WorldWideScience

Sample records for networking-based access control

  1. Medium Access Control for Wireless Sensor Networks based on Impulse Radio Ultra Wideband

    OpenAIRE

    Berthe, Abdoulaye; Lecointre, Aubin; Dragomirescu, Daniela; Plana, Robert

    2010-01-01

    This paper describes a detailed performance evaluation of distributed Medium Access Control (MAC) protocols for Wireless Sensor Networks based on Impulse Radio Ultra Wideband (IR-UWB) Physical layer (PHY). Two main classes of Medium Access Control protocol have been considered: Slotted and UnSlotted with reliability. The reliability is based on Automatic Repeat ReQuest (ARQ). The performance evaluation is performed using a complete Wireless Sensor Networks (WSN) simulator built on the Global ...

  2. Measuring geographic access to health care: raster and network-based methods

    Directory of Open Access Journals (Sweden)

    Delamater Paul L

    2012-05-01

    Full Text Available Abstract Background Inequalities in geographic access to health care result from the configuration of facilities, population distribution, and the transportation infrastructure. In recent accessibility studies, the traditional distance measure (Euclidean has been replaced with more plausible measures such as travel distance or time. Both network and raster-based methods are often utilized for estimating travel time in a Geographic Information System. Therefore, exploring the differences in the underlying data models and associated methods and their impact on geographic accessibility estimates is warranted. Methods We examine the assumptions present in population-based travel time models. Conceptual and practical differences between raster and network data models are reviewed, along with methodological implications for service area estimates. Our case study investigates Limited Access Areas defined by Michigan’s Certificate of Need (CON Program. Geographic accessibility is calculated by identifying the number of people residing more than 30 minutes from an acute care hospital. Both network and raster-based methods are implemented and their results are compared. We also examine sensitivity to changes in travel speed settings and population assignment. Results In both methods, the areas identified as having limited accessibility were similar in their location, configuration, and shape. However, the number of people identified as having limited accessibility varied substantially between methods. Over all permutations, the raster-based method identified more area and people with limited accessibility. The raster-based method was more sensitive to travel speed settings, while the network-based method was more sensitive to the specific population assignment method employed in Michigan. Conclusions Differences between the underlying data models help to explain the variation in results between raster and network-based methods. Considering that the

  3. Neural network based adaptive output feedback control: Applications and improvements

    Science.gov (United States)

    Kutay, Ali Turker

    Application of recently developed neural network based adaptive output feedback controllers to a diverse range of problems both in simulations and experiments is investigated in this thesis. The purpose is to evaluate the theory behind the development of these controllers numerically and experimentally, identify the needs for further development in practical applications, and to conduct further research in directions that are identified to ultimately enhance applicability of adaptive controllers to real world problems. We mainly focus our attention on adaptive controllers that augment existing fixed gain controllers. A recently developed approach holds great potential for successful implementations on real world applications due to its applicability to systems with minimal information concerning the plant model and the existing controller. In this thesis the formulation is extended to the multi-input multi-output case for distributed control of interconnected systems and successfully tested on a formation flight wind tunnel experiment. The command hedging method is formulated for the approach to further broaden the class of systems it can address by including systems with input nonlinearities. Also a formulation is adopted that allows the approach to be applied to non-minimum phase systems for which non-minimum phase characteristics are modeled with sufficient accuracy and treated properly in the design of the existing controller. It is shown that the approach can also be applied to augment nonlinear controllers under certain conditions and an example is presented where the nonlinear guidance law of a spinning projectile is augmented. Simulation results on a high fidelity 6 degrees-of-freedom nonlinear simulation code are presented. The thesis also presents a preliminary adaptive controller design for closed loop flight control with active flow actuators. Behavior of such actuators in dynamic flight conditions is not known. To test the adaptive controller design in

  4. neural network based load frequency control for restructuring power

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... Abstract. In this study, an artificial neural network (ANN) application of load frequency control. (LFC) of a Multi-Area power system by using a neural network controller is presented. The comparison between a conventional Proportional Integral (PI) controller and the proposed artificial neural networks ...

  5. Neural network based adaptive control for nonlinear dynamic regimes

    Science.gov (United States)

    Shin, Yoonghyun

    Adaptive control designs using neural networks (NNs) based on dynamic inversion are investigated for aerospace vehicles which are operated at highly nonlinear dynamic regimes. NNs play a key role as the principal element of adaptation to approximately cancel the effect of inversion error, which subsequently improves robustness to parametric uncertainty and unmodeled dynamics in nonlinear regimes. An adaptive control scheme previously named 'composite model reference adaptive control' is further developed so that it can be applied to multi-input multi-output output feedback dynamic inversion. It can have adaptive elements in both the dynamic compensator (linear controller) part and/or in the conventional adaptive controller part, also utilizing state estimation information for NN adaptation. This methodology has more flexibility and thus hopefully greater potential than conventional adaptive designs for adaptive flight control in highly nonlinear flight regimes. The stability of the control system is proved through Lyapunov theorems, and validated with simulations. The control designs in this thesis also include the use of 'pseudo-control hedging' techniques which are introduced to prevent the NNs from attempting to adapt to various actuation nonlinearities such as actuator position and rate saturations. Control allocation is introduced for the case of redundant control effectors including thrust vectoring nozzles. A thorough comparison study of conventional and NN-based adaptive designs for a system under a limit cycle, wing-rock, is included in this research, and the NN-based adaptive control designs demonstrate their performances for two highly maneuverable aerial vehicles, NASA F-15 ACTIVE and FQM-117B unmanned aerial vehicle (UAV), operated under various nonlinearities and uncertainties.

  6. Neural Network Based Load Frequency Control for Restructuring ...

    African Journals Online (AJOL)

    Electric load variations can happen independently in both units. Both neural controllers are trained with the back propagation-through-time algorithm. Use of a neural network to model the dynamic system is avoided by introducing the Jacobian matrices of the system in the back propagation chain used in controller training.

  7. Implementation of neural network based non-linear predictive control

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Ravn, Ole

    1999-01-01

    of non-linear systems. GPC is model based and in this paper we propose the use of a neural network for the modeling of the system. Based on the neural network model, a controller with extended control horizon is developed and the implementation issues are discussed, with particular emphasis...

  8. neural network based load frequency control for restructuring power

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... power system is chosen and load frequency con- trol of this system is made by a ANN controller and a conventional PI controller. Basically, power system consists of a governor, a turbine, and a generator with feedback of reg- ulation constant. System also includes step load change input to the generator.

  9. Ontology Based Access Control

    Directory of Open Access Journals (Sweden)

    Özgü CAN

    2010-02-01

    Full Text Available As computer technologies become pervasive, the need for access control mechanisms grow. The purpose of an access control is to limit the operations that a computer system user can perform. Thus, access control ensures to prevent an activity which can lead to a security breach. For the success of Semantic Web, that allows machines to share and reuse the information by using formal semantics for machines to communicate with other machines, access control mechanisms are needed. Access control mechanism indicates certain constraints which must be achieved by the user before performing an operation to provide a secure Semantic Web. In this work, unlike traditional access control mechanisms, an "Ontology Based Access Control" mechanism has been developed by using Semantic Web based policies. In this mechanism, ontologies are used to model the access control knowledge and domain knowledge is used to create policy ontologies.

  10. Modulation of grasping force in prosthetic hands using neural network-based predictive control.

    Science.gov (United States)

    Pasluosta, Cristian F; Chiu, Alan W L

    2015-01-01

    This chapter describes the implementation of a neural network-based predictive control system for driving a prosthetic hand. Nonlinearities associated with the electromechanical aspects of prosthetic devices present great challenges for precise control of this type of device. Model-based controllers may overcome this issue. Moreover, given the complexity of these kinds of electromechanical systems, neural network-based modeling arises as a good fit for modeling the fingers' dynamics. The results of simulations mimicking potential situations encountered during activities of daily living demonstrate the feasibility of this technique.

  11. Neural network based optimal control of HVAC&R systems

    Science.gov (United States)

    Ning, Min

    Heating, Ventilation, Air-Conditioning and Refrigeration (HVAC&R) systems have wide applications in providing a desired indoor environment for different types of buildings. It is well acknowledged that 30%-40% of the total energy generated is consumed by buildings and HVAC&R systems alone account for more than 50% of the building energy consumption. Low operational efficiency especially under partial load conditions and poor control are part of reasons for such high energy consumption. To improve energy efficiency, HVAC&R systems should be properly operated to maintain a comfortable and healthy indoor environment under dynamic ambient and indoor conditions with the least energy consumption. This research focuses on the optimal operation of HVAC&R systems. The optimization problem is formulated and solved to find the optimal set points for the chilled water supply temperature, discharge air temperature and AHU (air handling unit) fan static pressure such that the indoor environment is maintained with the least chiller and fan energy consumption. To achieve this objective, a dynamic system model is developed first to simulate the system behavior under different control schemes and operating conditions. The system model is modular in structure, which includes a water-cooled vapor compression chiller model and a two-zone VAV system model. A fuzzy-set based extended transformation approach is then applied to investigate the uncertainties of this model caused by uncertain parameters and the sensitivities of the control inputs with respect to the interested model outputs. A multi-layer feed forward neural network is constructed and trained in unsupervised mode to minimize the cost function which is comprised of overall energy cost and penalty cost when one or more constraints are violated. After training, the network is implemented as a supervisory controller to compute the optimal settings for the system. In order to implement the optimal set points predicted by the

  12. Spiking neural network-based control chart pattern recognition

    Directory of Open Access Journals (Sweden)

    Medhat H.A. Awadalla

    2012-03-01

    Full Text Available Due to an increasing competition in products, consumers have become more critical in choosing products. The quality of products has become more important. Statistical Process Control (SPC is usually used to improve the quality of products. Control charting plays the most important role in SPC. Control charts help to monitor the behavior of the process to determine whether it is stable or not. Unnatural patterns in control charts mean that there are some unnatural causes for variations in SPC. Spiking neural networks (SNNs are the third generation of artificial neural networks that consider time as an important feature for information representation and processing. In this paper, a spiking neural network architecture is proposed to be used for control charts pattern recognition (CCPR. Furthermore, enhancements to the SpikeProp learning algorithm are proposed. These enhancements provide additional learning rules for the synaptic delays, time constants and for the neurons thresholds. Simulated experiments have been conducted and the achieved results show a remarkable improvement in the overall performance compared with artificial neural networks.

  13. Neural-networks-based feedback linearization versus model predictive control of continuous alcoholic fermentation process

    Energy Technology Data Exchange (ETDEWEB)

    Mjalli, F.S.; Al-Asheh, S. [Chemical Engineering Department, Qatar University, Doha (Qatar)

    2005-10-01

    In this work advanced nonlinear neural networks based control system design algorithms are adopted to control a mechanistic model for an ethanol fermentation process. The process model equations for such systems are highly nonlinear. A neural network strategy has been implemented in this work for capturing the dynamics of the mechanistic model for the fermentation process. The neural network achieved has been validated against the mechanistic model. Two neural network based nonlinear control strategies have also been adopted using the model identified. The performance of the feedback linearization technique was compared to neural network model predictive control in terms of stability and set point tracking capabilities. Under servo conditions, the feedback linearization algorithm gave comparable tracking and stability. The feedback linearization controller achieved the control target faster than the model predictive one but with vigorous and sudden controller moves. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  14. Android Access Control Extension

    Directory of Open Access Journals (Sweden)

    Anton Baláž

    2015-12-01

    Full Text Available The main objective of this work is to analyze and extend security model of mobile devices running on Android OS. Provided security extension is a Linux kernel security module that allows the system administrator to restrict program's capabilities with per-program profiles. Profiles can allow capabilities like network access, raw socket access, and the permission to read, write, or execute files on matching paths. Module supplements the traditional Android capability access control model by providing mandatory access control (MAC based on path. This extension increases security of access to system objects in a device and allows creating security sandboxes per application.

  15. Radial Basis Function Neural Network-based PID model for functional electrical stimulation system control.

    Science.gov (United States)

    Cheng, Longlong; Zhang, Guangju; Wan, Baikun; Hao, Linlin; Qi, Hongzhi; Ming, Dong

    2009-01-01

    Functional electrical stimulation (FES) has been widely used in the area of neural engineering. It utilizes electrical current to activate nerves innervating extremities affected by paralysis. An effective combination of a traditional PID controller and a neural network, being capable of nonlinear expression and adaptive learning property, supply a more reliable approach to construct FES controller that help the paraplegia complete the action they want. A FES system tuned by Radial Basis Function (RBF) Neural Network-based Proportional-Integral-Derivative (PID) model was designed to control the knee joint according to the desired trajectory through stimulation of lower limbs muscles in this paper. Experiment result shows that the FES system with RBF Neural Network-based PID model get a better performance when tracking the preset trajectory of knee angle comparing with the system adjusted by Ziegler- Nichols tuning PID model.

  16. Improved methods in neural network-based adaptive output feedback control, with applications to flight control

    Science.gov (United States)

    Kim, Nakwan

    Utilizing the universal approximation property of neural networks, we develop several novel approaches to neural network-based adaptive output feedback control of nonlinear systems, and illustrate these approaches for several flight control applications. In particular, we address the problem of non-affine systems and eliminate the fixed point assumption present in earlier work. All of the stability proofs are carried out in a form that eliminates an algebraic loop in the neural network implementation. An approximate input/output feedback linearizing controller is augmented with a neural network using input/output sequences of the uncertain system. These approaches permit adaptation to both parametric uncertainty and unmodeled dynamics. All physical systems also have control position and rate limits, which may either deteriorate performance or cause instability for a sufficiently high control bandwidth. Here we apply a method for protecting an adaptive process from the effects of input saturation and time delays, known as "pseudo control hedging". This method was originally developed for the state feedback case, and we provide a stability analysis that extends its domain of applicability to the case of output feedback. The approach is illustrated by the design of a pitch-attitude flight control system for a linearized model of an R-50 experimental helicopter, and by the design of a pitch-rate control system for a 58-state model of a flexible aircraft consisting of rigid body dynamics coupled with actuator and flexible modes. A new approach to augmentation of an existing linear controller is introduced. It is especially useful when there is limited information concerning the plant model, and the existing controller. The approach is applied to the design of an adaptive autopilot for a guided munition. Design of a neural network adaptive control that ensures asymptotically stable tracking performance is also addressed.

  17. ACCESS Pointing Control System

    Science.gov (United States)

    Brugarolas, Paul; Alexander, James; Trauger, John; Moody, Dwight; Egerman, Robert; Vallone, Phillip; Elias, Jason; Hejal, Reem; Camelo, Vanessa; Bronowicki, Allen; hide

    2010-01-01

    ACCESS (Actively-Corrected Coronograph for Exoplanet System Studies) was one of four medium-class exoplanet concepts selected for the NASA Astrophysics Strategic Mission Concept Study (ASMCS) program in 2008/2009. The ACCESS study evaluated four major coronograph concepts under a common space observatory. This paper describes the high precision pointing control system (PCS) baselined for this observatory.

  18. Multirate IP traffic transmission in flexible access networks based on optical FFH-CDMA

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper, we propose a new IP transmission architecture over optical fast frequency hopping code-division multiple-access (OFFH-CDMA) network capable of supporting multirate transmissions for applications in flexible optical access networks. The proposed network architecture is independent...

  19. The Cybermobile: A Gateway for Public Access to Network-Based Information.

    Science.gov (United States)

    Drumm, John E.; Groom, Frank M.

    1997-01-01

    Though the bookmobile has fallen on hard times, the cybermobile, a technology platform combining personal computing, CD-ROMs, fiber network, and wireless access to the Internet, may be the next step in mobile library services. Discusses standard vehicle, computer hardware, software, wireless access, and alliances with users, vendors, and community…

  20. Neural network-based sliding mode control for atmospheric-actuated spacecraft formation using switching strategy

    Science.gov (United States)

    Sun, Ran; Wang, Jihe; Zhang, Dexin; Shao, Xiaowei

    2018-02-01

    This paper presents an adaptive neural networks-based control method for spacecraft formation with coupled translational and rotational dynamics using only aerodynamic forces. It is assumed that each spacecraft is equipped with several large flat plates. A coupled orbit-attitude dynamic model is considered based on the specific configuration of atmospheric-based actuators. For this model, a neural network-based adaptive sliding mode controller is implemented, accounting for system uncertainties and external perturbations. To avoid invalidation of the neural networks destroying stability of the system, a switching control strategy is proposed which combines an adaptive neural networks controller dominating in its active region and an adaptive sliding mode controller outside the neural active region. An optimal process is developed to determine the control commands for the plates system. The stability of the closed-loop system is proved by a Lyapunov-based method. Comparative results through numerical simulations illustrate the effectiveness of executing attitude control while maintaining the relative motion, and higher control accuracy can be achieved by using the proposed neural-based switching control scheme than using only adaptive sliding mode controller.

  1. Analysing Access Control Specifications

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, René Rydhof

    2009-01-01

    . Recent events have revealed intimate knowledge of surveillance and control systems on the side of the attacker, making it often impossible to deduce the identity of an inside attacker from logged data. In this work we present an approach that analyses the access control configuration to identify the set...

  2. Neural network based semi-active control strategy for structural vibration mitigation with magnetorheological damper

    DEFF Research Database (Denmark)

    Bhowmik, Subrata

    2011-01-01

    This paper presents a neural network based semi-active control method for a rotary type magnetorheological (MR) damper. The characteristics of the MR damper are described by the classic Bouc-Wen model, and the performance of the proposed control method is evaluated in terms of a base exited shear...... frame structure. As demonstrated in the literature effective damping of flexible structures is obtained by a suitable combination of pure friction and negative damper stiffness. This damper model is rate-independent and fully described by the desired shape of the hysteresis loops or force...... mode of the structure. The neural network control is then developed to reproduce the desired force based on damper displacement and velocity as network input, and it is therefore referred to as an amplitude dependent model reference control method. An inverse model of the MR damper is needed...

  3. Simulation and stability analysis of neural network based control scheme for switched linear systems.

    Science.gov (United States)

    Singh, H P; Sukavanam, N

    2012-01-01

    This paper proposes a new adaptive neural network based control scheme for switched linear systems with parametric uncertainty and external disturbance. A key feature of this scheme is that the prior information of the possible upper bound of the uncertainty is not required. A feedforward neural network is employed to learn this upper bound. The adaptive learning algorithm is derived from Lyapunov stability analysis so that the system response under arbitrary switching laws is guaranteed uniformly ultimately bounded. A comparative simulation study with robust controller given in [Zhang L, Lu Y, Chen Y, Mastorakis NE. Robust uniformly ultimate boundedness control for uncertain switched linear systems. Computers and Mathematics with Applications 2008; 56: 1709-14] is presented. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  4. A Predictive Neural Network-Based Cascade Control for pH Reactors

    Directory of Open Access Journals (Sweden)

    Mujahed AlDhaifallah

    2016-01-01

    Full Text Available This paper is concerned with the development of predictive neural network-based cascade control for pH reactors. The cascade structure consists of a master control loop (fuzzy proportional-integral and a slave one (predictive neural network. The master loop is chosen to be more accurate but slower than the slave one. The strong features found in cascade structure have been added to the inherent features in model predictive neural network. The neural network is used to alleviate modeling difficulties found with pH reactor and to predict its behavior. The parameters of predictive algorithm are determined using an optimization algorithm. The effectiveness and feasibility of the proposed design have been demonstrated using MatLab.

  5. Selected Flight Test Results for Online Learning Neural Network-Based Flight Control System

    Science.gov (United States)

    Williams-Hayes, Peggy S.

    2004-01-01

    The NASA F-15 Intelligent Flight Control System project team developed a series of flight control concepts designed to demonstrate neural network-based adaptive controller benefits, with the objective to develop and flight-test control systems using neural network technology to optimize aircraft performance under nominal conditions and stabilize the aircraft under failure conditions. This report presents flight-test results for an adaptive controller using stability and control derivative values from an online learning neural network. A dynamic cell structure neural network is used in conjunction with a real-time parameter identification algorithm to estimate aerodynamic stability and control derivative increments to baseline aerodynamic derivatives in flight. This open-loop flight test set was performed in preparation for a future phase in which the learning neural network and parameter identification algorithm output would provide the flight controller with aerodynamic stability and control derivative updates in near real time. Two flight maneuvers are analyzed - pitch frequency sweep and automated flight-test maneuver designed to optimally excite the parameter identification algorithm in all axes. Frequency responses generated from flight data are compared to those obtained from nonlinear simulation runs. Flight data examination shows that addition of flight-identified aerodynamic derivative increments into the simulation improved aircraft pitch handling qualities.

  6. Wireless sensor network-based greenhouse environment monitoring and automatic control system for dew condensation prevention.

    Science.gov (United States)

    Park, Dae-Heon; Park, Jang-Woo

    2011-01-01

    Dew condensation on the leaf surface of greenhouse crops can promote diseases caused by fungus and bacteria, affecting the growth of the crops. In this paper, we present a WSN (Wireless Sensor Network)-based automatic monitoring system to prevent dew condensation in a greenhouse environment. The system is composed of sensor nodes for collecting data, base nodes for processing collected data, relay nodes for driving devices for adjusting the environment inside greenhouse and an environment server for data storage and processing. Using the Barenbrug formula for calculating the dew point on the leaves, this system is realized to prevent dew condensation phenomena on the crop's surface acting as an important element for prevention of diseases infections. We also constructed a physical model resembling the typical greenhouse in order to verify the performance of our system with regard to dew condensation control.

  7. An Artificial Neural Network Based Robot Controller that Uses Rat’s Brain Signals

    Directory of Open Access Journals (Sweden)

    Marsel Mano

    2013-04-01

    Full Text Available Brain machine interface (BMI has been proposed as a novel technique to control prosthetic devices aimed at restoring motor functions in paralyzed patients. In this paper, we propose a neural network based controller that maps rat’s brain signals and transforms them into robot movement. First, the rat is trained to move the robot by pressing the right and left lever in order to get food. Next, we collect brain signals with four implanted electrodes, two in the motor cortex and two in the somatosensory cortex area. The collected data are used to train and evaluate different artificial neural controllers. Trained neural controllers are employed online to map brain signals and transform them into robot motion. Offline and online classification results of rat’s brain signals show that the Radial Basis Function Neural Networks (RBFNN outperforms other neural networks. In addition, online robot control results show that even with a limited number of electrodes, the robot motion generated by RBFNN matched the motion generated by the left and right lever position.

  8. Physical Access Control Database -

    Data.gov (United States)

    Department of Transportation — This data set contains the personnel access card data (photo, name, activation/expiration dates, card number, and access level) as well as data about turnstiles and...

  9. Neural-Network-Based Fuzzy Logic Navigation Control for Intelligent Vehicles

    Directory of Open Access Journals (Sweden)

    Ahcene Farah

    2002-06-01

    Full Text Available This paper proposes a Neural-Network-Based Fuzzy logic system for navigation control of intelligent vehicles. First, the use of Neural Networks and Fuzzy Logic to provide intelligent vehicles  with more autonomy and intelligence is discussed. Second, the system  for the obstacle avoidance behavior is developed. Fuzzy Logic improves Neural Networks (NN obstacle avoidance approach by handling imprecision and rule-based approximate reasoning. This system must make the vehicle able, after supervised learning, to achieve two tasks: 1- to make one’s way towards its target by a NN, and 2- to avoid static or dynamic obstacles by a Fuzzy NN capturing the behavior of a human expert. Afterwards, two association phases between each task and the appropriate actions are carried out by Trial and Error learning and their coordination allows to decide the appropriate action. Finally, the simulation results display the generalization and adaptation abilities of the system by testing it in new unexplored environments.

  10. Access control Tutorial 5

    CERN Document Server

    CERN. Geneva; Oberknapp, Bernd

    2007-01-01

    This tutorial will review current access management technologies and invite participants to discuss use cases and requirements for access management, particularly with respect to scholarly archives and their users. The presenters will describe the concepts and architecture of Federated Access Management (FAM) with reference to some large-scale federation implementations, and discuss the challenges faced particularly in Identity Management by academic institutions. The tutorial will include a practical demonstration of how FAM can be applied to an Open Archive repository.

  11. PID Neural Network Based Speed Control of Asynchronous Motor Using Programmable Logic Controller

    Directory of Open Access Journals (Sweden)

    MARABA, V. A.

    2011-11-01

    Full Text Available This paper deals with the structure and characteristics of PID Neural Network controller for single input and single output systems. PID Neural Network is a new kind of controller that includes the advantages of artificial neural networks and classic PID controller. Functioning of this controller is based on the update of controller parameters according to the value extracted from system output pursuant to the rules of back propagation algorithm used in artificial neural networks. Parameters obtained from the application of PID Neural Network training algorithm on the speed model of the asynchronous motor exhibiting second order linear behavior were used in the real time speed control of the motor. Programmable logic controller (PLC was used as real time controller. The real time control results show that reference speed successfully maintained under various load conditions.

  12. Bibliographic Access and Control System.

    Science.gov (United States)

    Kelly, Betsy; And Others

    1982-01-01

    Presents a brief summary of the functions of the Bibliographic Access & Control System (BACS) implemented at the Washington University School of Medicine Library, and outlines the design, development, and uses of the system. Bibliographic control of books and serials and user access to the system are also discussed. (Author/JL)

  13. Optimization of a neural network based direct inverse control for controlling a quadrotor unmanned aerial vehicle

    Directory of Open Access Journals (Sweden)

    Heryanto M Ary

    2015-01-01

    Full Text Available UAVs are mostly used for surveillance, inspection and data acquisition. We have developed a Quadrotor UAV that is constructed based on a four motors with a lift-generating propeller at each motors. In this paper, we discuss the development of a quadrotor and its neural networks direct inverse control model using the actual flight data. To obtain a better performance of the control system of the UAV, we proposed an Optimized Direct Inverse controller based on re-training the neural networks with the new data generated from optimal maneuvers of the quadrotor. Through simulation of the quadrotor using the developed DIC and Optimized DIC model, results show that both models have the ability to stabilize the quadrotor with a good tracking performance. The optimized DIC model, however, has shown a better performance, especially in the settling time parameter.

  14. Synchronization of Hierarchical Time-Varying Neural Networks Based on Asynchronous and Intermittent Sampled-Data Control.

    Science.gov (United States)

    Xiong, Wenjun; Patel, Ragini; Cao, Jinde; Zheng, Wei Xing

    In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.

  15. Network Access Control For Dummies

    CERN Document Server

    Kelley, Jay; Wessels, Denzil

    2009-01-01

    Network access control (NAC) is how you manage network security when your employees, partners, and guests need to access your network using laptops and mobile devices. Network Access Control For Dummies is where you learn how NAC works, how to implement a program, and how to take real-world challenges in stride. You'll learn how to deploy and maintain NAC in your environment, identify and apply NAC standards, and extend NAC for greater network security. Along the way you'll become familiar with what NAC is (and what it isn't) as well as the key business drivers for deploying NAC.Learn the step

  16. Service-Oriented Access Control

    Science.gov (United States)

    2014-09-01

    Relay Chat LAN local area network MAC media access control mDNS Multicast DNS NAT network address translation OSPF Open Shortest Path First PDU protocol...Open Shortest Path First ( OSPF ), or Dynamic Host Configuration Protocol (DHCP)). An algorithm for SOAC must have control over all such organization

  17. RBF neural network based PI pitch controller for a class of 5-MW wind turbines using particle swarm optimization algorithm.

    Science.gov (United States)

    Poultangari, Iman; Shahnazi, Reza; Sheikhan, Mansour

    2012-09-01

    In order to control the pitch angle of blades in wind turbines, commonly the proportional and integral (PI) controller due to its simplicity and industrial usability is employed. The neural networks and evolutionary algorithms are tools that provide a suitable ground to determine the optimal PI gains. In this paper, a radial basis function (RBF) neural network based PI controller is proposed for collective pitch control (CPC) of a 5-MW wind turbine. In order to provide an optimal dataset to train the RBF neural network, particle swarm optimization (PSO) evolutionary algorithm is used. The proposed method does not need the complexities, nonlinearities and uncertainties of the system under control. The simulation results show that the proposed controller has satisfactory performance. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Efficient Streaming Mass Spatio-Temporal Vehicle Data Access in Urban Sensor Networks Based on Apache Storm.

    Science.gov (United States)

    Zhou, Lianjie; Chen, Nengcheng; Chen, Zeqiang

    2017-04-10

    The efficient data access of streaming vehicle data is the foundation of analyzing, using and mining vehicle data in smart cities, which is an approach to understand traffic environments. However, the number of vehicles in urban cities has grown rapidly, reaching hundreds of thousands in number. Accessing the mass streaming data of vehicles is hard and takes a long time due to limited computation capability and backward modes. We propose an efficient streaming spatio-temporal data access based on Apache Storm (ESDAS) to achieve real-time streaming data access and data cleaning. As a popular streaming data processing tool, Apache Storm can be applied to streaming mass data access and real time data cleaning. By designing the Spout/bolt workflow of topology in ESDAS and by developing the speeding bolt and other bolts, Apache Storm can achieve the prospective aim. In our experiments, Taiyuan BeiDou bus location data is selected as the mass spatio-temporal data source. In the experiments, the data access results with different bolts are shown in map form, and the filtered buses' aggregation forms are different. In terms of performance evaluation, the consumption time in ESDAS for ten thousand records per second for a speeding bolt is approximately 300 milliseconds, and that for MongoDB is approximately 1300 milliseconds. The efficiency of ESDAS is approximately three times higher than that of MongoDB.

  19. Efficient Streaming Mass Spatio-Temporal Vehicle Data Access in Urban Sensor Networks Based on Apache Storm

    Directory of Open Access Journals (Sweden)

    Lianjie Zhou

    2017-04-01

    Full Text Available The efficient data access of streaming vehicle data is the foundation of analyzing, using and mining vehicle data in smart cities, which is an approach to understand traffic environments. However, the number of vehicles in urban cities has grown rapidly, reaching hundreds of thousands in number. Accessing the mass streaming data of vehicles is hard and takes a long time due to limited computation capability and backward modes. We propose an efficient streaming spatio-temporal data access based on Apache Storm (ESDAS to achieve real-time streaming data access and data cleaning. As a popular streaming data processing tool, Apache Storm can be applied to streaming mass data access and real time data cleaning. By designing the Spout/bolt workflow of topology in ESDAS and by developing the speeding bolt and other bolts, Apache Storm can achieve the prospective aim. In our experiments, Taiyuan BeiDou bus location data is selected as the mass spatio-temporal data source. In the experiments, the data access results with different bolts are shown in map form, and the filtered buses’ aggregation forms are different. In terms of performance evaluation, the consumption time in ESDAS for ten thousand records per second for a speeding bolt is approximately 300 milliseconds, and that for MongoDB is approximately 1300 milliseconds. The efficiency of ESDAS is approximately three times higher than that of MongoDB.

  20. Real-time neural network-based self-tuning control of a nonlinear electro-hydraulic servomotor

    Energy Technology Data Exchange (ETDEWEB)

    Canelon, J.I.; Ortega, A.G. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Electrical Engineering; Shieh, L.S. [Houston Univ., Houston, TX (United States). Dept. of Electrical and Computer Engineering; Bastidas, J.I. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Mechanical Engineering; Zhang, Y.; Akujuobi, C.M. [Prairie View A and M Univ., Prairie View, TX (United States). Center of Excellence for Communication Systems Technology Research and Dept. of Engineering Technology

    2010-08-13

    For high power applications, hydraulic actuators offer many advantages over electromagnetic actuators, including higher torque/mass ratios; smaller control gains; excellent torque capability; filtered high frequency noise; better heat transfer characteristics; smaller size; higher speed of response of the servomechanism; cheaper hardware; and higher reliability. Therefore, any application that requires a large force applied smoothly by an actuator is a candidate for hydraulic power. Examples of such applications include vehicle steering and braking systems; roll mills; drilling rigs; heavy duty crane and presses; and industrial robots and actuators for aircraft control surfaces such as ailerons and flaps. It is extremely important to create effective control strategies for hydraulic systems. This paper outlined the real-time implementation of a neural network-based approach, for self-tuning control of the angular position of a nonlinear electro-hydraulic servomotor. Using an online training algorithm, a neural network autoregressive moving-average model with exogenous input (ARMAX) model of the system was identified and continuously updated and an optimal linear ARMAX model was determined. The paper briefly depicted the neural network-based self-tuning control approach and a description of the experimental equipment (hardware and software) was presented including the implementation details. The experimental results were discussed and conclusions were summarized. It was found that the approach proved to be very effective in the control of this fast dynamics system, outperforming a fine tuned PI controller. Therefore, although the self-tuning approach was computationally demanding, it was feasible for real-time implementation. 22 refs., 6 figs.

  1. Neuro-fuzzy controller of low head hydropower plants using adaptive-network based fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M.S. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Vesovic, B.V. [Inst. Mihajlo Pupin, Belgrade (Yugoslavia). Dept. of Automatic Control; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1997-12-01

    This paper presents an attempt of nonlinear, multivariable control of low-head hydropower plants, by using adaptive-network based fuzzy inference system (ANFIS). The new design technique enhances fuzzy controllers with self-learning capability for achieving prescribed control objectives in a near optimal manner. The controller has flexibility for accepting more sensory information, with the main goal to improve the generator unit transients, by adjusting the exciter input, the wicket gate and runner blade positions. The developed ANFIS controller whose control signals are adjusted by using incomplete on-line measurements, can offer better damping effects to generator oscillations over a wide range of operating conditions, than conventional controllers. Digital simulations of hydropower plant equipped with low-head Kaplan turbine are performed and the comparisons of conventional excitation-governor control, state-feedback optimal control and ANFIS based output feedback control are presented. To demonstrate the effectiveness of the proposed control scheme and the robustness of the acquired neuro-fuzzy controller, the controller has been implemented on a complex high-order non-linear hydrogenerator model.

  2. Design, Implementation and Optimization of Innovative Internet Access Networks, based on Fog Computing and Software Defined Networking

    OpenAIRE

    Iotti, Nicola

    2017-01-01

    1. DESIGN In this dissertation we introduce a new approach to Internet access networks in public spaces, such as Wi-Fi network commonly known as Hotspot, based on Fog Computing (or Edge Computing), Software Defined Networking (SDN) and the deployment of Virtual Machines (VM) and Linux containers, on the edge of the network. In this vision we deploy specialized network elements, called Fog Nodes, on the edge of the network, able to virtualize the physical infrastructure and expose APIs to e...

  3. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    Science.gov (United States)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2017-08-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  4. Network-based regularization for matched case-control analysis of high-dimensional DNA methylation data.

    Science.gov (United States)

    Sun, Hokeun; Wang, Shuang

    2013-05-30

    The matched case-control designs are commonly used to control for potential confounding factors in genetic epidemiology studies especially epigenetic studies with DNA methylation. Compared with unmatched case-control studies with high-dimensional genomic or epigenetic data, there have been few variable selection methods for matched sets. In an earlier paper, we proposed the penalized logistic regression model for the analysis of unmatched DNA methylation data using a network-based penalty. However, for popularly applied matched designs in epigenetic studies that compare DNA methylation between tumor and adjacent non-tumor tissues or between pre-treatment and post-treatment conditions, applying ordinary logistic regression ignoring matching is known to bring serious bias in estimation. In this paper, we developed a penalized conditional logistic model using the network-based penalty that encourages a grouping effect of (1) linked Cytosine-phosphate-Guanine (CpG) sites within a gene or (2) linked genes within a genetic pathway for analysis of matched DNA methylation data. In our simulation studies, we demonstrated the superiority of using conditional logistic model over unconditional logistic model in high-dimensional variable selection problems for matched case-control data. We further investigated the benefits of utilizing biological group or graph information for matched case-control data. We applied the proposed method to a genome-wide DNA methylation study on hepatocellular carcinoma (HCC) where we investigated the DNA methylation levels of tumor and adjacent non-tumor tissues from HCC patients by using the Illumina Infinium HumanMethylation27 Beadchip. Several new CpG sites and genes known to be related to HCC were identified but were missed by the standard method in the original paper. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Investigation of Artificial Neural Network Based Direct Torque Control for PMSM by Numerical Simulations

    OpenAIRE

    Fatih Korkmaz; M.Faruk Çakır; İsmail Topaloğlu; Rıza Gürbüz

    2012-01-01

    The International Journal of Computer Networks & Communications (IJCNC) is a bi monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Computer Networks & Communications.The journal focuses on all technical and practical aspects of Computer Networks & data Communications. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced networking concepts and establishing new col...

  6. Active Queue Management in TCP Networks Based on Fuzzy-Pid Controller

    Directory of Open Access Journals (Sweden)

    Hossein ASHTIANI

    2012-01-01

    Full Text Available We introduce a novel and robust active queue management (AQM scheme based on a fuzzy controller, called hybrid fuzzy-PID controller. In the TCP network, AQM is important to regulate the queue length by passing or dropping the packets at the intermediate routers. RED, PI, and PID algorithms have been used for AQM. But these algorithms show weaknesses in the detection and control of congestion under dynamically changing network situations. In this paper a novel Fuzzy-based proportional-integral derivative (PID controller, which acts as an active queue manager (AQM for Internet routers, is proposed. These controllers are used to reduce packet loss and improve network utilization in TCP/IP networks. A new hybrid controller is proposed and compared with traditional RED based controller. Simulations are carried out to demonstrate the effectiveness of the proposed method and show that, the new hybrid fuzzy PID controller provides better performance than random early detection (RED and PID controllers

  7. The Study of Maglev Train Control and Diagnosis Networks Based on Role Automation Decentralization

    National Research Council Canada - National Science Library

    LIU, Zhigang; WANG, Qi; TAN, Yongdong

    2008-01-01

    The control and diagnosis networks in Maglev Train are the most important parts. In the paper, the control and diagnosis network structures are discussed, and the disadvantages of them are described and analyzed...

  8. Impairments Computation for Routing Purposes in a Transparent-Access Optical Network Based on Optical CDMA and WDM

    Science.gov (United States)

    Musa, Ahmed

    2016-06-01

    Optical access networks are becoming more widespread and the use of multiple services might require a transparent optical network (TON). Multiplexing and privacy could benefit from the combination of wavelength division multiplexing (WDM) and optical coding (OC) and wavelength conversion in optical switches. The routing process needs to be cognizant of different resource types and characteristics such as fiber types, fiber linear impairments such as attenuation, dispersion, etc. as well as fiber nonlinear impairments such as four-wave mixing, cross-phase modulation, etc. Other types of impairments, generated by optical nodes or photonic switches, also affect the signal quality (Q) or the optical signal to noise ratio (OSNR), which is related to the bit error rate (BER). Therefore, both link and switch impairments must be addressed and somehow incorporated into the routing algorithm. However, it is not practical to fully integrate all photonic-specific attributes in the routing process. In this study, new routing parameters and constraints are defined that reflect the distinct characteristics of photonic networking. These constraints are applied to the design phase of TON and expressed as a cost or metric form that will be used in the network routing algorithm.

  9. Virtualized Network Function Orchestration System and Experimental Network Based QR Recognition for a 5G Mobile Access Network

    Directory of Open Access Journals (Sweden)

    Misun Ahn

    2017-12-01

    Full Text Available This paper proposes a virtualized network function orchestration system based on Network Function Virtualization (NFV, one of the main technologies in 5G mobile networks. This system should provide connectivity between network devices and be able to create flexible network function and distribution. This system focuses more on access networks. By experimenting with various scenarios of user service established and activated in a network, we examine whether rapid adoption of new service is possible and whether network resources can be managed efficiently. The proposed method is based on Bluetooth transfer technology and mesh networking to provide automatic connections between network machines and on a Docker flat form, which is a container virtualization technology for setting and managing key functions. Additionally, the system includes a clustering and recovery measure regarding network function based on the Docker platform. We will briefly introduce the QR code perceived service as a user service to examine the proposal and based on this given service, we evaluate the function of the proposal and present analysis. Through the proposed approach, container relocation has been implemented according to a network device’s CPU usage and we confirm successful service through function evaluation on a real test bed. We estimate QR code recognition speed as the amount of network equipment is gradually increased, improving user service and confirm that the speed of recognition is increased as the assigned number of network devices is increased by the user service.

  10. Data Portal for the Library of Integrated Network-based Cellular Signatures (LINCS) program: integrated access to diverse large-scale cellular perturbation response data.

    Science.gov (United States)

    Koleti, Amar; Terryn, Raymond; Stathias, Vasileios; Chung, Caty; Cooper, Daniel J; Turner, John P; Vidovic, Dušica; Forlin, Michele; Kelley, Tanya T; D'Urso, Alessandro; Allen, Bryce K; Torre, Denis; Jagodnik, Kathleen M; Wang, Lily; Jenkins, Sherry L; Mader, Christopher; Niu, Wen; Fazel, Mehdi; Mahi, Naim; Pilarczyk, Marcin; Clark, Nicholas; Shamsaei, Behrouz; Meller, Jarek; Vasiliauskas, Juozas; Reichard, John; Medvedovic, Mario; Ma'ayan, Avi; Pillai, Ajay; Schürer, Stephan C

    2017-11-13

    The Library of Integrated Network-based Cellular Signatures (LINCS) program is a national consortium funded by the NIH to generate a diverse and extensive reference library of cell-based perturbation-response signatures, along with novel data analytics tools to improve our understanding of human diseases at the systems level. In contrast to other large-scale data generation efforts, LINCS Data and Signature Generation Centers (DSGCs) employ a wide range of assay technologies cataloging diverse cellular responses. Integration of, and unified access to LINCS data has therefore been particularly challenging. The Big Data to Knowledge (BD2K) LINCS Data Coordination and Integration Center (DCIC) has developed data standards specifications, data processing pipelines, and a suite of end-user software tools to integrate and annotate LINCS-generated data, to make LINCS signatures searchable and usable for different types of users. Here, we describe the LINCS Data Portal (LDP) (http://lincsportal.ccs.miami.edu/), a unified web interface to access datasets generated by the LINCS DSGCs, and its underlying database, LINCS Data Registry (LDR). LINCS data served on the LDP contains extensive metadata and curated annotations. We highlight the features of the LDP user interface that is designed to enable search, browsing, exploration, download and analysis of LINCS data and related curated content. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Neural network-based optimal adaptive output feedback control of a helicopter UAV.

    Science.gov (United States)

    Nodland, David; Zargarzadeh, Hassan; Jagannathan, Sarangapani

    2013-07-01

    Helicopter unmanned aerial vehicles (UAVs) are widely used for both military and civilian operations. Because the helicopter UAVs are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via an output feedback for trajectory tracking of a helicopter UAV, using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers and an NN observer. The online approximator-based dynamic controller learns the infinite-horizon Hamilton-Jacobi-Bellman equation in continuous time and calculates the corresponding optimal control input by minimizing a cost function, forward-in-time, without using the value and policy iterations. Optimal tracking is accomplished by using a single NN utilized for the cost function approximation. The overall closed-loop system stability is demonstrated using Lyapunov analysis. Finally, simulation results are provided to demonstrate the effectiveness of the proposed control design for trajectory tracking.

  12. Flexible Access Control for Dynamic Collaborative Environments

    NARCIS (Netherlands)

    Dekker, M.A.C.

    2009-01-01

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

  13. A Review of Neural Network Based Machine Learning Approaches for Rotor Angle Stability Control

    OpenAIRE

    Yousefian, Reza; Kamalasadan, Sukumar

    2017-01-01

    This paper reviews the current status and challenges of Neural Networks (NNs) based machine learning approaches for modern power grid stability control including their design and implementation methodologies. NNs are widely accepted as Artificial Intelligence (AI) approaches offering an alternative way to control complex and ill-defined problems. In this paper various application of NNs for power system rotor angle stabilization and control problem is discussed. The main focus of this paper i...

  14. Neural-network-based navigation and control of unmanned aerial vehicles for detecting unintended emissions

    Science.gov (United States)

    Zargarzadeh, H.; Nodland, David; Thotla, V.; Jagannathan, S.; Agarwal, S.

    2012-06-01

    Unmanned Aerial Vehicles (UAVs) are versatile aircraft with many applications, including the potential for use to detect unintended electromagnetic emissions from electronic devices. A particular area of recent interest has been helicopter unmanned aerial vehicles. Because of the nature of these helicopters' dynamics, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via output feedback control for trajectory tracking of a helicopter UAV using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic, virtual, and dynamic controllers and an observer. Optimal tracking is accomplished with a single NN utilized for cost function approximation. The controller positions the helicopter, which is equipped with an antenna, such that the antenna can detect unintended emissions. The overall closed-loop system stability with the proposed controller is demonstrated by using Lyapunov analysis. Finally, results are provided to demonstrate the effectiveness of the proposed control design for positioning the helicopter for unintended emissions detection.

  15. Neural network based adaptive control of nonlinear plants using random search optimization algorithms

    Science.gov (United States)

    Boussalis, Dhemetrios; Wang, Shyh J.

    1992-01-01

    This paper presents a method for utilizing artificial neural networks for direct adaptive control of dynamic systems with poorly known dynamics. The neural network weights (controller gains) are adapted in real time using state measurements and a random search optimization algorithm. The results are demonstrated via simulation using two highly nonlinear systems.

  16. Controlling Access to Suicide Means

    Directory of Open Access Journals (Sweden)

    Miriam Iosue

    2011-12-01

    Full Text Available Background: Restricting access to common means of suicide, such as firearms, toxic gas, pesticides and other, has been shown to be effective in reducing rates of death in suicide. In the present review we aimed to summarize the empirical and clinical literature on controlling the access to means of suicide. Methods: This review made use of both MEDLINE, ISI Web of Science and the Cochrane library databases, identifying all English articles with the keywords “suicide means”, “suicide method”, “suicide prediction” or “suicide prevention” and other relevant keywords. Results: A number of factors may influence an individual’s decision regarding method in a suicide act, but there is substantial support that easy access influences the choice of method. In many countries, restrictions of access to common means of suicide has lead to lower overall suicide rates, particularly regarding suicide by firearms in USA, detoxification of domestic and motor vehicle gas in England and other countries, toxic pesticides in rural areas, barriers at jumping sites and hanging, by introducing “safe rooms” in prisons and hospitals. Moreover, decline in prescription of barbiturates and tricyclic antidepressants (TCAs, as well as limitation of drugs pack size for paracetamol and salicylate has reduced suicides by overdose, while increased prescription of SSRIs seems to have lowered suicidal rates. Conclusions: Restriction to means of suicide may be particularly effective in contexts where the method is popular, highly lethal, widely available, and/or not easily substituted by other similar methods. However, since there is some risk of means substitution, restriction of access should be implemented in conjunction with other suicide prevention strategies.

  17. Neural network based control of an absorption column in the process of bioethanol production

    Directory of Open Access Journals (Sweden)

    Eduardo Eyng

    2009-08-01

    Full Text Available Gaseous ethanol may be recovered from the effluent gas mixture of the sugar cane fermentation process using a staged absorption column. In the present work, the development of a nonlinear controller, based on a neural network inverse model (ANN controller, was proposed and tested to manipulate the absorbent flow rate in order to control the residual ethanol concentration in the effluent gas phase. Simulation studies were carried out, in which a noise was applied to the ethanol concentration signals from the rigorous model. The ANN controller outperformed the dynamic matrix control (DMC when step disturbances were imposed to the gas mixture composition. A security device, based on a conventional feedback algorithm, and a digital filter were added to the proposed strategy to improve the system robustness when unforeseen operating and environmental conditions occured. The results demonstrated that ANN controller was a robust and reliable tool to control the absorption column.Deseja-se recuperar o etanol perdido por evaporação durante o processo de fermentação da cana-de-açúcar. Para tanto, faz-se uso de uma coluna de absorção. O controle da concentração de etanol no efluente gasoso da coluna é realizado pela manipulação da vazão de solvente, sendo esta determinada pelo controlador não linear proposto, baseado em um modelo inverso de redes neurais (controlador ANN. Foram feitas simulações adicionando-se um sinal de ruído a medida de concentração de etanol na fase gasosa. Quando perturbações degrau foram inseridas na mistura gasosa afluente, o controlador ANN demonstrou desempenho superior ao controle por matriz dinâmica (DMC. Um dispositivo de segurança, baseado em um controlador feedback convencional, e um filtro digital foram implementados à estratégia de controle proposta para agregar robustez no tratamento de distúrbios ocorridos no ambiente operacional. Os resultados demonstraram que o controlador ANN é uma

  18. Visual Servoing for an Autonomous Hexarotor Using a Neural Network Based PID Controller.

    Science.gov (United States)

    Lopez-Franco, Carlos; Gomez-Avila, Javier; Alanis, Alma Y; Arana-Daniel, Nancy; Villaseñor, Carlos

    2017-08-12

    In recent years, unmanned aerial vehicles (UAVs) have gained significant attention. However, we face two major drawbacks when working with UAVs: high nonlinearities and unknown position in 3D space since it is not provided with on-board sensors that can measure its position with respect to a global coordinate system. In this paper, we present a real-time implementation of a servo control, integrating vision sensors, with a neural proportional integral derivative (PID), in order to develop an hexarotor image based visual servo control (IBVS) that knows the position of the robot by using a velocity vector as a reference to control the hexarotor position. This integration requires a tight coordination between control algorithms, models of the system to be controlled, sensors, hardware and software platforms and well-defined interfaces, to allow the real-time implementation, as well as the design of different processing stages with their respective communication architecture. All of these issues and others provoke the idea that real-time implementations can be considered as a difficult task. For the purpose of showing the effectiveness of the sensor integration and control algorithm to address these issues on a high nonlinear system with noisy sensors as cameras, experiments were performed on the Asctec Firefly on-board computer, including both simulation and experimenta results.

  19. Diagonal recurrent neural network based adaptive control of nonlinear dynamical systems using lyapunov stability criterion.

    Science.gov (United States)

    Kumar, Rajesh; Srivastava, Smriti; Gupta, J R P

    2017-03-01

    In this paper adaptive control of nonlinear dynamical systems using diagonal recurrent neural network (DRNN) is proposed. The structure of DRNN is a modification of fully connected recurrent neural network (FCRNN). Presence of self-recurrent neurons in the hidden layer of DRNN gives it an ability to capture the dynamic behaviour of the nonlinear plant under consideration (to be controlled). To ensure stability, update rules are developed using lyapunov stability criterion. These rules are then used for adjusting the various parameters of DRNN. The responses of plants obtained with DRNN are compared with those obtained when multi-layer feed forward neural network (MLFFNN) is used as a controller. Also, in example 4, FCRNN is also investigated and compared with DRNN and MLFFNN. Robustness of the proposed control scheme is also tested against parameter variations and disturbance signals. Four simulation examples including one-link robotic manipulator and inverted pendulum are considered on which the proposed controller is applied. The results so obtained show the superiority of DRNN over MLFFNN as a controller. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Visual Servoing for an Autonomous Hexarotor Using a Neural Network Based PID Controller

    Science.gov (United States)

    Lopez-Franco, Carlos; Alanis, Alma Y.; Arana-Daniel, Nancy; Villaseñor, Carlos

    2017-01-01

    In recent years, unmanned aerial vehicles (UAVs) have gained significant attention. However, we face two major drawbacks when working with UAVs: high nonlinearities and unknown position in 3D space since it is not provided with on-board sensors that can measure its position with respect to a global coordinate system. In this paper, we present a real-time implementation of a servo control, integrating vision sensors, with a neural proportional integral derivative (PID), in order to develop an hexarotor image based visual servo control (IBVS) that knows the position of the robot by using a velocity vector as a reference to control the hexarotor position. This integration requires a tight coordination between control algorithms, models of the system to be controlled, sensors, hardware and software platforms and well-defined interfaces, to allow the real-time implementation, as well as the design of different processing stages with their respective communication architecture. All of these issues and others provoke the idea that real-time implementations can be considered as a difficult task. For the purpose of showing the effectiveness of the sensor integration and control algorithm to address these issues on a high nonlinear system with noisy sensors as cameras, experiments were performed on the Asctec Firefly on-board computer, including both simulation and experimenta results. PMID:28805689

  1. Artificial neural networks based controller for glucose monitoring during clamp test.

    Directory of Open Access Journals (Sweden)

    Merav Catalogna

    Full Text Available Insulin resistance (IR is one of the most widespread health problems in modern times. The gold standard for quantification of IR is the hyperinsulinemic-euglycemic glucose clamp technique. During the test, a regulated glucose infusion is delivered intravenously to maintain a constant blood glucose concentration. Current control algorithms for regulating this glucose infusion are based on feedback control. These models require frequent sampling of blood, and can only partly capture the complexity associated with regulation of glucose. Here we present an improved clamp control algorithm which is motivated by the stochastic nature of glucose kinetics, while using the minimal need in blood samples required for evaluation of IR. A glucose pump control algorithm, based on artificial neural networks model was developed. The system was trained with a data base collected from 62 rat model experiments, using a back-propagation Levenberg-Marquardt optimization. Genetic algorithm was used to optimize network topology and learning features. The predictive value of the proposed algorithm during the temporal period of interest was significantly improved relative to a feedback control applied at an equivalent low sampling interval. Robustness to noise analysis demonstrates the applicability of the algorithm in realistic situations.

  2. Projective synchronization of nonidentical fractional-order neural networks based on sliding mode controller.

    Science.gov (United States)

    Ding, Zhixia; Shen, Yi

    2016-04-01

    This paper investigates global projective synchronization of nonidentical fractional-order neural networks (FNNs) based on sliding mode control technique. We firstly construct a fractional-order integral sliding surface. Then, according to the sliding mode control theory, we design a sliding mode controller to guarantee the occurrence of the sliding motion. Based on fractional Lyapunov direct methods, system trajectories are driven to the proposed sliding surface and remain on it evermore, and some novel criteria are obtained to realize global projective synchronization of nonidentical FNNs. As the special cases, some sufficient conditions are given to ensure projective synchronization of identical FNNs, complete synchronization of nonidentical FNNs and anti-synchronization of nonidentical FNNs. Finally, one numerical example is given to demonstrate the effectiveness of the obtained results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Two-layer wireless distributed sensor/control network based on RF

    Science.gov (United States)

    Feng, Li; Lin, Yuchi; Zhou, Jingjing; Dong, Guimei; Xia, Guisuo

    2006-11-01

    A project of embedded Wireless Distributed Sensor/Control Network (WDSCN) based on RF is presented after analyzing the disadvantages of traditional measure and control system. Because of high-cost and complexity, such wireless techniques as Bluetooth and WiFi can't meet the needs of WDSCN. The two-layer WDSCN is designed based on RF technique, which operates in the ISM free frequency channel with low power and high transmission speed. Also the network is low cost, portable and moveable, integrated with the technologies of computer network, sensor, microprocessor and wireless communications. The two-layer network topology is selected in the system; a simple but efficient self-organization net protocol is designed to fit the periodic data collection, event-driven and store-and-forward. Furthermore, adaptive frequency hopping technique is adopted for anti-jamming apparently. The problems about power reduction and synchronization of data in wireless system are solved efficiently. Based on the discussion above, a measure and control network is set up to control such typical instruments and sensors as temperature sensor and signal converter, collect data, and monitor environmental parameters around. This system works well in different rooms. Experiment results show that the system provides an efficient solution to WDSCN through wireless links, with high efficiency, low power, high stability, flexibility and wide working range.

  4. Neural network-based adaptive dynamic surface control for permanent magnet synchronous motors.

    Science.gov (United States)

    Yu, Jinpeng; Shi, Peng; Dong, Wenjie; Chen, Bing; Lin, Chong

    2015-03-01

    This brief considers the problem of neural networks (NNs)-based adaptive dynamic surface control (DSC) for permanent magnet synchronous motors (PMSMs) with parameter uncertainties and load torque disturbance. First, NNs are used to approximate the unknown and nonlinear functions of PMSM drive system and a novel adaptive DSC is constructed to avoid the explosion of complexity in the backstepping design. Next, under the proposed adaptive neural DSC, the number of adaptive parameters required is reduced to only one, and the designed neural controllers structure is much simpler than some existing results in literature, which can guarantee that the tracking error converges to a small neighborhood of the origin. Then, simulations are given to illustrate the effectiveness and potential of the new design technique.

  5. Neural Network-Based Self-Tuning PID Control for Underwater Vehicles.

    Science.gov (United States)

    Hernández-Alvarado, Rodrigo; García-Valdovinos, Luis Govinda; Salgado-Jiménez, Tomás; Gómez-Espinosa, Alfonso; Fonseca-Navarro, Fernando

    2016-09-05

    For decades, PID (Proportional + Integral + Derivative)-like controllers have been successfully used in academia and industry for many kinds of plants. This is thanks to its simplicity and suitable performance in linear or linearized plants, and under certain conditions, in nonlinear ones. A number of PID controller gains tuning approaches have been proposed in the literature in the last decades; most of them off-line techniques. However, in those cases wherein plants are subject to continuous parametric changes or external disturbances, online gains tuning is a desirable choice. This is the case of modular underwater ROVs (Remotely Operated Vehicles) where parameters (weight, buoyancy, added mass, among others) change according to the tool it is fitted with. In practice, some amount of time is dedicated to tune the PID gains of a ROV. Once the best set of gains has been achieved the ROV is ready to work. However, when the vehicle changes its tool or it is subject to ocean currents, its performance deteriorates since the fixed set of gains is no longer valid for the new conditions. Thus, an online PID gains tuning algorithm should be implemented to overcome this problem. In this paper, an auto-tune PID-like controller based on Neural Networks (NN) is proposed. The NN plays the role of automatically estimating the suitable set of PID gains that achieves stability of the system. The NN adjusts online the controller gains that attain the smaller position tracking error. Simulation results are given considering an underactuated 6 DOF (degrees of freedom) underwater ROV. Real time experiments on an underactuated mini ROV are conducted to show the effectiveness of the proposed scheme.

  6. Neural Network-Based Self-Tuning PID Control for Underwater Vehicles

    Science.gov (United States)

    Hernández-Alvarado, Rodrigo; García-Valdovinos, Luis Govinda; Salgado-Jiménez, Tomás; Gómez-Espinosa, Alfonso; Fonseca-Navarro, Fernando

    2016-01-01

    For decades, PID (Proportional + Integral + Derivative)-like controllers have been successfully used in academia and industry for many kinds of plants. This is thanks to its simplicity and suitable performance in linear or linearized plants, and under certain conditions, in nonlinear ones. A number of PID controller gains tuning approaches have been proposed in the literature in the last decades; most of them off-line techniques. However, in those cases wherein plants are subject to continuous parametric changes or external disturbances, online gains tuning is a desirable choice. This is the case of modular underwater ROVs (Remotely Operated Vehicles) where parameters (weight, buoyancy, added mass, among others) change according to the tool it is fitted with. In practice, some amount of time is dedicated to tune the PID gains of a ROV. Once the best set of gains has been achieved the ROV is ready to work. However, when the vehicle changes its tool or it is subject to ocean currents, its performance deteriorates since the fixed set of gains is no longer valid for the new conditions. Thus, an online PID gains tuning algorithm should be implemented to overcome this problem. In this paper, an auto-tune PID-like controller based on Neural Networks (NN) is proposed. The NN plays the role of automatically estimating the suitable set of PID gains that achieves stability of the system. The NN adjusts online the controller gains that attain the smaller position tracking error. Simulation results are given considering an underactuated 6 DOF (degrees of freedom) underwater ROV. Real time experiments on an underactuated mini ROV are conducted to show the effectiveness of the proposed scheme. PMID:27608018

  7. Neural Network-Based Self-Tuning PID Control for Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Rodrigo Hernández-Alvarado

    2016-09-01

    Full Text Available For decades, PID (Proportional + Integral + Derivative-like controllers have been successfully used in academia and industry for many kinds of plants. This is thanks to its simplicity and suitable performance in linear or linearized plants, and under certain conditions, in nonlinear ones. A number of PID controller gains tuning approaches have been proposed in the literature in the last decades; most of them off-line techniques. However, in those cases wherein plants are subject to continuous parametric changes or external disturbances, online gains tuning is a desirable choice. This is the case of modular underwater ROVs (Remotely Operated Vehicles where parameters (weight, buoyancy, added mass, among others change according to the tool it is fitted with. In practice, some amount of time is dedicated to tune the PID gains of a ROV. Once the best set of gains has been achieved the ROV is ready to work. However, when the vehicle changes its tool or it is subject to ocean currents, its performance deteriorates since the fixed set of gains is no longer valid for the new conditions. Thus, an online PID gains tuning algorithm should be implemented to overcome this problem. In this paper, an auto-tune PID-like controller based on Neural Networks (NN is proposed. The NN plays the role of automatically estimating the suitable set of PID gains that achieves stability of the system. The NN adjusts online the controller gains that attain the smaller position tracking error. Simulation results are given considering an underactuated 6 DOF (degrees of freedom underwater ROV. Real time experiments on an underactuated mini ROV are conducted to show the effectiveness of the proposed scheme.

  8. Neural network-based motion control of an underactuated wheeled inverted pendulum model.

    Science.gov (United States)

    Yang, Chenguang; Li, Zhijun; Cui, Rongxin; Xu, Bugong

    2014-11-01

    In this paper, automatic motion control is investigated for one of wheeled inverted pendulum (WIP) models, which have been widely applied for modeling of a large range of two wheeled modern vehicles. First, the underactuated WIP model is decomposed into a fully actuated second order subsystem Σa consisting of planar movement of vehicle forward and yaw angular motions, and a nonactuated first order subsystem Σb of pendulum motion. Due to the unknown dynamics of subsystem Σa and the universal approximation ability of neural network (NN), an adaptive NN scheme has been employed for motion control of subsystem Σa . The model reference approach has been used whereas the reference model is optimized by the finite time linear quadratic regulation technique. The pendulum motion in the passive subsystem Σb is indirectly controlled using the dynamic coupling with planar forward motion of subsystem Σa , such that satisfactory tracking of a set pendulum tilt angle can be guaranteed. Rigours theoretic analysis has been established, and simulation studies have been performed to demonstrate the developed method.

  9. A programming environment to control switching networks based on STC104 packet routing chip

    Science.gov (United States)

    Legrand, I. C.; Schwendicke, U.; Leich, H.; Medinnis, M.; Koehler, A.; Wegner, P.; Sulanke, K.; Dippel, R.; Gellrich, A.

    1997-02-01

    The software environment used to control a large switching architecture based on SGS-Thomson STC104 (an asynchronous 32-way dynamic packet routing chip) is presented. We are evaluating this switching technology for large scale, real-time parallel systems. A Graphical User Interface (GUI) written as a multi-thread application in Java allows to set the switch configuration and to continuously monitor the state of each link. This GUI connects to a multi-thread server via TCP/IP sockets. The server is running on a PC-Linux system and implements the virtual channel protocol in communicating with the STC104 switching units using the Data Strobe link or the VME bus. Linux I/O drivers to control the Data Strobe link parallel adaptor (STC101) were developed. For each client the server creates a new thread and allocates a new socket for communications. The Java code of the GUI may be transferred to any client using the http protocol providing a user friendly interface to the system with real-time monitoring which is also platform independent.

  10. Network-based vaccination improves prospects for disease control in wild chimpanzees

    Science.gov (United States)

    Rushmore, Julie; Caillaud, Damien; Hall, Richard J.; Stumpf, Rebecca M.; Meyers, Lauren Ancel; Altizer, Sonia

    2014-01-01

    Many endangered wildlife populations are vulnerable to infectious diseases for which vaccines exist; yet, pragmatic considerations often preclude large-scale vaccination efforts. These barriers could be reduced by focusing on individuals with the highest contact rates. However, the question then becomes whether targeted vaccination is sufficient to prevent large outbreaks. To evaluate the efficacy of targeted wildlife vaccinations, we simulate pathogen transmission and control on monthly association networks informed by behavioural data from a wild chimpanzee community (Kanyawara N = 37, Kibale National Park, Uganda). Despite considerable variation across monthly networks, our simulations indicate that targeting the most connected individuals can prevent large outbreaks with up to 35% fewer vaccines than random vaccination. Transmission heterogeneities might be attributed to biological differences among individuals (e.g. sex, age, dominance and family size). Thus, we also evaluate the effectiveness of a trait-based vaccination strategy, as trait data are often easier to collect than interaction data. Our simulations indicate that a trait-based strategy can prevent large outbreaks with up to 18% fewer vaccines than random vaccination, demonstrating that individual traits can serve as effective estimates of connectivity. Overall, these results suggest that fine-scale behavioural data can help optimize pathogen control efforts for endangered wildlife. PMID:24872503

  11. Wireless Sensor Network Based Smart Grid Communications: Cyber Attacks, Intrusion Detection System and Topology Control

    Directory of Open Access Journals (Sweden)

    Lipi Chhaya

    2017-01-01

    Full Text Available The existing power grid is going through a massive transformation. Smart grid technology is a radical approach for improvisation in prevailing power grid. Integration of electrical and communication infrastructure is inevitable for the deployment of Smart grid network. Smart grid technology is characterized by full duplex communication, automatic metering infrastructure, renewable energy integration, distribution automation and complete monitoring and control of entire power grid. Wireless sensor networks (WSNs are small micro electrical mechanical systems that are deployed to collect and communicate the data from surroundings. WSNs can be used for monitoring and control of smart grid assets. Security of wireless sensor based communication network is a major concern for researchers and developers. The limited processing capabilities of wireless sensor networks make them more vulnerable to cyber-attacks. The countermeasures against cyber-attacks must be less complex with an ability to offer confidentiality, data readiness and integrity. The address oriented design and development approach for usual communication network requires a paradigm shift to design data oriented WSN architecture. WSN security is an inevitable part of smart grid cyber security. This paper is expected to serve as a comprehensive assessment and analysis of communication standards, cyber security issues and solutions for WSN based smart grid infrastructure.

  12. BIOMETRIC ACCESS CONTROL SYSTEMS BASED ON FINGERPRINTS

    Directory of Open Access Journals (Sweden)

    V. V. Starovoitov

    2015-01-01

    Full Text Available Features of biometric access control system design for control people's access to certain facilitiesare described. Basic algorithms for fingerprint processing and analysis are given in details. Construction schemes of three variants of an access control system are presented.

  13. A social network-based intervention stimulating peer influence on children's self-reported water consumption: A randomized control trial.

    Science.gov (United States)

    Smit, Crystal R; de Leeuw, Rebecca N H; Bevelander, Kirsten E; Burk, William J; Buijzen, Moniek

    2016-08-01

    The current pilot study examined the effectiveness of a social network-based intervention using peer influence on self-reported water consumption. A total of 210 children (52% girls; M age = 10.75 ± SD = 0.80) were randomly assigned to either the intervention (n = 106; 52% girls) or control condition (n = 104; 52% girls). In the intervention condition, the most influential children in each classroom were trained to promote water consumption among their peers for eight weeks. The schools in the control condition did not receive any intervention. Water consumption, sugar-sweetened beverage (SSB) consumption, and intentions to drink more water in the near future were assessed by self-report measures before and immediately after the intervention. A repeated measure MANCOVA showed a significant multivariate interaction effect between condition and time (V = 0.07, F(3, 204) = 5.18, p = 0.002, pη(2) = 0.07) on the dependent variables. Further examination revealed significant univariate interaction effects between condition and time on water (p = 0.021) and SSB consumption (p = 0.015) as well as water drinking intentions (p = 0.049). Posthoc analyses showed that children in the intervention condition reported a significant increase in their water consumption (p = 0.018) and a decrease in their SSB consumption (p  0.05). The children who were exposed to the intervention did not report a change in their water drinking intentions over time (p = 0.576) whereas the nonexposed children decreased their intentions (p = 0.026). These findings show promise for a social network-based intervention using peer influence to positively alter consumption behaviors. This RCT was registered in the Australian New Zealand Clinical Trials Registry (ACTRN12614001179628). Study procedures were approved by the Ethics Committee of the Faculty of Social Sciences at Radboud University (ECSW2014-1003-203). Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Logical Access Control Mechanisms in Computer Systems.

    Science.gov (United States)

    Hsiao, David K.

    The subject of access control mechanisms in computer systems is concerned with effective means to protect the anonymity of private information on the one hand, and to regulate the access to shareable information on the other hand. Effective means for access control may be considered on three levels: memory, process and logical. This report is a…

  15. Efficient Access Control in Multimedia Social Networks

    Science.gov (United States)

    Sachan, Amit; Emmanuel, Sabu

    Multimedia social networks (MMSNs) have provided a convenient way to share multimedia contents such as images, videos, blogs, etc. Contents shared by a person can be easily accessed by anybody else over the Internet. However, due to various privacy, security, and legal concerns people often want to selectively share the contents only with their friends, family, colleagues, etc. Access control mechanisms play an important role in this situation. With access control mechanisms one can decide the persons who can access a shared content and who cannot. But continuously growing content uploads and accesses, fine grained access control requirements (e.g. different access control parameters for different parts in a picture), and specific access control requirements for multimedia contents can make the time complexity of access control to be very large. So, it is important to study an efficient access control mechanism suitable for MMSNs. In this chapter we present an efficient bit-vector transform based access control mechanism for MMSNs. The proposed approach is also compatible with other requirements of MMSNs, such as access rights modification, content deletion, etc. Mathematical analysis and experimental results show the effectiveness and efficiency of our proposed approach.

  16. Common Badging and Access Control System (CBACS)

    Science.gov (United States)

    Dischinger, Portia

    2005-01-01

    This slide presentation presents NASA's Common Badging and Access Control System. NASA began a Smart Card implementation in January 2004. Following site surveys, it was determined that NASA's badging and access control systems required upgrades to common infrastructure in order to provide flexibly, usability, and return on investment prior to a smart card implantation. Common Badging and Access Control System (CBACS) provides the common infrastructure from which FIPS-201 compliant processes, systems, and credentials can be developed and used.

  17. Traffic Control Algorithm Offering Multi-Class Fairness in PON Based Access Networks

    Science.gov (United States)

    Okumura, Yasuyuki

    This letter proposes a dynamic bandwidth allocation algorithm for access networks based PON (Passive Optical Network). It considers the mixture of transport layer protocols when responding to traffic congestion at the SNI (Service Node Interface). Simulations on a mixture of TCP (Transmission Control Protocol), and UDP (User Datagram Protocol) traffic flows show that the algorithm increases the throughput of TCP, improves the fairness between the two protocols, and solves the congestion problem at the SNI.

  18. A Component-Based Access Control Monitor

    Science.gov (United States)

    Liu, Zhiming; Morisset, Charles; Stolz, Volker

    A control of access to information is increasingly becoming necessary as the systems managing this information is more and more open and available through non secure networks. Integrating an access control monitor within a large system is a complex task, since it has to be an "all or nothing" integration. The least error or mistake could lead to jeopardize the whole system. We present a formal specification of an access control monitor using the calculus of refinement of component and object systems (rCOS). We illustrate this implementation with the well known Role Based Access Control (RBAC) policy and we show how to integrate it within a larger system. Keywords: Component, Access Control, RBAC, Composition

  19. Access control administration in healthcare applications.

    Science.gov (United States)

    Andreas, Mattas K; Ioannis, Mavridis K; George, Pangalos I

    2002-01-01

    The interconnection of information systems of different parties involved in healthcare applications leads to the need for information sharing across large-scale and highly distributed database systems. Applying appropriate access control policies in an effective and flexible way is a specific task for a number of local security officers that must operate according to a high-level access control administration system. The particular security requirements of healthcare information systems are reflected to the access control system, which must be flexible and dynamically adaptable to the daily activities. Decentralizing access control administration can be achieved in a uniform and consistent way when applying appropriate administrative rules and constraints. In this paper are presented the basic features of an access control administration model for interconnected information systems, as in the healthcare environment.

  20. Access control and personal identification systems

    CERN Document Server

    Bowers, Dan M

    1988-01-01

    Access Control and Personal Identification Systems provides an education in the field of access control and personal identification systems, which is essential in selecting the appropriate equipment, dealing intelligently with vendors in purchases of the equipment, and integrating the equipment into a total effective system. Access control devices and systems comprise an important part of almost every security system, but are seldom the sole source of security. In order for the goals of the total system to be met, the other portions of the security system must also be well planned and executed

  1. Mission-Aware Medium Access Control in Random Access Networks

    OpenAIRE

    Park, Jaeok; Van Der Schaar, Mihaela

    2009-01-01

    We study mission-critical networking in wireless communication networks, where network users are subject to critical events such as emergencies and crises. If a critical event occurs to a user, the user needs to send necessary information for help as early as possible. However, most existing medium access control (MAC) protocols are not adequate to meet the urgent need for information transmission by users in a critical situation. In this paer, we propose a novel class of MAC protocols that u...

  2. Access control, security, and trust a logical approach

    CERN Document Server

    Chin, Shiu-Kai

    2010-01-01

    Access Control, Security, Trust, and Logic Deconstructing Access Control Decisions A Logical Approach to Access Control PRELIMINARIES A Language for Access ControlSets and Relations Syntax SemanticsReasoning about Access Control Logical RulesFormal Proofs and Theorems Soundness of Logical RulesBasic Concepts Reference Monitors Access Control Mechanisms: Tickets and Lists Authentication Security PoliciesConfidentiality, Integrity, and Availability Discretionary Security Policies Mandatory Security Policies Military Security Policies Commercial PoliciesDISTRIBUTED ACCESS CONTROL Digital Authenti

  3. Network-Based Effectiveness

    National Research Council Canada - National Science Library

    Friman, Henrik

    2006-01-01

    ... (extended from Leavitt, 1965). This text identifies aspects of network-based effectiveness that can benefit from a better understanding of leadership and management development of people, procedures, technology, and organizations...

  4. Access Control Based on Trail Inference

    Directory of Open Access Journals (Sweden)

    ALBARELO, P. C.

    2015-06-01

    Full Text Available Professionals are constantly seeking qualification and consequently increasing their knowledge in their area of expertise. Thus, it is interesting to develop a computer system that knows its users and their work history. Using this information, even in the case of professional role change, the system could allow the renewed authorization for activities, based on previously authorized use. This article proposes a model for user access control that is embedded in a context-aware environment. The model applies the concept of trails to manage access control, recording activities usage in contexts and applying this history as a criterion to grant new accesses. Despite the fact that previous related research works consider contexts, none of them uses the concept of trails. Hence, the main contribution of this work is the use of a new access control criterion, namely, the history of previous accesses (trails. A prototype was implemented and applied in an evaluation based on scenarios. The results demonstrate the feasibility of the proposal, allowing for access control systems to use an alternative way to support access rights.

  5. Role-based access control permissions

    Science.gov (United States)

    Staggs, Kevin P.; Markham, Thomas R.; Hull Roskos, Julie J.; Chernoguzov, Alexander

    2017-04-25

    Devices, systems, and methods for role-based access control permissions are disclosed. One method includes a policy decision point that receives up-to-date security context information from one or more outside sources to determine whether to grant access for a data client to a portion of the system and creates an access vector including the determination; receiving, via a policy agent, a request by the data client for access to the portion of the computing system by the data client, wherein the policy agent checks to ensure there is a session established with communications and user/application enforcement points; receiving, via communications policy enforcement point, the request from the policy agent, wherein the communications policy enforcement point determines whether the data client is an authorized node, based upon the access vector received from the policy decision point; and receiving, via the user/application policy enforcement point, the request from the communications policy enforcement point.

  6. Access Control Management for SCADA Systems

    Science.gov (United States)

    Hong, Seng-Phil; Ahn, Gail-Joon; Xu, Wenjuan

    The information technology revolution has transformed all aspects of our society including critical infrastructures and led a significant shift from their old and disparate business models based on proprietary and legacy environments to more open and consolidated ones. Supervisory Control and Data Acquisition (SCADA) systems have been widely used not only for industrial processes but also for some experimental facilities. Due to the nature of open environments, managing SCADA systems should meet various security requirements since system administrators need to deal with a large number of entities and functions involved in critical infrastructures. In this paper, we identify necessary access control requirements in SCADA systems and articulate access control policies for the simulated SCADA systems. We also attempt to analyze and realize those requirements and policies in the context of role-based access control that is suitable for simplifying administrative tasks in large scale enterprises.

  7. Access Agent Improving The Performance Of Access Control Lists

    Directory of Open Access Journals (Sweden)

    Thelis R. S.

    2015-08-01

    Full Text Available The main focus of the proposed research is maintaining the security of a network. Extranet is a popular network among most of the organizations where network access is provided to a selected group of outliers. Limiting access to an extranet can be carried out using Access Control Lists ACLs method. However handling the workload of ACLs is an onerous task for the router. The purpose of the proposed research is to improve the performance and to solidify the security of the ACLs used in a small organization. Using a high performance computer as a dedicated device to share and handle the router workload is suggested in order to increase the performance of the router when handling ACLs. Methods of detecting and directing sensitive data is also discussed in this paper. A framework is provided to help increase the efficiency of the ACLs in an organization network using the above mentioned procedures thus helping the organizations ACLs performance to be improved to be more secure and the system to perform faster. Inbuilt methods of Windows platform or Software for open source platforms can be used to make a computer function as a router. Extended ACL features allow the determining of the type of packets flowing through the router. Combining these mechanisms allows the ACLs to be improved and perform in a more efficient manner.

  8. Integrated mandatory access control for digital data

    Science.gov (United States)

    Hsieh, George; Patrick, Gregory; Foster, Keith; Emamali, Gerald; Marvel, Lisa

    2008-03-01

    This paper presents an integrated mandatory access control (MAC) framework that incorporates MAC mechanisms at both operating system and application layers for digital data. The framework uses Security-Enhanced Linux (SELinux) as the foundation for MAC at the operating system layer. It uses XACML (eXtensible Access Control Markup Language) as the base mechanism for specifying and embedding information-layer MAC policies. This framework is designed to be general-purpose, flexible, and capable of providing fine-grained access control. This paper also describes a high-level architecture of a prototype being developed for the framework. One targeted application domain for this framework is information sharing and dissemination in a multi-level security environment.

  9. Time dependent policy-based access control

    DEFF Research Database (Denmark)

    Vasilikos, Panagiotis; Nielson, Flemming; Nielson, Hanne Riis

    2017-01-01

    also on other attributes of the environment such as the time. In this paper, we use systems of Timed Automata to model distributed systems and we present a logic in which one can express time-dependent policies for access control. We show how a fragment of our logic can be reduced to a logic...... that current model checkers for Timed Automata such as UPPAAL can handle and we present a translator that performs this reduction. We then use our translator and UPPAAL to enforce time-dependent policy-based access control on an example application from the aerospace industry....

  10. Access control mechanism of wireless gateway based on open flow

    Science.gov (United States)

    Peng, Rong; Ding, Lei

    2017-08-01

    In order to realize the access control of wireless gateway and improve the access control of wireless gateway devices, an access control mechanism of SDN architecture which is based on Open vSwitch is proposed. The mechanism utilizes the features of the controller--centralized control and programmable. Controller send access control flow table based on the business logic. Open vSwitch helps achieve a specific access control strategy based on the flow table.

  11. Predictive access control for distributed computation

    DEFF Research Database (Denmark)

    Yang, Fan; Hankin, Chris; Nielson, Flemming

    2013-01-01

    We show how to use aspect-oriented programming to separate security and trust issues from the logical design of mobile, distributed systems. The main challenge is how to enforce various types of security policies, in particular predictive access control policies — policies based on the future...

  12. An electronically controlled automatic security access gate

    Directory of Open Access Journals (Sweden)

    Jonathan A. ENOKELA

    2014-11-01

    Full Text Available The security challenges being encountered in many places require electronic means of controlling access to communities, recreational centres, offices, and homes. The electronically controlled automated security access gate being proposed in this work helps to prevent an unwanted access to controlled environments. This is achieved mainly through the use of a Radio Frequency (RF transmitter-receiver pair. In the design a microcontroller is programmed to decode a given sequence of keys that is entered on a keypad and commands a transmitter module to send out this code as signal at a given radio frequency. Upon reception of this RF signal by the receiver module, another microcontroller activates a driver circuitry to operate the gate automatically. The codes for the microcontrollers were written in C language and were debugged and compiled using the KEIL Micro vision 4 integrated development environment. The resultant Hex files were programmed into the memories of the microcontrollers with the aid of a universal programmer. Software simulation was carried out using the Proteus Virtual System Modeling (VSM version 7.7. A scaled-down prototype of the system was built and tested. The electronically controlled automated security access gate can be useful in providing security for homes, organizations, and automobile terminals. The four-character password required to operate the gate gives the system an increased level of security. Due to its standalone nature of operation the system is cheaper to maintain in comparison with a manually operated type.

  13. Access Control from an Intrusion Detection Perspective

    NARCIS (Netherlands)

    Nunes Leal Franqueira, V.

    Access control and intrusion detection are essential components for securing an organization's information assets. In practice, these components are used in isolation, while their fusion would contribute to increase the range and accuracy of both. One approach to accomplish this fusion is the

  14. Multi-channel Dual Clocks three-dimensional probability Random Multiple Access protocol for Wireless Public Bus Networks based on RTS/CTS mechanism

    Directory of Open Access Journals (Sweden)

    Zhou Sheng Jie

    2016-01-01

    Full Text Available A MAC protocol for public bus networks, called Bus MAC protocol, designed to provide high quality Internet service for bus passengers. The paper proposed a multi-channel dual clocks three-demission probability random multiple access protocol based on RTS/CTS mechanism, decreasing collisions caused by multiple access from multiple passengers. Use the RTS/CTS mechanism increases the reliability and stability of the system, reducing the collision possibility of the information packets to a certain extent, improves the channel utilization; use the multi-channel mechanism, not only enables the channel load balancing, but also solves the problem of the hidden terminal and exposed terminal. Use the dual clocks mechanism, reducing the system idle time. At last, the different selection of the three-dimensional probabilities can make the system throughput adapt to the network load which could realize the maximum of the system throughput.

  15. A Review of Fuzzy Logic and Neural Network Based Intelligent Control Design for Discrete-Time Systems

    Directory of Open Access Journals (Sweden)

    Yiming Jiang

    2016-01-01

    Full Text Available Over the last few decades, the intelligent control methods such as fuzzy logic control (FLC and neural network (NN control have been successfully used in various applications. The rapid development of digital computer based control systems requires control signals to be calculated in a digital or discrete-time form. In this background, the intelligent control methods developed for discrete-time systems have drawn great attentions. This survey aims to present a summary of the state of the art of the design of FLC and NN-based intelligent control for discrete-time systems. For discrete-time FLC systems, numerous remarkable design approaches are introduced and a series of efficient methods to deal with the robustness, stability, and time delay of FLC discrete-time systems are recommended. Techniques for NN-based intelligent control for discrete-time systems, such as adaptive methods and adaptive dynamic programming approaches, are also reviewed. Overall, this paper is devoted to make a brief summary for recent progresses in FLC and NN-based intelligent control design for discrete-time systems as well as to present our thoughts and considerations of recent trends and potential research directions in this area.

  16. Mandatory Access Control applications to web hosting

    Science.gov (United States)

    Prandini, Marco; Faldella, Eugenio; Laschi, Roberto

    "Hosting" represents a commonplace solution for the low-cost implementation of web sites through the efficient sharing of the resources of a single server. The arising security problems, however, are not always easily dealt with under the Discretionary Access Control model implemented by traditional operating systems. More robust separation between the hosted sites, as well as more robust protection of the host system, can be attained by exploiting the features typical of Mandatory Access Control systems. Recently, these systems have recently been made available to the vast Linux community through projects like SELinux and grsecurity. This paper describes the architecture of a secure hosting server, integrating SELinux functionalities into the Apache/PHP platform, designed with the goal of increasing security without adding administrative burdens or impacting performance.

  17. Database access control within a Java application

    OpenAIRE

    Plantec, Alain; Ribaud, Vincent; Saliou, Philippe

    2003-01-01

    International audience; The purpose of the work described in this article is to use database security mechanism as a data access control model in a Java application, developed through an UML-based process. This work relies on the CASE tool Designer from the Oracle company and its associated user and security policy. The three axis of this work are the following ones : • Introducing class diagrams towards Designer analysis and design models (entity-relation ship diagram, design diagrams). • Us...

  18. Social Network Privacy via Evolving Access Control

    Science.gov (United States)

    di Crescenzo, Giovanni; Lipton, Richard J.

    We study the problem of limiting privacy loss due to data shared in a social network, where the basic underlying assumptions are that users are interested in sharing data and cannot be assumed to constantly follow appropriate privacy policies. Note that if these two assumptions do not hold, social network privacy is theoretically very easy to achieve; for instance, via some form of access control and confidentiality transformation on the data.

  19. Distributed medium access control in wireless networks

    CERN Document Server

    Wang, Ping

    2013-01-01

    This brief investigates distributed medium access control (MAC) with QoS provisioning for both single- and multi-hop wireless networks including wireless local area networks (WLANs), wireless ad hoc networks, and wireless mesh networks. For WLANs, an efficient MAC scheme and a call admission control algorithm are presented to provide guaranteed QoS for voice traffic and, at the same time, increase the voice capacity significantly compared with the current WLAN standard. In addition, a novel token-based scheduling scheme is proposed to provide great flexibility and facility to the network servi

  20. An Attribute Based Access Control Framework for Healthcare System

    Science.gov (United States)

    Afshar, Majid; Samet, Saeed; Hu, Ting

    2018-01-01

    Nowadays, access control is an indispensable part of the Personal Health Record and supplies for its confidentiality by enforcing policies and rules to ensure that only authorized users gain access to requested resources in the system. In other words, the access control means protecting patient privacy in healthcare systems. Attribute-Based Access Control (ABAC) is a new access control model that can be used instead of other traditional types of access control such as Discretionary Access Control, Mandatory Access Control, and Role-Based Access Control. During last five years ABAC has shown some applications in both recent academic fields and industry purposes. ABAC by using user’s attributes and resources, makes a decision according to an access request. In this paper, we propose an ABAC framework for healthcare system. We use the engine of ABAC for rendering and enforcing healthcare policies. Moreover, we handle emergency situations in this framework.

  1. A neural network-based design of an on-off adaptive control for Deep Brain Stimulation in movement disorders.

    Science.gov (United States)

    Shukla, Pitamber; Basu, Ishita; Graupe, Daniel; Tuninetti, Daniela; Slavin, Konstantin V

    2012-01-01

    The current Food and Drug Administration approved system for the treatment of tremor disorders through Deep Brain Stimulation (DBS) of the area of the brain that controls movement, operates open-loop. It does not automatically adapt to the instantaneous patient's needs or to the progression of the disease. This paper demonstrates an adaptive closed-loop controlled DBS that, after switching off stimulation, tracks few physiological signals to predict the reappearance of tremor before the patient experiences discomfort, at which point it instructs the DBS controller to switch on stimulation again. The core of the proposed approach is a Neural Network (NN) which effectively extracts tremor predictive information from non-invasively recorded surface-electromyogram(sEMG) and accelerometer signals measured at the symptomatic extremities. A simple feed-forward back-propagation NN architecture is shown to successfully predict tremor in 31 out of 33 trials in two Parkinson's Disease patients with an overall accuracy of 75.8% and sensitivity of 92.3%. This work therefore shows that closed-loop DBS control is feasible in the near future and that it can be achieved without modifications of the electrodes implanted in the brain, i.e., is backward compatible with approved DBS systems.

  2. Application of fuzzy logic-neural network based reinforcement learning to proximity and docking operations: Translational controller results

    Science.gov (United States)

    Jani, Yashvant

    1992-01-01

    The reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Maximum Mission (SMM) satellite simulation. In utilizing these fuzzy learning techniques, we also use the Approximate Reasoning based Intelligent Control (ARIC) architecture, and so we use two terms interchangeable to imply the same. This activity is carried out in the Software Technology Laboratory utilizing the Orbital Operations Simulator (OOS). This report is the deliverable D3 in our project activity and provides the test results of the fuzzy learning translational controller. This report is organized in six sections. Based on our experience and analysis with the attitude controller, we have modified the basic configuration of the reinforcement learning algorithm in ARIC as described in section 2. The shuttle translational controller and its implementation in fuzzy learning architecture is described in section 3. Two test cases that we have performed are described in section 4. Our results and conclusions are discussed in section 5, and section 6 provides future plans and summary for the project.

  3. Application of fuzzy logic-neural network based reinforcement learning to proximity and docking operations: Attitude control results

    Science.gov (United States)

    Jani, Yashvant

    1992-01-01

    As part of the RICIS activity, the reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Max satellite simulation. This activity is carried out in the software technology laboratory utilizing the Orbital Operations Simulator (OOS). This report is deliverable D2 Altitude Control Results and provides the status of the project after four months of activities and outlines the future plans. In section 2 we describe the Fuzzy-Learner system for the attitude control functions. In section 3, we provide the description of test cases and results in a chronological order. In section 4, we have summarized our results and conclusions. Our future plans and recommendations are provided in section 5.

  4. Practice network-based care management for patients with type 2 diabetes and multiple comorbidities (GEDIMAplus): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bozorgmehr, Kayvan; Szecsenyi, Joachim; Ose, Dominik; Besier, Werner; Mayer, Manfred; Krisam, Johannes; Jacke, Christian O; Salize, Hans-Joachim; Brandner, Ralf; Schmitt, Sandra; Kiel, Marion; Kamradt, Martina; Freund, Tobias

    2014-06-21

    Care management interventions in the German health-care system have been evaluated with promising results, but further research is necessary to explore their full potential in the context of multi-morbidity. Our aim in this trial is to assess the efficacy of a primary care practice network-based care management intervention in improving self-care behaviour among patients with type 2 diabetes mellitus and multiple co-occurring chronic conditions. The study is designed as a prospective, 18-month, multicentre, investigator-blinded, two-arm, open-label, individual-level, randomized parallel-group superiority trial. We will enrol 582 patients with type 2 diabetes mellitus and at least two severe chronic conditions and one informal caregiver per patient. Data will be collected at baseline (T0), at the primary endpoint after 9 months (T1) and at follow-up after 18 months (T2). The primary outcome will be the differences between the intervention and control groups in changes of diabetes-related self-care behaviours from baseline to T1 using a German version of the revised Summary of Diabetes Self-Care Activities (SDSCA-G). The secondary outcomes will be the differences between the intervention and control groups in: changes in scores on the SDSCA-G subscales, glycosylated haemoglobin A level, health-related quality of life, self-efficacy, differences in (severe) symptomatic hypoglycaemia, cost-effectiveness and financial family burden. The intervention will be delivered by trained health-care assistants as an add-on to usual care and will consist of three main elements: (1) three home visits, including structured assessment of medical and social needs; (2) 24 structured telephone monitoring contacts; and (3) self-monitoring of blood glucose levels after T1 in 3-month intervals. The control group will receive usual care. The confirmatory primary analysis will be performed following the intention-to-treat (ITT) principle. The efficacy of the intervention will be quantified

  5. Neural Network Based Active Disturbance Rejection Control of a Novel Electrohydraulic Servo System for Simultaneously Balancing and Positioning by Isoactuation Configuration

    Directory of Open Access Journals (Sweden)

    Qiang Gao

    2016-01-01

    Full Text Available To satisfy the lightweight requirements of large pipe weapons, a novel electrohydraulic servo (EHS system where the hydraulic cylinder possesses three cavities is developed and investigated in the present study. In the EHS system, the balancing cavity of the EHS is especially designed for active compensation for the unbalancing force of the system, whereas the two driving cavities are employed for positioning and disturbance rejection of the large pipe. Aiming at simultaneously balancing and positioning of the EHS system, a novel neural network based active disturbance rejection control (NNADRC strategy is developed. In the NNADRC, the radial basis function (RBF neural network is employed for online updating of parameters of the extended state observer (ESO. Thereby, the nonlinear behavior and external disturbance of the system can be accurately estimated and compensated in real time. The efficiency and superiority of the system are critically investigated by conducting numerical simulations, showing that much higher steady accuracy as well as system robustness is achieved when comparing with conventional ADRC control system. It indicates that the NNADRC is a very promising technique for achieving fast, stable, smooth, and accurate control of the novel EHS system.

  6. Attributes Enhanced Role-Based Access Control Model

    DEFF Research Database (Denmark)

    Mahmood Rajpoot, Qasim; Jensen, Christian D.; Krishnan, Ram

    2015-01-01

    Attribute-based access control (ABAC) and role-based access control (RBAC) are currently the two most popular access control models. Yet, they both have known limitations and offer features com- plimentary to each other. Due to this fact, integration of RBAC and ABAC has recently emerged as an im......Attribute-based access control (ABAC) and role-based access control (RBAC) are currently the two most popular access control models. Yet, they both have known limitations and offer features com- plimentary to each other. Due to this fact, integration of RBAC and ABAC has recently emerged...

  7. A service-oriented data access control model

    Science.gov (United States)

    Meng, Wei; Li, Fengmin; Pan, Juchen; Song, Song; Bian, Jiali

    2017-01-01

    The development of mobile computing, cloud computing and distributed computing meets the growing individual service needs. Facing with complex application system, it's an urgent problem to ensure real-time, dynamic, and fine-grained data access control. By analyzing common data access control models, on the basis of mandatory access control model, the paper proposes a service-oriented access control model. By regarding system services as subject and data of databases as object, the model defines access levels and access identification of subject and object, and ensures system services securely to access databases.

  8. Cardea: Dynamic Access Control in Distributed Systems

    Science.gov (United States)

    Lepro, Rebekah

    2004-01-01

    Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

  9. A recurrent neural-network-based sensor and actuator fault detection and isolation for nonlinear systems with application to the satellite's attitude control subsystem.

    Science.gov (United States)

    Talebi, H A; Khorasani, K; Tafazoli, S

    2009-01-01

    This paper presents a robust fault detection and isolation (FDI) scheme for a general class of nonlinear systems using a neural-network-based observer strategy. Both actuator and sensor faults are considered. The nonlinear system considered is subject to both state and sensor uncertainties and disturbances. Two recurrent neural networks are employed to identify general unknown actuator and sensor faults, respectively. The neural network weights are updated according to a modified backpropagation scheme. Unlike many previous methods developed in the literature, our proposed FDI scheme does not rely on availability of full state measurements. The stability of the overall FDI scheme in presence of unknown sensor and actuator faults as well as plant and sensor noise and uncertainties is shown by using the Lyapunov's direct method. The stability analysis developed requires no restrictive assumptions on the system and/or the FDI algorithm. Magnetorquer-type actuators and magnetometer-type sensors that are commonly employed in the attitude control subsystem (ACS) of low-Earth orbit (LEO) satellites for attitude determination and control are considered in our case studies. The effectiveness and capabilities of our proposed fault diagnosis strategy are demonstrated and validated through extensive simulation studies.

  10. Information-flow-based Access Control for Virtualized Systems

    Directory of Open Access Journals (Sweden)

    Dmitriy Aleksandrovich Postoev

    2014-12-01

    Full Text Available The article is devoted to the method of information-flow-based access control, adopted for virtualized systems. General structure of access control system for virtual infrastructure is proposed.

  11. Integrating Attributes into Role-Based Access Control

    DEFF Research Database (Denmark)

    Mahmood Rajpoot, Qasim; Jensen, Christian D.; Krishnan, Ram

    2015-01-01

    Role-based access control (RBAC) and attribute-based access control (ABAC) are currently the most prominent access control models. However, they both suffer from limitations and have features complimentary to each other. Due to this fact, integration of RBAC and ABAC has become a hot area...

  12. Break-glass handling exceptional situations in access control

    CERN Document Server

    Petritsch, Helmut

    2014-01-01

    Helmut Petritsch describes the first holistic approach to Break-Glass which covers the whole life-cycle: from access control modeling (pre-access), to logging the security-relevant system state during Break-Glass accesses (at-access), and the automated analysis of Break-Glass accesses (post-access). Break-Glass allows users to override security restrictions in exceptional situations. While several Break-Glass models specific to given access control models have already been discussed in research (e.g., extending RBAC with Break-Glass), the author introduces a generic Break-Glass model. The pres

  13. Towards Location-Based Access Control in Healthcare Emergency Response

    DEFF Research Database (Denmark)

    Vicente, Carmen Ruiz; Kirkpatrick, Michael; Ghinita, Gabriel

    2009-01-01

    Recent advances in positioning and tracking technologies have led to the emergence of novel location-based applications that allow participants to access information relevant to their spatio-temporal context. Traditional access control models, such as role-based access control (RBAC...... of complex access control decisions based on spatio-temporal relationships among subjects and objects. Furthermore, such relationships change frequently in dynamic environments, requiring efficient mechanisms to monitor and re-evaluate access control decisions. In this position paper, we present a healthcare...... emergency response scenario which highlights the novel challenges that arise when enforcing access control in an environment with moving subjects and objects. To address a realistic application scenario, we consider movement on road networks, and we identify complex access control decisions relevant...

  14. XACML to build access control policies for Internet of Things

    OpenAIRE

    Atlam, Hany F.; Alassafi, Madini, Obad; Alenezi, Ahmed; Walters, Robert; Wills, Gary

    2018-01-01

    Although the Internet of things (IoT) brought unlimited benefits, it also brought many security issues. The access control is one of the main elements to address these issues. It provides the access to system resources only to authorized users and ensures that they behave in an authorized manner during their access sessions. One of the significant components of any access control model is access policies. They are used to build the criteria to permit or deny any access request. Building an ef...

  15. 10 CFR 36.23 - Access control.

    Science.gov (United States)

    2010-01-01

    ... sources are not in the shielded position. Product conveyor systems may serve as barriers as long as they... entry while the sources are exposed. Detection of entry while the sources are exposed must cause the... have access to keys to the personnel access barrier. There must be an intrusion alarm to detect...

  16. Linear Time Algorithms to Restrict Insider Access using Multi-Policy Access Control Systems.

    Science.gov (United States)

    Mell, Peter; Shook, James; Harang, Richard; Gavrila, Serban

    2017-03-01

    An important way to limit malicious insiders from distributing sensitive information is to as tightly as possible limit their access to information. This has always been the goal of access control mechanisms, but individual approaches have been shown to be inadequate. Ensemble approaches of multiple methods instantiated simultaneously have been shown to more tightly restrict access, but approaches to do so have had limited scalability (resulting in exponential calculations in some cases). In this work, we take the Next Generation Access Control (NGAC) approach standardized by the American National Standards Institute (ANSI) and demonstrate its scalability. The existing publicly available reference implementations all use cubic algorithms and thus NGAC was widely viewed as not scalable. The primary NGAC reference implementation took, for example, several minutes to simply display the set of files accessible to a user on a moderately sized system. In our approach, we take these cubic algorithms and make them linear. We do this by reformulating the set theoretic approach of the NGAC standard into a graph theoretic approach and then apply standard graph algorithms. We thus can answer important access control decision questions (e.g., which files are available to a user and which users can access a file) using linear time graph algorithms. We also provide a default linear time mechanism to visualize and review user access rights for an ensemble of access control mechanisms. Our visualization appears to be a simple file directory hierarchy but in reality is an automatically generated structure abstracted from the underlying access control graph that works with any set of simultaneously instantiated access control policies. It also provide an implicit mechanism for symbolic linking that provides a powerful access capability. Our work thus provides the first efficient implementation of NGAC while enabling user privilege review through a novel visualization approach. This

  17. Open versus Controlled-Access Data | Office of Cancer Genomics

    Science.gov (United States)

    OCG employs stringent human subjects’ protection and data access policies to protect the privacy and confidentiality of the research participants. Depending on the risk of patient identification, OCG programs data are available to the scientific community in two tiers: open or controlled access. Both types of data can be accessed through its corresponding OCG program-specific data matrix or portal. Open-access Data

  18. A Network Access Control Framework for 6LoWPAN Networks

    Science.gov (United States)

    Oliveira, Luís M. L.; Rodrigues, Joel J. P. C.; de Sousa, Amaro F.; Lloret, Jaime

    2013-01-01

    Low power over wireless personal area networks (LoWPAN), in particular wireless sensor networks, represent an emerging technology with high potential to be employed in critical situations like security surveillance, battlefields, smart-grids, and in e-health applications. The support of security services in LoWPAN is considered a challenge. First, this type of networks is usually deployed in unattended environments, making them vulnerable to security attacks. Second, the constraints inherent to LoWPAN, such as scarce resources and limited battery capacity, impose a careful planning on how and where the security services should be deployed. Besides protecting the network from some well-known threats, it is important that security mechanisms be able to withstand attacks that have not been identified before. One way of reaching this goal is to control, at the network access level, which nodes can be attached to the network and to enforce their security compliance. This paper presents a network access security framework that can be used to control the nodes that have access to the network, based on administrative approval, and to enforce security compliance to the authorized nodes. PMID:23334610

  19. REACT: REcommending Access Control decisions To social media users

    OpenAIRE

    Misra, Gaurav; Such, Jose M.

    2017-01-01

    The problems that social media users have in appropriately controlling access to their content has been well documented in previous research. A promising method of providing assistance to users is by learning from the access control decisions made by them and making future recommendations. In this paper, we present REACT, a learning mechanism which utilizes information available in the social network in conjunction with information about the content to be shared to provide users with access c...

  20. 49 CFR 1542.207 - Access control systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures for...

  1. Analysis of Access Control Policies in Operating Systems

    Science.gov (United States)

    Chen, Hong

    2009-01-01

    Operating systems rely heavily on access control mechanisms to achieve security goals and defend against remote and local attacks. The complexities of modern access control mechanisms and the scale of policy configurations are often overwhelming to system administrators and software developers. Therefore, mis-configurations are common, and the…

  2. Dynamic User Role Assignment in Remote Access Control

    NARCIS (Netherlands)

    Saffarian, M.; Tang, Qiang; Jonker, Willem; Hartel, Pieter H.

    2009-01-01

    The Role-Based Access Control (RBAC) model has been widely applied to a single domain in which users are known to the administrative unit of that domain, beforehand. However, the application of the conventional RBAC model for remote access control scenarios is not straightforward. In such scenarios,

  3. Task Delegation Based Access Control Models for Workflow Systems

    Science.gov (United States)

    Gaaloul, Khaled; Charoy, François

    e-Government organisations are facilitated and conducted using workflow management systems. Role-based access control (RBAC) is recognised as an efficient access control model for large organisations. The application of RBAC in workflow systems cannot, however, grant permissions to users dynamically while business processes are being executed. We currently observe a move away from predefined strict workflow modelling towards approaches supporting flexibility on the organisational level. One specific approach is that of task delegation. Task delegation is a mechanism that supports organisational flexibility, and ensures delegation of authority in access control systems. In this paper, we propose a Task-oriented Access Control (TAC) model based on RBAC to address these requirements. We aim to reason about task from organisational perspectives and resources perspectives to analyse and specify authorisation constraints. Moreover, we present a fine grained access control protocol to support delegation based on the TAC model.

  4. MOFAC : model for fine grained access control

    OpenAIRE

    2014-01-01

    M.Sc. (Computer Science) Computer security is a key component in any computer system. Traditionally computers were not connected to one another. This centralized configuration made the implementation of computer security a relatively easy task. The closed nature of the system limited the number of unknown factors that could cause security breaches. The users and their access rights were generally well defined and the system was protected from outside threats through simple, yet effective c...

  5. Flexible logical-link-identifier assignment policy for Ethernet passive optical networks based on extended multipoint-control-protocol du flow control

    Science.gov (United States)

    Hajduczenia, Marek; da Silva, Henrique J.; Monteiro, Paulo P.

    2006-09-01

    We present a novel proposal for the extension of the currently approved multipoint control protocol (MPCP), as defined in the IEEE 802.3ah standard, clause 64, in the form of two new MPCP messages (extended GATE and extended REPORT), maintaining full backward compatibility with the already-deployed Ethernet passive optical network (EPON) systems and allowing for coexistence with legacy MPCP flow-control messages within the same network structure. Both currently existing logical-link identifier (LLID) assignment systems [namely, one LLID per optical network unit (ONU) and one LLID per queue] are examined in depth, and a missing scenario (one LLID per multiqueue) is discussed. Simulation results conducted using C++ based implementation of standard EPON networks with support for extended GATE-REPORT MPCP data units (DUs) prove that the design assumptions for both new flow-control messages were met to their fullest extent. The eGATE/eREPORT MPCP DUs allow for per-queue scheduling from the central packet controller in the optical line terminal (OLT) at the cost of ONU-based operation, thereby maintaining the benefits of two standard solutions. The obtained simulation results indicate superiority of the proposed IEEE 802.3ah, clause 64 extension in terms of network resource management, bandwidth efficiency, and system setup flexibility.

  6. A design of tamper resistant prescription RFID access control system.

    Science.gov (United States)

    Chen, Yu-Yi; Huang, Der-Chen; Tsai, Meng-Lin; Jan, Jinn-Ke

    2012-10-01

    In this paper, we propose a tamper resistant prescription RFID access control protocol for different authorized readers. Not only the authentication mechanism but also the access right authorization mechanism is designed in our scheme. Only the specific doctor, usually the patient's doctor, can access the tag. Moreover, some related information of patient's prescription is attached to a RFID tag for tamper resistance. The patients' rights will be guaranteed.

  7. Content sensitivity based access control framework for Hadoop

    Directory of Open Access Journals (Sweden)

    T.K. Ashwin Kumar

    2017-11-01

    Full Text Available Big data technologies have seen tremendous growth in recent years. They are widely used in both industry and academia. In spite of such exponential growth, these technologies lack adequate measures to protect data from misuse/abuse. Corporations that collect data from multiple sources are at risk of liabilities due to the exposure of sensitive information. In the current implementation of Hadoop, only file-level access control is feasible. Providing users with the ability to access data based on the attributes in a dataset or the user’s role is complicated because of the sheer volume and multiple formats (structured, unstructured and semi-structured of data. In this paper, we propose an access control framework, which enforces access control policies dynamically based on the sensitivity of the data. This framework enforces access control policies by harnessing the data context, usage patterns and information sensitivity. Information sensitivity changes over time with the addition and removal of datasets, which can lead to modifications in access control decisions. The proposed framework accommodates these changes. The proposed framework is automated to a large extent as the data itself determines the sensitivity with minimal user intervention. Our experimental results show that the proposed framework is capable of enforcing access control policies on non-multimedia datasets with minimal overhead.

  8. Access control management for e-Healthcare in cloud environment

    Directory of Open Access Journals (Sweden)

    Lili Sun

    2014-03-01

    Full Text Available Data outsourcing is a major component for cloud computing that allows data owners to distribute resources to external services for users and organizations who can apply the resources. A crucial problem for owners is how to make sure their sensitive information accessed by legitimate users only using the trusted services but not authorized to read the actual information. With the increased development of cloud computing, it brings challenges for data security and access control when outsourcing users’ data and sharing sensitive data in cloud environment since it is not within the same trusted domain as data owners’. Access control policies have become an important issue in the security filed in cloud computing. Semantic web technologies represent much richer forms of relationships among users, resources and actions among different web applications such as clouding computing. However, Semantic web applications pose new requirements for security mechanisms especially in the access control models. This paper addresses existing access control methods and presents a semantic based access control model which considers semantic relations among different entities in cloud computing environment. We have enriched the research for semantic web technology with role-based access control that is able to be applied in the field of medical information system or e-Healthcare system. This work shows how the semantic web technology provides efficient solutions for the management of complex and distributed data in heterogeneous systems, and it can be used in the medical information systems as well.

  9. Urban Studies: A Study of Bibliographic Access and Control.

    Science.gov (United States)

    Anderson, Barbara E.

    This paper analyzes: (1) the bibliographic access to publications in urban studies via printed secondary sources; (2) development and scope of classification systems and of vocabulary control for urban studies; and (3) currently accessible automated collections of bibliographic citations. Urban studies is defined as "an agglomeration of…

  10. Access Control of Web- and Java-Based Applications

    Science.gov (United States)

    Tso, Kam S.; Pajevski, Michael J.

    2013-01-01

    Cybersecurity has become a great concern as threats of service interruption, unauthorized access, stealing and altering of information, and spreading of viruses have become more prevalent and serious. Application layer access control of applications is a critical component in the overall security solution that also includes encryption, firewalls, virtual private networks, antivirus, and intrusion detection. An access control solution, based on an open-source access manager augmented with custom software components, was developed to provide protection to both Web-based and Javabased client and server applications. The DISA Security Service (DISA-SS) provides common access control capabilities for AMMOS software applications through a set of application programming interfaces (APIs) and network- accessible security services for authentication, single sign-on, authorization checking, and authorization policy management. The OpenAM access management technology designed for Web applications can be extended to meet the needs of Java thick clients and stand alone servers that are commonly used in the JPL AMMOS environment. The DISA-SS reusable components have greatly reduced the effort for each AMMOS subsystem to develop its own access control strategy. The novelty of this work is that it leverages an open-source access management product that was designed for Webbased applications to provide access control for Java thick clients and Java standalone servers. Thick clients and standalone servers are still commonly used in businesses and government, especially for applications that require rich graphical user interfaces and high-performance visualization that cannot be met by thin clients running on Web browsers

  11. Distributed Access Control for Web and Business Processes

    OpenAIRE

    Koshutanski, Hristo

    2003-01-01

    Middleware influenced the research community in developing a number of systems for controlling access to distributed resources. Nowadays a new paradigm for the lightweight integration of business resources from different partners is starting to take hold – Web Services and Business Processes for Web Services. Security and access control policies for Web Services protocols and distributed systems are well studied and almost standardized, but there is not yet a comprehensive proposal for an acc...

  12. A mobile console for local access to accelerator control systems.

    CERN Multimedia

    1981-01-01

    Microprocessors were installed as auxiliary crate controllers (ACCs) in the CAMAC interface of control systems for various accelerators. The same ACC was also at the hearth of a stand-alone system in the form of a mobile console. This was also used for local access to the control systems for tests and development work (Annual Report 1981, p. 80, Fig. 10).

  13. Role Based Access Control system in the ATLAS experiment

    CERN Document Server

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F; Avolio, G

    2011-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  14. Role Based Access Control System in the ATLAS Experiment

    CERN Document Server

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Avolio, G; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F

    2010-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  15. A Survey of Access Control Models in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Htoo Aung Maw

    2014-06-01

    Full Text Available Wireless sensor networks (WSNs have attracted considerable interest in the research community, because of their wide range of applications. However, due to the distributed nature of WSNs and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. Resource constraints in sensor nodes mean that security mechanisms with a large overhead of computation and communication are impractical to use in WSNs; security in sensor networks is, therefore, a challenge. Access control is a critical security service that offers the appropriate access privileges to legitimate users and prevents illegitimate users from unauthorized access. However, access control has not received much attention in the context of WSNs. This paper provides an overview of security threats and attacks, outlines the security requirements and presents a state-of-the-art survey on access control models, including a comparison and evaluation based on their characteristics in WSNs. Potential challenging issues for access control schemes in WSNs are also discussed.

  16. 75 FR 47464 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Science.gov (United States)

    2010-08-06

    ... circumvention of copyright protection systems for access control technologies which was published July 27, 2010... for Access Control Technologies AGENCY: Copyright Office, Library of Congress. ACTION: Final Rule... prohibition against circumvention of technological measures that effectively control access to copyrighted...

  17. Task-role-based Access Control Model in Smart Health-care System

    OpenAIRE

    Wang Peng; Jiang Lingyun

    2015-01-01

    As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for...

  18. Information-Flow-Based Access Control for Web Browsers

    Science.gov (United States)

    Yoshihama, Sachiko; Tateishi, Takaaki; Tabuchi, Naoshi; Matsumoto, Tsutomu

    The emergence of Web 2.0 technologies such as Ajax and Mashup has revealed the weakness of the same-origin policy[1], the current de facto standard for the Web browser security model. We propose a new browser security model to allow fine-grained access control in the client-side Web applications for secure mashup and user-generated contents. We propose a browser security model that is based on information-flow-based access control (IBAC) to overcome the dynamic nature of the client-side Web applications and to accurately determine the privilege of scripts in the event-driven programming model.

  19. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2015-06-16

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

  20. A Comparative Analysis of Wiki Discretionary Access Control in a CONOPS Environment

    National Research Council Canada - National Science Library

    Crawford, Frederick L

    2008-01-01

    This research conducts a comparative analysis of discretionary access controls of current wikis by experimenting with their discretionary access controls and functionality, comparing the wiki software...

  1. Regulatory Accessibility and Social Influences on State Self-Control

    OpenAIRE

    vanDellen, Michelle R.; Hoyle, Rick H.

    2009-01-01

    The current work examined how social factors influence self-control. Current conceptions of state self-control treat it largely as a function of regulatory capacity. The authors propose that state self-control might also be influenced by social factors because of regulatory accessibility. Studies 1 through 4 provide evidence that individuals’ state self-control is influenced by the trait and state self-control of salient others such that thinking of others with good trait or state self-contro...

  2. Database design for Physical Access Control System for nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sathishkumar, T., E-mail: satishkumart@igcar.gov.in; Rao, G. Prabhakara, E-mail: prg@igcar.gov.in; Arumugam, P., E-mail: aarmu@igcar.gov.in

    2016-08-15

    Highlights: • Database design needs to be optimized and highly efficient for real time operation. • It requires a many-to-many mapping between Employee table and Doors table. • This mapping typically contain thousands of records and redundant data. • Proposed novel database design reduces the redundancy and provides abstraction. • This design is incorporated with the access control system developed in-house. - Abstract: A (Radio Frequency IDentification) RFID cum Biometric based two level Access Control System (ACS) was designed and developed for providing access to vital areas of nuclear facilities. The system has got both hardware [Access controller] and software components [server application, the database and the web client software]. The database design proposed, enables grouping of the employees based on the hierarchy of the organization and the grouping of the doors based on Access Zones (AZ). This design also illustrates the mapping between the Employee Groups (EG) and AZ. By following this approach in database design, a higher level view can be presented to the system administrator abstracting the inner details of the individual entities and doors. This paper describes the novel approach carried out in designing the database of the ACS.

  3. Access Control of Web and Java Based Applications

    Science.gov (United States)

    Tso, Kam S.; Pajevski, Michael J.; Johnson, Bryan

    2011-01-01

    Cyber security has gained national and international attention as a result of near continuous headlines from financial institutions, retail stores, government offices and universities reporting compromised systems and stolen data. Concerns continue to rise as threats of service interruption, and spreading of viruses become ever more prevalent and serious. Controlling access to application layer resources is a critical component in a layered security solution that includes encryption, firewalls, virtual private networks, antivirus, and intrusion detection. In this paper we discuss the development of an application-level access control solution, based on an open-source access manager augmented with custom software components, to provide protection to both Web-based and Java-based client and server applications.

  4. Automated Model-Based Testing of Role-Based Access Control Using Predicate/Transition Nets

    OpenAIRE

    Xu, Dianxiang; Kent, Michael; Thomas, Lijo; Mouelhi, Tejeddine; Le Traon, Yves

    2015-01-01

    Role-based access control is an important access control method for securing computer systems. A role-based access control policy can be implemented incorrectly due to various reasons, such as programming errors. Defects in the implementation may lead to unauthorized access and security breaches. To reveal access control defects, this paper presents a model-based approach to automated generation of executable access control tests using predicate/transition nets. Role-permission test models ar...

  5. Audit-Based Access Control for Electronic Health Records

    NARCIS (Netherlands)

    Dekker, M.A.C.; Etalle, Sandro; Gadducci, F.

    Traditional access control mechanisms aim to prevent illegal actions a-priori occurrence, i.e.before granting a request for a document. There are scenarios however where the security decision can not be made on the fly. For these settings we developed a language and a framework for a-posteriori

  6. Audit-Based Access Control for Electronic Health Records

    NARCIS (Netherlands)

    Dekker, M.A.C.; Etalle, Sandro

    2006-01-01

    Traditional access control mechanisms aim to prevent illegal actions a-priori occurrence, i.e. before granting a request for a document. There are scenarios however where the security decision can not be made on the fly. For these settings we developed a language and a framework for a-posteriori

  7. An intelligent trust-based access control model for affective ...

    African Journals Online (AJOL)

    In this study, a fuzzy expert system Trust-Based Access Control (TBAC) model for improving the Quality of crowdsourcing using emotional affective computing is presented. This model takes into consideration a pre-processing module consisting of three inputs such as crowd-workers category, trust metric and emotional ...

  8. Assessment of Digital Access Control Methods Used by Selected ...

    African Journals Online (AJOL)

    Assessment of Digital Access Control Methods Used by Selected Academic Libraries in South-West Nigeria. ... information professionals with the knowledge that would enable them establish an effective strategy to protect e-resources from such abuses as plagiarism, piracy and infringement of intellectual property rights.

  9. Adaptive Media Access Control for Energy Harvesting - Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Dragoni, Nicola

    2012-01-01

    ODMAC (On-Demand Media Access Control) is a recently proposed MAC protocol designed to support individual duty cycles for Energy Harvesting — Wireless Sensor Networks (EH-WSNs). Individual duty cycles are vital for EH-WSNs, because they allow nodes to adapt their energy consumption to the ever...

  10. Fine-Grained Access Control for Electronic Health Record Systems

    Science.gov (United States)

    Hue, Pham Thi Bach; Wohlgemuth, Sven; Echizen, Isao; Thuy, Dong Thi Bich; Thuc, Nguyen Dinh

    There needs to be a strategy for securing the privacy of patients when exchanging health records between various entities over the Internet. Despite the fact that health care providers such as Google Health and Microsoft Corp.'s Health Vault comply with the U.S Health Insurance Portability and Accountability Act (HIPAA), the privacy of patients is still at risk. Several encryption schemes and access control mechanisms have been suggested to protect the disclosure of a patient's health record especially from unauthorized entities. However, by implementing these approaches, data owners are not capable of controlling and protecting the disclosure of the individual sensitive attributes of their health records. This raises the need to adopt a secure mechanism to protect personal information against unauthorized disclosure. Therefore, we propose a new Fine-grained Access Control (FGAC) mechanism that is based on subkeys, which would allow a data owner to further control the access to his data at the column-level. We also propose a new mechanism to efficiently reduce the number of keys maintained by a data owner in cases when the users have different access privileges to different columns of the data being shared.

  11. Ubiquitous access control and policy management in personal networks

    DEFF Research Database (Denmark)

    Kyriazanos, Dimitris M.; Stassinopoulos, George I.; Prasad, Neeli R.

    2006-01-01

    In this paper the authors present the challenges for enabling Security Policies Management and subsequent Ubiquitous Access Control on the Personal Network (PN) environment. A solution based on Security Profiles is proposed, supporting both partially distributed architectures-having in this case...

  12. SAFE: SPARQL Federation over RDF Data Cubes with Access Control.

    Science.gov (United States)

    Khan, Yasar; Saleem, Muhammad; Mehdi, Muntazir; Hogan, Aidan; Mehmood, Qaiser; Rebholz-Schuhmann, Dietrich; Sahay, Ratnesh

    2017-02-01

    Several query federation engines have been proposed for accessing public Linked Open Data sources. However, in many domains, resources are sensitive and access to these resources is tightly controlled by stakeholders; consequently, privacy is a major concern when federating queries over such datasets. In the Healthcare and Life Sciences (HCLS) domain real-world datasets contain sensitive statistical information: strict ownership is granted to individuals working in hospitals, research labs, clinical trial organisers, etc. Therefore, the legal and ethical concerns on (i) preserving the anonymity of patients (or clinical subjects); and (ii) respecting data ownership through access control; are key challenges faced by the data analytics community working within the HCLS domain. Likewise statistical data play a key role in the domain, where the RDF Data Cube Vocabulary has been proposed as a standard format to enable the exchange of such data. However, to the best of our knowledge, no existing approach has looked to optimise federated queries over such statistical data. We present SAFE: a query federation engine that enables policy-aware access to sensitive statistical datasets represented as RDF data cubes. SAFE is designed specifically to query statistical RDF data cubes in a distributed setting, where access control is coupled with source selection, user profiles and their access rights. SAFE proposes a join-aware source selection method that avoids wasteful requests to irrelevant and unauthorised data sources. In order to preserve anonymity and enforce stricter access control, SAFE's indexing system does not hold any data instances-it stores only predicates and endpoints. The resulting data summary has a significantly lower index generation time and size compared to existing engines, which allows for faster updates when sources change. We validate the performance of the system with experiments over real-world datasets provided by three clinical organisations as

  13. Secure Dynamic access control scheme of PHR in cloud computing.

    Science.gov (United States)

    Chen, Tzer-Shyong; Liu, Chia-Hui; Chen, Tzer-Long; Chen, Chin-Sheng; Bau, Jian-Guo; Lin, Tzu-Ching

    2012-12-01

    With the development of information technology and medical technology, medical information has been developed from traditional paper records into electronic medical records, which have now been widely applied. The new-style medical information exchange system "personal health records (PHR)" is gradually developed. PHR is a kind of health records maintained and recorded by individuals. An ideal personal health record could integrate personal medical information from different sources and provide complete and correct personal health and medical summary through the Internet or portable media under the requirements of security and privacy. A lot of personal health records are being utilized. The patient-centered PHR information exchange system allows the public autonomously maintain and manage personal health records. Such management is convenient for storing, accessing, and sharing personal medical records. With the emergence of Cloud computing, PHR service has been transferred to storing data into Cloud servers that the resources could be flexibly utilized and the operation cost can be reduced. Nevertheless, patients would face privacy problem when storing PHR data into Cloud. Besides, it requires a secure protection scheme to encrypt the medical records of each patient for storing PHR into Cloud server. In the encryption process, it would be a challenge to achieve accurately accessing to medical records and corresponding to flexibility and efficiency. A new PHR access control scheme under Cloud computing environments is proposed in this study. With Lagrange interpolation polynomial to establish a secure and effective PHR information access scheme, it allows to accurately access to PHR with security and is suitable for enormous multi-users. Moreover, this scheme also dynamically supports multi-users in Cloud computing environments with personal privacy and offers legal authorities to access to PHR. From security and effectiveness analyses, the proposed PHR access

  14. Development of RFID EPC Gen2 Tag for Multi Access Control System

    National Research Council Canada - National Science Library

    Evizal Evizal; Tharek Abd Rahman; Sharul Kamal Abdul Rahim; Sri Listia Rosa

    2013-01-01

    .... This paper explore and develop the use of RFID EPC Class1 Gen2 tag for multipurpose access system for identification and access control, such as personal identity identification, door access control...

  15. Controlling user access to electronic resources without password

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Fred Hewitt

    2017-08-22

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

  16. Access control and privacy in large distributed systems

    Science.gov (United States)

    Leiner, B. M.; Bishop, M.

    1986-01-01

    Large scale distributed systems consists of workstations, mainframe computers, supercomputers and other types of servers, all connected by a computer network. These systems are being used in a variety of applications including the support of collaborative scientific research. In such an environment, issues of access control and privacy arise. Access control is required for several reasons, including the protection of sensitive resources and cost control. Privacy is also required for similar reasons, including the protection of a researcher's proprietary results. A possible architecture for integrating available computer and communications security technologies into a system that meet these requirements is described. This architecture is meant as a starting point for discussion, rather that the final answer.

  17. A network-based dynamical ranking system

    CERN Document Server

    Motegi, Shun

    2012-01-01

    Ranking players or teams in sports is of practical interests. From the viewpoint of networks, a ranking system is equivalent a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score (i.e., strength) of a player, for example, depends on time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. Our ranking system, also interpreted as a centrality measure for directed temporal networks, has two parameters. One parameter represents the exponential decay rate of the past score, and the other parameter controls the effect of indirect wins on the score. We derive a set of linear online update equ...

  18. Information access for event-driven smart grid controllers

    DEFF Research Database (Denmark)

    Kristensen, Thomas Le Fevre; Olsen, Rasmus Løvenstein; Rasmussen, Jakob Gulddahl

    2018-01-01

    have been crossed at any measurement point in the grid. We assess the information access methods on information reliability and how this affects control performance. We focus on two different information quality metrics; (1) information age and (2) mismatch probability, which are expressed via...... stochastic models. We investigate in this paper the suitability for using these two metrics for optimization in a voltage grid control scenario. We conclude that, while the mismatch probability is very useful compared to the simpler information age metric from a network designers and operators point of view...... in setting quality of service requirements, it is not as helpful for control engineers....

  19. Improving the Authentication Scheme and Access Control Protocol for VANETs

    Directory of Open Access Journals (Sweden)

    Wei-Chen Wu

    2014-11-01

    Full Text Available Privacy and security are very important in vehicular ad hoc networks (VANETs. VANETs are negatively affected by any malicious user’s behaviors, such as bogus information and replay attacks on the disseminated messages. Among various security threats, privacy preservation is one of the new challenges of protecting users’ private information. Existing authentication protocols to secure VANETs raise challenges, such as certificate distribution and reduction of the strong reliance on tamper-proof devices. In 2011, Yeh et al. proposed a PAACP: a portable privacy-preserving authentication and access control protocol in vehicular ad hoc networks. However, PAACP in the authorization phase is breakable and cannot maintain privacy in VANETs. In this paper, we present a cryptanalysis of an attachable blind signature and demonstrate that the PAACP’s authorized credential (AC is not secure and private, even if the AC is secretly stored in a tamper-proof device. An eavesdropper can construct an AC from an intercepted blind document. Any eavesdropper can determine who has which access privileges to access which service. For this reason, this paper copes with these challenges and proposes an efficient scheme. We conclude that an improving authentication scheme and access control protocol for VANETs not only resolves the problems that have appeared, but also is more secure and efficient.

  20. Development and evaluation of on/off control for electrolaryngeal speech via artificial neural network based on visual information of lips.

    Science.gov (United States)

    Wu, Liang; Wan, Congying; Wang, Supin; Wan, Mingxi

    2013-03-01

    To realize an accurate and automatic on/off control of electrolarynx (EL), an artificial neural network (ANN) was introduced for switch identification based on visual information of lips and implemented by an experimental system (ANN-EL). The objective was to confirm the feasibility of the ANN method and evaluate the performance of ANN-EL in Mandarin speech. Totally five volunteers (one laryngectomee and four normal speakers) participated in the whole process of experiments. First, trained ANN was tested to assess switch identification performance of ANN method. Then, voice initiation/termination time, speech fluency, and word intelligibility were measured and compared with button-EL and video-EL to evaluate on/off control performance of ANN-EL. The test showed that ANN method performed accurate switch identification (>99%). ANN-EL was as fast as normal voice and button-EL in onset control, but a little slower in offset control. ANN-EL could provide a fluent voice source with rare breaks (speech. The results also indicated that on/off control performance of ANN-EL had a significant impact on perception, lowering the word intelligibility compared with button-EL. However, the words produced by ANN-EL were more intelligible than video-EL by approximately 20%. The ANN method was proved feasible and effective for switch identification based on visual information of lips. The ANN-EL could provide an accurate on/off control for fluent Mandarin speech. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  1. Access Control with RFID in the Internet of Things

    DEFF Research Database (Denmark)

    Jensen, Steffen Elstrøm Holst; Jacobsen, Rune Hylsberg

    2013-01-01

    , to the Internet is suggested. The solution uses virtual representations of objects by using low-cost, passive RFID tags to give objects identities on the Internet. A prototype that maps an RFID identity into an IPv6 address is constructed. It is illustrated how this approach can be used in access control systems......Future Internet research is needed to bring the Internet and the Things closer to each other to form the Internet of Things. As objects in our daily life gradually become smarter, there is an increasing benefit of networking these objects. In this article, a method to couple objects, the Things...... based on open network protocols and packet filtering. The solution includes a novel RFID reader architecture that supports the internetworking of components of a future access control system based on network layer technology....

  2. Tag Content Access Control with Identity-based Key Exchange

    Science.gov (United States)

    Yan, Liang; Rong, Chunming

    2010-09-01

    Radio Frequency Identification (RFID) technology that used to identify objects and users has been applied to many applications such retail and supply chain recently. How to prevent tag content from unauthorized readout is a core problem of RFID privacy issues. Hash-lock access control protocol can make tag to release its content only to reader who knows the secret key shared between them. However, in order to get this shared secret key required by this protocol, reader needs to communicate with a back end database. In this paper, we propose to use identity-based secret key exchange approach to generate the secret key required for hash-lock access control protocol. With this approach, not only back end database connection is not needed anymore, but also tag cloning problem can be eliminated at the same time.

  3. Safety of Mixed Model Access Control in a Multilevel System

    Science.gov (United States)

    2014-06-01

    are those of the author and do not reflect the official policy or position of the Department of Defense or the U.S. Government . I.R.B. Protocol...136  3.  Using RuleML for a CDS Data Sanitization Policy ......................137  4.  Formal Patterns for Access Control Model Composition...Figure 4.  Lattice Demonstrating Non-Linear Ordering, from [3] ...................................27  Figure 5.  Basic SOA Components and Design

  4. An Access Control Model for the Uniframe Framework

    Science.gov (United States)

    2005-05-01

    is called active software capabilities framework ( ASCap ) that centers around the idea of a policy object, which instead of being embedded into the...access control component, is delivered by the client. The client firsts requests an ASCap (policy object) from the security server. Then the client...and the object server both must instantiate proxies. The client ASCap proxy may then request additional credentials from other servers which may

  5. Integrating CERN e-groups into TWiki access control.

    CERN Document Server

    Jones, PL; Hoymr, N; CERN. Geneva. IT Department

    2010-01-01

    Wikis allow for easy collaborative editing of documents on the web for users located in different buildings, cities or even countries. TWiki culture lends to open free form editing and most pages are world readable and editable by CERN authenticated users, however access control is possible and is used to protect sensitive documents. This note discusses the integration of E-groups for authorisation purposes at CERN.

  6. A distributed access control system for cloud federations

    OpenAIRE

    Alansari, Shorouq; Paci, Federica; Sassone, Vladimiro

    2017-01-01

    Cloud federations are a new collaboration paradigm where organizations share data across their private cloud infrastructures. However, the adoption of cloud federations is hindered by federated organizations’ concerns on potential risks of data leakage and data misuse. For cloud federations to be viable, federated organizations’ privacy concerns should be alleviated by providing mechanisms that allow organizations to control which users from other federated organizations can access which data...

  7. Material control and surveillance for high frequency access vaults project

    Energy Technology Data Exchange (ETDEWEB)

    Longmire, V. L. (Victoria L.); Stevens, R. S. (Rebecca S.); Martinez, B. J. (Benny J.); Butler, G. W. (Gilbert W.); Huang, J. Y. (John Y.); Pickett, C. (Chris); Younkin, J. (James); Dunnigan, Janelle; Gaby, Jane; Lawson, R. (Roger)

    2004-01-01

    The 'Material Control and Surveillance for High Frequency Access Vaults' project sponsored by United States Department of Energy's Office of Security Policy, Policy Integration and Technical Support Program (SO-20.3) focuses on enhancing nuclear materials control and surveillance in vaults that are frequently accessed. The focus of this effort is to improve materials control and accountability (MC&A) while decreasing the operational impact of these activities. Los Alamos and Y-12 have developed a testbed at the Los Alamos National Laboratory for evaluating and demonstrating integrated technologies for use in enhancing materials control and accountability in active nuclear material storage vaults. An update will be provided on the new systems demonstrated in the test-bed including a 'confirmatory cart' for expediting the performance of inventory and radio-frequency actuated video that demonstrates the concept of automated data entry for materials moving between MBA's. The United States Department of Energy's Office of Security Policy, Policy Integration and Technical Support Program (SO-20.3) has sponsored a project where nuclear material inventory, control and surveillance systems are evaluated, developed, and demonstrated in an effort to provide technologies that reduce risk, increase material assurance, and provide cost-efficient alternatives to manpower-intensive physical inventory and surveillance approaches for working (high-frequency-access) vaults. This Fiscal Year has been largely focused on evaluating and developing components of two sub-systems that could be used either separately in nuclear material vaults or as part of a larger integrated system for nuclear materials accountability, control and surveillance.

  8. A Fine-Grained Data Access Control System in Wireless Sensor Network

    National Research Council Canada - National Science Library

    Boniface K. Alese; Sylvester O. Olatunji; Oluwatoyin C. Agbonifo; Aderonke F. Thompson

    2015-01-01

    .... Consequently, data insecurity becomes a big concern. This study, therefore, proposes a fine-grained access control system which only requires the right set of users to access a particular data, based on their access privileges in the sensor networks...

  9. Multihop Medium Access Control for WSNs: An Energy Analysis Model

    Directory of Open Access Journals (Sweden)

    Haapola Jussi

    2005-01-01

    Full Text Available We present an energy analysis technique applicable to medium access control (MAC and multihop communications. Furthermore, the technique's application gives insight on using multihop forwarding instead of single-hop communications. Using the technique, we perform an energy analysis of carrier-sense-multiple-access (CSMA- based MAC protocols with sleeping schemes. Power constraints set by battery operation raise energy efficiency as the prime factor for wireless sensor networks. A detailed energy expenditure analysis of the physical, the link, and the network layers together can provide a basis for developing new energy-efficient wireless sensor networks. The presented technique provides a set of analytical tools for accomplishing this. With those tools, the energy impact of radio, MAC, and topology parameters on the network can be investigated. From the analysis, we extract key parameters of selected MAC protocols and show that some traditional mechanisms, such as binary exponential backoff, have inherent problems.

  10. Access Control Model for Sharing Composite Electronic Health Records

    Science.gov (United States)

    Jin, Jing; Ahn, Gail-Joon; Covington, Michael J.; Zhang, Xinwen

    The adoption of electronically formatted medical records, so called Electronic Health Records (EHRs), has become extremely important in healthcare systems to enable the exchange of medical information among stakeholders. An EHR generally consists of data with different types and sensitivity degrees which must be selectively shared based on the need-to-know principle. Security mechanisms are required to guarantee that only authorized users have access to specific portions of such critical record for legitimate purposes. In this paper, we propose a novel approach for modelling access control scheme for composite EHRs. Our model formulates the semantics and structural composition of an EHR document, from which we introduce a notion of authorized zones of the composite EHR at different granularity levels, taking into consideration of several important criteria such as data types, intended purposes and information sensitivities.

  11. An Artificial Neural Network Based Analysis of Factors Controlling Particle Size in a Virgin Coconut Oil-Based Nanoemulsion System Containing Copper Peptide.

    Directory of Open Access Journals (Sweden)

    Shazwani Samson

    Full Text Available A predictive model of a virgin coconut oil (VCO nanoemulsion system for the topical delivery of copper peptide (an anti-aging compound was developed using an artificial neural network (ANN to investigate the factors that influence particle size. Four independent variables including the amount of VCO, Tween 80: Pluronic F68 (T80:PF68, xanthan gum and water were the inputs whereas particle size was taken as the response for the trained network. Genetic algorithms (GA were used to model the data which were divided into training sets, testing sets and validation sets. The model obtained indicated the high quality performance of the neural network and its capability to identify the critical composition factors for the VCO nanoemulsion. The main factor controlling the particle size was found out to be xanthan gum (28.56% followed by T80:PF68 (26.9%, VCO (22.8% and water (21.74%. The formulation containing copper peptide was then successfully prepared using optimum conditions and particle sizes of 120.7 nm were obtained. The final formulation exhibited a zeta potential lower than -25 mV and showed good physical stability towards centrifugation test, freeze-thaw cycle test and storage at temperature 25°C and 45°C.

  12. Admission Control and Interference Management in Dynamic Spectrum Access Networks

    Directory of Open Access Journals (Sweden)

    Jorge Martinez-Bauset

    2010-01-01

    Full Text Available We study two important aspects to make dynamic spectrum access work in practice: the admission policy of secondary users (SUs to achieve a certain degree of quality of service and the management of the interference caused by SUs to primary users (PUs. In order to limit the forced termination probability of SUs, we evaluate the Fractional Guard Channel reservation scheme to give priority to spectrum handovers over new arrivals. We show that, contrary to what has been proposed, the throughput of SUs cannot be maximized by configuring the reservation parameter. We also study the interference caused by SUs to PUs. We propose and evaluate different mechanisms to reduce the interference, which are based on simple spectrum access algorithms for both PUs and SUs and channel repacking algorithms for SUs. Numerical results show that the reduction can be of one order of magnitude or more with respect to the random access case. Finally, we propose an adaptive admission control scheme that is able to limit simultaneously the forced termination probability of SUs and what we define as the probability of interference. Our scheme does not require any configuration parameters beyond the probability objectives. Besides, it is simple to implement and it can operate with any arrival process and distribution of the session duration.

  13. Design of a control-channel-based media-access-control protocol for HORNET

    Science.gov (United States)

    White, Ian M.; Rogge, Matthew S.; Shrikhande, Kapil; Kazovsky, Leonid G.

    2002-12-01

    The HORNET (hybrid optoelectronic ring network) architecture is a packet-over-WDM ring network that utilizes fast-tunable packet transmitters and wavelength routing to enable it to scale cost-effectively to ultrahigh capacities. Here we present the design of a novel control-channel-based media-access-control (MAC) protocol, which is optimized for variable-sized IP packets and addresses inherent fairness control issues in multiple-access ring networks. The design of the control channel, including the frame structure and a frame-synchronization protocol, is described in detail.

  14. METHOD AND ABSTRACT MODEL FOR CONTROL AND ACCESS RIGHTS BY REQUESTS REDIRECTION

    OpenAIRE

    K. A. Shcheglov; A. Y. Shcheglov

    2015-01-01

    We have researched implementation problems of control and access rights of subjects to objects in modern computer systems. We have suggested access control method based on objects access requests redirection. The method possesses a distinctive feature as compared to discretional access control. In case when a subject needs to deny writing (object modification), it is not denied but redirected (access rights are not changed, but operation is performed with another object). This gives the possi...

  15. Hierarchical Slotted Wireless Random Channel Access with Power Control

    Directory of Open Access Journals (Sweden)

    Abdelillah Karouit

    2015-01-01

    Full Text Available This paper introduces a hierarchical Wireless Random Access scheme based on power control where intelligence is split among the mobile users in order to drive the outcome of the system towards an efficient point. The hierarchical game is obtained by introducing a special user who plays the role of altruistic leader whereas the other users assume the role of followers. We define the power control scheme in such a way that the leader_first chooses the lowest power to transmit its packets among N available levels whereas the followers re-transmit by randomly choosing a power level picked from N-1 higher distinct power levels. Using a 3D Markovian model, we compute the steady state of the system and derive the average system throughput and expected packet transmission delay. Our numerical results show that the proposed scheme considerably improves the global performance of the system avoiding the well known throughput collapse at high loads commonly characterizing most random channel access mechanisms.

  16. Wireless Sensor Network Based Smart Parking System

    Directory of Open Access Journals (Sweden)

    Jeffrey JOSEPH

    2014-01-01

    Full Text Available Ambient Intelligence is a vision in which various devices come together and process information from multiple sources in order to exert control on the physical environment. In addition to computation and control, communication plays a crucial role in the overall functionality of such a system. Wireless Sensor Networks are one such class of networks, which meet these criteria. These networks consist of spatially distributed sensor motes which work in a co-operative manner to sense and control the environment. In this work, an implementation of an energy-efficient and cost-effective, wireless sensor networks based vehicle parking system for a multi-floor indoor parking facility has been introduced. The system monitors the availability of free parking slots and guides the vehicle to the nearest free slot. The amount of time the vehicle has been parked is monitored for billing purposes. The status of the motes (dead/alive is also recorded. Information like slot allocated, directions to the slot and billing data is sent as a message to customer’s mobile phones. This paper extends our previous work 1 with the development of a low cost sensor mote, about one tenth the cost of a commercially available mote, keeping in mind the price sensitive markets of the developing countries.

  17. A Knowledge-Constrained Access Control Model for Protecting Patient Privacy in Hospital Information Systems.

    Science.gov (United States)

    Zhang, Runtong; Chen, Donghua; Shang, Xiaopu; Zhu, Xiaomin; Liu, Kecheng

    2017-04-24

    Current access control mechanisms of the hospital information system can hardly identify the real access intention of system users. A relaxed access control increases the risk of compromise of patient privacy. To reduce unnecessary access of patient information by hospital staff, this paper proposes a Knowledge-Constrained Role-Based Access Control (KC-RBAC) model in which a variety of medical domain knowledge is considered in access control. Based on the proposed Purpose Tree and knowledge-involved algorithms, the model can dynamically define the boundary of access to the patient information according to the context, which helps protect patient privacy by controlling access. Compared with the Role-Based Access Control model, KC-RBAC can effectively protect patient information according to the results of the experiments.

  18. Modelling and Analysing Access Control Policies in XACML 3.0

    DEFF Research Database (Denmark)

    Ramli, Carroline Dewi Puspa Kencana

    XACML (eXtensible Access Control Markup Language) is a prominent access control language that is widely adopted both in industry and academia. XACML is an international standard in the field of information security. The problem with XACML is that its specification is described in natural language...... applications in analysing access control properties and a case study. We present access control security policies in a Smart Grid from Smart Meter perspective....

  19. Access control violation prevention by low-cost infrared detection

    Science.gov (United States)

    Rimmer, Andrew N.

    2004-09-01

    A low cost 16x16 un-cooled pyroelectric detector array, allied with advanced tracking and detection algorithms, has enabled the development of a universal detector with a wide range of applications in people monitoring and homeland security. Violation of access control systems, whether controlled by proximity card, biometrics, swipe card or similar, may occur by 'tailgating' or 'piggybacking' where an 'approved' entrant with a valid entry card is accompanied by a closely spaced 'non-approved' entrant. The violation may be under duress, where the accompanying person is attempting to enter a secure facility by force or threat. Alternatively, the violation may be benign where staff members collude either through habit or lassitude, either with each other or with third parties, without considering the security consequences. Examples of the latter could include schools, hospitals or maternity homes. The 16x16 pyroelectric array is integrated into a detector or imaging system which incorporates data processing, target extraction and decision making algorithms. The algorithms apply interpolation to the array output, allowing a higher level of resolution than might otherwise be expected from such a low resolution array. The pyroelectric detection principle means that the detection will work in variable light conditions and even in complete darkness, if required. The algorithms can monitor the shape, form, temperature and number of persons in the scene and utilise this information to determine whether a violation has occurred or not. As people are seen as 'hot blobs' and are not individually recognisable, civil liberties are not infringed in the detection process. The output from the detector is a simple alarm signal which may act as input to the access control system as an alert or to trigger CCTV image display and storage. The applications for a tailgate detector can be demonstrated across many medium security applications where there are no physical means to prevent this

  20. 75 FR 80886 - Third Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2010-12-23

    ... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control... Federal Aviation Administration Third Meeting: RTCA Special Committee 224: Airport Security Access Control...

  1. 76 FR 38742 - Seventh Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-07-01

    ... Committee 224 meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is... Access Control Systems. DATES: The meeting will be held July 15, 2011, from 10 a.m. to 1 p.m. ADDRESSES... 2), notice is hereby given for a Special Committee 224, Airport Security Access Control Systems...

  2. 77 FR 2343 - Eleventh Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-01-17

    ...). ACTION: Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY: The FAA..., Airport Security Access Control Systems. DATES: The meeting will be held February 9, 2012, from 10 a.m.-4..., Airport Security Access Control Systems. The agenda will include the following: February 9, 2012 Welcome...

  3. 78 FR 51810 - Twenty-Fourth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-08-21

    ... Security Access Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control... RTCA Special Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on...

  4. 75 FR 61819 - First Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2010-10-06

    ... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control... Federal Aviation Administration First Meeting: RTCA Special Committee 224: Airport Security Access Control...

  5. 76 FR 59481 - Ninth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-09-26

    ... Committee 224 meeting: Airport Security Access Control Systems. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control Systems... hereby given for a Special Committee 224, Airport Security Access Control Systems (Update to DO-230B...

  6. 76 FR 9632 - Fifth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-02-18

    ... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this... Access Control Systems (Update to DO-230B): Agenda March 10, 2011 Welcome/Introductions/Administrative... Federal Aviation Administration Fifth Meeting: RTCA Special Committee 224: Airport Security Access Control...

  7. 78 FR 31627 - Twenty-Second Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-05-24

    ...: RTCA Special Committee 224, Airport Security Access Control Systems AGENCY: Federal Aviation... 224, Airport Security Access Control Systems. SUMMARY: The FAA is issuing this notice to advise the public of the twenty-second meeting of the RTCA Special Committee 224, Airport Security Access Control...

  8. 77 FR 25525 - Thirteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems.

    Science.gov (United States)

    2012-04-30

    ... Access Control Systems. AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held May 30, 2012, from 10...

  9. 75 FR 71790 - Second Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2010-11-24

    ... Committee 224 meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is... Access Control Systems. DATES: The meeting will be held December 9, 2010, from 10 a.m. to 5 p.m...: Airport Security Access Control Systems (Update to DO-230B): Agenda December 9, 2010 Welcome/Introductions...

  10. 76 FR 16470 - Sixth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-03-23

    ... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control... Federal Aviation Administration Sixth Meeting: RTCA Special Committee 224: Airport Security Access Control...

  11. 76 FR 3931 - Fourth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-01-21

    ... Committee 224 Meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is... Access Control Systems. DATES: The meeting will be held February 8, 2011, from 10 a.m. to 5 p.m... Committee 224, Airport Security Access Control Systems (Update to DO-230B): Agenda February 8, 2011 Welcome...

  12. 76 FR 50811 - Eighth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Science.gov (United States)

    2011-08-16

    ... Access Control Systems AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 224 meeting: Airport Security Access Control Systems. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control Systems...

  13. 75 FR 4007 - Risk Management Controls for Brokers or Dealers With Market Access

    Science.gov (United States)

    2010-01-26

    ... COMMISSION 17 CFR Part 240 RIN 3235-AK53 Risk Management Controls for Brokers or Dealers With Market Access... market access to customers or other persons, to implement risk management controls and supervisory... pre-trade risk management controls (i.e., ``unfiltered'' or ``naked'' access),\\10\\ and thus could be...

  14. Dynamic Access Control Model for Security Client Services in Smart Grid

    OpenAIRE

    Sang-Soo Yeo; Si-Jung Kim; Do-Eun Cho

    2014-01-01

    In the next-generation intelligent power grid, known as the smart grid, various objects can access systems in several network environments, and, accordingly, access control security becomes critical. Thus, to provide users with secure services in the smart grid, a new access control security model is needed. This paper proposes a dynamic access model for secure user services in the smart grid environment. The proposed model analyzes the user's various access contexts and chooses an appropriat...

  15. Trust-based Access Control in Virtual Learning Community

    Science.gov (United States)

    Wang, Shujuan; Liu, Qingtang

    The virtual learning community is an important application pattern of E-Learning. It emphasizes the cooperation of the members in the community, the members would like to share their learning resources, to exchange their experience and complete the study task together. This instructional mode has already been proved as an effective way to improve the quality and efficiency of instruction. At the present time, the virtual learning communities are mostly designed using static access control policy by which the access permission rights are authorized by the super administrator, the super administrator assigns different rights to different roles, but the virtual and social characteristics of virtual learning community make information sharing and collaboration a complex problem, the community realizes its instructional goal only if the members in it believe that others will offer the knowledge they owned and believe the knowledge others offered is well-meaning and worthy. This paper tries to constitute an effective trust mechanism, which could promise favorable interaction and lasting knowledge sharing.

  16. Building a Network Based Laboratory Environment

    Directory of Open Access Journals (Sweden)

    Sea Shuan Luo

    2009-12-01

    Full Text Available This paper presents a comparative study about the development of a network based laboratory environment in the “Unix introduction” course for the undergraduate students. The study results and the response from the students from 2005 to 2006 will be used to better understand what kind of method is more suitable for students. We also use the data collected to adjust our teaching strategy and try to build up a network based laboratory environment.

  17. First Experiences Using XACML for Access Control in Distributed Systems

    Science.gov (United States)

    Lorch, Marcus; Proctor, Seth; Lepro, Rebekah; Kafura, Dennis; Shah, Sumit

    2003-01-01

    Authorization systems today are increasingly complex. They span domains of administration, rely on many different authentication sources, and manage permissions that can be as complex as the system itself. Worse still, while there are many standards that define authentication mechanisms, the standards that address authorization are less well defined and tend to work only within homogeneous systems. This paper presents XACML, a standard access control language, as one component of a distributed and inter-operable authorization framework. Several emerging systems which incorporate XACML are discussed. These discussions illustrate how authorization can be deployed in distributed, decentralized systems. Finally, some new and future topics are presented to show where this work is heading and how it will help connect the general components of an authorization system.

  18. Suction catheter for enhanced control and accuracy of transseptal access.

    Science.gov (United States)

    Sulkin, Matthew S; Berwick, Zachary C; Hermiller, James B; Navia, Jose A; Kassab, Ghassan S

    2016-12-20

    Percutaneous structural heart therapies, such as mitral value repair, require site-specific transseptal access (TSA). This can be challenging for interventional cardiologists. We describe a TSA catheter (TSAC) that utilises suction for enhanced control and puncture accuracy. Here, we aim to evaluate the safety and efficacy of the device. Ex vivo interatrial septum preparations were dissected from swine (n=8) and diseased human hearts (n=6) to quantify TSAC suction and needle puncture force. TSAC suction was 6.5-fold greater than the opposing needle puncture force, and thus provides sufficient stabilisation for punctures. The safety and efficacy of TSAC was evaluated in a chronic mitral regurgitation swine model (n=10) and compared to a conventional TSA device. MR was induced by disrupting one to three mitral chordae tendineae, and the progression of heart disease was followed for three weeks. During device testing, procedure time and fluoroscopy exposure were not statistically different between devices. TSAC reduced septal displacement from 8.7±0.30 mm to 3.60±0.19 mm (p<0.05) and improved puncture accuracy 1.75-fold. TSAC provides controlled TSA and improves puncture accuracy, while maintaining procedure time and workflow. These findings provide a strong rationale for a first-in-man study to demonstrate the clinical utility of the device.

  19. Evaluation of secure capability-based access control in the M2M local cloud platform

    DEFF Research Database (Denmark)

    Anggorojati, Bayu; Prasad, Neeli R.; Prasad, Ramjee

    2016-01-01

    delegation. Recently, the capability based access control has been considered as method to manage access in the Internet of Things (IoT) or M2M domain. In this paper, the implementation and evaluation of a proposed secure capability based access control in the M2M local cloud platform is presented......Managing access to and protecting resources is one of the important aspect in managing security, especially in a distributed computing system such as Machine-to-Machine (M2M). One such platform known as the M2M local cloud platform, referring to BETaaS architecture [1], which conceptually consists...... of multiple distributed M2M gateways, creating new challenges in the access control. Some existing access control systems lack in scalability and flexibility to manage access from users or entity that belong to different authorization domains, or fails to provide fine grained and flexible access right...

  20. Dynamic Access Control Model for Security Client Services in Smart Grid

    National Research Council Canada - National Science Library

    Yeo, Sang-Soo; Kim, Si-Jung; Cho, Do-Eun

    2014-01-01

    In the next-generation intelligent power grid, known as the smart grid, various objects can access systems in several network environments, and, accordingly, access control security becomes critical...

  1. The new biometric access control system resembles a big electronic eye. It will be used to control access to the LHC from 2007 onwards.

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The new LHC access control systems will soon be using the latest technology: optical recognition based on iris image data. In order to gain access to the tunnel it will be your eye, not your credentials that you'll be required to show! As of September, the entrance point at Point 8 should be the first to be fitted out with iris recognition equipment. The other access shafts will then gradually be equipped one by one.

  2. Principles of Eliminating Access Control Lists within a Domain

    Directory of Open Access Journals (Sweden)

    Vic Grout

    2012-04-01

    Full Text Available The infrastructure of large networks is broken down into areas that have a common security policy called a domain. Security within a domain is commonly implemented at all nodes. However this can have a negative effect on performance since it introduces a delay associated with packet filtering. When Access Control Lists (ACLs are used within a router for this purpose then a significant overhead is introduced associated with this process. It is likely that identical checks are made at multiple points within a domain prior to a packet reaching its destination. Therefore by eliminating ACLs within a domain by modifying the ingress/egress points with equivalent functionality an improvement in the overall performance can be obtained. This paper considers the effect of the delays when using router operating systems offering different levels of functionality. It considers factors which contribute to the delay particularly due to ACLs and by using theoretical principles modified by practical calculation a model is created. Additionally this paper provides an example of an optimized solution which reduces the delay through network routers by distributing the security rules to the ingress/egress points of the domain without affecting the security policy.

  3. Concurrency control and recovery on lightweight directory access protocol

    Science.gov (United States)

    Potnis, Rohit R.; Sathaye, Archana S.

    2003-04-01

    In this paper we provide a concurrency control and recovery (CCR) mechanism over cached LDAP objects. An LDAP server can be directly queried using system calls to retrieve data. Existing LDAP implementations do not provide CCR mechanisms. In such cases, it is up to the application to verify that accesses remain serialized. Our mechanism provides an independent layer over an existing LDAP server (Sun One Directory Server), which handles all user requests, serializes them based on 2 Phase Locking and Timestamp Ordering mechanisms and provides XML-based logging for recovery management. Furthermore, while current LDAP servers only provide object-level locking, our scheme serializes transactions on individual attributes of LDAP objects (attribute-level locking). We have developed a Directory Enabled Network (DEN) Simulator that operates on a subset of directory objects on an existing LDAP server to test the proposed mechanism. We perform experiments to show that our mechanism can gracefully address concurrency and recovery related issues over and LDAP server.

  4. Bureau of Prisons access control system: functional and operational requirements

    Science.gov (United States)

    Janus, Michael; Carlson, Peter M.; Kane, Thomas

    1997-01-01

    The Federal Bureau of Prisons (BOP) operates 86 correctional institutions nationwide. The BOP has grown dramatically, the size of its inmate population growing from just over 41,000 inmates in 1987 to over 100,000 today. The number of BOP staff managing these facilities has grown correspondingly, more than doubling in number in the same ten year period. Technology has paid a major role in keeping up with this growth while maintaining high standards of security in BOP institutions. In an attempt to further enhance security in its institutions, the BOP has recently begun pilot testing an access control and entry system (ACES). ACES is intended to provide an automated record of very entry and exit to a correctional institution. ACES takes advantage of several methods of identifying an individual (inmate, staff or visitor) to assure that the individual exiting the institution is the same as the individual entering. The pilot test has raised a number of questions regarding the implementation of a technologically sophisticated system in a correctional institution. Questions of training, support, 'ownership,' cost effectiveness, and future potential all influence the deployment of this system. Preliminary results indicate that an adequate training and support system is essential to the performance of any sophisticated system and that other organizational issues need to be addressed before the decision to implement is made.

  5. Simplified Key Management for Digital Access Control of Information Objects

    Science.gov (United States)

    2016-07-02

    when access criteria are verified. With increasing requirements for records management and maintenance of more and more electronic objects, the...before the arrival of digital or even electronic media, copyright holders, content producers, and other financially or artistically interested... piracy ) much easier. DRM technologies have enabled publishers to enforce access policies that discourage copyright infringements. DRM is most commonly

  6. Keep on Blockin’ in the Free World: Personal Access Control for Low-Cost RFID Tags

    OpenAIRE

    Rieback, Melanie; Crispo, Bruno; Tanenbaum, Andrew

    2007-01-01

    This paper introduces an off-tag RFID access control mechanism called “Selective RFID Jamming”. Selective RFID Jamming protects low-cost RFID tags by enforcing access control on their behalf, in a similar manner to the RFID Blocker Tag. However, Selective RFID Jamming is novel because it uses an active mobile device to enforce centralized ACL-based access control policies. Selective RFID Jamming also solves a Differential Signal Analysis attack to which the RFID Blocker Tag is susceptible.

  7. 78 FR 22025 - Twenty First Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-04-12

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 9-10, 2013...

  8. 78 FR 16757 - Twentieth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-03-18

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 4, 2013 from 9...

  9. 78 FR 43963 - Twenty-Third Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-07-22

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on June 20, 2013...

  10. 78 FR 7850 - Nineteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-02-04

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held February 21, 2013...

  11. 77 FR 55894 - Fifteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-09-11

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held September 27-28, 2012...

  12. 77 FR 15448 - Twelfth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-03-15

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Notice of meeting RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... 224, Airport Security Access Control Systems DATES: The meeting will be held April 5, 2012, from 10 a...

  13. 77 FR 64838 - Sixteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-10-23

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held November 15, 2012...

  14. 77 FR 71474 - Seventeenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-11-30

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held December 13, 2012...

  15. 75 FR 69791 - Risk Management Controls for Brokers or Dealers With Market Access

    Science.gov (United States)

    2010-11-15

    ... CFR Part 240 Risk Management Controls for Brokers or Dealers With Market Access; Final Rule #0;#0... 3235-AK53 Risk Management Controls for Brokers or Dealers With Market Access AGENCY: Securities and... system of risk management controls and supervisory procedures that, among other things, are reasonably...

  16. 36 CFR 1256.70 - What controls access to national security-classified information?

    Science.gov (United States)

    2010-07-01

    ... national security-classified information? 1256.70 Section 1256.70 Parks, Forests, and Public Property... HISTORICAL MATERIALS Access to Materials Containing National Security-Classified Information § 1256.70 What controls access to national security-classified information? (a) The declassification of and public access...

  17. Designing a Secure E-commerce with Credential Purpose-based Access Control

    OpenAIRE

    Norjihan Abdul Ghani; Harihodin Selamat; Zailani Mohamed Sidek

    2014-01-01

    The rapid growth of e-commerce has created a great opportunities for both businesses and end users. The essential e-commerce process is required for the successful operation and management of e-commerce activities. One of the processes is access control and security. E-commerce must establish a secure access between the parties in an e-commerce transaction by authenticating users, authorizing access, and enforcing security features. The e-commerce application must authorize access to only tho...

  18. G-Cloud on Openstack : Adressing access control and regulation requirements

    OpenAIRE

    Yonis Omar, Ibrahim; Laborde, Romain; Wazan, Ahmad Samer; Barrère, François; Benzekri, Abdelmalek

    2015-01-01

    It is well known that e-Government applications bring several benefits to citizens in terms of efficiency, accessibility and transparency. Today, most of governments tend to propose cloud computing based e-services to their citizens. A key component in these services is the access control management issue. In this paper, we present our research works for building an access control system for the Djiboutian e-Government project that is built using Openstack framework. Specifically, we demonstr...

  19. A Security Architecture for Data Aggregation and Access Control in Smart Grids

    OpenAIRE

    Ruj, Sushmita; Nayak, Amiya; Stojmenovic, Ivan

    2011-01-01

    We propose an integrated architecture for smart grids, that supports data aggregation and access control. Data can be aggregated by home area network, building area network and neighboring area network in such a way that the privacy of customers is protected. We use homomorphic encryption technique to achieve this. The consumer data that is collected is sent to the substations where it is monitored by remote terminal units (RTU). The proposed access control mechanism gives selective access to...

  20. Random access procedures and radio access network (RAN) overload control in standard and advanced long-term evolution (LTE and LTE-A) networks

    DEFF Research Database (Denmark)

    Kiilerich Pratas, Nuno; Thomsen, Henning; Popovski, Petar

    2015-01-01

    In this chapter, we describe and discuss the current LTE random access procedure and the Radio Access Network Load Control solution within LTE/LTE-A. We provide an overview of the several considered load control solutions and give a detailed description of the standardized Extended Access Class B...

  1. On the performance of shared access control strategy for femtocells

    KAUST Repository

    Magableh, Amer M.

    2013-02-18

    Femtocells can be employed in cellular systems to enhance the indoor coverage, especially in the areas with high capacity growing demands and high traffic rates. In this paper, we propose an efficient resource utilization protocol, named as shared access protocol (SAP), to enable the unauthorized macrocell user equipment to communicate with partially closed-access femtocell base station to improve and enhance the system performance. The system model considers a femtocell that is equipped with a total of N separated antennas or channels to multiplex independent traffic. Then, a set of N1 channels is used for closed access only by the authorized users, and the remaining set of channel resources can be used for open access by either authorized or unauthorized users upon their demands and spatial locations. For this system model, we obtain the signal-to-interference ratio characteristics, such as the distribution and the moment generating function, in closed forms for two fading models of indoor and outdoor environments. The signal-tointerference ratio statistics are then used to derive some important performance measures of the proposed SAP in closed form, such as the average bit error rate, outage probability, and average channel capacity for the two fading models under consideration. Numerical results for the obtained expressions are provided and supported by Monte Carlo simulations to validate the analytical development and study the effectiveness of the proposed SAP under different conditions. Copyright © 2012 John Wiley and Sons, Ltd.

  2. Analytical Modeling of Medium Access Control Protocols in Wireless Networks

    Science.gov (United States)

    2006-03-01

    Imperatives and chal- lenges. Ad Hoc Networks, 1(1):13–64, July 2003. [28] I. Chlamtac and A. Faragó. Making transmission schedules immune to topology changes...P. Karn. MACA - a new channel access method for packet radio. In ARRL/CRRL Amateur Radio 9th Computer Networking Conference, pages 134–140, 1990

  3. Tolerance to freezing stress in Cicer accessions under controlled ...

    African Journals Online (AJOL)

    USER

    2010-05-03

    May 3, 2010 ... Some 'kabuli' types such as FLIP 93-261C and. x03TH21 which presented high freezing tolerance during early seedling stage, withstood -15.6°C without snow cover. Based on severity score data, the highest freezing tolerance sources were all accessions of Cicer echinospermum and Cicer reticulatum ...

  4. Tolerance to freezing stress in Cicer accessions under controlled ...

    African Journals Online (AJOL)

    Some 'kabuli' types such as FLIP 93-261C and x03TH21 which presented high freezing tolerance during early seedling stage, withstood -15.6°C without snow cover. Based on severity score data, the highest freezing tolerance sources were all accessions of Cicer echinospermum and Cicer reticulatum and 15 lines from C.

  5. Owner-Based Role-Based Access Control OB-RBAC

    NARCIS (Netherlands)

    Saffarian, M.; Sadighi, Babak

    Administration of an access control model deals with the question of who is authorized to update policies defined on the basis of that model. One of the models whose administration has absorbed relatively large research is the Role-Based Access Control (RBAC) model. All the existing role-based

  6. Keep on Blockin’ in the Free World: Personal Access Control for Low-Cost RFID Tags

    NARCIS (Netherlands)

    Rieback, Melanie; Crispo, Bruno; Tanenbaum, Andrew

    2007-01-01

    This paper introduces an off-tag RFID access control mechanism called “Selective RFID Jamming”. Selective RFID Jamming protects low-cost RFID tags by enforcing access control on their behalf, in a similar manner to the RFID Blocker Tag. However, Selective RFID Jamming is novel because it uses an

  7. Keep on Blockin' in the Free World: Personal Access Control for Low-Cost RFID Tags

    NARCIS (Netherlands)

    Rieback, M.R.; Crispo, B.; Tanenbaum, A.S.

    2005-01-01

    This paper introduces an off-tag RFID access control mechanism called "Selective RFID Jamming". Selective RFID Jamming protects low-cost RFID tags by enforcing access control on their behalf, in a similar manner to the RFID Blocker Tag. However, Selective RFID Jamming is novel because it uses an

  8. Enhancing Security and Privacy in Video Surveillance through Role-Oriented Access Control Mechanism

    DEFF Research Database (Denmark)

    Mahmood Rajpoot, Qasim

    the explicitly stated ones due to the hierarchical relations between the attributes of different entities. We implement a prototype of the proposed mechanism and demonstrate that the access control policies using our approach may be specified via eXtensible Access Control Markup Language (XACML)....

  9. Access control and privilege management in electronic health record: a systematic literature review.

    Science.gov (United States)

    Jayabalan, Manoj; O'Daniel, Thomas

    2016-12-01

    This study presents a systematic literature review of access control for electronic health record systems to protect patient's privacy. Articles from 2006 to 2016 were extracted from the ACM Digital Library, IEEE Xplore Digital Library, Science Direct, MEDLINE, and MetaPress using broad eligibility criteria, and chosen for inclusion based on analysis of ISO22600. Cryptographic standards and methods were left outside the scope of this review. Three broad classes of models are being actively investigated and developed: access control for electronic health records, access control for interoperability, and access control for risk analysis. Traditional role-based access control models are extended with spatial, temporal, probabilistic, dynamic, and semantic aspects to capture contextual information and provide granular access control. Maintenance of audit trails and facilities for overriding normal roles to allow full access in emergency cases are common features. Access privilege frameworks utilizing ontology-based knowledge representation for defining the rules have attracted considerable interest, due to the higher level of abstraction that makes it possible to model domain knowledge and validate access requests efficiently.

  10. Accessibility to tuberculosis control services and tuberculosis programme performance in southern Ethiopia

    National Research Council Canada - National Science Library

    Dangisso, Mesay Hailu; Datiko, Daniel Gemechu; Lindtjørn, Bernt

    2015-01-01

    ... with the performance of tuberculosis (TB) control programmes. We aim to assess the geographical distribution of and physical accessibility to TB control services and their relationship with TB case notification rates (CNRs...

  11. Capability-based Access Control Delegation Model on the Federated IoT Network

    DEFF Research Database (Denmark)

    Anggorojati, Bayu; Mahalle, Parikshit N.; Prasad, Neeli R.

    2012-01-01

    Flexibility is an important property for general access control system and especially in the Internet of Things (IoT), which can be achieved by access or authority delegation. Delegation mechanisms in access control that have been studied until now have been intended mainly for a system that has...... no resource constraint, such as a web-based system, which is not very suitable for a highly pervasive system such as IoT. To this end, this paper presents an access delegation method with security considerations based on Capability-based Context Aware Access Control (CCAAC) model intended for federated...... machine-to-machine communication or IoT networks. The main idea of our proposed model is that the access delegation is realized by means of a capability propagation mechanism, and incorporating the context information as well as secure capability propagation under federated IoT environments. By using...

  12. The competitive dynamics of network-based businesses.

    Science.gov (United States)

    Coyne, K P; Dye, R

    1998-01-01

    Telecommunications carriers, transportation companies, and banks are among the many network-based businesses--companies that move people, goods, or information from various points to various other points. Managers have long assumed that customers valued all links in these networks equally. It was thought that banking customers, for example, sought access to all of the branches throughout the network or that shipping customers wanted to be able to send packages everywhere. Intuitively, managers thought that many of their customers' needs were, in reality, narrower, but they had no way of knowing which links were most important. New computing power and robust mapping software now make it possible to understand network customers better. In applying this technology, the authors, both consultants from McKinsey & Company, have uncovered three distinct usage patterns: one in which all links are, indeed, valued equally; another in which customers concentrate their use in particular zones; and a third in which customers value only individual links. Each of these patterns requires a different strategy to direct executives in making the decisions fundamental to managing any network-based business: whether to open or close outlets, whether to connect their network to others, and how to organize business units so that they reflect the network's structure. Those who don't spot the patterns or understand their strategic implications will find themselves on the losing end of the network battle.

  13. Secure Remote Access Issues in a Control Center Environment

    Science.gov (United States)

    Pitts, Lee; McNair, Ann R. (Technical Monitor)

    2002-01-01

    The ISS finally reached an operational state and exists for local and remote users. Onboard payload systems are managed by the Huntsville Operations Support Center (HOSC). Users access HOSC systems by internet protocols in support of daily operations, preflight simulation, and test. In support of this diverse user community, a modem security architecture has been implemented. The architecture has evolved over time from an isolated but open system to a system which supports local and remote access to the ISS over broad geographic regions. This has been accomplished through the use of an evolved security strategy, PKI, and custom design. Through this paper, descriptions of the migration process and the lessons learned are presented. This will include product decision criteria, rationale, and the use of commodity products in the end architecture. This paper will also stress the need for interoperability of various products and the effects of seemingly insignificant details.

  14. Capability-based Cryptographic Data Access Control in Cloud Computing

    OpenAIRE

    Chittaranjan Hota; Sunil Sanka; Muttukrishnan Rajarajan; Nair, Srijith K.

    2011-01-01

    Cloud computing has emerged as a popular model in computing world to support processing large volumetric data using clusters of commodity computers. It is the latest effort in delivering computing resources as a service. It is used to describe both a platform and a type of application. A cloud computing platform dynamically provisions, configures, and deprovisions servers as needed. Cloud computing also describes applications that are extended to be accessible through the Internet. Data se...

  15. Identity driven Capability based Access Control (ICAC) Scheme for the Internet of Things

    DEFF Research Database (Denmark)

    Mahalle, Parikshit N.; Anggorojati, Bayu; Prasad, Neeli R.

    2012-01-01

    Internet of Things (IoT) becomes discretionary part of everyday life. Scalability and manageability is daunting due to unbounded number of devices and services. Access control and authorization in IoT with least privilege is equally important to establish secure communication between multiple...... devices and services. In this paper, the concept of capability for access control is introduced where the identities of the involved devices are entrenched in the access capabilities. Identity driven capability based access control (ICAC) scheme presented in this paper helps to alleviate issues related...... to complexity and dynamics of device identities. ICAC is implemented for 802.11 and results shows that ICAC has less scalability issues and better performance analysis compared with other access control schemes. The ICAC evaluation by using security protocol verification tool shows that ICAC is secure against...

  16. Requirements and Challenges of Location-Based Access Control in Healthcare Emergency Response

    DEFF Research Database (Denmark)

    Vicente, Carmen Ruiz; Kirkpatrick, Michael; Ghinita, Gabriel

    2009-01-01

    ), are not sufficient to address the new challenges introduced by these location-based applications. Several recent research efforts have enhanced RBAC with spatio-temporal features. Nevertheless, the state-of-the-art does not deal with mobility of both subjects and objects and does not support the utilization......Recent advances in positioning and tracking technologies have led to the emergence of novel location-based applications that allow participants to access information relevant to their spatio-temporal context. Traditional access control models, such as role-based access control (RBAC...... emergency response scenario which highlights the novel challenges that arise when enforcing access control in an environment with moving subjects and objects. To address a realistic application scenario, we consider movement on road networks, and we identify complex access control decisions relevant...

  17. Design of an Accessible, Powered Myoelectrically Controlled Hand Prosthesis

    Directory of Open Access Journals (Sweden)

    Osman Onur Akirmak

    2017-08-01

    Full Text Available In this paper we describe accessible myoelectric prosthetic hand design based on modification of existing mechanical prosthesis and off-the-shelf parts and components. Despite significant advances in myoelectric prosthetics, such existing devices remain out of reach of the majority of the patients needing them due to high costs and complexity. We describe a simple design that can be assembled based on existing or readily acquirable parts at approximately 1/100 of the cheapest commercially available alternative. Our design offers wrist disarticulation patients in developing countries an affordable myoelectric prosthesis with significant capacity for improving their quality of life.

  18. Cloud Multidomain Access Control Model Based on Role and Trust-Degree

    Directory of Open Access Journals (Sweden)

    Lixia Xie

    2016-01-01

    Full Text Available In order to solve the problem of access control among different security domains in cloud networks, this paper presents an access control model based on role and trust-degree. The model combines role-based access control and trust-based access control. The role assessment weights are defined based on the user’s role classes, and the trust-degree is calculated according to the role assessment weights and the role’s behavior. In order to increase the accuracy of access control, the model gives the concept and calculation methods of feedback trust-degree. To achieve fine-grained access control, the model introduces direct trust-degree, recommendation trust-degree, and feedback trust-degree, all of which participate in comprehensive trust-degree by adjusting their weights. A simulation experiment was conducted in the LAN environment, and a web system was used to construct an access control model with multisecurity domains in the experiment. The experimental results demonstrate that our model has higher security, expansibility, and flexibility.

  19. Identity Establishment and Capability Based Access Control (IECAC) Scheme for Internet of Things

    DEFF Research Database (Denmark)

    Mahalle, Parikshit N.; Anggorojati, Bayu; Prasad, Neeli R.

    2012-01-01

    Internet of Things (IoT) become discretionary part of everyday life and could befall a threat if security is not considered before deployment. Authentication and access control in IoT is equally important to establish secure communication between devices. To protect IoT from man in middle, replay...... and denial of service attacks, the concept of capability for access control is introduced. This paper presents Identity establishment and capability based access control (IECAC) protocol using ECC (Elliptical Curve Cryptography) for IoT along with protocol evaluation, which protect against the aforementioned...

  20. Assessment of current practices in creating and using passwords as a control mechanism for information access

    Directory of Open Access Journals (Sweden)

    P. L. Wessels

    2007-11-01

    Full Text Available One of the critical issues in managing information within an organization is to ensure that proper controls exist and are applied in allowing people access to information. Passwords are used extensively as the main control mechanism to identify users wanting access to systems, applications, data files, network servers or personal information. In this article, the issues involved in selecting and using passwords are discussed and the current practices employed by users in creating and storing passwords to gain access to sensitive information are assessed. The results of this survey conclude that information managers cannot rely only on users to employ proper password control in order to protect sensitive information.

  1. A Distributed Architecture for Sharing Ecological Data Sets with Access and Usage Control Guarantees

    DEFF Research Database (Denmark)

    Bonnet, Philippe; Gonzalez, Javier; Granados, Joel Andres

    2014-01-01

    new insights, there are signicant barriers to the realization of this vision. One of the key challenge is to allow scientists to share their data widely while retaining some form of control over who accesses this data (access control) and more importantly how it is used (usage control). Access...... and usage control is necessary to enforce existing open data policies. We have proposed the vision of trusted cells: A decentralized infrastructure, based on secure hardware running on devices equipped with trusted execution environments at the edges of the Internet. We originally described the utilization...... data sets with access and usage control guarantees. We rely on examples from terrestrial research and monitoring in the arctic in the context of the INTERACT project....

  2. Formalization of the Access Control on ARM-Android Platform with the B Method

    Science.gov (United States)

    Ren, Lu; Wang, Wei; Zhu, Xiaodong; Man, Yujia; Yin, Qing

    2018-01-01

    ARM-Android is a widespread mobile platform with multi-layer access control mechanisms, security-critical in the system. Many access control vulnerabilities still exist due to the course-grained policy and numerous engineering defects, which have been widely studied. However, few researches focus on the mechanism formalization, including the Android permission framework, kernel process management and hardware isolation. This paper first develops a comprehensive formal access control model on the ARM-Android platform using the B method, from the Android middleware to hardware layer. All the model specifications are type checked and proved to be well-defined, with 75%of proof obligations demonstrated automatically. The results show that the proposed B model is feasible to specify and verify access control schemes in the ARM-Android system, and capable of implementing a practical control module.

  3. The Smart Card concept applied to access control

    Energy Technology Data Exchange (ETDEWEB)

    Seidman, S.

    1986-01-01

    Passwords tend to be handled carelessly, and so are easily lost or stolen. Because they are intangible, their loss or theft generally goes unnoticed. Because they are constant, they may be used by anyone for as long as they remain in active use by a legitimate user. A step up in password security is offered by a new range of products which generate a new code each time the device is used. Devices are being produced in packages as small as a standard plastic credit card, including internal battery power, integral keyboard and LCD display. Security features of the Smart Card are reviewed, and several random access code generators currently available in the commercial marketplace are described.

  4. An Efficient Medium Access Control Strategy for High Speed WDM Multiaccess Networks

    NARCIS (Netherlands)

    Laarhuis, Jan H.; Laarhuis, Jan; Koonen, A.M.J.

    1993-01-01

    A medium access control (MAC) strategy that accounts for the limited tunability of present-day lasers and filters and yet supports a large total number of wavelengths in the network is proposed. Full interconnectivity, contention-free access and a high value of concurrency are achieved by dividing

  5. Identity Authentication and Capability Based Access Control (IACAC) for the Internet of Things

    DEFF Research Database (Denmark)

    Mahalle, Parikshit N.; Anggorojati, Bayu; Prasad, Neeli R.

    2013-01-01

    In the last few years the Internet of Things (IoT) has seen widespread application and can be found in each field. Authentication and access control are important and critical functionalities in the context of IoT to enable secure communication between devices. Mobility, dynamic network topology...... and weak physical security of low power devices in IoT networks are possible sources for security vulnerabilities. It is promising to make an authentication and access control attack resistant and lightweight in a resource constrained and distributed IoT environment. This paper presents the Identity...... Authentication and Capability based Access Control (IACAC) model with protocol evaluation and performance analysis. To protect IoT from man-in-the-middle, replay and denial of service (Dos) attacks, the concept of capability for access control is introduced. The novelty of this model is that, it presents...

  6. The assessment of exploitation process of power for access control system

    National Research Council Canada - National Science Library

    Wiśnios Michał; Paś Jacek

    2017-01-01

    ... functioning of their power supply systems. The authors of the research paper analysed the power supply systems, which are used in buildings for the access control system that is integrated with the closed-circuit TV...

  7. Access control system for RFID-tagged documents in supply chain management

    National Research Council Canada - National Science Library

    Tadeusz Nowicki; Maciej Kiedrowicz; Robert Waszkowski; Agata Chodowska; Agnieszka Lach

    2017-01-01

    .... The aim of the paper is to prepare appropriate models and design of the RFID-based access control system, as well as its architecture, including the domain model, requirements, business process...

  8. On the Protection of Personal Data in the Access Control System

    Directory of Open Access Journals (Sweden)

    A. P. Durakovskiy

    2012-03-01

    Full Text Available The aim is to prove the qualification system of access control systems (ACS as an information system for personal data (ISPDn. Applications: systems of physical protection of facilities.

  9. 21 CFR 1311.130 - Requirements for establishing logical access control-Institutional practitioner.

    Science.gov (United States)

    2010-04-01

    ... ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Electronic Prescriptions § 1311.130 Requirements for establishing logical access control—Institutional... practitioner's electronic prescription application to indicate that controlled substances prescriptions are...

  10. Access Control in the ATLAS TDAQ Online Cluster

    CERN Document Server

    Leahu, Marius Constantin; Stoichescu, D A; Lehmann Miotto, G

    ATLAS (A Toroidal LHC Apparatus) is a general-purpose detector for studying high-energy particle interactions: it is the largest particle detector experiment at CERN and it is built around one of the interaction points of the proton beams accelerated by the Large Hadron Collider (LHC). The detector generates an impressive amount of raw data: 64 TB per second as a result of 40 MHz proton-proton collision rate with 1.6 MB data for each such event. The handling of such data rate is managed by a three levels Trigger and Data Acquisition (TDAQ) system, which filters out the events not relevant from physics research point of view and selects in the end in the order of 1000 events per second to be stored for offline analyses. This system comprises a significant number of hardware devices, software applications and human personnel to supervise the experiment operation. Their protection against damages as a result of misuse and their optimized exploitation by avoiding the conflicting accesses to resources are key requ...

  11. IAACaaS: IoT Application-Scoped Access Control as a Service

    OpenAIRE

    Álvaro Alonso; Federico Fernández; Lourdes Marco; Joaquín Salvachúa

    2017-01-01

    access control is a key element when guaranteeing the security of online services. However, devices that make the Internet of Things have some special requirements that foster new approaches to access control mechanisms. Their low computing capabilities impose limitations that make traditional paradigms not directly applicable to sensors and actuators. In this paper, we propose a dynamic, scalable, IoT-ready model that is based on the OAuth 2.0 protocol and that allows the complete delegation...

  12. Privilege management and access control in Shared Care IS and EHR.

    Science.gov (United States)

    Blobel, Bernd; Nordberg, Ragnar

    2003-01-01

    Realising the shared care concept based on distributed health information systems, we have to meet the challenge for advanced security and privacy based on a Public Key Infrastructure (PKI) Beside strong authentication, authorisation of principals and access control using role concepts and security object classification schemes are essential application security services. The paper presents the actual drafts of ISO and CEN standards dealing with privilege management and access control.

  13. 76 FR 38293 - Risk Management Controls for Brokers or Dealers With Market Access

    Science.gov (United States)

    2011-06-30

    ... COMMISSION 17 CFR Part 240 RIN 3235-AK53 Risk Management Controls for Brokers or Dealers With Market Access... establish, document, and maintain a system of risk management controls and supervisory procedures that... develop, test, and implement the relevant risk management controls and supervisory procedures required...

  14. Advanced Techniques for Deploying Reliable and Efficient Access Control: Application to E-healthcare.

    Science.gov (United States)

    Jaïdi, Faouzi; Labbene-Ayachi, Faten; Bouhoula, Adel

    2016-12-01

    Nowadays, e-healthcare is a main advancement and upcoming technology in healthcare industry that contributes to setting up automated and efficient healthcare infrastructures. Unfortunately, several security aspects remain as main challenges towards secure and privacy-preserving e-healthcare systems. From the access control perspective, e-healthcare systems face several issues due to the necessity of defining (at the same time) rigorous and flexible access control solutions. This delicate and irregular balance between flexibility and robustness has an immediate impact on the compliance of the deployed access control policy. To address this issue, the paper defines a general framework to organize thinking about verifying, validating and monitoring the compliance of access control policies in the context of e-healthcare databases. We study the problem of the conformity of low level policies within relational databases and we particularly focus on the case of a medical-records management database defined in the context of a Medical Information System. We propose an advanced solution for deploying reliable and efficient access control policies. Our solution extends the traditional lifecycle of an access control policy and allows mainly managing the compliance of the policy. We refer to an example to illustrate the relevance of our proposal.

  15. Privacy-preserving access control in cloud federations

    OpenAIRE

    Alansari, Shorouq; Paci, Federica; Margheri, Andrea; Sassone, Vladimiro

    2017-01-01

    A Cloud federation is a collaboration of organizations sharing data hosted on their private cloud infrastructures in order to exploit a common business opportunity. However, the adoption of cloud federations is hindered by member organizations’ concerns on sharing their data with potentially competing organizations. For cloud federations to be viable, federated organizations’ privacy concerns should be alleviated by providing mechanisms that allow organizations to control which users from oth...

  16. Network-based recommendation algorithms: A review

    Science.gov (United States)

    Yu, Fei; Zeng, An; Gillard, Sébastien; Medo, Matúš

    2016-06-01

    Recommender systems are a vital tool that helps us to overcome the information overload problem. They are being used by most e-commerce web sites and attract the interest of a broad scientific community. A recommender system uses data on users' past preferences to choose new items that might be appreciated by a given individual user. While many approaches to recommendation exist, the approach based on a network representation of the input data has gained considerable attention in the past. We review here a broad range of network-based recommendation algorithms and for the first time compare their performance on three distinct real datasets. We present recommendation topics that go beyond the mere question of which algorithm to use-such as the possible influence of recommendation on the evolution of systems that use it-and finally discuss open research directions and challenges.

  17. Designing Network-based Business Model Ontology

    DEFF Research Database (Denmark)

    Hashemi Nekoo, Ali Reza; Ashourizadeh, Shayegheh; Zarei, Behrouz

    2015-01-01

    Survival on dynamic environment is not achieved without a map. Scanning and monitoring of the market show business models as a fruitful tool. But scholars believe that old-fashioned business models are dead; as they are not included the effect of internet and network in themselves. This paper...... is going to propose e-business model ontology from the network point of view and its application in real world. The suggested ontology for network-based businesses is composed of individuals` characteristics and what kind of resources they own. also, their connections and pre-conceptions of connections...... such as shared-mental model and trust. However, it mostly covers previous business model elements. To confirm the applicability of this ontology, it has been implemented in business angel network and showed how it works....

  18. Network Based High Speed Product Innovation

    DEFF Research Database (Denmark)

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted...... to be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product development...... - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on how NPD...

  19. Trust-Based Access Control Model from Sociological Approach in Dynamic Online Social Network Environment

    Science.gov (United States)

    Kim, Seungjoo

    2014-01-01

    There has been an explosive increase in the population of the OSN (online social network) in recent years. The OSN provides users with many opportunities to communicate among friends and family. Further, it facilitates developing new relationships with previously unknown people having similar beliefs or interests. However, the OSN can expose users to adverse effects such as privacy breaches, the disclosing of uncontrolled material, and the disseminating of false information. Traditional access control models such as MAC, DAC, and RBAC are applied to the OSN to address these problems. However, these models are not suitable for the dynamic OSN environment because user behavior in the OSN is unpredictable and static access control imposes a burden on the users to change the access control rules individually. We propose a dynamic trust-based access control for the OSN to address the problems of the traditional static access control. Moreover, we provide novel criteria to evaluate trust factors such as sociological approach and evaluate a method to calculate the dynamic trust values. The proposed method can monitor negative behavior and modify access permission levels dynamically to prevent the indiscriminate disclosure of information. PMID:25374943

  20. Trust-Based Access Control Model from Sociological Approach in Dynamic Online Social Network Environment

    Directory of Open Access Journals (Sweden)

    Seungsoo Baek

    2014-01-01

    Full Text Available There has been an explosive increase in the population of the OSN (online social network in recent years. The OSN provides users with many opportunities to communicate among friends and family. Further, it facilitates developing new relationships with previously unknown people having similar beliefs or interests. However, the OSN can expose users to adverse effects such as privacy breaches, the disclosing of uncontrolled material, and the disseminating of false information. Traditional access control models such as MAC, DAC, and RBAC are applied to the OSN to address these problems. However, these models are not suitable for the dynamic OSN environment because user behavior in the OSN is unpredictable and static access control imposes a burden on the users to change the access control rules individually. We propose a dynamic trust-based access control for the OSN to address the problems of the traditional static access control. Moreover, we provide novel criteria to evaluate trust factors such as sociological approach and evaluate a method to calculate the dynamic trust values. The proposed method can monitor negative behavior and modify access permission levels dynamically to prevent the indiscriminate disclosure of information.

  1. A novel and efficient user access control scheme for wireless body area sensor networks

    Directory of Open Access Journals (Sweden)

    Santanu Chatterjee

    2014-07-01

    Full Text Available Wireless body area networks (WBANs can be applied to provide healthcare and patient monitoring. However, patient privacy can be vulnerable in a WBAN unless security is considered. Access to authorized users for the correct information and resources for different services can be provided with the help of efficient user access control mechanisms. This paper proposes a new user access control scheme for a WBAN. The proposed scheme makes use of a group-based user access ID, an access privilege mask, and a password. An elliptic curve cryptography-based public key cryptosystem is used to ensure that a particular legitimate user can only access the information for which he/she is authorized. We show that our scheme performs better than previously existing user access control schemes. Through a security analysis, we show that our scheme is secure against possible known attacks. Furthermore, through a formal security verification using the AVISPA (Automated Validation of Internet Security Protocols and Applications tool, we show that our scheme is also secure against passive and active attacks.

  2. Medium Access Control in Energy Harvesting - Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon

    Control (MAC) protocols that are following the receiver-initiated paradigm of asynchronous communication. According to the receiver-initiated paradigm the communication is initiated by the receiver that states its availability to receive data through beacons. The sender is passively listening...... to the channel until it receives the beacon of interest. In this context, the dissertation begins with an in-depth survey of all the receiverinitiated MAC protocols and presents their unique optimization features, which deal with several challenges of the link layer such as mitigation of the energy consumption......-efficient features that aim to adapt the consumed energy to match the harvested energy, distribute the load with respect to the harvested energy, decrease the overhead of the communication, address the requirements for collision avoidance, prioritize urgent traffic and secure the system against beacon replay attacks...

  3. ACAFD: Secure and Scalable Access Control with Assured File Deletion for Outsourced Data in Cloud

    Directory of Open Access Journals (Sweden)

    Sudha Senthilkumar

    2014-11-01

    Full Text Available Cloud storage has emerged as a popular paradigm to outsource data to third party and share it with the collaborators. While this new paradigm enables users to outsource their sensitive data and reduces data management costs, it brings forth the new challenges to the user to keep their data secure. Data storage security and access control in the cloud is one of the challenging ongoing research works to alleviate the data leakage problem from unauthorized users. Existing solutions that use pure cryptographic techniques suffers from heavy computation work with respect to key management and key distribution.  Attribute based encryption is an alternative solution that map the user access structure with the data file attributes to control the data access. However any of the existing schemes doesn’t address the access control with assured deletion of the files upon revocation of user access. This article addresses this open issue using a trusted authority that manages the access control list and takes care of key management and key distribution and file deletion upon user revocation. The prototype of model has been presented and analyzed the security features over existing scheme.

  4. Halloysite Nanotubes: Controlled Access and Release by Smart Gates.

    Science.gov (United States)

    Cavallaro, Giuseppe; Danilushkina, Anna A; Evtugyn, Vladimir G; Lazzara, Giuseppe; Milioto, Stefana; Parisi, Filippo; Rozhina, Elvira V; Fakhrullin, Rawil F

    2017-07-28

    Hollow halloysite nanotubes have been used as nanocontainers for loading and for the triggered release of calcium hydroxide for paper preservation. A strategy for placing end-stoppers into the tubular nanocontainer is proposed and the sustained release from the cavity is reported. The incorporation of Ca(OH)₂ into the nanotube lumen, as demonstrated using transmission electron microscopy (TEM) imaging and Energy Dispersive X-ray (EDX) mapping, retards the carbonatation, delaying the reaction with CO₂ gas. This effect can be further controlled by placing the end-stoppers. The obtained material is tested for paper deacidification. We prove that adding halloysite filled with Ca(OH)₂ to paper can reduce the impact of acid exposure on both the mechanical performance and pH alteration. The end-stoppers have a double effect: they preserve the calcium hydroxide from carbonation, and they prevent from the formation of highly basic pH and trigger the response to acid exposure minimizing the pH drop-down. These features are promising for a composite nanoadditive in the smart protection of cellulose-based materials.

  5. [Public control and equity of access to hospitals under non-State public administration].

    Science.gov (United States)

    Carneiro Junior, Nivaldo; Elias, Paulo Eduardo

    2006-10-01

    To analyze social health organizations in the light of public control and the guarantee of equity of access to health services. Utilizing the case study technique, two social health organizations in the metropolitan region of São Paulo were selected. The analytical categories were equity of access and public control, and these were based on interviews with key informants and technical-administrative reports. It was observed that the overall funding and administrative control of the social health organizations are functions of the state administrator. The presence of a local administrator is important for ensuring equity of access. Public control is expressed through supervisory actions, by means of accounting and financial procedures. Equity of access and public control are not taken into consideration in the administration of these organizations. The central question lies in the capacity of the public authorities to have a presence in implementing this model at the local level, thereby ensuring equity of access and taking public control into consideration.

  6. A novel decentralized hierarchical access control scheme for the medical scenario

    DEFF Research Database (Denmark)

    Eskeland, Sigurd; Prasad, Neeli R.

    2006-01-01

    Electronic patient records contains highly personal and confidential information that it is essential to keep private. Thus, only the medical professionals providing care to a patient should access the patient record of the concerning patient. As personal medical data can be considered...... to be the property of the corresponding patient, it is justified that patients should have the opportunity to exert control over their own data. In this paper, we propose a cryptographic access control scheme allowing patients to grant medical teams authorizations to access their medical data. Moreover......, the hierarchical aspects of teams are taken into account so that the modules of the patient record are to be accessed according to the individual privileges of the medical professionals of the team. Thus, more privileged users obtain larger portions of the data than less privileged users....

  7. A novel decentralized hierarchical access control scheme for the medical scenario

    DEFF Research Database (Denmark)

    Eskeland, Sigurd; Prasad, Neeli R.

    2006-01-01

    Electronic patient records contains highly personal and confidential information that it is essential to keep private. Thus, only the medical professionals providing care to a patient should access the patient record of the concerning patient. As personal medical data can be considered......, the hierarchical aspects of teams are taken into account so that the modules of the patient record are to be accessed according to the individual privileges of the medical professionals of the team. Thus, more privileged users obtain larger portions of the data than less privileged users....... to be the property of the corresponding patient, it is justified that patients should have the opportunity to exert control over their own data. In this paper, we propose a cryptographic access control scheme allowing patients to grant medical teams authorizations to access their medical data. Moreover...

  8. A hybrid medium access control for convergence of broadband wireless and wireline ATM networks

    DEFF Research Database (Denmark)

    Liu, Hong; Gliese, Ulrik Bo; Dittmann, Lars

    2000-01-01

    In this paper, we propose a hybrid medium access control protocol for supporting broadband integrated services in the wireless ATM networks. The integrated services include CBR, VBR and ABR traffic varying from low bit-rate to very high bit-rate. The proposed protocol is an excellent compromise...... of contention, reservation and polling access techniques based on the dynamic TDMA system. Extensive simulation results using realistic data traffic sources, show that the proposed medium access scheme may provide QoS guarantees to different ATM traffic including the realistic MPEG video traces with low cell...

  9. Cognitive Self-Scheduled Mechanism for Access Control in Noisy Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Mario Manzano

    2015-01-01

    Full Text Available Within the challenging environment of intelligent transportation systems (ITS, networked control systems such as platooning guidance of autonomous vehicles require innovative mechanisms to provide real-time communications. Although several proposals are currently under discussion, the design of a rapid, efficient, flexible, and reliable medium access control mechanism which meets the specific constraints of such real-time communications applications remains unsolved in this highly dynamic environment. However, cognitive radio (CR combines the capacity to sense the radio spectrum with the flexibility to adapt to transmission parameters in order to maximize system performance and has thus become an effective approach for the design of dynamic spectrum access (DSA mechanisms. This paper presents the enhanced noncooperative cognitive division multiple access (ENCCMA proposal combining time division multiple access (TDMA and frequency division multiple access (FDMA schemes with CR techniques to obtain a mechanism fulfilling the requirements of real-time communications. The analysis presented here considers the IEEE WAVE and 802.11p as reference standards; however, the proposed medium access control (MAC mechanism can be adapted to operate on the physical layer of different standards. The mechanism also offers the advantage of avoiding signaling, thus enhancing system autonomy as well as behavior in adverse scenarios.

  10. Accessibility to tuberculosis control services and tuberculosis programme performance in southern Ethiopia.

    Science.gov (United States)

    Dangisso, Mesay Hailu; Datiko, Daniel Gemechu; Lindtjørn, Bernt

    2015-01-01

    Despite the expansion of health services and community-based interventions in Ethiopia, limited evidence exists about the distribution of and access to health facilities and their relationship with the performance of tuberculosis (TB) control programmes. We aim to assess the geographical distribution of and physical accessibility to TB control services and their relationship with TB case notification rates (CNRs) and treatment outcome in the Sidama Zone, southern Ethiopia. We carried out an ecological study to assess physical accessibility to TB control facilities and the association of physical accessibility with TB CNRs and treatment outcome. We collected smear-positive pulmonary TB (PTB) cases treated during 2003-2012 from unit TB registers and TB service data such as availability of basic supplies for TB control and geographic locations of health services. We used ArcGIS 10.2 to measure the distance from each enumeration location to the nearest TB control facilities. A linear regression analysis was employed to assess factors associated with TB CNRs and treatment outcome. Over a decade the health service coverage (the health facility-to-population ratio) increased by 36% and the accessibility to TB control facilities also improved. Thus, the mean distance from TB control services was 7.6 km in 2003 (ranging from 1.8 to 25.5 km) between kebeles (the smallest administrative units) and had decreased to 3.2 km in 2012 (ranging from 1.5 to 12.4 km). In multivariate linear regression, as distance from TB diagnostic facilities (b-estimate=-0.25, pcontrol facilities (b-estimate=-0.27, pcontrol services improved despite the geographic variations. TB CNRs were higher in areas where people had better access to diagnostic and treatment centres. Community-based interventions also played an important role for the increased CNRs in most areas.

  11. Network-Based and Binless Frequency Analyses.

    Directory of Open Access Journals (Sweden)

    Sybil Derrible

    Full Text Available We introduce and develop a new network-based and binless methodology to perform frequency analyses and produce histograms. In contrast with traditional frequency analysis techniques that use fixed intervals to bin values, we place a range ±ζ around each individual value in a data set and count the number of values within that range, which allows us to compare every single value of a data set with one another. In essence, the methodology is identical to the construction of a network, where two values are connected if they lie within a given a range (±ζ. The value with the highest degree (i.e., most connections is therefore assimilated to the mode of the distribution. To select an optimal range, we look at the stability of the proportion of nodes in the largest cluster. The methodology is validated by sampling 12 typical distributions, and it is applied to a number of real-world data sets with both spatial and temporal components. The methodology can be applied to any data set and provides a robust means to uncover meaningful patterns and trends. A free python script and a tutorial are also made available to facilitate the application of the method.

  12. Network-based analysis of proteomic profiles

    KAUST Repository

    Wong, Limsoon

    2016-01-26

    Mass spectrometry (MS)-based proteomics is a widely used and powerful tool for profiling systems-wide protein expression changes. It can be applied for various purposes, e.g. biomarker discovery in diseases and study of drug responses. Although RNA-based high-throughput methods have been useful in providing glimpses into the underlying molecular processes, the evidences they provide are indirect. Furthermore, RNA and corresponding protein levels have been known to have poor correlation. On the other hand, MS-based proteomics tend to have consistency issues (poor reproducibility and inter-sample agreement) and coverage issues (inability to detect the entire proteome) that need to be urgently addressed. In this talk, I will discuss how these issues can be addressed by proteomic profile analysis techniques that use biological networks (especially protein complexes) as the biological context. In particular, I will describe several techniques that we have been developing for network-based analysis of proteomics profile. And I will present evidence that these techniques are useful in identifying proteomics-profile analysis results that are more consistent, more reproducible, and more biologically coherent, and that these techniques allow expansion of the detected proteome to uncover and/or discover novel proteins.

  13. Cognitive radio networks medium access control for coexistence of wireless systems

    CERN Document Server

    Bian, Kaigui; Gao, Bo

    2014-01-01

    This book gives a comprehensive overview of the medium access control (MAC) principles in cognitive radio networks, with a specific focus on how such MAC principles enable different wireless systems to coexist in the same spectrum band and carry out spectrum sharing.  From algorithm design to the latest developments in the standards and spectrum policy, readers will benefit from leading-edge knowledge of how cognitive radio systems coexist and share spectrum resources.  Coverage includes cognitive radio rendezvous, spectrum sharing, channel allocation, coexistence in TV white space, and coexistence of heterogeneous wireless systems.   • Provides a comprehensive reference on medium access control (MAC)-related problems in the design of cognitive radio systems and networks; • Includes detailed analysis of various coexistence problems related to medium access control in cognitive radio networks; • Reveals novel techniques for addressing the challenges of coexistence protocol design at a higher level ...

  14. A bioinspired approach for controlling accessibility in calix[4]arene-bound metal cluster catalysts

    Science.gov (United States)

    de Silva, Namal; Ha, Jeong-Myeong; Solovyov, Andrew; Nigra, Michael M.; Ogino, Isao; Yeh, Sheila W.; Durkin, Kathleen A.; Katz, Alexander

    2010-12-01

    In enzymes, the electronic and steric environments of active centres, and therefore their activity in biological processes, are controlled by the surrounding amino acids. In a similar manner, organic ligands have been used for the `passivation' of metal clusters, that is, inhibition of their aggregation and control of their environment. However, the ability of enzymes to maintain large degrees of accessibility has remained difficult to mimic in synthetic systems in which little room, if any, is typically left to bind to other species. Here, using calix[4]arene macrocycles bearing phosphines as crude mimics of the rigid backbones of proteins, we demonstrate the synthesis of gold clusters and the control of their accessibility through an interplay between the sizes of the calixarene ligands and metal cores. For 0.9-nm cores, 25% of all the gold atoms within the cluster bind to the chemisorption probe 2-naphthalenethiol. This accessibility dramatically decreases with 1.1-nm and 4-nm gold cores.

  15. Secure Access Control and Authority Delegation Based on Capability and Context Awareness for Federated IoT

    DEFF Research Database (Denmark)

    Anggorojati, Bayu; Mahalle, Parikshit N.; Prasad, Neeli R.

    2013-01-01

    Access control is a critical functionality in Internet of Things (IoT), and it is particularly promising to make access control secure, efficient and generic in a distributed environment. Another an important property of access control system in the IoT is flexibility which can be achieved...... by access or authority delegation. Delegation mechanisms in access control that have been studied until now have been intended mainly for a system that has no resource constraint, such as a web-based system, which is not very suitable for a highly pervasive system such as IoT. This chapter presents...... the Capability-based Context Aware Access Control (CCAAC) model including the authority delegation method, along with specification and protocol evaluation intended for federated Machine-to-Machine (M2M)/IoT. By using the identity and capability-based access control approach together with the contextual...

  16. A Generic Role Based Access Control Model for Wind Power Systems

    DEFF Research Database (Denmark)

    Nagarajan, Anand; Jensen, Christian D.

    2010-01-01

    arise in the emerging energy distribution infrastructure. In particular, we examine the security problems that arise in the area of wind power communication infrastructures based on the IEC 61400-25 and IEC 62351 standards. These standards define ways of representing elements of the wind power...... infrastructure in a software domain in a manufacturer independent manner as well as establishing secure communication and authenticating the other parties in electrical power infrastructures, but they do not address the problem of access control. We therefore propose a generic model for access control in wind...

  17. RFID-Based Monitoring And Access Control System For Parliamentary Campus

    OpenAIRE

    Sai Thu Rein Htun; Su Su Yi Mon; Hla Myo Tun

    2015-01-01

    This paper is to implement monitoring and access control system based on RFID and Zigbee technology which can be used at Parliamentary Campus. Nowadays RFID technology is widely used for access control system because it is cheap waterproof and easy to use as well as it contains unique EPC electronic protect code .In addition Zigbee wireless module is cost-effective and can be reliable for security. Sothis system consists of RFID tag RFID reader Arduino Uno and Zigbee. This system can also be ...

  18. Performance Evaluation of Virtualization Techniques for Control and Access of Storage Systems in Data Center Applications

    Science.gov (United States)

    Ahmadi, Mohammad Reza

    2013-09-01

    Virtualization is a new technology that creates virtual environments based on the existing physical resources. This article evaluates effect of virtualization techniques on control servers and access method in storage systems [1, 2]. In control server virtualization, we have presented a tile based evaluation based on heterogeneous workloads to compare several key parameters and demonstrate effectiveness of virtualization techniques. Moreover, we have evaluated the virtualized model using VMotion techniques and maximum consolidation. In access method, we have prepared three different scenarios using direct, semi-virtual, and virtual attachment models. We have evaluated the proposed models with several workloads including OLTP database, data streaming, file server, web server, etc. Results of evaluation for different criteria confirm that server virtualization technique has high throughput and CPU usage as well as good performance with noticeable agility. Also virtual technique is a successful alternative for accessing to the storage systems especially in large capacity systems. This technique can therefore be an effective solution for expansion of storage area and reduction of access time. Results of different evaluation and measurements demonstrate that the virtualization in control server and full virtual access provide better performance and more agility as well as more utilization in the systems and improve business continuity plan.

  19. Accessibility to tuberculosis control services and tuberculosis programme performance in southern Ethiopia

    Directory of Open Access Journals (Sweden)

    Mesay Hailu Dangisso

    2015-11-01

    Full Text Available Background: Despite the expansion of health services and community-based interventions in Ethiopia, limited evidence exists about the distribution of and access to health facilities and their relationship with the performance of tuberculosis (TB control programmes. We aim to assess the geographical distribution of and physical accessibility to TB control services and their relationship with TB case notification rates (CNRs and treatment outcome in the Sidama Zone, southern Ethiopia. Design: We carried out an ecological study to assess physical accessibility to TB control facilities and the association of physical accessibility with TB CNRs and treatment outcome. We collected smear-positive pulmonary TB (PTB cases treated during 2003–2012 from unit TB registers and TB service data such as availability of basic supplies for TB control and geographic locations of health services. We used ArcGIS 10.2 to measure the distance from each enumeration location to the nearest TB control facilities. A linear regression analysis was employed to assess factors associated with TB CNRs and treatment outcome. Results: Over a decade the health service coverage (the health facility–to-population ratio increased by 36% and the accessibility to TB control facilities also improved. Thus, the mean distance from TB control services was 7.6 km in 2003 (ranging from 1.8 to 25.5 km between kebeles (the smallest administrative units and had decreased to 3.2 km in 2012 (ranging from 1.5 to 12.4 km. In multivariate linear regression, as distance from TB diagnostic facilities (b-estimate=−0.25, p<0.001 and altitude (b-estimate=−0.31, p<0.001 increased, the CNRs of TB decreased, whereas a higher population density was associated with increased TB CNRs. Similarly, distance to TB control facilities (b-estimate=−0.27, p<0.001 and altitude (b-estimate=−0.30, p<0.001 were inversely associated with treatment success (proportion of treatment completed or cured cases

  20. Toward Federated Security and Data Access Control within a Services Oriented Architecture for Publishing Hydrologic Data

    Science.gov (United States)

    Horsburgh, J. S.; Tarboton, D. G.; Schreuders, K.; Patil, K. S.

    2010-12-01

    Academic researchers who manage experimental watersheds, observatories, and research sites need the ability to effectively collect, manage, and publish hydrologic data. This often requires the ability to control and document access to the data. One current mechanism for publishing data from experimental sites uses the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS). The CUAHSI HIS Project has developed a software stack called HydroServer for publishing hydrologic data. HydroServer relies on a standard relational database schema for storing hydrologic observations, called the Observations Data Model (ODM), a standard set of web services for publishing observations stored in an ODM database, called WaterOneFlow, and a standard XML schema for exchanging hydrologic observations data, called Water Markup Language (WaterML). These standards make is possible for disparate investigators to publish their data as web services within a federated network of HydroServers. Once a HydroServer is operational, all Internet users can access all of the data on the server, with no requirement for users to identify themselves, or restriction on what can be accessed. There are a number of situations where data producers want to take advantage of the organization and functionality that ODM and the HydroServer software stack provides, but without providing unrestricted and unlogged access to all of the data that they are putting on their server. These include the desire of academic data collectors to: 1) control who can access/download data; 2) publish research results based on data before the data are released to the general public; 3) keep track of who is downloading and using their data to evaluate and document its impact on the community; 4) have and use a data use/access agreement and ensure that they get credit and appropriate citation for the data that they publish; 5) expose the best or highest quality data

  1. Network-based reading system for lung cancer screening CT

    Science.gov (United States)

    Fujino, Yuichi; Fujimura, Kaori; Nomura, Shin-ichiro; Kawashima, Harumi; Tsuchikawa, Megumu; Matsumoto, Toru; Nagao, Kei-ichi; Uruma, Takahiro; Yamamoto, Shinji; Takizawa, Hotaka; Kuroda, Chikazumi; Nakayama, Tomio

    2006-03-01

    This research aims to support chest computed tomography (CT) medical checkups to decrease the death rate by lung cancer. We have developed a remote cooperative reading system for lung cancer screening over the Internet, a secure transmission function, and a cooperative reading environment. It is called the Network-based Reading System. A telemedicine system involves many issues, such as network costs and data security if we use it over the Internet, which is an open network. In Japan, broadband access is widespread and its cost is the lowest in the world. We developed our system considering human machine interface and security. It consists of data entry terminals, a database server, a computer aided diagnosis (CAD) system, and some reading terminals. It uses a secure Digital Imaging and Communication in Medicine (DICOM) encrypting method and Public Key Infrastructure (PKI) based secure DICOM image data distribution. We carried out an experimental trial over the Japan Gigabit Network (JGN), which is the testbed for the Japanese next-generation network, and conducted verification experiments of secure screening image distribution, some kinds of data addition, and remote cooperative reading. We found that network bandwidth of about 1.5 Mbps enabled distribution of screening images and cooperative reading and that the encryption and image distribution methods we proposed were applicable to the encryption and distribution of general DICOM images via the Internet.

  2. A test bed for the future access control system the AD Project

    CERN Document Server

    Scibile, L

    1999-01-01

    This paper describes the design, management and development of the new access control system for the Antiproton Deceleration experimental area, called the AD Project. As this project includes all the elements for the industrial evolution of the present access control system it is an ideal test bed for future access systems. The adoption of new technologies and techniques are described, and the benefits and the shortfalls are highlighted. The open redundant architecture solution, based on a PROFIBUS network and standard industrial components (HP-UNIX, Siemens S7 PLC, Siemens Industrial PC, door locks), guarantees reliability, safety and optimal integration. The project team took advantage of the Goal Directed Project Management technique and managed to define a clear and effective strategy.

  3. Integrating the lightweight authentication protocol (LAP) with access control mechanisms in wireless health care information systems.

    Science.gov (United States)

    Chousiadis, C; Georgiadis, C K; Pangalos, G

    2002-01-01

    Health information networks are expected to support information exchange that is authentic, accurate, private and available when, where and to whom is needed. With the increase of the shared medical information and resources in healthcare wireless information systems, unauthorized access to the information by illegal users also increases. The security of the transmitted information is a vital issue. In this paper, we report on the development of the Lightweight Authentication Protocol (LAP), which makes a mobile and distributed system more secure and flexible and we implement it in a Health Care Environment where the clinicians use mobile and wireless devices like PDAs. We also provide an indicative example of integrating the LAP with access control mechanisms. Context-based Team Access Control (C-TMAC) model is used in this example, since it provides great flexibility on user-permissions management in collaborative healthcare environments. LAP is indeed capable to support efficiently the advanced authorization procedures of such demanding active security models.

  4. Developing Access Control Model of Web OLAP over Trusted and Collaborative Data Warehouses

    Science.gov (United States)

    Fugkeaw, Somchart; Mitrpanont, Jarernsri L.; Manpanpanich, Piyawit; Juntapremjitt, Sekpon

    This paper proposes the design and development of Role- based Access Control (RBAC) model for the Single Sign-On (SSO) Web-OLAP query spanning over multiple data warehouses (DWs). The model is based on PKI Authentication and Privilege Management Infrastructure (PMI); it presents a binding model of RBAC authorization based on dimension privilege specified in attribute certificate (AC) and user identification. Particularly, the way of attribute mapping between DW user authentication and privilege of dimensional access is illustrated. In our approach, we apply the multi-agent system to automate flexible and effective management of user authentication, role delegation as well as system accountability. Finally, the paper culminates in the prototype system A-COLD (Access Control of web-OLAP over multiple DWs) that incorporates the OLAP features and authentication and authorization enforcement in the multi-user and multi-data warehouse environment.

  5. On the Impact of information access delays on remote control of a wind turbine

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Barradas Berglind, Jose de Jesus; Madsen, Tatiana Kozlova

    2015-01-01

    farm controller. The controller attempts to reduce fatigue on the wind turbine, which is used as a measure of the controller performance. Via simulation analysis, we show the degradation of the controller performance when subject to network delays. We analyse different access strategies useable......It is important to reduce the impact of renewable production in the power grid by means of control, due to increased frequency deviations and imbalances caused by these assets. Cost efficient deployment of asset control frequently results in a distributed control architecture where the controller...... is connected via a communication network to the sensors and actuators on the asset. Such a distributed control scheme may be implemented over a communication network that introduces delay and possibly also message loss. In this paper, we look at the impact of such an imperfect communication network on a wind...

  6. An Optimal Medium Access Control with Partial Observations for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Servetto Sergio D

    2005-01-01

    Full Text Available We consider medium access control (MAC in multihop sensor networks, where only partial information about the shared medium is available to the transmitter. We model our setting as a queuing problem in which the service rate of a queue is a function of a partially observed Markov chain representing the available bandwidth, and in which the arrivals are controlled based on the partial observations so as to keep the system in a desirable mildly unstable regime. The optimal controller for this problem satisfies a separation property: we first compute a probability measure on the state space of the chain, namely the information state, then use this measure as the new state on which the control decisions are based. We give a formal description of the system considered and of its dynamics, we formalize and solve an optimal control problem, and we show numerical simulations to illustrate with concrete examples properties of the optimal control law. We show how the ergodic behavior of our queuing model is characterized by an invariant measure over all possible information states, and we construct that measure. Our results can be specifically applied for designing efficient and stable algorithms for medium access control in multiple-accessed systems, in particular for sensor networks.

  7. Functional requirements with survey results for integrated intrusion detection and access control annunciator systems

    Energy Technology Data Exchange (ETDEWEB)

    Arakaki, L.H.; Monaco, F.M.

    1995-09-01

    This report contains the guidance Functional Requirements for an Integrated Intrusion Detection and Access Control Annunciator System, and survey results of selected commercial systems. The survey questions were based upon the functional requirements; therefore, the results reflect which and sometimes how the guidance recommendations were met.

  8. Multi-level access control in the data pipeline of the international supply chain system

    NARCIS (Netherlands)

    Pruksasri, P.; Berg, J. van den; Hofman, W.; Daskapan, S.

    2013-01-01

    The Seamless Integrated Data Pipeline system was proposed to the European Union in order to overcome the information quality shortcomings of the current international supply chain information exchange systems. Next to identification and authorization of stakeholders, secure access control needs to

  9. Access To and Control of Resources Among The Maasai Women of ...

    African Journals Online (AJOL)

    The majority of the respondents had access to and control over milk and its products, ornaments and traditional food prepared for sale to customers, and used the income generated from these resources to buy food, clothes, school uniform, and other domestic requirements. Others sometimes save the balance. On the other ...

  10. Gender Relations in Access to and Control over Resources in Awra ...

    African Journals Online (AJOL)

    This paper explores gender relations in access to and control over resources in Awra Amba Community of Amhara Region, Ethiopia. The study employed primary and secondary data sources. The primary data were gathered through semistructured interviews with selected community members and key informants, focus ...

  11. Policy Based Access Control in Dynamic Grid-based Collaborative Environment

    NARCIS (Netherlands)

    Demchenko, Y.; Gommans, L.; Tokmakoff, A.; van Buuren, R.

    2006-01-01

    This paper describes the design and development of a flexible, customer-driven, security infrastructure for Gridbased Collaborative Environments. The paper proposes further development of the access control model built around a service or resource provisioning agreement (e.g., an experiment or

  12. Benefits of Location-Based Access Control:A Literature Study

    NARCIS (Netherlands)

    van Cleeff, A.; Pieters, Wolter; Wieringa, Roelf J.

    2010-01-01

    Location-based access control (LBAC) has been suggested as a means to improve IT security. By 'grounding' users and systems to a particular location, attackers supposedly have more difficulty in compromising a system. However, the motivation behind LBAC and its potential benefits have not been

  13. Mining Roles and Access Control for Relational Data under Privacy and Accuracy Constraints

    Science.gov (United States)

    Pervaiz, Zahid

    2013-01-01

    Access control mechanisms protect sensitive information from unauthorized users. However, when sensitive information is shared and a Privacy Protection Mechanism (PPM) is not in place, an authorized insider can still compromise the privacy of a person leading to identity disclosure. A PPM can use suppression and generalization to anonymize and…

  14. Using Face Recognition in the Automatic Door Access Control in a Secured Room

    Directory of Open Access Journals (Sweden)

    Gheorghe Gilca

    2017-06-01

    Full Text Available The aim of this paper is to help users improve the door security of sensitive locations by using face detection and recognition. This paper is comprised mainly of three subsystems: face detection, face recognition and automatic door access control. The door will open automatically for the known person due to the command of the microcontroller.

  15. Socio-economic status influences blood pressure control despite equal access to care

    DEFF Research Database (Denmark)

    Paulsen, M S; Andersen, M; Munck, A P

    2012-01-01

    OBJECTIVE: Denmark has a health care system with free and equal access to care irrespective of age and socio-economic status (SES). We conducted a cross-sectional study to investigate a possible association between SES and blood pressure (BP) control of hypertensive patients treated in general...

  16. Secure Access Control and Large Scale Robust Representation for Online Multimedia Event Detection

    Science.gov (United States)

    Liu, Changyu; Li, Huiling

    2014-01-01

    We developed an online multimedia event detection (MED) system. However, there are a secure access control issue and a large scale robust representation issue when we want to integrate traditional event detection algorithms into the online environment. For the first issue, we proposed a tree proxy-based and service-oriented access control (TPSAC) model based on the traditional role based access control model. Verification experiments were conducted on the CloudSim simulation platform, and the results showed that the TPSAC model is suitable for the access control of dynamic online environments. For the second issue, inspired by the object-bank scene descriptor, we proposed a 1000-object-bank (1000OBK) event descriptor. Feature vectors of the 1000OBK were extracted from response pyramids of 1000 generic object detectors which were trained on standard annotated image datasets, such as the ImageNet dataset. A spatial bag of words tiling approach was then adopted to encode these feature vectors for bridging the gap between the objects and events. Furthermore, we performed experiments in the context of event classification on the challenging TRECVID MED 2012 dataset, and the results showed that the robust 1000OBK event descriptor outperforms the state-of-the-art approaches. PMID:25147840

  17. The Use of Passwords for Controlled Access to Computer Resources. Computer Science & Technology.

    Science.gov (United States)

    Wood, Helen M.

    This paper considers the generation of passwords and their effective application to the problem of controlling access to computer resources. After describing the need for and uses of passwords, password schemes are categorized according to selection technique, lifetime, physical characteristics, and information content. Password protection, both…

  18. Predicting Health Care Utilization among Latinos: Health Locus of Control Beliefs or Access Factors?

    Science.gov (United States)

    De Jesus, Maria; Xiao, Chenyang

    2014-01-01

    There are two competing research explanations to account for Latinos' underutilization of health services relative to non-Latino Whites in the United States. One hypothesis examines the impact of health locus of control (HLOC) beliefs, while the other focuses on the role of access factors on health care use. To date, the relative strength of…

  19. An Access Control and Trust Management Framework for Loosely-Coupled Multidomain Environments

    Science.gov (United States)

    Zhang, Yue

    2010-01-01

    Multidomain environments where multiple organizations interoperate with each other are becoming a reality as can be seen in emerging Internet-based enterprise applications. Access control to ensure secure interoperation in such an environment is a crucial challenge. A multidomain environment can be categorized as "tightly-coupled" and…

  20. Access and control of agro-biotechnology : Bt cotton, ecological change and risk in China

    NARCIS (Netherlands)

    Ho, Peter; Zhao, Jennifer H.; Xue, Dayuan

    2009-01-01

    This article argues that if the introduction of genetically modified crops (GM crops) in developing countries is to be successful, we can and should not evade questions of access and control of technology. It implies probing into the experiences, perceptions and understanding of GM crops by the

  1. An Annotated and Cross-Referenced Bibliography on Computer Security and Access Control in Computer Systems.

    Science.gov (United States)

    Bergart, Jeffrey G.; And Others

    This paper represents a careful study of published works on computer security and access control in computer systems. The study includes a selective annotated bibliography of some eighty-five important published results in the field and, based on these papers, analyzes the state of the art. In annotating these works, the authors try to be…

  2. Automatic Access Control Based on Face and Hand Biometrics in A Non-Cooperative Context

    DEFF Research Database (Denmark)

    Jahromi, Mohammad Naser Sabet; Bonderup, Morten Bojesen; Nasrollahi, Kamal

    2018-01-01

    Automatic access control systems (ACS) based on the human biometrics or physical tokens are widely employed in public and private areas. Yet these systems, in their conventional forms, are restricted to active interaction from the users. In scenarios where users are not cooperating with the system...

  3. RCT: Module 2.10, Access Control and Work Area Setup, Course 8776

    Energy Technology Data Exchange (ETDEWEB)

    Hillmer, Kurt T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-11

    This course presents information on radiological work permits (RWPs), various types of postings used in radiological areas, radiological area setups, access controls, and releases of material from radiological areas. All of these are fundamental duties of RCTs. This course will prepare the student with the skills necessary for radiological control technician (RCT) qualification by passing quizzes, tests, and the RCT Comprehensive Phase 1, Unit 2 Examination (TEST 27566) and providing in-thefield skills.

  4. Toward an open-access global database for mapping, control, and surveillance of neglected tropical diseases

    DEFF Research Database (Denmark)

    Hürlimann, Eveline; Schur, Nadine; Boutsika, Konstantina

    2011-01-01

    for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken...... toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs....

  5. Optimizing data access for wind farm control over hierarchical communication networks

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Findrik, Mislav; Madsen, Tatiana Kozlova

    2016-01-01

    In this paper we investigate a centralized wind farm controller which runs periodically. The controller attempts to reduce the damage a wind turbine sustains during operation by estimating fatigue based on the wind turbine state. The investigation focuses on the impact of information access...... with respect to the communication network delays. These measurements are done in regards to packet loss and communication delays, and the simulations are rerun using either the traces from the measurements or scenarios constructed from the delay parameters....

  6. Media access control and resource allocation for next generation passive optical networks

    CERN Document Server

    Ansari, Nirwan

    2013-01-01

    This book focuses on various Passive optical networks (PONs)  types, including currently deployed Ethernet PON (EPON) and Gigabit PON (GPON) as well as next generation WDM PON and OFDM PON. Also this book examines the integrated optical and wireless access networks. Concentrating on two issues in these networks: media access control (MAC) and resource allocation. These two problems can greatly affect performances of PONs such as network resource utilization and QoS of end users. Finally this book will discuss various solutions to address the MAC and resource allocation issues in various PON networks.

  7. Extending AAA operational model for profile-based access control in ethernet-based Neutral Access Networks

    NARCIS (Netherlands)

    Matias, J.; Jacob, E.; Demchenko, Y.; de Laat, C.; Gommans, L.; Macías López, E.M.; Bogliolo, A.; Perry, M.; Ran, M

    2010-01-01

    Neutral Access Networks (NAN) have appeared as a new model to overcome some restrictions and lack of flexibility that are present currently in broadband access networks. NAN brings new business opportunities by opening this market to new stakeholders. Although the NAN model is accepted, there are

  8. Implementation of a Cross-Layer Sensing Medium-Access Control Scheme.

    Science.gov (United States)

    Su, Yishan; Fu, Xiaomei; Han, Guangyao; Xu, Naishen; Jin, Zhigang

    2017-04-10

    In this paper, compressed sensing (CS) theory is utilized in a medium-access control (MAC) scheme for wireless sensor networks (WSNs). We propose a new, cross-layer compressed sensing medium-access control (CL CS-MAC) scheme, combining the physical layer and data link layer, where the wireless transmission in physical layer is considered as a compress process of requested packets in a data link layer according to compressed sensing (CS) theory. We first introduced using compressive complex requests to identify the exact active sensor nodes, which makes the scheme more efficient. Moreover, because the reconstruction process is executed in a complex field of a physical layer, where no bit and frame synchronizations are needed, the asynchronous and random requests scheme can be implemented without synchronization payload. We set up a testbed based on software-defined radio (SDR) to implement the proposed CL CS-MAC scheme practically and to demonstrate the validation. For large-scale WSNs, the simulation results show that the proposed CL CS-MAC scheme provides higher throughput and robustness than the carrier sense multiple access (CSMA) and compressed sensing medium-access control (CS-MAC) schemes.

  9. Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2018-01-01

    Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

  10. A Quantum Cryptography Communication Network Based on Software Defined Network

    Directory of Open Access Journals (Sweden)

    Zhang Hongliang

    2018-01-01

    Full Text Available With the development of the Internet, information security has attracted great attention in today’s society, and quantum cryptography communication network based on quantum key distribution (QKD is a very important part of this field, since the quantum key distribution combined with one-time-pad encryption scheme can guarantee the unconditional security of the information. The secret key generated by quantum key distribution protocols is a very valuable resource, so making full use of key resources is particularly important. Software definition network (SDN is a new type of network architecture, and it separates the control plane and the data plane of network devices through OpenFlow technology, thus it realizes the flexible control of the network resources. In this paper, a quantum cryptography communication network model based on SDN is proposed to realize the flexible control of quantum key resources in the whole cryptography communication network. Moreover, we propose a routing algorithm which takes into account both the hops and the end-to-end availible keys, so that the secret key generated by QKD can be used effectively. We also simulate this quantum cryptography communication network, and the result shows that based on SDN and the proposed routing algorithm the performance of this network is improved since the effective use of the quantum key resources.

  11. Design and implementation of fingerprint access control system based on ZigBee wireless network

    Directory of Open Access Journals (Sweden)

    Zhang Jin

    2017-01-01

    Full Text Available this paper mainly introduces a kind of fingerprint access control system based on ZigBee wireless network design and implementation method, specify when passengers should fingerprints collected and stored in the system at the information desk PC, and then assign rooms;Guests entered the room according to the fingerprint module, the system will be fingerprint information through ZigBee coordinator node module and network to transmit the fingerprint characteristic value to management system and the fingerprint information stored, if consistent with the electromagnetic lock open, allowed to enter the room, does not conform to the issued a warning sound.Additional access control system can control the corresponding fingerprint information storage room and remove, such as is required for a security incident broke in situation is special open mode can be set up.System software design consists of two aspects of the bottom and upper machine.

  12. On the Need of Novel Medium Access Control Schemes for Network Coding enabled Wireless Mesh Networks

    DEFF Research Database (Denmark)

    Paramanathan, Achuthan; Pahlevani, Peyman; Roetter, Daniel Enrique Lucani

    2013-01-01

    This paper advocates for a new Medium Access Control (MAC) strategy for wireless meshed networks by identifying overload scenarios in order to provide additional channel access priority to the relay. The key behind our MAC protocol is that the relay will adjust its back off window size according...... that network coding will improve the throughput in such systems, but our novel medium access scheme improves the performance in the cross topology by another 66 % for network coding and 150 % for classical forwarding in theory. These gains translate in a theoretical gain of 33 % of network coding over...... classical forwarding when both systems implement the improved MAC. However, our measurement results show an even larger gain for network coding, namely, up to 65 % over forwarding, as it copes better with channel losses under high load scenarios....

  13. SmartVeh: Secure and Efficient Message Access Control and Authentication for Vehicular Cloud Computing.

    Science.gov (United States)

    Huang, Qinlong; Yang, Yixian; Shi, Yuxiang

    2018-02-24

    With the growing number of vehicles and popularity of various services in vehicular cloud computing (VCC), message exchanging among vehicles under traffic conditions and in emergency situations is one of the most pressing demands, and has attracted significant attention. However, it is an important challenge to authenticate the legitimate sources of broadcast messages and achieve fine-grained message access control. In this work, we propose SmartVeh, a secure and efficient message access control and authentication scheme in VCC. A hierarchical, attribute-based encryption technique is utilized to achieve fine-grained and flexible message sharing, which ensures that vehicles whose persistent or dynamic attributes satisfy the access policies can access the broadcast message with equipped on-board units (OBUs). Message authentication is enforced by integrating an attribute-based signature, which achieves message authentication and maintains the anonymity of the vehicles. In order to reduce the computations of the OBUs in the vehicles, we outsource the heavy computations of encryption, decryption and signing to a cloud server and road-side units. The theoretical analysis and simulation results reveal that our secure and efficient scheme is suitable for VCC.

  14. State of the Art Authentication, Access Control, and Secure Integration in Smart Grid

    Directory of Open Access Journals (Sweden)

    Neetesh Saxena

    2015-10-01

    Full Text Available The smart grid (SG is a promising platform for providing more reliable, efficient, and cost effective electricity to the consumers in a secure manner. Numerous initiatives across the globe are taken by both industry and academia in order to compile various security issues in the smart grid network. Unfortunately, there is no impactful survey paper available in the literature on authentications in the smart grid network. Therefore, this paper addresses the required objectives of an authentication protocol in the smart grid network along with the focus on mutual authentication, access control, and secure integration among different SG components. We review the existing authentication protocols, and analyze mutual authentication, privacy, trust, integrity, and confidentiality of communicating information in the smart grid network. We review authentications between the communicated entities in the smart grid, such as smart appliance, smart meter, energy provider, control center (CC, and home/building/neighborhood area network gateways (GW. We also review the existing authentication schemes for the vehicle-to-grid (V2G communication network along with various available secure integration and access control schemes. We also discuss the importance of the mutual authentication among SG entities while providing confidentiality and privacy preservation, seamless integration, and required access control with lower overhead, cost, and delay. This paper will help to provide a better understanding of current authentication, authorization, and secure integration issues in the smart grid network and directions to create interest among researchers to further explore these promising areas.

  15. Neural Network Based Intrusion Detection System for Critical Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Ondrej Linda; Milos Manic

    2009-07-01

    Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

  16. CP-ABE Access Control Scheme for Sensitive Data Set Constraint with Hidden Access Policy and Constraint Policy

    National Research Council Canada - National Science Library

    Nurmamat Helil; Kaysar Rahman

    2017-01-01

    .... However, a mechanism to prevent users from achieving successive access to a data owner’s certain number of data objects, which present a conflict of interest or whose combination thereof is sensitive, has yet to be studied...

  17. Network-based in silico drug efficacy screening

    National Research Council Canada - National Science Library

    Guney, Emre; Menche, Jörg; Vidal, Marc; Barábasi, Albert-László

    2016-01-01

    .... Here, we take advantage of our increasing understanding of the network-based origins of diseases to introduce a drug-disease proximity measure that quantifies the interplay between drugs targets and diseases...

  18. A Secure and Verifiable Outsourced Access Control Scheme in Fog-Cloud Computing.

    Science.gov (United States)

    Fan, Kai; Wang, Junxiong; Wang, Xin; Li, Hui; Yang, Yintang

    2017-07-24

    With the rapid development of big data and Internet of things (IOT), the number of networking devices and data volume are increasing dramatically. Fog computing, which extends cloud computing to the edge of the network can effectively solve the bottleneck problems of data transmission and data storage. However, security and privacy challenges are also arising in the fog-cloud computing environment. Ciphertext-policy attribute-based encryption (CP-ABE) can be adopted to realize data access control in fog-cloud computing systems. In this paper, we propose a verifiable outsourced multi-authority access control scheme, named VO-MAACS. In our construction, most encryption and decryption computations are outsourced to fog devices and the computation results can be verified by using our verification method. Meanwhile, to address the revocation issue, we design an efficient user and attribute revocation method for it. Finally, analysis and simulation results show that our scheme is both secure and highly efficient.

  19. An internet of things example: classrooms access control over near field communication.

    Science.gov (United States)

    Palma, Daniel; Agudo, Juan Enrique; Sánchez, Héctor; Macías, Miguel Macías

    2014-04-21

    The Internet of Things is one of the ideas that has become increasingly relevant in recent years. It involves connecting things to the Internet in order to retrieve information from them at any time and from anywhere. In the Internet of Things, sensor networks that exchange information wirelessly via Wi-Fi, Bluetooth, Zigbee or RF are common. In this sense, our paper presents a way in which each classroom control is accessed through Near Field Communication (NFC) and the information is shared via radio frequency. These data are published on the Web and could easily be used for building applications from the data collected. As a result, our application collects information from the classroom to create a control classroom tool that displays access to and the status of all the classrooms graphically and also connects this data with social networks.

  20. An Internet of Things Example: Classrooms Access Control over Near Field Communication

    Directory of Open Access Journals (Sweden)

    Daniel Palma

    2014-04-01

    Full Text Available The Internet of Things is one of the ideas that has become increasingly relevant in recent years. It involves connecting things to the Internet in order to retrieve information from them at any time and from anywhere. In the Internet of Things, sensor networks that exchange information wirelessly via Wi-Fi, Bluetooth, Zigbee or RF are common. In this sense, our paper presents a way in which each classroom control is accessed through Near Field Communication (NFC and the information is shared via radio frequency. These data are published on the Web and could easily be used for building applications from the data collected. As a result, our application collects information from the classroom to create a control classroom tool that displays access to and the status of all the classrooms graphically and also connects this data with social networks.

  1. RFID-Based Monitoring And Access Control System For Parliamentary Campus

    Directory of Open Access Journals (Sweden)

    Sai Thu Rein Htun

    2015-08-01

    Full Text Available This paper is to implement monitoring and access control system based on RFID and Zigbee technology which can be used at Parliamentary Campus. Nowadays RFID technology is widely used for access control system because it is cheap waterproof and easy to use as well as it contains unique EPC electronic protect code .In addition Zigbee wireless module is cost-effective and can be reliable for security. Sothis system consists of RFID tag RFID reader Arduino Uno and Zigbee. This system can also be used for industrial amp commercial and security HVAC closures. This paper describes the results of point-to-point connection and point-to-multipoint connection using Zigbee and RFID technology.

  2. A METHOD OF AND A SYSTEM FOR CONTROLLING ACCESS TO A SHARED RESOURCE

    DEFF Research Database (Denmark)

    2006-01-01

    A method and a system of controlling access of data items to a shared resource, wherein the data items each is assigned to one of a plurality of priorities, and wherein, when a predetermined number of data items of a priority have been transmitted to the shared resource, that priority will be awa...... will be awaiting, i.e. no further data items are transmitted with that priority, until all lower, non-awaiting priorities have had one or more data items transmitted to the shared resource. In this manner, guarantees services may be obtained for all priorities.......A method and a system of controlling access of data items to a shared resource, wherein the data items each is assigned to one of a plurality of priorities, and wherein, when a predetermined number of data items of a priority have been transmitted to the shared resource, that priority...

  3. Dynamic network-based epistasis analysis: Boolean examples

    Directory of Open Access Journals (Sweden)

    Eugenio eAzpeitia

    2011-12-01

    Full Text Available In this review we focus on how the hierarchical and single-path assumptions of epistasis analysis can bias the topologies of gene interactions infered. This has been acknowledged in several previous papers and reviews, but here we emphasize the critical importance of dynamic analyses, and specifically illustrate the use of Boolean network models. Epistasis in a broad sense refers to gene interactions, however, as originally proposed by Bateson (herein, classical epistasis, defined as the blocking of a particular allelic effect due to the effect of another allele at a different locus. Classical epistasis analysis has proven powerful and useful, allowing researchers to infer and assign directionality to gene interactions. As larger data sets are becoming available, the analysis of classical epistasis is being complemented with computer science tools and system biology approaches. We show that when the hierarchical and single-path assumptions are not met in classical epistasis analysis, the access to relevant information and the correct gene interaction topologies are hindered, and it becomes necessary to consider the temporal dynamics of gene interactions. The use of dynamical networks can overcome these limitations. We particularly focus on the use of Boolean networks that, like classical epistasis analysis, relies on logical formalisms, and hence can complement classical epistasis analysis and relax its assumptions. We develop a couple of theoretical examples and analyze them from a dynamic Boolean network model perspective. Boolean networks could help to guide additional experiments and discern among alternative regulatory schemes that would be impossible or difficult to infer without the elimination of these assumption from the classical epistasis analysis. We also use examples from the literature to show how a Boolean network-based approach has resolved ambiguities and guided epistasis analysis. Our review complements previous accounts, not

  4. Situational Awareness based Risk-Adapatable Access Control in Enterprise Networks

    OpenAIRE

    Lee, Brian; Vanickis, Roman; Rogelio, Franklin; Jacob, Paul

    2017-01-01

    As the computing landscape evolves towards distributed architectures such as Internet of Things (IoT),enterprises are moving away from traditional perimeter based security models toward so called zero trust networking (ZTN) models that treat both the intranet and Internet as equally untrustworthy. Such security models incorporate risk arising from dynamic and situational factors, such as device location and security risk level risk, into the access control decision. Researchers have developed...

  5. IAACaaS: IoT Application-Scoped Access Control as a Service

    Directory of Open Access Journals (Sweden)

    Álvaro Alonso

    2017-10-01

    Full Text Available access control is a key element when guaranteeing the security of online services. However, devices that make the Internet of Things have some special requirements that foster new approaches to access control mechanisms. Their low computing capabilities impose limitations that make traditional paradigms not directly applicable to sensors and actuators. In this paper, we propose a dynamic, scalable, IoT-ready model that is based on the OAuth 2.0 protocol and that allows the complete delegation of authorization, so that an as a service access control mechanism is provided. Multiple tenants are also supported by means of application-scoped authorization policies, whose roles and permissions are fine-grained enough to provide the desired flexibility of configuration. Besides, OAuth 2.0 ensures interoperability with the rest of the Internet, yet preserving the computing constraints of IoT devices, because its tokens provide all the necessary information to perform authorization. The proposed model has been fully implemented in an open-source solution and also deeply validated in the scope of FIWARE, a European project with thousands of users, the goal of which is to provide a framework for developing smart applications and services for the future Internet. We provide the details of the deployed infrastructure and offer the analysis of a sample smart city setup that takes advantage of the model. We conclude that the proposed solution enables a new access control as a service paradigm that satisfies the special requirements of IoT devices in terms of performance, scalability and interoperability.

  6. Electronic Wallet and Access Control Solution Based on RFID MiFare Cards

    OpenAIRE

    Stefan Victor Lefter

    2013-01-01

    With the advent of Radio Frequency Identification technologies or RFID for short, different types of products and security-relevant applications have been developed for use in fields and businesses like: inventory management, product tracking, access control, passports or transport fare collection. Even though RFID has been around for quite some time, there are some types of businesses like theme parks, water parks or music festivals that haven’t yet tested the benefits that this technology b...

  7. Design of Novel Online Access and Control Interface for Remote Experiment on DC Drives

    Directory of Open Access Journals (Sweden)

    Jagadeesh Chandra A.P

    2009-05-01

    Full Text Available Internet has revolutionized the way in which the information is delivered. Laboratory based courses play an important role in technical education. Automation is changing the nature of these laboratories and the system designer’s focus on Internet accessed experiments owing to the availability of several tools to integrate electronic and mechanical hardware with the World Wide Web. Stand-alone approaches in remote learning have grown tremendously in the recent years. One of the important components in remote experimentation is the integration of Virtual Instruments to perform real hardware tasks in near real-time. The paper describes a web interface to the electrical hardware and integration of LabVIEW Virtual Instruments to the remote access and control of DC Drives. Customized electrical hardware serves as the web interface, supporting various features to remotely control and measure the parameters of the electrical machine. Novel techniques have been used to interface a low power data acquisition system with the DC machine driven by the AC power supply. The system uses the client-server architecture to access the web page of the Virtual Instruments through web browser. The developed system imitates the real control of experiment hardware, but being operated remotely through Internet.

  8. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks.

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-02-01

    Hybrid mobile applications (apps) combine the features of Web applications and "native" mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources-file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies "bridges" that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources-the ability to read and write contacts list, local files, etc.-to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign-origin Web content

  9. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-01-01

    Hybrid mobile applications (apps) combine the features of Web applications and “native” mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources—file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies “bridges” that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources—the ability to read and write contacts list, local files, etc.—to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign

  10. A method for controlling enterprises access to an eco-industrial park.

    Science.gov (United States)

    Zhu, Li; Zhou, Jianren; Cui, Zhaojie; Liu, Lei

    2010-09-15

    Member enterprises have a vital effect on the stability and system efficiency of an eco-industrial park (EIP), and a selection and control for them is an important part. This paper proposes a new method which is an establishment of both an access indicator system and an extendable optimal degree evaluation model. The indicator system comprises seven primary indicators and twenty-seven secondary indicators. The first three primary indicators, matching the existing industrial chains or not, park capacity and park environmental performance improvement, are proposed from the perspective of an EIP. The others including eco-design, economic benefit, utilization of resources, and pollution control, are suggested from the point of view of enterprises. This new access indicator system provides a basis for evaluating candidate enterprises. The extendable optimal degree evaluation which was proposed by Prof. Caiwen is a method to assess the satisfactoriness of all the indicators and to assign an optimal degree order to each candidate enterprise accordingly. There are four steps to conduct the evaluation after establishing the access indicator system: (1) selecting correlation function; (2) calculating correlations; (3) assigning weights and current values of indicators; and (4) calculating the optimal degree of all the candidate enterprises. The enterprises can be ranked based on optimal degree results. The highest-ranked enterprise should have the highest priority of entering the EIP. This study provides the specifics of applying the method by examining the case of Yantai Economy Technology Development Zone EIP (YTEIP) in Shandong province. The method provides a practical tool for controling enterprise access to an EIP. However, the reasonability and validity of indicators and effectiveness of the established method of extendable optimal degree evaluation merit further studies. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Biomedical Big Data: New Models of Control Over Access, Use and Governance.

    Science.gov (United States)

    Vayena, Effy; Blasimme, Alessandro

    2017-12-01

    Empirical evidence suggests that while people hold the capacity to control their data in high regard, they increasingly experience a loss of control over their data in the online world. The capacity to exert control over the generation and flow of personal information is a fundamental premise to important values such as autonomy, privacy, and trust. In healthcare and clinical research this capacity is generally achieved indirectly, by agreeing to specific conditions of informational exposure. Such conditions can be openly stated in informed consent documents or be implicit in the norms of confidentiality that govern the relationships of patients and healthcare professionals. However, with medicine becoming a data-intense enterprise, informed consent and medical confidentiality, as mechanisms of control, are put under pressure. In this paper we explore emerging models of informational control in data-intense healthcare and clinical research, which can compensate for the limitations of currently available instruments. More specifically, we discuss three approaches that hold promise in increasing individual control: the emergence of data portability rights as means to control data access, new mechanisms of informed consent as tools to control data use, and finally, new participatory governance schemes that allow individuals to control their data through direct involvement in data governance. We conclude by suggesting that, despite the impression that biomedical big data diminish individual control, the synergistic effect of new data management models can in fact improve it.

  12. An enhancement of the role-based access control model to facilitate information access management in context of team collaboration and workflow.

    Science.gov (United States)

    Le, Xuan Hung; Doll, Terry; Barbosu, Monica; Luque, Amneris; Wang, Dongwen

    2012-12-01

    Although information access control models have been developed and applied to various applications, few of the previous works have addressed the issue of managing information access in the combined context of team collaboration and workflow. To facilitate this requirement, we have enhanced the Role-Based Access Control (RBAC) model through formulating universal constraints, defining bridging entities and contributing attributes, extending access permissions to include workflow contexts, synthesizing a role-based access delegation model to target on specific objects, and developing domain ontologies as instantiations of the general model to particular applications. We have successfully applied this model to the New York State HIV Clinical Education Initiative (CEI) project to address the specific needs of information management in collaborative processes. An initial evaluation has shown this model achieved a high level of agreement with an existing system when applied to 4576 cases (kappa=0.801). Comparing to a reference standard, the sensitivity and specificity of the enhanced RBAC model were at the level of 97-100%. These results indicate that the enhanced RBAC model can be effectively used for information access management in context of team collaboration and workflow to coordinate clinical education programs. Future research is required to incrementally develop additional types of universal constraints, to further investigate how the workflow context and access delegation can be enriched to support the various needs on information access management in collaborative processes, and to examine the generalizability of the enhanced RBAC model for other applications in clinical education, biomedical research, and patient care. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. An interaction-based access control model (IBAC) for collaborative services

    Energy Technology Data Exchange (ETDEWEB)

    Altunay, Mine; /Fermilab; Byrd, Gregory T.; Brown, Doug E.; Dean, Ralph A.; /North Carolina State U.

    2008-04-01

    A collaboration is a collection of services that work together to achieve a common goal. Although collaborations help when tackling difficult problems, they lead to security issues. First, a collaboration is often performed by services that are drawn from different security domains. Second, a service interacts with multiple peer services during the collaboration. These interactions are not isolated from one another--e.g., data may flow through a sequence of different services. As a result, a service is exposed to multiple peer services in varying degrees, leading to different security threats. We identify the types of interactions that can be present in collaborations, and discuss the security threats due to each type. We propose a model for representing the collaboration context so that a service can be made aware of the existing interactions. We provide an access control model for a service participating in a collaboration. We couple our access control model with a policy model, so that the access requirements from collaborations can be expressed and evaluated.

  14. Frequency-selective design of wireless power transfer systems for controlled access applications

    Science.gov (United States)

    Maschino, Tyler Stephen

    Wireless power transfer (WPT) has become a common way to charge or power many types of devices, ranging from cell phones to electric toothbrushes. WPT became popular through the introduction of a transmission mode known as strongly coupled magnetic resonance (SCMR). This means of transmission is non-radiative and enables mid-range WPT. Shortly after the development of WPT via SCMR, a group of researchers introduced the concept of resonant repeaters, which allows power to hop from the source to the device. These repeaters are in resonance with the WPT system, which enables them to propagate the power wirelessly with minimal losses to the environment. Resonant repeaters have rekindled the dream of ubiquitous wireless power. Inherent risks come with the realization of such a dream. One of the most prominent risks, which we set out in this thesis to address, is that of accessibility to the WPT system. We propose the incorporation of a controlled access schema within a WPT system to prevent unwarranted use of wireless power. Our thesis discusses the history of electromagnetism, examines the inception of WPT via SCMR, evaluates recent developments in WPT, and further elaborates on the controlled access schema we wish to contribute to the field.

  15. Design of IP Camera Access Control Protocol by Utilizing Hierarchical Group Key

    Directory of Open Access Journals (Sweden)

    Jungho Kang

    2015-08-01

    Full Text Available Unlike CCTV, security video surveillance devices, which we have generally known about, IP cameras which are connected to a network either with or without wire, provide monitoring services through a built-in web-server. Due to the fact that IP cameras can use a network such as the Internet, multiple IP cameras can be installed at a long distance and each IP camera can utilize the function of a web server individually. Even though IP cameras have this kind of advantage, it has difficulties in access control management and weakness in user certification, too. Particularly, because the market of IP cameras did not begin to be realized a long while ago, systems which are systematized from the perspective of security have not been built up yet. Additionally, it contains severe weaknesses in terms of access authority to the IP camera web server, certification of users, and certification of IP cameras which are newly installed within a network, etc. This research grouped IP cameras hierarchically to manage them systematically, and provided access control and data confidentiality between groups by utilizing group keys. In addition, IP cameras and users are certified by using PKI-based certification, and weak points of security such as confidentiality and integrity, etc., are improved by encrypting passwords. Thus, this research presents specific protocols of the entire process and proved through experiments that this method can be actually applied.

  16. On the designing of a tamper resistant prescription RFID access control system.

    Science.gov (United States)

    Safkhani, Masoumeh; Bagheri, Nasour; Naderi, Majid

    2012-12-01

    Recently, Chen et al. have proposed a novel tamper resistant prescription RFID access control system, published in the Journal of Medical Systems. In this paper we consider the security of the proposed protocol and identify some existing weaknesses. The main attack is a reader impersonation attack which allows an active adversary to impersonate a legitimate doctor, e.g. the patient's doctor, to access the patient's tag and change the patient prescription. The presented attack is quite efficient. To impersonate a doctor, the adversary should eavesdrop one session between the doctor and the patient's tag and then she can impersonate the doctor with the success probability of '1'. In addition, we present efficient reader-tag to back-end database impersonation, de-synchronization and traceability attacks against the protocol. Finally, we propose an improved version of protocol which is more efficient compared to the original protocol while provides the desired security against the presented attacks.

  17. A fuzzy expert system to Trust-Based Access Control in crowdsourcing environments

    Directory of Open Access Journals (Sweden)

    Olusegun Folorunso

    2015-07-01

    Full Text Available Crowdsourcing has been widely accepted across a broad range of application areas. In crowdsourcing environments, the possibility of performing human computation is characterized with risks due to the openness of their web-based platforms where each crowd worker joins and participates in the process at any time, causing serious effect on the quality of its computation. In this paper, a combination of Trust-Based Access Control (TBAC strategy and fuzzy-expert systems was used to enhance the quality of human computation in crowdsourcing environment. A TBAC-fuzzy algorithm was developed and implemented using MATLAB 7.6.0 to compute trust value (Tvalue, priority value as evaluated by fuzzy inference system (FIS and finally generate access decision to each crowd-worker. In conclusion, the use of TBAC is feasible in improving quality of human computation in crowdsourcing environments.

  18. Randomized controlled trials in central vascular access devices: A scoping review

    Science.gov (United States)

    Keogh, Samantha; Rickard, Claire M.

    2017-01-01

    Background Randomized controlled trials evaluate the effectiveness of interventions for central venous access devices, however, high complication rates remain. Scoping reviews map the available evidence and demonstrate evidence deficiencies to focus ongoing research priorities. Method A scoping review (January 2006–December 2015) of randomized controlled trials evaluating the effectiveness of interventions to improve central venous access device outcomes; including peripherally inserted central catheters, non-tunneled, tunneled and totally implanted venous access catheters. MeSH terms were used to undertake a systematic search with data extracted by two independent researchers, using a standardized data extraction form. Results In total, 178 trials were included (78 non-tunneled [44%]; 40 peripherally inserted central catheters [22%]; 20 totally implanted [11%]; 12 tunneled [6%]; 6 non-specified [3%]; and 22 combined device trials [12%]). There were 119 trials (68%) involving adult participants only, with 18 (9%) pediatric and 20 (11%) neonatal trials. Insertion-related themes existed in 38% of trials (67 RCTs), 35 RCTs (20%) related to post-insertion patency, with fewer trials on infection prevention (15 RCTs, 8%), education (14RCTs, 8%), and dressing and securement (12 RCTs, 7%). There were 46 different study outcomes reported, with the most common being infection outcomes (161 outcomes; 37%), with divergent definitions used for catheter-related bloodstream and other infections. Conclusion More high quality randomized trials across central venous access device management are necessary, especially in dressing and securement and patency. These can be encouraged by having more studies with multidisciplinary team involvement and consumer engagement. Additionally, there were extensive gaps within population sub-groups, particularly in tunneled devices, and in pediatrics and neonates. Finally, outcome definitions need to be unified for results to be meaningful and

  19. Human Rights and Drug Control : Access to Controlled Essential Medicines in Resource-Constrained Countries

    NARCIS (Netherlands)

    Gispen, M.E.C.

    2017-01-01

    Millions of people worldwide suffer a range of health and socio-economic related problems because of inadequate availability and use of controlled essential medicines like morphine and codeine for pain treatment. As a result, millions of people, often living in lesser-advanced conditions, suffer in

  20. Artificial neural network based modeling and controlling of ...

    African Journals Online (AJOL)

    Further for developing the model has been selected suitable adaptive filter. Two types of ... The simulation results revealed that NN-IMC with appropriate learning rate - momentum is capable to pursue the set-point changes and to reject the disturbance changes without steady state error or oscillations. NN-IMC with inverse ...

  1. A stochastic control approach to Slotted-ALOHA random access protocol

    Science.gov (United States)

    Pietrabissa, Antonio

    2013-12-01

    ALOHA random access protocols are distributed protocols based on transmission probabilities, that is, each node decides upon packet transmissions according to a transmission probability value. In the literature, ALOHA protocols are analysed by giving necessary and sufficient conditions for the stability of the queues of the node buffers under a control vector (whose elements are the transmission probabilities assigned to the nodes), given an arrival rate vector (whose elements represent the rates of the packets arriving in the node buffers). The innovation of this work is that, given an arrival rate vector, it computes the optimal control vector by defining and solving a stochastic control problem aimed at maximising the overall transmission efficiency, while keeping a grade of fairness among the nodes. Furthermore, a more general case in which the arrival rate vector changes in time is considered. The increased efficiency of the proposed solution with respect to the standard ALOHA approach is evaluated by means of numerical simulations.

  2. Directional Medium Access Control (MAC Protocols in Wireless Ad Hoc and Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    David Tung Chong Wong

    2015-06-01

    Full Text Available This survey paper presents the state-of-the-art directional medium access control (MAC protocols in wireless ad hoc and sensor networks (WAHSNs. The key benefits of directional antennas over omni-directional antennas are longer communication range, less multipath interference, more spatial reuse, more secure communications, higher throughput and reduced latency. However, directional antennas lead to single-/multi-channel directional hidden/exposed terminals, deafness and neighborhood, head-of-line blocking, and MAC-layer capture which need to be overcome. Addressing these problems and benefits for directional antennas to MAC protocols leads to many classes of directional MAC protocols in WAHSNs. These classes of directional MAC protocols presented in this survey paper include single-channel, multi-channel, cooperative and cognitive directional MACs. Single-channel directional MAC protocols can be classified as contention-based or non-contention-based or hybrid-based, while multi-channel directional MAC protocols commonly use a common control channel for control packets/tones and one or more data channels for directional data transmissions. Cooperative directional MAC protocols improve throughput in WAHSNs via directional multi-rate/single-relay/multiple-relay/two frequency channels/polarization, while cognitive directional MAC protocols leverage on conventional directional MAC protocols with new twists to address dynamic spectrum access. All of these directional MAC protocols are the pillars for the design of future directional MAC protocols in WAHSNs.

  3. The assessment of exploitation process of power for access control system

    Science.gov (United States)

    Wiśnios, Michał; Paś, Jacek

    2017-10-01

    The safety of public utility facilities is a function not only of effectiveness of the electronic safety systems, used for protection of property and persons, but it also depends on the proper functioning of their power supply systems. The authors of the research paper analysed the power supply systems, which are used in buildings for the access control system that is integrated with the closed-circuit TV. The Access Control System is a set of electronic, electromechanical and electrical devices and the computer software controlling the operation of the above-mentioned elements, which is aimed at identification of people, vehicles allowed to cross the boundary of the reserved area, to prevent from crossing the reserved area and to generate the alarm signal informing about the attempt of crossing by an unauthorised entity. The industrial electricity with appropriate technical parameters is a basis of proper functioning of safety systems. Only the electricity supply to the systems is not equivalent to the operation continuity provision. In practice, redundant power supply systems are used. In the carried out reliability analysis of the power supply system, various power circuits of the system were taken into account. The reliability and operation requirements for this type of system were also included.

  4. Hybrid Solution for Privacy-Preserving Access Control for Healthcare Data

    Directory of Open Access Journals (Sweden)

    SMITHAMOL, M. B.

    2017-05-01

    Full Text Available The booming in cloud and IoT technologies has accelerated the growth of healthcare system. The IoT devices monitor the patient's health, and upload collected data as Electronic Medical Records (EMRs to the cloud for storage and sharing. Outsourcing EMRs to the cloud introduce new security and privacy challenges. In this paper, we proposed a novel architecture ensuring security and privacy for the outsourced health records. The proposed model uses partially ordered set (POSET for constructing the group based access structure and Ciphertext-Policy Attribute-Based Encryption (CP-ABE to provide fine-grained EMR access control. The modified group based CP-ABE (G-CP-ABE minimizes the computational overhead by reducing the number of leaf nodes in the access tree. Also, the proposed G-CP-ABE framework merges symmetric encryption and CP-ABE scheme to minimize the overall encryption time. As a result, G-CP-ABE can be used to monitor health conditions even from a resource constrained IoT device. The performance analysis shows the efficiency of the proposed model, making it suitable for practical use.

  5. A High Throughput Medium Access Control Implementation Based on IEEE 802.11e Standard

    Science.gov (United States)

    Huang, Min Li; Lee, Jin; Setiawan, Hendra; Ochi, Hiroshi; Park, Sin-Chong

    With the growing demand for high-performance multimedia applications over wireless channels, we need to develop a Medium Access Control (MAC) system that supports high throughput and quality of service enhancements. This paper presents the standard analysis, design architecture and design issues leading to the implementation of an IEEE 802.11e based MAC system that supports MAC throughput of over 100Mbps. In order to meet the MAC layer timing constraints, a hardware/software co-design approach is adopted. The proposed MAC architecture is implemented on the Xilinx Virtex-II Pro Field-Programmable Gate Array (FPGA) (XC2VP70-5FF1704C) prototype, and connected to a host computer through an external Universal Serial Bus (USB) interface. The total FPGA resource utilization is 11, 508 out of 33, 088 (34%) available slices. The measured MAC throughput is 100.7Mbps and 109.2Mbps for voice and video access categories, transmitted at a data rate of 260Mbps based on IEEE 802.11n Physical Layer (PHY), using the contention-based hybrid coordination function channel access mechanism.

  6. Medium Access Control Protocols for Cognitive Radio Ad Hoc Networks: A Survey.

    Science.gov (United States)

    Zareei, Mahdi; Islam, A K M Muzahidul; Baharun, Sabariah; Vargas-Rosales, Cesar; Azpilicueta, Leyre; Mansoor, Nafees

    2017-09-16

    New wireless network paradigms will demand higher spectrum use and availability to cope with emerging data-hungry devices. Traditional static spectrum allocation policies cause spectrum scarcity, and new paradigms such as Cognitive Radio (CR) and new protocols and techniques need to be developed in order to have efficient spectrum usage. Medium Access Control (MAC) protocols are accountable for recognizing free spectrum, scheduling available resources and coordinating the coexistence of heterogeneous systems and users. This paper provides an ample review of the state-of-the-art MAC protocols, which mainly focuses on Cognitive Radio Ad Hoc Networks (CRAHN). First, a description of the cognitive radio fundamental functions is presented. Next, MAC protocols are divided into three groups, which are based on their channel access mechanism, namely time-slotted protocol, random access protocol and hybrid protocol. In each group, a detailed and comprehensive explanation of the latest MAC protocols is presented, as well as the pros and cons of each protocol. A discussion on future challenges for CRAHN MAC protocols is included with a comparison of the protocols from a functional perspective.

  7. A Model-driven Role-based Access Control for SQL Databases

    Directory of Open Access Journals (Sweden)

    Raimundas Matulevičius

    2015-07-01

    Full Text Available Nowadays security has become an important aspect in information systems engineering. A mainstream method for information system security is Role-based Access Control (RBAC, which restricts system access to authorised users. While the benefits of RBAC are widely acknowledged, the implementation and administration of RBAC policies remains a human intensive activity, typically postponed until the implementation and maintenance phases of system development. This deferred security engineering approach makes it difficult for security requirements to be accurately captured and for the system’s implementation to be kept aligned with these requirements as the system evolves. In this paper we propose a model-driven approach to manage SQL database access under the RBAC paradigm. The starting point of the approach is an RBAC model captured in SecureUML. This model is automatically translated to Oracle Database views and instead-of triggers code, which implements the security constraints. The approach has been fully instrumented as a prototype and its effectiveness has been validated by means of a case study.

  8. An Access Control Protocol for Wireless Sensor Network Using Double Trapdoor Chameleon Hash Function

    Directory of Open Access Journals (Sweden)

    Tejeshwari Thakur

    2016-01-01

    Full Text Available Wireless sensor network (WSN, a type of communication system, is normally deployed into the unattended environment where the intended user can get access to the network. The sensor nodes collect data from this environment. If the data are valuable and confidential, then security measures are needed to protect them from the unauthorized access. This situation requires an access control protocol (ACP in the design of sensor network because of sensor nodes which are vulnerable to various malicious attacks during the authentication and key establishment and the new node addition phase. In this paper, we propose a secured ACP for such WSN. This protocol is based on Elliptic Curve Discrete Log Problem (ECDLP and double trapdoor chameleon hash function which secures the WSN from malicious attacks such as node masquerading attack, replay attack, man-in-the-middle attack, and forgery attacks. Proposed ACP has a special feature known as session key security. Also, the proposed ACP is more efficient as it requires only one modular multiplication during the initialization phase.

  9. Medium Access Control Protocols for Cognitive Radio Ad Hoc Networks: A Survey

    Science.gov (United States)

    Islam, A. K. M. Muzahidul; Baharun, Sabariah; Mansoor, Nafees

    2017-01-01

    New wireless network paradigms will demand higher spectrum use and availability to cope with emerging data-hungry devices. Traditional static spectrum allocation policies cause spectrum scarcity, and new paradigms such as Cognitive Radio (CR) and new protocols and techniques need to be developed in order to have efficient spectrum usage. Medium Access Control (MAC) protocols are accountable for recognizing free spectrum, scheduling available resources and coordinating the coexistence of heterogeneous systems and users. This paper provides an ample review of the state-of-the-art MAC protocols, which mainly focuses on Cognitive Radio Ad Hoc Networks (CRAHN). First, a description of the cognitive radio fundamental functions is presented. Next, MAC protocols are divided into three groups, which are based on their channel access mechanism, namely time-slotted protocol, random access protocol and hybrid protocol. In each group, a detailed and comprehensive explanation of the latest MAC protocols is presented, as well as the pros and cons of each protocol. A discussion on future challenges for CRAHN MAC protocols is included with a comparison of the protocols from a functional perspective. PMID:28926952

  10. Gain transient control for wavelength division multiplexed access networks using semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Osadchiy, Alexey Vladimirovich; Kjær, Rasmus

    2009-01-01

    measurements how a near-saturated semiconductor optical amplifier (SOA) can be used to control these gain transients. An SOA is shown to reduce the penalty of transients originating in an EDFA from 2.3 dB to 0.2 dB for 10 Gb/s transmission over standard single mode fiber using a 231-1 PRBS pattern. The results......Gain transients can severely hamper the upstream network performance in wavelength division multiplexed (WDM) access networks featuring erbium doped fiber amplifiers (EDFAs) or Raman amplification. We experimentally demonstrate for the first time using 10 Gb/s fiber transmission bit error rate...

  11. Evaluation of Standards for Access Control Enabling PHR-S Federation.

    Science.gov (United States)

    Mense, Alexander; Urbauer, Philipp; Sauermann, Stefan

    2017-01-01

    The adoption of the Internet of Things (IoT) and mobile applications in the healthcare may transform the healthcare industry by offering better disease tracking and management as well as patient empowerment. Unfortunately, almost all of these new systems set up their own ecosystem and to be really valuable for the care process they need to be integrated or federated with user managed access control services based on international standards and profiles to enable interoperability. Thus, this work presents the results of an evaluation of available specifications for federated authorization, based on a set of basic requirements.

  12. Cerberus, an Access Control Scheme for Enforcing Least Privilege in Patient Cohort Study Platforms : A Comprehensive Access Control Scheme Applied to the GENIDA Project - Study of Genetic Forms of Intellectual Disabilities and Autism Spectrum Disorders.

    Science.gov (United States)

    Parrend, Pierre; Mazzucotelli, Timothée; Colin, Florent; Collet, Pierre; Mandel, Jean-Louis

    2017-11-16

    Cohort Study Platforms (CSP) are emerging as a key tool for collecting patient information, providing new research data, and supporting family and patient associations. However they pose new ethics and regulatory challenges since they cross the gap between patients and medical practitioners. One of the critical issues for CSP is to enforce a strict control on access privileges whilst allowing the users to take advantage of the breadth of the available data. We propose Cerberus, a new access control scheme spanning the whole life-cycle of access right management: design, implementation, deployment and maintenance, operations. Cerberus enables switching from a dual world, where CSP data can be accessed either from the users who entered it or fully de-identified, to an access-when-required world, where patients, practitioners and researchers can access focused medical data through explicit authorisation by the data owner. Efficient access control requires application-specific access rights, as well as the ability to restrict these rights when they are not used. Cerberus is implemented and evaluated in the context of the GENIDA project, an international CSP for Genetically determined Intellectual Disabilities and Autism Spectrum Disorders. As a result of this study, the software is made available for the community, and validated specifications for CSPs are given.

  13. A Flexible Component based Access Control Architecture for OPeNDAP Services

    Science.gov (United States)

    Kershaw, Philip; Ananthakrishnan, Rachana; Cinquini, Luca; Lawrence, Bryan; Pascoe, Stephen; Siebenlist, Frank

    2010-05-01

    Network data access services such as OPeNDAP enable widespread access to data across user communities. However, without ready means to restrict access to data for such services, data providers and data owners are constrained from making their data more widely available. Even with such capability, the range of different security technologies available can make interoperability between services and user client tools a challenge. OPeNDAP is a key data access service in the infrastructure under development to support the CMIP5 (Couple Model Intercomparison Project Phase 5). The work is being carried out as part of an international collaboration including the US Earth System Grid and Curator projects and the EU funded IS-ENES and Metafor projects. This infrastructure will bring together Petabytes of climate model data and associated metadata from over twenty modelling centres around the world in a federation with a core archive mirrored at three data centres. A security system is needed to meet the requirements of organisations responsible for model data including the ability to restrict data access to registered users, keep them up to date with changes to data and services, audit access and protect finite computing resources. Individual organisations have existing tools and services such as OPeNDAP with which users in the climate research community are already familiar. The security system should overlay access control in a way which maintains the usability and ease of access to these services. The BADC (British Atmospheric Data Centre) has been working in collaboration with the Earth System Grid development team and partner organisations to develop the security architecture. OpenID and MyProxy were selected at an early stage in the ESG project to provide single sign-on capability across the federation of participating organisations. Building on the existing OPeNDAP specification an architecture based on pluggable server side components has been developed at the BADC

  14. CFD Optimization on Network-Based Parallel Computer System

    Science.gov (United States)

    Cheung, Samson H.; VanDalsem, William (Technical Monitor)

    1994-01-01

    Combining multiple engineering workstations into a network-based heterogeneous parallel computer allows application of aerodynamic optimization with advance computational fluid dynamics codes, which is computationally expensive in mainframe supercomputer. This paper introduces a nonlinear quasi-Newton optimizer designed for this network-based heterogeneous parallel computer on a software called Parallel Virtual Machine. This paper will introduce the methodology behind coupling a Parabolized Navier-Stokes flow solver to the nonlinear optimizer. This parallel optimization package has been applied to reduce the wave drag of a body of revolution and a wing/body configuration with results of 5% to 6% drag reduction.

  15. Dynamic social networks based on movement

    Science.gov (United States)

    Scharf, Henry; Hooten, Mevin B.; Fosdick, Bailey K.; Johnson, Devin S.; London, Joshua M.; Durban, John W.

    2016-01-01

    Network modeling techniques provide a means for quantifying social structure in populations of individuals. Data used to define social connectivity are often expensive to collect and based on case-specific, ad hoc criteria. Moreover, in applications involving animal social networks, collection of these data is often opportunistic and can be invasive. Frequently, the social network of interest for a given population is closely related to the way individuals move. Thus, telemetry data, which are minimally invasive and relatively inexpensive to collect, present an alternative source of information. We develop a framework for using telemetry data to infer social relationships among animals. To achieve this, we propose a Bayesian hierarchical model with an underlying dynamic social network controlling movement of individuals via two mechanisms: an attractive effect and an aligning effect. We demonstrate the model and its ability to accurately identify complex social behavior in simulation, and apply our model to telemetry data arising from killer whales. Using auxiliary information about the study population, we investigate model validity and find the inferred dynamic social network is consistent with killer whale ecology and expert knowledge.

  16. Neural Network Based Intelligent Sootblowing System

    Energy Technology Data Exchange (ETDEWEB)

    Mark Rhode

    2005-04-01

    . Due to the composition of coal, particulate matter is also a by-product of coal combustion. Modern day utility boilers are usually fitted with electrostatic precipitators to aid in the collection of particulate matter. Although extremely efficient, these devices are sensitive to rapid changes in inlet mass concentration as well as total mass loading. Traditionally, utility boilers are equipped with devices known as sootblowers, which use, steam, water or air to dislodge and clean the surfaces within the boiler and are operated based upon established rule or operator's judgment. Poor sootblowing regimes can influence particulate mass loading to the electrostatic precipitators. The project applied a neural network intelligent sootblowing system in conjunction with state-of-the-art controls and instruments to optimize the operation of a utility boiler and systematically control boiler slagging/fouling. This optimization process targeted reduction of NOx of 30%, improved efficiency of 2% and a reduction in opacity of 5%. The neural network system proved to be a non-invasive system which can readily be adapted to virtually any utility boiler. Specific conclusions from this neural network application are listed below. These conclusions should be used in conjunction with the specific details provided in the technical discussions of this report to develop a thorough understanding of the process.

  17. F2AC: A Lightweight, Fine-Grained, and Flexible Access Control Scheme for File Storage in Mobile Cloud Computing

    Directory of Open Access Journals (Sweden)

    Wei Ren

    2016-01-01

    Full Text Available Current file storage service models for cloud servers assume that users either belong to single layer with different privileges or cannot authorize privileges iteratively. Thus, the access control is not fine-grained and flexible. Besides, most access control methods at cloud servers mainly rely on computationally intensive cryptographic algorithms and, especially, may not be able to support highly dynamic ad hoc groups with addition and removal of group members. In this paper, we propose a scheme called F2AC, which is a lightweight, fine-grained, and flexible access control scheme for file storage in mobile cloud computing. F2AC can not only achieve iterative authorization, authentication with tailored policies, and access control for dynamically changing accessing groups, but also provide access privilege transition and revocation. A new access control model called directed tree with linked leaf model is proposed for further implementations in data structures and algorithms. The extensive analysis is given for justifying the soundness and completeness of F2AC.

  18. An Effective Massive Sensor Network Data Access Scheme Based on Topology Control for the Internet of Things.

    Science.gov (United States)

    Yi, Meng; Chen, Qingkui; Xiong, Neal N

    2016-11-03

    This paper considers the distributed access and control problem of massive wireless sensor networks' data access center for the Internet of Things, which is an extension of wireless sensor networks and an element of its topology structure. In the context of the arrival of massive service access requests at a virtual data center, this paper designs a massive sensing data access and control mechanism to improve the access efficiency of service requests and makes full use of the available resources at the data access center for the Internet of things. Firstly, this paper proposes a synergistically distributed buffer access model, which separates the information of resource and location. Secondly, the paper divides the service access requests into multiple virtual groups based on their characteristics and locations using an optimized self-organizing feature map neural network. Furthermore, this paper designs an optimal scheduling algorithm of group migration based on the combination scheme between the artificial bee colony algorithm and chaos searching theory. Finally, the experimental results demonstrate that this mechanism outperforms the existing schemes in terms of enhancing the accessibility of service requests effectively, reducing network delay, and has higher load balancing capacity and higher resource utility rate.

  19. An Effective Massive Sensor Network Data Access Scheme Based on Topology Control for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Meng Yi

    2016-11-01

    Full Text Available This paper considers the distributed access and control problem of massive wireless sensor networks’ data access center for the Internet of Things, which is an extension of wireless sensor networks and an element of its topology structure. In the context of the arrival of massive service access requests at a virtual data center, this paper designs a massive sensing data access and control mechanism to improve the access efficiency of service requests and makes full use of the available resources at the data access center for the Internet of things. Firstly, this paper proposes a synergistically distributed buffer access model, which separates the information of resource and location. Secondly, the paper divides the service access requests into multiple virtual groups based on their characteristics and locations using an optimized self-organizing feature map neural network. Furthermore, this paper designs an optimal scheduling algorithm of group migration based on the combination scheme between the artificial bee colony algorithm and chaos searching theory. Finally, the experimental results demonstrate that this mechanism outperforms the existing schemes in terms of enhancing the accessibility of service requests effectively, reducing network delay, and has higher load balancing capacity and higher resource utility rate.

  20. Overview of the Altair Lunar Lander Thermal Control System Design and the Impacts of Global Access

    Science.gov (United States)

    Stephan, Ryan A.

    2011-01-01

    NASA's Constellation Program (CxP) was developed to successfully return humans to the Lunar surface prior to 2020. The CxP included several different project offices including Altair, which was planned to be the next generation Lunar Lander. The Altair missions were architected to be quite different than the Lunar missions accomplished during the Apollo era. These differences resulted in a significantly dissimilar Thermal Control System (TCS) design. The current paper will summarize the Altair mission architecture and the various operational phases associated with the planned mission. In addition, the derived thermal requirements and the TCS designed to meet these unique and challenging thermal requirements will be presented. During the past year, the design team has focused on developing a vehicle architecture capable of accessing the entire Lunar surface. Due to the widely varying Lunar thermal environment, this global access requirement resulted in major changes to the thermal control system architecture. These changes, and the rationale behind the changes, will be detailed throughout the current paper.

  1. Stability of multiple access network control schemes with carrier sensing and exponential backoff

    Science.gov (United States)

    Barany, Ernest; Krupa, Maciej

    2006-05-01

    A new approach to determine the stability of multiple access network control schemes is presented. A “busy” network (the precise meaning of the term “busy” will be presented in the text) is modelled as a switched single-server hybrid dynamical system whose switching laws are stochastic and are based on typical multiple access network control protocols such as ALOHA and ethernet. The techniques are used to compute the critical ratio of traffic production per network node to total available bandwidth that ensures that data packets will not accumulate unboundedly in waiting queues at each node. This is a measure of stability of the network and is an emergent, global, property determined by decentralized, autonomous behavior of each node. The behavior of each individual node is regarded as “microscopic” and the collective behavior of the network as a whole are emergent consequences of such microscopic laws. The results follow from the stationary distribution property of ergodic Markov chains.

  2. Design of a Distributed Personal Information Access Control Scheme for Secure Integrated Payment in NFC

    Directory of Open Access Journals (Sweden)

    Jungho Kang

    2015-06-01

    Full Text Available At the center of core technologies for a future cyber world, such as Internet of Things (IoT or big data, is a context-rich system that offers services by using situational information. The field where context-rich systems were first introduced is near-field communication (NFC-based electronic payments. Near-field Communication (NFC integrated payment services collect the payment information of the credit card and the location information to generate patterns in the user’s consumption or movement through big data technology. Based on such pattern information, tailored services, such as advertisement, are offered to users. However, there is difficulty in controlling access to personal information, as there is a collaborative relationship focused on the trusted service manager (TSM that is close knit to shared personal information. Moreover, in the case of Hadoop, among the many big data analytical technologies, it offers access control functions, but not a way to authorize the processing of personal information, making it impossible to grant authority between service providers to process information. As such, this paper proposes a key generation and distribution method, as well as a secure communication protocol. The analysis has shown that the efficiency was greater for security and performance compared to relation works.

  3. CONTEXT BASED ANDROID APPLICATIONADMINISTRATIVE ACCESS CONTROL (CBAA–AAC FOR SMART PHONES

    Directory of Open Access Journals (Sweden)

    S. Sharavanan

    2016-07-01

    Full Text Available Android applications in smart phones are generally towards provide greater flexibility and convince for users. Considering the fact that the Android applications are having privilege to access data and resources in mobile after it gets installed (one time permission provided by end user on the time installation, these application may also lead to issues in security for the user data as well as issues relate smart phone with peripheral environment. A practical example for an issue which relates smart phone with peripheral environment can be even an Android smart phone application of a college student use camera resource to capture photos of R&D cell and transfer without user or organization permission. The security of the organization and user should be prevented by providing an adoptable solution. The proposed concept of CBAA-AAC (Context Based Android Application Administrative Access Control is used to control the privileges of any Android application over a corresponding longitude and latitude by the organization administrator. In this way, administrator is able to block malicious application of every individual smart phone which can have activity towards utilizing services and resources that may affect the security of the organization, such an move is must for assuring security of any organization and educational institutions while they allow users to “bring their own smart phones/mobile devices” into the campus.

  4. Security analysis and improvements of authentication and access control in the Internet of Things.

    Science.gov (United States)

    Ndibanje, Bruce; Lee, Hoon-Jae; Lee, Sang-Gon

    2014-08-13

    Internet of Things is a ubiquitous concept where physical objects are connected over the internet and are provided with unique identifiers to enable their self-identification to other devices and the ability to continuously generate data and transmit it over a network. Hence, the security of the network, data and sensor devices is a paramount concern in the IoT network as it grows very fast in terms of exchanged data and interconnected sensor nodes. This paper analyses the authentication and access control method using in the Internet of Things presented by Jing et al. (Authentication and Access Control in the Internet of Things. In Proceedings of the 2012 32nd International Conference on Distributed Computing Systems Workshops, Macau, China, 18-21 June 2012, pp. 588-592). According to our analysis, Jing et al.'s protocol is costly in the message exchange and the security assessment is not strong enough for such a protocol. Therefore, we propose improvements to the protocol to fill the discovered weakness gaps. The protocol enhancements facilitate many services to the users such as user anonymity, mutual authentication, and secure session key establishment. Finally, the performance and security analysis show that the improved protocol possesses many advantages against popular attacks, and achieves better efficiency at low communication cost.

  5. The Arabidopsis SWI/SNF protein BAF60 mediates seedling growth control by modulating DNA accessibility

    KAUST Repository

    Jégu, Teddy

    2017-06-15

    Plant adaptive responses to changing environments involve complex molecular interplays between intrinsic and external signals. Whilst much is known on the signaling components mediating diurnal, light, and temperature controls on plant development, their influence on chromatin-based transcriptional controls remains poorly explored.In this study we show that a SWI/SNF chromatin remodeler subunit, BAF60, represses seedling growth by modulating DNA accessibility of hypocotyl cell size regulatory genes. BAF60 binds nucleosome-free regions of multiple G box-containing genes, opposing in cis the promoting effect of the photomorphogenic and thermomorphogenic regulator Phytochrome Interacting Factor 4 (PIF4) on hypocotyl elongation. Furthermore, BAF60 expression level is regulated in response to light and daily rhythms.These results unveil a short path between a chromatin remodeler and a signaling component to fine-tune plant morphogenesis in response to environmental conditions.

  6. Analysis of the TDRS multiple access system for possible use as an attitude control system sensor

    Science.gov (United States)

    Blevins, Bruce Allyn; Sank, Victor J.

    1993-01-01

    A member of the constellation of TDR satellites (TDRS) has experienced a failure of its prime earth sensor. Failure of the remaining earth sensor could result in the inability of the satellite to control its attitude and provide user services. Loss of the satellite would be a serious event. The multiple access (MA) antenna array on the TDRS has been proposed for use as a backup sensor for the attitude control system. This paper describes our analysis of the performance of the MA array as an interferometer used for accurate attitude determination. A least squares fit of a plane to the MA phase information appears to represent the TDRS body roll and pitch within about 0.1 deg. This is sufficient for SGL pointing and MA and SSA user services. Analytic improvements that include ionospheric correction may yield sufficient accuracy for KSA user services.

  7. Controllable quantized conductance for multilevel data storage applications using conductive bridge random access memory

    Science.gov (United States)

    Gochole Aga, Fekadu; Woo, Jiyong; Song, Jeonghwan; Park, Jaehyuk; Lim, Seokjae; Sung, Changhyuck; Hwang, Hyunsang

    2017-03-01

    In this paper, we investigate the quantized conduction behavior of conductive bridge random access memory (CBRAM) with varied materials and ramping rates. We report stable and reproducible quantized conductance states with integer multiples of fundamental conductance obtained by optimizing the voltage ramping rate and the Ti-diffusion barrier (DB) at the Cu/HfO2 interface. Owing to controlled diffusion of Cu ions by the Ti-DB and the optimized ramping rate, through which it was possible to control the time delay of Cu ion reduction, more than seven levels of discrete conductance states were clearly observed. Analytical modeling was performed to determine the rate-limiting step in filament growth based on an electrochemical redox reaction. Our understanding of the fundamental mechanisms of quantized conductance behaviors provide a promising future for the multi-bit CBRAM device.

  8. Infection control in hemodialysis units: A quick access to essential elements

    Directory of Open Access Journals (Sweden)

    Ayman Karkar

    2014-01-01

    Full Text Available Infection is the most common cause of hospitalization and the second most common cause of mortality among hemodialysis (HD patients, after cardiovascular disease. HD patients as well as the dialysis staff are vulnerable to contracting health-care-associated infections (HAIs due to frequent and prolonged exposure to many possible contaminants in the dialysis environment. The extracorporeal nature of the therapy, the associated common environmental conditions and the immune compromised status of HD patients are major predisposing factors. The evident increased potential for transmission of infections in the HD settings led to the creation and implementation of specific and stricter infection prevention and control measures in addition to the usual standard precautions. Different international organizations have generated guidelines and recommendations on infection prevention and control for implementation in the HD settings. These include the Centers for Disease Control and Prevention (CDC, the Association of Professionals in Infection Control (APIC, the Kidney Disease Outcomes Quality Initiative (K/DOQI, the European Best Practice Guidelines/European Renal Best Practice (EBPG/ERBP and the Kidney Disease: Improving Global Outcomes (KDIGO. However, these guidelines are extensive and sometimes vary among different guideline-producing bodies. Our aim in this review is to facilitate the access, increase the awareness and encourage implementation among dialysis providers by reviewing, extracting and comparing the essential elements of guidelines and recommendations on infection prevention and control in HD units.

  9. On the Design of Energy Efficient Optical Networks with Software Defined Networking Control Across Core and Access Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Yan, Ying; Dittmann, Lars

    2013-01-01

    This paper presents a Software Defined Networking (SDN) control plane based on an overlay GMPLS control model. The SDN control platform manages optical core networks (WDM/DWDM networks) and the associated access networks (GPON networks), which makes it possible to gather global information...

  10. Artificial Neural Network Based State Estimators Integrated into Kalmtool

    DEFF Research Database (Denmark)

    Bayramoglu, Enis; Ravn, Ole; Poulsen, Niels Kjølstad

    2012-01-01

    In this paper we present a toolbox enabling easy evaluation and comparison of dierent ltering algorithms. The toolbox is called Kalmtool and is a set of MATLAB tools for state estimation of nonlinear systems. The toolbox now contains functions for Articial Neural Network Based State Estimation...

  11. IPTV inter-destination synchronization: A network-based approach

    NARCIS (Netherlands)

    Stokking, H.M.; Deventer, M.O. van; Niamut, O.A.; Walraven, F.A.; Mekuria, R.N.

    2010-01-01

    This paper introduces a novel network-based approach to inter-destination media synchronization. The approach meets the need for synchronization in advanced TV concepts like social TV and offers high scalability, unlike conventional end-point based approaches. The solution for interdestination media

  12. PANATIKI: a network access control implementation based on PANA for IoT devices.

    Science.gov (United States)

    Moreno Sanchez, Pedro; Marin Lopez, Rafa; Gomez Skarmeta, Antonio F

    2013-11-01

    Internet of Things (IoT) networks are the pillar of recent novel scenarios, such as smart cities or e-healthcare applications. Among other challenges, these networks cover the deployment and interaction of small devices with constrained capabilities and Internet protocol (IP)-based networking connectivity. These constrained devices usually require connection to the Internet to exchange information (e.g., management or sensing data) or access network services. However, only authenticated and authorized devices can, in general, establish this connection. The so-called authentication, authorization and accounting (AAA) services are in charge of performing these tasks on the Internet. Thus, it is necessary to deploy protocols that allow constrained devices to verify their credentials against AAA infrastructures. The Protocol for Carrying Authentication for Network Access (PANA) has been standardized by the Internet engineering task force (IETF) to carry the Extensible Authentication Protocol (EAP), which provides flexible authentication upon the presence of AAA. To the best of our knowledge, this paper is the first deep study of the feasibility of EAP/PANA for network access control in constrained devices. We provide light-weight versions and implementations of these protocols to fit them into constrained devices. These versions have been designed to reduce the impact in standard specifications. The goal of this work is two-fold: (1) to demonstrate the feasibility of EAP/PANA in IoT devices; (2) to provide the scientific community with the first light-weight interoperable implementation of EAP/PANA for constrained devices in the Contiki operating system (Contiki OS), called PANATIKI. The paper also shows a testbed, simulations and experimental results obtained from real and simulated constrained devices.

  13. PANATIKI: A Network Access Control Implementation Based on PANA for IoT Devices

    Directory of Open Access Journals (Sweden)

    Antonio F. Gomez Skarmeta

    2013-11-01

    Full Text Available Internet of Things (IoT networks are the pillar of recent novel scenarios, such as smart cities or e-healthcare applications. Among other challenges, these networks cover the deployment and interaction of small devices with constrained capabilities and Internet protocol (IP-based networking connectivity. These constrained devices usually require connection to the Internet to exchange information (e.g., management or sensing data or access network services. However, only authenticated and authorized devices can, in general, establish this connection. The so-called authentication, authorization and accounting (AAA services are in charge of performing these tasks on the Internet. Thus, it is necessary to deploy protocols that allow constrained devices to verify their credentials against AAA infrastructures. The Protocol for Carrying Authentication for Network Access (PANA has been standardized by the Internet engineering task force (IETF to carry the Extensible Authentication Protocol (EAP, which provides flexible authentication upon the presence of AAA. To the best of our knowledge, this paper is the first deep study of the feasibility of EAP/PANA for network access control in constrained devices. We provide light-weight versions and implementations of these protocols to fit them into constrained devices. These versions have been designed to reduce the impact in standard specifications. The goal of this work is two-fold: (1 to demonstrate the feasibility of EAP/PANA in IoT devices; (2 to provide the scientific community with the first light-weight interoperable implementation of EAP/PANA for constrained devices in the Contiki operating system (Contiki OS, called PANATIKI. The paper also shows a testbed, simulations and experimental results obtained from real and simulated constrained devices.

  14. Energy-efficient boarder node medium access control protocol for wireless sensor networks.

    Science.gov (United States)

    Razaque, Abdul; Elleithy, Khaled M

    2014-03-12

    This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC) for wireless sensor networks (WSNs), which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN), which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS), which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM) model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS), which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  15. Energy-Efficient Boarder Node Medium Access Control Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Abdul Razaque

    2014-03-01

    Full Text Available This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC for wireless sensor networks (WSNs, which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN, which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS, which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS, which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  16. Point and counterpoint: patient control of access to data in their electronic health records.

    Science.gov (United States)

    Caine, Kelly; Tierney, William M

    2015-01-01

    Information collection, storage, and management is central to the practice of health care. For centuries, patients' and providers' expectations kept medical records confidential between providers and patients. With the advent of electronic health records, patient health information has become more widely available to providers and health care managers and has broadened its potential use beyond individual patient care. Adhering to the principles of Fair Information Practice, including giving patients control over the availability and use of their individual health records, would improve care by fostering the sharing of sensitive information between patients and providers. However, adherence to such principles could put patients at risk for unsafe care as a result of both missed opportunities for providing needed care as well as provision of contraindicated care, as it would prevent health care providers from having full access to health information. Patients' expectations for the highest possible quality and safety of care, therefore, may be at odds with their desire to limit provider access to their health records. Conversely, provider expectations that patients would willingly seek care for embarrassing conditions and disclose sensitive information may be at odds with patients' information privacy rights. An open dialogue between patients and providers will be necessary to balance respect for patient rights with provider need for patient information.

  17. Anticipating, complete and lag synchronizations in RC phase-shift network based coupled Chua's circuits without delay.

    Science.gov (United States)

    Srinivasan, K; Senthilkumar, D V; Raja Mohamed, I; Murali, K; Lakshmanan, M; Kurths, J

    2012-06-01

    We construct a new RC phase shift network based Chua's circuit, which exhibits a period-doubling bifurcation route to chaos. Using coupled versions of such a phase-shift network based Chua's oscillators, we describe a new method for achieving complete synchronization (CS), approximate lag synchronization (LS), and approximate anticipating synchronization (AS) without delay or parameter mismatch. Employing the Pecora and Carroll approach, chaos synchronization is achieved in coupled chaotic oscillators, where the drive system variables control the response system. As a result, AS or LS or CS is demonstrated without using a variable delay line both experimentally and numerically.

  18. Central or peripheral catheters for initial venous access of ICU patients: a randomized controlled trial.

    Science.gov (United States)

    Ricard, Jean-Damien; Salomon, Laurence; Boyer, Alexandre; Thiery, Guillaume; Meybeck, Agnes; Roy, Carine; Pasquet, Blandine; Le Mière, Eric; Dreyfuss, Didier

    2013-09-01

    The vast majority of ICU patients require some form of venous access. There are no evidenced-based guidelines concerning the use of either central or peripheral venous catheters, despite very different complications. It remains unknown which to insert in ICU patients. We investigated the rate of catheter-related insertion or maintenance complications in two strategies: one favoring the central venous catheters and the other peripheral venous catheters. Multicenter, controlled, parallel-group, open-label randomized trial. Three French ICUs. Adult ICU patients with equal central or peripheral venous access requirement. Patients were randomized to receive central venous catheters or peripheral venous catheters as initial venous access. The primary endpoint was the rate of major catheter-related complications within 28 days. Secondary endpoints were the rate of minor catheter-related complications and a composite score-assessing staff utilization and time spent to manage catheter insertions. Analysis was intention to treat. We randomly assigned 135 patients to receive a central venous catheter and 128 patients to receive a peripheral venous catheter. Major catheter-related complications were greater in the peripheral venous catheter than in the central venous catheter group (133 vs 87, respectively, p=0.02) although none of those was life threatening. Minor catheter-related complications were 201 with central venous catheters and 248 with peripheral venous catheters (p=0.06). 46% (60/128) patients were managed throughout their ICU stay with peripheral venous catheters only. There were significantly more peripheral venous catheter-related complications per patient in patients managed solely with peripheral venous catheter than in patients that received peripheral venous catheter and at least one central venous catheter: 1.92 (121/63) versus 1.13 (226/200), pcentral venous catheter-related complications per patient between patients initially randomized to peripheral

  19. Access Control in IoT/M2M - Cloud Platform

    DEFF Research Database (Denmark)

    Anggorojati, Bayu

    Billions of devices are connected to the Internet nowadays, and the number will continue to grow in the future thanks to the advances in the electronics and telecommunication technology developments. Its application in broad aspects of human’s life brings a lot of benefits by improving productivity...... and quality of life. This paradigm, which is often called Internet of Things (IoT) or Machine-to-Machine (M2M), will provide an unprecedented opportunity to create applications and services that go far beyond the mere purpose of each participant. Many studies on the both technical and social aspects of Io......T have shown that the concern about the security and privacy play a huge role for the mass adoption of the IoT/M2M as cloud services. Among the important topics within the security and privacy, the access control is an important mechanism, which essentially manages how the important assets or resource...

  20. New scheme of variable optical buffer for IP packets used in access control of HORNET

    Science.gov (United States)

    Fang, Nian; Wang, Lutang; Huang, Zhaoming

    2002-09-01

    A new scheme of variable optical buffer for IP packets is reported. It may be used in access control of HORNET (Hybrid Optoelectronic Ring NETwork), to avoid collision of added packet and the packet already on the ring and improve the loss ratio of the packets. In this scheme, a new multi-wavelength fiber loop memory technique is employed. This architecture uses the wavelength converter (WC) to specify the packets delay and wavelength conversion is accomplished by the technique of four-wave-mixing (FWM) with a semiconductor optical amplifier (SOA). The range of delay is 10 to 9990 bytes periods. First, architecture, operation principle, characteristics and applications of this scheme of variable optical buffer are introduced. Next, a new unslotted CSMA/CA MAC scheme based on the variable optical buffer is briefly introduced too. Finally, the simulation results are presented.

  1. An Extended Role-Based Access Control Model for Delegating Obligations

    Science.gov (United States)

    Ben-Ghorbel-Talbi, Meriam; Cuppens, Frédéric; Cuppens-Boulahia, Nora; Bouhoula, Adel

    The main aim of access control models is to provide means to simplify the management of the security policy, which is a fastidious and error-prone task. Supporting delegation is considered as an important mean to decentralize the administration and therefore to allow security policy to be more flexible and easier to manipulate. Our main contribution is the proposition of a unified model to the administration and delegation of obligations. Managing such delegations implies more requirements than managing traditional privileges delegation. In fact, delegating obligations may include two interpretations: the delegation of the obligation and the delegation of the responsibility related to this obligation. Therefore, it is important to deal with these two notions separately. Moreover, since delegating an obligation involves the delegation of sanctions, then the consent of the user who receives this delegation may be required in some cases. We address in this paper these requirements and we propose a formalism to deal with them.

  2. Spectrum sharing in cognitive radio networks medium access control protocol based approach

    CERN Document Server

    Pandit, Shweta

    2017-01-01

    This book discusses the use of the spectrum sharing techniques in cognitive radio technology, in order to address the problem of spectrum scarcity for future wireless communications. The authors describe a cognitive radio medium access control (MAC) protocol, with which throughput maximization has been achieved. The discussion also includes use of this MAC protocol for imperfect sensing scenarios and its effect on the performance of cognitive radio systems. The authors also discuss how energy efficiency has been maximized in this system, by applying a simple algorithm for optimizing the transmit power of the cognitive user. The study about the channel fading in the cognitive user and licensed user and power adaption policy in this scenario under peak transmit power and interference power constraint is also present in this book.

  3. A Cloud-Assisted Random Linear Network Coding Medium Access Control Protocol for Healthcare Applications

    Directory of Open Access Journals (Sweden)

    Elli Kartsakli

    2014-03-01

    Full Text Available Relay sensor networks are often employed in end-to-end healthcare applications to facilitate the information flow between patient worn sensors and the medical data center. Medium access control (MAC protocols, based on random linear network coding (RLNC, are a novel and suitable approach to efficiently handle data dissemination. However, several challenges arise, such as additional delays introduced by the intermediate relay nodes and decoding failures, due to channel errors. In this paper, we tackle these issues by adopting a cloud architecture where the set of relays is connected to a coordinating entity, called cloud manager. We propose a cloud-assisted RLNC-based MAC protocol (CLNC-MAC and develop a mathematical model for the calculation of the key performance metrics, namely the system throughput, the mean completion time for data delivery and the energy efficiency. We show the importance of central coordination in fully exploiting the gain of RLNC under error-prone channels.

  4. Medium Access Control for Thermal Energy Harvesting in Advanced Metering Infrastructures

    DEFF Research Database (Denmark)

    Vithanage, Madava D.; Fafoutis, Xenofon; Andersen, Claus Bo

    2013-01-01

    In this paper we investigate the feasibility of powering wireless metering devices, namely heat cost allocators, by thermal energy harvested from radiators. The goal is to take a first step toward the realization of Energy-Harvesting Advanced Metering Infrastructures (EH-AMIs). While traditional...... the potential energy that can be harvested from Low Surface Temperature (LST) radiators. The experiments are based on a developed Energy-Harvesting Heat Cost Allocator (EH-HCA) prototype. On the basis of this measured power budget, we model and analytically compare the currently used Medium Access Control (MAC......) scheme of an industrial case study (IMR+) to a MAC scheme specifically designed for energy harvesting systems (ODMAC). Our analytical comparison shows the efficiency of the latter, as well as its ability to adapt to harvested ambient energy....

  5. Flexible and Lightweight Access Control for Online Healthcare Social Networks in the Context of the Internet of Things

    Directory of Open Access Journals (Sweden)

    Zhen Qin

    2017-01-01

    Full Text Available Online healthcare social networks (OHSNs play an essential role in sharing information among medical experts and patients who are equipped with similar experiences. To access other patients’ data or experts’ diagnosis anywhere and anytime, it is necessary to integrate the OHSN into the Internet as part of the Internet of Things (IoT. Therefore, it is crucial to design an efficient and versatile access control scheme that can grant and revoke a user to access the OHSN. In this paper, we propose novel attribute-based encryption (ABE features with user revocation and verifiable decryption outsourcing to control the access privilege of the users. The security of the proposed ABE scheme is given in the well-studied random oracle model. With the proposed ABE scheme, the malicious users can be excluded from the system and the user can offload most of the overhead in the decryption to an untrusted cloud server in a verifiable manner. An access control scheme for the OHSN has been given in the context of the IoT based on the proposed ABE scheme. The simulation demonstrates that our access control mechanism is practical.

  6. A method to implement fine-grained access control for personal health records through standard relational database queries.

    Science.gov (United States)

    Sujansky, Walter V; Faus, Sam A; Stone, Ethan; Brennan, Patricia Flatley

    2010-10-01

    Online personal health records (PHRs) enable patients to access, manage, and share certain of their own health information electronically. This capability creates the need for precise access-controls mechanisms that restrict the sharing of data to that intended by the patient. The authors describe the design and implementation of an access-control mechanism for PHR repositories that is modeled on the eXtensible Access Control Markup Language (XACML) standard, but intended to reduce the cognitive and computational complexity of XACML. The authors implemented the mechanism entirely in a relational database system using ANSI-standard SQL statements. Based on a set of access-control rules encoded as relational table rows, the mechanism determines via a single SQL query whether a user who accesses patient data from a specific application is authorized to perform a requested operation on a specified data object. Testing of this query on a moderately large database has demonstrated execution times consistently below 100ms. The authors include the details of the implementation, including algorithms, examples, and a test database as Supplementary materials. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Thermal Control System Development to Support the Crew Exploration Vehicle and Lunar Surface Access Module

    Science.gov (United States)

    Anderson, Molly; Westheimer, David

    2006-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has recently evaluated all of the agency s technology development work and identified key areas that must be addressed to aid in the successful development of a Crew Exploration Vehicle (CEV) and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  8. Coordinated Scheduling and Power Control in Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed

    2015-12-01

    This paper addresses the joint coordinated scheduling and power control problem in cloud-enabled networks. Consider the downlink of a cloud-radio access network (CRAN), where the cloud is only responsible for the scheduling policy, power control, and synchronization of the transmit frames across the single-antenna base-stations (BS). The transmit frame consists of several time/frequency blocks, called power-zones (PZ). The paper considers the problem of scheduling users to PZs and determining their power levels (PL), by maximizing the weighted sum-rate under the practical constraints that each user cannot be served by more than one base-station, but can be served by one or more power-zones within each base-station frame. The paper solves the problem using a graph theoretical approach by introducing the joint scheduling and power control graph formed by several clusters, where each is formed by a set of vertices, representing the possible association of users, BSs, and PLs for one specific PZ. The problem is, then, formulated as a maximumweight clique problem, in which the weight of each vertex is the sum of the benefits of the individual associations belonging to that vertex. Simulation results suggest that the proposed crosslayer scheme provides appreciable performance improvement as compared to schemes from recent literature.

  9. Free choice access to multipoint wellness education and related services positively impacts employee wellness: a randomized and controlled trial.

    Science.gov (United States)

    Sforzo, Gary A; Kaye, Miranda P; Calleri, David; Ngai, Nancy

    2012-04-01

    Examine effects of voluntary participation in employer-sponsored, multipoint wellness education programming on employee wellness. A randomized and controlled design was used to organize 96 participants into an education + access group; an access-only group, and control group. Outcome measures were made at start and end of a 12-week intervention period. Education + access improved wellness knowledge, which, in turn, enhanced life satisfaction, employee morale, and energy, and nearly improved stress level. Those who received facility access without educational programming did not reap health benefits. Employees voluntarily used the fitness facility and healthy meal cards only 1.3 and 1.5 times per week, respectively. Participants made limited and likely inadequate use of wellness opportunities. As a result, physical health benefits (eg, blood pressure, fitness parameters) were not seen in the present study. However, multipoint wellness education resulted in psychosocial health benefits in 12 weeks.

  10. Bayesian-network-based fault diagnosis methodology of subsea jumper

    Science.gov (United States)

    Cai, Baoping; Liu, Yonghong; Huang, Lei; Hu, Song; Xue, Haitao; Wang, Jiaxing

    2017-10-01

    The paper proposes a Bayesian-network-based real-time fault diagnosis methodology of M-shaped subsea jumper. Finite element models of a typical M-shaped subsea jumper system are built to get the data for diagnosis. Netica is Bayesian-network -based software and is used to construct diagnosis models of the jumper in two main loading conditions which are falling objects and seabed moving. The results show that the accuracy of falling objects diagnosis model with four faults is 100%, and the accuracy of seabed moving diagnosis model with two faults is also 100%. Combine the two models into one and the accuracy of combined model is 96.59%. The effectiveness of the proposed method is validated.

  11. A network-based dynamical ranking system for competitive sports

    Science.gov (United States)

    Motegi, Shun; Masuda, Naoki

    2012-12-01

    From the viewpoint of networks, a ranking system for players or teams in sports is equivalent to a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score of a player (or team) fluctuates over time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. We derive a set of linear online update equations for the score of each player. The proposed ranking system predicts the outcome of the future games with a higher accuracy than the static counterparts.

  12. A network-based dynamical ranking system for competitive sports.

    Science.gov (United States)

    Motegi, Shun; Masuda, Naoki

    2012-01-01

    From the viewpoint of networks, a ranking system for players or teams in sports is equivalent to a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score of a player (or team) fluctuates over time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. We derive a set of linear online update equations for the score of each player. The proposed ranking system predicts the outcome of the future games with a higher accuracy than the static counterparts.

  13. Performance evaluation of cellular phone network based portable ECG device.

    Science.gov (United States)

    Hong, Joo-Hyun; Cha, Eun-Jong; Lee, Tae-Soo

    2008-01-01

    In this study, cellular phone network based portable ECG device was developed and three experiments were performed to evaluate the accuracy, reliability and operability, applicability during daily life of the developed device. First, ECG signals were measured using the developed device and Biopac device (reference device) during sitting and marking time and compared to verify the accuracy of R-R intervals. Second, the reliable data transmission to remote server was verified on two types of simulated emergency event using patient simulator. Third, during daily life with five types of motion, accuracy of data transmission to remote server was verified on two types of event occurring. By acquiring and comparing subject's biomedical signal and motion signal, the accuracy, reliability and operability, applicability during daily life of the developed device were verified. Therefore, cellular phone network based portable ECG device can monitor patient with inobtrusive manner.

  14. A Neural Network-Based Interval Pattern Matcher

    Directory of Open Access Journals (Sweden)

    Jing Lu

    2015-07-01

    Full Text Available One of the most important roles in the machine learning area is to classify, and neural networks are very important classifiers. However, traditional neural networks cannot identify intervals, let alone classify them. To improve their identification ability, we propose a neural network-based interval matcher in our paper. After summarizing the theoretical construction of the model, we take a simple and a practical weather forecasting experiment, which show that the recognizer accuracy reaches 100% and that is promising.

  15. Wireless Sensor Network Based Subsurface Contaminant Plume Monitoring

    Science.gov (United States)

    2012-04-16

    conventional WSN . VSN enabled closed loop system consumes more energy than the VSN only system, because of the commands that are send to the nodes. Energy ...predict future plume behavior. This proof-of-concept research aimed at demonstrating the use of an intelligent Wireless Sensor Network ( WSN ) to...Network ( WSN ) to monitor contaminant plume movement in naturally heterogeneous subsurface formations to advance the sensor networking based monitoring

  16. [REM sleep behavior disorder: an overt access to motor and cognitive control during sleep].

    Science.gov (United States)

    Arnulf, I

    2010-10-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by violent, or potentially violent, movements during REM sleep, corresponding to enacted dreams. During sleep monitoring, there is a partial or total loss of the normal muscle atonia during REM sleep. REM sleep behavior disorder predominantly affects elderly subjects without any other disease (idiopathic RBD, a precursor of Parkinson disease and Lewy body dementia) or suffering from various neurological and neurodegenerative diseases, mainly synucleinopathies. In addition to being a treatable cause of nocturnal injury of the patients or their bed-partners, RBD is a fantastic window into motor and cognitive control during REM sleep. Notably, parkinsonism transiently disappears during RBD. The patient's voice is louder and better articulated than when awake, and movements are rapid (but jerky) suggesting that the deleterious message from the basal ganglia to the primary motor cortex is reduced or bypassed. As we observed culturally-acquired behaviors, retired patients practicing their former work with mastered gestures, as well as sentences pronounced with appropriate prosody, gesturing, fluency, and syntax during the RBD, we suggest that these behaviors are generated by the same cortical areas as during wakefulness. This model also enables the demonstration that REM during REM sleep are coded in the same direction as the arm and hand movements, as if the dreamer were scanning the dream images. This online access to the motor and verbal dream scenario (through the video and audio monitoring), and the physiological measures (via the EEG, eye movements, muscle tone, respiration, heart rate), together with the offline access to the mental content (dream report after the awakening) constitute a triangulation for validating new hypotheses about REM sleep and dreams. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  17. An Efficient Radio Access Control Mechanism for Wireless Network-On-Chip Architectures

    Directory of Open Access Journals (Sweden)

    Maurizio Palesi

    2015-03-01

    Full Text Available Modern systems-on-chip (SoCs today contain hundreds of cores, and this number is predicted to reach the thousands by the year 2020. As the number of communicating elements increases, there is a need for an efficient, scalable and reliable communication infrastructure. As technology geometries shrink to the deep submicron regime, however, the communication delay and power consumption of global interconnections become the major bottleneck. The network-on-chip (NoC design paradigm, based on a modular packet-switched mechanism, can address many of the on-chip communication issues, such as the performance limitations of long interconnects and integration of large number of cores on a chip. Recently, new communication technologies based on the NoC concept have emerged with the aim of improving the scalability limitations of conventional NoC-based architectures. Among them, wireless NoCs (WiNoCs use the radio medium for reducing the performance and energy penalties of long-range and multi-hop communications. As the radio medium can be accessed by a single transmitter at a time, a radio access control mechanism (RACM is needed. In this paper, we present a novel RACM, which allows one to improve both the performance and energy figures of the WiNoC. Experiments, carried out on both synthetic and real traffic scenarios, have shown the effectiveness of the proposed RACM. On average, a 30% reduction in communication delay and a 25% energy savings have been observed when the proposed RACM is applied to a known WiNoC architecture.

  18. Access to controlled medicines for anesthesia and surgical care in low-income countries: a narrative review of international drug control systems and policies.

    Science.gov (United States)

    Nickerson, Jason W; Pettus, Katherine; Wheeler, Kathleen E; Hallam, Christopher; Bewley-Taylor, David R; Attaran, Amir; Gelb, Adrian W

    2017-03-01

    This article describes the functioning of the international drug control system, its integration into national legislation and policy, and the collective impact on access to medicines. We conducted a review of the three international drug control conventions, peer-reviewed articles, and grey literature known to the authors that describes national and international drug control systems and their impact on access to controlled medicines. This review was supplemented with literature derived from a structured search of MEDLINE(®) for articles relating to medical uses of ketamine in low- and middle-income countries conducted to strengthen an advocacy campaign. We illustrate the impact of the drug control system on access to medicines through an analysis of current levels of availability of opioids in many countries as well as through a description of the ongoing advocacy work to ensure the availability of ketamine for medical care in low-income countries. The complexity of the international drug control system, along with health providers' lack of knowledge regarding key provisions, presents a barrier to improving access to safe anesthesia care in low- and middle-income countries. Fifteen of the 46 essential medicines of potential relevance to perioperative care are listed under one or more of the schedules of the three international drug control conventions and, subsequently, are required to be under national controls, potentially decreasing their availability for medical use. Improving the capacity and quality of anesthesia care in low- and middle-income countries requires attention to improving access to controlled medicines. Anesthesiologists and others involved in global health work should collaborate with policymakers and others to improve national and international drug control legislation to ensure that attempts to thwart illicit drug trafficking and use do not compromise availability of controlled medicines.

  19. Presidential Management Fellows (PMF) Talent Acquisition System, PMF-TAS (ACCESS CONTROLLED)

    Data.gov (United States)

    Office of Personnel Management — Application and Assessment system for Presidential Management Fellows (PMF) and PMF Science, Technology, Engineering, and Math (STEM) programs. This sytem is access...

  20. An Evaluation and Demonstration of a Network Based Aircraft Telemetry System

    Science.gov (United States)

    Waldersen, Matt; Schnarr, Otto, III

    2017-01-01

    The primary topics of this presentation describe the testing of network based telemetry and RF modulation techniques. The overall intend is to aid the aerospace industry in transitioning to a network based telemetry system.

  1. Ongoing Spontaneous Activity Controls Access to Consciousness: A Neuronal Model for Inattentional Blindness

    Science.gov (United States)

    Changeux, Jean-Pierre

    2005-01-01

    Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden “ignition” of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of “inattentional blindness,” in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness. PMID:15819609

  2. Improving cancer patients' knowledge about totally implantable access port: a randomized controlled trial.

    Science.gov (United States)

    Piredda, Michela; Biagioli, Valentina; Giannarelli, Diana; Incletoli, Daniele; Grieco, Francesca; Carassiti, Massimiliano; De Marinis, Maria Grazia

    2016-02-01

    Providing patients with written information about totally implantable access ports (TIAPs) is recommended during the pre-implantation period to reduce anxiety and to help recalling information. No study tested the effectiveness of information about TIAP neither with oral communication nor with booklets. This study aimed at evaluating the effectiveness of an information booklet, alone or together with answers to clarification questions, both in improving patients' short- and long-time knowledge about TIAP and in decreasing patients' physiological indicators of anxiety immediately after TIAP implantation. This is a randomized controlled trial with three parallel groups: group A (n = 34) receiving only the booklet, group B (n = 34) receiving the booklet with answers to clarification questions, and group C (n = 37) receiving routine care. After 3 months, pair comparisons revealed a significant improvement in knowledge of TIAP in each group (p difference in group C compared with groups A (p knowledge about TIAP immediately and at 3 months. Adding answers to clarification questions to the booklet was not more effective than the booklet alone. A well-designed booklet with attention both to scientific content and to communication techniques is useful in improving patients' knowledge about TIAP and reducing anxiety.

  3. Security Analysis and Improvements of Authentication and Access Control in the Internet of Things

    Directory of Open Access Journals (Sweden)

    Bruce Ndibanje

    2014-08-01

    Full Text Available Internet of Things is a ubiquitous concept where physical objects are connected over the internet and are provided with unique identifiers to enable their self-identification to other devices and the ability to continuously generate data and transmit it over a network. Hence, the security of the network, data and sensor devices is a paramount concern in the IoT network as it grows very fast in terms of exchanged data and interconnected sensor nodes. This paper analyses the authentication and access control method using in the Internet of Things presented by Jing et al. According to our analysis, Jing et al.’s protocol is costly in the message exchange and the security assessment is not strong enough for such a protocol. Therefore, we propose improvements to the protocol to fill the discovered weakness gaps. The protocol enhancements facilitate many services to the users such as user anonymity, mutual authentication, and secure session key establishment. Finally, the performance and security analysis show that the improved protocol possesses many advantages against popular attacks, and achieves better efficiency at low communication cost.

  4. Authenticated Blind Issuing of Symmetric Keys for Mobile Access Control System without Trusted Parties

    Directory of Open Access Journals (Sweden)

    Shin-Yan Chiou

    2013-01-01

    Full Text Available Mobile authentication can be used to verify a mobile user’s identity. Normally this is accomplished through the use of logon passwords, but this can raise the secret-key agreement problem between entities. This issue can be resolved by using a public-key cryptosystem, but mobile devices have limited computation ability and battery capacity and a PKI is needed. In this paper, we propose an efficient, non-PKI, authenticated, and blind issued symmetric key protocol for mobile access control systems. An easy-to-deploy authentication and authenticated key agreement system is designed such that empowered mobile devices can directly authorize other mobile devices to exchange keys with the server upon authentication using a non-PKI system without trusted parties. Empowered mobile users do not know the key value of the other mobile devices, preventing users from impersonating other individuals. Also, for security considerations, this system can revoke specific keys or keys issued by a specific user. The scheme is secure, efficient, and feasible and can be implemented in existing environments.

  5. Ongoing spontaneous activity controls access to consciousness: a neuronal model for inattentional blindness.

    Directory of Open Access Journals (Sweden)

    Stanislas Dehaene

    2005-05-01

    Full Text Available Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden "ignition" of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of "inattentional blindness," in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness.

  6. Medium Access Control Protocols for Wireless Sensor Networks with Energy Harvesting

    CERN Document Server

    Iannello, Fabio; Spagnolini, Umberto

    2011-01-01

    The design of Medium Access Control (MAC) protocols for wireless sensor networks (WSNs) has been conventionally tackled by assuming battery-powered devices and by adopting the network lifetime as the main performance criterion. While WSNs operated by energy-harvesting (EH) devices are not limited by network lifetime, they pose new design challenges due to the uncertain amount of harvestable energy. Novel design criteria are thus required to capture the trade-offs between the potentially infinite network lifetime and the uncertain energy availability. This paper addresses the analysis and design of WSNs with EH devices by focusing on conventional MAC protocols, namely TDMA, Framed-ALOHA (FA) and Dynamic-FA (DFA), and by accounting for the performance trade-offs and design issues arising due to EH. A novel metric, referred to as delivery probability, is introduced to measure the capability of a MAC protocol to deliver the measure of any sensor in the network to the intended destination (or fusion center, FC). T...

  7. Unified Information Access in Product Creation with an Integrated Control Desk

    Science.gov (United States)

    Wrasse, Kevin; Diener, Holger; Hayka, Haygazun; Stark, Rainer

    2017-06-01

    Customers demand for individualized products leads to a large variety of different products in small series and single-unit production. A high flexibility pressure in product creation is one result of this trend. In order to counteract the pressure, the information steadily increasing by Industry 4.0 must be made available at the workplace. Additionally, a better exchange of information between product development, production planning and production is necessary. The improvement of individual systems, like CAD, PDM, ERP and MES, can only achieve this to a limited extent. Since they mostly use systems from different manufacturers, the necessary deeper integration of information is only feasible for SMEs to a limited extend. The presented control desk helps to ensure a more flexible product creation as well as information exchange. It captures information from different IT systems in the production process and presents them integrated, task-oriented and oriented to the user’s mental model, e.g. information of the production combined with the 3D model of product parts, or information about product development on the 3D model of the production. The solution is a digital 3D model of the manufacturing environment, which is enriched by billboards for a quick information overview and web service windows to access detailed MES and PDM information. By this, the level of abstraction can be reduced and reacts to changed requirements in the short term, making informed decisions. The interaction with the control stands utilizes the touch skills of mobile and fixed systems such as smartphones, tablets and multitouch tables.

  8. Design of Active Queue Management for Robust Control on Access Router for Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Åhlund Christer

    2011-01-01

    Full Text Available The Internet architecture is a packet switching technology that allows dynamic sharing of bandwidth among different flows with in an IP network. Packets are stored and forwarded from one node to the next until reaching their destination. Major issues in this integration are congestion control and how to meet different quality of service requirements associated with various services. In other words streaming media quality degrades with increased packet delay and jitter caused by network congestion. To mitigate the impact of network congestion, various techniques have been used to improve multimedia quality and one of those techniques is Active Queue Management (AQM. Access routers require a buffer to hold packets during times of congestion. A large buffer can absorb the bursty arrivals, and this tends to increase the link utilizations but results in higher queuing delays. Traffic burstiness has a considerable negative impact on network performance. AQM is now considered an effective congestion control mechanism for enhancing transport protocol performance over wireless links. In order to have good link utilization, it is necessary for queues to adapt to varying traffic loads. This paper considers a particular scheme which is called Adaptive AQM (AAQM and studies its performance in the presence of feedback delays and its ability to maintain a small queue length as well as its robustness in the presence of traffic burstiness. The paper also presents a method based on the well-known Markov Modulated Poisson Process (MPP to capture traffic burstiness and buffer occupancy. To demonstrate the generality of the presented method, an analytic model is described and verified by extensive simulations of different adaptive AQM algorithms. The analysis and simulations show that AAQM outperforms the other AQMs with respect to responsiveness and robustness.

  9. An Ounce of Prevention: Technologists Use Network-Access Control to Protect System Resources, Students

    Science.gov (United States)

    Bolch, Matt

    2009-01-01

    Whether for an entire district, a single campus, or one classroom, allowing authorized access to a computer network can be fraught with challenges. The login process should be fairly seamless to approved users, giving them speedy access to approved Web sites, databases, and other sources of information. It also should be tough on unauthorized…

  10. Network Medicine: A Network-based Approach to Human Diseases

    Science.gov (United States)

    Ghiassian, Susan Dina

    With the availability of large-scale data, it is now possible to systematically study the underlying interaction maps of many complex systems in multiple disciplines. Statistical physics has a long and successful history in modeling and characterizing systems with a large number of interacting individuals. Indeed, numerous approaches that were first developed in the context of statistical physics, such as the notion of random walks and diffusion processes, have been applied successfully to study and characterize complex systems in the context of network science. Based on these tools, network science has made important contributions to our understanding of many real-world, self-organizing systems, for example in computer science, sociology and economics. Biological systems are no exception. Indeed, recent studies reflect the necessity of applying statistical and network-based approaches in order to understand complex biological systems, such as cells. In these approaches, a cell is viewed as a complex network consisting of interactions among cellular components, such as genes and proteins. Given the cellular network as a platform, machinery, functionality and failure of a cell can be studied with network-based approaches, a field known as systems biology. Here, we apply network-based approaches to explore human diseases and their associated genes within the cellular network. This dissertation is divided in three parts: (i) A systematic analysis of the connectivity patterns among disease proteins within the cellular network. The quantification of these patterns inspires the design of an algorithm which predicts a disease-specific subnetwork containing yet unknown disease associated proteins. (ii) We apply the introduced algorithm to explore the common underlying mechanism of many complex diseases. We detect a subnetwork from which inflammatory processes initiate and result in many autoimmune diseases. (iii) The last chapter of this dissertation describes the

  11. Study protocol for a cluster-randomised controlled trial of an NCD access to medicines initiative: evaluation of Novartis Access in Kenya.

    Science.gov (United States)

    Rockers, Peter C; Wirtz, Veronika J; Vian, Taryn; Onyango, Monica A; Ashigbie, Paul G; Laing, Richard

    2016-11-25

    Novartis recently launched Novartis Access, an initiative to provide a basket of reduced price medicines for non-communicable diseases (NCDs) to be sold through the public and private non-profit sectors in programme countries. This study will evaluate the impact of Novartis Access on the availability and price of NCD medicines at health facilities and households in Kenya, the first country to receive the programme. This study will be a cluster-randomised controlled trial. 8 counties in Kenya will be randomly assigned to the intervention or control group using a covariate constrained randomisation method to maximise balance on demographic and health characteristics. In intervention counties, public and private non-profit health facilities will be able to order Novartis Access NCD medicines from the Mission for Essential Drugs and Supplies (MEDS). Data will be collected from a random sample of 384 health facilities and 800 households at baseline, midline after 1-year of intervention, and end-line after 2 years. Quarterly surveillance data will also be collected from health facilities and a subsample of households through phone-based interviews. Households will be eligible if at least one resident has been previously diagnosed and prescribed a medicine for an NCD addressed by Novartis Access, including hypertension and diabetes. The primary outcomes will be availability and price of NCD medicines at health facilities, and availability, price, and expenditures on NCD medicines at households. Impacts will be estimated using intention-to-treat analysis. This protocol was approved by the Institutional Review Boards at Strathmore University and at Boston University. Informed consent will be obtained from all participants at the start of the trial. The findings of the trial will be disseminated through peer-reviewed journals, international conferences, and meetings and events organised with local stakeholders. NCT02773095. Published by the BMJ Publishing Group Limited

  12. Optical-Correlator Neural Network Based On Neocognitron

    Science.gov (United States)

    Chao, Tien-Hsin; Stoner, William W.

    1994-01-01

    Multichannel optical correlator implements shift-invariant, high-discrimination pattern-recognizing neural network based on paradigm of neocognitron. Selected as basic building block of this neural network because invariance under shifts is inherent advantage of Fourier optics included in optical correlators in general. Neocognitron is conceptual electronic neural-network model for recognition of visual patterns. Multilayer processing achieved by iteratively feeding back output of feature correlator to input spatial light modulator and updating Fourier filters. Neural network trained by use of characteristic features extracted from target images. Multichannel implementation enables parallel processing of large number of selected features.

  13. A reconsideration of negative ratings for network-based recommendation

    Science.gov (United States)

    Hu, Liang; Ren, Liang; Lin, Wenbin

    2018-01-01

    Recommendation algorithms based on bipartite networks have become increasingly popular, thanks to their accuracy and flexibility. Currently, many of these methods ignore users' negative ratings. In this work, we propose a method to exploit negative ratings for the network-based inference algorithm. We find that negative ratings play a positive role regardless of sparsity of data sets. Furthermore, we improve the efficiency of our method and compare it with the state-of-the-art algorithms. Experimental results show that the present method outperforms the existing algorithms.

  14. Worktime control access, need and use in relation to work-home interference, fatigue, and job motivation

    NARCIS (Netherlands)

    Nijp, H.H.; Beckers, D.G.J.; Kompier, M.A.J.; Bossche, S.N.J. van den; Geurts, S.A.E.

    2015-01-01

    OBJECTIVE: Worktime control (WTC) has been suggested as a tool to reduce employees' work-home interference and fatigue and improve job motivation. The purpose of this study was twofold: (i) to examine the prevalence of employees' need for, access to, and use of WTC, as well as the incongruence

  15. Suppressing NOM access to controlled porous TiO2 particles enhances the decomposition of target water contaminants

    Science.gov (United States)

    Suppressing access of natural organic matter (NOM) to TiO2 is a key to the successful photocatalytic decomposition of a target contaminant in water. This study first demonstrates simply controlling the porous structure of TiO2 can significantly improve the selective oxidation.

  16. A Brief Survey of Media Access Control, Data Link Layer, and Protocol Technologies for Lunar Surface Communications

    Science.gov (United States)

    Wallett, Thomas M.

    2009-01-01

    This paper surveys and describes some of the existing media access control and data link layer technologies for possible application in lunar surface communications and the advanced wideband Direct Sequence Code Division Multiple Access (DSCDMA) conceptual systems utilizing phased-array technology that will evolve in the next decade. Time Domain Multiple Access (TDMA) and Code Division Multiple Access (CDMA) are standard Media Access Control (MAC) techniques that can be incorporated into lunar surface communications architectures. Another novel hybrid technique that is recently being developed for use with smart antenna technology combines the advantages of CDMA with those of TDMA. The relatively new and sundry wireless LAN data link layer protocols that are continually under development offer distinct advantages for lunar surface applications over the legacy protocols which are not wireless. Also several communication transport and routing protocols can be chosen with characteristics commensurate with smart antenna systems to provide spacecraft communications for links exhibiting high capacity on the surface of the Moon. The proper choices depend on the specific communication requirements.

  17. Medium access control and hardware prototype designs for low-energy wireless sensor networks

    Energy Technology Data Exchange (ETDEWEB)

    Kohvakka, M.

    2009-07-01

    A Wireless Sensor Network (WSN) is an emerging technology consisting of small, cheap, and ultra-low energy sensor nodes, which cooperatively monitor physical quantities, actuate, and perform data processing tasks. A deployment may comprise thousands of randomly distributed autonomous nodes, which must self-configure and create a multi-hop network topology.This thesis focuses on low-energy WSNs targeting to long network lifetime. The main research problem is the combination of adaptive and scalable multi-hop networking with constrained energy budget, processing power, and communication bandwidth. The research problem is approached by energy-efficient protocols and low-power sensor node platforms. The main contribution of this thesis is an energy-efficient Medium Access Control (MAC) design for TUTWSN (Tampere University of Technology Wireless Sensor Network). The design comprises channel access and networking mechanisms, which specify data exchange, link synchronization, network self-configuration, and neighbor discovery operations. The second outcome are several low-power sensor node platforms, which have been designed and implemented to evaluate the performance of the MAC design and hardware components in real deployments. The third outcome are the performance models and analysis of several MAC designs including TUTWSN, IEEE 802.15.4, and the most essential research proposals.The results and conclusion of this Thesis indicate that it is possible to implement multi-hop WSNs in harsh and dynamic operation conditions with years of lifetime using current low-cost components and batteries. Energy analysis results indicate that the lowest energy consumption is achieved by using simple and high data-rate transceivers. It is also critical to minimize sleep mode power consumption of all components and to use accurate wake-up timers. However, the selection of components constitutes only a minor part of the solution, and an energy-efficient MAC layer design being able to

  18. Feasibility of a Friendship Network-Based Pediatric Obesity Intervention.

    Science.gov (United States)

    Giannini, Courtney M; Irby, Megan B; Skelton, Joseph A; Gesell, Sabina B

    2017-02-01

    There is growing evidence supporting social network-based interventions for adolescents with obesity. This study's aim was to determine the feasibility of a social network-based intervention by assessing adolescents' friendship networks, willingness to involve friends in treatment, and how these factors influence enjoyment. Adolescents (N = 42) were recruited from a tertiary care obesity clinic. Participants gave a list of closest friends, friendship characteristics, and which of their friends they would involve in treatment. A subset (N = 14) participated in group treatment, were encouraged to bring friends, and invited to a second interview. Participants nominated a mean of 4.0 (standard deviation [SD] = 1.6) friends and were more likely to nominate closer friends (p = 0.003). Friends who attended group sessions were more likely to have multiple friendships in common with the participant's own network (p = 0.04). Involving friends in treatment is feasible and desired by adolescents and may be a novel approach for augmenting obesity treatment outcomes.

  19. Analog neural network-based helicopter gearbox health monitoring system.

    Science.gov (United States)

    Monsen, P T; Dzwonczyk, M; Manolakos, E S

    1995-12-01

    The development of a reliable helicopter gearbox health monitoring system (HMS) has been the subject of considerable research over the past 15 years. The deployment of such a system could lead to a significant saving in lives and vehicles as well as dramatically reduce the cost of helicopter maintenance. Recent research results indicate that a neural network-based system could provide a viable solution to the problem. This paper presents two neural network-based realizations of an HMS system. A hybrid (digital/analog) neural system is proposed as an extremely accurate off-line monitoring tool used to reduce helicopter gearbox maintenance costs. In addition, an all analog neural network is proposed as a real-time helicopter gearbox fault monitor that can exploit the ability of an analog neural network to directly compute the discrete Fourier transform (DFT) as a sum of weighted samples. Hardware performance results are obtained using the Integrated Neural Computing Architecture (INCA/1) analog neural network platform that was designed and developed at The Charles Stark Draper Laboratory. The results indicate that it is possible to achieve a 100% fault detection rate with 0% false alarm rate by performing a DFT directly on the first layer of INCA/1 followed by a small-size two-layer feed-forward neural network and a simple post-processing majority voting stage.

  20. Enhancing Data Security and Access Control in Cloud Environment using Modified Attribute Based Encryption Mechanism

    National Research Council Canada - National Science Library

    Apurva R Naik; Lalit B Damahe

    2016-01-01

    .... File sharing and distribution are the frequently used services provided by cloud service providers, although these facilities reduce cost of data sharing but at the same time data security and access...

  1. Report: EPA Could Improve Physical Access and Service Continuity/Contingency Controls for Financial and Mixed-Financial Systems Located at its Research Triangle Park Campus

    Science.gov (United States)

    Report #2006-P-00005, December 14, 2005. Controls needed to be improved in areas such as visitor access to facilities, use of contractor access badges, and general physical access to the NCC, computer rooms outside the NCC, and media storage rooms.

  2. Development of a Network-Based Information Infrastructure for Fisheries and Hydropower Information in the Columbia River Basin : Final Project Report.

    Energy Technology Data Exchange (ETDEWEB)

    Scheibe, Timothy D.; Johnson, Gary E.; Perkins, Bill

    1997-05-01

    The goal of this project was to help develop technology and a unified structure to access and disseminate information related to the Bonneville Power Administration's fish and wildlife responsibility in the Pacific Northwest. BPA desires to increase access to, and exchange of, information produced by the Environment Fish, and Wildlife Group in concert with regional partners. Historically, data and information have been managed through numerous centralized, controlled information systems. Fisheries information has been fragmented and not widely exchanged. Where exchange has occurred, it often is not timely enough to allow resource managers to effectively use the information to guide planning and decision making. This project (and related projects) have successfully developed and piloted a network-based infrastructure that will serve as a vehicle to transparently connect existing information systems in a manner that makes information exchange efficient and inexpensive. This project was designed to provide a mechanism to help BPA address measures in the Northwest Power Planning Council's (NPPC) Fish and Wildlife program: 3.2H Disseminate Research and Monitoring Information and 5.1A.5 manage water supplies in accordance with the Annual Implementation Work Plan. This project also provided resources that can be used to assist monitoring and evaluation of the Program.

  3. A Network Based Approach to Data Access, Visualization, Interactive Analysis and Distribution

    Science.gov (United States)

    Elson, L.; Allen, M.; Goldsmith, J.; Orton, M.; Weibel, W.

    1999-01-01

    In today's heterogeneous computing environment of proliferating platforms and operating systems, the Internet, through the World Wide Web (WWW), is becoming the preferred interface to much of the world's archive of digital data.

  4. Bio-Inspired Dynamic Radio Access in Cognitive Networks based on Social Foraging Swarms

    OpenAIRE

    di Lorenzo, Paolo

    2012-01-01

    There is strong trend, in current research on communication and sensor networks, to study selforganizing, self-healing systems. This poses great challenges to the research on decentralized systems, but at the same offers great potentials for future developments, especially in view of the current trend towards miniaturized systems. Even if the development of self-organizing systems is probably at the beginning, biological systems offers many examples of self-organization and ...

  5. Worktime control access, need and use in relation to work-home interference, fatigue, and job motivation.

    Science.gov (United States)

    Nijp, Hylco H; Beckers, Debby G J; Kompier, Michiel A J; van den Bossche, Seth N J; Geurts, Sabine A E

    2015-07-01

    Worktime control (WTC) has been suggested as a tool to reduce employees' work-home interference and fatigue and improve job motivation. The purpose of this study was twofold: (i) to examine the prevalence of employees' need for, access to, and use of WTC, as well as the incongruence between need for and access to WTC (ie, mismatch); and (ii) to examine the associations of this mismatch and the use of WTC with employees' work-home interference (WHI), fatigue and job motivation. Questionnaire data were collected among a large (N=2420) quasi-representative sample of Dutch employees. The prevalence of WTC need, access, use, and mismatch was assessed by means of descriptive statistics. Associations with employees' outcomes were assessed by analyses of covariance. The need for WTC was highly prevalent. For many employees, we observed a negative mismatch between access to and need for WTC (ie, accessmotivation. The use of WTC was also highly prevalent, but no meaningful associations were found with the outcome variables. It is relevant to examine WTC comprehensively, that is, to include measurements of employees' need for and access to WTC and assess employees' (mis)match between components of WTC. For practice, we recommend to introduce WTC on an organizational level and assess employees' need for WTC on an individual basis.

  6. An Expressive, Lightweight and Secure Construction of Key Policy Attribute-Based Cloud Data Sharing Access Control

    Science.gov (United States)

    Lin, Guofen; Hong, Hanshu; Xia, Yunhao; Sun, Zhixin

    2017-10-01

    Attribute-based encryption (ABE) is an interesting cryptographic technique for flexible cloud data sharing access control. However, some open challenges hinder its practical application. In previous schemes, all attributes are considered as in the same status while they are not in most of practical scenarios. Meanwhile, the size of access policy increases dramatically with the raise of its expressiveness complexity. In addition, current research hardly notices that mobile front-end devices, such as smartphones, are poor in computational performance while too much bilinear pairing computation is needed for ABE. In this paper, we propose a key-policy weighted attribute-based encryption without bilinear pairing computation (KP-WABE-WB) for secure cloud data sharing access control. A simple weighted mechanism is presented to describe different importance of each attribute. We introduce a novel construction of ABE without executing any bilinear pairing computation. Compared to previous schemes, our scheme has a better performance in expressiveness of access policy and computational efficiency.

  7. Impact of patient access to Internet health records on glaucoma medication: randomized controlled trial.

    Science.gov (United States)

    Kashiwagi, Kenji; Tsukahara, Shigeo

    2014-01-15

    Glaucoma is one of the leading causes of blindness. Reduction of intraocular pressure is the only proven way to prevent progression of glaucomatous optic neuropathy. The majority of glaucoma patients need to use antiglaucoma ophthalmic solutions over the course of their life. Thus, good adherence and persistency of glaucoma treatment are important factors for better glaucoma care. The purpose of this study was to investigate the impact of an Internet-based glaucoma care support system on glaucoma medication use. Patients were randomly divided into two groups. The non-Internet access (NIA) group consisted of patients who had access to the Internet-based glaucoma care support system during the 4-year period only when they were examined by ophthalmologists. The Internet access (IA) group consisted of patients who had the same Internet-based glaucoma care support system access as the NIA group for the first 2 years following enrollment but who were also given free access to the glaucoma care support system for the remaining 2 years. Changes in glaucoma medication use were investigated. In total, 81 patients in the IA group and 90 patients in the NIA group satisfied the study protocol. The number of antiglaucoma ophthalmic solutions used during the study period significantly increased in the NIA group (PInternet access significantly shifted from an increasing intraocular pressure trend to a decreasing trend in the IA group (P=.002) among the patients who did not have any medication changes. Allowing patients to browse their medical data may reduce the use and improve the effectiveness of glaucoma medication. UMIN-CTR Clinical Trial Number: UMIN000006982; https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000008238&language=E (Archived by WebCite at http://www.webcitation.org/6MRPQeEAv).

  8. Is Congenital Amusia a Disconnection Syndrome? A Study Combining Tract- and Network-Based Analysis.

    Science.gov (United States)

    Wang, Jieqiong; Zhang, Caicai; Wan, Shibiao; Peng, Gang

    2017-01-01

    Previous studies on congenital amusia mainly focused on the impaired fronto-temporal pathway. It is possible that neural pathways of amusia patients on a larger scale are affected. In this study, we investigated changes in structural connections by applying both tract-based and network-based analysis to DTI data of 12 subjects with congenital amusia and 20 demographic-matched normal controls. TBSS (tract-based spatial statistics) was used to detect microstructural changes. The results showed that amusics had higher diffusivity indices in the corpus callosum, the right inferior/superior longitudinal fasciculus, and the right inferior frontal-occipital fasciculus (IFOF). The axial diffusivity values of the right IFOF were negatively correlated with musical scores in the amusia group. Network-based analysis showed that the efficiency of the brain network was reduced in amusics. The impairments of WM tracts were also found to be correlated with reduced network efficiency in amusics. This suggests that impaired WM tracts may lead to the reduced network efficiency seen in amusics. Our findings suggest that congenital amusia is a disconnection syndrome.

  9. Is Congenital Amusia a Disconnection Syndrome? A Study Combining Tract- and Network-Based Analysis

    Directory of Open Access Journals (Sweden)

    Jieqiong Wang

    2017-09-01

    Full Text Available Previous studies on congenital amusia mainly focused on the impaired fronto-temporal pathway. It is possible that neural pathways of amusia patients on a larger scale are affected. In this study, we investigated changes in structural connections by applying both tract-based and network-based analysis to DTI data of 12 subjects with congenital amusia and 20 demographic-matched normal controls. TBSS (tract-based spatial statistics was used to detect microstructural changes. The results showed that amusics had higher diffusivity indices in the corpus callosum, the right inferior/superior longitudinal fasciculus, and the right inferior frontal-occipital fasciculus (IFOF. The axial diffusivity values of the right IFOF were negatively correlated with musical scores in the amusia group. Network-based analysis showed that the efficiency of the brain network was reduced in amusics. The impairments of WM tracts were also found to be correlated with reduced network efficiency in amusics. This suggests that impaired WM tracts may lead to the reduced network efficiency seen in amusics. Our findings suggest that congenital amusia is a disconnection syndrome.

  10. Adaptive QoS provision for IEEE 802.16e BWA networks based on cross-layer design

    Directory of Open Access Journals (Sweden)

    Kuo GS

    2011-01-01

    Full Text Available Abstract This article proposes an integrated framework for adaptive QoS provision in IEEE 802.16e broadband wireless access networks based on cross-layer design. On one hand, an efficient admission control (AC algorithm is proposed along with a semi-reservation scheme to guarantee the connection-level QoS. First, to guarantee the service continuity for handoff connections and resource efficiency, our semi-reservation scheme considers both users' handoff probability and average resource consumption together, which effectively avoids resource over-reservation and insufficient reservation. For AC, a new/handoff connection is accepted only when the target cell has enough resource to afford both instantaneous and average resource consumption to meet the average source rate request. On the other hand, a joint resource allocation and packet scheduling scheme is designed to provide packet-level QoS guarantee in term of "QoS rate", which can ensure fairness for the services with identical priority level in case of bandwidth shortage. Particularly, an enhanced bandwidth request scheme is designed to reduce unnecessary BR delay and redundant signaling overhead caused by the existing one in IEEE 802.16e, which further improves the packet-level QoS performance and resource efficiency for uplink transmission. Simulation results show that the proposed approach not only balances the tradeoff among connection blocking rate, connection dropping rate, and connection failure rate, but also achieves low mean packet dropping rate (PDR, small deviation of PDR, and low QoS outage rate. Moreover, high resource efficiency is ensured.

  11. Neural network based feed-forward high density associative memory

    Science.gov (United States)

    Daud, T.; Moopenn, A.; Lamb, J. L.; Ramesham, R.; Thakoor, A. P.

    1987-01-01

    A novel thin film approach to neural-network-based high-density associative memory is described. The information is stored locally in a memory matrix of passive, nonvolatile, binary connection elements with a potential to achieve a storage density of 10 to the 9th bits/sq cm. Microswitches based on memory switching in thin film hydrogenated amorphous silicon, and alternatively in manganese oxide, have been used as programmable read-only memory elements. Low-energy switching has been ascertained in both these materials. Fabrication and testing of memory matrix is described. High-speed associative recall approaching 10 to the 7th bits/sec and high storage capacity in such a connection matrix memory system is also described.

  12. Semisupervised Clustering for Networks Based on Fast Affinity Propagation

    Directory of Open Access Journals (Sweden)

    Mu Zhu

    2013-01-01

    Full Text Available Most of the existing clustering algorithms for networks are unsupervised, which cannot help improve the clustering quality by utilizing a small number of prior knowledge. We propose a semisupervised clustering algorithm for networks based on fast affinity propagation (SCAN-FAP, which is essentially a kind of similarity metric learning method. Firstly, we define a new constraint similarity measure integrating the structural information and the pairwise constraints, which reflects the effective similarities between nodes in networks. Then, taking the constraint similarities as input, we propose a fast affinity propagation algorithm which keeps the advantages of the original affinity propagation algorithm while increasing the time efficiency by passing only the messages between certain nodes. Finally, by extensive experimental studies, we demonstrate that the proposed algorithm can take fully advantage of the prior knowledge and improve the clustering quality significantly. Furthermore, our algorithm has a superior performance to some of the state-of-art approaches.

  13. VT Limited Access Highways

    Data.gov (United States)

    Vermont Center for Geographic Information — A limited-access road, known by various terms worldwide, including limited-access highway, dual carriageway, expressway, and partial controlled access highway, is a...

  14. Resilient Disaster Network Based on Software Defined Cognitive Wireless Network Technology

    Directory of Open Access Journals (Sweden)

    Goshi Sato

    2015-01-01

    Full Text Available In order to temporally recover the information network infrastructure in disaster areas from the Great East Japan Earthquake in 2011, various wireless network technologies such as satellite IP network, 3G, and Wi-Fi were effectively used. However, since those wireless networks are individually introduced and installed but not totally integrated, some of networks were congested due to the sudden network traffic generation and unbalanced traffic distribution, and eventually the total network could not effectively function. In this paper, we propose a disaster resilient network which integrates various wireless networks into a cognitive wireless network that users can use as an access network to the Internet at the serious disaster occurrence. We designed and developed the disaster resilient network based on software defined network (SDN technology to automatically select the best network link and route among the possible access networks to the Internet by periodically monitoring their network states and evaluate those using extended AHP method. In order to verify the usefulness of our proposed system, a prototype system is constructed and its performance is evaluated.

  15. Access to the Birth Control Pill and the Career Plans of Young Men and Women

    DEFF Research Database (Denmark)

    Steingrimsdottir, Herdis

    plans of both men and women, and by separating the effect by level of academic ability, race and family income. The results show that unrestricted access to the pill caused high ability women to move towards occupations with higher wages, higher occupational prestige scores and higher male ratios...

  16. Enrollment Quota Control, Elite Selection and Access to Education in Rural China

    Science.gov (United States)

    Zhao, Luan

    2010-01-01

    In China, the access to education is determined by not only student's demand for schooling, but also the allocation of educational resources and the schools' selection of candidate students. Based on the data obtained from the rural life level and rural social assistance household surveys in four provinces in 2005, the demand-identified bivariate…

  17. Evaluation of a flexible column-based access control security model ...

    African Journals Online (AJOL)

    Despite these benefits, EMR poses great security and privacy challenges due to the fact that all patients' medical records are maintained and sustained in a centralized system which as a result may inadvertently, deliberately and carelessly be accessed, modified, manipulated, altered or misused by illegal and unauthorized ...

  18. 76 FR 78866 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Science.gov (United States)

    2011-12-20

    .... Literary works, distributed electronically, that: (1) Contain digital rights management and/or other access... Deaf and Hard of Hearing, Inc., Gallaudet University, and Participatory Culture Foundation (filing...., Gallaudet University, and Participatory Culture Foundation (filing jointly). 9C. Motion pictures and other...

  19. An effective and secure key-management scheme for hierarchical access control in E-medicine system.

    Science.gov (United States)

    Odelu, Vanga; Das, Ashok Kumar; Goswami, Adrijit

    2013-04-01

    Recently several hierarchical access control schemes are proposed in the literature to provide security of e-medicine systems. However, most of them are either insecure against 'man-in-the-middle attack' or they require high storage and computational overheads. Wu and Chen proposed a key management method to solve dynamic access control problems in a user hierarchy based on hybrid cryptosystem. Though their scheme improves computational efficiency over Nikooghadam et al.'s approach, it suffers from large storage space for public parameters in public domain and computational inefficiency due to costly elliptic curve point multiplication. Recently, Nikooghadam and Zakerolhosseini showed that Wu-Chen's scheme is vulnerable to man-in-the-middle attack. In order to remedy this security weakness in Wu-Chen's scheme, they proposed a secure scheme which is again based on ECC (elliptic curve cryptography) and efficient one-way hash function. However, their scheme incurs huge computational cost for providing verification of public information in the public domain as their scheme uses ECC digital signature which is costly when compared to symmetric-key cryptosystem. In this paper, we propose an effective access control scheme in user hierarchy which is only based on symmetric-key cryptosystem and efficient one-way hash function. We show that our scheme reduces significantly the storage space for both public and private domains, and computational complexity when compared to Wu-Chen's scheme, Nikooghadam-Zakerolhosseini's scheme, and other related schemes. Through the informal and formal security analysis, we further show that our scheme is secure against different attacks and also man-in-the-middle attack. Moreover, dynamic access control problems in our scheme are also solved efficiently compared to other related schemes, making our scheme is much suitable for practical applications of e-medicine systems.

  20. A Novel Architecture for Adaptive Traffic Control in Network on Chip using Code Division Multiple Access Technique

    OpenAIRE

    Fatemeh. Dehghani; Shahram. Darooei

    2016-01-01

    Network on chip has emerged as a long-term and effective method in Multiprocessor System-on-Chip communications in order to overcome the bottleneck in bus based communication architectures. Efficiency and performance of network on chip is so dependent on the architecture and structure of the network. In this paper a new structure and architecture for adaptive traffic control in network on chip using Code Division Multiple Access technique is presented. To solve the problem of synchronous acce...

  1. Massive Access Control Aided by Knowledge-Extraction for Co-Existing Periodic and Random Services over Wireless Clinical Networks.

    Science.gov (United States)

    Du, Qinghe; Zhao, Weidong; Li, Weimin; Zhang, Xuelin; Sun, Bo; Song, Houbing; Ren, Pinyi; Sun, Li; Wang, Yichen

    2016-07-01

    The prosperity of e-health is boosted by fast development of medical devices with wireless communications capability such as wearable devices, tiny sensors, monitoring equipments, etc., which are randomly distributed in clinic environments. The drastically-increasing population of such devices imposes new challenges on the limited wireless resources. To relieve this problem, key knowledge needs to be extracted from massive connection attempts dispersed in the air towards efficient access control. In this paper, a hybrid periodic-random massive access (HPRMA) scheme for wireless clinical networks employing ultra-narrow band (UNB) techniques is proposed. In particular, the proposed scheme towards accommodating a large population of devices include the following new features. On one hand, it can dynamically adjust the resource allocated for coexisting periodic and random services based on the traffic load learned from signal collision status. On the other hand, the resource allocation within periodic services is thoroughly designed to simultaneously align with the timing requests of differentiated services. Abundant simulation results are also presented to demonstrate the superiority of the proposed HPRMA scheme over baseline schemes including time-division multiple access (TDMA) and random access approach, in terms of channel utilization efficiency, packet drop ratio, etc., for the support of massive devices' services.

  2. Unsynchronized Energy-Efficient Medium Access Control and Routing in Wireless Sensor Networks

    Science.gov (United States)

    Hurni, Philipp

    This master thesis investigates optimizations on recently proposed fully unsynchronized power saving sensor MAC protocols. In contrast to many other sensor MAC protocols, unsynchronized sensor MAC protocols renounce on any kind of network- or cluster-wide synchronization for channel access coordination and maintenance of a common wake-sleep pattern, because in wireless sensor networks with low traffic requirements, the overhead for maintaining synchronization is likely to exceed the energy spent for the actual data traffic.

  3. CONTEXT BASED ANDROID APPLICATIONADMINISTRATIVE ACCESS CONTROL (CBAA–AAC) FOR SMART PHONES

    OpenAIRE

    S. Sharavanan; R.M. Balajee

    2016-01-01

    Android applications in smart phones are generally towards provide greater flexibility and convince for users. Considering the fact that the Android applications are having privilege to access data and resources in mobile after it gets installed (one time permission provided by end user on the time installation), these application may also lead to issues in security for the user data as well as issues relate smart phone with peripheral environment. A practical example for an issue which relat...

  4. Cross-layer Control for Adaptive Video Streaming over Wireless Access Networks

    OpenAIRE

    Abdallah AbouSheaisha, Abdallah Sabry

    2016-01-01

    Over the last decade, the wide deployment of wireless access technologies (e.g. WiFi, 3G, and LTE) and the remarkable growth in the volume of streaming video content have significantly altered the telecommunications field. These developments introduce new challenges to the research community including the need to develop new solutions (e.g. traffic models and transport protocols) to address changing traffic patterns and the characteristics of wireless links and the need for new evaluation me...

  5. Improving access and quality of care in a TB control programme.

    Science.gov (United States)

    Scott, Vera; Azevedo, Virginia; Caldwell, Judy

    2012-09-18

    To use a quality improvement approach to improve access to and quality of tuberculosis (TB) diagnosis and care in Cape Town. Five HIV/AIDS/sexually transmitted infections/TB (HAST) evaluations were conducted from 2008 to 2010, with interviews with 99 facility managers and a folder review of over 850 client records per evaluation cycle. The data were used in a local quality improvement process: sub-district workshops identified key weaknesses and facility managers drew up action plans. Lessons learnt and successful strategies were shared at quarterly district-wide HIV/TB meetings. Geographical access was good, but there were delays in treatment commencement times. Access for high-risk clients improved significantly with intensified TB case finding made routine in both the HIV counselling and testing and antiretroviral treatment (ART) services (p42% investigated and treated). Quality of care was mostly high at baseline (adherence to treatment protocols 95%). Measurement of body mass index improved from 20% to 62%. The assessment of contraception improved from 27% to 58%. Care for co-infected clients showed improved use of customised HIV stationery and increased assessment for ART eligibility. The HAST audit contributed to the improved TB cure rates by supplementing routine information and involving sub-district managers, facility managers and facility staff in a quality improvement process that identified local opportunities for programme strengthening.

  6. An efficient neural network based method for medical image segmentation.

    Science.gov (United States)

    Torbati, Nima; Ayatollahi, Ahmad; Kermani, Ali

    2014-01-01

    The aim of this research is to propose a new neural network based method for medical image segmentation. Firstly, a modified self-organizing map (SOM) network, named moving average SOM (MA-SOM), is utilized to segment medical images. After the initial segmentation stage, a merging process is designed to connect the objects of a joint cluster together. A two-dimensional (2D) discrete wavelet transform (DWT) is used to build the input feature space of the network. The experimental results show that MA-SOM is robust to noise and it determines the input image pattern properly. The segmentation results of breast ultrasound images (BUS) demonstrate that there is a significant correlation between the tumor region selected by a physician and the tumor region segmented by our proposed method. In addition, the proposed method segments X-ray computerized tomography (CT) and magnetic resonance (MR) head images much better than the incremental supervised neural network (ISNN) and SOM-based methods. © 2013 Published by Elsevier Ltd.

  7. Deep Network Based on Stacked Orthogonal Convex Incremental ELM Autoencoders

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2016-01-01

    Full Text Available Extreme learning machine (ELM as an emerging technology has recently attracted many researchers’ interest due to its fast learning speed and state-of-the-art generalization ability in the implementation. Meanwhile, the incremental extreme learning machine (I-ELM based on incremental learning algorithm was proposed which outperforms many popular learning algorithms. However, the incremental algorithms with ELM do not recalculate the output weights of all the existing nodes when a new node is added and cannot obtain the least-squares solution of output weight vectors. In this paper, we propose orthogonal convex incremental learning machine (OCI-ELM with Gram-Schmidt orthogonalization method and Barron’s convex optimization learning method to solve the nonconvex optimization problem and least-squares solution problem, and then we give the rigorous proofs in theory. Moreover, in this paper, we propose a deep architecture based on stacked OCI-ELM autoencoders according to stacked generalization philosophy for solving large and complex data problems. The experimental results verified with both UCI datasets and large datasets demonstrate that the deep network based on stacked OCI-ELM autoencoders (DOC-IELM-AEs outperforms the other methods mentioned in the paper with better performance on regression and classification problems.

  8. Network-based analysis of software change propagation.

    Science.gov (United States)

    Wang, Rongcun; Huang, Rubing; Qu, Binbin

    2014-01-01

    The object-oriented software systems frequently evolve to meet new change requirements. Understanding the characteristics of changes aids testers and system designers to improve the quality of softwares. Identifying important modules becomes a key issue in the process of evolution. In this context, a novel network-based approach is proposed to comprehensively investigate change distributions and the correlation between centrality measures and the scope of change propagation. First, software dependency networks are constructed at class level. And then, the number of times of cochanges among classes is minded from software repositories. According to the dependency relationships and the number of times of cochanges among classes, the scope of change propagation is calculated. Using Spearman rank correlation analyzes the correlation between centrality measures and the scope of change propagation. Three case studies on java open source software projects Findbugs, Hibernate, and Spring are conducted to research the characteristics of change propagation. Experimental results show that (i) change distribution is very uneven; (ii) PageRank, Degree, and CIRank are significantly correlated to the scope of change propagation. Particularly, CIRank shows higher correlation coefficient, which suggests it can be a more useful indicator for measuring the scope of change propagation of classes in object-oriented software system.

  9. Identifying node role in social network based on multiple indicators.

    Directory of Open Access Journals (Sweden)

    Shaobin Huang

    Full Text Available It is a classic topic of social network analysis to evaluate the importance of nodes and identify the node that takes on the role of core or bridge in a network. Because a single indicator is not sufficient to analyze multiple characteristics of a node, it is a natural solution to apply multiple indicators that should be selected carefully. An intuitive idea is to select some indicators with weak correlations to efficiently assess different characteristics of a node. However, this paper shows that it is much better to select the indicators with strong correlations. Because indicator correlation is based on the statistical analysis of a large number of nodes, the particularity of an important node will be outlined if its indicator relationship doesn't comply with the statistical correlation. Therefore, the paper selects the multiple indicators including degree, ego-betweenness centrality and eigenvector centrality to evaluate the importance and the role of a node. The importance of a node is equal to the normalized sum of its three indicators. A candidate for core or bridge is selected from the great degree nodes or the nodes with great ego-betweenness centrality respectively. Then, the role of a candidate is determined according to the difference between its indicators' relationship with the statistical correlation of the overall network. Based on 18 real networks and 3 kinds of model networks, the experimental results show that the proposed methods perform quite well in evaluating the importance of nodes and in identifying the node role.

  10. Visualization of Complex Networks Based on Dyadic Curvelet Transform

    Directory of Open Access Journals (Sweden)

    Kaoru Hirota

    2006-07-01

    Full Text Available A visualization method is proposed for understanding the structure of complex networks based on an extended Curvelet transform named Dyadic Curvelet Transform (DClet. The proposed visualization method comes to answer specific questions about structures of complex networks by mapping data into orthogonal localized events with a directional component via the Cartesian sampling sets of detail coefficients. It behaves in the same matter as human visual system, seeing in terms of segments and distinguishing them by scale and orientation. Compressing the network is another fact. The performance of the proposed method is evaluated by two different networks with structural properties of small world networks with N = 16 vertices, and a globally coupled network with size N = 1024 and 523 776 edges. As the most large scale real networks are not fully connected, it is tested on the telecommunication network of Iran as a real extremely complex network with 92 intercity switching vertices, 706 350 E1 traffic channels and 315 525 transmission channels. It is shown that the proposed method performs as a simulation tool for successfully design of network and establishing the necessary group sizes. It can clue the network designer in on all structural properties that network has.

  11. Optimizing data access for wind farm control over hierarchical communication networks

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Findrik, Mislav; Madsen, Tatiana Kozlova

    2016-01-01

    delays and also by the choice of the time instances at which sensor information is accessed. In order to optimize the latter, we introduce an information quality metric and a mathematical model based on Markov chains, which are compared performance-wise to a heuristic approach for finding this parameter....... This information quality metric is called mismatch probability, mmPr, and is used to express quantitatively the information accuracy in a given scenario. Lastly measurements of different communication technologies have been performed in order to carry out the analysis in a practically relevant scenario...

  12. Advance reservation access control using software-defined networking and tokens

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Joaquin; Jung, Eun-Sung; Kettimuthu, Rajkumar; Rao, Nageswara S. V.; Foster, Ian T.; Clark, Russ; Owen, Henry

    2018-02-01

    Advance reservation systems allow users to reserve dedicated bandwidth connection resources from advanced high-speed networks. A common use case for such systems is data transfers in distributed science environments in which a user wants exclusive access to the reservation. However, current advance network reservation methods cannot ensure exclusive access of a network reservation to the specific flow for which the user made the reservation. We present here a novel network architecture that addresses this limitation and ensures that a reservation is used only by the intended flow. We achieve this by leveraging software-defined networking (SDN) and token-based authorization. We use SDN to orchestrate and automate the reservation of networking resources, end-to-end and across multiple administrative domains, and tokens to create a strong binding between the user or application that requested the reservation and the flows provisioned by SDN. We conducted experiments on the ESNet 100G SDN testbed, and demonstrated that our system effectively protects authorized flows from competing traffic in the network. (C) 2017 Elsevier B.V. All rights reserved.

  13. Accessing memory

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Doe Hyun; Muralimanohar, Naveen; Chang, Jichuan; Ranganthan, Parthasarathy

    2017-09-26

    A disclosed example method involves performing simultaneous data accesses on at least first and second independently selectable logical sub-ranks to access first data via a wide internal data bus in a memory device. The memory device includes a translation buffer chip, memory chips in independently selectable logical sub-ranks, a narrow external data bus to connect the translation buffer chip to a memory controller, and the wide internal data bus between the translation buffer chip and the memory chips. A data access is performed on only the first independently selectable logical sub-rank to access second data via the wide internal data bus. The example method also involves locating a first portion of the first data, a second portion of the first data, and the second data on the narrow external data bus during separate data transfers.

  14. Gendered Access and Control Over Land and Water Resources in the Southern Agricultural Growth Corridor of Tanzania

    Directory of Open Access Journals (Sweden)

    Anna N. Sikira

    2016-12-01

    Full Text Available This paper assessed the gendered access and control over land and water, using the Ihemi cluster of the Southern Agricultural Growth Corridor of Tanzania (SAGCOT as a study area. Specifically, the paper answered the question on how decisions are made between men and women over land and water in the SAGCOT area, as well as how access and control over land and water is conducted. Data for this paper was drawn from the baseline study which was conducted for the project known as Laying Foundation for Effective Landscape-level Planning for Sustainable Development (LiFELand. A cross-sectional research design was used, whereby a questionnaire was administered to 167 women and 440 men. In addition, focus group discussions and key informant interviews were also conducted to complement and allow triangulation of data. Quantitative data was analyzed descriptively; while, qualitative data was analyzed using content analysis. In general, the results show that female headed households accounted for more than a quarter of the surveyed households; the number was slightly higher in the Njombe region. Results further show that women had no control over land and water as important productive resources in rural areas. The results also show that a larger proportion of both men and women had no right of occupancy over the land they owned hence their inability to use it as collateral in accessing loans from formal financial institutions. The paper therefore recommends efforts be made to empower women, hence enabling them to actively participate in decision-making, particularly regarding land and water. Equitable decision-making power can immensely enhance ecosystem conservation and sustainable utilization over land and water as women are the major actors in agriculture. To achieve gender equality there is a need for awareness creation for both men and women using gender sensitive programs that will allow not only equality in use but a sustainable utilization of Land

  15. Generalized control and data access at the LANSCE Accelerator Complex -- Gateway, migrators, and other servers

    Energy Technology Data Exchange (ETDEWEB)

    Schaller, S.C.; Oothoudt, M.A.

    1995-12-01

    All large accelerator control systems eventually outlast the technologies with which they were built. This has happened several times during the lifetime of the accelerators at Los Alamos in the LAMPF/PSR beam delivery complex. Most recently, the EPICS control system has been integrated with the existing LAMPF and PSR control systems. In this paper, the authors discuss the provisions that were made to provide uniform, and nearly transparent sharing of data among the three control systems. The data sharing mechanisms have now been in use during a very successful beam production period. They comment on the successes and failures of the project and indicate the control system properties that make such sharing possible.

  16. Practical considerations to guide development of access controls and decision support for genetic information in electronic medical records.

    Science.gov (United States)

    Darcy, Diana C; Lewis, Eleanor T; Ormond, Kelly E; Clark, David J; Trafton, Jodie A

    2011-11-02

    Genetic testing is increasingly used as a tool throughout the health care system. In 2011 the number of clinically available genetic tests is approaching 2,000, and wide variation exists between these tests in their sensitivity, specificity, and clinical implications, as well as the potential for discrimination based on the results. As health care systems increasingly implement electronic medical record systems (EMRs) they must carefully consider how to use information from this wide spectrum of genetic tests, with whom to share information, and how to provide decision support for clinicians to properly interpret the information. Although some characteristics of genetic tests overlap with other medical test results, there are reasons to make genetic test results widely available to health care providers and counterbalancing reasons to restrict access to these test results to honor patient preferences, and avoid distracting or confusing clinicians with irrelevant but complex information. Electronic medical records can facilitate and provide reasonable restrictions on access to genetic test results and deliver education and decision support tools to guide appropriate interpretation and use. This paper will serve to review some of the key characteristics of genetic tests as they relate to design of access control and decision support of genetic test information in the EMR, emphasizing the clear need for health information technology (HIT) to be part of optimal implementation of genetic medicine, and the importance of understanding key characteristics of genetic tests when designing HIT applications.

  17. Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

    Science.gov (United States)

    Chow, Edward T.; Woo, Simon S.; James, Mark; Paloulian, George K.

    2012-01-01

    As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are

  18. Dynamic neural network-based methods for compensation of nonlinear effects in multimode communication lines

    Science.gov (United States)

    Sidelnikov, O. S.; Redyuk, A. A.; Sygletos, S.

    2017-12-01

    We consider neural network-based schemes of digital signal processing. It is shown that the use of a dynamic neural network-based scheme of signal processing ensures an increase in the optical signal transmission quality in comparison with that provided by other methods for nonlinear distortion compensation.

  19. Combining Host-based and network-based intrusion detection system

    African Journals Online (AJOL)

    These attacks were simulated using hping. The proposed system is implemented in Java. The results show that the proposed system is able to detect attacks both from within (host-based) and outside sources (network-based). Key Words: Intrusion Detection System (IDS), Host-based, Network-based, Signature, Security log.

  20. Network-Based Substrate of Cognitive Reserve in Alzheimer's Disease.

    Science.gov (United States)

    Serra, Laura; Mancini, Matteo; Cercignani, Mara; Di Domenico, Carlotta; Spanò, Barbara; Giulietti, Giovanni; Koch, Giacomo; Marra, Camillo; Bozzali, Marco

    2017-01-01

    Cognitive reserve (CR) is known to modulate the clinical features of Alzheimer's disease (AD). This concept may be critical for the development of non-pharmacological interventions able to slow down patients' cognitive decline in the absence of disease-modifying treatments. We aimed at identifying the neurobiological substrates of CR (i.e., neural reserve) over the transition between normal aging and AD, by assessing the underlying brain networks and their topological properties. A cohort of 154 participants (n = 68 with AD, n = 61 with amnestic mild cognitive impairment (aMCI), and 25 healthy subjects) underwent resting-state functional MRI and neuropsychological testing. Within each group, participants were classified as having high or low CR, and functional connectivity measures were compared, within group, between high and low CR individuals. Network-based statistics and topological network properties derived from graph theory were explored. Connectivity differences between high and low CR were evident only for aMCI patients, with participants with high CR showing a significant increase of connectivity in a network involving mainly fronto-parietal nodes. Conversely, they showed significantly decreased connectivity in a network involving fronto-temporo-cerebellar nodes. Consistently, changes to topological measures were observed in either direction, and were associated with measures of global cognitive function. These findings support the hypothesis that CR impacts on neurodegenerative process in the early phase of AD only. In addition, they fit with the existence of a "neural reserve", characterized by specific neural networks and their efficiency. It remains to be demonstrated whether interventions later in life can modulate this "neural reserve".

  1. Network-based collaborative research environment LDRD final report

    Energy Technology Data Exchange (ETDEWEB)

    Davies, B.R.; McDonald, M.J.

    1997-09-01

    The Virtual Collaborative Environment (VCE) and Distributed Collaborative Workbench (DCW) are new technologies that make it possible for diverse users to synthesize and share mechatronic, sensor, and information resources. Using these technologies, university researchers, manufacturers, design firms, and others can directly access and reconfigure systems located throughout the world. The architecture for implementing VCE and DCW has been developed based on the proposed National Information Infrastructure or Information Highway and a tool kit of Sandia-developed software. Further enhancements to the VCE and DCW technologies will facilitate access to other mechatronic resources. This report describes characteristics of VCE and DCW and also includes background information about the evolution of these technologies.

  2. Oversight Review: Quality Control Review of Naval Audit Service's Special Access Program Audits

    National Research Council Canada - National Science Library

    2005-01-01

    .... The Government Auditing Standards (GAS) require that an audit organization performing audits and/or attestation engagements in accordance with GAS should have an appropriate internal quality control system in place and undergo an external...

  3. Oversight Review: Quality Control Review of Air Force Audit Agency's Special Access Program Audits

    National Research Council Canada - National Science Library

    2005-01-01

    .... The Government Auditing Standards (GAS) require that an audit organization performing audits and/or attestation engagements in accordance with GAS should have an appropriate internal quality control system in place and undergo an external...

  4. Oversight Review: Quality Control Review of Army Audit Agency's Special Access Program Audits

    National Research Council Canada - National Science Library

    2005-01-01

    .... The Government Auditing Standards (GAS) require that an audit organization performing audits and/or attestation engagements in accordance with GAS should have an appropriate internal quality control system in place and undergo an external...

  5. On the control, stability, and waiting time in a slotted ALOHA random-access system

    Science.gov (United States)

    Ferguson, M. J.

    1975-01-01

    This paper explores some of the boundaries in performance of slotted ALOHA systems by analyzing a simple and almost optimal centrally supervised control. The control results in a very simple Markov chain model and allows an examination of stability, conditional waiting time distribution of transmitting terminals, and many other system measures. The key to the simplicity is to have a probability of successful packet transmission that is independent of the number of transmitting terminals. In considering waiting time, we calculate the mean and other moments of the waiting time of a terminal when it enters the system to find (n - 1) other terminals already there competing for the channel. Under this control, the average time is proportional to n. The control requires exact knowledge of the number of terminals contending for the channel, and hence is not implementable, except as an approximation.

  6. Bathymetric control of warm ocean water access along the East Antarctic Margin

    Science.gov (United States)

    Nitsche, F. O.; Porter, D.; Williams, G.; Cougnon, E. A.; Fraser, A. D.; Correia, R.; Guerrero, R.

    2017-09-01

    Observed thinning of the Totten Glacier in East Antarctica has cast doubt upon the stability of the East Antarctic Ice Sheet. Recent oceanographic observations at the front of the Totten Ice Shelf have confirmed the presence of modified Circumpolar Deep Water (mCDW), which likely promotes enhanced melting. Details of how this water accesses the shelf remain uncertain. Here we present new bathymetry and autumnal oceanographic data from the outer continental shelf, north of the Totten Glacier, that show up to 0.7°C mCDW in a >100 km wide and >500 m deep depression within the shelf break. In other parts of East Antarctica, a shelf break bathymetry shallower than 400 m prevents these warmer waters from entering the shelf environment. Our observations demonstrate that detailed knowledge of the bathymetry is critical to correctly model the across-shelf exchange of warm water to the various glaciers/ice shelves of Antarctica for future sea level prediction.

  7. Improving Access to Online Health Information With Conversational Agents: A Randomized Controlled Experiment.

    Science.gov (United States)

    Bickmore, Timothy W; Utami, Dina; Matsuyama, Robin; Paasche-Orlow, Michael K

    2016-01-04

    Conventional Web-based search engines may be unusable by individuals with low health literacy for finding health-related information, thus precluding their use by this population. We describe a conversational search engine interface designed to allow individuals with low health and computer literacy identify and learn about clinical trials on the Internet. A randomized trial involving 89 participants compared the conversational search engine interface (n=43) to the existing conventional keyword- and facet-based search engine interface (n=46) for the National Cancer Institute Clinical Trials database. Each participant performed 2 tasks: finding a clinical trial for themselves and finding a trial that met prespecified criteria. Results indicated that all participants were more satisfied with the conversational interface based on 7-point self-reported satisfaction ratings (task 1: mean 4.9, SD 1.8 vs mean 3.2, SD 1.8, Phealth literacy failed to find any trials that satisfied the prespecified criteria for task 2 using the conventional search engine interface, whereas 36% (5/14) were successful at this task using the conversational interface (P=.05). Conversational agents can be used to improve accessibility to Web-based searches in general and clinical trials in particular, and can help decrease recruitment bias against disadvantaged populations.

  8. The dynamic mechanism of presenilin-function: Sensitive gate dynamics and loop unplugging control protein access

    DEFF Research Database (Denmark)

    Somavarapu, Arun Kumar; Kepp, Kasper Planeta

    2016-01-01

    There is no molecular explanation for the many presenilin 1 (PSEN1) mutations causing Alzheimer's disease, but both gain of function relating to amyloid production and loss of isolated PSEN1 function have been implied. We report here the first detailed dynamic all-atom model of mature PSEN1 from ......-plug mechanism is relevant for designing PSEN1 modulating therapies for treatment of Alzheimer's disease within both the amyloid/γ-secretase hypothesis and within the PSEN1 loss of function paradigm.......There is no molecular explanation for the many presenilin 1 (PSEN1) mutations causing Alzheimer's disease, but both gain of function relating to amyloid production and loss of isolated PSEN1 function have been implied. We report here the first detailed dynamic all-atom model of mature PSEN1 from....... Dynamically, these features seem linked. The long-range sensitivity of this gate-plug system to subtle conformational changes can explain why so many PSEN1 mutants cause disease. Reduced access and imprecise substrate cleavage associated with impaired gate-plug dynamics is directly illustrated by the effect...

  9. Performance of a Frequency-Hopped Real-Time Remote Control System in a Multiple Access Scenario

    Science.gov (United States)

    Cervantes, Frank

    A recent trend is observed in the context of the radio-controlled aircrafts and automobiles within the hobby grade category and Unmanned Aerial Vehicles (UAV) applications moving to the well-known Industrial, Scientific and Medical (ISM) band. Based on this technological fact, the present thesis evaluates an individual user performance by featuring a multiple-user scenario where several point-to-point co-located real-time Remote Control (RC) applications operate using Frequency Hopping Spread Spectrum (FHSS) as a medium access technique in order to handle interference efficiently. Commercial-off-the-shelf wireless transceivers ready to operate in the ISM band are considered as the operational platform supporting the above-mentioned applications. The impact of channel impairments and of different critical system engineering issues, such as working with real clock oscillators and variable packet duty cycle, are considered. Based on the previous, simulation results allowed us to evaluate the range of variation for those parameters for an acceptable system performance under Multiple Access (MA) environments.

  10. Well controlled multiple resistive switching states in the Al local doped HfO2 resistive random access memory device

    Science.gov (United States)

    Chen, Y. S.; Chen, B.; Gao, B.; Liu, L. F.; Liu, X. Y.; Kang, J. F.

    2013-04-01

    The resistive switching behaviors in the sandwiched Ti/HfO2/Pt devices with different doping condition were systematically investigated. We show that, comparing with the undoped and the Al layer doped HfO2 devices, significant improvement of switching characteristics is achieved in the Al local doped HfO2 device, including uniformity, reliability, and operation current. As a result, well controlled multiple switching states are obtained in the local doping device by modulating the set current compliance or the maximal reset voltage, respectively. Our results suggest that the switching characteristics of HfO2 device are very closely related to the inducement and controlling of conductive filaments' growth in the dielectric layer, which can be considered in the optimization of resistive random access memory device design.

  11. Electromagnetic malfunction of semiconductor-type electronic personal dosimeters caused by access control systems for radiation facilities.

    Science.gov (United States)

    Deji, Shizuhiko; Ito, Shigeki; Ariga, Eiji; Mori, Kazuyuki; Hirota, Masahiro; Saze, Takuya; Nishizawa, Kunihide

    2006-08-01

    High frequency electromagnetic fields in the 120 kHz band emitted from card readers for access control systems in radiation control areas cause abnormally high and erroneous indicated dose readings on semiconductor-type electronic personal dosimeters (SEPDs). All SEPDs malfunctioned but recovered their normal performance by resetting after the exposure ceased. The minimum distances required to prevent electromagnetic interference varied from 5.0 to 38.0 cm. The electric and magnetic immunity levels ranged from 35.1 to 267.6 V m(-1) and from 1.0 to 16.6 A m(-1), respectively. Electromagnetic immunity levels of SEPDs should be strengthened from the standpoint of radiation protection.

  12. Reputation-based ontology alignment for autonomy and interoperability in distributed access control

    NARCIS (Netherlands)

    Trivellato, Daniel; Spiessens, Fred; Zannone, Nicola; Etalle, Sandro

    2009-01-01

    Vocabulary alignment is a main challenge in distributedaccess control as peers should understand each other’spolicies unambiguously. Ontologies enable mutual understanding among peers by providing a precise semantics to concepts and relationships in a domain. However, due to the distributed nature

  13. Implementing the Victory Access Control Framework in a Military Ground Vehicle

    Science.gov (United States)

    2015-08-01

    or the Department of the Army ( DoA ). The opinions of the authors expressed herein do not necessarily state or reflect those of the United States...Government or the DoA , and shall not be used for advertising or product endorsement purposes. ABSTRACT The Vehicular Integration for Command, Control

  14. Suicidal Behavior and Firearm Access: Results from the Second Injury Control and Risk Survey

    Science.gov (United States)

    Betz, Marian E.; Barber, Catherine; Miller, Matthew

    2011-01-01

    The association between home firearms and the likelihood and nature of suicidal thoughts and plans was examined using the Second Injury Control and Risk Survey, a 2001-2003 representative telephone survey of U.S. households. Of 9,483 respondents, 7.4% reported past-year suicidal thoughts, 21.3% with a plan. Similar proportions of those with and…

  15. Nectar accessibility determines fitness, flower choice and abundance of hoverflies that provide natural pest control

    NARCIS (Netherlands)

    van Rijn, P.C.J.; Wäckers, F.L.

    2016-01-01

    1. In modern agricultural landscapes, many organisms providing ecosystem services such as pollination and natural pest control are likely constrained by shortage of nectar and/or pollen required for adult nutrition. More and more flower-rich field margin strips and other habitats are created to

  16. A Rapid Assessment Tool for Space Access Vehicle Configurations in Guidance and Control Performance (Preprint)

    Science.gov (United States)

    2006-08-01

    following equations from Roskam :3 Ixx = W g (kx b)2 (1) Iyy = W g (ky l)2 (2) Izz = W g (kz b+ l 2 )2 (3) The non-dimensional radii of gyration (k...Proceedings of the 2003 AIAA Guidance Navigation and Control Conference, AIAA 2003-5738, August 2003. 3Roskam, J., Airplane Design, Roskam Aviation

  17. 21 CFR 1311.125 - Requirements for establishing logical access control-Individual practitioner.

    Science.gov (United States)

    2010-04-01

    ... control-Individual practitioner. 1311.125 Section 1311.125 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Electronic... each registered location where one or more individual practitioners wish to use an electronic...

  18. Design and Implementation of a Multi-Modal Biometric System for Company Access Control

    Directory of Open Access Journals (Sweden)

    Elisabetta Stefani

    2017-05-01

    Full Text Available This paper is about the design, implementation, and deployment of a multi-modal biometric system to grant access to a company structure and to internal zones in the company itself. Face and iris have been chosen as biometric traits. Face is feasible for non-intrusive checking with a minimum cooperation from the subject, while iris supports very accurate recognition procedure at a higher grade of invasivity. The recognition of the face trait is based on the Local Binary Patterns histograms, and the Daughman’s method is implemented for the analysis of the iris data. The recognition process may require either the acquisition of the user’s face only or the serial acquisition of both the user’s face and iris, depending on the confidence level of the decision with respect to the set of security levels and requirements, stated in a formal way in the Service Level Agreement at a negotiation phase. The quality of the decision depends on the setting of proper different thresholds in the decision modules for the two biometric traits. Any time the quality of the decision is not good enough, the system activates proper rules, which ask for new acquisitions (and decisions, possibly with different threshold values, resulting in a system not with a fixed and predefined behaviour, but one which complies with the actual acquisition context. Rules are formalized as deduction rules and grouped together to represent “response behaviors” according to the previous analysis. Therefore, there are different possible working flows, since the actual response of the recognition process depends on the output of the decision making modules that compose the system. Finally, the deployment phase is described, together with the results from the testing, based on the AT&T Face Database and the UBIRIS database.

  19. Implementation of neural network based non-linear predictive

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Ravn, Ole

    1998-01-01

    The paper describes a control method for non-linear systems based on generalized predictive control. Generalized predictive control (GPC) was developed to control linear systems including open loop unstable and non-minimum phase systems, but has also been proposed extended for the control of non......-linear systems. GPC is model-based and in this paper we propose the use of a neural network for the modeling of the system. Based on the neural network model a controller with extended control horizon is developed and the implementation issues are discussed, with particular emphasis on an efficient Quasi......-Newton optimization algorithm. The performance is demonstrated on a pneumatic servo system....

  20. Command and Control in the Anti-Access/Area Denial Environment

    Science.gov (United States)

    2014-02-13

    buying into this concept simultaneously. The USAF culturally values broad battlespace awareness and is psychologically equipped to lead this...14 JOAC, 19, 29, 34. 15 Ibid., 11. 16 Ibid., 28. 17 Maj Damon Matlock, Maj Jonathan Gaustad, Maj Jason Scott, and Capt Danielle Bales , “Command and... Bales . "Command and Control in Africa: Three Case Studies Before and After Tactical C2." Air and Space Power Journal 28, no. 4 (July-August 2014

  1. A system for precise temperature control of isolated nervous tissue under optical access: application to multi-electrode recordings.

    Science.gov (United States)

    Ahlers, Malte T; Ammermüller, Josef

    2013-09-30

    Since temperature severely affects all physiological processes, exact temperature control during electrophysiological measurements is indispensable. However, none of the tempering system approaches previously described is fully satisfactory for extracellular recordings with sharp multi-electrode arrays (MEAs). We developed a set-up offering a homogeneously tempered and at the same time light-transparent stage for an ex vivo preparation. The Peltier element based tempering unit of our system is physically separated from the preparation stage avoiding electrical disturbances of extracellular recordings. We implemented a digital feedback controller on a microcontroller to minimise the deviation between actual and set point temperature. Our tempering system allows operation from 10°C to 45°C with a control error in steady state between 0.052°C (RMSE) and 0.115°C (RMSE). To document the versatility of our system, we performed extracellular MEA recordings from retinal ganglion cells of isolated retina under different temperature conditions. We found strong influences on light response properties, even for small temperature changes. Currently used heating systems that allow top and bottom side optical access to a preparation typically exhibit low temperature accuracy, precision or homogeneity. Our system is adequate not only for experiments on a variety of species under physiological temperature conditions but also for studies on temperature effects on physiology in general. Though the setup was developed for the context of MEA recordings from retina it may be useful in other cases where optical access to the preparation from both, top and bottom side is required. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Integrating end-user feedback in the concept stage of development of a novel sensor access system for environmental control.

    Science.gov (United States)

    Fager, Susan Koch; Sorenson, Tabatha; Butte, Susanne; Nelson, Alexander; Banerjee, Nilanjan; Robucci, Ryan

    2017-05-19

    This article illustrates user-centred design of a novel sensor access system for environmental control in the concept stage of development. Focus groups of individuals with disabilities and rehabilitation healthcare professionals were provided with video illustration of the technology and asked to provide quantitative and qualitative feedback through a semistructured interview process. Qualitative methods were employed to analyse transcribed comments to develop themes supporting ongoing development of the technology. Both end-user streams rated the original design features of the sensor access system (alternative interface to assistive technologies, having wireless capabilities and not requiring batteries) as having high potential value. Both groups identified a need for the future design of the sensor technology to be able to capture minimal/reduced movements for those with severe physical impairments. Themes included (1) the sensor technology could be individualized/customized to accommodate the user, (2) minimal positioning and set-up requirement and (3) technology that alleviated problems encountered with touch-based solutions. Inclusion of end-user feedback provided the research team with valuable information that supported the initial conceptualization of the design features of the technology and provided valuable data to support development of a new prototype that can capture more reduced/minimal movements. Implication for Rehabilitation User-centered design of assistive technology is essential to the development of technology that can meet the unique needs of those with the most severe physical impairments. New sensor technology may alleviate some of the access challenges faced by individuals with severe physical impairments. Collaboration between all key stakeholders (individuals with disabilities, rehabilitation professionals, researchers, and developers) is an essential component in the iterative assistive technology design process.

  3. Network based management for multiplexed electric vehicle charging

    Science.gov (United States)

    Gadh, Rajit; Chung, Ching Yen; Qui, Li

    2017-04-11

    A system for multiplexing charging of electric vehicles, comprising a server coupled to a plurality of charging control modules over a network. Each of said charging modules being connected to a voltage source such that each charging control module is configured to regulate distribution of voltage from the voltage source to an electric vehicle coupled to the charging control module. Data collection and control software is provided on the server for identifying a plurality of electric vehicles coupled to the plurality of charging control modules and selectively distributing charging of the plurality of charging control modules to multiplex distribution of voltage to the plurality of electric vehicles.

  4. Towards a quality-controlled and accessible Pitzer model for seawater and related systems

    Directory of Open Access Journals (Sweden)

    David Turner

    2016-09-01

    Full Text Available We elaborate the need for a quality-controlled chemical speciation model for seawater and related natural waters, work which forms the major focus of SCOR Working Group 145. Model development is based on Pitzer equations for the seawater electrolyte and trace components. These equations can be used to calculate activities of dissolved ions and molecules and, in combination with thermodynamic equilibrium constants, chemical speciation. The major tasks to be addressed are ensuring internal consistency of the Pitzer model parameters (expressing the interactions between pairs and triplets of species, which ultimately determines the calculated activities, assessing uncertainties, and identifying important data gaps that should be addressed by new measurements. It is recognised that natural organic matter plays an important role in many aquatic ecosystems, and options for including this material in a Pitzer-based model are discussed. The process of model development begins with the core components which include the seawater electrolyte and the weak acids controlling pH. This core model can then be expanded by incorporating additional chemical components, changing the standard seawater composition and/or broadening the range of temperature and pressure, without compromising its validity. Seven important areas of application are identified: open ocean acidification; micro-nutrient biogeochemistry and geochemical tracers; micro-nutrient behaviour in laboratory studies; water quality in coastal and estuarine waters; cycling of nutrients and trace metals in pore waters; chemical equilibria in hydrothermal systems; brines and salt lakes.

  5. Non-Hermitian acoustic metamaterial for the complete control of sound by accessing the exceptional points

    CERN Document Server

    Zhu, Yi-Fan; Fan, Xu-Dong; Liang, Bin; Zou, Xin-Ye; Yang, Jing; Cheng, Jian-Chun

    2016-01-01

    Non-Hermitian systems always play a negative role in wave manipulations due to inherent non-conservation of energy as well as loss of information. Recently, however, there has been a paradigm shift on utilizing non-Hermitian systems to implement varied miraculous wave controlling. For example, parity-time symmetric media with well-designed loss and gain are presented to create a nontrivial effect of unidirectional diffraction, which is observed near the exceptional points (EPs) in the non-Hermitian systems. Here, we report the design and realization of non-Hermitian acoustic metamaterial (NHAM) and show that by judiciously tailoring the inherent loss, the phase and amplitude of reflection can possibly be tuned in a decoupled manner. Such decoupled tuning of phase and amplitude is closely related to the EPs. As a demonstration of functionality, we experimentally generate a high-quality acoustic hologram via NHAM. Our work may open a new degree of freedom for realizing the complete control of sound.

  6. Metadata Standard and Data Exchange Specifications to Describe, Model, and Integrate Complex and Diverse High-Throughput Screening Data from the Library of Integrated Network-based Cellular Signatures (LINCS).

    Science.gov (United States)

    Vempati, Uma D; Chung, Caty; Mader, Chris; Koleti, Amar; Datar, Nakul; Vidović, Dušica; Wrobel, David; Erickson, Sean; Muhlich, Jeremy L; Berriz, Gabriel; Benes, Cyril H; Subramanian, Aravind; Pillai, Ajay; Shamu, Caroline E; Schürer, Stephan C

    2014-06-01

    The National Institutes of Health Library of Integrated Network-based Cellular Signatures (LINCS) program is generating extensive multidimensional data sets, including biochemical, genome-wide transcriptional, and phenotypic cellular response signatures to a variety of small-molecule and genetic perturbations with the goal of creating a sustainable, widely applicable, and readily accessible systems biology knowledge resource. Integration and analysis of diverse LINCS data sets depend on the availability of sufficient metadata to describe the assays and screening results and on their syntactic, structural, and semantic consistency. Here we report metadata specifications for the most important molecular and cellular components and recommend them for adoption beyond the LINCS project. We focus on the minimum required information to model LINCS assays and results based on a number of use cases, and we recommend controlled terminologies and ontologies to annotate assays with syntactic consistency and semantic integrity. We also report specifications for a simple annotation format (SAF) to describe assays and screening results based on our metadata specifications with explicit controlled vocabularies. SAF specifically serves to programmatically access and exchange LINCS data as a prerequisite for a distributed information management infrastructure. We applied the metadata specifications to annotate large numbers of LINCS cell lines, proteins, and small molecules. The resources generated and presented here are freely available. © 2014 Society for Laboratory Automation and Screening.

  7. Medical-Grade Channel Access and Admission Control in 802.11e EDCA for Healthcare Applications.

    Science.gov (United States)

    Son, Sunghwa; Park, Kyung-Joon; Park, Eun-Chan

    2016-01-01

    In this paper, we deal with the problem of assuring medical-grade quality of service (QoS) for real-time medical applications in wireless healthcare systems based on IEEE 802.11e. Firstly, we show that the differentiated channel access of IEEE 802.11e cannot effectively assure medical-grade QoS because of priority inversion. To resolve this problem, we propose an efficient channel access algorithm. The proposed algorithm adjusts arbitrary inter-frame space (AIFS) in the IEEE 802.11e protocol depending on the QoS measurement of medical traffic, to provide differentiated near-absolute priority for medical traffic. In addition, based on rigorous capacity analysis, we propose an admission control scheme that can avoid performance degradation due to network overload. Via extensive simulations, we show that the proposed mechanism strictly assures the medical-grade QoS and improves the throughput of low-priority traffic by more than several times compared to the conventional IEEE 802.11e.

  8. Dynamic Cognitive Self-Organized TDMA for Medium Access Control in Real-Time Vehicle to Vehicle Communications

    Directory of Open Access Journals (Sweden)

    Mario Manzano

    2013-01-01

    Full Text Available The emergence of intelligent transport systems has brought out a new set of requirements on wireless communication. To cope with these requirements, several proposals are currently under discussion. In this highly mobile environment, the design of a prompt, efficient, flexible, and reliable medium access control, able to cover the specific constraints of the named real-time communications applications, is still unsolved. This paper presents the original proposal integrating Non-Cooperative Cognitive Time Division Multiple Access (NCC-TDMA based on Cognitive Radio (CR techniques to obtain a mechanism which complies with the requirements of real-time communications. Though the proposed MAC uses a slotted channel, it can be adapted to operate on the physical layer of different standards. The authors’ analysis considers the IEEE WAVE and 802.11p as the standards of reference. The mechanism also offers other advantages, such as avoiding signalling and the adaptation capacity to channel conditions and interferences. The solution is applied to the problem of units merging a convoy. Comparison results between NCC-TDMA and Slotted-Aloha are included.

  9. Family Access to a Dentist Study (FADS): A Multi-Center Randomized Controlled Trial

    Science.gov (United States)

    Nelson, Suchitra; Riedy, Christine; Albert, Jeffrey M; Lee, Wonik; Slusar, Mary Beth; Curtan, Shelley; Ferretti, Gerald; Cunha-Cruz, Joana; Milgrom, Peter

    2015-01-01

    Introduction Many low-income parent/caregivers do not understand the importance of cavity-free primary (baby) teeth and the chronic nature of dental caries (tooth decay). As a consequence, dental preventive and treatment utilization is low even when children are screened in schools and referred for care. This study aims to test a referral letter and Dental Information Guide (DIG) designed using the Common-Sense Model of Self-Regulation (CSM) framework to improve caregivers’ illness perception of dental caries and increase utilization of care by children with restorative dental needs. Methods A multi-site randomized controlled trial with caregivers of Kindergarten to 4th grade children in urban Ohio and rural Washington State will compare five arms: (1) CSM referral letter alone; (2) CSM referral letter + DIG; (3) reduced CSM referral letter alone; (4) reduced CSM referral letter + DIG; (5) standard (control) referral. At baseline, children will be screened at school to determine restorative dental needs. If in need of treatment, caregivers will be randomized to study arms and an intervention packet will be sent home. The primary outcome will be dental care based on a change in oral health status by clinical examination 7 months post-screening (ICDAS sealant codes 1 and 2; restoration codes 3–8; extraction). Enrollment commenced summer 2015 with results in summer 2016. Conclusion This study uses the CSM framework to develop and test behavioral interventions to increase dental utilization among low-income caregivers. If effective this simple intervention has broad applicability in clinical and community-based settings. PMID:26500170

  10. Family Access to a Dentist Study (FADS): A multi-center randomized controlled trial.

    Science.gov (United States)

    Nelson, Suchitra; Riedy, Christine; Albert, Jeffrey M; Lee, Wonik; Slusar, Mary Beth; Curtan, Shelley; Ferretti, Gerald; Cunha-Cruz, Joana; Milgrom, Peter

    2015-11-01

    Many low-income parent/caregivers do not understand the importance of cavity-free primary (baby) teeth and the chronic nature of dental caries (tooth decay). As a consequence, dental preventive and treatment utilization is low even when children are screened in schools and referred for care. This study aims to test a referral letter and Dental Information Guide (DIG) designed using the Common-Sense Model of Self-Regulation (CSM) framework to improve caregivers' illness perception of dental caries and increase utilization of care by children with restorative dental needs. A multi-site randomized controlled trial with caregivers of Kindergarten to 4th grade children in urban Ohio and rural Washington State will compare five arms: (1) CSM referral letter alone; (2) CSM referral letter+DIG; (3) reduced CSM referral letter alone; (4) reduced CSM referral letter+DIG; and (5) standard (control) referral. At baseline, children will be screened at school to determine restorative dental needs. If in need of treatment, caregivers will be randomized to study arms and an intervention packet will be sent home. The primary outcome will be dental care based on a change in oral health status by clinical examination 7 months post-screening (ICDAS sealant codes 1 and 2; restoration codes 3-8; extraction). Enrollment commenced summer 2015 with results in summer 2016. This study uses the CSM framework to develop and test behavioral interventions to increase dental utilization among low-income caregivers. If effective this simple intervention has broad applicability in clinical and community-based settings. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Preserving Smart Objects Privacy through Anonymous and Accountable Access Control for a M2M-Enabled Internet of Things

    Directory of Open Access Journals (Sweden)

    José L. Hernández-Ramos

    2015-07-01

    Full Text Available As we get into the Internet of Things era, security and privacy concerns remain as the main obstacles in the development of innovative and valuable services to be exploited by society. Given the Machine-to-Machine (M2M nature of these emerging scenarios, the application of current privacy-friendly technologies needs to be reconsidered and adapted to be deployed in such global ecosystem. This work proposes different privacy-preserving mechanisms through the application of anonymous credential systems and certificateless public key cryptography. The resulting alternatives are intended to enable an anonymous and accountable access control approach to be deployed on large-scale scenarios, such as Smart Cities. Furthermore, the proposed mechanisms have been deployed on constrained devices, in order to assess their suitability for a secure and privacy-preserving M2M-enabled Internet of Things.

  12. Preserving Smart Objects Privacy through Anonymous and Accountable Access Control for a M2M-Enabled Internet of Things.

    Science.gov (United States)

    Hernández-Ramos, José L; Bernabe, Jorge Bernal; Moreno, M Victoria; Skarmeta, Antonio F

    2015-07-01

    As we get into the Internet of Things era, security and privacy concerns remain as the main obstacles in the development of innovative and valuable services to be exploited by society. Given the Machine-to-Machine (M2M) nature of these emerging scenarios, the application of current privacy-friendly technologies needs to be reconsidered and adapted to be deployed in such global ecosystem. This work proposes different privacy-preserving mechanisms through the application of anonymous credential systems and certificateless public key cryptography. The resulting alternatives are intended to enable an anonymous and accountable access control approach to be deployed on large-scale scenarios, such as Smart Cities. Furthermore, the proposed mechanisms have been deployed on constrained devices, in order to assess their suitability for a secure and privacy-preserving M2M-enabled Internet of Things.

  13. Rat Strain Ontology: structured controlled vocabulary designed to facilitate access to strain data at RGD.

    Science.gov (United States)

    Nigam, Rajni; Munzenmaier, Diane H; Worthey, Elizabeth A; Dwinell, Melinda R; Shimoyama, Mary; Jacob, Howard J

    2013-11-22

    The Rat Genome Database (RGD) ( http://rgd.mcw.edu/) is the premier site for comprehensive data on the different strains of the laboratory rat (Rattus norvegicus). The strain data are collected from various publications, direct submissions from individual researchers, and rat providers worldwide. Rat strain, substrain designation and nomenclature follow the Guidelines for Nomenclature of Mouse and Rat Strains, instituted by the International Committee on Standardized Genetic Nomenclature for Mice. While symbols and names aid in identifying strains correctly, the flat nature of this information prohibits easy search and retrieval, as well as other data mining functions. In order to improve these functionalities, particularly in ontology-based tools, the Rat Strain Ontology (RS) was developed. The Rat Strain Ontology (RS) reflects the breeding history, parental background, and genetic manipulation of rat strains. This controlled vocabulary organizes strains by type: inbred, outbred, chromosome altered, congenic, mutant and so on. In addition, under the chromosome altered category, strains are organized by chromosome, and further by type of manipulations, such as mutant or congenic. This allows users to easily retrieve strains of interest with modifications in specific genomic regions. The ontology was developed using the Open Biological and Biomedical Ontology (OBO) file format, and is organized on the Directed Acyclic Graph (DAG) structure. Rat Strain Ontology IDs are included as part of the strain report (RS: ######). As rat researchers are often unaware of the number of substrains or altered strains within a breeding line, this vocabulary now provides an easy way to retrieve all substrains and accompanying information. Its usefulness is particularly evident in tools such as the PhenoMiner at RGD, where users can now easily retrieve phenotype measurement data for related strains, strains with similar backgrounds or those with similar introgressed regions. This

  14. Network-based analysis reveals functional connectivity related to internet addiction tendency

    Directory of Open Access Journals (Sweden)

    Tanya eWen

    2016-02-01

    Full Text Available IntroductionPreoccupation and compulsive use of the internet can have negative psychological effects, such that it is increasingly being recognized as a mental disorder. The present study employed network-based statistics to explore how whole-brain functional connections at rest is related to the extent of individual’s level of internet addiction, indexed by a self-rated questionnaire. We identified two topologically significant networks, one with connections that are positively correlated with internet addiction tendency, and one with connections negatively correlated with internet addiction tendency. The two networks are interconnected mostly at frontal regions, which might reflect alterations in the frontal region for different aspects of cognitive control (i.e., for control of internet usage and gaming skills. Next, we categorized the brain into several large regional subgroupings, and found that the majority of proportions of connections in the two networks correspond to the cerebellar model of addiction which encompasses the four-circuit model. Lastly, we observed that the brain regions with the most inter-regional connections associated with internet addiction tendency replicate those often seen in addiction literature, and is corroborated by our meta-analysis of internet addiction studies. This research provides a better understanding of large-scale networks involved in internet addiction tendency and shows that pre-clinical levels of internet addiction are associated with similar regions and connections as clinical cases of addiction.

  15. A web of possibilities: network-based discovery of protein interaction codes.

    Science.gov (United States)

    Winter, Daniel L; Erce, Melissa A; Wilkins, Marc R

    2014-12-05

    Many proteins, including p53, the FoxO transcription factors, RNA polymerase II, pRb, and the chaperones, have extensive post-translational modifications (PTMs). Many of these modifications modulate protein-protein interactions, controlling interaction presence/absence and specificity. Here we propose the notion of the interaction code, a widespread means by which modifications are used to control interactions in the proteome. Minimal interaction codes are likely to exist on proteins that have two modifications and two or more interaction partners. By contrast, complex interaction codes are likely to be found on "date hub" proteins that have many interactions, many PTMs, or are targeted by many modifying and demodifying enzymes. Proteins with new interaction codes should be discoverable by examining protein interaction networks, annotated with PTMs and protein-modifying enzyme-substrate links. Multiple instances or combinations of phosphorylation, acetylation, methylation, O-GlcNAc, or ubiquitination will likely form interaction codes, especially when colocated on a protein's single interaction interface. A network-based example of code discovery is given, predicting the yeast protein Npl3p to have a methylation/phosphorylation-dependent interaction code.

  16. Measuring the wisdom of the crowds in network-based gene function inference.

    Science.gov (United States)

    Verleyen, W; Ballouz, S; Gillis, J

    2015-03-01

    Network-based gene function inference methods have proliferated in recent years, but measurable progress remains elusive. We wished to better explore performance trends by controlling data and algorithm implementation, with a particular focus on the performance of aggregate predictions. Hypothesizing that popular methods would perform well without hand-tuning, we used well-characterized algorithms to produce verifiably 'untweaked' results. We find that most state-of-the-art machine learning methods obtain 'gold standard' performance as measured in critical assessments in defined tasks. Across a broad range of tests, we see close alignment in algorithm performances after controlling for the underlying data being used. We find that algorithm aggregation provides only modest benefits, with a 17% increase in area under the ROC (AUROC) above the mean AUROC. In contrast, data aggregation gains are enormous with an 88% improvement in mean AUROC. Altogether, we find substantial evidence to support the view that additional algorithm development has little to offer for gene function prediction. The supplementary information contains a description of the algorithms, the network data parsed from different biological data resources and a guide to the source code (available at: http://gillislab.cshl.edu/supplements/). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. A Fairness-Based Access Control Scheme to Optimize IPTV Fast Channel Changing

    Directory of Open Access Journals (Sweden)

    Junyu Lai

    2014-01-01

    Full Text Available IPTV services are typically featured with a longer channel changing delay compared to the conventional TV systems. The major contributor to this lies in the time spent on intraframe (I-frame acquisition during channel changing. Currently, most widely adopted fast channel changing (FCC methods rely on promptly transmitting to the client (conducting the channel changing a retained I-frame of the targeted channel as a separate unicasting stream. However, this I-frame acceleration mechanism has an inherent scalability problem due to the explosions of channel changing requests during commercial breaks. In this paper, we propose a fairness-based admission control (FAC scheme for the original I-frame acceleration mechanism to enhance its scalability by decreasing the bandwidth demands. Based on the channel changing history of every client, the FAC scheme can intelligently decide whether or not to conduct the I-frame acceleration for each channel change request. Comprehensive simulation experiments demonstrate the potential of our proposed FAC scheme to effectively optimize the scalability of the I-frame acceleration mechanism, particularly in commercial breaks. Meanwhile, the FAC scheme only slightly increases the average channel changing delay by temporarily disabling FCC (i.e., I-frame acceleration for the clients who are addicted to frequent channel zapping.

  18. Whistler mode waves from lightning on Venus: Magnetic control of ionospheric access

    Science.gov (United States)

    Russell, C. T.; Zhang, T. L.; Wei, H. Y.

    2008-09-01

    The fluxgate magnetometer on Venus Express samples the magnetic field near periapsis at 128 Hz. Bursts of plane-polarized magnetic waves in the vicinity of 100 Hz are observed propagating at small angles to the magnetic field. The magnetic field is generally horizontal in the region around periapsis, located at high northern latitudes. When the magnetic field remains within 15° of horizontal during the 2-min periapsis pass, no such waves are observed; but when there are brief periods during which the local magnetic field dips into the atmosphere by more than 15°, the bursts begin to appear. Such radial excursions of the magnetic field occur 25% of the time in the region around periapsis. The bursts are seen only on passes with these excursions. We interpret this magnetic control in terms of the coupling between the electromagnetic wave from lightning discharges refracted vertically by the increasing electron density and the nearly horizontal ionospheric magnetic field along which the energy is guided to the spacecraft. The inferred rate of electric discharges in the Venus atmosphere is about 20% of that seen in the Earth's atmosphere.

  19. Analysis and application of intelligence network based on FTTH

    Science.gov (United States)

    Feng, Xiancheng; Yun, Xiang

    2008-12-01

    With the continued rapid growth of Internet, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. The bandwidth requirement increase continuously. Network technique, optical device technical development is swift and violent. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. Firstly, it introduces the main service which FTTH supports, main analysis key technology such as FTTH system composition way, topological structure, multiplexing, optical cable and device. It focus two kinds of realization methods - PON, P2P technology. Then it proposed that the solution of FTTH can support comprehensive access (service such as broadband data, voice, video and narrowband private line). Finally, it shows the engineering application for FTTH in the district and building. It brings enormous economic benefits and social benefit.

  20. Surveillance in easy to access population subgroups as a tool for evaluating malaria control progress: A systematic review.

    Science.gov (United States)

    Sesay, Sanie S S; Giorgi, Emanuele; Diggle, Peter J; Schellenberg, David; Lalloo, David G; Terlouw, Dianne J

    2017-01-01

    The need for surveillance systems generating targeted, data-driven, responsive control efforts to accelerate and sustain malaria transmission reduction has been emphasized by programme managers, policy makers and scientists. Surveillance using easy-to-access population subgroups (EAGs) may result in considerable cost saving compared to household surveys as the identification and selection of individuals to be surveyed is simplified, fewer personnel are needed, and logistics are simpler. We reviewed available literature on the validation of estimates of key indicators of malaria control progress derived from EAGs, and describe the options to deal with the context specific bias that may occur. A literature search was conducted of all documents reporting validation of estimates of malaria control indicators from EAG surveys before the 31st of December 2016. Additional records were identified through cross-reference from selected records, other applicable policy documents and grey literature. After removal of duplicates, 13, 180 abstracts were evaluated and 2,653 eligible abstracts were identified mentioning surveillance in EAGs, of which 29 full text articles were selected for detailed review. The nine articles selected for systematic review compared estimates from health facility and school surveys with those of a contemporaneous sample of the same population in the same geographic area. Review of the available literature on EAGs suitable for surveillance of malaria control progress revealed that little effort has been made to explore the potential approach and settings for use of EAGs; and that there was wide variation in the precision of estimates of control progress between and within studies, particularly for estimates of control intervention coverage. Only one of the studies evaluated the geospatial representativeness of EAG samples, or carried out geospatial analyses to assess or control for lack of geospatial representativeness. Two studies attempted to