LANSCE personnel access control system (PACS)

International Nuclear Information System (INIS)

Sturrock, J.C.; Gallegos, F.R.; Hall, M.J.

1997-01-01

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described

The design and implementation of access control management system in IHEP network

International Nuclear Information System (INIS)

Wang Yanming; An Dehai; Qi Fazhi

2010-01-01

In campus network environment of Institute of High Energy Physics, because of the number of Network devices and computers are large scale, ensuring the access validity of network devices and user's computer, and aiming at effective control the exceptional network communication are technological means to achieve network normal running. The access control system of Campus network of institute of High Energy Physics using MySQL database in the behind, and using CGI PHP HTML language to develop the front interface. The System achieves user information management, user computer access control, cutting down the exceptional network communication and alarm function. Increasing the management effective of network, to ensure campus network safety and reliable running. (authors)

ITS Multi-path Communications Access Decision Scheme

Directory of Open Access Journals (Sweden)

Miroslav Svitek

2008-02-01

Full Text Available Intelligent Transport Systems (ITS require widely spread and guarantied quality communications services. Method of ITS decomposition to set of subsystems and quantification of communications subsystems parameters is introduced. Due to typical complexity of the IST solution and mobility as the typical system elements property idea of communications systems with multipath multivendor structures is adopted. Resolution of seamless switching within a set of available wireless access solutions is presented. CALM based system or specifically designed and configured L3/L2 switching can be relevant solution for multi-path access communication system. These systems meet requirements of the seamless secure communications functionality within even extensive cluster of moving objects. Competent decision processes based on precisely quantified system requirements and each performance indicator tolerance range must be implemented to keep service up and running with no influence of continuously changing conditions in time and served space. Method of different paths service quality evaluation and selection of the best possible active communications access path is introduced. Proposed approach is based on Kalman filtering, which separates reasonable part of noise and also allows prediction of the individual parameters near future behavior. Presented classification algorithm applied on filtered measured data combined with deterministic parameters is trained using training data, i.e. combination of parameters vectors line and relevant decisions. Quality of classification is dependent on the size and quality of the training sets. This method is studied within projects e-Ident, DOTEK and SRATVU which are elaborating results of project CAMNA.

Wireless ad hoc networks access for aeronautical communications

OpenAIRE

Besse , Frédéric; Garcia , Fabien; Pirovano , Alain; Radzik , José

2010-01-01

International audience; There is an increasing interest in the current aeronautical context to offer new services for civil aircraft passengers. For example, airlines want to offer their customers the opportunity to access the Internet, to manage their mails, to watch video on demand, to access corporate VPNs.... All these services represent a new type of air-ground communications called APC (Aeronautical Passenger Communications) in the ATN (Aeronautical Telecommunication Network) context. I...

Use of action requests to control communications

International Nuclear Information System (INIS)

Brady, J.

1988-01-01

This paper discusses the Plant Information Management System (PIMS) that is implemented at Pacific Gas and Electric Company's (PG and E) Diablo Canyon Power Plant (DCPP). PIMS is implemented on IBM mainframes located at the plant, is on-line and interactive, and is accessed via a computer communication system that supports more than 450 IBM 3270 PC workstations. This paper discusses the role of the ACTION REQUEST module of PIMS and how it is used to control plant sensitive communications. The ACTION REQUEST module of PIMS can be accessed from any workstation and during the first year of Commercial Operation of DCPP replaced numerous and redundant forms of manual communication mechanisms. Also in this first year, users at the plant generated approximately 25,000 Action Requests which were controlled through review and approval cycles by PIMS. Each organization assigned action were immediately notified of their responsibilities so that action could be taken in a timely manner. The Diablo Canyon Power Plant broke Westinghouse world-wide operating records for the first year of operation (over 90% availability) due to a well built and reliable plant and due to a responsive Operations organization, which was well informed and controlled

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......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...

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.

Policy-based secure communication with automatic key management for industrial control and automation systems

Science.gov (United States)

Chernoguzov, Alexander; Markham, Thomas R.; Haridas, Harshal S.

2016-11-22

A method includes generating at least one access vector associated with a specified device in an industrial process control and automation system. The specified device has one of multiple device roles. The at least one access vector is generated based on one or more communication policies defining communications between one or more pairs of devices roles in the industrial process control and automation system, where each pair of device roles includes the device role of the specified device. The method also includes providing the at least one access vector to at least one of the specified device and one or more other devices in the industrial process control and automation system in order to control communications to or from the specified device.

40 CFR 264.34 - Access to communications or alarm system.

Science.gov (United States)

2010-07-01

... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID...

40 CFR 265.34 - Access to communications or alarm system.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or alarm...

Visual accessibility in graphic design: A client–designer communication failure

OpenAIRE

Cornish, Katie; Goodman-Deane, Joy; Ruggeri, Kai; Clarkson, P. John

2015-01-01

It is essential that graphic design is visually clear and accessible. However, evidence suggests that a lack of consideration is given to visual accessibility in print-based graphic design. Furthermore, effective client-designer communication is a vital component in this. This paper investigates current graphic design practice, with regard to visual accessibility, specifically focussing on client-designer communication. A survey of 122 graphic designers and clients identified that these two g...

Global communications: democratic access for women.

Science.gov (United States)

1995-01-01

In preparation for the 1995 World Conference on Women, women of the Latin American Information Agency prepared a statement for the UN about the importance of communications and information in the contemporary world and the role of women in the media. The statement includes the following specific suggestions: 1) that the UN promote the democratization of communications with a gender focus, 2) that women be assured access to new communications technologies that empower their communicational capacity, 3) that steps be taken to ensure that media content projects a positive and nondiscriminatory image of women, and 4) that guidelines be drawn up to promote labor equality between the genders and a greater presence of women in decision-making positions in the media.

A multi-radio, multi-hop ad-hoc radio communication network for Communications-Based Train Control (CBTC)

DEFF Research Database (Denmark)

Farooq, Jahanzeb; Bro, Lars; Karstensen, Rasmus Thystrup

2018-01-01

Communications-Based Train Control (CBTC) is a modern signalling system that uses radio communication to transfer train control information between train and wayside. The trackside networks in these systems are mostly based on conventional infrastructure Wi-Fi (IEEE 802.11). It means a train has...... to continuously associate (i.e. perform handshake) with the trackside Wi-Fi Access Points (AP) as it moves, which incurs communication delays. Additionally, these APs are connected to the wayside infrastructure via optical fiber cables that incurs huge costs. This paper presents a novel design in which trackside...

Code-Expanded Random Access for Machine-Type Communications

DEFF Research Database (Denmark)

Kiilerich Pratas, Nuno; Thomsen, Henning; Stefanovic, Cedomir

2012-01-01

Abstract—The random access methods used for support of machine-type communications (MTC) in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. Motivated by the random access method employed in LTE, we propose...

Controlling user access to electronic resources without password

Science.gov (United States)

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.

Implementation of Multiple Access Techniques Applicable for Maritime Satellite Communications

Directory of Open Access Journals (Sweden)

Stojce Dimov Ilcev

2013-12-01

Full Text Available In this paper are introduced fundamentals, characteristics, advantages and disadvantages of Multiple Access (MA employed as transmission techniques in the Maritime Mobile Satellite Communications (MMSC between ships and Coast Earth Station (CES via Geostationary Earth Orbit (GEO or Not-GEO satellite constellations. In fixed satellite communication, as a rule, especially in MMSC many users are active at the same time. The problem of simultaneous communications between many single or multipoint mobile satellite users can be solved by using MA technique, such as Frequency Division Multiple Access (FDMA, Time Division Multiple Access (TDMA, Code Division Multiple Access (CDMA, Space Division Multiple Access (SDMA and Random (Packet Division Multiple Access (RDMA. Since the resources of the systems such as the transmitting power and the bandwidth are limited, it is advisable to use the channels with complete charge and to create a different MA to the channel. This generates a problem of summation and separation of signals in the transmission and reception parts, respectively. Deciding this problem consists in the development of orthogonal channels of transmission in order to divide signals from various users unambiguously on the reception part.

Code-expanded radio access protocol for machine-to-machine communications

DEFF Research Database (Denmark)

Thomsen, Henning; Kiilerich Pratas, Nuno; Stefanovic, Cedomir

2013-01-01

The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated b...... subframes and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the massive support of Machine-Type Communication users that is beyond the reach of current systems.......The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated...... by the random access method employed in LTE, which significantly increases the amount of contention resources without increasing the system resources, such as contention subframes and preambles. This is accomplished by a logical, rather than physical, extension of the access method in which the available system...

Scholarly Communications and Access to Knowledge Workshop

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

03341

2009-06-10

Jun 10, 2009 ... One of the key drivers of this project has been an understanding which has evolved over the last ... Communication and Access to Knowledge in Africa Project. ... Institutional capacities include human resources and skills,.

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...

Collaborative Access Control For Critical Infrastructures

Science.gov (United States)

Baina, Amine; El Kalam, Anas Abou; Deswarte, Yves; Kaaniche, Mohamed

A critical infrastructure (CI) can fail with various degrees of severity due to physical and logical vulnerabilities. Since many interdependencies exist between CIs, failures can have dramatic consequences on the entire infrastructure. This paper focuses on threats that affect information and communication systems that constitute the critical information infrastructure (CII). A new collaborative access control framework called PolyOrBAC is proposed to address security problems that are specific to CIIs. The framework offers each organization participating in a CII the ability to collaborate with other organizations while maintaining control of its resources and internal security policy. The approach is demonstrated on a practical scenario involving the electrical power grid.

On Novel Access and Scheduling Schemes for IoT Communications

Directory of Open Access Journals (Sweden)

Zheng Jiang

2016-01-01

Full Text Available The Internet of Things (IoT is expected to foster the development of 5G wireless networks and requires the efficient support for a large number of simultaneous short message communications. To address these challenges, some existing works utilize new waveform and multiuser superposition transmission schemes to improve the capacity of IoT communication. In this paper, we will investigate the spatial degree of freedom of IoT devices based on their distribution, then extend the multiuser shared access (MUSA which is one of the typical MUST schemes to spatial domain, and propose two novel schemes, that is, the preconfigured access scheme and the joint spatial and code domain scheduling scheme, to enhance IoT communication. The results indicate that the proposed schemes can reduce the collision rate dramatically during the IoT random access procedure and improve the performance of IoT communication obviously. Based on the simulation results, it is also shown that the proposed scheduling scheme can achieve the similar performance to the corresponding brute-force scheduling but with lower complexity.

Communication access in the library for individuals who use augmentative and alternative communication.

Science.gov (United States)

Shepherd, Tracy A; McDougall, Stacy

2008-12-01

Libraries for All is a community-based program that aims to enhance communication access to the library for individuals who use augmentative and alternative communication (AAC), by providing resources and instruction. The goals are to (a) provide communication boards, (b) complete facilitator training, and (c) promote the program. To accomplish these goals, four communication boards were created and provided to all public libraries in London, Ontario. A train-the-trainer model was employed to ensure that all members of the library staff were familiar with the boards and aware of strategies to communicate more effectively with individuals who use AAC. Marketing materials were sent to potential stakeholders. The success of the program in meeting these three goals is highlighted.

Method for Evaluation of Outage Probability on Random Access Channel in Mobile Communication Systems

Science.gov (United States)

Kollár, Martin

2012-05-01

In order to access the cell in all mobile communication technologies a so called random-access procedure is used. For example in GSM this is represented by sending the CHANNEL REQUEST message from Mobile Station (MS) to Base Transceiver Station (BTS) which is consequently forwarded as an CHANNEL REQUIRED message to the Base Station Controller (BSC). If the BTS decodes some noise on the Random Access Channel (RACH) as random access by mistake (so- called ‘phantom RACH') then it is a question of pure coincidence which èstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

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...

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...

Access Request Trustworthiness in Weighted Access Control Framework

Institute of Scientific and Technical Information of China (English)

WANG Lun-wei; LIAO Xiang-ke; WANG Huai-min

2005-01-01

Weighted factor is given to access control policies to express the importance of policy and its effect on access control decision. According to this weighted access control framework, a trustworthiness model for access request is also given. In this model, we give the measure of trustworthiness factor to access request, by using some idea of uncertainty reasoning of expert system, present and prove the parallel propagation formula of request trustworthiness factor among multiple policies, and get the final trustworthiness factor to decide whether authorizing. In this model, authorization decision is given according to the calculation of request trustworthiness factor, which is more understandable, more suitable for real requirement and more powerful for security enhancement than traditional methods. Meanwhile the finer access control granularity is another advantage.

Cognitive-communication disorder following right hemisphere stroke: exploring rehabilitation access and outcomes.

Science.gov (United States)

Hewetson, Ronelle; Cornwell, Petrea; Shum, David

2017-07-01

Rehabilitation positively influences return to activities and social roles in people with aphasia. The cognitive-communication disorder (CCD) found following a right hemisphere stroke has been less extensively researched with rehabilitation access and outcomes yet to be determined. To document rehabilitation access and outcomes for people with CCD post-stroke; and compare outcomes based on presence (viz CCD; aphasia) or absence of communication impairment. A retrospective chart audit was completed for patients with first onset unilateral stroke, with a hospital length of stay (LOS) of at least two days and a communication assessment by a speech pathologist. Data extracted included presence and severity of communication impairment, access to and LOS in a rehabilitation unit, and functional outcome measures recorded at rehabilitation discharge. The majority of the 115 patients who met inclusion criteria were living independently (n = 112, 97.4%) at the time of stroke. CCD (66%) was diagnosed with similar frequency to aphasia (68%). The presence of communication impairment did not result in significant differences in rehabilitation LOS and discharge destination when compared to hemispheric strokes without communication impairment. Severity of CCD was an independent predictor of functional gain by rehabilitation discharge. People with CCD require comparable access to rehabilitation as people with aphasia, and severity of CCD should be considered in determining rehabilitation LOS. A large number of people are discharged with ongoing CCD which warrants exploration of potential participation restrictions created by the communication impairment.

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.

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...

Making the innovation case in Open Access scholary communication

CERN Multimedia

CERN. Geneva

2005-01-01

It seems almost unnecessary to have to elaborate additional reasons for the adoption of Open Access scholarly communication (OA sc) as manifested through Open Access journals and self-archiving practices. To those active within the OA arena, the case has been convincingly made, and current arguments merely need to be disseminated beyond the Library and Information Science (LIS) sphere. However, it is my contention that a convincing argument for OA sc needs to be launched from the Science Policy perspective if any government mandated pro-OA policy changes are to be effected. This paper, then, is an attempt at taking the OA discussion beyond the LIS arena and into the realm of Science and Innovation Policy. Using Innovation Theory as its theoretical framework, it is argued that Open Access scholarly communication can only serve to bolster Innovation Systems, be they national, regional, or sectoral. The case of South Africa is taken as an illustrative example, though the case can and will be generalised to beyon...

Information and communication technology resources access and ...

African Journals Online (AJOL)

Journal Home > Vol 14, No 1 (2017) > ... The ability to undertake effective legal research is one of the skills required of a lawyer but ... The use of Information and communication technology by Nigerian lawyers deals with ... for Researchers · for Journals · for Authors · for Policy Makers · about Open Access · Journal Quality.

Virus spreading in wireless sensor networks with a medium access control mechanism

International Nuclear Information System (INIS)

Wang Ya-Qi; Yang Xiao-Yuan

2013-01-01

In this paper, an extended version of standard susceptible-infected (SI) model is proposed to consider the influence of a medium access control mechanism on virus spreading in wireless sensor networks. Theoretical analysis shows that the medium access control mechanism obviously reduces the density of infected nodes in the networks, which has been ignored in previous studies. It is also found that by increasing the network node density or node communication radius greatly increases the number of infected nodes. The theoretical results are confirmed by numerical simulations. (general)

Implementation of Multiple Access Techniques Applicable for Maritime Satellite Communications

OpenAIRE

Stojce Dimov Ilcev

2013-01-01

In this paper are introduced fundamentals, characteristics, advantages and disadvantages of Multiple Access (MA) employed as transmission techniques in the Maritime Mobile Satellite Communications (MMSC) between ships and Coast Earth Station (CES) via Geostationary Earth Orbit (GEO) or Not-GEO satellite constellations. In fixed satellite communication, as a rule, especially in MMSC many users are active at the same time. The problem of simultaneous communications between many single or multip...

Multiple access chaotic digital communication based on generalized synchronization

International Nuclear Information System (INIS)

Lu Junguo

2005-01-01

A novel method for multiple access chaotic digital communication based on the concept of chaos generalized synchronization and the on-line least square method is proposed. This method can be used for transmitting multiple digital information signals concurrently. We illustrate the method using a Lorenz system driving a Chua's circuit and then examine the robustness of the proposed method with respect to noise in communication channel

76 FR 21741 - Twenty-First Century Communications and Video Programming Accessibility Act; Announcement of Town...

Science.gov (United States)

2011-04-18

... equipment distribution program for people who are deaf-blind. In addition, the law will fill accessibility... Programming Accessibility Act; Announcement of Town Hall Meeting AGENCY: Federal Communications Commission... The Twenty-First Century Communications and Video Programming Accessibility Act (the Act or CVAA...

Awareness, access and use of information and communication ...

African Journals Online (AJOL)

This study ascertained the awareness, access and use of information and communication technologies in extension service delivery by ADP extension personnel in Abia State, Nigeria. The study described the socio-economic characteristics of ADP extension personnel in Abia State; ascertained the extent of awareness, ...

Digital Autonomous Terminal Access Communication (DATAC) system

Science.gov (United States)

Novacki, Stanley M., III

1987-01-01

In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

Promoting open access to science through effective communication

Science.gov (United States)

Egger, A. E.

2006-12-01

Geology is a difficult subject to communicate effectively. Many people associate geology with memorizing rock and mineral names and not with dynamic earth processes. Even more challenging for the non-geologist is the concept of deep time, and why processes that happened millions of years ago are important to us today. Additionally, many people view science itself as inaccessible and difficult. And yet, geology is a naturally accessible subject, as it is all around us. In order to communicate effectively, geologists must convince others that their work is both accessible and relevant, even though it may not directly generate economic benefits or lend insight into solutions for our modern problems like climate change. As scientists, we know the connections are there, but convincing others requires creating face-to-face, positive interactions through the use of active techniques to help bring the audience to an understanding of the process of science in addition to the subject matter itself. My overarching motive for creating and participating in communication activities with a broad audience is thus to demonstrate that science is accessible to everyone, that a scientific way of thinking can be both fun and useful, and that a little knowledge about geology can give you a new perspective on the world. Using this motivation as a guiding principle regardless of the specific audience, two techniques are important to make the communication effective. First, whenever possible, I conduct activities in the field (broadly speaking), or at least bring the field into the talk, and model the scientific process by asking for participation. This allows the audience to fully understand how geologic work is done, including the mundane and the mistakes. Second, I take my audience seriously, including all questions and observations, in order to build confidence in everyone that they are able to contribute to and understand both geology and the scientific process in general. Despite the

A Reinforcement Learning Approach to Call Admission Control in HAPS Communication System

Directory of Open Access Journals (Sweden)

Ni Shu Yan

2017-01-01

Full Text Available The large changing of link capacity and number of users caused by the movement of both platform and users in communication system based on high altitude platform station (HAPS will resulting in high dropping rate of handover and reduce resource utilization. In order to solve these problems, this paper proposes an adaptive call admission control strategy based on reinforcement learning approach. The goal of this strategy is to maximize long-term gains of system, with the introduction of cross-layer interaction and the service downgraded. In order to access different traffics adaptively, the access utility of handover traffics and new call traffics is designed in different state of communication system. Numerical simulation result shows that the proposed call admission control strategy can enhance bandwidth resource utilization and the performances of handover traffics.

Asynchronous Free-Space Optical CDMA Communications System for Last-mile Access Network

DEFF Research Database (Denmark)

Jurado-Navas, Antonio; Raddo, Thiago R.; Sanches, Anderson L.

2016-01-01

We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed.......We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed....

A Multi-Vehicles, Wireless Testbed for Networked Control, Communications and Computing

Science.gov (United States)

Murray, Richard; Doyle, John; Effros, Michelle; Hickey, Jason; Low, Steven

2002-03-01

We have constructed a testbed consisting of 4 mobile vehicles (with 4 additional vehicles being completed), each with embedded computing and communications capability for use in testing new approaches for command and control across dynamic networks. The system is being used or is planned to be used for testing of a variety of communications-related technologies, including distributed command and control algorithms, dynamically reconfigurable network topologies, source coding for real-time transmission of data in lossy environments, and multi-network communications. A unique feature of the testbed is the use of vehicles that have second order dynamics. Requiring real-time feedback algorithms to stabilize the system while performing cooperative tasks. The testbed was constructed in the Caltech Vehicles Laboratory and consists of individual vehicles with PC-based computation and controls, and multiple communications devices (802.11 wireless Ethernet, Bluetooth, and infrared). The vehicles are freely moving, wheeled platforms propelled by high performance dotted fairs. The room contains an access points for an 802.11 network, overhead visual sensing (to allow emulation of CI'S signal processing), a centralized computer for emulating certain distributed computations, and network gateways to control and manipulate communications traffic.

Privacy and Access Control for IHE-Based Systems

Science.gov (United States)

Katt, Basel; Breu, Ruth; Hafner, Micahel; Schabetsberger, Thomas; Mair, Richard; Wozak, Florian

Electronic Health Record (EHR) is the heart element of any e-health system, which aims at improving the quality and efficiency of healthcare through the use of information and communication technologies. The sensitivity of the data contained in the health record poses a great challenge to security. In this paper we propose a security architecture for EHR systems that are conform with IHE profiles. In this architecture we are tackling the problems of access control and privacy. Furthermore, a prototypical implementation of the proposed model is presented.

High-Capacity Hybrid Optical Fiber-Wireless Communications Links in Access Networks

DEFF Research Database (Denmark)

Pang, Xiaodan

of broadband services access. To realize the seamless convergence between the two network segments, the lower capacity of wireless systems need to be increased to match the continuously increasing bandwidth of fiber-optic systems. The research works included in this thesis are devoted to experimental...... investigations of photonic-wireless links with record high capacities to fulfill the requirements of next generation hybrid optical fiber-wireless access networks. The main contributions of this thesis have expanded the state-of-the-art in two main areas: high speed millimeter-wave (mm-wave) communication links......Integration between fiber-optic and wireless communications systems in the "last mile" access networks is currently considered as a promising solution for both service providers and users, in terms of minimizing deployment cost, shortening upgrading period and increasing mobility and flexibility...

A slotted access control protocol for metropolitan WDM ring networks

Science.gov (United States)

Baziana, P. A.; Pountourakis, I. E.

2009-03-01

In this study we focus on the serious scalability problems that many access protocols for WDM ring networks introduce due to the use of a dedicated wavelength per access node for either transmission or reception. We propose an efficient slotted MAC protocol suitable for WDM ring metropolitan area networks. The proposed network architecture employs a separate wavelength for control information exchange prior to the data packet transmission. Each access node is equipped with a pair of tunable transceivers for data communication and a pair of fixed tuned transceivers for control information exchange. Also, each access node includes a set of fixed delay lines for synchronization reasons; to keep the data packets, while the control information is processed. An efficient access algorithm is applied to avoid both the data wavelengths and the receiver collisions. In our protocol, each access node is capable of transmitting and receiving over any of the data wavelengths, facing the scalability issues. Two different slot reuse schemes are assumed: the source and the destination stripping schemes. For both schemes, performance measures evaluation is provided via an analytic model. The analytical results are validated by a discrete event simulation model that uses Poisson traffic sources. Simulation results show that the proposed protocol manages efficient bandwidth utilization, especially under high load. Also, comparative simulation results prove that our protocol achieves significant performance improvement as compared with other WDMA protocols which restrict transmission over a dedicated data wavelength. Finally, performance measures evaluation is explored for diverse numbers of buffer size, access nodes and data wavelengths.

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.

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

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.

IBM 3705 Communications Controller

CERN Multimedia

1972-01-01

The IBM 3705 Communications Controller is a simple computer which attaches to an IBM System/360 or System/370. Its purpose is to connect communication lines to the mainframe channel. It was a first communications controller of the popular IBM 37xx series.

Advanced Communication Technology Satellite (ACTS) Very Small Aperture Terminal (VSAT) Network Control Performance

Science.gov (United States)

Coney, T. A.

1996-01-01

This paper discusses the performance of the network control function for the Advanced Communications Technology Satellite (ACTS) very small aperture terminal (VSAT) full mesh network. This includes control of all operational activities such as acquisition, synchronization, timing and rain fade compensation as well as control of all communications activities such as on-demand integrated services (voice, video, and date) connects and disconnects Operations control is provided by an in-band orderwire carried in the baseboard processor (BBP) control burst, the orderwire burst, the reference burst, and the uplink traffic burst. Communication services are provided by demand assigned multiple access (DAMA) protocols. The ACTS implementation of DAMA protocols ensures both on-demand and integrated voice, video and data services. Communications services control is also provided by the in-band orderwire but uses only the reference burst and the uplink traffic burst. The performance of the ACTS network control functions have been successfully tested during on-orbit checkout and in various VSAT networks in day to day operations. This paper discusses the network operations and services control performance.

C-DAM: CONTENTION BASED DISTRIBUTED RESERVATION PROTOCOL ALLOCATION ALGORITHM FOR WIMEDIA MEDIUM ACCESS CONTROL

Directory of Open Access Journals (Sweden)

UMADEVI K. S.

2017-07-01

Full Text Available WiMedia Medium Access Control (MAC provides high rate data transfer for wireless networking thereby enables construction of high speed home networks. It facilitates data communication between the nodes through two modes namely: i Distributed Reservation Protocol (DRP for isochronous traffic and ii Prioritized Contention Access (PCA for asynchronous traffic. PCA mode enables medium access using CSMA/CA similar to IEEE 802.11e. In the presence of DRP, the throughput of PCA saturates when there is an increase in the number of devices accessing PCA channel. Researchers suggest that the better utilization of medium resolves many issues in an effective way. To demonstrate the effective utilization of the medium, Contention Based Distributed Reservation Protocol Allocation Algorithm for WiMedia Medium Access Control is proposed for reserving Medium Access Slots under DRP in the presence of PCA. The proposed algorithm provides a better medium access, reduces energy consumption and enhances the throughput when compared to the existing methodologies.

Parental Expertise, Trustworthiness, and Accessibility: Parent-Adolescent Communication and Adolescent Risk Behavior

Science.gov (United States)

Guilamo-Ramos, Vincent; Jaccard, James; Dittus, Patricia; Bouris, Alida, M.

2006-01-01

A communication framework of persuasion and attitude change was utilized to analyze parent-adolescent communication about adolescent risk behavior. Three parent dimensions were deemed important: (a) perceived expertise, (b) perceived trustworthiness, and (c) perceived accessibility. Data were collected in surveys from 668 mother-adolescent dyads…

Power Control for Passive QAM Multisensor Backscatter Communication Systems

Directory of Open Access Journals (Sweden)

Shengbo Hu

2017-01-01

Full Text Available To achieve good quality of service level such as throughput, power control is of great importance to passive quadrature amplitude modulation (QAM multisensor backscatter communication systems. First, we established the RF energy harvesting model and gave the energy condition. In order to minimize the interference of subcarriers and increase the spectral efficiency, then, the colocated passive QAM backscatter communication signal model is presented and the nonlinear optimization problems of power control are solved for passive QAM backscatter communication systems. Solutions include maximum and minimum access interval, the maximum and minimum duty cycle, and the minimal RF-harvested energy under the energy condition for node operating. Using the solutions above, the maximum throughput of passive QAM backscatter communication systems is analyzed and numerical calculation is made finally. Numerical calculation shows that the maximal throughput decreases with the consumed power and the number of sensors, and the maximum throughput is decreased quickly with the increase of the number of sensors. Especially, for a given consumed power of sensor, it can be seen that the throughput decreases with the duty cycle and the number of sensors has little effect on the throughput.

Secure and Efficient Access Control Scheme for Wireless Sensor Networks in the Cross-Domain Context of the IoT

Directory of Open Access Journals (Sweden)

Ming Luo

2018-01-01

Full Text Available Nowadays wireless sensor network (WSN is increasingly being used in the Internet of Things (IoT for data collection, and design of an access control scheme that allows an Internet user as part of IoT to access the WSN becomes a hot topic. A lot of access control schemes have been proposed for the WSNs in the context of the IoT. Nevertheless, almost all of these schemes assume that communication nodes in different network domains share common system parameters, which is not suitable for cross-domain IoT environment in practical situations. To solve this shortcoming, we propose a more secure and efficient access control scheme for wireless sensor networks in the cross-domain context of the Internet of Things, which allows an Internet user in a certificateless cryptography (CLC environment to communicate with a sensor node in an identity-based cryptography (IBC environment with different system parameters. Moreover, our proposed scheme achieves known session-specific temporary information security (KSSTIS that most of access control schemes cannot satisfy. Performance analysis is given to show that our scheme is well suited for wireless sensor networks in the cross-domain context of the IoT.

Digital autonomous terminal access communications

Science.gov (United States)

Novacki, S.

1987-01-01

A significant problem for the Bus Monitor Unit is to identify the source of a given transmission. This problem arises from the fact that the label which identifies the source of the transmission as it is put into the bus is intercepted by the Digital Autonomous Terminal Access Communications (DATAC) terminal and removed from the transmission. Thus, a given subsystem will see only data associated with a label and never the identifying label itself. The Bus Monitor must identify the source of the transmission so as to be able to provide some type of error identification/location in the event that some problem with the data transmission occurs. Steps taken to alleviate this problem by modifications to the DATAC terminal are discussed.

A CDMA system implementation with dimming control for visible light communication

Science.gov (United States)

Chen, Danyang; Wang, Jianping; Jin, Jianli; Lu, Huimin; Feng, Lifang

2018-04-01

Visible light communication (VLC), using solid-state lightings to transmit information, has become a complement technology to wireless radio communication. As a realistic multiple access scheme for VLC system, code division multiple access (CDMA) has attracted more and more attentions in recent years. In this paper, we address and implement an improved CDMA scheme for VLC system. The simulation results reveal that the improved CDMA scheme not only supports multi-users' transmission but also maintains dimming value at about 50% and enhances the system efficiency. It can also realize the flexible dimming control by adjusting some parameters of system structure, which rarely affects the system BER performance. A real-time experimental VLC system with improved CDMA scheme is performed based on field programmable gate array (FPGA), reaching a good BER performance.

22 CFR 203.11 - Access to records and communications.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Access to records and communications. 203.11 Section 203.11 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT REGISTRATION OF PRIVATE VOLUNTARY... documents that are made available to USAID pursuant to this regulation must be made available for public...

Communicative social capital and collective efficacy as determinants of access to health-enhancing resources in residential communities.

Science.gov (United States)

Matsaganis, Matthew D; Wilkin, Holley A

2015-04-01

This article contributes to the burgeoning literature on the social determinants of health disparities. The authors investigate how communication resources and collective efficacy, independently and in combination, shape residents' access to health enhancing resources (including healthcare services, sources of healthier food options, and public recreation spaces) in their communities. Using random digit dial telephone survey data from 833 residents of South Los Angeles communities the authors show that communicative social capital-that is, an information and problem-solving resource that accrues to residents as they become more integrated into their local communication network of neighbors, community organizations, and local media-plays a significant role in access to health resources. This relationship is complicated by individuals' health insurance and health status, as communicative social capital magnifies the sense of absence of resources for those who are in worse health and lack insurance. Communicative social capital builds collective efficacy, which is positively related to access to health-enhancing resources, but it also mediates the negative relationship between communicative social capital and access to health resources. Residents with richer stores of communicative social capital and collective efficacy report better access to health resources. The authors conclude with a discussion of implications of these findings and suggestions for future research.

Multiparty-controlled quantum secure direct communication

International Nuclear Information System (INIS)

Xiu, X.-M.; Dong, L.; Gao, Y.-J.; Chi, F.

2007-01-01

A theoretical scheme of a multiparty-controlled quantum secure direct communication is proposed. The supervisor prepares a communication network with Einstein-Podolsky-Rosen pairs and auxiliary particles. After passing a security test of the communication network, a supervisor tells the users the network is secure and they can communicate. If the controllers allow the communicators to communicate, the controllers should perform measurements and inform the communicators of the outcomes. The communicators then begin to communicate after they perform a security test of the quantum channel and verify that it is secure. The recipient can decrypt the secret message in a classical message from the sender depending on the protocol. Any two users in the network can communicate through the above processes under the control of the supervisor and the controllers

Data communications and computer communications network

International Nuclear Information System (INIS)

Kim, Jang Gwon; Gu, Chang Hoe

2005-03-01

This textbook is composed of twelve chapters, which are communication network introduction, foundation of data communication, data link control, circuit switching system, packet switching system, multiple access communication system, protocol and architecture, LAN, MAN communication network, integrated service digital network, internet and Asymmetric digital subscriber Line and Wireless Local Loop. Each chapter has the introduction of the technique, structure, function and practice problems. It also has the appendix on electricity and communication standards organization, characteristic table and glossary.

Polarization division multiple access with polarization modulation for LOS wireless communications

Directory of Open Access Journals (Sweden)

Cao Bin

2011-01-01

Full Text Available Abstract In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS of electromagnetic (EM waves for line-of-sight (LOS communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate, the discussed polarization division multiple access (PDMA and polarization modulation (PM are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.

An Access Control Framework for Reflective Middleware

Institute of Scientific and Technical Information of China (English)

Gang Huang; Lian-Shan Sun

2008-01-01

Reflective middleware opens up the implementation details of middleware platform and applications at runtime for improving the adaptability of middleware-based systems. However, such openness brings new challenges to access control of the middleware-based systems.Some users can access the system via reflective entities, which sometimes cannot be protected by access control mechanisms of traditional middleware. To deliver high adaptability securely, reflective middleware should be equipped with proper access control mechanisms for potential access control holes induced by reflection. One reason of integrating these mechanisms in reflective middleware is that one goal of reflective middleware is to equip applications with reflection capabilities as transparent as possible. This paper studies how to design a reflective J2EE middlewarePKUAS with access control in mind. At first, a computation model of reflective system is built to identify all possible access control points induced by reflection. Then a set of access control mechanisms, including the wrapper of MBeans and a hierarchy of Java class loaders, are equipped for controlling the identified access control points. These mechanisms together with J2EE access control mechanism form the access control framework for PKUAS. The paper evaluates the security and the performance overheads of the framework in quality and quantity.

Access to Justice for Communications Surveillance and Interception : Scrutinising Intelligence Gathering Reform Legislation

NARCIS (Netherlands)

Quirine Eijkman

2018-01-01

By analysing intelligence-gathering reform legislation this article discusses access to justice for communications interception by the intelligence and security services. In the aftermath of the Snowden revelations, sophisticated oversight systems for bulk communications surveillance are being

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.

Strategic use of communication to market cancer prevention and control to vulnerable populations.

Science.gov (United States)

Kreps, Gary L

2008-01-01

There are significant challenges to communicating relevant cancer prevention and control information to health care consumers due both to the complexities of the health information to be communicated and the complexities of health communication, especially with vulnerable populations. The need for effective communication about cancer risks, early detection, prevention, care, and survivorship is particularly acute, yet also tremendously complex, for reaching vulnerable populations, those groups of people who are most likely to suffer significantly higher levels of morbidity and mortality from cancers than other segments of the population. These vulnerable populations, typically the poorest, lowest educated, and most disenfranchised members of modern society, are heir to serious cancer-related health disparities. Vulnerable populations often have health literacy difficulties, cultural barriers, and economic challenges to accessing and making sense of relevant health information. This paper examines these challenges to communicating relevant information to vulnerable populations and suggests strategies for effectively using different communication media for marketing cancer prevention and control to reduce health disparities and promote public health.

Perti Net-Based Workflow Access Control Model

Institute of Scientific and Technical Information of China (English)

陈卓; 骆婷; 石磊; 洪帆

2004-01-01

Access control is an important protection mechanism for information systems. This paper shows how to make access control in workflow system. We give a workflow access control model (WACM) based on several current access control models. The model supports roles assignment and dynamic authorization. The paper defines the workflow using Petri net. It firstly gives the definition and description of the workflow, and then analyzes the architecture of the workflow access control model (WACM). Finally, an example of an e-commerce workflow access control model is discussed in detail.

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.

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.

Communication and Control in the Canadian North: The Role of Interactive Satellites.

Science.gov (United States)

Valaskakis, Gail G.

In 1972 the Canadian government launched its first domestic communications satellite, Anik A, which relays direct broadcast television and telephone messages to northern communities. The impact of television on Inuit life has raised issues and concerns pertaining to native language broadcasting, media access and control, and cultural identity…

Access control system operation

International Nuclear Information System (INIS)

Barnes, L.D.

1981-06-01

An automated method for the control and monitoring of personnel movement throughout the site was developed under contract to the Department of Energy by Allied-General Nuclear Services (AGNS) at the Barnwell Nuclear Fuel Plant (BNFP). These automated features provide strict enforcement of personnel access policy without routine patrol officer involvement. Identification methods include identification by employee ID number, identification by voice verification and identification by physical security officer verification. The ability to grant each level of access authority is distributed over the organization to prevent any single individual at any level in the organization from being capable of issuing an authorization for entry into sensitive areas. Each access event is recorded. As access events occur, the inventory of both the entered and the exited control area is updated so that a current inventory is always available for display. The system has been operated since 1979 in a development mode and many revisions have been implemented in hardware and software as areas were added to the system. Recent changes have involved the installation of backup systems and other features required to achieve a high reliability. The access control system and recent operating experience are described

ICSW2AN : An Inter-vehicle Communication System Using Mobile Access Point over Wireless Wide Area Networks

Science.gov (United States)

Byun, Tae-Young

This paper presents a prototype of inter-vehicle communication system using mobile access point that internetworks wired or wireless LAN and wireless WAN anywhere. Implemented mobile access point can be equipped with various wireless WAN interfaces such as WCDMA and HSDPA. Mobile access point in the IP mechanism has to process connection setup procedure to one wireless WAN. To show the applicability of the mobile access point to inter-vehicle communication, a simplified V2I2V-based car communication system called ICSW2AN is implemented to evaluate major performance metrics by road test. In addition, results of road test for traffic information service are investigated in view of RTT, latency and server processing time. The experimental result indicates that V2I2V-based car communication system sufficiently can provide time-tolerant traffic information to moving vehicles while more than two mobile devices in restricted spaces such as car, train and ship access wireless Internet simultaneously.

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.

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

Enterprise Dynamic Access Control (EDAC)

National Research Council Canada - National Science Library

Fernandez, Richard

2005-01-01

.... Resources can represent software applications, web services and even facility access. An effective access control model should be capable of evaluating resource access based on user characteristics and environmentals...

The potential use of mobile technology: enhancing accessibility and communication in a blended learning course

Directory of Open Access Journals (Sweden)

Tabisa Mayisela

2013-01-01

Full Text Available Mobile technology is increasingly being used to support blended learning beyond computer centres. It has been considered as a potential solution to the problem of a shortage of computers for accessing online learning materials (courseware in a blended learning course. The purpose of the study was to establish how the use of mobile technology could enhance accessibility and communication in a blended learning course. Data were solicitedfrom a purposive convenience sample of 36 students engaged in the blended learning course. The case study utilized a mixed-methods approach. An unstructured interview was conducted with the course lecturer and these data informed the design of the students' semi-structured questionnaire. It was found that students with access to mobile technology had an increased opportunity to access the courseware of the blended learning course. Mobile technology further enhanced student-to-student and student-to-lecturer communication by means of social networks. The study concludes that mobile technology has the potential to increase accessibility and communication in a blended learning course. Recommendations, limitations of the present study, and suggestionsforfuture research were made.

Random Access for Machine-Type Communication based on Bloom Filtering

DEFF Research Database (Denmark)

Pratas, Nuno; Stefanovic, Cedomir; Madueño, Germán Corrales

2016-01-01

utilizes the system resources more efficiently and achieves similar or lower latency of connection establishment in case of synchronous arrivals, compared to the variant of the LTE-A access protocol that is optimized for MTC traffic. A dividend of the proposed method is that allows the base station (BS......We present a random access method inspired on Bloom filters that is suited for Machine-Type Communications (MTC). Each accessing device sends a signature during the contention process. A signature is constructed using the Bloom filtering method and contains information on the device identity...... and the connection establishment cause. We instantiate the proposed method over the current LTE-A access protocol. However, the method is applicable to a more general class of random access protocols that use preambles or other reservation sequences, as expected to be the case in 5G systems. We show that our method...

A Protective Mechanism for the Access Control System in the Virtual Domain

Institute of Scientific and Technical Information of China (English)

Jinan Shen; Deqing Zou; Hai Jin; Kai Yang; Bin Yuan; Weiming Li

2016-01-01

In traditional framework,mandatory access control (MAC) system and malicious software are run in kernel mode.Malicious software can stop MAC systems to be started and make it do invalid.This problem cannot be solved under the traditional framework if the operating system (OS) is comprised since malwares are running in ring0 level.In this paper,we propose a novel way to use hypervisors to protect kernel integrity and the access control system in commodity operating systems.We separate the access control system into three parts:policy management (PM),security server (SS) and policy enforcement (PE).Policy management and the security server reside in the security domain to protect them against malware and the isolation feather of the hypervisor can protect them from attacks.We add an access vector cache (AVC) between SS and PE in the guest OS,in order to speed up communication between the guest OS and the security domain.The policy enforcement module is retained in the guest OS for performance.The security of AVC and PE can be ensured by using a memory protection mechanism.The goal of protecting the OS kemel is to ensure the security of the execution path.We implement the system by a modified Xen hypervisor.The result shows that we can secure the security of the access control system in the guest OS with no overhead compared with modules in the latter.Our system offers a centralized security policy for virtual domains in virtual machine environments.

Development of Remote Monitoring and a Control System Based on PLC and WebAccess for Learning Mechatronics

Directory of Open Access Journals (Sweden)

Wen-Jye Shyr

2013-02-01

Full Text Available This study develops a novel method for learning mechatronics using remote monitoring and control, based on a programmable logic controller (PLC and WebAccess. A mechatronics module, a Web-CAM and a PLC were integrated with WebAccess software to organize a remote laboratory. The proposed system enables users to access the Internet for remote monitoring and control of the mechatronics module via a web browser, thereby enhancing work flexibility by enabling personnel to control mechatronics equipment from a remote location. Mechatronics control and long-distance monitoring were realized by establishing communication between the PLC and WebAccess. Analytical results indicate that the proposed system is feasible. The suitability of this system is demonstrated in the department of industrial education and technology at National Changhua University of Education, Taiwan. Preliminary evaluation of the system was encouraging and has shown that it has achieved success in helping students understand concepts and master remote monitoring and control techniques.

Denying Access to Commercial Communications Satellites

National Research Council Canada - National Science Library

Washington, Tania

1999-01-01

.... Commercial systems such as Orion, Panamsat, Iridium and Globalstar will provide the U.S. military and its potential adversaries with a relatively inexpensive and highly effective means to increase the command, control and communications (C3...

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

Access Contested

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

Transforming Global Information and Communication Markets: The Political Economy of ... 8 Control and Resistance: Attacks on Burmese Opposition Media 153 ...... “Reluctant Gatekeepers: Corporate Ethics on a Filtered Internet,” in Access ...

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.

Tactile band : accessing gaze signals from the sighted in face-to-face communication

NARCIS (Netherlands)

Qiu, S.; Rauterberg, G.W.M.; Hu, J.

2016-01-01

Gaze signals, frequently used by the sighted in social interactions as visual cues, are hardly accessible for low-vision and blind people. A concept is proposed to help the blind people access and react to gaze signals in face-to-face communication. 20 blind and low-vision participants were

Reduction of the near-far effect in mobile communication systems with Code-Division Multiple-Access

Science.gov (United States)

Purchla, Magdalena

2006-02-01

In this paper the basic methods for reducing Multiple Access Interference (MAI) and combating the near-far effect in Direct-Sequence Code-Division Multiple-Access (DS-CDMA) mobile communication systems are presented. MAI and the near-far effect are inevitable in DS-CDMA systems with quasi-orthogonal spreading sequences. An effective method of reducing MAI can increase the capacity of the system that is why so many researchers are working in this field. In this article three most important techniques of decreasing MAI are presented: power control, multiuser detection and space-time processing. There is a short introduction to each topic and one or more examples found in literature of algorithms suitable for practical applications (although not all algorithms are yet used in existing systems).

75 FR 43825 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

Science.gov (United States)

2010-07-27

... switching service on that cellphone to another wireless communication network. The access controls in... means, such as the use of screen capture software, exist that permit the making of lower-quality film... handsets to execute software applications, where circumvention is accomplished for the sole purpose of...

Interference-Assisted Techniques for Transmission and Multiple Access in Optical Communications

Science.gov (United States)

Guan, Xun

Optical communications can be in wired or wireless form. Fiber optics communication (FOC) connects transmitters and receivers with optical fiber. Benefiting from its high bandwidth, low cost per volume and stability, it gains a significant market share in long-haul networks, access networks and data centers. Meanwhile, optical wireless communication (OWC) is also emerging as a crucial player in the communication market. In OWC, free-space optical communication (FSO) and visible light communication (VLC) are being studied and commercially deployed extensively. Interference is a common phenomenon in multi-user communication systems. In both FOC and OWC, interference has long been treated as a detrimental effect. However, it could also be beneficial to system applications. The effort of harnessing interference has spurred numerous innovations. Interesting examples are physical-layer network coding (PNC) and non-orthogonal multiple access (NOMA). The first part of this thesis in on the topic of PNC. PNC was firstly proposed in wireless communication to improve the throughput of a two-way relay network (TWRN). As a variation of network coding (NC), PNC turns the common channel interference (CCI) as a natural network coding operation. In this thesis, PNC is introduced into optical communication. Three schemes are proposed in different scenarios. Firstly, PNC is applied to a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system so as to improve the throughput of the multicast network. The optical signal to noise ratio (OSNR) penalty is quite low. Secondly, we investigate the application of PNC in an OFDM passive optical network (OFDM-PON) supporting heterogeneous services. It is found that only minor receiver power penalties are observed to realize PNC-based virtual private networks (VPN), both in the wired service part and the wireless service part in an OFDM-PON with heterogeneous services. Thirdly, we innovate relay-based visible light

Attributes Enhanced Role-Based Access Control Model

DEFF Research Database (Denmark)

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

2015-01-01

as an important area of research. In this paper, we propose an access control model that combines the two models in a novel way in order to unify their benefits. Our approach provides a fine-grained access control mechanism that not only takes contextual information into account while making the access control...... decisions but is also suitable for applications where access to resources is controlled by exploiting contents of the resources in the policy....

Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

Science.gov (United States)

Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.

2014-01-01

Unmanned aircraft (UA) represent a new capability that will provide a variety of services in the Government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized because of the lack of a common understanding of what is required to safely operate Unmanned Aircraft Systems in the National Airspace System (UAS in the NAS). The desire and ability to fly UA is of increasing urgency. The application of UA to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UA to the NAS. Existing Federal Aviation Regulations, procedures, and technologies do not allow routine UA access to the NAS. Access to the NAS is hampered by challenges such as the lack of an onboard pilot to see and avoid other aircraft; the ability of a single pilot or operator to control multiple UA; the reliance on command and control (C2) links; the altitudes, speeds, and duration at which the aircraft fly; and the wide variation in UA size and performance. NASA is working with other Government agencies to provide solutions that reduce technical barriers and make access to the NAS routine. This goal will be accomplished through system-level integration of key concepts, technologies, or procedures and through demonstrations of these integrated capabilities in an operationally relevant environment. This project provides an opportunity to transition the acquired empirical data and knowledge to the Federal Aviation Administration and other stakeholders to help them define the requirements for routine UA access to the NAS.Radio communications channels for UA are currently managed through exceptions and use either Department of Defense frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Industrial/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for safety and

On the performance of shared access control strategy for femtocells

KAUST Repository

Magableh, Amer M.; Radaydeh, Redha Mahmoud; Alouini, Mohamed-Slim

2013-01-01

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

Joint control algorithm in access network

Institute of Scientific and Technical Information of China (English)

2008-01-01

To deal with long probing delay and inaccurate probing results in the endpoint admission control method,a joint local and end-to-end admission control algorithm is proposed,which introduces local probing of access network besides end-to-end probing.Through local probing,the algorithm accurately estimated the resource status of the access network.Simulation shows that this algorithm can improve admission control performance and reduce users' average waiting time when the access network is heavily loaded.

Integrating Attributes into Role-Based Access Control

DEFF Research Database (Denmark)

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

2015-01-01

of research recently. We propose an access control model that combines the two models in a novel way in order to unify their benefits. Our approach provides a fine-grained access control mechanism that takes into account the current contextual information while making the access control decisions....

System control and communication

International Nuclear Information System (INIS)

Bindner, H.; Oestergaard, J.

2005-01-01

Rapid and ongoing development in the energy sector has consequences for system control at all levels. In relation to system control and communication the control system is challenged in five important ways: 1) Expectations for security of supply, robustness and vulnerability are becoming more stringent, and the control system plays a big part in meeting these expectations. 2) Services are becoming increasingly based on markets that involve the transmission system operators (TSOs), generators and distribution companies. Timely, accurate and secure communication is essential to the smooth running of the markets. 3) Adding large amounts of renewable energy (RE) to the mix is a challenge for control systems because of the intermittent availability of many RE sources. 4) Increasing the number of active components in the system, such as small CHP plants, micro-CHP and intelligent loads, means that the system control will be much more complex. 5) In the future it is likely that power, heat, gas, transport and communication systems will be tighter coupled and interact much more. (au)

Towards Communication and Information Access for Deaf People

Directory of Open Access Journals (Sweden)

Edwin Blake

2014-10-01

Full Text Available In tightly circumscribed communication situations an interactive system resident on a mobile device can assist Deaf people with their communication and information needs. The Deaf users considered here use South African Sign Language and information is conveyed by a collection of pre-recorded video clips and images. The system was developed according to our method of community-based co-design. We present several stages of the development as a series of case studies and highlight our experience. The first stage involved ethnographically inspired methods such as cultural probes. In the next stage we co-designed a medical consultation system that was ultimately dropped for technical reasons. A smaller system was developed for pharmaceutical dispensing and successfully implemented and tested. It now awaits deployment in an actual pharmacy. We also developed a preliminary authoring tool to tackle the problem of content generation for interactive computer literacy training. We are also working on another medical health information tool. We intend that a generic authoring tool be able to generate mobile applications for all of these scenarios. These mobile applications bridge communication gaps for Deaf people via accessible and affordable assistive technology.

Power adaptive multi-filter carrierless amplitude and phase access scheme for visible light communication network

Science.gov (United States)

Li, Wei; Huang, Zhitong; Li, Haoyue; Ji, Yuefeng

2018-04-01

Visible light communication (VLC) is a promising candidate for short-range broadband access due to its integration of advantages for both optical communication and wireless communication, whereas multi-user access is a key problem because of the intra-cell and inter-cell interferences. In addition, the non-flat channel effect results in higher losses for users in high frequency bands, which leads to unfair qualities. To solve those issues, we propose a power adaptive multi-filter carrierless amplitude and phase access (PA-MF-CAPA) scheme, and in the first step of this scheme, the MF-CAPA scheme utilizing multiple filters as different CAP dimensions is used to realize multi-user access. The character of orthogonality among the filters in different dimensions can mitigate the effect of intra-cell and inter-cell interferences. Moreover, the MF-CAPA scheme provides different channels modulated on the same frequency bands, which further increases the transmission rate. Then, the power adaptive procedure based on MF-CAPA scheme is presented to realize quality fairness. As demonstrated in our experiments, the MF-CAPA scheme yields an improved throughput compared with multi-band CAP access scheme, and the PA-MF-CAPA scheme enhances the quality fairness and further improves the throughput compared with the MF-CAPA scheme.

Provably Secure Heterogeneous Access Control Scheme for Wireless Body Area Network.

Science.gov (United States)

Omala, Anyembe Andrew; Mbandu, Angolo Shem; Mutiria, Kamenyi Domenic; Jin, Chunhua; Li, Fagen

2018-04-28

Wireless body area network (WBAN) provides a medium through which physiological information could be harvested and transmitted to application provider (AP) in real time. Integrating WBAN in a heterogeneous Internet of Things (IoT) ecosystem would enable an AP to monitor patients from anywhere and at anytime. However, the IoT roadmap of interconnected 'Things' is still faced with many challenges. One of the challenges in healthcare is security and privacy of streamed medical data from heterogeneously networked devices. In this paper, we first propose a heterogeneous signcryption scheme where a sender is in a certificateless cryptographic (CLC) environment while a receiver is in identity-based cryptographic (IBC) environment. We then use this scheme to design a heterogeneous access control protocol. Formal security proof for indistinguishability against adaptive chosen ciphertext attack and unforgeability against adaptive chosen message attack in random oracle model is presented. In comparison with some of the existing access control schemes, our scheme has lower computation and communication cost.

Design of pulse waveform for waveform division multiple access UWB wireless communication system.

Science.gov (United States)

Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

2014-01-01

A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

Scholarly communication : the role of oai in the context of open access

Directory of Open Access Journals (Sweden)

Ana Alice Baptista

2007-12-01

Full Text Available This paper discusses Open Access to scientific knowledge and its impacts on research. It overviews some of the major issues regarding the use of information technologies in scholarly communication activities, highlighting recent issues such as repository selfarchiving (green road and Open Access journals (golden road. Such issues are focused both as a reaction of researchers to the current business models of commercial scholarly publishers and as an awareness of the increasingly impact of documents available in Open Access. It adds to this discussion information about the necessary policies to fully implement Open Access. Authors describe the main technology facilities that support Open Access, such as OAI compliant Repositories and Journal Management systems. Moreover, future perspectives that should guide academic and government policies, decisions and actions that can assure Open Access, particularly in Portuguese Speaking Countries, are discussed.

Communication for command and control systems

CERN Document Server

Morris, D J

1983-01-01

Communication for Command and Control Systems provides a thorough exposition of the basic theoretical and practical features involved in the design of communication networks for command and control systems. This book focuses primarily on the practical side of computer-controlled communication. This text concentrates on the communication sides of the subject by surveying the means of transferring data between the various processing points and by appraising their potential advantages and possible defects in implementation. In this respect, this book should prove useful for the practicing enginee

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

40 CFR 267.34 - When must personnel have access to communication equipment or an alarm system?

Science.gov (United States)

2010-07-01

... to an internal alarm or emergency communication device, either directly or through visual or voice... communication equipment or an alarm system? 267.34 Section 267.34 Protection of Environment ENVIRONMENTAL... have access to communication equipment or an alarm system? (a) Whenever hazardous waste is being poured...

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.

Re-connect: designing accessible email communication support for persons with aphasia

NARCIS (Netherlands)

Mahmud, Al A.; Martens, J.B.O.S.

2010-01-01

In this paper we present some preliminary outcomes concerning the design of an email communication tool for persons with expressive aphasia. The purpose of our design is to make email accessible for aphasics. It is based on interviews with persons with aphasia and their partners and has been

Access control and service-oriented architectures

NARCIS (Netherlands)

Leune, C.J.

2007-01-01

Access Control and Service-Oriented Architectures" investigates in which way logical access control can be achieved effectively, in particular in highly dynamic environments such as service-oriented architectures (SOA's). The author combines state-of-the-art best-practice and projects these onto the

Development of an instrument to measure Faculty's information and communication technology access (FICTA).

Science.gov (United States)

Soomro, Kamal Ahmed; Kale, Ugur; Curtis, Reagan; Akcaoglu, Mete; Bernstein, Malayna

2018-01-01

The phenomenon of "digital divide" is complex and multidimensional, extending beyond issues of physical access. The purpose of this study was to develop a scale to measure a range of factors related to digital divide among higher education faculty and to evaluate its reliability and validity. Faculty's Information and Communication Technology Access (FICTA) scale was tested and validated with 322 faculty teaching in public and private sector universities. Principal components analysis with varimax rotation confirmed an 8-factor solution corresponding to various dimensions of ICT access. The 57-item FICTA scale demonstrated good psychometric properties and offers researchers a tool to examine faculty's access to ICT at four levels - motivational, physical, skills, and usage access.

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

BARTER: Behavior Profile Exchange for Behavior-Based Admission and Access Control in MANETs

Science.gov (United States)

Frias-Martinez, Vanessa; Stolfo, Salvatore J.; Keromytis, Angelos D.

Mobile Ad-hoc Networks (MANETs) are very dynamic networks with devices continuously entering and leaving the group. The highly dynamic nature of MANETs renders the manual creation and update of policies associated with the initial incorporation of devices to the MANET (admission control) as well as with anomaly detection during communications among members (access control) a very difficult task. In this paper, we present BARTER, a mechanism that automatically creates and updates admission and access control policies for MANETs based on behavior profiles. BARTER is an adaptation for fully distributed environments of our previously introduced BB-NAC mechanism for NAC technologies. Rather than relying on a centralized NAC enforcer, MANET members initially exchange their behavior profiles and compute individual local definitions of normal network behavior. During admission or access control, each member issues an individual decision based on its definition of normalcy. Individual decisions are then aggregated via a threshold cryptographic infrastructure that requires an agreement among a fixed amount of MANET members to change the status of the network. We present experimental results using content and volumetric behavior profiles computed from the ENRON dataset. In particular, we show that the mechanism achieves true rejection rates of 95% with false rejection rates of 9%.

Research of user access control for networked manufacturing system

Institute of Scientific and Technical Information of China (English)

ZHENG Xiao-lin; LEI Yu; CHEN De-ren

2006-01-01

An integrated user access control method was proposed to address the issues of security and management in networked manufacturing systems (NMS).Based on the analysis of the security issues in networked manufacturing system,an integrated user access control method composed of role-based access control (RBAC),task-based access control (TBAC),relationship-driven access control (RDAC)and coalition-based access control (CBAC) was proposed,including the hierarchical user relationship model,the reference model and the process model.The elements and their relationships were defined,and the expressions of constraints authorization were given.The extensible access control markup language (XACML) was used to implement this method.This method was used in the networked manufacturing system in the Shaoxing spinning region of China.The results show that the integrated user access control method can reduce the costs of system security maintenance and management.

New control system: net communications on VAX; Nouveau systeme de controle: communications reseau sur VAX

Energy Technology Data Exchange (ETDEWEB)

David, L; Maugeais, C

1993-12-31

The control system is made of five different types of processors: a server (VAX 3800), stations (VS4000) as setting interfaces for operators, CAMAC VANTAGE controllers, VME controllers and industrial programmable automates. These automates are treated with the IMAGIN supervision software and with the OSI communication protocol. All the processors are of the VAX family and use DECNET communication protocol on ETHERNET net. (A.B.). 3 figs.

The equipment access software for a distributed UNIX-based accelerator control system

International Nuclear Information System (INIS)

Trofimov, Nikolai; Zelepoukine, Serguei; Zharkov, Eugeny; Charrue, Pierre; Gareyte, Claire; Poirier, Herve

1994-01-01

This paper presents a generic equipment access software package for a distributed control system using computers with UNIX or UNIX-like operating systems. The package consists of three main components, an application Equipment Access Library, Message Handler and Equipment Data Base. An application task, which may run in any computer in the network, sends requests to access equipment through Equipment Library calls. The basic request is in the form Equipment-Action-Data and is routed via a remote procedure call to the computer to which the given equipment is connected. In this computer the request is received by the Message Handler. According to the type of the equipment connection, the Message Handler either passes the request to the specific process software in the same computer or forwards it to a lower level network of equipment controllers using MIL1553B, GPIB, RS232 or BITBUS communication. The answer is then returned to the calling application. Descriptive information required for request routing and processing is stored in the real-time Equipment Data Base. The package has been written to be portable and is currently available on DEC Ultrix, LynxOS, HPUX, XENIX, OS-9 and Apollo domain. ((orig.))

Performance evaluation of a multi-radio, multi-hop ad-hoc radio communication network for Communications-Based Train Control (CBTC)

DEFF Research Database (Denmark)

Farooq, Jahanzeb; Bro, Lars; Karstensen, Rasmus Thystrup

2017-01-01

Communications-Based Train Control (CBTC) is a modern signalling system that uses radio communication to transfer train control information between the train and the wayside. A vast majority of CBTC systems worldwide use IEEE 802.11 Wi-Fi as the radio technology mostly due to its costeffectiveness....... The trackside networks in these systems are mostly based on conventional infrastructure Wi-Fi. It means a train has to continuously associate (i.e. perform handshake) with the trackside Wi-Fi Access Points (AP) as it moves. This is a timeconsuming process associated with a certain delay. Additionally, these APs...... are connected to the wayside infrastructure via optical fiber cables that incurs huge costs. This paper presents a novel design in which trackside nodes function in ad-hoc Wi-Fi mode, which means no association has to be performed with them prior to transmitting. A train simply broadcasts packets to any nodes...

Broadband and scalable mobile satellite communication system for future access networks

Science.gov (United States)

Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

2005-07-01

Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

Time division multiple access for vehicular communications

CERN Document Server

Omar, Hassan Aboubakr

2014-01-01

This brief focuses on medium access control (MAC) in vehicular ad hoc networks (VANETs), and presents VeMAC, a novel MAC scheme based on distributed time division multiple access (TDMA) for VANETs. The performance of VeMAC is evaluated via mathematical analysis and computer simulations in comparison with other existing MAC protocols, including the IEEE 802.11p standard. This brief aims at proposing TDMA as a suitable MAC scheme for VANETs, which can support the quality-of-service requirements of high priority VANET applications.

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......Access control policies are essential to determine who is allowed to access data in a system without compromising the data's security. However, applications inside a distributed environment may require those policies to be dependent on the actual content of the data, the flow of information, while...... 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....

Dynamic Resource Allocation and Access Class Barring Scheme for Delay-Sensitive Devices in Machine to Machine (M2M) Communications.

Science.gov (United States)

Li, Ning; Cao, Chao; Wang, Cong

2017-06-15

Supporting simultaneous access of machine-type devices is a critical challenge in machine-to-machine (M2M) communications. In this paper, we propose an optimal scheme to dynamically adjust the Access Class Barring (ACB) factor and the number of random access channel (RACH) resources for clustered machine-to-machine (M2M) communications, in which Delay-Sensitive (DS) devices coexist with Delay-Tolerant (DT) ones. In M2M communications, since delay-sensitive devices share random access resources with delay-tolerant devices, reducing the resources consumed by delay-sensitive devices means that there will be more resources available to delay-tolerant ones. Our goal is to optimize the random access scheme, which can not only satisfy the requirements of delay-sensitive devices, but also take the communication quality of delay-tolerant ones into consideration. We discuss this problem from the perspective of delay-sensitive services by adjusting the resource allocation and ACB scheme for these devices dynamically. Simulation results show that our proposed scheme realizes good performance in satisfying the delay-sensitive services as well as increasing the utilization rate of the random access resources allocated to them.

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

Geospacial information utilized under the access control strategy

Institute of Scientific and Technical Information of China (English)

TIAN Jie; ZHANG Xin-fang; WANG Tong-yang; XIANG Wei; Cheng Ming

2007-01-01

This paper introduces a solution to the secure requirement for digital rights management (DRM) by the way of geospacial access control named geospacial access control (GeoAC) in geospacial field. The issues of authorization for geospacial DRM are concentrated on. To geospacial DRM, one aspect is the declaration and enforcement of access rights, based on geographic aspects. To the approbation of digital geographic content, it is important to adopt online access to geodata through a spacial data infrastructure (SDI). This results in the interoperability requirements on three different levels: data model level, service level and access control level. The interaction between the data model and service level can be obtained by criterions of the open geospacial consortium (OGC), and the interaction of the access control level may be reached by declaring and enforcing access restrictions in GeoAC. Then an archetype enforcement based on GeoAC is elucidated. As one aspect of performing usage rights, the execution of access restrictions as an extension to a regular SDI is illuminated.

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.

mCRAN : a radio access network architecture for 5G indoor communications

NARCIS (Netherlands)

Chandra, Kishor; Cao, Zizheng; Bruintjes, T. M.; Prasad, R. Venkatesha; Karagiannis, G.; Tangdiongga, Eduward; van den Boom, H.P.A.; Kokkeler, A. B J

2015-01-01

Millimeter wave (mmWave) communication is being seen as a disruptive technology for 5G era. In particular, 60GHz frequency band has emerged as a promising candidate for multi-Gbps connectivity in indoor and hotspot areas. In terms of network architecture, cloud radio access network (CRAN) has

Dependability analysis of the data communication system in train control system

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

Communication based train control (CBTC) system is based on mobile communication and overcomes fixed blocks in order to increase track utilization and train safety. The data communication system (DCS) between trains and wayside equipment is a crucial factor for the safe and efficient operation of CBTC system. The dependability under various transmission conditions needs to be modeled and evaluated. In this paper,a stochastic reward net (SRN) model for DCS based IEEE 802.11 standard was developed,which captures all relevant failure and failure recovery behavior system aspects in a concise way. We compared the reliability,availability for DCS with and without access point (AP) and antenna redundant configuration. We also quantitatively evaluated and compared the frame loss probability for three DCS configurations with different train velocities and train numbers in one radio cell. Fixed-point iteration was adopted to simplify the analysis. Numerical results showed the significant improvement of the reliability,availability and the frame loss probability index for the full redundant configuration.

Cancer control and the communication innovation in South Korea: implications for cancer disparities.

Science.gov (United States)

Jung, Minsoo

2013-01-01

Over the last 10 years, the number of cancer survivors in South Korea has reached nearly one million with a survival rate of 49.4%. However, integrated supportive care for cancer survivors is lagging. One area in which the current cancer control policy needs updating is in the utilization of information and communication technology (ICT). The remarkable progress in the field of ICT over the past 10 years presents exciting new opportunities for health promotion. Recent communication innovations are conducive to the exchange of meta-information, giving rise to a new service area and transforming patients into active medical consumers. Consequently, such innovations encourage active participation in the mutual utilization and sharing of high-quality information. However, these benefits from new ICTs will almost certainly not be equally available to all, leading to so-called communication inequalities where cancer survivors from lower socioeconomic classes will likely have more limited access to the best means of making use of the health information. Therefore, most essentially, emphasis must be placed on helping cancer survivors and their caregivers utilize such advances in ICT to create a more efficient flow of health information, thereby reducing communication inequalities and expanding social support. Once we enhance access to health information and better manage the quality of information, as a matter of fact, we can expect an alleviation of the health inequalities faced by cancer survivors.

Accessibility

DEFF Research Database (Denmark)

Brooks, Anthony Lewis

2017-01-01

This contribution is timely as it addresses accessibility in regards system hardware and software aligned with introduction of the Twenty-First Century Communications and Video Accessibility Act (CVAA) and adjoined game industry waiver that comes into force January 2017. This is an act created...... by the USA Federal Communications Commission (FCC) to increase the access of persons with disabilities to modern communications, and for other purposes. The act impacts advanced communications services and products including text messaging; e-mail; instant messaging; video communications; browsers; game...... platforms; and games software. However, the CVAA has no legal status in the EU. This text succinctly introduces and questions implications, impact, and wider adoption. By presenting the full CVAA and game industry waiver the text targets to motivate discussions and further publications on the subject...

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.

Researchers' perspectives on open access scholarly communication in Tanzanian public universities

Directory of Open Access Journals (Sweden)

F.W. Dulle

2009-04-01

Full Text Available This research explored the awareness, usage and perspectives of Tanzanian researchers on open access as a mode of scholarly communication. A survey questionnaire targeted 544 respondents selected through stratified random sampling from a population of 1088 university researchers of the six public universities in Tanzania. With a response rate of 73%, the data were analysed using the Statistical Package for Social Sciences. The study reveals that the majority of the researchers were aware of and were positive towards open access. Findings further indicate that the majority of researchers in Tanzanian public universities used open access outlets more to access scholarly content than to disseminate their own research findings. It seems that most of these researchers would support open access publishing more if issues of recognition, quality and ownership were resolved. Thus many of them supported the idea of establishing institutional repositories at their respective universities as a way of improving the dissemination of local content. The study recommends that public universities and other research institutions in the country should consider establishing institutional repositories, with appropriate quality assurance measures, to improve the dissemination of research output emanating from these institutions.

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.

Institutional Repositories, Open Access, and Scholarly Communication: A Study of Conflicting Paradigms

Science.gov (United States)

Cullen, Rowena; Chawner, Brenda

2011-01-01

The Open Access movement of the past decade, and institutional repositories developed by universities and academic libraries as a part of that movement, have openly challenged the traditional scholarly communication system. This article examines the growth of repositories around the world, and summarizes a growing body of evidence of the response…

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

Directory of Open Access Journals (Sweden)

Wang Peng

2015-01-01

Full Text Available 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 the medical health-care environment, task-role-based access control model, which overcomes the disadvantages of traditional access control models. The task-role-based access control (T-RBAC model introduces a task concept, dividing tasks into four categories. It also supports supervision role hierarchy. T-RBAC is a proper access control model for Smart Health-care System, and it improves the management of access rights. This paper also proposes an implementation of T-RBAC, a binary two-key-lock pair access control scheme using prime factorization.

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

Predicting Social Networking Site Use and Online Communication Practices among Adolescents: The Role of Access and Device Ownership

Directory of Open Access Journals (Sweden)

Drew P. Cingel

2014-01-01

Full Text Available Given adolescents' heavy social media use, this study examined a number of predictors of adolescent social media use, as well as predictors of online communication practices. Using data collected from a national sample of 467 adolescents between the ages of 13 and 17, results indicate that demographics, technology access, and technology ownership are related to social media use and communication practices. Specifically, females log onto and use more constructive communication practices on Facebook compared to males. Additionally, adolescents who own smartphones engage in more constructive online communication practices than those who share regular cell phones or those who do not have access to a cell phone. Overall, results imply that ownership of mobile technologies, such as smartphones and iPads, may be more predictive of social networking site use and online communication practices than general ownership of technology.

Predicting Social Networking Site Use and Online Communication Practices among Adolescents: The Role of Access and Device Ownership

Directory of Open Access Journals (Sweden)

Drew P. Cingel

2014-06-01

Full Text Available Given adolescents' heavy social media use, this study examined a number of predictors of adolescent social media use, as well as predictors of online communication practices. Using data collected from a national sample of 467 adolescents between the ages of 13 and 17, results indicate that demographics, technology access, and technology ownership are related to social media use and communication practices. Specifically, females log onto and use more constructive com-munication practices on Facebook compared to males. Additionally, adolescents who own smartphones engage in more constructive online communication practices than those who share regular cell phones or those who do not have access to a cell phone. Overall, results imply that ownership of mobile technologies, such as smartphones and iPads, may be more predictive of social networking site use and online communication practices than general ownership of technology.

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.

Performance Evaluation of TDMA Medium Access Control Protocol in Cognitive Wireless Networks

Directory of Open Access Journals (Sweden)

Muhammed Enes Bayrakdar

2017-02-01

Full Text Available Cognitive radio paradigm has been revealed as a new communication technology that shares channels in wireless networks. Channel assignment is a crucial issue in the field of cognitive wireless networks because of the spectrum scarcity. In this work, we have evaluated the performance of TDMA medium access control protocol. In our simulation scenarios, primary users and secondary users utilize TDMA as a medium access control protocol. We have designed a network environment in Riverbed simulation software that consists of primary users, secondary users, and base stations. In our system model, secondary users sense the spectrum and inform the base station about empty channels. Then, the base station decides accordingly which secondary user may utilize the empty channel. Energy detection technique is employed as a spectrum sensing technique because it is the best when information about signal of primary user is acquired. Besides, different number of users is selected in simulation scenarios in order to obtain accurate delay and throughput results. Comparing analytical model with simulation results, we have shown that performance analysis of our system model is consistent and accurate.

Communication systems in JT-60 control

International Nuclear Information System (INIS)

Kimura, T.; Hosogane, N.; Kondo, I.; Kumahara, T.; Kurihara, K.; Yonekawa, I.; Yoshino, R.

1983-01-01

A new concept in communication is applied to the JT-60 control system which handles a large amount of data for the plant support and monitoring and for the discharge control including plasma feedback control. The communication systems are characterized by 1) adoption of an efficient protocol in the central highways which are composed of dual serial CAMAC ones, 2) standardization of the protocol and data format between the central controller and each subsystem one, 3) adoption of a polling method for plant monitoring and of block transfer for discharge conditions and results, and 4) use of novel modules for the fast data transfer in the real-time systems. A compact tool has also been developed for testing the data communication

Low-sampling-rate M-ary multiple access UWB communications in multipath channels

KAUST Repository

Alkhodary, Mohammad T.

2015-08-31

The desirable characteristics of ultra-wideband (UWB) technology are challenged by formidable sampling frequency, performance degradation in the presence of multi-user interference, and complexity of the receiver due to the channel estimation process. In this paper, a low-rate-sampling technique is used to implement M-ary multiple access UWB communications, in both the detection and channel estimation stages. A novel approach is used for multiple-access-interference (MAI) cancelation for the purpose of channel estimation. Results show reasonable performance of the proposed receiver for different number of users operating many times below Nyquist rate.

Low-sampling-rate M-ary multiple access UWB communications in multipath channels

KAUST Repository

Alkhodary, Mohammad T.; Ballal, Tarig; Al-Naffouri, Tareq Y.; Muqaibel, Ali H.

2015-01-01

The desirable characteristics of ultra-wideband (UWB) technology are challenged by formidable sampling frequency, performance degradation in the presence of multi-user interference, and complexity of the receiver due to the channel estimation process. In this paper, a low-rate-sampling technique is used to implement M-ary multiple access UWB communications, in both the detection and channel estimation stages. A novel approach is used for multiple-access-interference (MAI) cancelation for the purpose of channel estimation. Results show reasonable performance of the proposed receiver for different number of users operating many times below Nyquist rate.

Communication and control for networked complex systems

CERN Document Server

Peng, Chen; Han, Qing-Long

2015-01-01

This book reports on the latest advances in the study of Networked Control Systems (NCSs). It highlights novel research concepts on NCSs; the analysis and synthesis of NCSs with special attention to their networked character; self- and event-triggered communication schemes for conserving limited network resources; and communication and control co-design for improving the efficiency of NCSs. The book will be of interest to university researchers, control and network engineers, and graduate students in the control engineering, communication and network sciences interested in learning the core principles, methods, algorithms and applications of NCSs.

WP EMPLACEMENT CONTROL AND COMMUNICATION EQUIPMENT DESCRIPTIONS

International Nuclear Information System (INIS)

Raczka, N.T.

1997-01-01

The objective and scope of this document are to list and briefly describe the major control and communication equipment necessary for waste package emplacement at the proposed nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the required equipment are explained and summarized in the individual subsections of this document. This task was evaluated in accordance with QAP-2-0 and found not to be quality affecting. Therefore, this document was prepared in accordance with NAP-MG-012. The following control and communication equipment are addressed in this document: (1) Programmable Logic Controllers (PLC's); (2) Leaky Feeder Radio Frequency Communication Equipment; (3) Slotted Microwave guide Communication Equipment; (4) Vision Systems; (5) Radio Control Equipment; and (6) Enclosure Cooling Systems

New strategies for collision resolution of multi-access channel

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Multi-access protocol is one of the commonlyapplied access control protocols,in which commonchannels is shared by multi-users(as shown inFig.1).In recent years,this protocol has been suc-cessfully applied to various communication sys-tems[1].Typical examples are satellite communica-tion system,mobile communication system,localarea net work(LAN)and metropolitan area net work(MAN).There are chiefly three kinds of Multi-ac-cess channel models,i.e.fixed allocation model,self-adjusting allocation model and rando...

Dynamically Authorized Role-Based Access Control for Grid Applications

Institute of Scientific and Technical Information of China (English)

YAO Hanbing; HU Heping; LU Zhengding; LI Ruixuan

2006-01-01

Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed "virtual organizations". The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user's environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid application is also described.

Medium Access Control in Energy Harvesting - Wireless Sensor Networks

DEFF Research Database (Denmark)

Fafoutis, Xenofon

Focusing on Wireless Sensor Networks (WSN) that are powered by energy harvesting, this dissertation focuses on energy-efficient communication links between senders and receivers that are alternating between active and sleeping states of operation. In particular, the focus lies on Medium Access...

Communication technology access, use, and preferences among primary care patients: from the Residency Research Network of Texas (RRNeT).

Science.gov (United States)

Hill, Jason H; Burge, Sandra; Haring, Anna; Young, Richard A

2012-01-01

The digital revolution is changing the manner in which patients communicate with their health care providers, yet many patients still lack access to communication technology. We conducted this study to evaluate access to, use of, and preferences for using communication technology among a predominantly low-income patient population. We determined whether access, use, and preferences were associated with type of health insurance, sex, age, and ethnicity. In 2011, medical student researchers administered questionnaires to patients of randomly selected physicians within 9 primary care clinics in the Residency Research Network of Texas. Surveys addressed access to and use of cell phones and home computers and preferences for communicating with health care providers. In this sample of 533 patients (77% response rate), 448 (84%) owned a cell phone and 325 (62%) owned computers. Only 48% reported conducting Internet searches, sending and receiving E-mails, and looking up health information on the Internet. Older individuals, those in government sponsored insurance programs, and individuals from racial/ethnic minority groups had the lowest levels of technology adoption. In addition, more than 60% of patients preferred not to send and receive health information over the Internet, by instant messaging, or by text messaging. Many patients in this sample did not seek health information electronically nor did they want to communicate electronically with their physicians. This finding raises concerns about the vision of the patient-centered medical home to enhance the doctor-patient relationship through communication technology. Our patients represent some of the more vulnerable populations in the United States and, as such, deserve attention from health care policymakers who are promoting widespread use of communication technology.

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.

47 CFR 90.465 - Control of systems of communication.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Control of systems of communication. 90.465... communication. (a) Depending on design considerations, control of a system of communication may be exercised in... mobile-only systems, control may be exercised by the mobile operator. In communication systems involving...

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...

Analysing Access Control Specifications

DEFF Research Database (Denmark)

Probst, Christian W.; Hansen, René Rydhof

2009-01-01

When prosecuting crimes, the main question to answer is often who had a motive and the possibility to commit the crime. When investigating cyber crimes, the question of possibility is often hard to answer, as in a networked system almost any location can be accessed from almost anywhere. The most...... common tool to answer this question, analysis of log files, faces the problem that the amount of logged data may be overwhelming. This problems gets even worse in the case of insider attacks, where the attacker’s actions usually will be logged as permissible, standard actions—if they are logged at all....... 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...

Disk access controller for Multi 8 computer

International Nuclear Information System (INIS)

Segalard, Jean

1970-01-01

After having presented the initial characteristics and weaknesses of the software provided for the control of a memory disk coupled with a Multi 8 computer, the author reports the development and improvement of this controller software. He presents the different constitutive parts of the computer and the operation of the disk coupling and of the direct access to memory. He reports the development of the disk access controller: software organisation, loader, subprograms and statements

Development of a wireless protection against imitation system for identification and control of vehicle access

Directory of Open Access Journals (Sweden)

Aleksei A. Gavrishev

2018-03-01

Full Text Available This article deals with wireless systems for identification and control of vehicle access to protected objects. Known systems are considered. As a result, it has been established that one of the most promising approaches to identifying and controlling vehicle access to protected objects is the use of systems based on the "friend or foe" principle. Among these systems, there are "one-directional" and "bedirectional" identification and access control systems. "Bidirectional" systems are more preferable for questions of identification and access control. However, at present, these systems should have a reduced probability of recognizing the structure of the request and response signals because the potential attacker can easily perform unauthorized access to the radio channel of the system. On this basis, developed a wireless system identification and control vehicle access to protected objects based on the principle of "friend or foe", featuring increased protection from unauthorized access and jamming through the use of rewritable drives chaotic sequences. In addition, it’s proposed to use to identify the vehicle's RFID tag containing additional information about it. Are some specifications of the developed system (the possible frequency range of the request-response signals, the communication range, data rate, the size of the transmitted data, guidelines for choosing RFID. Also, with the help of fuzzy logic, was made the security assessment from unauthorized access request-response signals based on the system of "friend or foe", which are transferred via radio channel, developed systems and analogues. The security assessment of the developed system shows an adequate degree of protection against complex threats (view, spoofing, interception and jamming of traffic in comparison with known systems of this class. Among the main advantages of the developed system it’s necessary to mention increased security from unauthorized access and jamming

The linked medical data access control framework.

Science.gov (United States)

Kamateri, Eleni; Kalampokis, Evangelos; Tambouris, Efthimios; Tarabanis, Konstantinos

2014-08-01

The integration of medical data coming from multiple sources is important in clinical research. Amongst others, it enables the discovery of appropriate subjects in patient-oriented research and the identification of innovative results in epidemiological studies. At the same time, the integration of medical data faces significant ethical and legal challenges that impose access constraints. Some of these issues can be addressed by making available aggregated instead of raw record-level data. In many cases however, there is still a need for controlling access even to the resulting aggregated data, e.g., due to data provider's policies. In this paper we present the Linked Medical Data Access Control (LiMDAC) framework that capitalizes on Linked Data technologies to enable controlling access to medical data across distributed sources with diverse access constraints. The LiMDAC framework consists of three Linked Data models, namely the LiMDAC metadata model, the LiMDAC user profile model, and the LiMDAC access policy model. It also includes an architecture that exploits these models. Based on the framework, a proof-of-concept platform is developed and its performance and functionality are evaluated by employing two usage scenarios. Copyright © 2014 Elsevier Inc. All rights reserved.

Communicative Access Measures for Stroke: Development and Evaluation of a Quality Improvement Tool.

Science.gov (United States)

Kagan, Aura; Simmons-Mackie, Nina; Victor, J Charles; Chan, Melodie T

2017-11-01

To (1) develop a systems-level quality improvement tool targeting communicative access to information and decision-making for stroke patients with language disorders; and (2) evaluate the resulting tool-the Communicative Access Measures for Stroke (CAMS). Survey development and evaluation was in line with accepted guidelines and included item generation and reduction, survey formatting and composition, pretesting, pilot testing, and reliability assessment. Development and evaluation were carried out in hospital and community agency settings. The project used a convenience sample of 31 participants for the survey development, and 63 participants for the CAMS reliability study (broken down into 6 administrators/managers, 32 frontline staff, 25 participants with aphasia). Eligible participants invited to the reliability study included individuals from 45 community-based organizations in Ontario as well as 4400 individuals from communities of practice. Not applicable. Data were analyzed using kappa statistics and intraclass correlations for each item score on all surveys. A tool, the CAMS, comprising 3 surveys, was developed for health facilities from the perspectives of (1) administrators/policymakers, (2) staff/frontline health care providers, and (3) patients with aphasia (using a communicatively accessible version). Reliability for items on the CAMS-Administrator and CAMS-Staff surveys was moderate to high (kappa/intraclass correlation coefficients [ICCs], .54-1.00). As expected, reliability was lower for the CAMS-Patient survey, with most items having ICCs between 0.4 and 0.6. These findings suggest that CAMS may provide useful quality improvement information for health care facilities with an interest in improving care for patients with stroke and aphasia. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

A Tractable Model of the LTE Access Reservation Procedure for Machine-Type Communications

DEFF Research Database (Denmark)

Nielsen, Jimmy Jessen; Min Kim, Dong; Madueño, Germán Corrales

2015-01-01

A canonical scenario in Machine-Type Communications (MTC) is the one featuring a large number of devices, each of them with sporadic traffic. Hence, the number of served devices in a single LTE cell is not determined by the available aggregate rate, but rather by the limitations of the LTE access...

Access control based on attribute certificates for medical intranet applications.

Science.gov (United States)

Mavridis, I; Georgiadis, C; Pangalos, G; Khair, M

2001-01-01

Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications. To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications. We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC. Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework. Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy.

Using Twitter to access the human right of communication for people who use Augmentative and Alternative Communication (AAC).

Science.gov (United States)

Hemsley, Bronwyn; Palmer, Stuart; Dann, Stephen; Balandin, Susan

2018-02-01

Articles 19, 26 and 27 of the Universal Declaration of Human Rights and Articles 4, 9 and 21 of the Convention on the Rights of Persons with Disabilities promote the human rights of communication, education, use of technology and access to information. Social media is an important form of online communication, and Twitter increases users' visibility, influence and reach online. The aim of this sociotechnical research was to determine the impact of teaching three people who use Augmentative and Alternative Communication (AAC) to use Twitter. Three participants were trained in ways of using Twitter strategically. Data collected from participants' Twitter profiles were examined to determine the impact of training on Twitter follower count, frequency of tweeting, tweet content and the development of social networks. Data were also examined using (1) KH Coder software analysis and visualisation of co-occurring networks in the text data, based on word frequencies; and (2) Gephi software analysis to show the Twitter network for each participant. Two participants showed an improvement in Twitter skills and strategies. Twitter can be used to improve social connectedness of people who use AAC, and should not be overlooked in relation to communication rights.

Improvement The Transmission Efficiency For Wireless Packet Communication Systems Using Automatic Control for power And Time Slot Width Of Slotted Non persistent ISMA Protocol

Directory of Open Access Journals (Sweden)

Saad M. Hardan

2013-05-01

Full Text Available In packed communication systems which use a protocol, the protocol should perform the allocation of channels such that the transmission channel is used efficiently. Efficiency is usually measured in terms of channel throughput and the average transmission  delay. The Slotted Nonpersistent ISMA protocol is one of random access protocols used in packed communication systems. In this research a Slotted Nonpersistent ISMA protocol Model with automatic control for power and time slot is proposed. the suggested algorithm enable the base station(access point to control  the protocol time slot length and  transmission power in a dynamic way to control the normalized propagation delay d and to maintain all the uplink signals in the limit of captured power threshold (capture ratio in order to control the  throughput and the average transmission delay of the communication system by an automatic method. the computer simulation results  confirm the activity of the  proposed algorithm for increasing the  throughput and decreasing the average transmission delay by an accepted ratios.

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.

Design of a control system for self-shielded irradiators with remote access capability

International Nuclear Information System (INIS)

Iyengar, R.D.; Verma, P.B.; Prasad, V.V.S.S.; George, Jain R.; Das, Tripti; Deshmukh, D.K.

2001-01-01

With self-shielded irradiators like Gamma chambers, and Blood irradiators are being sold by BRIT to customers both within and outside the country, it has become necessary to improve the quality of service without increasing the overheads. The recent advances in the field of communications and information technology can be exploited for improving the quality of service to the customers. A state of the art control system with remote accessibility has been designed for these irradiators enhancing their performance. This will provide an easy access to these units wherever they might be located, through the Internet. With this technology it will now be possible to attend to the needs of the customers, as regards fault rectification, error debugging, system software update, performance testing, data acquisition etc. This will not only reduce the downtime of these irradiators but also reduce the overheads. (author)

Role Based Access Control system in the ATLAS experiment

International Nuclear Information System (INIS)

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

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 RBAC implementation uses a directory service based on Lightweight Directory Access Protocol to store the users (∼3000), roles (∼320), groups (∼80) and access policies. The information is kept in sync with various other databases and directory services: human resources, central CERN IT, CERN Active Directory and the Access Control Database used by DCS. The paper concludes with a detailed description of the integration across all areas of the system.

RFID Based Security Access Control System with GSM Technology

OpenAIRE

Peter Adole; Joseph M. Môm; Gabriel A. Igwue

2016-01-01

The security challenges being encountered in many places today require electronic means of controlling access to secured premises in addition to the available security personnel. Various technologies were used in different forms to solve these challenges. The Radio Frequency Identification (RFID) Based Access Control Security system with GSM technology presented in this work helps to prevent unauthorized access to controlled environments (secured premises). This is achieved mainly...

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...

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...

Channel access: A software bus for the LAACS

International Nuclear Information System (INIS)

Hill, J.O.

1990-01-01

The host processor for a code running within a distributed process control system is often predetermined by constraints built into the software architecture of the control system. Input/output (I/O) channels directly connected to the host processors are usually easier to access in software than channels on remote processors. It is often difficult to modernize selective parts of a control system's software while leaving the other parts unchanged. Likewise, software developed at one laboratory is often difficult to integrate into a control system developed at another laboratory. Software that runs in one machine or operating-system architecture is often unable to communicate with control-system software running on a different platform. For the Los Alamos Accelerator Control System (LAACS) we have attempted to address the above difficulties with a software communication facility which we call Channel Access. Channel Access provides a 'software bus' that allows programs to be connected through a network to I/O channels on real-time processors in a manner similar to the way in which hardware modules are integrated within a standardized hardware bus such as CAMAC or VME. We have already placed an operator interface on Channel Access and we are currently designing alarm, archiving and sequencing tools as well. Numerous application-specific programs use Channel Access. This paper describes the unique feature of this approach and its performance as an integral part of the Los Alamos Accelerator Control System. (orig.)

STAR-TYPE LOCAL AREA NETWORK ACCESS CONTROL

Institute of Scientific and Technical Information of China (English)

逯昭义; 齐藤忠夫

1990-01-01

The multiple access fashion is a new resolution for the star-type local area network (LAN) access control and star-type optical fibre LAN. Arguments about this network are discussed, and the results are introduced.

Role based access control design using Triadic concept analysis

Institute of Scientific and Technical Information of China (English)

Ch Aswani Kumar; S Chandra Mouliswaran; LI Jin-hai; C Chandrasekar

2016-01-01

Role based access control is one of the widely used access control models. There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis (FCA), description logics, and Ontology for representing access control mechanism. However, while using FCA, investigations reported in the literature so far work on the logic that transforms the three dimensional access control matrix into dyadic formal contexts. This transformation is mainly to derive the formal concepts, lattice structure and implications to represent role hierarchy and constraints of RBAC. In this work, we propose a methodology that models RBAC using triadic FCA without transforming the triadic access control matrix into dyadic formal contexts. Our discussion is on two lines of inquiry. We present how triadic FCA can provide a suitable representation of RBAC policy and we demonstrate how this representation follows role hierarchy and constraints of RBAC on sample healthcare network available in the literature.

The potential use of mobile technology: enhancing accessibility and communication in a blended learning course

OpenAIRE

Mayisela, Tabisa

2013-01-01

Mobile technology is increasingly being used to support blended learning beyond computer centres. It has been considered as a potential solution to the problem of a shortage of computers for accessing online learning materials (courseware) in a blended learning course. The purpose of the study was to establish how the use of mobile technology could enhance accessibility and communication in a blended learning course. Data were solicitedfrom a purposive convenience sample of 36 students engage...

New control system: net communications on VAX

International Nuclear Information System (INIS)

David, L.; Maugeais, C.

1992-01-01

The control system is made of five different types of processors: a server (VAX 3800), stations (VS4000) as setting interfaces for operators, CAMAC VANTAGE controllers, VME controllers and industrial programmable automates. These automates are treated with the IMAGIN supervision software and with the OSI communication protocol. All the processors are of the VAX family and use DECNET communication protocol on ETHERNET net. (A.B.). 3 figs

Network Communication for Low Level RF Control

International Nuclear Information System (INIS)

Liu Weiqing; Yin Chengke; Zhang Tongxuan; Fu Zechuan; Liu Jianfei

2009-01-01

Low Level RF (LLRF) control system for storage ring of Shanghai Synchrotron Radiation Facility (SSRF) has been built by digital technology. The settings of parameters and the feedback loop status are carried out through the network communication interface, and the local oscillation and clock, which is the important component of the digital LLRF control system, are also configured through network communication. NIOS II processor was employed as a core to build the embedded system with a real-time operating system MicroC/OS-II, finally Lightweight TCP/IP (LwIP) was used to achieve the communication interface. The communication network is stable after a long-term operation. (authors)

Wireless communication technology for modular mechatronic controllers

CSIR Research Space (South Africa)

Bright, G

2010-08-01

Full Text Available architecture. This further introduces problems that are concerned with timing, such as lag effect of zero-order hold (ZOH) and problems with re- spect to motion control. Problems of time variations can be addressed in control 2 design, e.g., by using... to determine the correct controller reaction time. Controlled process(es) System components } } } } } } } } Mechatronics sub-systems Level 2 communications Mechatronics system Level 3 communications Other systems D ec re as in g tim e de...

Access to hands-on mathematics measurement activities using robots controlled via speech generating devices: three case studies.

Science.gov (United States)

Adams, Kim; Cook, Al

2014-07-01

To examine how using a robot controlled via a speech generating device (SGD) influences the ways students with physical and communication limitations can demonstrate their knowledge in math measurement activities. Three children with severe physical disabilities and complex communication needs used the robot and SGD system to perform four math measurement lessons in comparing, sorting and ordering objects. The performance of the participants was measured and the process of using the system was described in terms of manipulation and communication events. Stakeholder opinions were solicited regarding robot use. Robot use revealed some gaps in the procedural knowledge of the participants. Access to both the robot and SGD was shown to provide several benefits. Stakeholders thought the intervention was important and feasible for a classroom environment. The participants were able to participate actively in the hands-on and communicative measurement activities and thus meet the demands of current math instruction methods. Current mathematics pedagogy encourages doing hands-on activities while communicating about concepts. Adapted Lego robots enabled children with severe physical disabilities to perform hands-on length measurement activities. Controlling the robots from speech generating devices (SGD) enabled the children, who also had complex communication needs, to reflect and report on results during the activities. By using the robots combined with SGDs, children both exhibited their knowledge of and experienced the concepts of mathematical measurements.

Videophone Technology and Students with Deaf-Blindness: A Method for Increasing Access and Communication

Science.gov (United States)

Emerson, Judith; Bishop, John

2012-01-01

Introduction: Seeing the Possibilities with Videophone Technology began as research project funded by the National Center for Technology Innovation. The project implemented a face-to-face social networking program for students with deaf-blindness to investigate the potential for increasing access and communication using videophone technology.…

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

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…

Future Computer, Communication, Control and Automation

CERN Document Server

2011 International Conference on Computer, Communication, Control and Automation

2012-01-01

The volume includes a set of selected papers extended and revised from the 2011 International Conference on Computer, Communication, Control and Automation (3CA 2011). 2011 International Conference on Computer, Communication, Control and Automation (3CA 2011) has been held in Zhuhai, China, November 19-20, 2011. This volume topics covered include wireless communications, advances in wireless video, wireless sensors networking, security in wireless networks, network measurement and management, hybrid and discrete-event systems, internet analytics and automation, robotic system and applications, reconfigurable automation systems, machine vision in automation. We hope that researchers, graduate students and other interested readers benefit scientifically from the proceedings and also find it stimulating in the process.

Towards an Approach of Semantic Access Control for Cloud Computing

Science.gov (United States)

Hu, Luokai; Ying, Shi; Jia, Xiangyang; Zhao, Kai

With the development of cloud computing, the mutual understandability among distributed Access Control Policies (ACPs) has become an important issue in the security field of cloud computing. Semantic Web technology provides the solution to semantic interoperability of heterogeneous applications. In this paper, we analysis existing access control methods and present a new Semantic Access Control Policy Language (SACPL) for describing ACPs in cloud computing environment. Access Control Oriented Ontology System (ACOOS) is designed as the semantic basis of SACPL. Ontology-based SACPL language can effectively solve the interoperability issue of distributed ACPs. This study enriches the research that the semantic web technology is applied in the field of security, and provides a new way of thinking of access control in cloud computing.

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

Directory of Open Access Journals (Sweden)

K. A. Shcheglov

2015-11-01

Full Text Available 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 possibility to implement access policies to system objects without breaking the system and applications operability, and share correctly access objects between subjects. This important property of suggested access control method enables to solve fundamentally new system objects securing problems like system resources virtualization aimed to protect system objects from users’ and applications attacks. We have created an abstract model, and it shows that this method (access control from subjects to objects based on requests redirection can be used as self-sufficient access control method, implementing any access control policy (from subjects to objects, thus being an alternative to discretional access control method.

Future Communication, Computing, Control and Management Volume 1

CERN Document Server

2012-01-01

This volume contains revised and extended research articles written by prominent researchers participating in the ICF4C 2011 conference. 2011 International Conference on Future Communication, Computing, Control and Management (ICF4C 2011) has been held on December 16-17, 2011, Phuket, Thailand. Topics covered include intelligent computing, network management, wireless networks, telecommunication, power engineering, control engineering, Signal and Image Processing, Machine Learning, Control Systems and Applications, The book will offer the states of arts of tremendous advances in Computing, Communication, Control, and Management and also serve as an excellent reference work for researchers and graduate students working on Computing, Communication, Control, and Management Research.

Future Communication, Computing, Control and Management Volume 2

CERN Document Server

2012-01-01

This volume contains revised and extended research articles written by prominent researchers participating in the ICF4C 2011 conference. 2011 International Conference on Future Communication, Computing, Control and Management (ICF4C 2011) has been held on December 16-17, 2011, Phuket, Thailand. Topics covered include intelligent computing, network management, wireless networks, telecommunication, power engineering, control engineering, Signal and Image Processing, Machine Learning, Control Systems and Applications, The book will offer the states of arts of tremendous advances in Computing, Communication, Control, and Management and also serve as an excellent reference work for researchers and graduate students working on Computing, Communication, Control, and Management Research.

Future Computing, Communication, Control and Management Volume 2

CERN Document Server

2012-01-01

This volume contains revised and extended research articles written by prominent researchers participating in the ICF4C 2011 conference. 2011 International Conference on Future Communication, Computing, Control and Management (ICF4C 2011) has been held on December 16-17, 2011, Phuket, Thailand. Topics covered include intelligent computing, network management, wireless networks, telecommunication, power engineering, control engineering, Signal and Image Processing, Machine Learning, Control Systems and Applications, The book will offer the states of arts of tremendous advances in Computing, Communication, Control, and Management and also serve as an excellent reference work for researchers and graduate students working on Computing, Communication, Control, and Management Research.

Real-time communication for distributed plasma control systems

Energy Technology Data Exchange (ETDEWEB)

Luchetta, A. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)], E-mail: adriano.luchetta@igi.cnr.it; Barbalace, A.; Manduchi, G.; Soppelsa, A.; Taliercio, C. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)

2008-04-15

Real-time control applications will benefit in the near future from the enhanced performance provided by multi-core processor architectures. Nevertheless real-time communication will continue to be critical in distributed plasma control systems where the plant under control typically is distributed over a wide area. At RFX-mod real-time communication is crucial for hard real-time plasma control, due to the distributed architecture of the system, which consists of several VMEbus stations. The system runs under VxWorks and uses Gigabit Ethernet for sub-millisecond real-time communication. To optimize communication in the system, a set of detailed measurements has been carried out on the target platforms (Motorola MVME5100 and MVME5500) using either the VxWorks User Datagram Protocol (UDP) stack or raw communication based on the data link layer. Measurements have been carried out also under Linux, using its UDP stack or, in alternative, RTnet, an open source hard real-time network protocol stack. RTnet runs under Xenomai or RTAI, two popular real-time extensions based on the Linux kernel. The paper reports on the measurements carried out and compares the results, showing that the performance obtained by using open source code is suitable for sub-millisecond real-time communication in plasma control.

Improving access to medicines for non-communicable diseases in rural India: a mixed methods study protocol using quasi-experimental design.

Science.gov (United States)

Prashanth, N S; Elias, Maya Annie; Pati, Manoj Kumar; Aivalli, Praveenkumar; Munegowda, C M; Bhanuprakash, Srinath; Sadhana, S M; Criel, Bart; Bigdeli, Maryam; Devadasan, Narayanan

2016-08-22

India has the distinction of financing its healthcare mainly through out-of-pocket expenses by individual families contributing to catastrophic health expenditure and impoverishment. Nearly 70 % of the expenditure is on medicines purchased at private pharmacies. Patients with chronic ailments are especially affected, as they often need lifelong medicines. Over the past years in India, there have been several efforts to improve drug availability at government primary health centres. In this study, we aim to understand health system factors that affect utilisation and access to generic medicines for people with non-communicable diseases. This study aims to understand if (and how) a package of interventions targeting primary health centres and community participation platforms affect utilisation and access to generic medicines for people with non-communicable diseases in the current district context in India. This study will employ a quasi-experimental design and a qualitative theory-driven approach. PHCs will be randomly assigned to one of three arms of the intervention. In one arm, PHCs will receive inputs to optimise service delivery for non-communicable diseases, while the second arm will receive an additional package of interventions to strengthen community participation platforms for improving non-communicable disease care. The third arm will be the control. We will conduct household and facility surveys, before and after the intervention and will estimate the effect of the intervention by difference-in-difference analysis. Sample size for measuring effects was calculated based on obtaining at least 30 households for each primary health centre spread across three distance-based clusters. Primary outcomes include availability and utilisation of medicines at primary health centres and out-of-pocket expenditure for medicines by non-communicable disease households. Focus group discussions with patients and in-depth interviews with health workers will also be

Vibration noise control in laser satellite communication

Science.gov (United States)

Saksonov, Avigdor; Shlomi, Arnon; Kopeika, Norman S.

2001-08-01

Laser satellite communication has become especially attractive in recent years. Because the laser beam width is narrow than in the RF or microwave range, the transmitted optical power may be significantly reduced. This leads to development of miniature communication systems with extremely low power consumption. On the other hand, the laser communication channel is very sensitive to vibrations of the optical platform. These vibrations cause angular noise in laser beam pointing, comparable to the laser beam width. As result, as significant portion of the optical power between transmitter and receiver is lost and the bit error rate is increased. Consequently, vibration noise control is a critical problem in laser satellite communication. The direction of the laser beam is corrected with a fast steering mirror (FSM). In this paper are presented two approaches for the FSM control. One is the feedback control that uses an LQG algorithm. The second is the direct feed- forward control when vibration noise is measured by three orthogonal accelerometers and drives directly the F SM. The performances of each approach are evaluated using MATLAB simulations.

Real-Time Communication in Wireless Home Networks

NARCIS (Netherlands)

Scholten, Johan; Jansen, P.G.

This paper describes a medium access protocol for real-time communication in wireless networks. Medium access is controlled by a scheduler, which utilizes a pre-emptive earliest deadline first (PEDF) scheduling algorithm. The scheduler prevents collisions in the network, where normally only

Task-and-role-based access-control model for computational grid

Institute of Scientific and Technical Information of China (English)

LONG Tao; HONG Fan; WU Chi; SUN Ling-li

2007-01-01

Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.

Public Access ICT across Cultures

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

3 Impact of Public Access to ICT Skills on Job Prospects in Rwanda ... reform and information and communication technology (ICT) policies, particularly in developing countries. ... (From internal memoranda prepared by Amy Mahan, 2008) ..... little decision-making autonomy, power, or financial control within the household.

Distributed Role-based Access Control for Coaliagion Application

Institute of Scientific and Technical Information of China (English)

HONG Fan; ZHU Xian; XING Guanglin

2005-01-01

Access control in multi-domain environments is one of the important questions of building coalition between domains.On the basis of RBAC access control model, the concepts of role delegation and role mapping are proposed, which support the third-party authorization.Then, a distributed RBAC model is presented.Finally the implementation issues are discussed.

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...

Effective use of multibeam antenna and space-time multiple access technology in modern mobile communication systems

OpenAIRE

Moskalets, N. V.

2015-01-01

A possibility for efficient use of radio-frequency spectrum and of corresponding increase in productivity of mobile communication system with space-time multiple access obtained by use of multibeam antenna of base station is considered.

Global system data bus using the Digital Autonomous Terminal Access Communication protocol

Science.gov (United States)

Holmes, David C. E.

1986-01-01

Modern digital avionic systems with distributed processing require networking to connect the many elements. Digital Autonomous Terminal Access Communication (DATAC) is one of many such networks. DATAC has been implemented on the Transport Systems Research Vehicle (TSRV), a Boeing 737 aircraft operated by the National Aeronautics and Space Administration's Advanced Transport Operating Systems Program Office (ATOPS). This paper presents the TSRV implementation of the DATAC bus, a description of the DATAC system, a synchronization mechanism, details of data flow throughout the system, and a discussion of the modes available with DATAC. Numerous flight tests have been conducted using DATAC as the only means of communication between systems with outstanding results. DATAC is now an integral part of the TSRV and is expected to satisfy near term as well as future requirements for growth and flexibility.

The network communication of BEPC control system

International Nuclear Information System (INIS)

Xu Jingwei

1997-01-01

The author introduces the application of network communication of BEPC control system. The authors use non-transparent communication to transfer the data and command information from node VAX750 to VAX4500

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.

A Theorem on Grid Access Control

Institute of Scientific and Technical Information of China (English)

XU ZhiWei(徐志伟); BU GuanYing(卜冠英)

2003-01-01

The current grid security research is mainly focused on the authentication of grid systems. A problem to be solved by grid systems is to ensure consistent access control. This problem is complicated because the hosts in a grid computing environment usually span multiple autonomous administrative domains. This paper presents a grid access control model, based on asynchronous automata theory and the classic Bell-LaPadula model. This model is useful to formally study the confidentiality and integrity problems in a grid computing environment. A theorem is proved, which gives the necessary and sufficient conditions to a grid to maintain confidentiality.These conditions are the formalized descriptions of local (node) relations or relationship between grid subjects and node subjects.

How Drug Control Policy and Practice Undermine Access to Controlled Medicines.

Science.gov (United States)

Burke-Shyne, Naomi; Csete, Joanne; Wilson, Duncan; Fox, Edward; Wolfe, Daniel; Rasanathan, Jennifer J K

2017-06-01

Drug conventions serve as the cornerstone for domestic drug laws and impose a dual obligation upon states to prevent the misuse of controlled substances while ensuring their adequate availability for medical and scientific purposes. Despite the mandate that these obligations be enforced equally, the dominant paradigm enshrined in the drug conventions is an enforcement-heavy criminal justice response to controlled substances that prohibits and penalizes their misuse. Prioritizing restrictive control is to the detriment of ensuring adequate availability of and access to controlled medicines, thereby violating the rights of people who need them. This paper argues that the drug conventions' prioritization of criminal justice measures-including efforts to prevent non-medical use of controlled substances-undermines access to medicines and infringes upon the right to health and the right to enjoy the benefits of scientific progress. While the effects of criminalization under drug policy limit the right to health in multiple ways, we draw on research and documented examples to highlight the impact of drug control and criminalization on access to medicines. The prioritization and protection of human rights-specifically the right to health and the right to enjoy the benefits of scientific progress-are critical to rebalancing drug policy.

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.

Willingness to Communicate and Action Control

Science.gov (United States)

MacIntyre, Peter D.; Doucette, Jesslyn

2010-01-01

Being willing to communicate is part of becoming fluent in a second language, which often is the ultimate goal of L2 learners. Julius Kuhl's theory of action control is introduced as an expansion of the conceptual framework for the study of Willingness to Communicate. Kuhl proposed three key concepts, preoccupation, volatility, and hesitation,…

Foundation for a Time Interval Access Control Model

National Research Council Canada - National Science Library

Afinidad, Francis B; Levin, Timothy E; Irvine, Cynthia E; Nguyen, Thuy D

2005-01-01

A new model for representing temporal access control policies is introduced. In this model, temporal authorizations are represented by time attributes associated with both subjects and objects, and a time interval access graph...

Performance estimates for personnel access control systems

International Nuclear Information System (INIS)

Bradley, R.G.

1980-10-01

Current performance estimates for personnel access control systems use estimates of Type I and Type II verification errors. A system performance equation which addresses normal operation, the insider, and outside adversary attack is developed. Examination of this equation reveals the inadequacy of classical Type I and II error evaluations which require detailed knowledge of the adversary threat scenario for each specific installation. Consequently, new performance measures which are consistent with the performance equation and independent of the threat are developed as an aid in selecting personnel access control systems

Decentralized control and communication

Czech Academy of Sciences Publication Activity Database

Bakule, Lubomír; Papík, Martin

2012-01-01

Roč. 36, č. 1 (2012), s. 1-10 ISSN 1367-5788 R&D Projects: GA MŠk(CZ) LG12014 Institutional research plan: CEZ:AV0Z10750506 Keywords : decentralization * communication * large-scale complex systems Subject RIV: BC - Control Systems Theory Impact factor: 1.289, year: 2012

Using a Checklist to Access Communication Skills in Last Year Medical Students

Directory of Open Access Journals (Sweden)

Mitra Amini

2009-11-01

Full Text Available Background and purpose: Available data indicate the quality of doctor-patient communication has a significant impact on patient satisfaction, medical outcomes, medical costs, and the likelihood of a physician experiencing a malpractice claim. Assessment of communication skills is a very important issue. Since a good assessment can show strengths and weaknesses of this process and feedback can improve the behavior, this study was designed to measure communication skill of last year medicalstudents (interns in Jahrom medical school by an observational checklist.Methods: This study is a cross sectional study to access communication skills of interns of Jahrom medical school in southeast Iran, a checklist was designed for this purpose. Checklist completed with direct observation by an educated general practitioner. The researcher observed the interns inMotahari and Peymanie,(2 teaching hospitals of Jahrom medical school.The interns ignored about checklist material to prevent observational bias. Findings were analyzed using SPSS software.Results: 32(55%of medical interns were female and 26(45% were male. under category of interview conduction the best results was due to acceptable appearance of interns that 48 interns(82.8%hadacceptable appearance. nearly half of the interns didn’t say hello to patients and great them. none of the interns introduce themselves to patients. . Under category of interview conduction the bestresults was due to responding properly to patient questions. Under category of interview completion the results showed that the behavior of interns in this part was not acceptable and this part of communication was the worst part.Conclusion: The results of our study reflect that it is necessary to introduce a sustained, coherent and integrated communication skill training program into the medical curriculum.Key words: COMMUNICATION SKILLS, INTERNS, ASSESSMENT

High speed serial communications for control systems

International Nuclear Information System (INIS)

Mathieson, D.; Kalbfleisch, C.; Hunt, S.; Low, K.

1993-01-01

The Superconducting Super Collider Laboratory is a complex of accelerators being built in Ellis County, Texas. The SSCL control system consists of front-end processors and their associated control points remotely distributed from the Central and Regional control rooms. Control messages passing between these locations require timely (deterministic) distribution. A prototype network consisting of point-to-point links utilizing commercial T1 (1.544 Mb/s) communication boards has been implemented. These dedicated communication links will replace networking services traditionally provided for by shared medium networks like Ethernet(IEEE 802.3) and FDDI(IEEE 802.5). A seamless migration will be achieved by using packet encapsulation based on PPP(Point-to-Point Protocol, RFC 1171). All other networking functions including routing and reliable delivery are still being handled by the usual internet services. A distributed control system that currently uses Ethernet for communication is being re-implemented using these point-to-point links. The authors report on throughput measurements, timing constraints and ease of transition of a point-to-point network

Characterization of coded random access with compressive sensing based multi user detection

DEFF Research Database (Denmark)

Ji, Yalei; Stefanovic, Cedomir; Bockelmann, Carsten

2014-01-01

The emergence of Machine-to-Machine (M2M) communication requires new Medium Access Control (MAC) schemes and physical (PHY) layer concepts to support a massive number of access requests. The concept of coded random access, introduced recently, greatly outperforms other random access methods...... coded random access with CS-MUD on the PHY layer and show very promising results for the resulting protocol....

Application of Information and Communication Technology (ICT) in Health Information Access and Dissemination in Uganda

Science.gov (United States)

Omona, Walter; Ikoja-Odongo, Robert

2006-01-01

This paper reports on a study which assessed the application of information and communication technologies (ICT) in health information access and dissemination in Uganda. The project focused not only on information obtainable through libraries for research, teaching, learning and practice, but also on ICT applications concerned with the…

Scholarly communication changing

DEFF Research Database (Denmark)

Faber Frandsen, Tove

2009-01-01

Abstract The dissertation aims at investigating the changing scholarly communication in general and more specifically the implications of open access on scholarly communication. The overall research question is: What are the effects of open access on scholarly communication? The dissertation...... consists of five empirical studies of various aspects of the implications of open access on scholarly communication. The five studies, published as journal articles, are bibliometric studies conducted on three different levels. The first level consists of two studies of a general, more explorative....... Furthermore, the dissertation includes a chapter that presents and discusses the research findings in a theoretical framework. Initially the chapter presents and discusses terminology needed for analysing open access and scholarly communication. Following the necessary definitions and clarifications...

A Universal Communication Framework and Navigation Control Software for Mobile Prototyping Platforms

Directory of Open Access Journals (Sweden)

Andreas Mitschele-Thiel

2010-09-01

Full Text Available In our contribution we would like to describe two new aspects of our low-cost mobile prototyping platform concept: a new hardware communication framework as well as new software features for navigation and control of our mobile platform. The paper is an extension of the ideas proposed in REV2009 [1] and is based on the therein used hardware platform and the monitoring and management software. This platform is based on the Quadrocopter concept – autonomous flying helicopter-style robots – and includes additional off-the-shelf parts. This leads to a universal mobile prototyping platform for communication tasks providing both mobile phone and WiFi access. However, the platform can provide these functions far more quickly than a technician on the ground might be able to. We will show that with our concept we can easily adapt the platform to the individual needs of the user, which leads to a very flexible and semi-autonomous system.

Inter-Vehicle Communication System Utilizing Autonomous Distributed Transmit Power Control

Science.gov (United States)

Hamada, Yuji; Sawa, Yoshitsugu; Goto, Yukio; Kumazawa, Hiroyuki

In ad-hoc network such as inter-vehicle communication (IVC) system, safety applications that vehicles broadcast the information such as car velocity, position and so on periodically are considered. In these applications, if there are many vehicles broadcast data in a communication area, congestion incurs a problem decreasing communication reliability. We propose autonomous distributed transmit power control method to keep high communication reliability. In this method, each vehicle controls its transmit power using feed back control. Furthermore, we design a communication protocol to realize the proposed method, and we evaluate the effectiveness of proposed method using computer simulation.

High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

Science.gov (United States)

Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

2016-06-01

Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

The Practice of Hospital Intranet Terminal Access Control Solution

Institute of Scientific and Technical Information of China (English)

QI Shi-tao; TANG Li-ming

2016-01-01

Along with the increasingly urgent management needs of intranet terminals in hospital, and large scaled deployment of terminal management system, terminal access control has become one of the standard functions of terminal management. This paper mainly aims at some simple research for the system construction of hospital intranet terminal access control.

A utility perspective on radiation worker access control systems

International Nuclear Information System (INIS)

Watson, B.A.; Goff, T.E.

1984-01-01

Based on an evaluation of the current commercial Radiation Worker Access Control Software Systems, Baltimore Gas and Electric Company has elected to design and develop a site specific access control and accountability system for the Calvert Cliffs Nuclear Power Plant. The vendor provided systems allow for radiation worker access control based on training and external exposure records and authorizations. These systems do not afford internal exposure control until after bioassay measurements or maximum permissible concentration-hours are tabulated. The vendor provided systems allow for data trending for ALARA purposes, but each software package must be modified to meet site specific requirements. Unlike the commercial systems, the Calvert Cliffs Radiological Controls and Accountability System (RCAS) will provide radiation worker exposure control, both internal and external. The RCAS is designed to fulfill the requirements by integrating the existing Radiation Safety, Dosemetry, and Training data bases with a comprehensive radiological surveillance program. Prior to each worker's entry into the Radiological Control Area; his training and qualifications, radiation exposure history and authorization, will be compared with administrative controls, such as radiation work permits, and respiratory protection requirements and the radiological conditions in the work area. The RCAS, a computer based applied health physics access control system is described as it is presently configured for development. The mechanisms for enhancing worker internal and external exposure controls are discussed. Proposed data application to both the Calvert Cliffs ALARA and outage planning programs is included

Development of a generic system for real-time data access and remote control of multiple in-situ water quality monitoring instruments

Science.gov (United States)

Wright, S. A.; Bennett, G. E.; Andrews, T.; Melis, T. S.; Topping, D. J.

2005-05-01

Currently, in-situ monitoring of water quality parameters (e.g. water temperature, conductivity, turbidity) in the Colorado River ecosystem typically consists of deploying instruments in the river, retrieving them at a later date, downloading the datalogger, then examining the data; an arduous process in the remote settings of Grand Canyon. Under this protocol, data is not available real-time and there is no way to detect problems with the instrumentation until after retrieval. The next obvious stage in the development of in-situ monitoring in Grand Canyon was the advent of one-way telemetry, i.e. streaming data in real-time from the instrument to the office and/or the world-wide-web. This protocol allows for real-time access to data and the identification of instrumentation problems, but still requires a site visit to address instrument malfunctions, i.e. the user does not have the ability to remotely control the instrument. At some field sites, such as the Colorado River in Grand Canyon, site visitation is restricted by remoteness and lack of traditional access routes (i.e. roads). Even at less remote sites, it may still be desirable to have two-way communication with instruments in order to, for example, diagnose and potentially fix instrumentation problems, change sampling parameters to save battery power, etc., without having to visit the site. To this end, the U.S. Geological Survey, Grand Canyon Monitoring and Research Center, is currently developing and testing a high-speed, two-way communication system that allows for real-time data access and remote control of instrumentation. The approach tested relies on internet access and may be especially useful in areas where land-line or cellular connections are unavailable. The system is composed of off-the-shelf products, uses a commercial broadband satellite service, and is designed in a generic way such that any instrument that communicates through RS-232 communication (i.e. a serial port) is compatible with

1st International Conference on Intelligent Communication, Control and Devices

CERN Document Server

Choudhury, Sushabhan

2017-01-01

The book presents high-quality research papers presented at the first international conference, ICICCD 2016, organised by the Department of Electronics, Instrumentation and Control Engineering of University of Petroleum and Energy Studies, Dehradun on 2nd and 3rd April, 2016. The book is broadly divided into three sections: Intelligent Communication, Intelligent Control and Intelligent Devices. The areas covered under these sections are wireless communication and radio technologies, optical communication, communication hardware evolution, machine-to-machine communication networks, routing techniques, network analytics, network applications and services, satellite and space communications, technologies for e-communication, wireless Ad-Hoc and sensor networks, communications and information security, signal processing for communications, communication software, microwave informatics, robotics and automation, optimization techniques and algorithms, intelligent transport, mechatronics system, guidance and navigat...

The human communication space towards I-centric communications

CERN Document Server

Arbanowski, S; Steglich, S; Popescu-Zeletin, R

2001-01-01

A variety of concepts for service integration and corresponding systems have been developed. On one hand, they aim for the interworking and integration of classical telecommunications and data communications services. On the other, they are focusing on universal service access from a variety of end-user systems. Many of the technical problems, resulting from service integration and service personalisation, have been solved. However, all these systems are driven by the concept of providing several technologies to users by keeping the peculiarity of each service. Looking at human communication behaviour and communication space, it is obvious that human beings interact habitually in a set of contexts with their environment. The individual information preferences and needs, persons to interact with, and the set of devices controlled by each individual define their personal communication space. Following this view, a new approach is to build communication systems not on the basis of specific technologies, but on t...

NASA Unmanned Aircraft (UA) Control and Non-Payload Communication (CNPC) System Waveform Trade Studies

Science.gov (United States)

Chavez, Carlos; Hammel, Bruce; Hammel, Allan; Moore, John R.

2014-01-01

Unmanned Aircraft Systems (UAS) represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the National Airspace System (NAS). To address this deficiency, NASA has established a project called UAS Integration in the NAS (UAS in the NAS), under the Integrated Systems Research Program (ISRP) of the Aeronautics Research Mission Directorate (ARMD). This project provides an opportunity to transition concepts, technology, algorithms, and knowledge to the Federal Aviation Administration (FAA) and other stakeholders to help them define the requirements, regulations, and issues for routine UAS access to the NAS. The safe, routine, and efficient integration of UAS into the NAS requires new radio frequency (RF) spectrum allocations and a new data communications system which is both secure and scalable with increasing UAS traffic without adversely impacting the Air Traffic Control (ATC) communication system. These data communications, referred to as Control and Non-Payload Communications (CNPC), whose purpose is to exchange information between the unmanned aircraft and the ground control station to ensure safe, reliable, and effective unmanned aircraft flight operation. A Communications Subproject within the UAS in the NAS Project has been established to address issues related to CNPC development, certification and fielding. The focus of the Communications Subproject is on validating and allocating new RF spectrum and data link communications to enable civil UAS integration into the NAS. The goal is to validate secure, robust data links within the allocated frequency spectrum for UAS. A vision, architectural concepts, and seed requirements for the future commercial UAS CNPC system have been developed by RTCA Special Committee 203 (SC-203) in the process

Experience with ActiveX control for simple channel access

International Nuclear Information System (INIS)

Timossi, C.; Nishimura, H.; McDonald, J.

2003-01-01

Accelerator control system applications at Berkeley Lab's Advanced Light Source (ALS) are typically deployed on operator consoles running Microsoft Windows 2000 and utilize EPICS[2]channel access for data access. In an effort to accommodate the wide variety of Windows based development tools and developers with little experience in network programming, ActiveX controls have been deployed on the operator stations. Use of ActiveX controls for use in the accelerator control environment has been presented previously[1]. Here we report on some of our experiences with the use and development of these controls

AAL Platform with a "De Facto" Standard Communication Interface (TICO): Training in Home Control in Special Education.

Science.gov (United States)

Guillomía San Bartolomé, Miguel A; Falcó Boudet, Jorge L; Artigas Maestre, José Ignacio; Sánchez Agustín, Ana

2017-10-12

Framed within a long-term cooperation between university and special education teachers, training in alternative communication skills and home control was realized using the "TICO" interface, a communication panel editor extensively used in special education schools. From a technological view we follow AAL technology trends by integrating a successful interface in a heterogeneous services AAL platform, focusing on a functional view. Educationally, a very flexible interface in line with communication training allows dynamic adjustment of complexity, enhanced by an accessible mindset and virtual elements significance already in use, offers specific interaction feedback, adapts to the evolving needs and capacities and improves the personal autonomy and self-confidence of children at school and home. TICO-home-control was installed during the last school year in the library of a special education school to study adaptations and training strategies to enhance the autonomy opportunities of its pupils. The methodology involved a case study and structured and semi-structured observations. Five children, considered unable to use commercial home control systems were trained obtaining good results in enabling them to use an open home control system. Moreover this AAL platform has proved efficient in training children in previous cognitive steps like virtual representation and cause-effect interaction.

Real-time data access layer for MDSplus

International Nuclear Information System (INIS)

Manduchi, G.; Luchetta, A.; Taliercio, C.; Fredian, T.; Stillerman, J.

2008-01-01

Recent extensions to MDSplus allow data handling in long discharges and provide a real-time data access and communication layer. The real-time data access layer is an additional component of MDSplus: it is possible to use the traditional MDSplus API during normal operation, and to select a subset of data items to be used in real time. Real-time notification is provided by a communication layer using a publish-subscribe pattern. The notification covers processes sharing the same data items even running on different machines, thus allowing the implementation of distributed control systems. The real-time data access layer has been developed for Windows, Linux, and VxWorks; it is currently being ported to Linux RTAI. In order to quantify the fingerprint of the presented system, the performance of the real-time access layer approach is compared with that of an ad hoc, manually optimized program in a sample real-time application

The Methods and Mechanisms for Access Control of Encrypted Data in Clouds

Directory of Open Access Journals (Sweden)

Sergey Vladimirovich Zapechnikov

2013-09-01

Full Text Available The paper is about the problem of data access control in clouds. The main mechanisms for access control of encrypted data in untrusted cloud environments are analyzed and described. The comparative analysis of access control algorithms and implementation issues are offered. The main practical result of research is a web-based (Wikipedia-like reference and information system devoted to the access control methods and mechanisms.

Pharma Pricing & Market Access Europe 2016--Health Network Communications' Tenth Annual Conference (February 23-25, 2016--London, UK).

Science.gov (United States)

D'Souza, P

2016-03-01

Tighter national budgets and escalating drug prices continue to present challenges for pharmaceutical market access strategies and societal cost of care. As pharmaceutical companies and medical governmental advisory organizations enter tougher negotiations, hospital trusts and other dispensary firms face barriers to receiving the best medical treatment, and as a result patient access is limited. The 2016 HealthNetwork Communications' Pharma Pricing & Market Access Europe meeting brought together pharmaceutical, medical governmental advisory and stakeholders and market access/pricing consultants, to encourage discussions and negotiations into how to improve the drug pricing system and consequential market access strategies while achieving the respective reimbursement and affordability objectives. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

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.

Use of a web 2.0 portal to improve education and communication in young patients with families: randomized controlled trial.

Science.gov (United States)

Hanberger, Lena; Ludvigsson, Johnny; Nordfeldt, Sam

2013-08-23

Diabetes requires extensive self-care and comprehensive knowledge, making patient education central to diabetes self-management. Web 2.0 systems have great potential to enhance health information and open new ways for patients and practitioners to communicate. To develop a Web portal designed to facilitate self-management, including diabetes-related information and social networking functions, and to study its use and effects in pediatric patients with diabetes. A Web 2.0 portal was developed in collaboration with patients, parents, and practitioners. It offered communication with local practitioners, interaction with peers, and access to relevant information and services. Children and adolescents with diabetes in a geographic population of two pediatric clinics in Sweden were randomized to a group receiving passwords for access to the portal or a control group with no access (n=230) for 1 year. All subjects had access during a second study year. Users' activity was logged by site and page visits. Health-related quality of life (HRQOL), empowerment (DES), and quality of information (QPP) questionnaires were given at baseline and after 1 and 2 study years. Clinical data came from the Swedish pediatric diabetes quality registry SWEDIABKIDS. There was a continuous flow of site visits, decreasing in summer and Christmas periods. In 119/233 families (51%), someone visited the portal the first study year and 169/484 (35%) the second study year. The outcome variables did not differ between intervention and control group. No adverse treatment or self-care effects were identified. A higher proportion of mothers compared to fathers visited once or more the first year (PInternational Standard Randomized Controlled Trial Number (ISRCTN):92107365; http://www.controlled-trials.com/ISRCTN92107365/ (Archived by WebCite at http://webcitation.org/6IkiIvtSb).

IEPLC Framework, Automated Communication in a Heterogeneous Control System Environment

CERN Document Server

Locci, F

2014-01-01

In CERN accelerators control system several components are essential such as: Programmable Logic Controller (PLC), PCI Extensions for Instrumentation (PXI), and other micro-controller families. Together with their weaknesses and their strength points they typically present custom communication protocols and it is therefore difficult to federate them into the control system using a single communication strategy. Furthermore this dependency to the physical device interfaces and protocols makes most of the code not reusable and the replacement of old technology a difficult problem. The purpose of IEPLC ([1]) is to mitigate the communication issues given by this heterogeneity; it proposes a framework to define communication interfaces in a hardware independent manner. In addition it automatically generates all the resources needed on master side (typically represented by a FEC: Front-End Computer) and slave side (typically represented by the controller) to implement a common and generic Ethernet communication. Th...

Mandatory and Location-Aware Access Control for Relational Databases

Science.gov (United States)

Decker, Michael

Access control is concerned with determining which operations a particular user is allowed to perform on a particular electronic resource. For example, an access control decision could say that user Alice is allowed to perform the operation read (but not write) on the resource research report. With conventional access control this decision is based on the user's identity whereas the basic idea of Location-Aware Access Control (LAAC) is to evaluate also a user's current location when making the decision if a particular request should be granted or denied. LAAC is an interesting approach for mobile information systems because these systems are exposed to specific security threads like the loss of a device. Some data models for LAAC can be found in literature, but almost all of them are based on RBAC and none of them is designed especially for Database Management Systems (DBMS). In this paper we therefore propose a LAAC-approach for DMBS and describe a prototypical implementation of that approach that is based on database triggers.

Miniature Transportable Communications Central (MTCC): answering law enforcement needs for worldwide access to command, control, communications, and intelligence (C3I)

Science.gov (United States)

Maxey, W. John

1997-02-01

The Mini-Transportable Communications Central (MTCC), developed by Rome Laboratories C3 Directorate, provides the U.S. Coast Guard (USCG) with a transportable, fast reaction communications terminal. The MTCC is capable of operating as a self-contained miniature command center supporting efforts such as the President's War on Drugs, or the rescue services necessary in the wake of man-made or natural disasters. The MTCC is capable of communicating with field elements including ships, small water-craft, aircraft, other elements of the USCG law enforcement agencies (LEAs), the FAA, and a wide range of U.S. and foreign armed forces. The MTCC terminal is contained in a trailer-mounted shelter suitable for towing by a 3/4 ton truck or for transport by C-130 aircraft. The MTCC provides simultaneous one-way and two-way communications in the HF, VHF, and UHF frequency bands, as well as the INMARSAT international satellite band. The MTCC also offers communications through subscriber and trunk telephone connectivity via ISDN compatible PABX. The MTCC's three channel operations personnel cellular telephone system provides self-contained cellular telephone operations in the vicinity of the deployed shelter. In the USCG application, an operator console inside the air-conditioned shelter serves as the source and destination for voice, data, and fax traffic, by means of secure fax telephone, operator headsets, and a powerful computer workstation that provides word processing, e-mail, and data communications capabilities. The communications operator may reconfigure the system for a specific mission by means of patchfields that enable the selection of radios, encrypted or clear-text operations, audio termination, and antennas.

Semi-quantum communication: protocols for key agreement, controlled secure direct communication and dialogue

Science.gov (United States)

Shukla, Chitra; Thapliyal, Kishore; Pathak, Anirban

2017-12-01

Semi-quantum protocols that allow some of the users to remain classical are proposed for a large class of problems associated with secure communication and secure multiparty computation. Specifically, first-time semi-quantum protocols are proposed for key agreement, controlled deterministic secure communication and dialogue, and it is shown that the semi-quantum protocols for controlled deterministic secure communication and dialogue can be reduced to semi-quantum protocols for e-commerce and private comparison (socialist millionaire problem), respectively. Complementing with the earlier proposed semi-quantum schemes for key distribution, secret sharing and deterministic secure communication, set of schemes proposed here and subsequent discussions have established that almost every secure communication and computation tasks that can be performed using fully quantum protocols can also be performed in semi-quantum manner. Some of the proposed schemes are completely orthogonal-state-based, and thus, fundamentally different from the existing semi-quantum schemes that are conjugate coding-based. Security, efficiency and applicability of the proposed schemes have been discussed with appropriate importance.

Communication Needs Assessment for Distributed Turbine Engine Control

Science.gov (United States)

Culley, Dennis E.; Behbahani, Alireza R.

2008-01-01

Control system architecture is a major contributor to future propulsion engine performance enhancement and life cycle cost reduction. The control system architecture can be a means to effect net weight reduction in future engine systems, provide a streamlined approach to system design and implementation, and enable new opportunities for performance optimization and increased awareness about system health. The transition from a centralized, point-to-point analog control topology to a modular, networked, distributed system is paramount to extracting these system improvements. However, distributed engine control systems are only possible through the successful design and implementation of a suitable communication system. In a networked system, understanding the data flow between control elements is a fundamental requirement for specifying the communication architecture which, itself, is dependent on the functional capability of electronics in the engine environment. This paper presents an assessment of the communication needs for distributed control using strawman designs and relates how system design decisions relate to overall goals as we progress from the baseline centralized architecture, through partially distributed and fully distributed control systems.

Development of an access control system for the LHD experimental hall

International Nuclear Information System (INIS)

Kawano, T.; Inoue, N.; Sakuma, Y.; Uda, T.; Yamanishi, H.; Miyake, H.; Tanahashi, S.; Motozima, O.

2000-01-01

An access control system for the LHD (Large Helical Device) experimental hall had been constructed and its practical operation started in March 1998. Continuously, the system has been improved. The present system keeps watch on involved entrance and exit for the use of persons at four entrances by using five turnstile gates while watching on eight shielding doors at eight positions (four entrances, three carriage entrances and a hall overview) and a stairway connecting the LHD main hall with the LHD basement. Besides, for the security of safety operation of the LHD, fifteen kinds of interlock signals are exchanged between the access control system and the LHD control system. Seven of the interlock signals are properly sent as the occasional demands from the access control system to the LHD control system, in which three staple signals are B Personnel Access to Controlled Area, D Shielding Door Closed, and E No Entrance. It is important that any plasma experiments of the LHD are not permitted while the signal B being sent or D being not sent. The signal E is sent to inform the LHD control system that the turnstile gates are locked. All the plasma experiments should not be done unless the lock procedure of the turnstile is confirmed. When the turnstile gates are locked, any persons cannot enter into the LHD controlled area, but are permissible to exit only. Six of the interlock signals are used to send the information of the working at that time in the LHD controlled area to the access control system. When one signal of the operation mode is sent to the access control system from the LHD, the access control system sets the turnstile gate in situation corresponding to the operation mode, A Equipment Operation, B Vacuum Pumping, C Coil Cooling, D Coil Excitation, and E Plasma Experiment. If the access control system receives, for example, the signal B, this system sets the turnstile gate in the condition of control such that only persons assigned to the work of vacuum

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

Communication and control tools, systems, and new dimensions

CERN Document Server

MacDougall, Robert; Cummings, Kevin

2015-01-01

Communication and Control: Tools, Systems, and New Dimensions advocates a systems view of human communication in a time of intelligent, learning machines. This edited collection sheds new light on things as mundane yet still profoundly consequential (and seemingly "low-tech") today as push buttons, pagers and telemarketing systems. Contributors also investigate aspects of "remote control" related to education, organizational design, artificial intelligence, cyberwarfa

An Extended Role Based Access Control Method for XML Documents

Institute of Scientific and Technical Information of China (English)

MENG Xiao-feng; LUO Dao-feng; OU Jian-bo

2004-01-01

As XML has been increasingly important as the Data-change format of Internet and Intranet, access-control-on-XML-properties rises as a new issue.Role-based access control (RBAC) is an access control method that has been widely used in Internet, Operation System and Relation Data Base these 10 years.Though RBAC is already relatively mature in the above fields, new problems occur when it is used in XML properties.This paper proposes an integrated model to resolve these problems, after the fully analysis on the features of XML and RBAC.

[Access to health care in Dakar (Senegal): frequency, type of provider, and non-communicable chronic diseases].

Science.gov (United States)

Duboz, P; Gueye, L; Boetsch, G; Macia, E

2015-01-01

(1) To describe access to health care in the population of Dakar; (2) to analyze the influence of socioeconomic and demographic characteristics on access to health care; (3) and to describe the fraction of consultations accounted for by chronic non-communicable diseases. These data come from a 2009 survey of 600 individuals aged 20 years and over. Socioeconomic and demographic characteristics and information about access to health care were collected. Chi-square tests and binary logistic regressions were used for the statistical analyses. Men, people with no schooling, and poor people were underrepresented among users of health care services. Moreover, the majority of Dakar residents who sought health care during the year preceding the survey went to see a doctor (as opposed to a traditional healer, pharmacist, nurse, midwife, or dentist). Finally, chronic diseases accounted for the smallest fraction of reasons for medical consultations; they were mentioned most often by those aged 50 years or older who consult more than 5 times a year. Dakar residents have an access to health care similar to that of people in other African countries, but this conclusion hides major inequalities. Moreover, at the same time that Senegal is undergoing an epidemiological transition, chronic non-communicable diseases are not a major reason for consultations. The epidemiological projections made for Africa for the next 15 years indicate that the development of strategies to avert the development of these diseases in Senegal must be a priority objective.

Advanced Data Communications for Downhole Data Logging and Control Applications in the Oil Industry

International Nuclear Information System (INIS)

Spracklen, C T; Aslam, Tariq

2013-01-01

We present details of 'Mercury', a high-speed downhole communications system that utilizes the (metallic) wall of a gas or oil pipeline or a drill 'string' as the communications 'channel' to control or monitor equipment or sensors used in the oil industry. Conventional downhole communication systems typically use 'mud pulse' telemetry for 'Measurement While Drilling' (MWD) operations. Current mud pulse telemetry technology offers bandwidths of up to 40 bit/s. However the data rate drops with increasing length of the wellbore and is typically as low as 1.5 bit/s – 3.0 bit/s at a depth of 35,000 ft. – 40,000 ft. The system described, by contrast, offers data rates of several megabits per second over distances of many kilometres and uses Orthogonal Frequency Division Multiplexing (OFDM) coupled with Wideband Frequency Division Multiple Access (W-CDMA). This paper presents details of our system; results of several trials undertaken on actual gas pipelines in the UK will be presented at the Conference

Information and communication technology platforms deployment: Technology access reaches South African rural areas

CSIR Research Space (South Africa)

Foko, TF

2017-05-01

Full Text Available though these Platforms were intended to provide unsupervised and unstructured form of learning. Fig. 1: Map showing the sites of deployed ICT Platform 2. Objectives The container Platform project rolled out ICT Platforms for the following purposes...: (i) As information and communication resources; (ii) As learning centres; (iii) As access points to ICTs; (iv) As practical tools for development; and (v) As a tool for bridging the digital Divide. Therefore, the purpose of this paper...

A Secure and Scalable Data Communication Scheme in Smart Grids

Directory of Open Access Journals (Sweden)

Chunqiang Hu

2018-01-01

Full Text Available The concept of smart grid gained tremendous attention among researchers and utility providers in recent years. How to establish a secure communication among smart meters, utility companies, and the service providers is a challenging issue. In this paper, we present a communication architecture for smart grids and propose a scheme to guarantee the security and privacy of data communications among smart meters, utility companies, and data repositories by employing decentralized attribute based encryption. The architecture is highly scalable, which employs an access control Linear Secret Sharing Scheme (LSSS matrix to achieve a role-based access control. The security analysis demonstrated that the scheme ensures security and privacy. The performance analysis shows that the scheme is efficient in terms of computational cost.

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.

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.

AAL Platform with a “De Facto” Standard Communication Interface (TICO): Training in Home Control in Special Education

Science.gov (United States)

Guillomía San Bartolomé, Miguel A.; Artigas Maestre, José Ignacio; Sánchez Agustín, Ana

2017-01-01

Framed within a long-term cooperation between university and special education teachers, training in alternative communication skills and home control was realized using the “TICO” interface, a communication panel editor extensively used in special education schools. From a technological view we follow AAL technology trends by integrating a successful interface in a heterogeneous services AAL platform, focusing on a functional view. Educationally, a very flexible interface in line with communication training allows dynamic adjustment of complexity, enhanced by an accessible mindset and virtual elements significance already in use, offers specific interaction feedback, adapts to the evolving needs and capacities and improves the personal autonomy and self-confidence of children at school and home. TICO-home-control was installed during the last school year in the library of a special education school to study adaptations and training strategies to enhance the autonomy opportunities of its pupils. The methodology involved a case study and structured and semi-structured observations. Five children, considered unable to use commercial home control systems were trained obtaining good results in enabling them to use an open home control system. Moreover this AAL platform has proved efficient in training children in previous cognitive steps like virtual representation and cause-effect interaction. PMID:29023383

AAL Platform with a “De Facto” Standard Communication Interface (TICO: Training in Home Control in Special Education

Directory of Open Access Journals (Sweden)

Miguel A. Guillomía San Bartolomé

2017-10-01

Full Text Available Framed within a long-term cooperation between university and special education teachers, training in alternative communication skills and home control was realized using the “TICO” interface, a communication panel editor extensively used in special education schools. From a technological view we follow AAL technology trends by integrating a successful interface in a heterogeneous services AAL platform, focusing on a functional view. Educationally, a very flexible interface in line with communication training allows dynamic adjustment of complexity, enhanced by an accessible mindset and virtual elements significance already in use, offers specific interaction feedback, adapts to the evolving needs and capacities and improves the personal autonomy and self-confidence of children at school and home. TICO-home-control was installed during the last school year in the library of a special education school to study adaptations and training strategies to enhance the autonomy opportunities of its pupils. The methodology involved a case study and structured and semi-structured observations. Five children, considered unable to use commercial home control systems were trained obtaining good results in enabling them to use an open home control system. Moreover this AAL platform has proved efficient in training children in previous cognitive steps like virtual representation and cause-effect interaction.

Local-area communication networks - An overview

International Nuclear Information System (INIS)

Kuemmerle, K.

1982-01-01

Local-area communication networks represent a new field of activity. In this paper we first describe three scenarios for the use of these networks, and then discuss various technical approaches. Particular emphasis is put on bus and ring systems with various media access control mechanisms. Specifically, we compare the delay-throughput characteristic of two access methods, carrier-sense multiple access with collision detection and token passing, and discuss some significant differences of bus and ring systems concerning wiring, media, transmission, and reliability. (orig.)

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.

Regulatory accessibility and social influences on state self-control.

Science.gov (United States)

vanDellen, Michelle R; Hoyle, Rick H

2010-02-01

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-control leads to increases in state self-control and thinking of others with bad trait or state self-control leads to decreases in state self-control. Study 5 provides evidence that the salience of significant others influences both regulatory accessibility and state self-control. Combined, these studies suggest that the effects of social influences on state self-control occur through multiple mechanisms.

Ad Hoc Access Gateway Selection Algorithm

Science.gov (United States)

Jie, Liu

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

Content dependent information flow control

DEFF Research Database (Denmark)

Nielson, Hanne Riis; Nielson, Flemming

2017-01-01

Information flow control extends access control by not only regulating who is allowed to access what data but also the subsequent use of the data. Applications within communications systems require such information flow control to be dependent on the actual contents of the data. We develop...

Object oriented programming techniques applied to device access and control

International Nuclear Information System (INIS)

Goetz, A.; Klotz, W.D.; Meyer, J.

1992-01-01

In this paper a model, called the device server model, has been presented for solving the problem of device access and control faced by all control systems. Object Oriented Programming techniques were used to achieve a powerful yet flexible solution. The model provides a solution to the problem which hides device dependancies. It defines a software framework which has to be respected by implementors of device classes - this is very useful for developing groupware. The decision to implement remote access in the root class means that device servers can be easily integrated in a distributed control system. A lot of the advantages and features of the device server model are due to the adoption of OOP techniques. The main conclusion that can be drawn from this paper is that 1. the device access and control problem is adapted to being solved with OOP techniques, 2. OOP techniques offer a distinct advantage over traditional programming techniques for solving the device access problem. (J.P.N.)

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.

Demand management through centralized control system using power line communication for existing buildings

International Nuclear Information System (INIS)

Al-Mulla, A.; ElSherbini, A.

2014-01-01

Highlights: • A pilot system was developed for demand management of equipment in buildings. • The networking was based on LonWorks platform and power line communication. • Demand strategies led to load reductions up to 74% and energy savings up to 25%. • The peak load reduction is expected to reach 3.44 GW by the year 2030. - Abstract: Managing peak demand efficiently is vital for maintaining uninterrupted supply of electrical power by utility providers. In this work, a pilot system was developed for managing and controlling the demand of major power consuming equipment in buildings from a central server, while relying mostly on existing infrastructure and maintaining consumer comfort. The system was successfully demonstrated on a selected group of buildings using the LonWorks networking platform. At the building level, the system utilized power line and twisted pair communication to control the thermostats of air-conditioning (A/C) units. The higher level communication was executed through extensible markup language (XML) and simple object access protocol (SOAP). The system provided control capabilities based on A/C unit priority, thermostat temperature, building type and geographic location. The development and execution of demand management strategies for selected buildings led to peak load reductions up to 74%, in addition to energy savings up to 25%. Implementing such a system at a national level in Kuwait is estimated to reduce peak demand by 3.44 GW, amounting to capital savings of $4.13 billion. The use of existing infrastructure reduced the cost and installation time of the system. Based on the successful testing of this pilot system, a larger-scale system is being developed

A New Key-lock Method for User Authentication and Access Control

Institute of Scientific and Technical Information of China (English)

JI Dongyao; ZHANG Futai; WANG Yumin

2001-01-01

We propose a new key-lock methodfor user authentication and access control based onChinese remainder theorem, the concepts of the ac-cess control matrix, key-lock-pair, time stamp, and the NS public key protocol. Our method is dynamicand needs a minimum amount of computation in thesense that it only updates at most one key/lock foreach access request. We also demonstrate how an au-thentication protocol can be integrated into the ac-cess control method. By applying a time stamp, themethod can not only withstand replay attack, butalso strengthen the authenticating mechanism, whichcould not be achieved simultaneously in previous key-lock methods.

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.

A General Attribute and Rule Based Role-Based Access Control Model

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Growing numbers of users and many access control policies which involve many different resource attributes in service-oriented environments bring various problems in protecting resource. This paper analyzes the relationships of resource attributes to user attributes in all policies, and propose a general attribute and rule based role-based access control(GAR-RBAC) model to meet the security needs. The model can dynamically assign users to roles via rules to meet the need of growing numbers of users. These rules use different attribute expression and permission as a part of authorization constraints, and are defined by analyzing relations of resource attributes to user attributes in many access policies that are defined by the enterprise. The model is a general access control model, and can support many access control policies, and also can be used to wider application for service. The paper also describes how to use the GAR-RBAC model in Web service environments.

I/O Standard Based Thermal/Energy Efficient Green Communication For Wi-Fi Protected Access on FPGA

DEFF Research Database (Denmark)

Kumar, Tanesh; Pandey, Bishwajeet; Das, Teerath

2014-01-01

In this paper, we analyzed how does life and reliability of an integrated circuit is affected when it is operated in different regions under different temperatures. We have taken Fibonacci generator as our target circuit and LVCMOS as I/O standards. WPA and WPA2 (Wi-Fi Protected Access) key can...... be generated with Fibonacci generator. Here, thermal efficient green Fibonacci Generator is used to generate key for Wi-Fi Protected Access in order to make green communication possible under different room temperature. By analysis it is observed that at standard normal temperature (21degrees C), LVCMOS12 have...

Broadband wireless communications for railway applications for onboard internet access and other applications

CERN Document Server

Masson, Émilie

2017-01-01

This book focuses on the needs of railway operators in terms of wireless communications, divided in two main categories: the commercial services and the operational needs. Then, all available technologies that can be used to provide Internet access on board trains and all the other operational applications requiring high capacity are detailed. Finally, challenges and trends in railway telecommunications are highlighted, through the presentation of the future and emerging technologies, the current discussions and works in the different authorities, and the key challenges and scientific barriers.

Implementing Discretionary Access Control with Time Character in Linux and Performance Analysis

Institute of Scientific and Technical Information of China (English)

TAN Liang; ZHOU Ming-Tian

2006-01-01

DAC (Discretionary Access Control Policy) is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T (Discretionary Access Control Policy with Time Character) is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC (General Framework for Access Control), and the algorithm is put forward. Finally, the performance analysis for the DAC_T_Linux is carried out. It is proved that the DAC_T_Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.

Access and control of information and intellectual property

Science.gov (United States)

Lang, Gerald S.

1996-03-01

This paper introduces the technology of two pioneering patents for the secure distribution of information and intellectual property. The seminal technology has been used in the control of sensitive material such as medical records and imagery in distributed networks. It lends itself to the implementation of an open architecture access control system that provides local or remote user selective access to digital information stored on any computer system or storage medium, down to the data element, pixel, and sub-pixel levels. Use of this technology is especially suited for electronic publishing, health care records, MIS, and auditing.

Spatiotemporal Access Model Based on Reputation for the Sensing Layer of the IoT

Directory of Open Access Journals (Sweden)

Yunchuan Guo

2014-01-01

Full Text Available Access control is a key technology in providing security in the Internet of Things (IoT. The mainstream security approach proposed for the sensing layer of the IoT concentrates only on authentication while ignoring the more general models. Unreliable communications and resource constraints make the traditional access control techniques barely meet the requirements of the sensing layer of the IoT. In this paper, we propose a model that combines space and time with reputation to control access to the information within the sensing layer of the IoT. This model is called spatiotemporal access control based on reputation (STRAC. STRAC uses a lattice-based approach to decrease the size of policy bases. To solve the problem caused by unreliable communications, we propose both nondeterministic authorizations and stochastic authorizations. To more precisely manage the reputation of nodes, we propose two new mechanisms to update the reputation of nodes. These new approaches are the authority-based update mechanism (AUM and the election-based update mechanism (EUM. We show how the model checker UPPAAL can be used to analyze the spatiotemporal access control model of an application. Finally, we also implement a prototype system to demonstrate the efficiency of our model.

Spatiotemporal access model based on reputation for the sensing layer of the IoT.

Science.gov (United States)

Guo, Yunchuan; Yin, Lihua; Li, Chao; Qian, Junyan

2014-01-01

Access control is a key technology in providing security in the Internet of Things (IoT). The mainstream security approach proposed for the sensing layer of the IoT concentrates only on authentication while ignoring the more general models. Unreliable communications and resource constraints make the traditional access control techniques barely meet the requirements of the sensing layer of the IoT. In this paper, we propose a model that combines space and time with reputation to control access to the information within the sensing layer of the IoT. This model is called spatiotemporal access control based on reputation (STRAC). STRAC uses a lattice-based approach to decrease the size of policy bases. To solve the problem caused by unreliable communications, we propose both nondeterministic authorizations and stochastic authorizations. To more precisely manage the reputation of nodes, we propose two new mechanisms to update the reputation of nodes. These new approaches are the authority-based update mechanism (AUM) and the election-based update mechanism (EUM). We show how the model checker UPPAAL can be used to analyze the spatiotemporal access control model of an application. Finally, we also implement a prototype system to demonstrate the efficiency of our model.

Controlled and secure direct communication using GHZ state and teleportation

International Nuclear Information System (INIS)

Gao, T.

2004-01-01

A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), alice encodes the secret message directly on a sequence of particle states in the GHZ state and transmits them to Bob, supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on his qubits. In this scheme, the controlled quantum teleportation transmits alice's message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret messages between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if a perfect quantum channel is used. The feature of this scheme is that the communication between two sides depends on the agreement of a third side. (orig.)

Minimizing communication cost among distributed controllers in software defined networks

Science.gov (United States)

Arlimatti, Shivaleela; Elbreiki, Walid; Hassan, Suhaidi; Habbal, Adib; Elshaikh, Mohamed

2016-08-01

Software Defined Networking (SDN) is a new paradigm to increase the flexibility of today's network by promising for a programmable network. The fundamental idea behind this new architecture is to simplify network complexity by decoupling control plane and data plane of the network devices, and by making the control plane centralized. Recently controllers have distributed to solve the problem of single point of failure, and to increase scalability and flexibility during workload distribution. Even though, controllers are flexible and scalable to accommodate more number of network switches, yet the problem of intercommunication cost between distributed controllers is still challenging issue in the Software Defined Network environment. This paper, aims to fill the gap by proposing a new mechanism, which minimizes intercommunication cost with graph partitioning algorithm, an NP hard problem. The methodology proposed in this paper is, swapping of network elements between controller domains to minimize communication cost by calculating communication gain. The swapping of elements minimizes inter and intra communication cost among network domains. We validate our work with the OMNeT++ simulation environment tool. Simulation results show that the proposed mechanism minimizes the inter domain communication cost among controllers compared to traditional distributed controllers.

Smart Control of Energy Distribution Grids over Heterogeneous Communication Networks

DEFF Research Database (Denmark)

Schwefel, Hans-Peter; Silva, Nuno; Olsen, Rasmus Løvenstein

2018-01-01

Off-the shelf wireless communication technologies reduce infrastructure deployment costs and are thus attractive for distribution system control. Wireless communication however may lead to variable network performance. Hence the impact of this variability on overall distribution system control be...

Hopping control channel MAC protocol for opportunistic spectrum access networks

Institute of Scientific and Technical Information of China (English)

FU Jing-tuan; JI Hong; MAO Xu

2010-01-01

Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

High-speed narrowband PLC - High-performance Access Powerline Communication structures in smart grid; High-Speed Narrowband PLC. Leistungsfaehige Access-Powerline-Kommunikationsstrukturen im Smart Grid

Energy Technology Data Exchange (ETDEWEB)

Offner, Georg [devolo AG, Aachen (Germany)

2012-07-01

The smart grid provides a stable operation of a decentralized power system which is fed more and more by small providers by means of solar technology and wind power technology. Furthermore, commercial and private clients profit from the smart grid, as they may capture information about their current consumption in real time or can obtain these data from the Internet. The author of the contribution under consideration presents new approaches to access powerline communications that enable efficient communication between IPv6 based household meter and network station. The contribution under consideration describes the technologies used as well as practical experiences and initial results from field tests. Here insights from the integration of G3-PLC are in the foreground.

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.

46 CFR 122.320 - Steering gear, controls, and communication system tests.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for a...

Implementation of emergency department transfer communication measures in Minnesota critical access hospitals.

Science.gov (United States)

Klingner, Jill; Moscovice, Ira; Casey, Michelle; McEllistrem Evenson, Alex

2015-01-01

Previously published findings based on field tests indicated that emergency department patient transfer communication measures are feasible and worthwhile to implement in rural hospitals. This study aims to expand those findings by focusing on the wide-scale implementation of these measures in the 79 Critical Access Hospitals (CAHs) in Minnesota from 2011 to 2013. Information was obtained from interviews with key informants involved in implementing the emergency department patient transfer communication measures in Minnesota as part of required statewide quality reporting. The first set of interviews targeted state-level organizations regarding their experiences working with providers. A second set of interviews targeted quality and administrative staff from CAHs regarding their experiences implementing measures. Implementing the measures in Minnesota CAHs proved to be successful in a number of respects, but informants also faced new challenges. Our recommendations, addressed to those seeking to successfully implement these measures in other states, take these challenges into account. Field-testing new quality measure implementations with volunteers may not be indicative of a full-scale implementation that requires facilities to participate. The implementation team's composition, communication efforts, prior relationships with facilities and providers, and experience with data collection and abstraction tools are critical factors in successfully implementing required reporting of quality measures on a wide scale. © 2014 National Rural Health Association.

Human engineering considerations in designing a computerized controlled access security system

International Nuclear Information System (INIS)

Moore, J.W.; Banks, W.W.

1988-01-01

This paper describes a human engineering effort in the design of a major security system upgrade at Lawrence Livermore National Laboratory. This upgrade was to be accomplished by replacing obsolete and difficult-to-man (i.e., multiple operator task actions required) security equipment and systems with a new, automated, computer-based access control system. The initial task was to assist the electronic and mechanical engineering staff in designing a computerized security access system too functionally and ergonomically accommodate 100% of the Laboratory user population. The new computerized access system was intended to control entry into sensitive exclusion areas by requiring personnel to use an entry booth-based system and/or a remote access control panel system. The primary user interface with the system was through a control panel containing a magnetic card reader, function buttons, LCD display, and push-button keypad

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

Science.gov (United States)

2010-01-26

... 3235-AK53 Risk Management Controls for Brokers or Dealers With Market Access AGENCY: Securities and... or other persons, to implement risk management controls and supervisory procedures reasonably... access may not utilize any pre-trade risk management controls (i.e., ``unfiltered'' or ``naked'' access...

Authenticated IGMP for Controlling Access to Multicast Distribution Tree

Science.gov (United States)

Park, Chang-Seop; Kang, Hyun-Sun

A receiver access control scheme is proposed to protect the multicast distribution tree from DoS attack induced by unauthorized use of IGMP, by extending the security-related functionality of IGMP. Based on a specific network and business model adopted for commercial deployment of IP multicast applications, a key management scheme is also presented for bootstrapping the proposed access control as well as accounting and billing for CP (Content Provider), NSP (Network Service Provider), and group members.

Scholarly Publishing's Evolving Landscape: Impact Metrics, Electronic-Only Journals, and Open Access in Journalism and Communication Research

Science.gov (United States)

Antell, Karen; Foote, Joe S.; Foote, Jody Bales

2016-01-01

This study surveys the landscape of scholarly publishing, with particular emphasis on scholarly journals in the communication discipline, measuring the shift to electronic publishing in six selected disciplines and exploring two other important emerging topics: open-access publishing and new journal citation metrics. The goals are to inform…

Design & Test of Radio Communication and Control System for Aquaculture

Directory of Open Access Journals (Sweden)

Fengrong Jia

2013-05-01

Full Text Available Aiming at low automation degree and backward aquatic product management of current aquaculture in China, this paper designed a set of radio communication and control system which consists of 3 parts of information collection module, control module and radio communication module. This system both realizes wireless monitoring of quality parameters of water for aquaculture and realizes wireless control of water level and dissolved oxygen value through radio communication. Test results show that data transfer is more accurate and reliable after adding customized protocol and answer signals in radio communication. The highest error and missing rate within 1000 m is 0.36, the lowest error and missing rate is 0.05 and the longest response time is 49 ms. The dissolved oxygen value detection system designed in this paper is close to the testing value of existing dissolved oxygen value transmitter DO6309. With wireless data transfer mode, it has higher practicality. The wireless control of dissolved oxygen value and water level can be controlled within the appropriate range with stable and precise control. The study results can provide intelligent aquaculture model with simple operation and precise control for enormous aquatic breeders

A new method for chaos control in communication systems

International Nuclear Information System (INIS)

Lin, S.-L.; Tung, P.-C.

2009-01-01

With the increasing needs of global communication, the improvement of secure communication is of vital importance. This study proposes a new scheme for establishing secure communication systems. The new scheme separates white Gaussian noises from the chaotic signals with modified Independent Component Analysis (ICA) and then controls each chaotic signal. This scheme is able to deal with white Gaussian noises in the natural world. However, the signals separated by traditional ICA shows opposite phase and unequal amplitude, making chaos control impossible. Our study proposed a modified ICA, which can calculate accurately the phase and amplitude and ensure control of the chaotic systems. The result indicates that our proposed system can successfully separate white Gaussian noise and stabilize all the chaotic signals.

Test-bed Assessment of Communication Technologies for a Power-Balancing Controller

DEFF Research Database (Denmark)

Findrik, Mislav; Pedersen, Rasmus; Hasenleithner, Eduard

2016-01-01

and control. In this paper, we present a Smart Grid test-bed that integrates various communication technologies and deploys a power balancing controller for LV grids. Control performance of the introduced power balancing controller is subsequently investigated and its robustness to communication network cross......Due to growing need for sustainable energy, increasing number of different renewable energy resources are being connected into distribution grids. In order to efficiently manage a decentralized power generation units, the smart grid will rely on communication networks for information exchange...

Role-Based Access Control in Retrospect

NARCIS (Netherlands)

Nunes Leal Franqueira, V.; Wieringa, Roelf J.

Role-Based Access Control (RBAC) has been a success in terms of the amount of research that went into it, its uptake in international standards, and its adoption by major software vendors. Yet, RBAC remains complex to implement in user organizations. In this paper we review the state of the art of

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...

Requirements for Scalable Access Control and Security Management Architectures

National Research Council Canada - National Science Library

Keromytis, Angelos D; Smith, Jonathan M

2005-01-01

Maximizing local autonomy has led to a scalable Internet. Scalability and the capacity for distributed control have unfortunately not extended well to resource access control policies and mechanisms...

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…

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.

Database design for Physical Access Control System for nuclear facilities

International Nuclear Information System (INIS)

Sathishkumar, T.; Rao, G. Prabhakara; Arumugam, P.

2016-01-01

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.

Decentralized Control of Unmanned Aerial Robots for Wireless Airborne Communication Networks

Directory of Open Access Journals (Sweden)

Deok-Jin Lee

2010-09-01

Full Text Available This paper presents a cooperative control strategy for a team of aerial robotic vehicles to establish wireless airborne communication networks between distributed heterogeneous vehicles. Each aerial robot serves as a flying mobile sensor performing a reconfigurable communication relay node which enabls communication networks with static or slow-moving nodes on gorund or ocean. For distributed optimal deployment of the aerial vehicles for communication networks, an adaptive hill-climbing type decentralized control algorithm is developed to seek out local extremum for optimal localization of the vehicles. The sensor networks estabilished by the decentralized cooperative control approach can adopt its configuraiton in response to signal strength as the function of the relative distance between the autonomous aerial robots and distributed sensor nodes in the sensed environment. Simulation studies are conducted to evaluate the effectiveness of the proposed decentralized cooperative control technique for robust communication networks.

The integration of open access journals in the scholarly communication system: Three science fields

DEFF Research Database (Denmark)

Faber Frandsen, Tove

2009-01-01

across disciplines. This study is an analysis of the citing behaviour in journals within three science fields: biology, mathematics, and pharmacy and pharmacology. It is a statistical analysis of OAJs as well as non-OAJs including both the citing and cited side of the journal to journal citations......The greatest number of open access journals (OAJs) is found in the sciences and their influence is growing. However, there are only a few studies on the acceptance and thereby integration of these OAJs in the scholarly communication system. Even fewer studies provide insight into the differences....... The multivariate linear regression reveals many similarities in citing behaviour across fields and media. But it also points to great differences in the integration of OAJs. The integration of OAJs in the scholarly communication system varies considerably across fields. The implications for bibliometric research...

Concentration of Access to Information and Communication Technologies in the Municipalities of the Brazilian Legal Amazon.

Directory of Open Access Journals (Sweden)

Silvana Rossy de Brito

Full Text Available This study fills demand for data on access and use of information and communication technologies (ICT in the Brazilian legal Amazon, a region of localities with identical economic, political, and social problems. We use the 2010 Brazilian Demographic Census to compile data on urban and rural households (i with computers and Internet access, (ii with mobile phones, and (iii with fixed phones. To compare the concentration of access to ICT in the municipalities of the Brazilian Amazon with other regions of Brazil, we use a concentration index to quantify the concentration of households in the following classes: with computers and Internet access, with mobile phones, with fixed phones, and no access. These data are analyzed along with municipal indicators on income, education, electricity, and population size. The results show that for urban households, the average concentration in the municipalities of the Amazon for computers and Internet access and for fixed phones is lower than in other regions of the country; meanwhile, that for no access and mobile phones is higher than in any other region. For rural households, the average concentration in the municipalities of the Amazon for computers and Internet access, mobile phones, and fixed phones is lower than in any other region of the country; meanwhile, that for no access is higher than in any other region. In addition, the study shows that education and income are determinants of inequality in accessing ICT in Brazilian municipalities and that the existence of electricity in rural households is directly associated with the ownership of ICT resources.

Concentration of Access to Information and Communication Technologies in the Municipalities of the Brazilian Legal Amazon.

Science.gov (United States)

de Brito, Silvana Rossy; da Silva, Aleksandra do Socorro; Cruz, Adejard Gaia; Monteiro, Maurílio de Abreu; Vijaykumar, Nandamudi Lankalapalli; da Silva, Marcelino Silva; Costa, João Crisóstomo Weyl Albuquerque; Francês, Carlos Renato Lisboa

2016-01-01

This study fills demand for data on access and use of information and communication technologies (ICT) in the Brazilian legal Amazon, a region of localities with identical economic, political, and social problems. We use the 2010 Brazilian Demographic Census to compile data on urban and rural households (i) with computers and Internet access, (ii) with mobile phones, and (iii) with fixed phones. To compare the concentration of access to ICT in the municipalities of the Brazilian Amazon with other regions of Brazil, we use a concentration index to quantify the concentration of households in the following classes: with computers and Internet access, with mobile phones, with fixed phones, and no access. These data are analyzed along with municipal indicators on income, education, electricity, and population size. The results show that for urban households, the average concentration in the municipalities of the Amazon for computers and Internet access and for fixed phones is lower than in other regions of the country; meanwhile, that for no access and mobile phones is higher than in any other region. For rural households, the average concentration in the municipalities of the Amazon for computers and Internet access, mobile phones, and fixed phones is lower than in any other region of the country; meanwhile, that for no access is higher than in any other region. In addition, the study shows that education and income are determinants of inequality in accessing ICT in Brazilian municipalities and that the existence of electricity in rural households is directly associated with the ownership of ICT resources.

A federated capability-based access control mechanism for internet of things (IoTs)

Science.gov (United States)

Xu, Ronghua; Chen, Yu; Blasch, Erik; Chen, Genshe

2018-05-01

The prevalence of Internet of Things (IoTs) allows heterogeneous embedded smart devices to collaboratively provide intelligent services with or without human intervention. While leveraging the large-scale IoT-based applications like Smart Gird and Smart Cities, IoT also incurs more concerns on privacy and security. Among the top security challenges that IoTs face is that access authorization is critical in resource and information protection over IoTs. Traditional access control approaches, like Access Control Lists (ACL), Role-based Access Control (RBAC) and Attribute-based Access Control (ABAC), are not able to provide a scalable, manageable and efficient mechanisms to meet requirement of IoT systems. The extraordinary large number of nodes, heterogeneity as well as dynamicity, necessitate more fine-grained, lightweight mechanisms for IoT devices. In this paper, a federated capability-based access control (FedCAC) framework is proposed to enable an effective access control processes to devices, services and information in large scale IoT systems. The federated capability delegation mechanism, based on a propagation tree, is illustrated for access permission propagation. An identity-based capability token management strategy is presented, which involves registering, propagation and revocation of the access authorization. Through delegating centralized authorization decision-making policy to local domain delegator, the access authorization process is locally conducted on the service provider that integrates situational awareness (SAW) and customized contextual conditions. Implemented and tested on both resources-constrained devices, like smart sensors and Raspberry PI, and non-resource-constrained devices, like laptops and smart phones, our experimental results demonstrate the feasibility of the proposed FedCAC approach to offer a scalable, lightweight and fine-grained access control solution to IoT systems connected to a system network.

Control and estimation methods over communication networks

CERN Document Server

Mahmoud, Magdi S

2014-01-01

This book provides a rigorous framework in which to study problems in the analysis, stability and design of networked control systems. Four dominant sources of difficulty are considered: packet dropouts, communication bandwidth constraints, parametric uncertainty, and time delays. Past methods and results are reviewed from a contemporary perspective, present trends are examined, and future possibilities proposed. Emphasis is placed on robust and reliable design methods. New control strategies for improving the efficiency of sensor data processing and reducing associated time delay are presented. The coverage provided features: ·        an overall assessment of recent and current fault-tolerant control algorithms; ·        treatment of several issues arising at the junction of control and communications; ·        key concepts followed by their proofs and efficient computational methods for their implementation; and ·        simulation examples (including TrueTime simulations) to...

Reputation, relationships, risk communication, and the role of trust in the prevention and control of communicable disease: a review.

Science.gov (United States)

Cairns, Georgina; de Andrade, Marisa; MacDonald, Laura

2013-01-01

Population-level compliance with health protective behavioral advice to prevent and control communicable disease is essential to optimal effectiveness. Multiple factors affect perceptions of trustworthiness, and trust in advice providers is a significant predeterminant of compliance. While competency in assessment and management of communicable disease risks is critical, communications competency may be equally important. Organizational reputation, quality of stakeholder relationships and risk information provision strategies are trust moderating factors, whose impact is strongly influenced by the content, timing and coordination of communications. This article synthesizes the findings of 2 literature reviews on trust moderating communications and communicable disease prevention and control. We find a substantial evidence base on risk communication, but limited research on other trust building communications. We note that awareness of good practice historically has been limited although interest and the availability of supporting resources is growing. Good practice and policy elements are identified: recognition that crisis and risk communications require different strategies; preemptive dialogue and planning; evidence-based approaches to media relations and messaging; and building credibility for information sources. Priority areas for future research include process and cost-effectiveness evaluation and the development of frameworks that integrate communication and biomedical disease control and prevention functions, conceptually and at scale.

External access to ALICE controls conditions data

International Nuclear Information System (INIS)

Jadlovský, J; Jadlovská, A; Sarnovský, J; Jajčišin, Š; Čopík, M; Jadlovská, S; Papcun, P; Bielek, R; Čerkala, J; Kopčík, M; Chochula, P; Augustinus, A

2014-01-01

ALICE Controls data produced by commercial SCADA system WINCCOA is stored in ORACLE database on the private experiment network. The SCADA system allows for basic access and processing of the historical data. More advanced analysis requires tools like ROOT and needs therefore a separate access method to the archives. The present scenario expects that detector experts create simple WINCCOA scripts, which retrieves and stores data in a form usable for further studies. This relatively simple procedure generates a lot of administrative overhead – users have to request the data, experts needed to run the script, the results have to be exported outside of the experiment network. The new mechanism profits from database replica, which is running on the CERN campus network. Access to this database is not restricted and there is no risk of generating a heavy load affecting the operation of the experiment. The developed tools presented in this paper allow for access to this data. The users can use web-based tools to generate the requests, consisting of the data identifiers and period of time of interest. The administrators maintain full control over the data – an authorization and authentication mechanism helps to assign privileges to selected users and restrict access to certain groups of data. Advanced caching mechanism allows the user to profit from the presence of already processed data sets. This feature significantly reduces the time required for debugging as the retrieval of raw data can last tens of minutes. A highly configurable client allows for information retrieval bypassing the interactive interface. This method is for example used by ALICE Offline to extract operational conditions after a run is completed. Last but not least, the software can be easily adopted to any underlying database structure and is therefore not limited to WINCCOA.

29 CFR 1615.160 - Communications.

Science.gov (United States)

2010-07-01

... COMMISSION AND IN ACCESSIBILITY OF COMMISSION ELECTRONIC AND INFORMATION TECHNOLOGY § 1615.160 Communications... Commission communicates with applicants and beneficiaries by telephone, telecommunication devices for deaf... symbol for accessibility shall be used at each primary entrance of an accessible facility. (d) This...

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

2014-01-01

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. PMID:25123464

Communication Dependent Control of Multi-Vehicle Formations

Science.gov (United States)

2016-05-11

On Maximizing the Second Smallest Eigen- value of a State-Dependent Graph Laplacian,” IEEE Transactions on Au- tomatic Control, vol. 51, no. 1, pp...Collective Motion With Limited Communication,” IEEE Transactions on Au- tomatic Control, vol. 53, no. 3, pp. 706–719, 2008. [Online]. Available: http

A novel asynchronous access method with binary interfaces

Directory of Open Access Journals (Sweden)

Torres-Solis Jorge

2008-10-01

Full Text Available Abstract Background Traditionally synchronous access strategies require users to comply with one or more time constraints in order to communicate intent with a binary human-machine interface (e.g., mechanical, gestural or neural switches. Asynchronous access methods are preferable, but have not been used with binary interfaces in the control of devices that require more than two commands to be successfully operated. Methods We present the mathematical development and evaluation of a novel asynchronous access method that may be used to translate sporadic activations of binary interfaces into distinct outcomes for the control of devices requiring an arbitrary number of commands to be controlled. With this method, users are required to activate their interfaces only when the device under control behaves erroneously. Then, a recursive algorithm, incorporating contextual assumptions relevant to all possible outcomes, is used to obtain an informed estimate of user intention. We evaluate this method by simulating a control task requiring a series of target commands to be tracked by a model user. Results When compared to a random selection, the proposed asynchronous access method offers a significant reduction in the number of interface activations required from the user. Conclusion This novel access method offers a variety of advantages over traditionally synchronous access strategies and may be adapted to a wide variety of contexts, with primary relevance to applications involving direct object manipulation.

Optical label-controlled transparent metro-access network interface

DEFF Research Database (Denmark)

Osadchiy, Alexey Vladimirovich

This thesis presents results obtained during the course of my PhD research on optical signal routing and interfacing between the metropolitan and access segments of optical networks. Due to both increasing capacity demands and variety of emerging services types, new technological challenges...... control. Highlights of my research include my proposal and experimental proof of principle of an optical coherent detection based optical access network architecture providing support for a large number of users over a single distribution fiber; a spectral amplitude encoded label detection technique...... are arising for seamlessly interfacing metropolitan and access networks. Therefore, in this PhD project, I have analyzed those technological challenges and identified the key aspects to be addressed. I have also proposed and experimentally verified a number of solutions to metropolitan and access networks...

A multi-radio, multi-hop ad-hoc radio communication network for Communications-Based Train Control (CBTC): Introducing frequency separation for train-to-trackside communication

DEFF Research Database (Denmark)

Farooq, Jahanzeb; Bro, Lars; Karstensen, Rasmus Thystrup

2018-01-01

Communications-Based Train Control (CBTC) is a modern signalling system that uses radio communication to transfer train control information between train and wayside. The trackside networks in these systems are mostly based on conventionalinfrastructureWi-Fi(IEEE802.11).Itmeansatrain has to conti...

AN AUTOMATIC AND METHODOLOGICAL APPROACH FOR ACCESSIBLE WEB APPLICATIONS

Directory of Open Access Journals (Sweden)

Lourdes Moreno

2007-06-01

Full Text Available Semantic Web approaches try to get the interoperability and communication among technologies and organizations. Nevertheless, sometimes it is forgotten that the Web must be useful for every user, consequently it is necessary to include tools and techniques doing Semantic Web be accessible. Accessibility and usability are two usually joined concepts widely used in web application development, however their meaning are different. Usability means the way to make easy the use but accessibility is referred to the access possibility. For the first one, there are many well proved approaches in real cases. However, accessibility field requires a deeper research that will make feasible the access to disable people and also the access to novel non-disable people due to the cost to automate and maintain accessible applications. In this paper, we propose one architecture to achieve the accessibility in web-environments dealing with the WAI accessibility standard and the Universal Design paradigm. This architecture tries to control the accessibility in web applications development life-cycle following a methodology starting from a semantic conceptual model and leans on description languages and controlled vocabularies.

Optimizing data access in the LAMPF control system

International Nuclear Information System (INIS)

Schaller, S.C.; Corley, J.K.; Rose, P.A.

1985-01-01

The LAMPF control system data access software offers considerable power and flexibility to application programs through symbolic device naming and an emphasis on hardware independence. This paper discusses optimizations aimed at improving the performance of the data access software while retaining these capabilities. The only aspects of the optimizations visible to the application programs are ''vector devices'' and ''aggregate devices.'' A vector device accesses a set of hardware related data items through a single device name. Aggregate devices allow run-time optimization of references to groups of unrelated devices. Optimizations not visible on the application level include careful handling of: network message traffic; the sharing of global resources; and storage allocation

Policy reconciliation for access control in dynamic cross-enterprise collaborations

Science.gov (United States)

Preuveneers, D.; Joosen, W.; Ilie-Zudor, E.

2018-03-01

In dynamic cross-enterprise collaborations, different enterprises form a - possibly temporary - business relationship. To integrate their business processes, enterprises may need to grant each other limited access to their information systems. Authentication and authorization are key to secure information handling. However, access control policies often rely on non-standardized attributes to describe the roles and permissions of their employees which convolutes cross-organizational authorization when business relationships evolve quickly. Our framework addresses the managerial overhead of continuous updates to access control policies for enterprise information systems to accommodate disparate attribute usage. By inferring attribute relationships, our framework facilitates attribute and policy reconciliation, and automatically aligns dynamic entitlements during the evaluation of authorization decisions. We validate our framework with a Industry 4.0 motivating scenario on networked production where such dynamic cross-enterprise collaborations are quintessential. The evaluation reveals the capabilities and performance of our framework, and illustrates the feasibility of liberating the security administrator from manually provisioning and aligning attributes, and verifying the consistency of access control policies for cross-enterprise collaborations.

VCSEL-based gigabit IR-UWB link for converged communication and sensing applications in optical metro-access networks

DEFF Research Database (Denmark)

Pham, Tien Thang; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

2012-01-01

We report on experimental demonstration of an impulse radio ultrawideband (IR-UWB) based converged communication and sensing system. A 1550-nm VCSEL-generated IR-UWB signal is used for 2-Gbps wireless data distribution over 800-m and 50-km single mode fiber links which present short-range in-buil...... application, paving the way forward for the development and deployment of converged UWB VCSEL-based technologies in access and in-building networks of the future.......We report on experimental demonstration of an impulse radio ultrawideband (IR-UWB) based converged communication and sensing system. A 1550-nm VCSEL-generated IR-UWB signal is used for 2-Gbps wireless data distribution over 800-m and 50-km single mode fiber links which present short-range in......-building and long-reach access network applications. The IR-UWB signal is also used to simultaneously measure the rotational speed of a blade spinning between 18 and 30 Hz. To the best of our knowledge, this is the very first demonstration of a simultaneous gigabit UWB telecommunication and wireless UWB sensing...

[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.

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

Technology-based Intervention Programs to Promote Stimulation Control and Communication in Post-coma Persons with Different Levels of Disability

Directory of Open Access Journals (Sweden)

Giulio E. Lancioni

2014-02-01

Full Text Available Post-coma persons in a minimally conscious state and with extensive motor impairment or emerging/emerged from such a state, but affected by lack of speech and motor impairment, tend to be passive and isolated. A way to help them develop functional responding to control environmental events and communication involves the use of intervention programs relying on assistive technology. This paper provides an overview of technology-based intervention programs for enabling the participants to (a access brief periods of stimulation through one or two microswitches, (b pursue stimulation and social contact through the combination of a microswitch and a sensor connected to a speech generating device (SGD or through two SGD-related sensors, (c control stimulation options through computer or radio systems and a microswitch, (d communicate through modified messaging or telephone systems operated via microswitch, and (e control combinations of leisure and communication options through computer systems operated via microswitch. Twenty-six studies, involving a total of 52 participants, were included in this paper. The intervention programs were carried out using single-subject methodology, and their outcomes were generally considered positive from the standpoint of the participants and their context. Practical implications of the programs are discussed.

Automated biometric access control system for two-man-rule enforcement

International Nuclear Information System (INIS)

Holmes, J.P.; Maxwell, R.L.; Henderson, R.W.

1991-01-01

This paper describes a limited access control system for nuclear facilities which makes use of the eye retinal identity verifier to control the passage of personnel into and out of one or a group of security controlled working areas. This access control system requires no keys, cards or credentials. The user simply enters his Personal Identification Number (PIN) and takes an eye reading to request passage. The PIN does not have to be kept secret. The system then relies on biometric identity verification of the user, along with other system information, to make the decision of whether or not to unlock the door. It also enforces multiple zones control with personnel tracking and the two-man-rule

Public Access; Public Interest. The Network Project. Notebook Number 11.

Science.gov (United States)

Columbia Univ., New York, NY. Network Project.

The transcript of a panel discussion and an essay on public access to and control of society's information resources are presented. It is contended that the electronic Media--including radio, television, and communication satellites--are controlled by a select group of individuals and corporations and that they are not meeting the public interest.…

An Access Control Model for the Uniframe Framework

National Research Council Canada - National Science Library

Crespi, Alexander M

2005-01-01

... security characteristics from the properties of individual components would aid in the creation of more secure systems In this thesis, a framework for characterizing the access control properties...

Perceived control and communication about sex: a study of South African families.

Science.gov (United States)

Goodnight, Bradley; Salama, Christina; Grim, Elizabeth C; Anthony, Elizabeth R; Armistead, Lisa; Cook, Sarah L; Skinner, Donald; Toefy, Yoesrie

2014-01-01

Caregiver-youth communication about sex protects youth against HIV/AIDS, and caregivers who believe that sex knowledge is important are more likely to talk to their youth about sex. However, caregivers who experience barriers to communication about sex may not talk to their youth about sex even if the caregiver believes that sex education is important. The Theory of Planned Behaviour predicts that an actor has perceived control is necessary for behavioural change. This study therefore hypothesised that caregivers' perceived control moderates the relationship between caregiver attitudes about youth sex knowledge and caregiver-youth communication about sex. Results from a sample of 99 female South African caregivers of adolescent (10-14 year old) youth supported our hypothesis, indicating that caregiver attitudes about providing youth with sex knowledge positively predict communication about sex only when caregivers have perceived control. This finding illustrates the importance of perceived control in predicting caregiver-youth communication, and therefore has implications for family-based interventions aimed at improving caregiver-youth communication about sex.

Airborne wireless communication systems, airborne communication methods, and communication methods

Science.gov (United States)

Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

2011-12-13

An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

Journal of Development and Communication Studies Vol. 4. No. 2 ...

African Journals Online (AJOL)

Thomas Gill

degradation and inequalities in access and control of resources is innovation. ... programme development (top-down communication approach and centralized decision making ..... community, national, sub regional, Africa and global levels.

End-to-End Flow Control for Visual-Haptic Communication under Bandwidth Change

Science.gov (United States)

Yashiro, Daisuke; Tian, Dapeng; Yakoh, Takahiro

This paper proposes an end-to-end flow controller for visual-haptic communication. A visual-haptic communication system transmits non-real-time packets, which contain large-size visual data, and real-time packets, which contain small-size haptic data. When the transmission rate of visual data exceeds the communication bandwidth, the visual-haptic communication system becomes unstable owing to buffer overflow. To solve this problem, an end-to-end flow controller is proposed. This controller determines the optimal transmission rate of visual data on the basis of the traffic conditions, which are estimated by the packets for haptic communication. Experimental results confirm that in the proposed method, a short packet-sending interval and a short delay are achieved under bandwidth change, and thus, high-precision visual-haptic communication is realized.

Home-based family intervention increases knowledge, communication and living donation rates: a randomized controlled trial.

Science.gov (United States)

Ismail, S Y; Luchtenburg, A E; Timman, R; Zuidema, W C; Boonstra, C; Weimar, W; Busschbach, J J V; Massey, E K

2014-08-01

Our aim was to develop and test an educational program to support well-informed decision making among patients and their social network regarding living donor kidney transplantation (LDKT). One hundred sixty-three patients who were unable to find a living donor were randomized to standard care or standard care plus home-based education. In the education condition, patients and members of their social network participated in home-based educational meetings and discussed renal replacement therapy options. Patients and invitees completed pre-post self-report questionnaires measuring knowledge, risk perception, communication, self-efficacy and subjective norm. LDKT activities were observed for 6 months postintervention. Patients in the experimental group showed significantly more improvements in knowledge (p communication (p = 0.012) compared with the control group. The invitees showed pre-post increases in knowledge (p decision making and promotes access to LDKT. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

Efficient medium access control protocol for geostationary satellite systems

Institute of Scientific and Technical Information of China (English)

王丽娜; 顾学迈

2004-01-01

This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing,which uses a method of random reservation access with movable boundaries to dynamically request the transmission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

Advances in Computer, Communication, Control and Automation

CERN Document Server

011 International Conference on Computer, Communication, Control and Automation

2012-01-01

The volume includes a set of selected papers extended and revised from the 2011 International Conference on Computer, Communication, Control and Automation (3CA 2011). 2011 International Conference on Computer, Communication, Control and Automation (3CA 2011) has been held in Zhuhai, China, November 19-20, 2011. This volume  topics covered include signal and Image processing, speech and audio Processing, video processing and analysis, artificial intelligence, computing and intelligent systems, machine learning, sensor and neural networks, knowledge discovery and data mining, fuzzy mathematics and Applications, knowledge-based systems, hybrid systems modeling and design, risk analysis and management, system modeling and simulation. We hope that researchers, graduate students and other interested readers benefit scientifically from the proceedings and also find it stimulating in the process.

TCP/IP Communication System for Controlling a Vehicular Traffic Intersection

Directory of Open Access Journals (Sweden)

Pedraza-Martínez Luis Fernando

2013-10-01

Full Text Available This paper describes the development of a prototype of a vehicular traffic controller, whose system of communication is based on the TCP/IP protocol, in order to re- motely monitor and control the operation of traffic lights for a vehicular intersection. The results show the times of communication between the central and the traffic controller. The conclusions highlight the importance of using the TCP/IP protocol in traffic light systems.

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...

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

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), are not suf...... to such settings. We overview the main technical issues to be addressed, and we describe the architecture for policy decision and enforcement points....

Intervehicle Communication Research – Communication Scenarios

Directory of Open Access Journals (Sweden)

Šarūnas Stanaitis

2011-03-01

Full Text Available Recently intervehicle communications are attracting much attention from industry and academia. Upcoming standard for intervehicle communication IEEE 802.11p, known as Wireless Access in Vehicular Environments (WAVE, is still in its draft stage, but already coming into final standardization phase. Problematic, regarding mobile WAVE nodes, are described in several articles, simulations prepared and experiments done. But most of these works do not consider possible maximal communication load. This paper presents intervehicle communication scenario in respect to radio communications, mobility and other aspects of vehicular environments.Article in English

Cooperative vehicular communications in the drive-thru internet

CERN Document Server

Zhou, Haibo; Yu, Quan; Shen, Xuemin (Sherman)

2015-01-01

This brief presents a unified analytical framework for the evaluation of drive-thru Internet performance and accordingly proposes an optimal spatial access control management approach. A comprehensive overview and in-depth discussion of the research literature is included. It summarizes the main concepts and methods, and highlights future research directions. The brief also introduces a novel cooperative vehicular communication framework together with a delicate linear cluster formation scheme and low-delay content forwarding approach to provide a flexible and efficient vehicular content distribution in the drive-thru Internet. The presented medium access control and vehicular content distribution related research results in this brief provide useful insights for the design approach of Wi-Fi enabled vehicular communications and it motivates a new line of thinking for the performance enhancements of future vehicular networking. Advanced-level students, researchers and professionals interested in vehicular netw...

Access to mobile communications by older people.

Science.gov (United States)

Nguyen, Toan; Irizarry, Carol; Garrett, Rob; Downing, Andrew

2015-06-01

To investigate how older people effectively identify, select and learn to use mobile communications technologies to enhance communication and safety, and support independent living. One hundred and fifty-three older South Australians participated in a purpose-designed survey questionnaire. Older people relied on family and friends for information and advice (76%), and their children's assistance with buying (45%) and learning to use (48%) new technology. The most preferred learning method was face-to-face training (56%). Less than half (44%) were interested in trying out new designs/applications, functions and capabilities that could assist with independent living. The highest need was for personal security and emergencies (88%). Findings suggest that the family and friends of older people play an important role in identifying, selecting and learning to use mobile communication technologies. The safety and emergency capabilities of mobile communications technologies were more important than having functions that could assist with independent living. © 2014 ACOTA.

A Trusted Host's Authentication Access and Control Model Faced on User Action

Institute of Scientific and Technical Information of China (English)

ZHANG Miao; XU Guoai; HU Zhengming; YANG Yixian

2006-01-01

The conception of trusted network connection (TNC) is introduced, and the weakness of TNC to control user's action is analyzed. After this, the paper brings out a set of secure access and control model based on access, authorization and control, and related authentication protocol. At last the security of this model is analyzed. The model can improve TNC's security of user control and authorization.

Controlling Access to Input/Output Peripheral Devices

Directory of Open Access Journals (Sweden)

E. Y. Rodionov

2010-03-01

Full Text Available In this paper the author proposes a system that manages information security policy on enterprise. Problems related to managing information security policy on enterprise and access to peripheral devices in computer systems functioning under control of Microsoft Windows NT operating systems are considered.

An Internet of Things Based Multi-Level Privacy-Preserving Access Control for Smart Living

Directory of Open Access Journals (Sweden)

Usama Salama

2018-05-01

Full Text Available The presence of the Internet of Things (IoT in healthcare through the use of mobile medical applications and wearable devices allows patients to capture their healthcare data and enables healthcare professionals to be up-to-date with a patient’s status. Ambient Assisted Living (AAL, which is considered as one of the major applications of IoT, is a home environment augmented with embedded ambient sensors to help improve an individual’s quality of life. This domain faces major challenges in providing safety and security when accessing sensitive health data. This paper presents an access control framework for AAL which considers multi-level access and privacy preservation. We focus on two major points: (1 how to use the data collected from ambient sensors and biometric sensors to perform the high-level task of activity recognition; and (2 how to secure the collected private healthcare data via effective access control. We achieve multi-level access control by extending Public Key Infrastructure (PKI for secure authentication and utilizing Attribute-Based Access Control (ABAC for authorization. The proposed access control system regulates access to healthcare data by defining policy attributes over healthcare professional groups and data classes classifications. We provide guidelines to classify the data classes and healthcare professional groups and describe security policies to control access to the data classes.

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

Dual Fine Tracking Control of a Satellite Laser Communication Uplink

National Research Council Canada - National Science Library

Noble, Louis A

2006-01-01

A dual fine tracking control system (FTCS) is developed for a single aperture optical communication receiver to compensate for high frequency disturbances affecting tracking of two incident laser communication beams...

NOVANET: communications network for a control system

International Nuclear Information System (INIS)

Hill, J.R.; Severyn, J.R.; VanArsdall, P.J.

1983-01-01

NOVANET is a control system oriented fiber optic local area network that was designed to meet the unique and often conflicting requirements of the Nova laser control system which will begin operation in 1984. The computers and data acquisition devices that form the distributed control system for a large laser fusion research facility need reliable, high speed communications. Both control/status messages and experimental data must be handled. A subset of NOVANET is currently operating on the two beam Novette laser system

EPICS Input/Output Controller (IOC) application developer's guide. APS Release 3.12

International Nuclear Information System (INIS)

Kraimer, M.R.

1994-11-01

This document describes the core software that resides in an Input/Output Controller (IOC), one of the major components of EPICS. The basic components are: (OPI) Operator Interface; this is a UNIX based workstation which can run various EPICS tools; (IOC) Input/Output Controller; this is a VME/VXI based chassis containing a Motorola 68xxx processor, various I/O modules, and VME modules that provide access to other I/O buses such as GPIB, (LAN), Local Area Network; and this is the communication network which allows the IOCs and OPIs to communicate. Epics provides a software component, Channel Access, which provides network transparent communication between a Channel Access client and an arbitrary number of Channel Access servers

Need an Information Security in Access Control System?

Directory of Open Access Journals (Sweden)

V. R. Petrov

2011-12-01

Full Text Available The purpose of this paper is the general problems of information security in access control system. The field of using is the in project of reconstruction Physical protection system.

Improving nurse-patient communication with patients with communication impairments: hospital nurses' views on the feasibility of using mobile communication technologies.

Science.gov (United States)

Sharpe, Bridget; Hemsley, Bronwyn

2016-05-01

Nurses communicating with patients who are unable to speak often lack access to tools and technologies to support communication. Although mobile communication technologies are ubiquitous, it is not known whether their use to support communication is feasible on a busy hospital ward. The aim of this study was to determine the views of hospital nurses on the feasibility of using mobile communication technologies to support nurse-patient communication with individuals who have communication impairments. This study involved an online survey followed by a focus group, with findings analyzed across the two data sources. Nurses expected that mobile communication devices could benefit patient care but lacked access to these devices, encountered policies against use, and held concerns over privacy and confidentiality. The use of mobile communication technologies with patients who have communication difficulties is feasible and may lead to improvements in communication and care, provided environmental barriers are removed and facilitators enhanced. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

Science.gov (United States)

Blocksome, Michael A.; Mamidala, Amith R.

2013-09-03

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

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.

Open Access. Chapter 6 of Scholarly Communication for Librarians.

OpenAIRE

Morrison, Heather

2008-01-01

In-depth overview of open access, covering definitions (open access publishing, open access archives, gratis and libre, open access works versus open access processes), major statements and declarations, types of open access, major initiatives, trends, advocacy and lobbying.

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.

Task-Oriented and Relationship-Building Communications between Air Traffic Controllers and Pilots

Directory of Open Access Journals (Sweden)

Inwon Kang

2017-09-01

Full Text Available By questioning the lopsided attention on task-oriented factors in air traffic controller-pilot communication, the current study places an equal weighting on both task-oriented and relationship-building communications, and investigates how each type of communication influences sustainable performance in airline operation team. Results show that both task-oriented and relationship-building communications in terms of sustainability of team process predicted greater communication satisfaction at work. Also, both task interdependence and shared leadership influenced both types of air traffic controller-pilot communication. However, only relationship-building communication had a direct influence on perceived work performance whereas task-oriented communication had not. Along with task-oriented factors, this study raises the relationship-oriented factors as important resources for the sustainable team performance in airline industry.

A Dynamic Active Multicast Group Access Control Framework Based on Trust Management System

Institute of Scientific and Technical Information of China (English)

YANG Chang; CHEN Xiaolin; ZHANG Huanguo

2006-01-01

The current multicast model provides no access control mechanism. Any host can send data directly to a multicast address or join a multicast group to become a member, which brings safety problems to multicast. In this paper, we present a new active multicast group access control mechanism that is founded on trust management. This structure can solve the problem that exists in multicast members' access control and distributing authorization of traditional IP multicast.

Evaluating the Impact of Communication Network Performance on Supervisory Supermarket Control

DEFF Research Database (Denmark)

Madsen, Jacob Theilgaard; Minko, Tomasz; Madsen, Tatiana Kozlova

2017-01-01

This paper addresses the evaluation of the impact of non-ideal communication networks on system performance of hierarchical control systems. It develops a stepwise evaluation approach that is applied to the example scenario of a supervisory controller for supermarket temperature control, addressing...... of communication network performance on the supermarket refrigeration control and resulting energy costs using simulation models. The results show that the controller is resilient to downstream information delays, however upstream delays or up- and downstream information loss can cause significant performance...

Communication Access for Deaf People in Healthcare Settings: Understanding the Work of American Sign Language Interpreters.

Science.gov (United States)

Olson, Andrea M; Swabey, Laurie

Despite federal laws that mandate equal access and communication in all healthcare settings for deaf people, consistent provision of quality interpreting in healthcare settings is still not a reality, as recognized by deaf people and American Sign Language (ASL)-English interpreters. The purpose of this study was to better understand the work of ASL interpreters employed in healthcare settings, which can then inform on training and credentialing of interpreters, with the ultimate aim of improving the quality of healthcare and communication access for deaf people. Based on job analysis, researchers designed an online survey with 167 task statements representing 44 categories. American Sign Language interpreters (N = 339) rated the importance of, and frequency with which they performed, each of the 167 tasks. Categories with the highest average importance ratings included language and interpreting, situation assessment, ethical and professional decision making, manage the discourse, monitor, manage and/or coordinate appointments. Categories with the highest average frequency ratings included the following: dress appropriately, adapt to a variety of physical settings and locations, adapt to working with variety of providers in variety of roles, deal with uncertain and unpredictable work situations, and demonstrate cultural adaptability. To achieve health equity for the deaf community, the training and credentialing of interpreters needs to be systematically addressed.

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 beh...... behavior of a program. A novel feature of our approach is that we can define policies concerning secondary use of data....

Future Naval Concepts -- Crew Reductions through Improved Damage Control Communications (FNC-CRIDCC)

National Research Council Canada - National Science Library

Street, Thomas T; Williams, Frederick W; Cooper, L. S; Halloway, III, Kenneth E; Rininger, Michael; Miller, Charles; Shirley, Bradley; Genovese, Samuel; Showalter, David; Zak, Stephen

2007-01-01

The object of the Damage Control (DC) Triad program was to develop a Damage Control Communications system, which would be damage tolerant and remain operable in casualty situations where DC communications are vital...

Research into command, control, and communications in space construction

Science.gov (United States)

Davis, Randal

1990-01-01

Coordinating and controlling large numbers of autonomous or semi-autonomous robot elements in a space construction activity will present problems that are very different from most command and control problems encountered in the space business. As part of our research into the feasibility of robot constructors in space, the CSC Operations Group is examining a variety of command, control, and communications (C3) issues. Two major questions being asked are: can we apply C3 techniques and technologies already developed for use in space; and are there suitable terrestrial solutions for extraterrestrial C3 problems? An overview of the control architectures, command strategies, and communications technologies that we are examining is provided and plans for simulations and demonstrations of our concepts are described.

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

Plastic optical fiber serial communications link for distributed control system

Science.gov (United States)

Saxena, Piyush; Sharangpani, K. K.; Vora, H. S.; Nakhe, S. V.; Jain, R.; Shenoy, N. M.; Bhatnagar, R.; Shirke, N. D.

2001-09-01

One of the most common interface for communications specified is RS 232C standard. Though widely accepted, RS232 has limited transmission speed, range and networking capabilities. RS 422 standard overcomes limitations by using differential signal lines. In automation of the operation of gas discharge lasers, multiple processors are used for control of lasers, cooling system, vacuum system etc. High EMI generated by lasers interfere through galvanic transmission or by radiation over the length of cables, and hang up operation of processors or control PC. A serial communications link was designed eliminating copper transmission media, using plastic optical fiber cables and components, to connect local controllers with the master PC working on RS232 protocols. The paper discusses the design and implementation of a high ly reliable EMI harden serial communications link.

Stabilization of Networked Control Systems Under Feedback-based Communication

National Research Council Canada - National Science Library

Zhang, Lei; Hristu-Varsakelis, Dimitrios

2004-01-01

We study the stabilization of a networked control system (NSC) in which multiple sensors and actuators of a physical plant share a communication medium to exchange information with a remote controller...

Performance Analysis of Direct-Sequence Code-Division Multiple-Access Communications with Asymmetric Quadrature Phase-Shift-Keying Modulation

Science.gov (United States)

Wang, C.-W.; Stark, W.

2005-01-01

This article considers a quaternary direct-sequence code-division multiple-access (DS-CDMA) communication system with asymmetric quadrature phase-shift-keying (AQPSK) modulation for unequal error protection (UEP) capability. Both time synchronous and asynchronous cases are investigated. An expression for the probability distribution of the multiple-access interference is derived. The exact bit-error performance and the approximate performance using a Gaussian approximation and random signature sequences are evaluated by extending the techniques used for uniform quadrature phase-shift-keying (QPSK) and binary phase-shift-keying (BPSK) DS-CDMA systems. Finally, a general system model with unequal user power and the near-far problem is considered and analyzed. The results show that, for a system with UEP capability, the less protected data bits are more sensitive to the near-far effect that occurs in a multiple-access environment than are the more protected bits.

Problems and Concerns Regarding Access Control System Construction in Radiation Facilities Based on the NIFS Experience

International Nuclear Information System (INIS)

Kawano, T.; Inoue, N.; Sakuma, Y.; Motojima, O.

2001-01-01

Full text: In 1998, access control system for the large helical device (LHD) experimental hall was constructed and put into operation at the National Institute for Fusion Science (NIFS) in Toki, Japan. Since then, the system has been continuously improved. It now controls access into the LHD controlled area through four entrances. The system has five turnstile gates and enables control of access at the four entrances. The system is always checking whether the shielding doors are open or closed at eight positions. The details pertaining to the construction of the system were reported at IRPA-10 held in Hiroshima, Japan, in 2000. Based on our construction experience of the NIFS access control system, we will discuss problems related to software and operational design of the system. We will also discuss some concerns regarding the use of the system in radiation facilities. The problems we will present concern, among other thing, individual registration, time control, turnstile control, interlock signal control, data aggregation and transactions, automatic and manual control, and emergency procedures. For example, in relation to the time control and turnstile control functions, we will discuss the gate-opening time interval for an access event, the timing of access data recording, date changing, turn bar control, double access, and access error handling. (author)

An improved cooperative adaptive cruise control (CACC) algorithm considering invalid communication

Science.gov (United States)

Wang, Pangwei; Wang, Yunpeng; Yu, Guizhen; Tang, Tieqiao

2014-05-01

For the Cooperative Adaptive Cruise Control (CACC) Algorithm, existing research studies mainly focus on how inter-vehicle communication can be used to develop CACC controller, the influence of the communication delays and lags of the actuators to the string stability. However, whether the string stability can be guaranteed when inter-vehicle communication is invalid partially has hardly been considered. This paper presents an improved CACC algorithm based on the sliding mode control theory and analyses the range of CACC controller parameters to maintain string stability. A dynamic model of vehicle spacing deviation in a platoon is then established, and the string stability conditions under improved CACC are analyzed. Unlike the traditional CACC algorithms, the proposed algorithm can ensure the functionality of the CACC system even if inter-vehicle communication is partially invalid. Finally, this paper establishes a platoon of five vehicles to simulate the improved CACC algorithm in MATLAB/Simulink, and the simulation results demonstrate that the improved CACC algorithm can maintain the string stability of a CACC platoon through adjusting the controller parameters and enlarging the spacing to prevent accidents. With guaranteed string stability, the proposed CACC algorithm can prevent oscillation of vehicle spacing and reduce chain collision accidents under real-world circumstances. This research proposes an improved CACC algorithm, which can guarantee the string stability when inter-vehicle communication is invalid.

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...

CSchema: A Downgrading Policy Language for XML Access Control

Institute of Scientific and Technical Information of China (English)

Dong-Xi Liu

2007-01-01

The problem of regulating access to XML documents has attracted much attention from both academic and industry communities.In existing approaches, the XML elements specified by access policies are either accessible or inac-cessible according to their sensitivity.However, in some cases, the original XML elements are sensitive and inaccessible, but after being processed in some appropriate ways, the results become insensitive and thus accessible.This paper proposes a policy language to accommodate such cases, which can express the downgrading operations on sensitive data in XML documents through explicit calculations on them.The proposed policy language is called calculation-embedded schema (CSchema), which extends the ordinary schema languages with protection type for protecting sensitive data and specifying downgrading operations.CSchema language has a type system to guarantee the type correctness of the embedded calcula-tion expressions and moreover this type system also generates a security view after type checking a CSchema policy.Access policies specified by CSchema are enforced by a validation procedure, which produces the released documents containing only the accessible data by validating the protected documents against CSchema policies.These released documents are then ready tobe accessed by, for instance, XML query engines.By incorporating this validation procedure, other XML processing technologies can use CSchema as the access control module.

Access, interest, and attitudes toward electronic communication for health care among patients in the medical safety net.

Science.gov (United States)

Schickedanz, Adam; Huang, David; Lopez, Andrea; Cheung, Edna; Lyles, C R; Bodenheimer, Tom; Sarkar, Urmimala

2013-07-01

Electronic and internet-based tools for patient-provider communication are becoming the standard of care, but disparities exist in their adoption among patients. The reasons for these disparities are unclear, and few studies have looked at the potential communication technologies have to benefit vulnerable patient populations. To characterize access to, interest in, and attitudes toward internet-based communication in an ethnically, economically, and linguistically diverse group of patients from a large urban safety net clinic network. Observational, cross-sectional study Adult patients (≥ 18 years) in six resource-limited community clinics in the San Francisco Department of Public Health (SFDPH) MAIN MEASURES: Current email use, interest in communicating electronically with health care professionals, barriers to and facilitators of electronic health-related communication, and demographic data-all self-reported via survey. Sixty percent of patients used email, 71 % were interested in using electronic communication with health care providers, and 19 % reported currently using email informally with these providers for health care. Those already using any email were more likely to express interest in using it for health matters. Most patients agreed electronic communication would improve clinic efficiency and overall communication with clinicians. A significant majority of safety net patients currently use email, text messaging, and the internet, and they expressed an interest in using these tools for electronic communication with their medical providers. This interest is currently unmet within safety net clinics that do not offer a patient portal or secure messaging. Tools such as email encounters and electronic patient portals should be implemented and supported to a greater extent in resource-poor settings, but this will require tailoring these tools to patients' language, literacy level, and experience with communication technology.

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...

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...

Study on load temperature control system of ground laser communication

Science.gov (United States)

Zhai, Xunhua; Zhang, Hongtao; Liu, Wangsheng; Zhang, Chijun; Zhou, Xun

2007-12-01

The ground laser communication terminal as the termination of a communication system, works at the temperature which varies from -40°C to 50°C. We design a temperature control system to keep optical and electronic components working properly in the load. The load is divided into two sections to control temperature respectively. Because the space is limited, we use heater film and thermoelectric cooler to clearify and refrigerate the load. We design a hardware and a software for the temperature control system, establish mathematic model, and emulate it with Matlab.

Intersections between the Autism Spectrum and the Internet: Perceived Benefits and Preferred Functions of Computer-Mediated Communication

Science.gov (United States)

Gillespie-Lynch, Kristen; Kapp, Steven K.; Shane-Simpson, Christina; Smith, David Shane; Hutman, Ted

2014-01-01

An online survey compared the perceived benefits and preferred functions of computer-mediated communication of participants with (N = 291) and without ASD (N = 311). Participants with autism spectrum disorder (ASD) perceived benefits of computer-mediated communication in terms of increased comprehension and control over communication, access to…

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.

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...

Proceedings of the 9. international symposium on power-line communications and its applications

Energy Technology Data Exchange (ETDEWEB)

Lampe, L. (comp.) [British Columbia Univ., Vancouver, BC (Canada). Dept. of Electrical and Computer Engineering

2005-07-01

The 2005 International Symposium on Power Line Communications and Its Applications (ISPLC 2005) is the leading international scientific conference on technology and applications for communication over power lines. The conference addresses the latest technological advances in power-line communications and current and future applications of power-line communication systems including broadband Internet access, indoor home networking, power-line based communications in vehicles, power-line control networks, and automatic meter reading systems. Specific conference papers included measurements, channel characterization and modeling; standards and regulations; electromagnetic compatibility; information and communication theory; modulation and error-control coding techniques; single carrier, OFDM, and spread spectrum techniques; detection, estimation, and iterative processing techniques; signal processing algorithms and devices; multiple-access techniques; modem and LSI design; networks and protocols; system architectures; automatic meter reading systems; applications and services; and, experimental systems and field trials. A total of 90 papers were featured and organized into 14 regular sessions and one poster session. Seven of these presentations have been catalogued separately for inclusion in this database. In addition to the technical program, 3 keynotes speeches and 2 panel discussions were presented and chaired by distinguished speakers and moderators. tabs., figs.

Tango for experiment control

International Nuclear Information System (INIS)

Meyer, J.; Claustre, L.; Petitdemange, S.; Svensson, O.; Götz, A.; Coutinho, T.; Klora, J.; Picca, F.; Ounsy, M.; Buteau, A.

2012-01-01

The Tango control system framework allows you to control an accelerator complex as well as single equipment. The framework contains the communication bus with the standard communication modes (synchronous, asynchronous, event driven) as well as the basic hardware access modules, GUI tools and development kits, bindings to commercial products (LabView, Matlab, IgorPro) and services (administration, archiving, access control) to set up a control system. Tango was mainly developed by several synchrotron light sources that have to support not only the accelerator complex but also a lot of experimental end stations. For synchrotron experiments we have to control the whole process from basic hardware access over data taking to data analysis. This paper describes in the first part the special features of Tango allowing flexible experiment control. The dynamic configuration, the rapid hardware interface development and the sequencing and scanning framework are some examples. The second part gives an overview of some packages developed in the Tango community for experiment control: A HKL library for diffraction computation and diffractometer control, a library to control 2D detectors and a data analysis workbench with workflow engine for on-line and off-line data analysis. These packages are not part of Tango and can be used with other control systems. (author)

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...

A cross-layer communication framework for wireless networked control systems

NARCIS (Netherlands)

Israr, N.; Scanlon, W.G.; Irwin, G.W.

2009-01-01

This paper presents a robust, dynamic cross-layer wireless communication architecture for wireless networked control systems. Each layer in the proposed protocol architecture contributes to the overall goal of reliable, energy efficient communication. The protocol stack also features a

An Efficient Role and Object Based Access Control Model Implemented in a PDM System

Institute of Scientific and Technical Information of China (English)

HUANG Xiaowen; TAN Jian; HUANG Xiangguo

2006-01-01

An effective and reliable access control is crucial to a PDM system. This article has discussed the commonly used access control models, analyzed their advantages and disadvantages, and proposed a new Role and Object based access control model that suits the particular needs of a PDM system. The new model has been implemented in a commercial PDM system, which has demonstrated enhanced flexibility and convenience.

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

Directory of Open Access Journals (Sweden)

Boniface K. Alese

2015-12-01

Full Text Available The evolving realities of Wireless Sensor Network (WSN deployed to various terrain of life require serving multiple applications. As large amount of sensed data are distributed and stored in individual sensors nodes, the illegal access to these sensitive data can be devastating. 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. It is designed using Priccess Protocol with Access policy formulation adopting the principle of Bell Lapadula model as well as Attribute-Based Encryption (ABE to control access to sensor data. The functionality of the proposed system is simulated using Netbeans. The performance analysis of the proposed system using execution time and size of the key show that the higher the key size, the harder it becomes for the attacker to hack the system. Additionally, the time taken for the proposed work is lesser which makes the work faster than the existing work. Consequently, a well secure interactive web-based application that could facilitates the field officers access to stored data in safe and secure manner is developed.

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....

Directional antenna array (DAA) for communications, control, and data link protection

Science.gov (United States)

Molchanov, Pavlo A.; Contarino, Vincent M.

2013-06-01

A next generation of Smart antennas with point-to-point communication and jam, spoof protection capability by verification of spatial position is offered. A directional antenna array (DAA) with narrow irradiation beam provides counter terrorism protection for communications, data link, control and GPS. Communications are "invisible" to guided missiles because of 20 dB smaller irradiation outside the beam and spatial separation. This solution can be implemented with current technology. Directional antennas have higher gain and can be multi-frequency or have wide frequency band in contrast to phase antenna arrays. This multi-directional antenna array provides a multi-functional communication network and simultaneously can be used for command control, data link and GPS.

A hybrid MAC protocol design for energy-efficient very-high-throughput millimeter wave, wireless sensor communication networks

Science.gov (United States)

Jian, Wei; Estevez, Claudio; Chowdhury, Arshad; Jia, Zhensheng; Wang, Jianxin; Yu, Jianguo; Chang, Gee-Kung

2010-12-01

This paper presents an energy-efficient Medium Access Control (MAC) protocol for very-high-throughput millimeter-wave (mm-wave) wireless sensor communication networks (VHT-MSCNs) based on hybrid multiple access techniques of frequency division multiplexing access (FDMA) and time division multiplexing access (TDMA). An energy-efficient Superframe for wireless sensor communication network employing directional mm-wave wireless access technologies is proposed for systems that require very high throughput, such as high definition video signals, for sensing, processing, transmitting, and actuating functions. Energy consumption modeling for each network element and comparisons among various multi-access technologies in term of power and MAC layer operations are investigated for evaluating the energy-efficient improvement of proposed MAC protocol.

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...

A novel decentralized hierarchical access control scheme for the medical scenario

DEFF Research Database (Denmark)

Eskeland, Sigurd; Prasad, Neeli R.

2006-01-01

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......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....

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....

Database application research in real-time data access of accelerator control system

International Nuclear Information System (INIS)

Chen Guanghua; Chen Jianfeng; Wan Tianmin

2012-01-01

The control system of Shanghai Synchrotron Radiation Facility (SSRF) is a large-scale distributed real-time control system, It involves many types and large amounts of real-time data access during the operating. Database system has wide application prospects in the large-scale accelerator control system. It is the future development direction of the accelerator control system, to replace the differently dedicated data structures with the mature standardized database system. This article discusses the application feasibility of database system in accelerators based on the database interface technology, real-time data access testing, and system optimization research and to establish the foundation of the wide scale application of database system in the SSRF accelerator control system. Based on the database interface technology, real-time data access testing and system optimization research, this article will introduce the application feasibility of database system in accelerators, and lay the foundation of database system application in the SSRF accelerator control system. (authors)

Access control system for two person rule at Rokkasho Reprocessing Plant

International Nuclear Information System (INIS)

Yanagisawa, Sawako; Ino, Munekazu; Yamada, Noriyuki; Oota, Hiroto; Iwasaki, Mitsuaki; Kodani, Yoshiki; Iwamoto, Tomonori

2014-01-01

Following the amendment and enforcement of Regulation of Reprocessing Activity on March 29th 2012, two person rule has become compulsory for the specific rooms to counter and prevent the sabotage or theft of nuclear materials by the insiders at reprocessing plant in Japan. The rooms will include those which contains cooling systems for decay heat removal from spent fuels and so on, scavenging systems to prevent the hydrogen accumulation, and those which contains nuclear material. To ensure the two person rule at Rokkasho Reprocessing Plant, JNFL has recently, after comprehensive study, introduced efficient and effective access control system for the rooms mentioned above. The system is composed of bio-attestation devices, surveillance cameras and electronic locks to establish access control system. This report outlines the access control system for two person rule and introduces the operation. (author)

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.

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

Simple measurement-based admission control for DiffServ access networks

Science.gov (United States)

Lakkakorpi, Jani

2002-07-01

In order to provide good Quality of Service (QoS) in a Differentiated Services (DiffServ) network, a dynamic admission control scheme is definitely needed as an alternative to overprovisioning. In this paper, we present a simple measurement-based admission control (MBAC) mechanism for DiffServ-based access networks. Instead of using active measurements only or doing purely static bookkeeping with parameter-based admission control (PBAC), the admission control decisions are based on bandwidth reservations and periodically measured & exponentially averaged link loads. If any link load on the path between two endpoints is over the applicable threshold, access is denied. Link loads are periodically sent to Bandwidth Broker (BB) of the routing domain, which makes the admission control decisions. The information needed in calculating the link loads is retrieved from the router statistics. The proposed admission control mechanism is verified through simulations. Our results prove that it is possible to achieve very high bottleneck link utilization levels and still maintain good QoS.

Information Security and Wireless: Alternate Approaches for Controlling Access to Critical Information

National Research Council Canada - National Science Library

Nandram, Winsome

2004-01-01

.... Typically, network managers implement countermeasures to augment security. The goal of this thesis is to research approaches that compliment existing security measures with fine grain access control measures. The Extensible Markup Language (XML) is adopted to accommodate such granular access control as it provides the mechanisms for scaling security down to the document content level.

Impact of postgraduate training on communication skills teaching: a controlled study.

Science.gov (United States)

Junod Perron, Noelle; Nendaz, Mathieu; Louis-Simonet, Martine; Sommer, Johanna; Gut, Anne; Cerutti, Bernard; van der Vleuten, Cees P; Dolmans, Diana

2014-04-14

Observation of performance followed by feedback is the key to good teaching of communication skills in clinical practice. The fact that it occurs rarely is probably due to clinical supervisors' perceived lack of competence to identify communication skills and give effective feedback. We evaluated the impact of a faculty development programme on communication skills teaching on clinical supervisors' ability to identify residents' good and poor communication skills and to discuss them interactively during feedback. We conducted a pre-post controlled study in which clinical supervisors took part to a faculty development program on teaching communication skills in clinical practice. Outcome measures were the number and type of residents' communication skills identified by supervisors in three videotaped simulated resident-patient encounters and the number and type of communication skills discussed interactively with residents during three feedback sessions. 48 clinical supervisors (28 intervention group; 20 control group) participated. After the intervention, the number and type of communication skills identified did not differ between both groups. There was substantial heterogeneity in the number and type of communication skills identified. However, trained participants engaged in interactive discussions with residents on a significantly higher number of communication items (effect sizes 0.53 to 1.77); communication skills items discussed interactively included both structural and patient-centered elements that were considered important to be observed by expert teachers. The faculty development programme did not increase the number of communication skills recognised by supervisors but was effective in increasing the number of communication issues discussed interactively in feedback sessions. Further research should explore the respective impact of accurate identification of communication skills and effective teaching skills on achieving more effective communication

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.

Design and Implementation of Linux Access Control Model

Institute of Scientific and Technical Information of China (English)

Wei Xiaomeng; Wu Yongbin; Zhuo Jingchuan; Wang Jianyun; Haliqian Mayibula

2017-01-01

In this paper,the design and implementation of an access control model for Linux system are discussed in detail. The design is based on the RBAC model and combines with the inherent characteristics of the Linux system,and the support for the process and role transition is added.The core idea of the model is that the file is divided into different categories,and access authority of every category is distributed to several roles.Then,roles are assigned to users of the system,and the role of the user can be transited from one to another by running the executable file.

Automated personal identification: a new technique for controlling access to nuclear materials and facilities

International Nuclear Information System (INIS)

Eccles, D.R.

1975-01-01

Special nuclear materials must be protected against the threat of diversion or theft, and nuclear facilities against the threat of industrial sabotage. Implicit in this protection is the means of controlling access to protected areas, material access areas, and vital areas. With the advent of automated personal identification technology, the processes of access control can be automated to yield both higher security and reduced costs. This paper first surveys the conventional methods of access control; next, automated personal identification concepts are presented and various systems approaches are highlighted; finally, Calspan's FINGERSCAN /sub TM/ system for identity verification is described

ACCESS: Detector Control and Performance

Science.gov (United States)

Morris, Matthew J.; Kaiser, M.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Bohlin, R.; Kurucz, R. L.; Riess, A. G.; Pelton, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Mott, D. B.; Wen, Y.; Benford, D. J.; Gardner, J. P.; Feldman, P. D.; Moos, H. W.; Lampton, M.; Perlmutter, S.; Woodgate, B. E.

2014-01-01

ACCESS, Absolute Color Calibration Experiment for Standard Stars, is a series of rocket-borne sub-orbital missions and ground-based experiments that will enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass (companion poster, Kaiser et al.). The flight detector and detector spare have been selected and integrated with their electronics and flight mount. The controller electronics have been flight qualified. Vibration testing to launch loads and thermal vacuum testing of the detector, mount, and housing have been successfully performed. Further improvements to the flight controller housing have been made. A cryogenic ground test system has been built. Dark current and read noise tests have been performed, yielding results consistent with the initial characterization tests of the detector performed by Goddard Space Flight Center’s Detector Characterization Lab (DCL). Detector control software has been developed and implemented for ground testing. Performance and integration of the detector and controller with the flight software will be presented. NASA APRA sounding rocket grant NNX08AI65G supports this work.

Optimal Load Control via Frequency Measurement and Neighborhood Area Communication

Energy Technology Data Exchange (ETDEWEB)

Zhao, CH; Topcu, U; Low, SH

2013-11-01

We propose a decentralized optimal load control scheme that provides contingency reserve in the presence of sudden generation drop. The scheme takes advantage of flexibility of frequency responsive loads and neighborhood area communication to solve an optimal load control problem that balances load and generation while minimizing end-use disutility of participating in load control. Local frequency measurements enable individual loads to estimate the total mismatch between load and generation. Neighborhood area communication helps mitigate effects of inconsistencies in the local estimates due to frequency measurement noise. Case studies show that the proposed scheme can balance load with generation and restore the frequency within seconds of time after a generation drop, even when the loads use a highly simplified power system model in their algorithms. We also investigate tradeoffs between the amount of communication and the performance of the proposed scheme through simulation-based experiments.

2011 International Conference in Electrics, Communication and Automatic Control Proceedings

CERN Document Server

2012-01-01

This two-volume set contains the very latest, cutting-edge material in electrics, communication and automatic control. As a vital field of research that is highly relevant to current developments in a number of technological domains, the subjects it covers include micro-electronics and integrated circuit control, signal processing technology, next-generation network infrastructure, wireless communication and scientific instruments. The aim of the International Conference in Electrics, Communication and Automatic Control, held in Chongqing, China, in June 2011 was to provide a valuable inclusive platform for researchers, engineers, academicians and industrial professionals from all over the world to share their research results with fellow scientists in the sector. The call for papers netted well over 600 submissions, of which 224 were selected for presentation. This fully peer-reviewed collection of papers from the conference can be viewed as a single-source compendium of the latest trends and techniques in t...

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

Science.gov (United States)

Razaque, Abdul; Elleithy, Khaled M.

2014-01-01

-synchronous feature with a low duty cycle, which is advantageous for reducing the latency and energy consumption for several WSN application areas to improve the throughput. BN-MAC uses a unique window slot size to enhance the contention resolution issue for improved throughput. BN-MAC also prefers to communicate within a one-hop destination using Anycast, which maintains load balancing to maintain network reliability. BN-MAC is introduced with the goal of supporting four major application areas: monitoring and behavioral areas, controlling natural disasters, human-centric applications, and tracking mobility and static home automation devices from remote places. These application areas require a congestion-free mobility-supported MAC protocol to guarantee reliable data delivery. BN-MAC was evaluated using network simulator-2 (ns2) and compared with other hybrid MAC protocols, such as Zebra medium access control (Z-MAC), advertisement-based MAC (A-MAC), Speck-MAC, adaptive duty cycle SMAC (ADC-SMAC), and low-power real-time medium access control (LPR-MAC). The simulation results indicate that BN-MAC is a robust and energy-efficient protocol that outperforms other hybrid MAC protocols in the context of quality of service (QoS) parameters, such as energy consumption, latency, throughput, channel access time, successful delivery rate, coverage efficiency, and average duty cycle. PMID:24625737

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

Science.gov (United States)

Razaque, Abdul; Elleithy, Khaled M

2014-03-12

-synchronous feature with a low duty cycle, which is advantageous for reducing the latency and energy consumption for several WSN application areas to improve the throughput. BN-MAC uses a unique window slot size to enhance the contention resolution issue for improved throughput. BN-MAC also prefers to communicate within a one-hop destination using Anycast, which maintains load balancing to maintain network reliability. BN-MAC is introduced with the goal of supporting four major application areas: monitoring and behavioral areas, controlling natural disasters, human-centric applications, and tracking mobility and static home automation devices from remote places. These application areas require a congestion-free mobility-supported MAC protocol to guarantee reliable data delivery. BN-MAC was evaluated using network simulator-2 (ns2) and compared with other hybrid MAC protocols, such as Zebra medium access control (Z-MAC), advertisement-based MAC (A-MAC), Speck-MAC, adaptive duty cycle SMAC (ADC-SMAC), and low-power real-time medium access control (LPR-MAC). The simulation results indicate that BN-MAC is a robust and energy-efficient protocol that outperforms other hybrid MAC protocols in the context of quality of service (QoS) parameters, such as energy consumption, latency, throughput, channel access time, successful delivery rate, coverage efficiency, and average duty cycle.

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

Directory of Open Access Journals (Sweden)

Abdul Razaque

2014-03-01

-synchronous feature with a low duty cycle, which is advantageous for reducing the latency and energy consumption for several WSN application areas to improve the throughput. BN-MAC uses a unique window slot size to enhance the contention resolution issue for improved throughput. BN-MAC also prefers to communicate within a one-hop destination using Anycast, which maintains load balancing to maintain network reliability. BN-MAC is introduced with the goal of supporting four major application areas: monitoring and behavioral areas, controlling natural disasters, human-centric applications, and tracking mobility and static home automation devices from remote places. These application areas require a congestion-free mobility-supported MAC protocol to guarantee reliable data delivery. BN-MAC was evaluated using network simulator-2 (ns2 and compared with other hybrid MAC protocols, such as Zebra medium access control (Z-MAC, advertisement-based MAC (A-MAC, Speck-MAC, adaptive duty cycle SMAC (ADC-SMAC, and low-power real-time medium access control (LPR-MAC. The simulation results indicate that BN-MAC is a robust and energy-efficient protocol that outperforms other hybrid MAC protocols in the context of quality of service (QoS parameters, such as energy consumption, latency, throughput, channel access time, successful delivery rate, coverage efficiency, and average duty cycle.

Open access and scholarly communication, part 4

CERN Document Server

Eden, Brad

2009-01-01

This fourth e-book on the subject of open access in the academic field includes a Latin American case study on open access penetration, a paper from Germany on the promotion of OA illustrated by a project at the University of Konstanz, and a case study on OA at Bioline International, a non-profit scholarly publications aggregator, distributor, publisher and publishing assistance service.

TRBAC:基于信任的访问控制模型%TRBAC: Trust Based Access Control Model

Institute of Scientific and Technical Information of China (English)

刘武; 段海新; 张洪; 任萍; 吴建平

2011-01-01

访问控制是根据网络用户的身份或属性,对该用户执行某些操作或访问某些网络资源进行控制的过程.对现有访问控制模型进行分析,并针对其不足对RBAC模型进行了扩展,提出了基于信任的访问控制模型TRBAC(trust based access control model).该模型可以提供更加安全、灵活以及细粒度的动态访问授权机制,从而提高授权机制的安全性与可靠性.%Access control is a process which controls users to execute some operations or access some network resources according to the users' identity or attribution. The discretionary access control and mandatory access control are two main access control modes which are broadly used in secure operating systems. Discretionary access control is based on user identity and/or groups and mandatory access control is usually based on sensitivity labels. Neither of these two modes can completely satisfy the requirements of all access control. Discretionary access control is too loose to restrict the propagation of privileges while mandatory access control is too rigid to use flexibly. This paper analyzes current access control models, and extends the RBAC (role based access control) model aiming at its deficiency, and based on which we propose a trust based access control model (TRBAC). The TRBAC model can provide more security, flexible and fine-grained dynamic access control mechanism, and therefore improve both the security and the reliability of authorization mechanism.

Impact of postgraduate training on communication skills teaching: a controlled study

Science.gov (United States)

2014-01-01

Background Observation of performance followed by feedback is the key to good teaching of communication skills in clinical practice. The fact that it occurs rarely is probably due to clinical supervisors’ perceived lack of competence to identify communication skills and give effective feedback. We evaluated the impact of a faculty development programme on communication skills teaching on clinical supervisors’ ability to identify residents’ good and poor communication skills and to discuss them interactively during feedback. Methods We conducted a pre-post controlled study in which clinical supervisors took part to a faculty development program on teaching communication skills in clinical practice. Outcome measures were the number and type of residents’ communication skills identified by supervisors in three videotaped simulated resident-patient encounters and the number and type of communication skills discussed interactively with residents during three feedback sessions. Results 48 clinical supervisors (28 intervention group; 20 control group) participated. After the intervention, the number and type of communication skills identified did not differ between both groups. There was substantial heterogeneity in the number and type of communication skills identified. However, trained participants engaged in interactive discussions with residents on a significantly higher number of communication items (effect sizes 0.53 to 1.77); communication skills items discussed interactively included both structural and patient-centered elements that were considered important to be observed by expert teachers. Conclusions The faculty development programme did not increase the number of communication skills recognised by supervisors but was effective in increasing the number of communication issues discussed interactively in feedback sessions. Further research should explore the respective impact of accurate identification of communication skills and effective teaching

Optical code division multiple access secure communications systems with rapid reconfigurable polarization shift key user code

Science.gov (United States)

Gao, Kaiqiang; Wu, Chongqing; Sheng, Xinzhi; Shang, Chao; Liu, Lanlan; Wang, Jian

2015-09-01

An optical code division multiple access (OCDMA) secure communications system scheme with rapid reconfigurable polarization shift key (Pol-SK) bipolar user code is proposed and demonstrated. Compared to fix code OCDMA, by constantly changing the user code, the performance of anti-eavesdropping is greatly improved. The Pol-SK OCDMA experiment with a 10 Gchip/s user code and a 1.25 Gb/s user data of payload has been realized, which means this scheme has better tolerance and could be easily realized.

Communication Among Melanoma Family Members

Science.gov (United States)

Bowen, Deborah J; Albrecht, Terrance; Hay, Jennifer; Eggly, Susan; Harris-Wei, Julie; Meischke, Hendrika; Burke, Wylie

2017-01-01

Interventions to improve communication among family members may facilitate information flow about familial risk and preventive health behaviors. This is a secondary analysis of the effects of an interactive website intervention aimed at increasing communication frequency and agreement about health risk among melanoma families. Participants were family units, consisting of one family member with melanoma identified from a previous research study (the case) and an additional first degree relative and a parent of a child 0–17. Family triads were randomized to receive access to the website intervention or to serve as control families. Family communication frequency and agreement about melanoma prevention behaviors and beliefs were measured at baseline and again at one year post randomization. Intervention participants of all three types significantly increased the frequency of communication to their first degree relatives (Parents, siblings, children; range =14–18 percentage points; all pcommunication about cancer risk. PMID:28248624

No access to LHC from 7 to 13 January 2008

CERN Multimedia