rapidio protocol layer: Topics by WorldWideScience.org

Sample records for rapidio protocol layer

RapidIO as a multi-purpose interconnect

Science.gov (United States)

Baymani, Simaolhoda; Alexopoulos, Konstantinos; Valat, Sébastien

2017-10-01

RapidIO (http://rapidio.org/) technology is a packet-switched high-performance fabric, which has been under active development since 1997. Originally meant to be a front side bus, it developed into a system level interconnect which is today used in all 4G/LTE base stations world wide. RapidIO is often used in embedded systems that require high reliability, low latency and scalability in a heterogeneous environment - features that are highly interesting for several use cases, such as data analytics and data acquisition (DAQ) networks. We will present the results of evaluating RapidIO in a data analytics environment, from setup to benchmark. Specifically, we will share the experience of running ROOT and Hadoop on top of RapidIO. To demonstrate the multi-purpose characteristics of RapidIO, we will also present the results of investigating RapidIO as a technology for high-speed DAQ networks using a generic multi-protocol event-building emulation tool. In addition we will present lessons learned from implementing native ports of CERN applications to RapidIO.
Cross-Layer Protocol as a Better Option in Wireless Mesh Network with Respect to Layered-Protocol

OpenAIRE

Ahmed Abdulwahab Al-Ahdal; Dr. V. P. Pawar; G. N. Shinde

2014-01-01

The Optimal way to improve Wireless Mesh Networks (WMNs) performance is to use a better network protocol, but whether layered-protocol design or cross-layer design is a better option to optimize protocol performance in WMNs is still an on-going research topic. In this paper, we focus on cross-layer protocol as a better option with respect to layered-protocol. The layered protocol architecture (OSI) model divides networking tasks into layers and defines a pocket of services for each layer to b...
Design and testing of RapidIO application and verification model%RapidIO应用系统及其验证模型的设计与测试

Institute of Scientific and Technical Information of China (English)

梁光胜; 刘倩茹; 姚海洋

2011-01-01

Aiming at the problem existed in the traditional interconnection of embedded system, a scheme of RapidIO application and verification model, which can be used for the communication in the embedded system, is proposed. Based on the IP Core and Cyclone serial FPGA of Ahera Company, this scheme builds communication system of Serial RapidIO （SRIO） whose functions are verified. The structure and operation principle of RapidIO application and verification model are elaborated, which give a solution to the improvement of communication rate in the embedded system.%针对传统嵌入式系统中互连通信的问题．提出一种可用于嵌入式系统内部通信的基于RapidIO的应用系统及其验证模型。该方案采／8Ahera公司的IP核和Cyclone系列FPGA，建立了串行RapidIO（SRIO）4g-口通信系统，并对其功能进行验证。详细分析了RapidIO应用系统及其验证模型的功能结构和运行原理．为提高嵌入式系统内部模块的通信速率提供了解决方案。
Implementation of a Multichannel Serial Data Streaming Algorithm using the Xilinx Serial RapidIO Solution

Science.gov (United States)

Doxley, Charles A.

2016-01-01

In the current world of applications that use reconfigurable technology implemented on field programmable gate arrays (FPGAs), there is a need for flexible architectures that can grow as the systems evolve. A project has limited resources and a fixed set of requirements that development efforts are tasked to meet. Designers must develop robust solutions that practically meet the current customer demands and also have the ability to grow for future performance. This paper describes the development of a high speed serial data streaming algorithm that allows for transmission of multiple data channels over a single serial link. The technique has the ability to change to meet new applications developed for future design considerations. This approach uses the Xilinx Serial RapidIO LOGICORE Solution to implement a flexible infrastructure to meet the current project requirements with the ability to adapt future system designs.
The case for a network protocol isolation layer

KAUST Repository

Il Choi, Jung

2009-01-01

Network protocols are typically designed and tested individually. In practice, however, applications use multiple protocols concurrently. This discrepancy can lead to failures from unanticipated interactions between protocols. In this paper, we argue that sensor network communication stacks should have an isolation layer, whose purpose is to make each protocol\\'s perception of the wireless channel independent of what other protocols are running. We identify two key mechanisms the isolation layer must provide: shared collision avoidance and fair channel allocation. We present an example design of an isolation layer that builds on the existing algorithms of grant-to-send and fair queueing. However, the complexities of wireless make these mechanisms insufficient by themselves. We therefore propose two new mechanisms that address these limitations: channel decay and fair cancellation. Incorporating these new mechanisms reduces the increase in end-to-end delivery cost associated with concurrently operating two protocols by more than 60%. The isolation layer improves median protocol fairness from 0.52 to 0.96 in Jain\\'s fairness index. Together, these results show that using an isolation layer makes protocols more efficient and robust. Copyright 2009 ACM.
The case for a network protocol isolation layer

KAUST Repository

Il Choi, Jung; Kazandjieva, Maria A.; Jain, Mayank; Levis, Philip

2009-01-01

Network protocols are typically designed and tested individually. In practice, however, applications use multiple protocols concurrently. This discrepancy can lead to failures from unanticipated interactions between protocols. In this paper, we argue that sensor network communication stacks should have an isolation layer, whose purpose is to make each protocol's perception of the wireless channel independent of what other protocols are running. We identify two key mechanisms the isolation layer must provide: shared collision avoidance and fair channel allocation. We present an example design of an isolation layer that builds on the existing algorithms of grant-to-send and fair queueing. However, the complexities of wireless make these mechanisms insufficient by themselves. We therefore propose two new mechanisms that address these limitations: channel decay and fair cancellation. Incorporating these new mechanisms reduces the increase in end-to-end delivery cost associated with concurrently operating two protocols by more than 60%. The isolation layer improves median protocol fairness from 0.52 to 0.96 in Jain's fairness index. Together, these results show that using an isolation layer makes protocols more efficient and robust. Copyright 2009 ACM.
Hardware demonstration of high-speed networks for satellite applications.

Energy Technology Data Exchange (ETDEWEB)

Donaldson, Jonathon W.; Lee, David S.

2008-09-01

This report documents the implementation results of a hardware demonstration utilizing the Serial RapidIO{trademark} and SpaceWire protocols that was funded by Sandia National Laboratories (SNL's) Laboratory Directed Research and Development (LDRD) office. This demonstration was one of the activities in the Modeling and Design of High-Speed Networks for Satellite Applications LDRD. This effort has demonstrated the transport of application layer packets across both RapidIO and SpaceWire networks to a common downlink destination using small topologies comprised of commercial-off-the-shelf and custom devices. The RapidFET and NEX-SRIO debug and verification tools were instrumental in the successful implementation of the RapidIO hardware demonstration. The SpaceWire hardware demonstration successfully demonstrated the transfer and routing of application data packets between multiple nodes and also was able reprogram remote nodes using configuration bitfiles transmitted over the network, a key feature proposed in node-based architectures (NBAs). Although a much larger network (at least 18 to 27 nodes) would be required to fully verify the design for use in a real-world application, this demonstration has shown that both RapidIO and SpaceWire are capable of routing application packets across a network to a common downlink node, illustrating their potential use in real-world NBAs.
A Protocol Layer Trust-Based Intrusion Detection Scheme for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Jian Wang

2017-05-01

Full Text Available This article proposes a protocol layer trust-based intrusion detection scheme for wireless sensor networks. Unlike existing work, the trust value of a sensor node is evaluated according to the deviations of key parameters at each protocol layer considering the attacks initiated at different protocol layers will inevitably have impacts on the parameters of the corresponding protocol layers. For simplicity, the paper mainly considers three aspects of trustworthiness, namely physical layer trust, media access control layer trust and network layer trust. The per-layer trust metrics are then combined to determine the overall trust metric of a sensor node. The performance of the proposed intrusion detection mechanism is then analyzed using the t-distribution to derive analytical results of false positive and false negative probabilities. Numerical analytical results, validated by simulation results, are presented in different attack scenarios. It is shown that the proposed protocol layer trust-based intrusion detection scheme outperforms a state-of-the-art scheme in terms of detection probability and false probability, demonstrating its usefulness for detecting cross-layer attacks.
Analytical approach to cross-layer protocol optimization in wireless sensor networks

Science.gov (United States)

Hortos, William S.

2008-04-01

In the distributed operations of route discovery and maintenance, strong interaction occurs across mobile ad hoc network (MANET) protocol layers. Quality of service (QoS) requirements of multimedia service classes must be satisfied by the cross-layer protocol, along with minimization of the distributed power consumption at nodes and along routes to battery-limited energy constraints. In previous work by the author, cross-layer interactions in the MANET protocol are modeled in terms of a set of concatenated design parameters and associated resource levels by multivariate point processes (MVPPs). Determination of the "best" cross-layer design is carried out using the optimal control of martingale representations of the MVPPs. In contrast to the competitive interaction among nodes in a MANET for multimedia services using limited resources, the interaction among the nodes of a wireless sensor network (WSN) is distributed and collaborative, based on the processing of data from a variety of sensors at nodes to satisfy common mission objectives. Sensor data originates at the nodes at the periphery of the WSN, is successively transported to other nodes for aggregation based on information-theoretic measures of correlation and ultimately sent as information to one or more destination (decision) nodes. The "multimedia services" in the MANET model are replaced by multiple types of sensors, e.g., audio, seismic, imaging, thermal, etc., at the nodes; the QoS metrics associated with MANETs become those associated with the quality of fused information flow, i.e., throughput, delay, packet error rate, data correlation, etc. Significantly, the essential analytical approach to MANET cross-layer optimization, now based on the MVPPs for discrete random events occurring in the WSN, can be applied to develop the stochastic characteristics and optimality conditions for cross-layer designs of sensor network protocols. Functional dependencies of WSN performance metrics are described in
A Performance Evaluation of NACK-Oriented Protocols as the Foundation of Reliable Delay- Tolerant Networking Convergence Layers

Science.gov (United States)

Iannicca, Dennis; Hylton, Alan; Ishac, Joseph

2012-01-01

Delay-Tolerant Networking (DTN) is an active area of research in the space communications community. DTN uses a standard layered approach with the Bundle Protocol operating on top of transport layer protocols known as convergence layers that actually transmit the data between nodes. Several different common transport layer protocols have been implemented as convergence layers in DTN implementations including User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and Licklider Transmission Protocol (LTP). The purpose of this paper is to evaluate several stand-alone implementations of negative-acknowledgment based transport layer protocols to determine how they perform in a variety of different link conditions. The transport protocols chosen for this evaluation include Consultative Committee for Space Data Systems (CCSDS) File Delivery Protocol (CFDP), Licklider Transmission Protocol (LTP), NACK-Oriented Reliable Multicast (NORM), and Saratoga. The test parameters that the protocols were subjected to are characteristic of common communications links ranging from terrestrial to cis-lunar and apply different levels of delay, line rate, and error.
Cross-layer protocol design for QoS optimization in real-time wireless sensor networks

Science.gov (United States)

Hortos, William S.

2010-04-01

The metrics of quality of service (QoS) for each sensor type in a wireless sensor network can be associated with metrics for multimedia that describe the quality of fused information, e.g., throughput, delay, jitter, packet error rate, information correlation, etc. These QoS metrics are typically set at the highest, or application, layer of the protocol stack to ensure that performance requirements for each type of sensor data are satisfied. Application-layer metrics, in turn, depend on the support of the lower protocol layers: session, transport, network, data link (MAC), and physical. The dependencies of the QoS metrics on the performance of the higher layers of the Open System Interconnection (OSI) reference model of the WSN protocol, together with that of the lower three layers, are the basis for a comprehensive approach to QoS optimization for multiple sensor types in a general WSN model. The cross-layer design accounts for the distributed power consumption along energy-constrained routes and their constituent nodes. Following the author's previous work, the cross-layer interactions in the WSN protocol are represented by a set of concatenated protocol parameters and enabling resource levels. The "best" cross-layer designs to achieve optimal QoS are established by applying the general theory of martingale representations to the parameterized multivariate point processes (MVPPs) for discrete random events occurring in the WSN. Adaptive control of network behavior through the cross-layer design is realized through the parametric factorization of the stochastic conditional rates of the MVPPs. The cross-layer protocol parameters for optimal QoS are determined in terms of solutions to stochastic dynamic programming conditions derived from models of transient flows for heterogeneous sensor data and aggregate information over a finite time horizon. Markov state processes, embedded within the complex combinatorial history of WSN events, are more computationally
L2-LBMT: A Layered Load Balance Routing Protocol for underwater multimedia data transmission

Science.gov (United States)

Lv, Ze; Tang, Ruichun; Tao, Ye; Sun, Xin; Xu, Xiaowei

2017-12-01

Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater acoustic network communication protocols, from physical layer, data link layer, network layer to transport layer, the existing routing protocols for underwater wireless sensor network (UWSN) still cannot well deal with the problems in transmitting multimedia data because of the difficulties involved in high energy consumption, low transmission reliability or high transmission delay. It prevents us from applying underwater multimedia data to real-time monitoring of marine environment in practical application, especially in emergency search, rescue operation and military field. Therefore, the inefficient transmission of marine multimedia data has become a serious problem that needs to be solved urgently. In this paper, A Layered Load Balance Routing Protocol (L2-LBMT) is proposed for underwater multimedia data transmission. In L2-LBMT, we use layered and load-balance Ad Hoc Network to transmit data, and adopt segmented data reliable transfer (SDRT) protocol to improve the data transport reliability. And a 3-node variant of tornado (3-VT) code is also combined with the Ad Hoc Network to transmit little emergency data more quickly. The simulation results show that the proposed protocol can balance energy consumption of each node, effectively prolong the network lifetime and reduce transmission delay of marine multimedia data.
A review on transport layer protocol performance for delivering video on an adhoc network

Science.gov (United States)

Suherman; Suwendri; Al-Akaidi, Marwan

2017-09-01

The transport layer protocol is responsible for the end to end data transmission. Transmission control protocol (TCP) provides a reliable connection and user datagram protocol (UDP) offers fast but unguaranteed data transfer. Meanwhile, the 802.11 (wireless fidelity/WiFi) networks have been widely used as internet hotspots. This paper evaluates TCP, TCP variants and UDP performances for video transmission on an adhoc network. The transport protocol - medium access cross-layer is proposed by prioritizing TCP acknowledgement to reduce delay. The NS-2 evaluations show that the average delays increase linearly for all the evaluated protocols and the average packet losses grow logarithmically. UDP produces the lowest transmission delay; 5.4% and 5.8% lower than TCP and TCP variant, but experiences the highest packet loss. Both TCP and TCP Vegas maintain packet loss as low as possible. The proposed cross-layer successfully decreases TCP and TCP Vegas delay about 0.12 % and 0.15%, although losses remain similar.
An Energy-Efficient Link Layer Protocol for Reliable Transmission over Wireless Networks

Directory of Open Access Journals (Sweden)

Iqbal Adnan

2009-01-01

Full Text Available In multihop wireless networks, hop-by-hop reliability is generally achieved through positive acknowledgments at the MAC layer. However, positive acknowledgments introduce significant energy inefficiencies on battery-constrained devices. This inefficiency becomes particularly significant on high error rate channels. We propose to reduce the energy consumption during retransmissions using a novel protocol that localizes bit-errors at the MAC layer. The proposed protocol, referred to as Selective Retransmission using Virtual Fragmentation (SRVF, requires simple modifications to the positive-ACK-based reliability mechanism but provides substantial improvements in energy efficiency. The main premise of the protocol is to localize bit-errors by performing partial checksums on disjoint parts or virtual fragments of a packet. In case of error, only the corrupted virtual fragments are retransmitted. We develop stochastic models of the Simple Positive-ACK-based reliability, the previously-proposed Packet Length Optimization (PLO protocol, and the SRVF protocol operating over an arbitrary-order Markov wireless channel. Our analytical models show that SRVF provides significant theoretical improvements in energy efficiency over existing protocols. We then use bit-error traces collected over different real networks to empirically compare the proposed and existing protocols. These experimental results further substantiate that SRVF provides considerably better energy efficiency than Simple Positive-ACK and Packet Length Optimization protocols.
Feature-Driven Domain Analysis of Session Layer Protocols of Internet of Things

NARCIS (Netherlands)

Köksal, Omer; Tekinerdogan, B.

2017-01-01

The Internet of Things (IoT) architecture is defined as a layered structure in which each layer represents a coherent set of services. For supporting the communication among the different IoT entities many different communication protocols are now available in practice. For practitioners, it is
Application Protocol, Initial Graphics Exchange Specification (IGES), Layered Electrical Product

Energy Technology Data Exchange (ETDEWEB)

O`Connell, L.J. [ed.

1994-12-01

An application protocol is an information systems engineering view of a specific product The view represents an agreement on the generic activities needed to design and fabricate the product the agreement on the information needed to support those activities, and the specific constructs of a product data standard for use in transferring some or all of the information required. This application protocol describes the data for electrical and electronic products in terms of a product description standard called the Initial Graphics Exchange Specification (IGES). More specifically, the Layered Electrical Product IGES Application Protocol (AP) specifies the mechanisms for defining and exchanging computer-models and their associated data for those products which have been designed in two dimensional geometry so as to be produced as a series of layers in IGES format The AP defines the appropriateness of the data items for describing the geometry of the various parts of a product (shape and location), the connectivity, and the processing and material characteristics. Excluded is the behavioral requirements which the product was intended to satisfy, except as those requirements have been recorded as design rules or product testing requirements.
OPTIMISATION OF BUFFER SIZE FOR ENHANCING QOS OF VIDEO TRAFFIC USING CROSS LAYERED HYBRID TRANSPORT LAYER PROTOCOL APPROACH

Directory of Open Access Journals (Sweden)

S. Matilda

2011-03-01

Full Text Available Video streaming is gaining importance, with the wide popularity of multimedia rich applications in the Internet. Video streams are delay sensitive and require seamless flow for continuous visualization. Properly designed buffers offer a solution to queuing delay. The diagonally opposite QoS metrics associated with video traffic poses an optimization problem, in the design of buffers. This paper is a continuation of our previous work [1] and deals with the design of buffers. It aims at finding the optimum buffer size for enhancing QoS offered to video traffic. Network-centric QoS provisioning approach, along with hybrid transport layer protocol approach is adopted, to arrive at an optimum size which is independent of RTT. In this combinational approach, buffers of routers and end devices are designed to satisfy the various QoS parameters at the transport layer. OPNET Modeler is used to simulate environments for testing the design. Based on the results of simulation it is evident that the hybrid transport layer protocol approach is best suited for transmitting video traffic as it supports the economical design.
Layered Electrical Product Application Protocol (AP). Draft: Initial Graphics Exchange Specification (IGES)

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

An application protocol is an information systems engineering view of a specific product. The view represents an agreement on the generic activities needed to design and fabricate the product, the agreement on the information needed to support those activities, and the specific constructs of a product data standard for use in transfering some or all of the information required. This applications protocol describes the data for electrical and electronic products in terms of a product description standard called the Initial Graphics Exchange Specification (IGES). More specifically, the Layered Electrical Product IGES Application Protocol (AP) specifies the mechanisms for defining and exchanging computer-models and their associated data for those products which have been designed in two dimensional geometry so as to be produced as a series of layers in IGES format. The AP defines the appropriateness of the data items for describing the geometry of the various parts of a product (shape and location), the connectivity, and the processing and material characteristics. Excluded is the behavioral requirements which the product was intended to satisfy, except as those requirements have been recorded as design rules or product testing requirements.
Cross Layer PHY-MAC Protocol for Wireless Static and Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Chris Blondia

2008-11-01

Full Text Available Multihop mobile wireless networks have drawn a lot of attention in recent years thanks to their wide applicability in civil and military environments. Since the existing IEEE 802.11 distributed coordination function (DCF standard does not provide satisfactory access to the wireless medium in multihop mobile networks, we have designed a cross-layer protocol, (CroSs-layer noise aware power driven MAC (SNAPdMac, which consists of two parts. The protocol first concentrates on the flexible adjustment of the upper and lower bounds of the contention window (CW to lower the number of collisions. In addition, it uses a power control scheme, triggered by the medium access control (MAC layer, to limit the waste of energy and also to decrease the number of collisions. Thanks to a noticeable energy conservation and decrease of the number of collisions, it prolongs significantly the lifetime of the network and delays the death of the first node while increasing both the throughput performance and the sending bit rate/throughput fairness among contending flows.
Criteria for Evaluating Alternative Network and Link Layer Protocols for the NASA Constellation Program Communication Architecture

Science.gov (United States)

Benbenek, Daniel; Soloff, Jason; Lieb, Erica

2010-01-01

Selecting a communications and network architecture for future manned space flight requires an evaluation of the varying goals and objectives of the program, development of communications and network architecture evaluation criteria, and assessment of critical architecture trades. This paper uses Cx Program proposed exploration activities as a guideline; lunar sortie, outpost, Mars, and flexible path options are described. A set of proposed communications network architecture criteria are proposed and described. They include: interoperability, security, reliability, and ease of automating topology changes. Finally a key set of architecture options are traded including (1) multiplexing data at a common network layer vs. at the data link layer, (2) implementing multiple network layers vs. a single network layer, and (3) the use of a particular network layer protocol, primarily IPv6 vs. Delay Tolerant Networking (DTN). In summary, the protocol options are evaluated against the proposed exploration activities and their relative performance with respect to the criteria are assessed. An architectural approach which includes (a) the capability of multiplexing at both the network layer and the data link layer and (b) a single network layer for operations at each program phase, as these solutions are best suited to respond to the widest array of program needs and meet each of the evaluation criteria.

A Cross-Layer Duty Cycle MAC Protocol Supporting a Pipeline Feature for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Young-Chon Kim

2011-05-01

Full Text Available Although the conventional duty cycle MAC protocols for Wireless Sensor Networks (WSNs such as RMAC perform well in terms of saving energy and reducing end-to-end delivery latency, they were designed independently and require an extra routing protocol in the network layer to provide path information for the MAC layer. In this paper, we propose a new cross-layer duty cycle MAC protocol with data forwarding supporting a pipeline feature (P-MAC for WSNs. P-MAC first divides the whole network into many grades around the sink. Each node identifies its grade according to its logical hop distance to the sink and simultaneously establishes a sleep/wakeup schedule using the grade information. Those nodes in the same grade keep the same schedule, which is staggered with the schedule of the nodes in the adjacent grade. Then a variation of the RTS/CTS handshake mechanism is used to forward data continuously in a pipeline fashion from the higher grade to the lower grade nodes and finally to the sink. No extra routing overhead is needed, thus increasing the network scalability while maintaining the superiority of duty-cycling. The simulation results in OPNET show that P-MAC has better performance than S-MAC and RMAC in terms of packet delivery latency and energy efficiency.
Two-Layer Hierarchy Optimization Model for Communication Protocol in Railway Wireless Monitoring Networks

Directory of Open Access Journals (Sweden)

Xiaoping Ma

2018-01-01

Full Text Available The wireless monitoring system is always destroyed by the insufficient energy of the sensors in railway. Hence, how to optimize the communication protocol and extend the system lifetime is crucial to ensure the stability of system. However, the existing studies focused primarily on cluster-based or multihop protocols individually, which are ineffective in coping with the complex communication scenarios in the railway wireless monitoring system (RWMS. This study proposes a hybrid protocol which combines the cluster-based and multihop protocols (CMCP to minimize and balance the energy consumption in different sections of the RWMS. In the first hierarchy, the total energy consumption is minimized by optimizing the cluster quantities in the cluster-based protocol and the number of hops and the corresponding hop distances in the multihop protocol. In the second hierarchy, the energy consumption is balanced through rotating the cluster head (CH in the subnetworks and further optimizing the hops and the corresponding hop distances in the backbone network. On this basis, the system lifetime is maximized with the minimum and balance energy consumption among the sensors. Furthermore, the hybrid particle swarm optimization and genetic algorithm (PSO-GA are adopted to optimize the energy consumption from the two-layer hierarchy. Finally, the effectiveness of the proposed CMCP is verified in the simulation. The performances of the proposed CMCP in system lifetime, residual energy, and the corresponding variance are all superior to the LEACH protocol widely applied in the previous research. The effective protocol proposed in this study can facilitate the application of the wireless monitoring network in the railway system and enhance safety operation of the railway.
Adaptive MAC-layer protocol for multiservice digital access via tree and branch communication networks

Science.gov (United States)

Sriram, Kotikalapudi; Li, Chia-Chang; Magill, Peter; Whitaker, Norman A.; Dail, James E.; Dajer, Miguel A.; Siller, Curtis A.

1995-11-01

Described here is an adaptive MAC-layer protocol that supports multiservice (STM and ATM) applications in the context of subscriber access to tree and branch (e.g., fiber-coaxial cable) networks. The protocol adapts to changing demands for a mix of circuit and cell mode applications, and efficiently allocates upstream and downstream bandwidth to a variety of bursty and isochronous traffic sources. In the case of a hybrid fiber-coaxial (HFC) network the protocol resides in customer premises equipment and a common head-end controller. A medium-access control (MAC) processor provides for dividing the time domain for a given digital bitstream into successive frames, each with multiple STM and ATM time slots. Within the STM region of a frame, variable length time slots are allocated to calls (e.g., telephony, video telephony) requiring different amounts of bandwidth. A contention access signaling channel is also provided in this region for call control and set-up requests. Within the ATM region fixed-length time slots accommodate one individual ATM cell. These ATM time slots may be reserved for a user for the duration of a call or burst of successive ATM cells, or shared via a contention process. At least one contention time slot is available for signaling messages related to ATM call control and set-up requests. Further, the fixed-length ATM time slots may be reserved by a user for the duration of a call, or shared through a contention process. This paper describes the MAC-layer protocol, its relation to circuit- and ATM- amenable applications, and its performance with respect to signaling throughput and latency, and bandwidth efficiency for several service scenarios.
ANALISIS QOS PADA PEMBAGIAN BANDWIDTH DENGAN METODE LAYER 7 PROTOCOL, PCQ, HTB DAN HOTSPOT DI SMK SWASTA AL-WASHLIYAH PASAR SENEN

Directory of Open Access Journals (Sweden)

Dian Kurnia

2017-07-01

Full Text Available Pada penelitian ini akan dilakukan analisis QoS Pada Pembagian Bandwidth menggunakan metode HTB (Hierarchical Tocken Bucket, PCQ(Per Connection Queue dengan Layer 7 protocol sebagai limit file berekstensi, PCQ dan Hotspot. Pada HTB menggunakan teknik antrian queue tree, PCQ dengan Layer 7 protocol, PCQ menggunakan teknik antrian simple queue, hotspot menggunakan teknik antrian simple queue. Sehingga didapat perbandingan dari metode HTB (Hierarchical Tocken Bucket, PCQ dengan Layer 7 protocol, PCQ dan hotspot akan diterapkan pada mikrotik RB750GL. Hasil akhir penelitian ini diukur dengan parameter-parameter QoS throughput, delay (latency, jitter (variasi kedatangan paket, Packet loss. Adapun hasil pengujian dalam penelitian ini dilakukan pada trafik jam sibuk untuk mengetahui sejauh mana kinerja performansi management bandwidth dengan metode-metode tersebut. Dari hasil penelitian untuk performance QoS yang lebih baik untuk memanagement bandwidth di dapat nilai throughput, jitter dan delay terbaik yaitu menggunakan metode HTB.
A Brief Survey of Media Access Control, Data Link Layer, and Protocol Technologies for Lunar Surface Communications

Science.gov (United States)

Wallett, Thomas M.

2009-01-01

This paper surveys and describes some of the existing media access control and data link layer technologies for possible application in lunar surface communications and the advanced wideband Direct Sequence Code Division Multiple Access (DSCDMA) conceptual systems utilizing phased-array technology that will evolve in the next decade. Time Domain Multiple Access (TDMA) and Code Division Multiple Access (CDMA) are standard Media Access Control (MAC) techniques that can be incorporated into lunar surface communications architectures. Another novel hybrid technique that is recently being developed for use with smart antenna technology combines the advantages of CDMA with those of TDMA. The relatively new and sundry wireless LAN data link layer protocols that are continually under development offer distinct advantages for lunar surface applications over the legacy protocols which are not wireless. Also several communication transport and routing protocols can be chosen with characteristics commensurate with smart antenna systems to provide spacecraft communications for links exhibiting high capacity on the surface of the Moon. The proper choices depend on the specific communication requirements.
Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling.

Science.gov (United States)

Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

2015-09-18

This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols.
Impact of Transport Layer Protocols on Reliable Information Access in Smart Grids

DEFF Research Database (Denmark)

Shahid, Kamal; Saeed, Aamir; Kristensen, Thomas le Fevre

2017-01-01

Time is critical for certain types of dynamic information (e.g. frequency control) in a smart grid scenario. The usefulness of such information depends upon the arrival within a specific frame of time, which in other case may not serve the purpose and effect controller’s performance....... The question is addressed by analyzing the performance of UDP and TCP over imperfect network conditions to show how the selection of transport layer protocol can dramatically affect controller’s performance. This analysis is based on a quality metric called mismatch probability that considers occurrence...
Network Layer Protocol Activation for Packet Data Access in UMTS WCDMA Laboratory Network

OpenAIRE

Lakkisto, Erkka

2011-01-01

The purpose of this Bachelor’s Thesis was to set up the UMTS WCDMA network in the laboratory environment of Helsinki Metropolia University of Applied Sciences and to study the network layer protocol activation for packet data access. The development of 3G technology has been very rapid and it can be considered as one of the main technologies in telecommunication. Implementing the laboratory network in Metropolia enables teaching and researching of the modern network technology. Labora...
Sub-Transport Layer Coding

DEFF Research Database (Denmark)

Hansen, Jonas; Krigslund, Jeppe; Roetter, Daniel Enrique Lucani

2014-01-01

Packet losses in wireless networks dramatically curbs the performance of TCP. This paper introduces a simple coding shim that aids IP-layer traffic in lossy environments while being transparent to transport layer protocols. The proposed coding approach enables erasure correction while being...... oblivious to the congestion control algorithms of the utilised transport layer protocol. Although our coding shim is indifferent towards the transport layer protocol, we focus on the performance of TCP when ran on top of our proposed coding mechanism due to its widespread use. The coding shim provides gains...
Latency-Optimized and Energy-Efficient MAC Protocol for Underwater Acoustic Sensor Networks: A Cross-Layer Approach

Directory of Open Access Journals (Sweden)

Cheng Xiuzhen

2010-01-01

Full Text Available Considering the energy constraint for fixed sensor nodes and the unacceptable long propagation delay, especially for latency sensitive applications of underwater acoustic sensor networks, we propose a MAC protocol that is latency-optimized and energy-efficient scheme and combines the physical layer and the MAC layer to shorten transmission delay. On physical layer, we apply convolution coding and interleaver for transmitted information. Moreover, dynamic code rate is exploited at the receiver side to accelerate data reception rate. On MAC layer, unfixed frame length scheme is applied to reduce transmission delay, and to ensure the data successful transmission rate at the same time. Furthermore, we propose a network topology: an underwater acoustic sensor network with mobile agent. Through fully utilizing the supper capabilities on computation and mobility of autonomous underwater vehicles, the energy consumption for fixed sensor nodes can be extremely reduced, so that the lifetime of networks is extended.
A Review of Protocol Implementations and Energy Efficient Cross-Layer Design for Wireless Body Area Networks

Directory of Open Access Journals (Sweden)

Tao Chen

2012-11-01

Full Text Available The issues inherent in caring for an ever-increasing aged population has been the subject of endless debate and continues to be a hot topic for political discussion. The use of hospital-based facilities for the monitoring of chronic physiological conditions is expensive and ties up key healthcare professionals. The introduction of wireless sensor devices as part of a Wireless Body Area Network (WBAN integrated within an overall eHealth solution could bring a step change in the remote management of patient healthcare. Sensor devices small enough to be placed either inside or on the human body can form a vital part of an overall health monitoring network. An effectively designed energy efficient WBAN should have a minimal impact on the mobility and lifestyle of the patient. WBAN technology can be deployed within a hospital, care home environment or in the patient’s own home. This study is a review of the existing research in the area of WBAN technology and in particular protocol adaptation and energy efficient cross-layer design. The research reviews the work carried out across various layers of the protocol stack and highlights how the latest research proposes to resolve the various challenges inherent in remote continual healthcare monitoring.
Multimode Communication Protocols Enabling Reconfigurable Radios

Directory of Open Access Journals (Sweden)

Berlemann Lars

2005-01-01

Full Text Available This paper focuses on the realization and application of a generic protocol stack for reconfigurable wireless communication systems. This focus extends the field of software-defined radios which usually concentrates on the physical layer. The generic protocol stack comprises common protocol functionality and behavior which are extended through specific parts of the targeted radio access technology. This paper considers parameterizable modules of basic protocol functions residing in the data link layer of the ISO/OSI model. System-specific functionality of the protocol software is realized through adequate parameterization and composition of the generic modules. The generic protocol stack allows an efficient realization of reconfigurable protocol software and enables a completely reconfigurable wireless communication system. It is a first step from side-by-side realized, preinstalled modes in a terminal towards a dynamic reconfigurable anymode terminal. The presented modules of the generic protocol stack can also be regarded as a toolbox for the accelerated and cost-efficient development of future communication protocols.
Selecting corporate political tactics: The Montreal Protocol on substances that deplete the ozone layer

International Nuclear Information System (INIS)

Getz, K.A.

1991-01-01

This study examines factors influencing the choice of one set of tactics over others. The case of ozone depletion is used as the research context, and the data are drawn from US companies having a stake in this issue. A model is developed which suggests that a firm's choice of political tactics (dependent variable) is dependent on the targets of political activity and the nature of the issue of concern (independent variables), and a variety of organizational and industry factors (moderating variables). The paradigm of agency is used to systematically assess the relative importance of these factors. To test the relevance of the model, an empirical study was done. The case of the Montreal protocol on Substances That Deplete the Ozone Layer was chosen as a setting; and 551 firms directly affected by policy intended to protect the ozone layer were surveyed. There were 151 usable responses. Generally, the findings were consistent with the model
A software defined RTU multi-protocol automatic adaptation data transmission method

Science.gov (United States)

Jin, Huiying; Xu, Xingwu; Wang, Zhanfeng; Ma, Weijun; Li, Sheng; Su, Yong; Pan, Yunpeng

2018-02-01

Remote terminal unit (RTU) is the core device of the monitor system in hydrology and water resources. Different devices often have different communication protocols in the application layer, which results in the difficulty in information analysis and communication networking. Therefore, we introduced the idea of software defined hardware, and abstracted the common feature of mainstream communication protocols of RTU application layer, and proposed a uniformed common protocol model. Then, various communication protocol algorithms of application layer are modularized according to the model. The executable codes of these algorithms are labeled by the virtual functions and stored in the flash chips of embedded CPU to form the protocol stack. According to the configuration commands to initialize the RTU communication systems, it is able to achieve dynamic assembling and loading of various application layer communication protocols of RTU and complete the efficient transport of sensor data from RTU to central station when the data acquisition protocol of sensors and various external communication terminals remain unchanged.
Fast and easy protocol for the purification of recombinant S-layer protein for synthetic biology applications

KAUST Repository

Norville, Julie E.

2011-06-17

A goal of synthetic biology is to make biological systems easier to engineer. One of the aims is to design, with nanometer-scale precision, biomaterials with well-defined properties. The surface-layer protein SbpA forms 2D arrays naturally on the cell surface of Lysinibacillus sphaericus, but also as the purified protein in solution upon the addition of divalent cations. The high propensity of SbpA to form crystalline arrays, which can be simply controlled by divalent cations, and the possibility to genetically alter the protein, make SbpA an attractive molecule for synthetic biology. To be a useful tool, however, it is important that a simple protocol can be used to produce recombinant wild-type and modified SbpA in large quantities and in a biologically active form. The present study addresses this requirement by introducing a mild and non-denaturing purification protocol to produce milligram quantities of recombinant, active SbpA.
Modelling the protocol stack in NCS with deterministic and stochastic petri net

Science.gov (United States)

Hui, Chen; Chunjie, Zhou; Weifeng, Zhu

2011-06-01

Protocol stack is the basis of the networked control systems (NCS). Full or partial reconfiguration of protocol stack offers both optimised communication service and system performance. Nowadays, field testing is unrealistic to determine the performance of reconfigurable protocol stack; and the Petri net formal description technique offers the best combination of intuitive representation, tool support and analytical capabilities. Traditionally, separation between the different layers of the OSI model has been a common practice. Nevertheless, such a layered modelling analysis framework of protocol stack leads to the lack of global optimisation for protocol reconfiguration. In this article, we proposed a general modelling analysis framework for NCS based on the cross-layer concept, which is to establish an efficiency system scheduling model through abstracting the time constraint, the task interrelation, the processor and the bus sub-models from upper and lower layers (application, data link and physical layer). Cross-layer design can help to overcome the inadequacy of global optimisation based on information sharing between protocol layers. To illustrate the framework, we take controller area network (CAN) as a case study. The simulation results of deterministic and stochastic Petri-net (DSPN) model can help us adjust the message scheduling scheme and obtain better system performance.
Interoperability and Reliability of Multiplatform MPLS VPN: Comparison of Traffic Engineering with RSVP-TE Protocol and LDP Protocol

Directory of Open Access Journals (Sweden)

Nanang Ismail

2017-10-01

48% of packet loss per 100 sent packets while on RSVP packet loss percentage is 35.5% per 100 sent packets. Both protocols have interoperability on the third layer of multiplatform MPLS VPN, but on heavy loaded traffic condition, RSVP protocol has better reliability than the LDP protocol.
Link-layer Jamming Attacks on S-MAC

NARCIS (Netherlands)

Law, Y.W.; Hartel, Pieter H.; den Hartog, Jeremy; Havinga, Paul J.M.

2004-01-01

We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone.
Link-layer jamming attacks on S-MAC

NARCIS (Netherlands)

Law, Y.W.; Hartel, Pieter H.; den Hartog, Jeremy; Havinga, Paul J.M.

We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone.
The Network Protocol Analysis Technique in Snort

Science.gov (United States)

Wu, Qing-Xiu

Network protocol analysis is a network sniffer to capture data for further analysis and understanding of the technical means necessary packets. Network sniffing is intercepted by packet assembly binary format of the original message content. In order to obtain the information contained. Required based on TCP / IP protocol stack protocol specification. Again to restore the data packets at protocol format and content in each protocol layer. Actual data transferred, as well as the application tier.

High-Performance CCSDS AOS Protocol Implementation in FPGA

Science.gov (United States)

Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.
Protocol for Communication Networking for Formation Flying

Science.gov (United States)

Jennings, Esther; Okino, Clayton; Gao, Jay; Clare, Loren

2009-01-01

An application-layer protocol and a network architecture have been proposed for data communications among multiple autonomous spacecraft that are required to fly in a precise formation in order to perform scientific observations. The protocol could also be applied to other autonomous vehicles operating in formation, including robotic aircraft, robotic land vehicles, and robotic underwater vehicles. A group of spacecraft or other vehicles to which the protocol applies could be characterized as a precision-formation- flying (PFF) network, and each vehicle could be characterized as a node in the PFF network. In order to support precise formation flying, it would be necessary to establish a corresponding communication network, through which the vehicles could exchange position and orientation data and formation-control commands. The communication network must enable communication during early phases of a mission, when little positional knowledge is available. Particularly during early mission phases, the distances among vehicles may be so large that communication could be achieved only by relaying across multiple links. The large distances and need for omnidirectional coverage would limit communication links to operation at low bandwidth during these mission phases. Once the vehicles were in formation and distances were shorter, the communication network would be required to provide high-bandwidth, low-jitter service to support tight formation-control loops. The proposed protocol and architecture, intended to satisfy the aforementioned and other requirements, are based on a standard layered-reference-model concept. The proposed application protocol would be used in conjunction with conventional network, data-link, and physical-layer protocols. The proposed protocol includes the ubiquitous Institute of Electrical and Electronics Engineers (IEEE) 802.11 medium access control (MAC) protocol to be used in the datalink layer. In addition to its widespread and proven use in
Distributed Cross-layer Monitoring in Wireless Mesh Networks

OpenAIRE

Panmin, Ye; Yong,

2009-01-01

Wireless mesh networks has rapid development over the last few years. However, due to properties such as distributed infrastructure and interference, which strongly affect the performance of wireless mesh networks, developing technology has to face the challenge of architecture and protocol design issues. Traditional layered protocols do not function efficiently in multi-hop wireless environments. To get deeper understanding on interaction of the layered protocols and optimize the performance...
Satellite Communications Using Commercial Protocols

Science.gov (United States)

Ivancic, William D.; Griner, James H.; Dimond, Robert; Frantz, Brian D.; Kachmar, Brian; Shell, Dan

2000-01-01

NASA Glenn Research Center has been working with industry, academia, and other government agencies in assessing commercial communications protocols for satellite and space-based applications. In addition, NASA Glenn has been developing and advocating new satellite-friendly modifications to existing communications protocol standards. This paper summarizes recent research into the applicability of various commercial standard protocols for use over satellite and space- based communications networks as well as expectations for future protocol development. It serves as a reference point from which the detailed work can be readily accessed. Areas that will be addressed include asynchronous-transfer-mode quality of service; completed and ongoing work of the Internet Engineering Task Force; data-link-layer protocol development for unidirectional link routing; and protocols for aeronautical applications, including mobile Internet protocol routing for wireless/mobile hosts and the aeronautical telecommunications network protocol.
Energy Efficient Network Protocols for Wireless and Mobile Networks

National Research Council Canada - National Science Library

Sivalingam, Krishna

2001-01-01

... (also called power aware) network protocols for wireless and mobile networks. Battery power limitations are a very serious concern, and it is essential to study energy efficient protocol design at different layers of the network protocol stack...
Study on Cloud Security Based on Trust Spanning Tree Protocol

Science.gov (United States)

Lai, Yingxu; Liu, Zenghui; Pan, Qiuyue; Liu, Jing

2015-09-01

Attacks executed on Spanning Tree Protocol (STP) expose the weakness of link layer protocols and put the higher layers in jeopardy. Although the problems have been studied for many years and various solutions have been proposed, many security issues remain. To enhance the security and credibility of layer-2 network, we propose a trust-based spanning tree protocol aiming at achieving a higher credibility of LAN switch with a simple and lightweight authentication mechanism. If correctly implemented in each trusted switch, the authentication of trust-based STP can guarantee the credibility of topology information that is announced to other switch in the LAN. To verify the enforcement of the trusted protocol, we present a new trust evaluation method of the STP using a specification-based state model. We implement a prototype of trust-based STP to investigate its practicality. Experiment shows that the trusted protocol can achieve security goals and effectively avoid STP attacks with a lower computation overhead and good convergence performance.
A Scenario-Based Protocol Checker for Public-Key Authentication Scheme

Science.gov (United States)

Saito, Takamichi

Security protocol provides communication security for the internet. One of the important features of it is authentication with key exchange. Its correctness is a requirement of the whole of the communication security. In this paper, we introduce three attack models realized as their attack scenarios, and provide an authentication-protocol checker for applying three attack-scenarios based on the models. We also utilize it to check two popular security protocols: Secure SHell (SSH) and Secure Socket Layer/Transport Layer Security (SSL/TLS).
Comparison of different histological protocols for the preservation and quantification of the intestinal mucus layer in pigs.

Science.gov (United States)

Röhe, Ilen; Hüttner, Friedrich Joseph; Plendl, Johanna; Drewes, Barbara; Zentek, Jürgen

2018-02-05

The histological characterization of the intestinal mucus layer is important for many scientific experiments investigating the interaction between intestinal microbiota, mucosal immune response and intestinal mucus production. The aim of this study was to examine and compare different fixation protocols for displaying and quantifying the intestinal mucus layer in piglets and to test which histomorphological parameters may correlate with the determined mucus layer thickness. Jejunal and colonal tissue samples of weaned piglets (n=10) were either frozen in liquid nitrogen or chemically fixed using methacarn solution. The frozen tissue samples were cryosectioned and subsequently postfixed using three different postfixatives: paraformaldehyde vapor, neutrally buffered formalin solution and ethanol solution. After dehydration, methacarn fixed tissues were embedded in paraffin wax. Both sections of cryopreserved and methacarn fixed tissue samples were stained with Alcian blue (AB)-PAS followed by the microscopically determination of the mucus layer thickness. Different pH values of the Alcian Blue staining solution and two mucus layer thickness measuring methods were compared. In addition, various histomorphological parameters of methacarn fixed tissue samples were evaluated including the number of goblet cells and the mucin staining area. Cryopreservation in combination with chemical postfixation led to mucus preservation in the colon of piglets allowing mucus thickness measurements. Mucus could be only partly preserved in cryosections of the jejunum impeding any quantitative description of the mucus layer thickness. The application of different postfixations, varying pH values of the AB solution and different mucus layer measuring methods led to comparable results regarding the mucus layer thickness. Methacarn fixation proved to be unsuitable for mucus depiction as only mucus patches were found in the jejunum or a detachment of the mucus layer from the epithelium was
MAC-layer protocol for TCP fairness in Wireless Mesh Networks

KAUST Repository

Nawab, Faisal

2012-08-01

In this paper we study the interactions of TCP and IEEE 802.11 MAC in Wireless Mesh Networks (WMNs). We use a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue utilization and packet relaying. A closed form solution is derived to numerically determine the throughput. Based on the developed model, we propose a distributed MAC protocol to alleviate the unfairness problem in WMNs. Our protocol uses the age of packet as a priority metric for packet scheduling. Simulation is conducted to validate our model and to illustrate the fairness characteristics of our proposed MAC protocol. We conclude that we can achieve fairness with only little impact on network capacity.
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
Layer-by-layer assembly of patchy particles as a route to nontrivial structures

Science.gov (United States)

Patra, Niladri; Tkachenko, Alexei V.

2017-08-01

We propose a strategy for robust high-quality self-assembly of nontrivial periodic structures out of patchy particles and investigate it with Brownian dynamics simulations. Its first element is the use of specific patch-patch and shell-shell interactions between the particles, which can be implemented through differential functionalization of patched and shell regions with specific DNA strands. The other key element of our approach is the use of a layer-by-layer protocol that allows one to avoid the formation of undesired random aggregates. As an example, we design and self-assemble in silico a version of a double diamond lattice in which four particle types are arranged into bcc crystal made of four fcc sublattices. The lattice can be further converted to cubic diamond by selective removal of the particles of certain types. Our results demonstrate that by combining the directionality, selectivity of interactions, and the layer-by-layer protocol, a high-quality robust self-assembly can be achieved.
Optimization and Verification of the TR-MAC Protocol for Wireless Sensor Networks

NARCIS (Netherlands)

Morshed, S.; Heijenk, Geert

2015-01-01

Energy-efficiency is an important requirement in the design of communication protocols for wireless sensor networks (WSN). TR-MAC is an energy-efficient medium access control (MAC) layer protocol for low power WSN that exploits transmitted-reference (TR) modulation in the physical layer. The
Comparison of different histological protocols for the preservation and quantification of the intestinal mucus layer in pigs

Directory of Open Access Journals (Sweden)

Ilen Röhe

2018-02-01

Full Text Available The histological characterization of the intestinal mucus layer is important for many scientific experiments investigating the interaction between intestinal microbiota, mucosal immune response and intestinal mucus production. The aim of this study was to examine and compare different fixation protocols for displaying and quantifying the intestinal mucus layer in piglets and to test which histomorphological parameters may correlate with the determined mucus layer thickness. Jejunal and colonal tissue samples of weaned piglets (n=10 were either frozen in liquid nitrogen or chemically fixed using methacarn solution. The frozen tissue samples were cryosectioned and subsequently postfixed using three different postfixatives: paraformaldehyde vapor, neutrally buffered formalin solution and ethanol solution. After dehydration, methacarn fixed tissues were embedded in paraffin wax. Both sections of cryopreserved and methacarn fixed tissue samples were stained with Alcian blue (AB-PAS followed by the microscopically determination of the mucus layer thickness. Different pH values of the Alcian Blue staining solution and two mucus layer thickness measuring methods were compared. In addition, various histomorphological parameters of methacarn fixed tissue samples were evaluated including the number of goblet cells and the mucin staining area. Cryopreservation in combination with chemical postfixation led to mucus preservation in the colon of piglets allowing mucus thickness measurements. Mucus could be only partly preserved in cryosections of the jejunum impeding any quantitative description of the mucus layer thickness. The application of different postfixations, varying pH values of the AB solution and different mucus layer measuring methods led to comparable results regarding the mucus layer thickness. Methacarn fixation proved to be unsuitable for mucus depiction as only mucus patches were found in the jejunum or a detachment of the mucus layer from
Ambient Layer-by-Layer ZnO Assembly for Highly Efficient Polymer Bulk Heterojunction Solar Cells

KAUST Repository

Eita, Mohamed Samir; El Labban, Abdulrahman; Cruciani, Federico; Usman, Anwar; Beaujuge, Pierre; Mohammed, Omar F.

2015-01-01

The use of metal oxide interlayers in polymer solar cells has great potential because metal oxides are abundant, thermally stable, and can be used in fl exible devices. Here, a layer-by-layer (LbL) protocol is reported as a facile, room
Radio protocols for LTE and LTE-advanced

CERN Document Server

Yi, SeungJune; Lee, YoungDae; Park, SungJun; Jung, SungHoon

2012-01-01

Provides a unique focus on radio protocols for LTE and LTE-Advanced (LTE-A) Giving readers a valuable understanding of LTE radio protocols, this book covers LTE (Long-Term Evolution) Layer 2/3 radio protocols as well as new features including LTE-Advanced. It is divided into two sections to differentiate between the two technologies' characteristics. The authors systematically explain the design principles and functions of LTE radio protocols during the development of mobile handsets. The book also provides essential knowledge on the interaction between mobile networks a
Analyzing the effect of routing protocols on media access control protocols in radio networks

Energy Technology Data Exchange (ETDEWEB)

Barrett, C. L. (Christopher L.); Drozda, M. (Martin); Marathe, A. (Achla); Marathe, M. V. (Madhav V.)

2002-01-01

We study the effect of routing protocols on the performance of media access control (MAC) protocols in wireless radio networks. Three well known MAC protocols: 802.11, CSMA, and MACA are considered. Similarly three recently proposed routing protocols: AODV, DSR and LAR scheme 1 are considered. The experimental analysis was carried out using GloMoSim: a tool for simulating wireless networks. The main focus of our experiments was to study how the routing protocols affect the performance of the MAC protocols when the underlying network and traffic parameters are varied. The performance of the protocols was measured w.r.t. five important parameters: (i) number of received packets, (ii) average latency of each packet, (iii) throughput (iv) long term fairness and (v) number of control packets at the MAC layer level. Our results show that combinations of routing and MAC protocols yield varying performance under varying network topology and traffic situations. The result has an important implication; no combination of routing protocol and MAC protocol is the best over all situations. Also, the performance analysis of protocols at a given level in the protocol stack needs to be studied not locally in isolation but as a part of the complete protocol stack. A novel aspect of our work is the use of statistical technique, ANOVA (Analysis of Variance) to characterize the effect of routing protocols on MAC protocols. This technique is of independent interest and can be utilized in several other simulation and empirical studies.
PROTOCOLS FOR INCREASING THE LIFETIME OF NODES OF AD HOC WIRELESS NETWORKS

Directory of Open Access Journals (Sweden)

B.Malarkodi

2010-03-01

Full Text Available Power consumption of nodes in ad hoc networks is a critical issue as they predominantly operate on batteries. In order to improve the lifetime of an ad hoc network, all the nodes must be utilized evenly and the power required for connections must be minimized. Energy management deals with the process of managing energy resources by means of controlling the battery discharge, adjusting the transmission power and scheduling of power sources so as to increase the lifetime of the nodes of an ad hoc wireless network. In this paper, two protocols are proposed to improve the lifetime of the nodes. The first protocol assumes smart battery packages with L cells and uses dynamic programming (DP to optimally select the set of cells used to satisfy a request for power. The second one proposes a MAC layer protocol denoted as Power Aware medium Access Control (PAMAC protocol which enables the network layer to select a route with minimum total power requirement among the possible routes between a source and a destination provided all nodes in the routes have battery capacity above a threshold. The life time of the nodes using the DP based scheduling policy is found through simulation and compared with that obtained using the techniques reported in the literature. It is found that DP based policy increases the lifetime of the mobile nodes by a factor of 1.15 to 1.8. The life expectancy, the average power consumption and throughput of the network using PAMAC protocol are computed through simulation and compared with that of the other MAC layer protocols 802.11, MACA, and CSMA. Besides this, the life expectancy and average power consumption of the network for different values of threshold are also compared. From the simulation results, it is observed that PAMAC consumes the least power and provides the longest lifetime among the various MAC Layer protocols. Moreover, using PAMAC as the MAC layer protocol, the performance obtained using different routing layer
Telemetry Standards, IRIG Standard 106-17, Chapter 22, Network Based Protocol Suite

Science.gov (United States)

2017-07-01

requirements. 22.2 Network Access Layer 22.2.1 Physical Layer Connectors and cable media should meet the electrical or optical properties required by the...Telemetry Standards, IRIG Standard 106-17 Chapter 22, July 2017 i CHAPTER 22 Network -Based Protocol Suite Acronyms...iii Chapter 22. Network -Based Protocol Suite
A robust ECC based mutual authentication protocol with anonymity for session initiation protocol.

Science.gov (United States)

Mehmood, Zahid; Chen, Gongliang; Li, Jianhua; Li, Linsen; Alzahrani, Bander

2017-01-01

Over the past few years, Session Initiation Protocol (SIP) is found as a substantial application-layer protocol for the multimedia services. It is extensively used for managing, altering, terminating and distributing the multimedia sessions. Authentication plays a pivotal role in SIP environment. Currently, Lu et al. presented an authentication protocol for SIP and profess that newly proposed protocol is protected against all the familiar attacks. However, the detailed analysis describes that the Lu et al.'s protocol is exposed against server masquerading attack and user's masquerading attack. Moreover, it also fails to protect the user's identity as well as it possesses incorrect login and authentication phase. In order to establish a suitable and efficient protocol, having ability to overcome all these discrepancies, a robust ECC-based novel mutual authentication mechanism with anonymity for SIP is presented in this manuscript. The improved protocol contains an explicit parameter for user to cope the issues of security and correctness and is found to be more secure and relatively effective to protect the user's privacy, user's masquerading and server masquerading as it is verified through the comprehensive formal and informal security analysis.
A robust ECC based mutual authentication protocol with anonymity for session initiation protocol.

Directory of Open Access Journals (Sweden)

Zahid Mehmood

Full Text Available Over the past few years, Session Initiation Protocol (SIP is found as a substantial application-layer protocol for the multimedia services. It is extensively used for managing, altering, terminating and distributing the multimedia sessions. Authentication plays a pivotal role in SIP environment. Currently, Lu et al. presented an authentication protocol for SIP and profess that newly proposed protocol is protected against all the familiar attacks. However, the detailed analysis describes that the Lu et al.'s protocol is exposed against server masquerading attack and user's masquerading attack. Moreover, it also fails to protect the user's identity as well as it possesses incorrect login and authentication phase. In order to establish a suitable and efficient protocol, having ability to overcome all these discrepancies, a robust ECC-based novel mutual authentication mechanism with anonymity for SIP is presented in this manuscript. The improved protocol contains an explicit parameter for user to cope the issues of security and correctness and is found to be more secure and relatively effective to protect the user's privacy, user's masquerading and server masquerading as it is verified through the comprehensive formal and informal security analysis.

Power Saving MAC Protocols for WSNs and Optimization of S-MAC Protocol

Directory of Open Access Journals (Sweden)

Simarpreet Kaur

2012-11-01

Full Text Available Low power MAC protocols have received a lot of consideration in the last few years because of their influence on the lifetime of wireless sensor networks. Since, sensors typically operate on batteries, replacement of which is often difficult. A lot of work has been done to minimize the energy expenditure and prolong the sensor lifetime through energy efficient designs, across layers. Meanwhile, the sensor network should be able to maintain a certain throughput in order to fulfill the QoS requirements of the end user, and to ensure the constancy of the network. This paper introduces different types of MAC protocols used for WSNs and proposes S‐MAC, a Medium‐Access Control protocol designed for Wireless Sensor Networks. S‐MAC uses a few innovative techniques to reduce energy consumption and support selfconfiguration. A new protocol is suggested to improve the energy efficiency, latency and throughput of existing MAC protocol for WSNs. A modification of the protocol is then proposed to eliminate the need for some nodes to stay awake longer than the other nodes which improves the energy efficiency, latency and throughput and hence increases the life span of a wireless sensor network.
Cross-Layer Active Predictive Congestion Control Protocol for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Yinfeng Wu

2009-10-01

Full Text Available In wireless sensor networks (WSNs, there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node‟s neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.
Cross-layer active predictive congestion control protocol for wireless sensor networks.

Science.gov (United States)

Wan, Jiangwen; Xu, Xiaofeng; Feng, Renjian; Wu, Yinfeng

2009-01-01

In wireless sensor networks (WSNs), there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC) for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node's neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.
SPP: A data base processor data communications protocol

Science.gov (United States)

Fishwick, P. A.

1983-01-01

The design and implementation of a data communications protocol for the Intel Data Base Processor (DBP) is defined. The protocol is termed SPP (Service Port Protocol) since it enables data transfer between the host computer and the DBP service port. The protocol implementation is extensible in that it is explicitly layered and the protocol functionality is hierarchically organized. Extensive trace and performance capabilities have been supplied with the protocol software to permit optional efficient monitoring of the data transfer between the host and the Intel data base processor. Machine independence was considered to be an important attribute during the design and implementation of SPP. The protocol source is fully commented and is included in Appendix A of this report.
Ad hoc mobile wireless networks principles, protocols, and applications

CERN Document Server

Sarkar, Subir Kumar

2013-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Van Leeuwen, Brian P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eldridge, John M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-11-01

Wireless networking and mobile communications is increasing around the world and in all sectors of our lives. With increasing use, the density and complexity of the systems increase with more base stations and advanced protocols to enable higher data throughputs. The security of data transported over wireless networks must also evolve with the advances in technologies enabling more capable wireless networks. However, means for analysis of the effectiveness of security approaches and implementations used on wireless networks are lacking. More specifically a capability to analyze the lower-layer protocols (i.e., Link and Physical layers) is a major challenge. An analysis approach that incorporates protocol implementations without the need for RF emissions is necessary. In this research paper several emulation tools and custom extensions that enable an analysis platform to perform cyber security analysis of lower layer wireless networks is presented. A use case of a published exploit in the 802.11 (i.e., WiFi) protocol family is provided to demonstrate the effectiveness of the described emulation platform.
A Lightweight Protocol for Secure Video Streaming.

Science.gov (United States)

Venčkauskas, Algimantas; Morkevicius, Nerijus; Bagdonas, Kazimieras; Damaševičius, Robertas; Maskeliūnas, Rytis

2018-05-14

The Internet of Things (IoT) introduces many new challenges which cannot be solved using traditional cloud and host computing models. A new architecture known as fog computing is emerging to address these technological and security gaps. Traditional security paradigms focused on providing perimeter-based protections and client/server point to point protocols (e.g., Transport Layer Security (TLS)) are no longer the best choices for addressing new security challenges in fog computing end devices, where energy and computational resources are limited. In this paper, we present a lightweight secure streaming protocol for the fog computing "Fog Node-End Device" layer. This protocol is lightweight, connectionless, supports broadcast and multicast operations, and is able to provide data source authentication, data integrity, and confidentiality. The protocol is based on simple and energy efficient cryptographic methods, such as Hash Message Authentication Codes (HMAC) and symmetrical ciphers, and uses modified User Datagram Protocol (UDP) packets to embed authentication data into streaming data. Data redundancy could be added to improve reliability in lossy networks. The experimental results summarized in this paper confirm that the proposed method efficiently uses energy and computational resources and at the same time provides security properties on par with the Datagram TLS (DTLS) standard.
Protocol independent transmission method in software defined optical network

Science.gov (United States)

Liu, Yuze; Li, Hui; Hou, Yanfang; Qiu, Yajun; Ji, Yuefeng

2016-10-01

With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.i., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). Using a proprietary protocol or encoding format is a way to improve information security. However, the flow, which carried by proprietary protocol or code, cannot go through the traditional IP network. In addition, ultra- high-definition video transmission service once again become a hot spot. Traditionally, in the IP network, the Serial Digital Interface (SDI) signal must be compressed. This approach offers additional advantages but also bring some disadvantages such as signal degradation and high latency. To some extent, HD-SDI can also be regard as a proprietary protocol, which need transparent transmission such as optical channel. However, traditional optical networks cannot support flexible traffics . In response to aforementioned challenges for future network, one immediate solution would be to use NFV technology to abstract the network infrastructure and provide an all-optical switching topology graph for the SDN control plane. This paper proposes a new service-based software defined optical network architecture, including an infrastructure layer, a virtualization layer, a service abstract layer and an application layer. We then dwell on the corresponding service providing method in order to implement the protocol-independent transport. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit the HD-SDI signal in the software-defined optical network.
Protocol and Topology Issues for Wide-Area Satellite Interconnection of Terrestrial Optical LANs

Science.gov (United States)

Parraga, N.

2002-01-01

Apart from broadcasting, the satellite business is targeting niche markets. Wide area interconnection is considered as one of these niche markets, since it addresses operators and business LANs (B2B, business to business) in remote areas where terrestrial infrastructure is not available. These LANs - if high-speed - are typically based on optical networks such as SONET. One of the advantages of SONET is its architecture flexibility and capacity to transport all kind of applications including multimedia with a range of different transmission rates. The applications can be carried by different protocols among which the Internet Protocol (IP) or the Asynchronous Transfer Mode (ATM) are the most prominent ones. Thus, the question arises how these protocols can be interconnected via the satellite segment. The paper addresses several solutions for interworking with different protocols. For this investigation we distinguish first of all between the topology and the switching technology of the satellites. In case of a star network with transparent satellite, the satellite protocol consists of physical layer and data layer which can be directly interconnected with layer 2 interworking function to their terrestrial counterparts in the SONET backbone. For regenerative satellites the situation is more complex: here we need to distinguish the types of transport protocols being used in the terrestrial and satellite segment. Whereas IP, ATM, MPEG dominate in the terrestrial networks, satellite systems usually do not follow these standards. Some might employ minor additions (for instance, satellite specific packet headers), some might be completely proprietary. In general, interworking must be done for the data plane on top of layer 2 (data link layer), whereas for the signaling plane the interworking is on top of layer 3. In the paper we will discuss the protocol stacks for ATM, IP, and MPEG with a regenerative satellite system. As an example we will use the EuroSkyWay satellite
TULIP: A Link-Level Protocol for Improving TCP over Wireless Links

National Research Council Canada - National Science Library

Parsa, Christina; Garcia-Luna-Aceves, J. J

1999-01-01

We present the transport unaware link improvement protocol (TULIP), which dramatically improves the performance of TCP over lossy wireless links, without competing with or modifying the transport- or network-layer protocols...
CBHRP: A Cluster Based Routing Protocol for Wireless Sensor Network

OpenAIRE

Rashed, M. G.; Kabir, M. Hasnat; Rahim, M. Sajjadur; Ullah, Sk. Enayet

2012-01-01

A new two layer hierarchical routing protocol called Cluster Based Hierarchical Routing Protocol (CBHRP) is proposed in this paper. It is an extension of LEACH routing protocol. We introduce cluster head-set idea for cluster-based routing where several clusters are formed with the deployed sensors to collect information from target field. On rotation basis, a head-set member receives data from the neighbor nodes and transmits the aggregated results to the distance base station. This protocol ...
Ambient Layer-by-Layer ZnO Assembly for Highly Efficient Polymer Bulk Heterojunction Solar Cells

KAUST Repository

Eita, Mohamed Samir

2015-02-04

The use of metal oxide interlayers in polymer solar cells has great potential because metal oxides are abundant, thermally stable, and can be used in fl exible devices. Here, a layer-by-layer (LbL) protocol is reported as a facile, room-temperature, solution-processed method to prepare electron transport layers from commercial ZnO nanoparticles and polyacrylic acid (PAA) with a controlled and tunable porous structure, which provides large interfacial contacts with the active layer. Applying the LbL approach to bulk heterojunction polymer solar cells with an optimized ZnO layer thickness of H25 nm yields solar cell power-conversion effi ciencies (PCEs) of ≈6%, exceeding the effi ciency of amorphous ZnO interlayers formed by conventional sputtering methods. Interestingly, annealing the ZnO/PAA interlayers in nitrogen and air environments in the range of 60-300 ° C reduces the device PCEs by almost 20% to 50%, indicating the importance of conformational changes inherent to the PAA polymer in the LbL-deposited fi lms to solar cell performance. This protocol suggests a new fabrication method for solution-processed polymer solar cell devices that does not require postprocessing thermal annealing treatments and that is applicable to fl exible devices printed on plastic substrates.
A Secure Key Establishment Protocol for ZigBee Wireless Sensor Networks

DEFF Research Database (Denmark)

Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

2009-01-01

ZigBee is a wireless sensor network standard that defines network and application layers on top of IEEE 802.15.4’s physical and medium access control layers. In the latest version of ZigBee, enhancements are prescribed for the security sublayer but we show in this paper that problems persist....... In particular we show that the End-to-End Application Key Establishment Protocol is flawed and we propose a secure protocol instead. We do so by using formal verification techniques based on static program analysis and process algebras. We present a way of using formal methods in wireless network security......, and propose a secure key establishment protocol for ZigBee networks....
Protocol Interoperability Between DDN and ISO (Defense Data Network and International Organization for Standardization) Protocols

Science.gov (United States)

1988-08-01

services and protocols above the transport layer are usually implemented as user- callable utilities on the host computers, it is desirable to offer them...Networks, Prentice-hall, New Jersey, 1987 [ BOND 87] Bond , John, "Parallel-Processing Concepts Finally Come together in Real Systems", Computer Design
Protocol design and analysis for cooperative wireless networks

CERN Document Server

Song, Wei; Jin, A-Long

2017-01-01

This book focuses on the design and analysis of protocols for cooperative wireless networks, especially at the medium access control (MAC) layer and for crosslayer design between the MAC layer and the physical layer. It highlights two main points that are often neglected in other books: energy-efficiency and spatial random distribution of wireless devices. Effective methods in stochastic geometry for the design and analysis of wireless networks are also explored. After providing a comprehensive review of existing studies in the literature, the authors point out the challenges that are worth further investigation. Then, they introduce several novel solutions for cooperative wireless network protocols that reduce energy consumption and address spatial random distribution of wireless nodes. For each solution, the book offers a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate th...
Multichannel MAC Layer In Mobile Ad—Hoc Network

Science.gov (United States)

Logesh, K.; Rao, Samba Siva

2010-11-01

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

Science.gov (United States)

2013-03-01

today. The protocol operates at the application layer of the open systems interconnection ( OSI ) model, meaning it operates independently of the...the OSI model. Their job is to receive serial data from an MTU in the Modbus RTU or ASCII protocol, encapsulate and transmit the data to another modem...facing connection and out-of-band logging capabilities over the other LAN -facing connection. Despite the fact that the hardware configuration of the
Communicating systems with UML 2 modeling and analysis of network protocols

CERN Document Server

Barrera, David Garduno

2013-01-01

This book gives a practical approach to modeling and analyzing communication protocols using UML 2. Network protocols are always presented with a point of view focusing on partial mechanisms and starting models. This book aims at giving the basis needed for anybody to model and validate their own protocols. It follows a practical approach and gives many examples for the description and analysis of well known basic network mechanisms for protocols.The book firstly shows how to describe and validate the main protocol issues (such as synchronization problems, client-server interactions, layer
Cross-Layer Design in Dynamic Spectrum Sharing Systems

Directory of Open Access Journals (Sweden)

Shadmand A

2010-01-01

Full Text Available We consider a dynamic spectrum sharing system consisting of a primary user, whose licensed spectrum is allowed to be accessed by a secondary user as long as it does not violate the prescribed interference limit inflicted on the primary user. Assuming the Nakagami- block-fading environment, we aim at maximizing the performance of secondary user's link in terms of average spectral efficiency (ASE and error performance under the specified packet error rate (PER and average interference limit constraints. To this end, we employ a cross-layer design policy which combines adaptive power and coded discrete M-QAM modulation scheme at the physical layer with a truncated automatic repeat request (ARQ protocol at the data link layer, and simultaneously satisfies the aforementioned constraints. Numerical results affirm that the secondary link of spectrum sharing system combining ARQ with adaptive modulation and coding (AMC achieves significant gain in ASE depending on the maximum number of retransmissions initiated by the ARQ protocol. The results further indicate that the ARQ protocol essentially improves the packet loss rate performance of the secondary link.
Real-time communication protocols: an overview

NARCIS (Netherlands)

Hanssen, F.T.Y.; Jansen, P.G.

2003-01-01

This paper describes several existing data link layer protocols that provide real-time capabilities on wired networks, focusing on token-ring and Carrier Sense Multiple Access based networks. Existing modifications to provide better real-time capabilities and performance are also described. Finally

An Improved 6LoWPAN Hierarchical Routing Protocol

Directory of Open Access Journals (Sweden)

Xue Li

2015-10-01

Full Text Available IETF 6LoWPAN working group is engaged in the IPv6 protocol stack research work based on IEEE802.15.4 standard. In this working group, the routing protocol is one of the important research contents. In the 6LoWPAN, HiLow is a well-known layered routing protocol. This paper puts forward an improved hierarchical routing protocol GHiLow by improving HiLow parent node selection and path restoration strategy. GHiLow improves the parent node selection by increasing the choice of parameters. Simutaneously, it also improves path recovery by analysing different situations to recovery path. Therefore, GHiLow contributes to the ehancement of network performance and the decrease of network energy consumption.
Advertisement-Based Energy Efficient Medium Access Protocols for Wireless Sensor Networks

Science.gov (United States)

Ray, Surjya Sarathi

One of the main challenges that prevents the large-scale deployment of Wireless Sensor Networks (WSNs) is providing the applications with the required quality of service (QoS) given the sensor nodes' limited energy supplies. WSNs are an important tool in supporting applications ranging from environmental and industrial monitoring, to battlefield surveillance and traffic control, among others. Most of these applications require sensors to function for long periods of time without human intervention and without battery replacement. Therefore, energy conservation is one of the main goals for protocols for WSNs. Energy conservation can be performed in different layers of the protocol stack. In particular, as the medium access control (MAC) layer can access and control the radio directly, large energy savings is possible through intelligent MAC protocol design. To maximize the network lifetime, MAC protocols for WSNs aim to minimize idle listening of the sensor nodes, packet collisions, and overhearing. Several approaches such as duty cycling and low power listening have been proposed at the MAC layer to achieve energy efficiency. In this thesis, I explore the possibility of further energy savings through the advertisement of data packets in the MAC layer. In the first part of my research, I propose Advertisement-MAC or ADV-MAC, a new MAC protocol for WSNs that utilizes the concept of advertising for data contention. This technique lets nodes listen dynamically to any desired transmission and sleep during transmissions not of interest. This minimizes the energy lost in idle listening and overhearing while maintaining an adaptive duty cycle to handle variable loads. Additionally, ADV-MAC enables energy efficient MAC-level multicasting. An analytical model for the packet delivery ratio and the energy consumption of the protocol is also proposed. The analytical model is verified with simulations and is used to choose an optimal value of the advertisement period
A Mac Protocol Implementation for Wireless Sensor Network

Directory of Open Access Journals (Sweden)

Jamila Bhar

2015-01-01

Full Text Available IEEE 802.15.4 is an important standard for Low Rate Wireless Personal Area Network (LRWPAN. The IEEE 802.15.4 presents a flexible MAC protocol that provides good efficiency for data transmission by adapting its parameters according to characteristics of different applications. In this research work, some restrictions of this standard are explained and an improvement of traffic efficiency by optimizing MAC layer is proposed. Implementation details for several blocks of communication system are carefully modeled. The protocol implementation is done using VHDL language. The analysis gives a full understanding of the behavior of the MAC protocol with regard to backoff delay, data loss probability, congestion probability, slot effectiveness, and traffic distribution for terminals. Two ideas are proposed and tested to improve efficiency of CSMA/CA mechanism for IEEE 802.15.4 MAC Layer. Primarily, we dynamically adjust the backoff exponent (BE according to queue level of each node. Secondly, we vary the number of consecutive clear channel assessment (CCA for packet transmission. We demonstrate also that slot compensation provided by the enhanced MAC protocol can greatly avoid unused slots. The results show the significant improvements expected by our approach among the IEEE 802.15.4 MAC standards. Synthesis results show also hardware performances of our proposed architecture.
New secure communication-layer standard for medical image management (ISCL)

Science.gov (United States)

Kita, Kouichi; Nohara, Takashi; Hosoba, Minoru; Yachida, Masuyoshi; Yamaguchi, Masahiro; Ohyama, Nagaaki

1999-07-01

This paper introduces a summary of the standard draft of ISCL 1.00 which will be published by MEDIS-DC officially. ISCL is abbreviation of Integrated Secure Communication Layer Protocols for Secure Medical Image Management Systems. ISCL is a security layer which manages security function between presentation layer and TCP/IP layer. ISCL mechanism depends on basic function of a smart IC card and symmetric secret key mechanism. A symmetry key for each session is made by internal authentication function of a smart IC card with a random number. ISCL has three functions which assure authentication, confidently and integrity. Entity authentication process is done through 3 path 4 way method using functions of internal authentication and external authentication of a smart iC card. Confidentially algorithm and MAC algorithm for integrity are able to be selected. ISCL protocols are communicating through Message Block which consists of Message Header and Message Data. ISCL protocols are evaluating by applying to regional collaboration system for image diagnosis, and On-line Secure Electronic Storage system for medical images. These projects are supported by Medical Information System Development Center. These project shows ISCL is useful to keep security.
Cross-layer cluster-based energy-efficient protocol for wireless sensor networks.

Science.gov (United States)

Mammu, Aboobeker Sidhik Koyamparambil; Hernandez-Jayo, Unai; Sainz, Nekane; de la Iglesia, Idoia

2015-04-09

Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs). One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE) can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs) and a cluster head (CH). The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH) and hybrid energy-efficient distributed clustering (HEED).
Cross-Layer Cluster-Based Energy-Efficient Protocol for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Aboobeker Sidhik Koyamparambil Mammu

2015-04-01

Full Text Available Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs. One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs and a cluster head (CH. The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH and hybrid energy-efficient distributed clustering (HEED.
Next Generation Space Interconnect Standard (NGSIS): a modular open standards approach for high performance interconnects for space

Science.gov (United States)

Collier, Charles Patrick

2017-04-01

The Next Generation Space Interconnect Standard (NGSIS) effort is a Government-Industry collaboration effort to define a set of standards for interconnects between space system components with the goal of cost effectively removing bandwidth as a constraint for future space systems. The NGSIS team has selected the ANSI/VITA 65 OpenVPXTM standard family for the physical baseline. The RapidIO protocol has been selected as the basis for the digital data transport. The NGSIS standards are developed to provide sufficient flexibility to enable users to implement a variety of system configurations, while meeting goals for interoperability and robustness for space. The NGSIS approach and effort represents a radical departure from past approaches to achieve a Modular Open System Architecture (MOSA) for space systems and serves as an exemplar for the civil, commercial, and military Space communities as well as a broader high reliability terrestrial market.
The Unification of Space Qualified Integrated Circuits by Example of International Space Project GAMMA-400

Science.gov (United States)

Bobkov, S. G.; Serdin, O. V.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Suchkov, S. I.; Topchiev, N. P.

The problem of electronic component unification at the different levels (circuits, interfaces, hardware and software) used in space industry is considered. The task of computer systems for space purposes developing is discussed by example of scientific data acquisition system for space project GAMMA-400. The basic characteristics of high reliable and fault tolerant chips developed by SRISA RAS for space applicable computational systems are given. To reduce power consumption and enhance data reliability, embedded system interconnect made hierarchical: upper level is Serial RapidIO 1x or 4x with rate transfer 1.25 Gbaud; next level - SpaceWire with rate transfer up to 400 Mbaud and lower level - MIL-STD-1553B and RS232/RS485. The Ethernet 10/100 is technology interface and provided connection with the previously released modules too. Systems interconnection allows creating different redundancy systems. Designers can develop heterogeneous systems that employ the peer-to-peer networking performance of Serial RapidIO using multiprocessor clusters interconnected by SpaceWire.
A Review of Communications Protocol for Intelligent Remote Terminal Unit Development

Directory of Open Access Journals (Sweden)

Mohd Ruddin Ab. Ghani

2013-11-01

Full Text Available This paper reviewed all the possible interfacing communication protocols for remote terminal unit (RTU. Supervisory Control and Data Acquisition (SCADA system is a central station that can communicate with other network using the protocol. Fundamentally, the architectures of all networks are based on the seven layers of open system interconnection (OSI and International Standard Organization (ISO. The objective of designing the protocols is to check the status of all the input and output field devices and send the report according to that status. The corresponding protocol and communication parameters between the connecting devices will be included in designing a complex SCADA system. The available protocols to develop the communication of RTU are Modbus/ASCII, distributed network protocol (DNP3, controller area network (CAN, International Electro-technical Commission (IEC 60870, transmission control protocol/internet protocol (TCP/IP.
TOOL: The Open Opinion Layer

OpenAIRE

Masum, Hassan

2002-01-01

Shared opinions drive society: what we read, how we vote, and where we shop are all heavily influenced by the choices of others. However, the cost in time and money to systematically share opinions remains high, while the actual performance history of opinion generators is often not tracked. This article explores the development of a distributed open opinion layer, which is given the generic name of TOOL. Similar to the evolution of network protocols as an underlying layer for many comput...
The CCSDS Next Generation Space Data Link Protocol (NGSLP)

Science.gov (United States)

Kazz, Greg J.; Greenberg, Edward

2014-01-01

next leap in performance for space link communications. Field Programmable Gate Arrays (FPGAs) provide the capability to incorporate high performance forward error correcting codes implemented within software transponders providing improved performance in data transfer, ranging, link security, and time correlation. Given these synergistic technological breakthroughs, the time has come to take advantage of them in applying them to both on going (e.g., command, telemetry) and emerging (e.g., space link security, optical communication) space link applications. However one of the constraining factors within the Data Link Layer in realizing these performance gains is the lack of a generic transfer frame format and common supporting services amongst the existing CCSDS link layer protocols. Currently each of the four CCSDS link layer protocols (TM, TC, AOS, and Proximity-1) have unique formats and services which prohibits their reuse across the totality of all space link applications of CCSDS member space agencies. For example, Mars missions. These missions implement their proximity data link layer using the Proximity-1 frame format and the services it supports but is still required to support the direct from Earth (TC) protocols and the Direct To Earth (AOS/TM) protocols. The prime purpose of this paper, is to describe a new general purpose CCSDS Data Link layer protocol, the NGSLP that will provide the required services along with a common transfer frame format for all the CCSDS space links (ground to/from space and space to space links) targeted for emerging missions after a CCSDS agency-wide coordinated date. This paper will also describe related options that can be included for the Coding and Synchronization sub-layer of the Data Link layer to extend the capacities of the link and additionally provide an independence of the transfer frame sub-layer from the coding sublayer. This feature will provide missions the option of running either the currently performed
Catalyst layers for PEMFC manufactured by flexography printing process: performances and structure

Energy Technology Data Exchange (ETDEWEB)

Bois, C.; Blayo, A.; Chaussy, D. [Laboratory of Pulp and Paper Science and Graphic Arts (LGP2) (UMR 5518 CNRS-CTP-INPG), Grenoble Institute of Technology (INP Grenoble - PAGORA), St Martin d' Heres (France); Vincent, R.; Mercier, A.G.; Nayoze, C. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA)/DRT/LITEN, Laboratoire des Composants Piles a Combustible, Electrolyse et Modelisation (LCPEM), Grenoble (France)

2012-04-15

This article focuses on the potential of a classic printing process, flexography, for manufacturing proton exchange membrane fuel cells (PEMFCs). Gas diffusion electrodes (GDEs) are produced by deposition of a water-based catalyst ink on a gas diffusion layer (GDL). The affinity between the ink and the GDL is quantified. Thus, the strong hydrophobic character of the GDL and the poor printability of the ink are demonstrated. However, the permeability of the GDL allows developing a multilayer protocol. The deposition by superimposition of ink layers allows control of the platinum amount and to obtain catalyst layers with a similar density of platinum nanoparticles to coated samples. At similar platinum loading, flexography and coating made catalyst layers offer similar performances, which confirm the relevance of flexography in catalyst layer manufacturing. Structural characterization shows that manufacturing protocol and process has an influence on catalyst layer microstructure. However, catalyst layer cracking and aggregation are increased with the catalyst layer thickness, diminishing the charge and gas diffusion into the catalyst layer resulting in performance degradation. Consequently, a catalyst layer with 0.46 mgPt cm{sup -2} reaches similar performances to catalyst layers with 1.77 and 2.01 times less platinum loading. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
A Novel UDT-Based Transfer Speed-Up Protocol for Fog Computing

Directory of Open Access Journals (Sweden)

Zhijie Han

2018-01-01

Full Text Available Fog computing is a distributed computing model as the middle layer between the cloud data center and the IoT device/sensor. It provides computing, network, and storage devices so that cloud based services can be closer to IOT devices and sensors. Cloud computing requires a lot of bandwidth, and the bandwidth of the wireless network is limited. In contrast, the amount of bandwidth required for “fog computing” is much less. In this paper, we improved a new protocol Peer Assistant UDT-Based Data Transfer Protocol (PaUDT, applied to Iot-Cloud computing. Furthermore, we compared the efficiency of the congestion control algorithm of UDT with the Adobe’s Secure Real-Time Media Flow Protocol (RTMFP, based on UDP completely at the transport layer. At last, we built an evaluation model of UDT in RTT and bit error ratio which describes the performance. The theoretical analysis and experiment result have shown that UDT has good performance in IoT-Cloud computing.
Control System For Cryogenic THD Layering At The National Ignition Facility

International Nuclear Information System (INIS)

Fedorov, M.; Blubaugh, J.; Edwards, O.; Mauvais, M.; Sanchez, R.; Wilson, B.

2011-01-01

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 (micro)m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.
Silanization of silica and glass slides for DNA microarrays by impregnation and gas phase protocols: A comparative study

International Nuclear Information System (INIS)

Phaner-Goutorbe, Magali; Dugas, Vincent; Chevolot, Yann; Souteyrand, Eliane

2011-01-01

Surface immobilization of oligonucleotide probes (oligoprobes) is a key issue in the development of DNA-chips. The immobilization protocol should guarantee good availability of the probes, low non-specific adsorption and reproducibility. We have previously reported a silanization protocol with tert-butyl-11-(dimethylamino)silylundecanoate performed by impregnation (Impregnation Protocol, IP) of silica substrates from dilute silane solutions, leading to surfaces bearing carboxylic groups. In this paper, the Impregnation protocol is compared with a Gas phase Protocol (GP) which is more suited to industrial requirements such as reliable and robust processing, cost efficiency, etc.... The morphology of the oligoprobe films at the nanoscale (characterized by Atomic Force Microscopy) and the reproducibility of subsequent oligoprobes immobilization steps have been investigated for the two protocols on thermal silica (Si/SiO 2 ) and glass slide substrates. IP leads to smooth surfaces whereas GP induces the formation of islands features suggesting a non-continuous silane layer. The reproducibility of the overall surface layer (18.75 mm 2 ) has been evaluated through the covalent immobilization of a fluorescent oligoprobes. Average fluorescent signals of 6 (a.u.) and 4 (a.u.) were observed for IP and GP, respectively, with a standard deviation of 1 for both protocols. Thus, despite a morphological difference of the silane layer at the nanometer scale, the density of the immobilized probes remained similar.
A History of the Improvement of Internet Protocols Over Satellites Using ACTS

Science.gov (United States)

Allman, Mark; Kruse, Hans; Ostermann, Shawn

2000-01-01

This paper outlines the main results of a number of ACTS experiments on the efficacy of using standard Internet protocols over long-delay satellite channels. These experiments have been jointly conducted by NASAs Glenn Research Center and Ohio University over the last six years. The focus of our investigations has been the impact of long-delay networks with non-zero bit-error rates on the performance of the suite of Internet protocols. In particular, we have focused on the most widely used transport protocol, the Transmission Control Protocol (TCP), as well as several application layer protocols. This paper presents our main results, as well as references to more verbose discussions of our experiments.
The depletion of the stratospheric ozone layer

International Nuclear Information System (INIS)

Sabogal Nelson

2000-01-01

The protection of the Earth's ozone layer is of the highest importance to mankind. The dangers of its destruction are by now well known. The depletion of that layer has reached record levels. The Antarctic ozone hole covered this year a record area. The ozone layer is predicted to begin recovery in the next one or two decades and should be restored to pre-1980 levels by 2050. This is the achievement of the regime established by the 1985 Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. The regime established by these two agreements has been revised, and made more effective in London (1990), Copenhagen (1992), Vienna (1995), and Beijing (1999)
Cluster Based Hierarchical Routing Protocol for Wireless Sensor Network

OpenAIRE

Rashed, Md. Golam; Kabir, M. Hasnat; Rahim, Muhammad Sajjadur; Ullah, Shaikh Enayet

2012-01-01

The efficient use of energy source in a sensor node is most desirable criteria for prolong the life time of wireless sensor network. In this paper, we propose a two layer hierarchical routing protocol called Cluster Based Hierarchical Routing Protocol (CBHRP). We introduce a new concept called head-set, consists of one active cluster head and some other associate cluster heads within a cluster. The head-set members are responsible for control and management of the network. Results show that t...
A Pattern Language for Designing Application-Level Communication Protocols and the Improvement of Computer Science Education through Cloud Computing

OpenAIRE

Lascano, Jorge Edison

2017-01-01

Networking protocols have been developed throughout time following layered architectures such as the Open Systems Interconnection model and the Internet model. These protocols are grouped in the Internet protocol suite. Most developers do not deal with low-level protocols, instead they design application-level protocols on top of the low-level protocol. Although each application-level protocol is different, there is commonality among them and developers can apply lessons learned from one prot...
The Performance of a Second Generation Service Discovery Protocol In Response to Message Loss

NARCIS (Netherlands)

Sundramoorthy, V.; van de Glind, G.J.; Hartel, Pieter H.; Scholten, Johan

We analyze the behavior of FRODO, a second generation service discovery protocol, in response to message loss in the network. Earlier protocols, like UPnP and Jini rely on underlying network layers to enhance their failure recovery. A comparison with UPnP and Jini shows that FRODO performs more

The Performance of a Second Generation Service Discovery Protocol In Response to Message Loss

NARCIS (Netherlands)

Sundramoorthy, V.; van de Glind, G.J.; Hartel, Pieter H.; Scholten, Johan

We analyze the behavior of FRODO, a second generation service discovery protocol, in response to message loss in the network. First generation protocols, like UPnP and Jini rely on underlying network layers to enhance their failure recovery. A comparison with UPnP and Jini shows that FRODO performs
Energy consumption and quality of service in WBAN: A performance evaluation between cross-layer and IEEE802.15.4

OpenAIRE

Correa-Chica, Juan Camilo; Botero-Vega, Juan Felipe; Gaviria-Gómez, Natalia

2017-01-01

Abstract Different communication schemes for Wireless Body Area Networks (WBAN) pretend to achieve a fair tradeoff between efficient energy consumption and the accomplishment of performance metrics. Among those schemes are the Cross-layer protocols that constitute a good choice to achieve the aforementioned tradeoff by introducing novel protocol techniques which are away from the traditional communications model. In this work we assessed the performance of a WBAN cross-layer protocol stack by...
Multi-area layered multicast scheme for MPLS networks

Science.gov (United States)

Ma, Yajie; Yang, Zongkai; Wang, Yuming; Chen, Jingwen

2005-02-01

Multi-protocol label switching (MPLS) is multiprotocols both at layer 2 and layer 3. It is suggested to overcome the shortcomings of performing complex longest prefix matching in layer 3 routing by using short, fixed length labels. The MPLS community has put more effort into the label switching of unicast IP traffic, but less in the MPLS multicast mechanism. The reasons are the higher label consumption, the dynamical mapping of L3 multicast tree to L2 LSPs and the 20-bit shim header which is much fewer than the IPv4 IP header. On the other hand, heterogeneity of node capability degrades total performance of a multicast group. In order to achieve the scalability as well as the heterogeneity in MPLS networks, a novel scheme of MPLS-based Multi-area Layered Multicast Scheme (MALM) is proposed. Unlike the existing schemes which focus on aggregating the multicast stream, we construct the multicast tree based on the virtual topology aggregation. The MPLS area is divided into different sub-areas to form the hierarchical virtual topology and the multicast group is reconstructed into multiple layers according to the node capability. At the same time, the label stack is used to save the label space. For stability of the MALM protocol, a multi-layer protection scheme is also discussed. The experiment results show that the proposed scheme saves label space and decrease the Multicast Forwarding Table in much degree.
QoS-aware self-adaptation of communication protocols in a pervasive service middleware

DEFF Research Database (Denmark)

Zhang, Weishan; Hansen, Klaus Marius; Fernandes, João

2010-01-01

Pervasive computing is characterized by heterogeneous devices that usually have scarce resources requiring optimized usage. These devices may use different communication protocols which can be switched at runtime. As different communication protocols have different quality of service (Qo......S) properties, this motivates optimized self-adaption of protocols for devices, e.g., considering power consumption and other QoS requirements, e.g. round trip time (RTT) for service invocations, throughput, and reliability. In this paper, we present an extensible approach for self-adaptation of communication...... protocols for pervasive web services, where protocols are designed as reusable connectors and our middleware infrastructure can hide the complexity of using different communication protocols to upper layers. We also propose to use Genetic Algorithms (GAs) to find optimized configurations at runtime...
Lingual orthodontics for children and adolescents: improvement of the indirect bonding protocol

Science.gov (United States)

2013-01-01

Introduction Demineralization of the dental enamel is a finding associated with fixed orthodontic treatment. When an indirect bonding procedure is used in children and adolescents the area beneath the bracket base may be affected. Aim To evaluate if the addition of an extra layer of a hydrophilic resin, to a conventional indirect bonding protocol, can reduce the incidence of demineralization beneath the bracket base. Methods 40 patients under 18 years of age were treated with completely customized lingual appliances. Two different bonding protocols were used either with or without the application of an additional layer of hydrophilic resin. Demineralization beneath the bracket base, after de-bonding, was evaluated by standardized intra-oral photographs. Results The addition of an extra layer of a hydrophilic resin helps to reduce the number of demineralized areas beneath the bracket bases significantly (three times less). The severity of the few remaining defects were minor and without any clinical consequence. Conclusion When bonding a completely customized lingual appliance in children and adolescents, an extra layer of a hydrophilic resin should be added to the teeth. PMID:24025345
Protecting the ozone layer.

Science.gov (United States)

Munasinghe, M; King, K

1992-06-01

Stratospheric ozone layer depletion has been recognized as a problem by the Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol (MP). The ozone layer shields the earth from harmful ultraviolet radiation (UV-B), which is more pronounced at the poles and around the equator. Industrialized countries have contributed significantly to the problem by releasing chlorofluorocarbons (CFCs) and halons into the atmosphere. The effect of these chemicals, which were known for their inertness, nonflammability, and nontoxicity, was discovered in 1874. Action to deal with the effects of CFCs and halons was initiated in 1985 in a 49-nation UN meeting. 21 nations signed a protocol limiting ozone depleting substances (ODS): CFCs and halons. Schedules were set based on each country's use in 1986; the target phaseout was set for the year 2000. The MP restricts trade in ODSs and weights the impact of substances to reflect the extent of damage; i.e., halons are 10 times more damaging than CFCs. ODS requirements for developing countries were eased to accommodate scarce resources and the small fraction of ODS emissions. An Interim Multilateral Fund under the Montreal Protocol (IMFMP) was established to provide loans to finance the costs to developing countries in meeting global environmental requirements. The IMFMP is administered by the World Bank, the UN Environmental Program, and the UN Development Program. Financing is available to eligible countries who use .3 kg of ODS/person/year. Rapid phaseout in developed countries has occurred due to strong support from industry and a lower than expected cost. Although there are clear advantages to rapid phaseout, there were no incentives included in the MP for rapid phaseout. Some of the difficulties occur because the schedules set minimum targets at the lowest possible cost. Also, costs cannot be minimized by a country-specific and ODS-specific process. The ways to improve implementation in scheduling and
The importance of the Montreal Protocol in protecting climate

NARCIS (Netherlands)

Velders, G.J.M.; Andersen, S.O.; Daniel, J.S.; Fahey, D.W.; McFarland, M.

2007-01-01

The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer is a landmark agreement that has successfully reduced the global production, consumption, and emissions of ozone-depleting substances (ODSs). ODSs are also greenhouse gases that contribute to the radiative forcing of climate
Energy efficient routing protocols for wireless sensor networks: comparison and future directions

Directory of Open Access Journals (Sweden)

Loganathan Murukesan

2017-01-01

Full Text Available Wireless sensor network consists of nodes with limited resources. Hence, it is important to design protocols or algorithms which increases energy efficiency in order to improve the network lifetime. In this paper, techniques used in the network layer (routing of the internet protocol stack to achieve energy efficiency are reviewed. Usually, the routing protocols are classified into four main schemes: (1 Network Structure, (2 Communication Model, (3 Topology Based, and (4 Reliable Routing. In this work, only network structure based routing protocols are reviewed due to the page constraint. Besides, this type of protocols are much popular among the researchers since they are fairly simple to implement and produce good results as presented in this paper. Also, the pros and cons of each protocols are presented. Finally, the paper concludes with possible further research directions.
Automatic Traffic-Based Internet Control Message Protocol (ICMP) Model Generation for ns-3

Science.gov (United States)

2015-12-01

more protocols (especially at different layers of the OSI model ), implementing an inference engine to extract inter- and intrapacket dependencies, and...ARL-TR-7543 ● DEC 2015 US Army Research Laboratory Automatic Traffic-Based Internet Control Message Protocol (ICMP) Model ...ICMP) Model Generation for ns-3 by Jaime C Acosta and Felipe Jovel Survivability/Lethality Analysis Directorate, ARL Felipe Sotelo and Caesar
Mac protocols for wireless sensor network (wsn): a comparative study

International Nuclear Information System (INIS)

Arshad, J.; Akram, Q.; Saleem, Y.

2014-01-01

Data communication between nodes is carried out under Medium Access Control (MAC) protocol which is defined at data link layer. The MAC protocols are responsible to communicate and coordinate between nodes according to the defined standards in WSN (Wireless Sensor Networks). The design of a MAC protocol should also address the issues of energy efficiency and transmission efficiency. There are number of MAC protocols that exist in the literature proposed for WSN. In this paper, nine MAC protocols which includes S-MAC, T-MAC, Wise-MAC, Mu-MAC, Z-MAC, A-MAC, D-MAC, B-MAC and B-MAC+ for WSN have been explored, studied and analyzed. These nine protocols are classified in contention based and hybrid (combination of contention and schedule based) MAC protocols. The goal of this comparative study is to provide a basis for MAC protocols and to highlight different mechanisms used with respect to parameters for the evaluation of energy and transmission efficiency in WSN. This study also aims to give reader a better understanding of the concepts, processes and flow of information used in these MAC protocols for WSN. A comparison with respect to energy reservation scheme, idle listening avoidance, latency, fairness, data synchronization, and throughput maximization has been presented. It was analyzed that contention based MAC protocols are less energy efficient as compared to hybrid MAC protocols. From the analysis of contention based MAC protocols in term of energy consumption, it was being observed that protocols based on preamble sampling consume lesser energy than protocols based on static or dynamic sleep schedule. (author)
UV Impacts Avoided by the Montreal Protocol

Science.gov (United States)

Newman, Paul; McKenzie, Richard

2010-01-01

Temporal and geographical variabilities in the future "World Expected" UV environment are compared with the "World Avoided", which would have occurred without the Montreal Protocol on protection of the ozone layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes which could also be important.
Research and implementation of intelligent gateway driver layer based on Linux bus

Directory of Open Access Journals (Sweden)

ZHANG Jian

2016-10-01

Full Text Available Currently,in the field of smart home,there is no relevant organization that yet has proposed an unified protocol standard.It increases the complexity and limitations of heterogeneous gateway software framework design that different vendor′s devices have different communication mode and protocol standards.In this paper,a serial of interfaces are provided by Linux kernel,and a virtual bus is registered under Linux.The physical device drivers are able to connect to the virtual bus.The detailed designs of the communication protocol are placed in the underlying adapters,making the integration of heterogeneous networks more natural.At the same time,designing the intelligent gateway system driver layer based on Linux bus can let the application layer be more unified and clear logical.And it also let the hardware access network become more convenient and distinct.
Optimised cross-layer synchronisation schemes for wireless sensor networks

Science.gov (United States)

Nasri, Nejah; Ben Fradj, Awatef; Kachouri, Abdennaceur

2017-07-01

This paper aims at synchronisation between the sensor nodes. Indeed, in the context of wireless sensor networks, it is necessary to take into consideration the energy cost induced by the synchronisation, which can represent the majority of the energy consumed. On communication, an already identified hard point consists in imagining a fine synchronisation protocol which must be sufficiently robust to the intermittent energy in the sensors. Hence, this paper worked on aspects of performance and energy saving, in particular on the optimisation of the synchronisation protocol using cross-layer design method such as synchronisation between layers. Our approach consists in balancing the energy consumption between the sensors and choosing the cluster head with the highest residual energy in order to guarantee the reliability, integrity and continuity of communication (i.e. maximising the network lifetime).
Identifying Opportunities for Exploiting Cross-Layer Interactions in Adaptive Wireless Systems

Directory of Open Access Journals (Sweden)

Troy Weingart

2007-01-01

Full Text Available The flexibility of cognitive and software-defined radio heralds an opportunity for researchers to reexamine how network protocol layers operate with respect to providing quality of service aware transmission among wireless nodes. This opportunity is enhanced by the continued development of spectrally responsive devices—ones that can detect and respond to changes in the radio frequency environment. Present wireless network protocols define reliability and other performance-related tasks narrowly within layers. For example, the frame size employed on 802.11 can substantially influence the throughput, delay, and jitter experienced by an application, but there is no simple way to adapt this parameter. Furthermore, while the data link layer of 802.11 provides error detection capabilities across a link, it does not specify additional features, such as forward error correction schemes, nor does it provide a means for throttling retransmissions at the transport layer (currently, the data link and transport layer can function counterproductively with respect to reliability. This paper presents an analysis of the interaction of physical, data link, and network layer parameters with respect to throughput, bit error rate, delay, and jitter. The goal of this analysis is to identify opportunities where system designers might exploit cross-layer interactions to improve the performance of Voice over IP (VoIP, instant messaging (IM, and file transfer applications.
Cross-Layer Handover Scheme for Multimedia Communications in Next Generation Wireless Networks

Directory of Open Access Journals (Sweden)

Lin Chun-Cheng

2010-01-01

Full Text Available In order to achieve seamless handover for real-time applications in the IP Multimedia Subsystem (IMS of next generation network, a multiprotocol combined handover mechanism is proposed in this paper. We combine SIP (Session Initiation Protocol, FMIP (Fast Mobile IPv6 Protocol, and MIH (Media Independent Handover protocols by cross-layer design and optimize those protocols' signaling flows to improve the performance of vertical handover. Theoretical analysis and simulation results illustrate that our proposed mechanism performs better than the original SIP and MIH combined handover mechanism in terms of service interruption time and packet loss.
On the security of the Mobile IP protocol family

NARCIS (Netherlands)

Meyer, Ulrike; Tschofenig, Hannes; Karagiannis, Georgios; Devetsikiotis, M.; Michailidis, G.

2007-01-01

The Internet Engineering Task Force (IETF) has worked on network layer mobility for more than 10 years and a number of RFCs are available by now. Although the IETF mobility protocols are not present in the Internet infrastructure as of today, deployment seems to be imminent since a number of
A SURVEY ON MULTICAST ROUTING PROTOCOLS FOR PERFORMANCE EVALUATION IN WIRELESS SENSOR NETWORK

Directory of Open Access Journals (Sweden)

A. Suruliandi

2015-03-01

Full Text Available Multicast is a process used to transfer same message to multiple receivers at the same time. This paper presents the simulation and analysis of the performance of six different multicast routing protocols for Wireless Sensor Network (WSN. They are On Demand Multicast Routing Protocol (ODMRP, Protocol for Unified Multicasting through Announcement (PUMA, Multicast Adhoc On demand Distance Vector Protocol (MAODV, Overlay Boruvka-based Adhoc Multicast Protocol (OBAMP, Application Layer Multicast Algorithm (ALMA and enhanced version of ALMA (ALMA-H for WSN. Among them, ODMRP, MAODV and PUMA are reactive protocols while OBAMP, ALMA and ALMA-H are proactive protocols. This paper compares the performance of these protocols with common parameters such as Throughput, Reliability, End-to-End delay and Packet Delivery Ratio (PDR with increasing the numbers of nodes and increasing the speed of the nodes. The main objective of this work is to select the efficient multicast routing protocol for WSN among six multicast routing protocol based on relative strength and weakness of each protocol. The summary of above six multicast routing protocols is presented with a table of different performance characteristics. Experimental result shows that ODMRP attains higher throughput, reliability and higher packet delivery ratio than other multicast routing protocol, while incurring far less end-to-end delay.
Experimental Evaluation of Simulation Abstractions for Wireless Sensor Network MAC Protocols

Directory of Open Access Journals (Sweden)

G. P. Halkes

2010-01-01

Full Text Available The evaluation of MAC protocols for Wireless Sensor Networks (WSNs is often performed through simulation. These simulations necessarily abstract away from reality in many ways. However, the impact of these abstractions on the results of the simulations has received only limited attention. Moreover, many studies on the accuracy of simulation have studied either the physical layer and per link effects or routing protocol effects. To the best of our knowledge, no other work has focused on the study of the simulation abstractions with respect to MAC protocol performance. In this paper, we present the results of an experimental study of two often used abstractions in the simulation of WSN MAC protocols. We show that a simple SNR-based reception model can provide quite accurate results for metrics commonly used to evaluate MAC protocols. Furthermore, we provide an analysis of what the main sources of deviation are and thereby how the simulations can be improved to provide even better results.
Equation Chapter 1 Section 1Cross Layer Design for Localization in Large-Scale Underwater Sensor Networks

Directory of Open Access Journals (Sweden)

Yuanfeng ZHANG

2014-02-01

Full Text Available There are many technical challenges for designing large-scale underwater sensor networks, especially the sensor node localization. Although many papers studied for large-scale sensor node localization, previous studies mainly study the location algorithm without the cross layer design for localization. In this paper, by utilizing the network hierarchical structure of underwater sensor networks, we propose a new large-scale underwater acoustic localization scheme based on cross layer design. In this scheme, localization is performed in a hierarchical way, and the whole localization process focused on the physical layer, data link layer and application layer. We increase the pipeline parameters which matched the acoustic channel, added in MAC protocol to increase the authenticity of the large-scale underwater sensor networks, and made analysis of different location algorithm. We conduct extensive simulations, and our results show that MAC layer protocol and the localization algorithm all would affect the result of localization which can balance the trade-off between localization accuracy, localization coverage, and communication cost.
Protocol for characterization of clay as a backfill and coverage layers for surface repository

International Nuclear Information System (INIS)

Santos, Daisy M.M.; Tello, Clédola C.O.

2017-01-01

The Radioactive Waste Management includes the operations since generation of the waste until its storage in repository, ensuring the protection of human beings and the environment from the possible negative impacts. The radioactive waste is segregated, treated, conditioned in suitable packages for posterior storage or disposal in repository. The 'RBMN Project' objective is to implement the repository for the disposal of low and intermediate level radioactive wastes generated by nuclear activities in Brazil, proposing a definitive solution for their storage. Engineered and natural barriers as the backfill and coverage layers will compose the disposal system of a near surface repository, concept proposed by the 'RBMN Project'. The use of these barriers aims to avoid or restrict the release of radionuclides from the waste to the human beings and environment. The waterproofing barriers are composed of clays. Certainly, for the national repository, will be used those clays existing in the place where it will be constructed. Them some basic tests will have to be carried out to verify the suitability of these clays as barriers. These tests were determined and performed with reference clay, a Brazilian bentonite constituted of 67.2% montmorillonite. The results were compared with national and international literature of materials with similar mineralogical features. The values found with 95% of confidence interval were 9.73±0,35 μm for granulometric size; 13,3±0,6% for the moisture content and 816±9 mmol.kg -1 for the capacity of cationic exchange. A protocol for characterization of clay was elaborated presenting these tests for it future use. (author)

Protocol for characterization of clay as a backfill and coverage layers for surface repository

Energy Technology Data Exchange (ETDEWEB)

Santos, Daisy M.M.; Tello, Clédola C.O., E-mail: marymarchezini@gmail.com, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

The Radioactive Waste Management includes the operations since generation of the waste until its storage in repository, ensuring the protection of human beings and the environment from the possible negative impacts. The radioactive waste is segregated, treated, conditioned in suitable packages for posterior storage or disposal in repository. The 'RBMN Project' objective is to implement the repository for the disposal of low and intermediate level radioactive wastes generated by nuclear activities in Brazil, proposing a definitive solution for their storage. Engineered and natural barriers as the backfill and coverage layers will compose the disposal system of a near surface repository, concept proposed by the 'RBMN Project'. The use of these barriers aims to avoid or restrict the release of radionuclides from the waste to the human beings and environment. The waterproofing barriers are composed of clays. Certainly, for the national repository, will be used those clays existing in the place where it will be constructed. Them some basic tests will have to be carried out to verify the suitability of these clays as barriers. These tests were determined and performed with reference clay, a Brazilian bentonite constituted of 67.2% montmorillonite. The results were compared with national and international literature of materials with similar mineralogical features. The values found with 95% of confidence interval were 9.73±0,35 μm for granulometric size; 13,3±0,6% for the moisture content and 816±9 mmol.kg{sup -1} for the capacity of cationic exchange. A protocol for characterization of clay was elaborated presenting these tests for it future use. (author)
A Survey on Multimedia-Based Cross-Layer Optimization in Visual Sensor Networks

Science.gov (United States)

Costa, Daniel G.; Guedes, Luiz Affonso

2011-01-01

Visual sensor networks (VSNs) comprised of battery-operated electronic devices endowed with low-resolution cameras have expanded the applicability of a series of monitoring applications. Those types of sensors are interconnected by ad hoc error-prone wireless links, imposing stringent restrictions on available bandwidth, end-to-end delay and packet error rates. In such context, multimedia coding is required for data compression and error-resilience, also ensuring energy preservation over the path(s) toward the sink and improving the end-to-end perceptual quality of the received media. Cross-layer optimization may enhance the expected efficiency of VSNs applications, disrupting the conventional information flow of the protocol layers. When the inner characteristics of the multimedia coding techniques are exploited by cross-layer protocols and architectures, higher efficiency may be obtained in visual sensor networks. This paper surveys recent research on multimedia-based cross-layer optimization, presenting the proposed strategies and mechanisms for transmission rate adjustment, congestion control, multipath selection, energy preservation and error recovery. We note that many multimedia-based cross-layer optimization solutions have been proposed in recent years, each one bringing a wealth of contributions to visual sensor networks. PMID:22163908
Experimental investigation of Cu-based, double-layered, microchannel heat exchangers

International Nuclear Information System (INIS)

Lu, Bin; Meng, W J; Mei, Fanghua

2013-01-01

Cu-based, single- and double-layered, microchannel heat exchangers (MHEs) were fabricated and assembled. Comparative measurements on liquid flow characteristics and heat transfer performance were conducted on these devices. Results were compared at the individual microchannel level as well as at the device level. The present results demonstrate that double-layered MHEs exhibit similar heat transfer performance while suffering a much lower pressure drop penalty compared to single-layered MHEs. Another Cu-based, double-layered, liquid–liquid counter-flow MHE was fabricated, assembled and tested. Results show that a low-volume, multilayered, high-performance, liquid-to-liquid MHE is achievable following the manufacturing protocols of the present double-layered, liquid–liquid counter-flow MHE. (paper)
An improved network layer protocol based on mobile IPv6

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The mobile [Pv6 proposed by the IETF aims at providing mobility support on the next generation Internet. First, the authors described the basic principle of mobile lPv6 in brief and analyzed the advantages and disadvantages of it, presented a new idea of allocating a specific address space for mobile node ( MN ) and developed a new extension header and two ICMP message types for mobile IPv6. Lastly the authors proposed an optimization strategy, for mobile IPv6 based on these extensions of protocol, which has the following advantages:1 ) It is more convenient to manage the MNs because MN can be judged from its IP address; 2) When the correspondent node (CN) is not actively communicating with a MN, the MN and its home agent (HA) need not send Binding Update to tire CN, and the CN need not send Binding Request to the MN. Only when the CN really wants to send a packet to the MN, will the CN voluntarily send a MN Discover Request message to acquire the MN's care-of address. In this way, the transmission of Binding Update and Binding Request is greatly reduced, consequently the network overhead is also decreased; 3) While sending packets, the CN simply uses a MN Home Address Extension Header without using IPinlP encapsulation and routing header, which can reduce the redundant information in the packet and the message delay; 4) All the packets sent by the CN can be directly routed to the MN and the triangle routing can be completely avoided. By using these protocol extensions, the overhead of the network is greatly reduced and the network quality of services (QoS) is improved.
Formal Specification and Description Language and Message Sequence Chart to Model and Validate Session Initiation Protocol Services

OpenAIRE

Sa'ed Abed; Mohammad H. Al Shayeji; Ovais Ahmed; Sahel Alouneh

2016-01-01

Session Initiation Protocol (SIP) is a signaling layer protocol for building, adjusting and ending sessions among participants including Internet conferences, telephone calls and multimedia distribution. SIP facilitates user movement by proxying and forwarding requests to the present location of the user. In this paper, we provide a formal Specification and Description Language (SDL) and Message Sequence Chart (MSC) to model and define the Internet Engineering Task Force (IETF) SIP protocol a...
Effect of Duration of Irrigation with Sodium Hypochlorite in Clinical Protocol of MTAD on Removal of Smear Layer and Creating Dentinal Erosion

Science.gov (United States)

Lotfi, Mehrdad; Moghaddam, Negar; Vosoughhosseini, Sepideh; Zand, Vahid; Saghiri, Mohammad Ali

2012-01-01

Background and aims The aim of the present study was to compare 1.3% sodium hypochlorite (NaOCl) in MTAD (mixture of tetracycline isomer, acid, and detergent) for the removal of the smear layer and induction of canal erosion. Materials and methods 38 maxillary incisors were divided in three experimental groups of 10 and two positive and negative control groups of each 4 teeth, and prepared using rotary files. In test groups, 1.3% NaOCl was used for 5, 10 and 20 minutes during preparation followed by MTAD as the final rinse. In negative control group, 5.25% NaOCl was used for 10 minutes followed by 17% Ethylenediamine Tetra-Acetic Acid (EDTA) as the final rinse. In positive control group, dis-tilled water was used for 10 minutes during preparation and then as the final rinse. The samples were examined under scan-ning electron microscope, and the smear layer and dentinal erosion scores were recorded. Results Five and 10 min groups had significant differences with 20 min group (p < 0.05). In apical third, 5 and 10 min groups had also significant differences with 20 min (p < 0.05). In the coronal thirds, when the time of irrigation with 1.3% NaOCl increased from 5 min to 20 min, erosion also increased significantly. However, 5 and 10 min groups had no signifi-cant differences with negative control group. Conclusion The use of 1.3% sodium hypochlorite for 5 and 10 minutes in the MTAD protocol removes the smear layer in the coronal and middle thirds but does not induce erosion. PMID:22991642
A Survey on Application Layer Protocols for the Internet of Things

OpenAIRE

Karagiannis, Vasileios; Chatzimisios, Periklis; Vázquez-Gallego, Francisco; Alonso-Zárate, Jesús

2015-01-01

It has been more than fifteen years since the term Internet of Things (IoT) was introduced to the public. However, despite the efforts of research groups and innovative corporations, still today it is not possible to say that IoT is upon us. This is mainly due to the fact that a unified IoT architecture has not been yet clearly defined and there is no common agreement in defining protocols and standards for all IoT parts. The framework that current IoT platforms use consists mostly in technol...
Development of high-reliable real-time communication network protocol for SMART

Energy Technology Data Exchange (ETDEWEB)

Song, Ki Sang; Kim, Young Sik [Korea National University of Education, Chongwon (Korea); No, Hee Chon [Korea Advanced Institute of Science and Technology, Taejon (Korea)

1999-04-01

In this research, we first define protocol subsets for SMART(System-integrated Modular Advanced Reactor) communication network based on the requirement of SMART MMIS transmission delay and traffic requirements and OSI(Open System Interconnection) 7 layers' network protocol functions. Also, current industrial purpose LAN protocols are analyzed and the applicability of commercialized protocols are checked. For the suitability test, we have applied approximated SMART data traffic and maximum allowable transmission delay requirement. With the simulation results, we conclude that IEEE 802.5 and FDDI which is an ANSI standard, is the most suitable for SMART. We further analyzed the FDDI and token ring protocols for SMART and nuclear plant network environment including IEEE 802.4, IEEE 802.5, and ARCnet. The most suitable protocol for SMART is FDDI and FDDI MAC and RMT protocol specifications have been verified with LOTOS and the verification results show that FDDI MAC and RMT satisfy the reachability and liveness, but does not show deadlock and livelock. Therefore, we conclude that FDDI MAC and RMT is highly reliable protocol for SMART MMIS network. After that, we consider the stacking fault of IEEE 802.5 token ring protocol and propose a fault tolerant MAM(Modified Active Monitor) protocol. The simulation results show that the MAM protocol improves lower priority traffic service rate when stacking fault occurs. Therefore, proposed MAM protocol can be applied to SMART communication network for high reliability and hard real-time communication purpose in data acquisition and inter channel network. (author). 37 refs., 79 figs., 39 tabs.
Cross-Layer Design of Source Rate Control and Congestion Control for Wireless Video Streaming

Directory of Open Access Journals (Sweden)

Peng Zhu

2007-01-01

Full Text Available Cross-layer design has been used in streaming video over the wireless channels to optimize the overall system performance. In this paper, we extend our previous work on joint design of source rate control and congestion control for video streaming over the wired channel, and propose a cross-layer design approach for wireless video streaming. First, we extend the QoS-aware congestion control mechanism (TFRCC proposed in our previous work to the wireless scenario, and provide a detailed discussion about how to enhance the overall performance in terms of rate smoothness and responsiveness of the transport protocol. Then, we extend our previous joint design work to the wireless scenario, and a thorough performance evaluation is conducted to investigate its performance. Simulation results show that by cross-layer design of source rate control at application layer and congestion control at transport layer, and by taking advantage of the MAC layer information, our approach can avoid the throughput degradation caused by wireless link error, and better support the QoS requirements of the application. Thus, the playback quality is significantly improved, while good performance of the transport protocol is still preserved.
Backup key generation model for one-time password security protocol

Science.gov (United States)

Jeyanthi, N.; Kundu, Sourav

2017-11-01

The use of one-time password (OTP) has ushered new life into the existing authentication protocols used by the software industry. It introduced a second layer of security to the traditional username-password authentication, thus coining the term, two-factor authentication. One of the drawbacks of this protocol is the unreliability of the hardware token at the time of authentication. This paper proposes a simple backup key model that can be associated with the real world applications’user database, which would allow a user to circumvent the second authentication stage, in the event of unavailability of the hardware token.
Report on the behalf of the Foreign Affairs Commission on the bill project authorizing the approval of the amendment to the Montreal protocol of 16 September 1987 related to substances which impoverish the ozone layer, and its Annexe: text of the foreign affairs Commission. Nr 415

International Nuclear Information System (INIS)

Di Pompeo, Christophe

2017-01-01

The objective of the Montreal protocol, adopted in 1987, was to banish the chlorofluorocarbons (CFC) used as refrigerants since the 1930's, as they are responsible for the impoverishment of the ozone layer. While this objective has been met (the ozone layer is progressively restored), substitutes to CFC have been developed; however some of these substitutes, hydro-fluorocarbons, have been proved to be powerful greenhouse gases. The banishment of HFCs has thus been decided, leading to the Kigali amendment to the Montreal protocol. This report explains the CFC and HFC context and issues in details, and presents its examination by the French Commission of Foreign Affairs. The full text of the report is included (in an annex) at the end of the report
A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states

International Nuclear Information System (INIS)

Xu Shu-Jiang; Wang Lian-Hai; Chen Xiu-Bo; Niu Xin-Xin; Yang Yi-Xian

2015-01-01

Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication (QSDC) channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security. (paper)
A Simple XML Producer-Consumer Protocol

Science.gov (United States)

Smith, Warren; Gunter, Dan; Quesnel, Darcy; Biegel, Bryan (Technical Monitor)

2001-01-01

performance data. These standard protocols and representations must support tasks such as profiling parallel applications, monitoring the status of computers and networks, and monitoring the performance of services provided by a computational grid. This paper describes a proposed protocol and data representation for the exchange of events in a distributed system. The protocol exchanges messages formatted in XML and it can be layered atop any low-level communication protocol such as TCP or UDP Further, we describe Java and C++ implementations of this protocol and discuss their performance. The next section will provide some further background information. Section 3 describes the main communication patterns of our protocol. Section 4 describes how we represent events and related information using XML. Section 5 describes our protocol and Section 6 discusses the performance of two implementations of the protocol. Finally, an appendix provides the XML Schema definition of our protocol and event information.
AR-RBFS: Aware-Routing Protocol Based on Recursive Best-First Search Algorithm for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Farzad Kiani

2016-01-01

Full Text Available Energy issue is one of the most important problems in wireless sensor networks. They consist of low-power sensor nodes and a few base station nodes. They must be adaptive and efficient in data transmission to sink in various areas. This paper proposes an aware-routing protocol based on clustering and recursive search approaches. The paper focuses on the energy efficiency issue with various measures such as prolonging network lifetime along with reducing energy consumption in the sensor nodes and increasing the system reliability. Our proposed protocol consists of two phases. In the first phase (network development phase, the sensors are placed into virtual layers. The second phase (data transmission is related to routes discovery and data transferring so it is based on virtual-based Classic-RBFS algorithm in the lake of energy problem environments but, in the nonchargeable environments, all nodes in each layer can be modeled as a random graph and then begin to be managed by the duty cycle method. Additionally, the protocol uses new topology control, data aggregation, and sleep/wake-up schemas for energy saving in the network. The simulation results show that the proposed protocol is optimal in the network lifetime and packet delivery parameters according to the present protocols.
Cross-Layer Design Approach for Power Control in Mobile Ad Hoc Networks

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A. Sarfaraz Ahmed

2015-03-01

Full Text Available In mobile ad hoc networks, communication among mobile nodes occurs through wireless medium The design of ad hoc network protocol, generally based on a traditional “layered approach”, has been found ineffective to deal with receiving signal strength (RSS-related problems, affecting the physical layer, the network layer and transport layer. This paper proposes a design approach, deviating from the traditional network design, toward enhancing the cross-layer interaction among different layers, namely physical, MAC and network. The Cross-Layer design approach for Power control (CLPC would help to enhance the transmission power by averaging the RSS values and to find an effective route between the source and the destination. This cross-layer design approach was tested by simulation (NS2 simulator and its performance over AODV was found to be better.
Architecture Design Approaches and Issues in Cross Layer Systems

DEFF Research Database (Denmark)

Cattoni, Andrea Fabio; Sørensen, Troels Bundgaard; Mogensen, Preben

2012-01-01

the traditional protocol stack design methodology. However, Cross Layer also carries a risk due to possibly unexpected and undesired effects. In this chapter we want to provide architecture designers with a set of tools and recommendations synthesized from an analysis of the state of art, but enriched...
About the Design of QUIC Firefox Transport Protocol

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Vraj Pandya

2017-07-01

Full Text Available QUIC (Quick UDP Internet Connections Chrome is an experimental transport layer network protocol designed by Jim Roskind at Google, initially implemented in 2012 and announced publicly in 2013. One of the QUIC's goals is to improve performance of connection-oriented web applications that are currently using the Transmission Control Protocol (TCP. To do that, QUIC achieves a reduced latency and a better stream-multiplexing support to avoid network congestion. In 2015, Firefox Mozilla started to work on an equivalent QUIC transport protocol for their browser. This idea was motivated by the differences between Chrome and Firefox. Despite the fact that Mozilla Firefox and Google Chrome are both web browser engines, there are some significant differences between them, such as file hierarchy, open source policies (Firefox is completely, while Chrome is only partial, tabs design, continuous integration, and more. Likewise QUIC Chrome, QUIC Firefox is a new multiplexed and secure transport based on User Datagram Protocol (UDP, designed from the ground up and optimized for Hyper-Text Transfer Protocol 2 (HTTP/2 semantics. While built with HTTP/2 as the primary application protocol, QUIC builds on decades of transport and security experience, and implements mechanisms that make it attractive as a modern general-purpose transport. In addition to describing the main design of QUIC Firefox, this paper will compare Firefox with QUIC Firefox. Our preliminary experimental results support that QUIC Firefox has a faster execution time, less latency time, and a better throughput time than the traditional Firefox.
An efficient multi-carrier position-based packet forwarding protocol for wireless sensor networks

KAUST Repository

Bader, Ahmed

2012-01-01

Beaconless position-based forwarding protocols have recently evolved as a promising solution for packet forwarding in wireless sensor networks. However, as the node density grows, the overhead incurred in the process of relay selection grows significantly. As such, end-to-end performance in terms of energy and latency is adversely impacted. With the motivation of developing a packet forwarding mechanism that is tolerant to variation in node density, an alternative position-based protocol is proposed in this paper. In contrast to existing beaconless protocols, the proposed protocol is designed such that it eliminates the need for potential relays to undergo a relay selection process. Rather, any eligible relay may decide to forward the packet ahead, thus significantly reducing the underlying overhead. The operation of the proposed protocol is empowered by exploiting favorable features of orthogonal frequency division multiplexing (OFDM) at the physical layer. The end-to-end performance of the proposed protocol is evaluated against existing beaconless position-based protocols analytically and as well by means of simulations. The proposed protocol is demonstrated in this paper to be more efficient. In particular, it is shown that for the same amount of energy the proposed protocol transports one bit from source to destination much quicker. © 2012 IEEE.
Self-assembled Nano-layering at the Adhesive interface.

Science.gov (United States)

Yoshida, Y; Yoshihara, K; Nagaoka, N; Hayakawa, S; Torii, Y; Ogawa, T; Osaka, A; Meerbeek, B Van

2012-04-01

According to the 'Adhesion-Decalcification' concept, specific functional monomers within dental adhesives can ionically interact with hydroxyapatite (HAp). Such ionic bonding has been demonstrated for 10-methacryloyloxydecyl dihydrogen phosphate (MDP) to manifest in the form of self-assembled 'nano-layering'. However, it remained to be explored if such nano-layering also occurs on tooth tissue when commercial MDP-containing adhesives (Clearfil SE Bond, Kuraray; Scotchbond Universal, 3M ESPE) were applied following common clinical application protocols. We therefore characterized adhesive-dentin interfaces chemically, using x-ray diffraction (XRD) and energy-dispersive x-ray spectroscopy (EDS), and ultrastructurally, using (scanning) transmission electron microscopy (TEM/STEM). Both adhesives revealed nano-layering at the adhesive interface, not only within the hybrid layer but also, particularly for Clearfil SE Bond (Kuraray), extending into the adhesive layer. Since such self-assembled nano-layering of two 10-MDP molecules, joined by stable MDP-Ca salt formation, must make the adhesive interface more resistant to biodegradation, it may well explain the documented favorable clinical longevity of bonds produced by 10-MDP-based adhesives.
A Two-Layered Mobility Architecture Using Fast Mobile IPv6 and Session Initiation Protocol

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Nursimloo DeeyaS

2008-01-01

Full Text Available Abstract This paper proposes an integrated mobility scheme that combines the procedures of fast handover for Mobile IPv6 (FMIPv6 and session initiation protocol (SIP mobility for realtime communications. This integrated approach is based on the context of the applications utilized. Furthermore, to reduce system redundancies and signaling loads, several functionalities of FMIPv6 and SIP have been integrated to optimize the integrated mobility scheme. The proposed scheme aims at reducing the handover latency and packet loss for an ongoing realtime traffic. Using ns-2 simulation, we analyze the performance of the proposed integrated scheme and compare it with the existing protocols for a VoIP and for a video stream traffic. This mobility architecture achieves lower handover delay and less packet loss than using either FMIPv6 or SIP and hence presents a powerful handover mobility scheme for next generation IP-based wireless systems.

A Two-Layered Mobility Architecture Using Fast Mobile IPv6 and Session Initiation Protocol

Directory of Open Access Journals (Sweden)

Deeya S. Nursimloo

2007-12-01

Full Text Available This paper proposes an integrated mobility scheme that combines the procedures of fast handover for Mobile IPv6 (FMIPv6 and session initiation protocol (SIP mobility for realtime communications. This integrated approach is based on the context of the applications utilized. Furthermore, to reduce system redundancies and signaling loads, several functionalities of FMIPv6 and SIP have been integrated to optimize the integrated mobility scheme. The proposed scheme aims at reducing the handover latency and packet loss for an ongoing realtime traffic. Using ns-2 simulation, we analyze the performance of the proposed integrated scheme and compare it with the existing protocols for a VoIP and for a video stream traffic. This mobility architecture achieves lower handover delay and less packet loss than using either FMIPv6 or SIP and hence presents a powerful handover mobility scheme for next generation IP-based wireless systems.
Design and Development of Layered Security: Future Enhancements and Directions in Transmission

Science.gov (United States)

Shahzad, Aamir; Lee, Malrey; Kim, Suntae; Kim, Kangmin; Choi, Jae-Young; Cho, Younghwa; Lee, Keun-Kwang

2016-01-01

Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA) systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3) design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack. PMID:26751443
Design and Development of Layered Security: Future Enhancements and Directions in Transmission

Directory of Open Access Journals (Sweden)

Aamir Shahzad

2016-01-01

Full Text Available Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3 design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack.
ABORt: Acknowledgement-Based Opportunistic Routing Protocol for High Data Rate Multichannel WSNs

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Hamadoun Tall

2017-10-01

Full Text Available The ease of deployment and the auto-configuration capabilities of Wireless Sensor Networks (WSNs make them very attractive in different domains like environmental, home automation or heath care applications. The use of multichannel communications in WSNs helps to improve the overall performance of the network. However, in heavy traffic scenarios, routing protocols should be adapted to allow load balancing and to avoid losing data packets due to congestion and queue overflow. In this paper, we present an Acknowledgement-Based Opportunistic Routing (ABORt protocol designed for high data rate multichannel WSNs. It is a low overhead protocol that does not rely on synchronization for control traffic exchange during the operational phase of the network. ABORt is an opportunistic protocol that relies on link layer acknowledgements to disseminate routing metrics, which helps to reduce overhead. The performance of ABORt is evaluated using the Cooja simulator and the obtained results show that ABORt has a high packet delivery ratio with reduced packet end-to-end delay compared to two single channel routing protocols and two multichannel routing protocols that use number of hops and expected transmission count as routing metrics.
Vienna Agreement law 15.986 it approve Vienna Agreement for Protection ozone layer and annex

International Nuclear Information System (INIS)

1988-01-01

The Agreement of Vienna is approved with respect to the protection of the Layer of Ozono, definitions,general duties, research and observations systematics, co-operation in the Spheres Scientific Juridical, and information, Technological Conference, transmission from the protocols, amends, secretariat, adoption to the agreement or the protocols, adoption and amendment of controversy, signing, ratify, approve annexes, solution or vote, relation approving, adhesion, rights between the present agreement and its protocols, entrance in vigor, reserves, retirement, deposition, exchange of information [es
The Importance of the Montreal Protocol in Protecting the Earth's Hydroclimate

Science.gov (United States)

Seager, R.; Wu, Y.; Polvani, L. M.

2012-12-01

The 1987 Montreal Protocol regulating emissions of ozone depleting chlorofluorocarbons (CFCs) was motivated primarily by the harm to human health and ecosystems arising from increased exposure to ultraviolet-B (UV-B) radiation associated with depletion from the ozone layer. It is now known that the Montreal Protocol has reduced global warming since CFCs are greenhouse gases (GHGs). In this paper we show that the Montreal Protocol also significantly protects the Earth's hydroclimate, even though this was also not a motivating factor in the decision-making that led to the Protocol. General Circulation Model (GCM) results show that in the coming decade (2020-29), under the 'World Avoided' scenario of no regulations on CFC emissions, the subtropical dry zones would in general get drier, and the middle and high latitude regions wetter. This change is similar, in both pattern and magnitude, to that in the coming decade caused by projected increases in carbon dioxide concentrations. This implies that because of the Montreal Protocol, and the ozone depletion and global warming associated with CFCs thus avoided, the hydrological cycle changes in the coming decade will be significantly less than what they otherwise would have been.
A universal data access and protocol integration mechanism for smart home

Science.gov (United States)

Shao, Pengfei; Yang, Qi; Zhang, Xuan

2013-03-01

With the lack of standardized or completely missing communication interfaces in home electronics, there is no perfect solution to address every aspect in smart homes based on existing protocols and technologies. In addition, the central control unit (CCU) of smart home system working point-to-point between the multiple application interfaces and the underlying hardware interfaces leads to its complicated architecture and unpleasant performance. A flexible data access and protocol integration mechanism is required. The current paper offers a universal, comprehensive data access and protocol integration mechanism for a smart home. The universal mechanism works as a middleware adapter with unified agreements of the communication interfaces and protocols, offers an abstraction of the application level from the hardware specific and decoupling the hardware interface modules from the application level. Further abstraction for the application interfaces and the underlying hardware interfaces are executed based on adaption layer to provide unified interfaces for more flexible user applications and hardware protocol integration. This new universal mechanism fundamentally changes the architecture of the smart home and in some way meets the practical requirement of smart homes more flexible and desirable.
Compact Modbus TCP/IP protocol for data acquisition systems based on limited hardware resources

Science.gov (United States)

Bai, Q.; Jin, B.; Wang, D.; Wang, Y.; Liu, X.

2018-04-01

The Modbus TCP/IP has been a standard industry communication protocol and widely utilized for establishing sensor-cloud platforms on the Internet. However, numerous existing data acquisition systems built on traditional single-chip microcontrollers without sufficient resources cannot support it, because the complete Modbus TCP/IP protocol always works dependent on a full operating system which occupies abundant hardware resources. Hence, a compact Modbus TCP/IP protocol is proposed in this work to make it run efficiently and stably even on a resource-limited hardware platform. Firstly, the Modbus TCP/IP protocol stack is analyzed and the refined protocol suite is rebuilt by streamlining the typical TCP/IP suite. Then, specific implementation of every hierarchical layer is respectively presented in detail according to the protocol structure. Besides, the compact protocol is implemented in a traditional microprocessor to validate the feasibility of the scheme. Finally, the performance of the proposed scenario is assessed. The experimental results demonstrate that message packets match the frame format of Modbus TCP/IP protocol and the average bandwidth reaches to 1.15 Mbps. The compact protocol operates stably even based on a traditional microcontroller with only 4-kB RAM and 12-MHz system clock, and no communication congestion or frequent packet loss occurs.
MOS-Based Multiuser Multiapplication Cross-Layer Optimization for Mobile Multimedia Communication

Directory of Open Access Journals (Sweden)

Shoaib Khan

2007-01-01

Full Text Available We propose a cross-layer optimization strategy that jointly optimizes the application layer, the data-link layer, and the physical layer of a wireless protocol stack using an application-oriented objective function. The cross-layer optimization framework provides efficient allocation of wireless network resources across multiple types of applications run by different users to maximize network resource usage and user perceived quality of service. We define a novel optimization scheme based on the mean opinion score (MOS as the unifying metric over different application classes. Our experiments, applied to scenarios where users simultaneously run three types of applications, namely voice communication, streaming video and file download, confirm that MOS-based optimization leads to significant improvement in terms of user perceived quality when compared to conventional throughput-based optimization.
Software Modules for the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

Science.gov (United States)

Woo, Simon S.; Veregge, John R.; Gao, Jay L.; Clare, Loren P.; Mills, David

2012-01-01

The Proximity-1 Space Link Interleaved Time Synchronization (PITS) protocol provides time distribution and synchronization services for space systems. A software prototype implementation of the PITS algorithm has been developed that also provides the test harness to evaluate the key functionalities of PITS with simulated data source and sink. PITS integrates time synchronization functionality into the link layer of the CCSDS Proximity-1 Space Link Protocol. The software prototype implements the network packet format, data structures, and transmit- and receive-timestamp function for a time server and a client. The software also simulates the transmit and receive-time stamp exchanges via UDP (User Datagram Protocol) socket between a time server and a time client, and produces relative time offsets and delay estimates.
Cross Layer Optimization and Simulation of Smart Grid Home Area Network

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Lipi K. Chhaya

2018-01-01

Full Text Available An electrical “Grid” is a network that carries electricity from power plants to customer premises. Smart Grid is an assimilation of electrical and communication infrastructure. Smart Grid is characterized by bidirectional flow of electricity and information. Smart Grid is a complex network with hierarchical architecture. Realization of complete Smart Grid architecture necessitates diverse set of communication standards and protocols. Communication network protocols are engineered and established on the basis of layered approach. Each layer is designed to produce an explicit functionality in association with other layers. Layered approach can be modified with cross layer approach for performance enhancement. Complex and heterogeneous architecture of Smart Grid demands a deviation from primitive approach and reworking of an innovative approach. This paper describes a joint or cross layer optimization of Smart Grid home/building area network based on IEEE 802.11 standard using RIVERBED OPNET network design and simulation tool. The network performance can be improved by selecting various parameters pertaining to different layers. Simulation results are obtained for various parameters such as WLAN throughput, delay, media access delay, and retransmission attempts. The graphical results show that various parameters have divergent effects on network performance. For example, frame aggregation decreases overall delay but the network throughput is also reduced. To prevail over this effect, frame aggregation is used in combination with RTS and fragmentation mechanisms. The results show that this combination notably improves network performance. Higher value of buffer size considerably increases throughput but the delay is also greater and thus the choice of optimum value of buffer size is inevitable for network performance optimization. Parameter optimization significantly enhances the performance of a designed network. This paper is expected to serve
A Study of Application Layer Paradigm for Lower Layer Energy Saving Potentials in Cloud-Edge Social User Wireless Image Sharing

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Wei Wang

2015-08-01

Full Text Available Energy saving becomes critical in modern cloud wireless multimedia and mobile communication systems. In this paper we propose to study a new paradigm named application layer Position-Value diversity for wireless image sharing for cloud-edge communications, which has significant energy saving potentials for modern wireless networking systems. In this new paradigm, saving energy is achieved by looking into application layer imaging traffic, in stead of MAC-PHY protocols at lower layers, and partitioning it into important positions and unimportant values. This paradigm could be integrated to existing wavelet-based tree compression, and truncation of image bit streams could be performed with regards to wireless communication energy budget estimation. Simulation results demonstrated that there are significant potentials of communication energy efficiency gain and Quality of Experience (QoE enhancement in wireless image communication systems.
Cross layers security approach via an implementation of data privacy and by authentication mechanism for mobile WSNs

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Imen Bouabidi

2017-01-01

Full Text Available To implement a new secure network with high mobility and low energy consumption, we use smart sensors. These sensors are powered by micro batteries generally non rechargeable. So, to extend their lifetime, it is necessary to implement new energy conservation techniques. Existing works separate the two features (security, energy conservation and are interested specifically in only one layer. Consequently, the originality of this work consists to combine together the two features using a crossing between three layers: physical layer, data link layer and network layer. Our proposition consists firstly in developing a new network deployment in hierarchical areas. This model takes place at the network layer. Secondly, implementing an energy efficient and secure MAC protocol providing a secure authentication, data privacy and integrity in a mobile WSN. Finally, implementing an intrusion detection system protecting the physical layer from malware and viruses that threaten it. We have been used OMNet++ for simulation .Our proposed protocol SXMachiavel offered the best performances and more reliability at the mobility rate (can reach 99% compared with XMachiavel, which doesn’t exceed 35%, loss packets rate (0.05% for a small network size and energy consumption (decreases by 0.01% for each exchanged packet.
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.
Redundancy scheme for multi-layered accelerator control system

International Nuclear Information System (INIS)

Chauhan, Amit; Fatnani, Pravin

2009-01-01

The control system for SRS Indus-2 has three-layered architecture. There are VMEbus based stations at the lower two layers that are controlled by their respective CPU board. The 'Profibus' fieldbus standard is used for communication between these VME stations distributed in the field. There is a Profibus controller board at each station to implement the communication protocol. The mode of communication is master-slave (command-response) type. This paper proposes a scheme to implement redundancy at the lower two layers namely Layer-2 (Supervisory Layer / Profibus-master) and Layer-3 (Equipment Unit Interface Layer / Profibus-slave). The redundancy is for both the CPU and the communication board. The scheme uses two CPU boards and two Profi controller boards at each L-3 station. This helps in decreasing any downtime resulting either from CPU faults or communication board faults that are placed in the field area. Redundancy of Profi boards provides two active communication channels between the stations that can be used in different ways thereby increasing the availability on a communication link. Redundancy of CPU boards provides certain level of auto fault-recovery as one CPU remains active and the other CPU remains in standby mode, which takes over the control of VMEbus in case of any fault in the main CPU. (author)
Microscopic Characterization of Individual Submicron Bubbles during the Layer-by-Layer Deposition: Towards Creating Smart Agents

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Riku Kato

2015-07-01

Full Text Available We investigated the individual properties of various polyion-coated bubbles with a mean diameter ranging from 300 to 500 nm. Dark field microscopy allows one to track the individual particles of the submicron bubbles (SBs encapsulated by the layer-by-layer (LbL deposition of cationic and anionic polyelectrolytes (PEs. Our focus is on the two-step charge reversals of PE-SB complexes: the first is a reversal from negatively charged bare SBs with no PEs added to positive SBs encapsulated by polycations (monolayer deposition, and the second is overcharging into negatively charged PE-SB complexes due to the subsequent addition of polyanions (double-layer deposition. The details of these phenomena have been clarified through the analysis of a number of trajectories of various PE-SB complexes that experience either Brownian motion or electrophoresis. The contrasted results obtained from the analysis were as follows: an amount in excess of the stoichiometric ratio of the cationic polymers was required for the first charge-reversal, whereas the stoichiometric addition of the polyanions lead to the electrical neutralization of the PE-SB complex particles. The recovery of the stoichiometry in the double-layer deposition paves the way for fabricating multi-layered SBs encapsulated solely with anionic and cationic PEs, which provides a simple protocol to create smart agents for either drug delivery or ultrasound contrast imaging.
Microscopic Characterization of Individual Submicron Bubbles during the Layer-by-Layer Deposition: Towards Creating Smart Agents

Science.gov (United States)

Kato, Riku; Frusawa, Hiroshi

2015-07-01

We investigated the individual properties of various polyion-coated bubbles with a mean diameter ranging from 300 to 500 nm. Dark field microscopy allows one to track the individual particles of the submicron bubbles (SBs) encapsulated by the layer-by-layer (LbL) deposition of cationic and anionic polyelectrolytes (PEs). Our focus is on the two-step charge reversals of PE-SB complexes: the first is a reversal from negatively charged bare SBs with no PEs added to positive SBs encapsulated by polycations (monolayer deposition), and the second is overcharging into negatively charged PE-SB complexes due to the subsequent addition of polyanions (double-layer deposition). The details of these phenomena have been clarified through the analysis of a number of trajectories of various PE-SB complexes that experience either Brownian motion or electrophoresis. The contrasted results obtained from the analysis were as follows: an amount in excess of the stoichiometric ratio of the cationic polymers was required for the first charge-reversal, whereas the stoichiometric addition of the polyanions lead to the electrical neutralization of the PE-SB complex particles. The recovery of the stoichiometry in the double-layer deposition paves the way for fabricating multi-layered SBs encapsulated solely with anionic and cationic PEs, which provides a simple protocol to create smart agents for either drug delivery or ultrasound contrast imaging.
Wireless Intelligent Sensors Management Application Protocol-WISMAP

Directory of Open Access Journals (Sweden)

Antonio Jesus Yuste-Delgado

2010-09-01

Full Text Available Although many recent studies have focused on the development of new applications for wireless sensor networks, less attention has been paid to knowledge-based sensor nodes. The objective of this work is the development in a real network of a new distributed system in which every sensor node can execute a set of applications, such as fuzzy ruled-base systems, measures, and actions. The sensor software is based on a multi-agent structure that is composed of three components: management, application control, and communication agents; a service interface, which provides applications the abstraction of sensor hardware and other components; and an application layer protocol. The results show the effectiveness of the communication protocol and that the proposed system is suitable for a wide range of applications. As real world applications, this work presents an example of a fuzzy rule-based system and a noise pollution monitoring application that obtains a fuzzy noise indicator.
Analysis of the radius and diameter protocols in terms of pricing telecommunication services

Directory of Open Access Journals (Sweden)

Vesna M. Radonjić

2013-06-01

Full Text Available Accounting of telecommunication services is closely related to the functions of authentication and authorization. These functions are usually considered together and implemented within the same server using a common protocol. The most renowned protocols for authentication, authorization and accounting are the RADIUS and Diameter protocols. AAA functions and related protocols In this chapter, the accounting management architecture developed by IETF is presented. It includes the interaction between network elements, accounting servers and billing and charging servers. Accounting data can be used for management, planning and charging users as well as other (specific purposes. Authentication is the process of confirming a user's digital identity, usually through some type of identifiers and related data. Authorization determines whether a particular entity is authorized to perform an activity. Basic Functions of the RADIUS Protocol The RADIUS architecture is based on a client-server model. It uses UDP on the transport layer. Transactions between the client and the server are authenticated, which is achieved by using a common secret key that is never sent through the network. Given the limited resources available to network devices, RADIUS facilitates and centralizes charging end users, provides some protection against active attacks by unauthorized users and it has great support from different network equipment vendors. Although RADIUS is a widely accepted protocol for the mechanisms of authentication, authorization and accounting, it has certain shortcomings that may be caused by the protocol itself or by its poor implementation. Architecture and Operation of the Diameter Protocol Diameter is a scalable protocol designed by the IETF working group in order to eliminate shortcomings and functional limitations of the RADIUS protocol and eventually to replace it in the near future. Most of the basic Diameter mechanisms and its
Energy-Efficient Link-Layer Jamming Attacks against Wireless Sensor Network MAC Protocols

NARCIS (Netherlands)

Law, Y.W.; van Hoesel, L.F.W.; Doumen, J.M.; Hartel, Pieter H.; Havinga, Paul J.M.; Atluri, V.; Samarati, P.; Ning, P.; Du, W.

2005-01-01

A typical wireless sensor node has little protection against radio jamming. The situation becomes worse if energy efficient jamming can be achieved by exploiting knowledge of the data link layer. Encrypting the packets may help prevent the jammer from taking actions based on the content of the

Multi-media communication system: Upper layers in the OSI reference model

NARCIS (Netherlands)

Zafirovic-Vukotic, M.; Niemegeers, I.G.M.M.

1992-01-01

The structuring, services, and major protocol functions that are required in the upper layers of the OSI reference model in order to support end-to-end multimedia communication, assuming a simple transport service, are examined. It is assumed that variable-bit-rate (VBR) coding techniques will be
A Cross-Layer Route Discovery Framework for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Wu Jieyi

2005-01-01

Full Text Available Most reactive routing protocols in MANETs employ a random delay between rebroadcasting route requests (RREQ in order to avoid "broadcast storms." However this can lead to problems such as "next hop racing" and "rebroadcast redundancy." In addition to this, existing routing protocols for MANETs usually take a single routing strategy for all flows. This may lead to inefficient use of resources. In this paper we propose a cross-layer route discovery framework (CRDF to address these problems by exploiting the cross-layer information. CRDF solves the above problems efficiently and enables a new technique: routing strategy automation (RoSAuto. RoSAuto refers to the technique that each source node automatically decides the routing strategy based on the application requirements and each intermediate node further adapts the routing strategy so that the network resource usage can be optimized. To demonstrate the effectiveness and the efficiency of CRDF, we design and evaluate a macrobian route discovery strategy under CRDF.
Prevention of intra-abdominal adhesion by bi-layer electrospun membrane.

Science.gov (United States)

Jiang, Shichao; Wang, Wei; Yan, Hede; Fan, Cunyi

2013-06-04

The aim of this study was to compare the anti-adhesion efficacy of a bi-layer electrospun fibrous membrane consisting of hyaluronic acid-loaded poly(ε-caprolactone) (PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer with a single-layer PCL electrospun fibrous membrane in a rat cecum abrasion model. The rat model utilized a cecal abrasion and abdominal wall insult surgical protocol. The bi-layer and PCL membranes were applied between the cecum and the abdominal wall, respectively. Control animals did not receive any treatment. After postoperative day 14, a visual semiquantitative grading scale was used to grade the extent of adhesion. Histological analysis was performed to reveal the features of adhesion tissues. Bi-layer membrane treated animals showed significantly lower adhesion scores than control animals (p compared with the PCL membrane. Histological analysis of the bi-layer membrane treated rat rarely demonstrated tissue adhesion while that of the PCL membrane treated rat and control rat showed loose and dense adhesion tissues, respectively. Bi-layer membrane can efficiently prevent adhesion formation in abdominal cavity and showed a significantly decreased adhesion tissue formation compared with the control.
Cross-Layer Techniques for Adaptive Video Streaming over Wireless Networks

Directory of Open Access Journals (Sweden)

Yufeng Shan

2005-02-01

Full Text Available Real-time streaming media over wireless networks is a challenging proposition due to the characteristics of video data and wireless channels. In this paper, we propose a set of cross-layer techniques for adaptive real-time video streaming over wireless networks. The adaptation is done with respect to both channel and data. The proposed novel packetization scheme constructs the application layer packet in such a way that it is decomposed exactly into an integer number of equal-sized radio link protocol (RLP packets. FEC codes are applied within an application packet at the RLP packet level rather than across different application packets and thus reduce delay at the receiver. A priority-based ARQ, together with a scheduling algorithm, is applied at the application layer to retransmit only the corrupted RLP packets within an application layer packet. Our approach combines the flexibility and programmability of application layer adaptations, with low delay and bandwidth efficiency of link layer techniques. Socket-level simulations are presented to verify the effectiveness of our approach.
An FEC Adaptive Multicast MAC Protocol for Providing Reliability in WLANs

Science.gov (United States)

Basalamah, Anas; Sato, Takuro

For wireless multicast applications like multimedia conferencing, voice over IP and video/audio streaming, a reliable transmission of packets within short delivery delay is needed. Moreover, reliability is crucial to the performance of error intolerant applications like file transfer, distributed computing, chat and whiteboard sharing. Forward Error Correction (FEC) is frequently used in wireless multicast to enhance Packet Error Rate (PER) performance, but cannot assure full reliability unless coupled with Automatic Repeat Request forming what is knows as Hybrid-ARQ. While reliable FEC can be deployed at different levels of the protocol stack, it cannot be deployed on the MAC layer of the unreliable IEEE802.11 WLAN due to its inability to exchange ACKs with multiple recipients. In this paper, we propose a Multicast MAC protocol that enhances WLAN reliability by using Adaptive FEC and study it's performance through mathematical analysis and simulation. Our results show that our protocol can deliver high reliability and throughput performance.
Development of Information Assurance Protocol for Low Bandwidth Nanosatellite Communications

Science.gov (United States)

2017-09-01

14. SUBJECT TERMS commercial off-the-shelf technology , nanosatellites, CubeSat, encrypted communications 15. NUMBER OF PAGES 161 16. PRICE...integrate with several physical layer technologies . While this protocol does provide some additional functionality at a lower cost, it is limited to...G. S. Vernam, “Secret signaling system.” U.S. Patent U.S. 1310719 A, 22 July 1919. [22] D. Kahn, Codebreakers: The Story of Secret Writing, New
Real cause of detrimental carbonation in chemically stabilized layers and possible solutions

CSIR Research Space (South Africa)

Botha, PB

2005-10-01

Full Text Available to determine the other reaction that may take place in the material. KEYWORDS CARBONATION/ CHEMICAL REACTIONS/ WATER CURING/ NEW TESTING PROTOCOL 1 INTRODUCTION This paper deals with the problems related to the “curing” of the stabilized layers... than CO2 driven. In actually fact the so-called “detrimental carbonation” chemical reaction cannot even take place without free water being available. The water is normally supplied by the specified curing 2 technique to keep the layer moist...
Implantable Body Sensor Network MAC Protocols Using Wake-up Radio – Evaluation in Animal Tissue

NARCIS (Netherlands)

Karuppiah Ramachandran, Vignesh Raja; van der Zwaag, B.J.; Meratnia, Nirvana; Havinga, Paul J.M.

Applications of implantable sensor networks in the health-care industry have increased tremendously over the last decade. There are different types of medium access control (MAC) protocols that are designed for implantable body sensor networks, using different physical layer technologies such as
Streetlight Control System Based on Wireless Communication over DALI Protocol

Science.gov (United States)

Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

2016-01-01

Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed. PMID:27128923
Streetlight Control System Based on Wireless Communication over DALI Protocol.

Science.gov (United States)

Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

2016-04-27

Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed.
A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

Science.gov (United States)

Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

2005-01-01

Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.
A transport layer protocol for the future high speed grid computing: SCTP versus fast tcp multihoming

International Nuclear Information System (INIS)

Arshad, M.J.; Mian, M.S.

2010-01-01

TCP (Transmission Control Protocol) is designed for reliable data transfer on the global Internet today. One of its strong points is its use of flow control algorithm that allows TCP to adjust its congestion window if network congestion is occurred. A number of studies and investigations have confirmed that traditional TCP is not suitable for each and every type of application, for example, bulk data transfer over high speed long distance networks. TCP sustained the time of low-capacity and short-delay networks, however, for numerous factors it cannot be capable to efficiently deal with today's growing technologies (such as wide area Grid computing and optical-fiber networks). This research work surveys the congestion control mechanism of transport protocols, and addresses the different issues involved for transferring the huge data over the future high speed Grid computing and optical-fiber networks. This work also presents the simulations to compare the performance of FAST TCP multihoming with SCTP (Stream Control Transmission Protocol) multihoming in high speed networks. These simulation results show that FAST TCP multihoming achieves bandwidth aggregation efficiently and outperforms SCTP multihoming under a similar network conditions. The survey and simulation results presented in this work reveal that multihoming support into FAST TCP does provide a lot of benefits like redundancy, load-sharing and policy-based routing, which largely improves the whole performance of a network and can meet the increasing demand of the future high-speed network infrastructures (such as in Grid computing). (author)
Cross-Layer Design for Two-Way Relaying Networks with Multiple Antennas

Directory of Open Access Journals (Sweden)

zhuo wu

2015-10-01

Full Text Available In this paper, we developed a cross-layer design for two-way relaying (TWR networks with multiple antennas, where two single antenna source nodes exchange information with the aid of one multiple antenna relay node. The proposed cross-layer design considers adaptive modulation (AM and space-time block coding (STBC at the physical layer with an automatic repeat request (ARQ protocol at the data link layer, in order to maximize the spectral efficiency under specific delay and packet error ratio (PER constraints. An MMSE-interference cancellation (IC receiver is employed at the relay node, to remove the interference in the fist phase of the TWR transmission. The transmission mode is updated for each phase of the TWR transmission on a frame-by-frame basis, to match the time-varying channel conditions and exploit the system performance and throughput gain. Simulation results show that retransmission at the data link layer could alleviate rigorous error-control requirements at the physical layer, and thereby allows higher data transmission. As a result, cross-layer design helps to achieve considerable system spectral efficiency gain for TWR networks, compared to those without cross-layer design.
Protocol Implementation Generator

DEFF Research Database (Denmark)

Carvalho Quaresma, Jose Nuno; Probst, Christian W.

2010-01-01

Users expect communication systems to guarantee, amongst others, privacy and integrity of their data. These can be ensured by using well-established protocols; the best protocol, however, is useless if not all parties involved in a communication have a correct implementation of the protocol and a...... Generator framework based on the LySatool and a translator from the LySa language into C or Java....... necessary tools. In this paper, we present the Protocol Implementation Generator (PiG), a framework that can be used to add protocol generation to protocol negotiation, or to easily share and implement new protocols throughout a network. PiG enables the sharing, verification, and translation...
Improving the physical layer security of wireless communication networks using spread spectrum coding and artificial noise approach

CSIR Research Space (South Africa)

Adedeji, K

2016-09-01

Full Text Available at the application layer to protect the messages against eavesdropping. However, the evolution of strong deciphering mechanisms has made conventional cryptography-based security techniques ineffective against attacks from an intruder. Figure 1: Layer protocol... communication networks with passive and active eavesdropper,” IEEE Globecom; Wireless Communication System, pp. 4868-4873, 2012. [9] Y. Zou, X. Wang and W. Shen, “Optimal relay selection for physical layer security in cooperative wireless networks,” IEEE...
Vertical Protocol Composition

DEFF Research Database (Denmark)

Groß, Thomas; Mödersheim, Sebastian Alexander

2011-01-01

The security of key exchange and secure channel protocols, such as TLS, has been studied intensively. However, only few works have considered what happens when the established keys are actually used—to run some protocol securely over the established “channel”. We call this a vertical protocol.......e., that the combination cannot introduce attacks that the individual protocols in isolation do not have. In this work, we prove a composability result in the symbolic model that allows for arbitrary vertical composition (including self-composition). It holds for protocols from any suite of channel and application...
A Survey of MAC Protocols for Cognitive Radio Body Area Networks.

Science.gov (United States)

Bhandari, Sabin; Moh, Sangman

2015-04-20

The advancement in electronics, wireless communications and integrated circuits has enabled the development of small low-power sensors and actuators that can be placed on, in or around the human body. A wireless body area network (WBAN) can be effectively used to deliver the sensory data to a central server, where it can be monitored, stored and analyzed. For more than a decade, cognitive radio (CR) technology has been widely adopted in wireless networks, as it utilizes the available spectra of licensed, as well as unlicensed bands. A cognitive radio body area network (CRBAN) is a CR-enabled WBAN. Unlike other wireless networks, CRBANs have specific requirements, such as being able to automatically sense their environments and to utilize unused, licensed spectra without interfering with licensed users, but existing protocols cannot fulfill them. In particular, the medium access control (MAC) layer plays a key role in cognitive radio functions, such as channel sensing, resource allocation, spectrum mobility and spectrum sharing. To address various application-specific requirements in CRBANs, several MAC protocols have been proposed in the literature. In this paper, we survey MAC protocols for CRBANs. We then compare the different MAC protocols with one another and discuss challenging open issues in the relevant research.
Physical layer simulation study for the coexistence of WLAN standards

Energy Technology Data Exchange (ETDEWEB)

Howlader, M. K. [Marquette Univ., 222 Haggerty Hall, P. O. Box 1881, Milwaukee, WI 53201 (United States); Keiger, C. [Analysis and Measurement Services Corporation, 9111 Cross Park Drive, Knoxville, TN 37923 (United States); Ewing, P. D. [Oak Ridge National Laboratory, MS-6006, P. O. Box 2008, Oak Ridge, TN 37831 (United States); Govan, T. V. [U.S. Nuclear Regulatory Commission, MS T-10-D20, 11545 Rockville Pike, Rockville, MD 20852 (United States)

2006-07-01

This paper presents the results of a study on the performance of wireless local area network (WLAN) devices in the presence of interference from other wireless devices. To understand the coexistence of these wireless protocols, simplified physical-layer-system models were developed for the Bluetooth, Wireless Fidelity (WiFi), and Zigbee devices, all of which operate within the 2.4-GHz frequency band. The performances of these protocols were evaluated using Monte-Carlo simulations under various interference and channel conditions. The channel models considered were basic additive white Gaussian noise (AWGN), Rayleigh fading, and site-specific fading. The study also incorporated the basic modulation schemes, multiple access techniques, and channel allocations of the three protocols. This research is helping the U.S. Nuclear Regulatory Commission (NRC) understand the coexistence issues associated with deploying wireless devices and could prove useful in the development of a technical basis for guidance to address safety-related issues with the implementation of wireless systems in nuclear facilities. (authors)
Physical layer simulation study for the coexistence of WLAN standards

International Nuclear Information System (INIS)

Howlader, M. K.; Keiger, C.; Ewing, P. D.; Govan, T. V.

2006-01-01

This paper presents the results of a study on the performance of wireless local area network (WLAN) devices in the presence of interference from other wireless devices. To understand the coexistence of these wireless protocols, simplified physical-layer-system models were developed for the Bluetooth, Wireless Fidelity (WiFi), and Zigbee devices, all of which operate within the 2.4-GHz frequency band. The performances of these protocols were evaluated using Monte-Carlo simulations under various interference and channel conditions. The channel models considered were basic additive white Gaussian noise (AWGN), Rayleigh fading, and site-specific fading. The study also incorporated the basic modulation schemes, multiple access techniques, and channel allocations of the three protocols. This research is helping the U.S. Nuclear Regulatory Commission (NRC) understand the coexistence issues associated with deploying wireless devices and could prove useful in the development of a technical basis for guidance to address safety-related issues with the implementation of wireless systems in nuclear facilities. (authors)
Evaluating Application-Layer Traffic Optimization Cost Metrics for P2P Multimedia Streaming

DEFF Research Database (Denmark)

Poderys, Justas; Soler, José

2017-01-01

To help users of P2P communication systems perform better-than-random selection of communication peers, Internet Engineering Task Force standardized the Application Layer Traffic Optimization (ALTO) protocol. The ALTO provided data-routing cost metric, can be used to rank peers in P2P communicati...

Advanced Measurements of the Aggregation Capability of the MPT Network Layer Multipath Communication Library

Directory of Open Access Journals (Sweden)

Gábor Lencse

2015-05-01

Full Text Available The MPT network layer multipath communicationlibrary is a novel solution for several problems including IPv6transition, reliable data transmission using TCP, real-time transmissionusing UDP and also wireless network layer routingproblems. MPT can provide an IPv4 or an IPv6 tunnel overone or more IPv4 or IPv6 communication channels. MPT canalso aggregate the capacity of multiple physical channels. In thispaper, the channel aggregation capability of the MPT libraryis measured up to twelve 100Mbps speed channels. Differentscenarios are used: both IPv4 and IPv6 are used as the underlyingand also as the encapsulated protocols and also both UDP andTCP are used as transport protocols. In addition, measurementsare taken with both 32-bit and 64-bit version of the MPT library.In all cases, the number of the physical channels is increased from1 to 12 and the aggregated throughput is measured.
BTP: a Block Transfer Protocol for Delay Tolerant Wireless Sensor Networks

DEFF Research Database (Denmark)

Hansen, Morten Tranberg; Biagioni, Edoardo S.

2010-01-01

Wireless sensor networks that are energy-constrained must transmit and receive data as efficiently as possible. If the transmission is delay tolerant, transferring blocks of accumulated data can be more efficient than transferring each sensed measurement as soon as it is available. This paper...... proposes a Block Transfer Protocol (BTP) designed for efficient and reliable transmission in wireless sensor networks. BTP reduces the time it takes to reliably transfer a block of packets compared to conventional link layer protocols, by piggybacking in data packets information about the transfer......, minimizing the number of acknowledgements needed for reliable transmission, and reducing the need for timeouts, which can substantially slow down communication when transmission is unreliable. In addition, BTP improves reliability by handling false positive acknowledgements and by letting the receivers...
Smear layer removal evaluation of different protocol of Bio Race file and XP- endo Finisher file in corporation with EDTA 17% and NaOCl.

Science.gov (United States)

Zand, Vahid; Mokhtari, Hadi; Reyhani, Mohammad-Frough; Nahavandizadeh, Neda; Azimi, Shahram

2017-11-01

The aim of the present study was to compare the amount of the smear layer remaining in prepared root canals with different protocols of Bio RaCe files and XP-endo Finisher file (XPF) in association with 17% EDTA and sodium hypochlorite solution. A total of 68 extracted single-rooted teeth were randomly divided into 4 experimental groups (n=14) and two control groups (n=6). The root canals were prepared with Bio RaCe files (FKG Dentaire, Switzerland) using the crown-down technique based on manufacturer's instructions and irrigated according to the following irrigation techniques: Group 1: XPF with 2 mL of 2.5% NaOCl for 1 minute. Group 2:, XPF with 1 mL of 17% EDTA for one minute. Group 3: XPF was used for 1 minute in association with normal saline solution. Group 4: XP-endo Finisher file for 30 seconds in association with 2.5% NaOCl and 17% EDTA for 30 seconds. The negative control group: NaOCl (2.5%) was used during root canal preparation, followed by irrigation with 17% EDTA at the end of root canal preparation. The positive control group: Normal saline solution was used for irrigation during root canal preparation. In all the groups, during preparation of the root canals with Bio RaCe file, 20 mL of 2.5% NaOCl was used for root canal irrigation and at the end of the procedural steps 20 mL of normal saline solution was used as a final irrigant. The samples were analyzed under SEM at ×1000‒2000 magnification and evaluated using Torabinejad scoring system. Data were analyzed with non-parametric Kruskal-Wallis test and post hoc Mann-Whitney U test, using SPSS. Statistical significant was defined at P <0.05. The results of the study showed the least amount of the smear layer at coronal, middle and apical thirds of the root canals in groups 2, which was not significantly different from the negative control group ( P <0.5). Under the limitations of the present study, use of a combination of NaOCl and EDTA in association with XPF exhibited the best efficacy for the
Streetlight Control System Based on Wireless Communication over DALI Protocol

Directory of Open Access Journals (Sweden)

Francisco José Bellido-Outeiriño

2016-04-01

Full Text Available Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed.
The Montreal Protocol treaty and its illuminating history of science-policy decision-making

Science.gov (United States)

Grady, C.

2017-12-01

The Montreal Protocol on Substances that Deplete the Ozone Layer, hailed as one of the most effective environmental treaties of all time, has a thirty year history of science-policy decision-making. The partnership between Parties to the Montreal Protocol and its technical assessment panels serve as a basis for understanding successes and evaluating stumbles of global environmental decision-making. Real-world environmental treaty negotiations can be highly time-sensitive, politically motivated, and resource constrained thus scientists and policymakers alike are often unable to confront the uncertainties associated with the multitude of choices. The science-policy relationship built within the framework of the Montreal Protocol has helped constrain uncertainty and inform policy decisions but has also highlighted the limitations of the use of scientific understanding in political decision-making. This talk will describe the evolution of the scientist-policymaker relationship over the history of the Montreal Protocol. Examples will illustrate how the Montreal Protocol's technical panels inform decisions of the country governments and will characterize different approaches pursued by different countries with a particular focus on the recently adopted Kigali Amendment. In addition, this talk will take a deeper dive with an analysis of the historic technical panel assessments on estimating financial resources necessary to enable compliance to the Montreal Protocol compared to the political financial decisions made through the Protocol's Multilateral Fund replenishment negotiation process. Finally, this talk will describe the useful lessons and challenges from these interactions and how they may be applicable in other environmental management frameworks across multiple scales under changing climatic conditions.
Application Filters for TCP/IP Industrial Automation Protocols

Science.gov (United States)

Batista, Aguinaldo B.; Kobayashi, Tiago H.; Medeiros, João Paulo S.; Brito, Agostinho M.; Motta Pires, Paulo S.

The use of firewalls is a common approach usually meant to secure Automation Technology (AT) from Information Technology (TI) networks. This work proposes a filtering system for TCP/IP-based automation networks in which only certain kind of industrial traffic is permitted. All network traffic which does not conform with a proper industrial protocol pattern or with specific rules for its actions is supposed to be abnormal and must be blocked. As a case study, we developed a seventh layer firewall application with the ability of blocking spurious traffic, using an IP packet queueing engine and a regular expression library.
Economics of "essential use exemptions" for metered-dose inhalers under the Montreal Protocol.

Science.gov (United States)

DeCanio, Stephen J; Norman, Catherine S

2007-10-01

The Montreal Protocol on Substances that Deplete the Ozone Layer has led to rapid reductions in the use of ozone-depleting substances worldwide. However, the Protocol provides for "essential use exemptions" (EUEs) if there are no "technically and economically feasible" alternatives. An application that might qualify as an "essential use" is CFC-powered medical metered-dose inhalers (MDIs) for the treatment of asthma and chronic obstructive pulmonary disease (COPD), and the US and other nations have applied for exemptions in this case. One concern is that exemptions are necessary to ensure access to medications for low-income uninsureds. We examine the consequences of granting or withholding such exemptions, and conclude that government policies and private-sector programs are available that make it economically feasible to phase out chlorofluorocarbons (CFCs) in this application, thereby furthering the global public health objectives of the Montreal Protocol without compromising the treatment of patients who currently receive medication by means of MDIs.
Layers And Processes In The Model Of Technological Postal System

Directory of Open Access Journals (Sweden)

Madleňáková Lucia

2015-12-01

Full Text Available The paper include important aspects of layer model of postal technological system such as makes the possibility to define rules for regulating, technical and technological requirements and interfaces to communicate with other postal systems. The current postal reform is mainly attributable to release of network access and ensuring full interoperability between technological systems. Not only to ensure the development and protection of competition but also in respect to the conservation of requirements to provide the universal service, which is the performance of public interest. There is a space here to examine the postal system, not only from a procedural point of view, but to be viewed as an open communication system. It is possible to find there the commonalities with other communication sector branches and to handle the technological postal system in more layers; similarly as the electronic communication systems are handled. Model of layer postal system, based not only on the processes but on layers functionality, will enable to identify communication protocols and interfaces determining interoperability. It also opens the question of appropriate regulation model.
A Cross-Layer Routing Design for Multi-Interface Wireless Mesh Networks

Directory of Open Access Journals (Sweden)

Tzu-Chieh Tsai

2009-01-01

Full Text Available In recent years, Wireless Mesh Networks (WMNs technologies have received significant attentions. WMNs not only accede to the advantages of ad hoc networks but also provide hierarchical multi-interface architecture. Transmission power control and routing path selections are critical issues in the past researches of multihop networks. Variable transmission power levels lead to different network connectivity and interference. Further, routing path selections among different radio interfaces will also produce different intra-/interflow interference. These features tightly affect the network performance. Most of the related works on the routing protocol design do not consider transmission power control and multi-interface environment simultaneously. In this paper, we proposed a cross-layer routing protocol called M2iRi2 which coordinates transmission power control and intra-/interflow interference considerations as routing metrics. Each radio interface calculates the potential tolerable-added transmission interference in the physical layer. When the route discovery starts, the M2iRi2 will adopt the appropriate power level to evaluate each interface quality along paths. The simulation results demonstrate that our design can enhance both network throughput and end-to-end delay.
Fault-tolerant and QoS based Network Layer for Security Management

Directory of Open Access Journals (Sweden)

Mohamed Naceur Abdelkrim

2013-07-01

Full Text Available Wireless sensor networks have profound effects on many application fields like security management which need an immediate, fast and energy efficient route. In this paper, we define a fault-tolerant and QoS based network layer for security management of chemical products warehouse which can be classified as real-time and mission critical application. This application generate routine data packets and alert packets caused by unusual events which need a high reliability, short end to end delay and low packet loss rate constraints. After each node compute his hop count and build his neighbors table in the initialization phase, packets can be routed to the sink. We use FELGossiping protocol for routine data packets and node-disjoint multipath routing protocol for alert packets. Furthermore, we utilize the information gathering phase of FELGossiping to update the neighbors table and detect the failed nodes, and we adapt the network topology changes by rerun the initialization phase when chemical units were added or removed from the warehouse. Analysis shows that the network layer is energy efficient and can meet the QoS constraints of unusual events packets.
Multi-protocol header generation system

Energy Technology Data Exchange (ETDEWEB)

Roberts, David A.; Ignatowski, Michael; Jayasena, Nuwan; Loh, Gabriel

2017-09-05

A communication device includes a data source that generates data for transmission over a bus, and a data encoder that receives and encodes outgoing data. An encoder system receives outgoing data from a data source and stores the outgoing data in a first queue. An encoder encodes outgoing data with a header type that is based upon a header type indication from a controller and stores the encoded data that may be a packet or a data word with at least one layered header in a second queue for transmission. The device is configured to receive at a payload extractor, a packet protocol change command from the controller and to remove the encoded data and to re-encode the data to create a re-encoded data packet and placing the re-encoded data packet in the second queue for transmission.
An Enhanced LoRaWAN Security Protocol for Privacy Preservation in IoT with a Case Study on a Smart Factory-Enabled Parking System.

Science.gov (United States)

You, Ilsun; Kwon, Soonhyun; Choudhary, Gaurav; Sharma, Vishal; Seo, Jung Taek

2018-06-08

The Internet of Things (IoT) utilizes algorithms to facilitate intelligent applications across cities in the form of smart-urban projects. As the majority of devices in IoT are battery operated, their applications should be facilitated with a low-power communication setup. Such facility is possible through the Low-Power Wide-Area Network (LPWAN), but at a constrained bit rate. For long-range communication over LPWAN, several approaches and protocols are adopted. One such protocol is the Long-Range Wide Area Network (LoRaWAN), which is a media access layer protocol for long-range communication between the devices and the application servers via LPWAN gateways. However, LoRaWAN comes with fewer security features as a much-secured protocol consumes more battery because of the exorbitant computational overheads. The standard protocol fails to support end-to-end security and perfect forward secrecy while being vulnerable to the replay attack that makes LoRaWAN limited in supporting applications where security (especially end-to-end security) is important. Motivated by this, an enhanced LoRaWAN security protocol is proposed, which not only provides the basic functions of connectivity between the application server and the end device, but additionally averts these listed security issues. The proposed protocol is developed with two options, the Default Option (DO) and the Security-Enhanced Option (SEO). The protocol is validated through Burrows⁻Abadi⁻Needham (BAN) logic and the Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. The proposed protocol is also analyzed for overheads through system-based and low-power device-based evaluations. Further, a case study on a smart factory-enabled parking system is considered for its practical application. The results, in terms of network latency with reliability fitting and signaling overheads, show paramount improvements and better performance for the proposed protocol compared with the two
An Enhanced LoRaWAN Security Protocol for Privacy Preservation in IoT with a Case Study on a Smart Factory-Enabled Parking System

Directory of Open Access Journals (Sweden)

Ilsun You

2018-06-01

Full Text Available The Internet of Things (IoT utilizes algorithms to facilitate intelligent applications across cities in the form of smart-urban projects. As the majority of devices in IoT are battery operated, their applications should be facilitated with a low-power communication setup. Such facility is possible through the Low-Power Wide-Area Network (LPWAN, but at a constrained bit rate. For long-range communication over LPWAN, several approaches and protocols are adopted. One such protocol is the Long-Range Wide Area Network (LoRaWAN, which is a media access layer protocol for long-range communication between the devices and the application servers via LPWAN gateways. However, LoRaWAN comes with fewer security features as a much-secured protocol consumes more battery because of the exorbitant computational overheads. The standard protocol fails to support end-to-end security and perfect forward secrecy while being vulnerable to the replay attack that makes LoRaWAN limited in supporting applications where security (especially end-to-end security is important. Motivated by this, an enhanced LoRaWAN security protocol is proposed, which not only provides the basic functions of connectivity between the application server and the end device, but additionally averts these listed security issues. The proposed protocol is developed with two options, the Default Option (DO and the Security-Enhanced Option (SEO. The protocol is validated through Burrows–Abadi–Needham (BAN logic and the Automated Validation of Internet Security Protocols and Applications (AVISPA tool. The proposed protocol is also analyzed for overheads through system-based and low-power device-based evaluations. Further, a case study on a smart factory-enabled parking system is considered for its practical application. The results, in terms of network latency with reliability fitting and signaling overheads, show paramount improvements and better performance for the proposed protocol compared with
Distributed Processing System for Restoration of Electric Power Distribution Network Using Two-Layered Contract Net Protocol

Science.gov (United States)

Kodama, Yu; Hamagami, Tomoki

Distributed processing system for restoration of electric power distribution network using two-layered CNP is proposed. The goal of this study is to develop the restoration system which adjusts to the future power network with distributed generators. The state of the art of this study is that the two-layered CNP is applied for the distributed computing environment in practical use. The two-layered CNP has two classes of agents, named field agent and operating agent in the network. In order to avoid conflicts of tasks, operating agent controls privilege for managers to send the task announcement messages in CNP. This technique realizes the coordination between agents which work asynchronously in parallel with others. Moreover, this study implements the distributed processing system using a de-fact standard multi-agent framework, JADE(Java Agent DEvelopment framework). This study conducts the simulation experiments of power distribution network restoration and compares the proposed system with the previous system. We confirmed the results show effectiveness of the proposed system.
Construction of an Anthropomorphic Phantom for Use in Evaluating Pediatric Airway Digital Tomosynthesis Protocols

Directory of Open Access Journals (Sweden)

Nima Kasraie

2018-01-01

Full Text Available Interpretation of radiolucent foreign bodies (FBs is a common task charged to pediatric radiologists. The use of a motion compensated technique to decrease breathing motion on images would greatly decrease overall exposure to ionizing radiation and increase access to treatment yielding a great impact on clinical care. This study reports on the methodology and materials used to construct an in-house anthropomorphic phantom for investigating image quality in digital tomosynthesis protocols for volumetric imaging of the pediatric airway. Availability and cost of possible substitute materials were considered and simplifying assumptions were made. Two different modular phantoms were assembled in coronal slab layers using materials designed to approximate a one- and three-year-old thorax at diagnostic photon energies for use with digital tomosynthesis protocols such as those offered on GE’s VolumeRAD application. Exposures were made using both phantoms with inserted food particles inside an oscillating airway. The goal of the phantom is to help evaluate (1 whether the currently used protocol is sufficient to image the airway despite breathing motion and (2 whether it is not, to find the optimal protocol by testing various commercially available protocols using this phantom. The affordable construction of the pediatric sized phantom aimed at optimizing GE’s VolumeRAD protocol for airway foreign body imaging is demonstrated in this study which can be used to test VolumeRAD’s ability to image the airways with and without a low-density foreign body within the airways.
A proposed architecture for a satellite-based mobile communications network - The lowest three layers

Science.gov (United States)

Yan, T. Y.; Naderi, F. M.

1986-01-01

Architecture for a commercial mobile satellite network is proposed. The mobile satellite system (MSS) is composed of a network management center, mobile terminals, base stations, and gateways; the functions of each component are described. The satellite is a 'bent pipe' that performs frequency translations, and it has multiple UHF beams. The development of the MSS design based on the seven-layer open system interconnection model is examined. Consideration is given to the functions of the physical, data link, and network layers and the integrated adaptive mobile access protocol.
Blockchain protocols in clinical trials: Transparency and traceability of consent

Science.gov (United States)

Benchoufi, Mehdi; Porcher, Raphael; Ravaud, Philippe

2018-01-01

Clinical trial consent for protocols and their revisions should be transparent for patients and traceable for stakeholders. Our goal is to implement a process allowing for collection of patients’ informed consent, which is bound to protocol revisions, storing and tracking the consent in a secure, unfalsifiable and publicly verifiable way, and enabling the sharing of this information in real time. For that, we build a consent workflow using a trending technology called Blockchain. This is a distributed technology that brings a built-in layer of transparency and traceability. From a more general and prospective point of view, we believe Blockchain technology brings a paradigmatical shift to the entire clinical research field. We designed a Proof-of-Concept protocol consisting of time-stamping each step of the patient’s consent collection using Blockchain, thus archiving and historicising the consent through cryptographic validation in a securely unfalsifiable and transparent way. For each protocol revision, consent was sought again. We obtained a single document, in an open format, that accounted for the whole consent collection process: a time-stamped consent status regarding each version of the protocol. This document cannot be corrupted and can be checked on any dedicated public website. It should be considered a robust proof of data. However, in a live clinical trial, the authentication system should be strengthened to remove the need for third parties, here trial stakeholders, and give participative control to the peer users. In the future, the complex data flow of a clinical trial could be tracked by using Blockchain, which core functionality, named Smart Contract, could help prevent clinical trial events not occurring in the correct chronological order, for example including patients before they consented or analysing case report form data before freezing the database. Globally, Blockchain could help with reliability, security, transparency and could be
Blockchain protocols in clinical trials: Transparency and traceability of consent.

Science.gov (United States)

Benchoufi, Mehdi; Porcher, Raphael; Ravaud, Philippe

2017-01-01

Clinical trial consent for protocols and their revisions should be transparent for patients and traceable for stakeholders. Our goal is to implement a process allowing for collection of patients' informed consent, which is bound to protocol revisions, storing and tracking the consent in a secure, unfalsifiable and publicly verifiable way, and enabling the sharing of this information in real time. For that, we build a consent workflow using a trending technology called Blockchain. This is a distributed technology that brings a built-in layer of transparency and traceability. From a more general and prospective point of view, we believe Blockchain technology brings a paradigmatical shift to the entire clinical research field. We designed a Proof-of-Concept protocol consisting of time-stamping each step of the patient's consent collection using Blockchain, thus archiving and historicising the consent through cryptographic validation in a securely unfalsifiable and transparent way. For each protocol revision, consent was sought again. We obtained a single document, in an open format, that accounted for the whole consent collection process: a time-stamped consent status regarding each version of the protocol. This document cannot be corrupted and can be checked on any dedicated public website. It should be considered a robust proof of data. However, in a live clinical trial, the authentication system should be strengthened to remove the need for third parties, here trial stakeholders, and give participative control to the peer users. In the future, the complex data flow of a clinical trial could be tracked by using Blockchain, which core functionality, named Smart Contract, could help prevent clinical trial events not occurring in the correct chronological order, for example including patients before they consented or analysing case report form data before freezing the database. Globally, Blockchain could help with reliability, security, transparency and could be a
Utilizing Cross-Layer Information to Improve Performance in JPEG2000 Decoding

Directory of Open Access Journals (Sweden)

Hannes Persson

2007-01-01

Full Text Available We focus on wireless multimedia communication and investigate how cross-layer information can be used to improve performance at the application layer, using JPEG2000 as an example. The cross-layer information is in the form of soft information from the physical layer. The soft information, which is supplied by a soft decision demodulator, yields reliability measures for the received bits and is fed into two soft input iterative JPEG2000 image decoders. When errors are detected with the error detecting mechanisms in JPEG2000, the decoders utilize the soft information to point out likely transmission errors. Hence, the decoders can correct errors and increase the image quality without making time-consuming retransmissions. We believe that the proposed decoding method utilizing soft information is suitable for a general IP-based network and that it keeps the principles of a layered structure of the protocol stack intact. Further, experimental results with images transmitted over a simulated wireless channel show that a simple decoding algorithm that utilizes soft information can give high gains in image quality compared to the standard hard-decision decoding.
Photoreceptor layer map using spectral-domain optical coherence tomography.

Science.gov (United States)

Lee, Ji Eun; Lim, Dae Won; Bae, Han Yong; Park, Hyun Jin

2009-12-01

To develop a novel method for analysis of the photoreceptor layer map (PLM) generated using spectral-domain optical coherence tomography (OCT). OCT scans were obtained from 20 eyes, 10 with macular holes (MH) and 10 with central serous chorioretinopathy (CSC) using the Macular Cube (512 x 128) protocol of the Cirrus HD-OCT (Carl Zeiss). The scanned data were processed using embedded tools of the advanced visualization. A partial thickness OCT fundus image of the photoreceptor layer was generated by setting the region of interest to a 50-microm thick layer that was parallel and adjacent to the retinal pigment epithelium. The resulting image depicted the photoreceptor layer as a map of the reflectivity in OCT. The PLM was compared with fundus photography, auto-fluorescence, tomography, and retinal thickness map. The signal from the photoreceptor layer of every OCT scan in each case was demonstrated as a single image of PLM in a fundus photograph fashion. In PLM images, detachment of the sensory retina is depicted as a hypo-reflective area, which represents the base of MH and serous detachment in CSC. Relative hypo-reflectivity, which was also noted at closed MH and at recently reattached retina in CSC, was associated with reduced signal from the junction between the inner and outer segments of photoreceptors in OCT images. Using PLM, changes in the area of detachment and reflectivity of the photoreceptor layer could be efficiently monitored. The photoreceptor layer can be analyzed as a map using spectral-domain OCT. In the treatment of both MH and CSC, PLM may provide new pathological information about the photoreceptor layer to expand our understanding of these diseases.

Robust and Efficient Authentication Scheme for Session Initiation Protocol

Directory of Open Access Journals (Sweden)

Yanrong Lu

2015-01-01

Full Text Available The session initiation protocol (SIP is a powerful application-layer protocol which is used as a signaling one for establishing, modifying, and terminating sessions among participants. Authentication is becoming an increasingly crucial issue when a user asks to access SIP services. Hitherto, many authentication schemes have been proposed to enhance the security of SIP. In 2014, Arshad and Nikooghadam proposed an enhanced authentication and key agreement scheme for SIP and claimed that their scheme could withstand various attacks. However, in this paper, we show that Arshad and Nikooghadam’s authentication scheme is still susceptible to key-compromise impersonation and trace attacks and does not provide proper mutual authentication. To conquer the flaws, we propose a secure and efficient ECC-based authentication scheme for SIP. Through the informal and formal security analyses, we demonstrate that our scheme is resilient to possible known attacks including the attacks found in Arshad et al.’s scheme. In addition, the performance analysis shows that our scheme has similar or better efficiency in comparison with other existing ECC-based authentication schemes for SIP.
Security Analysis of DTN Architecture and Bundle Protocol Specification for Space-Based Networks

Science.gov (United States)

Ivancic, William D.

2009-01-01

A Delay-Tolerant Network (DTN) Architecture (Request for Comment, RFC-4838) and Bundle Protocol Specification, RFC-5050, have been proposed for space and terrestrial networks. Additional security specifications have been provided via the Bundle Security Specification (currently a work in progress as an Internet Research Task Force internet-draft) and, for link-layer protocols applicable to Space networks, the Licklider Transport Protocol Security Extensions. This document provides a security analysis of the current DTN RFCs and proposed security related internet drafts with a focus on space-based communication networks, which is a rather restricted subset of DTN networks. Note, the original focus and motivation of DTN work was for the Interplanetary Internet . This document does not address general store-and-forward network overlays, just the current work being done by the Internet Research Task Force (IRTF) and the Consultative Committee for Space Data Systems (CCSDS) Space Internetworking Services Area (SIS) - DTN working group under the DTN and Bundle umbrellas. However, much of the analysis is relevant to general store-and-forward overlays.
A Comparison Between Inter-Asterisk eXchange Protocol and Jingle Protocol: Session Time

Directory of Open Access Journals (Sweden)

H. S. Haj Aliwi

2016-08-01

Full Text Available Over the last few years, many multimedia conferencing and Voice over Internet Protocol (VoIP applications have been developed due to the use of signaling protocols in providing video, audio and text chatting services between at least two participants. This paper compares between two widely common signaling protocols: InterAsterisk eXchange Protocol (IAX and the extension of the eXtensible Messaging and Presence Protocol (Jingle in terms of delay time during call setup, call teardown, and media sessions.
Development of an acquisition protocol and a segmentation algortihm for wounds of cutaneous Leishmaniasis in digital images

Science.gov (United States)

Diaz, Kristians; Castañeda, Benjamín; Miranda, César; Lavarello, Roberto; Llanos, Alejandro

2010-03-01

We developed a protocol for the acquisition of digital images and an algorithm for a color-based automatic segmentation of cutaneous lesions of Leishmaniasis. The protocol for image acquisition provides control over the working environment to manipulate brightness, lighting and undesirable shadows on the injury using indirect lighting. Also, this protocol was used to accurately calculate the area of the lesion expressed in mm2 even in curved surfaces by combining the information from two consecutive images. Different color spaces were analyzed and compared using ROC curves in order to determine the color layer with the highest contrast between the background and the wound. The proposed algorithm is composed of three stages: (1) Location of the wound determined by threshold and mathematical morphology techniques to the H layer of the HSV color space, (2) Determination of the boundaries of the wound by analyzing the color characteristics in the YIQ space based on masks (for the wound and the background) estimated from the first stage, and (3) Refinement of the calculations obtained on the previous stages by using the discrete dynamic contours algorithm. The segmented regions obtained with the algorithm were compared with manual segmentations made by a medical specialist. Broadly speaking, our results support that color provides useful information during segmentation and measurement of wounds of cutaneous Leishmaniasis. Results from ten images showed 99% specificity, 89% sensitivity, and 98% accuracy.
Surface Sampling-Based Decontamination Studies and Protocol for Determining Sporicidal Efficacy of Gaseous Fumigants on Military-Relevant Surfaces

Science.gov (United States)

2008-09-01

non-porous surfaces is vital to decon protocol development. Spore density (spore number per unit area) can result in layering and clustering over a...1999, 281, 1735-1745. 9. AOAC International Method 966.04; Official Methods of Analisis , 21’t ed.; Chapter 6: AOAC International: Gaithersburg, MD
Behavioral Modeling of WSN MAC Layer Security Attacks: A Sequential UML Approach

DEFF Research Database (Denmark)

Pawar, Pranav M.; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

2012-01-01

is the vulnerability to security attacks/threats. The performance and behavior of a WSN are vastly affected by such attacks. In order to be able to better address the vulnerabilities of WSNs in terms of security, it is important to understand the behavior of the attacks. This paper addresses the behavioral modeling...... of medium access control (MAC) security attacks in WSNs. The MAC layer is responsible for energy consumption, delay and channel utilization of the network and attacks on this layer can introduce significant degradation of the individual sensor nodes due to energy drain and in performance due to delays....... The behavioral modeling of attacks will be beneficial for designing efficient and secure MAC layer protocols. The security attacks are modeled using a sequential diagram approach of Unified Modeling Language (UML). Further, a new attack definition, specific to hybrid MAC mechanisms, is proposed....
Network coding at different layers in wireless networks

CERN Document Server

2016-01-01

This book focuses on how to apply network coding at different layers in wireless networks – including MAC, routing, and TCP – with special focus on cognitive radio networks. It discusses how to select parameters in network coding (e.g., coding field, number of packets involved, and redundant information ration) in order to be suitable for the varying wireless environments. The book explores how to deploy network coding in MAC to improve network performance and examines joint network coding with opportunistic routing to improve the successful rate of routing. In regards to TCP and network coding, the text considers transport layer protocol working with network coding to overcome the transmission error rate, particularly with how to use the ACK feedback of TCP to enhance the efficiency of network coding. The book pertains to researchers and postgraduate students, especially whose interests are in opportunistic routing and TCP in cognitive radio networks.
MAC-Layer Active Dropping for Real-Time Video Streaming in 4G Access Networks

KAUST Repository

She, James

2010-12-01

This paper introduces a MAC-layer active dropping scheme to achieve effective resource utilization, which can satisfy the application-layer delay for real-time video streaming in time division multiple access based 4G broadband wireless access networks. When a video frame is not likely to be reconstructed within the application-layer delay bound at a receiver for the minimum decoding requirement, the MAC-layer protocol data units of such video frame will be proactively dropped before the transmission. An analytical model is developed to evaluate how confident a video frame can be delivered within its application-layer delay bound by jointly considering the effects of time-varying wireless channel, minimum decoding requirement of each video frame, data retransmission, and playback buffer. Extensive simulations with video traces are conducted to prove the effectiveness of the proposed scheme. When compared to conventional cross-layer schemes using prioritized-transmission/retransmission, the proposed scheme is practically implementable for more effective resource utilization, avoiding delay propagation, and achieving better video qualities under certain conditions.
Performance comparison between S-ALOHA and R3T protocols for multirate OFFH-CDMA systems in optical packet networks

Science.gov (United States)

Inaty, Elie; Raad, Robert; Fortier, Paul; Shalaby, Hossam M.

2006-12-01

We discuss two newly proposed multiple-access control (MAC) protocols for multirate optical code-division multiple access (OCDMA) networks. The first protocol is slotted ALOHA/optical fast-frequency-hopping code-division multiple access (S-ALOHA/OFFH-CDMA), and the second is round-robin receiver-transmitter/optical fast-frequency-hopping code-division multiple access (R3/OFFH-CDMA). Our main subject is to exploit the potential of the optical fast-frequency-hopping CDMA using a fiber Bragg grating when jointly used with two different MAC protocols in a link layer as an effective way of integrating multirate traffic. The system throughput and the average packet delay are compared for both systems. It is shown that S-ALOHA is better than R3T when the user's activity and the offered load are high, whereas R3T is better for smaller values. Both protocols can be competitive in terms of the system throughput, with the advantage going to the R3T protocol at a moderate offered load. However, the R3T protocol suffers a higher delay mainly because of the presence of additional modes. Finally, the overlapped OCDMA system always outperforms the variable processing gain (VPG) OCDMA system regardless of the protocol used.
The Generation of Human Induced Pluripotent Stem Cells from Blood Cells: An Efficient Protocol Using Serial Plating of Reprogrammed Cells by Centrifugation

OpenAIRE

Youngkyun Kim; Yeri Alice Rim; Hyoju Yi; Narae Park; Sung-Hwan Park; Ji Hyeon Ju

2016-01-01

Human induced pluripotent stem cells (hiPSCs) have demonstrated great potential for differentiation into diverse tissues. We report a straightforward and highly efficient method for the generation of iPSCs from PBMCs. By plating the cells serially to a newly coated plate by centrifugation, this protocol provides multiple healthy iPSC colonies even from a small number of PBMCs. The generated iPSCs expressed pluripotent markers and differentiated into all three germ layer lineages. The protocol...
Design and FPGA implementation for MAC layer of Ethernet PON

Science.gov (United States)

Zhu, Zengxi; Lin, Rujian; Chen, Jian; Ye, Jiajun; Chen, Xinqiao

2004-04-01

Ethernet passive optical network (EPON), which represents the convergence of low-cost, high-bandwidth and supporting multiple services, appears to be one of the best candidates for the next-generation access network. The work of standardizing EPON as a solution for access network is still underway in the IEEE802.3ah Ethernet in the first mile (EFM) task force. The final release is expected in 2004. Up to now, there has been no standard application specific integrated circuit (ASIC) chip available which fulfills the functions of media access control (MAC) layer of EPON. The MAC layer in EPON system has many functions, such as point-to-point emulation (P2PE), Ethernet MAC functionality, multi-point control protocol (MPCP), network operation, administration and maintenance (OAM) and link security. To implement those functions mentioned above, an embedded real-time operating system (RTOS) and a flexible programmable logic device (PLD) with an embedded processor are used. The software and hardware functions in MAC layer are realized through programming embedded microprocessor and field programmable gate array(FPGA). Finally, some experimental results are given in this paper. The method stated here can provide a valuable reference for developing EPON MAC layer ASIC.
Cross-layer designed adaptive modulation algorithm with packet combining and truncated ARQ over MIMO Nakagami fading channels

KAUST Repository

Aniba, Ghassane

2011-04-01

This paper presents an optimal adaptive modulation (AM) algorithm designed using a cross-layer approach which combines truncated automatic repeat request (ARQ) protocol and packet combining. Transmissions are performed over multiple-input multiple-output (MIMO) Nakagami fading channels, and retransmitted packets are not necessarily modulated using the same modulation format as in the initial transmission. Compared to traditional approach, cross-layer design based on the coupling across the physical and link layers, has proven to yield better performance in wireless communications. However, there is a lack for the performance analysis and evaluation of such design when the ARQ protocol is used in conjunction with packet combining. Indeed, previous works addressed the link layer performance of AM with truncated ARQ but without packet combining. In addition, previously proposed AM algorithms are not optimal and can provide poor performance when packet combining is implemented. Herein, we first show that the packet loss rate (PLR) resulting from the combining of packets modulated with different constellations can be well approximated by an exponential function. This model is then used in the design of an optimal AM algorithm for systems employing packet combining, truncated ARQ and MIMO antenna configurations, considering transmission over Nakagami fading channels. Numerical results are provided for operation with or without packet combining, and show the enhanced performance and efficiency of the proposed algorithm in comparison with existing ones. © 2011 IEEE.
The French dosimetry protocol

International Nuclear Information System (INIS)

Dutreix, A.

1985-01-01

After a general introduction the protocol is divided in five sections dealing with: determination of the quality of X-ray, γ-ray and electron beams; the measuring instrument; calibration of the reference instrument; determination of the reference absorbed dose in the user's beams; determination of the absorbed dose in water at other points, in other conditions. The French protocol is not essentially different from the Nordic protocol and it is based on the experience gained in using both the American and the Nordic protocols. Therefore, only the main difference with the published protocols are discussed. (Auth.)
Cross-Layer Design of the Inter-RAT Handover between UMTS and WiMAX

Directory of Open Access Journals (Sweden)

Bertin Philippe

2010-01-01

Full Text Available In future mobile networks, different radio access technologies will have to coexist. IEEE 802.21 MIH (Media-Independent Handover provides primitive mechanisms that ease the implementation of a seamless vertical handover (inter-RAT handover between different radio access technologies. However, it does not specify any handover execution mechanism. The first objective of this paper is to propose a novel MIHF (Media-Independent Handover Function variant, which is renamed interworking (IW sublayer. IW sublayer provides a seamless inter-RAT handover procedure between UMTS and WiMAX systems. It relies on a new intersystem retransmission mechanism with cross-layer interaction ability providing lossless handover while keeping acceptable delays. The second objective of this paper is to design a new TCP snoop agent (TCP Snoop, which interacts with the IW layer in order to mitigate BDP (Bandwidth Delay Product mismatch and to solve spurious RTO (Retransmission TimeOut problems. The cross-layer effects on the handover performance are evaluated by simulations. Our results show that cross-layer interaction between IW layer and TCP Snoop smoothes the handover procedure for TCP traffics. Additionally, this novel inter-RAT cross-layer scheme has the merit of keeping existing TCP protocol stacks unchanged.
The HPA photon protocol and proposed electron protocol

International Nuclear Information System (INIS)

Pitchford, W.G.

1985-01-01

The Hospital Physicists Association (HPA) photon dosimetry protocol has been produced and was published in 1983. Revised values of some components of Csub(lambda) and refinements introduced into the theory in the last few years have enabled new Csub(lambda) values to be produced. The proposed HPA electron protocol is at present in draft form and will be published shortly. Both protocels are discussed. (Auth.)
A Mechanically Proved and an Incremental Development of the Session Initiation Protocol INVITE Transaction

Directory of Open Access Journals (Sweden)

Rajaa Filali

2014-01-01

Full Text Available The Session Initiation Protocol (SIP is an application layer signaling protocol used to create, manage, and terminate sessions in an IP based network. SIP is considered as a transactional protocol. There are two main SIP transactions, the INVITE transaction and the non-INVITE transaction. The SIP INVITE transaction specification is described in an informal way in Request for Comments (RFC 3261 and modified in RFC 6026. In this paper we focus on the INVITE transaction of SIP, over reliable and unreliable transport mediums, which is used to initiate a session. In order to ensure the correctness of SIP, the INVITE transaction is modeled and verified using event-B method and its Rodin platform. The Event-B refinement concept allows an incremental development by defining the studied system at different levels of abstraction, and Rodin discharges almost all proof obligations at each level. This interaction between modeling and proving reduces the complexity and helps in assuring that the INVITE transaction SIP specification is correct, unambiguous, and easy to understand.
Physical Layer Security for Cooperative NOMA Systems

KAUST Repository

Chen, Jianchao

2018-01-09

In this correspondence, we investigate the physical layer security for cooperative non-orthogonal multiple access (NOMA) systems, where both amplify-and-forward (AF) and decode-and-forward (DF) protocols are considered. More specifically, some analytical expressions are derived for secrecy outage probability (SOP) and strictly positive secrecy capacity (SPSC). Results show that AF and DF almost achieve the same secrecy performance. Moreover, asymptotic results demonstrate that the SOP tends to a constant at high signal-to-noise ratio (SNR). Finally, our results show that the secrecy performance of considered NOMA systems is independent of the channel conditions between the relay and the poor user.
Physical Layer Security for Cooperative NOMA Systems

KAUST Repository

Chen, Jianchao; Yang, Liang; Alouini, Mohamed-Slim

2018-01-01

In this correspondence, we investigate the physical layer security for cooperative non-orthogonal multiple access (NOMA) systems, where both amplify-and-forward (AF) and decode-and-forward (DF) protocols are considered. More specifically, some analytical expressions are derived for secrecy outage probability (SOP) and strictly positive secrecy capacity (SPSC). Results show that AF and DF almost achieve the same secrecy performance. Moreover, asymptotic results demonstrate that the SOP tends to a constant at high signal-to-noise ratio (SNR). Finally, our results show that the secrecy performance of considered NOMA systems is independent of the channel conditions between the relay and the poor user.
Security Protocols in a Nutshell

OpenAIRE

Toorani, Mohsen

2016-01-01

Security protocols are building blocks in secure communications. They deploy some security mechanisms to provide certain security services. Security protocols are considered abstract when analyzed, but they can have extra vulnerabilities when implemented. This manuscript provides a holistic study on security protocols. It reviews foundations of security protocols, taxonomy of attacks on security protocols and their implementations, and different methods and models for security analysis of pro...
A Service Differentiated MAC Protocol for OFDM/TDMA Wireless Systems

Institute of Scientific and Technical Information of China (English)

WANG Ying; ZHANG Ping

2005-01-01

This paper proposes a Service Differentiated-Dynamic Slotted Multiple Access (SD-DSMA) protocol with QoS guarantee. The Media Access Control (MAC) frame format is variable according to the traffic of uplink and downlink and the traffic of control and data. In addition, the services are divided into two categories, Guaranteed Bandwidth (GB) and Best Effort (BE). Uplink control message slots are designed for the GB users to reduce contention. Taking into consideration the techniques in physical layer, a two-Dimensional Radio Resource Allocation (2-D RRA) method is proposed. The 2-D RRA is an efficient way to allocate radio resources for multi-cell, multi-user OFDM/TDMA system as it takes into consideration both the channel condition and the co-channel interference. The piggyback mechanism and fair scheduling algorithm are adopted for GB services, and the max C/I scheduling algorithm is used for BE services. The simulation results show that the proposed MAC protocol has better performance in terms of delay, probability of successful access request.

Cross-layer model design in wireless ad hoc networks for the Internet of Things.

Science.gov (United States)

Yang, Xin; Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.
Cross-layer model design in wireless ad hoc networks for the Internet of Things.

Directory of Open Access Journals (Sweden)

Xin Yang

Full Text Available Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.
A Cross-Layer Wireless Sensor Network Energy-Efficient Communication Protocol for Real-Time Monitoring of the Long-Distance Electric Transmission Lines

Directory of Open Access Journals (Sweden)

Jun Yu

2015-01-01

Full Text Available Optimization of energy consumption in Wireless Sensor Network (WSN nodes has become a critical link that constrains the engineering application of the smart grid due to the fact that the smart grid is characterized by long-distance transmission in a special environment. The paper proposes a linear hierarchical network topological structure specific to WSN energy conservation in environmental monitoring of the long-distance electric transmission lines in the smart grid. Based on the topological structural characteristics and optimization of network layers, the paper also proposes a Topological Structure be Layered Configurations (TSLC routing algorithm to improve the quality of WSN data transmission performance. Coprocessing of the network layer and the media access control (MAC layer is achieved by using the cross-layer design method, accessing the status for the nodes in the network layer and obtaining the status of the network nodes of the MAC layer. It efficiently saves the energy of the whole network, improves the quality of the network service performance, and prolongs the life cycle of the network.
Availability improvement of layer 2 seamless networks using OpenFlow.

Science.gov (United States)

Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

2015-01-01

The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path.
Performance Analysis of a Cluster-Based MAC Protocol for Wireless Ad Hoc Networks

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Jesús Alonso-Zárate

2010-01-01

Full Text Available An analytical model to evaluate the non-saturated performance of the Distributed Queuing Medium Access Control Protocol for Ad Hoc Networks (DQMANs in single-hop networks is presented in this paper. DQMAN is comprised of a spontaneous, temporary, and dynamic clustering mechanism integrated with a near-optimum distributed queuing Medium Access Control (MAC protocol. Clustering is executed in a distributed manner using a mechanism inspired by the Distributed Coordination Function (DCF of the IEEE 802.11. Once a station seizes the channel, it becomes the temporary clusterhead of a spontaneous cluster and it coordinates the peer-to-peer communications between the clustermembers. Within each cluster, a near-optimum distributed queuing MAC protocol is executed. The theoretical performance analysis of DQMAN in single-hop networks under non-saturation conditions is presented in this paper. The approach integrates the analysis of the clustering mechanism into the MAC layer model. Up to the knowledge of the authors, this approach is novel in the literature. In addition, the performance of an ad hoc network using DQMAN is compared to that obtained when using the DCF of the IEEE 802.11, as a benchmark reference.
Business protocol in integrated Europe

OpenAIRE

Pavelová, Nina

2009-01-01

The first chapter devotes to definitions of basic terms such as protocol or business protocol, to differences between protocol and etiquette, and between social etiquette and business etiquette. The second chapter focuses on the factors influencing the European business protocol. The third chapter is devoted to the etiquette of business protocol in the European countries. It touches the topics such as punctuality and planning of business appointment, greeting, business cards, dress and appear...
The Effect of Different Cleaning Protocols on Post Space: A SEM Study

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Giuseppe Lo Giudice

2016-01-01

Full Text Available Aim. Purpose of the present paper is to analyze the efficiency of different post-space irrigation protocols. Methods. 28 single rooted teeth were endodontically treated. After post-space preparation every sample was assigned to one of three experimental groups and to one control group. In each group different irrigation protocols were performed as follows: EDTA (Group A, 37% orthophosphoric acid (Group B, and EDTA + 37% orthophosphoric acid with ultrasounds activation (Group C. In the control group (Group D the irrigate association was not activated by ultrasounds. Three zones (coronal, middle, and apical of each sample were analyzed by using Scan Electron Microscopy (SEM without any metallization procedures. The presence of smear layer on the canal surface was qualitatively evaluated by applying Serafino’s score with values included between 0 and 2. Results. The results of the research showed how Group C recorded the better results (0.81±0.72. Group A and Group B showed lower mean scores (1.06±0.69 and 1.08±0.77; Group D showed the lowest mean score of 1.30±0.69. The SEM observation analysis demonstrated how the smear layer presence decreased in the crown-apical direction. Conclusions. The different post-space treatments statistically determine significant differences on the dentinal surfaces cleansing. The absence of ultrasonic activation lowers the cleansing efficacy of endocanalar irrigants, showing sensible differences among each post-space zone.
Research and application of ARP protocol vulnerability attack and defense technology based on trusted network

Science.gov (United States)

Xi, Huixing

2017-03-01

With the continuous development of network technology and the rapid spread of the Internet, computer networks have been around the world every corner. However, the network attacks frequently occur. The ARP protocol vulnerability is one of the most common vulnerabilities in the TCP / IP four-layer architecture. The network protocol vulnerabilities can lead to the intrusion and attack of the information system, and disable or disable the normal defense function of the system [1]. At present, ARP spoofing Trojans spread widely in the LAN, the network security to run a huge hidden danger, is the primary threat to LAN security. In this paper, the author summarizes the research status and the key technologies involved in ARP protocol, analyzes the formation mechanism of ARP protocol vulnerability, and analyzes the feasibility of the attack technique. Based on the summary of the common defensive methods, the advantages and disadvantages of each defense method. At the same time, the current defense method is improved, and the advantage of the improved defense algorithm is given. At the end of this paper, the appropriate test method is selected and the test environment is set up. Experiment and test are carried out for each proposed improved defense algorithm.
Miracle: The Multi-Interface Cross-Layer Extension of ns2

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Guerra Federico

2010-01-01

Full Text Available We present Miracle, a novel framework which extends ns2 to facilitate the simulation and the design of beyond 4G networks. Miracle enhances ns2 by providing an efficient and embedded engine for handling cross-layer messages and, at the same time, enabling the coexistence of multiple modules within each layer of the protocol stack. We also present a novel framework developed as an extension of Miracle called Miracle PHY and MAC. This framework facilitates the development of more realistic Channel, PHY and MAC modules, considering features currently lacking in most state-of-the-art simulators, while at the same time giving a strong emphasis on code modularity, interoperability and reusability. Finally, we provide an overview of the wireless technologies implemented in Miracle, discussing in particular the models for the IEEE 802.11, UMTS and WiMAX standards and for Underwater Acoustic Networks. We observe that, thanks to Miracle and its extensions, it is possible to carefully simulate complex network architectures at all the OSI layers, from the physical reception model to standard applications and system management schemes. This allows to have a comprehensive view of all the interactions among network components, which play an important role in many research areas, such as cognitive networking and cross-layer design.
Modelling multimedia teleservices with OSI upper layers framework: Short paper

Science.gov (United States)

Widya, I.; Vanrijssen, E.; Michiels, E.

The paper presents the use of the concepts and modelling principles of the Open Systems Interconnection (OSI) upper layers structure in the modelling of multimedia teleservices. It puts emphasis on the revised Application Layer Structure (OSI/ALS). OSI/ALS is an object based reference model which intends to coordinate the development of application oriented services and protocols in a consistent and modular way. It enables the rapid deployment and integrated use of these services. The paper emphasizes further on the nesting structure defined in OSI/ALS which allows the design of scalable and user tailorable/controllable teleservices. OSI/ALS consistent teleservices are moreover implementable on communication platforms of different capabilities. An analysis of distributed multimedia architectures which can be found in the literature, confirms the ability of the OSI/ALS framework to model the interworking functionalities of teleservices.
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.
Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal.

Science.gov (United States)

Çapar, İsmail Davut; Aydinbelge, Hale Ari

2014-01-01

The purpose of the present study is to evaluate smear layer generation and residual debris after using self-adjusting file (SAF) or rotary instrumentation and to compare the debris and smear layer removal efficacy of the SAF cleaning/shaping irrigation system against final agitation techniques. One hundred and eight maxillary lateral incisor teeth were randomly divided into nine experimental groups (n = 12), and root canals were prepared using ProTaper Universal rotary files, with the exception of the SAF instrumentation group. During instrumentation, root canals were irrigated with a total of 16 mL of 5% NaOCl. For final irrigation, rotary-instrumented groups were irrigated with 10 mL of 17% EDTA and 10 mL of 5% NaOCl using different irrigation agitation regimens (syringe irrigation with needles, NaviTip FX, manual dynamic irrigation, CanalBrush, EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and SAF irrigation). In the SAF instrumentation group, root canals were instrumented for 4 min at a rate of 4 mL/min with 5% NaOCl and received a final flush with same as syringe irrigation with needles. The surface of the root dentin was observed using a scanning electron microscope. The SAF instrumentation group generated less smear layer and yielded cleaner canals compared to rotary instrumentation. The EndoActivator, EndoVac, PUI, and SAF irrigation groups increased the efficacy of irrigating solutions on the smear layer and debris removal. The SAF instrumentation yielded cleaner canal walls when compared to rotary instrumentation. None of the techniques completely removed the smear layer from the root canal walls. © 2014 Wiley Periodicals, Inc.
Security in the data link layer of the OSI model on LANs wired Cisco

Directory of Open Access Journals (Sweden)

María Genoveva Moreira Santos

2018-02-01

Full Text Available There are no technologies or protocols completely secure in network infrastructures, for this reason, this document aims to demonstrate the importance of configuring security options on network equipments. On this occasion we will focus on the data link layer of the OSI model, which is where controls have begun to be implemented at level of protocols. The tools that are used in the research facilitate the implementation of a virtual laboratory, which consists of a base operating system (windows in which virtualbox is installed to mount linux mint, which will generate attacks; while in VMware, we installed a virtual machine that allows you to add the image of a switch to our network simulation software (GNS3, which integrates all the components. The tests were able to identify the vulnerabilities in MAC, ARP, VLAN and STP, and then to proceed to patch these security aws. Keeping the setting by default or ignoring the characteristics of network equipment are usually the reasons why these vulnerabilities exist. Finally, it was proved how easy it can be to run an attack and at the same time to implement security measures on the layer 2 of the OSI.
Passing Corrupt Data Across Network Layers: An Overview of Recent Developments and Issues

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Michael Welzl

2005-02-01

Full Text Available Recent Internet developments seem to make a point for passing corrupt data from the link to the network layer and above instead of ensuring data integrity with a checksum and ARQ. We give an overview of these efforts (the UDP Lite and DCCP protocols and explain which circumstances would justify delivery of erroneous data; clearly, the missing piece in the puzzle is efficient and meaningful interlayer communication.
[Multidisciplinary protocol for computed tomography imaging and angiographic embolization of splenic injury due to trauma: assessment of pre-protocol and post-protocol outcomes].

Science.gov (United States)

Koo, M; Sabaté, A; Magalló, P; García, M A; Domínguez, J; de Lama, M E; López, S

2011-11-01

To assess conservative treatment of splenic injury due to trauma, following a protocol for computed tomography (CT) and angiographic embolization. To quantify the predictive value of CT for detecting bleeding and need for embolization. The care protocol developed by the multidisciplinary team consisted of angiography with embolization of lesions revealed by contrast extravasation under CT as well as embolization of grade III-V injuries observed, or grade I-II injuries causing hemodynamic instability and/or need for blood transfusion. We collected data on demographic variables, injury severity score (ISS), angiographic findings, and injuries revealed by CT. Pre-protocol and post-protocol outcomes were compared. The sensitivity and specificity of CT findings were calculated for all patients who required angiographic embolization. Forty-four and 30 angiographies were performed in the pre- and post-protocol periods, respectively. The mean (SD) ISSs in the two periods were 25 (11) and 26 (12), respectively. A total of 24 (54%) embolizations were performed in the pre-protocol period and 28 (98%) after implementation of the protocol. Two and 7 embolizations involved the spleen in the 2 periods, respectively; abdominal laparotomies numbered 32 and 25, respectively, and 10 (31%) vs 4 (16%) splenectomies were performed. The specificity and sensitivity values for contrast extravasation found on CT and followed by embolization were 77.7% and 79.5%. The implementation of this multidisciplinary protocol using CT imaging and angiographic embolization led to a decrease in the number of splenectomies. The protocol allows us to take a more conservative treatment approach.
A middle layer solution to support ACID properties for NoSQL databases

Directory of Open Access Journals (Sweden)

Ayman E. Lotfy

2016-01-01

Full Text Available The main objective of this paper is to keep the strengths of RDBMSs as consistency and ACID properties and at the same time providing the benefits that inspired the NoSQL movement through a middle layer. The proposed middle layer uses a four phase commit protocol to ensure: the use of recent data, the use of the Pessimistic technique to forbid others dealing with data while it is used and the data updates residing in many locations to avoid the loss of data and disappointment. This mechanism is required, especially in distributed database application NoSQL based environment, because allowing conflicting transactions to continue not only wastes constrained computing power and decreases bandwidth, but also exacerbates conflicts. The middle layer keeps tracking all running transactions and manages with other layers the execution of concurrent transactions. This solution will help increase both of the scalability, and throughput. Finally, the experimental results show that the throughput of the system improves on increasing the number of middle layers in scenarios and the amount of updates to read in a transaction increases. Also the data are consistent with executing many transactions related to each other through updating the same data. The scalability and availability of the system is not affected while ensuring strict consistency.
The Generation of Human Induced Pluripotent Stem Cells from Blood Cells: An Efficient Protocol Using Serial Plating of Reprogrammed Cells by Centrifugation

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Youngkyun Kim

2016-01-01

Full Text Available Human induced pluripotent stem cells (hiPSCs have demonstrated great potential for differentiation into diverse tissues. We report a straightforward and highly efficient method for the generation of iPSCs from PBMCs. By plating the cells serially to a newly coated plate by centrifugation, this protocol provides multiple healthy iPSC colonies even from a small number of PBMCs. The generated iPSCs expressed pluripotent markers and differentiated into all three germ layer lineages. The protocol can also be used with umbilical cord blood mononuclear cells (CBMCs. In this study, we present a simple and efficient protocol that improved the yield of iPSCs from floating cells such as PBMCs and CBMCs by serial plating and centrifugation.
Adaptation of a MR imaging protocol into a real-time clinical biometric ultrasound protocol for persons with spinal cord injury at risk for deep tissue injury: A reliability study.

Science.gov (United States)

Swaine, Jillian M; Moe, Andrew; Breidahl, William; Bader, Daniel L; Oomens, Cees W J; Lester, Leanne; O'Loughlin, Edmond; Santamaria, Nick; Stacey, Michael C

2018-02-01

High strain in soft tissues that overly bony prominences are considered a risk factor for pressure ulcers (PUs) following spinal cord impairment (SCI) and have been computed using Finite Element methods (FEM). The aim of this study was to translate a MRI protocol into ultrasound (US) and determine between-operator reliability of expert sonographers measuring diameter of the inferior curvature of the ischial tuberosity (IT) and the thickness of the overlying soft tissue layers on able-bodied (AB) and SCI using real-time ultrasound. Part 1: Fourteen AB participants with a mean age of 36.7 ± 12.09 years with 7 males and 7 females had their 3 soft tissue layers in loaded and unloaded sitting measured independently by 2 sonographers: tendon/muscle, skin/fat and total soft tissue and the diameter of the IT in its short and long axis. Part 2: Nineteen participants with SCI were screened, three were excluded due to abnormal skin signs, and eight participants (42%) were excluded for abnormal US signs with normal skin. Eight SCI participants with a mean age of 31.6 ± 13.6 years and all male with 4 paraplegics and 4 tetraplegics were measured by the same sonographers for skin, fat, tendon, muscle and total. Skin/fat and tendon/muscle were computed. AB between-operator reliability was good (ICC = 0.81-0.90) for 3 soft tissues layers in unloaded and loaded sitting and poor for both IT short and long axis (ICC = -0.028 and -0.01). SCI between-operator reliability was good in unloaded and loaded for total, muscle, fat, skin/fat, tendon/muscle (ICC = 0.75-0.97) and poor for tendon (ICC = 0.26 unloaded and ICC = -0.71 loaded) and skin (ICC = 0.37 unloaded and ICC = 0.10). A MRI protocol was successfully adapted for a reliable 3 soft tissue layer model and could be used in a 2-D FEM model designed to estimate soft tissue strain as a novel risk factor for the development of a PU. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Cryptographic Protocols:

DEFF Research Database (Denmark)

Geisler, Martin Joakim Bittel

cryptography was thus concerned with message confidentiality and integrity. Modern cryptography cover a much wider range of subjects including the area of secure multiparty computation, which will be the main topic of this dissertation. Our first contribution is a new protocol for secure comparison, presented...... implemented the comparison protocol in Java and benchmarks show that is it highly competitive and practical. The biggest contribution of this dissertation is a general framework for secure multiparty computation. Instead of making new ad hoc implementations for each protocol, we want a single and extensible...... in Chapter 2. Comparisons play a key role in many systems such as online auctions and benchmarks — it is not unreasonable to say that when parties come together for a multiparty computation, it is because they want to make decisions that depend on private information. Decisions depend on comparisons. We have...
Ancestors protocol for scalable key management

Directory of Open Access Journals (Sweden)

Dieter Gollmann

2010-06-01

Full Text Available Group key management is an important functional building block for secure multicast architecture. Thereby, it has been extensively studied in the literature. The main proposed protocol is Adaptive Clustering for Scalable Group Key Management (ASGK. According to ASGK protocol, the multicast group is divided into clusters, where each cluster consists of areas of members. Each cluster uses its own Traffic Encryption Key (TEK. These clusters are updated periodically depending on the dynamism of the members during the secure session. The modified protocol has been proposed based on ASGK with some modifications to balance the number of affected members and the encryption/decryption overhead with any number of the areas when a member joins or leaves the group. This modified protocol is called Ancestors protocol. According to Ancestors protocol, every area receives the dynamism of the members from its parents. The main objective of the modified protocol is to reduce the number of affected members during the leaving and joining members, then 1 affects n overhead would be reduced. A comparative study has been done between ASGK protocol and the modified protocol. According to the comparative results, it found that the modified protocol is always outperforming the ASGK protocol.

Fast and easy protocol for the purification of recombinant S-layer protein for synthetic biology applications

KAUST Repository

Norville, Julie E.; Kelly, Deborah F.; Knight, Thomas F.; Belcher, Angela M.; Walz, Thomas

2011-01-01

A goal of synthetic biology is to make biological systems easier to engineer. One of the aims is to design, with nanometer-scale precision, biomaterials with well-defined properties. The surface-layer protein SbpA forms 2D arrays naturally
Epistemic Protocols for Distributed Gossiping

Directory of Open Access Journals (Sweden)

Krzysztof R. Apt

2016-06-01

Full Text Available Gossip protocols aim at arriving, by means of point-to-point or group communications, at a situation in which all the agents know each other's secrets. We consider distributed gossip protocols which are expressed by means of epistemic logic. We provide an operational semantics of such protocols and set up an appropriate framework to argue about their correctness. Then we analyze specific protocols for complete graphs and for directed rings.
Using semantics for representing experimental protocols.

Science.gov (United States)

Giraldo, Olga; García, Alexander; López, Federico; Corcho, Oscar

2017-11-13

An experimental protocol is a sequence of tasks and operations executed to perform experimental research in biological and biomedical areas, e.g. biology, genetics, immunology, neurosciences, virology. Protocols often include references to equipment, reagents, descriptions of critical steps, troubleshooting and tips, as well as any other information that researchers deem important for facilitating the reusability of the protocol. Although experimental protocols are central to reproducibility, the descriptions are often cursory. There is the need for a unified framework with respect to the syntactic structure and the semantics for representing experimental protocols. In this paper we present "SMART Protocols ontology", an ontology for representing experimental protocols. Our ontology represents the protocol as a workflow with domain specific knowledge embedded within a document. We also present the S ample I nstrument R eagent O bjective (SIRO) model, which represents the minimal common information shared across experimental protocols. SIRO was conceived in the same realm as the Patient Intervention Comparison Outcome (PICO) model that supports search, retrieval and classification purposes in evidence based medicine. We evaluate our approach against a set of competency questions modeled as SPARQL queries and processed against a set of published and unpublished protocols modeled with the SP Ontology and the SIRO model. Our approach makes it possible to answer queries such as Which protocols use tumor tissue as a sample. Improving reporting structures for experimental protocols requires collective efforts from authors, peer reviewers, editors and funding bodies. The SP Ontology is a contribution towards this goal. We build upon previous experiences and bringing together the view of researchers managing protocols in their laboratory work. Website: https://smartprotocols.github.io/ .
Understanding protocol performance: impact of test performance.

Science.gov (United States)

Turner, Robert G

2013-01-01

This is the second of two articles that examine the factors that determine protocol performance. The objective of these articles is to provide a general understanding of protocol performance that can be used to estimate performance, establish limits on performance, decide if a protocol is justified, and ultimately select a protocol. The first article was concerned with protocol criterion and test correlation. It demonstrated the advantages and disadvantages of different criterion when all tests had the same performance. It also examined the impact of increasing test correlation on protocol performance and the characteristics of the different criteria. To examine the impact on protocol performance when individual tests in a protocol have different performance. This is evaluated for different criteria and test correlations. The results of the two articles are combined and summarized. A mathematical model is used to calculate protocol performance for different protocol criteria and test correlations when there are small to large variations in the performance of individual tests in the protocol. The performance of the individual tests that make up a protocol has a significant impact on the performance of the protocol. As expected, the better the performance of the individual tests, the better the performance of the protocol. Many of the characteristics of the different criteria are relatively independent of the variation in the performance of the individual tests. However, increasing test variation degrades some criteria advantages and causes a new disadvantage to appear. This negative impact increases as test variation increases and as more tests are added to the protocol. Best protocol performance is obtained when individual tests are uncorrelated and have the same performance. In general, the greater the variation in the performance of tests in the protocol, the more detrimental this variation is to protocol performance. Since this negative impact is increased as
Static Validation of Security Protocols

DEFF Research Database (Denmark)

Bodei, Chiara; Buchholtz, Mikael; Degano, P.

2005-01-01

We methodically expand protocol narrations into terms of a process algebra in order to specify some of the checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we demonstrate that these techniques ...... suffice to identify several authentication flaws in symmetric and asymmetric key protocols such as Needham-Schroeder symmetric key, Otway-Rees, Yahalom, Andrew secure RPC, Needham-Schroeder asymmetric key, and Beller-Chang-Yacobi MSR...
A class-chest for deriving transport protocols

Energy Technology Data Exchange (ETDEWEB)

Strayer, W.T.

1996-10-01

Development of new transport protocols or protocol algorithms suffers from the complexity of the environment in which they are intended to run. Modeling techniques attempt to avoid this by simulating the environment. Another approach to promoting rapid prototyping of protocols and protocol algorithms is to provide a pre-built infrastructure that is common to transport protocols, so that the focus is placed on the protocol-specific aspects. The Meta-Transport Library is a library of C++ base classes that implement or abstract out the mundane functions of a protocol, new protocol implementations are derived from base classes. The result is a fully viable user- level transport protocol implementation, with emphasis on modularity. The collection of base classes form a ``class-chest`` of tools .from which protocols can be developed and studied with as little change to a normal UNIX environment as possible.
Effective dose comparison between protocols stitched and usual protocols in dental cone beam CT for complete arcade

International Nuclear Information System (INIS)

Soares, M. R.; Maia, A. F.; Batista, W. O. G.; Lara, P. A.

2014-08-01

To visualization a complete dental radiology dental lives together with two separate proposals: [1] protocols diameter encompassing the entire arch (single) or [2] protocol with multiple fields of view (Fov) which together encompass the entire arch (stitched Fov s). The objective of this study is to evaluate effective dose values in examination protocols for all dental arcade available in different outfits with these two options. For this, a female anthropomorphic phantom manufactured by Radiology Support Devices twenty six thermoluminescent dosimeters inserted in relevant bodies and positions was used. Irradiate the simulator in the clinical conditions. The protocols were averaged and compared: [a] 14.0 cm x 8.5 cm and [b] 8.5 cm x 8.5 cm (Gendex Tomography GXCB 500), [c] protocol stitched for jaw combination of three volumes of 5.0 cm x 3.7 cm (Kodak 9000 3D scanner) [d] protocol stitched Fov s 5.0 cm x 8.0 cm (Planmeca Pro Max 3D) and [e] single technical Fov 14 cm x 8 cm (i-CAT Classical). Our results for the effective dose were: a range between 43.1 and 111.1 micro Sv for technical single Fov and 44.5 and 236.2 for technical stitched Fov s. The protocol presented the highest estimated effective dose was [d] and showed that lowest index was registered [a]. These results demonstrate that the protocol stitched Fov generated in Kodak 9000 3D machine applied the upper dental arch has practically equal value effective dose obtained by protocol extended diameter of, [a], which evaluates in a single image upper and lower arcade. It also demonstrates that the protocol [d] gives an estimate of five times higher than the protocol [a]. Thus, we conclude that in practical terms the protocol [c] stitched Fov s, not presents dosimetric advantages over other protocols. (Author)
Effective dose comparison between protocols stitched and usual protocols in dental cone beam CT for complete arcade

Energy Technology Data Exchange (ETDEWEB)

Soares, M. R.; Maia, A. F. [Universidade Federal de Sergipe, Departamento de Fisica, Cidade Universitaria Prof. Jose Aloisio de Campos, Marechal Rondon s/n, Jardim Rosa Elze, 49-100000 Sao Cristovao, Sergipe (Brazil); Batista, W. O. G. [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Barbalho, Salvador, 40301015 Bahia (Brazil); Lara, P. A., E-mail: wilsonottobatista@gmail.com [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

2014-08-15

To visualization a complete dental radiology dental lives together with two separate proposals: [1] protocols diameter encompassing the entire arch (single) or [2] protocol with multiple fields of view (Fov) which together encompass the entire arch (stitched Fov s). The objective of this study is to evaluate effective dose values in examination protocols for all dental arcade available in different outfits with these two options. For this, a female anthropomorphic phantom manufactured by Radiology Support Devices twenty six thermoluminescent dosimeters inserted in relevant bodies and positions was used. Irradiate the simulator in the clinical conditions. The protocols were averaged and compared: [a] 14.0 cm x 8.5 cm and [b] 8.5 cm x 8.5 cm (Gendex Tomography GXCB 500), [c] protocol stitched for jaw combination of three volumes of 5.0 cm x 3.7 cm (Kodak 9000 3D scanner) [d] protocol stitched Fov s 5.0 cm x 8.0 cm (Planmeca Pro Max 3D) and [e] single technical Fov 14 cm x 8 cm (i-CAT Classical). Our results for the effective dose were: a range between 43.1 and 111.1 micro Sv for technical single Fov and 44.5 and 236.2 for technical stitched Fov s. The protocol presented the highest estimated effective dose was [d] and showed that lowest index was registered [a]. These results demonstrate that the protocol stitched Fov generated in Kodak 9000 3D machine applied the upper dental arch has practically equal value effective dose obtained by protocol extended diameter of, [a], which evaluates in a single image upper and lower arcade. It also demonstrates that the protocol [d] gives an estimate of five times higher than the protocol [a]. Thus, we conclude that in practical terms the protocol [c] stitched Fov s, not presents dosimetric advantages over other protocols. (Author)
Measuring Gene Expression in Bombarded Barley Aleurone Layers with Increased Throughput.

Science.gov (United States)

Uwase, Grace; Enrico, Taylor P; Chelimo, David S; Keyser, Benjamin R; Johnson, Russell R

2018-03-30

The aleurone layer of barley grains is an important model system for hormone-regulated gene expression in plants. In aleurone cells, genes required for germination or early seedling development are activated by gibberellin (GA), while genes associated with stress responses are activated by abscisic acid (ABA). The mechanisms of GA and ABA signaling can be interrogated by introducing reporter gene constructs into aleurone cells via particle bombardment, with the resulting transient expression measured using enzyme assays. An improved protocol is reported that partially automates and streamlines the grain homogenization step and the enzyme assays, allowing significantly more throughput than existing methods. Homogenization of the grain samples is carried out using an automated tissue homogenizer, and GUS (β-glucuronidase) assays are carried out using a 96-well plate system. Representative results using the protocol suggest that phospholipase D activity may play an important role in the activation of HVA1 gene expression by ABA, through the transcription factor TaABF1.
Selective Route Based on SNR with Cross-Layer Scheme in Wireless Ad Hoc Network

Directory of Open Access Journals (Sweden)

Istikmal

2017-01-01

Full Text Available In this study, we developed network and throughput formulation models and proposed new method of the routing protocol algorithm with a cross-layer scheme based on signal-to-noise ratio (SNR. This method is an enhancement of routing protocol ad hoc on-demand distance vector (AODV. This proposed scheme uses selective route based on the SNR threshold in the reverse route mechanism. We developed AODV SNR-selective route (AODV SNR-SR for a mechanism better than AODV SNR, that is, the routing protocol that used average or sum of path SNR, and also better than AODV which is hop-count-based. We also used selective reverse route based on SNR mechanism, replacing the earlier method to avoid routing overhead. The simulation results show that AODV SNR-SR outperforms AODV SNR and AODV in terms of throughput, end-to-end delay, and routing overhead. This proposed method is expected to support Device-to-Device (D2D communications that are concerned with the quality of the channel awareness in the development of the future Fifth Generation (5G.
Automatic Validation of Protocol Narration

DEFF Research Database (Denmark)

Bodei, Chiara; Buchholtz, Mikael; Degano, Pierpablo

2003-01-01

We perform a systematic expansion of protocol narrations into terms of a process algebra in order to make precise some of the detailed checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we...
Fault recovery in the reliable multicast protocol

Science.gov (United States)

Callahan, John R.; Montgomery, Todd L.; Whetten, Brian

1995-01-01

The Reliable Multicast Protocol (RMP) provides a unique, group-based model for distributed programs that need to handle reconfiguration events at the application layer. This model, called membership views, provides an abstraction in which events such as site failures, network partitions, and normal join-leave events are viewed as group reformations. RMP provides access to this model through an application programming interface (API) that notifies an application when a group is reformed as the result of a some event. RMP provides applications with reliable delivery of messages using an underlying IP Multicast (12, 5) media to other group members in a distributed environment even in the case of reformations. A distributed application can use various Quality of Service (QoS) levels provided by RMP to tolerate group reformations. This paper explores the implementation details of the mechanisms in RMP that provide distributed applications with membership view information and fault recovery capabilities.
Efficient secure two-party protocols

CERN Document Server

Hazay, Carmit

2010-01-01

The authors present a comprehensive study of efficient protocols and techniques for secure two-party computation -- both general constructions that can be used to securely compute any functionality, and protocols for specific problems of interest. The book focuses on techniques for constructing efficient protocols and proving them secure. In addition, the authors study different definitional paradigms and compare the efficiency of protocols achieved under these different definitions.The book opens with a general introduction to secure computation and then presents definitions of security for a
Using Ovsynch protocol versus Cosynch protocol in dairy cows

Directory of Open Access Journals (Sweden)

Ion Valeriu Caraba

2013-10-01

Full Text Available As a research on the reproductive physiology and endocrinology surrounding the estrous cycle in dairy cattle has been compiled, several estrous synchronization programs have been developed for use with dairy cows. These include several programs that facilitate the mass breeding of all animals at a predetermined time (timed-AI rather than the detection of estrus. We studied on 15 dary cows which were synchronized by Ovsynch and Cosynch programs. The estrus response for cows in Ovsynch protocol was of 63%. Pregnancy per insemination at 60 days was of 25%. Estrus response for cow in Cosynch protocol was of 57%. Pregnancy per insemination at 60 days was of 57%. Synchronization of ovulation using Ovsynch protocols can provide an effective way to manage reproduction in lactating dairy cows by eliminating the need for estrus detection. These are really efficient management programs for TAI of dairy cows that are able to reduce both the labour costs and the extra handling to daily estrus detection and AI.
Trade restrictions as a means of enforcing compliance with international environmental law. Montreal Protocol on Substances that Deplete the Ozone Layer

International Nuclear Information System (INIS)

Lang, W.

1996-01-01

The contribution reviews primarily Art. 4 of the Montreal Protocol and its efficiency for enforcing compliance with obligations under international environmental law and discusses aspects of possible conflicts with GATT law. (CB)
A family of multi-party authentication protocols

NARCIS (Netherlands)

Cremers, C.J.F.; Mauw, S.

2006-01-01

We introduce a family of multi-party authentication protocols and discuss six novel protocols, which are members of this family. The first three generalize the well-known Needham-Schroeder-Lowe public-key protocol, the Needham-Schroeder private-key protocol, and the Bilateral Key Exchange protocol.
The second report of the German Government to the German Bundestag about measures to protect the ozone layer

International Nuclear Information System (INIS)

1992-11-01

The second report presented by the German Government to the Bundestag about measures for the protection of the ozone layer reveals germany's international leading role in the phaseout of CFCs and halogenated hydrocarbons. In no other country in the world has such an extensive plan for withdrawing from use of substances harmful to the ozone layer been implemented. Manufacturers and users have proved, by their impressive promises of undercutting the time limits set in the ordinance on a ban on CFCs, that the cooperation principle, always placed first in environmental policy, can be successfully practised. The Montreal Protocol establishes successful international measures, backed by international law, for an abandonment of substances that are harmful to the ozone layer. (orig.) [de
Interplanetary Overlay Network Bundle Protocol Implementation

Science.gov (United States)

Burleigh, Scott C.

2011-01-01

The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.
Layering and Ordering in Electrochemical Double Layers

Energy Technology Data Exchange (ETDEWEB)

Liu, Yihua [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Kawaguchi, Tomoya [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Pierce, Michael S. [Rochester Institute of Technology, School of Physics and Astronomy, Rochester, New York 14623, United States; Komanicky, Vladimir [Faculty of Science, Safarik University, 041 54 Kosice, Slovakia; You, Hoydoo [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States

2018-02-26

Electrochemical double layers (EDL) form at electrified interfaces. While Gouy-Chapman model describes moderately charged EDL, formation of Stern layers was predicted for highly charged EDL. Our results provide structural evidence for a Stern layer of cations, at potentials close to hydrogen evolution in alkali fluoride and chloride electrolytes. Layering was observed by x-ray crystal truncation rods and atomic-scale recoil responses of Pt(111) surface layers. Ordering in the layer is confirmed by glancing-incidence in-plane diffraction measurements.
A Cryptographic Moving-Knife Cake-Cutting Protocol

Directory of Open Access Journals (Sweden)

Yoshifumi Manabe

2012-02-01

Full Text Available This paper proposes a cake-cutting protocol using cryptography when the cake is a heterogeneous good that is represented by an interval on a real line. Although the Dubins-Spanier moving-knife protocol with one knife achieves simple fairness, all players must execute the protocol synchronously. Thus, the protocol cannot be executed on asynchronous networks such as the Internet. We show that the moving-knife protocol can be executed asynchronously by a discrete protocol using a secure auction protocol. The number of cuts is n-1 where n is the number of players, which is the minimum.

The Simplest Protocol for Oblivious Transfer

DEFF Research Database (Denmark)

Chou, Tung; Orlandi, Claudio

2015-01-01

Oblivious Transfer (OT) is the fundamental building block of cryptographic protocols. In this paper we describe the simplest and most efficient protocol for 1-out-of-n OT to date, which is obtained by tweaking the Diffie-Hellman key-exchange protocol. The protocol achieves UC-security against...... active and adaptive corruptions in the random oracle model. Due to its simplicity, the protocol is extremely efficient and it allows to perform m 1-out-of-n OTs using only: - Computation: (n+1)m+2 exponentiations (mn for the receiver, mn+2 for the sender) and - Communication: 32(m+1) bytes (for the group...... optimizations) is at least one order of magnitude faster than previous work. Category / Keywords: cryptographic protocols / Oblivious Transfer, UC Security, Elliptic Curves, Efficient Implementation...
Coded Splitting Tree Protocols

DEFF Research Database (Denmark)

Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

2013-01-01

This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...
Playing With Population Protocols

Directory of Open Access Journals (Sweden)

Xavier Koegler

2009-06-01

Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.
Model Additional Protocol

International Nuclear Information System (INIS)

Rockwood, Laura

2001-01-01

Since the end of the cold war a series of events has changed the circumstances and requirements of the safeguards system. The discovery of a clandestine nuclear weapons program in Iraq, the continuing difficulty in verifying the initial report of Democratic People's Republic of Korea upon entry into force of their safeguards agreement, and the decision of the South African Government to give up its nuclear weapons program and join the Treaty on the Non-Proliferation of Nuclear Weapons have all played a role in an ambitious effort by IAEA Member States and the Secretariat to strengthen the safeguards system. A major milestone in this effort was reached in May 1997 when the IAEA Board of Governors approved a Model Protocol Additional to Safeguards Agreements. The Model Additional Protocol was negotiated over a period of less than a year by an open-ended committee of the Board involving some 70 Member States and two regional inspectorates. The IAEA is now in the process of negotiating additional protocols, State by State, and implementing them. These additional protocols will provide the IAEA with rights of access to information about all activities related to the use of nuclear material in States with comprehensive safeguards agreements and greatly expanded physical access for IAEA inspectors to confirm or verify this information. In conjunction with this, the IAEA is working on the integration of these measures with those provided for in comprehensive safeguards agreements, with a view to maximizing the effectiveness and efficiency, within available resources, the implementation of safeguards. Details concerning the Model Additional Protocol are given. (author)
Asymptotic adaptive bipartite entanglement-distillation protocol

International Nuclear Information System (INIS)

Hostens, Erik; Dehaene, Jeroen; De Moor, Bart

2006-01-01

We present an asymptotic bipartite entanglement-distillation protocol that outperforms all existing asymptotic schemes. This protocol is based on the breeding protocol with the incorporation of two-way classical communication. Like breeding, the protocol starts with an infinite number of copies of a Bell-diagonal mixed state. Breeding can be carried out as successive stages of partial information extraction, yielding the same result: one bit of information is gained at the cost (measurement) of one pure Bell state pair (ebit). The basic principle of our protocol is at every stage to replace measurements on ebits by measurements on a finite number of copies, whenever there are two equiprobable outcomes. In that case, the entropy of the global state is reduced by more than one bit. Therefore, every such replacement results in an improvement of the protocol. We explain how our protocol is organized as to have as many replacements as possible. The yield is then calculated for Werner states
The use of Wavelight® Contoura to create a uniform cornea: the LYRA protocol. Part 3: the results of 50 treated eyes

Directory of Open Access Journals (Sweden)

Motwani M

2017-05-01

Full Text Available Manoj Motwani Motwani LASIK Institute, San Diego, CA, USA Purpose: To demonstrate how using the Wavelight Contoura measured astigmatism and axis eliminates corneal astigmatism and creates uniformly shaped corneas. Patients and methods: A retrospective analysis was conducted of the first 50 eyes to have bilateral full WaveLight® Contoura LASIK correction of measured astigmatism and axis (vs conventional manifest refraction, using the Layer Yolked Reduction of Astigmatism Protocol in all cases. All patients had astigmatism corrected, and had at least 1 week of follow-up. Accuracy to desired refractive goal was assessed by postoperative refraction, aberration reduction via calculation of polynomials, and postoperative visions were analyzed as a secondary goal. Results: The average difference of astigmatic power from manifest to measured was 0.5462D (with a range of 0–1.69D, and the average difference of axis was 14.94° (with a range of 0°–89°. Forty-seven of 50 eyes had a goal of plano, 3 had a monovision goal. Astigmatism was fully eliminated from all but 2 eyes, and 1 eye had regression with astigmatism. Of the eyes with plano as the goal, 80.85% were 20/15 or better, and 100% were 20/20 or better. Polynomial analysis postoperatively showed that at 6.5 mm, the average C3 was reduced by 86.5% and the average C5 by 85.14%. Conclusions: Using WaveLight® Contoura measured astigmatism and axis removes higher order aberrations and allows for the creation of a more uniform cornea with accurate removal of astigmatism, and reduction of aberration polynomials. WaveLight® Contoura successfully links the refractive correction layer and aberration repair layer using the Layer Yolked Reduction of Astigmatism Protocol to demonstrate how aberration removal can affect refractive correction. Keywords: WaveLight Contoura, topographic guided ablation, LASIK, PRK, uniform cornea, Contoura with LYRA Protocol, measured astigmatism
Constraints of nonresponding flows based on cross layers in the networks

Science.gov (United States)

Zhou, Zhi-Chao; Xiao, Yang; Wang, Dong

2016-02-01

In the active queue management (AQM) scheme, core routers cannot manage and constrain user datagram protocol (UDP) data flows by the sliding window control mechanism in the transport layer due to the nonresponsive nature of such traffic flows. However, the UDP traffics occupy a large part of the network service nowadays which brings a great challenge to the stability of the more and more complex networks. To solve the uncontrollable problem, this paper proposes a cross layers random early detection (CLRED) scheme, which can control the nonresponding UDP-like flows rate effectively when congestion occurs in the access point (AP). The CLRED makes use of the MAC frame acknowledgement (ACK) transmitting congestion information to the sources nodes and utilizes the back-off windows of the MAC layer throttling data rate. Consequently, the UDP-like flows data rate can be restrained timely by the sources nodes in order to alleviate congestion in the complex networks. The proposed CLRED can constrain the nonresponsive flows availably and make the communication expedite, so that the network can sustain stable. The simulation results of network simulator-2 (NS2) verify the proposed CLRED scheme.
The scientific data acquisition system of the GAMMA-400 space project

Science.gov (United States)

Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Arkhangelskiy, A. I.; Topchiev, N. P.

2016-02-01

The description of scientific data acquisition system (SDAS) designed by SRISA for the GAMMA-400 space project is presented. We consider the problem of different level electronics unification: the set of reliable fault-tolerant integrated circuits fabricated on Silicon-on-Insulator 0.25 mkm CMOS technology and the high-speed interfaces and reliable modules used in the space instruments. The characteristics of reliable fault-tolerant very large scale integration (VLSI) technology designed by SRISA for the developing of computation systems for space applications are considered. The scalable net structure of SDAS based on Serial RapidIO interface including real-time operating system BAGET is described too.
A Comparison Between the OSI Reference Model and the B-ISDN Protocol Reference Model

DEFF Research Database (Denmark)

Staalhagen, Lars

1996-01-01

This article aims at comparing the Open Systems Interconnection (OSI) Reference Model (RM) and the broadband integrated services digital network (B-ISDN) Protocol Reference Model (PRM). According to the International Telecommunications Union - Telecommunications Sector (ITU-T), the exact...... relationship between the lower layers of the OSI RM and the B-ISDN PRM is for further study. It is therefore the intention of this article to present some views on these relationships which hopefully could facilitate an interconnection between B-ISDN and data networks conforming to the OSI standards....
ASSESSMENT OF RIP-V1 AND OSPF-V2 PROTOCOL WITH CONSIDERATION OF CONVERGENCE CRITERIA AND SENDING PROTOCOLS TRAFFIC

Directory of Open Access Journals (Sweden)

Hamed Jelodar

2014-03-01

Full Text Available Routing Protocols are underlying principles in networks like internet, transport and mobile. Routing Protocols include a series of rules and algorithms that consider routing metric and select the best way for sending healthy data packets from origin to destination. Dynamic routing protocol compatible to topology has a changeable state. RIP and OSPF are dynamic routing protocol that we consider criteria like convergence and sending protocols traffic assessment RIP first version and OSPF second version. By the test we have done on OPNET stimulation we understood that the OSPF protocol was more efficient than RIP protocol.
Objective and automated protocols for the evaluation of biomedical search engines using No Title Evaluation protocols.

Science.gov (United States)

Campagne, Fabien

2008-02-29

The evaluation of information retrieval techniques has traditionally relied on human judges to determine which documents are relevant to a query and which are not. This protocol is used in the Text Retrieval Evaluation Conference (TREC), organized annually for the past 15 years, to support the unbiased evaluation of novel information retrieval approaches. The TREC Genomics Track has recently been introduced to measure the performance of information retrieval for biomedical applications. We describe two protocols for evaluating biomedical information retrieval techniques without human relevance judgments. We call these protocols No Title Evaluation (NT Evaluation). The first protocol measures performance for focused searches, where only one relevant document exists for each query. The second protocol measures performance for queries expected to have potentially many relevant documents per query (high-recall searches). Both protocols take advantage of the clear separation of titles and abstracts found in Medline. We compare the performance obtained with these evaluation protocols to results obtained by reusing the relevance judgments produced in the 2004 and 2005 TREC Genomics Track and observe significant correlations between performance rankings generated by our approach and TREC. Spearman's correlation coefficients in the range of 0.79-0.92 are observed comparing bpref measured with NT Evaluation or with TREC evaluations. For comparison, coefficients in the range 0.86-0.94 can be observed when evaluating the same set of methods with data from two independent TREC Genomics Track evaluations. We discuss the advantages of NT Evaluation over the TRels and the data fusion evaluation protocols introduced recently. Our results suggest that the NT Evaluation protocols described here could be used to optimize some search engine parameters before human evaluation. Further research is needed to determine if NT Evaluation or variants of these protocols can fully substitute
A highly efficient protocol for micropropagation of Begonia tuberous.

Science.gov (United States)

Duong, Tan Nhut; Nguyen, Thanh Hai; Mai, Xuan Phan

2010-01-01

A protocol for micropropagation of begonia was established utilizing a thin cell layer (TCL) system. This system has been employed to produce several thousand shoots per sample. Explant size and position, and plant growth regulators (PGRs) contribute to the tissue morphogenesis. By optimizing the size of the tissue and applying an improved selection procedure, shoots were elongated in 8 weeks of culture, with an average number of 210 +/- 9.7 shoots per segment. This system has facilitated a number of studies using TCL as a model for micropropagation and will enable the large-scale production of begonia. On an average, the best treatment would allow production of about 10,000 plantlets by the micropropagation of the axillary buds of one plant with five petioles, within a period of 8 months.
USA-USSR protocol

CERN Multimedia

1970-01-01

On 30 November the USA Atomic Energy Commission and the USSR State Committee for the Utilization of Atomic Energy signed, in Washington, a protocol 'on carrying out of joint projects in the field of high energy physics at the accelerators of the National Accelerator Laboratory (Batavia) and the Institute for High Energy Physics (Serpukhov)'. The protocol will be in force for five years and can be extended by mutual agreement.
[Computerized clinical protocol for occlusion].

Science.gov (United States)

Salsench, J; Ferrer, J; Nogueras, J

1988-11-01

In making a protocol it is necessary that all members of the team who are going to collect information have the same unity of criterion about the different variables that compose it. The drawing up of this document is as much or more necessary than the protocol itself. In this work we all data collected in the protocol and we give the explanations of each concept.
Bioremediation protocols

National Research Council Canada - National Science Library

Sheehan, David

1997-01-01

..., .. . . . . .. ,. . . .. . . . . . . . .. . . . . .. . . .. . .. 3 2 Granular Nina Sludge Christiansen, Consortia lndra for Bioremediation, M. Mathrani, and Birgitte K. Ahring . 23 PART II PROTOCOLS...
Modeling MAC layer for powerline communications networks

Science.gov (United States)

Hrasnica, Halid; Haidine, Abdelfatteh

2001-02-01

The usage of electrical power distribution networks for voice and data transmission, called Powerline Communications, becomes nowadays more and more attractive, particularly in the telecommunication access area. The most important reasons for that are the deregulation of the telecommunication market and a fact that the access networks are still property of former monopolistic companies. In this work, first we analyze a PLC network and system structure as well as a disturbance scenario in powerline networks. After that, we define a logical structure of the powerline MAC layer and propose the reservation MAC protocols for the usage in the PLC network which provides collision free data transmission. This makes possible better network utilization and realization of QoS guarantees which can make PLC networks competitive to other access technologies.
Macular Choroidal Small-Vessel Layer, Sattler's Layer and Haller's Layer Thicknesses: The Beijing Eye Study.

Science.gov (United States)

Zhao, Jing; Wang, Ya Xing; Zhang, Qi; Wei, Wen Bin; Xu, Liang; Jonas, Jost B

2018-03-13

To study macular choroidal layer thickness, 3187 study participants from the population-based Beijing Eye Study underwent spectral-domain optical coherence tomography with enhanced depth imaging for thickness measurements of the macular small-vessel layer, including the choriocapillaris, medium-sized choroidal vessel layer (Sattler's layer) and large choroidal vessel layer (Haller's layer). In multivariate analysis, greater thickness of all three choroidal layers was associated (all P 0.05) associated with the prevalence of open-angle glaucoma or diabetic retinopathy. There was a tendency (0.07 > P > 0.02) toward thinner choroidal layers in chronic angle-closure glaucoma. The ratio of small-vessel layer thickness to total choroidal thickness increased (P layer and Haller's layer thickness to total choroidal thickness decreased. A higher ratio of small-vessel layer thickness to total choroidal thickness was significantly associated with a lower prevalence of AMD (early type, intermediate type, late geographic type). Axial elongation-associated and aging-associated choroidal thinning affected Haller's and Sattler's layers more markedly than the small-vessel layer. Non-exudative and exudative AMD, except for geographic atrophy, was associated with slightly increased choroidal thickness.
ATM and Internet protocol

CERN Document Server

Bentall, M; Turton, B

1998-01-01

Asynchronous Transfer Mode (ATM) is a protocol that allows data, sound and video being transferred between independent networks via ISDN links to be supplied to, and interpreted by, the various system protocols.ATM and Internet Protocol explains the working of the ATM and B-ISDN network for readers with a basic understanding of telecommunications. It provides a handy reference to everyone working with ATM who may not require the full standards in detail, but need a comprehensive guide to ATM. A substantial section is devoted to the problems of running IP over ATM and there is some discussion o
Group covariant protocols for quantum string commitment

International Nuclear Information System (INIS)

Tsurumaru, Toyohiro

2006-01-01

We study the security of quantum string commitment (QSC) protocols with group covariant encoding scheme. First we consider a class of QSC protocol, which is general enough to incorporate all the QSC protocols given in the preceding literatures. Then among those protocols, we consider group covariant protocols and show that the exact upperbound on the binding condition can be calculated. Next using this result, we prove that for every irreducible representation of a finite group, there always exists a corresponding nontrivial QSC protocol which reaches a level of security impossible to achieve classically
Families of quantum fingerprinting protocols

Science.gov (United States)

Lovitz, Benjamin; Lütkenhaus, Norbert

2018-03-01

We introduce several families of quantum fingerprinting protocols to evaluate the equality function on two n -bit strings in the simultaneous message passing model. The original quantum fingerprinting protocol uses a tensor product of a small number of O (logn ) -qubit high-dimensional signals [H. Buhrman et al., Phys. Rev. Lett. 87, 167902 (2001), 10.1103/PhysRevLett.87.167902], whereas a recently proposed optical protocol uses a tensor product of O (n ) single-qubit signals, while maintaining the O (logn ) information leakage of the original protocol [J. M. Arazola and N. Lütkenhaus, Phys. Rev. A 89, 062305 (2014), 10.1103/PhysRevA.89.062305]. We find a family of protocols which interpolate between the original and optical protocols while maintaining the O (logn ) information leakage, thus demonstrating a tradeoff between the number of signals sent and the dimension of each signal. There has been interest in experimental realization of the recently proposed optical protocol using coherent states [F. Xu et al., Nat. Commun. 6, 8735 (2015), 10.1038/ncomms9735; J.-Y. Guan et al., Phys. Rev. Lett. 116, 240502 (2016), 10.1103/PhysRevLett.116.240502], but as the required number of laser pulses grows linearly with the input size n , eventual challenges for the long-time stability of experimental setups arise. We find a coherent state protocol which reduces the number of signals by a factor 1/2 while also reducing the information leakage. Our reduction makes use of a simple modulation scheme in optical phase space, and we find that more complex modulation schemes are not advantageous. Using a similar technique, we improve a recently proposed coherent state protocol for evaluating the Euclidean distance between two real unit vectors [N. Kumar et al., Phys. Rev. A 95, 032337 (2017), 10.1103/PhysRevA.95.032337] by reducing the number of signals by a factor 1/2 and also reducing the information leakage.

In-memory interconnect protocol configuration registers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.
In-memory interconnect protocol configuration registers

Science.gov (United States)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.
Effectiveness of oxaliplatin desensitization protocols.

Science.gov (United States)

Cortijo-Cascajares, Susana; Nacle-López, Inmaculada; García-Escobar, Ignacio; Aguilella-Vizcaíno, María José; Herreros-de-Tejada, Alberto; Cortés-Funes Castro, Hernán; Calleja-Hernández, Miguel-Ángel

2013-03-01

Hypersensitivity reaction (HSR) to antineoplastic drugs can force doctors to stop treatment and seek other alternatives. These alternatives may be less effective, not as well tolerated and/or more expensive. Another option is to use desensitization protocols that induce a temporary state of tolerance by gradually administering small quantities of the antineoplastic drug until the therapeutic dosage is reached. The aim of this study is to assess the effectiveness of oxaliplatin desensitization protocols. A retrospective observational study was carried out between January 2006 and May 2011. The inclusion criteria were patients undergoing chemotherapy treatment with oxaliplatin who had developed an HSR to the drug and who were candidates for continuing the treatment using a desensitization protocol. The patients' clinical records were reviewed and variables were gathered relating to the patient, the treatment, the HSR, and the desensitization protocol administered. The data were analysed using version 18.0 of the statistics program SPSS. A total of 53 desensitization protocols were administered to 21 patients. In 89 % of these cases, no new reactions occurred while the drug was being administered. New reactions of mild severity only occurred in 11 % of cases, and none of these reactions were severe enough for treatment to be stopped. All patients were able to complete the desensitization protocol. This study confirms that oxaliplatin desensitization protocols are safe and effective and allow patients to continue with the treatment that initially caused an HSR.
Cross-layer combining of adaptive modulation and truncated ARQ under cognitive radio resource requirements

KAUST Repository

Yang, Yuli; Ma, Hao; Aï ssa, Sonia

2012-01-01

In addressing the issue of taking full advantage of the shared spectrum under imposed limitations in a cognitive radio (CR) network, we exploit a cross-layer design for the communications of secondary users (SUs), which combines adaptive modulation and coding (AMC) at the physical layer with truncated automatic repeat request (ARQ) protocol at the data link layer. To achieve high spectral efficiency (SE) while maintaining a target packet loss probability (PLP), switching among different transmission modes is performed to match the time-varying propagation conditions pertaining to the secondary link. Herein, by minimizing the SU's packet error rate (PER) with each transmission mode subject to the spectrum-sharing constraints, we obtain the optimal power allocation at the secondary transmitter (ST) and then derive the probability density function (pdf) of the received SNR at the secondary receiver (SR). Based on these statistics, the SU's packet loss rate and average SE are obtained in closed form, considering transmissions over block-fading channels with different distributions. Our results quantify the relation between the performance of a secondary link exploiting the cross-layer-designed adaptive transmission and the interference inflicted on the primary user (PU) in CR networks. © 1967-2012 IEEE.
Cross-layer design for intrusion detection and data security in wireless ad hoc sensor networks

Science.gov (United States)

Hortos, William S.

2007-09-01

A wireless ad hoc sensor network is a configuration for area surveillance that affords rapid, flexible deployment in arbitrary threat environments. There is no infrastructure support and sensor nodes communicate with each other only when they are in transmission range. The nodes are severely resource-constrained, with limited processing, memory and power capacities and must operate cooperatively to fulfill a common mission in typically unattended modes. In a wireless sensor network (WSN), each sensor at a node can observe locally some underlying physical phenomenon and sends a quantized version of the observation to sink (destination) nodes via wireless links. Since the wireless medium can be easily eavesdropped, links can be compromised by intrusion attacks from nodes that may mount denial-of-service attacks or insert spurious information into routing packets, leading to routing loops, long timeouts, impersonation, and node exhaustion. A cross-layer design based on protocol-layer interactions is proposed for detection and identification of various intrusion attacks on WSN operation. A feature set is formed from selected cross-layer parameters of the WSN protocol to detect and identify security threats due to intrusion attacks. A separate protocol is not constructed from the cross-layer design; instead, security attributes and quantified trust levels at and among nodes established during data exchanges complement customary WSN metrics of energy usage, reliability, route availability, and end-to-end quality-of-service (QoS) provisioning. Statistical pattern recognition algorithms are applied that use observed feature-set patterns observed during network operations, viewed as security audit logs. These algorithms provide the "best" network global performance in the presence of various intrusion attacks. A set of mobile (software) agents distributed at the nodes implement the algorithms, by moving among the layers involved in the network response at each active node
DNA repair protocols

DEFF Research Database (Denmark)

Bjergbæk, Lotte

In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...
Physical Layer Security Using Two-Path Successive Relaying

Directory of Open Access Journals (Sweden)

Qian Yu Liau

2016-06-01

Full Text Available Relaying is one of the useful techniques to enhance wireless physical-layer security. Existing literature shows that employing full-duplex relay instead of conventional half-duplex relay improves secrecy capacity and secrecy outage probability, but this is at the price of sophisticated implementation. As an alternative, two-path successive relaying has been proposed to emulate operation of full-duplex relay by scheduling a pair of half-duplex relays to assist the source transmission alternately. However, the performance of two-path successive relaying in secrecy communication remains unexplored. This paper proposes a secrecy two-path successive relaying protocol for a scenario with one source, one destination and two half-duplex relays. The relays operate alternately in a time division mode to forward messages continuously from source to destination in the presence of an eavesdropper. Analytical results reveal that the use of two half-duplex relays in the proposed scheme contributes towards a quadratically lower probability of interception compared to full-duplex relaying. Numerical simulations show that the proposed protocol achieves the ergodic achievable secrecy rate of full-duplex relaying while delivering the lowest probability of interception and secrecy outage probability compared to the existing half duplex relaying, full duplex relaying and full duplex jamming schemes.
Phase Transition in Protocols Minimizing Work Fluctuations

Science.gov (United States)

Solon, Alexandre P.; Horowitz, Jordan M.

2018-05-01

For two canonical examples of driven mesoscopic systems—a harmonically trapped Brownian particle and a quantum dot—we numerically determine the finite-time protocols that optimize the compromise between the standard deviation and the mean of the dissipated work. In the case of the oscillator, we observe a collection of protocols that smoothly trade off between average work and its fluctuations. However, for the quantum dot, we find that as we shift the weight of our optimization objective from average work to work standard deviation, there is an analog of a first-order phase transition in protocol space: two distinct protocols exchange global optimality with mixed protocols akin to phase coexistence. As a result, the two types of protocols possess qualitatively different properties and remain distinct even in the infinite duration limit: optimal-work-fluctuation protocols never coalesce with the minimal-work protocols, which therefore never become quasistatic.
Generalized routing protocols for multihop relay networks

KAUST Repository

Khan, Fahd Ahmed

2011-07-01

Performance of multihop cooperative networks depends on the routing protocols employed. In this paper we propose the last-n-hop selection protocol, the dual path protocol, the forward-backward last-n-hop selection protocol and the forward-backward dual path protocol for the routing of data through multihop relay networks. The average symbol error probability performance of the schemes is analysed by simulations. It is shown that close to optimal performance can be achieved by using the last-n-hop selection protocol and its forward-backward variant. Furthermore we also compute the complexity of the protocols in terms of number of channel state information required and the number of comparisons required for routing the signal through the network. © 2011 IEEE.
Cross Layer QoS Provisioning in Home Networks

DEFF Research Database (Denmark)

Wang, Jiayuan; Brewka, Lukasz Jerzy; Ruepp, Sarah Renée

2011-01-01

This paper introduces an innovative QoS provisioning scheme in home networks, by utilizing Optical Wireless (OW) MAC specification proposed by Home Gigabit Access Project (OMEGA) project. The specification is characterized by its resource reservation protocol and the use of Time Division Multiple...... Access (TDMA). By adopting OW MAC to the widely supported Universal Plug and Play – Quality of Service (UPnP-QoS) Architecture in the simulated home domain, algorithms for cross layer mapping QoS requirements are proposed. Compared to utilizing WLAN MAC, our scheme is able to provide guaranteed Qo......S levels to streams with different priorities, especially to delay-sensitive services. Efficiencies of the algorithms and network performance are validated by analyzing the results collected from OPNET simulation models....
Bioinspired Security Analysis of Wireless Protocols

DEFF Research Database (Denmark)

Petrocchi, Marinella; Spognardi, Angelo; Santi, Paolo

2016-01-01

work, this paper investigates feasibility of adopting fraglets as model for specifying security protocols and analysing their properties. In particular, we give concrete sample analyses over a secure RFID protocol, showing evolution of the protocol run as chemical dynamics and simulating an adversary...
A security analysis of the 802.11s wireless mesh network routing protocol and its secure routing protocols.

Science.gov (United States)

Tan, Whye Kit; Lee, Sang-Gon; Lam, Jun Huy; Yoo, Seong-Moo

2013-09-02

Wireless mesh networks (WMNs) can act as a scalable backbone by connecting separate sensor networks and even by connecting WMNs to a wired network. The Hybrid Wireless Mesh Protocol (HWMP) is the default routing protocol for the 802.11s WMN. The routing protocol is one of the most important parts of the network, and it requires protection, especially in the wireless environment. The existing security protocols, such as the Broadcast Integrity Protocol (BIP), Counter with cipher block chaining message authentication code protocol (CCMP), Secure Hybrid Wireless Mesh Protocol (SHWMP), Identity Based Cryptography HWMP (IBC-HWMP), Elliptic Curve Digital Signature Algorithm HWMP (ECDSA-HWMP), and Watchdog-HWMP aim to protect the HWMP frames. In this paper, we have analyzed the vulnerabilities of the HWMP and developed security requirements to protect these identified vulnerabilities. We applied the security requirements to analyze the existing secure schemes for HWMP. The results of our analysis indicate that none of these protocols is able to satisfy all of the security requirements. We also present a quantitative complexity comparison among the protocols and an example of a security scheme for HWMP to demonstrate how the result of our research can be utilized. Our research results thus provide a tool for designing secure schemes for the HWMP.
Maximally efficient protocols for direct secure quantum communication

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Anindita [Department of Physics and Materials Science Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India); Department of Physics and Center for Astroparticle Physics and Space Science, Bose Institute, Block EN, Sector V, Kolkata 700091 (India); Pathak, Anirban, E-mail: anirban.pathak@jiit.ac.in [Department of Physics and Materials Science Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India); RCPTM, Joint Laboratory of Optics of Palacky University and Institute of Physics of Academy of Science of the Czech Republic, Faculty of Science, Palacky University, 17. Listopadu 12, 77146 Olomouc (Czech Republic)

2012-10-01

Two protocols for deterministic secure quantum communication (DSQC) using GHZ-like states have been proposed. It is shown that one of these protocols is maximally efficient and that can be modified to an equivalent protocol of quantum secure direct communication (QSDC). Security and efficiency of the proposed protocols are analyzed and compared. It is shown that dense coding is sufficient but not essential for DSQC and QSDC protocols. Maximally efficient QSDC protocols are shown to be more efficient than their DSQC counterparts. This additional efficiency arises at the cost of message transmission rate. -- Highlights: ► Two protocols for deterministic secure quantum communication (DSQC) are proposed. ► One of the above protocols is maximally efficient. ► It is modified to an equivalent protocol of quantum secure direct communication (QSDC). ► It is shown that dense coding is sufficient but not essential for DSQC and QSDC protocols. ► Efficient QSDC protocols are always more efficient than their DSQC counterparts.
Physical Therapy Protocols for Arthroscopic Bankart Repair.

Science.gov (United States)

DeFroda, Steven F; Mehta, Nabil; Owens, Brett D

Outcomes after arthroscopic Bankart repair can be highly dependent on compliance and participation in physical therapy. Additionally, there are many variations in physician-recommended physical therapy protocols. The rehabilitation protocols of academic orthopaedic surgery departments vary widely despite the presence of consensus protocols. Descriptive epidemiology study. Level 3. Web-based arthroscopic Bankart rehabilitation protocols available online from Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedic surgery programs were included for review. Individual protocols were reviewed to evaluate for the presence or absence of recommended therapies, goals for completion of ranges of motion, functional milestones, exercise start times, and recommended time to return to sport. Thirty protocols from 27 (16.4%) total institutions were identified out of 164 eligible for review. Overall, 9 (30%) protocols recommended an initial period of strict immobilization. Variability existed between the recommended time periods for sling immobilization (mean, 4.8 ± 1.8 weeks). The types of exercises and their start dates were also inconsistent. Goals to full passive range of motion (mean, 9.2 ± 2.8 weeks) and full active range of motion (mean, 12.2 ± 2.8 weeks) were consistent with other published protocols; however, wide ranges existed within the reviewed protocols as a whole. Only 10 protocols (33.3%) included a timeline for return to sport, and only 3 (10%) gave an estimate for return to game competition. Variation also existed when compared with the American Society of Shoulder and Elbow Therapists' (ASSET) consensus protocol. Rehabilitation protocols after arthroscopic Bankart repair were found to be highly variable. They also varied with regard to published consensus protocols. This discrepancy may lead to confusion among therapists and patients. This study highlights the importance of attending surgeons being very clear and specific with
Welfare Quality assessment protocol for laying hens = Welfare Quality assessment protocol voor leghennen

NARCIS (Netherlands)

Niekerk, van T.G.C.M.; Gunnink, H.; Reenen, van C.G.

2012-01-01

Results of a study on the Welfare Quality® assessment protocol for laying hens. It reports the development of the integration of welfare assessment as scores per criteria as well as simplification of the Welfare Quality® assessment protocol. Results are given from assessment of 122 farms.
Publication trends of study protocols in rehabilitation.

Science.gov (United States)

Jesus, Tiago S; Colquhoun, Heather L

2017-09-04

Growing evidence points for the need to publish study protocols in the health field. To observe whether the growing interest in publishing study protocols in the broader health field has been translated into increased publications of rehabilitation study protocols. Observational study using publication data and its indexation in PubMed. Not applicable. Not applicable. PubMed was searched with appropriate combinations of Medical Subject Headings up to December 2014. The effective presence of study protocols was manually screened. Regression models analyzed the yearly growth of publications. Two-sample Z-tests analyzed whether the proportion of Systematic Reviews (SRs) and Randomized Controlled Trials (RCTs) among study protocols differed from that of the same designs for the broader rehabilitation research. Up to December 2014, 746 publications of rehabilitation study protocols were identified, with an exponential growth since 2005 (r2=0.981; p<0.001). RCT protocols were the most common among rehabilitation study protocols (83%), while RCTs were significantly more prevalent among study protocols than among the broader rehabilitation research (83% vs. 35.8%; p<0.001). For SRs, the picture was reversed: significantly less common among study protocols (2.8% vs. 9.3%; p<0.001). Funding was more often reported by rehabilitation study protocols than the broader rehabilitation research (90% vs. 53.1%; p<0.001). Rehabilitation journals published a significantly lower share of rehabilitation study protocols than they did for the broader rehabilitation research (1.8% vs.16.7%; p<0.001). Identifying the reasons for these discrepancies and reverting unwarranted disparities (e.g. low rate of publication for rehabilitation SR protocols) are likely new avenues for rehabilitation research and its publication. SRs, particularly those aggregating RCT results, are considered the best standard of evidence to guide rehabilitation clinical practice; however, that standard can be improved
Protocol Fuel Mix reporting

International Nuclear Information System (INIS)

2002-07-01

The protocol in this document describes a method for an Electricity Distribution Company (EDC) to account for the fuel mix of electricity that it delivers to its customers, based on the best available information. Own production, purchase and sale of electricity, and certificates trading are taken into account. In chapter 2 the actual protocol is outlined. In the appendixes additional (supporting) information is given: (A) Dutch Standard Fuel Mix, 2000; (B) Calculation of the Dutch Standard fuel mix; (C) Procedures to estimate and benchmark the fuel mix; (D) Quality management; (E) External verification; (F) Recommendation for further development of the protocol; (G) Reporting examples
Cooperative Cloud Service Aware Mobile Internet Coverage Connectivity Guarantee Protocol Based on Sensor Opportunistic Coverage Mechanism

Directory of Open Access Journals (Sweden)

Qin Qin

2015-01-01

Full Text Available In order to improve the Internet coverage ratio and provide connectivity guarantee, based on sensor opportunistic coverage mechanism and cooperative cloud service, we proposed the coverage connectivity guarantee protocol for mobile Internet. In this scheme, based on the opportunistic covering rules, the network coverage algorithm of high reliability and real-time security was achieved by using the opportunity of sensor nodes and the Internet mobile node. Then, the cloud service business support platform is created based on the Internet application service management capabilities and wireless sensor network communication service capabilities, which is the architecture of the cloud support layer. The cooperative cloud service aware model was proposed. Finally, we proposed the mobile Internet coverage connectivity guarantee protocol. The results of experiments demonstrate that the proposed algorithm has excellent performance, in terms of the security of the Internet and the stability, as well as coverage connectivity ability.
Development and Evaluation of Secure Socket Layer Visualization Tool with Packet Capturing Function

Directory of Open Access Journals (Sweden)

Arai Masayuki

2015-01-01

Full Text Available Secure Socket Layer (SSL has become a fundamental technology that secures browser-processed personal details sent to the server. As a result, communication and computer engineers are advised to learn the protocol. However, understanding SSL is very difficult because of its intricate communication procedure. To solve this problem, we developed a visualization tool for understanding SSL. This paper describes the design, implementation methods, and evaluation of the tool. The evaluation results show that the visualization tool is effective for learning SSL.
Universally composable protocols with relaxed set-up assumptions

DEFF Research Database (Denmark)

Barak, Boaz; Canetti, Ran; Nielsen, Jesper Buus

2004-01-01

A desirable goal for cryptographic protocols is to guarantee security when the protocol is composed with other protocol instances. Universally composable (UC) protocols provide this guarantee in a strong sense: A protocol remains secure even when composed concurrently with an unbounded number of ...

In silico toxicology protocols.

Science.gov (United States)

Myatt, Glenn J; Ahlberg, Ernst; Akahori, Yumi; Allen, David; Amberg, Alexander; Anger, Lennart T; Aptula, Aynur; Auerbach, Scott; Beilke, Lisa; Bellion, Phillip; Benigni, Romualdo; Bercu, Joel; Booth, Ewan D; Bower, Dave; Brigo, Alessandro; Burden, Natalie; Cammerer, Zoryana; Cronin, Mark T D; Cross, Kevin P; Custer, Laura; Dettwiler, Magdalena; Dobo, Krista; Ford, Kevin A; Fortin, Marie C; Gad-McDonald, Samantha E; Gellatly, Nichola; Gervais, Véronique; Glover, Kyle P; Glowienke, Susanne; Van Gompel, Jacky; Gutsell, Steve; Hardy, Barry; Harvey, James S; Hillegass, Jedd; Honma, Masamitsu; Hsieh, Jui-Hua; Hsu, Chia-Wen; Hughes, Kathy; Johnson, Candice; Jolly, Robert; Jones, David; Kemper, Ray; Kenyon, Michelle O; Kim, Marlene T; Kruhlak, Naomi L; Kulkarni, Sunil A; Kümmerer, Klaus; Leavitt, Penny; Majer, Bernhard; Masten, Scott; Miller, Scott; Moser, Janet; Mumtaz, Moiz; Muster, Wolfgang; Neilson, Louise; Oprea, Tudor I; Patlewicz, Grace; Paulino, Alexandre; Lo Piparo, Elena; Powley, Mark; Quigley, Donald P; Reddy, M Vijayaraj; Richarz, Andrea-Nicole; Ruiz, Patricia; Schilter, Benoit; Serafimova, Rositsa; Simpson, Wendy; Stavitskaya, Lidiya; Stidl, Reinhard; Suarez-Rodriguez, Diana; Szabo, David T; Teasdale, Andrew; Trejo-Martin, Alejandra; Valentin, Jean-Pierre; Vuorinen, Anna; Wall, Brian A; Watts, Pete; White, Angela T; Wichard, Joerg; Witt, Kristine L; Woolley, Adam; Woolley, David; Zwickl, Craig; Hasselgren, Catrin

2018-04-17

The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information. Copyright © 2018. Published by Elsevier Inc.
Summary Report on Unconditionally Secure Protocols

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre; Salvail, Louis; Cachin, Christian

This document describes the state of the art snd some of the main open problems in the area of unconditionally secure cryptographic protocols. The most essential part of a cryptographic protocol is not its being secure. Imagine a cryptographic protocol which is secure, but where we do not know...... that it is secure. Such a protocol would do little in providing security. When all comes to all, cryptographic security is done for the sake of people, and the essential part of security is for people what it has always been, namely to feel secure. To feel secure employing a given cryptographic protocol we need...... to know that is is secure. I.e. we need a proof that it is secure. Today the proof of security of essentially all practically employed cryptographic protocols relies on computational assumptions. To prove that currently employed ways to communicate securely over the Internet are secure we e.g. need...
Network-topology-adaptive quantum conference protocols

International Nuclear Information System (INIS)

Zhang Sheng; Wang Jian; Tang Chao-Jing; Zhang Quan

2011-01-01

As an important application of the quantum network communication, quantum multiparty conference has made multiparty secret communication possible. Previous quantum multiparty conference schemes based on quantum data encryption are insensitive to network topology. However, the topology of the quantum network significantly affects the communication efficiency, e.g., parallel transmission in a channel with limited bandwidth. We have proposed two distinctive protocols, which work in two basic network topologies with efficiency higher than the existing ones. We first present a protocol which works in the reticulate network using Greeberger—Horne—Zeilinger states and entanglement swapping. Another protocol, based on quantum multicasting with quantum data compression, which can improve the efficiency of the network, works in the star-like network. The security of our protocols is guaranteed by quantum key distribution and one-time-pad encryption. In general, the two protocols can be applied to any quantum network where the topology can be equivalently transformed to one of the two structures we propose in our protocols. (general)
TosNet: An easy-to-use, real-time communications protocol for modular, distributed robot controllers

DEFF Research Database (Denmark)

Falsig, Simon; Sørensen, Anders Stengaard

2009-01-01

Net supports up to 15 nodes, with cycle-rates up to 25 kHz, depending on the configuration. The protocol stack is completely specified as VHDL code, implemented in an FPGA. The physical layer is implemented with Toslink fiberoptic links, offering a compact, robust and highly available link technology......This paper presents the TosNet network, created for robotics research, education, and prototyping, emphasizing ease of use, robustness, compactness, flexibility and fast hard realtime response, to allow distribution of all levels of the robot control system. The current implementation of Tos...
Tensiometry and dilational rheology of mixed β-lactoglobulin/ionic surfactant adsorption layers at water/air and water/hexane interfaces.

Science.gov (United States)

Dan, Abhijit; Gochev, Georgi; Miller, Reinhard

2015-07-01

Oscillating drop tensiometry was applied to study adsorbed interfacial layers at water/air and water/hexane interfaces formed from mixed solutions of β-lactoglobulin (BLG, 1 μM in 10 mM buffer, pH 7 - negative net charge) and the anionic surfactant SDS or the cationic DoTAB. The interfacial pressure Π and the dilational viscoelasticity modulus |E| of the mixed layers were measured for mixtures of varying surfactant concentrations. The double capillary technique was employed which enables exchange of the protein solution in the drop bulk by surfactant solution (sequential adsorption) or by pure buffer (washing out). The first protocol allows probing the influence of the surfactant on a pre-adsorbed protein layer thus studying the protein/surfactant interactions at the interface. The second protocol gives access to the residual values of Π and |E| measured after the washing out procedure thus bringing information about the process of protein desorption. The DoTAB/BLG complexes exhibit higher surface activity and higher resistance to desorption in comparison with those for the SDS/BLG complexes due to hydrophobization via electrostatic binding of surfactant molecules. The neutral DoTAB/BLG complexes achieve maximum elastic response of the mixed layer. Mixed BLG/surfactant layers at the water/oil interface are found to reach higher surface pressure and lower maximum dilational elasticity than those at the water/air surface. The sequential adsorption mode experiments and the desorption study reveal that binding of DoTAB to pre-adsorbed BLG globules is somehow restricted at the water/air surface in comparison with the case of complex formation in the solution bulk and subsequently adsorbed at the water/air surface. Maximum elasticity is achieved with washed out layers obtained after simultaneous adsorption, i.e. isolation of the most surface active DoTAB/BLG complex. These specific effects are much less pronounced at the W/H interface. Copyright © 2015 Elsevier Inc
FTR: Performance-Aware and Energy-Efficient Communication Protocol for Integrating Sensor Networks into the Internet

Directory of Open Access Journals (Sweden)

Sinung Suakanto

2014-11-01

Full Text Available Integrating sensor networks into the Internet brings many advantages. For example, users can monitor or control the state of the sensors remotely without visiting the field. Some researchers have proposed methods using a REST-based web service or HTTP to establish communication between sensors and server via the Internet. Unfortunately, as we know, HTTP is a best-effort service. In some cases this means that if the number of sensors increases the end-to-end Quality of Service will decrease. The end-to-end network delay increases, as well as the failure rate of data sending caused by HTTP timeouts. In this paper, we propose Finite Time Response (FTR HTTP as a communication protocol suitable for integrating sensor networks into the Internet. We have defined a cross-layer approach that coordinates between the application layer and the physical layer to control not only performance but also energy efficiency. The HTTP request-response delay measured at the application layer is used as the decision factor at the physical layer to control the active and sleep periods. We also propose a forced-sleep period as a control mechanism to guarantee average performance for all nodes. The experimental results have shown that FTR has the ability to maintain better performance, indicated by a lower average response time and a lower average timeout experience. Optimization is still needed to gain better performance and better energy efficiency while also considering the average value of the update time.
Secure Protocol and IP Core for Configuration of Networking Hardware IPs in the Smart Grid

Directory of Open Access Journals (Sweden)

Marcelo Urbina

2018-02-01

Full Text Available Nowadays, the incorporation and constant evolution of communication networks in the electricity sector have given rise to the so-called Smart Grid, which is why it is necessary to have devices that are capable of managing new communication protocols, guaranteeing the strict requirements of processing required by the electricity sector. In this context, intelligent electronic devices (IEDs with network architectures are currently available to meet the communication, real-time processing and interoperability requirements of the Smart Grid. The new generation IEDs include an Field Programmable Gate Array (FPGA, to support specialized networking switching architectures for the electric sector, as the IEEE 1588-aware High-availability Seamless Redundancy/Parallel Redundancy Protocol (HSR/PRP. Another advantage to using an FPGA is the ability to update or reconfigure the design to support new requirements that are being raised to the standards (IEC 61850. The update of the architecture implemented in the FPGA can be done remotely, but it is necessary to establish a cyber security mechanism since the communication link generates vulnerability in the case the attacker gains physical access to the network. The research presented in this paper proposes a secure protocol and Intellectual Property (IP core for configuring and monitoring the networking IPs implemented in a Field Programmable Gate Array (FPGA. The FPGA based implementation proposed overcomes this issue using a light Layer-2 protocol fully implemented on hardware and protected by strong cryptographic algorithms (AES-GCM, defined in the IEC 61850-90-5 standard. The proposed secure protocol and IP core are applicable in any field where remote configuration over Ethernet is required for IP cores in FPGAs. In this paper, the proposal is validated in communications hardware for Smart Grids.
Intelligent Local Avoided Collision (iLAC) MAC Protocol for Very High Speed Wireless Network

Science.gov (United States)

Hieu, Dinh Chi; Masuda, Akeo; Rabarijaona, Verotiana Hanitriniala; Shimamoto, Shigeru

Future wireless communication systems aim at very high data rates. As the medium access control (MAC) protocol plays the central role in determining the overall performance of the wireless system, designing a suitable MAC protocol is critical to fully exploit the benefit of high speed transmission that the physical layer (PHY) offers. In the latest 802.11n standard [2], the problem of long overhead has been addressed adequately but the issue of excessive colliding transmissions, especially in congested situation, remains untouched. The procedure of setting the backoff value is the heart of the 802.11 distributed coordination function (DCF) to avoid collision in which each station makes its own decision on how to avoid collision in the next transmission. However, collision avoidance is a problem that can not be solved by a single station. In this paper, we introduce a new MAC protocol called Intelligent Local Avoided Collision (iLAC) that redefines individual rationality in choosing the backoff counter value to avoid a colliding transmission. The distinguishing feature of iLAC is that it fundamentally changes this decision making process from collision avoidance to collaborative collision prevention. As a result, stations can avoid colliding transmissions with much greater precision. Analytical solution confirms the validity of this proposal and simulation results show that the proposed algorithm outperforms the conventional algorithms by a large margin.
e-SCP-ECG+ Protocol: An Expansion on SCP-ECG Protocol for Health Telemonitoring—Pilot Implementation

Directory of Open Access Journals (Sweden)

George J. Mandellos

2010-01-01

Full Text Available Standard Communication Protocol for Computer-assisted Electrocardiography (SCP-ECG provides standardized communication among different ECG devices and medical information systems. This paper extends the use of this protocol in order to be included in health monitoring systems. It introduces new sections into SCP-ECG structure for transferring data for positioning, allergies, and five additional biosignals: noninvasive blood pressure (NiBP, body temperature (Temp, Carbon dioxide (CO2, blood oxygen saturation (SPO2, and pulse rate. It also introduces new tags in existing sections for transferring comprehensive demographic data. The proposed enhanced version is referred to as e-SCP-ECG+ protocol. This paper also considers the pilot implementation of the new protocol as a software component in a Health Telemonitoring System.
Mac protocols for cyber-physical systems

CERN Document Server

Xia, Feng

2015-01-01

This book provides a literature review of various wireless MAC protocols and techniques for achieving real-time and reliable communications in the context of cyber-physical systems (CPS). The evaluation analysis of IEEE 802.15.4 for CPS therein will give insights into configuration and optimization of critical design parameters of MAC protocols. In addition, this book also presents the design and evaluation of an adaptive MAC protocol for medical CPS, which exemplifies how to facilitate real-time and reliable communications in CPS by exploiting IEEE 802.15.4 based MAC protocols. This book wil
Influence of surface layer removal of shade guide tabs on the measured color by spectrophotometer and spectroradiometer.

Science.gov (United States)

Kim, Jin-Cheol; Yu, Bin; Lee, Yong-Keun

2008-12-01

To determine the changes in color parameters of Vitapan 3D-Master shade guide tabs by a spectrophotometer (SP) or a spectroradiometer (SR), and by the removal of the surface layer of the tabs that was performed to make a flat measuring surface for the SP color measurement. Color of the shade tabs was measured before and after removing the surface layer of the tabs using SP and SR. Correlations between the color parameters between the original (OR) and the surface layer removed (RM) tabs and between the SP and the SR measurements were determined (alpha=0.05). Based on SP, the lightness, chroma, CIE a* and b* values measured after the surface layer removal were higher than those of the original tabs except a few cases. Based on SR, the chroma and CIE a* and b* values measured after surface layer removal were higher than those of the original tabs except a few cases; however, in case of the lightness, the changes varied by the shade designation. Type of instrument influenced the changes in color parameters based on paired t-test (pspectrophotometer or a spectroradiometer, measurement protocols should be specified because color difference by the surface layer removal and the instrument was high.
Short Review on Quantum Key Distribution Protocols.

Science.gov (United States)

Giampouris, Dimitris

2017-01-01

Cryptographic protocols and mechanisms are widely investigated under the notion of quantum computing. Quantum cryptography offers particular advantages over classical ones, whereas in some cases established protocols have to be revisited in order to maintain their functionality. The purpose of this paper is to provide the basic definitions and review the most important theoretical advancements concerning the BB84 and E91 protocols. It also aims to offer a summary on some key developments on the field of quantum key distribution, closely related with the two aforementioned protocols. The main goal of this study is to provide the necessary background information along with a thorough review on the theoretical aspects of QKD, concentrating on specific protocols. The BB84 and E91 protocols have been chosen because most other protocols are similar to these, a fact that makes them important for the general understanding of how the QKD mechanism functions.
Incorporating ethical principles into clinical research protocols: a tool for protocol writers and ethics committees.

Science.gov (United States)

Li, Rebecca H; Wacholtz, Mary C; Barnes, Mark; Boggs, Liam; Callery-D'Amico, Susan; Davis, Amy; Digilova, Alla; Forster, David; Heffernan, Kate; Luthin, Maeve; Lynch, Holly Fernandez; McNair, Lindsay; Miller, Jennifer E; Murphy, Jacquelyn; Van Campen, Luann; Wilenzick, Mark; Wolf, Delia; Woolston, Cris; Aldinger, Carmen; Bierer, Barbara E

2016-04-01

A novel Protocol Ethics Tool Kit ('Ethics Tool Kit') has been developed by a multi-stakeholder group of the Multi-Regional Clinical Trials Center of Brigham and Women's Hospital and Harvard. The purpose of the Ethics Tool Kit is to facilitate effective recognition, consideration and deliberation of critical ethical issues in clinical trial protocols. The Ethics Tool Kit may be used by investigators and sponsors to develop a dedicated Ethics Section within a protocol to improve the consistency and transparency between clinical trial protocols and research ethics committee reviews. It may also streamline ethics review and may facilitate and expedite the review process by anticipating the concerns of ethics committee reviewers. Specific attention was given to issues arising in multinational settings. With the use of this Tool Kit, researchers have the opportunity to address critical research ethics issues proactively, potentially speeding the time and easing the process to final protocol approval. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Large family of quantum weak coin-flipping protocols

International Nuclear Information System (INIS)

Mochon, Carlos

2005-01-01

Each classical public-coin protocol for coin flipping is naturally associated with a quantum protocol for weak coin flipping. The quantum protocol is obtained by replacing classical randomness with quantum entanglement and by adding a cheat detection test in the last round that verifies the integrity of this entanglement. The set of such protocols defines a family which contains the protocol with bias 0.192 previously found by the author, as well as protocols with bias as low as 1/6 described herein. The family is analyzed by identifying a set of optimal protocols for every number of messages. In the end, tight lower bounds for the bias are obtained which prove that 1/6 is optimal for all protocols within the family
Nonblocking and orphan free message logging protocols

Science.gov (United States)

Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

1992-12-01

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.
The Kyoto Protocol. An economic appraisal

International Nuclear Information System (INIS)

Grubb, M.

2000-05-01

This paper examines the overall economics of the Kyoto Protocol on climate change, in three main parts. The first part explores the structure of the Protocol and how this matches against classical economic criteria of an 'optimal' climate change agreement. This discussion also considers the nature of and reasons for shortcomings, and the prospects for its evolution. Given the various flexibilities in the agreement, the Kyoto Protocol is far more economically efficient in its structure than any previous global environmental agreement. The central conclusion is that, from an economic perspective, the Protocol's structure for industrialised country commitments is as good as could reasonably be expected. The second part of the paper explores more closely the economics of the commitments themselves and how they combine with the various flexibilities, briefly reviewing the available literature and using a simple spreadsheet model of how the commitments might combine with trading mechanisms under a range of assumptions. Flexibility is intrinsic and necessary, but it is argued that the allocations to Russia and Ukraine in particular mean that unlimited flexibility could render the Protocol's commitments weaker in their impacts than is economically desirable to address climate change. It is argued that, should this prove to be the case, access to the large surplus in the transition economies could be used as a control valve to limit the costs of the Protocol to within acceptable limits. Finally, the paper considers the issues of developing country involvement in the Kyoto Protocol, and the Protocol's longer-term impact and evolution, including its impact on technological evolution and dissemination and the evolution of future commitments. It is argued that taking account of such issues critically affects views of the Protocol
Investigating the Effect of Growth Phase on the Surface-Layer Associated Proteome of Lactobacillus acidophilus Using Quantitative Proteomics

Directory of Open Access Journals (Sweden)

Courtney Klotz

2017-11-01

Full Text Available Bacterial surface-layers (S-layers are semi-porous crystalline arrays that self-assemble to form the outermost layer of some cell envelopes. S-layers have been shown to act as scaffolding structures for the display of auxiliary proteins externally. These S-layer associated proteins have recently gained attention in probiotics due to their direct physical contact with the intestinal mucosa and potential role in cell proliferation, adhesion, and immunomodulation. A number of studies have attempted to catalog the S-layer associated proteome of Lactobacillus acidophilus NCFM under a single condition. However, due to the versatility of the cell surface, we chose to employ a multiplexing-based approach with the intention of accurately contrasting multiple conditions. In this study, a previously described lithium chloride isolation protocol was used to release proteins bound to the L. acidophilus S-layer during logarithmic and early stationary growth phases. Protein quantification values were obtained via TMT (tandem mass tag labeling combined with a triple-stage mass spectrometry (MS3 method. Results showed significant growth stage-dependent alterations to the surface-associated proteome while simultaneously highlighting the sensitivity and reproducibility of the technology. Thus, this study establishes a framework for quantifying condition-dependent changes to cell surface proteins that can easily be applied to other S-layer forming bacteria.
Protocolos de Montreal e Kyoto: pontos em comum e diferenças fundamentais Montreal and Kyoto Protocols: common points and essential differences

Directory of Open Access Journals (Sweden)

Darly Henriques da Silva

2009-12-01

Full Text Available Os Protocolos de Montreal e Kyoto, tratados internacionais de defesa do meio ambiente e da vida, controlam gases que provocam o buraco na camada de ozônio e o efeito estufa, respectivamente, resultantes de atividades industriais e uso da terra. O artigo enfatiza pontos comuns e diferenças entre eles, fornecendo atualização dos protocolos.Montreal and Kyoto Protocols, international treaties, aim at safeguarding the environment and life by controlling the use of gases which deplete the ozone layer and cause the greenhouse effect, respectively, due to industrial and land use activities. The article highlights common points and differences and provides an update discussion about the protocols.
Analysis of energy efficient routing protocols for implementation of a ubiquitous health system

Science.gov (United States)

Kwon, Jongwon; Park, Yongman; Koo, Sangjun; Ayurzana, Odgeral; Kim, Hiesik

2007-12-01

The innovative Ubiquitous-Health was born through convergence of medical service, with development of up to date information technologies and ubiquitous IT. The U-Health can be applied to a variety of special situations for managing functions of each medical center efficiently. This paper focuses on estimation of various routing protocols for implementation of U-health monitoring system. In order to facilitate wireless communication over the network, a routing protocol on the network layer is used to establish precise and efficient route between sensor nodes so that information acquired from sensors may be delivered in a timely manner. A route establishment should be considered to minimize overhead, data loss and power consumption because wireless networks for U-health are organized by a large number of sensor nodes which are small in size and have limited processing power, memory and battery life. In this paper a overview of wireless sensor network technologies commonly known is described as well as evaluation of three multi hop routing protocols which are flooding, gossiping and modified low energy adaptive clustering hierarchy(LEACH) for use with these networks using TOSSIM simulator. As a result of evaluation the integrated wireless sensor board was developed in particular. The board is embedded device based on AVR128 porting TinyOS. Also it employs bio sensor measures blood pressure, pulse frequency and ZigBee module for wireless communication. This paper accelerates the digital convergence age through continual research and development of technologies related the U-Health.
A Unified NET-MAC-PHY Cross-layer Framework for Performance Evaluation of Multi-hop Ad hoc WLANs

Directory of Open Access Journals (Sweden)

Rachid El-Azouzi

2014-09-01

Full Text Available Most of the existing works have been evaluated the performance of 802.11 multihop networks by considering the MAC layer or network layer separately. Knowing the nature of the multi-hop ad hoc networks, many factors in different layers are crucial for study the performance of MANET. In this paper we present a new analytic model for evaluating average end-to-end throughput in IEEE 802.11e multihop wireless networks. In particular, we investigate an intricate interaction among PHY, MAC and Network layers. For instance, we incorporate carrier sense threshold, transmission power, contention window size, retransmissions retry limit, multi rates, routing protocols and network topology together. We build a general cross-layered framework to represent multi-hop ad hoc networks with asymmetric topology and asymmetric traffic. We develop an analytical model to predict throughput of each connection as well as stability of forwarding queues at intermediate nodes in saturated networks. To the best of our knowledge, it seems that our work is the first wherein general topology and asymmetric parameters setup are considered in PHY/MAC/Network layers. Performance of such a system is also evaluated through simulation. We show that performance measures of the MAC layer are affected by the traffic intensity of flows to be forwarded. More precisely, attempt rate and collision probability are dependent on traffic flows, topology and routing.

SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs.

Science.gov (United States)

Aslam, Muhammad; Hu, Xiaopeng; Wang, Fan

2017-12-13

Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN). Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs) utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR) routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR's routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS). This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR) to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime and stability
SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs

Directory of Open Access Journals (Sweden)

Muhammad Aslam

2017-12-01

Full Text Available Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN. Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR’s routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS. This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime
Principles of the new quantum cryptography protocols building

International Nuclear Information System (INIS)

Kurochkin, V.; Kurochkin, Yu.

2009-01-01

The main aim of the quantum cryptography protocols is the maximal secrecy under the conditions of the real experiment. This work presents the result of the new protocol building with the use of the secrecy maximization. While using some well-known approaches this method has allowed one to achieve completely new results in quantum cryptography. The process of the protocol elaboration develops from the standard BB84 protocol upgrading to the building of completely new protocol with arbitrary large bases number. The secrecy proofs of the elaborated protocol appear to be natural continuation of the protocol building process. This approach reveals possibility to reach extremely high parameters of the protocol. It suits both the restrictions of contemporary technologies and requirements for high bit rate while being absolutely secret
Low Latency MAC Protocol in Wireless Sensor Networks Using Timing Offset

Science.gov (United States)

Choi, Seung Sik

This paper proposes a low latency MAC protocol that can be used in sensor networks. To extend the lifetime of sensor nodes, the conventional solution is to synchronize active/sleep periods of all sensor nodes. However, due to these synchronized sensor nodes, packets in the intermediate nodes must wait until the next node wakes up before it can forward a packet. This induces a large delay in sensor nodes. To solve this latency problem, a clustered sensor network which uses two types of sensor nodes and layered architecture is considered. Clustered heads in each cluster are synchronized with different timing offsets to reduce the sleep delay. Using this concept, the latency problem can be solved and more efficient power usage can be obtained.
Attack strategies on quantum cryptographic protocols

International Nuclear Information System (INIS)

Schauer, S.; Suda, M.

2006-01-01

Full text: Quantum key distribution (QKD) and quantum authentication (QA) have been a topic of extensive research in the last 20 years. In course of that many attacks on QKD and QA protocols have been studied. Among these, Zhang, Lee and Guo presented an attack on a QKD protocol using entanglement swapping. Based on that strategy we take a look at other protocols to inspect how much information an adversary may get if he shares entanglement with either one or both parties. We will present some protocols where an adversary can even get full information about the key using entanglement. (author)
Protein structure modeling for CASP10 by multiple layers of global optimization.

Science.gov (United States)

Joo, Keehyoung; Lee, Juyong; Sim, Sangjin; Lee, Sun Young; Lee, Kiho; Heo, Seungryong; Lee, In-Ho; Lee, Sung Jong; Lee, Jooyoung

2014-02-01

In the template-based modeling (TBM) category of CASP10 experiment, we introduced a new protocol called protein modeling system (PMS) to generate accurate protein structures in terms of side-chains as well as backbone trace. In the new protocol, a global optimization algorithm, called conformational space annealing (CSA), is applied to the three layers of TBM procedure: multiple sequence-structure alignment, 3D chain building, and side-chain re-modeling. For 3D chain building, we developed a new energy function which includes new distance restraint terms of Lorentzian type (derived from multiple templates), and new energy terms that combine (physical) energy terms such as dynamic fragment assembly (DFA) energy, DFIRE statistical potential energy, hydrogen bonding term, etc. These physical energy terms are expected to guide the structure modeling especially for loop regions where no template structures are available. In addition, we developed a new quality assessment method based on random forest machine learning algorithm to screen templates, multiple alignments, and final models. For TBM targets of CASP10, we find that, due to the combination of three stages of CSA global optimizations and quality assessment, the modeling accuracy of PMS improves at each additional stage of the protocol. It is especially noteworthy that the side-chains of the final PMS models are far more accurate than the models in the intermediate steps. Copyright © 2013 Wiley Periodicals, Inc.
Network protocols and sockets

OpenAIRE

BALEJ, Marek

2010-01-01

My work will deal with network protocols and sockets and their use in programming language C#. It will therefore deal programming network applications on the platform .NET from Microsoft and instruments, which C# provides to us. There will describe the tools and methods for programming network applications, and shows a description and sample applications that work with sockets and application protocols.
Barrier layer arrangement for conductive layers on silicon substrates

International Nuclear Information System (INIS)

Hung, L.S.; Agostinelli, J.A.

1990-01-01

This patent describes a circuit element comprised of a silicon substrate and a conductive layer located on the substrate. It is characterized in that the conductive layer consists essentially of a rare earth alkaline earth copper oxide and a barrier layer triad is interposed between the silicon substrate and the conductive layer comprised of a first triad layer located adjacent the silicon substrate consisting essentially of silica, a third triad layer remote from the silicon substrate consisting essentially of a least one Group 4 heavy metal oxide, and a second triad layer interposed between the first and third triad layers consisting essentially of a mixture of silica and at lease one Group 4 heavy metal oxide
SET: Session Layer-Assisted Efficient TCP Management Architecture for 6LoWPAN with Multiple Gateways

Directory of Open Access Journals (Sweden)

Akbar AliHammad

2010-01-01

Full Text Available 6LoWPAN (IPv6 based Low-Power Personal Area Network is a protocol specification that facilitates communication of IPv6 packets on top of IEEE 802.15.4 so that Internet and wireless sensor networks can be inter-connected. This interconnection is especially required in commercial and enterprise applications of sensor networks where reliable and timely data transfers such as multiple code updates are needed from Internet nodes to sensor nodes. For this type of inbound traffic which is mostly bulk, TCP as transport layer protocol is essential, resulting in end-to-end TCP session through a default gateway. In this scenario, a single gateway tends to become the bottleneck because of non-uniform connectivity to all the sensor nodes besides being vulnerable to buffer overflow. We propose SET; a management architecture for multiple split-TCP sessions across a number of serving gateways. SET implements striping and multiple TCP session management through a shim at session layer. Through analytical modeling and ns2 simulations, we show that our proposed architecture optimizes communication for ingress bulk data transfer while providing associated load balancing services. We conclude that multiple split-TCP sessions managed in parallel across a number of gateways result in reduced latency for bulk data transfer and provide robustness against gateway failures.
A Priority-aware Frequency Domain Polling MAC Protocol for OFDMA-based Networks in Cyber-physical Systems

Institute of Scientific and Technical Information of China (English)

Meng Zheng; Junru Lin; Wei Liang; Haibin Yu

2015-01-01

Wireless networking in cyber-physical systems(CPSs) is characteristically different from traditional wireless systems due to the harsh radio frequency environment and applications that impose high real-time and reliability constraints.One of the fundamental considerations for enabling CPS networks is the medium access control protocol. To this end, this paper proposes a novel priority-aware frequency domain polling medium access control(MAC) protocol, which takes advantage of an orthogonal frequency-division multiple access(OFDMA)physical layer to achieve instantaneous priority-aware polling.Based on the polling result, the proposed work then optimizes the resource allocation of the OFDMA network to further improve the data reliability. Due to the non-polynomial-complete nature of the OFDMA resource allocation, we propose two heuristic rules,based on which an efficient solution algorithm to the OFDMA resource allocation problem is designed. Simulation results show that the reliability performance of CPS networks is significantly improved because of this work.
Physical layer impairments tolerance based lightpath provision in software defined optical network

Institute of Scientific and Technical Information of China (English)

Zhao Xianlong; Xu Xianze; Bai Huifeng

2017-01-01

As all-optical networks grow with ever increasing ultra-high speed, the communication quality suffers seriously from physical layer impairments ( PLIs) .The same problem still exists in software defined optical network ( SDON) controlled by OpenFlow.Aimed to solve this problem, a PLIs tol-erance based lightpath provision scheme is proposed for OpenFlow controlled optical networks.This proposed approach not only takes the OSNR model to represent those linear PLIs factors, but also in-troduces those nonlinear factors into the OSNR model.Thus, the proposed scheme is able to cover most PLIs factors of each optical link and conduct optical lightpath provison with better communica-tion quality.Moreover, PLIs tolerance model is also set up and considered in this work with some necessary extension to OpenFlow protocols to achieve better compatibility between physical layer im-pairments factors and various services connections.Simulation results show that the proposed scheme is able to get better performance in terms of packet loss rate and connection setup time.
SIP protocol model for OMNET++

Directory of Open Access Journals (Sweden)

Jan Kucerak

2016-01-01

Full Text Available The article describes our new SIP protocol implementation for the OMNeT++ simulation framework. OMNeT++ simulation framework provides an extensive support of IP related protocols, nevertheless a working SIP protocol implementation is missing. Real measurements were also done using a SIPp traffic generator and the results are compared to those obtained by our new SIP model. Since this work is a part of bigger project concerned strictly on measuring "first response times" over networks with a faulty transmission links, the actually collected statistics are focused only this way.
Simple algorithm for improved security in the FDDI protocol

Science.gov (United States)

Lundy, G. M.; Jones, Benjamin

1993-02-01

We propose a modification to the Fiber Distributed Data Interface (FDDI) protocol based on a simple algorithm which will improve confidential communication capability. This proposed modification provides a simple and reliable system which exploits some of the inherent security properties in a fiber optic ring network. This method differs from conventional methods in that end to end encryption can be facilitated at the media access control sublayer of the data link layer in the OSI network model. Our method is based on a variation of the bit stream cipher method. The transmitting station takes the intended confidential message and uses a simple modulo two addition operation against an initialization vector. The encrypted message is virtually unbreakable without the initialization vector. None of the stations on the ring will have access to both the encrypted message and the initialization vector except the transmitting and receiving stations. The generation of the initialization vector is unique for each confidential transmission and thus provides a unique approach to the key distribution problem. The FDDI protocol is of particular interest to the military in terms of LAN/MAN implementations. Both the Army and the Navy are considering the standard as the basis for future network systems. A simple and reliable security mechanism with the potential to support realtime communications is a necessary consideration in the implementation of these systems. The proposed method offers several advantages over traditional methods in terms of speed, reliability, and standardization.
MR efficiency using automated MRI-desktop eProtocol

Science.gov (United States)

Gao, Fei; Xu, Yanzhe; Panda, Anshuman; Zhang, Min; Hanson, James; Su, Congzhe; Wu, Teresa; Pavlicek, William; James, Judy R.

2017-03-01

MRI protocols are instruction sheets that radiology technologists use in routine clinical practice for guidance (e.g., slice position, acquisition parameters etc.). In Mayo Clinic Arizona (MCA), there are over 900 MR protocols (ranging across neuro, body, cardiac, breast etc.) which makes maintaining and updating the protocol instructions a labor intensive effort. The task is even more challenging given different vendors (Siemens, GE etc.). This is a universal problem faced by all the hospitals and/or medical research institutions. To increase the efficiency of the MR practice, we designed and implemented a web-based platform (eProtocol) to automate the management of MRI protocols. It is built upon a database that automatically extracts protocol information from DICOM compliant images and provides a user-friendly interface to the technologists to create, edit and update the protocols. Advanced operations such as protocol migrations from scanner to scanner and capability to upload Multimedia content were also implemented. To the best of our knowledge, eProtocol is the first MR protocol automated management tool used clinically. It is expected that this platform will significantly improve the radiology operations efficiency including better image quality and exam consistency, fewer repeat examinations and less acquisition errors. These protocols instructions will be readily available to the technologists during scans. In addition, this web-based platform can be extended to other imaging modalities such as CT, Mammography, and Interventional Radiology and different vendors for imaging protocol management.
Use of SU8 as a stable and biocompatible adhesion layer for gold bioelectrodes.

Science.gov (United States)

Matarèse, Bruno F E; Feyen, Paul L C; Falco, Aniello; Benfenati, Fabio; Lugli, Paolo; deMello, John C

2018-04-03

Gold is the most widely used electrode material for bioelectronic applications due to its high electrical conductivity, good chemical stability and proven biocompatibility. However, it adheres only weakly to widely used substrate materials such as glass and silicon oxide, typically requiring the use of a thin layer of chromium between the substrate and the metal to achieve adequate adhesion. Unfortunately, this approach can reduce biocompatibility relative to pure gold films due to the risk of the underlying layer of chromium becoming exposed. Here we report on an alternative adhesion layer for gold and other metals formed from a thin layer of the negative-tone photoresist SU-8, which we find to be significantly less cytotoxic than chromium, being broadly comparable to bare glass in terms of its biocompatibility. Various treatment protocols for SU-8 were investigated, with a view to attaining high transparency and good mechanical and biochemical stability. Thermal annealing to induce partial cross-linking of the SU-8 film prior to gold deposition, with further annealing after deposition to complete cross-linking, was found to yield the best electrode properties. The optimized glass/SU8-Au electrodes were highly transparent, resilient to delamination, stable in biological culture medium, and exhibited similar biocompatibility to glass.
Cross-layer combining of adaptive modulation and truncated ARQ under cognitive radio resource requirements

KAUST Repository

Yang, Yuli

2012-11-01

In addressing the issue of taking full advantage of the shared spectrum under imposed limitations in a cognitive radio (CR) network, we exploit a cross-layer design for the communications of secondary users (SUs), which combines adaptive modulation and coding (AMC) at the physical layer with truncated automatic repeat request (ARQ) protocol at the data link layer. To achieve high spectral efficiency (SE) while maintaining a target packet loss probability (PLP), switching among different transmission modes is performed to match the time-varying propagation conditions pertaining to the secondary link. Herein, by minimizing the SU\\'s packet error rate (PER) with each transmission mode subject to the spectrum-sharing constraints, we obtain the optimal power allocation at the secondary transmitter (ST) and then derive the probability density function (pdf) of the received SNR at the secondary receiver (SR). Based on these statistics, the SU\\'s packet loss rate and average SE are obtained in closed form, considering transmissions over block-fading channels with different distributions. Our results quantify the relation between the performance of a secondary link exploiting the cross-layer-designed adaptive transmission and the interference inflicted on the primary user (PU) in CR networks. © 1967-2012 IEEE.
Deterministic secure communication protocol without using entanglement

OpenAIRE

Cai, Qing-yu

2003-01-01

We show a deterministic secure direct communication protocol using single qubit in mixed state. The security of this protocol is based on the security proof of BB84 protocol. It can be realized with current technologies.
Predictors of death and production performance of layer chickens in opened and sealed pens in a tropical savannah environment.

Science.gov (United States)

Shittu, Aminu; Raji, Abdullahi Abdullahi; Madugu, Shuaibu A; Hassan, Akinola Waheed; Fasina, Folorunso Oludayo

2014-09-12

Layer chickens are exposed to high risks of production losses and mortality with impact on farm profitability. The harsh tropical climate and severe disease outbreaks, poor biosecurity, sub-minimal vaccination and treatment protocols, poor management practices, poor chick quality, feed-associated causes, and unintended accidents oftentimes aggravate mortality and negatively affect egg production. The objectives of this study were to estimate the probability of survival and evaluate risk factors for death under different intensive housing conditions in a tropical climate, and to assess the production performance in the housing systems. Daily mean mortality percentages and egg production figures were significantly lower and higher in the sealed pens and open houses (P ratio for mortality of layers raised in sealed pens was 0.568 (56.8%). Reasons for spiked mortality in layer chickens may not always be associated with disease. Hot-dry climatic environment is associated with heat stress, waning immunity and inefficient feed usage and increase probability of death with reduced egg production; usage of environmentally controlled building in conditions where environmental temperature may rise significantly above 25°C will reduce this impact. Since younger birds (19-38 weeks) are at higher risk of death due to stress of coming into production, management changes and diseases, critical implementation of protocols that will reduce death at this precarious period becomes mandatory. Whether older chickens' better protection from death is associated with many prophylactic and metaphylactic regimen of medications/vaccination will need further investigation.
Simulation and Evaluation of CTP and Secure-CTP Protocols

Directory of Open Access Journals (Sweden)

P. Pecho

2010-04-01

Full Text Available The paper discusses characteristics and qualities of two routing protocols – Collection Tree Protocol and its secure modiﬁcation. The original protocol, as well as other protocols for wireless sensors, solves only problems of ra- dio communication and limited resources. Our design of the secure protocol tries to solve also the essential security ob- jectives. For the evaluation of properties of our protocol in large networks, a TOSSIM simulator was used. Our effort was to show the inﬂuence of the modiﬁcation of the routing protocol to its behavior and quality of routing trees. We have proved that adding security into protocol design does not necessarily mean higher demands for data transfer, power consumption or worse protocol efﬁciency. In the paper, we manifest that security in the protocol may be achieved with low cost and may offer similar performance as the original protocol.
The Resin-Embedded Cornea Prepared Via Rapid Processing Protocol : A Good Histomorphometric Target for Clinical Investigation in Ophthalmology and Optometry

Science.gov (United States)

Cheah, Pike See; Mohidin, Norhani; Mohd Ali, Bariah; Maung, Myint; Latif, Azian Abdul

2008-01-01

This study illustrates and quantifies the changes on corneal tissue between the paraffin-embedded and resin-embedded blocks and thus, selects a better target in investigational ophthalmology and optometry via light microscopy. Corneas of two cynomolgus monkeys (Macaca fascicularis) were used in this study. The formalin-fixed cornea was prepared in paraffin block via the conventional tissue processing protocol (4-day protocol) and stained with haematoxylin and eosin. The glutaraldehyde-fixed cornea was prepared in resin block via the rapid and modified tissue processing procedure (1.2-day protocol) and stained with toluidine blue. The paraffin-embedded sample exhibits various undesired tissue damage and artifact such as thinner epithelium (due to the substantial volumic extraction from the tissue), thicker stroma layer (due to the separation of lamellae and the presence of voids) and the distorted endothelium. In contrast, the resin-embedded corneal tissue has demonstrated satisfactory corneal ultrastructural preservation. The rapid and modified tissue processing method for preparing the resin-embedded is particularly beneficial to accelerate the microscopic evaluation in ophthalmology and optometry. PMID:22570589

Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers

DEFF Research Database (Denmark)

Christensen, M.; Burcharth, H. F.

1995-01-01

A new design for Dolos breakwater armour layers is presented: Dolos armour units are placed in a selected geometric pattern in a single layer. A series of model tests have been performed in order to determine the stability of such single-layer Dolos armour layers. The test results are presented...... and compared to the stability formula for the traditional double-layer, randomly placed Dolos armour layer design presented by Burcharth (1992). The results of a series of stability tests performed with Accropode® armour layers is presented and compared to the test results obtained with single-layer Dolos...... armour layers. Run-up and reflection are presented for both single-layer Dolos armour and Accropode armour....
Low-temperature atomic layer epitaxy of AlN ultrathin films by layer-by-layer, in-situ atomic layer annealing.

Science.gov (United States)

Shih, Huan-Yu; Lee, Wei-Hao; Kao, Wei-Chung; Chuang, Yung-Chuan; Lin, Ray-Ming; Lin, Hsin-Chih; Shiojiri, Makoto; Chen, Miin-Jang

2017-01-03

Low-temperature epitaxial growth of AlN ultrathin films was realized by atomic layer deposition (ALD) together with the layer-by-layer, in-situ atomic layer annealing (ALA), instead of a high growth temperature which is needed in conventional epitaxial growth techniques. By applying the ALA with the Ar plasma treatment in each ALD cycle, the AlN thin film was converted dramatically from the amorphous phase to a single-crystalline epitaxial layer, at a low deposition temperature of 300 °C. The energy transferred from plasma not only provides the crystallization energy but also enhances the migration of adatoms and the removal of ligands, which significantly improve the crystallinity of the epitaxial layer. The X-ray diffraction reveals that the full width at half-maximum of the AlN (0002) rocking curve is only 144 arcsec in the AlN ultrathin epilayer with a thickness of only a few tens of nm. The high-resolution transmission electron microscopy also indicates the high-quality single-crystal hexagonal phase of the AlN epitaxial layer on the sapphire substrate. The result opens a window for further extension of the ALD applications from amorphous thin films to the high-quality low-temperature atomic layer epitaxy, which can be exploited in a variety of fields and applications in the near future.
The Development of Korea Additional Protocol System

International Nuclear Information System (INIS)

Shim, Hye Won; Yeo, Jin Kyun

2008-01-01

The Agreement between the Republic of Korea (ROK) and the IAEA for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons (the Safeguards Agreement) entered into force on 14 November 1975. The Additional Protocol to the Safeguards Agreement (the Additional Protocol) was signed on 21 June 1999 and entered into force on 19 February 2004. ROK has been submitting annual updated reports of initial declaration on every May 15th since August 2004. Additional protocol reports were submitted through Protocol Reporter provided by IAEA. Annual declarations were simply uploaded and stored in the Accounting Information Treatment System of KINAC, which did not provide data analysis and management function. There have been demands for improvement to handle ever-increasing information. KAPS (Korea Additional Protocol System) has been developed to assist and administrate the additional protocol related works effectively. The new system enables integrated management including composition of additional protocol report and version control, periodical update of related information, results of IAEA complementary access to each facility
Influence of Surface Conditioning Protocols on Reparability of CAD/CAM Zirconia-reinforced Lithium Silicate Ceramic.

Science.gov (United States)

Al-Thagafi, Rana; Al-Zordk, Walid; Saker, Samah

2016-01-01

To test the effect of surface conditioning protocols on the reparability of CAD/CAM zirconia-reinforced lithium silicate ceramic compared to lithium-disilicate glass ceramic. Zirconia-reinforced lithium silicate ceramic (Vita Suprinity) and lithium disilicate glass-ceramic blocks (IPS e.max CAD) were categorized into four groups based on the surface conditioning protocol used. Group C: no treatment (control); group HF: 5% hydrofluoric acid etching for 60 s, silane (Monobond-S) application for 60 s, air drying; group HF-H: 5% HF acid etching for 60 s, application of silane for 60 s, air drying, application of Heliobond, light curing for 20 s; group CO: sandblasting with CoJet sand followed by silanization. Composite resin (Tetric EvoCeram) was built up into 4 x 6 x 3 mm blocks using teflon molds. All specimens were subjected to thermocycling (5000x, 5°C to 55°C). The microtensile bond strength test was employed at a crosshead speed of 1 mm/min. SEM was employed for evaluation of all the debonded microbars, the failure type was categorized as either adhesive (failure at adhesive layer), cohesive (failure at ceramic or composite resin), or mixed (failure between adhesive layer and substrate). Two-way ANOVA and the Tukey's HSD post-hoc test were applied to test for significant differences in bond strength values in relation to different materials and surface pretreatment (p ceramic types used (p ceramics and lithium-disilicate glass ceramic could be improved when ceramic surfaces are sandblasted with CoJet sand followed by silanization.
Developing frameworks for protocol implementation

NARCIS (Netherlands)

de Barros Barbosa, C.; de barros Barbosa, C.; Ferreira Pires, Luis

1999-01-01

This paper presents a method to develop frameworks for protocol implementation. Frameworks are software structures developed for a specific application domain, which can be reused in the implementation of various different concrete systems in this domain. The use of frameworks support a protocol
Quantum-key-distribution protocol with pseudorandom bases

Science.gov (United States)

Trushechkin, A. S.; Tregubov, P. A.; Kiktenko, E. O.; Kurochkin, Y. V.; Fedorov, A. K.

2018-01-01

Quantum key distribution (QKD) offers a way for establishing information-theoretical secure communications. An important part of QKD technology is a high-quality random number generator for the quantum-state preparation and for post-processing procedures. In this work, we consider a class of prepare-and-measure QKD protocols, utilizing additional pseudorandomness in the preparation of quantum states. We study one of such protocols and analyze its security against the intercept-resend attack. We demonstrate that, for single-photon sources, the considered protocol gives better secret key rates than the BB84 and the asymmetric BB84 protocols. However, the protocol strongly requires single-photon sources.
Efficient SCT Protocol for Post Disaster Communication

Science.gov (United States)

Ramesh, T. K.; Giriraja, C. V.

2017-08-01

Natural and catastrophic disasters can cause damage to the communication system, the damage may be complete or it may be partial. In such areas communication and exchange of information plays a very important role and become difficult to happen in such situations. So, the rescue systems should be installed in those areas for the rescue operations and to take important decisions about how to make a connection from there to the outside world. Wireless communication network architecture should be setup in disaster areas for the communication to happen and to gather information. Wireless ad-hoc network architecture is proposed in this paper with access nodes. These access nodes acts as hotspot for certain area in which they are set up such that the Wi-Fi capable devices get connected to them for communication to happen. If the mobile battery is drained in such situations wireless charging using microwave is shown in this paper. Performance analysis of the communication transport layer protocols is shown and Efficient SCTP (ESTP) algorithm is developed which shows better results in terms of cumulative packet loss.
Energy-Efficient Boarder Node Medium Access Control Protocol for Wireless Sensor Networks

Science.gov (United States)

Razaque, Abdul; Elleithy, Khaled M.

2014-01-01

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

Science.gov (United States)

Razaque, Abdul; Elleithy, Khaled M

2014-03-12

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

Directory of Open Access Journals (Sweden)

Abdul Razaque

2014-03-01

Full Text Available This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC for wireless sensor networks (WSNs, which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN, which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS, which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS, which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi
Perancangan dan Realisasi Web-Based Data Logging System menggunakan ATmega16 melalui Hypertext Transfer Protocol (HTTP

Directory of Open Access Journals (Sweden)

RATNA SUSANA

2016-02-01

Full Text Available Abstrak Hypertext Transfer Protocol (HTTP merupakan protokol jaringan pada lapisan aplikasi TCP/IP yang menjadi dasar komunikasi pada World Wide Web (WWW. Penelitian ini merancang dan merealisasikan web-based data logging system yang bertujuan untuk memperkenalkan aturan HTTP, sehingga perangkat elektronik dapat berkomunikasi dengan website secara langsung. Sistem dirancang dengan dua sub sistem utama yaitu website data logger dan website. Data logger direalisasikan menggunakan ATMega16 yang diintegrasikan dengan sumber data analog dan digital, RTC serta modem GSM. Data logger berfungsi sebagai pengirim data, sedangkan website berfungsi sebagai pengatur, penerima, pengolah dan penyaji data. Sistem ini telah berhasil melakukan komunikasi antara data logger dengan website melalui HTTP, artinya protokol ini dapat diimplementasikan pada data logger yang menggunakan ATmega16. Perubahan data analog dan status logika 0 dan 1 dari data digital yang terjadi pada data logger dapat dilihat pada tampilan di website. Kata kunci: basis data, data logger, Hypertext Transfer Protocol (HTTP, website, protokol jaringan. Abstract Hypertext Transfer Protocol (HTTP is an application layer network protocols in TCP/IP is the basis of communication on the World Wide Web (WWW. This research was to design and realize a web-based data logging system that aims to introduce the rules of HTTP, so that electronic devices could communicate with the website directly. The system was designed with two main sub-system, namely data logger and website. The data logger was realized using ATmega16 are integrated with analog and digital data sources, RTC and a GSM modem. Data logger function as the sender of data, while the website functions as regulator, receiver, processing and presenter data. This system had been successfully perform communication between the data logger to a website via HTTP, meaning that this protocol could be implemented on a data logger that uses ATmega16
A comprehensive survey of energy-aware routing protocols in wireless body area sensor networks.

Science.gov (United States)

Effatparvar, Mehdi; Dehghan, Mehdi; Rahmani, Amir Masoud

2016-09-01

-Based', 'Cross-Layer', 'Opportunistic', and 'Medium Access Control'. We, then, provide a full description of the statistical analysis of each category in relation to all papers, current hybrid protocols, and the type of simulators used in each paper. Next, we analyze the distribution of papers in each category during various years. Moreover, for each category, the advantages and disadvantages as well as the number of issued papers in different years are given. We also analyze the type of layer and deployment of mathematical models or algorithmic techniques in each category. Finally, after introducing certain important protocols for each category, the goals, advantages, and disadvantages of the protocols are discussed and compared with each other.
An Optimal Non-Interactive Message Authentication Protocol

OpenAIRE

Pasini, Sylvain; Vaudenay, Serge

2006-01-01

Vaudenay recently proposed a message authentication protocol which is interactive and based on short authenticated strings (SAS). We study here SAS-based non-interactive message authentication protocols (NIMAP). We start by the analysis of two popular non-interactive message authentication protocols. The first one is based on a collision-resistant hash function and was presented by Balfanz et al. The second protocol is based on a universal hash function family and was proposed by Gehrmann, Mi...
Nucleic acid protocols: Extraction and optimization

Directory of Open Access Journals (Sweden)

Saeed El-Ashram

2016-12-01

Full Text Available Yield and quality are fundamental features for any researchers during nucleic acid extraction. Here, we describe a simplified, semi-unified, effective, and toxic material free protocol for extracting DNA and RNA from different prokaryotic and eukaryotic sources exploiting the physical and chemical properties of nucleic acids. Furthermore, this protocol showed that DNA and RNA are under triple protection (i.e. EDTA, SDS and NaCl during lysis step, and this environment is improper for RNase to have DNA liberated of RNA and even for DNase to degrade the DNA. Therefore, the complete removal of RNA under RNase influence is achieved when RNase is added after DNA extraction, which gives optimal quality with any protocols. Similarly, DNA contamination in an isolated RNA is degraded by DNase to obtain high-quality RNA. Our protocol is the protocol of choice in terms of simplicity, recovery time, environmental safety, amount, purity, PCR and RT-PCR applicability.
A Lightweight Buyer-Seller Watermarking Protocol

Directory of Open Access Journals (Sweden)

Yongdong Wu

2008-01-01

Full Text Available The buyer-seller watermarking protocol enables a seller to successfully identify a traitor from a pirated copy, while preventing the seller from framing an innocent buyer. Based on finite field theory and the homomorphic property of public key cryptosystems such as RSA, several buyer-seller watermarking protocols (N. Memon and P. W. Wong (2001 and C.-L. Lei et al. (2004 have been proposed previously. However, those protocols require not only large computational power but also substantial network bandwidth. In this paper, we introduce a new buyer-seller protocol that overcomes those weaknesses by managing the watermarks. Compared with the earlier protocols, ours is n times faster in terms of computation, where n is the number of watermark elements, while incurring only O(1/lN times communication overhead given the finite field parameter lN. In addition, the quality of the watermarked image generated with our method is better, using the same watermark strength.
Bitcoin-NG: A Scalable Blockchain Protocol

OpenAIRE

Eyal, Ittay; Gencer, Adem Efe; Sirer, Emin Gun; van Renesse, Robbert

2015-01-01

Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous online payments, cheap remittance, trustless digital asset exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade-off between throughput and latency and withhold the realization of this potential. This paper presents Bitcoin-NG, a new blockchain protocol designed to scale. Based on Bitcoin's blockchain protocol, Bitcoin-NG is By...
A case for evaluating sensor network protocols concurrently

KAUST Repository

Gnawali, Omprakash; Guibas, Leonidas; Levis, Philip

2010-01-01

Researchers typically evaluate and compare protocols on the testbeds by running them one at a time. This methodology ignores the variation in link qualities and wireless environment across these experiments. These variations can introduce significant noise in the results. Evaluating two protocols concurrently, however, suffers from inter-protocol interactions. These interactions can perturb performance even under very light load, especially timing and timing sensitive protocols. We argue that the benefits of running protocols concurrently greatly outweigh the disadvantages. Protocols rarely run in isolation in real networks, and so considering such interactions is valuable. Although the wireless environment is still uncontrolled, concurrent evaluations make comparisons fair and more statistically sound. Through experiments on two testbeds, we make the case for evaluating and comparing low data-rate sensor network protocols by running them concurrently. Copyright 2010 ACM.
MODELLING AND VERIFICATION OF KITSAT PACKET COMMUNICATION PROTOCOLS

Directory of Open Access Journals (Sweden)

Young-Ro Lee

1996-06-01

Full Text Available In this paper, in order to verify KITSAT 1/2 packet communication protocols, we model the AX.25 protocol and PACSAT protocol by using an extended Petri net and then verify the correctness, boundedness, liveness and deadlock freeness of packet protocols by utilizing reachability trees.
Game-theoretic perspective of Ping-Pong protocol

Science.gov (United States)

Kaur, Hargeet; Kumar, Atul

2018-01-01

We analyse Ping-Pong protocol from the point of view of a game. The analysis helps us in understanding the different strategies of a sender and an eavesdropper to gain the maximum payoff in the game. The study presented here characterizes strategies that lead to different Nash equilibriums. We further demonstrate the condition for Pareto optimality depending on the parameters used in the game. Moreover, we also analysed LM05 protocol and compared it with PP protocol from the point of view of a generic two-way QKD game with or without entanglement. Our results provide a deeper understanding of general two-way QKD protocols in terms of the security and payoffs of different stakeholders in the protocol.
Venezuelan contribution to the ozone layer preservation

Energy Technology Data Exchange (ETDEWEB)

Pereira, M.H.; Coltters, R.; Damian, A. [Universidad La Urbina, Caracas (Venezuela). Escuela de Ingenieria Mecanica

1995-12-31

There are two ways to solve the problem of the ozone layer destruction in the upper atmosphere by the harmful chlorine which comes from CFC refrigerants and from aerosols. The first one is to replace the old equipment by new ones which work with non-contaminant refrigerants and the second solution is to establish a conversion program according to the Montreal Protocol and the Vienna Convention. According to this, some Venezuelan Companies are beginning to replace the car`s air conditioning equipment, and others like CVG-SIDOR are making an accelerated program for its central air conditioning system. Another company, C.A. Metro de Caracas, has made a progressive program for the replacement of Freon R-11 and R-12 for HFC 123 and HFC-134a respectively. The results indicate that the most economical solution is to replace these refrigerants instead of replacing the equipment completely.

Technical Analysis of SSP-21 Protocol

Energy Technology Data Exchange (ETDEWEB)

Bromberger, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-06-09

As part of the California Energy Systems for the Twenty-First Century (CES-21) program, in December 2016 San Diego Gas and Electric (SDG&E) contracted with Lawrence Livermore National Laboratory (LLNL) to perform an independent verification and validation (IV&V) of a white paper describing their Secure SCADA Protocol for the Twenty-First Century (SSP-21) in order to analyze the effectiveness and propriety of cryptographic protocol use within the SSP-21 specification. SSP-21 is designed to use cryptographic protocols to provide (optional) encryption, authentication, and nonrepudiation, among other capabilities. The cryptographic protocols to be used reflect current industry standards; future versions of SSP-21 will use other advanced technologies to provide a subset of security services.
Structural and Optothermal Properties of Iron Ditelluride Layered Structures in the Framework of the Lattice Compatibility Theory

Directory of Open Access Journals (Sweden)

K. Ben Messaoud

2014-01-01

Full Text Available This study concerns structural and optothermal properties of iron ditelluride layered structures which were fabricated via a low-cost protocol. The main precursors were FeCl3 · 6H2O and Fe2O3. After a heat treatment within a tellurium-rich medium at various temperatures (470°C, 500°C, and 530°C during 24 h, classical analyses have been applied to the iron ditelluride layered structures. A good crystalline state with a preferential orientation of the crystallites along (111 direction has been recorded. Moreover, additional opto-thermal investigation and analyses within the framework of the Lattice Compatibility Theory gave plausible explanation for prompt temperature-dependent incorporation of tellurium element inside hematite elaborated matrices.
Formal analysis of a fair payment protocol

NARCIS (Netherlands)

J.G. Cederquist; M.T. Dashti (Mohammad)

2004-01-01

textabstractWe formally specify a payment protocol. This protocol is intended for fair exchange of time-sensitive data. Here the ?-CRL language is used to formalize the protocol. Fair exchange properties are expressed in the regular alternation-free ?-calculus. These properties are then verified
Formal Analysis of a Fair Payment Protocol

NARCIS (Netherlands)

Cederquist, J.G.; Dashti, M.T.

2004-01-01

We formally specify a payment protocol. This protocol is intended for fair exchange of timesensitive data. Here the μCRL language is used to formalize the protocol. Fair exchange properties are expressed in the regular alternation-free μ-calculus. These properties are then verified using the finite
The comparative cost analysis of EAP Re-authentication Protocol and EAP TLS Protocol

OpenAIRE

Seema Mehla; Bhawna Gupta

2010-01-01

the Extensible Authentication Protocol (EAP) is a generic framework supporting multiple types of authentication methods. In systems where EAP is used for authentication, it is desirable to not repeat the entire EAP exchange with another authenticator. The EAP reauthentication Protocol provides a consistent, methodindependentand low-latency re-authentication. It is extension to current EAP mechanism to support intradomain handoff authentication. This paper analyzed the performance of the EAP r...
Blockchain Consensus Protocols in the Wild

OpenAIRE

Cachin, Christian; Vukolić, Marko

2017-01-01

A blockchain is a distributed ledger for recording transactions, maintained by many nodes without central authority through a distributed cryptographic protocol. All nodes validate the information to be appended to the blockchain, and a consensus protocol ensures that the nodes agree on a unique order in which entries are appended. Consensus protocols for tolerating Byzantine faults have received renewed attention because they also address blockchain systems. This work discusses the process o...
Security analysis of session initiation protocol

OpenAIRE

Dobson, Lucas E.

2010-01-01

Approved for public release; distribution is unlimited The goal of this thesis is to investigate the security of the Session Initiation Protocol (SIP). This was accomplished by researching previously discovered protocol and implementation vulnerabilities, evaluating the current state of security tools and using those tools to discover new vulnerabilities in SIP software. The CVSS v2 system was used to score protocol and implementation vulnerabilities to give them a meaning that was us...
Development of a vitrification-based cryopreservation protocol for the storage of saltcedar (Tamarix boveana Bunge).

Science.gov (United States)

Cano-Castillo, M; Casas, J L

2012-01-01

We cryopreserved in vitro shoot tips of saltcedar (Tamarix boveana Bunge) using the vitrification technique. The success of the cryopreservation protocol was strongly affected by preculture, loading duration, dehydration duration in plant vitrification solution 2 (PVS2), and medium composition during post-warming regrowth. The highest explant regrowth (50 percent) occurred when the following conditions were employed: preculture in 0.4 M glycerol; treatment with a loading solution (LS) consisting of 2 M glycerol + 0.4 M sucrose in culture medium for 40 min at room temperature; and dehydration in PVS2 at 0 degree C for 45 min before rapid immersion in liquid nitrogen (LN). Rewarming was performed in a water-bath at 40 degree C for 2 min. Explants were then immersed in unloading solution for 10 min before plating on recovery medium supplemented with 0.01 mg per liter thidiazuron (TDZ). TDZ was progressively eliminated from the medium over a period of 6 weeks. Plantlets were transferred to a double-layer medium to enhance rooting. This protocol was successfully applied to three individuals of T. boveana harvested from the wild.
Processes for multi-layer devices utilizing layer transfer

Science.gov (United States)

Nielson, Gregory N; Sanchez, Carlos Anthony; Tauke-Pedretti, Anna; Kim, Bongsang; Cederberg, Jeffrey; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

2015-02-03

A method includes forming a release layer over a donor substrate. A plurality of devices made of a first semiconductor material are formed over the release layer. A first dielectric layer is formed over the plurality of devices such that all exposed surfaces of the plurality of devices are covered by the first dielectric layer. The plurality of devices are chemically attached to a receiving device made of a second semiconductor material different than the first semiconductor material, the receiving device having a receiving substrate attached to a surface of the receiving device opposite the plurality of devices. The release layer is etched to release the donor substrate from the plurality of devices. A second dielectric layer is applied over the plurality of devices and the receiving device to mechanically attach the plurality of devices to the receiving device.
Differential phase-time shifting protocol for QKD (DPTS)

DEFF Research Database (Denmark)

Usuga Castaneda, Mario A.; Bacco, Davide; Christensen, Jesper Bjerge

2016-01-01

We explore the implementation of a novel protocol for fiber-based high-dimensional quantum key distribution (QKD) which improves over the traditional DPS-QKD and COW protocols.......We explore the implementation of a novel protocol for fiber-based high-dimensional quantum key distribution (QKD) which improves over the traditional DPS-QKD and COW protocols....
Formal Analysis of a Fair Payment Protocol

NARCIS (Netherlands)

Cederquist, J.G.; Dashti, Muhammad Torabi; Dimitrakos, Theo; Martinelli, Fabio

We formally specify a payment protocol described by Vogt et al. This protocol is intended for fair exchange of time-sensitive data. Here the mCRL language is used to formalize the protocol. Fair exchange properties are expressed in the regular alternation-free mu-calculus. These properties are then
Optimizing the ASC WAN: evaluating network performance tools for comparing transport protocols.

Energy Technology Data Exchange (ETDEWEB)

Lydick, Christopher L.

2007-07-01

The Advanced Simulation & Computing Wide Area Network (ASC WAN), which is a high delay-bandwidth network connection between US Department of Energy National Laboratories, is constantly being examined and evaluated for efficiency. One of the current transport-layer protocols which is used, TCP, was developed for traffic demands which are different from that on the ASC WAN. The Stream Control Transport Protocol (SCTP), on the other hand, has shown characteristics which make it more appealing to networks such as these. Most important, before considering a replacement for TCP on any network, a testing tool that performs well against certain criteria needs to be found. In order to try to find such a tool, two popular networking tools (Netperf v.2.4.3 & v.2.4.6 (OpenSS7 STREAMS), and Iperf v.2.0.6) were tested. These tools implement both TCP and SCTP and were evaluated using four metrics: (1) How effectively can the tool reach a throughput near the bandwidth? (2) How much of the CPU does the tool utilize during operation? (3) Is the tool freely and widely available? And, (4) Is the tool actively developed? Following the analysis of those tools, this paper goes further into explaining some recommendations and ideas for future work.
The UMTS-AKA Protocols for Intelligent Transportation Systems

Directory of Open Access Journals (Sweden)

Hwang Min-Shiang

2009-01-01

Full Text Available The integration of communication protocols into transport systems is a much adored research area today. Much of seminal work has been reported on the topic of intelligent transportation systems (ITS in the recent years. Many advanced techniques have been garnered to improve online communication and to promote the security, comfort, and efficiency of ITS. Of primary importance to the effective application of ITS is the communication protocol used. A fascinating development is that the yesterday's Global System for Mobile Communication protocol is being replaced by the Universal Mobile Telecommunication System protocol, which is the third-generation mobile technology. This article attempts to identify a suitable communication system for ITS applications. It is impracticable to substantially modify the original UMTS-IMS-AKA protocol which is in practice because it can disturb the operation of the current system, and thus we explore other possibilities through this research. We investigate a novel protocol to make the original UMTS-IMS-AKA protocol compliant with ITS as well as adaptable into the current UMTS protocol.
Cryptanalysis of the arbitrated quantum signature protocols

International Nuclear Information System (INIS)

Gao Fei; Qin Sujuan; Guo Fenzhuo; Wen Qiaoyan

2011-01-01

As a new model for signing quantum messages, arbitrated quantum signature (AQS) has recently received a lot of attention. In this paper we study the cryptanalysis of previous AQS protocols from the aspects of forgery and disavowal. We show that in these protocols the receiver, Bob, can realize existential forgery of the sender's signature under known message attack. Bob can even achieve universal forgery when the protocols are used to sign a classical message. Furthermore, the sender, Alice, can successfully disavow any of her signatures by simple attack. The attack strategies are described in detail and some discussions about the potential improvements of the protocols are given. Finally we also present several interesting topics on AQS protocols that can be studied in future.
Design and Analysis of QoS Routing Framework integrated with OLSR protocol for Multimedia Traffic in Mobile Adhoc Networks

Directory of Open Access Journals (Sweden)

S. Soni

2017-06-01

Full Text Available MANETs (Mobile Ad-hoc Networks is the self organizing wireless structure of mobile hosts. Wireless media is used for communication in MANETs. Considering the developing requirements for multimedia and real-time traffic applications in real world, QoS (Quality-of-Service support is essential in MANETs. But most of the characteristics of MANETs make QoS support a difficult problem. It is challenging to support QoS routing in MANET due to dynamic behavior and mobility of the hosts. The OLSR (Optimized Link State Routing protocol can be efficiently used in MANETs to provide QoS routing because of its dynamic MPR (Multi Point Relay selection criteria and proactive nature. In this paper, a design of QoS routing framework integrated with OLSR protocol is proposed and also analyzed using network simulator. Proposed QoS framework combines a bandwidth estimation algorithm with explicit resource reservation, QoS routing and connection admission control (CAC. OLSR protocol is extended for QoS framework to solve performance issues related to node mobility using cross layer approach. Results after simulation conclude about efficiency of the proposed QoS routing framework.
Hardening CISCO Devices based on Cryptography and Security Protocols - Part One: Background Theory

Directory of Open Access Journals (Sweden)

Faisal Waheed

2018-07-01

Full Text Available Network Security is a vital part of any corporate and enterprise network. Network attacks greatly compromise not only the sensitive data of the consumers but also cause outages to these networks. Thus inadequately protected networks need to be “hardened”. The hardening of network devices refers to the hardware and software components, device operating system’s features, management controls, access-list restrictions, operational configurations and above all making sure that the data and credentials are not stored or transferred in ‘plaintext’ over the network. This article investigates the use of cryptography and network protocols based on encryption, to meet the need for essential security requirements. Use of non-secure protocols, underrating and misconfigurations of management protection are reasons behind network devices not properly being hardened; hence leaving vulnerabilities for the intruders. The gap identified after conducting intense search and review of past work is used as the foundation to present solutions. When performing cryptography techniques by encrypting packets using tunnelling and security protocols, management level credentials are encrypted. These include password encryption and exceptional analysis of the emulated IOS (Internetwork Operating System. Necessary testing is carried out to evaluate an acceptable level of protection of these devices. In a virtual testing environment, security flaws are found mainly in the emulated IOS. The discoveries does not depend on the hardware or chassis of a networking device. Since routers primarily rely on its Operating System (OS, attackers focus on manipulating the command line configuration before initiating an attack. Substantial work is devoted to implementation and testing of a router based on Cryptography and Security Protocols in the border router. This is deployed at the core layer and acts as the first point of entry of any trusted and untrusted traffic. A step
A Clustering Routing Protocol for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Jinke Huang

2016-01-01

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

Science.gov (United States)

Evans, B. G.; Coakley, F. P.; El Amin, M. H. M.

The paper discusses the nature and mix of traffic in business satellite systems and describes the limitations on the protocol imposed by the differing impairments of speech, video, and data. A simple TDMA system protocol is presented which meets the requirements of mixed-service operation. The efficiency of the protocol together with implications for allocation, scheduling and synchronisation are discussed. Future-generation satellites will probably use on-board processing. Some initial work on protocols that make use of on-board processing and the implications for satellite and earth-station equipment are presented.
Tool Supported Analysis of Web Services Protocols

DEFF Research Database (Denmark)

Marques, Abinoam P.; Ravn, Anders Peter; Srba, Jiri

2011-01-01

We describe an abstract protocol model suitable for modelling of web services and other protocols communicating via unreliable, asynchronous communication channels. The model is supported by a tool chain where the first step translates tables with state/transition protocol descriptions, often used...... e.g. in the design of web services protocols, into an intermediate XML format. We further translate this format into a network of communicating state machines directly suitable for verification in the model checking tool UPPAAL. We introduce two types of communication media abstractions in order...
Gene probes: principles and protocols

National Research Council Canada - National Science Library

Aquino de Muro, Marilena; Rapley, Ralph

2002-01-01

... of labeled DNA has allowed genes to be mapped to single chromosomes and in many cases to a single chromosome band, promoting significant advance in human genome mapping. Gene Probes: Principles and Protocols presents the principles for gene probe design, labeling, detection, target format, and hybridization conditions together with detailed protocols, accom...

S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers

Science.gov (United States)

2015-07-09

AFRL-OSR-VA-TR-2015-0161 S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers Dietmar Pum ZENTRUM FUER NANOBIOTECHNOLOGIE Final Report 07/09...COVERED (From - To) 01-06-2012 to 31-05-2015 4. TITLE AND SUBTITLE S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers 5a. CONTRACT...technology for the fabrication of nano patterned thin film imprints by using functional S-layer protein arrays as templates. The unique feature of
New logistics protocols for distributed interactive simulation

Science.gov (United States)

Taylor, Darrin; Morrison, John; Katz, Warren; Felton, Erik; Herman, Deborah A.

1995-06-01

In today's environment, the transportation and maintenance of military forces is nearly as important as combat operations. Rapid deployment to regions of low-intensity conflict will become a very common training scenario for the U.S. military. Thus it is desirable to apply distributed simulation technology to train logistics personnel in their combat support roles. Currently, distributed interactive simulation (DIS) only contains rudimentary logistics protocols. This paper introduces new protocols designed to handle the logistics problem. The Newtonian protocol takes a physics-based approach to modeling interactions on the simulation network. This protocol consists of a family of protocol data units (PDUs) which are used to communicate forces in different circumstances. The protocol implements a small set of physical relations. This represents a flexible and general mechanism to describe battlefield interactions between network entities. The migratory object protocol (MOP) family addresses the transfer of control. General mechanisms provide the means to simulate resupply, repair, and maintenance of entities at any level of abstraction (individual soldier to division). It can also increase the fidelity of mine laying, enable handover of weapons for terminal guidance, allow for the distribution of aggregate-level simulation entities, provide capabilities for the simulation of personnel, etc.
The Application of Layer Theory to Design: The Control Layer

Science.gov (United States)

Gibbons, Andrew S.; Langton, Matthew B.

2016-01-01

A theory of design layers proposed by Gibbons ("An Architectural Approach to Instructional Design." Routledge, New York, 2014) asserts that each layer of an instructional design is related to a body of theory closely associated with the concerns of that particular layer. This study focuses on one layer, the control layer, examining…
Investigating And Evaluating Of Network Failures And Performance Over Distributed WAN In Application Protocol Layer

Directory of Open Access Journals (Sweden)

Enoch Okoh Kofi

2015-08-01

Full Text Available The Experiment was done to find out network failures and application performance relationship over distributed Wide Area Net WAN. In order to access related application over the cloud there must be an internet connectivity which will help the respective workstations to access the remote server for applications being deployed over the network. Bandwidth improvement helps in reducing utilization over the network and it also helps in improving Application Efficiency of these Applications in terms of Response Time. Routers were configured under Enhance Interior Gateway Routing Protocol EIGRP to reduce utilization and to ensure load sharing over the network. Three scenarios were modeled and their performance efficiency was evaluated. A modeled computer Network with and without a fail Router under different scenarios and such Network was simulated with emphasis on the Application Performance. The Experiment was done for fifty workstations under three scenarios and these three scenarios were accessed and evaluated on experimental basis using Riverbed modeler to show the Effect of Application Network performance. The performance results show that increasing the bandwidth reduces utilization and also with the failure of one communication bandwidth users can still access Network Application with a minimal cost.
VANET Routing Protocols: Pros and Cons

OpenAIRE

Paul, Bijan; Ibrahim, Md.; Bikas, Md. Abu Naser

2012-01-01

VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol h...
Advanced Internet Protocols, Services, and Applications

CERN Document Server

Oki, Eiji; Tatipamula, Mallikarjun; Vogt, Christian

2012-01-01

Today, the internet and computer networking are essential parts of business, learning, and personal communications and entertainment. Virtually all messages or transactions sent over the internet are carried using internet infrastructure- based on advanced internet protocols. Advanced internet protocols ensure that both public and private networks operate with maximum performance, security, and flexibility. This book is intended to provide a comprehensive technical overview and survey of advanced internet protocols, first providing a solid introduction and going on to discu
A thin layer fiber-coupled luminescence dosimeter based on Al2O3:C

DEFF Research Database (Denmark)

Klein, F.A.; Greilich, Steffen; Andersen, Claus Erik

2011-01-01

In this paper we present a fiber-coupled luminescent Al2O3:C dosimeter probe with high spatial resolution (0.1 mm). It is based on thin layers of Al2O3:C crystal powder and a UV-cured acrylate monomer composition. The fabrication of the thin layers is described in detail. No influence of the intr......In this paper we present a fiber-coupled luminescent Al2O3:C dosimeter probe with high spatial resolution (0.1 mm). It is based on thin layers of Al2O3:C crystal powder and a UV-cured acrylate monomer composition. The fabrication of the thin layers is described in detail. No influence...... of the introduced polymer host matrix on the dosimetric properties was observed. Depth-dose measurements with the new detectors in a 142.66 MeV proton and 270.55 MeV/u carbon ion beam are presented as example applications. We used an RL protocol with saturated crystals allowing for time-effective measurements...... without sensitivity corrections. For protons, a relative luminescence efficiency hHCP of 0.715 0.014 was found in the Bragg peak. For carbon ions, a value of 0.498 0.001 was found in the entrance channel, 0.205 0.015 in the Bragg peak, and a mean of 0.413 0.050 in the tail region. The mean range...
A Self-Stabilizing Synchronization Protocol for Arbitrary Digraphs

Science.gov (United States)

Malekpour, Mahyar R.

2011-01-01

This paper presents a self-stabilizing distributed clock synchronization protocol in the absence of faults in the system. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period. We present an outline of a deductive proof of the correctness of the protocol. A bounded model of the protocol was mechanically verified for a variety of topologies. Results of the mechanical proof of the correctness of the protocol are provided. The model checking results have verified the correctness of the protocol as they apply to the networks with unidirectional and bidirectional links. In addition, the results confirm the claims of determinism and linear convergence. As a result, we conjecture that the protocol solves the general case of this problem. We also present several variations of the protocol and discuss that this synchronization protocol is indeed an emergent system.
Extraction protocols for orthodontic treatment: A retrospective study

Directory of Open Access Journals (Sweden)

Vaishnevi N Thirunavukkarasu

2016-01-01

Full Text Available Background and Objectives: Various extraction protocols have been followed for successful orthodontic treatment. The purpose of this study was to evaluate the extraction protocols in patients who had previously undergone orthodontic treatment and also who had reported for continuing orthodontic treatment from other clinics. Materials and Methods: One hundred thirty eight patients who registered for orthodontic treatment at the Faculty of Dentistry were divided into 10 extraction protocols based on the Orthodontic treatment protocol given by Janson et al. and were evaluated for statistical significance. Results: The descriptive statistics of the study revealed a total of 40 (29% patients in protocol 1, 43 (31.2% in protocol 2, 18 (13% in protocol 3, 16 (11.6% in protocol 5, and 12 (8.7% in Type 3 category of protocol 9. The Type 3 category in protocol 9 was statistically significant compared to other studies. Midline shift and collapse of the arch form were noticed in these individuals. Conclusion: Extraction of permanent teeth such as canine and lateral incisors without rational reasons could have devastating consequences on the entire occlusion. The percentage of cases wherein extraction of permanent teeth in the crowded region was adopted as a treatment option instead of orthodontic treatment is still prevalent in dental practice. The shortage of orthodontists in Malaysia, the long waiting period, and lack of subjective need for orthodontic treatment at an earlier age group were the reasons for the patient's to choose extraction of the mal-aligned teeth such as the maxillary canine or maxillary lateral incisors.
Layer-by-layer cell membrane assembly

Science.gov (United States)

Matosevic, Sandro; Paegel, Brian M.

2013-11-01

Eukaryotic subcellular membrane systems, such as the nuclear envelope or endoplasmic reticulum, present a rich array of architecturally and compositionally complex supramolecular targets that are as yet inaccessible. Here we describe layer-by-layer phospholipid membrane assembly on microfluidic droplets, a route to structures with defined compositional asymmetry and lamellarity. Starting with phospholipid-stabilized water-in-oil droplets trapped in a static droplet array, lipid monolayer deposition proceeds as oil/water-phase boundaries pass over the droplets. Unilamellar vesicles assembled layer-by-layer support functional insertion both of purified and of in situ expressed membrane proteins. Synthesis and chemical probing of asymmetric unilamellar and double-bilayer vesicles demonstrate the programmability of both membrane lamellarity and lipid-leaflet composition during assembly. The immobilized vesicle arrays are a pragmatic experimental platform for biophysical studies of membranes and their associated proteins, particularly complexes that assemble and function in multilamellar contexts in vivo.
Assembly of 1D nanofibers into a 2D bi-layered composite nanofibrous film with different functionalities at the two layers via layer-by-layer electrospinning.

Science.gov (United States)

Wang, Zijiao; Ma, Qianli; Dong, Xiangting; Li, Dan; Xi, Xue; Yu, Wensheng; Wang, Jinxian; Liu, Guixia

2016-12-21

A two-dimensional (2D) bi-layered composite nanofibrous film assembled by one-dimensional (1D) nanofibers with trifunctionality of electrical conduction, magnetism and photoluminescence has been successfully fabricated by layer-by-layer electrospinning. The composite film consists of a polyaniline (PANI)/Fe 3 O 4 nanoparticle (NP)/polyacrylonitrile (PAN) tuned electrical-magnetic bifunctional layer on one side and a Tb(TTA) 3 (TPPO) 2 /polyvinylpyrrolidone (PVP) photoluminescent layer on the other side, and the two layers are tightly combined face-to-face together into the novel bi-layered composite film of trifunctionality. The brand-new film has totally different characteristics at the double layers. The electrical conductivity and magnetism of the electrical-magnetic bifunctional layer can be, respectively, tunable via modulating the PANI and Fe 3 O 4 NP contents, and the highest electrical conductivity can reach up to the order of 10 -2 S cm -1 , and predominant intense green emission at 545 nm is obviously observed in the photoluminescent layer under the excitation of 357 nm single-wavelength ultraviolet light. More importantly, the luminescence intensity of the photoluminescent layer remains almost unaffected by the electrical-magnetic bifunctional layer because the photoluminescent materials have been successfully isolated from dark-colored PANI and Fe 3 O 4 NPs. By comparing with the counterpart single-layered composite nanofibrous film, it is found that the bi-layered composite nanofibrous film has better performance. The novel bi-layered composite nanofibrous film with trifunctionality has potential in the fields of nanodevices, molecular electronics and biomedicine. Furthermore, the design conception and fabrication technique for the bi-layered multifunctional film provide a new and facile strategy towards other films of multifunctionality.
Structural characterization of birnessite: influence of the way of synthesis; Caracterisation structurale de la birnessite: influence du protocole de synthese

Energy Technology Data Exchange (ETDEWEB)

Gaillot, A.C.

2002-01-15

Birnessite is a lamellar manganese oxide whose layers are built up of edge sharing MnO{sub 6} octahedra. The presence of hetero-valent Mn cations and/or of vacant sites in these layers leads to a charge deficit compensated for by the presence of hydrated cations in the interlayer space. Because of their high specific area and of their strong oxidative character, these ubiquitous manganese oxides play a fundamental role in the fate of organic and metallic pollutants in the environment, but our imperfect knowledge of their structure limits the understanding and the modeling of this impact. This study aimed at classifying all different kinds of birnessite obtained using existing synthesis protocols according to two relevant criteria: layer symmetry and layer stacking mode, and at determining the structure of several essential varieties using X-ray and electron diffraction. Layers of hydrothermal birnessite contain vacant sites and, as a result, possess an hexagonal symmetry. Their stacking mode is 3R. In high-temperature birnessites, adjacent layers have an opposite orientation, which results in a two-layer polytype. The symmetry of these layers, linked to the origin of the layer charge deficit, depends on the temperature of synthesis. At 800 C the presence of vacant sites results in an hexagonal symmetry (2H polytype). At 1000 C, the layer charge deficit originates from the presence of Mn{sup 3+} cations in the layer lowering the layer symmetry (2O polytype). A variety of chemical and structural heterogeneities was also described in these samples, along with the occurrence of a new type of structural disorder. Finally we proved both the fundamental link between the origin of the layer charge and the layer symmetry, and the influence of physico-chemical parameters during synthesis (temperature, average manganese oxidation degree, nature of the interlayer cation) on the structure of the obtained compound. The chemical and thermal stabilities of these birnessites are
The use of WaveLight® Contoura to create a uniform cornea: the LYRA Protocol. Part 3: the results of 50 treated eyes.

Science.gov (United States)

Motwani, Manoj

2017-01-01

To demonstrate how using the Wavelight Contoura measured astigmatism and axis eliminates corneal astigmatism and creates uniformly shaped corneas. A retrospective analysis was conducted of the first 50 eyes to have bilateral full WaveLight ® Contoura LASIK correction of measured astigmatism and axis (vs conventional manifest refraction), using the Layer Yolked Reduction of Astigmatism Protocol in all cases. All patients had astigmatism corrected, and had at least 1 week of follow-up. Accuracy to desired refractive goal was assessed by postoperative refraction, aberration reduction via calculation of polynomials, and postoperative visions were analyzed as a secondary goal. The average difference of astigmatic power from manifest to measured was 0.5462D (with a range of 0-1.69D), and the average difference of axis was 14.94° (with a range of 0°-89°). Forty-seven of 50 eyes had a goal of plano, 3 had a monovision goal. Astigmatism was fully eliminated from all but 2 eyes, and 1 eye had regression with astigmatism. Of the eyes with plano as the goal, 80.85% were 20/15 or better, and 100% were 20/20 or better. Polynomial analysis postoperatively showed that at 6.5 mm, the average C3 was reduced by 86.5% and the average C5 by 85.14%. Using WaveLight ® Contoura measured astigmatism and axis removes higher order aberrations and allows for the creation of a more uniform cornea with accurate removal of astigmatism, and reduction of aberration polynomials. WaveLight ® Contoura successfully links the refractive correction layer and aberration repair layer using the Layer Yolked Reduction of Astigmatism Protocol to demonstrate how aberration removal can affect refractive correction.
Survey of protocols for the manual segmentation of the hippocampus: preparatory steps towards a joint EADC-ADNI harmonized protocol.

Science.gov (United States)

Boccardi, Marina; Ganzola, Rossana; Bocchetta, Martina; Pievani, Michela; Redolfi, Alberto; Bartzokis, George; Camicioli, Richard; Csernansky, John G; de Leon, Mony J; deToledo-Morrell, Leyla; Killiany, Ronald J; Lehéricy, Stéphane; Pantel, Johannes; Pruessner, Jens C; Soininen, H; Watson, Craig; Duchesne, Simon; Jack, Clifford R; Frisoni, Giovanni B

2011-01-01

Manual segmentation from magnetic resonance imaging (MR) is the gold standard for evaluating hippocampal atrophy in Alzheimer's disease (AD). Nonetheless, different segmentation protocols provide up to 2.5-fold volume differences. Here we surveyed the most frequently used segmentation protocols in the AD literature as a preliminary step for international harmonization. The anatomical landmarks (anteriormost and posteriormost slices, superior, inferior, medial, and lateral borders) were identified from 12 published protocols for hippocampal manual segmentation ([Abbreviation] first author, publication year: [B] Bartzokis, 1998; [C] Convit, 1997; [dTM] deToledo-Morrell, 2004; [H] Haller, 1997; [J] Jack, 1994; [K] Killiany, 1993; [L] Lehericy, 1994; [M] Malykhin, 2007; [Pa] Pantel, 2000; [Pr] Pruessner, 2000; [S] Soininen, 1994; [W] Watson, 1992). The hippocampi of one healthy control and one AD patient taken from the 1.5T MR ADNI database were segmented by a single rater according to each protocol. The accuracy of the protocols' interpretation and translation into practice was checked with lead authors of protocols through individual interactive web conferences. Semantically harmonized landmarks and differences were then extracted, regarding: (a) the posteriormost slice, protocol [B] being the most restrictive, and [H, M, Pa, Pr, S] the most inclusive; (b) inclusion [C, dTM, J, L, M, Pr, W] or exclusion [B, H, K, Pa, S] of alveus/fimbria; (c) separation from the parahippocampal gyrus, [C] being the most restrictive, [B, dTM, H, J, Pa, S] the most inclusive. There were no substantial differences in the definition of the anteriormost slice. This survey will allow us to operationalize differences among protocols into tracing units, measure their impact on the repeatability and diagnostic accuracy of manual hippocampal segmentation, and finally develop a harmonized protocol.
A secure key agreement protocol based on chaotic maps

International Nuclear Information System (INIS)

Wang Xing-Yuan; Luan Da-Peng

2013-01-01

To guarantee the security of communication in the public channel, many key agreement protocols have been proposed. Recently, Gong et al. proposed a key agreement protocol based on chaotic maps with password sharing. In this paper, Gong et al.'s protocol is analyzed, and we find that this protocol exhibits key management issues and potential security problems. Furthermore, the paper presents a new key agreement protocol based on enhanced Chebyshev polynomials to overcome these problems. Through our analysis, our key agreement protocol not only provides mutual authentication and the ability to resist a variety of common attacks, but also solve the problems of key management and security issues existing in Gong et al.'s protocol
Gastroesophageal anastomosis: single-layer versus double-layer technique

International Nuclear Information System (INIS)

Aslam, V.A.; Bilal, A.; Khan, A.; Ahmed, M.

2008-01-01

Considerable controversy exists regarding the optimum technique for gastroesophageal anastomosis. Double layer technique has long been considered important for safe healing but there is evidence that single layer technique is also safe and can be performed in much shorter time. The purpose of this study was to compare the outcome of single layer and double layer techniques for gastroesophageal anastomosis. A prospective randomized study was conducted in cardiothoracic unit, Lady Reading Hospital from Jan 2006 to Jan 2008. Fifty patients with oesophageal carcinoma undergoing subtotal oesophagectomy were randomized to have the anastomosis by single layer continuous or double layer continuous technique (group A (n=24) and B (n=26) respectively). The demographic data, operative and anastomosis time, postoperative complications and hospital mortality were recorded on a proforma and analyzed on SPSS 10. There was no significant difference between group A and B in terms of age, gender, postoperative complications and duration of hospital stay. Anastomotic leak occurred in 4.2% patients in group A and 7.7% in group B (p=NS). Mean anastomosis time was 10.04 minutes in group A and 19.2 minutes in group B (p=0.0001). Mean operative time was 163.83 minutes and 170.96 minutes in group A and B respectively. Overall hospital mortality was 2%; no deaths occurred due to anastomotic leak. Single layer continuous technique is equally safe and can be performed in shorter time and at a lower cost than the double layer technique. (author)
The protocol amending the 1963 Vienna Convention

International Nuclear Information System (INIS)

Lamm, V.

2006-01-01

Technically the Vienna Convention was revised by the adoption of the protocol to amend the instrument. and according to Article 19 of the protocol 'A State which is Party to this Protocol but not to the 1963 Vienna Convention shall be bound by the provisions of that Convention as amended by this Protocol in relation to other States Parties hereto, and failing an expression of a different intention by that State at the time of deposit of an instrument referred to in Article 20 shall be bound by the provisions of the 1963 Vienna Convention in relation to States which are only Parties thereto'. This solution has created a special situation, because after the entry into force of the protocol there will be living together or operating in practice 'two' Vienna Conventions, notably the convention's original text of 1963 and its new version as amended by the protocol. After the protocol has come into force, a state may only accede to the amended version, but in the inter se relations of the States Party to the 'old' Vienna Convention the provisions of that convention will remain in force until such time as they have acceded to the new protocol. This rather complicated situation is nevertheless understandable and is fully in accord with Article 40 of the 1969 Vienna Convention on the Law of Treaties, which provides for the amendment of multilateral treaties. In 1989 the negotiations on the revision of the Vienna Convention had begun with the aim of strengthening the existing nuclear liability regime and of improving the situation of potential victims of nuclear accidents. The Protocol to Amend the Vienna Convention serves those purposes; it also reflects a good compromise, since it is the outcome of a negotiation process in which experts from both nuclear and non-nuclear states, from Contacting Parties and non-Contracting Parties were very active. That affords some assurance that the compromise solution reached is acceptable to all States participating in the adoption of
Security Protocol Review Method Analyzer(SPRMAN)

OpenAIRE

Navaz, A. S. Syed; Narayanan, H. Iyyappa; Vinoth, R.

2013-01-01

This Paper is designed using J2EE (JSP, SERVLET), HTML as front end and a Oracle 9i is back end. SPRMAN is been developed for the client British Telecom (BT) UK., Telecom company. Actually the requirement of BT is, they are providing Network Security Related Products to their IT customers like Virtusa,Wipro,HCL etc., This product is framed out by set of protocols and these protocols are been associated with set of components. By grouping all these protocols and components together, product is...
Black layers on historical architecture.

Science.gov (United States)

Toniolo, Lucia; Zerbi, Carlotta M; Bugini, Roberto

2009-03-01

The external surface of any building in urban polluted environment is unavoidably destined to be covered with layers that assume a grey to black colour and are generally called 'black crusts'. These, according to standard protocols and glossary, are deteriorated surface layers of stone material; they can have variable thickness, are hard and fragile and can detach spontaneously from the substrate, which, in general, is quite decayed. Plain visual examination may lead to consider 'black crusts' all similar, whilst only a careful diagnostic investigation can distinguish 'black crusts' and the consequences of their formation on stone substrates. In this paper, various black layers on marble are studied and compared and the morphological and compositional characteristics discussed according to the related mechanisms of formation. Differences between old (hundred years) and recent crusts (30 years) are investigated and pointed out. Samples of black crusts collected from the Milan Cathedral façade (Candoglia Marble) have been studied and compared with the careful and synergic employ of traditional techniques: optical (transmission and reflected VIS light) and electron microscopy, X-ray spectrometry and micro-Fourier transform infrared spectroscopy. Visual examination of loose fragments does not allow to point out outstanding differences amongst the various samples; black layers have similar main mineral components, gypsum and airborne particles, with different spatial distribution. The microscopic studies allowed to point out the porosity differences, the gypsum crystallisation habit, different amount of embedded particles, level and progress of marble decay. The observations lead to define three main types of black crusts: black crust deriving from marble sulphation, compact deposit and encrustation due to exogenic materials deposition. Black crusts show evidence of sulphation in progress, without a clear continuity solution between crust and marble; the lack of
Comparison of the Nanostructure and Mechanical Performance of Highly Exfoliated Epoxy-Clay Nanocomposites Prepared by Three Different Protocols

Directory of Open Access Journals (Sweden)

Fatemeh Shiravand

2014-05-01

Full Text Available Three different protocols for the preparation of polymer layered silicate nanocomposites based upon a tri-functional epoxy resin, triglycidyl para-amino phenol (TGAP, have been compared in respect of the cure kinetics, the nanostructure and their mechanical properties. The three preparation procedures involve 2 wt% and 5 wt% of organically modified montmorillonite (MMT, and are: isothermal cure at selected temperatures; pre-conditioning of the resin-clay mixture before isothermal cure; incorporation of an initiator of cationic homopolymerisation, a boron tri-fluoride methyl amine complex, BF3·MEA, within the clay galleries. It was found that features of the cure kinetics and of the nanostructure correlate with the measured impact strength of the cured nanocomposites, which increases as the degree of exfoliation of the MMT is improved. The best protocol for toughening the TGAP/MMT nanocomposites is by the incorporation of 1 wt% BF3·MEA into the clay galleries of nanocomposites containing 2 wt% MMT.

Comparison of the Nanostructure and Mechanical Performance of Highly Exfoliated Epoxy-Clay Nanocomposites Prepared by Three Different Protocols.

Science.gov (United States)

Shiravand, Fatemeh; Hutchinson, John M; Calventus, Yolanda; Ferrando, Francesc

2014-05-30

Three different protocols for the preparation of polymer layered silicate nanocomposites based upon a tri-functional epoxy resin, triglycidyl para -amino phenol (TGAP), have been compared in respect of the cure kinetics, the nanostructure and their mechanical properties. The three preparation procedures involve 2 wt% and 5 wt% of organically modified montmorillonite (MMT), and are: isothermal cure at selected temperatures; pre-conditioning of the resin-clay mixture before isothermal cure; incorporation of an initiator of cationic homopolymerisation, a boron tri-fluoride methyl amine complex, BF₃·MEA, within the clay galleries. It was found that features of the cure kinetics and of the nanostructure correlate with the measured impact strength of the cured nanocomposites, which increases as the degree of exfoliation of the MMT is improved. The best protocol for toughening the TGAP/MMT nanocomposites is by the incorporation of 1 wt% BF₃·MEA into the clay galleries of nanocomposites containing 2 wt% MMT.
Energy-Aware RFID Anti-Collision Protocol.

Science.gov (United States)

Arjona, Laura; Simon, Hugo Landaluce; Ruiz, Asier Perallos

2018-06-11

The growing interest in mobile devices is transforming wireless identification technologies. Mobile and battery-powered Radio Frequency Identification (RFID) readers, such as hand readers and smart phones, are are becoming increasingly attractive. These RFID readers require energy-efficient anti-collision protocols to minimize the tag collisions and to expand the reader's battery life. Furthermore, there is an increasing interest in RFID sensor networks with a growing number of RFID sensor tags. Thus, RFID application developers must be mindful of tag anti-collision protocols. Energy-efficient protocols involve a low reader energy consumption per tag. This work presents a thorough study of the reader energy consumption per tag and analyzes the main factor that affects this metric: the frame size update strategy. Using the conclusion of this analysis, the anti-collision protocol Energy-Aware Slotted Aloha (EASA) is presented to decrease the energy consumption per tag. The frame size update strategy of EASA is configured to minimize the energy consumption per tag. As a result, EASA presents an energy-aware frame. The performance of the proposed protocol is evaluated and compared with several state of the art Aloha-based anti-collision protocols based on the current RFID standard. Simulation results show that EASA, with an average of 15 mJ consumed per tag identified, achieves a 6% average improvement in the energy consumption per tag in relation to the strategies of the comparison.
Symmetric cryptographic protocols

CERN Document Server

Ramkumar, Mahalingam

2014-01-01

This book focuses on protocols and constructions that make good use of symmetric pseudo random functions (PRF) like block ciphers and hash functions - the building blocks for symmetric cryptography. Readers will benefit from detailed discussion of several strategies for utilizing symmetric PRFs. Coverage includes various key distribution strategies for unicast, broadcast and multicast security, and strategies for constructing efficient digests of dynamic databases using binary hash trees. • Provides detailed coverage of symmetric key protocols • Describes various applications of symmetric building blocks • Includes strategies for constructing compact and efficient digests of dynamic databases
Event-by-event simulation of quantum cryptography protocols

NARCIS (Netherlands)

Zhao, S.; Raedt, H. De

We present a new approach to simulate quantum cryptography protocols using event-based processes. The method is validated by simulating the BB84 protocol and the Ekert protocol, both without and with the presence of an eavesdropper.
WDM Network and Multicasting Protocol Strategies

Directory of Open Access Journals (Sweden)

Pinar Kirci

2014-01-01

Full Text Available Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM, it is easier to take the advantage of optical networks and optical burst switching (OBS and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET and Just In Time (JIT reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes.
A More Efficient Contextuality Distillation Protocol

Science.gov (United States)

Meng, Hui-xian; Cao, Huai-xin; Wang, Wen-hua; Fan, Ya-jing; Chen, Liang

2018-03-01

Based on the fact that both nonlocality and contextuality are resource theories, it is natural to ask how to amplify them more efficiently. In this paper, we present a contextuality distillation protocol which produces an n-cycle box B ∗ B ' from two given n-cycle boxes B and B '. It works efficiently for a class of contextual n-cycle ( n ≥ 4) boxes which we termed as "the generalized correlated contextual n-cycle boxes". For any two generalized correlated contextual n-cycle boxes B and B ', B ∗ B ' is more contextual than both B and B '. Moreover, they can be distilled toward to the maximally contextual box C H n as the times of iteration goes to infinity. Among the known protocols, our protocol has the strongest approximate ability and is optimal in terms of its distillation rate. What is worth noting is that our protocol can witness a larger set of nonlocal boxes that make communication complexity trivial than the protocol in Brunner and Skrzypczyk (Phys. Rev. Lett. 102, 160403 2009), this might be helpful for exploring the problem that why quantum nonlocality is limited.
An one-time-pad key communication protocol with entanglement

OpenAIRE

Cai, Qing-yu

2003-01-01

We present an one-time-pad key communication protocol that allows secure direct communication with entanglement. Alice can send message to Bob in a deterministic manner by using local measurements and public communication. The theoretical efficiency of this protocol is double compared with BB84 protocol. We show this protocol is unconditional secure under arbitrary quantum attack. And we discuss that this protocol can be perfectly implemented with current technologies.
Prosthesis Prescription Protocol of the Arm (PPP-Arm) : The implementation of a national prosthesis prescription protocol

NARCIS (Netherlands)

Wijdenes, Paula; Brouwers, Michael; van der Sluis, Corry K

BACKGROUND AND AIM: In order to create more uniformity in the prescription of upper limb prostheses by Dutch rehabilitation teams, the development and implementation of a Prosthesis Prescription Protocol of the upper limb (PPP-Arm) was initiated. The aim was to create a national digital protocol to
Improvement In MAODV Protocol Using Location Based Routing Protocol

Directory of Open Access Journals (Sweden)

Kaur Sharnjeet

2016-01-01

Full Text Available Energy saving is difficult in wireless sensor network (WSN due to limited resources. Each node in WSN is constrained by their limited battery power for their energy. The energy is reduced as the time goes off due to the packet transmission and reception. Energy management techniques are necessary to minimize the total power consumption of all the nodes in the network in order to maximize its life span. Our proposed protocol Location based routing (LBR aimed to find a path which utilizes the minimum energy to transmit the packets between the source and the destination. The required energy for the transmission and reception of data is evaluated in MATLAB. LBR is implemented on Multicast Ad hoc On Demand Distance Vector Routing Protocol (MAODV to manage the energy consumption in the transmission and reception of data. Simulation results of LBR show the energy consumption has been reduced.
Analyzing security protocols in hierarchical networks

DEFF Research Database (Denmark)

Zhang, Ye; Nielson, Hanne Riis

2006-01-01

Validating security protocols is a well-known hard problem even in a simple setting of a single global network. But a real network often consists of, besides the public-accessed part, several sub-networks and thereby forms a hierarchical structure. In this paper we first present a process calculus...... capturing the characteristics of hierarchical networks and describe the behavior of protocols on such networks. We then develop a static analysis to automate the validation. Finally we demonstrate how the technique can benefit the protocol development and the design of network systems by presenting a series...
Developing security protocols in χ-Spaces

DEFF Research Database (Denmark)

Crazzolara, Federico; Milicia, Giuseppe

2002-01-01

It is of paramount importance that a security protocol effectively enforces the desired security requirements. The apparent simplicity of informal protocol descriptions hides the inherent complexity of their interactions which, often, invalidate informal correctness arguments and justify the effort...
Comparison of a new whole-body continuous-table-movement protocol versus a standard whole-body MR protocol for the assessment of multiple myeloma

International Nuclear Information System (INIS)

Weckbach, S.; Michaely, H.J.; Schoenberg, S.O.; Dinter, D.J.; Stemmer, A.

2010-01-01

To evaluate a whole body (WB) continuous-table-movement (CTM) MR protocol for the assessment of multiple myeloma (MM) in comparison to a step-by-step WB protocol. Eighteen patients with MM were examined at 1.5T using a WB CTM protocol (axial T2-w fs BLADE, T1-w GRE sequence) and a step-by-step WB protocol including coronal/sagittal T1-w SE and STIR sequences as reference. Protocol time was assessed. Image quality, artefacts, liver/spleen assessability, and the ability to depict bone marrow lesions less than or greater than 1 cm as well as diffuse infiltration and soft tissue lesions were rated. Potential changes in the Durie and Salmon Plus stage and the detectability of complications were assessed. Mean protocol time was 6:38 min (CTM) compared to 24:32 min (standard). Image quality was comparable. Artefacts were more prominent using the CTM protocol (P = 0.0039). Organ assessability was better using the CTM protocol (P < 0.001). Depiction of bone marrow and soft tissue lesions was identical without a staging shift. Vertebral fractures were not detected using the CTM protocol. The new protocol allows a higher patient throughput and facilitates the depiction of extramedullary lesions. However, as long as vertebral fractures are not detectable, the protocol cannot be safely used for clinical routine without the acquisition of an additional sagittal sequence. (orig.)
Effectiveness and Limitations of E-Mail Security Protocols

OpenAIRE

M. Tariq Banday

2011-01-01

Simple Mail Transport Protocol is the most widely adopted protocol for e-mail delivery. However, it lackssecurity features for privacy, authentication of sending party, integrity of e-mail message, nonrepudiationand consistency of e-mail envelope. To make e-mail communication secure and private,e-mail servers incorporate one or more security features using add-on security protocols. The add-onsecurity protocols provide a reasonable security but have several limitations. This paper discussesli...
The use of Wavelight® Contoura to create a uniform cornea: the LYRA protocol. Part 3: the results of 50 treated eyes

OpenAIRE

Motwani M

2017-01-01

Manoj Motwani Motwani LASIK Institute, San Diego, CA, USA Purpose: To demonstrate how using the Wavelight Contoura measured astigmatism and axis eliminates corneal astigmatism and creates uniformly shaped corneas. Patients and methods: A retrospective analysis was conducted of the first 50 eyes to have bilateral full WaveLight® Contoura LASIK correction of measured astigmatism and axis (vs conventional manifest refraction), using the Layer Yolked Reduction of Astigmatism Protocol in...
Quantum Communication Attacks on Classical Cryptographic Protocols

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre

, one can show that the protocol remains secure even under such an attack. However, there are also cases where the honest players are quantum as well, even if the protocol uses classical communication. For instance, this is the case when classical multiparty computation is used as a “subroutine......In the literature on cryptographic protocols, it has been studied several times what happens if a classical protocol is attacked by a quantum adversary. Usually, this is taken to mean that the adversary runs a quantum algorithm, but communicates classically with the honest players. In several cases......” in quantum multiparty computation. Furthermore, in the future, players in a protocol may employ quantum computing simply to improve efficiency of their local computation, even if the communication is supposed to be classical. In such cases, it no longer seems clear that a quantum adversary must be limited...
Quantum Communication Attacks on Classical Cryptographic Protocols

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre

, one can show that the protocol remains secure even under such an attack. However, there are also cases where the honest players are quantum as well, even if the protocol uses classical communication. For instance, this is the case when classical multiparty computation is used as a “subroutine......” in quantum multiparty computation. Furthermore, in the future, players in a protocol may employ quantum computing simply to improve efficiency of their local computation, even if the communication is supposed to be classical. In such cases, it no longer seems clear that a quantum adversary must be limited......In the literature on cryptographic protocols, it has been studied several times what happens if a classical protocol is attacked by a quantum adversary. Usually, this is taken to mean that the adversary runs a quantum algorithm, but communicates classically with the honest players. In several cases...
Search and nonsearch protocols for radiographic consultation

International Nuclear Information System (INIS)

Swensson, R.G.; Theodore, G.H.

1989-01-01

Six radiologists, acting as film reviewers, used two different consultation protocols to differentiate among 292 ambiguous findings on chest films: 120 simulated nodules and 172 normal findings (previous readers' false-positive reports of nodules). The non-search protocol identified each finding (by location), and reviewers rated its likelihood as a nodule. The search protocol, which asked reviewers to report and rate all locations regarded as possible nodules on each film, assigned a default negative rating to any unreported finding (nodule or normal). Receiver operator characteristic analyses demonstrated a significantly higher accuracy for each reviewer's search- protocol discriminations between these nodules and confusing normal findings
Evaluation of white matter hyperintensities and retinal fiber layer, ganglion cell layer, inner-plexiform layer, and choroidal layer in migraine patients.

Science.gov (United States)

Tak, Ali Zeynel Abidin; Sengul, Yıldızhan; Bilak, Şemsettin

2018-03-01

The aim of our study is to assess retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL), inner-plexiform layer (IPL), and choroidal layer in migraine patients with white matter lesion (WML) or without WML, using spectral domain optical coherence tomography (OCT). To our study, 77 migraine patients who are diagnosed with migraine in accordance to the International Classification of Headache Disorders (ICHD)-3 beta and 43 healthy control are included. In accordance to cranial MRI, migraine patients are divided into two groups as those who have white matter lesions (39 patients), and those who do not have a lesion (38 patients). OCT was performed for participants. The average age of participants was comparable. The RNFL average thickness parameter in the migraine group was significantly lower than in the control group (p layer measuring scales. The proofs showing that affected retinal nerve fiber layer are increased in migraine patients. However, it is not known whether this may affect other layers of retina, or whether there is a correlation between affected retinal structures and white matter lesions. In our study, we found thinner RNFL in migraine patients when we compared with controls but IPL, GCL, and choroid layer values were similar between each patient groups and controls. Also, all parameters were similar between patients with WML and without WML. Studies in this regard are required.
An Authentication Protocol for Future Sensor Networks.

Science.gov (United States)

Bilal, Muhammad; Kang, Shin-Gak

2017-04-28

Authentication is one of the essential security services in Wireless Sensor Networks (WSNs) for ensuring secure data sessions. Sensor node authentication ensures the confidentiality and validity of data collected by the sensor node, whereas user authentication guarantees that only legitimate users can access the sensor data. In a mobile WSN, sensor and user nodes move across the network and exchange data with multiple nodes, thus experiencing the authentication process multiple times. The integration of WSNs with Internet of Things (IoT) brings forth a new kind of WSN architecture along with stricter security requirements; for instance, a sensor node or a user node may need to establish multiple concurrent secure data sessions. With concurrent data sessions, the frequency of the re-authentication process increases in proportion to the number of concurrent connections. Moreover, to establish multiple data sessions, it is essential that a protocol participant have the capability of running multiple instances of the protocol run, which makes the security issue even more challenging. The currently available authentication protocols were designed for the autonomous WSN and do not account for the above requirements. Hence, ensuring a lightweight and efficient authentication protocol has become more crucial. In this paper, we present a novel, lightweight and efficient key exchange and authentication protocol suite called the Secure Mobile Sensor Network (SMSN) Authentication Protocol. In the SMSN a mobile node goes through an initial authentication procedure and receives a re-authentication ticket from the base station. Later a mobile node can use this re-authentication ticket when establishing multiple data exchange sessions and/or when moving across the network. This scheme reduces the communication and computational complexity of the authentication process. We proved the strength of our protocol with rigorous security analysis (including formal analysis using the BAN
FLIP: An Internetwork Protocol for Supporting Distributed Systems

NARCIS (Netherlands)

Kaashoek, M.F.; van Renesse, R.; van Staveren, H.; Tanenbaum, A.S.

1993-01-01

Most modern network protocols give adequate support for traditional applications such as file transfer and remote login. Distributed applications, however, have different requirements 1993. Instead of using ad hoc protocols to meet each of the new requirements, we have designed a new protocol,

Biometrics based authentication scheme for session initiation protocol.

Science.gov (United States)

Xie, Qi; Tang, Zhixiong

2016-01-01

Many two-factor challenge-response based session initiation protocol (SIP) has been proposed, but most of them are vulnerable to smart card stolen attacks and password guessing attacks. In this paper, we propose a novel three-factor SIP authentication scheme using biometrics, password and smart card, and utilize the pi calculus-based formal verification tool ProVerif to prove that the proposed protocol achieves security and authentication. Furthermore, our protocol is highly efficient when compared to other related protocols.
Formalizing and proving a typing result for security protocols in Isabelle/HOL

DEFF Research Database (Denmark)

Hess, Andreas Viktor; Modersheim, Sebastian

2017-01-01

or the positive output of a verification tool. However several of these works have used a typed model, where the intruder is restricted to "well-typed" attacks. There also have been several works that show that this is actually not a restriction for a large class of protocols, but all these results so far...... are again pen-and-paper proofs. In this work we present a formalization of such a typing result in Isabelle/HOL. We formalize a constraint-based approach that is used in the proof argument of such typing results, and prove its soundness, completeness and termination. We then formalize and prove the typing...... result itself in Isabelle. Finally, to illustrate the real-world feasibility, we prove that the standard Transport Layer Security (TLS) handshake satisfies the main condition of the typing result....
Security of the arbitrated quantum signature protocols revisited

International Nuclear Information System (INIS)

Kejia, Zhang; Dan, Li; Qi, Su

2014-01-01

Recently, much attention has been paid to the study of arbitrated quantum signature (AQS). Among these studies, the cryptanalysis of some AQS protocols and a series of improved ideas have been proposed. Compared with the previous analysis, we present a security criterion, which can judge whether an AQS protocol is able to prevent the receiver (i.e. one participant in the signature protocol) from forging a legal signature. According to our results, it can be seen that most AQS protocols which are based on the Zeng and Keitel (ZK) model are susceptible to a forgery attack. Furthermore, we present an improved idea of the ZK protocol. Finally, some supplement discussions and several interesting topics are provided. (paper)
An electronic specimen collection protocol schema (eSCPS). Document architecture for specimen management and the exchange of specimen collection protocols between biobanking information systems.

Science.gov (United States)

Eminaga, O; Semjonow, A; Oezguer, E; Herden, J; Akbarov, I; Tok, A; Engelmann, U; Wille, S

2014-01-01

The integrity of collection protocols in biobanking is essential for a high-quality sample preparation process. However, there is not currently a well-defined universal method for integrating collection protocols in the biobanking information system (BIMS). Therefore, an electronic schema of the collection protocol that is based on Extensible Markup Language (XML) is required to maintain the integrity and enable the exchange of collection protocols. The development and implementation of an electronic specimen collection protocol schema (eSCPS) was performed at two institutions (Muenster and Cologne) in three stages. First, we analyzed the infrastructure that was already established at both the biorepository and the hospital information systems of these institutions and determined the requirements for the sufficient preparation of specimens and documentation. Second, we designed an eSCPS according to these requirements. Finally, a prospective study was conducted to implement and evaluate the novel schema in the current BIMS. We designed an eSCPS that provides all of the relevant information about collection protocols. Ten electronic collection protocols were generated using the supplementary Protocol Editor tool, and these protocols were successfully implemented in the existing BIMS. Moreover, an electronic list of collection protocols for the current studies being performed at each institution was included, new collection protocols were added, and the existing protocols were redesigned to be modifiable. The documentation time was significantly reduced after implementing the eSCPS (5 ± 2 min vs. 7 ± 3 min; p = 0.0002). The eSCPS improves the integrity and facilitates the exchange of specimen collection protocols in the existing open-source BIMS.
Investigation of coronal leakage of root fillings after smear-layer removal with EDTA or Nd:YAG lasing through capillary-flow porometry.

Science.gov (United States)

Michiels, Rafaël; Vergauwen, Tom Edgard Maria; Mavridou, Athina; Meire, Maarten; De Bruyne, Mieke; De Moor, Roeland Jozef Gentil

2010-10-01

This study investigates the effects of Nd:YAG laser irradiation combined with different irrigation protocols on the marginal seal of root fillings. Limited information exists regarding the effects of morphologic changes to root canal (RC) walls after Nd:YAG laser irradiation after smear-layer removal with EDTA on the sealing ability of root fillings. The 75 root-filled teeth (5 × 15 teeth) were analyzed for through-and-through leakage by using capillary flow porometry (CFP). The RC cleaning procedure determined the assignment to a group: (1) irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP), (2) SP + Nd:YAG lasing (dried RC), (3) NaOCl 2.5% + Nd:YAG lasing (dried RC), (4) SP + Nd:YAG lasing (wet RC), or (5) NaOCl 2.5% + Nd:YAG lasing (wet RC). Groups 1r to 5r consisted of the same filled teeth with resected apices up to the most apical point of the preparation length. Resection was performed after the first CFP measurement. Roots were filled with cold lateral condensation. CFP was used to assess minimum, mean flow and maximum pore diameters after 48 h, and immediately after these measurements, including root resection. Statistics were performed by using nonparametric tests (p > 0.05). An additional three roots per group were submitted to SEM of the RC wall. Through-and-through leakage was observed in all groups. Statistically significant differences were observed in maximum pore diameter: 1r > 3r, and 1r > 5r; in mean flow pore diameter: 1r > 2r, 2r < 4r (p < 0.05). Typical Nd:YAG glazing effects were observed when the smear layer was present and exposed to the laser fiber (i.e., in the groups without use of EDTA) or when the fiber tip made direct contact with a smear-layer free RC wall. The reduction in through-and-through leakage is significantly higher with the Nd:YAG laser as smear-layer modifier than when smear layer is removed with an EDTA rinsing solution.
Establishing treatment protocols for clinical mastitis.

Science.gov (United States)

Roberson, Jerry R

2003-03-01

Each farm has a unique mix of mastitis pathogens and management procedures that have evolved over time. The herd veterinarian should work with the manager/owner to systematically develop treatment protocols that meet the needs and management of the farm. To establish a mastitis treatment protocol, it is necessary to develop a system to routinely identify clinical mastitis cases, develop a herd-specific severity level assessment system, manage the clinical mastitis cases based on severity level and culture result (when available), avoid antibiotic residues, and monitor the success of the system and alter the protocol as necessary.
The Singapore protocol [for quantum cryptography

International Nuclear Information System (INIS)

Englert, B.

2005-01-01

The qubit protocol for quantum key distribution presented in this talk is fully tomographic and more efficient than other tomographic protocols. Under ideal circumstances the efficiency is log 2 (4/3) = 0.415 key bits per qubit sent, which is 25% more than the efficiency of 1/3 = 0.333 for the standard 6-state protocol. One can extract 0.4 key bits per qubit by a simple two-way communication scheme, and can so get close to the information-theoretical limit. The noise thresholds for secure key bit generation in the presence of unbiased noise will be reported and discussed. (author)
Securing statically-verified communications protocols against timing attacks

DEFF Research Database (Denmark)

Buchholtz, Mikael; Gilmore, Stephen; Hillston, Jane

2004-01-01

We present a federated analysis of communication protocols which considers both security properties and timing. These are not entirely independent observations of a protocol; by using timing observations of an executing protocol it is possible to deduce derived information about the nature...... of the communication even in the presence of unbreakable encryption. Our analysis is based on expressing the protocol as a process algebra model and deriving from this process models analysable by the Imperial PEPA Compiler and the LySatool....
Optimized UAV Communication Protocol Based on Prior Locations

OpenAIRE

Sboui, Lokman; Rabah, Abdullatif

2015-01-01

In this paper, we adopt a new communication protocol between the UAV and fixed on-ground nodes. This protocol tends to reduce communication power consumption by stopping communication if the channel is not good to communicate (i.e. far nodes, obstacles, etc.) The communication is performed using the XBee 868M standard and Libelium wapsmotes. Our designed protocol is based on a new communication model that we propose in this paper. The protocole decides wether to communicate or not after compu...
Decellularization of placentas: establishing a protocol

Directory of Open Access Journals (Sweden)

L.C.P.C. Leonel

2017-11-01

Full Text Available Biological biomaterials for tissue engineering purposes can be produced through tissue and/or organ decellularization. The remaining extracellular matrix (ECM must be acellular and preserve its proteins and physical features. Placentas are organs of great interest because they are discarded after birth and present large amounts of ECM. Protocols for decellularization are tissue-specific and have not been established for canine placentas yet. This study aimed at analyzing a favorable method for decellularization of maternal and fetal portions of canine placentas. Canine placentas were subjected to ten preliminary tests to analyze the efficacy of parameters such as the type of detergents, freezing temperatures and perfusion. Two protocols were chosen for further analyses using histology, scanning electron microscopy, immunofluorescence and DNA quantification. Sodium dodecyl sulfate (SDS was the most effective detergent for cell removal. Freezing placentas before decellularization required longer periods of incubation in different detergents. Both perfusion and immersion methods were capable of removing cells. Placentas decellularized using Protocol I (1% SDS, 5 mM EDTA, 50 mM TRIS, and 0.5% antibiotic preserved the ECM structure better, but Protocol I was less efficient to remove cells and DNA content from the ECM than Protocol II (1% SDS, 5 mM EDTA, 0.05% trypsin, and 0.5% antibiotic.
Verbal protocols as methodological resources: research evidence

Directory of Open Access Journals (Sweden)

Alessandra Baldo

2012-01-01

Full Text Available This article aims at reflecting on the use of verbal protocols as a methodological resource in qualitative research, more specifically on the aspect regarded as the main limitation of a study about lexical inferencing in L2 (BALDO; VELASQUES, 2010: its subjective trait. The article begins with a brief literature review on protocols, followed by a description of the study in which they were employed as methodological resources. Based on that, protocol subjectivity is illustrated through samples of unparalleled data classification, carried out independently by two researchers. In the final section, the path followed to minimize the problem is presented, intending to contribute to improve efficiency in the use of verbal protocols in future research.
A STRONG SECURITY PROTOCOL AGAINST FINGERPRINT DATABASE ATTACKS

Directory of Open Access Journals (Sweden)

U. Latha

2013-08-01

Full Text Available The Biometric data is subject to on-going changes and create a crucial problem in fingerprint database. To deal with this, a security protocol is proposed to protect the finger prints information from the prohibited users. Here, a security protocol is proposed to protect the finger prints information. The proposed system comprised of three phases namely, fingerprint reconstruction, feature extraction and development of trigon based security protocol. In fingerprint reconstruction, the different crack variance level finger prints images are reconstructed by the M-band Dual Tree Complex Wavelet Transform (DTCWT. After that features are extracted by binarization. A set of finger print images are utilized to evaluate the performance of security protocol and the result from this process guarantees the healthiness of the proposed trigon based security protocol. The implementation results show the effectiveness of proposed trigon based security protocol in protecting the finger print information and the achieved improvement in image reconstruction and the security process.
Cryptographic protocol security analysis based on bounded constructing algorithm

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

An efficient approach to analyzing cryptographic protocols is to develop automatic analysis tools based on formal methods. However, the approach has encountered the high computational complexity problem due to reasons that participants of protocols are arbitrary, their message structures are complex and their executions are concurrent. We propose an efficient automatic verifying algorithm for analyzing cryptographic protocols based on the Cryptographic Protocol Algebra (CPA) model proposed recently, in which algebraic techniques are used to simplify the description of cryptographic protocols and their executions. Redundant states generated in the analysis processes are much reduced by introducing a new algebraic technique called Universal Polynomial Equation and the algorithm can be used to verify the correctness of protocols in the infinite states space. We have implemented an efficient automatic analysis tool for cryptographic protocols, called ACT-SPA, based on this algorithm, and used the tool to check more than 20 cryptographic protocols. The analysis results show that this tool is more efficient, and an attack instance not offered previously is checked by using this tool.
MgAl-Layered Double Hydroxide Solid Base Catalysts for Henry Reaction: A Green Protocol

Directory of Open Access Journals (Sweden)

Magda H. Abdellattif

2018-03-01

Full Text Available A series of MgAl-layered double hydroxide (MgAl-HT, the calcined form at 500 °C (MgAlOx, and the rehydrated one at 25 °C (MgAl-HT-RH were synthesized. Physicochemical properties of the catalysts were characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM. Surface area of the as-synthesized, calcined, and rehydrated catalysts was determined by N2 physisorption at −196 °C. CO2 temperature-programmed desorption (CO2-TPD was applied to determine the basic sites of catalysts. The catalytic test reaction was carried out using benzaldehyde and their derivatives with nitromethane and their derivatives. The Henry products (1–15 were obtained in a very good yield using MgAl-HT-RH catalyst either by conventional method at 90 °C in liquid phase or under microwave irradiation method. The mesoporous structure and basic nature of the rehydrated solid catalyst were responsible for its superior catalytic efficiency. The robust nature was determined by using the same catalyst five times, where the product % yield was almost unchanged significantly.
Surface metal standards produced by ion implantation through a removable layer

International Nuclear Information System (INIS)

Schueler, B.W.; Granger, C.N.; McCaig, L.; McKinley, J.M.; Metz, J.; Mowat, I.; Reich, D.F.; Smith, S.; Stevie, F.A.; Yang, M.H.

2003-01-01

Surface metal concentration standards were produced by ion implantation and investigated for their suitability to calibrate surface metal measurements by secondary ion mass spectrometry (SIMS). Single isotope implants were made through a 100 nm oxide layer on silicon. The implant energies were chosen to place the peak of the implanted species at a depth of 100 nm. Subsequent removal of the oxide layer was used to expose the implant peak and to produce controlled surface metal concentrations. Surface metal concentration measurements by time-of-flight SIMS (TOF-SIMS) with an analysis depth of 1 nm agreed with the expected surface concentrations of the implant standards with a relative mean standard deviation of 20%. Since the TOF-SIMS relative sensitivity factors (RSFs) were originally derived from surface metal measurements of surface contaminated silicon wafers, the agreement implies that the implant standards can be used to measure RSF values. The homogeneity of the surface metal concentration was typically <10%. The dopant dose remaining in silicon after oxide removal was measured using the surface-SIMS protocol. The measured implant dose agreed with the expected dose with a mean relative standard deviation of 25%
Authentication Protocol using Quantum Superposition States

Energy Technology Data Exchange (ETDEWEB)

Kanamori, Yoshito [University of Alaska; Yoo, Seong-Moo [University of Alabama, Huntsville; Gregory, Don A. [University of Alabama, Huntsville; Sheldon, Frederick T [ORNL

2009-01-01

When it became known that quantum computers could break the RSA (named for its creators - Rivest, Shamir, and Adleman) encryption algorithm within a polynomial-time, quantum cryptography began to be actively studied. Other classical cryptographic algorithms are only secure when malicious users do not have sufficient computational power to break security within a practical amount of time. Recently, many quantum authentication protocols sharing quantum entangled particles between communicators have been proposed, providing unconditional security. An issue caused by sharing quantum entangled particles is that it may not be simple to apply these protocols to authenticate a specific user in a group of many users. An authentication protocol using quantum superposition states instead of quantum entangled particles is proposed. The random number shared between a sender and a receiver can be used for classical encryption after the authentication has succeeded. The proposed protocol can be implemented with the current technologies we introduce in this paper.
Entanglement distillation protocols and number theory

International Nuclear Information System (INIS)

Bombin, H.; Martin-Delgado, M.A.

2005-01-01

We show that the analysis of entanglement distillation protocols for qudits of arbitrary dimension D benefits from applying basic concepts from number theory, since the set Z D n associated with Bell diagonal states is a module rather than a vector space. We find that a partition of Z D n into divisor classes characterizes the invariant properties of mixed Bell diagonal states under local permutations. We construct a very general class of recursion protocols by means of unitary operations implementing these local permutations. We study these distillation protocols depending on whether we use twirling operations in the intermediate steps or not, and we study them both analytically and numerically with Monte Carlo methods. In the absence of twirling operations, we construct extensions of the quantum privacy algorithms valid for secure communications with qudits of any dimension D. When D is a prime number, we show that distillation protocols are optimal both qualitatively and quantitatively
Saudi Arabia and CERN sign protocol

CERN Multimedia

2008-01-01

On 9 May 2008, Mohammed I. Al Suwaiyel, President of the King Abdulaziz City of Science and Technology, representing the Government of Saudi Arabia, and CERN Director-General, Robert Aymar, signed a protocol to the 2006 cooperation agreement between CERN and Saudi Arabia. Members of the Saudi Arabian Government visit ATLAS.The purpose of the protocol is to define the operational framework needed to carry out various specific tasks provided for in the cooperation agreement in order to promote the development of a high energy particle physics community in Saudi Arabia and its ultimate visible participation as a member of the global CERN community. Signing the protocol, Mohammed I. Al-Suwaiyel said: "The Saudi Arabian Government has taken a number of initiatives to promote R&D in the interests of our country’s development and the advancement of science. Thanks to this protocol, Saudi scientists will be able to work towards this go...
Novel protocol for persister cells isolation.

Directory of Open Access Journals (Sweden)

Silvia J Cañas-Duarte

Full Text Available Bacterial persistence, where a fraction of a population presents a transient resistance to bactericidal substances, has great medical importance due to its relation with the appearance of antibiotic resistances and untreatable bacterial chronic infections. The mechanisms behind this phenomenon remain largely unknown in spite of recent advances, in great part because of the difficulty in isolating the very small fraction of the population that is in this state at any given time. Current protocols for persister isolation have resulted in possible biases because of the induction of this state by the protocol itself. Here we present a novel protocol that allows rapid isolation of persister cells both from exponential and stationary phase. Moreover, it is capable of differentiating between type I and type II persister cells, which should allow the field to move beyond its current state of studying only one type. While this protocol prompts a revision of many of the current results, it should greatly facilitate further advances in the field.
Feeling Is Believing: A Secure Template Exchange Protocol

NARCIS (Netherlands)

Buhan, I.R.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.; Lee, Seong-Whan; Li, Stan Z.

We use grip pattern based biometrics as a secure side channel to achieve pre-authentication in a protocol that sets up a secure channel between two hand held devices. The protocol efficiently calculates a shared secret key from biometric data. The protocol is used in an application where grip

Layer-dependent band alignment and work function of few-layer phosphorene.

Science.gov (United States)

Cai, Yongqing; Zhang, Gang; Zhang, Yong-Wei

2014-10-20

Using first-principles calculations, we study the electronic properties of few-layer phosphorene focusing on layer-dependent behavior of band gap, work function band alignment and carrier effective mass. It is found that few-layer phosphorene shows a robust direct band gap character, and its band gap decreases with the number of layers following a power law. The work function decreases rapidly from monolayer (5.16 eV) to trilayer (4.56 eV), and then slowly upon further increasing the layer number. Compared to monolayer phosphorene, there is a drastic decrease of hole effective mass along the ridge (zigzag) direction for bilayer phosphorene, indicating a strong interlayer coupling and screening effect. Our study suggests that 1). Few-layer phosphorene with a layer-dependent band gap and a robust direct band gap character is promising for efficient solar energy harvest. 2). Few-layer phosphorene outperforms monolayer counterpart in terms of a lighter carrier effective mass, a higher carrier density and a weaker scattering due to enhanced screening. 3). The layer-dependent band edges and work functions of few-layer phosphorene allow for modification of Schottky barrier with enhanced carrier injection efficiency. It is expected that few-layer phosphorene will present abundant opportunities for a plethora of new electronic applications.
Optimizing the high-resolution manometry (HRM) study protocol.

Science.gov (United States)

Patel, A; Ding, A; Mirza, F; Gyawali, C P

2015-02-01

Intolerance of the esophageal manometry catheter may prolong high-resolution manometry (HRM) studies and increase patient distress. We assessed the impact of obtaining the landmark phase at the end of the study when the patient has acclimatized to the HRM catheter. 366 patients (mean age 55.4 ± 0.8 years, 62.0% female) undergoing esophageal HRM over a 1-year period were studied. The standard protocol consisted of the landmark phase, 10 5 mL water swallows 20-30 s apart, and multiple rapid swallows where 4-6 2 mL swallows were administered in rapid succession. The modified protocol consisted of the landmark phase at the end of the study after test swallows. Study duration, technical characteristics, indications, and motor findings were compared between standard and modified protocols. Of the 366 patients, 89.6% underwent the standard protocol (study duration 12.9 ± 0.3 min). In 10.4% with poor catheter tolerance undergoing the modified protocol, study duration was significantly longer (15.6 ± 1.0 min, p = 0.004) despite similar duration of study maneuvers. Only elevated upper esophageal sphincter basal pressures at the beginning of the study segregated modified protocol patients. The 95th percentile time to landmark phase in the standard protocol patients was 6.1 min; as many as 31.4% of modified protocol patients could not obtain their first study maneuver within this period (p = 0.0003). Interpretation was not impacted by shifting the landmark phase to the end of the study. Modification of the HRM study protocol with the landmark phase obtained at the end of the study optimizes study duration without compromising quality. © 2014 John Wiley & Sons Ltd.
Natural melanin composites by layer-by-layer assembly

Science.gov (United States)

Eom, Taesik; Shim, Bong Sub

2015-04-01

Melanin is an electrically conductive and biocompatible material, because their conjugated backbone structures provide conducting pathways from human skin, eyes, brain, and beyond. So there is a potential of using as materials for the neural interfaces and the implantable devices. Extracted from Sepia officinalis ink, our natural melanin was uniformly dispersed in mostly polar solvents such as water and alcohols. Then, the dispersed melanin was further fabricated to nano-thin layered composites by the layer-by-layer (LBL) assembly technique. Combined with polyvinyl alcohol (PVA), the melanin nanoparticles behave as an LBL counterpart to from finely tuned nanostructured films. The LBL process can adjust the smart performances of the composites by varying the layering conditions and sandwich thickness. We further demonstrated the melanin loading degree of stacked layers, combination nanostructures, electrical properties, and biocompatibility of the resulting composites by UV-vis spectrophotometer, scanning electron microscope (SEM), multimeter, and in-vitro cell test of PC12, respectively.
Electrical properties of GaAs metal–oxide–semiconductor structure comprising Al2O3 gate oxide and AlN passivation layer fabricated in situ using a metal–organic vapor deposition/atomic layer deposition hybrid system

Directory of Open Access Journals (Sweden)

Takeshi Aoki

2015-08-01

Full Text Available This paper presents a compressive study on the fabrication and optimization of GaAs metal–oxide–semiconductor (MOS structures comprising a Al2O3 gate oxide, deposited via atomic layer deposition (ALD, with an AlN interfacial passivation layer prepared in situ via metal–organic chemical vapor deposition (MOCVD. The established protocol afforded self-limiting growth of Al2O3 in the atmospheric MOCVD reactor. Consequently, this enabled successive growth of MOCVD-formed AlN and ALD-formed Al2O3 layers on the GaAs substrate. The effects of AlN thickness, post-deposition anneal (PDA conditions, and crystal orientation of the GaAs substrate on the electrical properties of the resulting MOS capacitors were investigated. Thin AlN passivation layers afforded incorporation of optimum amounts of nitrogen, leading to good capacitance–voltage (C–V characteristics with reduced frequency dispersion. In contrast, excessively thick AlN passivation layers degraded the interface, thereby increasing the interfacial density of states (Dit near the midgap and reducing the conduction band offset. To further improve the interface with the thin AlN passivation layers, the PDA conditions were optimized. Using wet nitrogen at 600 °C was effective to reduce Dit to below 2 × 1012 cm−2 eV−1. Using a (111A substrate was also effective in reducing the frequency dispersion of accumulation capacitance, thus suggesting the suppression of traps in GaAs located near the dielectric/GaAs interface. The current findings suggest that using an atmosphere ALD process with in situ AlN passivation using the current MOCVD system could be an efficient solution to improving GaAs MOS interfaces.
Multiprofissional electronic protocol in ophtalmology with enfasis in strabismus

Directory of Open Access Journals (Sweden)

CHRISTIE GRAF RIBEIRO

Full Text Available ABSTRACT Objective: to create and validate an electronic database in ophthalmology focused on strabismus, to computerize this database in the form of a systematic data collection software named Electronic Protocol, and to incorporate this protocol into the Integrated System of Electronic Protocols (SINPE(c. Methods: this is a descriptive study, with the methodology divided into three phases: (1 development of a theoretical ophthalmologic database with emphasis on strabismus; (2 computerization of this theoretical ophthalmologic database using SINPE(c and (3 interpretation of the information with demonstration of results to validate the protocol. We inputed data from the charts of fifty patients with known strabismus through the Electronic Protocol for testing and validation. Results: the new electronic protocol was able to store information regarding patient history, physical examination, laboratory exams, imaging results, diagnosis and treatment of patients with ophthalmologic diseases, with emphasis on strabismus. We included 2,141 items in this master protocol and created 20 new specific electronic protocols for strabismus, each with its own specifics. Validation was achieved through correlation and corroboration of the symptoms and confirmed diagnoses of the fifty included patients with the diagnostic criteria for the twenty new strabismus protocols. Conclusion: a new, validated electronic database focusing on ophthalmology, with emphasis on strabismus, was successfully created through the standardized collection of information, and computerization of the database using proprietary software. This protocol is ready for deployment to facilitate data collection, sorting and application for practitioners and researchers in numerous specialties.
Optical code-division multiple-access protocol with selective retransmission

Science.gov (United States)

Mohamed, Mohamed A. A.; Shalaby, Hossam M. H.; El-Badawy, El-Sayed A.

2006-05-01

An optical code-division multiple-access (OCDMA) protocol based on selective retransmission technique is proposed. The protocol is modeled using a detailed state diagram and is analyzed using equilibrium point analysis (EPA). Both traditional throughput and average delay are used to examine its performance for several network parameters. In addition, the performance of the proposed protocol is compared to that of the R3T protocol, which is based on a go-back-n technique. Our results show that a higher performance is achieved by the proposed protocol at the expense of system complexity.
Protocol Monitoring Energy Conservation; Protocol Monitoring Energiebesparing

Energy Technology Data Exchange (ETDEWEB)

Boonekamp, P.G.M. [ECN Beleidsstudies, Petten (Netherlands); Mannaerts, H. [Centraal Planburea CPB, Den Haag (Netherlands); Tinbergen, W. [Centraal Bureau voor de Statistiek CBS, Den Haag (Netherlands); Vreuls, H.H.J. [Nederlandse onderneming voor energie en milieu Novem, Utrecht (Netherlands); Wesselink, B. [Rijksinstituut voor Volksgezondheid en Milieuhygiene RIVM, Bilthoven (Netherlands)

2001-12-01

On request of the Dutch ministry of Economic Affairs five institutes have collaborated to create a 'Protocol Monitoring Energy Conservation', a common method and database to calculate the amount of energy savings realised in past years. The institutes concerned are the Central Bureau of Statistics (CBS), the Netherlands Bureau for Economic Policy Analysis (CPB), the Energy research Centre of the Netherlands (ECN), the National Agency for Energy and Environment (Novem) and the Netherlands Institute of Public Health and the Environment (RIVM). The institutes have agreed upon a clear definition of energy use and energy savings. The demarcation with renewable energy, the saving effects of substitution between energy carriers and the role of import and export of energy have been elaborated. A decomposition method is used to split up the observed change in energy use in a number of effects, on a national and sectoral level. This method includes an analysis of growth effects, effects of structural changes in production and consumption activities and savings on end use or with more efficient conversion processes. To calculate these effects the total energy use is desegregated as much as possible. For each segment a reference energy use is calculated according to the trend in a variable which is supposed to be representative for the use without savings. The difference with the actual energy use is taken as the savings realised. Results are given for the sectors households, industry, agriculture, services and government, transportation and the energy sector; as well as a national figure. A special feature of the protocol method is the application of primary energy use figures in the determination of savings for end users. This means that the use of each energy carrier is increased with a certain amount, according to the conversion losses caused elsewhere in the energy system. The losses concern the base year energy sector and losses abroad for imports of secondary
Sufficient Conditions for Vertical Composition of Security Protocols (Extended Version)

DEFF Research Database (Denmark)

Mödersheim, Sebastian Alexander; Viganò, Luca

a certain kind of channel as a goal and another secure protocol P2 that assumes this kind of channel, can we then derive that their vertical composition P2[P1] is secure? It is well known that protocol composition can lead to attacks even when the individual protocols are all secure in isolation......Vertical composition of security protocols means that an application protocol (e.g., a banking service) runs over a channel established by another protocol (e.g., a secure channel provided by TLS). This naturally gives rise to a compositionality question: given a secure protocol P1 that provides....... In this paper, we formalize seven easy-to-check static conditions that support a large class of channels and applications and that we prove to be su_cient for vertical security protocol composition....
A customised cold-water immersion protocol favours one-size-fits-all protocols in improving acute performance recovery

NARCIS (Netherlands)

Zandvoort, Coen S.; de Zwart, Jelmer R.; van Keeken, Brenda L.; Viroux, Patrick J.F.; Tiemessen, Ivo J.H.

The purpose of the present study was to investigate whether a customised cold-water immersion (CWIc) protocol was more effective in enhancing acute performance recovery than a one-size-fits-all CWI (CWIs) or active recovery (AR) protocol. On three separate testing days, 10 healthy, physically
Security Protocols: Specification, Verification, Implementation, and Composition

DEFF Research Database (Denmark)

Almousa, Omar

An important aspect of Internet security is the security of cryptographic protocols that it deploys. We need to make sure that such protocols achieve their goals, whether in isolation or in composition, i.e., security protocols must not suffer from any aw that enables hostile intruders to break...... results. The most important generalization is the support for all security properties of the geometric fragment proposed by [Gut14]....... their security. Among others, tools like OFMC [MV09b] and Proverif [Bla01] are quite efficient for the automatic formal verification of a large class of protocols. These tools use different approaches such as symbolic model checking or static analysis. Either approach has its own pros and cons, and therefore, we...
The Geneva Protocol of 1925

International Nuclear Information System (INIS)

Mc Elroy, R.J.

1991-01-01

This paper reports that when President Gerald Ford signed the instruments of ratification for the Geneva Protocol of 1925 on January 22, 1975, a tortured, half-century-long chapter in U.S. arms control policy was brought to a close. Fifty years earlier, at the Geneva Conference for the Control of the International Trade in Arms, Munitions and Implements of War, the United States had played a key role in drafting and reaching agreement on the Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases and of Bacteriological Methods of Warfare. The protocol, signed by thirty nations, including the United States, on June 17, 1925, prohibits the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices as well as the use of bacteriological methods of warfare
An entanglement concentration protocol for cluster states using ...

Indian Academy of Sciences (India)

Permanent link: http://www.ias.ac.in/article/fulltext/pram/086/05/0973-0983 ... The purpose of this paper is a proposal on entanglement concentration protocol forcluster states. The protocol ... We also make a comparative numerical study of the residual entanglement left out after the execution of each step of the protocol.
Breaking Megrelishvili protocol using matrix diagonalization

Science.gov (United States)

Arzaki, Muhammad; Triantoro Murdiansyah, Danang; Adi Prabowo, Satrio

2018-03-01

In this article we conduct a theoretical security analysis of Megrelishvili protocol—a linear algebra-based key agreement between two participants. We study the computational complexity of Megrelishvili vector-matrix problem (MVMP) as a mathematical problem that strongly relates to the security of Megrelishvili protocol. In particular, we investigate the asymptotic upper bounds for the running time and memory requirement of the MVMP that involves diagonalizable public matrix. Specifically, we devise a diagonalization method for solving the MVMP that is asymptotically faster than all of the previously existing algorithms. We also found an important counterintuitive result: the utilization of primitive matrix in Megrelishvili protocol makes the protocol more vulnerable to attacks.
Overview of the InterGroup protocols

Energy Technology Data Exchange (ETDEWEB)

Berket, Karlo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Agarwal, Deborah A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Melliar-Smith, P. Michael [Univ. of California, Santa Barbara, CA (United States); Moser, Louise E. [Univ. of California, Santa Barbara, CA (United States)

2001-03-01

Existing reliable ordered group communication protocols have been developed for local-area networks and do not, in general, scale well to large numbers of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces a novel approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable group timestamp ordered.
Frame Transmission Efficiency-Based Cross-Layer Congestion Notification Scheme in Wireless Ad Hoc Networks.

Science.gov (United States)

He, Huaguang; Li, Taoshen; Feng, Luting; Ye, Jin

2017-07-15

Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows.
Performance Analysis of IEEE 802.11e (EDCF) and IEEE 802.11(DCF) WLAN Incorporating Different Physical Layer Standards

Science.gov (United States)

Sharma, V.; Singh, H.; Malhotra, J.

2012-12-01

Medium access coordination function basically implements the distributed coordination function (DCF) which provides support to best effort services but limited to QoS services. Subsequently, a new standard, namely enhanced distributed channel access (EDCA) is reported. The IEEE 802.11e (EDCA) defines MAC procedures to support QoS requirements which specifies distributed contention based access scheme to access the shared wireless media. This paper evaluates the performance of EDCA based IEEE 802.11 WLAN for various access categories (ACs) using OPNET™ Modeller 14.5. Further, the computed results are compared with DCF protocols in terms of QoS parameters. Furthermore, the simulative observation is reported at data rate of 54 Mbps using different physical layer protocols such as IEEE 802.11a/b/g to stumble on the best one to be implemented with EDCF to achieve improved QoS.
Efficient Communication Protocols for Deciding Edit Distance

DEFF Research Database (Denmark)

Jowhari, Hossein

2012-01-01

In this paper we present two communication protocols on computing edit distance. In our first result, we give a one-way protocol for the following Document Exchange problem. Namely given x ∈ Σn to Alice and y ∈ Σn to Bob and integer k to both, Alice sends a message to Bob so that he learns x...... or truthfully reports that the edit distance between x and y is greater than k. For this problem, we give a randomized protocol in which Alice transmits at most O ˜ (klog 2 n) bits and each party’s time complexity is O ˜ (nlogn+k 2 log 2 n) . Our second result is a simultaneous protocol for edit distance over...... permutations. Here Alice and Bob both send a message to a third party (the referee) who does not have access to the input strings. Given the messages, the referee decides if the edit distance between x and y is at most k or not. For this problem we give a protocol in which Alice and Bob run a O...
Recommendations for Enhancing Implementation of Additional Protocol Declarations

International Nuclear Information System (INIS)

Niina, Toshiaki; Nidaira, Kazuo; Aono, Yosuke

2010-01-01

Japan signed the Additional Protocol (hereafter, AP) in December 1998. The domestic law and regulation had been revised to implement the initial and annual declarations for the Agency and the Additional Protocol came into force in December 1999. Since initial declaration in 2000, Japan has submitted the annual declaration in every May. Until 2010, Japan has made 10 annual declarations. This paper gives recommendations to enhance implementation of Additional Protocol declarations based on 10-year experience in Japan and addresses the following: Current status of additional protocol declaration in Japan; Outline of processing method; AP Information Management System; Recommendations for improving quality of declaration. Preparation of additional protocol declaration in NMCC has been conducted in the course of contract with Japan Safeguards Office (hereafter, JSGO) for safeguards information treatment. (author)
Development of IT-based Data Communication Protocol for Nuclear Power Plant

International Nuclear Information System (INIS)

Jeong, K. I.; Kim, D. H.; Lee, J. C.

2009-07-01

The communication protocol, which provide overall communication rules and methods and give ways how to exchange information, is the most important part and it can affect the overall performance of communication network. Therefore, the first step of development of the communication network of an NPP is its own communication protocol design, which conforms to the requirements and characteristics of an NPP I and C. To manage the protocol development process, we establish development procedure and define detail substantive based on the procedure and we examine the adaptability of existing commercial communication protocols to the communication protocol of an NPP I and C. Existing commercial communication protocols based on Information Technology(IT) can be categorized into 3 groups: general commercial communication protocols, industrial communication protocols, military communication protocols. We analyze the design criteria and performance requirements of popular protocols in each group. And also, we examine the adaptability to the communication protocol of an NPP. Based on these results, we developed our own protocol for NPP I and C, which meet the required specifications through design overall protocol architecture and data frame format, definition of functional requirements and specifications
The Protocol of Choice for Treatment of Snake Bite

Directory of Open Access Journals (Sweden)

Afshin Mohammad Alizadeh

2016-01-01

Full Text Available The aim of the current study is to compare three different methods of treatment of snake bite to determine the most efficient one. To unify the protocol of snake bite treatment in our center, we retrospectively reviewed files of the snake-bitten patients who had been referred to us between 2010 and 2014. They were contacted for follow-up using phone calls. Demographic and on-arrival characteristics, protocol used for treatment (WHO/Haddad/GF, and outcome/complications were evaluated. Patients were entered into one of the protocol groups and compared. Of a total of 63 patients, 56 (89% were males. Five, 19, and 28 patients were managed by Haddad, WHO, or GF protocols, respectively. Eleven patients had fallen into both GF and WHO protocols and were excluded. Serum sickness was significantly more common when WHO protocol was used while 100% of the compartment syndromes and 71% of deformities had been reported after GF protocol. The most important complications were considered to be deformity, compartment syndrome, and amputation and were more frequent after the use of WHO and GF protocols (23.1% versus 76.9%; none in Haddad; P = NS. Haddad protocol seems to be the best for treatment of snake-bitten patients in our region. However, this cannot be strictly concluded because of the limited sample size and nonsignificant P values.

Supporting Adaptation of Wireless Communication Protocols

International Nuclear Information System (INIS)

Dhomeja, L.D.; Soomro, I.A.; Malkani, Y.A.

2016-01-01

Pervasive devices such as mobile phones and PDAs (Personal Digital Assistants) come with different wireless communication capabilities, for example, WiFi (Wireless Fidelity), Bluetooth, IrDA (Infrared), etc. In order for pervasive devices to interact with each other, they need to have matching (alike) communication capabilities, otherwise such heterogeneous devices would not be able to interact with each other. In this paper we address this issue and propose a system that makes devices with heterogeneous wireless communication capabilities communicate with each other. The proposed system supports adaptation of wireless communication protocols through a proxy, which sits between a client and a server, and supports adaptation of wireless communication protocols. Its functionality involves intercepting a request made by a client with a different wireless communication capability (e.g. Bluetooth) from what the server has (e.g. WiFi), connecting to the server and then sending results back to the client. We have tested the system by implementing a messaging service application and running it on the system. The proxy supports all Bluetooth protocols, i.e. OBEX (Object Exchange), L2CAP (Logical Link Control and Adaptation Protocol), RFCOM (Radio Frequency Communication) and WiFi protocol and can run on (J2MW (Java 2 Micro Edition) enabled mobile phones which support both Bluetooth and WiFi capabilities. (author)
Two Cheers for the Trafficking Protocol

Directory of Open Access Journals (Sweden)

Anne T Gallagher

2015-04-01

Full Text Available The Trafficking Protocol makes an easy target for attack. Its origins lie in an attempt to control a particularly exploitative form of migration that was challenging the ability of States to control their own borders. Its parent instrument is a framework agreement to address transnational organised crime. While paying fleeting attention to the rights of victims, the Protocol, with its emphasis on criminalisation and border protection is nowhere near being a human rights treaty. On top of all that it does not even have a credible enforcement mechanism, allowing states parties wide latitude in interpreting and applying their obligations. Strangely, these seemingly insurmountable flaws have not stopped the Protocol’s emergence as perhaps the single most important development in the fight against human trafficking. Without the Protocol, arguments around definitions would have continued to block the evolution of principles and rules. Without the Protocol it is likely that the human rights system would have continued its shameful tradition of sidelining issues such as forced labour, forced sex, forced marriage and the ritual exploitation of migrant workers through debt. Most critically, the Protocol provided the impetus and template for a series of legal and political developments that, over time, have served to ameliorate some of its greatest weaknesses, including the lack of human rights protections and of a credible oversight mechanism.
Immunochemical protocols

National Research Council Canada - National Science Library

Pound, John D

1998-01-01

... easy and important refinements often are not published. This much anticipated 2nd edition of Immunochemzcal Protocols therefore aims to provide a user-friendly up-to-date handbook of reliable techniques selected to suit the needs of molecular biologists. It covers the full breadth of the relevant established immunochemical methods, from protein blotting and immunoa...
Authentication Test-Based the RFID Authentication Protocol with Security Analysis

Directory of Open Access Journals (Sweden)

Minghui Wang

2014-08-01

Full Text Available To the problem of many recently proposed RFID authentication protocol was soon find security holes, we analyzed the main reason, which is that protocol design is not rigorous, and the correctness of the protocol cannot be guaranteed. To this end, authentication test method was adopted in the process of the formal analysis and strict proof to the proposed RFID protocol in this paper. Authentication Test is a new type of analysis and design method of security protocols based on Strand space model, and it can be used for most types of the security protocols. After analysis the security, the proposed protocol can meet the RFID security demand: information confidentiality, data integrity and identity authentication.
Effectiveness and Value of Prophylactic 5-Layer Foam Sacral Dressings to Prevent Hospital-Acquired Pressure Injuries in Acute Care Hospitals: An Observational Cohort Study.

Science.gov (United States)

Padula, William V

The purpose of this study was to examine the effectiveness and value of prophylactic 5-layer foam sacral dressings to prevent hospital-acquired pressure injury rates in acute care settings. Retrospective observational cohort. We reviewed records of adult patients 18 years or older who were hospitalized at least 5 days across 38 acute care hospitals of the University Health System Consortium (UHC) and had a pressure injury as identified by Patient Safety Indicator #3 (PSI-03). All facilities are located in the United States. We collected longitudinal data pertaining to prophylactic 5-layer foam sacral dressings purchased by hospital-quarter for 38 academic medical centers between 2010 and 2015. Longitudinal data on acute care, hospital-level patient outcomes (eg, admissions and PSI-03 and pressure injury rate) were queried through the UHC clinical database/resource manager from the Johns Hopkins Medicine portal. Data on volumes of dressings purchased per UHC hospital were merged with UHC data. Mixed-effects negative binomial regression was used to test the longitudinal association of prophylactic foam sacral dressings on pressure injury rates, adjusted for hospital case-mix and Medicare payments rules. Significant pressure injury rate reductions in US acute care hospitals between 2010 and 2015 were associated with the adoption of prophylactic 5-layer foam sacral dressings within a prevention protocol (-1.0 cases/quarter; P = .002) and changes to Medicare payment rules in 2014 (-1.13 cases/quarter; P = .035). Prophylactic 5-layer foam sacral dressings are an effective component of a pressure injury prevention protocol. Hospitals adopting these technologies should expect good value for use of these products.
Routing protocol extension for resilient GMPLS multi-domain networks

DEFF Research Database (Denmark)

Manolova, Anna Vasileva; Ruepp, Sarah Renée; Romeral, Ricardo

2010-01-01

This paper evaluates the performance of multi-domain networks under the Generalized Multi-Protocol Label Switching control framework in case of a single inter-domain link failure. We propose and evaluate a routing protocol extension for the Border Gateway Protocol, which allows domains to obtain...... two Autonomous System disjoint paths and use them efficiently under failure conditions. Three main applications for the protocol extension are illustrated: reducing traffic loss on existing connections by xploiting pre-selected backup paths derived with our proposal, applying multi-domain restoration...... as survivability mechanism in case of single link failure, and employing proper failure notification mechanisms for routing of future connection requests under routing protocol re-convergence. Via simulations we illustrate the benefits of utilizing the proposed routing protocol extension for networks employing...
Electronic Voting Protocol Using Identity-Based Cryptography

Directory of Open Access Journals (Sweden)

Gina Gallegos-Garcia

2015-01-01

Full Text Available Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC, which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE. With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI. Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps.
Electronic Voting Protocol Using Identity-Based Cryptography.

Science.gov (United States)

Gallegos-Garcia, Gina; Tapia-Recillas, Horacio

2015-01-01

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps.
Implementation of the Additional Protocol in Japan

International Nuclear Information System (INIS)

Ogawa, T.

2001-01-01

The Additional Protocol between Japan and the IAEA entered into force in December 1999. To come into force a series of implementation trials of Additional Protocol was carried out at two Japanese representative nuclear research centers, i.e. Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI) and Oarai Engineering Center of Japan Nuclear Fuel Cycle Development Institute (JNC). These trials were proposed by Japan and were conducted in cooperation with the IAEA Secretariat. In addition, Japan amended 'the Law for the Regulation of Reactors etc.', to collect adequate information to submit to the IAEA, to arrange the surrounding for the complementary access, etc. In addition, Japan Submitted the Initial Declaration of the Additional Protocol within 180 days of the entry into force of the Protocol, in the middle of June, 2000
Performance analysis of routing protocols for IoT

Science.gov (United States)

Manda, Sridhar; Nalini, N.

2018-04-01

Internet of Things (IoT) is an arrangement of advancements that are between disciplinary. It is utilized to have compelling combination of both physical and computerized things. With IoT physical things can have personal virtual identities and participate in distributed computing. Realization of IoT needs the usage of sensors based on the sector for which IoT is integrated. For instance, in healthcare domain, IoT needs to have integration with wearable sensors used by patients. As sensor devices produce huge amount of data, often called big data, there should be efficient routing protocols in place. To the extent remote systems is worried there are some current protocols, for example, OLSR, DSR and AODV. It additionally tosses light into Trust based routing protocol for low-power and lossy systems (TRPL) for IoT. These are broadly utilized remote directing protocols. As IoT is developing round the corner, it is basic to investigate routing protocols that and evaluate their execution regarding throughput, end to end delay, and directing overhead. The execution experiences can help in settling on very much educated choices while incorporating remote systems with IoT. In this paper, we analyzed different routing protocols and their performance is compared. It is found that AODV showed better performance than other routing protocols aforementioned.
Database communication protocol analyses and security detection

International Nuclear Information System (INIS)

Luo Qun; Liu Qiushi

2003-01-01

In this paper we introduced the analysis of TDS protocol in the communication application between Client and Server about SYBASE and MICROSOFT SQL SERVER and do some test for some bugs existed in the protocol. (authors)
Layer-by-layer strippable Ag multilayer films fabricated by modular assembly.

Science.gov (United States)

Li, Yan; Chen, Xiaoyan; Li, Qianqian; Song, Kai; Wang, Shihui; Chen, Xiaoyan; Zhang, Kai; Fu, Yu; Jiao, Yong-Hua; Sun, Ting; Liu, Fu-Chun; Han, En-Hou

2014-01-21

We have developed a new method to fabricate multilayer films, which uses prepared thin films as modular blocks and transfer as operation mode to build up multilayer structures. In order to distinguish it from the in situ fabrication manner, this method is called modular assembly in this study. On the basis of such concept, we have fabricated a multilayer film using the silver mirror film as the modular block and poly(lactic acid) as the transfer tool. Due to the special double-layer structure of the silver mirror film, the resulting multilayer film had a well-defined stratified architecture with alternate porous/compact layers. As a consequence of the distinct structure, the interaction between the adjacent layers was so weak that the multilayer film could be layer-by-layer stripped. In addition, the top layer in the film could provide an effective protection on the morphology and surface property of the underlying layers. This suggests that if the surface of the film was deteriorated, the top layer could be peeled off and the freshly exposed surface would still maintain the original function. The successful preparation of the layer-by-layer strippable silver multilayer demonstrates that modular assembly is a feasible and effective method to build up multilayer films capable of creating novel and attractive micro/nanostructures, having great potential in the fabrication of nanodevices and coatings.
Quantum multi-signature protocol based on teleportation

International Nuclear Information System (INIS)

Wen Xiao-jun; Liu Yun; Sun Yu

2007-01-01

In this paper, a protocol which can be used in multi-user quantum signature is proposed. The scheme of signature and verification is based on the correlation of Greenberger-Horne-Zeilinger (GHZ) states and the controlled quantum teleportation. Different from the digital signatures, which are based on computational complexity, the proposed protocol has perfect security in the noiseless quantum channels. Compared to previous quantum signature schemes, this protocol can verify the signature independent of an arbitrator as well as realize multi-user signature together. (orig.)
Robust Multi-unit Auction Protocol against False-name Bids

Science.gov (United States)

Yokoo, Makoto; Sakurai, Yuko; Matsubara, Shigeo

This paper presents a new multi-unit auction protocol (IR protocol) that is robust against false-name bids. Internet auctions have become an integral part of Electronic Commerce and a promising field for applying agent and Artificial Intelligence technologies. Although the Internet provides an excellent infrastructure for executing auctions, the possibility of a new type of cheating called false-name bids has been pointed out. A false-name bid is a bid submitted under a fictitious name. A protocol called LDS has been developed for combinatorial auctions of multiple different items and has proven to be robust against false-name bids. Although we can modify the LDS protocol to handle multi-unit auctions, in which multiple units of an identical item are auctioned, the protocol is complicated and requires the auctioneer to carefully pre-determine the combination of bundles to obtain a high social surplus or revenue. For the auctioneer, our newly developed IR protocol is easier to use than the LDS, since the combination of bundles is automatically determined in a flexible manner according to the declared evaluation values of agents. The evaluation results show that the IR protocol can obtain a better social surplus than that obtained by the LDS protocol.
Removing Ambiguities of IP Telephony Traffic Using Protocol Scrubbers

Directory of Open Access Journals (Sweden)

Bazara I. A. Barry

2012-10-01

Full Text Available Network intrusion detection systems (NIDSs face the serious challenge of attacks such as insertion and evasion attacks that are caused by ambiguous network traffic. Such ambiguity comes as a result of the nature of network traffic which includes protocol implementation variations and errors alongside legitimate network traffic. Moreover, attackers can intentionally introduce further ambiguities in the traffic. Consequently, NIDSs need to be aware of these ambiguities when detection is performed and make sure to differentiate between true attacks and protocol implementation variations or errors; otherwise, detection accuracy can be affected negatively. In this paper we present the design and implementation of tools that are called protocol scrubbers whose main functionality is to remove ambiguities from network traffic before it is presented to the NIDS. The proposed protocol scrubbers are designed for session initiation and data transfer protocols in IP telephony systems. They guarantee that the traffic presented to NIDSs is unambiguous by eliminating ambiguous behaviors of protocols using well-designed protocol state machines, and walking through packet headers of protocols to make sure packets will be interpreted in the desired way by the NIDS. The experimental results shown in this paper demonstrate the good quality and applicability of the introduced scrubbers.
The double layers in the plasma sheet boundary layer during magnetic reconnection

Science.gov (United States)

Guo, J.; Yu, B.

2014-11-01

We studied the evolutions of double layers which appear after the magnetic reconnection through two-dimensional electromagnetic particle-in-cell simulation. The simulation results show that the double layers are formed in the plasma sheet boundary layer after magnetic reconnection. At first, the double layers which have unipolar structures are formed. And then the double layers turn into bipolar structures, which will couple with another new weak bipolar structure. Thus a new double layer or tripolar structure comes into being. The double layers found in our work are about several ten Debye lengths, which accords with the observation results. It is suggested that the electron beam formed during the magnetic reconnection is responsible for the production of the double layers.
Kyoto Protocol: trade versus the environment

International Nuclear Information System (INIS)

Loose, H.

2001-01-01

Could the signatories to the Kyoto Protocol find themselves up against the WTO? This paper examines how the climate change agreement could conflict with trade rules, and shows that there are potentially serious conflicts in the interface between the WTO and the Kyoto Protocol. It argues for dialogue and debate before it is too late. (author)
SPIRIT 2013 Statement: defining standard protocol items for clinical trials.

Science.gov (United States)

Chan, An-Wen; Tetzlaff, Jennifer M; Altman, Douglas G; Laupacis, Andreas; Gøtzsche, Peter C; Krle A-Jerić, Karmela; Hrobjartsson, Asbjørn; Mann, Howard; Dickersin, Kay; Berlin, Jesse A; Dore, Caroline J; Parulekar, Wendy R; Summerskill, William S M; Groves, Trish; Schulz, Kenneth F; Sox, Harold C; Rockhold, Frank W; Rennie, Drummond; Moher, David

2015-12-01

The protocol of a clinical trial serves as the foundation for study planning, conduct, reporting, and appraisal. However, trial protocols and existing protocol guidelines vary greatly in content and quality. This article describes the systematic development and scope of SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013, a guideline for the minimum content of a clinical trial protocol. The 33-item SPIRIT checklist applies to protocols for all clinical trials and focuses on content rather than format. The checklist recommends a full description of what is planned; it does not prescribe how to design or conduct a trial. By providing guidance for key content, the SPIRIT recommendations aim to facilitate the drafting of high-quality protocols. Adherence to SPIRIT would also enhance the transparency and completeness of trial protocols for the benefit of investigators, trial participants, patients, sponsors, funders, research ethics committees or institutional review boards, peer reviewers, journals, trial registries, policymakers, regulators, and other key stakeholders.
Optimistic protocol for partitioned distributed database systems

International Nuclear Information System (INIS)

Davidson, S.B.

1982-01-01

A protocol for transaction processing during partition failures is presented which guarantees mutual consistency between copies of data-items after repair is completed. The protocol is optimistic in that transactions are processed without restrictions during the failure; conflicts are detected at repair time using a precedence graph and are resolved by backing out transactions according to some backout strategy. The protocol is then evaluated using simulation and probabilistic modeling. In the simulation, several parameters are varied such as the number of transactions processed in a group, the type of transactions processed, the number of data-items present in the database, and the distribution of references to data-items. The simulation also uses different backout strategies. From these results we note conditions under which the protocol performs well, i.e., conditions under which the protocol backs out a small percentage of the transaction run. A probabilistic model is developed to estimate the expected number of transactions backed out using most of the above database and transaction parameters, and is shown to agree with simulation results. Suggestions are then made on how to improve the performance of the protocol. Insights gained from the simulation and probabilistic modeling are used to develop a backout strategy which takes into account individual transaction costs and attempts to minimize total backout cost. Although the problem of choosing transactions to minimize total backout cost is, in general, NP-complete, the backout strategy is efficient and produces very good results
Comparison of the ultrashort gonadotropin-releasing hormone agonist-antagonist protocol with microdose flare -up protocol in poor responders: a preliminary study.

Science.gov (United States)

Berker, Bülent; Duvan, Candan İltemir; Kaya, Cemil; Aytaç, Ruşen; Satıroğlu, Hakan

2010-01-01

To determine the potential effect of the ultrashort gonadotropin-releasing hormone (GnRH) agonist/GnRH antagonist protocol versus the microdose GnRH agonist protocol in poor responders undergoing intracytoplasmic sperm injection (ICSI). The patients in the Agonist-Antagonist Group (n=41) were administered the ultrashort GnRH-agonist/ antagonist protocol, while the patients in the Microdose Group (n=41) were stimulated according to the microdose flare-up protocol. The mean number of mature oocytes retrieved was the primary outcome measure. Fertilization rate, implantation rate per embryo and clinical pregnancy rates were secondary outcome measures. There was no differenc between the mean number of mature oocytes retrieved in the two groups. There were also no statistical differences between the two groups in terms of peak serum E2 level, canceled cycles, endometrial thickness on hCG day, number of 2 pronucleus and number of embryos transferred. However, the total gonadotropin consumption and duration of stimulation were significantly higher with the Agonist-Antagonist Group compared with the Microdose Group. The implantation and clinical pregnancy rates were similar between the two groups. Despite the high dose of gonadotropin consumption and longer duration of stimulation with the ultrashort GnRH agonist/ antagonist protocol, it seems that the Agonist-Antagonist Protocol is not inferior to the microdose protocol in poor responders undergoing ICSI.

Controlled Delegation Protocol in Mobile RFID Networks

Directory of Open Access Journals (Sweden)

Yang MingHour

2010-01-01

Full Text Available To achieve off-line delegation for mobile readers, we propose a delegation protocol for mobile RFID allowing its readers access to specific tags through back-end server. That is to say, reader-tag mutual authentication can be performed without readers being connected to back-end server. Readers are also allowed off-line access to tags' data. Compared with other delegation protocols, our scheme uniquely enables back-end server to limit each reader's reading times during delegation. Even in a multireader situation, our protocol can limit reading times and reading time periods for each of them and therefore makes back-end server's delegation more flexible. Besides, our protocol can prevent authorized readers from transferring their authority to the unauthorized, declining invalid access to tags. Our scheme is proved viable and secure with GNY logic; it is against certain security threats, such as replay attacks, denial of service (DoS attacks, Man-in-the-Middle attacks, counterfeit tags, and breaches of location and data privacy. Also, the performance analysis of our protocol proves that current tags can afford the computation load required in this scheme.
Nursing Music Protocol and Postoperative Pain.

Science.gov (United States)

Poulsen, Michael J; Coto, Jeffrey

2018-04-01

Pain has always been a major concern for patients and nurses during the postoperative period. Therapies, medicines, and protocols have been developed to improve pain and anxiety but have undesirable risks to the patient. Complementary and alternative medicine therapies have been studied but have not been applied as regular protocols in the hospital setting. Music is one type of complementary and alternative medicine therapy that has been reported to have favorable results on reducing postoperative pain, anxiety, and opioid usage. However, music lacks a protocol that nurses can implement during the perioperative process. This paper is an in-depth literature review assessing a best practice recommendation and protocol that establishes a consensus in the use of music therapy. The results suggest that music therapy may consist of calming, soft tones of 60-80 beats per minute for at least 15-30 minutes at least twice daily during the pre- and postoperative periods. It is suggested that music only be used in conjunction with standards of care and not as the primary intervention of pain or anxiety. This evidence suggests that proper use of music therapy can significantly reduce surgical pain. Implementing these protocols and allowing the freedom of nursing staff to use them may lead to greater reductions in surgical pain and anxiety and a reduction in opioid use. Copyright © 2017 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.
Compiling symbolic attacks to protocol implementation tests

Directory of Open Access Journals (Sweden)

Michael Rusinowitch

2013-07-01

Full Text Available Recently efficient model-checking tools have been developed to find flaws in security protocols specifications. These flaws can be interpreted as potential attacks scenarios but the feasability of these scenarios need to be confirmed at the implementation level. However, bridging the gap between an abstract attack scenario derived from a specification and a penetration test on real implementations of a protocol is still an open issue. This work investigates an architecture for automatically generating abstract attacks and converting them to concrete tests on protocol implementations. In particular we aim to improve previously proposed blackbox testing methods in order to discover automatically new attacks and vulnerabilities. As a proof of concept we have experimented our proposed architecture to detect a renegotiation vulnerability on some implementations of SSL/TLS, a protocol widely used for securing electronic transactions.
Data Exchange Protocol in Repsail

Directory of Open Access Journals (Sweden)

Gucma Maciej

2017-12-01

Full Text Available Article presents implantation and theoretical considerations of data exchange protocol developed for the RepSail project, where main objective was design and building innovative hybrid yacht. One of problems during the design process was improper functioning of data exchange protocols that were available in the commercially available devices to mention navigation purpose NMEA183 or 2000 as well as automation dedicated ones (CAN and similar. Author shows the basis of the dedicated format of exchange for in board devices.
The Groningen protocol: another perspective

OpenAIRE

Jotkowitz, A B; Glick, S

2006-01-01

The Groningen protocol allows for the euthanasia of severely ill newborns with a hopeless prognosis and unbearable suffering. We understand the impetus for such a protocol but have moral and ethical concerns with it. Advocates for euthanasia in adults have relied on the concept of human autonomy, which is lacking in the case of infants. In addition, biases can potentially influence the decision making of both parents and physicians. It is also very difficult to weigh the element of quality of...
A Logical Analysis of Quantum Voting Protocols

Science.gov (United States)

Rad, Soroush Rafiee; Shirinkalam, Elahe; Smets, Sonja

2017-12-01

In this paper we provide a logical analysis of the Quantum Voting Protocol for Anonymous Surveying as developed by Horoshko and Kilin in (Phys. Lett. A 375, 1172-1175 2011). In particular we make use of the probabilistic logic of quantum programs as developed in (Int. J. Theor. Phys. 53, 3628-3647 2014) to provide a formal specification of the protocol and to derive its correctness. Our analysis is part of a wider program on the application of quantum logics to the formal verification of protocols in quantum communication and quantum computation.
Two-party quantum key agreement protocols under collective noise channel

Science.gov (United States)

Gao, Hao; Chen, Xiao-Guang; Qian, Song-Rong

2018-06-01

Recently, quantum communication has become a very popular research field. The quantum key agreement (QKA) plays an important role in the field of quantum communication, based on its unconditional security in terms of theory. Among all kinds of QKA protocols, QKA protocols resisting collective noise are widely being studied. In this paper, we propose improved two-party QKA protocols resisting collective noise and present a feasible plan for information reconciliation. Our protocols' qubit efficiency has achieved 26.67%, which is the best among all the two-party QKA protocols against collective noise, thus showing that our protocol can improve the transmission efficiency of quantum key agreement.
IAEA to implement Safeguards Additional Protocols in the EU

International Nuclear Information System (INIS)

2004-01-01

Full text: IAEA Director General Mohamed ElBaradei welcomed the entry into force today of the Additional Protocols for 15 States of the European Union - France, the United Kingdom and the 13 non-nuclear weapon States of the EU - and the European Atomic Energy Community (EURATOM). The Protocols, which provide the Agency with better tools to verify compliance with nuclear non-proliferation commitments, entered into force when the European Commission informed the Agency that EURATOM's own requirements for entry into force had been met. The 15 States had provided similar notifications over the past years since signing the Protocols in 1998. The simultaneous entry into force of Additional Protocols for the 15 EU States is 'a very positive development and a milestone in our efforts to strengthen the verification regime', said Dr. ElBaradei. 'In my view, the Additional Protocol should become the standard for verification under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).' He added that the Agency had been preparing for the entry into force of the EU protocols and was confident that, in co-operation with the 15 States and EURATOM, it would be able to ensure effective and efficient implementation in the EU States. The Model Additional Protocol was developed following the discovery of Iraq's clandestine nuclear weapons programme to ensure that the IAEA is given the information and access it needs for timely discovery of any similar activities in States that have pledged not to use nuclear material and activities for weapons purposes. In the past year, Additional Protocols entered into force for 22 countries, and the Agency will now implement Additional Protocols in 58 States, which includes the 15 EU States. The 10 countries joining the EU on 1 May 2004 - seven of which already have brought into force Additional Protocols to their respective safeguards agreements - are expected to gradually accede to the Safeguards Agreement and Additional Protocol covering
Symbolic Model Checking and Analysis for E-Commerce Protocol

Institute of Scientific and Technical Information of China (English)

WEN Jing-Hua; ZHANG Mei; LI Xiang

2005-01-01

A new approach is proposed for analyzing non-repudiation and fairness of e-commerce protocols. The authentication e-mail protocol CMP1 is modeled as finite state machine and analyzed in two vital aspects - non-repudiation and fairness using SMV. As a result, the CMP1 protocol is not fair and we have improved it. This result shows that it is effective to analyze and check the new features of e-commerce protocols using SMV model checker
Re-examining the security of blind quantum signature protocols

International Nuclear Information System (INIS)

Wang Mingming; Chen Xiubo; Niu Xinxin; Yang Yixian

2012-01-01

Recently, blind quantum signature (BQS) protocols have been proposed with the help of a third-party verifier. However, our research shows that some of the BQS protocols are unable to complete the blind signature task fairly if the verifier is dishonest. Indeed, these protocols can be viewed as variants of the classical digital signature scheme of symmetric-key cryptography. If nobody is trusted in such protocols, digital signature cannot be implemented since disagreements cannot be solved fairly.
A model based security testing method for protocol implementation.

Science.gov (United States)

Fu, Yu Long; Xin, Xiao Long

2014-01-01

The security of protocol implementation is important and hard to be verified. Since the penetration testing is usually based on the experience of the security tester and the specific protocol specifications, a formal and automatic verification method is always required. In this paper, we propose an extended model of IOLTS to describe the legal roles and intruders of security protocol implementations, and then combine them together to generate the suitable test cases to verify the security of protocol implementation.
Comparison of protocols for measuring cosmetic ingredient distribution in human and pig skin.

Science.gov (United States)

Gerstel, D; Jacques-Jamin, C; Schepky, A; Cubberley, R; Eilstein, J; Grégoire, S; Hewitt, N; Klaric, M; Rothe, H; Duplan, H

2016-08-01

The Cosmetics Europe Skin Bioavailability and Metabolism Task Force aims to improve the measurement and prediction of the bioavailability of topically-exposed compounds for risk assessment. Key parameters of the experimental design of the skin penetration studies were compared. Penetration studies with frozen human and pig skin were conducted in two laboratories, according to the SCCS and OECD 428 guidelines. The disposition in skin was measured 24h after finite topical doses of caffeine, resorcinol and 7-ethoxycoumarin. The bioavailability distribution in skin layers of cold and radiolabelled chemicals were comparable. Furthermore, the distribution of each chemical was comparable in human and pig skin. The protocol was reproducible across the two laboratories. There were small differences in the amount of chemical detected in the skin layers, which were attributed to differences in washing procedures and anatomical sites of the skin used. In conclusion, these studies support the use of pig skin as an alternative source of skin should the availability of human skin become a limiting factor. If radiolabelled chemicals are not available, cold chemicals can be used, provided that the influence of chemical stability, reactivity or metabolism on the experimental design and the relevance of the data obtained is considered. Copyright © 2016. Published by Elsevier Ltd.
Intelligent routing protocol for ad hoc wireless network

Science.gov (United States)

Peng, Chaorong; Chen, Chang Wen

2006-05-01

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

NARCIS (Netherlands)

J. Pang

2002-01-01

textabstractNeedham-Schroeder public-key protocol; With the growth and commercialization of the Internet, the security of communication between computers becomes a crucial point. A variety of security protocols based on cryptographic primitives are used to establish secure communication over
HPTLC-aptastaining - Innovative protein detection system for high-performance thin-layer chromatography

Science.gov (United States)

Morschheuser, Lena; Wessels, Hauke; Pille, Christina; Fischer, Judith; Hünniger, Tim; Fischer, Markus; Paschke-Kratzin, Angelika; Rohn, Sascha

2016-05-01

Protein analysis using high-performance thin-layer chromatography (HPTLC) is not commonly used but can complement traditional electrophoretic and mass spectrometric approaches in a unique way. Due to various detection protocols and possibilities for hyphenation, HPTLC protein analysis is a promising alternative for e.g., investigating posttranslational modifications. This study exemplarily focused on the investigation of lysozyme, an enzyme which is occurring in eggs and technologically added to foods and beverages such as wine. The detection of lysozyme is mandatory, as it might trigger allergenic reactions in sensitive individuals. To underline the advantages of HPTLC in protein analysis, the development of innovative, highly specific staining protocols leads to improved sensitivity for protein detection on HPTLC plates in comparison to universal protein derivatization reagents. This study aimed at developing a detection methodology for HPTLC separated proteins using aptamers. Due to their affinity and specificity towards a wide range of targets, an aptamer based staining procedure on HPTLC (HPTLC-aptastaining) will enable manifold analytical possibilities. Besides the proof of its applicability for the very first time, (i) aptamer-based staining of proteins is applicable on different stationary phase materials and (ii) furthermore, it can be used as an approach for a semi-quantitative estimation of protein concentrations.
Multi-party quantum key agreement protocol secure against collusion attacks

Science.gov (United States)

Wang, Ping; Sun, Zhiwei; Sun, Xiaoqiang

2017-07-01

The fairness of a secure multi-party quantum key agreement (MQKA) protocol requires that all involved parties are entirely peer entities and can equally influence the outcome of the protocol to establish a shared key wherein no one can decide the shared key alone. However, it is found that parts of the existing MQKA protocols are sensitive to collusion attacks, i.e., some of the dishonest participants can collaborate to predetermine the final key without being detected. In this paper, a multi-party QKA protocol resisting collusion attacks is proposed. Different from previous QKA protocol resisting N-1 coconspirators or resisting 1 coconspirators, we investigate the general circle-type MQKA protocol which can be secure against t dishonest participants' cooperation. Here, t < N. We hope the results of the presented paper will be helpful for further research on fair MQKA protocols.
Protocols for pressure ulcer prevention: are they evidence-based?

Science.gov (United States)

Chaves, Lidice M; Grypdonck, Mieke H F; Defloor, Tom

2010-03-01

This study is a report of a study to determine the quality of protocols for pressure ulcer prevention in home care in the Netherlands. If pressure ulcer prevention protocols are evidence-based and practitioners use them correctly in practice, this will result a reduction in pressure ulcers. Very little is known about the evidence-based content and quality of the pressure ulcer prevention protocols. In 2008, current pressure ulcer prevention protocols from 24 home-care agencies in the Netherlands were evaluated. A checklist developed and validated by two pressure ulcer prevention experts was used to assess the quality of the protocols, and weighted and unweighted quality scores were computed and analysed using descriptive statistics. The 24 pressure ulcer prevention protocols had a mean weighted quality score of 63.38 points out of a maximum of 100 (sd 5). The importance of observing the skin at the pressure points at least once a day was emphasized in 75% of the protocols. Only 42% correctly warned against the use of materials that were 'less effective or that could potentially cause harm'. Pressure ulcer prevention commands a reasonable amount of attention in home care, but the incidence of pressure ulcers and lack of a consistent, standardized document for use in actual practice indicate a need for systematic implementation of national pressure ulcer prevention standards in the Netherlands to ensure adherence to the established protocols.
A Cross-Layer Key Management Scheme for MIPv6 Fast Handover over IEEE 802.11 Wireless LAN

Directory of Open Access Journals (Sweden)

Chang-Seop Park

2015-01-01

Full Text Available A new key management and security scheme is proposed to integrate Layer Two (L2 and Layer Three (L3 keys for secure and fast Mobile IPv6 handover over IEEE 802.11 Wireless Local Area Network (WLAN. Unlike the original IEEE 802.11-based Mobile IPv6 Fast Handover (FMIPv6 that requires time-consuming IEEE 802.1x-based Extensible Authentication Protocol (EAP authentication on each L3 handover, the newly proposed key management and security scheme requires only one 802.1x-EAP regardless of how many L3 handovers occur. Therefore, the proposed scheme reduces the handover latency that results from a lengthy 802.1x-based EAP. The proposed key management and security scheme is extensively analyzed in terms of security and performance, and the proposed security scheme is shown to be more secure than those that were previously proposed.
Layer-by-layer assembled biopolymer microcapsule with separate layer cavities generated by gas-liquid microfluidic approach.

Science.gov (United States)

Wang, Yifeng; Zhou, Jing; Guo, Xuecheng; Hu, Qian; Qin, Chaoran; Liu, Hui; Dong, Meng; Chen, Yanjun

2017-12-01

In this work, a layer-by-layer (LbL) assembled biopolymer microcapsule with separate layer cavities is generated by a novel and convenient gas-liquid microfluidic approach. This approach exhibits combined advantages of microfluidic approach and LbL assembly method, and it can straightforwardly build LbL-assembled capsules in mild aqueous environments at room temperature. In particular, using this approach we can build the polyelectrolyte multilayer capsule with favorable cavities in each layer, and without the need for organic solvent, emulsifying agent, or sacrificial template. Various components (e.g., drugs, proteins, fluorescent dyes, and nanoparticles) can be respectively encapsulated in the separate layer cavities of the LbL-assembled capsules. Moreover, the encapsulated capsules present the ability as colorimetric sensors, and they also exhibit the interesting release behavior. Therefore, the LbL-assembled biopolymer capsule is a promising candidate for biomedical applications in targeted delivery, controlled release, and bio-detection. Copyright © 2017 Elsevier B.V. All rights reserved.
Model checking the HAVi leader election protocol

NARCIS (Netherlands)

J.M.T. Romijn (Judi)

1999-01-01

textabstractThe HAVi specification proposes an architecture for audio/video interoperability in home networks. Part of the HAVi specification is a distributed leader election protocol. We have modelled this leader election protocol in Promela and Lotos and have checked several properties with the

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