E.

    2003-12-23

    The present invention provides an improved multi-channel analyzer designed to conveniently gather, process, and distribute spectrographic pulse data. The multi-channel analyzer may operate on a computer system having memory, a processor, and the capability to connect to a network and to receive digitized spectrographic pulses. The multi-channel analyzer may have a software module integrated with a general-purpose operating system that may receive digitized spectrographic pulses for at least 10,000 pulses per second. The multi-channel analyzer may further have a user-level software module that may receive user-specified controls dictating the operation of the multi-channel analyzer, making the multi-channel analyzer customizable by the end-user. The user-level software may further categorize and conveniently distribute spectrographic pulse data employing non-proprietary, standard communication protocols and formats.

  11. Distributing Planning and Control for Teams of Cooperating Mobile Robots

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Parker, L.E.

    2004-07-19

    This CRADA project involved the cooperative research of investigators in ORNL's Center for Engineering Science Advanced Research (CESAR) with researchers at Caterpillar, Inc. The subject of the research was the development of cooperative control strategies for autonomous vehicles performing applications of interest to Caterpillar customers. The project involved three Phases of research, conducted over the time period of November 1998 through December 2001. This project led to the successful development of several technologies and demonstrations in realistic simulation that illustrated the effectiveness of our control approaches for distributed planning and cooperation in multi-robot teams. The primary objectives of this researchmore » project were to: (1) Develop autonomous control technologies to enable multiple vehicles to work together cooperatively, (2) Provide the foundational capabilities for a human operator to exercise oversight and guidance during the multi-vehicle task execution, and (3) Integrate these capabilities to the ALLIANCE-based autonomous control approach for multi-robot teams. These objectives have been successfully met with the results implemented and demonstrated in a near real-time multi-vehicle simulation of up to four vehicles performing mission-relevant tasks.« less

  12. Interplay between cooperation-enhancing mechanisms in evolutionary games with tag-mediated interactions

    NASA Astrophysics Data System (ADS)

    Hadzibeganovic, Tarik; Stauffer, Dietrich; Han, Xiao-Pu

    2018-04-01

    Cooperation is fundamental for the long-term survival of biological, social, and technological networks. Previously, mechanisms for the enhancement of cooperation, such as network reciprocity, have largely been studied in isolation and with often inconclusive findings. Here, we present an evolutionary, multiagent-based, and spatially explicit computer model to specifically address the interactive interplay between such mechanisms. We systematically investigate the effects of phenotypic diversity, network structure, and rewards on cooperative behavior emerging in a population of reproducing artificial decision makers playing tag-mediated evolutionary games. Cooperative interactions are rewarded such that both the benefits of recipients and costs of donators are affected by the reward size. The reward size is determined by the number of cooperative acts occurring within a given reward time frame. Our computational experiments reveal that small reward frames promote unconditional cooperation in populations with both low and high diversity, whereas large reward frames lead to cycles of conditional and unconditional strategies at high but not at low diversity. Moreover, an interaction between rewards and spatial structure shows that relative to small reward frames, there is a strong difference between the frequency of conditional cooperators populating rewired versus non-rewired networks when the reward frame is large. Notably, in a less diverse population, the total number of defections is comparable across different network topologies, whereas in more diverse environments defections become more frequent in a regularly structured than in a rewired, small-world network of contacts. Acknowledging the importance of such interaction effects in social dilemmas will have inevitable consequences for the future design of cooperation-enhancing protocols in large-scale, distributed, and decentralized systems such as peer-to-peer networks.

  13. Extreme C2 and Multi-Touch, Multi-User Collaborative User Interfaces

    DTIC Science & Technology

    2008-06-01

    Organization: Office of the Chief Engineer , Space and Naval Warfare Systems Center Charleston Address: PO Box 190022 N. Charleston, SC 29419 843...collaborative development technique can increase the adaptability and quality of software, something of high value in the complex domain of enterprise...concept to C2 should be able to produce similar benefits for planning in military operations, particularly complex, multi- faceted operations. This

  14. Performance assessment and microbial diversity of two pilot scale multi-stage sub-surface flow constructed wetland systems.

    PubMed

    Babatunde, A O; Miranda-CasoLuengo, Raul; Imtiaz, Mehreen; Zhao, Y Q; Meijer, Wim G

    2016-08-01

    This study assessed the performance and diversity of microbial communities in multi-stage sub-surface flow constructed wetland systems (CWs). Our aim was to assess the impact of configuration on treatment performance and microbial diversity in the systems. Results indicate that at loading rates up to 100gBOD5/(m(2)·day), similar treatment performances can be achieved using either a 3 or 4 stage configuration. In the case of phosphorus (P), the impact of configuration was less obvious and a minimum of 80% P removal can be expected for loadings up to 10gP/(m(2)·day) based on the performance results obtained within the first 16months of operation. Microbial analysis showed an increased bacterial diversity in stage four compared to the first stage. These results indicate that the design and configuration of multi-stage constructed wetland systems may have an impact on the treatment performance and the composition of the microbial community in the systems, and such knowledge can be used to improve their design and performance. Copyright © 2016. Published by Elsevier B.V.

  15. Educational Cooperation: An Examination of Fourteen Consortia.

    ERIC Educational Resources Information Center

    Lepchenske, George L.

    The development of consortia and cooperative educational services in higher education in response to financial pressures and social and governmental influences is examined. Consortia or cooperatives may be multi-channeled efforts, with each member struggling to advance its own self-interest at the cost of united goals and efforts, or thriving…

  16. Multi-Agent Many-Objective Robust Decision Making: Supporting Cooperative Regional Water Portfolio Planning in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Herman, J. D.; Zeff, H. B.; Reed, P. M.; Characklis, G. W.

    2013-12-01

    In the Eastern United States, water infrastructure and institutional frameworks have evolved in a historically water-rich environment. However, large regional droughts over the past decade combined with continuing population growth have marked a transition to a state of water scarcity, for which current planning paradigms are ill-suited. Significant opportunities exist to improve the efficiency of water infrastructure via regional coordination, namely, regional 'portfolios' of water-related assets such as reservoirs, conveyance, conservation measures, and transfer agreements. Regional coordination offers the potential to improve reliability, cost, and environmental impact in the expected future state of the world, and, with informed planning, to improve robustness to future uncertainty. In support of this challenge, this study advances a multi-agent many-objective robust decision making (multi-agent MORDM) framework that blends novel computational search and uncertainty analysis tools to discover flexible, robust regional portfolios. Our multi-agent MORDM framework is demonstrated for four water utilities in the Research Triangle region of North Carolina, USA. The utilities supply nearly two million customers and have the ability to interact with one another via transfer agreements and shared infrastructure. We show that strategies for this region which are Pareto-optimal in the expected future state of the world remain vulnerable to performance degradation under alternative scenarios of deeply uncertain hydrologic and economic factors. We then apply the Patient Rule Induction Method (PRIM) to identify which of these uncertain factors drives the individual and collective vulnerabilities for the four cooperating utilities. Our results indicate that clear multi-agent tradeoffs emerge for attaining robustness across the utilities. Furthermore, the key factor identified for improving the robustness of the region's water supply is cooperative demand reduction. This type

  17. Ubiquitous User Localization in LBS - The Need for Implementing Ethical Thinking in Our Research Field

    NASA Astrophysics Data System (ADS)

    Retscher, Guenther; Obex, Franz

    2015-12-01

    Location-based Services (LBS) influence nowadays every individual's life due to the emerging market penetration of smartphones and other mobile devices. For smartphone Apps localization technologies are developed ranging from GNSS beyond to other alternative ubiquitous positioning methods as well as the use of the in-built inertial sensors, such as accelerometers, gyroscopes, magnetometer, barometer, etc. Moreover, signals-of-opportunity which are not intended for positioning at the first sight but are receivable in many environments such as in buildings and public spaces are more and more utilized for positioning and navigation. The use of Wi-Fi (Wireless Fidelity) is a typical example. These technologies, however, have become very powerful tools as the enable to track an individual or even a group of users. Most technical researchers imply that it is mainly about further enhancing technologies and algorithms including the development of new advanced Apps to improve personal navigation and to deliver location oriented information just in time to a single LBS user or group of users. The authors claim that there is a need that ethical and political issues have to be addressed within our research community from the very beginning. Although there is a lot of research going on in developing algorithms to keep ones data and LBS search request in private, researchers can no longer keep their credibility without cooperating with ethical experts or an ethical committee. In a study called InKoPoMoVer (Cooperative Positioning for Real-time User Assistance and Guidance at Multi-modal Public Transit Junctions) a cooperation with social scientists was initiated for the first time at the Vienna University of Technology, Austria, in this context. The major aims of this study in relation to ethical questions are addressed in this paper.

  18. Multi-User Spaceport Update News Conference

    NASA Image and Video Library

    2014-01-23

    CAPE CANAVERAL, Fla. – Sierra Nevada Corporation, or SNC, Space Systems, announces the steps the company will take to prepare for a November 2016 orbital flight of its Dream Chaser spacecraft from Florida’s Space Coast during a news conference at NASA’s Kennedy Space Center in Florida. Participants are, from left, Michael Curie, NASA spokesman, Bob Cabana, director of Kennedy, Michael Gass, president and CEO of United Launch Alliance, or ULA, Frank DiBello, president and CEO of Space Florida, Mark Sirangelo, corporate vice president and head of SNC Space Systems, Larry Price, Lockheed Martin Space Systems deputy program manager for NASA's Orion spacecraft, and Steve Lindsey, Dream Chaser program manager for SNC Space Systems. The steps are considered substantial for SNC and important to plans by NASA and Space Florida for Kennedy’s transformation into a multi-user spaceport for both commercial and government customers. SNC said it plans to work with ULA to launch the Dream Chaser spacecraft into orbit atop an Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station intends to land the winged spacecraft at Kennedy’s 3.5-mile long runway at the Shuttle Landing Facility lease office space at Exploration Park, right outside Kennedy’s gates and process the spacecraft in the high bay of the Operations and Checkout Building at Kennedy, with Lockheed Martin performing the work. Photo credit: NASA/Kim Shiflett

  19. Using Dynamic Multi-Task Non-Negative Matrix Factorization to Detect the Evolution of User Preferences in Collaborative Filtering

    PubMed Central

    Ju, Bin; Qian, Yuntao; Ye, Minchao; Ni, Rong; Zhu, Chenxi

    2015-01-01

    Predicting what items will be selected by a target user in the future is an important function for recommendation systems. Matrix factorization techniques have been shown to achieve good performance on temporal rating-type data, but little is known about temporal item selection data. In this paper, we developed a unified model that combines Multi-task Non-negative Matrix Factorization and Linear Dynamical Systems to capture the evolution of user preferences. Specifically, user and item features are projected into latent factor space by factoring co-occurrence matrices into a common basis item-factor matrix and multiple factor-user matrices. Moreover, we represented both within and between relationships of multiple factor-user matrices using a state transition matrix to capture the changes in user preferences over time. The experiments show that our proposed algorithm outperforms the other algorithms on two real datasets, which were extracted from Netflix movies and Last.fm music. Furthermore, our model provides a novel dynamic topic model for tracking the evolution of the behavior of a user over time. PMID:26270539

  20. Using Dynamic Multi-Task Non-Negative Matrix Factorization to Detect the Evolution of User Preferences in Collaborative Filtering.

    PubMed

    Ju, Bin; Qian, Yuntao; Ye, Minchao; Ni, Rong; Zhu, Chenxi

    2015-01-01

    Predicting what items will be selected by a target user in the future is an important function for recommendation systems. Matrix factorization techniques have been shown to achieve good performance on temporal rating-type data, but little is known about temporal item selection data. In this paper, we developed a unified model that combines Multi-task Non-negative Matrix Factorization and Linear Dynamical Systems to capture the evolution of user preferences. Specifically, user and item features are projected into latent factor space by factoring co-occurrence matrices into a common basis item-factor matrix and multiple factor-user matrices. Moreover, we represented both within and between relationships of multiple factor-user matrices using a state transition matrix to capture the changes in user preferences over time. The experiments show that our proposed algorithm outperforms the other algorithms on two real datasets, which were extracted from Netflix movies and Last.fm music. Furthermore, our model provides a novel dynamic topic model for tracking the evolution of the behavior of a user over time.

  1. Informationally Efficient Multi-User Communication

    DTIC Science & Technology

    2010-01-01

    DSM algorithms, the Op- timal Spectrum Balancing ( OSB ) algorithm and the Iterative Spectrum Balanc- ing (ISB) algorithm, were proposed to solve the...problem of maximization of a weighted rate-sum across all users [CYM06, YL06]. OSB has an exponential complexity in the number of users. ISB only has a...the duality gap min λ1,λ2 D (λ1, λ2) − max P1,P2 f (P1,P2) is not zero. Fig. 3.3 summarizes the three key steps of a dual method, the OSB algorithm

  2. Enhancing Learning Management Systems Utility for Blind Students: A Task-Oriented, User-Centered, Multi-Method Evaluation Technique

    ERIC Educational Resources Information Center

    Babu, Rakesh; Singh, Rahul

    2013-01-01

    This paper presents a novel task-oriented, user-centered, multi-method evaluation (TUME) technique and shows how it is useful in providing a more complete, practical and solution-oriented assessment of the accessibility and usability of Learning Management Systems (LMS) for blind and visually impaired (BVI) students. Novel components of TUME…

  3. Biological interactions and cooperative management of multiple species.

    PubMed

    Jiang, Jinwei; Min, Yong; Chang, Jie; Ge, Ying

    2017-01-01

    Coordinated decision making and actions have become the primary solution for the overexploitation of interacting resources within ecosystems. However, the success of coordinated management is highly sensitive to biological, economic, and social conditions. Here, using a game theoretic framework and a 2-species model that considers various biological relationships (competition, predation, and mutualism), we compute cooperative (or joint) and non-cooperative (or separate) management equilibrium outcomes of the model and investigate the effects of the type and strength of the relationships. We find that cooperation does not always show superiority to non-cooperation in all biological interactions: (1) if and only if resources are involved in high-intensity predation relationships, cooperation can achieve a win-win scenario for ecosystem services and resource diversity; (2) for competitive resources, cooperation realizes higher ecosystem services by sacrificing resource diversity; and (3) for mutual resources, cooperation has no obvious advantage for either ecosystem services or resource evenness but can slightly improve resource abundance. Furthermore, by using a fishery model of the North California Current Marine Ecosystem with 63 species and seven fleets, we demonstrate that the theoretical results can be reproduced in real ecosystems. Therefore, effective ecosystem management should consider the interconnection between stakeholders' social relationship and resources' biological relationships.

  4. Diverse strategy-learning styles promote cooperation in evolutionary spatial prisoner's dilemma game

    NASA Astrophysics Data System (ADS)

    Liu, Run-Ran; Jia, Chun-Xiao; Rong, Zhihai

    2015-11-01

    Observational learning and practice learning are two important learning styles and play important roles in our information acquisition. In this paper, we study a spacial evolutionary prisoner's dilemma game, where players can choose the observational learning rule or the practice learning rule when updating their strategies. In the proposed model, we use a parameter p controlling the preference of players choosing the observational learning rule, and found that there exists an optimal value of p leading to the highest cooperation level, which indicates that the cooperation can be promoted by these two learning rules collaboratively and one single learning rule is not favor the promotion of cooperation. By analysing the dynamical behavior of the system, we find that the observational learning rule can make the players residing on cooperative clusters more easily realize the bad sequence of mutual defection. However, a too high observational learning probability suppresses the players to form compact cooperative clusters. Our results highlight the importance of a strategy-updating rule, more importantly, the observational learning rule in the evolutionary cooperation.

  5. Do students with higher self-efficacy exhibit greater and more diverse scientific inquiry skills: An exploratory investigation in "River City", a multi-user virtual environment

    NASA Astrophysics Data System (ADS)

    Ketelhut, Diane Jass

    In this thesis, I conduct an exploratory study to investigate the relationship between students' self-efficacy on entry into authentic scientific activity and the scientific inquiry behaviors they employ while engaged in that process, over time. Scientific inquiry has been a major standard in most science education policy doctrines for the past two decades and is exemplified by activities such as making observations, formulating hypotheses, gathering and analyzing data, and forming conclusions from that data. The self-efficacy literature, however, indicates that self-efficacy levels affect perseverance and engagement. This study investigated the relationship between these two constructs. The study is conducted in a novel setting, using an innovative science curriculum delivered through an interactive computer technology that recorded each student's conversations, movements, and activities while behaving as a practicing scientist in a "virtual world" called River City. River City is a Multi-User Virtual Environment designed to engage students in a collaborative scientific inquiry-based learning experience. As a result, I was able to follow students' moment-by-moment choices of behavior while they were behaving as scientists. I collected data on students' total scientific inquiry behaviors over three visits to River City, as well as the number of sources from which they gathered their scientific data. I analyzed my longitudinal data on the 96 seventh-graders using individual growth modeling. I found that self-efficacy played a role in the number of data-gathering behaviors students engaged in initially, with high self-efficacy students engaging in more data gathering than students with low self-efficacy. However, the impact of student self-efficacy on rate of change in data gathering behavior differed by gender; by the end of the study, student self-efficacy did not impact data gathering. In addition, students' level of self-efficacy did not affect how many different

  6. User's guide to SSARRMENU

    USGS Publications Warehouse

    Mastin, M.C.; Le, Thanh

    2001-01-01

    The U.S. Geological Survey, in cooperation with Pierce County Department of Public Works, Washington, has developed an operational tool called the Puyallup Flood-Alert System to alert users of impending floods in the Puyallup River Basin. The system acquires and incorporates meteorological and hydrological data into the Streamflow Synthesis and Reservoir Regulation (SSARR) hydrologic flow-routing model to simulate floods in the Puyallup River Basin. SSARRMENU is the user-interactive graphical interface between the user, the input and output data, and the SSARR model. In a companion cooperative project with Pierce County, the SSARR model for the Puyallup River Basin was calibrated and validated. The calibrated model is accessed through SSARRMENU, which has been specifically programed for the Puyallup River and the needs of Pierce County. SSARRMENU automates the retrieval of data from ADAPS (Automated DAta Processing System, the U.S. Geological Survey?s real-time hydrologic database), formats the data for use with SSARR, initiates SSARR model runs, displays alerts for impending floods, and provides utilities to display the simulated and observed data. An on-screen map of the basin and a series of menu items provide the user wi

  7. The Worker's Cooperative = Cooperativas de Trabajadores Duenos.

    ERIC Educational Resources Information Center

    Hernandez, Mayra Lee

    Written in Spanish and English (on facing pages), this manual is a practical guide for those interested in forming a worker-owned cooperative. It includes examples based on the personal experience of teaching about cooperativism and worker-owned cooperatives to a group of construction workers with diverse levels of education; vocabulary and…

  8. Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data

    PubMed Central

    Majeed, Abdul; Ullah, Farman; Lee, Sungchang

    2017-01-01

    Personally identifiable information (PII) affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims. PMID:28481298

  9. Vulnerability- and Diversity-Aware Anonymization of Personally Identifiable Information for Improving User Privacy and Utility of Publishing Data.

    PubMed

    Majeed, Abdul; Ullah, Farman; Lee, Sungchang

    2017-05-08

    Personally identifiable information (PII) affects individual privacy because PII combinations may yield unique identifications in published data. User PII such as age, race, gender, and zip code contain private information that may assist an adversary in determining the user to whom such information relates. Each item of user PII reveals identity differently, and some types of PII are highly identity vulnerable. More vulnerable types of PII enable unique identification more easily, and their presence in published data increases privacy risks. Existing privacy models treat all types of PII equally from an identity revelation point of view, and they mainly focus on hiding user PII in a crowd of other users. Ignoring the identity vulnerability of each type of PII during anonymization is not an effective method of protecting user privacy in a fine-grained manner. This paper proposes a new anonymization scheme that considers the identity vulnerability of PII to effectively protect user privacy. Data generalization is performed adaptively based on the identity vulnerability of PII as well as diversity to anonymize data. This adaptive generalization effectively enables anonymous data, which protects user identity and private information disclosures while maximizing the utility of data for performing analyses and building classification models. Additionally, the proposed scheme has low computational overheads. The simulation results show the effectiveness of the scheme and verify the aforementioned claims.

  10. An Examination of Diversity within Three Southeastern Academic Libraries: A Mixed-Methods, Multi-Site Study

    ERIC Educational Resources Information Center

    Shaffer, Christopher A.

    2014-01-01

    The purpose of this study was to determine the extent to which three academic libraries in the Southeastern United States could be considered diverse. This was a multi-site, mixed methods study. It examined the climate and culture of the libraries, which was assessed through two methods; the first, through survey responses from full-time faculty…

  11. Cooperative Library Services in Southeast Florida: A Staff Perspective

    ERIC Educational Resources Information Center

    Hayashi, Maris L.

    2005-01-01

    This article presents the staff perspective on the advantages of collaboration between a library cooperative in Southeast Florida and one of its member libraries. Collaborative relationships between library cooperatives and member libraries exist primarily to benefit library patrons and community users. Important relationships between cooperatives…

  12. How interdisciplinary teams can create multi-disciplinary education: the interplay between team processes and educational quality.

    PubMed

    Stalmeijer, Renee E; Gijselaers, Wim H; Wolfhagen, Ineke H A P; Harendza, Sigrid; Scherpbier, Albert J J A

    2007-11-01

    Many undergraduate medical education programmes offer integrated multi-disciplinary courses, which are generally developed by a team of teachers from different disciplines. Research has shown that multi-disciplinary teams may encounter problems, which can be detrimental to productive co-operation, which in turn may diminish educational quality. Because we expected that charting these problems might yield suggestions for addressing them, we examined the relationships between team diversity, team processes and course quality. We administered a questionnaire to participants from 21 interdisciplinary teams from 1 Dutch and 1 German medical school, both of which were reforming their curriculum. An adapted questionnaire on team learning behaviours, which had been validated in business contexts, was used to collect data on team processes, team learning behaviours and diversity within teams. We examined the relationship between the team factors and educational quality measures of the courses designed by the teams. A total of 84 teachers (60%) completed the questionnaire. Bivariate correlation analysis showed that several aspects of diversity, conflict, working climate and learning behaviour were correlated with course quality. The negative effects of the diversity measures, notably, value diversity, on other team processes and course quality and the positive association between psychological safety and team learning suggest that educational quality might be improved by enhancing the functioning of multi-disciplinary teams responsible for course development. The relationship between team processes and educational quality should be studied among larger study populations. Student ratings should also be considered in measuring educational quality.

  13. Method and system for providing work machine multi-functional user interface

    DOEpatents

    Hoff, Brian D [Peoria, IL; Akasam, Sivaprasad [Peoria, IL; Baker, Thomas M [Peoria, IL

    2007-07-10

    A method is performed to provide a multi-functional user interface on a work machine for displaying suggested corrective action. The process includes receiving status information associated with the work machine and analyzing the status information to determine an abnormal condition. The process also includes displaying a warning message on the display device indicating the abnormal condition and determining one or more corrective actions to handle the abnormal condition. Further, the process includes determining an appropriate corrective action among the one or more corrective actions and displaying a recommendation message on the display device reflecting the appropriate corrective action. The process may also include displaying a list including the remaining one or more corrective actions on the display device to provide alternative actions to an operator.

  14. DiversePathsJ: diverse shortest paths for bioimage analysis.

    PubMed

    Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

    2018-02-01

    We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  15. The evolution of cooperation on geographical networks

    NASA Astrophysics Data System (ADS)

    Li, Yixiao; Wang, Yi; Sheng, Jichuan

    2017-11-01

    We study evolutionary public goods game on geographical networks, i.e., complex networks which are located on a geographical plane. The geographical feature effects in two ways: In one way, the geographically-induced network structure influences the overall evolutionary dynamics, and, in the other way, the geographical length of an edge influences the cost when the two players at the two ends interact. For the latter effect, we design a new cost function of cooperators, which simply assumes that the longer the distance between two players, the higher cost the cooperator(s) of them have to pay. In this study, network substrates are generated by a previous spatial network model with a cost-benefit parameter controlling the network topology. Our simulations show that the greatest promotion of cooperation is achieved in the intermediate regime of the parameter, in which empirical estimates of various railway networks fall. Further, we investigate how the distribution of edges' geographical costs influences the evolutionary dynamics and consider three patterns of the distribution: an approximately-equal distribution, a diverse distribution, and a polarized distribution. For normal geographical networks which are generated using intermediate values of the cost-benefit parameter, a diverse distribution hinders the evolution of cooperation, whereas a polarized distribution lowers the threshold value of the amplification factor for cooperation in public goods game. These results are helpful for understanding the evolution of cooperation on real-world geographical networks.

  16. Adjustably Autonomous Multi-agent Plan Execution with an Internal Spacecraft Free-Flying Robot Prototype

    NASA Technical Reports Server (NTRS)

    Dorais, Gregory A.; Nicewarner, Keith

    2006-01-01

    We present an multi-agent model-based autonomy architecture with monitoring, planning, diagnosis, and execution elements. We discuss an internal spacecraft free-flying robot prototype controlled by an implementation of this architecture and a ground test facility used for development. In addition, we discuss a simplified environment control life support system for the spacecraft domain also controlled by an implementation of this architecture. We discuss adjustable autonomy and how it applies to this architecture. We describe an interface that provides the user situation awareness of both autonomous systems and enables the user to dynamically edit the plans prior to and during execution as well as control these agents at various levels of autonomy. This interface also permits the agents to query the user or request the user to perform tasks to help achieve the commanded goals. We conclude by describing a scenario where these two agents and a human interact to cooperatively detect, diagnose and recover from a simulated spacecraft fault.

  17. Alteration and Implementation of the CP/M-86 Operating System for a Multi-User Environment.

    DTIC Science & Technology

    1982-12-01

    THE CP/M-86 OPERATING SYSTEM FOR A MULTI-USER ENVIRONMENT by Thomas V. Almquist and David S. Stevens C-, December 1982 ,LU Thesis Advisor : U. R. Kodres...tool$ 044, robo O0eA 6^900091 Approved for public release; distribution unlimited Alteration and Implementation of the CP/M-86 Operating System for a...SCIENCE IN COMPUTER SCIENCE from the NAVAL POSTGRADUATE SCHOOL December 1982 Authors: Approved by: ..... .. . . . . . . . . Thesis Advisor Second

  18. 77 FR 37879 - Cooperative Patent Classification External User Day

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... Classification External User Day AGENCY: United States Patent and Trademark Office, Commerce. ACTION: Notice... Classification (CPC) External User Day event at its Alexandria Campus. CPC is a partnership between the USPTO and... classification system that will incorporate the best classification practices of the two Offices. This CPC event...

  19. A Semantic Cooperation and Interoperability Platform for the European Chambers of Commerce

    NASA Astrophysics Data System (ADS)

    Missikoff, Michele; Taglino, Francesco

    The LD-CAST project aims at developing a semantic cooperation and interoperability platform for the European Chambers of Commerce. Some of the key issues that this platform addresses are: The variety and number of different kinds of resources (i.e., business processes, concrete services) that concur to achieve a business service The diversity of cultural and procedural models emerging when composing articulated cross-country services The limited possibility of reusing similar services in different contexts (for instance, supporting the same service between different countries: an Italian-Romanian cooperation is different from an Italian-Polish one) The objective of the LD-CAST platform, and in particular of the semantic services provided therein, is to address the above problems with flexible solutions. We aim at introducing high levels of flexibility, both at the time of development of business processes and concrete services (i.e., operational services offered by service providers), with the possibility of dynamically binding c-services to the selected BP, according to user needs. To this end, an approach based on semantic services and a reference ontology has been proposed.

  20. The opportunities and challenges of multi-site evaluations: lessons from the jail diversion and trauma recovery national cross-site evaluation.

    PubMed

    Stainbrook, Kristin; Penney, Darby; Elwyn, Laura

    2015-06-01

    Multi-site evaluations, particularly of federally funded service programs, pose a special set of challenges for program evaluation. Not only are there contextual differences related to project location, there are often relatively few programmatic requirements, which results in variations in program models, target populations and services. The Jail Diversion and Trauma Recovery-Priority to Veterans (JDTR) National Cross-Site Evaluation was tasked with conducting a multi-site evaluation of thirteen grantee programs that varied along multiple domains. This article describes the use of a mixed methods evaluation design to understand the jail diversion programs and client outcomes for veterans with trauma, mental health and/or substance use problems. We discuss the challenges encountered in evaluating diverse programs, the benefits of the evaluation in the face of these challenges, and offer lessons learned for other evaluators undertaking this type of evaluation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Multi-user quantum key distribution with entangled photons from an AlGaAs chip

    NASA Astrophysics Data System (ADS)

    Autebert, C.; Trapateau, J.; Orieux, A.; Lemaître, A.; Gomez-Carbonell, C.; Diamanti, E.; Zaquine, I.; Ducci, S.

    2016-12-01

    In view of real-world applications of quantum information technologies, the combination of miniature quantum resources with existing fibre networks is a crucial issue. Among such resources, on-chip entangled photon sources play a central role for applications spanning quantum communications, computing and metrology. Here, we use a semiconductor source of entangled photons operating at room temperature in conjunction with standard telecom components to demonstrate multi-user quantum key distribution, a core protocol for securing communications in quantum networks. The source consists of an AlGaAs chip-emitting polarisation entangled photon pairs over a large bandwidth in the main telecom band around 1550 nm without the use of any off-chip compensation or interferometric scheme; the photon pairs are directly launched into a dense wavelength division multiplexer (DWDM) and secret keys are distributed between several pairs of users communicating through different channels. We achieve a visibility measured after the DWDM of 87% and show long-distance key distribution using a 50-km standard telecom fibre link between two network users. These results illustrate a promising route to practical, resource-efficient implementations adapted to quantum network infrastructures.

  2. Proposed Requirements-driven User-scenario Development Protocol for the Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement

    NASA Astrophysics Data System (ADS)

    Wee, B.; Car, N.; Percivall, G.; Allen, D.; Fitch, P. G.; Baumann, P.; Waldmann, H. C.

    2014-12-01

    The Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement (CRA) is designed to foster a global community to collaborate on e-infrastructure challenges. One of the deliverables is an implementation plan to address global data infrastructure interoperability challenges and align existing domestic and international capabilities. Work package three (WP3) of the CRA focuses on the harmonization of global data infrastructure for sharing environmental data. One of the subtasks under WP3 is the development of user scenarios that guide the development of applicable deliverables. This paper describes the proposed protocol for user scenario development. It enables the solicitation of user scenarios from a broad constituency, and exposes the mechanisms by which those solicitations are evaluated against requirements that map to the Belmont Challenge. The underlying principle of traceability forms the basis for a structured, requirements-driven approach resulting in work products amenable to trade-off analyses and objective prioritization. The protocol adopts the ISO Reference Model for Open Distributed Processing (RM-ODP) as a top level framework. User scenarios are developed within RM-ODP's "Enterprise Viewpoint". To harmonize with existing frameworks, the protocol utilizes the conceptual constructs of "scenarios", "use cases", "use case categories", and use case templates as adopted by recent GEOSS Architecture Implementation Project (AIP) deliverables and CSIRO's eReefs project. These constructs are encapsulated under the larger construct of "user scenarios". Once user scenarios are ranked by goodness-of-fit to the Belmont Challenge, secondary scoring metrics may be generated, like goodness-of-fit to FutureEarth science themes. The protocol also facilitates an assessment of the ease of implementing given user scenario using existing GEOSS AIP deliverables. In summary, the protocol results in a traceability graph that can be extended to coordinate

  3. SHARP User Manual

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu, Y. Q.; Shemon, E. R.; Thomas, J. W.

    SHARP is an advanced modeling and simulation toolkit for the analysis of nuclear reactors. It is comprised of several components including physical modeling tools, tools to integrate the physics codes for multi-physics analyses, and a set of tools to couple the codes within the MOAB framework. Physics modules currently include the neutronics code PROTEUS, the thermal-hydraulics code Nek5000, and the structural mechanics code Diablo. This manual focuses on performing multi-physics calculations with the SHARP ToolKit. Manuals for the three individual physics modules are available with the SHARP distribution to help the user to either carry out the primary multi-physics calculationmore » with basic knowledge or perform further advanced development with in-depth knowledge of these codes. This manual provides step-by-step instructions on employing SHARP, including how to download and install the code, how to build the drivers for a test case, how to perform a calculation and how to visualize the results. Since SHARP has some specific library and environment dependencies, it is highly recommended that the user read this manual prior to installing SHARP. Verification tests cases are included to check proper installation of each module. It is suggested that the new user should first follow the step-by-step instructions provided for a test problem in this manual to understand the basic procedure of using SHARP before using SHARP for his/her own analysis. Both reference output and scripts are provided along with the test cases in order to verify correct installation and execution of the SHARP package. At the end of this manual, detailed instructions are provided on how to create a new test case so that user can perform novel multi-physics calculations with SHARP. Frequently asked questions are listed at the end of this manual to help the user to troubleshoot issues.« less

  4. Interactive Inverse Groundwater Modeling - Addressing User Fatigue

    NASA Astrophysics Data System (ADS)

    Singh, A.; Minsker, B. S.

    2006-12-01

    This paper builds on ongoing research on developing an interactive and multi-objective framework to solve the groundwater inverse problem. In this work we solve the classic groundwater inverse problem of estimating a spatially continuous conductivity field, given field measurements of hydraulic heads. The proposed framework is based on an interactive multi-objective genetic algorithm (IMOGA) that not only considers quantitative measures such as calibration error and degree of regularization, but also takes into account expert knowledge about the structure of the underlying conductivity field expressed as subjective rankings of potential conductivity fields by the expert. The IMOGA converges to the optimal Pareto front representing the best trade- off among the qualitative as well as quantitative objectives. However, since the IMOGA is a population-based iterative search it requires the user to evaluate hundreds of solutions. This leads to the problem of 'user fatigue'. We propose a two step methodology to combat user fatigue in such interactive systems. The first step is choosing only a few highly representative solutions to be shown to the expert for ranking. Spatial clustering is used to group the search space based on the similarity of the conductivity fields. Sampling is then carried out from different clusters to improve the diversity of solutions shown to the user. Once the expert has ranked representative solutions from each cluster a machine learning model is used to 'learn user preference' and extrapolate these for the solutions not ranked by the expert. We investigate different machine learning models such as Decision Trees, Bayesian learning model, and instance based weighting to model user preference. In addition, we also investigate ways to improve the performance of these models by providing information about the spatial structure of the conductivity fields (which is what the expert bases his or her rank on). Results are shown for each of these

  5. Improving User Access to the Integrated Multi-Satellite Retrievals for GPM (IMERG) Products

    NASA Astrophysics Data System (ADS)

    Huffman, George; Bolvin, David; Nelkin, Eric; Kidd, Christopher

    2016-04-01

    The U.S. Global Precipitation Measurement mission (GPM) team has developed the Integrated Multi-satellitE Retrievals for GPM (IMERG) algorithm to take advantage of the international constellation of precipitation-relevant satellites and the Global Precipitation Climatology Centre surface precipitation gauge analysis. The goal is to provide a long record of homogeneous, high-resolution quasi-global estimates of precipitation. While expert scientific researchers are major users of the IMERG products, it is clear that many other user communities and disciplines also desire access to the data for wide-ranging applications. Lessons learned during the Tropical Rainfall Measuring Mission, the predecessor to GPM, led to some basic design choices that provided the framework for supporting multiple user bases. For example, two near-real-time "runs" are computed, the Early and Late (currently 5 and 15 hours after observation time, respectively), then the Final Run about 3 months later. The datasets contain multiple fields that provide insight into the computation of the complete precipitation data field, as well as diagnostic (currently) estimates of the precipitation's phase. In parallel with this, the archive sites are working to provide the IMERG data in a variety of formats, and with subsetting and simple interactive analysis to make the data more easily available to non-expert users. The various options for accessing the data are summarized under the pmm.nasa.gov data access page. The talk will end by considering the feasibility of major user requests, including polar coverage, a simplified Data Quality Index, and reduced data latency for the Early Run. In brief, the first two are challenging, but under the team's control. The last requires significant action by some of the satellite data providers.

  6. A framework for diversifying recommendation lists by user interest expansion.

    PubMed

    Zhang, Zhu; Zheng, Xiaolong; Zeng, Daniel Dajun

    2016-08-01

    Recommender systems have been widely used to discover users' preferences and recommend interesting items to users during this age of information load. Researchers in the field of recommender systems have realized that the quality of a top-N recommendation list involves not only relevance but also diversity. Most traditional recommendation algorithms are difficult to generate a diverse item list that can cover most of his/her interests for each user, since they mainly focus on predicting accurate items similar to the dominant interests of users. Additionally, they seldom exploit semantic information such as item tags and users' interest labels to improve recommendation diversity. In this paper, we propose a novel recommendation framework which mainly adopts an expansion strategy of user interests based on social tagging information. The framework enhances the diversity of users' preferences by expanding the sizes and categories of the original user-item interaction records, and then adopts traditional recommendation models to generate recommendation lists. Empirical evaluations on three real-world data sets show that our method can effectively improve the accuracy and diversity of item recommendation.

  7. Human cooperation by lethal group competition.

    PubMed

    Egas, Martijn; Kats, Ralph; van der Sar, Xander; Reuben, Ernesto; Sabelis, Maurice W

    2013-01-01

    Why humans are prone to cooperate puzzles biologists, psychologists and economists alike. Between-group conflict has been hypothesized to drive within-group cooperation. However, such conflicts did not have lasting effects in laboratory experiments, because they were about luxury goods, not needed for survival ("looting"). Here, we find within-group cooperation to last when between-group conflict is implemented as "all-out war" (eliminating the weakest groups). Human subjects invested in helping group members to avoid having the lowest collective pay-off, whereas they failed to cooperate in control treatments with random group elimination or with no subdivision in groups. When the game was repeated, experience was found to promote helping. Thus, not within-group interactions alone, not random group elimination, but pay-off-dependent group elimination was found to drive within-group cooperation in our experiment. We suggest that some forms of human cooperation are maintained by multi-level selection: reciprocity within groups and lethal competition among groups acting together.

  8. Human cooperation by lethal group competition

    PubMed Central

    Egas, Martijn; Kats, Ralph; van der Sar, Xander; Reuben, Ernesto; Sabelis, Maurice W.

    2013-01-01

    Why humans are prone to cooperate puzzles biologists, psychologists and economists alike. Between-group conflict has been hypothesized to drive within-group cooperation. However, such conflicts did not have lasting effects in laboratory experiments, because they were about luxury goods, not needed for survival (“looting”). Here, we find within-group cooperation to last when between-group conflict is implemented as “all-out war” (eliminating the weakest groups). Human subjects invested in helping group members to avoid having the lowest collective pay-off, whereas they failed to cooperate in control treatments with random group elimination or with no subdivision in groups. When the game was repeated, experience was found to promote helping. Thus, not within-group interactions alone, not random group elimination, but pay-off-dependent group elimination was found to drive within-group cooperation in our experiment. We suggest that some forms of human cooperation are maintained by multi-level selection: reciprocity within groups and lethal competition among groups acting together. PMID:23459158

  9. Multiple Interests of Users in Collaborative Tagging Systems

    NASA Astrophysics Data System (ADS)

    Au Yeung, Ching-Man; Gibbins, Nicholas; Shadbolt, Nigel

    Performance of recommender systems depends on whether the user profiles contain accurate information about the interests of the users, and this in turn relies on whether enough information about their interests can be collected. Collaborative tagging systems allow users to use their own words to describe their favourite resources, resulting in some user-generated categorisation schemes commonly known as folksonomies. Folksonomies thus contain rich information about the interests of the users, which can be used to support various recommender systems. Our analysis of the folksonomy in Delicious reveals that the interests of a single user can be very diverse. Traditional methods for representing interests of users are usually not able to reflect such diversity. We propose a method to construct user profiles of multiple interests from folksonomies based on a network clustering technique. Our evaluation shows that the proposed method is able to generate user profiles which reflect the diversity of user interests and can be used as a basis of providing more focused recommendation to the users.

  10. Cooperative Localization for Multi-AUVs Based on GM-PHD Filters and Information Entropy Theory

    PubMed Central

    Zhang, Lichuan; Wang, Tonghao; Xu, Demin

    2017-01-01

    Cooperative localization (CL) is considered a promising method for underwater localization with respect to multiple autonomous underwater vehicles (multi-AUVs). In this paper, we proposed a CL algorithm based on information entropy theory and the probability hypothesis density (PHD) filter, aiming to enhance the global localization accuracy of the follower. In the proposed framework, the follower carries lower cost navigation systems, whereas the leaders carry better ones. Meanwhile, the leaders acquire the followers’ observations, including both measurements and clutter. Then, the PHD filters are utilized on the leaders and the results are communicated to the followers. The followers then perform weighted summation based on all received messages and obtain a final positioning result. Based on the information entropy theory and the PHD filter, the follower is able to acquire a precise knowledge of its position. PMID:28991191

  11. Cooperative Monocular-Based SLAM for Multi-UAV Systems in GPS-Denied Environments †

    PubMed Central

    Guerra, Edmundo

    2018-01-01

    This work presents a cooperative monocular-based SLAM approach for multi-UAV systems that can operate in GPS-denied environments. The main contribution of the work is to show that, using visual information obtained from monocular cameras mounted onboard aerial vehicles flying in formation, the observability properties of the whole system are improved. This fact is especially notorious when compared with other related visual SLAM configurations. In order to improve the observability properties, some measurements of the relative distance between the UAVs are included in the system. These relative distances are also obtained from visual information. The proposed approach is theoretically validated by means of a nonlinear observability analysis. Furthermore, an extensive set of computer simulations is presented in order to validate the proposed approach. The numerical simulation results show that the proposed system is able to provide a good position and orientation estimation of the aerial vehicles flying in formation. PMID:29701722

  12. A Multi-User Model for Effectively Communicating Research Through Electronic Media

    NASA Astrophysics Data System (ADS)

    Hinds, J. J.; Fairley, J. P.

    2003-12-01

    Electronic media have demonstrated potential for data exchange, dissemination of results to other scientists, communication with community interest groups, and education of the general public regarding scientific advances. Few researchers, however, receive training in the skills required to capture the attention of the broad spectrum of Internet users. Because different people assimilate information in different ways, effective communication is best accomplished using an appropriate mix of photographs, graphics, tables, and text. In addition, effective web page design requires a clear, consistent organizational structure, easily-navigated layout, and attention to details such as page printability, downloading time, and minimal page scrolling. One of the strengths of electronic media is that the user can chose an appropriate level of involvement for his or her interest. In designing a web page for the multidisciplinary NSF/EPSCoR "Biocomplexity in Extreme Environments" project, we divided potential users into three categories based on our perception of the level of detail they required: 1) project participants, 2) non-participants with technical backgrounds, and 3) the general public. By understanding the needs and expectations of potential viewers, it was possible to present each group with an appropriate balance of visual and textural elements. For example, project participants are often most interested in raw data, which can be effectively presented in tabular format. Non-participants with technical backgrounds are more interested in analyzed data, while a project overview, presented through photographs and graphics with minimal text, will be most effective for communicating with the general public. The completed web page illustrates one solution for effectively communicating with a diverse audience, and provides examples for meeting many of the challenges of web page design.

  13. Coded Cooperation for Multiway Relaying in Wireless Sensor Networks †

    PubMed Central

    Si, Zhongwei; Ma, Junyang; Thobaben, Ragnar

    2015-01-01

    Wireless sensor networks have been considered as an enabling technology for constructing smart cities. One important feature of wireless sensor networks is that the sensor nodes collaborate in some manner for communications. In this manuscript, we focus on the model of multiway relaying with full data exchange where each user wants to transmit and receive data to and from all other users in the network. We derive the capacity region for this specific model and propose a coding strategy through coset encoding. To obtain good performance with practical codes, we choose spatially-coupled LDPC (SC-LDPC) codes for the coded cooperation. In particular, for the message broadcasting from the relay, we construct multi-edge-type (MET) SC-LDPC codes by repeatedly applying coset encoding. Due to the capacity-achieving property of the SC-LDPC codes, we prove that the capacity region can theoretically be achieved by the proposed MET SC-LDPC codes. Numerical results with finite node degrees are provided, which show that the achievable rates approach the boundary of the capacity region in both binary erasure channels and additive white Gaussian channels. PMID:26131675

  14. Application of cooperative and non-cooperative games in large-scale water quantity and quality management: a case study.

    PubMed

    Mahjouri, Najmeh; Ardestani, Mojtaba

    2011-01-01

    In this paper, two cooperative and non-cooperative methodologies are developed for a large-scale water allocation problem in Southern Iran. The water shares of the water users and their net benefits are determined using optimization models having economic objectives with respect to the physical and environmental constraints of the system. The results of the two methodologies are compared based on the total obtained economic benefit, and the role of cooperation in utilizing a shared water resource is demonstrated. In both cases, the water quality in rivers satisfies the standards. Comparing the results of the two mentioned approaches shows the importance of acting cooperatively to achieve maximum revenue in utilizing a surface water resource while the river water quantity and quality issues are addressed.

  15. Heavy-tailed distribution of the SSH Brute-force attack duration in a multi-user environment

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Kook; Kim, Sung-Jun; Park, Chan Yeol; Hong, Taeyoung; Chae, Huiseung

    2016-07-01

    Quite a number of cyber-attacks to be place against supercomputers that provide highperformance computing (HPC) services to public researcher. Particularly, although the secure shell protocol (SSH) brute-force attack is one of the traditional attack methods, it is still being used. Because stealth attacks that feign regular access may occur, they are even harder to detect. In this paper, we introduce methods to detect SSH brute-force attacks by analyzing the server's unsuccessful access logs and the firewall's drop events in a multi-user environment. Then, we analyze the durations of the SSH brute-force attacks that are detected by applying these methods. The results of an analysis of about 10 thousands attack source IP addresses show that the behaviors of abnormal users using SSH brute-force attacks are based on human dynamic characteristics of a typical heavy-tailed distribution.

  16. Interaction Design and Usability of Learning Spaces in 3D Multi-user Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Minocha, Shailey; Reeves, Ahmad John

    Three-dimensional virtual worlds are multimedia, simulated environments, often managed over the Web, which users can 'inhabit' and interact via their own graphical, self-representations known as 'avatars'. 3D virtual worlds are being used in many applications: education/training, gaming, social networking, marketing and commerce. Second Life is the most widely used 3D virtual world in education. However, problems associated with usability, navigation and way finding in 3D virtual worlds may impact on student learning and engagement. Based on empirical investigations of learning spaces in Second Life, this paper presents design guidelines to improve the usability and ease of navigation in 3D spaces. Methods of data collection include semi-structured interviews with Second Life students, educators and designers. The findings have revealed that design principles from the fields of urban planning, Human- Computer Interaction, Web usability, geography and psychology can influence the design of spaces in 3D multi-user virtual environments.

  17. How the workload impacts on cognitive cooperation: A pilot study.

    PubMed

    Sciaraffa, Nicolina; Borghini, Gianluca; Arico, Pietro; Di Flumeri, Gianluca; Toppi, Jlenia; Colosimo, Alfredo; Bezerianos, Anastatios; Thakor, Nitish V; Babiloni, Fabio

    2017-07-01

    Cooperation degradation can be seen as one of the main causes of human errors. Poor cooperation could arise from aberrant mental processes, such as mental overload, that negatively affect the user's performance. Using different levels of difficulty in a cooperative task, we combined behavioural, subjective and neurophysiological data with the aim to i) quantify the mental workload under which the crew was operating, ii) evaluate the degree of their cooperation, and iii) assess the impact of the workload demands on the cooperation levels. The combination of such data showed that high workload demand impacted significantly on the performance, workload perception, and degree of cooperation.

  18. Atmospheric lidar multi-user instrument system definition study

    NASA Technical Reports Server (NTRS)

    Greco, R. V. (Editor)

    1980-01-01

    A spaceborne lidar system for atmospheric studies was defined. The primary input was the Science Objectives Experiment Description and Evolutionary Flow Document. The first task of the study was to perform an experiment evolutionary analysis of the SEED. The second task was the system definition effort of the instrument system. The third task was the generation of a program plan for the hardware phase. The fourth task was the supporting studies which included a Shuttle deficiency analysis, a preliminary safety hazard analysis, the identification of long lead items, and development studies required. As a result of the study an evolutionary Lidar Multi-User Instrument System (MUIS) was defined. The MUIS occupies a full Spacelab pallet and has a weight of 1300 kg. The Lidar MUIS laser provides a 2 joule frequency doubled Nd:YAG laser that can also pump a tuneable dye laser wide frequency range and bandwidth. The MUIS includes a 1.25 meter diameter aperture Cassegrain receiver, with a moveable secondary mirror to provide precise alignment with the laser. The receiver can transmit the return signal to three single and multiple photomultiple tube detectors by use of a rotating fold mirror. It is concluded that the Lidar MUIS proceed to program implementation.

  19. Ceiling effect of online user interests for the movies

    NASA Astrophysics Data System (ADS)

    Ni, Jing; Zhang, Yi-Lu; Hu, Zhao-Long; Song, Wen-Jun; Hou, Lei; Guo, Qiang; Liu, Jian-Guo

    2014-05-01

    Online users' collective interests play an important role for analyzing the online social networks and personalized recommendations. In this paper, we introduce the information entropy to measure the diversity of the user interests. We empirically analyze the information entropy of the objects selected by the users with the same degree in both the MovieLens and Netflix datasets. The results show that as the user degree increases, the entropy increases from the lowest value at first to the highest value and then begins to fall, which indicates that the interests of the small-degree and large-degree users are more centralized, while the interests of normal users are more diverse. Furthermore, a null model is proposed to compare with the empirical results. In a null model, we keep the number of users and objects as well as the user degrees unchangeable, but the selection behaviors are totally random in both datasets. Results show that the diversity of the majority of users in the real datasets is higher than that the random case, with the exception of the diversity of only a fraction of small-degree users. That may because new users just like popular objects, while with the increase of the user experiences, they quickly become users of broad interests. Therefore, small-degree users' interests are much easier to predict than the other users', which may shed some light for the cold-start problem.

  20. Structural diversity: a multi-dimensional approach to assess recreational services in urban parks.

    PubMed

    Voigt, Annette; Kabisch, Nadja; Wurster, Daniel; Haase, Dagmar; Breuste, Jürgen

    2014-05-01

    Urban green spaces provide important recreational services for urban residents. In general, when park visitors enjoy "the green," they are in actuality appreciating a mix of biotic, abiotic, and man-made park infrastructure elements and qualities. We argue that these three dimensions of structural diversity have an influence on how people use and value urban parks. We present a straightforward approach for assessing urban parks that combines multi-dimensional landscape mapping and questionnaire surveys. We discuss the method as well the results from its application to differently sized parks in Berlin and Salzburg.

  1. Embracing Diversity: The Exploration of User Motivations in Citizen Science Astronomy Projects

    NASA Astrophysics Data System (ADS)

    Lee, Lo

    2018-06-01

    Online citizen science projects ask members of the public to donate spare time on their personal computers to process large datasets. A critical challenge for these projects is volunteer recruitment and retention. Many of these projects use Berkeley Open Infrastructure for Network Computing (BOINC), a piece of middleware, to support their operations. This poster analyzes volunteer motivations in two large, BOINC-based astronomy projects, Einstein@Home and Milkyway@Home. Volunteer opinions are addressed to assess whether and how competitive elements, such as credit and ranking systems, motivate volunteers. Findings from a study of project volunteers, comprising surveys (n=2,031) and follow-up interviews (n=21), show that altruism is the main incentive for participation because volunteers consider scientific research to be critical for humans. Multiple interviewees also revealed a passion for extrinsic motivations, i.e. those that involve recognition from other people, such as opportunities to become co-authors of publications or to earn financial benefits. Credit and ranking systems motivate nearly half of interviewees. By analyzing user motivations in astronomical BOINC projects, this research provides scientists with deeper understandings about volunteer communities and various types of volunteers. Building on these findings, scientists can develop different strategies, for example, awarding volunteers badges, to recruit and retain diverse volunteers, and thus enhance long-term user participation in astronomical BOINC projects.

  2. Intelligent Cooperative MAC Protocol for Balancing Energy Consumption

    NASA Astrophysics Data System (ADS)

    Wu, S.; Liu, K.; Huang, B.; Liu, F.

    To extend the lifetime of wireless sensor networks, we proposed an intelligent balanced energy consumption cooperative MAC protocol (IBEC-CMAC) based on the multi-node cooperative transmission model. The protocol has priority to access high-quality channels for reducing energy consumption of each transmission. It can also balance the energy consumption among cooperative nodes by using high residual energy nodes instead of excessively consuming some node's energy. Simulation results show that IBEC-CMAC can obtain longer network lifetime and higher energy utilization than direct transmission.

  3. Communication and cooperation in networked environments: an experimental analysis.

    PubMed

    Galimberti, C; Ignazi, S; Vercesi, P; Riva, G

    2001-02-01

    Interpersonal communication and cooperation do not happen exclusively face to face. In work contexts, as in private life, there are more and more situations of mediated communication and cooperation in which new online tools are used. However, understanding how to use the Internet to support collaborative interaction presents a substantial challenge for the designers and users of this emerging technology. First, collaborative Internet environments are designed to serve a purpose, so must be designed with intended users' tasks and goals explicitly considered. Second, in cooperative activities the key content of communication is the interpretation of the situations in which actors are involved. So, the most effective way of clarifying the meaning of messages is to connect them to a shared context of meaning. However, this is more difficult in the Internet than in other computer-based activities. This paper tries to understand the characteristics of cooperative activities in networked environments--shared 3D virtual worlds--through two different studies. The first used the analysis of conversations to explore the characteristics of the interaction during the cooperative task; the second analyzed whether and how the level of immersion in the networked environments influenced the performance and the interactional process. The results are analyzed to identify the psychosocial roots used to support cooperation in a digital interactive communication.

  4. The Power of Ground User in Recommender Systems

    PubMed Central

    Zhou, Yanbo; Lü, Linyuan; Liu, Weiping; Zhang, Jianlin

    2013-01-01

    Accuracy and diversity are two important aspects to evaluate the performance of recommender systems. Two diffusion-based methods were proposed respectively inspired by the mass diffusion (MD) and heat conduction (HC) processes on networks. It has been pointed out that MD has high recommendation accuracy yet low diversity, while HC succeeds in seeking out novel or niche items but with relatively low accuracy. The accuracy-diversity dilemma is a long-term challenge in recommender systems. To solve this problem, we introduced a background temperature by adding a ground user who connects to all the items in the user-item bipartite network. Performing the HC algorithm on the network with ground user (GHC), it showed that the accuracy can be largely improved while keeping the diversity. Furthermore, we proposed a weighted form of the ground user (WGHC) by assigning some weights to the newly added links between the ground user and the items. By turning the weight as a free parameter, an optimal value subject to the highest accuracy is obtained. Experimental results on three benchmark data sets showed that the WGHC outperforms the state-of-the-art method MD for both accuracy and diversity. PMID:23936380

  5. Performance analysis of cooperative virtual MIMO systems for wireless sensor networks.

    PubMed

    Rafique, Zimran; Seet, Boon-Chong; Al-Anbuky, Adnan

    2013-05-28

    Multi-Input Multi-Output (MIMO) techniques can be used to increase the data rate for a given bit error rate (BER) and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN) applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST) multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM) modulation is a promising solution for future high data-rate and energy-efficient WSNs.

  6. Performance Analysis of Cooperative Virtual MIMO Systems for Wireless Sensor Networks

    PubMed Central

    Rafique, Zimran; Seet, Boon-Chong; Al-Anbuky, Adnan

    2013-01-01

    Multi-Input Multi-Output (MIMO) techniques can be used to increase the data rate for a given bit error rate (BER) and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN) applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST) multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM) modulation is a promising solution for future high data-rate and energy-efficient WSNs. PMID:23760087

  7. Optimal Periodic Cooperative Spectrum Sensing Based on Weight Fusion in Cognitive Radio Networks

    PubMed Central

    Liu, Xin; Jia, Min; Gu, Xuemai; Tan, Xuezhi

    2013-01-01

    The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic cooperative spectrum sensing model based on weight fusion is proposed in this paper. Moreover, the sensing period, the sensing time and the searching time are optimized, respectively. Firstly the sensing period is optimized to improve the spectrum utilization and reduce the interference, then the joint optimization algorithm of the local sensing time and the number of cooperative users, is proposed to obtain the optimal sensing time for improving the throughput of the cognitive radio user (CRU) during each period, and finally the water-filling principle is applied to optimize the searching time in order to make the CRU find an idle channel within the shortest time. The simulation results show that compared with the previous algorithms, the optimal sensing period can improve the spectrum utilization of the CRU and decrease the interference to the PU significantly, the optimal sensing time can make the CRU achieve the largest throughput, and the optimal searching time can make the CRU find an idle channel with the least time. PMID:23604027

  8. Visualization of diversity in large multivariate data sets.

    PubMed

    Pham, Tuan; Hess, Rob; Ju, Crystal; Zhang, Eugene; Metoyer, Ronald

    2010-01-01

    Understanding the diversity of a set of multivariate objects is an important problem in many domains, including ecology, college admissions, investing, machine learning, and others. However, to date, very little work has been done to help users achieve this kind of understanding. Visual representation is especially appealing for this task because it offers the potential to allow users to efficiently observe the objects of interest in a direct and holistic way. Thus, in this paper, we attempt to formalize the problem of visualizing the diversity of a large (more than 1000 objects), multivariate (more than 5 attributes) data set as one worth deeper investigation by the information visualization community. In doing so, we contribute a precise definition of diversity, a set of requirements for diversity visualizations based on this definition, and a formal user study design intended to evaluate the capacity of a visual representation for communicating diversity information. Our primary contribution, however, is a visual representation, called the Diversity Map, for visualizing diversity. An evaluation of the Diversity Map using our study design shows that users can judge elements of diversity consistently and as or more accurately than when using the only other representation specifically designed to visualize diversity.

  9. A generalized architecture of quantum secure direct communication for N disjointed users with authentication.

    PubMed

    Farouk, Ahmed; Zakaria, Magdy; Megahed, Adel; Omara, Fatma A

    2015-11-18

    In this paper, we generalize a secured direct communication process between N users with partial and full cooperation of quantum server. So, N - 1 disjointed users u1, u2, …, uN-1 can transmit a secret message of classical bits to a remote user uN by utilizing the property of dense coding and Pauli unitary transformations. The authentication process between the quantum server and the users are validated by EPR entangled pair and CNOT gate. Afterwards, the remained EPR will generate shared GHZ states which are used for directly transmitting the secret message. The partial cooperation process indicates that N - 1 users can transmit a secret message directly to a remote user uN through a quantum channel. Furthermore, N - 1 users and a remote user uN can communicate without an established quantum channel among them by a full cooperation process. The security analysis of authentication and communication processes against many types of attacks proved that the attacker cannot gain any information during intercepting either authentication or communication processes. Hence, the security of transmitted message among N users is ensured as the attacker introduces an error probability irrespective of the sequence of measurement.

  10. Comprehensive framework for visualizing and analyzing spatio-temporal dynamics of racial diversity in the entire United States

    PubMed Central

    Netzel, Pawel

    2017-01-01

    The United States is increasingly becoming a multi-racial society. To understand multiple consequences of this overall trend to our neighborhoods we need a methodology capable of spatio-temporal analysis of racial diversity at the local level but also across the entire U.S. Furthermore, such methodology should be accessible to stakeholders ranging from analysts to decision makers. In this paper we present a comprehensive framework for visualizing and analyzing diversity data that fulfills such requirements. The first component of our framework is a U.S.-wide, multi-year database of race sub-population grids which is freely available for download. These 30 m resolution grids have being developed using dasymetric modeling and are available for 1990-2000-2010. We summarize numerous advantages of gridded population data over commonly used Census tract-aggregated data. Using these grids frees analysts from constructing their own and allows them to focus on diversity analysis. The second component of our framework is a set of U.S.-wide, multi-year diversity maps at 30 m resolution. A diversity map is our product that classifies the gridded population into 39 communities based on their degrees of diversity, dominant race, and population density. It provides spatial information on diversity in a single, easy-to-understand map that can be utilized by analysts and end users alike. Maps based on subsequent Censuses provide information about spatio-temporal dynamics of diversity. Diversity maps are accessible through the GeoWeb application SocScape (http://sil.uc.edu/webapps/socscape_usa/) for an immediate online exploration. The third component of our framework is a proposal to quantitatively analyze diversity maps using a set of landscape metrics. Because of its form, a grid-based diversity map could be thought of as a diversity “landscape” and analyzed quantitatively using landscape metrics. We give a brief summary of most pertinent metrics and demonstrate how they can

  11. Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines

    PubMed Central

    Xu, Jingjing; Yang, Wei; Zhang, Linyuan; Han, Ruisong; Shao, Xiaotao

    2015-01-01

    In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization. PMID:26343660

  12. Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines.

    PubMed

    Xu, Jingjing; Yang, Wei; Zhang, Linyuan; Han, Ruisong; Shao, Xiaotao

    2015-08-27

    In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization.

  13. High resolution time of arrival estimation for a cooperative sensor system

    NASA Astrophysics Data System (ADS)

    Morhart, C.; Biebl, E. M.

    2010-09-01

    Distance resolution of cooperative sensors is limited by the signal bandwidth. For the transmission mainly lower frequency bands are used which are more narrowband than classical radar frequencies. To compensate this resolution problem the combination of a pseudo-noise coded pulse compression system with superresolution time of arrival estimation is proposed. Coded pulsecompression allows secure and fast distance measurement in multi-user scenarios which can easily be adapted for data transmission purposes (Morhart and Biebl, 2009). Due to the lack of available signal bandwidth the measurement accuracy degrades especially in multipath scenarios. Superresolution time of arrival algorithms can improve this behaviour by estimating the channel impulse response out of a band-limited channel view. For the given test system the implementation of a MUSIC algorithm permitted a two times better distance resolution as the standard pulse compression.

  14. A Cooperative Human-Adaptive Traffic Simulation (CHATS)

    NASA Technical Reports Server (NTRS)

    Phillips, Charles T.; Ballin, Mark G.

    1999-01-01

    NASA is considering the development of a Cooperative Human-Adaptive Traffic Simulation (CHATS), to examine and evaluate performance of the National Airspace System (NAS) as the aviation community moves toward free flight. CHATS will be specifically oriented toward simulating strategic decision-making by airspace users and by the service provider s traffic management personnel, within the context of different airspace and rules assumptions. It will use human teams to represent these interests and make decisions, and will rely on computer modeling and simulation to calculate the impacts of these decisions. The simulation objectives will be to examine: 1. evolution of airspace users and the service provider s strategies, through adaptation to new operational environments; 2. air carriers competitive and cooperative behavior; 3. expected benefits to airspace users and the service provider as compared to the current NAS; 4. operational limitations of free flight concepts due to congestion and safety concerns. This paper describes an operational concept for CHATS, and presents a high-level functional design which would utilize a combination of existing and new models and simulation capabilities.

  15. Teacher-Coordinator's Guide for Related Instruction in Multi-Occupation Cooperative Programs.

    ERIC Educational Resources Information Center

    Spooner, Kendrick, Ed.; Mutter, Marylouise, Ed.

    The product of two teacher-coordinator workshops, the guide represents the cooperative efforts of the teacher participants and provides supplementary instructional materials for secondary school multioccupational cooperative programs. The first section of the guide is intended for use in large group classroom instruction and deals with the goals,…

  16. Development of a Multi-Target Contingency Management Intervention for HIV Positive Substance Users.

    PubMed

    Stitzer, Maxine; Calsyn, Donald; Matheson, Timothy; Sorensen, James; Gooden, Lauren; Metsch, Lisa

    2017-01-01

    Contingency management (CM) interventions generally target a single behavior such as attendance or drug use. However, disease outcomes are mediated by complex chains of both healthy and interfering behaviors enacted over extended periods of time. This paper describes a novel multi-target contingency management (CM) program developed for use with HIV positive substance users enrolled in a CTN multi-site study (0049 Project HOPE). Participants were randomly assigned to usual care (referral to health care and SUD treatment) or 6-months strength-based patient navigation interventions with (PN+CM) or without (PN only) the CM program. Primary outcome of the trial was viral load suppression at 12-months post-randomization. Up to $1160 could be earned over 6 months under escalating schedules of reinforcement. Earnings were divided among eight CM targets; two PN-related (PN visits; paperwork completion; 26% of possible earnings), four health-related (HIV care visits, lab blood draw visits, medication check, viral load suppression; 47% of possible earnings) and two drug-use abatement (treatment entry; submission of drug negative UAs; 27% of earnings). The paper describes rationale for selection of targets, pay amounts and pay schedules. The CM program was compatible with and fully integrated into the PN intervention. The study design will allow comparison of behavioral and health outcomes for participants receiving PN with and without CM; results will inform future multi-target CM development. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Parallel Mutations Result in a Wide Range of Cooperation and Community Consequences in a Two-Species Bacterial Consortium

    DOE PAGES

    Douglas, Sarah M.; Chubiz, Lon M.; Harcombe, William R.; ...

    2016-09-12

    Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium,we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determinecommunity dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymousmutations in metA, encoding homoserine trans-succinylase (HTS), were detected in each evolved S. enterica methionine cooperator andmore » were shown to be necessary for cooperative consortia growth. Molecular modeling was used to predict that most of the non-synonymous mutations slightly increase the binding affinity for HTS homodimer formation. Despite this genetic parallelism and trend of increasing protein binding stability, these metA alleles gave rise to a wide range of phenotypic diversity in termsof individual versus group benefit. The cooperators with the highest methionine excretion permitted nearly two-fold faster consortia growth and supported the highest fraction of E. coli, yet also had the slowest individual growth rates compared to less cooperative strains. Thus, although the genetic basis of adaptation was quite similar across independent origins of cooperative phenotypes, quantitative measurements of metabolite production were required to predict either the individual-level growth consequences or how these propagate to community-level behavior.« less

  18. Parallel Mutations Result in a Wide Range of Cooperation and Community Consequences in a Two-Species Bacterial Consortium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Douglas, Sarah M.; Chubiz, Lon M.; Harcombe, William R.

    Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium,we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determinecommunity dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymousmutations in metA, encoding homoserine trans-succinylase (HTS), were detected in each evolved S. enterica methionine cooperator andmore » were shown to be necessary for cooperative consortia growth. Molecular modeling was used to predict that most of the non-synonymous mutations slightly increase the binding affinity for HTS homodimer formation. Despite this genetic parallelism and trend of increasing protein binding stability, these metA alleles gave rise to a wide range of phenotypic diversity in termsof individual versus group benefit. The cooperators with the highest methionine excretion permitted nearly two-fold faster consortia growth and supported the highest fraction of E. coli, yet also had the slowest individual growth rates compared to less cooperative strains. Thus, although the genetic basis of adaptation was quite similar across independent origins of cooperative phenotypes, quantitative measurements of metabolite production were required to predict either the individual-level growth consequences or how these propagate to community-level behavior.« less

  19. Markerless human motion tracking using hierarchical multi-swarm cooperative particle swarm optimization.

    PubMed

    Saini, Sanjay; Zakaria, Nordin; Rambli, Dayang Rohaya Awang; Sulaiman, Suziah

    2015-01-01

    The high-dimensional search space involved in markerless full-body articulated human motion tracking from multiple-views video sequences has led to a number of solutions based on metaheuristics, the most recent form of which is Particle Swarm Optimization (PSO). However, the classical PSO suffers from premature convergence and it is trapped easily into local optima, significantly affecting the tracking accuracy. To overcome these drawbacks, we have developed a method for the problem based on Hierarchical Multi-Swarm Cooperative Particle Swarm Optimization (H-MCPSO). The tracking problem is formulated as a non-linear 34-dimensional function optimization problem where the fitness function quantifies the difference between the observed image and a projection of the model configuration. Both the silhouette and edge likelihoods are used in the fitness function. Experiments using Brown and HumanEva-II dataset demonstrated that H-MCPSO performance is better than two leading alternative approaches-Annealed Particle Filter (APF) and Hierarchical Particle Swarm Optimization (HPSO). Further, the proposed tracking method is capable of automatic initialization and self-recovery from temporary tracking failures. Comprehensive experimental results are presented to support the claims.

  20. Diversity of neighborhoods promotes cooperation in evolutionary social dilemmas

    NASA Astrophysics Data System (ADS)

    Ma, Yongjuan; Lu, Jun; Shi, Lei

    2017-02-01

    Explaining the evolution of cooperative behavior is one of the most important and interesting problems in a myriad of disciplines, such as evolutionary biology, mathematics, statistical physics, social science and economics Up to now, there have been a great number of works aiming to this issue with the help of evolutionary game theory. However, vast majority of existing literatures simply assume that the interaction neighborhood and replacement neighborhood are symmetric, which seems inconsistent with real-world cases. In this paper, we consider the asymmetrical neighborhood: player of type A, whose factor is controlled by a parameter τ, has four interaction neighbors and four replacement neighbors, while player of type B, whose factor is controlled by a parameter 1 - τ, possess eight interaction neighbors and four replacement neighbors. By means of numerous Monte Carlo simulations, we found that middle τ can make the cooperation reach the highest level While for this finding, its robustness can be further validated in more games.

  1. Adaptive strategy for multi-user robotic rehabilitation games.

    PubMed

    Caurin, Glauco A P; Siqueira, Adriano A G; Andrade, Kleber O; Joaquim, Ricardo C; Krebs, Hermano I

    2011-01-01

    In this paper, we discuss a strategy for the adaptation of the "difficulty level" in games intended to include motor planning during robotic rehabilitation. We consider concurrently the motivation of the user and his/her performance in a Pong game. User motivation is classified in three levels (not motivated, well motivated and overloaded). User performance is measured as a combination of knowledge of results--achieved goals and score points in the game--and knowledge of performance--joint displacement, speed, aiming, user work, etc. Initial results of a pilot test with unimpaired healthy young volunteers are also presented showing a tendency for individualization of the parameter values.

  2. Hepatitis C Virus in Vietnam: High Prevalence of Infection in Dialysis and Multi-Transfused Patients Involving Diverse and Novel Virus Variants

    PubMed Central

    Dunford, Linda; Carr, Michael J.; Dean, Jonathan; Waters, Allison; Nguyen, Linh Thuy; Ta Thi, Thu Hong; Thi, Lan Anh Bui; Do, Huy Duong; Thi, Thu Thuy Duong; Nguyen, Ha Thu; Diem Do, Trinh Thi; Luu, Quynh Phuong; Connell, Jeff; Coughlan, Suzie; Nguyen, Hien Tran; Hall, William W.; Nguyen Thi, Lan Anh

    2012-01-01

    Hepatitis C virus (HCV) is a genetically diverse pathogen infecting approximately 2–3% of the world's population. Herein, we describe results of a large, multicentre serological and molecular epidemiological study cataloguing the prevalence and genetic diversity of HCV in five regions of Vietnam; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. Individuals (n = 8654) with varying risk factors for infection were analysed for the presence of HCV Ab/Ag and, in a subset of positive specimens, for HCV RNA levels (n = 475) and genotype (n = 282). In lower risk individuals, including voluntary blood donors, military recruits and pregnant women, the prevalence of infection was 0.5% (n = 26/5250). Prevalence rates were significantly higher (p<0.001) in intravenous drug users (IDUs; 55.6%, n = 556/1000), dialysis patients (26.6%, n = 153/575) commercial sex workers (CSWs; 8.7%, n = 87/1000), and recipients of multiple blood transfusions (6.0%, n = 32/529). The prevalence of HCV in dialysis patients varied but remained high in all regions (11–43%) and was associated with the receipt of blood transfusions [OR: 2.08 (1.85–2.34), p = 0.001], time from first transfusion [OR: 1.07 (1.01–1.13), p = 0.023], duration of dialysis [OR: 1.31 (1.19–1.43), p<0.001] and male gender [OR: 1.60 (1.06–2.41), p = 0.026]. Phylogenetic analysis revealed high genetic diversity, particularly amongst dialysis and multi-transfused patients, identifying subtypes 1a (33%), 1b (27%), 2a (0.4%), 3a (0.7%), 3b (1.1%), 6a (18.8%), 6e (6.0%), 6h (4.6%), 6l (6.4%) and 2 clusters of novel genotype 6 variants (2.1%). HCV genotype 1 predominated in Vietnam (60%, n = 169/282) but the proportion of infections attributable to genotype 1 varied between regions and risk groups and, in the Southern part of Vietnam, genotype 6 viruses dominated in dialysis and multi-transfused patients (73.9%). This study confirms a high prevalence of HCV infection in

  3. Outcomes of an International Cooperative Education Experience for Undergraduate Nursing Students.

    PubMed

    Hoffart, Nancy; Diani, Jacqueline A; Carney, Mary F

    2015-01-01

    A qualitative study was conducted to identify the outcomes of international cooperative education in nursing. Seventeen alumni who completed 19 cooperative work experiences were interviewed. International cooperative experiences support learning about culture and contribute to personal and professional development. Outcomes included increased maturation, confidence, and flexibility; elevated political and global awareness; and ability to create effective relationships with culturally diverse patients and coworkers.

  4. A generalized architecture of quantum secure direct communication for N disjointed users with authentication

    NASA Astrophysics Data System (ADS)

    Farouk, Ahmed; Zakaria, Magdy; Megahed, Adel; Omara, Fatma A.

    2015-11-01

    In this paper, we generalize a secured direct communication process between N users with partial and full cooperation of quantum server. So, N - 1 disjointed users u1, u2, …, uN-1 can transmit a secret message of classical bits to a remote user uN by utilizing the property of dense coding and Pauli unitary transformations. The authentication process between the quantum server and the users are validated by EPR entangled pair and CNOT gate. Afterwards, the remained EPR will generate shared GHZ states which are used for directly transmitting the secret message. The partial cooperation process indicates that N - 1 users can transmit a secret message directly to a remote user uN through a quantum channel. Furthermore, N - 1 users and a remote user uN can communicate without an established quantum channel among them by a full cooperation process. The security analysis of authentication and communication processes against many types of attacks proved that the attacker cannot gain any information during intercepting either authentication or communication processes. Hence, the security of transmitted message among N users is ensured as the attacker introduces an error probability irrespective of the sequence of measurement.

  5. A generalized architecture of quantum secure direct communication for N disjointed users with authentication

    PubMed Central

    Farouk, Ahmed; Zakaria, Magdy; Megahed, Adel; Omara, Fatma A.

    2015-01-01

    In this paper, we generalize a secured direct communication process between N users with partial and full cooperation of quantum server. So, N − 1 disjointed users u1, u2, …, uN−1 can transmit a secret message of classical bits to a remote user uN by utilizing the property of dense coding and Pauli unitary transformations. The authentication process between the quantum server and the users are validated by EPR entangled pair and CNOT gate. Afterwards, the remained EPR will generate shared GHZ states which are used for directly transmitting the secret message. The partial cooperation process indicates that N − 1 users can transmit a secret message directly to a remote user uN through a quantum channel. Furthermore, N − 1 users and a remote user uN can communicate without an established quantum channel among them by a full cooperation process. The security analysis of authentication and communication processes against many types of attacks proved that the attacker cannot gain any information during intercepting either authentication or communication processes. Hence, the security of transmitted message among N users is ensured as the attacker introduces an error probability irrespective of the sequence of measurement. PMID:26577473

  6. Exploring the Educational Potential of Three-Dimensional Multi-User Virtual Worlds for STEM Education: A Mixed-Method Systematic Literature Review

    ERIC Educational Resources Information Center

    Pellas, Nikolaos; Kazanidis, Ioannis; Konstantinou, Nikolaos; Georgiou, Georgia

    2017-01-01

    The present literature review builds on the results of 50 research articles published from 2000 until 2016. All these studies have successfully accomplished various learning tasks in the domain of Science, Technology, Engineering, and Mathematics (STEM) education using three-dimensional (3-D) multi-user virtual worlds for Primary, Secondary and…

  7. Integrating the Core Curriculum through Cooperative Learning. Lesson Plans for Teachers.

    ERIC Educational Resources Information Center

    Winget, Patricia L., Ed.

    Cooperative learning strategies are used to facilitate the integration of multicultural and multi-ability level students into California regular education classrooms. This handbook is a sampling of innovative lesson plans using cooperative learning activities developed by teachers to incorporate the core curriculum into their instruction. Three…

  8. 'Putting it on the table': direct-manipulative interaction and multi-user display technologies for semi-immersive environments and augmented reality applications.

    PubMed

    Encarnação, L Miguel; Bimber, Oliver

    2002-01-01

    Collaborative virtual environments for diagnosis and treatment planning are increasingly gaining importance in our global society. Virtual and Augmented Reality approaches promised to provide valuable means for the involved interactive data analysis, but the underlying technologies still create a cumbersome work environment that is inadequate for clinical employment. This paper addresses two of the shortcomings of such technology: Intuitive interaction with multi-dimensional data in immersive and semi-immersive environments as well as stereoscopic multi-user displays combining the advantages of Virtual and Augmented Reality technology.

  9. Managing Diversity: A Cooperative Course in Foreign Languages and Business.

    ERIC Educational Resources Information Center

    Sampsell, Martha; Thompson, Earl

    This very brief paper is a description of a business course, "Business 350 Managing Diversity," at Elmhurst College in Illinois. The course is taught in an intensive 6-day, 42-hour format. The underlying philosophy of the course is that one becomes more open to the diversity of others by better understanding the diversity within oneself.…

  10. Distributed user services for supercomputers

    NASA Technical Reports Server (NTRS)

    Sowizral, Henry A.

    1989-01-01

    User-service operations at supercomputer facilities are examined. The question is whether a single, possibly distributed, user-services organization could be shared by NASA's supercomputer sites in support of a diverse, geographically dispersed, user community. A possible structure for such an organization is identified as well as some of the technologies needed in operating such an organization.

  11. A framework for diversifying recommendation lists by user interest expansion

    PubMed Central

    Zhang, Zhu; Zeng, Daniel Dajun

    2017-01-01

    Recommender systems have been widely used to discover users’ preferences and recommend interesting items to users during this age of information load. Researchers in the field of recommender systems have realized that the quality of a top-N recommendation list involves not only relevance but also diversity. Most traditional recommendation algorithms are difficult to generate a diverse item list that can cover most of his/her interests for each user, since they mainly focus on predicting accurate items similar to the dominant interests of users. Additionally, they seldom exploit semantic information such as item tags and users’ interest labels to improve recommendation diversity. In this paper, we propose a novel recommendation framework which mainly adopts an expansion strategy of user interests based on social tagging information. The framework enhances the diversity of users’ preferences by expanding the sizes and categories of the original user-item interaction records, and then adopts traditional recommendation models to generate recommendation lists. Empirical evaluations on three real-world data sets show that our method can effectively improve the accuracy and diversity of item recommendation. PMID:28959089

  12. The Viking viewer for connectomics: scalable multi-user annotation and summarization of large volume data sets

    PubMed Central

    ANDERSON, JR; MOHAMMED, S; GRIMM, B; JONES, BW; KOSHEVOY, P; TASDIZEN, T; WHITAKER, R; MARC, RE

    2011-01-01

    Modern microscope automation permits the collection of vast amounts of continuous anatomical imagery in both two and three dimensions. These large data sets present significant challenges for data storage, access, viewing, annotation and analysis. The cost and overhead of collecting and storing the data can be extremely high. Large data sets quickly exceed an individual's capability for timely analysis and present challenges in efficiently applying transforms, if needed. Finally annotated anatomical data sets can represent a significant investment of resources and should be easily accessible to the scientific community. The Viking application was our solution created to view and annotate a 16.5 TB ultrastructural retinal connectome volume and we demonstrate its utility in reconstructing neural networks for a distinctive retinal amacrine cell class. Viking has several key features. (1) It works over the internet using HTTP and supports many concurrent users limited only by hardware. (2) It supports a multi-user, collaborative annotation strategy. (3) It cleanly demarcates viewing and analysis from data collection and hosting. (4) It is capable of applying transformations in real-time. (5) It has an easily extensible user interface, allowing addition of specialized modules without rewriting the viewer. PMID:21118201

  13. Culture and cooperation in a spatial public goods game

    NASA Astrophysics Data System (ADS)

    Stivala, Alex; Kashima, Yoshihisa; Kirley, Michael

    2016-09-01

    We study the coevolution of culture and cooperation by combining the Axelrod model of cultural dissemination with a spatial public goods game, incorporating both noise and social influence. Both participation and cooperation in public goods games are conditional on cultural similarity. We find that a larger "scope of cultural possibilities" in the model leads to the survival of cooperation, when noise is not present, and a higher probability of a multicultural state evolving, for low noise rates. High noise rates, however, lead to both rapid extinction of cooperation and collapse into cultural "anomie," in which stable cultural regions fail to form. These results suggest that cultural diversity can actually be beneficial for the evolution of cooperation, but that cultural information needs to be transmitted accurately in order to maintain both coherent cultural groups and cooperation.

  14. Evolutionary dynamics of public goods games with diverse contributions in finite populations

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Wu, Bin; Chen, Xiaojie; Wang, Long

    2010-05-01

    The public goods game is a powerful metaphor for exploring the maintenance of social cooperative behavior in a group of interactional selfish players. Here we study the emergence of cooperation in the public goods games with diverse contributions in finite populations. The theory of stochastic process is innovatively adopted to investigate the evolutionary dynamics of the public goods games involving a diversity of contributions. In the limit of rare mutations, the general stationary distribution of this stochastic process can be analytically approximated by means of diffusion theory. Moreover, we demonstrate that increasing the diversity of contributions greatly reduces the probability of finding the population in a homogeneous state full of defectors. This increase also raises the expectation of the total contribution in the entire population and thus promotes social cooperation. Furthermore, by investigating the evolutionary dynamics of optional public goods games with diverse contributions, we find that nonparticipation can assist players who contribute more in resisting invasion and taking over individuals who contribute less. In addition, numerical simulations are performed to confirm our analytical results. Our results may provide insight into the effect of diverse contributions on cooperative behaviors in the real world.

  15. Pilot users in agile development processes: motivational factors.

    PubMed

    Johannessen, Liv Karen; Gammon, Deede

    2010-01-01

    Despite a wealth of research on user participation, few studies offer insights into how to involve multi-organizational users in agile development methods. This paper is a case study of user involvement in developing a system for electronic laboratory requisitions using agile methodologies in a multi-organizational context. Building on an interpretive approach, we illuminate questions such as: How does collaboration between users and developers evolve and how might it be improved? What key motivational aspects are at play when users volunteer and continue contributing in the face of considerable added burdens? The study highlights how agile methods in themselves appear to facilitate mutually motivating collaboration between user groups and developers. Lessons learned for leveraging the advantages of agile development processes include acknowledging the substantial and ongoing contributions of users and their roles as co-designers of the system.

  16. End-User Applications of Real-Time Earthquake Information in Europe

    NASA Astrophysics Data System (ADS)

    Cua, G. B.; Gasparini, P.; Giardini, D.; Zschau, J.; Filangieri, A. R.; Reakt Wp7 Team

    2011-12-01

    The primary objective of European FP7 project REAKT (Strategies and Tools for Real-Time Earthquake Risk Reduction) is to improve the efficiency of real-time earthquake risk mitigation methods and their capability of protecting structures, infrastructures, and populations. REAKT aims to address the issues of real-time earthquake hazard and response from end-to-end, with efforts directed along the full spectrum of methodology development in earthquake forecasting, earthquake early warning, and real-time vulnerability systems, through optimal decision-making, and engagement and cooperation of scientists and end users for the establishment of best practices for use of real-time information. Twelve strategic test cases/end users throughout Europe have been selected. This diverse group of applications/end users includes civil protection authorities, railway systems, hospitals, schools, industrial complexes, nuclear plants, lifeline systems, national seismic networks, and critical structures. The scale of target applications covers a wide range, from two school complexes in Naples, to individual critical structures, such as the Rion Antirion bridge in Patras, and the Fatih Sultan Mehmet bridge in Istanbul, to large complexes, such as the SINES industrial complex in Portugal and the Thessaloniki port area, to distributed lifeline and transportation networks and nuclear plants. Some end-users are interested in in-depth feasibility studies for use of real-time information and development of rapid response plans, while others intend to install real-time instrumentation and develop customized automated control systems. From the onset, REAKT scientists and end-users will work together on concept development and initial implementation efforts using the data products and decision-making methodologies developed with the goal of improving end-user risk mitigation. The aim of this scientific/end-user partnership is to ensure that scientific efforts are applicable to operational

  17. The User Community and a Multi-Mission Data Project: Services, Experiences and Directions of the Space Physics Data Facility

    NASA Technical Reports Server (NTRS)

    Fung, Shing F.; Bilitza, D.; Candey, R.; Chimiak, R.; Cooper, John; Fung, Shing; Harris, B.; Johnson R.; King, J.; Kovalick, T.; hide

    2008-01-01

    From a user's perspective, the multi-mission data and orbit services of NASA's Space Physics Data Facility (SPDF) project offer a unique range of important data and services highly complementary to other services presently available or now evolving in the international heliophysics data environment. The VSP (Virtual Space Physics Observatory) service is an active portal to a wide range of distributed data sources. CDAWeb (Coordinate Data Analysis Web) enables plots, listings and file downloads for current data cross the boundaries of missions and instrument types (and now including data from THEMIS and STEREO). SSCWeb, Helioweb and our 3D Animated Orbit Viewer (TIPSOD) provide position data and query logic for most missions currently important to heliophysics science. OMNIWeb with its new extension to 1- and 5-minute resolution provides interplanetary parameters at the Earth's bow shock as a unique value-added data product. SPDF also maintains NASA's CDF (common Data Format) standard and a range of associated tools including translation services. These capabilities are all now available through webservices-based APIs as well as through our direct user interfaces. In this paper, we will demonstrate the latest data and capabilities now supported in these multi-mission services, review the lessons we continue to learn in what science users need and value in this class of services, and discuss out current thinking to the future role and appropriate focus of the SPDF effort in the evolving and increasingly distributed heliophysics data environment.

  18. Hormone-Diversity Fit: Collective Testosterone Moderates the Effect of Diversity on Group Performance.

    PubMed

    Akinola, Modupe; Page-Gould, Elizabeth; Mehta, Pranjal H; Liu, Zaijia

    2018-03-01

    Prior research has found inconsistent effects of diversity on group performance. The present research identifies hormonal factors as a critical moderator of the diversity-performance connection. Integrating the diversity, status, and hormone literatures, we predicted that groups collectively low in testosterone, which orients individuals less toward status competitions and more toward cooperation, would excel with greater group diversity. In contrast, groups collectively high in testosterone, which is associated with a heightened status drive, would be derailed by diversity. Analysis of 74 randomly assigned groups engaged in a group decision-making exercise provided support for these hypotheses. The findings suggest that diversity is beneficial for performance, but only if group-level testosterone is low; diversity has a negative effect on performance if group-level testosterone is high. Too much collective testosterone maximizes the pains and minimizes the gains from diversity.

  19. 3D Visualization of Cooperative Trajectories

    NASA Technical Reports Server (NTRS)

    Schaefer, John A.

    2014-01-01

    Aerodynamicists and biologists have long recognized the benefits of formation flight. When birds or aircraft fly in the upwash region of the vortex generated by leaders in a formation, induced drag is reduced for the trail bird or aircraft, and efficiency improves. The major consequence of this is that fuel consumption can be greatly reduced. When two aircraft are separated by a large enough longitudinal distance, the aircraft are said to be flying in a cooperative trajectory. A simulation has been developed to model autonomous cooperative trajectories of aircraft; however it does not provide any 3D representation of the multi-body system dynamics. The topic of this research is the development of an accurate visualization of the multi-body system observable in a 3D environment. This visualization includes two aircraft (lead and trail), a landscape for a static reference, and simplified models of the vortex dynamics and trajectories at several locations between the aircraft.

  20. Scenario driven data modelling: a method for integrating diverse sources of data and data streams

    PubMed Central

    2011-01-01

    Background Biology is rapidly becoming a data intensive, data-driven science. It is essential that data is represented and connected in ways that best represent its full conceptual content and allows both automated integration and data driven decision-making. Recent advancements in distributed multi-relational directed graphs, implemented in the form of the Semantic Web make it possible to deal with complicated heterogeneous data in new and interesting ways. Results This paper presents a new approach, scenario driven data modelling (SDDM), that integrates multi-relational directed graphs with data streams. SDDM can be applied to virtually any data integration challenge with widely divergent types of data and data streams. In this work, we explored integrating genetics data with reports from traditional media. SDDM was applied to the New Delhi metallo-beta-lactamase gene (NDM-1), an emerging global health threat. The SDDM process constructed a scenario, created a RDF multi-relational directed graph that linked diverse types of data to the Semantic Web, implemented RDF conversion tools (RDFizers) to bring content into the Sematic Web, identified data streams and analytical routines to analyse those streams, and identified user requirements and graph traversals to meet end-user requirements. Conclusions We provided an example where SDDM was applied to a complex data integration challenge. The process created a model of the emerging NDM-1 health threat, identified and filled gaps in that model, and constructed reliable software that monitored data streams based on the scenario derived multi-relational directed graph. The SDDM process significantly reduced the software requirements phase by letting the scenario and resulting multi-relational directed graph define what is possible and then set the scope of the user requirements. Approaches like SDDM will be critical to the future of data intensive, data-driven science because they automate the process of converting

  1. Synergy optimization and operation management on syndicate complementary knowledge cooperation

    NASA Astrophysics Data System (ADS)

    Tu, Kai-Jan

    2014-10-01

    The number of multi enterprises knowledge cooperation has grown steadily, as a result of global innovation competitions. I have conducted research based on optimization and operation studies in this article, and gained the conclusion that synergy management is effective means to break through various management barriers and solve cooperation's chaotic systems. Enterprises must communicate system vision and access complementary knowledge. These are crucial considerations for enterprises to exert their optimization and operation knowledge cooperation synergy to meet global marketing challenges.

  2. Cooperatives as a social enterprise in Italy: a place for social integration and rehabilitation.

    PubMed

    Savio, M; Righetti, A

    1993-10-01

    This article analyses the history and development of an integrated cooperative established in 1981 in northern Italy. Integrated cooperatives, otherwise known as social enterprises, are among the most interesting activities developed in the area of social assistance and rehabilitation in recent years in Italy. In particular, they acquired relevance in the care of mentally disordered people by providing them with job opportunities, which is an important rehabilitative and integrative factor. The aim of social enterprises is two-fold. They have the economic goal of offering remunerative work just as any other commercial enterprise, as well as the social mandate of promoting the physical, social, and mental health of their members. A positive coexistence between market competition and rehabilitation is therefore constantly pursued. This research aimed at analysing the working and social experience of people employed by the cooperative during its 10-year life. The study was limited to those who had a social or health problem when entering the cooperative. The investigation was promoted by cooperative members, who felt the need to document their experience and to undertake initiatives towards evaluating the rehabilitative value of the social enterprise. The results show that cooperative members come from different marginalized areas of social and health distress, of which the two largest are social service users and psychiatric service users. There is a noticeable turn-over rate, which underlines one function of the cooperative as being a transitional working context from which users can gain access to other more rewarding job opportunities in the labour market.

  3. Index-Based Insurance Contracts to FOSTER Cooperation Between Agents Exposed to Uncorrelated Drought and Flooding Risks

    NASA Astrophysics Data System (ADS)

    Denaro, S.; Giuliani, M.; Castelletti, A.; Characklis, G. W.

    2017-12-01

    Worldwide, conflict over shared water resources is exacerbated by population growth, economic development and climate change. In multi-purpose water systems, stakeholders can face higher financial risks as a consequence of increased hydrological uncertainty and recurrent extreme events. In this context, a financial hedging tool able to bundle together the uncorrelated risks faced by different stakeholders may be an efficient solution to both foster cooperation and manage the financial losses associated with extreme events. In this work we explore the potential of risk diversification strategies involving index-based insurance joint contract solutions, to manage financial risk in a multi-purpose water system prone to both drought and flood risk. Risk diversification can allow for reduced insurance premiums in situations in which the bundled risks are entirely, or mostly, uncorrelated. Jointly covering flood and drought related risks from competing users in the same geographic area represents a novel application. The approach is demonstrated using a case study on Lake Maggiore, a regulated lake whose management is highly controversial due to numerous and competing human activities. In particular we focus on the ongoing conflict among the lakeshore population, affected by flood risk, and the downstream farmers' districts, facing drought related losses. Results are promising and indicate that bundling uncorrelated risks from competing users is beneficial to both promoting insurance premium affordability and facilitating collaboration schemes at the catchment scale.

  4. The Impact of Student Self-Efficacy on Scientific Inquiry Skills: An Exploratory Investigation in "River City," a Multi-User Virtual Environment

    ERIC Educational Resources Information Center

    Ketelhut, Diane Jass

    2007-01-01

    This exploratory study investigated data-gathering behaviors exhibited by 100 seventh-grade students as they participated in a scientific inquiry-based curriculum project delivered by a multi-user virtual environment (MUVE). This research examined the relationship between students' self-efficacy on entry into the authentic scientific activity and…

  5. Structural diversity effect on hashtag adoption in Twitter

    NASA Astrophysics Data System (ADS)

    Zhang, Aihua; Zheng, Mingxing; Pang, Bowen

    2018-03-01

    With online social network developing rapidly these years, user' behavior in online social network has attracted a lot of attentions to it. In this paper, we study Twitter user's behavior of hashtag adoption from the perspective of social contagion and focus on "structure diversity" effect on individual's behavior in Twitter. We achieve data through Twitter's API by crawling and build a users' network to carry on empirical research. The Girvan-Newman (G-N) algorithm is used to analyze the structural diversity of user's ego network, and Logistic regression model is adopted to examine the hypothesis. The findings of our empirical study indicate that user' behavior in online social network is indeed influenced by his friends and his decision is significantly affected by the number of groups that these friends belong to, which we call structural diversity.

  6. UCSB FEL user-mode adaption project. Final report, 1 Jan 86-31 Dec 90

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jaccarino, V.

    1992-04-14

    This research sponsored by the SDIO Biomedical and Materials Sciences FEL Program held the following objectives. Provide a facility in which in-house and outside user research in the materials and biological sciences can be carried out in the Far Infrared using-the unique properties of the UCSB electrostatic accelerator-driven FEL. Develop and implement new FEL concepts and FIR technology and encourage the transfer and application of this research. Train graduate students, post doctoral researchers and technical personnel in varied aspects of scientific user disciplines, FEL science and FIR technology in a cooperative, interdisciplinary environment. In summary, a free electron laser facilitymore » has been developed which is operational from 200 GH z, (6.6 cm -1), to 4.8 THz, (160 cm-1) tunable under computer control and able to deliver kilowatts of millimeter wave and far-infrared power. This facility has a well equipped user lab that has been used to perform ground breaking experiments in scientific areas as diverse as bio-physics. Nine graduate students and post doctoral researchers have been trained in the operation, use and application of these free-electron lasers.« less

  7. Predicting Human Cooperation

    PubMed Central

    Nay, John J.; Vorobeychik, Yevgeniy

    2016-01-01

    The Prisoner’s Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner’s Dilemma (defection), when played by both players, is mutually harmful. Repetition of the Prisoner’s Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner’s Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational model of human behavior in repeated Prisoner’s Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. We demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation. PMID:27171417

  8. Force Control and Nonlinear Master-Slave Force Profile to Manage an Admittance Type Multi-Fingered Haptic User Interface

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anthony L. Crawford

    2012-08-01

    Natural movements and force feedback are important elements in using teleoperated equipment if complex and speedy manipulation tasks are to be accomplished in remote and/or hazardous environments, such as hot cells, glove boxes, decommissioning, explosives disarmament, and space to name a few. In order to achieve this end the research presented in this paper has developed an admittance type exoskeleton like multi-fingered haptic hand user interface that secures the user’s palm and provides 3-dimensional force feedback to the user’s fingertips. Atypical to conventional haptic hand user interfaces that limit themselves to integrating the human hand’s characteristics just into the system’smore » mechanical design this system also perpetuates that inspiration into the designed user interface’s controller. This is achieved by manifesting the property differences of manipulation and grasping activities as they pertain to the human hand into a nonlinear master-slave force relationship. The results presented in this paper show that the admittance-type system has sufficient bandwidth that it appears nearly transparent to the user when the user is in free motion and when the system is subjected to a manipulation task, increased performance is achieved using the nonlinear force relationship compared to the traditional linear scaling techniques implemented in the vast majority of systems.« less

  9. An architecture for diversity-aware search for medical web content.

    PubMed

    Denecke, K

    2012-01-01

    The Web provides a huge source of information, also on medical and health-related issues. In particular the content of medical social media data can be diverse due to the background of an author, the source or the topic. Diversity in this context means that a document covers different aspects of a topic or a topic is described in different ways. In this paper, we introduce an approach that allows to consider the diverse aspects of a search query when providing retrieval results to a user. We introduce a system architecture for a diversity-aware search engine that allows retrieving medical information from the web. The diversity of retrieval results is assessed by calculating diversity measures that rely upon semantic information derived from a mapping to concepts of a medical terminology. Considering these measures, the result set is diversified by ranking more diverse texts higher. The methods and system architecture are implemented in a retrieval engine for medical web content. The diversity measures reflect the diversity of aspects considered in a text and its type of information content. They are used for result presentation, filtering and ranking. In a user evaluation we assess the user satisfaction with an ordering of retrieval results that considers the diversity measures. It is shown through the evaluation that diversity-aware retrieval considering diversity measures in ranking could increase the user satisfaction with retrieval results.

  10. Multi-Mission Automated Task Invocation Subsystem

    NASA Technical Reports Server (NTRS)

    Cheng, Cecilia S.; Patel, Rajesh R.; Sayfi, Elias M.; Lee, Hyun H.

    2009-01-01

    Multi-Mission Automated Task Invocation Subsystem (MATIS) is software that establishes a distributed data-processing framework for automated generation of instrument data products from a spacecraft mission. Each mission may set up a set of MATIS servers for processing its data products. MATIS embodies lessons learned in experience with prior instrument- data-product-generation software. MATIS is an event-driven workflow manager that interprets project-specific, user-defined rules for managing processes. It executes programs in response to specific events under specific conditions according to the rules. Because requirements of different missions are too diverse to be satisfied by one program, MATIS accommodates plug-in programs. MATIS is flexible in that users can control such processing parameters as how many pipelines to run and on which computing machines to run them. MATIS has a fail-safe capability. At each step, MATIS captures and retains pertinent information needed to complete the step and start the next step. In the event of a restart, this information is retrieved so that processing can be resumed appropriately. At this writing, it is planned to develop a graphical user interface (GUI) for monitoring and controlling a product generation engine in MATIS. The GUI would enable users to schedule multiple processes and manage the data products produced in the processes. Although MATIS was initially designed for instrument data product generation,

  11. Public Auditing with Privacy Protection in a Multi-User Model of Cloud-Assisted Body Sensor Networks.

    PubMed

    Li, Song; Cui, Jie; Zhong, Hong; Liu, Lu

    2017-05-05

    Wireless Body Sensor Networks (WBSNs) are gaining importance in the era of the Internet of Things (IoT). The modern medical system is a particular area where the WBSN techniques are being increasingly adopted for various fundamental operations. Despite such increasing deployments of WBSNs, issues such as the infancy in the size, capabilities and limited data processing capacities of the sensor devices restrain their adoption in resource-demanding applications. Though providing computing and storage supplements from cloud servers can potentially enrich the capabilities of the WBSNs devices, data security is one of the prevailing issues that affects the reliability of cloud-assisted services. Sensitive applications such as modern medical systems demand assurance of the privacy of the users' medical records stored in distant cloud servers. Since it is economically impossible to set up private cloud servers for every client, auditing data security managed in the remote servers has necessarily become an integral requirement of WBSNs' applications relying on public cloud servers. To this end, this paper proposes a novel certificateless public auditing scheme with integrated privacy protection. The multi-user model in our scheme supports groups of users to store and share data, thus exhibiting the potential for WBSNs' deployments within community environments. Furthermore, our scheme enriches user experiences by offering public verifiability, forward security mechanisms and revocation of illegal group members. Experimental evaluations demonstrate the security effectiveness of our proposed scheme under the Random Oracle Model (ROM) by outperforming existing cloud-assisted WBSN models.

  12. Automated Cooperative Trajectories for a More Efficient and Responsive Air Transportation System

    NASA Technical Reports Server (NTRS)

    Hanson, Curt

    2015-01-01

    The NASA Automated Cooperative Trajectories project is developing a prototype avionics system that enables multi-vehicle cooperative control by integrating 1090 MHz ES ADS-B digital communications with onboard autopilot systems. This cooperative control capability will enable meta-aircraft operations for enhanced airspace utilization, as well as improved vehicle efficiency through wake surfing. This briefing describes the objectives and approach to a flight evaluation of this system planned for 2016.

  13. Deciding to Cooperate in Northern Ghana: Trust as an Evolutionary Constraint Across Cultural Diversity.

    PubMed

    Acedo-Carmona, Cristina; Gomila, Antoni

    2015-11-27

    The upper-east and northern regions of Ghana offers a unique opportunity to study the influence of evolutionary social dynamics in making cooperation possible, despite cultural differences. These regions are occupied by several distinct ethnic groups, in interaction, such as the Kussasi, Mamprusi, Bimoba, Konkomba, and Fulani. We will report our fieldwork related to how cooperation takes places there, both within each group and among people from the different groups. Methods included personal networks of cooperation (ego networks), interviews and analysis of group contexts. The most important result is that, while each ethnic group may differ in terms of family and clan structure, a similar pattern can be found in all of them, of cooperation structured around small groups of trust-based close relationships. The study suggests that habitual decisions about cooperation are not strategic or self-interested, but instead are based on unconscious processes sustained by the emotional bonds of trust. These kind of emotional bonds are claimed to be relevant from an evolutionary point of view.

  14. Community Extreme Tonnage User Service (CETUS): A 5000 Ton Open Research Facility in the United States

    NASA Astrophysics Data System (ADS)

    Danielson, L. R.; Righter, K.; Vander Kaaden, K. E.; Rowland, R. L., II; Draper, D. S.; McCubbin, F. M.

    2017-12-01

    Large sample volume 5000 ton multi-anvil presses have contributed to the exploration of deep Earth and planetary interiors, synthesis of ultra-hard and other novel materials, and serve as a sample complement to pressure and temperature regimes already attainable by diamond anvil cell experiments. However, no such facility exists in the Western Hemisphere. We are establishing an open user facility for the entire research community, with the unique capability of a 5000 ton multi-anvil and deformation press, HERA (High pressure Experimental Research Apparatus), supported by a host of extant co-located experimental and analytical laboratories and research staff. We offer wide range of complementary and/or preparatory experimental options. Any required synthesis of materials or follow up experiments can be carried out controlled atmosphere furnaces, piston cylinders, multi-anvil, or experimental impact apparatus. Additionally, our division houses two machine shops that would facilitate any modification or custom work necessary for development of CETUS, one for general fabrication and one located specifically within our experimental facilities. We also have a general sample preparation laboratory, specifically for experimental samples, that allows users to quickly and easily prepare samples for ebeam analyses and more. Our focus as contract staff is on serving the scientific needs of our users and collaborators. We are seeking community expert input on multiple aspects of this facility, such as experimental assembly design, module modifications, immediate projects, and future innovation initiatives. We've built a cooperative network of 12 (and growing) collaborating institutions, including COMPRES. CETUS is a coordinated effort leveraging HERA with our extant experimental, analytical, and planetary process modelling instrumentation and expertise in order to create a comprehensive model of the origin and evolution of our solar system and beyond. We are looking to engage

  15. 7 CFR 504.4 - Exemptions from user fee charges.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... OF AGRICULTURE USER FEES § 504.4 Exemptions from user fee charges. (a) USDA laboratories and ARS cooperators designated by the Curator of the ARS Patent Culture Collection are exempt from fee assessments. (b) The Curator of the ARS Patent Culture Collection is delegated the authority to approve and revoke...

  16. 7 CFR 504.4 - Exemptions from user fee charges.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... OF AGRICULTURE USER FEES § 504.4 Exemptions from user fee charges. (a) USDA laboratories and ARS cooperators designated by the Curator of the ARS Patent Culture Collection are exempt from fee assessments. (b) The Curator of the ARS Patent Culture Collection is delegated the authority to approve and revoke...

  17. 7 CFR 504.4 - Exemptions from user fee charges.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OF AGRICULTURE USER FEES § 504.4 Exemptions from user fee charges. (a) USDA laboratories and ARS cooperators designated by the Curator of the ARS Patent Culture Collection are exempt from fee assessments. (b) The Curator of the ARS Patent Culture Collection is delegated the authority to approve and revoke...

  18. 7 CFR 504.4 - Exemptions from user fee charges.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... OF AGRICULTURE USER FEES § 504.4 Exemptions from user fee charges. (a) USDA laboratories and ARS cooperators designated by the Curator of the ARS Patent Culture Collection are exempt from fee assessments. (b) The Curator of the ARS Patent Culture Collection is delegated the authority to approve and revoke...

  19. 7 CFR 504.4 - Exemptions from user fee charges.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... OF AGRICULTURE USER FEES § 504.4 Exemptions from user fee charges. (a) USDA laboratories and ARS cooperators designated by the Curator of the ARS Patent Culture Collection are exempt from fee assessments. (b) The Curator of the ARS Patent Culture Collection is delegated the authority to approve and revoke...

  20. The Viking viewer for connectomics: scalable multi-user annotation and summarization of large volume data sets.

    PubMed

    Anderson, J R; Mohammed, S; Grimm, B; Jones, B W; Koshevoy, P; Tasdizen, T; Whitaker, R; Marc, R E

    2011-01-01

    Modern microscope automation permits the collection of vast amounts of continuous anatomical imagery in both two and three dimensions. These large data sets present significant challenges for data storage, access, viewing, annotation and analysis. The cost and overhead of collecting and storing the data can be extremely high. Large data sets quickly exceed an individual's capability for timely analysis and present challenges in efficiently applying transforms, if needed. Finally annotated anatomical data sets can represent a significant investment of resources and should be easily accessible to the scientific community. The Viking application was our solution created to view and annotate a 16.5 TB ultrastructural retinal connectome volume and we demonstrate its utility in reconstructing neural networks for a distinctive retinal amacrine cell class. Viking has several key features. (1) It works over the internet using HTTP and supports many concurrent users limited only by hardware. (2) It supports a multi-user, collaborative annotation strategy. (3) It cleanly demarcates viewing and analysis from data collection and hosting. (4) It is capable of applying transformations in real-time. (5) It has an easily extensible user interface, allowing addition of specialized modules without rewriting the viewer. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  1. How user diversity and country of origin impact the readiness to adopt E-health technologies: an intercultural comparison.

    PubMed

    Wilkowsk, Wiktoria; Ziefle, Martina; Alagöz, Firat

    2012-01-01

    In recent years, due to the demographical change and the resulting overload of healthcare systems, there has been an increasing interest focusing on the global proliferation of assistive medical technologies (=E-health) in home environments. The present study examines how users' diversity influences the readiness to adopt novel medical technologies, comparing users' attitudes in terms of perceived advantages and disadvantages in three technically and culturally different countries: Germany, Poland and Turkey. This investigation also intended to verify if acceptance of information and communication technologies is associated with the sensitive acceptance of E-health. Results revealed overall a considerably higher motivation to use medical technology compared to perceived barriers, with Polish users more willing to use E-health, higher than German or Turkish ones. Older participants showed a highly positive attitude, comparable to young and middle-aged respondents' receptiveness, differing from the latter in terms of greater appreciation of the advantage of higher independency when being supported by medical technology. With respect to gender, woman showed higher motivation to use E-health technology than men, although utilization barriers were not gendered. Following these results, an unconditional transfer of acceptance from information and communication to medical technology is not justified.

  2. Synthesis of User Needs for Arctic Sea Ice Predictions

    NASA Astrophysics Data System (ADS)

    Wiggins, H. V.; Turner-Bogren, E. J.; Sheffield Guy, L.

    2017-12-01

    Forecasting Arctic sea ice on sub-seasonal to seasonal scales in a changing Arctic is of interest to a diverse range of stakeholders. However, sea ice forecasting is still challenging due to high variability in weather and ocean conditions and limits to prediction capabilities; the science needs for observations and modeling are extensive. At a time of challenged science funding, one way to prioritize sea ice prediction efforts is to examine the information needs of various stakeholder groups. This poster will present a summary and synthesis of existing surveys, reports, and other literature that examines user needs for sea ice predictions. The synthesis will include lessons learned from the Sea Ice Prediction Network (a collaborative, multi-agency-funded project focused on seasonal Arctic sea ice predictions), the Sea Ice for Walrus Outlook (a resource for Alaska Native subsistence hunters and coastal communities, that provides reports on weather and sea ice conditions), and other efforts. The poster will specifically compare the scales and variables of sea ice forecasts currently available, as compared to what information is requested by various user groups.

  3. Distributed Planning and Control for Teams of Cooperating Mobile Robots

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Parker, L.E.

    2004-06-15

    This CRADA project involved the cooperative research of investigators in ORNL's Center for Engineering Science Advanced Research (CESAR) with researchers at Caterpillar, Inc. The subject of the research was the development of cooperative control strategies for autonomous vehicles performing applications of interest to Caterpillar customers. The project involved three Phases of research, conducted over the time period of November 1998 through December 2001. This project led to the successful development of several technologies and demonstrations in realistic simulation that illustrated the effectiveness of the control approaches for distributed planning and cooperation in multi-robot teams.

  4. NHERI: Advancing the Research Infrastructure of the Multi-Hazard Community

    NASA Astrophysics Data System (ADS)

    Blain, C. A.; Ramirez, J. A.; Bobet, A.; Browning, J.; Edge, B.; Holmes, W.; Johnson, D.; Robertson, I.; Smith, T.; Zuo, D.

    2017-12-01

    The Natural Hazards Engineering Research Infrastructure (NHERI), supported by the National Science Foundation (NSF), is a distributed, multi-user national facility that provides the natural hazards research community with access to an advanced research infrastructure. Components of NHERI are comprised of a Network Coordination Office (NCO), a cloud-based cyberinfrastructure (DesignSafe-CI), a computational modeling and simulation center (SimCenter), and eight Experimental Facilities (EFs), including a post-disaster, rapid response research facility (RAPID). Utimately NHERI enables researchers to explore and test ground-breaking concepts to protect homes, businesses and infrastructure lifelines from earthquakes, windstorms, tsunamis, and surge enabling innovations to help prevent natural hazards from becoming societal disasters. When coupled with education and community outreach, NHERI will facilitate research and educational advances that contribute knowledge and innovation toward improving the resiliency of the nation's civil infrastructure to withstand natural hazards. The unique capabilities and coordinating activities over Year 1 between NHERI's DesignSafe-CI, the SimCenter, and individual EFs will be presented. Basic descriptions of each component are also found at https://www.designsafe-ci.org/facilities/. Additionally to be discussed are the various roles of the NCO in leading development of a 5-year multi-hazard science plan, coordinating facility scheduling and fostering the sharing of technical knowledge and best practices, leading education and outreach programs such as the recent Summer Institute and multi-facility REU program, ensuring a platform for technology transfer to practicing engineers, and developing strategic national and international partnerships to support a diverse multi-hazard research and user community.

  5. Human uniqueness-self-interest and social cooperation.

    PubMed

    Okada, Daijiro; Bingham, Paul M

    2008-07-21

    Humans are unique among all species of terrestrial history in both ecological dominance and individual properties. Many, or perhaps all, of the unique elements of this nonpareil status can be plausibly interpreted as evolutionary and strategic elements and consequences of the unprecedented intensity and scale of our social cooperation. Convincing explanation of this unique human social adaptation remains a central, unmet challenge to the scientific enterprise. We develop a hypothesis for the ancestral origin of expanded cooperative social behavior. Specifically, we present a game theoretic analysis demonstrating that a specific pattern of expanded social cooperation between conspecific individuals with conflicts of interest (including non-kin) can be strategically viable, but only in animals that possess a highly unusual capacity for conspecific violence (credible threat) having very specific properties that dramatically reduce the costs of coercive violence. The resulting reduced costs allow preemptive or compensated coercion to be an instantaneously self-interested behavior under diverse circumstances rather than in rare, idiosyncratic circumstances as in actors (animals) who do not have access to inexpensive coercive threat. Humans are apparently unique among terrestrial organisms in having evolved conspecific coercive capabilities that fulfill these stringent requirements. Thus, our results support the proposal that access to a novel capacity for projection of coercive threat might represent the essential initiating event for the evolution of a human-like pattern of social cooperation and the subsequent evolution of the diverse features of human uniqueness. Empirical evidence indicates that these constraints were, in fact, met only in our evolutionary lineage. The logic for the emergence of uniquely human cooperation suggested by our analysis apparently accounts simply for the human fossil record.

  6. CyanoGEBA: A Better Understanding of Cynobacterial Diversity through Large-Scale Genomics (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shih, Patrick

    2012-03-22

    Patrick Shih, representing both the University of California, Berkeley and JGI, gives a talk titled "CyanoGEBA: A Better Understanding of Cynobacterial Diversity through Large-scale Genomics" at the JGI 7th Annual Users Meeting: Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, California.

  7. CyanoGEBA: A Better Understanding of Cynobacterial Diversity through Large-Scale Genomics (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema

    Shih, Patrick

    2018-01-10

    Patrick Shih, representing both the University of California, Berkeley and JGI, gives a talk titled "CyanoGEBA: A Better Understanding of Cynobacterial Diversity through Large-scale Genomics" at the JGI 7th Annual Users Meeting: Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, California.

  8. Multi-agents and learning: Implications for Webusage mining.

    PubMed

    Lotfy, Hewayda M S; Khamis, Soheir M S; Aboghazalah, Maie M

    2016-03-01

    Characterization of user activities is an important issue in the design and maintenance of websites. Server weblog files have abundant information about the user's current interests. This information can be mined and analyzed therefore the administrators may be able to guide the users in their browsing activity so they may obtain relevant information in a shorter span of time to obtain user satisfaction. Web-based technology facilitates the creation of personally meaningful and socially useful knowledge through supportive interactions, communication and collaboration among educators, learners and information. This paper suggests a new methodology based on learning techniques for a Web-based Multiagent-based application to discover the hidden patterns in the user's visited links. It presents a new approach that involves unsupervised, reinforcement learning, and cooperation between agents. It is utilized to discover patterns that represent the user's profiles in a sample website into specific categories of materials using significance percentages. These profiles are used to make recommendations of interesting links and categories to the user. The experimental results of the approach showed successful user pattern recognition, and cooperative learning among agents to obtain user profiles. It indicates that combining different learning algorithms is capable of improving user satisfaction indicated by the percentage of precision, recall, the progressive category weight and F 1-measure.

  9. Visualising uncertainty: interpreting quantified geoscientific inversion outputs for a diverse user community.

    NASA Astrophysics Data System (ADS)

    Reading, A. M.; Morse, P. E.; Staal, T.

    2017-12-01

    Geoscientific inversion outputs, such as seismic tomography contour images, are finding increasing use amongst scientific user communities that have limited knowledge of the impact of output parameter uncertainty on subsequent interpretations made from such images. We make use of a newly written computer application which enables seismic tomography images to be displayed in a performant 3D graphics environment. This facilitates the mapping of colour scales to the human visual sensorium for the interactive interpretation of contoured inversion results incorporating parameter uncertainty. Two case examples of seismic tomography inversions or contoured compilations are compared from the southern hemisphere continents of Australia and Antarctica. The Australian example is based on the AuSREM contoured seismic wavespeed model while the Antarctic example is a valuable but less well constrained result. Through adjusting the multiple colour gradients, layer separations, opacity, illumination, shadowing and background effects, we can optimise the insights obtained from the 3D structure in the inversion compilation or result. Importantly, we can also limit the display to show information in a way that is mapped to the uncertainty in the 3D result. Through this practical application, we demonstrate that the uncertainty in the result can be handled through a well-posed mapping of the parameter values to displayed colours in the knowledge of what is perceived visually by a typical human. We found that this approach maximises the chance of a useful tectonic interpretation by a diverse scientific user community. In general, we develop the idea that quantified inversion uncertainty can be used to tailor the way that the output is presented to the analyst for scientific interpretation.

  10. Bacterial recombination promotes the evolution of multi-drug-resistance in functionally diverse populations

    PubMed Central

    Perron, Gabriel G.; Lee, Alexander E. G.; Wang, Yun; Huang, Wei E.; Barraclough, Timothy G.

    2012-01-01

    Bacterial recombination is believed to be a major factor explaining the prevalence of multi-drug-resistance (MDR) among pathogenic bacteria. Despite extensive evidence for exchange of resistance genes from retrospective sequence analyses, experimental evidence for the evolutionary benefits of bacterial recombination is scarce. We compared the evolution of MDR between populations of Acinetobacter baylyi in which we manipulated both the recombination rate and the initial diversity of strains with resistance to single drugs. In populations lacking recombination, the initial presence of multiple strains resistant to different antibiotics inhibits the evolution of MDR. However, in populations with recombination, the inhibitory effect of standing diversity is alleviated and MDR evolves rapidly. Moreover, only the presence of DNA harbouring resistance genes promotes the evolution of resistance, ruling out other proposed benefits for recombination. Together, these results provide direct evidence for the fitness benefits of bacterial recombination and show that this occurs by mitigation of functional interference between genotypes resistant to single antibiotics. Although analogous to previously described mechanisms of clonal interference among alternative beneficial mutations, our results actually highlight a different mechanism by which interactions among co-occurring strains determine the benefits of recombination for bacterial evolution. PMID:22048956

  11. Reliability and throughput issues for optical wireless and RF wireless systems

    NASA Astrophysics Data System (ADS)

    Yu, Meng

    . Most user cooperation protocols work in a time sharing manner, where a node forwards others' messages and sends its own message at different sections within a provisioned time slot. In the proposed scheme the two messages are encoded together in a single codework using network coding and transmitted in the given time slot. We also propose a general multiple-user cooperation framework. Under this framework, we show that network coding can achieve better diversity and provide effective better inter-user channels than time sharing. The last part of the dissertation focuses on multi-relay packet transmission. We propose an adaptive and distributive coding scheme for the relay nodes to adaptively cooperate and forward messages. The adaptive scheme shows performance gain over fixed schemes. Then we shift our viewpoint and represent the network as part of encoders and part of decoders.

  12. Enriching Spatial Data Infrastructure (sdi) by User Generated Contents for Transportation

    NASA Astrophysics Data System (ADS)

    Shakeri, M.; Alimohammadi, A.; Sadeghi-Niaraki, A.; Alesheikh, A. A.

    2013-09-01

    transportation systems requires the exchange of large volumes of spatial data and often close cooperation among the various organizations. However, there is no technical and organizational process to get a suitable data infrastructure to address diverse needs of the transportation. Hence, development of a common standards and a simple data exchange mechanism is strongly needed in the field of transportation for decision support. Since one of the main purposes of transportation projects is to improve the quality of services provided to users, it is necessary to involve the users themselves in the decision making processes. This should be done through a public participation and involvement in all stages of the transportation projects. In other words, using public knowledge and information as another source of information is very important to make better and more efficient decisions. Public participation in transportation projects can also help organizations to enhance their public supports; because the lack of public support can lead to failure of technically valid projects. However, due to complexity of the transportation tasks, lack of appropriate environment and methods for facilitation of the public participation, collection and analysis of the public information and opinions, public participation in this field has not been well considered so far. This paper reviews the previous researches based on the enriched SDI development and its movement toward the VGI by focusing on the public participation in transportation projects. To this end, methods and models that have been used in previous researches are studied and classified initially. Then, methods of the previous researchers on VGI and transportation are conceptualized in SDI. Finally, the suggested method for transportation projects is presented. Results indicate success of the new generation of SDI in integration with public participation for transportation projects.

  13. Predicting Human Cooperation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nay, John J.; Vorobeychik, Yevgeniy; Xia, Cheng -Yi

    The Prisoner’s Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner’s Dilemma (defection), when played by both players, is mutually harmful. Repetition of the Prisoner’s Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner’s Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational modelmore » of human behavior in repeated Prisoner’s Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. As a result, we demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation.« less

  14. Predicting Human Cooperation

    DOE PAGES

    Nay, John J.; Vorobeychik, Yevgeniy; Xia, Cheng -Yi

    2016-05-12

    The Prisoner’s Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner’s Dilemma (defection), when played by both players, is mutually harmful. Repetition of the Prisoner’s Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner’s Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational modelmore » of human behavior in repeated Prisoner’s Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. As a result, we demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation.« less

  15. Advanced Multi-Physics (AMP)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Philip, Bobby

    2012-06-01

    The Advanced Multi-Physics (AMP) code, in its present form, will allow a user to build a multi-physics application code for existing mechanics and diffusion operators and extend them with user-defined material models and new physics operators. There are examples that demonstrate mechanics, thermo-mechanics, coupled diffusion, and mechanical contact. The AMP code is designed to leverage a variety of mathematical solvers (PETSc, Trilinos, SUNDIALS, and AMP solvers) and mesh databases (LibMesh and AMP) in a consistent interchangeable approach.

  16. Cooperative wireless network control based health and activity monitoring system.

    PubMed

    Prakash, R; Ganesh, A Balaji; Girish, Siva V

    2016-10-01

    A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.

  17. User-Centric Multi-Criteria Information Retrieval

    NASA Technical Reports Server (NTRS)

    Wolfe, Shawn R.; Zhang, Yi

    2009-01-01

    Information retrieval models usually represent content only, and not other considerations, such as authority, cost, and recency. How could multiple criteria be utilized in information retrieval, and how would it affect the results? In our experiments, using multiple user-centric criteria always produced better results than a single criteria.

  18. Stable self-serving personality traits in recreational and dependent cocaine users

    PubMed Central

    Quednow, Boris B.; Hulka, Lea M.; Preller, Katrin H.; Baumgartner, Markus R.; Eisenegger, Christoph; Vonmoos, Matthias

    2017-01-01

    Chronic cocaine use has been associated with impairments in social cognition, self-serving and antisocial behavior, and socially relevant personality disorders (PD). Despite the apparent relationship between Machiavellianism and stimulant use, no study has explicitly examined this personality concept in cocaine users so far. In the frame of the longitudinal Zurich Cocaine Cognition Study, the Machiavellianism Questionnaire (MACH-IV) was assessed in 68 recreational and 30 dependent cocaine users as well as in 68 psychostimulant-naïve controls at baseline. Additionally, three closely related personality dimensions from the Temperament and Character Inventory (TCI)–cooperativeness, (social) reward dependence, and self-directedness–and the screening questionnaire of the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) were acquired. At the one-year follow-up, 57 cocaine users and 48 controls were reassessed with the MACH-IV. Finally, MACH-IV scores were correlated with measures of social cognition and interaction (cognitive/emotional empathy, Theory-of-Mind, prosocial behavior) and with SCID-II PD scores assessed at baseline. Both recreational and dependent cocaine users showed significantly higher Machiavellianism than controls, while dependent cocaine users additionally displayed significantly lower levels of TCI cooperativeness and self-directedness. During the one-year interval, MACH-IV scores showed high test-retest reliability and also the significant gap between cocaine users and controls remained. Moreover, in cocaine users, higher Machiavellianism correlated significantly with lower levels of cooperativeness and self-directedness, with less prosocial behavior, and with higher cluster B PD scores. However, Machiavellianism was not correlated with measures of cocaine use severity (r<-.15). Both recreational and dependent cocaine users display pronounced and stable Machiavellian personality traits. The lack of correlations

  19. Multiple UAV Cooperation for Wildfire Monitoring

    NASA Astrophysics Data System (ADS)

    Lin, Zhongjie

    Wildfires have been a major factor in the development and management of the world's forest. An accurate assessment of wildfire status is imperative for fire management. This thesis is dedicated to the topic of utilizing multiple unmanned aerial vehicles (UAVs) to cooperatively monitor a large-scale wildfire. This is achieved through wildfire spreading situation estimation based on on-line measurements and wise cooperation strategy to ensure efficiency. First, based on the understanding of the physical characteristics of the wildfire propagation behavior, a wildfire model and a Kalman filter-based method are proposed to estimate the wildfire rate of spread and the fire front contour profile. With the enormous on-line measurements from on-board sensors of UAVs, the proposed method allows a wildfire monitoring mission to benefit from on-line information updating, increased flexibility, and accurate estimation. An independent wildfire simulator is utilized to verify the effectiveness of the proposed method. Second, based on the filter analysis, wildfire spreading situation and vehicle dynamics, the influence of different cooperation strategies of UAVs to the overall mission performance is studied. The multi-UAV cooperation problem is formulated in a distributed network. A consensus-based method is proposed to help address the problem. The optimal cooperation strategy of UAVs is obtained through mathematical analysis. The derived optimal cooperation strategy is then verified in an independent fire simulation environment to verify its effectiveness.

  20. Prototyping a Hybrid Cooperative and Tele-robotic Surgical System for Retinal Microsurgery.

    PubMed

    Balicki, Marcin; Xia, Tian; Jung, Min Yang; Deguet, Anton; Vagvolgyi, Balazs; Kazanzides, Peter; Taylor, Russell

    2011-06-01

    This paper presents the design of a tele-robotic microsurgical platform designed for development of cooperative and tele-operative control schemes, sensor based smart instruments, user interfaces and new surgical techniques with eye surgery as the driving application. The system is built using the distributed component-based cisst libraries and the Surgical Assistant Workstation framework. It includes a cooperatively controlled EyeRobot2, a da Vinci Master manipulator, and a remote stereo visualization system. We use constrained optimization based virtual fixture control to provide Virtual Remote-Center-of-Motion (vRCM) and haptic feedback. Such system can be used in a hybrid setup, combining local cooperative control with remote tele-operation, where an experienced surgeon can provide hand-over-hand tutoring to a novice user. In another scheme, the system can provide haptic feedback based on virtual fixtures constructed from real-time force and proximity sensor information.

  1. Prototyping a Hybrid Cooperative and Tele-robotic Surgical System for Retinal Microsurgery

    PubMed Central

    Balicki, Marcin; Xia, Tian; Jung, Min Yang; Deguet, Anton; Vagvolgyi, Balazs; Kazanzides, Peter; Taylor, Russell

    2013-01-01

    This paper presents the design of a tele-robotic microsurgical platform designed for development of cooperative and tele-operative control schemes, sensor based smart instruments, user interfaces and new surgical techniques with eye surgery as the driving application. The system is built using the distributed component-based cisst libraries and the Surgical Assistant Workstation framework. It includes a cooperatively controlled EyeRobot2, a da Vinci Master manipulator, and a remote stereo visualization system. We use constrained optimization based virtual fixture control to provide Virtual Remote-Center-of-Motion (vRCM) and haptic feedback. Such system can be used in a hybrid setup, combining local cooperative control with remote tele-operation, where an experienced surgeon can provide hand-over-hand tutoring to a novice user. In another scheme, the system can provide haptic feedback based on virtual fixtures constructed from real-time force and proximity sensor information. PMID:24398557

  2. Continuum modeling of cooperative traffic flow dynamics

    NASA Astrophysics Data System (ADS)

    Ngoduy, D.; Hoogendoorn, S. P.; Liu, R.

    2009-07-01

    This paper presents a continuum approach to model the dynamics of cooperative traffic flow. The cooperation is defined in our model in a way that the equipped vehicle can issue and receive a warning massage when there is downstream congestion. Upon receiving the warning massage, the (up-stream) equipped vehicle will adapt the current desired speed to the speed at the congested area in order to avoid sharp deceleration when approaching the congestion. To model the dynamics of such cooperative systems, a multi-class gas-kinetic theory is extended to capture the adaptation of the desired speed of the equipped vehicle to the speed at the downstream congested traffic. Numerical simulations are carried out to show the influence of the penetration rate of the equipped vehicles on traffic flow stability and capacity in a freeway.

  3. Performance of a novel LED lamp arrangement to reduce SNR fluctuation for multi-user visible light communication systems.

    PubMed

    Wang, Zixiong; Yu, Changyuan; Zhong, Wen-De; Chen, Jian; Chen, Wei

    2012-02-13

    This paper investigates the performance of our recently proposed LED lamp arrangement to reduce the SNR fluctuation from different locations in the room for multi-user visible light communications. The LED lamp arrangement consists of 4 LED lamps positioned in the corners and 12 LED lamps spread evenly on a circle. Our studies show that the SNR fluctuation under such a LED lamp arrangement is reduced from 14.5 dB to 0.9 dB, which guarantees that users can obtain almost identical communication quality, regardless of their locations. After time domain zero-forcing (ZF) equalization, the BER performances and channel capacities of 100-Mbit/s and 200-Mbit/s bipolar on-off-keying (OOK) signal with most significant inter-symbol interference (ISI) are very close to that of the channel without any ISI caused by this LED lamp arrangement.

  4. Multiple tolerances dilute the second order cooperative dilemma

    NASA Astrophysics Data System (ADS)

    Sui, Xiukai; Wu, Bin; Wang, Long

    2017-12-01

    A peer punisher directly imposes fines upon defectors at a cost to himself. It is one of the mechanisms promoting cooperation, which is ubiquitous in nature. Typically, it is assumed that a peer punisher punishes provided that there is one defector in the group. The threshold that triggers punishment, however, is not necessarily one. The larger the threshold is, the more tolerant the peer punisher is. We study the evolutionary dynamics of those diverse tolerant peer punishment strategies in public goods game. We find that, i) less tolerant punishers prevail over tolerant ones; ii) large group size could enhance punishment, in contrast with the case in the first-order cooperative dilemma. Our analytical results are based on weak selection limit and large population size, which are verified by simulations. Our work sheds light on how punishment of diverse tolerance evolves.

  5. Interlibrary cooperation: from ILL to IAIMS and beyond.

    PubMed

    Riordan, M L; Perry, G J

    1999-07-01

    A recent solicitation over the MEDLIB-L e-mail discussion list revealed over thirty diverse examples of hospital library-based interlibrary cooperative initiatives currently underway. Many are familiar and have been featured in the professional literature. Most go unreported and unrecognized however, comprising invisible resource-sharing infrastructures that hospital librarians painstakingly piece together in order to provide their clients with expanded service options. This paper, drawing from the MEDLIB-L survey as well as descriptions in the published literature, provides a broad overview of such recent interlibrary cooperative efforts. Examples include interlibrary loan networks, collective purchasing initiatives, holder-of-record or union catalog access agreements, arrangements to provide e-mail and Internet access, and consortia to share electronic resources. Examples were chosen based on the initiatives' diversity of participants, and represent a wide range of locations across the United States. Such initiatives focus on local, statewide, or regional collaboration, and several involve partnerships between academic medical center libraries and regional hospital libraries. An early example of a hospital-based interlibrary cooperative IAIMS effort is described, pointing to future possibilities involving the Internet and regional hospital system intranets.

  6. Development of a task analysis tool to facilitate user interface design

    NASA Technical Reports Server (NTRS)

    Scholtz, Jean C.

    1992-01-01

    A good user interface is one that facilitates the user in carrying out his task. Such interfaces are difficult and costly to produce. The most important aspect in producing a good interface is the ability to communicate to the software designers what the user's task is. The Task Analysis Tool is a system for cooperative task analysis and specification of the user interface requirements. This tool is intended to serve as a guide to development of initial prototypes for user feedback.

  7. Exploring User Acceptance of FOSS: The Role of the Age of the Users

    NASA Astrophysics Data System (ADS)

    Gallego, M. Dolores; Bueno, Salvador

    Free and open source software (FOSS) movement essentially arises like answer to the evolution occurred in the market from the software, characterized by the closing of the source code. Furthermore, some FOSS characteristics, such as (1) the advance of this movement and (2) the attractiveness that contributes the voluntary and cooperative work, have increased the interest of the users towards free software. Traditionally, research in FOSS has focused on identifying individual personal motives for participating in the development of a FOSS project, analyzing specific FOSS solutions, or the FOSS movement itself. Nevertheless, the advantages of the FOSS for users and the effect of the demographic dimensions on user acceptance for FOSS have been two research topics with little attention. Specifically, this paper's aim is to focus on the influence of the userś age with FOSS the FOSS acceptance. Based on the literature, userś age is an essential demographic dimension for explaining the Information Systems acceptance. With this purpose, the authors have developed a research model based on the Technological Acceptance Model (TAM).

  8. Second Language Users and Emerging English Designs

    ERIC Educational Resources Information Center

    Jordan, Jay

    2009-01-01

    As English spreads as an international language, it evolves through diverse users' writing and speaking. However, traditional views of ESL users focus on their distance from fairly static notions of English-language competence. This research uses a grounded theory approach to describe a range of competencies that emerge in ESL users' interactions…

  9. Computerized Adaptive Testing (CAT): A User Manual

    DTIC Science & Technology

    1984-03-12

    NPRDC TR 84-32 COMPUTERIZED ADAPTIVE TESTING ( CAT ): A USER MANUAL Susan Hardwick Lawrence Eastman Ross Cooper Rehab Group, Incorporated San...a ~EI’IOD COVIRED COMPUTERIZED ADAPTIVE TESTING ( CAT ) Final Report Aug 1981-June 1982 A USER MANUAL 1. ~l:l’t,ORMINCI ORCI. RE~ORT NUM.I:R 62-83...II nee• .. _, entl ldentll)’ ,,. llloclr _,.,) A joint-service effort is underway to develop a computerized adaptive testing ( CAT ) system and to

  10. Robustness of norm-driven cooperation in the commons

    PubMed Central

    2016-01-01

    Sustainable use of common-pool resources such as fish, water or forests depends on the cooperation of resource users that restrain their individual extraction to socially optimal levels. Empirical evidence has shown that under certain social and biophysical conditions, self-organized cooperation in the commons can evolve. Global change, however, may drastically alter these conditions. We assess the robustness of cooperation to environmental variability in a stylized model of a community that harvests a shared resource. Community members follow a norm of socially optimal resource extraction, which is enforced through social sanctioning. Our results indicate that both resource abundance and a small increase in resource variability can lead to collapse of cooperation observed in the no-variability case, while either scarcity or large variability have the potential to stabilize it. The combined effects of changes in amount and variability can reinforce or counteract each other depending on their size and the initial level of cooperation in the community. If two socially separate groups are ecologically connected through resource leakage, cooperation in one can destabilize the other. These findings provide insights into possible effects of global change and spatial connectivity, indicating that there is no simple answer as to their effects on cooperation and sustainable resource use. PMID:26740611

  11. A game theory-reinforcement learning (GT-RL) method to develop optimal operation policies for multi-operator reservoir systems

    NASA Astrophysics Data System (ADS)

    Madani, Kaveh; Hooshyar, Milad

    2014-11-01

    Reservoir systems with multiple operators can benefit from coordination of operation policies. To maximize the total benefit of these systems the literature has normally used the social planner's approach. Based on this approach operation decisions are optimized using a multi-objective optimization model with a compound system's objective. While the utility of the system can be increased this way, fair allocation of benefits among the operators remains challenging for the social planner who has to assign controversial weights to the system's beneficiaries and their objectives. Cooperative game theory provides an alternative framework for fair and efficient allocation of the incremental benefits of cooperation. To determine the fair and efficient utility shares of the beneficiaries, cooperative game theory solution methods consider the gains of each party in the status quo (non-cooperation) as well as what can be gained through the grand coalition (social planner's solution or full cooperation) and partial coalitions. Nevertheless, estimation of the benefits of different coalitions can be challenging in complex multi-beneficiary systems. Reinforcement learning can be used to address this challenge and determine the gains of the beneficiaries for different levels of cooperation, i.e., non-cooperation, partial cooperation, and full cooperation, providing the essential input for allocation based on cooperative game theory. This paper develops a game theory-reinforcement learning (GT-RL) method for determining the optimal operation policies in multi-operator multi-reservoir systems with respect to fairness and efficiency criteria. As the first step to underline the utility of the GT-RL method in solving complex multi-agent multi-reservoir problems without a need for developing compound objectives and weight assignment, the proposed method is applied to a hypothetical three-agent three-reservoir system.

  12. visPIG--a web tool for producing multi-region, multi-track, multi-scale plots of genetic data.

    PubMed

    Scales, Matthew; Jäger, Roland; Migliorini, Gabriele; Houlston, Richard S; Henrion, Marc Y R

    2014-01-01

    We present VISual Plotting Interface for Genetics (visPIG; http://vispig.icr.ac.uk), a web application to produce multi-track, multi-scale, multi-region plots of genetic data. visPIG has been designed to allow users not well versed with mathematical software packages and/or programming languages such as R, Matlab®, Python, etc., to integrate data from multiple sources for interpretation and to easily create publication-ready figures. While web tools such as the UCSC Genome Browser or the WashU Epigenome Browser allow custom data uploads, such tools are primarily designed for data exploration. This is also true for the desktop-run Integrative Genomics Viewer (IGV). Other locally run data visualisation software such as Circos require significant computer skills of the user. The visPIG web application is a menu-based interface that allows users to upload custom data tracks and set track-specific parameters. Figures can be downloaded as PDF or PNG files. For sensitive data, the underlying R code can also be downloaded and run locally. visPIG is multi-track: it can display many different data types (e.g association, functional annotation, intensity, interaction, heat map data,…). It also allows annotation of genes and other custom features in the plotted region(s). Data tracks can be plotted individually or on a single figure. visPIG is multi-region: it supports plotting multiple regions, be they kilo- or megabases apart or even on different chromosomes. Finally, visPIG is multi-scale: a sub-region of particular interest can be 'zoomed' in. We describe the various features of visPIG and illustrate its utility with examples. visPIG is freely available through http://vispig.icr.ac.uk under a GNU General Public License (GPLv3).

  13. Topological Interference Management for K-User Downlink Massive MIMO Relay Network Channel.

    PubMed

    Selvaprabhu, Poongundran; Chinnadurai, Sunil; Li, Jun; Lee, Moon Ho

    2017-08-17

    In this paper, we study the emergence of topological interference alignment and the characterizing features of a multi-user broadcast interference relay channel. We propose an alternative transmission strategy named the relay space-time interference alignment (R-STIA) technique, in which a K -user multiple-input-multiple-output (MIMO) interference channel has massive antennas at the transmitter and relay. Severe interference from unknown transmitters affects the downlink relay network channel and degrades the system performance. An additional (unintended) receiver is introduced in the proposed R-STIA technique to overcome the above problem, since it has the ability to decode the desired signals for the intended receiver by considering cooperation between the receivers. The additional receiver also helps in recovering and reconstructing the interference signals with limited channel state information at the relay (CSIR). The Alamouti space-time transmission technique and minimum mean square error (MMSE) linear precoder are also used in the proposed scheme to detect the presence of interference signals. Numerical results show that the proposed R-STIA technique achieves a better performance in terms of the bit error rate (BER) and sum-rate compared to the existing broadcast channel schemes.

  14. Topological Interference Management for K-User Downlink Massive MIMO Relay Network Channel

    PubMed Central

    Li, Jun; Lee, Moon Ho

    2017-01-01

    In this paper, we study the emergence of topological interference alignment and the characterizing features of a multi-user broadcast interference relay channel. We propose an alternative transmission strategy named the relay space-time interference alignment (R-STIA) technique, in which a K-user multiple-input-multiple-output (MIMO) interference channel has massive antennas at the transmitter and relay. Severe interference from unknown transmitters affects the downlink relay network channel and degrades the system performance. An additional (unintended) receiver is introduced in the proposed R-STIA technique to overcome the above problem, since it has the ability to decode the desired signals for the intended receiver by considering cooperation between the receivers. The additional receiver also helps in recovering and reconstructing the interference signals with limited channel state information at the relay (CSIR). The Alamouti space-time transmission technique and minimum mean square error (MMSE) linear precoder are also used in the proposed scheme to detect the presence of interference signals. Numerical results show that the proposed R-STIA technique achieves a better performance in terms of the bit error rate (BER) and sum-rate compared to the existing broadcast channel schemes. PMID:28817071

  15. Multi-user investigation organizer

    NASA Technical Reports Server (NTRS)

    Panontin, Tina L. (Inventor); Williams, James F. (Inventor); Carvalho, Robert E. (Inventor); Sturken, Ian (Inventor); Wolfe, Shawn R. (Inventor); Gawdiak, Yuri O. (Inventor); Keller, Richard M. (Inventor)

    2009-01-01

    A system that allows a team of geographically dispersed users to collaboratively analyze a mishap event. The system includes a reconfigurable ontology, including instances that are related to and characterize the mishap, a semantic network that receives, indexes and stores, for retrieval, viewing and editing, the instances and links between the instances, a network browser interface for retrieving and viewing screens that present the instances and links to other instances and that allow editing thereof, and a rule-based inference engine, including a collection of rules associated with establishment of links between the instances. A possible conclusion arising from analysis of the mishap event may be characterized as one or more of: not a credible conclusion; an unlikely conclusion; a credible conclusion; conclusion needs analysis; conclusion needs supporting data; conclusion proposed to be closed; and an un-reviewed conclusion.

  16. Small groups and long memories promote cooperation.

    PubMed

    Stewart, Alexander J; Plotkin, Joshua B

    2016-06-01

    Complex social behaviors lie at the heart of many of the challenges facing evolutionary biology, sociology, economics, and beyond. For evolutionary biologists the question is often how group behaviors such as collective action, or decision making that accounts for memories of past experience, can emerge and persist in an evolving system. Evolutionary game theory provides a framework for formalizing these questions and admitting them to rigorous study. Here we develop such a framework to study the evolution of sustained collective action in multi-player public-goods games, in which players have arbitrarily long memories of prior rounds of play and can react to their experience in an arbitrary way. We construct a coordinate system for memory-m strategies in iterated n-player games that permits us to characterize all cooperative strategies that resist invasion by any mutant strategy, and stabilize cooperative behavior. We show that, especially when groups are small, longer-memory strategies make cooperation easier to evolve, by increasing the number of ways to stabilize cooperation. We also explore the co-evolution of behavior and memory. We find that even when memory has a cost, longer-memory strategies often evolve, which in turn drives the evolution of cooperation, even when the benefits for cooperation are low.

  17. From Management to Negotiation: Technical and Institutional Innovations for Integrated Water Resource Management in the Upper Comoé River Basin, Burkina Faso

    NASA Astrophysics Data System (ADS)

    Roncoli, Carla; Kirshen, Paul; Etkin, Derek; Sanon, Moussa; Somé, Léopold; Dembélé, Youssouf; Sanfo, Bienvenue J.; Zoungrana, Jacqueline; Hoogenboom, Gerrit

    2009-10-01

    This study focuses on the potential role of technical and institutional innovations for improving water management in a multi-user context in Burkina Faso. We focus on a system centered on three reservoirs that capture the waters of the Upper Comoé River Basin and servicing a diversity of users, including a sugar manufacturing company, a urban water supply utility, a farmer cooperative, and other downstream users. Due to variable and declining rainfall and expanding users’ needs, drastic fluctuations in water supply and demand occur during each dry season. A decision support tool was developed through participatory research to enable users to assess the impact of alternative release and diversion schedules on deficits faced by each user. The tool is meant to be applied in the context of consultative planning by a local user committee that has been created by a new national integrated water management policy. We contend that both solid science and good governance are instrumental in realizing efficient and equitable water management and adaptation to climate variability and change. But, while modeling tools and negotiation platforms may assist users in managing climate risk, they also introduce additional uncertainties into the deliberative process. It is therefore imperative to understand how these technological and institutional innovations frame water use issues and decisions to ensure that such framing is consistent with the goals of integrated water resource management.

  18. Joint Interference Alignment and Power Allocation for K-User Multicell MIMO Channel through Staggered Antenna Switching

    PubMed Central

    2018-01-01

    In this paper, we characterise the joint interference alignment (IA) and power allocation strategies for a K-user multicell multiple-input multiple-output (MIMO) Gaussian interference channel. We consider a MIMO interference channel with blind-IA through staggered antenna switching on the receiver. We explore the power allocation and feasibility condition for cooperative cell-edge (CE) mobile users (MUs) by assuming that the channel state information is unknown. The new insight behind the transmission strategy of the proposed scheme is premeditated (randomly generated transmission strategy) and partial cooperative CE MUs, where the transmitter is equipped with a conventional antenna, the receiver is equipped with a reconfigurable multimode antenna (staggered antenna switching pattern), and the receiver switches between preset T modes. Our proposed scheme assists and aligns the desired signals and interference signals to cancel the common interference signals because the received signal must have a corresponding independent signal subspace. The capacity for a K-user multicell MIMO Gaussian interference channel with reconfigurable multimode antennas is completely characterised. Furthermore, we show that the proposed K-user multicell MIMO scheduling and K-user L-cell CEUs partial cooperation algorithms elaborate the generalisation of K-user IA and power allocation strategies. The numerical results demonstrate that the proposed intercell interference scheme with partial-cooperative CE MUs achieves better capacity and signal-to-interference plus noise ratio (SINR) performance compared to noncooperative CE MUs and without intercell interference schemes. PMID:29382100

  19. Joint Interference Alignment and Power Allocation for K-User Multicell MIMO Channel through Staggered Antenna Switching.

    PubMed

    Selvaprabhu, Poongundran; Chinnadurai, Sunil; Sarker, Md Abdul Latif; Lee, Moon Ho

    2018-01-28

    In this paper, we characterise the joint interference alignment (IA) and power allocation strategies for a K -user multicell multiple-input multiple-output (MIMO) Gaussian interference channel. We consider a MIMO interference channel with blind-IA through staggered antenna switching on the receiver. We explore the power allocation and feasibility condition for cooperative cell-edge (CE) mobile users (MUs) by assuming that the channel state information is unknown. The new insight behind the transmission strategy of the proposed scheme is premeditated (randomly generated transmission strategy) and partial cooperative CE MUs, where the transmitter is equipped with a conventional antenna, the receiver is equipped with a reconfigurable multimode antenna (staggered antenna switching pattern), and the receiver switches between preset T modes. Our proposed scheme assists and aligns the desired signals and interference signals to cancel the common interference signals because the received signal must have a corresponding independent signal subspace. The capacity for a K -user multicell MIMO Gaussian interference channel with reconfigurable multimode antennas is completely characterised. Furthermore, we show that the proposed K -user multicell MIMO scheduling and K -user L -cell CEUs partial cooperation algorithms elaborate the generalisation of K -user IA and power allocation strategies. The numerical results demonstrate that the proposed intercell interference scheme with partial-cooperative CE MUs achieves better capacity and signal-to-interference plus noise ratio (SINR) performance compared to noncooperative CE MUs and without intercell interference schemes.

  20. An Adaptive Cooperative Strategy for Underlay MIMO Cognitive Radio Networks: An Opportunistic and Low-Complexity Approach

    NASA Astrophysics Data System (ADS)

    Mazoochi, M.; Pourmina, M. A.; Bakhshi, H.

    2015-03-01

    The core aim of this work is the maximization of the achievable data rate of the secondary user pairs (SU pairs), while ensuring the QoS of primary users (PUs). All users are assumed to be equipped with multiple antennas. It is assumed that when PUs are present, the direct communications between SU pairs introduces intolerable interference to PUs and thereby SUs transmit signal using the cooperation of other SUs and avoid transmitting in the direct channel. In brief, an adaptive cooperative strategy for multiple-input/multiple-output (MIMO) cognitive radio networks is proposed. At the presence of PUs, the issue of joint relay selection and power allocation in Underlay MIMO Cooperative Cognitive Radio Networks (U-MIMO-CCRN) is addressed. The optimal approach for determining the power allocation and the cooperating SU is proposed. Besides, the outage probability of the proposed communication protocol is further derived. Due to high complexity of the optimal approach, a low-complexity approach is further proposed and its performance is evaluated using simulations. The simulation results reveal that the performance loss due to the low-complexity approach is only about 14%, while the complexity is greatly reduced.

  1. Kennedy Space Center: Apollo to Multi-User Spaceport

    NASA Technical Reports Server (NTRS)

    Weber, Philip J.; Kanner, Howard S.

    2017-01-01

    future efforts of the transformation of the KSC Apollo and Space Shuttle heritage infrastructure into a more versatile, multi-user spaceport. The paper will also discuss the US Congressional and NASA initiatives for developing and supporting multiple commercial partners, while simultaneously supporting NASAs human exploration initiative, consisting of Space Launch System (SLS), Orion spacecraft and associated ground launch systems. In addition, the paper explains the approach with examples for NASA KSC to leverage new technologies and innovative capabilities developed to reduce the cost to individual users.

  2. Is cooperation viable in mobile organisms? Simple Walk Away rule favors the evolution of cooperation in groups

    PubMed Central

    Aktipis, C. Athena

    2011-01-01

    The evolution of cooperation through partner choice mechanisms is often thought to involve relatively complex cognitive abilities. Using agent-based simulations I model a simple partner choice rule, the ‘Walk Away’ rule, where individuals stay in groups that provide higher returns (by virtue of having more cooperators), and ‘Walk Away’ from groups providing low returns. Implementing this conditional movement rule in a public goods game leads to a number of interesting findings: 1) cooperators have a selective advantage when thresholds are high, corresponding to low tolerance for defectors, 2) high thresholds lead to high initial rates of movement and low final rates of movement (after selection), and 3) as cooperation is selected, the population undergoes a spatial transition from high migration (and a many small and ephemeral groups) to low migration (and large and stable groups). These results suggest that the very simple ‘Walk Away’ rule of leaving uncooperative groups can favor the evolution of cooperation, and that cooperation can evolve in populations in which individuals are able to move in response to local social conditions. A diverse array of organisms are able to leave degraded physical or social environments. The ubiquitous nature of conditional movement suggests that ‘Walk Away’ dynamics may play an important role in the evolution of social behavior in both cognitively complex and cognitively simple organisms. PMID:21666771

  3. Worst-Case Cooperative Jamming for Secure Communications in CIoT Networks.

    PubMed

    Li, Zhen; Jing, Tao; Ma, Liran; Huo, Yan; Qian, Jin

    2016-03-07

    The Internet of Things (IoT) is a significant branch of the ongoing advances in the Internet and mobile communications. The use of a large number of IoT devices makes the spectrum scarcity problem even more serious. The usable spectrum resources are almost entirely occupied, and thus, the increasing radio access demands of IoT devices cannot be met. To tackle this problem, the Cognitive Internet of Things (CIoT) has been proposed. In a CIoT network, secondary users, i.e., sensors and actuators, can access the licensed spectrum bands provided by licensed primary users (such as telephones). Security is a major concern in CIoT networks. However, the traditional encryption method at upper layers (such as symmetric cryptography and asymmetric cryptography) may be compromised in CIoT networks, since these types of networks are heterogeneous. In this paper, we address the security issue in spectrum-leasing-based CIoT networks using physical layer methods. Considering that the CIoT networks are cooperative networks, we propose to employ cooperative jamming to achieve secrecy transmission. In the cooperative jamming scheme, a certain secondary user is employed as the helper to harvest energy transmitted by the source and then uses the harvested energy to generate an artificial noise that jams the eavesdropper without interfering with the legitimate receivers. The goal is to minimize the signal to interference plus noise ratio (SINR) at the eavesdropper subject to the quality of service (QoS) constraints of the primary traffic and the secondary traffic. We formulate the considered minimization problem into a two-stage robust optimization problem based on the worst-case Channel State Information of the Eavesdropper. By using semi-definite programming (SDP), the optimal solutions of the transmit covariance matrices can be obtained. Moreover, in order to build an incentive mechanism for the secondary users, we propose an auction framework based on the cooperative jamming scheme

  4. Adaptation and development of software simulation methodologies for cardiovascular engineering: present and future challenges from an end-user perspective

    PubMed Central

    Díaz-Zuccarini, V.; Narracott, A.J.; Burriesci, G.; Zervides, C.; Rafiroiu, D.; Jones, D.; Hose, D.R.; Lawford, P.V.

    2009-01-01

    This paper describes the use of diverse software tools in cardiovascular applications. These tools were primarily developed in the field of engineering and the applications presented push the boundaries of the software to address events related to venous and arterial valve closure, exploration of dynamic boundary conditions or the inclusion of multi-scale boundary conditions from protein to organ levels. The future of cardiovascular research and the challenges that modellers and clinicians face from validation to clinical uptake are discussed from an end-user perspective. PMID:19487202

  5. Adaptation and development of software simulation methodologies for cardiovascular engineering: present and future challenges from an end-user perspective.

    PubMed

    Díaz-Zuccarini, V; Narracott, A J; Burriesci, G; Zervides, C; Rafiroiu, D; Jones, D; Hose, D R; Lawford, P V

    2009-07-13

    This paper describes the use of diverse software tools in cardiovascular applications. These tools were primarily developed in the field of engineering and the applications presented push the boundaries of the software to address events related to venous and arterial valve closure, exploration of dynamic boundary conditions or the inclusion of multi-scale boundary conditions from protein to organ levels. The future of cardiovascular research and the challenges that modellers and clinicians face from validation to clinical uptake are discussed from an end-user perspective.

  6. Communication and cooperation in underwater acoustic networks

    NASA Astrophysics Data System (ADS)

    Yerramalli, Srinivas

    In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve the achievable data rate on a point to point link using better physical layer techniques and then study sensor cooperation which improves the throughput and reliability in an underwater network. Robust point-to-point communications in underwater networks has become increasingly critical in several military and civilian applications related to underwater communications. We present several physical layer signaling and detection techniques tailored to the underwater channel model to improve the reliability of data detection. First, a simplified underwater channel model in which the time scale distortion on each path is assumed to be the same (single scale channel model in contrast to a more general multi scale model). A novel technique, which exploits the nature of OFDM signaling and the time scale distortion, called Partial FFT Demodulation is derived. It is observed that this new technique has some unique interference suppression properties and performs better than traditional equalizers in several scenarios of interest. Next, we consider the multi scale model for the underwater channel and assume that single scale processing is performed at the receiver. We then derive optimized front end pre-processing techniques to reduce the interference caused during single scale processing of signals transmitted on a multi-scale channel. We then propose an improvised channel estimation technique using dictionary optimization methods for compressive sensing and show that significant performance gains can be obtained using this technique. In the next part of this thesis, we consider the problem of sensor node cooperation among rational nodes whose objective is to improve their individual data rates. We first consider the problem of transmitter cooperation in a multiple access channel and investigate the stability of

  7. User Interface Design for Dynamic Geometry Software

    ERIC Educational Resources Information Center

    Kortenkamp, Ulrich; Dohrmann, Christian

    2010-01-01

    In this article we describe long-standing user interface issues with Dynamic Geometry Software and common approaches to address them. We describe first prototypes of multi-touch-capable DGS. We also give some hints on the educational benefits of proper user interface design.

  8. INL Multi-Robot Control Interface

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    2005-03-30

    The INL Multi-Robot Control Interface controls many robots through a single user interface. The interface includes a robot display window for each robot showing the robot’s condition. More than one window can be used depending on the number of robots. The user interface also includes a robot control window configured to receive commands for sending to the respective robot and a multi-robot common window showing information received from each robot.

  9. The Role of Diverse Strategies in Sustainable Knowledge Production

    PubMed Central

    Wu, Lingfei; Baggio, Jacopo A.; Janssen, Marco A.

    2016-01-01

    Online communities are becoming increasingly important as platforms for large-scale human cooperation. These communities allow users seeking and sharing professional skills to solve problems collaboratively. To investigate how users cooperate to complete a large number of knowledge-producing tasks, we analyze Stack Exchange, one of the largest question and answer systems in the world. We construct attention networks to model the growth of 110 communities in the Stack Exchange system and quantify individual answering strategies using the linking dynamics on attention networks. We identify two answering strategies. Strategy A aims at performing maintenance by doing simple tasks, whereas strategy B aims at investing time in doing challenging tasks. Both strategies are important: empirical evidence shows that strategy A decreases the median waiting time for answers and strategy B increases the acceptance rate of answers. In investigating the strategic persistence of users, we find that users tends to stick on the same strategy over time in a community, but switch from one strategy to the other across communities. This finding reveals the different sets of knowledge and skills between users. A balance between the population of users taking A and B strategies that approximates 2:1, is found to be optimal to the sustainable growth of communities. PMID:26934733

  10. The Role of Diverse Strategies in Sustainable Knowledge Production.

    PubMed

    Wu, Lingfei; Baggio, Jacopo A; Janssen, Marco A

    2016-01-01

    Online communities are becoming increasingly important as platforms for large-scale human cooperation. These communities allow users seeking and sharing professional skills to solve problems collaboratively. To investigate how users cooperate to complete a large number of knowledge-producing tasks, we analyze Stack Exchange, one of the largest question and answer systems in the world. We construct attention networks to model the growth of 110 communities in the Stack Exchange system and quantify individual answering strategies using the linking dynamics on attention networks. We identify two answering strategies. Strategy A aims at performing maintenance by doing simple tasks, whereas strategy B aims at investing time in doing challenging tasks. Both strategies are important: empirical evidence shows that strategy A decreases the median waiting time for answers and strategy B increases the acceptance rate of answers. In investigating the strategic persistence of users, we find that users tends to stick on the same strategy over time in a community, but switch from one strategy to the other across communities. This finding reveals the different sets of knowledge and skills between users. A balance between the population of users taking A and B strategies that approximates 2:1, is found to be optimal to the sustainable growth of communities.

  11. Active Cooperation Between Primary Users and Cognitive Radio Users in Heterogeneous Ad-Hoc Networks

    DTIC Science & Technology

    2012-04-01

    processing to wireless communications and networking, including space-time coding and modulation for MIMO wireless communications, MIMO - OFDM systems, and...multiinput-multioutput ( MIMO ) system that can significantly increase the link capacity and realize a new form of spatial diversity which has been termed

  12. Learning Analytics for Natural User Interfaces

    ERIC Educational Resources Information Center

    Martinez-Maldonado, Roberto; Shum, Simon Buckingham; Schneider, Bertrand; Charleer, Sven; Klerkx, Joris; Duval, Erik

    2017-01-01

    The continuous advancement of natural user interfaces (NUIs) allows for the development\tof novel and creative ways to support collocated collaborative work in a wide range of areas, including teaching and learning. The use of NUIs, such as those based on interactive multi-touch surfaces and tangible user interfaces (TUIs), can offer unique…

  13. Breaking the color barrier - a multi-selective antibody reporter offers innovative strategies of fluorescence detection.

    PubMed

    Gallo, Eugenio; Jarvik, Jonathan W

    2017-08-01

    A novel bi-partite fluorescence platform exploits the high affinity and selectivity of antibody scaffolds to capture and activate small-molecule fluorogens. In this report, we investigated the property of multi-selectivity activation by a single antibody against diverse cyanine family fluorogens. Our fluorescence screen identified three cell-impermeant fluorogens, each with unique emission spectra (blue, green and red) and nanomolar affinities. Most importantly, as a protein fusion tag to G-protein-coupled receptors, the antibody biosensor retained full activity - displaying bright fluorogen signals with minimal background on live cells. Because fluorogen-activating antibodies interact with their target ligands via non-covalent interactions, we were able to perform advanced multi-color detection strategies on live cells, previously difficult or impossible with conventional reporters. We found that by fine-tuning the concentrations of the different color fluorogen molecules in solution, a user may interchange the fluorescence signal (onset versus offset), execute real-time signal exchange via fluorogen competition, measure multi-channel fluorescence via co-labeling, and assess real-time cell surface receptor traffic via pulse-chase experiments. Thus, here we inform of an innovative reporter technology based on tri-color signal that allows user-defined fluorescence tuning in live-cell applications. © 2017. Published by The Company of Biologists Ltd.

  14. A Monte-Carlo game theoretic approach for Multi-Criteria Decision Making under uncertainty

    NASA Astrophysics Data System (ADS)

    Madani, Kaveh; Lund, Jay R.

    2011-05-01

    Game theory provides a useful framework for studying Multi-Criteria Decision Making problems. This paper suggests modeling Multi-Criteria Decision Making problems as strategic games and solving them using non-cooperative game theory concepts. The suggested method can be used to prescribe non-dominated solutions and also can be used as a method to predict the outcome of a decision making problem. Non-cooperative stability definitions for solving the games allow consideration of non-cooperative behaviors, often neglected by other methods which assume perfect cooperation among decision makers. To deal with the uncertainty in input variables a Monte-Carlo Game Theory (MCGT) approach is suggested which maps the stochastic problem into many deterministic strategic games. The games are solved using non-cooperative stability definitions and the results include possible effects of uncertainty in input variables on outcomes. The method can handle multi-criteria multi-decision-maker problems with uncertainty. The suggested method does not require criteria weighting, developing a compound decision objective, and accurate quantitative (cardinal) information as it simplifies the decision analysis by solving problems based on qualitative (ordinal) information, reducing the computational burden substantially. The MCGT method is applied to analyze California's Sacramento-San Joaquin Delta problem. The suggested method provides insights, identifies non-dominated alternatives, and predicts likely decision outcomes.

  15. A data encryption solution for mobile health apps in cooperation environments.

    PubMed

    Silva, Bruno M; Rodrigues, Joel J P C; Canelo, Fábio; Lopes, Ivo C; Zhou, Liang

    2013-04-25

    Mobile Health (mHealth) proposes health care delivering anytime and anywhere. It aims to answer several emerging problems in health services, including the increasing number of chronic diseases, high costs on national health services, and the need to provide direct access to health services, regardless of time and place. mHealth systems include the use of mobile devices and apps that interact with patients and caretakers. However, mobile devices present several constraints, such as processor, energy, and storage resource limitations. The constant mobility and often-required Internet connectivity also exposes and compromises the privacy and confidentiality of health information. This paper presents a proposal, construction, performance evaluation, and validation of a data encryption solution for mobile health apps (DE4MHA), considering a novel and early-proposed cooperation strategy. The goal was to present a robust solution based on encryption algorithms that guarantee the best confidentiality, integrity, and authenticity of users health information. In this paper, we presented, explained, evaluated the performance, and discussed the cooperation mechanisms and the proposed encryption solution for mHealth apps. First, we designed and deployed the DE4MHA. Then two studies were performed: (1) study and comparison of symmetric and asymmetric encryption/decryption algorithms in an mHealth app under a cooperation environment, and (2) performance evaluation of the DE4MHA. Its performance was evaluated through a prototype using an mHealth app for obesity prevention and cares, called SapoFit. We then conducted an evaluation study of the mHealth app with cooperation mechanisms and the DE4MHA using real users and a real cooperation scenario. In 5 days, 5 different groups of 7 students selected randomly agreed to use and experiment the SapoFit app using the 7 devices available for trials. There were 35 users of SapoFit that participated in this study. The performance

  16. The evolution of cooperation within the gut microbiota.

    PubMed

    Rakoff-Nahoum, Seth; Foster, Kevin R; Comstock, Laurie E

    2016-05-12

    Cooperative phenotypes are considered central to the functioning of microbial communities in many contexts, including communication via quorum sensing, biofilm formation, antibiotic resistance, and pathogenesis. The human intestine houses a dense and diverse microbial community critical to health, yet we know little about cooperation within this important ecosystem. Here we test experimentally for evolved cooperation within the Bacteroidales, the dominant Gram-negative bacteria of the human intestine. We show that during growth on certain dietary polysaccharides, the model member Bacteroides thetaiotaomicron exhibits only limited cooperation. Although this organism digests these polysaccharides extracellularly, mutants lacking this ability are outcompeted. In contrast, we discovered a dedicated cross-feeding enzyme system in the prominent gut symbiont Bacteroides ovatus, which digests polysaccharide at a cost to itself but at a benefit to another species. Using in vitro systems and gnotobiotic mouse colonization models, we find that extracellular digestion of inulin increases the fitness of B. ovatus owing to reciprocal benefits when it feeds other gut species such as Bacteroides vulgatus. This is a rare example of naturally-evolved cooperation between microbial species. Our study reveals both the complexity and importance of cooperative phenotypes within the mammalian intestinal microbiota.

  17. Improved Iterative Decoding of Network-Channel Codes for Multiple-Access Relay Channel.

    PubMed

    Majumder, Saikat; Verma, Shrish

    2015-01-01

    Cooperative communication using relay nodes is one of the most effective means of exploiting space diversity for low cost nodes in wireless network. In cooperative communication, users, besides communicating their own information, also relay the information of other users. In this paper we investigate a scheme where cooperation is achieved using a common relay node which performs network coding to provide space diversity for two information nodes transmitting to a base station. We propose a scheme which uses Reed-Solomon error correcting code for encoding the information bit at the user nodes and convolutional code as network code, instead of XOR based network coding. Based on this encoder, we propose iterative soft decoding of joint network-channel code by treating it as a concatenated Reed-Solomon convolutional code. Simulation results show significant improvement in performance compared to existing scheme based on compound codes.

  18. Public Auditing with Privacy Protection in a Multi-User Model of Cloud-Assisted Body Sensor Networks

    PubMed Central

    Li, Song; Cui, Jie; Zhong, Hong; Liu, Lu

    2017-01-01

    Wireless Body Sensor Networks (WBSNs) are gaining importance in the era of the Internet of Things (IoT). The modern medical system is a particular area where the WBSN techniques are being increasingly adopted for various fundamental operations. Despite such increasing deployments of WBSNs, issues such as the infancy in the size, capabilities and limited data processing capacities of the sensor devices restrain their adoption in resource-demanding applications. Though providing computing and storage supplements from cloud servers can potentially enrich the capabilities of the WBSNs devices, data security is one of the prevailing issues that affects the reliability of cloud-assisted services. Sensitive applications such as modern medical systems demand assurance of the privacy of the users’ medical records stored in distant cloud servers. Since it is economically impossible to set up private cloud servers for every client, auditing data security managed in the remote servers has necessarily become an integral requirement of WBSNs’ applications relying on public cloud servers. To this end, this paper proposes a novel certificateless public auditing scheme with integrated privacy protection. The multi-user model in our scheme supports groups of users to store and share data, thus exhibiting the potential for WBSNs’ deployments within community environments. Furthermore, our scheme enriches user experiences by offering public verifiability, forward security mechanisms and revocation of illegal group members. Experimental evaluations demonstrate the security effectiveness of our proposed scheme under the Random Oracle Model (ROM) by outperforming existing cloud-assisted WBSN models. PMID:28475110

  19. Members' sensemaking in a multi-professional team.

    PubMed

    Rovio-Johansson, Airi; Liff, Roy

    2012-01-01

    The aim of this study is to investigate sensemaking as interaction among team members in a multi-professional team setting in a new public management context at a Swedish Child and Youth Psychiatric Unit. A discursive pragmatic approach grounded in ethonomethodology is taken in the analysis of a treatment conference (TC). In order to interpret and understand the multi-voiced complexity of discourse and of talk-in-interaction, the authors use dialogism in the analysis of the members' sensemaking processes. The analysis is based on the theoretical assumption that language and texts are the primary tools actors use to comprehend the social reality and to make sense of their multi-professional discussions. Health care managers are offered insights, derived from theory and empirical evidence, into how professionals' communications influence multi-professional cooperation. The team leader and members are interviewed before and after the observed TC. Team members create their identities and positions in the group by interpreting and "misinterpreting" talk-in-interaction. The analyses reveal the ways the team members relate to their treatment methods in the discussion of a patient; advocating a treatment method means that the team member and the method are intertwined. The findings may be valuable to health care professionals and managers working in teams by showing them how to achieve greater cooperation through the use of verbal abilities. The findings and methods contribute to the international research on cooperation problems in multi-professional teams and to the empirical research on institutional discourse through text and talk.

  20. A MULTI-LOCUS, MULTI-TAXA PHYLOGEOGRAPHICAL ANALYSIS OF GENETIC DIVERSITY

    EPA Science Inventory

    In addition to measuring spatial patterns of genetic diversity, population genetic measures of biological resources should include temporal data that indicate whether the observed patterns are the result of historical or contemporary processes. In general, genetic measures focus...

  1. Perception without self-matching in conditional tag based cooperation.

    PubMed

    McAvity, David M; Bristow, Tristen; Bunker, Eric; Dreyer, Alex

    2013-09-21

    We consider a model for the evolution of cooperation in a population where individuals may have one of a number of different heritable and distinguishable markers or tags. Individuals interact with each of their neighbors on a square lattice by either cooperating by donating some benefit at a cost to themselves or defecting by doing nothing. The decision to cooperate or defect is contingent on each individual's perception of its interacting partner's tag. Unlike in other tag-based models individuals do not compare their own tag to that of their interaction partner. That is, there is no self-matching. When perception is perfect the cooperation rate is substantially higher than in the usual spatial prisoner's dilemma game when the cost of cooperation is high. The enhancement in cooperation is positively correlated with the number of different tags. The more diverse a population is the more cooperative it becomes. When individuals start with an inability to perceive tags the population evolves to a state where individuals gain at least partial perception. With some reproduction mechanisms perfect perception evolves, but with others the ability to perceive tags is imperfect. We find that perception of tags evolves to lower levels when the cost of cooperation is higher. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. A User''s Guide to the Zwikker-Kosten Transmission Line Code (ZKTL)

    NASA Technical Reports Server (NTRS)

    Kelly, J. J.; Abu-Khajeel, H.

    1997-01-01

    This user's guide documents updates to the Zwikker-Kosten Transmission Line Code (ZKTL). This code was developed for analyzing new liner concepts developed to provide increased sound absorption. Contiguous arrays of multi-degree-of-freedom (MDOF) liner elements serve as the model for these liner configurations, and Zwikker and Kosten's theory of sound propagation in channels is used to predict the surface impedance. Transmission matrices for the various liner elements incorporate both analytical and semi-empirical methods. This allows standard matrix techniques to be employed in the code to systematically calculate the composite impedance due to the individual liner elements. The ZKTL code consists of four independent subroutines: 1. Single channel impedance calculation - linear version (SCIC) 2. Single channel impedance calculation - nonlinear version (SCICNL) 3. Multi-channel, multi-segment, multi-layer impedance calculation - linear version (MCMSML) 4. Multi-channel, multi-segment, multi-layer impedance calculation - nonlinear version (MCMSMLNL) Detailed examples, comments, and explanations for each liner impedance computation module are included. Also contained in the guide are depictions of the interactive execution, input files and output files.

  3. Clonal cooperativity in heterogenous cancers

    PubMed Central

    Zhou, Hengbo; Neelakantan, Deepika; Ford, Heide L.

    2016-01-01

    Tumor heterogeneity is a major obstacle to the development of effective therapies and is thus an important focus of cancer research. Genetic and epigenetic alterations, as well as altered tumor microenvironments, result in tumors made up of diverse subclones with different genetic and phenotypic characteristics. Intratumor heterogeneity enables competition, but also supports clonal cooperation via cell-cell contact or secretion of factors, resulting in enhanced tumor progression. Here, we summarize recent findings related to interclonal interactions within a tumor and the therapeutic implications of such interactions, with an emphasis on how different subclones collaborate with each other to promote proliferation, metastasis and therapy-resistance. Furthermore, we propose that disruption of clonal cooperation by targeting key factors (such as Wnt and Hedgehog, amongst others) can be an alternative approach to improving clinical outcomes. PMID:27582427

  4. Novel Multi-Party Quantum Key Agreement Protocol with G-Like States and Bell States

    NASA Astrophysics Data System (ADS)

    Min, Shi-Qi; Chen, Hua-Ying; Gong, Li-Hua

    2018-03-01

    A significant aspect of quantum cryptography is quantum key agreement (QKA), which ensures the security of key agreement protocols by quantum information theory. The fairness of an absolute security multi-party quantum key agreement (MQKA) protocol demands that all participants can affect the protocol result equally so as to establish a shared key and that nobody can determine the shared key by himself/herself. We found that it is difficult for the existing multi-party quantum key agreement protocol to withstand the collusion attacks. Put differently, it is possible for several cooperated and untruthful participants to determine the final key without being detected. To address this issue, based on the entanglement swapping between G-like state and Bell states, a new multi-party quantum key agreement protocol is put forward. The proposed protocol makes full use of EPR pairs as quantum resources, and adopts Bell measurement and unitary operation to share a secret key. Besides, the proposed protocol is fair, secure and efficient without involving a third party quantum center. It demonstrates that the protocol is capable of protecting users' privacy and meeting the requirement of fairness. Moreover, it is feasible to carry out the protocol with existing technologies.

  5. Novel Multi-Party Quantum Key Agreement Protocol with G-Like States and Bell States

    NASA Astrophysics Data System (ADS)

    Min, Shi-Qi; Chen, Hua-Ying; Gong, Li-Hua

    2018-06-01

    A significant aspect of quantum cryptography is quantum key agreement (QKA), which ensures the security of key agreement protocols by quantum information theory. The fairness of an absolute security multi-party quantum key agreement (MQKA) protocol demands that all participants can affect the protocol result equally so as to establish a shared key and that nobody can determine the shared key by himself/herself. We found that it is difficult for the existing multi-party quantum key agreement protocol to withstand the collusion attacks. Put differently, it is possible for several cooperated and untruthful participants to determine the final key without being detected. To address this issue, based on the entanglement swapping between G-like state and Bell states, a new multi-party quantum key agreement protocol is put forward. The proposed protocol makes full use of EPR pairs as quantum resources, and adopts Bell measurement and unitary operation to share a secret key. Besides, the proposed protocol is fair, secure and efficient without involving a third party quantum center. It demonstrates that the protocol is capable of protecting users' privacy and meeting the requirement of fairness. Moreover, it is feasible to carry out the protocol with existing technologies.

  6. Preliminary operational requirements and acceptability criteria for the cooperative breath analyzer

    DOT National Transportation Integrated Search

    1971-09-01

    This report presents a series of criteria and requirements relevant to establishing user acceptability for the cooperative alcohol analyzer being developed by the Transportation Systems Center. The information presented herein was obtained with the c...

  7. Towards Gesture-Based Multi-User Interactions in Collaborative Virtual Environments

    NASA Astrophysics Data System (ADS)

    Pretto, N.; Poiesi, F.

    2017-11-01

    We present a virtual reality (VR) setup that enables multiple users to participate in collaborative virtual environments and interact via gestures. A collaborative VR session is established through a network of users that is composed of a server and a set of clients. The server manages the communication amongst clients and is created by one of the users. Each user's VR setup consists of a Head Mounted Display (HMD) for immersive visualisation, a hand tracking system to interact with virtual objects and a single-hand joypad to move in the virtual environment. We use Google Cardboard as a HMD for the VR experience and a Leap Motion for hand tracking, thus making our solution low cost. We evaluate our VR setup though a forensics use case, where real-world objects pertaining to a simulated crime scene are included in a VR environment, acquired using a smartphone-based 3D reconstruction pipeline. Users can interact using virtual gesture-based tools such as pointers and rulers.

  8. Operational Tree Species Mapping in a Diverse Tropical Forest with Airborne Imaging Spectroscopy.

    PubMed

    Baldeck, Claire A; Asner, Gregory P; Martin, Robin E; Anderson, Christopher B; Knapp, David E; Kellner, James R; Wright, S Joseph

    2015-01-01

    Remote identification and mapping of canopy tree species can contribute valuable information towards our understanding of ecosystem biodiversity and function over large spatial scales. However, the extreme challenges posed by highly diverse, closed-canopy tropical forests have prevented automated remote species mapping of non-flowering tree crowns in these ecosystems. We set out to identify individuals of three focal canopy tree species amongst a diverse background of tree and liana species on Barro Colorado Island, Panama, using airborne imaging spectroscopy data. First, we compared two leading single-class classification methods--binary support vector machine (SVM) and biased SVM--for their performance in identifying pixels of a single focal species. From this comparison we determined that biased SVM was more precise and created a multi-species classification model by combining the three biased SVM models. This model was applied to the imagery to identify pixels belonging to the three focal species and the prediction results were then processed to create a map of focal species crown objects. Crown-level cross-validation of the training data indicated that the multi-species classification model had pixel-level producer's accuracies of 94-97% for the three focal species, and field validation of the predicted crown objects indicated that these had user's accuracies of 94-100%. Our results demonstrate the ability of high spatial and spectral resolution remote sensing to accurately detect non-flowering crowns of focal species within a diverse tropical forest. We attribute the success of our model to recent classification and mapping techniques adapted to species detection in diverse closed-canopy forests, which can pave the way for remote species mapping in a wider variety of ecosystems.

  9. Information Diversity in Web Search

    ERIC Educational Resources Information Center

    Liu, Jiahui

    2009-01-01

    The web is a rich and diverse information source with incredible amounts of information about all kinds of subjects in various forms. This information source affords great opportunity to build systems that support users in their work and everyday lives. To help users explore information on the web, web search systems should find information that…

  10. Distributed, cooperating knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt

    1991-01-01

    Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

  11. The development concept of Taman Aloon-Aloon Tulungagung based on visual accessibility, diversity of activities and perception of users

    NASA Astrophysics Data System (ADS)

    Sasongko, W.; Kurniasanti, R. P.; Siregar, J. P.

    2017-06-01

    Tulungagung has a public space that actively used by the community named Taman Aloon-aloon Tulungagung. The importance of research on the Development Concept of Taman Aloon-aloon Tulungagung as open public space is requiring location structuring for appeal aspects of public space in order to spread evenly and can be enjoyed by users of public space. Therefore, this study aimed to assess users’ perceptions of the attractiveness of public space by Importance Performance Analysis (IPA) method and assess the level of users’ visual accessibility by Visibility Graph Analysis (VGA) method and assess the diversity of users’ activity by Behavior Mapping method. As this study shows that the condition of the floor surface, the location of a bird cage, shade conditions of public space and location of lighting lamp become the top priority in the development concept of Taman Aloon-aloon Tulungagung. The location for the prioritized attributes are adjusted to the results of the visual accessibility level evaluation matrix and activities diversity.

  12. Cooperative data dissemination to mission sites

    NASA Astrophysics Data System (ADS)

    Chen, Fangfei; Johnson, Matthew P.; Bar-Noy, Amotz; La Porta, Thomas F.

    2010-04-01

    Timely dissemination of information to mobile users is vital in many applications. In a critical situation, no network infrastructure may be available for use in dissemination, over and above the on-board storage capability of the mobile users themselves. We consider the following specialized content distribution application: a group of users equipped with wireless devices build an ad hoc network in order cooperatively to retrieve information from certain regions (the mission sites). Each user requires access to some set of information items originating from sources lying within a region. Each user desires low-latency access to its desired data items, upon request (i.e., when pulled). In order to minimize average response time, we allow users to pull data either directly from sources or, when possible, from other nearby users who have already pulled, and continue to carry, the desired data items. That is, we allow for data to be pushed to one user and then pulled by one or more additional users. The total latency experienced by a user vis-vis a certain data item is then in general a combination of the push delay and the pull delay. We assume each delay time is a function of the hop distance between the pair of points in question. Our goal in this paper is to assign data to mobile users, in order to minimize the total cost and the average latency experienced by all the users. In a static setting, we solve this problem in two different schemes, one of which is easy to solve but wasteful, one of which relates to NP-hard problems but is less so. Then in a dynamic setting, we adapt the algorithm for the static setting and develop a new algorithm with respect to users' gradual arrival. In the end we show a trade-off can be made between minimizing the cost and latency.

  13. Finite-SNR analysis for partial relaying cooperation with channel coding and opportunistic relay selection

    NASA Astrophysics Data System (ADS)

    Vu, Thang X.; Duhamel, Pierre; Chatzinotas, Symeon; Ottersten, Bjorn

    2017-12-01

    This work studies the performance of a cooperative network which consists of two channel-coded sources, multiple relays, and one destination. To achieve high spectral efficiency, we assume that a single time slot is dedicated to relaying. Conventional network-coded-based cooperation (NCC) selects the best relay which uses network coding to serve the two sources simultaneously. The bit error rate (BER) performance of NCC with channel coding, however, is still unknown. In this paper, we firstly study the BER of NCC via a closed-form expression and analytically show that NCC only achieves diversity of order two regardless of the number of available relays and the channel code. Secondly, we propose a novel partial relaying-based cooperation (PARC) scheme to improve the system diversity in the finite signal-to-noise ratio (SNR) regime. In particular, closed-form expressions for the system BER and diversity order of PARC are derived as a function of the operating SNR value and the minimum distance of the channel code. We analytically show that the proposed PARC achieves full (instantaneous) diversity order in the finite SNR regime, given that an appropriate channel code is used. Finally, numerical results verify our analysis and demonstrate a large SNR gain of PARC over NCC in the SNR region of interest.

  14. Empirical analysis of web-based user-object bipartite networks

    NASA Astrophysics Data System (ADS)

    Shang, Ming-Sheng; Lü, Linyuan; Zhang, Yi-Cheng; Zhou, Tao

    2010-05-01

    Understanding the structure and evolution of web-based user-object networks is a significant task since they play a crucial role in e-commerce nowadays. This letter reports the empirical analysis on two large-scale web sites, audioscrobbler.com and del.icio.us, where users are connected with music groups and bookmarks, respectively. The degree distributions and degree-degree correlations for both users and objects are reported. We propose a new index, named collaborative similarity, to quantify the diversity of tastes based on the collaborative selection. Accordingly, the correlation between degree and selection diversity is investigated. We report some novel phenomena well characterizing the selection mechanism of web users and outline the relevance of these phenomena to the information recommendation problem.

  15. User modeling techniques as support in the clinical decision-making process.

    PubMed

    Ferri, F

    1995-01-01

    This paper describes research work on the design and creation of a medical folder management system capable of establishing co-operative dialogue with users who have access to the information contained therein. The research work has addressed the problem of integrating into the system knowledge about the medical domain and that about users, both necessary to activate co-operative dialogue. The CADMIO [2] prototype has been developed since the study was made. The last version of the CADMIO system stores information about users for the use in recognizing and interpreting their behavior, providing help, and in acquiring and returning further information. Depending on this information the system retrieves and shows the data of the medical folder in an intelligent way by highlighting links between data. It simplifies and increases the speed of the interaction by focusing on the data useful to the decisional activity of the physician.

  16. A cloud-based semantic wiki for user training in healthcare process management.

    PubMed

    Papakonstantinou, D; Poulymenopoulou, M; Malamateniou, F; Vassilacopoulos, G

    2011-01-01

    Successful healthcare process design requires active participation of users who are familiar with the cooperative and collaborative nature of healthcare delivery, expressed in terms of healthcare processes. Hence, a reusable, flexible, agile and adaptable training material is needed with the objective to enable users instill their knowledge and expertise in healthcare process management and (re)configuration activities. To this end, social software, such as a wiki, could be used as it supports cooperation and collaboration anytime, anywhere and combined with semantic web technology that enables structuring pieces of information for easy retrieval, reuse and exchange between different systems and tools. In this paper a semantic wiki is presented as a means for developing training material for healthcare providers regarding healthcare process management. The semantic wiki should act as a collective online memory containing training material that is accessible to authorized users, thus enhancing the training process with collaboration and cooperation capabilities. It is proposed that the wiki is stored in a secure virtual private cloud that is accessible from anywhere, be it an excessively open environment, while meeting the requirements of redundancy, high performance and autoscaling.

  17. Higher plant diversity promotes higher diversity of fungal pathogens, while it decreases pathogen infection per plant.

    PubMed

    Rottstock, Tanja; Joshi, Jasmin; Kummer, Volker; Fischer, Markus

    2014-07-01

    Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen infection via increased variability in host density and spatial heterogeneity. Therefore, a comprehensive understanding of multi-host multi-pathogen interactions is of high significance in the context of biodiversity-ecosystem functioning. We investigated the relationship between plant diversity and aboveground obligate parasitic fungal pathogen ("pathogens" hereafter) diversity and infection in grasslands of a long-term, large-scale, biodiversity experiment with varying plant species (1-60 species) and plant functional group diversity (1-4 groups). To estimate pathogen infection of the plant communities, we visually assessed pathogen-group presence (i.e., rusts, powdery mildews, downy mildews, smuts, and leaf-spot diseases) and overall infection levels (combining incidence and severity of each pathogen group) in 82 experimental plots on all aboveground organs of all plant species per plot during four surveys in 2006. Pathogen diversity, assessed as the cumulative number of pathogen groups on all plant species per plot, increased log-linearly with plant species diversity. However, pathogen incidence and severity, and hence overall infection, decreased with increasing plant species diversity. In addition, co-infection of plant individuals by two or more pathogen groups was less likely with increasing plant community diversity. We conclude that plant community diversity promotes pathogen-community diversity while at the same time reducing pathogen infection levels of plant individuals.

  18. Cultural Diversity in Classrooms: What Teachers Need To Know.

    ERIC Educational Resources Information Center

    Sandhu, Daya Singh

    This paper emphasizes the significance of cultural diversity in American schools and its implications for the teaching and learning processes. Also highlighted is the importance of the realization that diversity is what makes the United States unique. The paper discusses the cultural dynamics of clashes and conflicts as well as of cooperation and…

  19. Sharing intelligence: Decision-making interactions between users and software in MAESTRO

    NASA Technical Reports Server (NTRS)

    Geoffroy, Amy L.; Gohring, John R.; Britt, Daniel L.

    1991-01-01

    By combining the best of automated and human decision-making in scheduling many advantages can accrue. The joint performance of the user and system is potentially much better than either alone. Features of the MAESTRO scheduling system serve to illustrate concepts of user/software cooperation. MAESTRO may be operated at a user-determinable and dynamic level of autonomy. Because the system allows so much flexibility in the allocation of decision-making responsibilities, and provides users with a wealth of information and other support for their own decision-making, better overall schedules may result.

  20. Binaural unmasking of multi-channel stimuli in bilateral cochlear implant users.

    PubMed

    Van Deun, Lieselot; van Wieringen, Astrid; Francart, Tom; Büchner, Andreas; Lenarz, Thomas; Wouters, Jan

    2011-10-01

    Previous work suggests that bilateral cochlear implant users are sensitive to interaural cues if experimental speech processors are used to preserve accurate interaural information in the electrical stimulation pattern. Binaural unmasking occurs in adults and children when an interaural delay is applied to the envelope of a high-rate pulse train. Nevertheless, for speech perception, binaural unmasking benefits have not been demonstrated consistently, even with coordinated stimulation at both ears. The present study aimed at bridging the gap between basic psychophysical performance on binaural signal detection tasks on the one hand and binaural perception of speech in noise on the other hand. Therefore, binaural signal detection was expanded to multi-channel stimulation and biologically relevant interaural delays. A harmonic complex, consisting of three sinusoids (125, 250, and 375 Hz), was added to three 125-Hz-wide noise bands centered on the sinusoids. When an interaural delay of 700 μs was introduced, an average BMLD of 3 dB was established. Outcomes are promising in view of real-life benefits. Future research should investigate the generalization of the observed benefits for signal detection to speech perception in everyday listening situations and determine the importance of coordination of bilateral speech processors and accentuation of envelope cues.

  1. Configuration of Wireless Cooperative/Sensor Networks

    DTIC Science & Technology

    2008-05-25

    WSN), the advantages of cooperation can be further exploited by optimally allocating the energy and bandwidth resources among users based on the... consumption and extend system lifetime [Sin98]. The implementation of a minimum energy routing protocol is discussed in [Dos02a, Dos02b]. An online...power consumption in the network given the required SER at the destination. For example, with source power Ps=20dB, the EP algorithm requires one relay

  2. Evolution of cooperation in Axelrod tournament using cellular automata

    NASA Astrophysics Data System (ADS)

    Schimit, P. H. T.; Santos, B. O.; Soares, C. A.

    2015-11-01

    Results of the Axelrod Tournament were published in 1981, and since then, evolutionary game theory emerged as an idea for understanding relations, like conflict and cooperation, between rational decision-makers. Robert Axelrod organized it as a round-robin tournament where strategies for iterated Prisoner's Dilemma were faced in a sequence of two players game. Here, we attempt to simulate the strategies submitted to the tournament in a multi-agent context, where individuals play a two-player game with their neighbors. Each individual has one of the strategies, and it plays the Prisoner's Dilemma with its neighbors. According to actions chosen (cooperate or defect), points of life are subtracted from their profiles. When an individual dies, some fitness functions are defined to choose the most successful strategy which the new individual will copy. Although tit-for-tat was the best strategy, on average, in the tournament, in our evolutionary multi-agent context, it has not been successful.

  3. Multi-agents and learning: Implications for Webusage mining

    PubMed Central

    Lotfy, Hewayda M.S.; Khamis, Soheir M.S.; Aboghazalah, Maie M.

    2015-01-01

    Characterization of user activities is an important issue in the design and maintenance of websites. Server weblog files have abundant information about the user’s current interests. This information can be mined and analyzed therefore the administrators may be able to guide the users in their browsing activity so they may obtain relevant information in a shorter span of time to obtain user satisfaction. Web-based technology facilitates the creation of personally meaningful and socially useful knowledge through supportive interactions, communication and collaboration among educators, learners and information. This paper suggests a new methodology based on learning techniques for a Web-based Multiagent-based application to discover the hidden patterns in the user’s visited links. It presents a new approach that involves unsupervised, reinforcement learning, and cooperation between agents. It is utilized to discover patterns that represent the user’s profiles in a sample website into specific categories of materials using significance percentages. These profiles are used to make recommendations of interesting links and categories to the user. The experimental results of the approach showed successful user pattern recognition, and cooperative learning among agents to obtain user profiles. It indicates that combining different learning algorithms is capable of improving user satisfaction indicated by the percentage of precision, recall, the progressive category weight and F1-measure. PMID:26966569

  4. Save medical personnel's time by improved user interfaces.

    PubMed

    Kindler, H

    1997-01-01

    Common objectives in the industrial countries are the improvement of quality of care, clinical effectiveness, and cost control. Cost control, in particular, has been addressed through the introduction of case mix systems for reimbursement by social-security institutions. More data is required to enable quality improvement, increases in clinical effectiveness and for juridical reasons. At first glance, this documentation effort is contradictory to cost reduction. However, integrated services for resource management based on better documentation should help to reduce costs. The clerical effort for documentation should be decreased by providing a co-operative working environment for healthcare professionals applying sophisticated human-computer interface technology. Additional services, e.g., automatic report generation, increase the efficiency of healthcare personnel. Modelling the medical work flow forms an essential prerequisite for integrated resource management services and for co-operative user interfaces. A user interface aware of the work flow provides intelligent assistance by offering the appropriate tools at the right moment. Nowadays there is a trend to client/server systems with relational databases or object-oriented databases as repository. The work flows used for controlling purposes and to steer the user interfaces must be represented in the repository.

  5. The economics of altruistic punishment and the maintenance of cooperation

    PubMed Central

    Egas, Martijn; Riedl, Arno

    2008-01-01

    Explaining the evolution and maintenance of cooperation among unrelated individuals is one of the fundamental problems in biology and the social sciences. Recent findings suggest that altruistic punishment is an important mechanism maintaining cooperation among humans. We experimentally explore the boundaries of altruistic punishment to maintain cooperation by varying both the cost and the impact of punishment, using an exceptionally extensive subject pool. Our results show that cooperation is only maintained if conditions for altruistic punishment are relatively favourable: low cost for the punisher and high impact on the punished. Our results indicate that punishment is strongly governed by its cost-to-impact ratio and that its effect on cooperation can be pinned down to one single variable: the threshold level of free-riding that goes unpunished. Additionally, actual pay-offs are the lowest when altruistic punishment maintains cooperation, because the pay-off destroyed through punishment exceeds the gains from increased cooperation. Our results are consistent with the interpretation that punishment decisions come from an amalgam of emotional response and cognitive cost–impact analysis and suggest that altruistic punishment alone can hardly maintain cooperation under multi-level natural selection. Uncovering the workings of altruistic punishment as has been done here is important because it helps predicting under which conditions altruistic punishment is expected to maintain cooperation. PMID:18198144

  6. Using a Multi-Trait Approach to Manipulate Plant Functional Diversity in a Biodiversity-Ecosystem Function Experiment

    PubMed Central

    Schittko, Conrad; Hawa, Mahmoud; Wurst, Susanne

    2014-01-01

    A frequent pattern emerging from biodiversity-ecosystem function studies is that functional group richness enhances ecosystem functions such as primary productivity. However, the manipulation of functional group richness goes along with major disadvantages like the transformation of functional trait data into categories or the exclusion of functional differences between organisms in the same group. In a mesocosm study we manipulated plant functional diversity based on the multi-trait Functional Diversity (FD)-approach of Petchey and Gaston by using database data of seven functional traits and information on the origin of the species in terms of being native or exotic. Along a gradient ranging from low to high FD we planted 40 randomly selected eight-species mixtures under controlled conditions. We found a significant positive linear correlation of FD with aboveground productivity and a negative correlation with invasibility of the plant communities. Based on community-weighted mean calculations for each functional trait, we figured out that the traits N-fixation and species origin, i.e. being native or exotic, played the most important role for community productivity. Our results suggest that the identification of the impact of functional trait diversity and the relative contributions of relevant traits is essential for a mechanistic understanding of the role of biodiversity for ecosystem functions such as aboveground biomass production and resistance against invasion. PMID:24897501

  7. A Data Encryption Solution for Mobile Health Apps in Cooperation Environments

    PubMed Central

    Silva, Bruno M; Canelo, Fábio; Lopes, Ivo C; Zhou, Liang

    2013-01-01

    Background Mobile Health (mHealth) proposes health care delivering anytime and anywhere. It aims to answer several emerging problems in health services, including the increasing number of chronic diseases, high costs on national health services, and the need to provide direct access to health services, regardless of time and place. mHealth systems include the use of mobile devices and apps that interact with patients and caretakers. However, mobile devices present several constraints, such as processor, energy, and storage resource limitations. The constant mobility and often-required Internet connectivity also exposes and compromises the privacy and confidentiality of health information. Objective This paper presents a proposal, construction, performance evaluation, and validation of a data encryption solution for mobile health apps (DE4MHA), considering a novel and early-proposed cooperation strategy. The goal was to present a robust solution based on encryption algorithms that guarantee the best confidentiality, integrity, and authenticity of users health information. In this paper, we presented, explained, evaluated the performance, and discussed the cooperation mechanisms and the proposed encryption solution for mHealth apps. Methods First, we designed and deployed the DE4MHA. Then two studies were performed: (1) study and comparison of symmetric and asymmetric encryption/decryption algorithms in an mHealth app under a cooperation environment, and (2) performance evaluation of the DE4MHA. Its performance was evaluated through a prototype using an mHealth app for obesity prevention and cares, called SapoFit. We then conducted an evaluation study of the mHealth app with cooperation mechanisms and the DE4MHA using real users and a real cooperation scenario. In 5 days, 5 different groups of 7 students selected randomly agreed to use and experiment the SapoFit app using the 7 devices available for trials. Results There were 35 users of SapoFit that participated in

  8. Accounting for User Diversity in Configuring Online Systems.

    ERIC Educational Resources Information Center

    Woolliams, Peter; Gee, David

    1992-01-01

    Discusses cultural diversity in human-computer interactions and in the design of online systems. Topics addressed include cognitive psychology; North American and European ethnocentricity; online systems and their organizational setting; models for organization culture; corporate culture; international systems and country-specific cultures; and…

  9. FEANICS: A Multi-User Facility For Conducting Solid Fuel Combustion Experiments On ISS

    NASA Technical Reports Server (NTRS)

    Frate, David T.; Tofil, Todd A.

    2001-01-01

    The Destiny Module on the International Space Station (ISS) will soon be home for the Fluids and Combustion Facility's (FCF) Combustion Integrated Rack (CIR), which is being developed at the NASA Glenn Research Center in Cleveland, Ohio. The CIR will be the platform for future microgravity combustion experiments. A multi-user mini-facility called FEANICS (Flow Enclosure Accommodating Novel Investigations in Combustion of Solids) will also be built at NASA Glenn. This mini-facility will be the primary means for conducting solid fuel combustion experiments in the CIR on ISS. The main focus of many of these solid combustion experiments will be to conduct basic and applied scientific investigations in fire-safety to support NASA's Bioastronautics Initiative. The FEANICS project team will work in conjunction with the CIR project team to develop upgradeable and reusable hardware to meet the science requirements of current and future investigators. Currently, there are six experiments that are candidates to use the FEANICS mini-facility. This paper will describe the capabilities of this mini-facility and the type of solid combustion testing and diagnostics that can be performed.

  10. Bimanual Interaction with Interscopic Multi-Touch Surfaces

    NASA Astrophysics Data System (ADS)

    Schöning, Johannes; Steinicke, Frank; Krüger, Antonio; Hinrichs, Klaus; Valkov, Dimitar

    Multi-touch interaction has received considerable attention in the last few years, in particular for natural two-dimensional (2D) interaction. However, many application areas deal with three-dimensional (3D) data and require intuitive 3D interaction techniques therefore. Indeed, virtual reality (VR) systems provide sophisticated 3D user interface, but then lack efficient 2D interaction, and are therefore rarely adopted by ordinary users or even by experts. Since multi-touch interfaces represent a good trade-off between intuitive, constrained interaction on a touch surface providing tangible feedback, and unrestricted natural interaction without any instrumentation, they have the potential to form the foundation of the next generation user interface for 2D as well as 3D interaction. In particular, stereoscopic display of 3D data provides an additional depth cue, but until now the challenges and limitations for multi-touch interaction in this context have not been considered. In this paper we present new multi-touch paradigms and interactions that combine both traditional 2D interaction and novel 3D interaction on a touch surface to form a new class of multi-touch systems, which we refer to as interscopic multi-touch surfaces (iMUTS). We discuss iMUTS-based user interfaces that support interaction with 2D content displayed in monoscopic mode and 3D content usually displayed stereoscopically. In order to underline the potential of the proposed iMUTS setup, we have developed and evaluated two example interaction metaphors for different domains. First, we present intuitive navigation techniques for virtual 3D city models, and then we describe a natural metaphor for deforming volumetric datasets in a medical context.

  11. Accelerating Science with the NERSC Burst Buffer Early User Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhimji, Wahid; Bard, Debbie; Romanus, Melissa

    NVRAM-based Burst Buffers are an important part of the emerging HPC storage landscape. The National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory recently installed one of the first Burst Buffer systems as part of its new Cori supercomputer, collaborating with Cray on the development of the DataWarp software. NERSC has a diverse user base comprised of over 6500 users in 700 different projects spanning a wide variety of scientific computing applications. The use-cases of the Burst Buffer at NERSC are therefore also considerable and diverse. We describe here performance measurements and lessons learned from the Burstmore » Buffer Early User Program at NERSC, which selected a number of research projects to gain early access to the Burst Buffer and exercise its capability to enable new scientific advancements. To the best of our knowledge this is the first time a Burst Buffer has been stressed at scale by diverse, real user workloads and therefore these lessons will be of considerable benefit to shaping the developing use of Burst Buffers at HPC centers.« less

  12. Working well in a culturally diverse team.

    PubMed

    Day-Calder, Mandy

    2016-10-05

    Cooperative working is a core part of the nursing role, and it involves respecting your colleagues' needs and values. If you are part of a diverse team, you may need to develop your cultural competence, treating everyone compassionately and respectfully.

  13. Intergroup Cooperation in Common Pool Resource Dilemmas.

    PubMed

    Sadowski, Jathan; Spierre, Susan G; Selinger, Evan; Seager, Thomas P; Adams, Elizabeth A; Berardy, Andrew

    2015-10-01

    Fundamental problems of environmental sustainability, including climate change and fisheries management, require collective action on a scale that transcends the political and cultural boundaries of the nation-state. Rational, self-interested neoclassical economic theories of human behavior predict tragedy in the absence of third party enforcement of agreements and practical difficulties that prevent privatization. Evolutionary biology offers a theory of cooperation, but more often than not in a context of discrimination against other groups. That is, in-group boundaries are necessarily defined by those excluded as members of out-groups. However, in some settings human's exhibit behavior that is inconsistent with both rational economic and group driven cooperation of evolutionary biological theory. This paper reports the results of a non-cooperative game-theoretic exercise that models a tragedy of the commons problem in which groups of players may advance their own positions only at the expense of other groups. Students enrolled from multiple universities and assigned to different multi-university identity groups participated in experiments that repeatedly resulted in cooperative outcomes despite intergroup conflicts and expressions of group identity. We offer three possible explanations: (1) students were cooperative because they were in an academic setting; (2) students may have viewed their instructors as the out-group; or (3) the emergence of a small number of influential, ethical leaders is sufficient to ensure cooperation amongst the larger groups. From our data and analysis, we draw out lessons that may help to inform approaches for institutional design and policy negotiations, particularly in climate change management.

  14. A Secure and Efficient Communications Architecture for Global Information Grid Users Via Cooperating Space Assets

    DTIC Science & Technology

    2008-06-19

    ground troop component of a deployed contingency, and not a stationary infrastructure. With respect to fast- moving vehicles and aircraft, troops...the rapidly- moving user. In fact, the Control Group users could have been randomly assigned the Stationary , Sea, or 134 Ground Mobility Category...additional re-keying on the non- stationary users, just as they induce no re-keying on the Stationary users (assuming those fast- moving aircraft have the

  15. ABrIL - Advanced Brain Imaging Lab : a cloud based computation environment for cooperative neuroimaging projects.

    PubMed

    Neves Tafula, Sérgio M; Moreira da Silva, Nádia; Rozanski, Verena E; Silva Cunha, João Paulo

    2014-01-01

    Neuroscience is an increasingly multidisciplinary and highly cooperative field where neuroimaging plays an important role. Neuroimaging rapid evolution is demanding for a growing number of computing resources and skills that need to be put in place at every lab. Typically each group tries to setup their own servers and workstations to support their neuroimaging needs, having to learn from Operating System management to specific neuroscience software tools details before any results can be obtained from each setup. This setup and learning process is replicated in every lab, even if a strong collaboration among several groups is going on. In this paper we present a new cloud service model - Brain Imaging Application as a Service (BiAaaS) - and one of its implementation - Advanced Brain Imaging Lab (ABrIL) - in the form of an ubiquitous virtual desktop remote infrastructure that offers a set of neuroimaging computational services in an interactive neuroscientist-friendly graphical user interface (GUI). This remote desktop has been used for several multi-institution cooperative projects with different neuroscience objectives that already achieved important results, such as the contribution to a high impact paper published in the January issue of the Neuroimage journal. The ABrIL system has shown its applicability in several neuroscience projects with a relatively low-cost, promoting truly collaborative actions and speeding up project results and their clinical applicability.

  16. Ultra-accurate collaborative information filtering via directed user similarity

    NASA Astrophysics Data System (ADS)

    Guo, Q.; Song, W.-J.; Liu, J.-G.

    2014-07-01

    A key challenge of the collaborative filtering (CF) information filtering is how to obtain the reliable and accurate results with the help of peers' recommendation. Since the similarities from small-degree users to large-degree users would be larger than the ones in opposite direction, the large-degree users' selections are recommended extensively by the traditional second-order CF algorithms. By considering the users' similarity direction and the second-order correlations to depress the influence of mainstream preferences, we present the directed second-order CF (HDCF) algorithm specifically to address the challenge of accuracy and diversity of the CF algorithm. The numerical results for two benchmark data sets, MovieLens and Netflix, show that the accuracy of the new algorithm outperforms the state-of-the-art CF algorithms. Comparing with the CF algorithm based on random walks proposed by Liu et al. (Int. J. Mod. Phys. C, 20 (2009) 285) the average ranking score could reach 0.0767 and 0.0402, which is enhanced by 27.3% and 19.1% for MovieLens and Netflix, respectively. In addition, the diversity, precision and recall are also enhanced greatly. Without relying on any context-specific information, tuning the similarity direction of CF algorithms could obtain accurate and diverse recommendations. This work suggests that the user similarity direction is an important factor to improve the personalized recommendation performance.

  17. 76 FR 50312 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Surface Transportation Environment and... Legacy for Users (SAFETEA-LU) established the Surface Transportation Environment and Planning Cooperative... national research on issues related to planning, environment, and realty will be included in future surface...

  18. 77 FR 38709 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Surface Transportation Environment and... Legacy for Users (SAFETEA-LU) established the Surface Transportation Environment and Planning Cooperative... national research on issues related to planning, environment, and realty will be included in future surface...

  19. 75 FR 38605 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Surface Transportation Environment and... Legacy for Users (SAFETEA-LU) established the Surface Transportation Environment and Planning Cooperative... national research on issues related to planning, environment, and realty will be included in future surface...

  20. Promotion of cooperation by adaptive interaction: The role of heterogeneity in neighborhoods

    NASA Astrophysics Data System (ADS)

    Han, Xu; Zhao, Xiaowei; Xia, Haoxiang

    2018-07-01

    Evolution of cooperation in prisoner's dilemma games has been studied extensively in the past decades. Recent studies have investigated the effect of adaptive interaction intensity on spatial prisoner's dilemma, showing that if individuals can adjust their interaction intensity with each opponent at the same extent, cooperation can be promoted in a proper scale. However, the previous studies about adaptive interaction willingness do not consider the heterogeneity of the opponents. In this paper, a simulative model is developed to examine whether and how the interactive diversity influences cooperation in the spatial prisoner's dilemma games, in which individuals consider the corresponding behavior of different opponents. The simulation results show that the proposed mechanism can effectively promote cooperation, and the average payoff of the system can significantly be improved by high interaction intensity between cooperators. In addition, we also show four kinds of different individuals to analyze the evolution progresses. The simulations show that cooperators on the boundary decrease their interaction willingness, which makes the boundary defectors lose their opportunity to participate in the interaction and be invaded by cooperators.

  1. Diversity begets diversity? The effects of board composition on the appointment and success of women CEOs.

    PubMed

    Cook, Alison; Glass, Christy

    2015-09-01

    Previous research on the effects of leadership diversity on firm outcomes has produced inconsistent and inconclusive findings. While some scholars argue that diversity increases organizational equity and enhances performance, others argue that diversity increases conflict, reduces cooperation and harms performance. This study tests the impact of a variety of compositional factors on firm outcomes. Specifically, we analyze whether and how board composition affects the advancement and mobility of women CEOs and firm performance. Our analysis relies on a unique data set of all Chief Executive Officers (CEOs) and Board of Directors (BODs) in Fortune 500 companies over a ten-year period. We find a marginally significant positive relationship between board diversity and the likelihood of a woman being appointed CEO. We further find that board diversity significantly and positively influences the post-promotion success of women CEOs. Our findings suggest that board composition is critical for the appointment and success of women CEOs, and increasing board diversity should be central to any organizational diversity efforts. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Dare To Be You: A Diversion Program for First Time Juvenile Offenders.

    ERIC Educational Resources Information Center

    Vail, Ann; Nest, Judy

    This document notes that community-based organizations such as the Cooperative Extension Service have joined the efforts to reduce juvenile delinquency through juvenile diversion programs. It then describes the "Dare to be You" program that was developed by the Colorado Cooperative Extension System. The six objectives of the program delineated in…

  3. Participatory Design, User Involvement and Health IT Evaluation.

    PubMed

    Kushniruk, Andre; Nøhr, Christian

    2016-01-01

    End user involvement and input into the design and evaluation of information systems has been recognized as being a critical success factor in the adoption of information systems. Nowhere is this need more critical than in the design of health information systems. Consistent with evidence from the general software engineering literature, the degree of user input into design of complex systems has been identified as one of the most important factors in the success or failure of complex information systems. The participatory approach goes beyond user-centered design and co-operative design approaches to include end users as more active participants in design ideas and decision making. Proponents of participatory approaches argue for greater end user participation in both design and evaluative processes. Evidence regarding the effectiveness of increased user involvement in design is explored in this contribution in the context of health IT. The contribution will discuss several approaches to including users in design and evaluation. Challenges in IT evaluation during participatory design will be described and explored along with several case studies.

  4. Cheating is evolutionarily assimilated with cooperation in the continuous snowdrift game

    PubMed Central

    Sasaki, Tatsuya; Okada, Isamu

    2015-01-01

    It is well known that in contrast to the Prisoner’s Dilemma, the snowdrift game can lead to a stable coexistence of cooperators and cheaters. Recent theoretical evidence on the snowdrift game suggests that gradual evolution for individuals choosing to contribute in continuous degrees can result in the social diversification to a 100% contribution and 0% contribution through so-called evolutionary branching. Until now, however, game-theoretical studies have shed little light on the evolutionary dynamics and consequences of the loss of diversity in strategy. Here, we analyze continuous snowdrift games with quadratic payoff functions in dimorphic populations. Subsequently, conditions are clarified under which gradual evolution can lead a population consisting of those with 100% contribution and those with 0% contribution to merge into one species with an intermediate contribution level. The key finding is that the continuous snowdrift game is more likely to lead to assimilation of different cooperation levels rather than maintenance of diversity. Importantly, this implies that allowing the gradual evolution of cooperative behavior can facilitate social inequity aversion in joint ventures that otherwise could cause conflicts that are based on commonly accepted notions of fairness. PMID:25868940

  5. Collaborative Strategic Reading on Multi-Touch and Multi-User Digital Tabletop Displays

    ERIC Educational Resources Information Center

    Maslamani, Jaber Ali; Windeatt, Scott; Olivier, Patrick; Heslop, Phil; Kharrufa, Ahmed; Shearer, John; Balaam, Madeline

    2012-01-01

    This paper is part of a work-in-progress that reports on the design, development, and evaluation of a Digital Collaborative Strategic Reading (DCSR) application with regard to its effectiveness in improving English as a second language (ESL) reading comprehension. The DCSR application allows users to read collaboratively on multitouch and…

  6. MDMA, serotonergic neurotoxicity, and the diverse functional deficits of recreational 'Ecstasy' users.

    PubMed

    Parrott, Andrew C

    2013-09-01

    Serotonergic neurotoxicity following MDMA is well-established in laboratory animals, and neuroimaging studies have found lower serotonin transporter (SERT) binding in abstinent Ecstasy/MDMA users. Serotonin is a modulator for many different psychobiological functions, and this review will summarize the evidence for equivalent functional deficits in recreational users. Declarative memory, prospective memory, and higher cognitive skills are often impaired. Neurocognitive deficits are associated with reduced SERT in the hippocampus, parietal cortex, and prefrontal cortex. EEG and ERP studies have shown localised reductions in brain activity during neurocognitive performance. Deficits in sleep, mood, vision, pain, psychomotor skill, tremor, neurohormonal activity, and psychiatric status, have also been demonstrated. The children of mothers who take Ecstasy/MDMA during pregnancy have developmental problems. These psychobiological deficits are wide-ranging, and occur in functions known to be modulated by serotonin. They are often related to lifetime dosage, with light users showing slight changes, and heavy users displaying more pronounced problems. In summary, abstinent Ecstasy/MDMA users can show deficits in a wide range of biobehavioral functions with a serotonergic component. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Evaluating green infrastructure in urban environments using a multi-taxa and functional diversity approach.

    PubMed

    Pinho, Pedro; Correia, Otília; Lecoq, Miguel; Munzi, Silvana; Vasconcelos, Sasha; Gonçalves, Paula; Rebelo, Rui; Antunes, Cristina; Silva, Patrícia; Freitas, Catarina; Lopes, Nuno; Santos-Reis, Margarida; Branquinho, Cristina

    2016-05-01

    Forested areas within cities host a large number of species, responsible for many ecosystem services in urban areas. The biodiversity in these areas is influenced by human disturbances such as atmospheric pollution and urban heat island effect. To ameliorate the effects of these factors, an increase in urban green areas is often considered sufficient. However, this approach assumes that all types of green cover have the same importance for species. Our aim was to show that not all forested green areas are equal in importance for species, but that based on a multi-taxa and functional diversity approach it is possible to value green infrastructure in urban environments. After evaluating the diversity of lichens, butterflies and other-arthropods, birds and mammals in 31 Mediterranean urban forests in south-west Europe (Almada, Portugal), bird and lichen functional groups responsive to urbanization were found. A community shift (tolerant species replacing sensitive ones) along the urbanization gradient was found, and this must be considered when using these groups as indicators of the effect of urbanization. Bird and lichen functional groups were then analyzed together with the characteristics of the forests and their surroundings. Our results showed that, contrary to previous assumptions, vegetation density and more importantly the amount of urban areas around the forest (matrix), are more important for biodiversity than forest quantity alone. This indicated that not all types of forested green areas have the same importance for biodiversity. An index of forest functional diversity was then calculated for all sampled forests of the area. This could help decision-makers to improve the management of urban green infrastructures with the goal of increasing functionality and ultimately ecosystem services in urban areas. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Cooperative Learning with a Computer in a Native Language Class.

    ERIC Educational Resources Information Center

    Bennett, Ruth

    In a cooperative task, American Indian elementary students produced bilingual natural history dictionaries using a Macintosh computer. Students in grades 3 through 8 attended weekly, multi-graded bilingual classes in Hupa/English or Yurok/English, held at two public school field sites for training elementary teaching-credential candidates. Teams…

  9. A Comparison of Two Measures of HIV Diversity in Multi-Assay Algorithms for HIV Incidence Estimation

    PubMed Central

    Cousins, Matthew M.; Konikoff, Jacob; Sabin, Devin; Khaki, Leila; Longosz, Andrew F.; Laeyendecker, Oliver; Celum, Connie; Buchbinder, Susan P.; Seage, George R.; Kirk, Gregory D.; Moore, Richard D.; Mehta, Shruti H.; Margolick, Joseph B.; Brown, Joelle; Mayer, Kenneth H.; Kobin, Beryl A.; Wheeler, Darrell; Justman, Jessica E.; Hodder, Sally L.; Quinn, Thomas C.; Brookmeyer, Ron; Eshleman, Susan H.

    2014-01-01

    Background Multi-assay algorithms (MAAs) can be used to estimate HIV incidence in cross-sectional surveys. We compared the performance of two MAAs that use HIV diversity as one of four biomarkers for analysis of HIV incidence. Methods Both MAAs included two serologic assays (LAg-Avidity assay and BioRad-Avidity assay), HIV viral load, and an HIV diversity assay. HIV diversity was quantified using either a high resolution melting (HRM) diversity assay that does not require HIV sequencing (HRM score for a 239 base pair env region) or sequence ambiguity (the percentage of ambiguous bases in a 1,302 base pair pol region). Samples were classified as MAA positive (likely from individuals with recent HIV infection) if they met the criteria for all of the assays in the MAA. The following performance characteristics were assessed: (1) the proportion of samples classified as MAA positive as a function of duration of infection, (2) the mean window period, (3) the shadow (the time period before sample collection that is being assessed by the MAA), and (4) the accuracy of cross-sectional incidence estimates for three cohort studies. Results The proportion of samples classified as MAA positive as a function of duration of infection was nearly identical for the two MAAs. The mean window period was 141 days for the HRM-based MAA and 131 days for the sequence ambiguity-based MAA. The shadows for both MAAs were <1 year. Both MAAs provided cross-sectional HIV incidence estimates that were very similar to longitudinal incidence estimates based on HIV seroconversion. Conclusions MAAs that include the LAg-Avidity assay, the BioRad-Avidity assay, HIV viral load, and HIV diversity can provide accurate HIV incidence estimates. Sequence ambiguity measures obtained using a commercially-available HIV genotyping system can be used as an alternative to HRM scores in MAAs for cross-sectional HIV incidence estimation. PMID:24968135

  10. [A cooperation learning program to improve health promotion approach].

    PubMed

    Dollet, Agnès

    2014-10-01

    Cooperation in the health and social welfare sectors enables the users to be taken care of, as a part of a health promotion approach. The aim of L'IRFSS Auvergne is to promote cooperation between future nurses and social workers within its training sessions. Based on that work, the objective was to implement a framework integrated to both the nursing and social work curriculum, enabling the students to develop team working skills on the field. A survey of nurses and social workers leads to the creation of a pedagogical tool adapted to issues encountered on the field. « the cooperation toolbox kit »In addition to this project, the study raised the question of the role of health promotion in the social work curriculum, the organization of the lifelong training department in a given area, and the role of coordination in the training of managerial staff.

  11. Social penalty promotes cooperation in a cooperative society.

    PubMed

    Ito, Hiromu; Yoshimura, Jin

    2015-08-04

    Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner's dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation.

  12. Social penalty promotes cooperation in a cooperative society

    PubMed Central

    Ito, Hiromu; Yoshimura, Jin

    2015-01-01

    Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner’s dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation. PMID:26238521

  13. Correlates of Cooperation in a One-Shot High-Stakes Televised Prisoners' Dilemma

    PubMed Central

    Burton-Chellew, Maxwell N.; West, Stuart A.

    2012-01-01

    Explaining cooperation between non-relatives is a puzzle for both evolutionary biology and the social sciences. In humans, cooperation is often studied in a laboratory setting using economic games such as the prisoners' dilemma. However, such experiments are sometimes criticized for being played for low stakes and by misrepresentative student samples. Golden balls is a televised game show that uses the prisoners' dilemma, with a diverse range of participants, often playing for very large stakes. We use this non-experimental dataset to investigate the factors that influence cooperation when “playing” for considerably larger stakes than found in economic experiments. The game show has earlier stages that allow for an analysis of lying and voting decisions. We found that contestants were sensitive to the stakes involved, cooperating less when the stakes were larger in both absolute and relative terms. We also found that older contestants were more likely to cooperate, that liars received less cooperative behavior, but only if they told a certain type of lie, and that physical contact was associated with reduced cooperation, whereas laughter and promises were reliable signals or cues of cooperation, but were not necessarily detected. PMID:22485141

  14. Correlates of cooperation in a one-shot high-stakes televised prisoners' dilemma.

    PubMed

    Burton-Chellew, Maxwell N; West, Stuart A

    2012-01-01

    Explaining cooperation between non-relatives is a puzzle for both evolutionary biology and the social sciences. In humans, cooperation is often studied in a laboratory setting using economic games such as the prisoners' dilemma. However, such experiments are sometimes criticized for being played for low stakes and by misrepresentative student samples. Golden balls is a televised game show that uses the prisoners' dilemma, with a diverse range of participants, often playing for very large stakes. We use this non-experimental dataset to investigate the factors that influence cooperation when "playing" for considerably larger stakes than found in economic experiments. The game show has earlier stages that allow for an analysis of lying and voting decisions. We found that contestants were sensitive to the stakes involved, cooperating less when the stakes were larger in both absolute and relative terms. We also found that older contestants were more likely to cooperate, that liars received less cooperative behavior, but only if they told a certain type of lie, and that physical contact was associated with reduced cooperation, whereas laughter and promises were reliable signals or cues of cooperation, but were not necessarily detected.

  15. Joint channel estimation and multi-user detection for multipath fading channels in DS-CDMA systems

    NASA Astrophysics Data System (ADS)

    Wu, Sau-Hsuan; Kuo, C.-C. Jay

    2002-11-01

    The technique of joint blind channel estimation and multiple access interference (MAI) suppression for an asynchronous code-division multiple-access (CDMA) system is investigated in this research. To identify and track dispersive time-varying fading channels and to avoid the phase ambiguity that come with the second-order statistic approaches, a sliding-window scheme using the expectation maximization (EM) algorithm is proposed. The complexity of joint channel equalization and symbol detection for all users increases exponentially with system loading and the channel memory. The situation is exacerbated if strong inter-symbol interference (ISI) exists. To reduce the complexity and the number of samples required for channel estimation, a blind multiuser detector is developed. Together with multi-stage interference cancellation using soft outputs provided by this detector, our algorithm can track fading channels with no phase ambiguity even when channel gains attenuate close to zero.

  16. ICPL: Intelligent Cooperative Planning and Learning for Multi-agent Systems

    DTIC Science & Technology

    2012-02-29

    objective was to develop a new planning approach for teams!of multiple UAVs that tightly integrates learning and cooperative!control algorithms at... algorithms at multiple levels of the planning architecture. The research results enabled a team of mobile agents to learn to adapt and react to uncertainty in...expressive representation that incorporates feature conjunctions. Our algorithm is simple to implement, fast to execute, and can be combined with any

  17. [Addictology, promoting users' power to act].

    PubMed

    Morel, Alain

    2018-01-01

    The notion of risk reduction applies to all uses, drinking of alcohol and smoking including, addictions without drugs likewise. With regard to drugs, mentalities change. We now talk more of risks than fault or deviance. Following, collaboration between health professionals and users, sharing and cooperation are the conditions necessary to develop a modern humanist and social addictology approach. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. A formation control strategy with coupling weights for the multi-robot system

    NASA Astrophysics Data System (ADS)

    Liang, Xudong; Wang, Siming; Li, Weijie

    2017-12-01

    The distributed formation problem of the multi-robot system with general linear dynamic characteristics and directed communication topology is discussed. In order to avoid that the multi-robot system can not maintain the desired formation in the complex communication environment, the distributed cooperative algorithm with coupling weights based on zipf distribution is designed. The asymptotic stability condition for the formation of the multi-robot system is given, and the theory of the graph and the Lyapunov theory are used to prove that the formation can converge to the desired geometry formation and the desired motion rules of the virtual leader under this condition. Nontrivial simulations are performed to validate the effectiveness of the distributed cooperative algorithm with coupling weights.

  19. Algorithmic and user study of an autocompletion algorithm on a large medical vocabulary.

    PubMed

    Sevenster, Merlijn; van Ommering, Rob; Qian, Yuechen

    2012-02-01

    Autocompletion supports human-computer interaction in software applications that let users enter textual data. We will be inspired by the use case in which medical professionals enter ontology concepts, catering the ongoing demand for structured and standardized data in medicine. Goal is to give an algorithmic analysis of one particular autocompletion algorithm, called multi-prefix matching algorithm, which suggests terms whose words' prefixes contain all words in the string typed by the user, e.g., in this sense, opt ner me matches optic nerve meningioma. Second we aim to investigate how well it supports users entering concepts from a large and comprehensive medical vocabulary (snomed ct). We give a concise description of the multi-prefix algorithm, and sketch how it can be optimized to meet required response time. Performance will be compared to a baseline algorithm, which gives suggestions that extend the string typed by the user to the right, e.g. optic nerve m gives optic nerve meningioma, but opt ner me does not. We conduct a user experiment in which 12 participants are invited to complete 40 snomed ct terms with the baseline algorithm and another set of 40 snomed ct terms with the multi-prefix algorithm. Our results show that users need significantly fewer keystrokes when supported by the multi-prefix algorithm than when supported by the baseline algorithm. The proposed algorithm is a competitive candidate for searching and retrieving terms from a large medical ontology. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Coalition Formation and Spectrum Sharing of Cooperative Spectrum Sensing Participants.

    PubMed

    Zhensheng Jiang; Wei Yuan; Leung, Henry; Xinge You; Qi Zheng

    2017-05-01

    In cognitive radio networks, self-interested secondary users (SUs) desire to maximize their own throughput. They compete with each other for transmit time once the absence of primary users (PUs) is detected. To satisfy the requirement of PU protection, on the other hand, they have to form some coalitions and cooperate to conduct spectrum sensing. Such dilemma of SUs between competition and cooperation motivates us to study two interesting issues: 1) how to appropriately form some coalitions for cooperative spectrum sensing (CSS) and 2) how to share transmit time among SUs. We jointly consider these two issues, and propose a noncooperative game model with 2-D strategies. The first dimension determines coalition formation, and the second indicates transmit time allocation. Considering the complexity of solving this game, we decompose the game into two more tractable ones: one deals with the formation of CSS coalitions, and the other focuses on the allocation of transmit time. We characterize the Nash equilibria (NEs) of both games, and show that the combination of these two NEs corresponds to the NE of the original game. We also develop a distributed algorithm to achieve a desirable NE of the original game. When this NE is achieved, the SUs obtain a Dhp-stable coalition structure and a fair transmit time allocation. Numerical results verify our analyses, and demonstrate the effectiveness of our algorithm.

  1. User Demographics for Embodiment Customization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cowell, Andrew J.; Stanney, Kay M.

    Attempts at interface agent personalization are usually aimed at helping the user perform a task or service. For example,scheduling of appointments, inspection of messages, discovering items of interest and different forms of negotiation. While this is very noble undertaking, it makes assumptions about the level of trust and credibility a user may place in such an agent in a realworld setting. If Microsoft's experiments in social user interfaces teach us anything, it is that a ''one size fits all'' solution does not truly engage the user and encourage reuse. This ''relationship management'' between the user and the character begins whenmore » the two first meet. As with human-human relationships, first impressions are essential. Instead of looking at the functional aspects of the relationship, we believe the characters embodiment is the best place to start the personalization process. We describe a study in which participants from several different age ranges,genders and ethnic groups were asked their preference of anthropomorphic character, based on a cooperative computer task. We found that participants generally selected characters from the same ethic group as themselves and that almost all participants selected a young character (instead of a middle aged or elderly character). No significant preference was found for character gender.« less

  2. Solving the stability-accuracy-diversity dilemma of recommender systems

    NASA Astrophysics Data System (ADS)

    Hou, Lei; Liu, Kecheng; Liu, Jianguo; Zhang, Runtong

    2017-02-01

    Recommender systems are of great significance in predicting the potential interesting items based on the target user's historical selections. However, the recommendation list for a specific user has been found changing vastly when the system changes, due to the unstable quantification of item similarities, which is defined as the recommendation stability problem. To improve the similarity stability and recommendation stability is crucial for the user experience enhancement and the better understanding of user interests. While the stability as well as accuracy of recommendation could be guaranteed by recommending only popular items, studies have been addressing the necessity of diversity which requires the system to recommend unpopular items. By ranking the similarities in terms of stability and considering only the most stable ones, we present a top- n-stability method based on the Heat Conduction algorithm (denoted as TNS-HC henceforth) for solving the stability-accuracy-diversity dilemma. Experiments on four benchmark data sets indicate that the TNS-HC algorithm could significantly improve the recommendation stability and accuracy simultaneously and still retain the high-diversity nature of the Heat Conduction algorithm. Furthermore, we compare the performance of the TNS-HC algorithm with a number of benchmark recommendation algorithms. The result suggests that the TNS-HC algorithm is more efficient in solving the stability-accuracy-diversity triple dilemma of recommender systems.

  3. Dual deep modeling: multi-level modeling with dual potencies and its formalization in F-Logic.

    PubMed

    Neumayr, Bernd; Schuetz, Christoph G; Jeusfeld, Manfred A; Schrefl, Michael

    2018-01-01

    An enterprise database contains a global, integrated, and consistent representation of a company's data. Multi-level modeling facilitates the definition and maintenance of such an integrated conceptual data model in a dynamic environment of changing data requirements of diverse applications. Multi-level models transcend the traditional separation of class and object with clabjects as the central modeling primitive, which allows for a more flexible and natural representation of many real-world use cases. In deep instantiation, the number of instantiation levels of a clabject or property is indicated by a single potency. Dual deep modeling (DDM) differentiates between source potency and target potency of a property or association and supports the flexible instantiation and refinement of the property by statements connecting clabjects at different modeling levels. DDM comes with multiple generalization of clabjects, subsetting/specialization of properties, and multi-level cardinality constraints. Examples are presented using a UML-style notation for DDM together with UML class and object diagrams for the representation of two-level user views derived from the multi-level model. Syntax and semantics of DDM are formalized and implemented in F-Logic, supporting the modeler with integrity checks and rich query facilities.

  4. Time evolving multi-city dependencies and robustness tradeoffs for risk-based portfolios of conservation, transfers, and cooperative water supply infrastructure development pathways

    NASA Astrophysics Data System (ADS)

    Trindade, B. C.; Reed, P. M.; Zeff, H. B.; Characklis, G. W.

    2016-12-01

    Water scarcity in historically water-rich regions such as the southeastern United States is becoming a more prevalent concern. It has been shown that cooperative short-term planning that relies on conservation and transfers of existing supplies amongst communities can be used by water utilities to mitigate the effects of water scarcity in the near future. However, in the longer term, infrastructure expansion is likely to be necessary to address imbalances between growing water demands and the available supply capacity. This study seeks to better diagnose and avoid candidate modes for system failure. Although it is becoming more common for water utilities to evaluate the robustness of their water supply, defined as the insensitivity of their systems to errors in deeply uncertain projections or assumptions, defining robustness is particularly challenging in multi-stakeholder regional contexts for decisions that encompass short management actions and long-term infrastructure planning. Planning and management decisions are highly interdependent and strongly shape how a region's infrastructure itself evolves. This research advances the concept of system robustness by making it evolve over time rather than static, so that it is applicable to an adaptive system and therefore more suited for use for combined short and long-term planning efforts. The test case for this research is the Research Triangle area of North Carolina, where the cities of Raleigh, Durham, Cary and Chapel Hill are experiencing rapid population growth and increasing concerns over drought. This study is facilitating their engagement in cooperative and robust regional water portfolio planning. The insights from this work have general merit for regions where adjacent municipalities can benefit from improving cooperative infrastructure investments and more efficient resource management strategies.

  5. Studying strategic interaction under environmental and economic uncertainties among water users in the Zambezi River Basin - From descriptive analysis to institutional design for better transboundary management

    NASA Astrophysics Data System (ADS)

    Beck, L.; Siegfried, T. U.; Bernauer, T.

    2009-12-01

    The Zambezi River Basin (ZRB) is one of the largest freshwater catchments in Africa and worldwide. Consumptive water use in the ZRB is currently estimated at 15 - 20 percent of total runoff. This suggests many development possibilities, particularly for irrigated agriculture and hydropower production. The key drivers in the basin are population development on the demand side as well as uncertain impacts from climate change for supply. Development plans of the riparian countries suggest that consumptive water use might increase up to 40 percent of total runoff by 2025. This suggests that expanding water use in the Zambezi basin could become a source of disputes among the eight riparian countries. We study the surface water allocation in the basin by means of a couple hydrological-economic modeling approach. A conceptual lumped-parameter rainfall-runoff model for the ZRB was constructed and calibrated on the best available runoff data for the basin. Water users are modeled based on an agent-based framework and implemented as distributed sequential decision makers that act in an uncertain environment. Given the current non-cooperative status quo, we use the stochastic optimization technique of reinforcement learning to model the individual agents’ behavior. Their goals include the maximization of a) their long-term reward as conditioned on the state of the multi-agent system and b) the immediate reward obtained from operational decisions of reservoirs and water diversions under their control. We feed a wide range of water demand drivers as well as climate change predictions into the model and assess agents’ responses and the resulting implications for runoff at key points in the water catchment, including Victoria Falls, Kariba reservoir, Kafue Gorge, and Cahora Bassa reservoir in the downstream. It will be shown that considerable benefits exist if the current non-cooperative regime is replaced by a basin-wide, coordinated allocation strategy that regulates water

  6. Learning and innovative elements of strategy adoption rules expand cooperative network topologies.

    PubMed

    Wang, Shijun; Szalay, Máté S; Zhang, Changshui; Csermely, Peter

    2008-04-09

    Cooperation plays a key role in the evolution of complex systems. However, the level of cooperation extensively varies with the topology of agent networks in the widely used models of repeated games. Here we show that cooperation remains rather stable by applying the reinforcement learning strategy adoption rule, Q-learning on a variety of random, regular, small-word, scale-free and modular network models in repeated, multi-agent Prisoner's Dilemma and Hawk-Dove games. Furthermore, we found that using the above model systems other long-term learning strategy adoption rules also promote cooperation, while introducing a low level of noise (as a model of innovation) to the strategy adoption rules makes the level of cooperation less dependent on the actual network topology. Our results demonstrate that long-term learning and random elements in the strategy adoption rules, when acting together, extend the range of network topologies enabling the development of cooperation at a wider range of costs and temptations. These results suggest that a balanced duo of learning and innovation may help to preserve cooperation during the re-organization of real-world networks, and may play a prominent role in the evolution of self-organizing, complex systems.

  7. Multi-factor authentication

    DOEpatents

    Hamlet, Jason R; Pierson, Lyndon G

    2014-10-21

    Detection and deterrence of spoofing of user authentication may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a user of the hardware device. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a PUF value. Combining logic is coupled to receive the PUF value, combines the PUF value with one or more other authentication factors to generate a multi-factor authentication value. A key generator is coupled to generate a private key and a public key based on the multi-factor authentication value while a decryptor is coupled to receive an authentication challenge posed to the hardware device and encrypted with the public key and coupled to output a response to the authentication challenge decrypted with the private key.

  8. [Potential of cooperative learning in project development : Relevance of cooperative participation procedure for the further development of generation-appropriate accomodation in structurally weak rural areas].

    PubMed

    Kaufmann, Gerd; Frankenberg, Olga; Sommer, Ralf-Rüdiger; Jost, Annemarie

    2017-04-01

    A joint initiative of existing senior care organizations, the municipality of Meyenburg and the state of Brandenburg was further developed by affiliation of an institute of the Brandenburg University of Technology Cottbus-Senftenberg (ABV) in cooperation with members of the architecture and social work departments in 2014. A cooperative process between different players was central to create an appropriate structure of services for this region. Cooperative projects are necessary to establish new forms of generation-appropriate living and care concepts in rural areas. Cooperative learning methods are needed to develop new forms of generation-appropriate living and care concepts in rural areas, which take the diversity of elderly people, the rural context, intergenerational residential arrangements and affordable accommodation that meets the requirements of the social security system into account. Furthermore, the project had to reflect the recent developments of the German care insurance. The article describes the participatory methods, the coordination process and the resulting concept.

  9. Human-Robot Cooperation with Commands Embedded in Actions

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kazuki; Yamada, Seiji

    In this paper, we first propose a novel interaction model, CEA (Commands Embedded in Actions). It can explain the way how some existing systems reduce the work-load of their user. We next extend the CEA and build ECEA (Extended CEA) model. The ECEA enables robots to achieve more complicated tasks. On this extension, we employ ACS (Action Coding System) which can describe segmented human acts and clarifies the relationship between user's actions and robot's actions in a task. The ACS utilizes the CEA's strong point which enables a user to send a command to a robot by his/her natural action for the task. The instance of the ECEA led by using the ACS is a temporal extension which has the user keep a final state of a previous his/her action. We apply the temporal extension of the ECEA for a sweeping task. The high-level task, a cooperative task between the user and the robot can be realized. The robot with simple reactive behavior can sweep the region of under an object when the user picks up the object. In addition, we measure user's cognitive loads on the ECEA and a traditional method, DCM (Direct Commanding Method) in the sweeping task, and compare between them. The results show that the ECEA has a lower cognitive load than the DCM significantly.

  10. Cooperative Buying for New Associates: Some Assembly Required. Important Safety Instructions.

    ERIC Educational Resources Information Center

    Talarico, Scott

    1998-01-01

    A guide for using cooperative buying to block-book campus activities or attractions through a campus activities convention provides a step-by-step process and outlines some specific considerations, including forms, pricing, preparation for the conference, follow-up approaches, and hints for new users of the system. (MSE)

  11. Effects of Dimers on Cooperation in the Spatial Prisoner's Dilemma Game

    NASA Astrophysics Data System (ADS)

    Li, Hai-Hong; Cheng, Hong-Yan; Dai, Qiong-Lin; Ju, Ping; Zhang, Mei; Yang, Jun-Zhong

    2011-11-01

    We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dimers on cooperation depend on the type of dimers and the population structure. For those dimers in which players interact with each other, the cooperation level increases with the number of dimers though the cooperation improvement level depends on the type of network structures. On the other hand, the dimers, in which there are not mutual interactions, will not do any good to the cooperation level in a single community, but interestingly, will improve the cooperation level in a population with two communities. We explore the relationship between dimers and self-interactions and find that the effects of dimers are similar to that of self-interactions. Also, we find that the dimers, which are established over two communities in a multi-community network, act as one type of interaction through which information between communities is communicated by the requirement that two players in a dimer hold a same strategy.

  12. UAV Cooperation Architectures for Persistent Sensing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roberts, R S; Kent, C A; Jones, E D

    2003-03-20

    With the number of small, inexpensive Unmanned Air Vehicles (UAVs) increasing, it is feasible to build multi-UAV sensing networks. In particular, by using UAVs in conjunction with unattended ground sensors, a degree of persistent sensing can be achieved. With proper UAV cooperation algorithms, sensing is maintained even though exceptional events, e.g., the loss of a UAV, have occurred. In this paper a cooperation technique that allows multiple UAVs to perform coordinated, persistent sensing with unattended ground sensors over a wide area is described. The technique automatically adapts the UAV paths so that on the average, the amount of time thatmore » any sensor has to wait for a UAV revisit is minimized. We also describe the Simulation, Tactical Operations and Mission Planning (STOMP) software architecture. This architecture is designed to help simulate and operate distributed sensor networks where multiple UAVs are used to collect data.« less

  13. Users/consumers differences regarding ergonomics and design theory and practice.

    PubMed

    Dejean, Pierre-Henri; Wagstaff, Peter

    2012-01-01

    This paper presents the concept of direct and indirect users, a key issue to cooperation between ergonomists, designers and managers involved in a sustainable approach to design. What issues for Ergonomics and Design are launched by this concept? User/consumer differences should be approached taking into account Ergonomics and Design theory and practice. What dialogue and tools could help the ergonomist/designer/manager to respond to all the requirements of the future clients of the product?

  14. Cooperative high-performance storage in the accelerated strategic computing initiative

    NASA Technical Reports Server (NTRS)

    Gary, Mark; Howard, Barry; Louis, Steve; Minuzzo, Kim; Seager, Mark

    1996-01-01

    The use and acceptance of new high-performance, parallel computing platforms will be impeded by the absence of an infrastructure capable of supporting orders-of-magnitude improvement in hierarchical storage and high-speed I/O (Input/Output). The distribution of these high-performance platforms and supporting infrastructures across a wide-area network further compounds this problem. We describe an architectural design and phased implementation plan for a distributed, Cooperative Storage Environment (CSE) to achieve the necessary performance, user transparency, site autonomy, communication, and security features needed to support the Accelerated Strategic Computing Initiative (ASCI). ASCI is a Department of Energy (DOE) program attempting to apply terascale platforms and Problem-Solving Environments (PSEs) toward real-world computational modeling and simulation problems. The ASCI mission must be carried out through a unified, multilaboratory effort, and will require highly secure, efficient access to vast amounts of data. The CSE provides a logically simple, geographically distributed, storage infrastructure of semi-autonomous cooperating sites to meet the strategic ASCI PSE goal of highperformance data storage and access at the user desktop.

  15. On Building a Diverse Democracy: Justice and Identity in the Twenty-First Century

    ERIC Educational Resources Information Center

    Patel, Eboo

    2017-01-01

    Passionate about making interfaith cooperation the social norm in a highly diverse religious world landscape, Eboo Patel is founder and president of Interfaith Youth Core. The organization brings together young people of different religious and moral traditions for cooperative service and dialogue around shared values. In this article, which is…

  16. An efficient biometric and password-based remote user authentication using smart card for Telecare Medical Information Systems in multi-server environment.

    PubMed

    Maitra, Tanmoy; Giri, Debasis

    2014-12-01

    The medical organizations have introduced Telecare Medical Information System (TMIS) to provide a reliable facility by which a patient who is unable to go to a doctor in critical or urgent period, can communicate to a doctor through a medical server via internet from home. An authentication mechanism is needed in TMIS to hide the secret information of both parties, namely a server and a patient. Recent research includes patient's biometric information as well as password to design a remote user authentication scheme that enhances the security level. In a single server environment, one server is responsible for providing services to all the authorized remote patients. However, the problem arises if a patient wishes to access several branch servers, he/she needs to register to the branch servers individually. In 2014, Chuang and Chen proposed an remote user authentication scheme for multi-server environment. In this paper, we have shown that in their scheme, an non-register adversary can successfully logged-in into the system as a valid patient. To resist the weaknesses, we have proposed an authentication scheme for TMIS in multi-server environment where the patients can register to a root telecare server called registration center (RC) in one time to get services from all the telecare branch servers through their registered smart card. Security analysis and comparison shows that our proposed scheme provides better security with low computational and communication cost.

  17. Bidirectional and Multi-User Telerehabilitation System: Clinical Effect on Balance, Functional Activity, and Satisfaction in Patients with Chronic Stroke Living in Long-Term Care Facilities

    PubMed Central

    Lin, Kwan-Hwa; Chen, Chin-Hsing; Chen, You-Yin; Huang, Wen-Tzeng; Lai, Jin-Shin; Yu, Shang-Ming; Chang, Yuan-Jen

    2014-01-01

    Background The application of internet technology for telerehabilitation in patients with stroke has developed rapidly. Objective The current study aimed to evaluate the effect of a bidirectional and multi-user telerehabilitation system on balance and satisfaction in patients with chronic stroke living in long-term care facilities (LTCFs). Method This pilot study used a multi-site, blocked randomization design. Twenty-four participants from three LTCFs were recruited, and the participants were randomly assigned into the telerehabilitation (Tele) and conventional therapy (Conv) groups within each LTCF. Tele group received telerehabilitation but the Conv group received conventional therapy with two persons in each group for three sessions per week and for four weeks. The outcome measures included Berg Balance Scale (BBS), Barthel Index (BI), and the telerehabilitation satisfaction of the participants. Setting A telerehabilitation system included “therapist end” in a laboratory, and the “client end” in LTCFs. The conventional therapy was conducted in LTCFs. Results Training programs conducted for both the Tele and Conv groups showed significant effects within groups on the participant BBS as well as the total and self-care scores of BI. No significant difference between groups could be demonstrated. The satisfaction of participants between the Tele and the Conv groups also did not show significant difference. Conclusions This pilot study indicated that the multi-user telerehabilitation program is feasible for improving the balance and functional activity similar to conventional therapy in patients with chronic stroke living in LTCFs. PMID:25019632

  18. Use Model for a User Centred Design in Multidisciplinary Teams.

    PubMed

    Clark, Colin; Michelle, Jess; Shahi, Sepideh; Stolarick, Kevin; Trevinarus, Jutta; Vanderheiden, Gregg; Vimarlund, Vivian

    2017-01-01

    The Use Model identifies user groups who will be using services and products the Prosperity4All infrastructure offers. The Model provides developers a tool to keep in mind the full diversity of users while building and designing the infrastructure.

  19. PAD-MAC: Primary User Activity-Aware Distributed MAC for Multi-Channel Cognitive Radio Networks

    PubMed Central

    Ali, Amjad; Piran, Md. Jalil; Kim, Hansoo; Yun, Jihyeok; Suh, Doug Young

    2015-01-01

    Cognitive radio (CR) has emerged as a promising technology to solve problems related to spectrum scarcity and provides a ubiquitous wireless access environment. CR-enabled secondary users (SUs) exploit spectrum white spaces opportunistically and immediately vacate the acquired licensed channels as primary users (PUs) arrive. Accessing the licensed channels without the prior knowledge of PU traffic patterns causes severe throughput degradation due to excessive channel switching and PU-to-SU collisions. Therefore, it is significantly important to design a PU activity-aware medium access control (MAC) protocol for cognitive radio networks (CRNs). In this paper, we first propose a licensed channel usage pattern identification scheme, based on a two-state Markov model, and then estimate the future idle slots using previous observations of the channels. Furthermore, based on these past observations, we compute the rank of each available licensed channel that gives SU transmission success assessment during the estimated idle slot. Secondly, we propose a PU activity-aware distributed MAC (PAD-MAC) protocol for heterogeneous multi-channel CRNs that selects the best channel for each SU to enhance its throughput. PAD-MAC controls SU activities by allowing them to exploit the licensed channels only for the duration of estimated idle slots and enables predictive and fast channel switching. To evaluate the performance of the proposed PAD-MAC, we compare it with the distributed QoS-aware MAC (QC-MAC) and listen-before-talk MAC schemes. Extensive numerical results show the significant improvements of the PAD-MAC in terms of the SU throughput, SU channel switching rate and PU-to-SU collision rate. PMID:25831084

  20. Cooperation prevails when individuals adjust their social ties.

    PubMed

    Santos, Francisco C; Pacheco, Jorge M; Lenaerts, Tom

    2006-10-20

    Conventional evolutionary game theory predicts that natural selection favours the selfish and strong even though cooperative interactions thrive at all levels of organization in living systems. Recent investigations demonstrated that a limiting factor for the evolution of cooperative interactions is the way in which they are organized, cooperators becoming evolutionarily competitive whenever individuals are constrained to interact with few others along the edges of networks with low average connectivity. Despite this insight, the conundrum of cooperation remains since recent empirical data shows that real networks exhibit typically high average connectivity and associated single-to-broad-scale heterogeneity. Here, a computational model is constructed in which individuals are able to self-organize both their strategy and their social ties throughout evolution, based exclusively on their self-interest. We show that the entangled evolution of individual strategy and network structure constitutes a key mechanism for the sustainability of cooperation in social networks. For a given average connectivity of the population, there is a critical value for the ratio W between the time scales associated with the evolution of strategy and of structure above which cooperators wipe out defectors. Moreover, the emerging social networks exhibit an overall heterogeneity that accounts very well for the diversity of patterns recently found in acquired data on social networks. Finally, heterogeneity is found to become maximal when W reaches its critical value. These results show that simple topological dynamics reflecting the individual capacity for self-organization of social ties can produce realistic networks of high average connectivity with associated single-to-broad-scale heterogeneity. On the other hand, they show that cooperation cannot evolve as a result of "social viscosity" alone in heterogeneous networks with high average connectivity, requiring the additional mechanism of

  1. Diversity among elephant grass genotypes using Bayesian multi-trait model.

    PubMed

    Rossi, D A; Daher, R F; Barbé, T C; Lima, R S N; Costa, A F; Ribeiro, L P; Teodoro, P E; Bhering, L L

    2017-09-27

    Elephant grass is a perennial tropical grass with great potential for energy generation from biomass. The objective of this study was to estimate the genetic diversity among elephant grass accessions based on morpho-agronomic and biomass quality traits and to identify promising genotypes for obtaining hybrids with high energetic biomass production capacity. The experiment was installed at experimental area of the State Agricultural College Antônio Sarlo, in Campos dos Goytacazes. Fifty-two elephant grass genotypes were evaluated in a randomized block design with two replicates. Components of variance and the genotypic means were obtained using a Bayesian multi-trait model. We considered 350,000 iterations in the Gibbs sampler algorithm for each parameter adopted, with a warm-up period (burn-in) of 50,000 Iterations. For obtaining an uncorrelated sample, we considered five iterations (thinning) as a spacing between sampled points, which resulted in a final sample size 60,000. Subsequently, the Mahalanobis distance between each pair of genotypes was estimated. Estimates of genotypic variance indicated a favorable condition for gains in all traits. Elephant grass accessions presented greater variability for biomass quality traits, for which three groups were formed, while for the agronomic traits, two groups were formed. Crosses between Mercker Pinda México x Mercker 86-México, Mercker Pinda México x Turrialba, and Mercker 86-México x Taiwan A-25 can be carried out for obtaining elephant grass hybrids for energy purposes.

  2. Heterogeneity of allocation promotes cooperation in public goods games

    NASA Astrophysics Data System (ADS)

    Lei, Chuang; Wu, Te; Jia, Jian-Yuan; Cong, Rui; Wang, Long

    2010-11-01

    We investigate the effects of heterogeneous investment and distribution on the evolution of cooperation in the context of the public goods games. To do this, we develop a simple model in which each individual allocates differing funds to his direct neighbors based upon their difference in connectivity, because of the heterogeneity of real social ties. This difference is characterized by the weight of the link between paired individuals, with an adjustable parameter precisely controlling the heterogeneous level of ties. By numerical simulations, it is found that allocating both too much and too little funds to diverse neighbors can remarkably improve the cooperation level. However, there exists a worst mode of funds allocation leading to the most unfavorable cooperation induced by the moderate values of the parameter. In order to better reveal the potential causes behind these nontrivial phenomena we probe the microscopic characteristics including the average payoff and the cooperator density for individuals of different degrees. It demonstrates rather different dynamical behaviors between the modes of these two types of cooperation promoter. Besides, we also investigate the total link weights of individuals numerically and theoretically for negative values of the parameter, and conclude that the payoff magnitude of middle-degree nodes plays a crucial role in determining the cooperators’ fate.

  3. [Approaches for suicide prevention in Osaka Psychiatric Medical Center: the importance of multi-disciplinary cooperation and partnerships with other organizations].

    PubMed

    Iwata, Kazuhiko

    2012-01-01

    Suicide is a very common problem in psychiatric practice today. Therefore, almost all staff of psychiatric hospitals have encountered the suicide of one or more of their patients. Our hospital, Osaka Psychiatric Medical Center, is a public psychiatric hospital in Japan. We provide treatment and support for patients from the acute to chronic phases of psychiatric disorders, and patients range from children to the elderly. Because we accept many patients with severe mental illness from other hospitals, many of our staff are routinely confronted with patients' violence or suicidal attempts. If a patient commits suicide, the relevant staff immediately have a conference to implement measures for preventing a recurrence. At the same time, information about the incident is conveyed to the medical safety management office and made known to all staff in our hospital. This office was established in 2007. Currently, all information about incidents and accidents in our hospital (e.g., suicide, problems between patients, problems with hospital facilities) is aggregated in the office and distributed to all staff members through the hospital intranet. This system makes it possible for staff to consider countermeasures against similar incidents and accidents, even if not involved in the incident. Additionally, we make an effort to develop cooperative relationships with organizations including the police, public health centers, and the fire department. The social welfare council in Hirakata City, where our hospital is located, provides some services to prevent suicide (e.g., telephone counseling, meetings with bereaved family members). Our hospital cooperates with these services by providing lecturers. The partnerships with these organizations help regarding the mental crises of patients in our hospital and fulfill a role to prevent suicide. Multi-disciplinary cooperation and partnerships with community organizations are not special approaches to suicide prevention, but ordinary

  4. Game-theoretic approach for improving cooperation in wireless multihop networks.

    PubMed

    Ng, See-Kee; Seah, Winston K G

    2010-06-01

    Traditional networks are built on the assumption that network entities cooperate based on a mandatory network communication semantic to achieve desirable qualities such as efficiency and scalability. Over the years, this assumption has been eroded by the emergence of users that alter network behavior in a way to benefit themselves at the expense of others. At one extreme, a malicious user/node may eavesdrop on sensitive data or deliberately inject packets into the network to disrupt network operations. The solution to this generally lies in encryption and authentication. In contrast, a rational node acts only to achieve an outcome that he desires most. In such a case, cooperation is still achievable if the outcome is to the best interest of the node. The node misbehavior problem would be more pronounced in multihop wireless networks like mobile ad hoc and sensor networks, which are typically made up of wireless battery-powered devices that must cooperate to forward packets for one another. However, cooperation may be hard to maintain as it consumes scarce resources such as bandwidth, computational power, and battery power. This paper applies game theory to achieve collusive networking behavior in such network environments. In this paper, pricing, promiscuous listening, and mass punishments are avoided altogether. Our model builds on recent work in the field of Economics on the theory of imperfect private monitoring for the dynamic Bertrand oligopoly, and adapts it to the wireless multihop network. The model derives conditions for collusive packet forwarding, truthful routing broadcasts, and packet acknowledgments under a lossy wireless multihop environment, thus capturing many important characteristics of the network layer and link layer in one integrated analysis that has not been achieved previously. We also provide a proof of the viability of the model under a theoretical wireless environment. Finally, we show how the model can be applied to design a generic

  5. Diverse users of four urban national forests: participation, preferences, and perceptions

    Treesearch

    Deborah J. Chavez; David D. Olson

    2008-01-01

    Diversity at outdoor recreation sites, particularly those near large and diverse urban populations, is occurring across the United States. It is likely that individuals who belong to these changing groups bring a set of values and behaviors to public lands that differ from that of White visitors, and perhaps, land managers. Reported here are findings from studies...

  6. Performance analysis of optimal power allocation in wireless cooperative communication systems

    NASA Astrophysics Data System (ADS)

    Babikir Adam, Edriss E.; Samb, Doudou; Yu, Li

    2013-03-01

    Cooperative communication has been recently proposed in wireless communication systems for exploring the inherent spatial diversity in relay channels.The Amplify-and-Forward (AF) cooperation protocols with multiple relays have not been sufficiently investigated even if it has a low complexity in term of implementation. We consider in this work a cooperative diversity system in which a source transmits some information to a destination with the help of multiple relay nodes with AF protocols and investigate the optimality of allocating powers both at the source and the relays system by optimizing the symbol error rate (SER) performance in an efficient way. Firstly we derive a closedform SER formulation for MPSK signal using the concept of moment generating function and some statistical approximations in high signal to noise ratio (SNR) for the system under studied. We then find a tight corresponding lower bound which converges to the same limit as the theoretical upper bound and develop an optimal power allocation (OPA) technique with mean channel gains to minimize the SER. Simulation results show that our scheme outperforms the equal power allocation (EPA) scheme and is tight to the theoretical approximation based on the SER upper bound in high SNR for different number of relays.

  7. Cheating is evolutionarily assimilated with cooperation in the continuous snowdrift game.

    PubMed

    Sasaki, Tatsuya; Okada, Isamu

    2015-05-01

    It is well known that in contrast to the Prisoner's Dilemma, the snowdrift game can lead to a stable coexistence of cooperators and cheaters. Recent theoretical evidence on the snowdrift game suggests that gradual evolution for individuals choosing to contribute in continuous degrees can result in the social diversification to a 100% contribution and 0% contribution through so-called evolutionary branching. Until now, however, game-theoretical studies have shed little light on the evolutionary dynamics and consequences of the loss of diversity in strategy. Here, we analyze continuous snowdrift games with quadratic payoff functions in dimorphic populations. Subsequently, conditions are clarified under which gradual evolution can lead a population consisting of those with 100% contribution and those with 0% contribution to merge into one species with an intermediate contribution level. The key finding is that the continuous snowdrift game is more likely to lead to assimilation of different cooperation levels rather than maintenance of diversity. Importantly, this implies that allowing the gradual evolution of cooperative behavior can facilitate social inequity aversion in joint ventures that otherwise could cause conflicts that are based on commonly accepted notions of fairness. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  8. Assessing Security Cooperation: Improving Methods to Maximize Effects

    DTIC Science & Technology

    2013-03-01

    Carl Builder notes, “Institutional and personal interest are not intrinsically bad; but they may be made so if they are always cloaked in altruism and...cooperation professional may be able to lay the groundwork for validating or disqualifying actions based on both countable metrics and anecdotal...Pre-decisional Working Draft), (Washington DC: Multi-Agency, July 31, 2012), 37. 6 Carl H. Builder , The Masks of War: American Military Styles in

  9. When Triple Helix Unravels: A Multi-Case Analysis of Failures in Industry-University Cooperative Research Centres

    ERIC Educational Resources Information Center

    Gray, Denis; Sundstrom, Eric; Tornatzky, Louis G.; McGowen, Lindsey

    2011-01-01

    Cooperative research centres (CRCs) increasingly foster Triple Helix (industry-university-government) collaboration and represent significant vehicles for cooperation across sectors, the promotion of knowledge and technology transfer and ultimately the acceleration of innovation. A growing social science literature on CRCs focuses on their…

  10. The oxidative costs of parental care in cooperative and pair-breeding African starlings.

    PubMed

    Guindre-Parker, Sarah; Rubenstein, Dustin R

    2018-06-01

    The cost of parental care has long been thought to favor the evolution of cooperative breeding, because breeders can provide reduced parental care when aided by alloparents. Oxidative stress-the imbalance between reactive oxygen species and neutralizing antioxidants-has been proposed to mediate the cost of parental care, though results from empirical studies remain equivocal. We measured changes in oxidative status during reproduction in cooperatively breeding superb starlings (Lamprotornis superbus) to gain insight into the relationships among breeding status, parental care, and oxidative stress. We also compared the oxidative cost of reproduction in the cooperatively breeding superb starling to that in a sympatric non-cooperatively breeding species, the greater blue-eared glossy starling (L. chalybaeus), to determine whether cooperatively breeding individuals face reduced oxidative costs of parental care relative to non-cooperatively breeding individuals. Breeders and alloparents of the cooperative species did not differ in oxidative status throughout a breeding attempt. However, individuals of the non-cooperative species incurred an increase in reactive oxygen metabolites proportionally to an individual's workload during offspring care. These findings suggest that non-cooperative starlings experience an oxidative cost of parental care, whereas cooperatively breeding starlings do not. It is possible that high nest predation risk and multi-brooding in the cooperatively breeding species may have favored reduced physiological costs of parental care more strongly compared to pair-breeding starlings. Reduced physiological costs of caring for young may thus represent a direct benefit that promotes cooperative breeding.

  11. NENIMF: Northeast National Ion Microprobe Facility - A Multi-User Facility for SIMS Microanalysis

    NASA Astrophysics Data System (ADS)

    Layne, G. D.; Shimizu, N.

    2002-12-01

    The MIT-Brown-Harvard Regional Ion Microprobe Facility was one of the earliest multi-user facilities enabled by Dan Weill's Instrumentation and Facilities Program - and began with the delivery of a Cameca IMS 3f ion microprobe to MIT in 1978. The Northeast National Ion Microprobe Facility (NENIMF) is the direct descendant of this original facility. Now housed at WHOI, the facility incorporates both the original IMS 3f, and a new generation, high transmission-high resolution instrument - the Cameca IMS 1270. Purchased with support from NSF, and from a consortium of academic institutions in the Northeast (The American Museum of Natural History, Brown University, The Lamont-Doherty Earth Observatory, MIT, Rensselaer Polytechnic Institute, WHOI) - this latest instrument was delivered and installed during 1996. NENIMF continues to be supported by NSF EAR I&F as a multi-user facility for geochemical research. Work at NENIMF has extended the original design strength of the IMS 1270 for microanalytical U-Pb zircon geochronology to a wide variety of novel and improved techniques for geochemical research. Isotope microanalysis for studies in volcanology and petrology is currently the largest single component of facility activity. This includes the direct measurement of Pb isotopes in melt inclusions, an application developed at NENIMF, which is making an increasingly significant contribution to our understanding of basalt petrogenesis. This same technique has also been extended to the determination of Pb isotopes in detrital feldspar grains, for the study of sedimentary provenance and tectonics of the Himalayas and other terrains. The determination of δ11B in volcanic melt inclusions has also proven to be a powerful tool in the modeling of subduction-related magmatism. The recent development of δ34S and δ37Cl determination in glasses is being applied to studies of the behavior of these volatile elements in both natural and experimental systems. Other recent undertakings

  12. Complex Cooperative Strategies in Group-Territorial African Lions

    NASA Astrophysics Data System (ADS)

    Heinsohn, Robert; Packer, Craig

    1995-09-01

    Female lions (Panthera leo) showed persistent individual differences in the extent to which they participated in group-territorial conflict. When intergroup encounters were simulated by playback of aggressive vocalizations, some individuals consistently led the approach to the recorded intruder, whereas others lagged behind and avoided the risks of fighting. The lead females recognized that certain companions were laggards but failed to punish them, which suggests that cooperation is not maintained by reciprocity. Modification of the "odds" in these encounters revealed that some females joined the group response when they were most needed, whereas other lagged even farther behind. The complexity of these responses emphasizes the great diversity of individual behavior in this species and the inadequacy of current theory to explain cooperation in large groups.

  13. A survey of users and non-users of a UK teaching hospital library and information service.

    PubMed

    Turtle, Kathleen M

    2005-12-01

    The Lancashire Teaching Hospitals NHS Trust was formed in 2002 with the merger of two existing trusts. The library services unified to create a new expanded service with 11 staff. The librarians wanted to test out users' opinions of the service, as a basis for a developmental strategy. They also wanted to find out to what extent they were offering a multi-disciplinary service, available to all staff. Therefore it was decided to include both users and non-users in the survey. A twenty-question questionnaire was sent out to a 10% sample of registered users in all staff categories. The same questionnaire was sent out to a 10% sample of non-users, with the help of the Human Resources Department. The library staff and facilities were generally well regarded. The stock needed expansion in various areas, especially allied health and biomedical science. Non-users were in fact often occasional or remote users. Other non-users needed informing that they were entitled to use the service. Further research is required, especially concerning the information needs of allied health and scientific staff. There is a need for stock expansion. A marketing strategy is required to capture the interest of potential users.

  14. Design method for multi-user workstations utilizing anthropometry and preference data.

    PubMed

    Mahoney, Joseph M; Kurczewski, Nicolas A; Froede, Erick W

    2015-01-01

    Past efforts have been made to design single-user workstations to accommodate users' anthropometric and preference distributions. However, there is a lack of methods for designing workstations for group interaction. This paper introduces a method for sizing workstations to allow for a personal work area for each user and a shared space for adjacent users. We first create a virtual population with the same anthropometric and preference distributions as an intended demographic of college-aged students. Members of the virtual population are randomly paired to test if their extended reaches overlap but their normal reaches do not. This process is repeated in a Monte Carlo simulation to estimate the total percentage of groups in the population that will be accommodated for a workstation size. We apply our method to two test cases: in the first, we size polygonal workstations for two populations and, in the second, we dimension circular workstations for different group sizes. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  15. Diversity-induced resonance in the response to social norms

    NASA Astrophysics Data System (ADS)

    Tessone, Claudio J.; Sánchez, Angel; Schweitzer, Frank

    2013-02-01

    In this paper we focus on diversity-induced resonance, which was recently found in bistable, excitable, and other physical systems. We study the appearance of this phenomenon in a purely economic model of cooperating and defecting agents. An agent's contribution to a public good is seen as a social norm, so defecting agents face a social pressure, which decreases if free riding becomes widespread. In this model, diversity among agents naturally appears because of the different sensitivities towards the social norm. We study the evolution of cooperation as a response to the social norm (i) for the replicator dynamics and (ii) for the logit dynamics by means of numerical simulations. Diversity-induced resonance is observed as a maximum in the response of agents to changes in the social norm as a function of the degree of heterogeneity in the population. We provide an analytical, mean-field approach for the logit dynamics and find very good agreement with the simulations. From a socioeconomic perspective, our results show that, counterintuitively, diversity in the individual sensitivity to social norms may result in a society that better follows such norms as a whole, even if part of the population is less prone to follow them.

  16. Downlink Cooperative Broadcast Transmission Based on Superposition Coding in a Relaying System for Future Wireless Sensor Networks.

    PubMed

    Liu, Yang; Han, Guangjie; Shi, Sulong; Li, Zhengquan

    2018-06-20

    This study investigates the superiority of cooperative broadcast transmission over traditional orthogonal schemes when applied in a downlink relaying broadcast channel (RBC). Two proposed cooperative broadcast transmission protocols, one with an amplify-and-forward (AF) relay, and the other with a repetition-based decode-and-forward (DF) relay, are investigated. By utilizing superposition coding (SupC), the source and the relay transmit the private user messages simultaneously instead of sequentially as in traditional orthogonal schemes, which means the channel resources are reused and an increased channel degree of freedom is available to each user, hence the half-duplex penalty of relaying is alleviated. To facilitate a performance evaluation, theoretical outage probability expressions of the two broadcast transmission schemes are developed, based on which, we investigate the minimum total power consumption of each scheme for a given traffic requirement by numerical simulation. The results provide details on the overall system performance and fruitful insights on the essential characteristics of cooperative broadcast transmission in RBCs. It is observed that better overall outage performances and considerable power gains can be obtained by utilizing cooperative broadcast transmissions compared to traditional orthogonal schemes.

  17. Can Higher Education Meet the Needs of an Increasingly Diverse and Global Society? Campus Diversity and Cross-Cultural Workforce Competencies

    ERIC Educational Resources Information Center

    Jayakumar, Uma M.

    2008-01-01

    In this article, Uma Jayakumar investigates the relationship between white individuals' exposure to racial diversity during college and their postcollege cross-cultural workforce competencies. Using survey data from the Cooperative Institutional Research Program, housed in the Higher Education Research Institute at the University of California at…

  18. Multi-focus and multi-level techniques for visualization and analysis of networks with thematic data

    NASA Astrophysics Data System (ADS)

    Cossalter, Michele; Mengshoel, Ole J.; Selker, Ted

    2013-01-01

    Information-rich data sets bring several challenges in the areas of visualization and analysis, even when associated with node-link network visualizations. This paper presents an integration of multi-focus and multi-level techniques that enable interactive, multi-step comparisons in node-link networks. We describe NetEx, a visualization tool that enables users to simultaneously explore different parts of a network and its thematic data, such as time series or conditional probability tables. NetEx, implemented as a Cytoscape plug-in, has been applied to the analysis of electrical power networks, Bayesian networks, and the Enron e-mail repository. In this paper we briefly discuss visualization and analysis of the Enron social network, but focus on data from an electrical power network. Specifically, we demonstrate how NetEx supports the analytical task of electrical power system fault diagnosis. Results from a user study with 25 subjects suggest that NetEx enables more accurate isolation of complex faults compared to an especially designed software tool.

  19. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Drummond, Mark; Hine, Butler; Genet, Russell; Genet, David; Talent, David; Boyd, Louis; Trueblood, Mark; Filippenko, Alexei V. (Editor)

    1991-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  20. Diversity Enhances NPP, N Retention, and Soil Microbial Diversity in Experimental Urban Grassland Assemblages

    PubMed Central

    Thompson, Grant L.; Kao-Kniffin, Jenny

    2016-01-01

    Urban grasslands, landscapes dominated by turfgrasses for aesthetic or recreational groundcovers, are rapidly expanding in the United States and globally. These managed ecosystems are often less diverse than the natural or agricultural lands they replace, leading to potential losses in ecosystem functioning. Research in non-urban systems has provided evidence for increases in multiple ecosystem functions associated with greater plant diversity. To test if biodiversity-ecosystem function findings are applicable to urban grasslands, we examined the effect of plant species and genotypic diversity on three ecosystem functions, using grassland assemblages of increasing diversity that were grown within a controlled environment facility. We found positive effects of plant diversity on reduced nitrate leaching and plant productivity. Soil microbial diversity (Mean Shannon Diversity, H’) of bacteria and fungi were also enhanced in multi-species plantings, suggesting that moderate increments in plant diversity influence the composition of soil biota. The results from this study indicate that plant diversity impacts multiple functions that are important in urban ecosystems; therefore, further tests of urban grassland biodiversity should be examined in situ to determine the feasibility of manipulating plant diversity as an explicit landscape design and function trait. PMID:27243768

  1. The Multi-Attribute Task Battery II (MATB-II) Software for Human Performance and Workload Research: A User's Guide

    NASA Technical Reports Server (NTRS)

    Santiago-Espada, Yamira; Myer, Robert R.; Latorella, Kara A.; Comstock, James R., Jr.

    2011-01-01

    The Multi-Attribute Task Battery (MAT Battery). is a computer-based task designed to evaluate operator performance and workload, has been redeveloped to operate in Windows XP Service Pack 3, Windows Vista and Windows 7 operating systems.MATB-II includes essentially the same tasks as the original MAT Battery, plus new configuration options including a graphical user interface for controlling modes of operation. MATB-II can be executed either in training or testing mode, as defined by the MATB-II configuration file. The configuration file also allows set up of the default timeouts for the tasks, the flow rates of the pumps and tank levels of the Resource Management (RESMAN) task. MATB-II comes with a default event file that an experimenter can modify and adapt

  2. An Improvement of Robust Biometrics-Based Authentication and Key Agreement Scheme for Multi-Server Environments Using Smart Cards.

    PubMed

    Moon, Jongho; Choi, Younsung; Jung, Jaewook; Won, Dongho

    2015-01-01

    In multi-server environments, user authentication is a very important issue because it provides the authorization that enables users to access their data and services; furthermore, remote user authentication schemes for multi-server environments have solved the problem that has arisen from user's management of different identities and passwords. For this reason, numerous user authentication schemes that are designed for multi-server environments have been proposed over recent years. In 2015, Lu et al. improved upon Mishra et al.'s scheme, claiming that their remote user authentication scheme is more secure and practical; however, we found that Lu et al.'s scheme is still insecure and incorrect. In this paper, we demonstrate that Lu et al.'s scheme is vulnerable to outsider attack and user impersonation attack, and we propose a new biometrics-based scheme for authentication and key agreement that can be used in multi-server environments; then, we show that our proposed scheme is more secure and supports the required security properties.

  3. Mental illness research in the Gulf Cooperation Council: a scoping review.

    PubMed

    Hickey, Jason E; Pryjmachuk, Steven; Waterman, Heather

    2016-08-04

    Rapid growth and development in recent decades has seen mental health and mental illness emerge as priority health concerns for the Gulf Cooperation Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates). As a result, mental health services in the region are being redefined and expanded. However, there is a paucity of local research to guide ongoing service development. Local research is important because service users' experience of mental illness and mental health services are linked to their sociocultural context. In order for service development to be most effective, there is a need for increased understanding of the people who use these services.This article aims to review and synthesize mental health research from the Gulf Cooperation Council. It also seeks to identify gaps in the literature and suggest directions for future research. A scoping framework was used to conduct this review. To identify studies, database searches were undertaken, regional journals were hand-searched, and reference lists of included articles were examined. Empirical studies undertaken in the Gulf Cooperation Council that reported mental health service users' experience of mental illness were included. Framework analysis was used to synthesize results. Fifty-five studies met inclusion criteria and the following themes were identified: service preferences, illness (symptomology, perceived cause, impact), and recovery (traditional healing, family support, religion). Gaps included contradictory findings related to the supportive role of the Arabic extended family and religion, under-representation of women in study samples, and limited attention on illness management outside of the hospital setting.From this review, it is clear that the sociocultural context in the region is linked to service users' experience of mental illness. Future research that aims to fill the identified gaps and develop and test culturally appropriate interventions will aid practice

  4. The ethics of conducting a co-operative inquiry with vulnerable people.

    PubMed

    Tee, Stephen R; Lathlean, Judith A

    2004-09-01

    Mental health services users have been calling for greater participation in clinical research. Participation in this context means research 'with' rather than 'on' groups of people. Conducting a co-operative inquiry involving the participation of vulnerable individuals as co-researchers, in particular those with a history of mental health problems, places an obligation on researchers to articulate and justify sound ethical procedures. The aim of this paper is to consider how the ethical issues encountered when conducting participative research with vulnerable people can be addressed in the implementation of a co-operative inquiry with users of mental health services. The study was based on personal reflection and a critical review of associated literature obtained from a database search using Boolean logic. The findings, presented under the headings of the four prima facie moral principles, suggest the need for researchers using participative approaches to demonstrate the humanistic attributes required for engaging and working with people over a period of time. These include building and maintaining trusting relationships, assessing competence to participate, managing interpersonal and group dynamics and making complex collaborative decisions about participants' continued participation in a study. When using a co-operative inquiry approach involving vulnerable individuals, researchers need to demonstrate clearly how a balance between autonomy and paternalism will be achieved, how risks will be anticipated and managed and how fairness will be maintained throughout all procedures. Researchers using participative approaches need to have developed a level of personal insight and self-awareness through access to supervision which focuses on sources of unintended manipulation and interpersonal dynamics that may arise at the inception of a study and throughout its course. Researchers and ethics committees have a shared responsibility to ensure that vulnerable people are

  5. The Effect of Power Asymmetries on Cooperation and Punishment in a Prisoner’s Dilemma Game

    PubMed Central

    Bone, Jonathan E.; Wallace, Brian; Bshary, Redouan; Raihani, Nichola J.

    2015-01-01

    Recent work has suggested that punishment is detrimental because punishment provokes retaliation, not cooperation, resulting in lower overall payoffs. These findings may stem from the unrealistic assumption that all players are equal: in reality individuals are expected to vary in the power with which they can punish defectors. Here, we allowed strong players to interact with weak players in an iterated prisoner's dilemma game with punishment. Defecting players were most likely to switch to cooperation if the partner cooperated: adding punishment yielded no additional benefit and, under some circumstances, increased the chance that the partner would both defect and retaliate against the punisher. Our findings show that, in a two-player game, cooperation begets cooperation and that punishment does not seem to yield any additional benefits. Further work should explore whether strong punishers might prevail in multi-player games. PMID:25629971

  6. vTrain: a novel curriculum for patient surge training in a multi-user virtual environment (MUVE).

    PubMed

    Greci, Laura S; Ramloll, Rameshsharma; Hurst, Samantha; Garman, Karen; Beedasy, Jaishree; Pieper, Eric B; Huang, Ricky; Higginbotham, Erin; Agha, Zia

    2013-06-01

    During a pandemic influenza, emergency departments will be overwhelmed with a large influx of patients seeking care. Although all hospitals should have a written plan for dealing with this surge of health care utilization, most hospitals struggle with ways to educate the staff and practice for potentially catastrophic events. Hypothesis/Problem To better prepare hospital staff for a patient surge, a novel educational curriculum was developed utilizing an emergency department for a patient surge functional drill. A multidisciplinary team of medical educators, evaluators, emergency preparedness experts, and technology specialists developed a curriculum to: (1) train novice users to function in their job class in a multi-user virtual environment (MUVE); (2) obtain appropriate pre-drill disaster preparedness training; (3) perform functional team exercises in a MUVE; and (4) reflect on their performance after the drill. A total of 14 students participated in one of two iterations of the pilot training program; seven nurses completed the emergency department triage course, and seven hospital administrators completed the Command Post (CP) course. All participants reported positive experiences in written course evaluations and structured verbal debriefings, and self-reported increase in disaster preparedness knowledge. Students also reported improved team communication, planning, team decision making, and the ability to visualize and reflect on their performance. Data from this pilot program suggest that the immersive, virtual teaching method is well suited to team-based, reflective practice and learning of disaster management skills.

  7. Cultural diversity: blind spot in medical curriculum documents, a document analysis.

    PubMed

    Paternotte, Emma; Fokkema, Joanne P I; van Loon, Karsten A; van Dulmen, Sandra; Scheele, Fedde

    2014-08-22

    Cultural diversity among patients presents specific challenges to physicians. Therefore, cultural diversity training is needed in medical education. In cases where strategic curriculum documents form the basis of medical training it is expected that the topic of cultural diversity is included in these documents, especially if these have been recently updated. The aim of this study was to assess the current formal status of cultural diversity training in the Netherlands, which is a multi-ethnic country with recently updated medical curriculum documents. In February and March 2013, a document analysis was performed of strategic curriculum documents for undergraduate and postgraduate medical education in the Netherlands. All text phrases that referred to cultural diversity were extracted from these documents. Subsequently, these phrases were sorted into objectives, training methods or evaluation tools to assess how they contributed to adequate curriculum design. Of a total of 52 documents, 33 documents contained phrases with information about cultural diversity training. Cultural diversity aspects were more prominently described in the curriculum documents for undergraduate education than in those for postgraduate education. The most specific information about cultural diversity was found in the blueprint for undergraduate medical education. In the postgraduate curriculum documents, attention to cultural diversity differed among specialties and was mainly superficial. Cultural diversity is an underrepresented topic in the Dutch documents that form the basis for actual medical training, although the documents have been updated recently. Attention to the topic is thus unwarranted. This situation does not fit the demand of a multi-ethnic society for doctors with cultural diversity competences. Multi-ethnic countries should be critical on the content of the bases for their medical educational curricula.

  8. Cooperation Among Theorem Provers

    NASA Technical Reports Server (NTRS)

    Waldinger, Richard J.

    1998-01-01

    This is a final report, which supports NASA's PECSEE (Persistent Cognizant Software Engineering Environment) effort and complements the Kestrel Institute project "Inference System Integration via Logic Morphism". The ultimate purpose of the project is to develop a superior logical inference mechanism by combining the diverse abilities of multiple cooperating theorem provers. In many years of research, a number of powerful theorem-proving systems have arisen with differing capabilities and strengths. Resolution theorem provers (such as Kestrel's KITP or SRI's, SNARK) deal with first-order logic with equality but not the principle of mathematical induction. The Boyer-Moore theorem prover excels at proof by induction but cannot deal with full first-order logic. Both are highly automated but cannot accept user guidance easily. The PVS system (from SRI) in only automatic within decidable theories, but it has well-designed interactive capabilities: furthermore, it includes higher-order logic, not just first-order logic. The NuPRL system from Cornell University and the STeP system from Stanford University have facilities for constructive logic and temporal logic, respectively - both are interactive. It is often suggested - for example, in the anonymous "QED Manifesto"-that we should pool the resources of all these theorem provers into a single system, so that the strengths of one can compensate for the weaknesses of others, and so that effort will not be duplicated. However, there is no straightforward way of doing this, because each system relies on its own language and logic for its success. Thus. SNARK uses ordinary first-order logic with equality, PVS uses higher-order logic. and NuPRL uses constructive logic. The purpose of this project, and the companion project at Kestrel, has been to use the category-theoretic notion of logic morphism to combine systems with different logics and languages. Kestrel's SPECWARE system has been the vehicle for the implementation.

  9. Multi-method laboratory user evaluation of an actionable clinical performance information system: Implications for usability and patient safety.

    PubMed

    Brown, Benjamin; Balatsoukas, Panos; Williams, Richard; Sperrin, Matthew; Buchan, Iain

    2018-01-01

    questionnaires revealed PINGR is user-friendly, and that improved information prioritisation could further promote useful user action. Comparing our results with the wider usability literature we refine a previously published set of interface design recommendations for e-A&F. The implications for patient safety are significant regarding: user engagement; actionability; and information prioritisation. Our results also support adopting multi-method approaches in usability studies to maximise issue discovery and the credibility of findings. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. MultiSpec: A Desktop and Online Geospatial Image Data Processing Tool

    NASA Astrophysics Data System (ADS)

    Biehl, L. L.; Hsu, W. K.; Maud, A. R. M.; Yeh, T. T.

    2017-12-01

    MultiSpec is an easy to learn and use, freeware image processing tool for interactively analyzing a broad spectrum of geospatial image data, with capabilities such as image display, unsupervised and supervised classification, feature extraction, feature enhancement, and several other functions. Originally developed for Macintosh and Windows desktop computers, it has a community of several thousand users worldwide, including researchers and educators, as a practical and robust solution for analyzing multispectral and hyperspectral remote sensing data in several different file formats. More recently MultiSpec was adapted to run in the HUBzero collaboration platform so that it can be used within a web browser, allowing new user communities to be engaged through science gateways. MultiSpec Online has also been extended to interoperate with other components (e.g., data management) in HUBzero through integration with the geospatial data building blocks (GABBs) project. This integration enables a user to directly launch MultiSpec Online from data that is stored and/or shared in a HUBzero gateway and to save output data from MultiSpec Online to hub storage, allowing data sharing and multi-step workflows without having to move data between different systems. MultiSpec has also been used in K-12 classes for which one example is the GLOBE program (www.globe.gov) and in outreach material such as that provided by the USGS (eros.usgs.gov/educational-activities). MultiSpec Online now provides teachers with another way to use MultiSpec without having to install the desktop tool. Recently MultiSpec Online was used in a geospatial data session with 30-35 middle school students at the Turned Onto Technology and Leadership (TOTAL) Camp in the summers of 2016 and 2017 at Purdue University. The students worked on a flood mapping exercise using Landsat 5 data to learn about land remote sensing using supervised classification techniques. Online documentation is available for Multi

  11. Leveraging International Cooperation Acquisition Opportunities for the Department of Defense

    DTIC Science & Technology

    2014-09-01

    International Involvement as it relates to Defense Acquisition can be conducted through three types of programs; international armaments cooperation...render them more effective coalition partners and assist with establishing stronger international relations . 58 THIS PAGE INTENTIONALLY LEFT...illicit manufacture and trafficking of narcotic and psychotropic drugs , money laundering, and precursor chemical diversion and the progressive

  12. The effect of heterogeneous defectors on the evolution of public cooperation

    NASA Astrophysics Data System (ADS)

    Chen, Tong; Hu, Xuezhi; Wang, Yongjie; Wang, Le

    2018-06-01

    In recent years,more and more private capital join the construction of cultural facilities and the organization of cultural activities in China. Actually, the organization of cultural activities by crowd-funding mechanism is a kind of multi-player game. Not all players who donate different amount of money are real cooperators. In fact, some cunning defectors may donate a little money to avoid the gossip and punishment. This part of people are very tricky. They could be seen as heterogeneous defectors. The role of heterogeneous defectors is investigated in cooperative behaviors of complex social network. Numerical results show that heterogeneous defectors could be a buffer for maintaining the public pool when synergy factor is low in public goods game (PGG). It is relatively easy to be cooperators for heterogeneous defectors when synergy factor is high in PGG. To better improve cooperation, punishment towards heterogeneous defectors and complete defectors is introduced. We are glad to find that when the defectors' loss is equal to or larger than the altruistic cooperators' punishment cost, the mechanism could make great effect. In addition, the role of heterogeneous defectors depends on the relationship between the punishment cost and the defectors' loss.

  13. [Medical doctors driving technological innovation: questions about and innovation management approaches to incentive structures for lead users].

    PubMed

    Bohnet-Joschko, Sabine; Kientzler, Fionn

    2010-01-01

    Management science defines user-generated innovations as open innovation and lead user innovation. The medical technology industry finds user-generated innovations profitable and even indispensable. Innovative medical doctors as lead users need medical technology innovations in order to improve patient care. Their motivation to innovate is mostly intrinsic. But innovations may also involve extrinsic motivators such as gain in reputation or monetary incentives. Medical doctors' innovative activities often take place in hospitals and are thus embedded into the hospital's organisational setting. Hospitals find it difficult to gain short-term profits from in-house generated innovations and sometimes hesitate to support them. Strategic investment in medical doctors' innovative activities may be profitable for hospitals in the long run if innovations provide first-mover competitive advantages. Industry co-operations with innovative medical doctors offer chances but also bear potential risks. Innovative ideas generated by expert users may result in even higher complexity of medical devices; this could cause mistakes when applied by less specialised users and thus affect patient safety. Innovations that yield benefits for patients, medical doctors, hospitals and the medical technology industry can be advanced by offering adequate support for knowledge transfer and co-operation models.

  14. MultiElec: A MATLAB Based Application for MEA Data Analysis.

    PubMed

    Georgiadis, Vassilis; Stephanou, Anastasis; Townsend, Paul A; Jackson, Thomas R

    2015-01-01

    We present MultiElec, an open source MATLAB based application for data analysis of microelectrode array (MEA) recordings. MultiElec displays an extremely user-friendly graphic user interface (GUI) that allows the simultaneous display and analysis of voltage traces for 60 electrodes and includes functions for activation-time determination, the production of activation-time heat maps with activation time and isoline display. Furthermore, local conduction velocities are semi-automatically calculated along with their corresponding vector plots. MultiElec allows ad hoc signal suppression, enabling the user to easily and efficiently handle signal artefacts and for incomplete data sets to be analysed. Voltage traces and heat maps can be simply exported for figure production and presentation. In addition, our platform is able to produce 3D videos of signal progression over all 60 electrodes. Functions are controlled entirely by a single GUI with no need for command line input or any understanding of MATLAB code. MultiElec is open source under the terms of the GNU General Public License as published by the Free Software Foundation, version 3. Both the program and source code are available to download from http://www.cancer.manchester.ac.uk/MultiElec/.

  15. Multi-locus and long amplicon sequencing approach to study microbial diversity at species level using the MinION™ portable nanopore sequencer

    PubMed Central

    Sanz, Yolanda

    2017-01-01

    Abstract The miniaturized and portable DNA sequencer MinION™ has demonstrated great potential in different analyses such as genome-wide sequencing, pathogen outbreak detection and surveillance, human genome variability, and microbial diversity. In this study, we tested the ability of the MinION™ platform to perform long amplicon sequencing in order to design new approaches to study microbial diversity using a multi-locus approach. After compiling a robust database by parsing and extracting the rrn bacterial region from more than 67000 complete or draft bacterial genomes, we demonstrated that the data obtained during sequencing of the long amplicon in the MinION™ device using R9 and R9.4 chemistries were sufficient to study 2 mock microbial communities in a multiplex manner and to almost completely reconstruct the microbial diversity contained in the HM782D and D6305 mock communities. Although nanopore-based sequencing produces reads with lower per-base accuracy compared with other platforms, we presented a novel approach consisting of multi-locus and long amplicon sequencing using the MinION™ MkIb DNA sequencer and R9 and R9.4 chemistries that help to overcome the main disadvantage of this portable sequencing platform. Furthermore, the nanopore sequencing library, constructed with the last releases of pore chemistry (R9.4) and sequencing kit (SQK-LSK108), permitted the retrieval of the higher level of 1D read accuracy sufficient to characterize the microbial species present in each mock community analysed. Improvements in nanopore chemistry, such as minimizing base-calling errors and new library protocols able to produce rapid 1D libraries, will provide more reliable information in the near future. Such data will be useful for more comprehensive and faster specific detection of microbial species and strains in complex ecosystems. PMID:28605506

  16. CLEW: A Cooperative Learning Environment for the Web.

    ERIC Educational Resources Information Center

    Ribeiro, Marcelo Blois; Noya, Ricardo Choren; Fuks, Hugo

    This paper outlines CLEW (collaborative learning environment for the Web). The project combines MUD (Multi-User Dimension), workflow, VRML (Virtual Reality Modeling Language) and educational concepts like constructivism in a learning environment where students actively participate in the learning process. The MUD shapes the environment structure.…

  17. Habitat heterogeneity drives the host diversity-begets-parasite diversity relationship: evidence from experimental and field studies

    PubMed Central

    Johnson, Pieter T. J.; Wood, Chelsea L.; Joseph, Maxwell B.; Preston, Daniel L.; Haas, Sarah E.; Springer, Yuri P.

    2016-01-01

    Despite a century of research into the factors that generate and maintain biodiversity, we know remarkably little about the drivers of parasite diversity. To identify the mechanisms governing parasite diversity, we combined surveys of 8,100 amphibian hosts with an outdoor experiment that tested theory developed for free-living species. Our analyses revealed that parasite diversity increased consistently with host diversity due to habitat (i.e., host) heterogeneity, with secondary contributions from parasite colonization and host abundance. Results of the experiment, in which host diversity was manipulated while parasite colonization and host abundance were fixed, further reinforced this conclusion. Finally, the coefficient of host diversity on parasite diversity increased with spatial grain, which was driven by differences in their species-area curves: while host richness quickly saturated, parasite richness continued to increase with neighborhood size. These results offer mechanistic insights into drivers of parasite diversity and provide a hierarchical framework for multi-scale disease research. PMID:27147106

  18. Preferential interactions promote blind cooperation and informed defection.

    PubMed

    Pérez-Escudero, Alfonso; Friedman, Jonathan; Gore, Jeff

    2016-12-06

    It is common sense that costs and benefits should be carefully weighed before deciding on a course of action. However, we often disapprove of people who do so, even when their actual decision benefits us. For example, we prefer people who directly agree to do us a favor over those who agree only after securing enough information to ensure that the favor will not be too costly. Why should we care about how people make their decisions, rather than just focus on the decisions themselves? Current models show that punishment of information gathering can be beneficial because it forces blind decisions, which under some circumstances enhances cooperation. Here we show that aversion to information gathering can be beneficial even in the absence of punishment, due to a different mechanism: preferential interactions with reliable partners. In a diverse population where different people have different-and unknown-preferences, those who seek additional information before agreeing to cooperate reveal that their preferences are close to the point where they would choose not to cooperate. Blind cooperators are therefore more likely to keep cooperating even if conditions change, and aversion to information gathering helps to interact preferentially with them. Conversely, blind defectors are more likely to keep defecting in the future, leading to a preference for informed defectors over blind ones. Both mechanisms-punishment to force blind decisions and preferential interactions-give qualitatively different predictions, which may enable experimental tests to disentangle them in real-world situations.

  19. A Multi-Agent System for Intelligent Online Education.

    ERIC Educational Resources Information Center

    O'Riordan, Colm; Griffith, Josephine

    1999-01-01

    Describes the system architecture of an intelligent Web-based education system that includes user modeling agents, information filtering agents for automatic information gathering, and the multi-agent interaction. Discusses information management; user interaction; support for collaborative peer-peer learning; implementation; testing; and future…

  20. xLPR Sim Editor 1.0 User's Guide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mariner, Paul E.

    2017-03-01

    The United States Nuclear Regulatory Commission in cooperation with the Electric Power Research Institute contracted Sandia National Laboratories to develop the framework of a probabilistic fracture mechanics assessment code called xLPR ( Extremely Low Probability of Rupture) Version 2.0 . The purpose of xLPR is to evaluate degradation mechanisms in piping systems at nuclear power plants and to predict the probability of rupture. This report is a user's guide for xLPR Sim Editor 1.0 , a graphical user interface for creating and editing the xLPR Version 2.0 input file and for creating, editing, and using the xLPR Version 2.0 databasemore » files . The xLPR Sim Editor, provides a user - friendly way for users to change simulation options and input values, s elect input datasets from xLPR data bases, identify inputs needed for a simulation, and create and modify an input file for xLPR.« less