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Sample records for aodv based manet

  1. A Source Anonymity-Based Lightweight Secure AODV Protocol for Fog-Based MANET.

    Science.gov (United States)

    Fang, Weidong; Zhang, Wuxiong; Xiao, Jinchao; Yang, Yang; Chen, Wei

    2017-06-17

    Fog-based MANET (Mobile Ad hoc networks) is a novel paradigm of a mobile ad hoc network with the advantages of both mobility and fog computing. Meanwhile, as traditional routing protocol, ad hoc on-demand distance vector (AODV) routing protocol has been applied widely in fog-based MANET. Currently, how to improve the transmission performance and enhance security are the two major aspects in AODV's research field. However, the researches on joint energy efficiency and security seem to be seldom considered. In this paper, we propose a source anonymity-based lightweight secure AODV (SAL-SAODV) routing protocol to meet the above requirements. In SAL-SAODV protocol, source anonymous and secure transmitting schemes are proposed and applied. The scheme involves the following three parts: the source anonymity algorithm is employed to achieve the source node, without being tracked and located; the improved secure scheme based on the polynomial of CRC-4 is applied to substitute the RSA digital signature of SAODV and guarantee the data integrity, in addition to reducing the computation and energy consumption; the random delayed transmitting scheme (RDTM) is implemented to separate the check code and transmitted data, and achieve tamper-proof results. The simulation results show that the comprehensive performance of the proposed SAL-SAODV is a trade-off of the transmission performance, energy efficiency, and security, and better than AODV and SAODV.

  2. A new method for improving security in MANETs AODV Protocol

    Directory of Open Access Journals (Sweden)

    Zahra Alishahi

    2012-10-01

    Full Text Available In mobile ad hoc network (MANET, secure communication is more challenging task due to its fundamental characteristics like having less infrastructure, wireless link, distributed cooperation, dynamic topology, lack of association, resource constrained and physical vulnerability of node. In MANET, attacks can be broadly classified in two categories: routing attacks and data forwarding attacks. Any action not following rules of routing protocols belongs to routing attacks. The main objective of routing attacks is to disrupt normal functioning of network by advertising false routing updates. On the other hand, data forwarding attacks include actions such as modification or dropping data packet, which does not disrupt routing protocol. In this paper, we address the “Packet Drop Attack”, which is a serious threat to operational mobile ad hoc networks. The consequence of not forwarding other packets or dropping other packets prevents any kind of communication to be established in the network. Therefore, there is a need to address the packet dropping event takes higher priority for the mobile ad hoc networks to emerge and to operate, successfully. In this paper, we propose a method to secure ad hoc on-demand distance vector (AODV routing protocol. The proposed method provides security for routing packets where the malicious node acts as a black-hole and drops packets. In this method, the collaboration of a group of nodes is used to make accurate decisions. Validating received RREPs allows the source to select trusted path to its destination. The simulation results show that the proposed mechanism is able to detect any number of attackers.

  3. MANET Performance for Source and Destination Moving Scenarios Considering OLSR and AODV protocols

    Directory of Open Access Journals (Sweden)

    Elis Kulla

    2010-01-01

    Full Text Available Recently, a great interest is shown in MANETs potential usage and applications in several fields such as military activities, rescue operations and time-critical applications. In this work, we implement and analyse a MANET testbed considering AODV and OLSR protocols for wireless multi-hop networking. We investigate the effect of mobility and topology changing in MANET and evaluate the performance of the network through experiments in a real environment. The performance assessment of our testbed is done considering throughput, number of dropped packets and delay. We designed four scenarios: Static, Source Moving, Destination Moving and Source-Destination Moving. From our experimental results, we concluded that when the communicating nodes are moving and the routes change quickly, OLSR (as a proactive protocol performs better than AODV, which is a reactive protocol.

  4. Evaluating performance of WRP and AODV MANETs routing ...

    African Journals Online (AJOL)

    The Mobile ad hoc networks (MANET) is a wireless networks which have no central bridge, and where each node acts as a destination as well as a router. The MANETs are dynamic networks because the network topology keeps on changing because of the mobility of the nodes. There are many protocols that have been ...

  5. SURVEY OF ENERGY COMPETENCE ROUTING PROTOCOL IN UTILIZING AODV IN MANETS (20150471)

    OpenAIRE

    TUSHAR SINGH RAJPUT; RAJ KUMAR PAUL

    2018-01-01

    In MANETs (Mobile unintentional Networks) communication at the mobile nodes will be achieved by mistreatment multihop wireless links. The aim of every protocol, in Associate in Nursing ad-hoc network, is to seek out valid routes between 2 communication nodes.

  6. SURVEI PENANGANAN BROADCAST STORM PROBLEM PADA PROTOKOL ROUTING AODV DI MANET

    Directory of Open Access Journals (Sweden)

    Indera Zainul Muttaqien

    2015-07-01

    Full Text Available Komunikasi multi-hop pada lingkungan MANET dapat melibatkan broadcast paket dalam proses route discovery. Protokol routing pada MANET akan melakukan broadcast paket RREQ dan menjalarkannya ke node tujuan secepat dan seefisien mungkin, dimana paket RREQ dari rute yang optimal adalah paket RREQ yang terlebih dahulu sampai ke tujuan. Aktifitas broadcast yang tidak terkontrol dapat menyebabkan suatu kondisi yang disebut broadcast storm problem. Broadcast storm problem dapat berdampak pada terganggunya kinerja dari protokol routing akibat adanya packet redundancy, contention, dan collision. Broadcast storm problem dapat ditangani dengan membatasi jumlah node yang dapat melakukan broadcast. Tujuan utama dari pembuatan makalah ini adalah merangkum beberapa mekanisme terbaru yang telah diakukan oleh para peneliti untuk menangani broadcast storm problem. Kami juga menyajikan perbandingan dari mekanisme tersebut berdasarkan karakteristik dari mekanisme ditinjau dari kesesuaian dengan beberapa skema penanganan broadcast storm problem yang diajukan oleh peneliti sebelumnya, kebutuhan informasi tertentu antar node, lingkungan uji coba dan apakah mekanisme ini dapat diterapkan pada protokol routing lainnya.

  7. FSM-F: Finite State Machine Based Framework for Denial of Service and Intrusion Detection in MANET.

    Science.gov (United States)

    N Ahmed, Malik; Abdullah, Abdul Hanan; Kaiwartya, Omprakash

    2016-01-01

    Due to the continuous advancements in wireless communication in terms of quality of communication and affordability of the technology, the application area of Mobile Adhoc Networks (MANETs) significantly growing particularly in military and disaster management. Considering the sensitivity of the application areas, security in terms of detection of Denial of Service (DoS) and intrusion has become prime concern in research and development in the area. The security systems suggested in the past has state recognition problem where the system is not able to accurately identify the actual state of the network nodes due to the absence of clear definition of states of the nodes. In this context, this paper proposes a framework based on Finite State Machine (FSM) for denial of service and intrusion detection in MANETs. In particular, an Interruption Detection system for Adhoc On-demand Distance Vector (ID-AODV) protocol is presented based on finite state machine. The packet dropping and sequence number attacks are closely investigated and detection systems for both types of attacks are designed. The major functional modules of ID-AODV includes network monitoring system, finite state machine and attack detection model. Simulations are carried out in network simulator NS-2 to evaluate the performance of the proposed framework. A comparative evaluation of the performance is also performed with the state-of-the-art techniques: RIDAN and AODV. The performance evaluations attest the benefits of proposed framework in terms of providing better security for denial of service and intrusion detection attacks.

  8. FSM-F: Finite State Machine Based Framework for Denial of Service and Intrusion Detection in MANET.

    Directory of Open Access Journals (Sweden)

    Malik N Ahmed

    Full Text Available Due to the continuous advancements in wireless communication in terms of quality of communication and affordability of the technology, the application area of Mobile Adhoc Networks (MANETs significantly growing particularly in military and disaster management. Considering the sensitivity of the application areas, security in terms of detection of Denial of Service (DoS and intrusion has become prime concern in research and development in the area. The security systems suggested in the past has state recognition problem where the system is not able to accurately identify the actual state of the network nodes due to the absence of clear definition of states of the nodes. In this context, this paper proposes a framework based on Finite State Machine (FSM for denial of service and intrusion detection in MANETs. In particular, an Interruption Detection system for Adhoc On-demand Distance Vector (ID-AODV protocol is presented based on finite state machine. The packet dropping and sequence number attacks are closely investigated and detection systems for both types of attacks are designed. The major functional modules of ID-AODV includes network monitoring system, finite state machine and attack detection model. Simulations are carried out in network simulator NS-2 to evaluate the performance of the proposed framework. A comparative evaluation of the performance is also performed with the state-of-the-art techniques: RIDAN and AODV. The performance evaluations attest the benefits of proposed framework in terms of providing better security for denial of service and intrusion detection attacks.

  9. Interface Assignment-Based AODV Routing Protocol to Improve Reliability in Multi-Interface Multichannel Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Won-Suk Kim

    2015-01-01

    Full Text Available The utilization of wireless mesh networks (WMNs has greatly increased, and the multi-interface multichannel (MIMC technic has been widely used for the backbone network. Unfortunately, the ad hoc on-demand distance vector (AODV routing protocol defined in the IEEE 802.11s standard was designed for WMNs using the single-interface single-channel technic. So, we define a problem that happens when the legacy AODV is used in MIMC WMNs and propose an interface assignment-based AODV (IA-AODV in order to resolve that problem. IA-AODV, which is based on multitarget path request, consists of the PREQ prediction scheme, the PREQ loss recovery scheme, and the PREQ sender assignment scheme. A detailed operation according to various network conditions and services is introduced, and the routing efficiency and network reliability of a network using IA-AODV are analyzed over the presented system model. Finally, after a real-world test-bed for MIMC WMNs using the IA-AODV routing protocol is implemented, the various indicators of the network are evaluated through experiments. When the proposed routing protocol is compared with the existing AODV routing protocol, it performs the path update using only 14.33% of the management frames, completely removes the routing malfunction, and reduces the UDP packet loss ratio by 0.0012%.

  10. An Adaptive QoS Routing Solution for MANET Based Multimedia Communications in Emergency Cases

    Science.gov (United States)

    Ramrekha, Tipu Arvind; Politis, Christos

    The Mobile Ad hoc Networks (MANET) is a wireless network deprived of any fixed central authoritative routing entity. It relies entirely on collaborating nodes forwarding packets from source to destination. This paper describes the design, implementation and performance evaluation of CHAMELEON, an adaptive Quality of Service (QoS) routing solution, with improved delay and jitter performances, enabling multimedia communication for MANETs in extreme emergency situations such as forest fire and terrorist attacks as defined in the PEACE project. CHAMELEON is designed to adapt its routing behaviour according to the size of a MANET. The reactive Ad Hoc on-Demand Distance Vector Routing (AODV) and proactive Optimized Link State Routing (OLSR) protocols are deemed appropriate for CHAMELEON through their performance evaluation in terms of delay and jitter for different MANET sizes in a building fire emergency scenario. CHAMELEON is then implemented in NS-2 and evaluated similarly. The paper concludes with a summary of findings so far and intended future work.

  11. Performance Analysis of AODV Routing Protocol for Wireless Sensor Network based Smart Metering

    International Nuclear Information System (INIS)

    Farooq, Hasan; Jung, Low Tang

    2013-01-01

    Today no one can deny the need for Smart Grid and it is being considered as of utmost importance to upgrade outdated electric infrastructure to cope with the ever increasing electric load demand. Wireless Sensor Network (WSN) is considered a promising candidate for internetworking of smart meters with the gateway using mesh topology. This paper investigates the performance of AODV routing protocol for WSN based smart metering deployment. Three case studies are presented to analyze its performance based on four metrics of (i) Packet Delivery Ratio, (ii) Average Energy Consumption of Nodes (iii) Average End-End Delay and (iv) Normalized Routing Load.

  12. Study of DSR and AODV under Sinkhole Attack and Its Proposed Prevention Technique

    OpenAIRE

    Winnie Main; Narendra M. Shekokar

    2014-01-01

    Mobile Ad-hoc Networks (MANET) are wireless mobile nodes that communicate without any predefined infrastructure. This allows MANETs to be easily setup in geographical and terrestrial constraints. To achieve this kind of communication MANET routing protocols play an important role. Two routing protocols, DSR and AODV are studied in detail. This basic trait of a MANET makes its routing protocols very vulnerable to security attacks. One such attack is the ‘Sinkhole’ attack which ...

  13. Comparison of MANET Routing Protocols in Different Traffic and Mobility Models

    Directory of Open Access Journals (Sweden)

    J. Baraković

    2010-06-01

    Full Text Available Routing protocol election in MANET (Mobile Ad Hoc Network is a great challenge, because of its frequent topology changes and routing overhead. This paper compares performances of three routing protocols: Destination Sequenced Distance Vector (DSDV, Ad Hoc Ondemand Distance Vector (AODV and Dynamic Source Routing (DSR, based on results analysis obtained using simulations with different load and mobility scenarios performed with Network Simulator version 2 (NS-2. In low load and low mobility scenarios routing protocols perform in a similar manner. However, with mobility and load increasing DSR outperforms AODV and DSDV protocols.

  14. An improved AODV routing protocol based on tower structure

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    Li Yong Qiang

    2016-01-01

    Full Text Available The paper proposed a new routing protocol(IAODV based on tower structure in the Ad Hoc network for the problem which Location Routing Protocol need hardware and Complex algorithm. By the simulation, The complexity of the new routing protocol is reduced without reducing the performance of the network.

  15. Management of Energy Consumption on Cluster Based Routing Protocol for MANET

    Science.gov (United States)

    Hosseini-Seno, Seyed-Amin; Wan, Tat-Chee; Budiarto, Rahmat; Yamada, Masashi

    The usage of light-weight mobile devices is increasing rapidly, leading to demand for more telecommunication services. Consequently, mobile ad hoc networks and their applications have become feasible with the proliferation of light-weight mobile devices. Many protocols have been developed to handle service discovery and routing in ad hoc networks. However, the majority of them did not consider one critical aspect of this type of network, which is the limited of available energy in each node. Cluster Based Routing Protocol (CBRP) is a robust/scalable routing protocol for Mobile Ad hoc Networks (MANETs) and superior to existing protocols such as Ad hoc On-demand Distance Vector (AODV) in terms of throughput and overhead. Therefore, based on this strength, methods to increase the efficiency of energy usage are incorporated into CBRP in this work. In order to increase the stability (in term of life-time) of the network and to decrease the energy consumption of inter-cluster gateway nodes, an Enhanced Gateway Cluster Based Routing Protocol (EGCBRP) is proposed. Three methods have been introduced by EGCBRP as enhancements to the CBRP: improving the election of cluster Heads (CHs) in CBRP which is based on the maximum available energy level, implementing load balancing for inter-cluster traffic using multiple gateways, and implementing sleep state for gateway nodes to further save the energy. Furthermore, we propose an Energy Efficient Cluster Based Routing Protocol (EECBRP) which extends the EGCBRP sleep state concept into all idle member nodes, excluding the active nodes in all clusters. The experiment results show that the EGCBRP decreases the overall energy consumption of the gateway nodes up to 10% and the EECBRP reduces the energy consumption of the member nodes up to 60%, both of which in turn contribute to stabilizing the network.

  16. Implementation of CAVENET and Its Usage for Performance Evaluation of AODV, OLSR and DYMO Protocols in Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Evjola Spaho

    2010-01-01

    Full Text Available Vehicle Ad-hoc Network (VANET is a kind of Mobile Ad-hoc Network (MANET that establishes wireless connection between cars. In VANETs and MANETs, the topology of the network changes very often, therefore implementation of efficient routing protocols is very important problem. In MANETs, the Random Waypoint (RW model is used as a simulation model for generating node mobility pattern. On the other hand, in VANETs, the mobility patterns of nodes is restricted along the roads, and is affected by the movement of neighbour nodes. In this paper, we present a simulation system for VANET called CAVENET (Cellular Automaton based VEhicular NETwork. In CAVENET, the mobility patterns of nodes are generated by an 1-dimensional cellular automata. We improved CAVENET and implemented some routing protocols. We investigated the performance of the implemented routing protocols by CAVENET. The simulation results have shown that DYMO protocol has better performance than AODV and OLSR protocols.

  17. Enhanced Secure Trusted AODV (ESTA Protocol to Mitigate Blackhole Attack in Mobile Ad Hoc Networks

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    Dilraj Singh

    2015-09-01

    Full Text Available The self-organizing nature of the Mobile Ad hoc Networks (MANETs provide a communication channel anywhere, anytime without any pre-existing network infrastructure. However, it is exposed to various vulnerabilities that may be exploited by the malicious nodes. One such malicious behavior is introduced by blackhole nodes, which can be easily introduced in the network and, in turn, such nodes try to crumble the working of the network by dropping the maximum data under transmission. In this paper, a new protocol is proposed which is based on the widely used Ad hoc On-Demand Distance Vector (AODV protocol, Enhanced Secure Trusted AODV (ESTA, which makes use of multiple paths along with use of trust and asymmetric cryptography to ensure data security. The results, based on NS-3 simulation, reveal that the proposed protocol is effectively able to counter the blackhole nodes in three different scenarios.

  18. SECURE SERVICE DISCOVERY BASED ON PROBE PACKET MECHANISM FOR MANETS

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    S. Pariselvam

    2015-03-01

    Full Text Available In MANETs, Service discovery process is always considered to be crucial since they do not possess a centralized infrastructure for communication. Moreover, different services available through the network necessitate varying categories. Hence, a need arises for devising a secure probe based service discovery mechanism to reduce the complexity in providing the services to the network users. In this paper, we propose a Secure Service Discovery Based on Probe Packet Mechanism (SSDPPM for identifying the DoS attack in MANETs, which depicts a new approach for estimating the level of trust present in each and every routing path of a mobile ad hoc network by using probe packets. Probing based service discovery mechanisms mainly identifies a mobile node’s genuineness using a test packet called probe that travels the entire network for the sake of computing the degree of trust maintained between the mobile nodes and it’s attributed impact towards the network performance. The performance of SSDPPM is investigated through a wide range of network related parameters like packet delivery, throughput, Control overhead and total overhead using the version ns-2.26 network simulator. This mechanism SSDPPM, improves the performance of the network in an average by 23% and 19% in terms of packet delivery ratio and throughput than the existing service discovery mechanisms available in the literature.

  19. Intelligent QoS routing algorithm based on improved AODV protocol for Ad Hoc networks

    Science.gov (United States)

    Huibin, Liu; Jun, Zhang

    2016-04-01

    Mobile Ad Hoc Networks were playing an increasingly important part in disaster reliefs, military battlefields and scientific explorations. However, networks routing difficulties are more and more outstanding due to inherent structures. This paper proposed an improved cuckoo searching-based Ad hoc On-Demand Distance Vector Routing protocol (CSAODV). It elaborately designs the calculation methods of optimal routing algorithm used by protocol and transmission mechanism of communication-package. In calculation of optimal routing algorithm by CS Algorithm, by increasing QoS constraint, the found optimal routing algorithm can conform to the requirements of specified bandwidth and time delay, and a certain balance can be obtained among computation spending, bandwidth and time delay. Take advantage of NS2 simulation software to take performance test on protocol in three circumstances and validate the feasibility and validity of CSAODV protocol. In results, CSAODV routing protocol is more adapt to the change of network topological structure than AODV protocol, which improves package delivery fraction of protocol effectively, reduce the transmission time delay of network, reduce the extra burden to network brought by controlling information, and improve the routing efficiency of network.

  20. A New MANET Wormhole Detection Algorithm Based on Traversal Time and Hop Count Analysis

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    Göran Pulkkis

    2011-11-01

    Full Text Available As demand increases for ubiquitous network facilities, infrastructure-less and self-configuring systems like Mobile Ad hoc Networks (MANET are gaining popularity. MANET routing security however, is one of the most significant challenges to wide scale adoption, with wormhole attacks being an especially severe MANET routing threat. This is because wormholes are able to disrupt a major component of network traffic, while concomitantly being extremely difficult to detect. This paper introduces a new wormhole detection paradigm based upon Traversal Time and Hop Count Analysis (TTHCA, which in comparison to existing algorithms, consistently affords superior detection performance, allied with low false positive rates for all wormhole variants. Simulation results confirm that the TTHCA model exhibits robust wormhole route detection in various network scenarios, while incurring only a small network overhead. This feature makes TTHCA an attractive choice for MANET environments which generally comprise devices, such as wireless sensors, which possess a limited processing capability.

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

    Science.gov (United States)

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

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

  2. An Enhanced Hybrid Social Based Routing Algorithm for MANET-DTN

    Directory of Open Access Journals (Sweden)

    Martin Matis

    2016-01-01

    Full Text Available A new routing algorithm for mobile ad hoc networks is proposed in this paper: an Enhanced Hybrid Social Based Routing (HSBR algorithm for MANET-DTN as optimal solution for well-connected multihop mobile networks (MANET and/or worse connected MANET with small density of the nodes and/or due to mobility fragmented MANET into two or more subnetworks or islands. This proposed HSBR algorithm is fully decentralized combining main features of both Dynamic Source Routing (DSR and Social Based Opportunistic Routing (SBOR algorithms. The proposed scheme is simulated and evaluated by replaying real life traces which exhibit this highly dynamic topology. Evaluation of new proposed HSBR algorithm was made by comparison with DSR and SBOR. All methods were simulated with different levels of velocity. The results show that HSBR has the highest success of packet delivery, but with higher delay in comparison with DSR, and much lower in comparison with SBOR. Simulation results indicate that HSBR approach can be applicable in networks, where MANET or DTN solutions are separately useless or ineffective. This method provides delivery of the message in every possible situation in areas without infrastructure and can be used as backup method for disaster situation when infrastructure is destroyed.

  3. Trust Based Algorithm for Candidate Node Selection in Hybrid MANET-DTN

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    Jan Papaj

    2014-01-01

    Full Text Available The hybrid MANET - DTN is a mobile network that enables transport of the data between groups of the disconnected mobile nodes. The network provides benefits of the Mobile Ad-Hoc Networks (MANET and Delay Tolerant Network (DTN. The main problem of the MANET occurs if the communication path is broken or disconnected for some short time period. On the other side, DTN allows sending data in the disconnected environment with respect to higher tolerance to delay. Hybrid MANET - DTN provides optimal solution for emergency situation in order to transport information. Moreover, the security is the critical factor because the data are transported by mobile devices. In this paper, we investigate the issue of secure candidate node selection for transportation of the data in a disconnected environment for hybrid MANET- DTN. To achieve the secure selection of the reliable mobile nodes, the trust algorithm is introduced. The algorithm enables select reliable nodes based on collecting routing information. This algorithm is implemented to the simulator OPNET modeler.

  4. Mobility-Aware and Load Balancing Based Clustering Algorithm for Energy Conservation in MANET

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHENG Bao-yu; GUO Gong-de

    2005-01-01

    Mobile ad hoc network (MANET) is one of wireless communication network architecture that has received a lot of attention. MANET is characterized by dynamic network topology and limited energy. With mobility-aware and load balancing based clustering algorithm (MLCA), this paper proposes a new topology management strategy to conserve energy. Performance simulation results show that the proposed MLCA strategy can balances the traffic load inside the whole network, so as to prolong the network lifetime, meanly, at the same time, achieve higher throughput ratio and network stability.

  5. Detecting and Mitigating Smart Insider Jamming Attacks in MANETs Using Reputation-Based Coalition Game

    Directory of Open Access Journals (Sweden)

    Ashraf Al Sharah

    2016-01-01

    Full Text Available Security in mobile ad hoc networks (MANETs is challenging due to the ability of adversaries to gather necessary intelligence to launch insider jamming attacks. The solutions to prevent external attacks on MANET are not applicable for defense against insider jamming attacks. There is a need for a formal framework to characterize the information required by adversaries to launch insider jamming attacks. In this paper, we propose a novel reputation-based coalition game in MANETs to detect and mitigate insider jamming attacks. Since there is no centralized controller in MANETs, the nodes rely heavily on availability of transmission rates and a reputation for each individual node in the coalition to detect the presence of internal jamming node. The nodes will form a stable grand coalition in order to make a strategic security defense decision, maintain the grand coalition based on node reputation, and exclude any malicious node based on reputation value. Simulation results show that our approach provides a framework to quantify information needed by adversaries to launch insider attacks. The proposed approach will improve MANET’s defense against insider attacks, while also reducing incorrect classification of legitimate nodes as jammers.

  6. Signcryption-Based Key Management for MANETs Applications in Mobile Commerce

    Institute of Scientific and Technical Information of China (English)

    LI Jingfeng; ZHU Yuefei; ZHANG Yajuan; PAN Heng

    2006-01-01

    Mobile commerce uses wireless device and wireless link to result in the transfer of values in exchange of information, services or goods. Wireless mobile ad hoc networks (MANETs) will bring a revolution to the business model of mobile commerce if such networks are used as the underlying network technology for mobile commerce. Mobile commerce will remain in a niche market until the security issue is properly addressed. Hence, security is also very important for MANET applications in mobile commerce. Robust key management is one of the most crucial technologies for security of MANETs. In this paper, a new solution for key management is proposed using identity-based (ID-based) signcryption and threshold secret sharing. It enables flexible and efficient key management while respecting the constraints of MANETs. In our solution, each mobile host uses its globally unique identity as its public key. It greatly decreases the computation and storage costs of mobile hosts, as well as communication cost for system key management.

  7. Fuzzy Based PC-PUSH in CR-MANETs

    Directory of Open Access Journals (Sweden)

    S. Nejatian

    2014-01-01

    Full Text Available In cognitive radio (CR, the secondary user (SU needs to hand off its ongoing communication to an idle channel in order to avoid interference to the primary user (PU. Spectrum hand off issue becomes challenging in CR mobile ad hoc networks (CR-MANETs because of the uncertainty in spectrum availability, broad range of spectrum bands and lack of central entity. The purpose of this study is to design a unified spectrum handoff (USH scheme for CR-MANETs that considers the spectrum heterogeneity and its availability over time and space. A local flow hand off is performed when spectrum hand off cannot be carried out due to the SUs mobility. To improve further USH, preemptive unified spectrum handoff (PUSH algorithm is proposed in which two different preemptive hand off threshold regions are defined. The PUSH algorithm also predicts the cognitive link availability considering the PU interference boundary. Although the PUSH scheme improves the hand off performance, the number of spectrum hand offs due to the PU activity should be reduced in this scheme. Therefore, the PC-PUSH (Power Controller-PUSH scheme is proposed in which the fuzzy logic is used to improve the PUSH in terms of the number of spectrum handoffs because of the PU activity. The PC-PUSH decreases the interference to the PUs, while reducing the number of spectrum handoffs. The results show that the proposed scheme improves the link maintenance probability, decreases the hand off delay, and reduces the number of spectrum handoffs.

  8. Improved AODV route recovery in mobile ad-hoc networks using a genetic algorithm

    Directory of Open Access Journals (Sweden)

    Ahmad Maleki

    2014-09-01

    Full Text Available An important issue in ad-hoc on-demand distance vector (AODV routing protocols is route failure caused by node mobility in the MANETs. The AODV requires a new route discovery procedure whenever a route breaks and these frequent route discoveries increase transmission delays and routing overhead. The present study proposes a new method for AODVs using a genetic algorithm to improve the route recovery mechanism. When failure occurs in a route, the proposed method (GAAODV makes decisions regarding the QOS parameter to select source or local repair. The task of the genetic algorithm is to find an appropriate combination of weights to optimize end-to-end delay. This paper evaluates the metrics of routing overhead, average end-to-end delay, and packet delivery ratio. Comparison of the new algorithm and AODV (RFC 3561 using a NS-2 simulator shows that GAAODV obtains better results for the QOS parameters.

  9. A Good IDS Response Protocol of MANET Containment Strategies

    Science.gov (United States)

    Cheng, Bo-Chao; Chen, Huan; Tseng, Ryh-Yuh

    Much recent research concentrates on designing an Intrusion Detection System (IDS) to detect the misbehaviors of the malicious node in MANET with ad-hoc and mobility natures. However, without rapid and appropriate IDS response mechanisms performing follow-up management services, even the best IDS cannot achieve the desired primary goal of the incident response. A competent containment strategy is needed to limit the extent of an attack in the Incident Response Life Cycle. Inspired by the T-cell mechanisms in the human immune system, we propose an efficient MANET IDS response protocol (T-SecAODV) that can rapidly and accurately disseminate alerts of the malicious node attacks to other nodes so as to modify their AODV routing tables to isolate the malicious nodes. Simulations are conducted by the network simulator (Qualnet), and the experiment results indicate that T-SecAODV is able to spread alerts steadily while greatly reduce faulty rumors under simultaneous multiple malicious node attacks.

  10. A Dynamic Probabilistic Based Broadcasting Scheme for MANETs

    Science.gov (United States)

    Shanmugam, Kannan; Subburathinam, Karthik; Velayuthampalayam Palanisamy, Arunachalam

    2016-01-01

    MANET is commonly known as Mobile Ad Hoc Network in which cluster of mobile nodes can communicate with each other without having any basic infrastructure. The basic characteristic of MANET is dynamic topology. Due to the dynamic behavior nature, the topology of the network changes very frequently, and this will lead to the failure of the valid route repeatedly. Thus, the process of finding the valid route leads to notable drop in the throughput of the network. To identify a new valid path to the targeted mobile node, available proactive routing protocols use simple broadcasting method known as simple flooding. The simple flooding method broadcasts the RREQ packet from the source to the rest of the nodes in mobile network. But the problem with this method is disproportionate repetitive retransmission of RREQ packet which could result in high contention on the available channel and packet collision due to extreme traffic in the network. A reasonable number of routing algorithms have been suggested for reducing the lethal impact of flooding the RREQ packets. However, most of the algorithms have resulted in considerable amount of complexity and deduce the throughput by depending on special hardware components and maintaining complex information which will be less frequently used. By considering routing complexity with the goal of increasing the throughput of the network, in this paper, we have introduced a new approach called Dynamic Probabilistic Route (DPR) discovery. The Node's Forwarding Probability (NFP) is dynamically calculated by the DPR mobile nodes using Probability Function (PF) which depends on density of local neighbor nodes and the cumulative number of its broadcast covered neighbors. PMID:27019868

  11. Power Management Based Grid Routing Protocol for IEEE 802.11 Based MANET

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHENG Bao-yu; YANG Zhen

    2004-01-01

    MANET ( Mobile Ad Hoc Network ) is a collection of wireless mobile nodes forming a temporary communication network without the aid of any established infrastructure or centralized administration. The lifetime of a MANET depends on the battery resources of the mobile nodes. So energy consumption may one of important design criterions for MANET. With changing the idle model to sleep model in the grid environment, this paper proposes a new energy-aware routing protocol. Performance simulation results show that the proposed strategy can dynamic balance the traffic load inside the whole network, extend the lifetime of a MANET, and without decreasing the throughput ratio.

  12. Energy efficient security in MANETs: a comparison of cryptographic and artificial immune systems

    International Nuclear Information System (INIS)

    Mazhar, N.

    2010-01-01

    MANET is characterized by a set of mobile nodes in an inherently insecure environment, having limited battery capacities. Provisioning of energy efficient security in MANETs is, therefore, an open problem for which a number of solutions have been proposed. In this paper, we present an overview and comparison of the MANET security at routing layer by using the cryptographic and Artificial Immune System (AIS) approaches. The BeeAdHoc protocol, which is a Bio-inspired MANET routing protocol based on the foraging principles of honey bee colony, is taken as case study. We carry out an analysis of the three security frameworks that we have proposed earlier for securing BeeAdHoc protocol; one based on asymmetric key encryption, i.e BeeSec, and the other two using the AIS approach, i.e BeeAIS based on self non-self discrimination from adaptive immune system and BeeAIS-DC based on Dendritic Cell (DC) behavior from innate immune system. We extensively evaluate the performance of the three protocols through network simulations in ns-2 and compare with BeeAdHoc, the base protocol, as well as with state-of-the-art MANET routing protocols DSR and AODV. Our results clearly indicate that AIS based systems provide security at much lower cost to energy as compared with the cryptographic systems. Moreover, the use of dendritic cells and danger signals instead of the classical self non-self discrimination allows to detect the non-self antigens with greater accuracy. Based on the results of this investigation, we also propose a composite AIS model for BeeAdHoc security by combining the concepts from both the adaptive and the innate immune systems by modelling the attributes and behavior of the B-cells and DCs. (author)

  13. Energy Reduction Multipath Routing Protocol for MANET Using Recoil Technique

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Sahu

    2018-04-01

    Full Text Available In Mobile Ad-hoc networks (MANET, power conservation and utilization is an acute problem and has received significant attention from academics and industry in recent years. Nodes in MANET function on battery power, which is a rare and limited energy resource. Hence, its conservation and utilization should be done judiciously for the effective functioning of the network. In this paper, a novel protocol namely Energy Reduction Multipath Routing Protocol for MANET using Recoil Technique (AOMDV-ER is proposed, which conserves the energy along with optimal network lifetime, routing overhead, packet delivery ratio and throughput. It performs better than any other AODV based algorithms, as in AOMDV-ER the nodes transmit packets to their destination smartly by using a varying recoil off time technique based on their geographical location. This concept reduces the number of transmissions, which results in the improvement of network lifetime. In addition, the local level route maintenance reduces the additional routing overhead. Lastly, the prediction based link lifetime of each node is estimated which helps in reducing the packet loss in the network. This protocol has three subparts: an optimal route discovery algorithm amalgamation with the residual energy and distance mechanism; a coordinated recoiled nodes algorithm which eliminates the number of transmissions in order to reduces the data redundancy, traffic redundant, routing overhead, end to end delay and enhance the network lifetime; and a last link reckoning and route maintenance algorithm to improve the packet delivery ratio and link stability in the network. The experimental results show that the AOMDV-ER protocol save at least 16% energy consumption, 12% reduction in routing overhead, significant achievement in network lifetime and packet delivery ratio than Ad hoc on demand multipath distance vector routing protocol (AOMDV, Ad hoc on demand multipath distance vector routing protocol life

  14. A Cross-Layer, Anomaly-Based IDS for WSN and MANET.

    Science.gov (United States)

    Amouri, Amar; Morgera, Salvatore D; Bencherif, Mohamed A; Manthena, Raju

    2018-02-22

    Intrusion detection system (IDS) design for mobile adhoc networks (MANET) is a crucial component for maintaining the integrity of the network. The need for rapid deployment of IDS capability with minimal data availability for training and testing is an important requirement of such systems, especially for MANETs deployed in highly dynamic scenarios, such as battlefields. This work proposes a two-level detection scheme for detecting malicious nodes in MANETs. The first level deploys dedicated sniffers working in promiscuous mode. Each sniffer utilizes a decision-tree-based classifier that generates quantities which we refer to as correctly classified instances (CCIs) every reporting time. In the second level, the CCIs are sent to an algorithmically run supernode that calculates quantities, which we refer to as the accumulated measure of fluctuation (AMoF) of the received CCIs for each node under test (NUT). A key concept that is used in this work is that the variability of the smaller size population which represents the number of malicious nodes in the network is greater than the variance of the larger size population which represents the number of normal nodes in the network. A linear regression process is then performed in parallel with the calculation of the AMoF for fitting purposes and to set a proper threshold based on the slope of the fitted lines. As a result, the malicious nodes are efficiently and effectively separated from the normal nodes. The proposed scheme is tested for various node velocities and power levels and shows promising detection performance even at low-power levels. The results presented also apply to wireless sensor networks (WSN) and represent a novel IDS scheme for such networks.

  15. Effective ANT based Routing Algorithm for Data Replication in MANETs

    Directory of Open Access Journals (Sweden)

    N.J. Nithya Nandhini

    2013-12-01

    Full Text Available In mobile ad hoc network, the nodes often move and keep on change its topology. Data packets can be forwarded from one node to another on demand. To increase the data accessibility data are replicated at nodes and made as sharable to other nodes. Assuming that all mobile host cooperative to share their memory and allow forwarding the data packets. But in reality, all nodes do not share the resources for the benefits of others. These nodes may act selfishly to share memory and to forward the data packets. This paper focuses on selfishness of mobile nodes in replica allocation and routing protocol based on Ant colony algorithm to improve the efficiency. The Ant colony algorithm is used to reduce the overhead in the mobile network, so that it is more efficient to access the data than with other routing protocols. This result shows the efficiency of ant based routing algorithm in the replication allocation.

  16. ZONE BASED PATH ROUTING APPROACH FOR THE DETECTION AND PREVENTION OF MALICIOUS BEHAVIOUR OF THE NODE IN MANET

    Directory of Open Access Journals (Sweden)

    Akansha Shrivastava

    2016-09-01

    Full Text Available Mobile Ad-hoc Network (MANET is one of the important research areas. MANET is a cluster of movable nodes that communicate without any wired connection. It refers to a network of moving nodes communicating with other mobile nodes in a multi-hop fashion. Mobile nodes provide flexibility to this network. Thus this flexible network is prone to a variety of attacks. Wormhole attack is a major threat to this network. In this attack, a tunnel is created between two nodes. These nodes transmit all communication through this tunnel. Detecting such attack is a major task. This paper presents a zone-based approach that detects and prevents such attack.

  17. RSRP: A Robust Secure Routing Protocol in MANET

    Directory of Open Access Journals (Sweden)

    Sinha Ditipriya

    2014-05-01

    Full Text Available In this paper, we propose a novel algorithm RSRP to build a robust secure routing protocol in mobile ad-hoc networks (MANETs. This algorithm is based on some basic schemes such as RSA_CRT for encryption and decryption of messages; CRT for safety key generation, Shamir’s secret sharing principle for generation of secure routes. Those routes which are free from any malicious node and which belong to the set of disjoint routes between a source-destination pair are considered as probable routes. Shamir’s secret sharing principle is applied on those probable routes to obtain secure routes. Finally, most trustworthy and stable route is selected among those secure routes. Selection of the final route depends on some criteria of the nodes present in a route e.g.: battery power, mobility and trust value. In addition, complexity of key generation is reduced to a large extent by using RSA-CRT instead of RSA. In turn, the routing becomes less expensive and most secure and robust one. Performance of this routing protocol is then compared with non-secure routing protocols (AODV and DSR, secure routing scheme using secret sharing, security routing protocol using ZRP and SEAD depending on basic characteristics of these protocols. All such comparisons show that RSRP shows better performance in terms of computational cost, end-to-end delay and packet dropping in presence of malicious nodes in the MANET, keeping the overhead in terms of control packets same as other secure routing protocols.

  18. Exponential Reliability Coefficient based Reputation Mechanism for isolating selfish nodes in MANETs

    Directory of Open Access Journals (Sweden)

    J. Sengathir

    2015-07-01

    Full Text Available In mobile ad hoc networks, cooperation among active mobile nodes is considered to play a vital role in reliable transmission of data. But, the selfish mobile nodes present in an ad hoc environment refuse to forward neighbouring nodes’ packet for conserving its own energy. This intentional selfish behaviour drastically reduces the degree of cooperation maintained between the mobile nodes. Hence, a need arises for devising an effective mechanism which incorporates both energy efficiency and reputation into account for mitigating selfish behaviour in MANETs. In this paper, we propose an Exponential Reliability Coefficient based reputation Mechanism (ERCRM which isolates the selfish nodes from the routing path based on Exponential Reliability Coefficient (ExRC. This reliability coefficient manipulated through exponential failure rate based on moving average method highlights the most recent past behaviour of the mobile nodes for quantifying its genuineness. From the simulation results, it is evident that, the proposed ERCRM approach outperforms the existing Packet Conservation Monitoring Algorithm (PCMA and Spilt Half Reliability Coefficient based Mathematical Model (SHRCM in terms of performance evaluation metrics such as packet delivery ratio, throughput, total overhead and control overhead. Further, this ERCRM mechanism has a successful rate of 28% in isolating the selfish nodes from the routing path. Furthermore, it also aids in framing the exponential threshold point of detection as 0.4, where a maximum number of selfish nodes are identified when compared to the existing models available in the literature.

  19. Performance Evaluation of AODV, DSR, DYMO & ZRP in Cost 231 Walfisch-Ikegami Path Loss Propagation Model

    Directory of Open Access Journals (Sweden)

    Rachit JAIN

    2011-07-01

    Full Text Available A Mobile Ad hoc NETwork is a kind of wireless ad-hoc network, and is a self configuring network of mobile routers connected by wireless links. Mobile Ad-Hoc Network (MANET is a wireless network without infrastructure. Self configurability and easy deployment feature of the MANET resulted in numerous applications in this modern era. Efficient routing protocols will make MANETs reliable. Various research communities are working in field of MANET and trying to adopt the protocols and technology in other applications as well. In this work, we present investigations on the behavior of various routing protocol of MANET with a Cost 231 Walfisch-Ikegami Propagation Model. We evaluate the performance of four different ad-hoc routing protocols on four performance metrics such as Average Jitter, Average End-to-End Delay, Throughput, and Packet Delivery Fraction with varying Pause Time. From the simulation results it is concluded that DSR is better in transmission of packets per unit time and maximum number of packets reached their destination successfully with some delays, i.e. PDF & Throughput is more and Average jitter & end-to-end delay is less. Whereas AODV & ZRP having almost same values in all of the performance metrics, they transmit packets with very less delay but transmits less packets to their destination as compare to DSR

  20. Effect of variation in active route timeout and my route timeout on the performance of AODV-ETX protocol in mobile adhoc network

    Science.gov (United States)

    Purnomo, A.; Widyawan; Najib, W.; Hartono, R.; Hartatik

    2018-03-01

    Mobile adhoc network (MANET) consists of nodes that are independent. A node can communicate each other without the presence of network infrastructure. A node can act as a transmitter and receiver as well as a router. This research has been variation in active route timeout and my route timeout on the performance of AODV-ETX protocol in MANET. The AODV-ETX protocol is the AODV protocol that uses the ETX metric. Performance testing is done on the static node topology with 5 m x 5 m node grid model where the distance between nodes is 100 m and node topology that consists of 25 nodes moves randomly with a moving speed of 1.38 m/s in an area of 1500 m x 300 m. From the test result, on the static node, AODV protocol-ETX shows optimal performance at a value MRT and ART of 10 s and 15 s, but showed a stable performance in the value of MRT and ART ≥60 s, while in randomly moved node topology shows stable performance in the value of MRT and ART ≥80 s.

  1. Performance Evaluation of AODV Routing Protocol in VANET with NS2

    Directory of Open Access Journals (Sweden)

    Divya Rathi

    2017-03-01

    Full Text Available In intelligent transportation systems, the collaboration between vehicles and the road side units is essential to bring these systems to realization. The emerging Vehicular Ad Hoc Network (VANET is becoming more and more important as it provides intelligent transportation application, comfort, safety, entertainment for people in vehicles. In order to provide stable routes and to get good performance in VANET, there is a need of proper routing protocols must be designed. In this paper, we are working with the very well-known ad-hoc on-demand distance vector (AODV routing protocol. The existing Routing protocol AODV-L which is based on the Link expiration time is extended to propose a more reliable AODV-AD which is based on multichannel MAC protocol. For the performance evaluation of routing protocols, a simulation tool ‘NS2’ has been used. Simulation results show that the proposed AODV-AD protocol can achieves better performances in forms of high Route stability, Packet Delivery ratio and packet loss rate than traditional AODV-L and traditional AODV.

  2. MQARR-AODV: A NOVEL MULTIPATH QOS AWARE RELIABLE REVERSE ON-DEMAND DISTANCE VECTOR ROUTING PROTOCOL FOR MOBILE AD-HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    K.G. Santhiya

    2012-12-01

    Full Text Available MANET (Mobile Ad-hoc Network is an infra structure less wireless ad-hoc network that does not require any basic central control. The topology of the network changes drastically due to very fast mobility of nodes. So an adaptive routing protocol is needed for routing in MANET. AODV (Ad-hoc On-demand Distance Vector routing is the effective and prominent on-demand Ad-hoc routing protocols. During route establishment phase in traditional AODV, only one route reply message will be sent in the reverse path to establish routing path. The high mobility of nodes may affect the reply messages which lead to the retransmission of route request message by the sender which in turn leads to higher communication delay, power consumption and the reduction in the ratio of packets delivered. Sending multiple route reply messages and establishing multiple paths in a single path discovery will reduce the routing overhead involved in maintaining the connection between source and destination nodes. Multipath routing can render high scalability, end-to-end throughput and provide load balancing in MANET. The new proposed novel Multipath QoS aware reliable routing protocol establishes two routes of maximum node disjoint paths and the data transfer is carried out in the two paths simultaneously. To select best paths, the new proposed protocol uses three parameters Link Eminence, MAC overhead and node residual energy. The experimental values prove that the MQARR-AODV protocol achieves high reliability, stability, low latency and outperforms AODV by the less energy consumption, overhead and delay.

  3. Real-world Bluetooth MANET Java Middleware

    DEFF Research Database (Denmark)

    Glenstrup, Arne John; Nielsen, Michael; Skytte, Frederik

    We present BEDnet, a Java based middleware for creating and maintaining a Bluetooth based mobile ad-hoc network (MANET). MANETs are key to nomadic computing: Mobile units can set up spontaneous local networks when needed, removing the need for fixed network infrastructure, either as wireless access....... Based on the Java JSR-82 specification, BEDnet is portable to a wide selection of mobile phones, and is publicly available as open source software. Experiments show that e.g. media streaming over Bluetooth is feasible, and that BEDnet is able to set up a scatternet within a couple of minutes...

  4. Protocolo W2LAN para transformar una red móvil 802.11 Ad-Hoc (MANET) en una LAN Ethernet

    OpenAIRE

    Burrull I Mestres, Francesco; García Haro, Juan; Malgosa Sanahuja, José María; Monzó Sánchez, Francisco Miguel

    2005-01-01

    Las redes MANET (Mobile Ad-Hoc Network) presentan el problema de la visibilidad parcial [1], por lo que hay que considerar protocolos de encaminamiento de nivel de enlace (capa 2 OSI) o superior. Algunos ejemplos de protocolos de encaminamiento en uso podrían ser el protocolo AODV (Ad Hoc On-demand Distance Vector[2]) -reactivo- y DSDV (Destination-Sequenced Distance Vector [3]) -proactivo-. En [4] se puede encontrar una comparativa extensa sobre protocolos de encaminamiento en redes MANET, o...

  5. SIP Signaling Implementations and Performance Enhancement over MANET: A Survey

    OpenAIRE

    Alshamrani, M; Cruickshank, Haitham; Sun, Zhili; Ansa, G; Alshahwan, F

    2016-01-01

    The implementation of the Session Initiation Protocol (SIP)-based Voice over Internet Protocol (VoIP) and multimedia over MANET is still a challenging issue. Many routing factors affect the performance of SIP signaling and the voice Quality of Service (QoS). Node mobility in MANET causes dynamic changes to route calculations, topology, hop numbers, and the connectivity status between the correspondent nodes. SIP-based VoIP depends on the caller’s registration, call initiation, and call termin...

  6. On the Performance of the Current MANET Routing Protocols for VoIP, HTTP, and FTP Applications

    Directory of Open Access Journals (Sweden)

    Waheb A. Jabbar

    2014-01-01

    Full Text Available The recent advances of ensemble mobile environment of smart devices with embedded sensors have enabled the MANET to play a key role in the smart cities as well as WSN and WMN. However, these smart devices are still limited in terms of energy, processor, and memory. Moreover, the efficient routing for reliable network connectivity at anytime, anywhere, and about everything is still a challenge in multihop wireless networks. This paper evaluates the QoS and energy efficiency of three active routing protocols: (i OLSRv2, a successor to OLSR, (ii DYMO, a successor to both DSR and AODV, and (iii MP-OLSR multipath extension to OLSRv2. In contrast to the related previous works which focused only on CBR traffic without considering the influence of specific traffic types on the performance of routing protocols, this work focused on this area from a different perspective. It evaluates the performance of three internet-based traffic types that can be used in the smart city applications: VoIP, HTTP, and FTP using different simulation models. The impact of the network density, load traffic, and nodes mobility on the considered protocols was evaluated by considering particular performance metrics for each traffic application. Based on the results, the study concludes by presenting useful recommendations for future work.

  7. A ROBUST CLUSTER HEAD SELECTION BASED ON NEIGHBORHOOD CONTRIBUTION AND AVERAGE MINIMUM POWER FOR MANETs

    Directory of Open Access Journals (Sweden)

    S.Balaji

    2015-06-01

    Full Text Available Mobile Adhoc network is an instantaneous wireless network that is dynamic in nature. It supports single hop and multihop communication. In this infrastructure less network, clustering is a significant model to maintain the topology of the network. The clustering process includes different phases like cluster formation, cluster head selection, cluster maintenance. Choosing cluster head is important as the stability of the network depends on well-organized and resourceful cluster head. When the node has increased number of neighbors it can act as a link between the neighbor nodes which in further reduces the number of hops in multihop communication. Promisingly the node with more number of neighbors should also be available with enough energy to provide stability in the network. Hence these aspects demand the focus. In weight based cluster head selection, closeness and average minimum power required is considered for purging the ineligible nodes. The optimal set of nodes selected after purging will compete to become cluster head. The node with maximum weight selected as cluster head. Mathematical formulation is developed to show the proposed method provides optimum result. It is also suggested that weight factor in calculating the node weight should give precise importance to energy and node stability.

  8. Analysis of MANET Security, Architecture and Assessment

    OpenAIRE

    Sweta Kaushik; Manorma Kaushik

    2012-01-01

    in these days, the Mobile ad hoc network (MANET) technology spreads widely. Architecture and security issue is the most sensitive challenge of MANET. MANET support to nodes for directly communications with all the other nodes within their radio ranges through multiple wireless links, where the nodes are not in the direct communication range using intermediate node(s) to communicate with each other. In a MANET, the users’ mobile devices behave as a network, and they must cooperatively provide ...

  9. CROSS LAYER COORDINATED ENERGY SAVING STRATEGY IN MANET

    Institute of Scientific and Technical Information of China (English)

    Xu Li; Zheng Baoyu

    2003-01-01

    Mobile Ad hoc NETwork (MANET) consists of a set of mobile hosts which can operate independently without infrastructure base stations. Energy saving is a critical issue for MANET since most mobile hosts will operate on battery powers. A cross layer coordinated framework for energy saving is proposed in this letter. On-demand power management, physical layer and medium access control layer dialogue based multi-packet reception, mobile agent based topology discovery and topology control based transmit power-aware and battery power-aware dynamic source routing are some of new ideas in this framework.

  10. OPTIMAL DATA REPLACEMENT TECHNIQUE FOR COOPERATIVE CACHING IN MANET

    Directory of Open Access Journals (Sweden)

    P. Kuppusamy

    2014-09-01

    Full Text Available A cooperative caching approach improves data accessibility and reduces query latency in Mobile Ad hoc Network (MANET. Maintaining the cache is challenging issue in large MANET due to mobility, cache size and power. The previous research works on caching primarily have dealt with LRU, LFU and LRU-MIN cache replacement algorithms that offered low query latency and greater data accessibility in sparse MANET. This paper proposes Memetic Algorithm (MA to locate the better replaceable data based on neighbours interest and fitness value of cached data to store the newly arrived data. This work also elects ideal CH using Meta heuristic search Ant Colony Optimization algorithm. The simulation results shown that proposed algorithm reduces the latency, control overhead and increases the packet delivery rate than existing approach by increasing nodes and speed respectively.

  11. When Reputation Enforces Evolutionary Cooperation in Unreliable MANETs.

    Science.gov (United States)

    Tang, Changbing; Li, Ang; Li, Xiang

    2015-10-01

    In self-organized mobile ad hoc networks (MANETs), network functions rely on cooperation of self-interested nodes, where a challenge is to enforce their mutual cooperation. In this paper, we study cooperative packet forwarding in a one-hop unreliable channel which results from loss of packets and noisy observation of transmissions. We propose an indirect reciprocity framework based on evolutionary game theory, and enforce cooperation of packet forwarding strategies in both structured and unstructured MANETs. Furthermore, we analyze the evolutionary dynamics of cooperative strategies and derive the threshold of benefit-to-cost ratio to guarantee the convergence of cooperation. The numerical simulations verify that the proposed evolutionary game theoretic solution enforces cooperation when the benefit-to-cost ratio of the altruistic exceeds the critical condition. In addition, the network throughput performance of our proposed strategy in structured MANETs is measured, which is in close agreement with that of the full cooperative strategy.

  12. Efficient Certification Path Discovery for MANET

    Directory of Open Access Journals (Sweden)

    Kambourakis Georgios

    2010-01-01

    Full Text Available A Mobile Ad Hoc Network (MANET is characterized by the lack of any infrastructure, absence of any kind of centralized administration, frequent mobility of nodes, network partitioning, and wireless connections. These properties make traditional wireline security solutions not straightforwardly applicable in MANETs, and of course, constitute the establishment of a Public Key Infrastructure (PKI in such networks a cumbersome task. After surveying related work, we propose a novel public key management scheme using the well-known web-of-trust or trust graph model. Our scheme is based on a binary tree formation of the network's nodes. The binary tree structure is proved very effective for building certificate chains between communicating nodes that are multihops away and the cumbersome problem of certificate chain discovery is avoided. We compare our scheme with related work and show that it presents several advantages, especially when a fair balancing between security and performance is desirable. Simulations of the proposed scheme under different scenarios demonstrate that it is effective in terms of tree formation, join and leave occurrences, and certificate chain establishment.

  13. Ad Hoc on-Demand Distance Vector (AODV Routing Protocol Performance Evaluation on Hybrid Ad Hoc Network: Comparison of Result of Ns-2 Simulation and Implementation on Testbed using PDA

    Directory of Open Access Journals (Sweden)

    Riri Sari

    2010-10-01

    Full Text Available In Mobile Ad hoc NETwork (MANET, node supplemented with wireless equipment has the capacity to manage and organise autonomously, without the presence of network infrastructures. Hybrid ad hoc network, enable several nodes to move freely (mobile to create instant communication. Independent from infrastructure. They could access the Local Area Network (LAN or the Internet. Functionalities of ad hoc network very much dependent on the routing protocol that determines the routing around node. Ad hoc On-demand Distance Vector (AODV is one of routing protocols in ad hoc network which has a reactive characteristic. This protocol is the most common protocol being researched and used. In this Research, AODV protocol investigation was conducted by developing a testbed using Personal Computer, several Laptops (the Linux Red Hat operation system 9.0 and Fedora Core 2, and Personal Digital Assistant (PDA. This research also made a complete package by mean of cross compilation for PDA iPAQ. In general, results obtained from the simulation of AODV protocol using Network Simulator NS-2 are packet delivery ratio 99.89%, end-to-end delay of 0.14 seconds and routing overhead of 1,756.61 byte per second. Afterwards results from simulation were compared to results from testbed. Results obtained from testbed are as follows: the packet delivery ratio is 99.57%, the end-to-end delay is 1.004 seconds and the routing overhead is 1,360.36 byte per second.

  14. Evaluación del retardo de los protocolos de ruteo reactivos para redes Manet

    Directory of Open Access Journals (Sweden)

    Matías Martínez

    2010-07-01

    Full Text Available Las redes inalámbricas han tenido un gran impacto en la industria y en los ámbitos académicos. Las MANETs (Mobile Ad-hoc NETwork agregan a las limitaciones de las redes inalámbricas características de movilidad, debido a esto, mantener la QoS (Quality of Service en este tipo de redes se hace imposible implementando los modelos tradicionales. Una característica importante que deben poseer los protocolos de ruteo para MANETs es que deben poder adaptarse rápidamente a lo cambios continuos de la red, con el fin de mantener las rutas entre los nodos que se están comunicando. Un protocolo de ruteo con capacidades de administrar las necesidades de QoS de las aplicaciones debería intentar establecer una ruta que satisficiese los requisitos de ancho de banda, retardo, jitter, etc. Inicialmente los protocolos reactivos serían más interesantes debido a su menor uso de recursos de red. En este trabajo se presentan resultados de simulaciones obtenidos con los protocolos bajo demanda AODV (Ad hoc On-Demand Distance Vector y DSR (Dynamic Source Routing. La elección se debe a que estos dos protocolos son los más conocidos dentro de los protocolos reactivos y son ampliamente utilizados como referencia para la comparación con las nuevas propuestas.

  15. Manet key management via Mobile Ficlke Key protocol (MFK ...

    African Journals Online (AJOL)

    Manet key management via Mobile Ficlke Key protocol (MFK) ... Journal of Fundamental and Applied Sciences. Journal Home · ABOUT THIS JOURNAL ... No Abstract. Keywords: MANET; key management scheme; simulation environment ...

  16. Collective Study On Security Threats In MANET

    Directory of Open Access Journals (Sweden)

    Muhammad Zunnurain Hussain

    2017-01-01

    Full Text Available In this paper the authors will be discussing the security issues in MANET amp the methods to protect it. Authors will be talk about related work in securing the network different type of attacks how to sense these sorts of attack what are the features of MANET then will be describing what the requirements for securing network are. Investigation had been done in past to maintain the network from attacks but due to the feature of MANET inappropriate infrastructure and due to the disperse network quality it is open to attack. Authors will be tackling the defence against each attack. Solution has been suggested So that the users can use proper authentication techniques and network resources can be properly utilized.

  17. A Multi-Hop Advertising Discovery and Delivering Protocol for Multi Administrative Domain MANET

    Directory of Open Access Journals (Sweden)

    Federico Mari

    2013-01-01

    Full Text Available A Mobile Ad-hoc NETwork (MANET is Multi Administrative Domain (MAD if each network node belongs to an independent authority, that is each node owns its resources and there is no central authority owning all network nodes. One of the main obstructions in designing Service Advertising, Discovery and Delivery (SADD protocol for MAD MANETs is the fact that, in an attempt to increase their own visibility, network nodes tend to flood the network with their advertisements. In this paper, we present a SADD protocol for MAD MANET, based on Bloom filters, that effectively prevents advertising floods due to such misbehaving nodes. Our results with the ns-2 simulator show that our SADD protocol is effective in counteracting advertising floods, it keeps low the collision rate as well as the energy consumption while ensuring that each peer receives all messages broadcasted by other peers.

  18. HARDWARE IMPLEMENTATION OF SECURE AODV FOR WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    S. Sharmila

    2010-12-01

    Full Text Available Wireless Sensor Networks are extremely vulnerable to any kind of routing attacks due to several factors such as wireless transmission and resource-constrained nodes. In this respect, securing the packets is of great importance when designing the infrastructure and protocols of sensor networks. This paper describes the hardware architecture of secure routing for wireless sensor networks. The routing path is selected using Ad-hoc on demand distance vector routing protocol (AODV. The data packets are converted into digest using hash functions. The functionality of the proposed method is modeled using Verilog HDL in MODELSIM simulator and the performance is compared with various target devices. The results show that the data packets are secured and defend against the routing attacks with minimum energy consumption.

  19. A recommender system for team formation in MANET

    Directory of Open Access Journals (Sweden)

    Waleed M. Al-Adrousy

    2015-04-01

    Full Text Available Mobile social networking is a new trend for social networking that enables users with similar interests to connect together through mobile devices. Therefore, it possesses the same features of a social network with added support to the features of a Mobile Ad-hoc Network (MANET in terms of limited computing power, limited coverage, and intermittent connectivity. One of the most important features in social networks is Team Formation. Team Formation aims to assemble a set of users with a set of skills required for a certain task. The team formation is a special type of recommendation which is important to enable cooperative work among users. Team formation is challenging since users’ interaction time is limited in MANET. The main objective of this paper is to introduce a peer-to-peer team formation technique based on zone routing protocol (ZRP. A comparison was made with Flooding and Adaptive Location Aided Mobile Ad Hoc Network Routing (ALARM techniques. The suggested technique achieves fast successful recommendations within the limited mobile resources and reduces exchanged messages. The suggested technique has fast response time, small required buffering and low power consumption. The testing results show better performance of the suggested technique compared to flooding and ALARM technique.

  20. : Manet's pictorial production : a forgetful recollection

    OpenAIRE

    Massonnaud , Dominique

    2000-01-01

    International audience; Manet's pictorial production is both a necessary step for the discourse about what is commonly called "modernity" -as well as the discourse coming from "modernity"-, and a blind spot for critical analysis: his work seems to be left out of, or buried under, contemporary commentaries that appear to miss the point of what they address. Baudelaire, Huysmans, Zola at the end of his life, or critics of that time that are now forgotten, all seem not to actually grasp the esse...

  1. Framework for developing realistic MANET simulations

    CSIR Research Space (South Africa)

    Burke, ID

    2010-04-01

    Full Text Available : Proceedings of the second ACM international workshop on Principles of mobile computing. Toulouse, France, 2002. ACM. Chin, K.-W., Judge, J., Williams, A. & Kermode, R., 2002. Implementation experience with MANET routing protocols. SIGCOMM Comput. Commun... & computing. Long Beach, CA, USA, 2001. ACM. Fall, K. & Varadhan, K., 2003. NS-Manual. [PDF] Available at: http://www.isi.edu/nsnam/ns/doc/ns_doc.pdf . Garrido, P.P., Malumbres, M.P. & Calafate, C.T., 2008. ns-2 vs. OPNET: a comparative study of the IEEE...

  2. Review paper of gateway selection schemes for MANET of NEMO (MANEMO)

    International Nuclear Information System (INIS)

    Mahmood, Z; Hashim, A; Khalifa, O; Anwar, F; Hameed, S

    2013-01-01

    The fast growth of Internet applications brings with it new challenges for researchers to provide new solutions that guarantee better Internet access for mobile hosts and networks. The globally reachable, Home-Agent based, infrastructure Network Mobility (NEMO) and the local, multi-hop, and infrastructure-less Mobile Ad hoc Network (MANET) developed by Internet Engineering Task Force (IETF) support different topologies of the mobile networks. A new architecture was proposed by combining both topologies to obtain Mobile Ad Hoc NEMO (MANEMO). However, the integration of NEMO and MANET introduces many challenges such as network loops, sub-optimal route, redundant tunnel problem, absence of communication without Home Agent reachability, and exit router selection when multiple Exit Routers to the Internet exist. This paper aims to review the different proposed models that could be used to implement the gateway selection mechanism and it highlights the strengths as well as the limitations of these approaches

  3. Sensors for Detection of Misbehaving Nodes in MANETs

    OpenAIRE

    Klenk, Andreas; Kragl, Frank; Schlott, Stefan; Weber, Michael

    2004-01-01

    The fact that security is a critical problem when implementing mobile ad hoc networks (MANETs) is widely acknowledged. One of the different kinds of misbehavior a node may exhibit is selfishness. A selfish node wants to preserve its resources while using the services of others and consuming their resources. One way of preventing selfishness in a MANET is a detection and exclusion mechanism. In this paper, we focus on the detection and present different kinds of sensors that wil...

  4. Integrating a Trust Framework with a Distributed Certificate Validation Scheme for MANETs

    Directory of Open Access Journals (Sweden)

    Marias Giannis F

    2006-01-01

    Full Text Available Many trust establishment solutions in mobile ad hoc networks (MANETs rely on public key certificates. Therefore, they should be accompanied by an efficient mechanism for certificate revocation and validation. Ad hoc distributed OCSP for trust (ADOPT is a lightweight, distributed, on-demand scheme based on cached OCSP responses, which provides certificate status information to the nodes of a MANET. In this paper we discuss the ADOPT scheme and issues on its deployment over MANETs. We present some possible threats to ADOPT and suggest the use of a trust assessment and establishment framework, named ad hoc trust framework (ATF, to support ADOPT's robustness and efficiency. ADOPT is deployed as a trust-aware application that provides feedback to ATF, which calculates the trustworthiness of the peer nodes' functions and helps ADOPT to improve its performance by rapidly locating valid certificate status information. Moreover, we introduce the TrustSpan algorithm to reduce the overhead that ATF produces, and the TrustPath algorithm to identify and use trusted routes for propagating sensitive information, such as third parties' accusations. Simulation results show that ATF adds limited overhead compared to its efficiency in detecting and isolating malicious and selfish nodes. ADOPT's reliability is increased, since it can rapidly locate a legitimate response by using information provided by ATF.

  5. Preventing the impact of selfish behavior under MANET using ...

    Indian Academy of Sciences (India)

    K Rama Abirami

    2018-04-13

    Apr 13, 2018 ... On Demand Distance Vector (AODV) routing protocol and an extensive analysis on the performance of the proposed .... flexible or adaptable to network dynamics. A secure ... change credit value, (v) did not pay attention to the fairness issue in .... the simulation, the wireless channel capacity of mobile.

  6. Power Balance AODV Routing Algorithm of WSN in Precision Agriculture Environment Monitoring

    Directory of Open Access Journals (Sweden)

    Xiaoqin Qin

    2013-11-01

    Full Text Available As one of important technologies of IOT (Internet of Things, WSN (Wireless Sensor Networks has been widely used in precision agriculture environment monitoring. WSN is a kind of energy-constrained network, but power balance is not taken into account in traditional routing protocols. A novel routing algorithm, named Power Balance Ad hoc On-Demand Distance Vector (PB-AODV, is proposed on cross-layer design. In the route discovery process of PB-AODV, routing path is established by the Received Signal Strength Indication (RSSI value. The optimal transmitting power, which is computed according to RSSI value, power threshold and node’s surplus energy, is encapsulated into Route Reply Packet. Hence, the sender node can adjust its transmission power to save energy according to the Route Reply Packet. Simulation results show that the proposed algorithm is effective for load balancing, and increases the WSN’s lifetime 14.3% consequently.

  7. Fracture toughness of manet II steel

    International Nuclear Information System (INIS)

    Gboneim, M.M.; Munz, D.

    1997-01-01

    High fracture toughness was evaluated according to the astm and chromium (9-12) martensitic steels combine high strength and toughness with good corrosion and oxidation resistance in a range of environments, and also show relatively high creep strength at intermediate temperatures. They therefore find applications in, for example, the offshore oil and gas production and chemical industries i pipe work and reaction vessels, and in high temperature steam plant in power generation systems. Recently, the use of these materials in the nuclear field was considered. They are candidates as tubing materials for breeder reactor steam generators and as structural materials for the first wall and blanket in fusion reactors. The effect of ageing on the tensile properties and fracture toughness of a 12 Cr-1 Mo-Nb-v steel, MANET II, was investigated in the present work. Tensile specimens and compact tension (CT) specimens were aged at 550 degree C for 1000 h. The japanese standards. Both microstructure and fracture surface were examined using optical and scanning electron microscopy (SEM). The results showed that ageing did not affect the tensile properties. However, the fracture toughness K Ic and the tearing modules T were reduced due to the ageing treatment. The results were discussed in the light of the chemical composition and the fracture surface morphology. 9 figs., 3 tabs

  8. Enhanced DSR Routing Protocol for the Short Time Disconnected MANET

    Directory of Open Access Journals (Sweden)

    PAPAJ Ján

    2013-05-01

    Full Text Available Data delivery in Mobile Ad-Hoc network (MANET is a very difficult task due to the fact the sporadic connections between mobile nodes. For this reason, we introduce the new modified routing protocol that enables the data delivery in the case that the connections are disconnected. A key aspect of the protocol is a process of finding connections between source and destination nodes that can provide low end-to-end delay and better delivery performance in a disconnected MANET. The protocol provides the concepts of opportunistic routing of the routing packets in disconnected MANETs. In this paper we present a modification of the DSR routing protocol and also some results of a simulation.

  9. SERVICE PROVISIONING IN MANETS USING SERVICE PROVIDER’S METRICS

    Directory of Open Access Journals (Sweden)

    K. Ponmozhi

    2012-09-01

    Full Text Available Service discovery technologies are exploited to enable services to advertise their existence in a dynamic way and can be discovered, configured and used by other devices with minimum of manual efforts. Automatic service discovery plays an important role in future network scenarios. Service discovery in distributed environment is difficult that too if the availability information of the services cannot be in a centralized node. The complexity is increased even further in the case of MANETs in which there will not be central intelligence also, the nodes involved may be on the move. The mobility issue leads to the situation of uncertainty about the service availability of the service provider. In this paper we propose a decentralized discovery mechanism. The basic idea is, distributing service information along with the availability metrics to the nodes. The metrics will give us the information to evaluate the goodness of the service provider. Every node will form multi-layered overlays of service providers sorted based on the metrics. When we send a query, each node will identify the service provider from the overlay with the good metric among the available providers (i.e. the one in the first position in the overlay. We define the message structures and methods needed for this proposal. The simulation result shows that in the high mobile environment too we could have a better convergence. We believe that the architecture presented here is a necessary component of any service provision framework.

  10. A Simulation Study: The Impact of Random and Realistic Mobility Models on the Performance of Bypass-AODV in Ad Hoc Wireless Networks

    Directory of Open Access Journals (Sweden)

    Baroudi Uthman

    2010-01-01

    Full Text Available To bring VANET into reality, it is crucial to devise routing protocols that can exploit the inherited characteristics of VANET environment to enhance the performance of the running applications. Previous studies have shown that a certain routing protocol behaves differently under different presumed mobility patterns. Bypass-AODV is a new optimization of the AODV routing protocol for mobile ad-hoc networks. It is proposed as a local recovery mechanism to enhance the performance of the AODV routing protocol. It shows outstanding performance under the Random Waypoint mobility model compared with AODV. However, Random Waypoint is a simple model that may be applicable to some scenarios but it is not sufficient to capture some important mobility characteristics of scenarios where VANETs are deployed. In this paper, we will investigate the performance of Bypass-AODV under a wide range of mobility models including other random mobility models, group mobility models, and vehicular mobility models. Simulation results show an interesting feature that is the insensitivity of Bypass-AODV to the selected random mobility model, and it has a clear performance improvement compared to AODV. For group mobility model, both protocols show a comparable performance, but for vehicular mobility models, Bypass-AODV suffers from performance degradation in high-speed conditions.

  11. Manet: A reliable Network in Disaster Areas. | Onwuka | Journal of ...

    African Journals Online (AJOL)

    This paper describes a communication network that is appropriate, suitable and reliable in any disaster: - Mobile Ad hoc Network (MANET). A mobile ad hoc network is formed dynamically by an autonomous system of mobile nodes that are connected via wireless links without using the existing network infrastructure or ...

  12. 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.

  13. RESILIENT SCHEME AGAINST REDUCTION OF QUALITY (ROQ DISTRIBUTED DENIAL OF SERVICE ATTACK IN MANET

    Directory of Open Access Journals (Sweden)

    S.A. Arunmozhi

    2011-09-01

    Full Text Available Defending against denial-of-service attacks (DoS in a mobile ad hoc network (MANET is challenging because of the dynamic network topology. Security primitives must be dynamically adjusted to cope with the network. The Reduction-of-Quality (RoQ Distributed Denial of Service (DDoS attack is one which throttles the tcp throughput heavily and reduces the quality-of-service (QoS to end systems gradually rather than refusing the clients from the services completely. Supporting QoS in MANET is a challenging task, particularly in the presence of malicious users. In this paper, we propose a DoS resilient technique that uses a flow table to detect the attackers. The proposed defense mechanism identifies the attackers based on the congestion bit notification and asks the sending node to reduce the sending rate. Once the attackers are identified, all the packets from those nodes will be blocked. The throughput and delay performance of TCP or UDP flows are very sensitive to such RoQ attacks. Through extensive ns2 network simulations, we demonstrate the achievement of high throughput and low delay for a network under the RoQ attack.

  14. De Manet a Yves Saint-Laurent: uma análise semiótica

    Directory of Open Access Journals (Sweden)

    Christiane Paula Godinho Santarelli

    2008-09-01

    Full Text Available A proposta deste artigo é fazer uma análise semiótica, com base na teoria greimasiana, da pintura original de Manet Le déjeuner sur l’herbe e de sua recriação para o anúncio da marca Yves Saint-Laurent. Os aspectos analisados nos dois “textos” são: os sistemas de valores, a estrutura narrativa, a estrutura de poder, os objetos de valor e a semântica profunda. A comparação dos dois discursos tem como objetivo atentar para as contradições no suposto discurso libertador da publicidade de Yves Saint-Laurent, que pode estar presente na publicidade de outras marcas. Palavras-chave: Publicidade; semiótica; arte; moda. ABSTRACT The purpose of this article is to offer a semiotical analysis of the original painting of Manet Le déjeuner sur l’herbe and of its recreation in an advertisement for the brand Yves Saint-Laurent. The aspects analyzed in the two “texts” are: the systems of enclosed values, the narrative structure, the power structure, the objects of value and deep semantics. The comparison between the two forms of speech aims to highlight the contradictions in the alleged liberating speech of the Yves Saint-Laurent advertisement, which may be present in advertising pieces from other brands. Keywords: Advertising; semiotics; art; fashion.

  15. MANETS and Internet of Things: The Development of a Data Routing Algorithm

    Directory of Open Access Journals (Sweden)

    I. A. Alameri

    2018-02-01

    Full Text Available Internet of things (IoT, is an innovative technology which allows the connection of physical things with the digital world through the use of heterogeneous networks and communication technologies. IoT in smart environments interacts with wireless sensor network (WSN and mobile ad‐hoc network (MANET, becoming even more attractive and economically successful. Interaction between wireless sensor and mobile ad‐hoc networks with the internet of things allows the creation of a new MANET‐IoT systems and IT‐based networks. Such systems give the user greater mobility and reduce costs. At the same time new challenging issues are opened in networking aspects. In this work, author proposed a routing solution for the IoT system using a combination of MANET protocols and WSN routing principles. The presented results of solution's investigation provide an effective approach to efficient energy consumption in the global MANET‐IoT system. That is a step forward to a reliable provision of services over global future internet infrastructure.

  16. Deployment of SIP in MANET: challenges and circumvention

    Directory of Open Access Journals (Sweden)

    Abdelhamid Salma R.

    2017-01-01

    Full Text Available The immense growth in wireless network applications has encouraged the researchers to enhance and propose new approaches that facilitate the deployment of the widely used services, protocols, and applications of the wired networking area in the wireless networks. Among which, the Session Initiation Protocol (SIP is a signaling protocol that allows the establishment of multimedia sessions and calls between different parties. SIP functionality totally depends on a centralized infrastructure, and complexity arises when deploying such a protocol in a special type of wireless networks, namely Mobile Ad-hoc Networks (MANET, due to the absence of a centralized infrastructure, and the dynamic topology of the later. This paper highlights the the challenges arising when deploying SIP in MANETs and presents an overview of different proposed approaches to overcome these challenges.

  17. The photographic subversion: Benjamin, Manet and Art(istic reproduction

    Directory of Open Access Journals (Sweden)

    Lauren Weingarden

    2006-12-01

    Full Text Available Besides referring to museum masterpieces in his 1863 paintings Le déjeuner sur l’herbe and Olympia, Édouard Manet used photography, of both academic and pornographic models, new genres of commercial photography that emerged during the early 1850s. I argue that Manet deliberately conflated fine art reproductions and mass media products, a practice that invites discussion in the light of Walter Benjamin’s “The Work of Art in the Age of Its Technological Reproducibility”. Since both engaged in a dialogue with Charles Baudelaire’s writings on art, culture, and photography, these writings provide a framework for discerning modernist paradoxes inherent in Manet’s and Benjamin’s critical interpretations of popular and material culture.

  18. An Efficient Method for Detecting Misbehaving Zone Manager in MANET

    Science.gov (United States)

    Rafsanjani, Marjan Kuchaki; Pakzad, Farzaneh; Asadinia, Sanaz

    In recent years, one of the wireless technologies increased tremendously is mobile ad hoc networks (MANETs) in which mobile nodes organize themselves without the help of any predefined infrastructure. MANETs are highly vulnerable to attack due to the open medium, dynamically changing network topology, cooperative algorithms, lack of centralized monitoring, management point and lack of a clear defense line. In this paper, we report our progress in developing intrusion detection (ID) capabilities for MANET. In our proposed scheme, the network with distributed hierarchical architecture is partitioned into zones, so that in each of them there is one zone manager. The zone manager is responsible for monitoring the cluster heads in its zone and cluster heads are in charge of monitoring their members. However, the most important problem is how the trustworthiness of the zone manager can be recognized. So, we propose a scheme in which "honest neighbors" of zone manager specify the validation of their zone manager. These honest neighbors prevent false accusations and also allow manager if it is wrongly misbehaving. However, if the manger repeats its misbehavior, then it will lose its management degree. Therefore, our scheme will be improved intrusion detection and also provide a more reliable network.

  19. Mobility and Cooperation to Thwart Node Capture Attacks in MANETs

    Directory of Open Access Journals (Sweden)

    Mauro Conti

    2009-01-01

    Full Text Available The nature of mobile ad hoc networks (MANETs, often unattended, makes this type of networks subject to some unique security issues. In particular, one of the most vexing problem for MANETs security is the node capture attack: an adversary can capture a node from the network eventually acquiring all the cryptographic material stored in it. Further, the captured node can be reprogrammed by the adversary and redeployed in the network in order to perform malicious activities. In this paper, we address the node capture attack in MANETs. We start from the intuition that mobility, in conjunction with a reduced amount of local cooperation, helps computing effectively and with a limited resource usage network global security properties. Then, we develop this intuition and use it to design a mechanism to detect the node capture attack. We support our proposal with a wide set of experiments showing that mobile networks can leverage mobility to compute global security properties, like node capture detection, with a small overhead.

  20. Unmanned Aerial ad Hoc Networks: Simulation-Based Evaluation of Entity Mobility Models’ Impact on Routing Performance

    Directory of Open Access Journals (Sweden)

    Jean-Daniel Medjo Me Biomo

    2015-06-01

    Full Text Available An unmanned aerial ad hoc network (UAANET is a special type of mobile ad hoc network (MANET. For these networks, researchers rely mostly on simulations to evaluate their proposed networking protocols. Hence, it is of great importance that the simulation environment of a UAANET replicates as much as possible the reality of UAVs. One major component of that environment is the movement pattern of the UAVs. This means that the mobility model used in simulations has to be thoroughly understood in terms of its impact on the performance of the network. In this paper, we investigate how mobility models affect the performance of UAANET in simulations in order to come up with conclusions/recommendations that provide a benchmark for future UAANET simulations. To that end, we first propose a few metrics to evaluate the mobility models. Then, we present five random entity mobility models that allow nodes to move almost freely and independently from one another and evaluate four carefully-chosen MANET/UAANET routing protocols: ad hoc on-demand distance vector (AODV, optimized link state routing (OLSR, reactive-geographic hybrid routing (RGR and geographic routing protocol (GRP. In addition, flooding is also evaluated. The results show a wide variation of the protocol performance over different mobility models. These performance differences can be explained by the mobility model characteristics, and we discuss these effects. The results of our analysis show that: (i the enhanced Gauss–Markov (EGM mobility model is best suited for UAANET; (ii OLSR, a table-driven proactive routing protocol, and GRP, a position-based geographic protocol, are the protocols most sensitive to the change of mobility models; (iii RGR, a reactive-geographic hybrid routing protocol, is best suited for UAANET.

  1. ANALISIS TRANSFER RATE PENAMBAHAN NODE PADA INFRASTRUKTUR MOBILE ADHOC NETWORK (MANET UNTUK FILE SERVER

    Directory of Open Access Journals (Sweden)

    Rudi Kurniawan

    2017-05-01

    Full Text Available Teknologi Wireless Network sudah lama ditemukan dan seiring waktu juga mengalami perkembangan, Namun sifat teknologi ini menggantungkan diri pada infrastruktur jaringan yang ada. Hal ini bias menjadi kelemahan tersendiri saat kondisi infrastruktur jaringan sedang mengalami gangguan, karena setiap komunikasi yang melewati infrastruktur jaringan tersebut tidak akan sampai pada tujuan. Teknologi jaringan Mobile Ad-hoc Network (MANET diciptakan sebagai antisipasi jika infrastruktur jaringan sedang mengalami gangguan. Dengan jaringan MANET sistem komunikasi yang dilakukan tidak membutuhkan infrastruktur jaringan karena tiap node pada jaringan tersebut bersifat mobile. Untuk menguji kemampuan MANET, pada penelitian ini akan menerapkan File Transfer Protocol (FTP sebagai media untuk melakukan komunikasi data file transfer yang diimplementasi pada jaringan MANET. Dari pengujian yang telah dilakukan diperoleh hasil bahwa File Transfer dapat berfungsi dengan baik saat diterapkan pada jaringan MANET.

  2. Mobility Model for Self-Organizing and Cooperative MSN and MANET Systems

    Directory of Open Access Journals (Sweden)

    Andrzej Sikora

    2012-03-01

    Full Text Available Self-organization mechanisms are used for building scalable systems consisting of a huge number of subsystems. In computer networks, self-organizing is especially important in ad hoc networking. A self-organizing ad hoc network is a collection of wireless devices that collaborate with each other to form a network system that adapts to achieve a goal or goals. Such network is often built from mobile devices that may spontaneously create a network and dynamically adapted to changes in an unknown environment. Mobility pattern is a critical element that influences the performance characteristics of mobile sensor networks (MSN and mobile ad hoc networks (MANET. In this paper, we survey main directions to mobility modeling. We describe a novel algorithm for calculating mobility patterns for mobile devices that is based on a cluster formation and an artificial potential function. Finally, we present the simulation results of its application to a rescue mission planning.

  3. Energy Efficient MANET Routing Using a Combination of Span and BECA/AFECA

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Bouvin, Niels Olof

    2008-01-01

    This paper presents some novel approaches for energy efficient routing in mobile ad-hoc networks. Two known energy preserving techniques, Span and BECA/AFECA, are combined with a well-known re-active routing protocol, AODV, to create a new energy efficient routing protocol. Furthermore, the proto......This paper presents some novel approaches for energy efficient routing in mobile ad-hoc networks. Two known energy preserving techniques, Span and BECA/AFECA, are combined with a well-known re-active routing protocol, AODV, to create a new energy efficient routing protocol. Furthermore...

  4. Designing Robust and Resilient Tactical MANETs

    Science.gov (United States)

    2014-09-25

    0. doi: B. Tan , J. Ni, R. Srikant. Q-CSMA: Queue-Length-Based CSMA/CA Algorithms for Achieving Maximum Throughput and Low Delay in Wireless Networks...INFOCOM 2012 Mini-Conference. 01-JAN-12, . : , J. Katz , Y. Lindell. Aggregate Message Authentication Codes, RSA 2008 . 01-JAN-08, . : , J. Ni, Bo Tan ...Haas, Yih-Chun Hu, Nicola Laurenti. Low-Cost Mitigation of Privacy Loss due to Radiometric Identification, Eighth ACM International Workshop on

  5. Energy Management Dynamic Control Topology In MANET

    Science.gov (United States)

    Madhusudan, G.; Kumar, TNR

    2017-08-01

    Topology management via per-node transmission power adjustment has been shown effective in extending network lifetime. The existing algorithms constructs static topologies which fail to take the residual energy of network nodes, and cannot balance energy consumption efficiently. To address this problem, a Light Weighted Distributed Topology Control algorithm EMDCT(Energy Management Dynamic Control Topology ) is proposed in this paper. Based on the link metric of the network, both the energy consumption rate level and residual energy levels at the two end nodes are considered. EMDCT generates a Dynamic Topology that changes with the variation of node energy without the aid of location information, each node determines its transmission power according to local network information, which reduces the overhead complexity of EMDCT greatly. The experiment results show that EMDCT preserves network connectivity and manitains minimum-cost property of the network also it can extend network lifetime more remarkably.

  6. Édouard Manet's Tabes Dorsalis: From Painful Ataxia to Phantom Limb.

    Science.gov (United States)

    Bogousslavsky, Julien; Tatu, Laurent

    2016-01-01

    Édouard Manet (1832-1883) is considered the 'father' of Impressionism and even of XXth century modern art. Manet's genius involved getting away from the classical narrative or historical topics and replacing them by the banality of daily life. Technically, he erased volumes into flat two-dimensional coloured planes, and distorted conventional perspective with often gross brushstrokes intentionally giving an 'unfinished' aspect to the work. It is little known that Manet had a very painful second part of his life, due to excruciating limb and chest pains, which developed in parallel with proprioceptive ataxia and gait imbalance. Manet always remained discreet about his private life, and we mainly know that his future wife was his family piano teacher, with whom he had a liaison already at age 17. Later, the great but platonic passion of his life was the painter Berthe Morisot (1841-1895), who got married to Manet's brother Eugène. In fact, we do not know whether he had any mistress at all, although he had several elegant 'flirts' in the mundane and artistic milieu. Thus, while Manet's progressive painful ataxia from age 40 yields little doubt on its tabetic origin, how he contracted syphilis at least 15-20 years before will probably remain a mystery. It is fascinating that Manet's daily struggle against pain and poor coordination may have led his art to become one of the most significant of modern times, opening the way to XXth century avant-gardes, along with another victim of syphilis, Paul Gauguin (1848-1903). Manet never showed any sign of General Paresis, and like his contemporary the writer Alphonse Daudet, his clinical picture remained dominated by paroxysmal pain and walking impairment. Difficult hand coordination made him quit watercolor painting, and during the last 2 years of his life, he had to focus on small format oil works, whose subject was nearly limited to modest bunches of fresh flowers, now often considered to be his maturity masterpieces

  7. Analisis Unjuk Kerja Aplikasi VoIP Call Android di Jaringan MANET [Performance Analysis of VoIP Call Application Android in MANET (Mobile Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Ryan Ari Setyawan

    2015-06-01

    Full Text Available Penelitian ini bertujuan menganalisis kinerja aplikasi  VoIP call android di jaringan MANET (mobile ad hoc network.  Hasil pengujian menunjukan bahwa aplikasi VoIP call android dapat digunakan di jaringan MANET. Delay yang dihasilkan paling besar di pengujian indoor dengan jarak 11-15 meter yakni sebesar 0,014624811 seconds. Packet loss yang dihasilkan pada range 1%-2% sedangkan standar packet loss yang ditetapkan oleh CISCO untuk layanan aplikasi VoIP adalah < 5%. Jitter yang dihasilkan yakni antara 0,01-0,06 seconds sedangkan standar yang ditetapkan oleh CISCO adalah ≤ 30 ms atau 0,03 seconds. Throughput yang dihasilkan pada proses pengujian yakni antar 161 kbps-481 kbps. *****This study aims to analyze the performance of VOIP call android application in the MANET (mobile ad hoc network. The results showed that VoIP applications could be implemented in MANET network. The highest  delay is produced in indoor testing  with distance of 11-15 meters,  which is equal to 0.014624811 seconds. Packet loss is generated in the range of 1% -2%, while packet loss standards set by Cisco for VoIP application services are <5%. The jitter is between 0.01 to 0.06 seconds, while the standard set by CISCO is ≤ 30 ms or 0.03 seconds. Throughput generated in the testing process is between 161 kbps-481 kbps.

  8. ANALISIS LAYANAN VOIP PADA JARINGAN MANET DENGAN CODEC YANG BERBEDA

    Directory of Open Access Journals (Sweden)

    Randa Oktavada Zein

    2016-12-01

    Full Text Available Voice Over Internet Protocol (VoIP merupakan layanan bersifat real-time, parameter yang dapat mempengaruhi kulitas layanan seperti delay, jitter dan packet loss. Dalam proses pengkodean sinyal analog menjadi sinyal digital menyebabkan terjadiya delay pada VoIP. Sistem pengcodean ini disebut codec, setiap codec memiliki bitrate yang berbeda pengkodeannya. Pada penelitian ini menggunakan codec G.711, G729 dan codec G.723.1 sebagai perbandingan untuk mengetahui qulity of service (QoS VoIP jika diterapkan pada jaringan MANET. Dengan penambahan aplikasi Hypertext Transfer Protovol (HTTP untuk mendapatkan parameter QoS VoIP dari codec G.711, G.729 dan G.723.1. Hasil yang didapat pada codec G.723.1 lebih baik jika dibandingkan dengan codec g.711 dan G.729 dilihat dari nilai dari parameter QoS seperti delay, jitter dan packet loss. Sesuai standar ITU-T G114 dimana perhitunan teoritis parameter dari codec G.723.1 didapat hasil terendah 7,68 kbps.

  9. An Evaluation of Media-Oriented Rate Selection Algorithm for Multimedia Transmission in MANETs

    Directory of Open Access Journals (Sweden)

    Guionnet Thomas

    2005-01-01

    Full Text Available We focus on the optimization of real-time multimedia transmission over 802.11-based ad hoc networks. In particular, we propose a simple and efficient cross-layer mechanism that considers both the channel conditions and characteristics of the media for dynamically selecting the transmission mode. This mechanism called media-oriented rate selection algorithm (MORSA targets loss-tolerant applications such as VoD that do not require full reliable transmission. We provide an evaluation of this mechanism for MANETs using simulations with NS and analyze the video quality obtained with a fine-grain scalable video encoder based on a motion-compensated spatiotemporal wavelet transform. Our results show that MORSA achieves up to 4 Mbps increase in throughput and that the routing overhead decreases significantly. Transmission of a sample video flow over an 802.11a wireless channel has been evaluated with MORSA. Important improvement is observed in throughput, latency, and jitter while keeping a good level of video quality.

  10. An efficient collaborative approach for black hole attack discovery and mitigating its impact in manet

    Science.gov (United States)

    Devipriya, K.; Ivy, B. Persis Urbana; Prabha, D.

    2018-04-01

    A mobile ad hoc network (MANET) is an assemblage of nodes composed of mobile devices coupled in various ways wirelessly which do not have any central administration. Each node in MANET cooperates in forwarding packets in the network. This type of collaboration incurs high cost but there exits nodes that declines to cooperate leading to selfish conduct of nodes which effects overall network performance. To discover the attacks caused by such nodes, a renowned mechanism using watchdog can be deployed. In infrastructure less network attack detection and reaction and high false positives, false negatives initiating black hole attack becomes major issue in watchdog. This paper put forward a collaborative approach for identifying such attacks in MANET. Through abstract analysis and extensive simulation of this approach, the detection time of misbehaved nodes is reduced and substantial enhancement in overhead and throughput is witnessed.

  11. A robust certification service for highly dynamic MANET in emergency tasks

    DEFF Research Database (Denmark)

    Ge, M; Lam, K Y; Gollmann, Dieter

    2009-01-01

    In emergency tasks, cross-agency operations being carried out in disaster-hit areas require some supporting communication system for command and control. Mobile Ad hoc Network (MANET) is a very suitable way to meet such communication requirements since it can function without any pre......-installed communication infrastructure. Owing to potential threats in the field environment and the unique features of MANET (e.g. the open nature of wireless links and the absence of security infrastructure), security of communications over MANET is a serious issue that is typically addressed by asymmetric cryptographic...... public keys in our scenario. For issuance and/or revocation of mission-specific certificate, a Mission-specific Certificate Authority (MCA), which consists of a collection of server nodes to operate the threshold cryptographic scheme, is proposed. Furthermore, to cater for the occurrence of network...

  12. Nitride and carbide thin films as hydrogen permeation barrier on Manet steel

    International Nuclear Information System (INIS)

    Benamati, G.; Checchetto, R.; Bonelli, M.; Gratton, L.M.; Guzman, L.; Miotello, A.; Terlain, A.

    1995-01-01

    TiC / TiN bilayers, ∼ 1.2 μm thick, were deposited on Manet II steel by the ion beam assisted deposition technique to investigate the possible use of this ceramic coating as hydrogen barrier. Hydrogen permeation experiments in the temperature range 470-570 K showed indeed that this coating is a very efficient barrier to the hydrogen permeation being able to reduce the hydrogen flux up to two order of magnitude with respect to the uncoated steel. Preliminary compatibility tests between coated Manet II and Pb-17Li showed no attack of Pb-17Li to the steel. (orig.)

  13. Nitride and carbide thin films as hydrogen permeation barrier on MANET steel

    International Nuclear Information System (INIS)

    Benamati, G.

    1994-01-01

    TiC/TiN bilayers, - 1.2 μm thick, were deposited on Manet II steel by the ion beam assisted deposition technique to investigate the possible use of this ceramic coating as hydrogen barrier. Hydrogen permeation experiments in the temperature range 470-570 K showed indeed that this coating is a very efficient barrier to the hydrogen permeation being able to reduce the hydrogen flux up to two order of magnitude with respect to the uncoated steel. Preliminary compatibility tests between coated Manet II and Pb-17Li showed no attack of Pb-17Li to the steel. (author) 8 refs.; 2 figs.; 1 tab

  14. Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs.

    Science.gov (United States)

    Alvarez, Carlos F; Palafox, Luis E; Aguilar, Leocundo; Sanchez, Mauricio A; Martinez, Luis G

    2016-01-01

    Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node's behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder.

  15. HOP: Achieving Efficient Anonymity in MANETs by Combining HIP, OLSR, and Pseudonyms

    Directory of Open Access Journals (Sweden)

    Campos Javier

    2011-01-01

    Full Text Available Offering secure and anonymous communications in mobile ad hoc networking environments is essential to achieve confidence and privacy, thus promoting widespread adoption of this kind of networks. In addition, some minimum performance levels must be achieved for any solution to be practical and become widely adopted. In this paper, we propose and implement HOP, a novel solution based on cryptographic Host Identity Protocol (HIP that offers security and user-level anonymity in MANET environments while maintaining good performance levels. In particular, we introduce enhancements to the authentication process to achieve Host Identity Tag (HIT relationship anonymity, along with source/destination HIT anonymity when combined with multihoming. Afterward we detail how we integrate our improved version of HIP with the OLSR routing protocol to achieve efficient support for pseudonyms. We implemented our proposal in an experimental testbed, and the results obtained show that performance levels achieved are quite good, and that the integration with OLSR is achieved with a low overhead.

  16. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. M G SUMITHRA. Articles written in Sadhana. Volume 43 Issue 4 April 2018 pp 60. Preventing the impact of selfish behavior under MANET using Neighbor Credit Value based AODV routing algorithm · K RAMA ABIRAMI M G SUMITHRA · More Details Abstract Fulltext PDF. Mobile Ad hoc Network ...

  17. Performance Analysis of the Enhanced DSR Routing Protocol for the Short Time Disconnected MANET to the OPNET Modeler

    Directory of Open Access Journals (Sweden)

    PAPAJ Ján

    2013-05-01

    Full Text Available Disconnected mobile ad-hoc networks (MANET are very important areas of the research. In this article, the performance analysis of the enhanced dynamic source routing protocol (OPP_DSR is introduced. This modification enables the routing process in the case when there are no connections to other mobile nodes. It also will enable the routing mechanisms when the routes, selected by routing mechanisms, are disconnected for some time. Disconnection can be for a short time and standard routing protocol DSR cannot reflect on this situation.The main idea is based on opportunistic forwarding where the nodes not only forward data but it's stored in the cache during long time. The network parameters throughput, routing load and are analysed.

  18. LITERATURE SURVEY ON EXISTING POWER SAVING ROUTING METHODS AND TECHNIQUES FOR INCREASING NETWORK LIFE TIME IN MANET

    Directory of Open Access Journals (Sweden)

    K Mariyappan

    2017-06-01

    Full Text Available Mobile ad hoc network (MANET is a special type of wireless network in which a collection of wireless mobile devices (called also nodes dynamically forming a temporary network without the need of any pre-existing network infrastructure or centralized administration. Currently, Mobile ad hoc networks (MANETs play a significant role in university campus, advertisement, emergency response, disaster recovery, military use in battle fields, disaster management scenarios, in sensor network, and so on. However, wireless network devices, especially in ad hoc networks, are typically battery-powered. Thus, energy efficiency is a critical issue for battery-powered mobile devices in ad hoc networks. This is due to the fact that failure of node or link allows re-routing and establishing a new path from source to destination which creates extra energy consumption of nodes and sparse network connectivity, leading to a more likelihood occurrences of network partition. Routing based on energy related parameters is one of the important solutions to extend the lifetime of the node and reduce energy consumption of the network. In this paper detail literature survey on existing energy efficient routing method are studied and compared for their performance under different condition. The result has shown that both the broadcast schemes and energy aware metrics have great potential in overcoming the broadcast storm problem associated with flooding. However, the performances of these approaches rely on either the appropriate selection of the broadcast decision parameter or an energy efficient path. In the earlier proposed broadcast methods, the forwarding probability is selected based on fixed probability or number of neighbors regardless of nodes battery capacity whereas in energy aware schemes energy inefficient node could be part of an established path. Therefore, in an attempt to remedy the paucity of research and to address the gaps identified in this area, a study

  19. 基于移动-能量代价函数的无线自组织网络路由策略研究%Research on the Routing Algorithm in MANETsBased on the Energy Cost Function

    Institute of Scientific and Technical Information of China (English)

    刘半藤; 周莹; 陈友荣; 王章权

    2017-01-01

    能量均衡技术一直是无线自组织网络的热点研究领域.在深入研究网络信息传输特性的基础上,提出了一种基于移动-能量代价函数的无线自组织网络路由策略,并用于网络信息传输.首先,本文考虑节点连通性、能量均衡性,提出了一种节点移动策略;然后,以传输路径节点集合中的瓶颈节点剩余能量、传输链路数量作为准则,建立以网络节点为对象的能量代价函数.基于移动-能量代价函数的路由策略从链路层的决策转移到节点层的决策.最后,采用MATLAB数值仿真该路由策略的性能,结果显示:本文提出的移动-能量代价函数的路由策略既保持了原有路由优化的精度,延迟网络瓶颈节点能量下降速度,提高网络生存时间.%The energy balance technology is a hot research field of the wireless selforganizing network.After the further study of the network information transmission characteristics,a kind of wireless selforganized network routing strategy used for network information transmission is proposed based on mobile-energy cost function.At first,considering the node connectivity and energy balance,a node mobile strategy is carried out;then a energy cost function is designed With residual energy of transmission path bottleneck nodes and transmission link number as criterion,and the routing strategy is determined in node layer instead of link layer;at last,the numerical simulation is performed on MATLAB,the result shows the routing strategy proposed keep the original optimal routing precision,delay the network bottleneck node energy falling speed and improve the network survival time.

  20. Adaptive, Tactical Mesh Networking: Control Base MANET Model

    Science.gov (United States)

    2010-09-01

    pp. 316–320 Available: IEEE Xplore , http://ieeexplore.ieee.org [Accessed: June 9, 2010]. [5] N. Sidiropoulos, “Multiuser Transmit Beamforming...Mobile Mesh Segments of TNT Testbed .......... 11 Figure 5. Infrastructure and Ad Hoc Mode of IEEE 802.11................................ 13 Figure...6. The Power Spectral Density of OFDM................................................ 14 Figure 7. A Typical IEEE 802.16 Network

  1. Genetic based optimization for multicast routing algorithm for MANET

    Indian Academy of Sciences (India)

    three main principles of natural evolution: reproduction, natural selection and species .... For example, figure 3 shows a six-node network with node reachability shown by ... sion range of each node is 220 m using an Omni directional antenna.

  2. A Novel Load Balancing Scheme for Multipath Routing Protocol in MANET

    Directory of Open Access Journals (Sweden)

    Kokilamani Mounagurusamy

    2016-09-01

    Full Text Available The recent advancements in information and communication technology create a great demand for multipath routing protocols. In MANET, nodes can be arbitrarily located and can move freely at any given time. The topology of MANET can change rapidly and unpredictably. Because wireless link capacities are usually limited, congestion is possible in MANETs. Hence, balancing the load in a MANET is important since nodes with high load will deplete their batteries quickly, thereby increasing the probability of disconnecting or partitioning the network. To overcome these, the multipath protocol should be aware of load at route discovery phase. The main objective of the proposed article is to balance the load on a node and to extend the lifetime of the node due to the congestion, energy depletion and link failures. This article describes a novel load and congestion aware scheme called Path Efficient Ad-hoc On-demand Multipath Distance Vector (PE-AOMDV protocol to increase the performance of routing process in MANET in terms of congestion, end-to-end delay and load balancing. A new threshold value and a counter variable are introduced to limit the number of communication paths passing over a node in route discovery phase. For every new request the counter variable is incremented by one and the threshold value is compared to see whether the maximum number of connections has been reached or not. The proposed method is network simulator ns-2 and it is found that there is a significant improvement in the proposed scheme. It reduces the energy consumption, average end-to-end delay and normalized routing overhead. Also the proposed scheme increases packet delivery ratio, throughput and minimizes routing overheads.

  3. Comparison of MANET routing protocols using a scaled indoor wireless grid

    CSIR Research Space (South Africa)

    Johnson, DL

    2008-04-01

    Full Text Available accumulation feature of Dynamic Source Routing (DSR) by adding the accumulated route, back to the source, to the Route Request packet. It retains the destination sequence number feature of AODV but HELLO packets are an optional feature and are normally left... than the inbound traffic as the routing algorithm makes a decision to rebroadcast the packet or not and Figure 20 confirms this. DYMO shows the least amount of routing traffic due to its lack of HELLO packets. This is also due to no further...

  4. Thermal and isothermal low cycle fatigue of MANET I and II

    International Nuclear Information System (INIS)

    Petersen, C.; Schmitt, R.; Garnier, D.

    1996-01-01

    Structural components of a DEMO-blanket are subjected during service to alternating thermal and mechanical stresses as a consequence of the pulsed reactor operation. Of particular concern is the fatigue endurance of martensitic steels like MANET under cyclic strains and stresses produced by these temperature changes. In order to design such structures, operating under combined mechanical and thermal cycling, fatigue life has to be calculated with reasonable accuracy. This paper proposes a description of thermal and isothermal mechanical low-cycle fatigue of MANET I and II steels using a single damage model, including plastic strain, temperature and strain rate as variables. This model presents notable advantages for the designer. As it corresponds to a single and continuous 'fatigue strength surface', it enables a reliable interpolation to be made throughout the studied domain of strains and temperatures, and allows for a reasonable extrapolation out of this domain, provided that no different metallurgical phenomena occur. (orig.)

  5. A Preemptive Link State Spanning Tree Source Routing Scheme for Opportunistic Data Forwarding in MANET

    OpenAIRE

    R. Poonkuzhali; M. Y. Sanavullah; A. Sabari

    2014-01-01

    Opportunistic Data Forwarding (ODF) has drawn much attention in mobile adhoc networking research in recent years. The effectiveness of ODF in MANET depends on a suitable routing protocol which provides a powerful source routing services. PLSR is featured by source routing, loop free and small routing overhead. The update messages in PLSR are integrated into a tree structure and no need to time stamp routing updates which reduces the routing overhead.

  6. MANETS and Internet of Things: The Development of a Data Routing Algorithm

    OpenAIRE

    Alameri, I. A.

    2018-01-01

    Internet of things (IoT), is an innovative technology which allows the connection of physical things with the digital world through the use of heterogeneous networks and communication technologies. IoT in smart environments interacts with wireless sensor network (WSN) and mobile ad‐hoc network (MANET), becoming even more attractive and economically successful. Interaction between wireless sensor and mobile ad‐hoc networks with the internet of things allows the creation of a new MANET‐IoT syst...

  7. Provisioning of adaptability to variable topologies for routing schemes in MANETs

    DEFF Research Database (Denmark)

    Jiang, Shengming; Liu, Yaoda; Jiang, Yuming

    2004-01-01

    .g., low, medium, and high mobility) have been proposed in the,literature. However, since a mobile node should not be limited to operate in a particular MANET assumed by-a routing scheme, an important issue is how to enable, a mobile node to achieve routing performance as high as possible when it roams...... in the dynamic source routing protocol to provide the adaptability to variable topologies caused by mobility through computer simulation in NS-2....

  8. Effect of 3 Key Factors on Average End to End Delay and Jitter in MANET

    Directory of Open Access Journals (Sweden)

    Saqib Hakak

    2015-01-01

    Full Text Available A mobile ad-hoc network (MANET is a self-configuring infrastructure-less network of mobile devices connected by wireless links where each node or mobile device is independent to move in any desired direction and thus the links keep moving from one node to another. In such a network, the mobile nodes are equipped with CSMA/CA (carrier sense multiple access with collision avoidance transceivers and communicate with each other via radio. In MANETs, routing is considered one of the most difficult and challenging tasks. Because of this, most studies on MANETs have focused on comparing protocols under varying network conditions. But to the best of our knowledge no one has studied the effect of other factors on network performance indicators like throughput, jitter and so on, revealing how much influence a particular factor or group of factors has on each network performance indicator. Thus, in this study the effects of three key factors, i.e. routing protocol, packet size and DSSS rate, were evaluated on key network performance metrics, i.e. average delay and average jitter, as these parameters are crucial for network performance and directly affect the buffering requirements for all video devices and downstream networks.

  9. Energy generation for an ad hoc wireless sensor network-based monitoring system using animal head movement

    DEFF Research Database (Denmark)

    S. Nadimi, Esmaeil; Blanes-Vidal, Victoria; Jørgensen, Rasmus Nyholm

    2011-01-01

    are not easily accessible. Therefore, exploring novel sources of energy generation rather than operating electronics only on limited power supplies such as batteries is a major challenge. Monitoring free-ranging animal behavior is an application in which the entities (animals) within the MANET are not readily...... that the amount of energy generated by the vertical neck–head movement of sheep during grazing can be converted to useful electrical power adequate to provide power for operation of wireless sensor nodes on a continuous basis within a MANET-based animal behavior monitoring system.......The supply of energy to electronics is an imperative constraining factor to be considered during the design process of mobile ad hoc wireless sensor networks (MANETs). This influence is especially important when the MANET is deployed unattended or the wireless modules within the MANET...

  10. An Analysis Platform for Mobile Ad Hoc Network (MANET) Scenario Execution Log Data

    Science.gov (United States)

    2016-01-01

    these technologies. 4.1 Backend Technologies • Java 1.8 • my-sql-connector- java -5.0.8.jar • Tomcat • VirtualBox • Kali MANET Virtual Machine 4.2...Frontend Technologies • LAMPP 4.3 Database • MySQL Server 5. Database The SEDAP database settings and structure are described in this section...contains all the backend java functionality including the web services, should be placed in the webapps directory inside the Tomcat installation

  11. A Hop-Count Analysis Scheme for Avoiding Wormhole Attacks in MANET

    Directory of Open Access Journals (Sweden)

    Chi-Sung Laih

    2009-06-01

    Full Text Available MANET, due to the nature of wireless transmission, has more security issues compared to wired environments. A specific type of attack, the Wormhole attack does not require exploiting any nodes in the network and can interfere with the route establishment process. Instead of detecting wormholes from the role of administrators as in previous methods, we implement a new protocol, MHA, using a hop-count analysis from the viewpoint of users without any special environment assumptions. We also discuss previous works which require the role of administrator and their reliance on impractical assumptions, thus showing the advantages of MHA.

  12. Notas sobre o escândalo e o cinismo de Manet

    Directory of Open Access Journals (Sweden)

    Tereza Calomeni

    2013-10-01

    Full Text Available Em 1971, Foucault profere, em Túnis, uma conferência sobre a pintura de Manet. Em 1984, em A coragem da verdade, último curso oferecido no Collège de France, analisando o cinismo como expressão da parresia, novamente se refere ao pintor ao relacionar arte moderna e cinismo. A partir dos dois textos, o artigo reflete sobre o escândalo de Olympia, uma das treze telas examinadas na conferência, e a relação, estabelecida no curso, entre arte moderna e cinismo.

  13. Data dissemination in the wild: A testbed for high-mobility MANETs

    DEFF Research Database (Denmark)

    Vingelmann, Peter; Pedersen, Morten Videbæk; Heide, Janus

    2012-01-01

    This paper investigates the problem of efficient data dissemination in Mobile Ad hoc NETworks (MANETs) with high mobility. A testbed is presented; which provides a high degree of mobility in experiments. The testbed consists of 10 autonomous robots with mobile phones mounted on them. The mobile...... information, and the goal is to convey that information to all devices. A strategy is proposed that uses UDP broadcast transmissions and random linear network coding to facilitate the efficient exchange of information in the network. An application is introduced that implements this strategy on Nokia phones...

  14. The afterlife of antiquity and modern art: Aby Warburg on Manet

    Directory of Open Access Journals (Sweden)

    Dimitrios Latsis

    2015-12-01

    Full Text Available Aby Warburg’s manuscript on Édouard Manet – unpublished during his lifetime and presented here for the first time in English – constitutes one of his rare, substantial commentaries on nineteenth century art. Using “Le Déjeuner sur l’herbe” as a departure point, Warburg proceeds from his customary meticulous investigation of the central motif’s “visual archeology,” to a larger reflection on the evolution of the representation of nature in art and the image of antiquity that modernity has created for itself.

  15. Analyzing the Effectiveness of the Self-organized Public-Key Management System on MANETs under the Lack of Cooperation and the Impersonation Attacks

    Science.gov (United States)

    da Silva, Eduardo; Dos Santos, Aldri Luiz; Lima, Michele N.; Albini, Luiz Carlos Pessoa

    Among the key management schemes for MANETs, the Self-Organized Public-Key Management System (PGP-Like) is the main chaining-based key management scheme. It is fully self-organized and does not require any certificate authority. Two kinds of misbehavior attacks are considered to be great threats to PGP-Like: lack of cooperation and impersonation attacks. This work quantifies the impact of such attacks on the PGP-Like. Simulation results show that PGP-Like was able to maintain its effectiveness when submitted to the lack of cooperation attack, contradicting previously theoretical results. It correctly works even in the presence of more than 60% of misbehaving nodes, although the convergence time is affected with only 20% of misbehaving nodes. On the other hand, PGP-Like is completely vulnerable to the impersonation attack. Its functionality is affected with just 5% of misbehaving nodes, confirming previously theoretical results.

  16. A COMPREHENSIVE SURVEY ON DETECTING BLACK HOLE ATTACK IN MOBILE AD-HOC NETWORK (MANET

    Directory of Open Access Journals (Sweden)

    Pascal Maniriho

    2018-01-01

    Full Text Available The infrastructure-less nature and mobility of nodes in mobile ad-hoc network (MANET make it to be very susceptible to various attacks. Besides, owing to its flexibility and simplicity, there is no predefined time or permission set for nodes to leave or join the network and each node can act as a client or server.  Nevertheless, securing communication between nodes has become a challenging problem than in other types of network. Attacks in MANET range into different categories. Black hole attack is one of the attacks that has been addressed by many researchers in the recent years. It does occur when a harmful mobile node called black hole becomes a part of the network and tries to use its malicious behaviors by sending fake route reply packets (RREP for any received route request packets (RREQ. When these faked packets arrive to the source node, it does reply to them by sending data packet via the established route. Once the packets are received by the black hole, it drops them before reaching the destination.  Hence, preventing the source node from reaching the intended destination. In this paper, we present an overview of a wide range of techniques suggested in the literature for detecting and preventing black hole attacks in mobile ad hoc network. Additionally, the effect of each approach on the network performance is also presented.

  17. The Inevitability of Sleep: Using Manet's Last Paintings to Envision a Pedagogy of Loss and Mourning

    Science.gov (United States)

    Otto, Stacy

    2013-01-01

    In this article, the author offers Manet's last paintings as metaphors for a bygone, psychically healthy conception of loss and mourning, what is called the pre-Freudian, Victorian notion of loss (Otto 2008), which contrasts with the post-Freudian, Modern notion of loss and mourning (Otto 2008). Otto argues this liminal, transitional moment…

  18. A time-based admission control mechanism for IEEE 802.11 ad Hoc networks

    OpenAIRE

    Costa, Luís Henrique M. K.; Cerveira, Carlos Rodrigo

    2006-01-01

    This paper presents a time-based admission control mechanism (TAC) for IEEE 802.11 ad hoc networks. The proposed mechanism was adapted to the QoS AODV routing protocol, which takes the quality of service requirements of the data flow into account in the route discovery process. TAC-AODV estimates the idle time of the physical medium based on the frames listened. The incoming traffic is admitted according to the offered load as well as the intra-flow interference, calculated based on the numbe...

  19. Clair de lune sur le port de Boulogne: enquête sur un tableau de Manet, traduction d'un article de Donald W. Olson

    Science.gov (United States)

    Borg, Janet

    2016-10-01

    The 19th-century artist Edouard Manet created a spectacular nocturnal painting showing a full Moon over the harbor of Boulogne. Art historians have dated this work to either 1868 or 1869. Calculations of lunar phases, 19th-century maps and photographs of Boulogne harbor, the correspondence of the artist, and other clues allow us to determine a date and precise time when Manet observed this moonlit scene.

  20. BLACK HOLE ATTACK IN AODV & FRIEND FEATURES UNIQUE EXTRACTION TO DESIGN DETECTION ENGINE FOR INTRUSION DETECTION SYSTEM IN MOBILE ADHOC NETWORK

    Directory of Open Access Journals (Sweden)

    HUSAIN SHAHNAWAZ

    2012-10-01

    Full Text Available Ad-hoc network is a collection of nodes that are capable to form dynamically a temporary network without the support of any centralized fixed infrastructure. Since there is no central controller to determine the reliable & secure communication paths in Mobile Adhoc Network, each node in the ad hoc network has to rely on each other in order to forward packets, thus highly cooperative nodes are required to ensure that the initiated data transmission process does not fail. In a mobile ad hoc network (MANET where security is a crucial issue and they are forced to rely on the neighbor node, trust plays an important role that could improve the number of successful data transmission. Larger the number of trusted nodes, higher successful data communication process rates could be expected. In this paper, Black Hole attack is applied in the network, statistics are collected to design intrusion detection engine for MANET Intrusion Detection System (IDS. Feature extraction and rule inductions are applied to find out the accuracy of detection engine by using support vector machine. In this paper True Positive generated by the detection engine is very high and this is a novel approach in the area of Mobile Adhoc Intrusion detection system.

  1. Mobility Tolerant Firework Routing for Improving Reachability in MANETs

    Directory of Open Access Journals (Sweden)

    Gen Motoyoshi

    2014-03-01

    Full Text Available In this paper, we investigate our mobility-assisted and adaptive broadcast routing mechanism, called Mobility Tolerant Firework Routing (MTFR, which utilizes the concept of potentials for routing and improves node reachability, especially in situations with high mobility, by including a broadcast mechanism. We perform detailed evaluations by simulations in a mobile environment and demonstrate the advantages of MTFR over conventional potential-based routing. In particular, we show that MTFR produces better reachability in many aspects at the expense of a small additional transmission delay and intermediate traffic overhead, making MTFR a promising routing protocol and feasible for future mobile Internet infrastructures.

  2. Robust against route failure using power proficient reliable routing in MANET

    Directory of Open Access Journals (Sweden)

    M. Malathi

    2018-03-01

    Full Text Available The aim of this paper was to propose a novel routing protocol for Mobile Adhoc Network communication which reduces the route failure during transmission. The proposed routing protocol uses 3 salient parameters to discover the path which ensure the reliable communication. The quality of the channel, link quality and energy level of the node are the major reasons for unintentional node failure in mobile Adhoc network. So the proposed routing protocol considers these three parameters to select the best forwarder node in the path. The reliable data communication is achieved by transmitting data via path selected by the proposed routing scheme has been proven using network simulator (NS2. Keywords: Channel quality, Link quality, Mobile Adhoc Network (MANET, Residual energy

  3. The adherence of aluminide coatings on MANET II stainless steel and their effect on its mechanical properties

    International Nuclear Information System (INIS)

    Sample, T.; Fenici, P.; Kolbe, H.; Orecchia, L.

    1994-01-01

    This paper describes the production and testing of two different aluminide coatings on the surface of MANET II stainless steel. The coatings were produced by heat treatment of a pure aluminium layer (∼ 100 μm) which had been deposited by vacuum plasma spray. Series 1 coatings were produced by a single heat treatment (1023 K/2h) while series 2 coatings were produced by two consecutive heat treatments (1348 K/30 min, 1023 K/2h). Series 1 coatings were ∼ 120 μm thick, richer in aluminium and harder than series 2 coatings which formed two layers of ∼ 120 μm each. Due to their softer character, series 2 coatings exhibited a greater resistance to cracking under cyclic testing than series 1 coatings. Tensile tests of coated specimens indicated that the coating procedures did not degrade the mechanical properties of the bulk MANET II. (author) 8 refs.; 3 figs.; 3 tabs

  4. ComboCoding: Combined intra-/inter-flow network coding for TCP over disruptive MANETs

    Directory of Open Access Journals (Sweden)

    Chien-Chia Chen

    2011-07-01

    Full Text Available TCP over wireless networks is challenging due to random losses and ACK interference. Although network coding schemes have been proposed to improve TCP robustness against extreme random losses, a critical problem still remains of DATA–ACK interference. To address this issue, we use inter-flow coding between DATA and ACK to reduce the number of transmissions among nodes. In addition, we also utilize a “pipeline” random linear coding scheme with adaptive redundancy to overcome high packet loss over unreliable links. The resulting coding scheme, ComboCoding, combines intra-flow and inter-flow coding to provide robust TCP transmission in disruptive wireless networks. The main contributions of our scheme are twofold; the efficient combination of random linear coding and XOR coding on bi-directional streams (DATA and ACK, and the novel redundancy control scheme that adapts to time-varying and space-varying link loss. The adaptive ComboCoding was tested on a variable hop string topology with unstable links and on a multipath MANET with dynamic topology. Simulation results show that TCP with ComboCoding delivers higher throughput than with other coding options in high loss and mobile scenarios, while introducing minimal overhead in normal operation.

  5. Mobility Aware Energy Efficient Clustering for MANET: A Bio-Inspired Approach with Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Naghma Khatoon

    2017-01-01

    Full Text Available Mobility awareness and energy efficiency are two indispensable optimization problems in mobile ad hoc networks (MANETs where nodes move unpredictably in any direction with restricted battery life, resulting in frequent change in topology. These constraints are widely studied to increase the lifetime of such networks. This paper focuses on the problems of mobility as well as energy efficiency to develop a clustering algorithm inspired by multiagent stochastic parallel search technique of particle swarm optimization. The election of cluster heads takes care of mobility and remaining energy as well as the degree of connectivity for selecting nodes to serve as cluster heads for longer duration of time. The cluster formation is presented by taking multiobjective fitness function using particle swarm optimization. The proposed work is experimented extensively in the NS-2 network simulator and compared with the other existing algorithms. The results show the effectiveness of our proposed algorithm in terms of network lifetime, average number of clusters formed, average number of reclustering required, energy consumption, and packet delivery ratio.

  6. Lifetime of Manet steel in load-cycling tests in vacuum at 20 and 550deg C

    International Nuclear Information System (INIS)

    Ullmaier, H.; Schmitz, W.

    1989-01-01

    Fatigue tests in vacuum were carried out on the Manet heat of DIN 1.4914 martensitic steel (X13Cr10.7Ni0.85Mo0.75V0.22) in push-pull type, stress-controlled experiments at room temperature and 823 K. The fatigue life was determined as a function of stress amplitude, mean stress, frequency and hold time. At 823 K creep has a strong influence on the life time, particularly at low frequencies and long hold times in tension. The results are phenomenologically described by a simple linear damage summation approach. Even at room temperature the life time of specimens tested in vacuum is about an order of magnitude higher than of those tested in air. This stresses the importance of providing the correct test environment in collecting fatigue data for the design of fusion devices. (orig./MM)

  7. Securing mobile ad hoc networks using danger theory-based artificial immune algorithm.

    Science.gov (United States)

    Abdelhaq, Maha; Alsaqour, Raed; Abdelhaq, Shawkat

    2015-01-01

    A mobile ad hoc network (MANET) is a set of mobile, decentralized, and self-organizing nodes that are used in special cases, such as in the military. MANET properties render the environment of this network vulnerable to different types of attacks, including black hole, wormhole and flooding-based attacks. Flooding-based attacks are one of the most dangerous attacks that aim to consume all network resources and thus paralyze the functionality of the whole network. Therefore, the objective of this paper is to investigate the capability of a danger theory-based artificial immune algorithm called the mobile dendritic cell algorithm (MDCA) to detect flooding-based attacks in MANETs. The MDCA applies the dendritic cell algorithm (DCA) to secure the MANET with additional improvements. The MDCA is tested and validated using Qualnet v7.1 simulation tool. This work also introduces a new simulation module for a flooding attack called the resource consumption attack (RCA) using Qualnet v7.1. The results highlight the high efficiency of the MDCA in detecting RCAs in MANETs.

  8. Adaptive MANET Multipath Routing Algorithm Based on the Simulated Annealing Approach

    Directory of Open Access Journals (Sweden)

    Sungwook Kim

    2014-01-01

    Full Text Available Mobile ad hoc network represents a system of wireless mobile nodes that can freely and dynamically self-organize network topologies without any preexisting communication infrastructure. Due to characteristics like temporary topology and absence of centralized authority, routing is one of the major issues in ad hoc networks. In this paper, a new multipath routing scheme is proposed by employing simulated annealing approach. The proposed metaheuristic approach can achieve greater and reciprocal advantages in a hostile dynamic real world network situation. Therefore, the proposed routing scheme is a powerful method for finding an effective solution into the conflict mobile ad hoc network routing problem. Simulation results indicate that the proposed paradigm adapts best to the variation of dynamic network situations. The average remaining energy, network throughput, packet loss probability, and traffic load distribution are improved by about 10%, 10%, 5%, and 10%, respectively, more than the existing schemes.

  9. Analysis of mechanical effects caused by plasma disruptions in the European breeder out of tube solid breeder blanket design with MANET as structural material

    International Nuclear Information System (INIS)

    Boccaccini, L.V.; Ruatto, P.

    1995-01-01

    In this paper we deal with some aspects related to the mechanical behaviour of the European breeder out of tube solid breeder blanket for the DEMO reactor during plasma disruptions. The first aspect regards the properties of the martensitic steel MANET which has been chosen as structural material. MANET is a magnetic material and its fracture toughness properties degrade considerably under irradiation. These two features have been taken into account in the calculation of magentic forces and in the assessment of conditions of unstable crack propagation respectively. As second aspect, a comparison between an electrically segmented and a continuous blanket design has been performed. The analysis reveals lower mechanical stresses for the second design during the DEMO reference disruption and in case of faster disruptions. (orig.)

  10. Evaluation of mobile ad hoc network reliability using propagation-based link reliability model

    International Nuclear Information System (INIS)

    Padmavathy, N.; Chaturvedi, Sanjay K.

    2013-01-01

    A wireless mobile ad hoc network (MANET) is a collection of solely independent nodes (that can move randomly around the area of deployment) making the topology highly dynamic; nodes communicate with each other by forming a single hop/multi-hop network and maintain connectivity in decentralized manner. MANET is modelled using geometric random graphs rather than random graphs because the link existence in MANET is a function of the geometric distance between the nodes and the transmission range of the nodes. Among many factors that contribute to the MANET reliability, the reliability of these networks also depends on the robustness of the link between the mobile nodes of the network. Recently, the reliability of such networks has been evaluated for imperfect nodes (transceivers) with binary model of communication links based on the transmission range of the mobile nodes and the distance between them. However, in reality, the probability of successful communication decreases as the signal strength deteriorates due to noise, fading or interference effects even up to the nodes' transmission range. Hence, in this paper, using a propagation-based link reliability model rather than a binary-model with nodes following a known failure distribution to evaluate the network reliability (2TR m , ATR m and AoTR m ) of MANET through Monte Carlo Simulation is proposed. The method is illustrated with an application and some imperative results are also presented

  11. Detection and Prevention of Denial of Service (DoS Attacks in Mobile Ad Hoc Networks using Reputation-based Incentive Schemes

    Directory of Open Access Journals (Sweden)

    Mieso, K Denko

    2005-08-01

    Full Text Available Mobile ad hoc networks (MANETs are dynamic mobile networks that can be formed in the absence of any pre-existing communication infrastructure. In addition to node mobility, a MANET is characterized by limited resources such as bandwidth, battery power, and storage space. The underlying assumption in MANETs is that the intermediate nodes cooperate in forwarding packets. However, this assumption does not hold in commercial and emerging civilian applications. MANETs are vulnerable to Denial of Service (DoS due to their salient characteristics. There is a need to provide an incentive mechanism that can provide cooperation among nodes in the network and improve overall network performance by reducing DoS attacks. In this paper, we propose a reputation-based incentive mechanism for detecting and preventing DoS attacks. DoS attacks committed by selfish and malicious nodes were investigated. Our scheme motivates nodes to cooperate and excludes them from the network only if they fail to do so. We evaluated the performance of our scheme using the packet delivery ratio, the routing and communication overhead, and misbehaving node detection in a discrete event-simulation environment. The results indicate that a reputation-based incentive mechanism can significantly reduce the effect of DoS attacks and improve performance in MANETs.

  12. DIRECTIONAL OPPORTUNISTIC MECHANISM IN CLUSTER MESSAGE CRITICALITY LEVEL BASED ZIGBEE ROUTING

    OpenAIRE

    B.Rajeshkanna *1, Dr.M.Anitha 2

    2018-01-01

    The cluster message criticality level based zigbee routing(CMCLZOR) has been proposed for routing the cluster messages in wireless smart energy home area networks. It employs zigbee opportunistic shortcut tree routing(ZOSTR) and AODV individually for routing normal messages and highly critical messages respectively. ZOSTR allows the receiving nodes to compete for forwarding a packet with the priority of left-over hops rather than stating single next hop node like unicast protocols. Since it h...

  13. Soporte de QoS con 802.11e para tráfico heterogéneo en ambientes MANET

    OpenAIRE

    Murazzo, María Antonia; Rodríguez, Nelson R.; Guevara, Miguel José; Scheffer, María

    2014-01-01

    Hoy en día existe una gran necesidad de mejorar la calidad de servicio (QoS) ofrecida en redes móviles Ad Hoc (Mobile Ad-Hoc Networks -MANET-) que actualmente sólo ofrecen servicio best effort. Esto posee gran impacto en las aplicaciones que se corren, las cuales generan tráficos con diferentes requerimientos de recursos de la red. El presente trabajo tiene como objetivo fundamental analizar el comportamiento de la implementación de QoS en la sub capa MAC mediante 802.11e en ambientes con trá...

  14. Analysis of mechanical effects caused by plasma disruptions in the European BOT solid breeder blanket design with MANET as structural material

    International Nuclear Information System (INIS)

    Boccaccini, L.V.; Ruatto, P.

    1994-01-01

    The Karlsruhe Nuclear Center is developing, through design and experimental work, a BOT (Breeder Out of Tube) Helium Cooled Solid Breeder Blanket for a DEMO application. One of the crucial problems in the blanket design is to demonstrate the capability of the structure to withstand the mechanical effects of a major plasma disruption as extrapolated to DEMO from the experience of present machines. In this paper the results of the assessment work are presented; the acceptability of the design is discussed on the basis of a stress analysis of the structure under combined thermal and electromagnetic loads. The martensitic steel MANET has been chosen as structural material, because it is able to withstand the high neutron fluence in Demo (70 dpa) without appreciably swelling and has good thermal-mechanical properties - lower thermal expansion and higher strength - in comparison to AISI 316L steel. As far as it concerns the mechanical effects of plasma disruptions, MANET presents two important features which have been carefully investigated in the assessment: the magnetic properties of the material and the degradation of the fracture toughness behavior under irradiation

  15. Secure and Fair Cluster Head Selection Protocol for Enhancing Security in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    B. Paramasivan

    2014-01-01

    Full Text Available Mobile ad hoc networks (MANETs are wireless networks consisting of number of autonomous mobile devices temporarily interconnected into a network by wireless media. MANETs become one of the most prevalent areas of research in the recent years. Resource limitations, energy efficiency, scalability, and security are the great challenging issues in MANETs. Due to its deployment nature, MANETs are more vulnerable to malicious attack. The secure routing protocols perform very basic security related functions which are not sufficient to protect the network. In this paper, a secure and fair cluster head selection protocol (SFCP is proposed which integrates security factors into the clustering approach for achieving attacker identification and classification. Byzantine agreement based cooperative technique is used for attacker identification and classification to make the network more attack resistant. SFCP used to solve this issue by making the nodes that are totally surrounded by malicious neighbors adjust dynamically their belief and disbelief thresholds. The proposed protocol selects the secure and energy efficient cluster head which acts as a local detector without imposing overhead to the clustering performance. SFCP is simulated in network simulator 2 and compared with two protocols including AODV and CBRP.

  16. Secure and fair cluster head selection protocol for enhancing security in mobile ad hoc networks.

    Science.gov (United States)

    Paramasivan, B; Kaliappan, M

    2014-01-01

    Mobile ad hoc networks (MANETs) are wireless networks consisting of number of autonomous mobile devices temporarily interconnected into a network by wireless media. MANETs become one of the most prevalent areas of research in the recent years. Resource limitations, energy efficiency, scalability, and security are the great challenging issues in MANETs. Due to its deployment nature, MANETs are more vulnerable to malicious attack. The secure routing protocols perform very basic security related functions which are not sufficient to protect the network. In this paper, a secure and fair cluster head selection protocol (SFCP) is proposed which integrates security factors into the clustering approach for achieving attacker identification and classification. Byzantine agreement based cooperative technique is used for attacker identification and classification to make the network more attack resistant. SFCP used to solve this issue by making the nodes that are totally surrounded by malicious neighbors adjust dynamically their belief and disbelief thresholds. The proposed protocol selects the secure and energy efficient cluster head which acts as a local detector without imposing overhead to the clustering performance. SFCP is simulated in network simulator 2 and compared with two protocols including AODV and CBRP.

  17. An Improvement over PBOA MAC Protocol by Considering Link Quality in MANET

    OpenAIRE

    Shariati, Nafiseh; Shirazinia, Amirpasha

    2008-01-01

    We propose a methodology for improving theperformance of Progressive Back Off Algorithm (PBOA)which is a protocol that performs medium access controljointly with power control in Ad-hoc networks.Our method selects the optimum SNR thresholds based onlink quality. It adjusts the role of nodes’ mobility in network throughput. Simulation results show that the improvedprotocol outperforms PBOA without adaptation taken from link quality. Qc 20120131

  18. Analysis of CBRP for UDP and TCP Traffic-Classes to measure throughput in MANETs

    Directory of Open Access Journals (Sweden)

    Hardeep Singh Rayait

    2013-01-01

    Full Text Available In this paper, we analyse the throughput of both TCP and UDP traffic classes for cluster based routing protocol for mobile ad hoc network. It uses clustering structure to improve throughput , decrease average end-to-end delay and improve the average packet delivery ratio. We simulate our routing protocol for nodes running the IEEE802.11 MAC for analysis of throughput for both UDP and TCP traffic classes. The application layer protocol used for UDP is CBR and for TCP is FTP.

  19. Where-Fi: a dynamic energy-efficient multimedia distribution framework for MANETs

    Science.gov (United States)

    Mohapatra, Shivajit; Carbunar, Bogdan; Pearce, Michael; Chaudhri, Rohit; Vasudevan, Venu

    2008-01-01

    Next generation mobile ad-hoc applications will revolve around users' need for sharing content/presence information with co-located devices. However, keeping such information fresh requires frequent meta-data exchanges, which could result in significant energy overheads. To address this issue, we propose distributed algorithms for energy efficient dissemination of presence and content usage information between nodes in mobile ad-hoc networks. First, we introduce a content dissemination protocol (called CPMP) for effectively distributing frequent small meta-data updates between co-located devices using multicast. We then develop two distributed algorithms that use the CPMP protocol to achieve "phase locked" wake up cycles for all the participating nodes in the network. The first algorithm is designed for fully-connected networks and then extended in the second to handle hidden terminals. The "phase locked" schedules are then exploited to adaptively transition the network interface to a deep sleep state for energy savings. We have implemented a prototype system (called "Where-Fi") on several Motorola Linux-based cell phone models. Our experimental results show that for all network topologies our algorithms were able to achieve "phase locking" between nodes even in the presence of hidden terminals. Moreover, we achieved battery lifetime extensions of as much as 28% for fully connected networks and about 20% for partially connected networks.

  20. Fault-tolerance of Cluster Management in (MANETs) by assistant and mobile agents

    International Nuclear Information System (INIS)

    Hamad, H.

    2007-01-01

    Most researches today trend to clustering in ad hoc networks as a solution to the management problem in flat ad hoc networks. Clustering aims to choose suitable nodes to lead the network i.e., the cluster heads. When a cluster head fails, reclustering is needed. However, this will be costly due to the characteristics of the ad hoc networks such as mobility and exhaustion. In this research we developed a fault tolerance mechanism to avoid re-clustering and other drawbacks that result from loosing the Cluster Head (CH). A Mobile Agent (MA) will be responsible of carrying out the jobs of the CH i.e., the CH will host the MA which will be the real manager of the cluster. Furthermore, the closest node to the CH will be chosen as an assistant and the MA will update the assistant. Each of the CH and the assistant will have Remote Objects (RO) to communicate with each other. The main jobs of the assistant are to temporarily replace the CH when fails; then it will choose the next CH based on clustering algorithm. Simulation results show an enhancement of the performance of using an assistant, MA and RO. (author)

  1. Verifikasi Dua Varian Protokol Ad hoc On demand Distance Vector dengan UPPAAL

    Directory of Open Access Journals (Sweden)

    Ika Oktavia Suzanti

    2015-01-01

    Abstract  MANET is a group of wireless mobile that connected one to each other without fixed infrastructure so topology could change at anytime. MANET routing protocol has two models which are reactive routing protocol that built routing table only when needed and proactive routing protocol that maintain routing table periodically. General property which had to be satisfied by ad-hoc network protocol are route discovery, packet delivery and loop freedom. AODV is a reactive protocol in MANET that has time standard to determine how long a route is valid to be used (route validity so route discovery and packet delivery property should be satisfied in a specifically certain time. Protocol verification process done by modeling protocol specification using technique, tool and mathematic language. In this research protocol modeled using timed automata which is a modeling language that could be used to model a time dependent system in each process. Verification using timed automata can automatically done by UPPAAL tool model checker. Protocol which will be verified are AODV Break Avoidance by Ali Khosrozadeh et al. and AODV Reliable Delivery by Liu Jian and Fang-Min. Result of this protocol verification prove that AODV BA could satisfied route discovery property and AODV Reliable Delivery could satisfied packet delivery property within their specification time.   Keywords—Protocol Verification, Timed Automata, AODV, UPPAAL

  2. Building Realistic Mobility Models for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Adrian Pullin

    2018-04-01

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

  3. A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

    Science.gov (United States)

    Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

    2014-01-01

    Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

  4. Coolant compatibility studies. The effect of irradiation on tensile properties and stress corrosion cracking sensitivity of martensitic steels. MANET 4 - complementary studies

    International Nuclear Information System (INIS)

    Nystrand, A.C.

    1994-02-01

    Tensile and stress corrosion cracking tests have been carried out on MANET-type (1.4914 and FV448) and reduced activation (LA12TaLC) high-chromium martensitic steels. The materials had previously been exposed up to 5000 h at ∼275 degrees C in the core, above the core and remote from the core of a high pressure water loop in the Studsvik R2 reactor. After the mechanical testing the materials were examined visually and metallographically. The steel samples exposed in the core section showed large increases in tensile yield strengths when tested at 250 degrees C. However, the magnitude of the radiation hardening was considerably smaller in the reduced activation steel compared to the commercial steels; this observation is consistent with published data on other high-chromium martensitic steels and is associated with the lower chromium content of the LA12TaLC steel (8.9%) compared with those of the commercial steels (10.6 and 11.3%). Irradiation assisted stress corrosion cracking (IASCC) was not detected in any of the stressed steel samples after autoclave testing for times up to 1500 h at 250 degrees C in air-saturated high purity water. This apparent resistance to IASCC may be due to the high chromium martensitic steels not being sensitized by the irradiation in a comparable manner to that shown by the austenitic steels. However, additional studies are required to clarify some of the existing uncertainties with respect to IASCC of these martensitic steels

  5. A Protocol for Content-Based Communication in Disconnected Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Julien Haillot

    2010-01-01

    Full Text Available In content-based communication, information flows towards interested hosts rather than towards specifically set destinations. This new style of communication perfectly fits the needs of applications dedicated to information sharing, news distribution, service advertisement and discovery, etc. In this paper we address the problem of supporting content-based communication in partially or intermittently connected mobile ad hoc networks (MANETs. The protocol we designed leverages on the concepts of opportunistic networking and delay-tolerant networking in order to account for the absence of end-to-end connectivity in disconnected MANETs. The paper provides an overview of the protocol, as well as simulation results that show how this protocol can perform in realistic conditions.

  6. Energy-Efficient Cluster Based Routing Protocol in Mobile Ad Hoc Networks Using Network Coding

    OpenAIRE

    Srinivas Kanakala; Venugopal Reddy Ananthula; Prashanthi Vempaty

    2014-01-01

    In mobile ad hoc networks, all nodes are energy constrained. In such situations, it is important to reduce energy consumption. In this paper, we consider the issues of energy efficient communication in MANETs using network coding. Network coding is an effective method to improve the performance of wireless networks. COPE protocol implements network coding concept to reduce number of transmissions by mixing the packets at intermediate nodes. We incorporate COPE into cluster based routing proto...

  7. Novel Clustering Method Based on K-Medoids and Mobility Metric

    Directory of Open Access Journals (Sweden)

    Y. Hamzaoui

    2018-06-01

    Full Text Available The structure and constraint of MANETS influence negatively the performance of QoS, moreover the main routing protocols proposed generally operate in flat routing. Hence, this structure gives the bad results of QoS when the network becomes larger and denser. To solve this problem we use one of the most popular methods named clustering. The present paper comes within the frameworks of research to improve the QoS in MANETs. In this paper we propose a new algorithm of clustering based on the new mobility metric and K-Medoid to distribute the nodes into several clusters. Intuitively our algorithm can give good results in terms of stability of the cluster, and can also extend life time of cluster head.

  8. Link reliability based hybrid routing for tactical mobile ad hoc network

    Institute of Scientific and Technical Information of China (English)

    Xie Xiaochuan; Wei Gang; Wu Keping; Wang Gang; Jia Shilou

    2008-01-01

    Tactical mobile ad hoc network (MANET) is a collection of mobile nodes forming a temporary network,without the aid of pre-established network infrastructure. The routing protocol has a crucial impact on the networkperformance in battlefields. Link reliability based hybrid routing (LRHR) is proposed, which is a novel hybrid routing protocol, for tactical MANET. Contrary to the traditional single path routing strategy, multiple paths are established between a pair of source-destination nodes. In the hybrid routing strategy, the rate of topological change provides a natural mechanism for switching dynamically between table-driven and on-demand routing. The simulation results indicate that the performances of the protocol in packet delivery ratio, routing overhead, and average end-to-end delay are better than the conventional routing protocol.

  9. Monitoring and classifying animal behavior using ZigBee-based mobile ad hoc wireless sensor networks and artificial neural networks

    DEFF Research Database (Denmark)

    S. Nadimi, Esmaeil; Nyholm Jørgensen, Rasmus; Blanes-Vidal, Victoria

    2012-01-01

    Animal welfare is an issue of great importance in modern food production systems. Because animal behavior provides reliable information about animal health and welfare, recent research has aimed at designing monitoring systems capable of measuring behavioral parameters and transforming them...... into their corresponding behavioral modes. However, network unreliability and high-energy consumption have limited the applicability of those systems. In this study, a 2.4-GHz ZigBee-based mobile ad hoc wireless sensor network (MANET) that is able to overcome those problems is presented. The designed MANET showed high...... communication reliability, low energy consumption and low packet loss rate (14.8%) due to the deployment of modern communication protocols (e.g. multi-hop communication and handshaking protocol). The measured behavioral parameters were transformed into the corresponding behavioral modes using a multilayer...

  10. Mobile Ad Hoc Network Energy Cost Algorithm Based on Artificial Bee Colony

    Directory of Open Access Journals (Sweden)

    Mustafa Tareq

    2017-01-01

    Full Text Available A mobile ad hoc network (MANET is a collection of mobile nodes that dynamically form a temporary network without using any existing network infrastructure. MANET selects a path with minimal number of intermediate nodes to reach the destination node. As the distance between each node increases, the quantity of transmission power increases. The power level of nodes affects the simplicity with which a route is constituted between a couple of nodes. This study utilizes the swarm intelligence technique through the artificial bee colony (ABC algorithm to optimize the energy consumption in a dynamic source routing (DSR protocol in MANET. The proposed algorithm is called bee DSR (BEEDSR. The ABC algorithm is used to identify the optimal path from the source to the destination to overcome energy problems. The performance of the BEEDSR algorithm is compared with DSR and bee-inspired protocols (BeeIP. The comparison was conducted based on average energy consumption, average throughput, average end-to-end delay, routing overhead, and packet delivery ratio performance metrics, varying the node speed and packet size. The BEEDSR algorithm is superior in performance than other protocols in terms of energy conservation and delay degradation relating to node speed and packet size.

  11. Energy-Aware Multipath Routing Scheme Based on Particle Swarm Optimization in Mobile Ad Hoc Networks.

    Science.gov (United States)

    Robinson, Y Harold; Rajaram, M

    2015-01-01

    Mobile ad hoc network (MANET) is a collection of autonomous mobile nodes forming an ad hoc network without fixed infrastructure. Dynamic topology property of MANET may degrade the performance of the network. However, multipath selection is a great challenging task to improve the network lifetime. We proposed an energy-aware multipath routing scheme based on particle swarm optimization (EMPSO) that uses continuous time recurrent neural network (CTRNN) to solve optimization problems. CTRNN finds the optimal loop-free paths to solve link disjoint paths in a MANET. The CTRNN is used as an optimum path selection technique that produces a set of optimal paths between source and destination. In CTRNN, particle swarm optimization (PSO) method is primly used for training the RNN. The proposed scheme uses the reliability measures such as transmission cost, energy factor, and the optimal traffic ratio between source and destination to increase routing performance. In this scheme, optimal loop-free paths can be found using PSO to seek better link quality nodes in route discovery phase. PSO optimizes a problem by iteratively trying to get a better solution with regard to a measure of quality. The proposed scheme discovers multiple loop-free paths by using PSO technique.

  12. Data delivery method based on neighbor nodes' information in a mobile ad hoc network.

    Science.gov (United States)

    Kashihara, Shigeru; Hayashi, Takuma; Taenaka, Yuzo; Okuda, Takeshi; Yamaguchi, Suguru

    2014-01-01

    This paper proposes a data delivery method based on neighbor nodes' information to achieve reliable communication in a mobile ad hoc network (MANET). In a MANET, it is difficult to deliver data reliably due to instabilities in network topology and wireless network condition which result from node movement. To overcome such unstable communication, opportunistic routing and network coding schemes have lately attracted considerable attention. Although an existing method that employs such schemes, MAC-independent opportunistic routing and encoding (MORE), Chachulski et al. (2007), improves the efficiency of data delivery in an unstable wireless mesh network, it does not address node movement. To efficiently deliver data in a MANET, the method proposed in this paper thus first employs the same opportunistic routing and network coding used in MORE and also uses the location information and transmission probabilities of neighbor nodes to adapt to changeable network topology and wireless network condition. The simulation experiments showed that the proposed method can achieve efficient data delivery with low network load when the movement speed is relatively slow.

  13. Data Delivery Method Based on Neighbor Nodes’ Information in a Mobile Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Shigeru Kashihara

    2014-01-01

    Full Text Available This paper proposes a data delivery method based on neighbor nodes’ information to achieve reliable communication in a mobile ad hoc network (MANET. In a MANET, it is difficult to deliver data reliably due to instabilities in network topology and wireless network condition which result from node movement. To overcome such unstable communication, opportunistic routing and network coding schemes have lately attracted considerable attention. Although an existing method that employs such schemes, MAC-independent opportunistic routing and encoding (MORE, Chachulski et al. (2007, improves the efficiency of data delivery in an unstable wireless mesh network, it does not address node movement. To efficiently deliver data in a MANET, the method proposed in this paper thus first employs the same opportunistic routing and network coding used in MORE and also uses the location information and transmission probabilities of neighbor nodes to adapt to changeable network topology and wireless network condition. The simulation experiments showed that the proposed method can achieve efficient data delivery with low network load when the movement speed is relatively slow.

  14. Estudio del comportamiento de una red Ad-Hoc MANET metropolitana basado en los protocolos de enrutamiento

    Directory of Open Access Journals (Sweden)

    Mario Garzón

    2011-11-01

    Full Text Available En el presente artículo se determina el comportamiento de una red de área metropolitana bajo el estándar IEEE 802.16 tanto para nodos fijos como móviles, utilizando NCTUns, considerando el comportamiento de los protocolos de enrutamiento. Mostrando en los resultados las velocidades de transmisión que se pueden obtener en redes Mesh y la distancia máxima a la cual pueden encontrarse los nodos y la estación radio base.

  15. A Conceptual Framework for Representing Human Behavior Characteristics in a System of Systems Agent-based Survivability Simulation-Intelligent Networks

    Science.gov (United States)

    2014-10-17

    2012: Leadership award, Biotechnology in Piedmond Triad. 2010-2012 Board member, Gateway University Research Park, Inc., Greensboro. 2010-2012...Carolina Biotechnology . 2010-2012 Board member, The Oak Ridge Associated Universities (ORAU) Historically Black Colleges and Universities/ Minority... Magazine , 50 (7), 121 – 127. Wei, W. & GuoSun, Z. (2010). Bayesian cognitive trust model based self-clustering algorithm for MANETs. Information

  16. ADAPTIVE CLUSTER BASED ROUTING PROTOCOL WITH ANT COLONY OPTIMIZATION FOR MOBILE AD-HOC NETWORK IN DISASTER AREA

    Directory of Open Access Journals (Sweden)

    Enrico Budianto

    2012-07-01

    Full Text Available In post-disaster rehabilitation efforts, the availability of telecommunication facilities takes important role. However, the process to improve telecommunication facilities in disaster area is risky if it is done by humans. Therefore, a network method that can work efficiently, effectively, and capable to reach the widest possible area is needed. This research introduces a cluster-based routing protocol named Adaptive Cluster Based Routing Protocol (ACBRP equipped by Ant Colony Optimization method, and its implementation in a simulator developed by author. After data analysis and statistical tests, it can be concluded that routing protocol ACBRP performs better than AODV and DSR routing protocol. Pada upaya rehabilitasi pascabencana, ketersediaan fasilitas telekomunikasi memiliki peranan yang sangat penting. Namun, proses untuk memperbaiki fasilitas telekomunikasi di daerah bencana memiliki resiko jika dilakukan oleh manusia. Oleh karena itu, metode jaringan yang dapat bekerja secara efisien, efektif, dan mampu mencapai area seluas mungkin diperlukan. Penelitian ini memperkenalkan sebuah protokol routing berbasis klaster bernama Adaptive Cluster Based Routing Protocol (ACBRP, yang dilengkapi dengan metode Ant Colony Optimization, dan diimplementasikan pada simulator yang dikembangkan penulis. Setelah data dianalisis dan dilakukan uji statistik, disimpulkan bahwa protokol routing ACBRP beroperasi lebih baik daripada protokol routing AODV maupun DSR.

  17. WEAMR — A Weighted Energy Aware Multipath Reliable Routing Mechanism for Hotline-Based WSNs

    Directory of Open Access Journals (Sweden)

    Ki-Hyung Kim

    2013-05-01

    Full Text Available Reliable source to sink communication is the most important factor for an efficient routing protocol especially in domains of military, healthcare and disaster recovery applications. We present weighted energy aware multipath reliable routing (WEAMR, a novel energy aware multipath routing protocol which utilizes hotline-assisted routing to meet such requirements for mission critical applications. The protocol reduces the number of average hops from source to destination and provides unmatched reliability as compared to well known reactive ad hoc protocols i.e., AODV and AOMDV. Our protocol makes efficient use of network paths based on weighted cost calculation and intelligently selects the best possible paths for data transmissions. The path cost calculation considers end to end number of hops, latency and minimum energy node value in the path. In case of path failure path recalculation is done efficiently with minimum latency and control packets overhead. Our evaluation shows that our proposal provides better end-to-end delivery with less routing overhead and higher packet delivery success ratio compared to AODV and AOMDV. The use of multipath also increases overall life time of WSN network using optimum energy available paths between sender and receiver in WDNs.

  18. Secure Communication and Information Exchange using Authenticated Ciphertext Policy Attribute-Based Encryption in Mobile Ad-hoc Network

    Directory of Open Access Journals (Sweden)

    Samsul Huda

    2016-08-01

    Full Text Available MANETs are considered as suitable for commercial applications such as law enforcement, conference meeting, and sharing information in a student classroom and critical services such as military operations, disaster relief, and rescue operations. Meanwhile, in military operation especially in the battlefield in freely medium which naturally needs high mobility and flexibility. Thus, applying MANETs make these networks vulnerable to various types of attacks such aspacket eavesdropping, data disseminating, message replay, message modification, and especially privacy issue. In this paper, we propose a secure communication and information exchange in MANET with considering secure adhoc routing and secure information exchange. Regarding privacy issue or anonymity, we use a reliable asymmetric encryption which protecting user privacy by utilizing insensitive user attributes as user identity, CP-ABE (Ciphertext-Policy Attribute-Based Encryption cryptographic scheme. We also design protocols to implement the proposed scheme for various battlefied scenarios in real evironment using embedded devices. Our experimental results showed that the additional of HMAC (Keyed-Hash Message Authentication Code and AES (Advanced Encryption standard schemes using processor 1.2GHz only take processing time about 4.452 ms,  we can confirm that our approach by using CP-ABE with added HMAC and AES schemes make low overhead.

  19. Characterizing Deficiencies of Path-Based Routing for Wireless Multi-Hop Networks

    Science.gov (United States)

    2017-05-01

    all traffic). In order to avoid the effects of congestion and queue overflows, data rates are set arbitrarily high. For both OLSR and AODV, we test two...Loadng: Towards aodv version 2,” in Vehicular Technology Conference (VTC Fall), 2012 IEEE. IEEE, 2012, pp. 1–5. [11] T. Clausen, A. C. de Verdiere, J

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

    Science.gov (United States)

    Kumar, Sumit; Mehfuz, Shabana

    2017-06-01

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

  1. IDMA: improving the defense against malicious attack for mobile ad hoc networks based on ARIP protocol

    Science.gov (United States)

    Peng, Chaorong; Chen, Chang Wen

    2008-04-01

    Malicious nodes are mounting increasingly sophisticated attacking operations on the Mobile Ad Hoc Networks (MANETs). This is mainly because the IP-based MANETs are vulnerable to attacks by various malicious nodes. However, the defense against malicious attack can be improved when a new layer of network architecture can be developed to separate true IP address from disclosing to the malicious nodes. In this paper, we propose a new algorithm to improve the defense against malicious attack (IDMA) that is based on a recently developed Assignment Router Identify Protocol (ARIP) for the clustering-based MANET management. In the ARIP protocol, we design the ARIP architecture based on the new Identity instead of the vulnerable IP addresses to provide the required security that is embedded seamlessly into the overall network architecture. We make full use of ARIP's special property to monitor gateway forward packets by Reply Request Route Packets (RREP) without additional intrusion detection layer. We name this new algorithm IDMA because of its inherent capability to improve the defense against malicious attacks. Through IDMA, a watching algorithm can be established so as to counterattack the malicious node in the routing path when it unusually drops up packets. We provide analysis examples for IDMA for the defense against a malicious node that disrupts the route discovery by impersonating the destination, or by responding with state of corrupted routing information, or by disseminating forged control traffic. The IDMA algorithm is able to counterattack the malicious node in the cases when the node lunch DoS attack by broadcast a large number of route requests, or make Target traffic congestion by delivering huge mount of data; or spoof the IP addresses and send forge packets with a fake ID to the same Target causing traffic congestion at that destination. We have implemented IDMA algorism using the GloMoSim simulator and have demonstrated its performance under a variety of

  2. Application of Swarm Intelligence Based Routingprotocols for Wireless Adhoc Sensor Network

    Directory of Open Access Journals (Sweden)

    Mrutyunjaya PANDA

    2011-07-01

    Full Text Available The enormous growth of wireless sensor network (WSN research has opined challenges about their ease in implementation and performance evaluation. Efficient swarm intelligence based routing protocols that can be used to obtain the application specific service guarantee are the key design issues in designing a WSN model. In this paper, an experimental testbed is designed with 100 sensor nodes deployed in a dense environment to address the scalability and performance issues of WSN. In this paper, we use Flooded Piggyback (FP and SC-MCBR ant colony based routing along with AODV and MCBR Tree in order to design an efficient WSN model. Finally, simulation results are presented with various performance measures to understand the efficacy of the proposed WSN design.

  3. Performance analysis and implementation of proposed mechanism for detection and prevention of security attacks in routing protocols of vehicular ad-hoc network (VANET

    Directory of Open Access Journals (Sweden)

    Parul Tyagi

    2017-07-01

    Full Text Available Next-generation communication networks have become widely popular as ad-hoc networks, broadly categorized as the mobile nodes based on mobile ad-hoc networks (MANET and the vehicular nodes based vehicular ad-hoc networks (VANET. VANET is aimed at maintaining safety to vehicle drivers by begin autonomous communication with the nearby vehicles. Each vehicle in the ad-hoc network performs as an intelligent mobile node characterized by high mobility and formation of dynamic networks. The ad-hoc networks are decentralized dynamic networks that need efficient and secure communication requirements due to the vehicles being persistently in motion. These networks are more susceptible to various attacks like Warm Hole attacks, denial of service attacks and Black Hole Attacks. The paper is a novel attempt to examine and investigate the security features of the routing protocols in VANET, applicability of AODV (Ad hoc On Demand protocol to detect and tackle a particular category of network attacks, known as the Black Hole Attacks. A new algorithm is proposed to enhance the security mechanism of AODV protocol and to introduce a mechanism to detect Black Hole Attacks and to prevent the network from such attacks in which source node stores all route replies in a look up table. This table stores the sequences of all route reply, arranged in ascending order using PUSH and POP operations. The priority is calculated based on sequence number and discard the RREP having presumably very high destination sequence number. The result show that proposed algorithm for detection and prevention of Black Hole Attack increases security in Intelligent Transportation System (ITS and reduces the effect of malicious node in the VANET. NCTUNs simulator is used in this research work.

  4. Illustration, detection and prevention of sleep deprivation anomaly in mobile ad hoc networks

    International Nuclear Information System (INIS)

    Nadeem, A.; Ahsan, K.; Sarim, M.

    2017-01-01

    MANETs (Mobile Ad Hoc Networks) have applications in various walks of life from rescue operations to battle field operations, personal and commercial. However, routing operations in MANETs are still vulnerable to anomalies and DoS (Denial of Service) attacks such as sleep deprivation. In SD (Sleep Deprivation) attack malicious node exploits the vulnerability in the route discovery function of the reactive routing protocol for example AODV (Ad Hoc On-Demand Distance Vector). In this paper, we first illustrate the SD anomaly in MANETs and then propose a SD detection and prevention algorithm which efficiently deals with this attack. We assess the performance of our proposed approach through simulation, evaluating its successfulness using different network scenarios. (author)

  5. Mobility Based Key Management Technique for Multicast Security in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    B. Madhusudhanan

    2015-01-01

    Full Text Available In MANET multicasting, forward and backward secrecy result in increased packet drop rate owing to mobility. Frequent rekeying causes large message overhead which increases energy consumption and end-to-end delay. Particularly, the prevailing group key management techniques cause frequent mobility and disconnections. So there is a need to design a multicast key management technique to overcome these problems. In this paper, we propose the mobility based key management technique for multicast security in MANET. Initially, the nodes are categorized according to their stability index which is estimated based on the link availability and mobility. A multicast tree is constructed such that for every weak node, there is a strong parent node. A session key-based encryption technique is utilized to transmit a multicast data. The rekeying process is performed periodically by the initiator node. The rekeying interval is fixed depending on the node category so that this technique greatly minimizes the rekeying overhead. By simulation results, we show that our proposed approach reduces the packet drop rate and improves the data confidentiality.

  6. CERTIFICATE REVOCATION SCHEME BASED ON WEIGHTED VOTING GAME AND RATIONAL SECURE MULTIPARTY COMPUTING

    Directory of Open Access Journals (Sweden)

    N Aravinthan

    2017-03-01

    Full Text Available The Mobile Adhoc Network consists of deployed mobile nodes which lead to the frequent changes in network topology. Due to topology changes, required infrastructure is unavailable for communication. Moreover, malicious nodes present in MANET make use of this modification and can easily launch highly vulnerable attacks on the routing path of the network. Hence, Security issue such as removing misbehaving nodes is the primary issue in MANET. Effective certificate revocation scheme was introduced to identify and eliminate the node with malicious activities in the network based on the weighted voting game (ECR-WVG approach. In this approach, weights and quota were two factors, determined for an effective revocation of malicious nodes certificates. However, security during multiparty transmission was not taken into account in ECR-WVG. In Effective Certificate Revocation Scheme based on Weighted Voting Game and Rational Secure Multi-Party Computing (ECR-WVG-RSMPC method, rational secret sharing scheme is introduced along with ECR-WVG approach for securing multiparty transmission. Performance evaluation can be done between ECR-WVG and ECR-WVG-RSMPC in terms of false revocation, malicious node revocation, normalized time for revocation and revocation accuracy ratio.

  7. AD HOC Networks for the Autonomous Car

    Science.gov (United States)

    Ron, Davidescu; Negrus, Eugen

    2017-10-01

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

  8. Emerging Radio and Manet Technology Study: Research Support for a Survey of State-of-the-art Commercial and Military Hardware/Software for Mobile Ad Hoc Networks

    Science.gov (United States)

    2014-10-01

    Exynos 4412 Prime, 1.17GHz ARMS Cortex -A9 quad core processor . It features Ethernet, 2x USB ports, audio, power connectors, micro HDMI, and micro SD...uses a camera mounted on the soldier’s helmet and a Harris video processor to gather and share video over the radio network. 3.1.1.4 Thales Group...on ARM processors . There are a limited few based on MIPS processors but they are uncommon and not well supported. This is in contrast to routers

  9. Applying self-organizing map and modified radial based neural network for clustering and routing optimal path in wireless network

    Science.gov (United States)

    Hoomod, Haider K.; Kareem Jebur, Tuka

    2018-05-01

    Mobile ad hoc networks (MANETs) play a critical role in today’s wireless ad hoc network research and consist of active nodes that can be in motion freely. Because it consider very important problem in this network, we suggested proposed method based on modified radial basis function networks RBFN and Self-Organizing Map SOM. These networks can be improved by the use of clusters because of huge congestion in the whole network. In such a system, the performance of MANET is improved by splitting the whole network into various clusters using SOM. The performance of clustering is improved by the cluster head selection and number of clusters. Modified Radial Based Neural Network is very simple, adaptable and efficient method to increase the life time of nodes, packet delivery ratio and the throughput of the network will increase and connection become more useful because the optimal path has the best parameters from other paths including the best bitrate and best life link with minimum delays. Proposed routing algorithm depends on the group of factors and parameters to select the path between two points in the wireless network. The SOM clustering average time (1-10 msec for stall nodes) and (8-75 msec for mobile nodes). While the routing time range (92-510 msec).The proposed system is faster than the Dijkstra by 150-300%, and faster from the RBFNN (without modify) by 145-180%.

  10. Testing Applications in MANET Environments through Emulation

    Directory of Open Access Journals (Sweden)

    Pietro Manzoni

    2009-01-01

    Full Text Available Mobile Ad Hoc Network solution testing is typically done using simulation. The simulated code is generally a simplified version of the real code, and thus code porting to actual operating systems lacks a strong validation. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for real ad hoc network environments using low-cost, off-the-shelf devices and open source software. Castadiva is also compatible with the ns-2 simulator, allowing a combined and more complete evaluation. In this work we present our tool and the results obtained when evaluating videocalls in different scenarios, both static and dynamic.

  11. Survey on Reputation and Trust in MANETS

    OpenAIRE

    A. S. Gowri

    2014-01-01

    Wireless Self organizing networks rely[1] on node cooperation to perform and support basic functions like packet forwarding, routing and network management . Lack of Infrastructure, resource constraints and organizational environment of self organizing nodes make them vulnerable to newer threats and challenges. By default, [2] non- cooperative misbehavior activities of the nodes will slowly lead to the performance deterioration of the network. Hence the responsibility of ensuring security and...

  12. Automatic Structure-Based Code Generation from Coloured Petri Nets

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Westergaard, Michael

    2010-01-01

    Automatic code generation based on Coloured Petri Net (CPN) models is challenging because CPNs allow for the construction of abstract models that intermix control flow and data processing, making translation into conventional programming constructs difficult. We introduce Process-Partitioned CPNs...... (PP-CPNs) which is a subclass of CPNs equipped with an explicit separation of process control flow, message passing, and access to shared and local data. We show how PP-CPNs caters for a four phase structure-based automatic code generation process directed by the control flow of processes....... The viability of our approach is demonstrated by applying it to automatically generate an Erlang implementation of the Dynamic MANET On-demand (DYMO) routing protocol specified by the Internet Engineering Task Force (IETF)....

  13. Performance Analysis of On-Demand Routing Protocols in Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Arafatur RAHMAN

    2009-01-01

    Full Text Available Wireless Mesh Networks (WMNs have recently gained a lot of popularity due to their rapid deployment and instant communication capabilities. WMNs are dynamically self-organizing, self-configuring and self-healing with the nodes in the network automatically establishing an adiej hoc network and preserving the mesh connectivity. Designing a routing protocol for WMNs requires several aspects to consider, such as wireless networks, fixed applications, mobile applications, scalability, better performance metrics, efficient routing within infrastructure, load balancing, throughput enhancement, interference, robustness etc. To support communication, various routing protocols are designed for various networks (e.g. ad hoc, sensor, wired etc.. However, all these protocols are not suitable for WMNs, because of the architectural differences among the networks. In this paper, a detailed simulation based performance study and analysis is performed on the reactive routing protocols to verify the suitability of these protocols over such kind of networks. Ad Hoc On-Demand Distance Vector (AODV, Dynamic Source Routing (DSR and Dynamic MANET On-demand (DYMO routing protocol are considered as the representative of reactive routing protocols. The performance differentials are investigated using varying traffic load and number of source. Based on the simulation results, how the performance of each protocol can be improved is also recommended.

  14. PERFORMANCE ANALYSIS OF DSR ROUTING PROTOCOL UNDER ENERGY BASED SELFISH ATTACK IN MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    T.V.P.Sundararajan

    2010-06-01

    Full Text Available Mobile Ad hoc Networks (MANETs rely on the cooperation of all participating nodes to provide the fundamental operations such as routing and data forwarding. However, due to the open structure and scarcely available battery-based energy, node misbehaviors may exist.[1]. One such routing misbehavior is that some selfish nodes will participate in the route discovery and maintenance processes but refuse to forward data packets. This paper pointed out Energy based selfish nodes (EBSN where these selfish nodes tend to use the network but do not cooperate, saving battery life for their own communications [2],[3]. We present a simulation study of the effects of Energy based selfish nodes (EBSN on DSR routing protocol and its impact over network performance in terms of throughput and delay of a mobile ad hoc network where a defined percentage of nodes were misbehaving.

  15. Research on routing algorithm based on the VANET

    Directory of Open Access Journals (Sweden)

    AN Li

    2016-01-01

    Full Text Available For the characteristics of high speed mobility of nodes, frequent changes of dynamic topology and frequent interrupts of the communication links in the VANET, this paper analyzed the defect of the current mobile ad-hoc network routing protocol, and carried on the simulation analysis on the adaptability of AODV, DSR and DSDV routing protocols in VANET applications in the VANET. Through the above research, this paper obtained the conclusion that the AODV routing protocol is more suitable for vehicular ad hoc network environment

  16. Trust-based hexagonal clustering for efficient certificate ...

    Indian Academy of Sciences (India)

    Clustering; certificate management; MANET; security; trust; Voronoi. ... terms of effectiveness of revocation scheme (with respect to revocation rate and time), security, ... Engineering, Thiagarajar College of Engineering, Madurai 625015, India ...

  17. A SURVEY ON DELAY AND NEIGHBOR NODE MONITORING BASED WORMHOLE ATTACK PREVENTION AND DETECTION

    Directory of Open Access Journals (Sweden)

    Sudhir T Bagade

    2016-12-01

    Full Text Available In Mobile Ad-hoc Networks (MANET, network layer attacks, for example wormhole attacks, disrupt the network routing operations and can be used for data theft. Wormhole attacks are of two types: hidden and exposed wormhole. There are various mechanisms in literature which are used to prevent and detect wormhole attacks. In this paper, we survey wormhole prevention and detection techniques and present our critical observations for each. These techniques are based on cryptographic mechanisms, monitoring of packet transmission delay and control packet forwarding behavior of neighbor nodes. We compare the techniques using the following criteria- extra resources needed applicability to different network topologies and routing protocols, prevention/detection capability, etc. We conclude the paper with potential research directions.

  18. A LOOP-BASED APPROACH IN CLUSTERING AND ROUTING IN MOBILE AD HOC NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Li Yanping; Wang Xin; Xue Xiangyang; C.K. Toh

    2006-01-01

    Although clustering is a convenient framework to enable traffic control and service support in Mobile Ad hoc NETworks (MANETs), it is seldom adopted in practice due to the additional traffic overhead it leads to for the resource limited ad hoc network. In order to address this problem, we proposed a loop-based approach to combine clustering and routing. By employing loop topologies, topology information is disseminated with a loop instead of a single node, which provides better robustness, and the nature of a loop that there are two paths between each pair of nodes within a loop suggests smart route recovery strategy. Our approach is composed of setup procedure, regular procedure and recovery procedure to achieve clustering, routing and emergent route recovering.

  19. GA-DoSLD: Genetic Algorithm Based Denial-of-Sleep Attack Detection in WSN

    Directory of Open Access Journals (Sweden)

    Mahalakshmi Gunasekaran

    2017-01-01

    Full Text Available Denial-of-sleep (DoSL attack is a special category of denial-of-service attack that prevents the battery powered sensor nodes from going into the sleep mode, thus affecting the network performance. The existing schemes used for the DoSL attack detection do not provide an optimal energy conservation and key pairing operation. Hence, in this paper, an efficient Genetic Algorithm (GA based denial-of-sleep attack detection (GA-DoSLD algorithm is suggested for analyzing the misbehaviors of the nodes. The suggested algorithm implements a Modified-RSA (MRSA algorithm in the base station (BS for generating and distributing the key pair among the sensor nodes. Before sending/receiving the packets, the sensor nodes determine the optimal route using Ad Hoc On-Demand Distance Vector Routing (AODV protocol and then ensure the trustworthiness of the relay node using the fitness calculation. The crossover and mutation operations detect and analyze the methods that the attackers use for implementing the attack. On determining an attacker node, the BS broadcasts the blocked information to all the other sensor nodes in the network. Simulation results prove that the suggested algorithm is optimal compared to the existing algorithms such as X-MAC, ZKP, and TE2P schemes.

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

    OpenAIRE

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

    2012-01-01

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

  1. Position-Based Packet Forwarding for Vehicular Ad-Hoc Networks

    OpenAIRE

    Füßler, Holger

    2007-01-01

    Mobile Ad-Hoc Networks, or MANETs, are data communication networks between (potentially) mobile computer systems equipped with wireless communication devices and — in their purest form — in complete absence of communication infrastructure. Usage scenarios for these systems include communication during disaster recovery or battlefield communications. One of the great research challenges concerning MANETs is the Packet Forwarding Problem, i.e., the question to which neighbor node a data packet ...

  2. Modelling of Picosatellite Constellation-Based Network and Effects on Quality of Service

    Science.gov (United States)

    2015-03-01

    7]. The successful launch of Sputnik, the first man- made satellite, by the Soviet Union in 1957 was momentous in mankind’s history . Fortunately the...Transmission Power 27 dBm MAC Protocol Generic MAC No. of IP Output Queue 1 Routing Protocol IPv4 Ad-hoc On-demand Distance Vector (AODV) [13

  3. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. N Shanthi. Articles written in Sadhana. Volume 40 Issue 8 December 2015 pp 2341-2352. Genetic based optimization for multicast routing algorithm for MANET · C Rajan N Shanthi · More Details Abstract Fulltext PDF. Mobile Ad hoc Network (MANET) is established for a limited period, for special ...

  4. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. C Rajan. Articles written in Sadhana. Volume 40 Issue 8 December 2015 pp 2341-2352. Genetic based optimization for multicast routing algorithm for MANET · C Rajan N Shanthi · More Details Abstract Fulltext PDF. Mobile Ad hoc Network (MANET) is established for a limited period, for special ...

  5. Wireless Power Control for Tactical MANET: Power Rate Bounds

    Science.gov (United States)

    2016-09-01

    J; P. Hande; T. Lan; C. W. Tan [2008] Power Control in Cellular Networks, Now Publishers Inc., Hanover, MA. 12. Chaves, Fabiano de Sousa; F. R. P...Asymptotically Fast Convergence, IEEE Selected Areas in Communications, 18(3). 36. Jian, Tao; Nicholas D. Sidiropoulos; Georgios B. Giannakis [2003] Kalman...Power Control and Its Imperfections in CDMA Cellular Systems, IEEE Transactions on Vehicular Technologies, 48, pages 1706–1777. 75. Tan , Chee Wei

  6. Fighting The Network: Manet Management In Support Of Littoral Operations

    Science.gov (United States)

    2016-03-01

    16 Figure 7. OSI 7-Layer Communication Model ...step towards exploring the complex interface between the two. 18 The Open Systems Interconnection ( OSI ) 7-Layer model provides a reference framework...interfaces. The layers in the OSI model represent seven related groups of functions, as depicted in Figure 7. While these functions are enabled by a

  7. Intelligent self-organization methods for wireless ad hoc sensor networks based on limited resources

    Science.gov (United States)

    Hortos, William S.

    2006-05-01

    A wireless ad hoc sensor network (WSN) 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. To a greater degree than the terminals found in mobile ad hoc networks (MANETs) for communications, sensor nodes are resource-constrained, with limited computational processing, bandwidth, memory, and power, and are typically unattended once in operation. Consequently, the level of information exchange among nodes, to support any complex adaptive algorithms to establish network connectivity and optimize throughput, not only deplete those limited resources and creates high overhead in narrowband communications, but also increase network vulnerability to eavesdropping by malicious nodes. Cooperation among nodes, critical to the mission of sensor networks, can thus be disrupted by the inappropriate choice of the method for self-organization. Recent published contributions to the self-configuration of ad hoc sensor networks, e.g., self-organizing mapping and swarm intelligence techniques, have been based on the adaptive control of the cross-layer interactions found in MANET protocols to achieve one or more performance objectives: connectivity, intrusion resistance, power control, throughput, and delay. However, few studies have examined the performance of these algorithms when implemented with the limited resources of WSNs. In this paper, self-organization algorithms for the initiation, operation and maintenance of a network topology from a collection of wireless sensor nodes are proposed that improve the performance metrics significant to WSNs. The intelligent algorithm approach emphasizes low computational complexity, energy efficiency and robust adaptation to change, allowing distributed implementation with the actual limited resources of the cooperative nodes of the network. Extensions of the

  8. Energy-Efficient Cluster Based Routing Protocol in Mobile Ad Hoc Networks Using Network Coding

    Directory of Open Access Journals (Sweden)

    Srinivas Kanakala

    2014-01-01

    Full Text Available In mobile ad hoc networks, all nodes are energy constrained. In such situations, it is important to reduce energy consumption. In this paper, we consider the issues of energy efficient communication in MANETs using network coding. Network coding is an effective method to improve the performance of wireless networks. COPE protocol implements network coding concept to reduce number of transmissions by mixing the packets at intermediate nodes. We incorporate COPE into cluster based routing protocol to further reduce the energy consumption. The proposed energy-efficient coding-aware cluster based routing protocol (ECCRP scheme applies network coding at cluster heads to reduce number of transmissions. We also modify the queue management procedure of COPE protocol to further improve coding opportunities. We also use an energy efficient scheme while selecting the cluster head. It helps to increase the life time of the network. We evaluate the performance of proposed energy efficient cluster based protocol using simulation. Simulation results show that the proposed ECCRP algorithm reduces energy consumption and increases life time of the network.

  9. PSO-Optimized Hopfield Neural Network-Based Multipath Routing for Mobile Ad-hoc Networks

    Directory of Open Access Journals (Sweden)

    Mansour Sheikhan

    2012-06-01

    Full Text Available Mobile ad-hoc network (MANET is a dynamic collection of mobile computers without the need for any existing infrastructure. Nodes in a MANET act as hosts and routers. Designing of robust routing algorithms for MANETs is a challenging task. Disjoint multipath routing protocols address this problem and increase the reliability, security and lifetime of network. However, selecting an optimal multipath is an NP-complete problem. In this paper, Hopfield neural network (HNN which its parameters are optimized by particle swarm optimization (PSO algorithm is proposed as multipath routing algorithm. Link expiration time (LET between each two nodes is used as the link reliability estimation metric. This approach can find either node-disjoint or link-disjoint paths in singlephase route discovery. Simulation results confirm that PSO-HNN routing algorithm has better performance as compared to backup path set selection algorithm (BPSA in terms of the path set reliability and number of paths in the set.

  10. Energy Efficient Routing in Wireless Sensor Networks based on Ant ...

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... improved Ant System and their application in WSN routing process. The simulation results show ... and Mobile ad-hoc networks (MANETs) are inappropriate for ... Dorigo in 1992 in his PhD thesis, the first algorithm was aiming ...

  11. Research on Innovating, Applying Multiple Paths Routing Technique Based on Fuzzy Logic and Genetic Algorithm for Routing Messages in Service - Oriented Routing

    Directory of Open Access Journals (Sweden)

    Nguyen Thanh Long

    2015-02-01

    Full Text Available MANET (short for Mobile Ad-Hoc Network consists of a set of mobile network nodes, network configuration changes very fast. In content based routing, data is transferred from source node to request nodes is not based on destination addresses. Therefore, it is very flexible and reliable, because source node does not need to know destination nodes. If We can find multiple paths that satisfies bandwidth requirement, split the original message into multiple smaller messages to transmit concurrently on these paths. On destination nodes, combine separated messages into the original message. Hence it can utilize better network resources, causes data transfer rate to be higher, load balancing, failover. Service Oriented Routing is inherited from the model of content based routing (CBR, combined with several advanced techniques such as Multicast, multiple path routing, Genetic algorithm to increase the data rate, and data encryption to ensure information security. Fuzzy logic is a logical field study evaluating the accuracy of the results based on the approximation of the components involved, make decisions based on many factors relative accuracy based on experimental or mathematical proof. This article presents some techniques to support multiple path routing from one network node to a set of nodes with guaranteed quality of service. By using these techniques can decrease the network load, congestion, use network resources efficiently.

  12. Evaluation and development the routing protocol of a fully functional simulation environment for VANETs

    Science.gov (United States)

    Ali, Azhar Tareq; Warip, Mohd Nazri Mohd; Yaakob, Naimah; Abduljabbar, Waleed Khalid; Atta, Abdu Mohammed Ali

    2017-11-01

    Vehicular Ad-hoc Networks (VANETs) is an area of wireless technologies that is attracting a great deal of interest. There are still several areas of VANETS, such as security and routing protocols, medium access control, that lack large amounts of research. There is also a lack of freely available simulators that can quickly and accurately simulate VANETs. The main goal of this paper is to develop a freely available VANETS simulator and to evaluate popular mobile ad-hoc network routing protocols in several VANETS scenarios. The VANETS simulator consisted of a network simulator, traffic (mobility simulator) and used a client-server application to keep the two simulators in sync. The VANETS simulator also models buildings to create a more realistic wireless network environment. Ad-Hoc Distance Vector routing (AODV), Dynamic Source Routing (DSR) and Dynamic MANET On-demand (DYMO) were initially simulated in a city, country, and highway environment to provide an overall evaluation.

  13. An Agent-Based Approach To Nodes Misbehaviour Detection In Mobile Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    Otor Samera U.

    2017-02-01

    Full Text Available Existing Misbehaviour Detection Systems in Mobile Ad-hoc Networks MANETs are challenged with routing overhead and high latency resulting from complexity and failure to isolate and block misbehaving nodes for the reason that it is difficult to detect them as they participate fully in route finding. In this work a Mobile Agent-Based Acknowledgement scheme MAACK was formulated to address this problem using an object oriented algorithm deployed to report misbehaving nodes to the source and destination by registering the Internet Protocol IP address of misbehaving nodes in their header. The scheme was simulated using Network Simulator-3 NS-3 and results benchmarked with an existing scheme the Enhanced Adaptive Acknowledgment EAACK using packet delivery ratio routing overhead and latency as performance metrics in the two scenarios. The results showed that the MAACK paradigm guaranteed a higher packet delivery ratio lower latency and routing overhead than the EAACK scheme. The model can be adapted by Ad-Hoc network protocol developers.

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

    Science.gov (United States)

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

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

  15. Organization model for Mobile Wireless Sensor Networks inspired in Artificial Bee Colony

    International Nuclear Information System (INIS)

    Julio de Mesquita Filho, Sao Jose do Rio Preto, SP (Brazil))" data-affiliation=" (Sao Paulo State Univerity Julio de Mesquita Filho, Sao Jose do Rio Preto, SP (Brazil))" >Roberto, Guilherme Freire; Julio de Mesquita Filho, Sao Jose do Rio Preto, SP (Brazil))" data-affiliation=" (Sao Paulo State Univerity Julio de Mesquita Filho, Sao Jose do Rio Preto, SP (Brazil))" >Neves, Leandro Alves; Maschi, Luis Fernando Castilho; Pigatto, Daniel Fernando; Branco, Kalinka Regina Lucas Jaquie Castelo; Montez, Carlos; Pinto, Alex Sandro Roschildt

    2015-01-01

    The purpose of this study is to find a self-organizing model for MWSN based on bee colonies in order to reduce the number of messages transmitted among nodes, and thus reduce the overall consumption energy while maintaining the efficiency of message delivery. The results obtained in this article are originated from simulations carried out with SINALGO software, which demonstrates the effectiveness of the proposed approach. The BeeAODV (Bee Ad-Hoc On Demand Distance Vector) proposed in this paper allows to considerably reduce message exchanges whether compared to AODV (Ad-Hoc On Demand Distance Vector)

  16. Base

    DEFF Research Database (Denmark)

    Hjulmand, Lise-Lotte; Johansson, Christer

    2004-01-01

    BASE - Engelsk basisgrammatik er resultatet af Lise-Lotte Hjulmands grundige bearbejdning og omfattende revidering af Christer Johanssons Engelska basgrammatik. Grammatikken adskiller sig fra det svenske forlæg på en lang række punkter. Den er bl.a. tilpasset til et dansk publikum og det danske...

  17. TIGeR : A Traffic-Aware Intersection-Based Geographical routing protocol for urban VANETs

    NARCIS (Netherlands)

    Tavakoli, Rasool; Nabi, M.

    2013-01-01

    In recent years, vehicular ad-hoc networks (VANETs) have received increasing interests because of their promising solutions in many urban applications. VANETs are distinguished from other kinds of ad-hoc networks, such as Mobile Ad-hoc Networks (MANETs), by high mobility and reduced communications.

  18. Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    M. Isabel Vara

    2015-07-01

    Full Text Available Service discovery plays an important role in mobile ad hoc networks (MANETs. The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2. In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1. In order to advertise services, we have added a new type-length-value structure (TLV to the OLSRv2 protocol, called service discovery message (SDM, according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV protocol, in terms of service discovery ratio, service latency and network overhead.

  19. Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks.

    Science.gov (United States)

    Vara, M Isabel; Campo, Celeste

    2015-07-20

    Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.

  20. Rollback recovery with low overhead for fault tolerance in mobile ad hoc networks

    Directory of Open Access Journals (Sweden)

    Parmeet Kaur Jaggi

    2015-10-01

    Full Text Available Mobile ad hoc networks (MANETs have significantly enhanced the wireless networks by eliminating the need for any fixed infrastructure. Hence, these are increasingly being used for expanding the computing capacity of existing networks or for implementation of autonomous mobile computing Grids. However, the fragile nature of MANETs makes the constituent nodes susceptible to failures and the computing potential of these networks can be utilized only if they are fault tolerant. The technique of checkpointing based rollback recovery has been used effectively for fault tolerance in static and cellular mobile systems; yet, the implementation of existing protocols for MANETs is not straightforward. The paper presents a novel rollback recovery protocol for handling the failures of mobile nodes in a MANET using checkpointing and sender based message logging. The proposed protocol utilizes the routing protocol existing in the network for implementing a low overhead recovery mechanism. The presented recovery procedure at a node is completely domino-free and asynchronous. The protocol is resilient to the dynamic characteristics of the MANET; allowing a distributed application to be executed independently without access to any wired Grid or cellular network access points. We also present an algorithm to record a consistent global snapshot of the MANET.

  1. Wireless Sensor Network Quality of Service Improvement on Flooding Attack Condition

    Science.gov (United States)

    Hartono, R.; Widyawan; Wibowo, S. B.; Purnomo, A.; Hartatik

    2018-03-01

    There are two methods of building communication using wireless media. The first method is building a base infrastructure as an intermediary between users. Problems that arise on this type of network infrastructure is limited space to build any network physical infrastructure and also the cost factor. The second method is to build an ad hoc network between users who will communicate. On ad hoc network, each user must be willing to send data from source to destination for the occurrence of a communication. One of network protocol in Ad Hoc, Ad hoc on demand Distance Vector (AODV), has the smallest overhead value, easier to adapt to dynamic network and has small control message. One AODV protocol’s drawback is route finding process’ security for sending the data. In this research, AODV protocol is optimized by determining Expanding Ring Search (ERS) best value. Random topology is used with variation in the number of nodes: 25, 50, 75, 100, 125 and 150 with node’s speed of 10m/s in the area of 1000m x 1000m on flooding network condition. Parameters measured are Throughput, Packet Delivery Ratio, Average Delay and Normalized Routing Load. From the test results of AODV protocol optimization with best value of Expanding Ring Search (ERS), throughput increased by 5.67%, packet delivery ratio increased by 5.73%, and as for Normalized Routing Load decreased by 4.66%. ERS optimal value for each node’s condition depending on the number of nodes on the network.

  2. Reputation-Based Internet Protocol Security: A Multilayer Security Framework for Mobile Ad Hoc Networks

    Science.gov (United States)

    2010-09-01

    motivated research in behavior grading systems [56]. Peer-to-peer eCommerce appli- cations such as eBay, Amazon, uBid, and Yahoo have performed research that...Security in Mobile Ad Hoc Networks”. IEEE Security & Privacy , 72–75, 2008. 15. Chakeres, ID and EM Belding-Royer. “AODV Routing Protocol Implementa...Detection System”. Proceedings of IEEE Computer Society Symposium on Research in Security and Privacy , 240–250. 1992. 21. Devore, J.L. and N.R. Farnum

  3. A New Intrusion Detection System Based on KNN Classification Algorithm in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Wenchao Li

    2014-01-01

    abnormal nodes from normal nodes by observing their abnormal behaviors, and we analyse parameter selection and error rate of the intrusion detection system. The paper elaborates on the design and implementation of the detection system. This system has achieved efficient, rapid intrusion detection by improving the wireless ad hoc on-demand distance vector routing protocol (Ad hoc On-Demand Distance the Vector Routing, AODV. Finally, the test results show that: the system has high detection accuracy and speed, in accordance with the requirement of wireless sensor network intrusion detection.

  4. Improving Network Performance with Affinity based Mobility Model in Opportunistic Network

    OpenAIRE

    Suvadip Batabyal; Parama Bhaumik

    2012-01-01

    Opportunistic network is a type of Delay Tolerant Network which is characterized by intermittent connectivity amongst the nodes and communication largely depends upon the mobility of the participating nodes. The network being highly dynamic, traditional MANET protocols cannot be applied and the nodes must adhere to store-carry-forward mechanism. Nodes do not have the information about the network topology, number of participating nodes and the location of the destination node. Hence, message ...

  5. Scalable Mobile Ad Hoc Network (MANET) to Enhance Situational Awareness in Distributed Small Unit Operations

    Science.gov (United States)

    2015-06-01

    computing the algorithm is written in Python, a simple terminal programming language. At the top of that script was the integration to ROS and the rest of...etError    (1) where the refresh frequency is represented by Network in units of Hz and the angular speed of the Marine’s sweep rate...starts with: Java , C++, Python, and more. There are literally thousands if not hundreds of thousands, of projects, platforms, sensors, actuators

  6. Aluminium-rich coatings as tritium permeation barriers on MANET (1.4914) stainless steel

    International Nuclear Information System (INIS)

    Terlain, A.; De Vito, E.

    1994-01-01

    Al-rich coatings on 1.4914 martensitic steel, produced by different techniques, have been investigated with optical and scanning electron microscopy, X-ray fluorescence and X-ray photoelectron spectroscopy. Tests for their Pb-17Li compatibility and thermo cycling behaviours have been performed on some coated specimens. Up to now, none of the investigated coatings can be eliminated on the basis of the tests and analyses performed. Further work is required to adapt 1.4914 steel coating techniques to fusion reactor requirements. (author) 9 refs.; 5 figs.; 1 tab

  7. On the Tradeoff Between Altruism and Selfishness in MANET Trust Management

    Science.gov (United States)

    2016-04-07

    network deployment, we assume that there is no predefined trust . Without prior interactions, the initial bootstrapping will establish a shallow level of...a challenge/response process (e.g., public key authentication). Over time, partic- ipating nodes will establish a stronger trust level with more...periodically. This will enable each node to compute trust values of other nodes considering the original recommen- dations from the 1-hop neighbors of

  8. IF-MANET: Interoperable framework for heterogeneous mobile ad hoc networks

    OpenAIRE

    Hassan, H.

    2015-01-01

    The advances in low power micro-processors, wireless networks and embedded systems have raised the need to utilize the significant resources of mobile devices. These devices for example, smart phones, tablets, laptops, wearables, and sensors are gaining enormous processing power, storage capacity and wireless bandwidth. In addition, the advancement in wireless mobile technology has created a new communication paradigm via which a wireless network can be created without any priori infrastructu...

  9. Leveraging Manet and Mobile Devices in Ship-to-Objective Maneuver and Expeditionary MAGTF Operations

    Science.gov (United States)

    2014-09-01

    support and firepower. ECO allows for the Marine Corps to deploy a lower- level maneuver unit as an economy of force measure to assert combat power over...to the Global Information Grid ( GIG ) is the course of action the Marine Corps should adopt (Price & McHuen, 2009). My proposed research addresses

  10. Mobility-Assisted on-Demand Routing Algorithm for MANETs in the Presence of Location Errors

    Directory of Open Access Journals (Sweden)

    Trung Kien Vu

    2014-01-01

    Full Text Available We propose a mobility-assisted on-demand routing algorithm for mobile ad hoc networks in the presence of location errors. Location awareness enables mobile nodes to predict their mobility and enhances routing performance by estimating link duration and selecting reliable routes. However, measured locations intrinsically include errors in measurement. Such errors degrade mobility prediction and have been ignored in previous work. To mitigate the impact of location errors on routing, we propose an on-demand routing algorithm taking into account location errors. To that end, we adopt the Kalman filter to estimate accurate locations and consider route confidence in discovering routes. Via simulations, we compare our algorithm and previous algorithms in various environments. Our proposed mobility prediction is robust to the location errors.

  11. Estimation of trust metrics for MANET using QoS parameter and source routing algorithms

    CSIR Research Space (South Africa)

    Umuhoza, D

    2007-08-01

    Full Text Available parameters. Probabilities of transit time variation, deleted, multiplied and inserted packets, processing delays are used to estimate and update trust. Functions which facilitate this are provided and evaluated. It has been shown that only two end nodes need...

  12. A DNA-Inspired Encryption Methodology for Secure, Mobile Ad Hoc Networks

    Science.gov (United States)

    Shaw, Harry

    2012-01-01

    Users are pushing for greater physical mobility with their network and Internet access. Mobile ad hoc networks (MANET) can provide an efficient mobile network architecture, but security is a key concern. A figure summarizes differences in the state of network security for MANET and fixed networks. MANETs require the ability to distinguish trusted peers, and tolerate the ingress/egress of nodes on an unscheduled basis. Because the networks by their very nature are mobile and self-organizing, use of a Public Key Infra structure (PKI), X.509 certificates, RSA, and nonce ex changes becomes problematic if the ideal of MANET is to be achieved. Molecular biology models such as DNA evolution can provide a basis for a proprietary security architecture that achieves high degrees of diffusion and confusion, and resistance to cryptanalysis. A proprietary encryption mechanism was developed that uses the principles of DNA replication and steganography (hidden word cryptography) for confidentiality and authentication. The foundation of the approach includes organization of coded words and messages using base pairs organized into genes, an expandable genome consisting of DNA-based chromosome keys, and a DNA-based message encoding, replication, and evolution and fitness. In evolutionary computing, a fitness algorithm determines whether candidate solutions, in this case encrypted messages, are sufficiently encrypted to be transmitted. The technology provides a mechanism for confidential electronic traffic over a MANET without a PKI for authenticating users.

  13. Implementing voice over Internet protocol in mobile ad hoc network – analysing its features regarding efficiency, reliability and security

    Directory of Open Access Journals (Sweden)

    Naveed Ahmed Sheikh

    2014-05-01

    Full Text Available Providing secure and efficient real-time voice communication in mobile ad hoc network (MANET environment is a challenging problem. Voice over Internet protocol (VoIP has originally been developed over the past two decades for infrastructure-based networks. There are strict timing constraints for acceptable quality VoIP services, in addition to registration and discovery issues in VoIP end-points. In MANETs, ad hoc nature of networks and multi-hop wireless environment with significant packet loss and delays present formidable challenges to the implementation. Providing a secure real-time VoIP service on MANET is the main design objective of this paper. The authors have successfully developed a prototype system that establishes reliable and efficient VoIP communication and provides an extremely flexible method for voice communication in MANETs. The authors’ cooperative mesh-based MANET implementation can be used for rapidly deployable VoIP communication with survivable and efficient dynamic networking using open source software.

  14. A Conceptual Framework for Representing Human Behavior Characteristics in a System of Systems Agent-Based Survivability Simulation

    Science.gov (United States)

    2010-11-22

    MANET system to reorganize. Soni and Dawra (2007) note that “self-organizing systems of agents with emergent system-level functions offer these...2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, 14-17. Burt, R. (1992). Structural...Bombay. Soni , D and Dawra, S (2007). AI System in (12th WSEAS Int. Conf. on Applied Mathematics, Cairo, Egypt, December 29-31, 2007 401. Sridhar

  15. Construction of Pipelined Strategic Connected Dominating Set for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ceronmani Sharmila

    2016-06-01

    Full Text Available Efficient routing between nodes is the most important challenge in a Mobile Ad Hoc Network (MANET. A Connected Dominating Set (CDS acts as a virtual backbone for routing in a MANET. Hence, the construction of CDS based on the need and its application plays a vital role in the applications of MANET. The PipeLined Strategic CDS (PLS-CDS is constructed based on strategy, dynamic diameter and transmission range. The strategy used for selecting the starting node is, any source node in the network, which has its entire destination within a virtual pipelined coverage, instead of the node with maximum connectivity. The other nodes are then selected based on density and velocity. The proposed CDS also utilizes the energy of the nodes in the network in an optimized manner. Simulation results showed that the proposed algorithm is better in terms of size of the CDS and average hop per path length.

  16. Construct mine environment monitoring system based on wireless mesh network

    Science.gov (United States)

    Chen, Xin; Ge, Gengyu; Liu, Yinmei; Cheng, Aimin; Wu, Jun; Fu, Jun

    2018-04-01

    The system uses wireless Mesh network as a network transmission medium, and strive to establish an effective and reliable underground environment monitoring system. The system combines wireless network technology and embedded technology to monitor the internal data collected in the mine and send it to the processing center for analysis and environmental assessment. The system can be divided into two parts: the main control network module and the data acquisition terminal, and the SPI bus technology is used for mutual communication between them. Multi-channel acquisition and control interface design Data acquisition and control terminal in the analog signal acquisition module, digital signal acquisition module, and digital signal output module. The main control network module running Linux operating system, in which the transplant SPI driver, USB card driver and AODV routing protocol. As a result, the internal data collection and reporting of the mine are realized.

  17. A Performance Evaluation Model for Mobile Ad Hoc Networks and Sensor Networks

    Directory of Open Access Journals (Sweden)

    Heng LUO

    2014-03-01

    Full Text Available Potential applications in areas such as military sites and disaster relief fields that are characterized by absence of prefixed infrastructure justify the development of mobile ad hoc networks (MANETs and wireless sensor networks (WSNs. However, unfavorable wireless links and dynamic topology are still challenging, leading to the proposal of a collection of routing protocols for MANETs and WSNs. Nevertheless the performance of algorithms may vary with deployment scenario due to the application dependent philosophy behind algorithms. In this paper, the performance evaluation problem for MANETs and WSNs is investigated and a novel performance ranking model, termed AHP-SAW, is proposed. For simplicity but without loss of generality, the performance of two routing protocols DSDV and DSR are studies based on which ranking results are provided. Extensive simulations show that an overall 37.2 %, at most, gain may be achieved based on the AHP-SAW model.

  18. Optimal JPWL Forward Error Correction Rate Allocation for Robust JPEG 2000 Images and Video Streaming over Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Benoit Macq

    2008-07-01

    Full Text Available Based on the analysis of real mobile ad hoc network (MANET traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS to wireless clients is demonstrated.

  19. Modelling and Initial Validation of the DYMO Routing Protocol for Mobile Ad-Hoc Networks

    DEFF Research Database (Denmark)

    Espensen, Kristian Asbjørn Leth; Kjeldsen, Mads Keblov; Kristensen, Lars Michael

    2008-01-01

    A mobile ad-hoc network (MANET) is an infrastructureless network established by a set of mobile devices using wireless communication. The Dynamic MANET On-demand (DYMO) protocol is a routing protocol for multi-hop communication in MANETs currently under development by the Internet Engineering Task...... Force (IETF). This paper presents a Coloured Petri Net (CPN) model of the mandatory parts of the DYMO protocol, and shows how scenario-based state space exploration has been used to validate key properties of the protocol. Our CPN modelling and verification work has spanned two revisions of the DYMO...... protocol specification and have had direct impact on the most recent version of the protocol specification....

  20. Drop-Burst Length Evaluation of Urban VANETs

    Directory of Open Access Journals (Sweden)

    Awos Kh. Ali

    2017-05-01

    Full Text Available Networks performance is traditionally evaluated using packet delivery ratio (PDR and latency (delay. We propose an addition mechanism the drop-burst length (DBL. Many traffic classes display varying application-level performance according to the pattern of drops, even if the PDR is similar. In this paper we study a number of VANET scenarios and evaluate them with these three metrics. Vehicular Ad-hoc Networks (VANETs are an emerging class of Mobile Ad-hoc Network (MANETs where nodes include both moving vehicles and fixed infrastructure. VANETs aim to make transportation systems more intelligent by sharing information to improve safety and comfort. Efficient and adaptive routing protocols are essential for achieving reliable and scalable network performance. However, routing in VANETs is challenging due to the frequent, high-speed movement of vehicles, which results in frequent network topology changes. Our simulations are carried out using NS2 (for network traffic and SUMO (for vehicular movement simulators, with scenarios configured to reflect real-world conditions. The results show that OLSR is able to achieve a best DBL performance and demonstrates higher PDR performance comparing to AODV and GPSR under low network load. However, with GPSR, the network shows more stable PDR under medium and high network load. In term of delay OLSR is outperformed by GPSR.

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  2. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Position based opportunistic routing (POR) is a stateless, robust, and reliable geographic routing protocol in Mobile AdHoc NETwork (MANET). The opportunistic routing embraces broadcast property of wireless channels and utilizes it for opportunistic forwarding. Both the malicious node behavior and the backupnodes' ...

  3. Analysis of Pervasive Mobile Ad Hoc Routing Protocols

    Science.gov (United States)

    Qadri, Nadia N.; Liotta, Antonio

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

  4. Mobile Ad Hoc Networks in Bandwidth-Demanding Mission-Critical Applications: Practical Implementation Insights

    KAUST Repository

    Bader, Ahmed

    2016-09-28

    There has been recently a growing trend of using live video feeds in mission-critical applications. Real-time video streaming from front-end personnel or mobile agents is believed to substantially improve situational awareness in mission-critical operations such as disaster relief, law enforcement, and emergency response. Mobile Ad Hoc Networks (MANET) is a natural contender in such contexts. However, classical MANET routing schemes fall short in terms of scalability, bandwidth and latency; all three metrics being quite essential for mission-critical applications. As such, autonomous cooperative routing (ACR) has gained traction as the most viable MANET proposition. Nonetheless, ACR is also associated with a few implementation challenges. If they go unaddressed, will deem ACR practically useless. In this paper, efficient and low-complexity remedies to those issues are presented, analyzed, and validated. The validation is based on field experiments carried out using software-defined radio (SDR) platforms. Compared to classical MANET routing schemes, ACR was shown to offer up to 2X better throughput, more than 4X reduction in end-to-end latency, while observing a given target of transport rate normalized to energy consumption.

  5. Intelligent Broadcasting in Mobile Ad Hoc Networks: Three Classes of Adaptive Protocols

    Directory of Open Access Journals (Sweden)

    Michael D. Colagrosso

    2006-11-01

    Full Text Available Because adaptability greatly improves the performance of a broadcast protocol, we identify three ways in which machine learning can be applied to broadcasting in a mobile ad hoc network (MANET. We chose broadcasting because it functions as a foundation of MANET communication. Unicast, multicast, and geocast protocols utilize broadcasting as a building block, providing important control and route establishment functionality. Therefore, any improvements to the process of broadcasting can be immediately realized by higher-level MANET functionality and applications. While efficient broadcast protocols have been proposed, no single broadcasting protocol works well in all possible MANET conditions. Furthermore, protocols tend to fail catastrophically in severe network environments. Our three classes of adaptive protocols are pure machine learning, intra-protocol learning, and inter-protocol learning. In the pure machine learning approach, we exhibit a new approach to the design of a broadcast protocol: the decision of whether to rebroadcast a packet is cast as a classification problem. Each mobile node (MN builds a classifier and trains it on data collected from the network environment. Using intra-protocol learning, each MN consults a simple machine model for the optimal value of one of its free parameters. Lastly, in inter-protocol learning, MNs learn to switch between different broadcasting protocols based on network conditions. For each class of learning method, we create a prototypical protocol and examine its performance in simulation.

  6. Intelligent Broadcasting in Mobile Ad Hoc Networks: Three Classes of Adaptive Protocols

    Directory of Open Access Journals (Sweden)

    Colagrosso Michael D

    2007-01-01

    Full Text Available Because adaptability greatly improves the performance of a broadcast protocol, we identify three ways in which machine learning can be applied to broadcasting in a mobile ad hoc network (MANET. We chose broadcasting because it functions as a foundation of MANET communication. Unicast, multicast, and geocast protocols utilize broadcasting as a building block, providing important control and route establishment functionality. Therefore, any improvements to the process of broadcasting can be immediately realized by higher-level MANET functionality and applications. While efficient broadcast protocols have been proposed, no single broadcasting protocol works well in all possible MANET conditions. Furthermore, protocols tend to fail catastrophically in severe network environments. Our three classes of adaptive protocols are pure machine learning, intra-protocol learning, and inter-protocol learning. In the pure machine learning approach, we exhibit a new approach to the design of a broadcast protocol: the decision of whether to rebroadcast a packet is cast as a classification problem. Each mobile node (MN builds a classifier and trains it on data collected from the network environment. Using intra-protocol learning, each MN consults a simple machine model for the optimal value of one of its free parameters. Lastly, in inter-protocol learning, MNs learn to switch between different broadcasting protocols based on network conditions. For each class of learning method, we create a prototypical protocol and examine its performance in simulation.

  7. Spectral imaging and archival data in analyzing the Madonna of the Rabbit painting by Manet and Titian

    Czech Academy of Sciences Publication Activity Database

    Striová, J.; Ruberto, C.; Barucci, M.; Blažek, Jan; Kunzelman, D.; Dal Fovo, A.; Pampaloni, E.; Fontana, R.

    (2018) ISSN 1433-7851 Institutional support: RVO:67985556 Keywords : spectral mapping * image processing * visible near-infrared multispectral scanner Subject RIV: JC - Computer Hardware ; Software OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 11.994, year: 2016 http://library.utia.cas.cz/separaty/2018/ZOI/blazek-0489046.pdf

  8. Hydrogen permeation rate reduction by post-oxidation of aluminide coatings on DIN 1.4914 martensitic steel (MANET)

    International Nuclear Information System (INIS)

    Perujo, A.; Sample, T.

    1996-01-01

    In a previous work, it has been shown that lower aluminium content aluminide, having the same permeation rate reduction as the higher aluminium content, exhibited a lower hardness and greater ductility and therefore greater crack resistance than the higher aluminium content. In this work we combine this characteristic with a post-oxidation to obtain a further deuterium permeation reduction. The post-oxidation was performed in air at 1023 K for 15 h and at 1223 K for 10 h and 1 h. The maximum deuterium permeation rate reduction obtained is very moderate (maximum of a factor 500 for 1 h at 1223 K) as compared to that of the non-oxidised aluminide specimen (two orders of magnitude) and is constant in the temperature range studied (573-800 K). This method has the technological appeal of using air rather than the controlled environment used by other authors. (orig.)

  9. Security-Based Mechanism for Proactive Routing Schema Using Game Theory Model

    Directory of Open Access Journals (Sweden)

    Hicham Amraoui

    2016-01-01

    Full Text Available Game theory may offer a useful mechanism to address many problems in mobile ad hoc networks (MANETs. One of the key concepts in the research field of such networks with Optimized Link State Routing Protocol (OLSR is the security problem. Relying on applying game theory to study this problem, we consider two strategies during this suggested model: cooperate and not-cooperate. However, in such networks, it is not easy to identify different actions of players. In this paper, we have essentially been inspired from recent advances provided in game theory to propose a new model for security in MANETs. Our proposal presents a powerful tool with a large number of players where interactions are played multiple times. Moreover, each node keeps a cooperation rate (CR record of other nodes to cope with the behaviors and mitigate aggregate effect of other malicious devices. Additionally, our suggested security mechanism does not only take into consideration security requirements, but also take into account system resources and network performances. The simulation results using Network Simulator 3 are presented to illustrate the effectiveness of the proposal.

  10. LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring.

    Science.gov (United States)

    Tseng, Chinyang Henry

    2016-05-31

    In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee's AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee's routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node's distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee's AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV.

  11. Enhancing On-Demand Multicast Routing Protocols using Mobility Prediction in Mobile Ad-hoc Network

    Directory of Open Access Journals (Sweden)

    Nermin Makhlouf

    2014-08-01

    Full Text Available A Mobile Ad hoc Network (MANET is a self-organizing wireless communication network in which mobile devices are based on no infrastructure like base stations or access points. Minimal configuration and quick deployment make ad hoc networks suitable for emergency situations like disaster recovery or military conflict. Since node mobility may cause links to be broken frequently, a very important issue for routing in MANETs is how to set reliable paths which can last as long as possible. To solve this problem, non-random behaviors for the mobility patterns that mobile users exhibit are exploited. This paper introduces a scheme to improve On-Demand Multicast Routing Protocol (ODMRP performances by using mobility prediction. 

  12. Trust Management in Mobile Ad Hoc Networks for Bias Minimization and Application Performance Maximization

    Science.gov (United States)

    2014-02-26

    4 develops a novel model-based approach to de- scribe dynamic behaviors of nodes in MANETs in the pres- ence of misbehaving nodes with the objective...bile node to subjectively yet informatively assess the trust levels of other mobile nodes. Further, SQTrust is resilient against misbehaving nodes. Given...objective trust’’ despite the presence of misbehaving nodes. The desirable output is to achieve high accuracy in peer-to-peer subjective trust evaluation

  13. Achieving sink node anonymity in tactical wireless sensor networks using a reactive routing protocol

    Science.gov (United States)

    2017-06-01

    node anonymity, base station anonymity, Wireless Sensor Networks (WSN), Mobile Ad hoc Network (MANET), Lightweight Ad hoc On-Demand – Next Generation ... Generation (LOADng) reactive-routing protocol to achieve anonymity. This modified protocol prevents an attacker from identifying the sink node without...within the constraints of WSN communication protocols, specifically IEEE 802.15.4. We use and modify the Lightweight Ad hoc On-Demand – Next Generation

  14. Analysis of Soldier Radio Waveform Performance in Operational Test

    Science.gov (United States)

    2015-05-01

    different frequencies based on carrier, uplink/downlink, and generation. In general, 2G and 3G cellular phones operate at 850 MHz uplink, and 1,900 MHz...spectrum management that may not be operationally feasible. These issues are not unique to SRW, but rather have plagued the mobile ad-hoc network... mobile ad-hoc network (MANET), enabling communication through a self-configuring, infrastructure-less network of mobile nodes. In the SS domain, these

  15. Delay-dependent asymptotic stability of mobile ad-hoc networks: A descriptor system approach

    International Nuclear Information System (INIS)

    Yang Juan; Yang Dan; Zhang Xiao-Hong; Huang Bin; Luo Jian-Lu

    2014-01-01

    In order to analyze the capacity stability of the time-varying-propagation and delay-dependent of mobile ad-hoc networks (MANETs), in this paper, a novel approach is proposed to explore the capacity asymptotic stability for the delay-dependent of MANETs based on non-cooperative game theory, where the delay-dependent conditions are explicitly taken into consideration. This approach is based on the Lyapunov—Krasovskii stability theory for functional differential equations and the linear matrix inequality (LMI) technique. A corresponding Lyapunov—Krasovskii functional is introduced for the stability analysis of this system with use of the descriptor and “neutral-type” model transformation without producing any additional dynamics. The delay-dependent stability criteria are derived for this system. Conditions are given in terms of linear matrix inequalities, and for the first time referred to neutral systems with the time-varying propagation and delay-dependent stability for capacity analysis of MANETs. The proposed criteria are less conservative since they are based on an equivalent model transformation. Furthermore, we also provide an effective and efficient iterative algorithm to solve the constrained stability control model. Simulation experiments have verified the effectiveness and efficiency of our algorithm. (general)

  16. A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks.

    Science.gov (United States)

    Mezher, Ahmad Mohamad; Igartua, Mónica Aguilar; de la Cruz Llopis, Luis J; Pallarès Segarra, Esteve; Tripp-Barba, Carolina; Urquiza-Aguiar, Luis; Forné, Jordi; Sanvicente Gargallo, Emilio

    2015-04-17

    The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc.) could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers) rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs) has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic. Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs.

  17. A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ahmad Mohamad Mezher

    2015-04-01

    Full Text Available The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc. could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic. Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs.

  18. A FSA Model for Performance Evaluation over Mobile Ad Hoc Networks with Low Traffic Volume

    Directory of Open Access Journals (Sweden)

    Heng LUO

    2014-07-01

    Full Text Available A Mobile Ad hoc network (MANET, which is composed of nodes that are able to move arbitrarily, differs from a direct connection network in the way that it is multi-hopping and self- organizing and thus able to operate without the help of prefixed infrastructures. However, problems such as unfavorable wireless links and dynamic topology are challenging, resulting in the proposal of a collection of routing protocols for MANETs. Nevertheless the performance of protocols may deteriorate dramatically as deployment scenario changes due to the application dependent philosophy behind algorithms. In this paper, the performance evaluation problem for MANETs and is explored and a novel performance ranking model, termed FSA, is proposed. For simplicity but without loss of generality, the performance of two routing protocols DSDV and DSR are studies. The FSA is able to rank the performance of DSDV and DSR depending on the average value and standard deviation results. Extensive simulations show that an overall 20.74 %, at most, gain may be achieved based on the FSA model.

  19. Exploiting Mobile Ad Hoc Networking and Knowledge Generation to Achieve Ambient Intelligence

    Directory of Open Access Journals (Sweden)

    Anna Lekova

    2012-01-01

    Full Text Available Ambient Intelligence (AmI joins together the fields of ubiquitous computing and communications, context awareness, and intelligent user interfaces. Energy, fault-tolerance, and mobility are newly added dimensions of AmI. Within the context of AmI the concept of mobile ad hoc networks (MANETs for “anytime and anywhere” is likely to play larger roles in the future in which people are surrounded and supported by small context-aware, cooperative, and nonobtrusive devices that will aid our everyday life. The connection between knowledge generation and communication ad hoc networking is symbiotic—knowledge generation utilizes ad hoc networking to perform their communication needs, and MANETs will utilize the knowledge generation to enhance their network services. The contribution of the present study is a distributed evolving fuzzy modeling framework (EFMF to observe and categorize relationships and activities in the user and application level and based on that social context to take intelligent decisions about MANETs service management. EFMF employs unsupervised online one-pass fuzzy clustering method to recognize nodes' mobility context from social scenario traces and ubiquitously learn “friends” and “strangers” indirectly and anonymously.

  20. Compromises Between Quality of Service Metrics and Energy Consumption of Hierarchical and Flat Routing Protocols for Wireless Sensors Network

    Directory of Open Access Journals (Sweden)

    Abdelbari BEN YAGOUTA

    2016-11-01

    Full Text Available Wireless Sensor Network (WSN is wireless network composed of spatially distributed and tiny autonomous nodes, which cooperatively monitor physical or environmental conditions. Among the concerns of these networks is prolonging the lifetime by saving nodes energy. There are several protocols specially designed for WSNs based on energy conservation. However, many WSNs applications require QoS (Quality of Service criteria, such as latency, reliability and throughput. In this paper, we will compare three routing protocols for wireless sensors network LEACH (Low Energy Adaptive Clustering Hierarchy, AODV (Ad hoc on demand Distance Vector and LABILE (Link Quality-Based Lexical Routing using Castalia simulator in terms of energy consumption, throughput, reliability and latency time of packets received by sink under different conditions to determinate the best configurations that offers the most suitable compromises between energy conservation and all QoS metrics for each routing protocols. The results show that, the best configurations that offer the suitable compromises between energy conservation and all QoS metrics is a large number of deployed nodes with low packet rate for LEACH (300 nodes and 1 packet/s, a medium number of deployed nodes with low packet rate For AODV (100 nodes and 1 packet/s and a very low nodes density with low packet rate for LABILE (50 nodes and 1 packet/s.

  1. 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.

  2. Model checking mobile ad hoc networks

    NARCIS (Netherlands)

    Ghassemi, Fatemeh; Fokkink, Wan

    2016-01-01

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

  3. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Preventing the impact of selfish behavior under MANET using Neighbor Credit Value ... Mobile Ad hoc Network (MANET) nodes exchange information using the ... Routing protocol plays a crucial role in an effective communication between ...

  4. Self-Configuration and Self-Optimization Process in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Eduardo Camponogara

    2010-12-01

    Full Text Available Self-organization in Wireless Mesh Networks (WMN is an emergent research area, which is becoming important due to the increasing number of nodes in a network. Consequently, the manual configuration of nodes is either impossible or highly costly. So it is desirable for the nodes to be able to configure themselves. In this paper, we propose an alternative architecture for self-organization of WMN based on Optimized Link State Routing Protocol (OLSR and the ad hoc on demand distance vector (AODV routing protocols as well as using the technology of software agents. We argue that the proposed self-optimization and self-configuration modules increase the throughput of network, reduces delay transmission and network load, decreases the traffic of HELLO messages according to network’s scalability. By simulation analysis, we conclude that the self-optimization and self-configuration mechanisms can significantly improve the performance of OLSR and AODV protocols in comparison to the baseline protocols analyzed.

  5. Optimized energy-delay sub-network routing protocol development and implementation for wireless sensor networks

    International Nuclear Information System (INIS)

    Fonda, James W; Zawodniok, Maciej; Jagannathan, S; Watkins, Steve E

    2008-01-01

    The development and the implementation issues of a reactive optimized energy-delay sub-network routing (OEDSR) protocol for wireless sensor networks (WSN) are introduced and its performance is contrasted with the popular ad hoc on-demand distance vector (AODV) routing protocol. Analytical results illustrate the performance of the proposed OEDSR protocol, while experimental results utilizing a hardware testbed under various scenarios demonstrate improvements in energy efficiency of the OEDSR protocol. A hardware platform constructed at the University of Missouri-Rolla (UMR), now the Missouri University of Science and Technology (MST), based on the Generation 4 Smart Sensor Node (G4-SSN) prototyping platform is also described. Performance improvements are shown in terms of end-to-end (E2E) delay, throughput, route-set-up time and drop rates and energy usage is given for three topologies, including a mobile topology. Additionally, results from the hardware testbed provide valuable lessons for network deployments. Under testing OEDSR provides a factor of ten improvement in the energy used in the routing session and extends network lifetime compared to AODV. Depletion experiments show that the time until the first node failure is extended by a factor of three with the network depleting and network lifetime is extended by 6.7%

  6. Self-Configuration and Self-Optimization Process in Heterogeneous Wireless Networks

    Science.gov (United States)

    Guardalben, Lucas; Villalba, Luis Javier García; Buiati, Fábio; Sobral, João Bosco Mangueira; Camponogara, Eduardo

    2011-01-01

    Self-organization in Wireless Mesh Networks (WMN) is an emergent research area, which is becoming important due to the increasing number of nodes in a network. Consequently, the manual configuration of nodes is either impossible or highly costly. So it is desirable for the nodes to be able to configure themselves. In this paper, we propose an alternative architecture for self-organization of WMN based on Optimized Link State Routing Protocol (OLSR) and the ad hoc on demand distance vector (AODV) routing protocols as well as using the technology of software agents. We argue that the proposed self-optimization and self-configuration modules increase the throughput of network, reduces delay transmission and network load, decreases the traffic of HELLO messages according to network’s scalability. By simulation analysis, we conclude that the self-optimization and self-configuration mechanisms can significantly improve the performance of OLSR and AODV protocols in comparison to the baseline protocols analyzed. PMID:22346584

  7. Lotus Base

    DEFF Research Database (Denmark)

    Mun, Terry; Bachmann, Asger; Gupta, Vikas

    2016-01-01

    exploration of Lotus genomic and transcriptomic data. Equally important are user-friendly in-browser tools designed for data visualization and interpretation. Here, we present Lotus Base, which opens to the research community a large, established LORE1 insertion mutant population containing an excess of 120...... such data, allowing users to construct, visualize, and annotate co-expression gene networks. Lotus Base takes advantage of modern advances in browser technology to deliver powerful data interpretation for biologists. Its modular construction and publicly available application programming interface enable...... developers to tap into the wealth of integrated Lotus data. Lotus Base is freely accessible at: https://lotus.au.dk....

  8. Touch BASE

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In a recent Nature article (see here), the BASE collaboration reported the most precise comparison of the charge-to-mass ratio of the proton to its antimatter equivalent, the antiproton. This result is just the beginning and many more challenges lie ahead.   CERN's AD Hall, where the BASE experiment is set-up. The Baryon Antibaryon Symmetry Experiment (BASE) was approved in June 2013 and was ready to take data in August 2014. During these 14 months, the BASE collaboration worked hard to set up its four cryogenic Penning traps, which are the heart of the whole experiment. As their name indicates, these magnetic devices are used to trap antiparticles – antiprotons coming from the Antiproton Decelerator – and particles of matter – negative hydrogen ions produced in the system by interaction with a degrader that slows the antiprotons down, allowing scientists to perform their measurements. “We had very little time to set up the wh...

  9. How Effective is Routing for Wireless Networking

    Science.gov (United States)

    2016-03-05

    order to avoid the effects of congestion and queue overflows, data rates are set arbitrarily high. For both OLSR and AODV, we test two variants...aodv version 2,” in Vehicular Technology Conference (VTC Fall), 2012 IEEE. IEEE, 2012, pp. 1–5. [11] T. Clausen, A. C. de Verdiere, J. Yi, A. Niktash, Y

  10. Fragmentation based

    Directory of Open Access Journals (Sweden)

    Shashank Srivastava

    2014-01-01

    Gaining the understanding of mobile agent architecture and the security concerns, in this paper, we proposed a security protocol which addresses security with mitigated computational cost. The protocol is a combination of self decryption, co-operation and obfuscation technique. To circumvent the risk of malicious code execution in attacking environment, we have proposed fragmentation based encryption technique. Our encryption technique suits the general mobile agent size and provides hard and thorny obfuscation increasing attacker’s challenge on the same plane providing better performance with respect to computational cost as compared to existing AES encryption.

  11. Explicit Context Matching in Content-Based Publish/Subscribe Systems

    Directory of Open Access Journals (Sweden)

    Miguel Jiménez

    2013-03-01

    Full Text Available Although context could be exploited to improve performance, elasticity and adaptation in most distributed systems that adopt the publish/subscribe (P/S communication model, only a few researchers have focused on the area of context-aware matching in P/S systems and have explored its implications in domains with highly dynamic context like wireless sensor networks (WSNs and IoT-enabled applications. Most adopted P/S models are context agnostic or do not differentiate context from the other application data. In this article, we present a novel context-aware P/S model. SilboPS manages context explicitly, focusing on the minimization of network overhead in domains with recurrent context changes related, for example, to mobile ad hoc networks (MANETs. Our approach represents a solution that helps to effciently share and use sensor data coming from ubiquitous WSNs across a plethora of applications intent on using these data to build context awareness. Specifically, we empirically demonstrate that decoupling a subscription from the changing context in which it is produced and leveraging contextual scoping in the filtering process notably reduces (unsubscription cost per node, while improving the global performance/throughput of the network of brokers without altering the cost of SIENA-like topology changes.

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

    Directory of Open Access Journals (Sweden)

    Mann Raminder P

    2005-01-01

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

  13. Fuzzy knowledge bases integration based on ontology

    OpenAIRE

    Ternovoy, Maksym; Shtogrina, Olena

    2012-01-01

    the paper describes the approach for fuzzy knowledge bases integration with the usage of ontology. This approach is based on metadata-base usage for integration of different knowledge bases with common ontology. The design process of metadata-base is described.

  14. Foundation: Transforming data bases into knowledge bases

    Science.gov (United States)

    Purves, R. B.; Carnes, James R.; Cutts, Dannie E.

    1987-01-01

    One approach to transforming information stored in relational data bases into knowledge based representations and back again is described. This system, called Foundation, allows knowledge bases to take advantage of vast amounts of pre-existing data. A benefit of this approach is inspection, and even population, of data bases through an intelligent knowledge-based front-end.

  15. 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

  16. DMP: Detouring Using Multiple Paths against Jamming Attack for Ubiquitous Networking System

    Directory of Open Access Journals (Sweden)

    Mihui Kim

    2010-04-01

    Full Text Available To successfully realize the ubiquitous network environment including home automation or industrial control systems, it is important to be able to resist a jamming attack. This has recently been considered as an extremely threatening attack because it can collapse the entire network, despite the existence of basic security protocols such as encryption and authentication. In this paper, we present a method of jamming attack tolerant routing using multiple paths based on zones. The proposed scheme divides the network into zones, and manages the candidate forward nodes of neighbor zones. After detecting an attack, detour nodes decide zones for rerouting, and detour packets destined for victim nodes through forward nodes in the decided zones. Simulation results show that our scheme increases the PDR (Packet Delivery Ratio and decreases the delay significantly in comparison with rerouting by a general routing protocol on sensor networks, AODV (Ad hoc On Demand Distance Vector, and a conventional JAM (Jammed Area Mapping service with one reroute.

  17. Cross-Layer Design Approach for Power Control in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    A. Sarfaraz Ahmed

    2015-03-01

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

  18. DMP: detouring using multiple paths against jamming attack for ubiquitous networking system.

    Science.gov (United States)

    Kim, Mihui; Chae, Kijoon

    2010-01-01

    To successfully realize the ubiquitous network environment including home automation or industrial control systems, it is important to be able to resist a jamming attack. This has recently been considered as an extremely threatening attack because it can collapse the entire network, despite the existence of basic security protocols such as encryption and authentication. In this paper, we present a method of jamming attack tolerant routing using multiple paths based on zones. The proposed scheme divides the network into zones, and manages the candidate forward nodes of neighbor zones. After detecting an attack, detour nodes decide zones for rerouting, and detour packets destined for victim nodes through forward nodes in the decided zones. Simulation results show that our scheme increases the PDR (Packet Delivery Ratio) and decreases the delay significantly in comparison with rerouting by a general routing protocol on sensor networks, AODV (Ad hoc On Demand Distance Vector), and a conventional JAM (Jammed Area Mapping) service with one reroute.

  19. A MODIFIED ROUTE DISCOVERY APPROACH FOR DYNAMIC SOURCE ROUTING (DSR PROTOCOL IN MOBILE AD-HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    Alaa Azmi Allahham

    2017-02-01

    Full Text Available Mobile Ad-hoc networks (MANETs involved in many applications, whether commercial or military because of their characteristics that do not depend on the infrastructure as well as the freedom movement of their elements, but in return has caused this random mobility of the nodes many of the challenges, where the routing is considered one of these challenges. There are many types of routing protocols that operate within MANET networks, which responsible for finding paths between the source and destination nodes with the modernization of these paths which are constantly changing due to the dynamic topology of the network stemming from the constant random movement of the nodes. The DSR (Dynamic Source Routing routing protocol algorithm is one of these routing protocols which consist of two main stages; route discovery and maintenance, where the route discovery algorithm operates based on blind flooding of request messages. blind flooding is considered as the most well known broadcasting mechanism, it is inefficient in terms of communication and resource utilization, which causing increasing the probability of collisions, repeating send several copies of the same message, as well as increasing the delay. Hence, a new mechanism in route discovery stage and in caching the routes in DSR algorithm according to the node's location in the network and the direction of the broadcast is proposed for better performance especially in terms of delay as well as redundant packets rate. The implementation of proposed algorithms showed positive results in terms of delay, overhead, and improve the performance of MANETs in general.

  20. Paper based electronics platform

    KAUST Repository

    Nassar, Joanna Mohammad; Sevilla, Galo Andres Torres; Hussain, Muhammad Mustafa

    2017-01-01

    A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors

  1. A novel approach to Service Discovery in Mobile Adhoc Network

    OpenAIRE

    Islam, Noman; Shaikh, Zubair A.

    2015-01-01

    Mobile Adhoc Network (MANET) is a network of a number of mobile routers and associated hosts, organized in a random fashion via wireless links. During recent years MANET has gained enormous amount of attention and has been widely used for not only military purposes but for search-and-rescue operations, intelligent transportation system, data collection, virtual classrooms and ubiquitous computing. Service Discovery is one of the most important issues in MANET. It is defined as the process of ...

  2. High throughput route selection in multi-rate wireless mesh networks

    Institute of Scientific and Technical Information of China (English)

    WEI Yi-fei; GUO Xiang-li; SONG Mei; SONG Jun-de

    2008-01-01

    Most existing Ad-hoc routing protocols use the shortest path algorithm with a hop count metric to select paths. It is appropriate in single-rate wireless networks, but has a tendency to select paths containing long-distance links that have low data rates and reduced reliability in multi-rate networks. This article introduces a high throughput routing algorithm utilizing the multi-rate capability and some mesh characteristics in wireless fidelity (WiFi) mesh networks. It uses the medium access control (MAC) transmission time as the routing metric, which is estimated by the information passed up from the physical layer. When the proposed algorithm is adopted, the Ad-hoc on-demand distance vector (AODV) routing can be improved as high throughput AODV (HT-AODV). Simulation results show that HT-AODV is capable of establishing a route that has high data-rate, short end-to-end delay and great network throughput.

  3. The physics data base

    International Nuclear Information System (INIS)

    Gault, F.D.

    1984-01-01

    The physics data base is introduced along with its associated data base management system. The emphasis is on data and their use and a classification of data and of data bases is developed to distinguish compilation organizations. The characteristics of these organizations are examined briefly and the long term consequences of the physics data base discussed. (orig.)

  4. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio

    2011-01-01

    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  5. Robust On-Demand Multipath Routing with Dynamic Path Upgrade for Delay-Sensitive Data over Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2013-01-01

    Full Text Available Node mobility in mobile ad hoc networks (MANETs causes frequent route breakages and intermittent link stability. In this paper, we introduce a robust routing scheme, known as ad hoc on-demand multipath distance vector with dynamic path update (AOMDV-DPU, for delay-sensitive data transmission over MANET. The proposed scheme improves the AOMDV scheme by incorporating the following features: (i a routing metric based on the combination of minimum hops and received signal strength indicator (RSSI for discovery of reliable routes; (ii a local path update mechanism which strengthens the route, reduces the route breakage frequency, and increases the route longevity; (iii a keep alive mechanism for secondary route maintenance which enables smooth switching between routes and reduces the route discovery frequency; (iv a packet salvaging scheme to improve packet delivery in the event of a route breakage; and (v low HELLO packet overhead. The simulations are carried out in ns-2 for varying node speeds, number of sources, and traffic load conditions. Our AOMDV-DPU scheme achieves significantly higher throughput, lower delay, routing overhead, and route discovery frequency and latency compared to AOMDV. For H.264 compressed video traffic, AOMDV-DPU scheme achieves 3 dB or higher PSNR gain over AOMDV at both low and high node speeds.

  6. Delay and cost performance analysis of the diffie-hellman key exchange protocol in opportunistic mobile networks

    Science.gov (United States)

    Soelistijanto, B.; Muliadi, V.

    2018-03-01

    Diffie-Hellman (DH) provides an efficient key exchange system by reducing the number of cryptographic keys distributed in the network. In this method, a node broadcasts a single public key to all nodes in the network, and in turn each peer uses this key to establish a shared secret key which then can be utilized to encrypt and decrypt traffic between the peer and the given node. In this paper, we evaluate the key transfer delay and cost performance of DH in opportunistic mobile networks, a specific scenario of MANETs where complete end-to-end paths rarely exist between sources and destinations; consequently, the end-to-end delays in these networks are much greater than typical MANETs. Simulation results, driven by a random node movement model and real human mobility traces, showed that DH outperforms a typical key distribution scheme based on the RSA algorithm in terms of key transfer delay, measured by average key convergence time; however, DH performs as well as the benchmark in terms of key transfer cost, evaluated by total key (copies) forwards.

  7. A Family of Key Agreement Mechanisms for Mission Critical Communications for Secure Mobile Ad Hoc and Wireless Mesh Internetworking

    Directory of Open Access Journals (Sweden)

    Tryfonas Theo

    2011-01-01

    Full Text Available Future wireless networks like mobile ad hoc networks and wireless mesh networks are expected to play important role in demanding communications such as mission critical communications. MANETs are ideal for emergency cases where the communication infrastructure has been completely destroyed and there is a need for quick set up of communications among the rescue/emergency workers. In such emergency scenarios wireless mesh networks may be employed in a later phase for providing advanced communications and services acting as a backbone network in the affected area. Internetworking of both types of future networks will provide a broad range of mission critical applications. While offering many advantages, such as flexibility, easy of deployment and low cost, MANETs and mesh networks face important security and resilience threats, especially for such demanding applications. We introduce a family of key agreement methods based on weak to strong authentication associated with several multiparty contributory key establishment methods. We examine the attributes of each key establishment method and how each method can be better applied in different scenarios. The proposed protocols support seamlessly both types of networks and consider system and application requirements such as efficient and secure internetworking, dynamicity of network topologies and support of thin clients.

  8. The microstructural stability and mechanical properties of two low activation martensitic steels

    International Nuclear Information System (INIS)

    Victoria, M.; Marmy, P.; Batawi, E.; Peters, J.; Briguet, C.; Rezai-Aria, F.; Gavillet, D.

    1996-01-01

    A desirable feature of future magnetically confined fusion reactors is the prospect of producing low level radioactive waste. In order to minimize the volume of radioactive material, in particular from the first wall and blanket structures, reduced long term activation alloys are being developed. Here, a low activation composition of a martensitic 9% Cr steel has been studied, based on the DIN (Deutsches Inst. fuer Normung) 1.4914 composition (MANET) but replacing Ni, Mo and Nb by the low activation elements W, V and Ta. Two casts were produced from high purity components, in which the effects of controlled additions of Mn (0.58 and 0.055 wt. %) and N (7 and 290 wt. ppm) were studied, so that the final compositions resulted in one cast with high Mn and low N (steel A) and the other with the opposite conditions (steel B). The two steels were evaluated in terms of structural stability and mechanical properties under tensile, fatigue and fracture toughness tests. It has been found that both alloys have a DBTT below room temperature, which in the case of the steel A is 70 K below that of MANET. Although the tensile strength is somewhat below that of the parent steel, both steels have longer fatigue life

  9. A miniaturized test method for the mechanical characterization of structural materials for fusion reactors

    International Nuclear Information System (INIS)

    Gondi, P.; Montanari, R.; Sili, A.

    1996-01-01

    This work deals with a non-destructive method for mechanical tests which is based on the indentation of materials at a constant rate by means of a cylinder with a small radius and penetrating flat surface. The load versus penetration depth curves obtained using this method have shown correspondences with those of tensile tests and have given indications about the mechanical properties on a reduced scale. In this work penetration tests have been carried out on various kinds of Cr martensitic steels (MANET-2, BATMAN and modified F82H) which are of interest for first wall and structural applications in future fusion reactors. The load versus penetration depth curves have been examined with reference to data obtained in tensile tests and to microhardness measurements. Penetration tests have been performed at various temperature (from -180 to 100 C). Conclusions, which can be drawn for the ductile to brittle transition, are discussed for MANET-2 steel. Preliminary results obtained on BATMAN and modified F82H steels are reported. The characteristics of the indenter imprints have been studied by scanning electron microscopy. (orig.)

  10. The Role of Electronic Learning Technology in Networks Systems

    International Nuclear Information System (INIS)

    Abd ELhamid, A.; Ayad, N.M.A.; Fouad, Y.; Abdelkader, T.

    2016-01-01

    Recently, Electronic Learning Technology (ELT) has been widely spread as one of the new technologies in the world through using Information and Communication Technology (ICT). One of the strategies of ELT is Simulation, for instance Military and Medical simulations that are used to avoid risks and reduce Costs. A wireless communication network refers to any network not physically connected by cables, which enables the desired convenience and mobility for the user. Wireless communication networks have been useful in areas such as commerce, education and defense. According to the nature of a particular application, they can be used in home-based and industrial systems or in commercial and military environments. Historically, Mobile Ad-hoc Networks (MANET) have primarily been used for tactical military network related applications to improve battlefield communications/ survivability. MANET is a collection of wireless nodes that can dynamically be set up anywhere and anytime without using any pre-existing network infrastructure. Mobility in wireless networks basically refers to nodes changing its point of attachment to the network. Also, how the end terminals can move, there are many mobility models described the movement of nodes, many researchers use the Random Way point Mobility Model (RWPM). In this paper, a Graphical User Interface (GUI) for RWPM simulation is introduced as a proposal to be used through ELT Project. In the research area of computer and communications networks, simulation is a very useful technique for the behavior of networks

  11. 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.

  12. Implementing a Topology Management Algorithm for Mobile Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    Mrinal K. Naskar

    2008-01-01

    Full Text Available In this paper, we propose to maintain the topology of a MANET by suitably selecting multiple coordinators among the nodes constituting the MANET. The maintenance of topology in a mobile ad–hoc network is of primary importance because the routing techniques can only work if we have a connected network. Thus of the burning issues at present is to device algorithms which ensure that the network topology is always maintained. The basic philosophy behind our algorithm is to isolate two coordinators amongst the system based on positional data. Once elected, they are entrusted with the responsibility to emit signals of different frequencies while the other nodes individually decide the logic they need to follow in order to maintain the topology, thereby greatly reducing the overhead. As far as our knowledge goes, we are the first ones to introduce the concept of multiple coordinators which not only reduces the workload of the coordinator, but also eliminates the need of different signal ranges thereby ensuring greater efficiency. We have simulated the algorithm with the help of a number of robots using embedded systems. The results we have obtained have been quite encouraging.

  13. Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz.

    Science.gov (United States)

    Sandoval, Ruben M; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan

    2016-12-31

    IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG) excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN) and Mobile Ad-hoc Networks (MANET), from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a "default" communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth) or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band.

  14. Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz

    Directory of Open Access Journals (Sweden)

    Ruben M. Sandoval

    2016-12-01

    Full Text Available IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN and Mobile Ad-hoc Networks (MANET, from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a “default” communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band.

  15. Beyond Zero Based Budgeting.

    Science.gov (United States)

    Ogden, Daniel M., Jr.

    1978-01-01

    Suggests that the most practical budgeting system for most managers is a formalized combination of incremental and zero-based analysis because little can be learned about most programs from an annual zero-based budget. (Author/IRT)

  16. VectorBase

    Data.gov (United States)

    U.S. Department of Health & Human Services — VectorBase is a Bioinformatics Resource Center for invertebrate vectors. It is one of four Bioinformatics Resource Centers funded by NIAID to provide web-based...

  17. Mobile Inquiry Based Learning

    NARCIS (Netherlands)

    Specht, Marcus

    2012-01-01

    Specht, M. (2012, 8 November). Mobile Inquiry Based Learning. Presentation given at the Workshop "Mobile inquiry-based learning" at the Mobile Learning Day 2012 at the Fernuniversität Hagen, Hagen, Germany.

  18. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas; Castro, David; Foulds, Ian G.; Parameswaran, Ash M.; Sumanpreet, K. Chhina

    2013-01-01

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling

  19. Carbon Based Nanotechnology: Review

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1999-01-01

    This presentation reviews publicly available information related to carbon based nanotechnology. Topics covered include nanomechanics, carbon based electronics, nanodevice/materials applications, nanotube motors, nano-lithography and H2O storage in nanotubes.

  20. The ground based plan

    International Nuclear Information System (INIS)

    1989-01-01

    The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

  1. Stolen Base Physics

    Science.gov (United States)

    Kagan, David

    2013-01-01

    Few plays in baseball are as consistently close and exciting as the stolen base. While there are several studies of sprinting, the art of base stealing is much more nuanced. This article describes the motion of the base-stealing runner using a very basic kinematic model. The model will be compared to some data from a Major League game. The…

  2. Convergent Filter Bases

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-09-01

    Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

  3. Cholinesterase-based biosensors.

    Science.gov (United States)

    Štěpánková, Šárka; Vorčáková, Katarína

    2016-01-01

    Recently, cholinesterase-based biosensors are widely used for assaying anticholinergic compounds. Primarily biosensors based on enzyme inhibition are useful analytical tools for fast screening of inhibitors, such as organophosphates and carbamates. The present review is aimed at compilation of the most important facts about cholinesterase based biosensors, types of physico-chemical transduction, immobilization strategies and practical applications.

  4. ARAC terrain data base

    International Nuclear Information System (INIS)

    Walker, H.

    1982-11-01

    A terrain data base covering the continental United States at 500-meter resolution has been generated. Its function is to provide terrain data for input to mesoscale atmospheric models that are used as part of the Atmospheric Release Advisory Capability at Lawrence Livermore Laboratory (LLNL). The structure of the data base as it exists on the LLNL computer system is described. The data base has been written to tapes for transfer to other systems and the format of these tapes is also described

  5. Base Station Performance Model

    OpenAIRE

    Walsh, Barbara; Farrell, Ronan

    2005-01-01

    At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

  6. Value-based pricing

    OpenAIRE

    Netseva-Porcheva Tatyana

    2010-01-01

    The main aim of the paper is to present the value-based pricing. Therefore, the comparison between two approaches of pricing is made - cost-based pricing and value-based pricing. The 'Price sensitively meter' is presented. The other topic of the paper is the perceived value - meaning of the perceived value, the components of perceived value, the determination of perceived value and the increasing of perceived value. In addition, the best company strategies in matrix 'value-cost' are outlined. .

  7. Network-Based Effectiveness

    National Research Council Canada - National Science Library

    Friman, Henrik

    2006-01-01

    ...) to increase competitive advantage, innovation, and mission effectiveness. Network-based effectiveness occurs due to the influence of various factors such as people, procedures, technology, and organizations...

  8. Case-based reasoning

    CERN Document Server

    Kolodner, Janet

    1993-01-01

    Case-based reasoning is one of the fastest growing areas in the field of knowledge-based systems and this book, authored by a leader in the field, is the first comprehensive text on the subject. Case-based reasoning systems are systems that store information about situations in their memory. As new problems arise, similar situations are searched out to help solve these problems. Problems are understood and inferences are made by finding the closest cases in memory, comparing and contrasting the problem with those cases, making inferences based on those comparisons, and asking questions whe

  9. Strengths-based Learning

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    -being. The Ph.D.-project in Strength-based learning took place in a Danish school with 750 pupils age 6-16 and a similar school was functioning as a control group. The presentation will focus on both the aware-explore-apply processes and the practical implications for the schools involved, and on measurable......Strength-based learning - Children͛s Character Strengths as Means to their Learning Potential͛ is a Ph.D.-project aiming to create a strength-based mindset in school settings and at the same time introducing strength-based interventions as specific tools to improve both learning and well...

  10. Monitoring Knowledge Base (MKB)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Monitoring Knowledge Base (MKB) is a compilation of emissions measurement and monitoring techniques associated with air pollution control devices, industrial...

  11. Imagery Data Base Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Imagery Data Base Facility supports AFRL and other government organizations by providing imagery interpretation and analysis to users for data selection, imagery...

  12. Game-Based Teaching

    DEFF Research Database (Denmark)

    Hanghøj, Thorkild

    2013-01-01

    This chapter outlines theoretical and empirical perspectives on how Game-Based Teaching can be integrated within the context of formal schooling. Initially, this is done by describing game scenarios as models for possible actions that need to be translated into curricular knowledge practices...... approaches to game-based teaching, which may or may not correspond with the pedagogical models of particular games....

  13. Secure base stations

    NARCIS (Netherlands)

    Bosch, Peter; Brusilovsky, Alec; McLellan, Rae; Mullender, Sape J.; Polakos, Paul

    2009-01-01

    With the introduction of the third generation (3G) Universal Mobile Telecommunications System (UMTS) base station router (BSR) and fourth generation (4G) base stations, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Evolved Node B (eNB), it has become important to

  14. Hydrogel based occlusion systems

    NARCIS (Netherlands)

    Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A.; Mendes, E.; Neves, H.P.; Herijgers, P.; Verbrugghe, Y.; Shacham, Y.; Engel, L.; Krylov, V.

    2013-01-01

    A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a

  15. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  16. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  17. Zero-Based Budgeting.

    Science.gov (United States)

    Wichowski, Chester

    1979-01-01

    The zero-based budgeting approach is designed to achieve the greatest benefit with the fewest undesirable consequences. Seven basic steps make up the zero-based decision-making process: (1) identifying program goals, (2) classifying goals, (3) identifying resources, (4) reviewing consequences, (5) developing decision packages, (6) implementing a…

  18. Office-based anaesthesia

    African Journals Online (AJOL)

    infection, and consistency in nursing personnel. In the USA 17 -. 24% of all elective ambulatory surgery is ... knowledge base or personality to deal with the OBA environment. Compared with hospitals, office-based facilities currently ... disease or major cardiovascular risk factors). Intravenous access via a flexible cannula is.

  19. Knowledge base mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Suwa, M; Furukawa, K; Makinouchi, A; Mizoguchi, T; Mizoguchi, F; Yamasaki, H

    1982-01-01

    One of the principal goals of the Fifth Generation Computer System Project for the coming decade is to develop a methodology for building knowledge information processing systems which will provide people with intelligent agents. The key notion of the fifth generation computer system is knowledge used for problem solving. In this paper the authors describe the plan of Randd on knowledge base mechanisms. A knowledge representation system is to be designed to support knowledge acquisition for the knowledge information processing systems. The system will include a knowledge representation language, a knowledge base editor and a debugger. It is also expected to perform as a kind of meta-inference system. In order to develop the large scale knowledge base systems, a knowledge base mechanism based on the relational model is to be studied in the earlier stage of the project. Distributed problem solving is also one of the main issues of the project. 19 references.

  20. Skull base tumours

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

    2008-06-15

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base.

  1. Evidence-based radiography

    International Nuclear Information System (INIS)

    Hafslund, Bjorg; Clare, Judith; Graverholt, Birgitte; Wammen Nortvedt, Monica

    2008-01-01

    Evidence-based practice (EBP) offers the integration of the best research evidence with clinical knowledge and expertise and patient values. EBP is a well known term in health care. This paper discusses the implementation of EBP into radiography and introduces the term evidence-based radiography. Evidence-based radiography is radiography informed and based on the combination of clinical expertise and the best available research-based evidence, patient preferences and resources available. In Norway, EBP in radiography is being debated and radiographers are discussing the challenges of implementing EBP in both academic and clinical practice. This discussion paper explains why EBP needs to be a basis for a radiography curriculum and a part of radiographers' practice. We argue that Norwegian radiographers must increase participation in research and developing practice within their specific radiographic domain

  2. Skull base tumours

    International Nuclear Information System (INIS)

    Borges, Alexandra

    2008-01-01

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  4. Decentralized position verification in geographic ad hoc routing

    NARCIS (Netherlands)

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

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

  5. Link mellem autisme og MFR-vaccine er dårlig videnskab

    DEFF Research Database (Denmark)

    Ramsøy, Thomas Z.

    2010-01-01

    En meget omdiskuteret frygt for en sammenhæng mellem MFR-vaccinen og autisme er for nylig manet til jorden......En meget omdiskuteret frygt for en sammenhæng mellem MFR-vaccinen og autisme er for nylig manet til jorden...

  6. Design-Based Research

    DEFF Research Database (Denmark)

    Gynther, Karsten; Christensen, Ove; Petersen, Trine Brun

    2012-01-01

    I denne artikel introduceres Design Based Research for første gang på dansk i et videnskabeligt tidsskrift. Artiklen præsenterer de grundlæggende antagelser, som ligger til grund for Design Based Research-traditionen, og artiklen diskuterer de principper, som ligger til grund for gennemførelse af...... et DBR-forskningsprojekt. Med udgangspunkt i forsknings- og udviklingsprojektet ELYK: E-læring, Yderområder og Klyngedannelse, præsenteres den innovationsmodel, som projektet har udviklet med udgangspunkt i Design Based Research traditionen. ELYKs DBR innovationsmodel har vist sig effektiv i forhold...

  7. Nature-based integration

    DEFF Research Database (Denmark)

    Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela

    Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....

  8. Data base management study

    Science.gov (United States)

    1976-01-01

    Data base management techniques and applicable equipment are described. Recommendations which will assist potential NASA data users in selecting and using appropriate data base management tools and techniques are presented. Classes of currently available data processing equipment ranging from basic terminals to large minicomputer systems were surveyed as they apply to the needs of potential SEASAT data users. Cost and capabilities projections for this equipment through 1985 were presented. A test of a typical data base management system was described, as well as the results of this test and recommendations to assist potential users in determining when such a system is appropriate for their needs. The representative system tested was UNIVAC's DMS 1100.

  9. Value-based pricing

    Directory of Open Access Journals (Sweden)

    Netseva-Porcheva Tatyana

    2010-01-01

    Full Text Available The main aim of the paper is to present the value-based pricing. Therefore, the comparison between two approaches of pricing is made - cost-based pricing and value-based pricing. The 'Price sensitively meter' is presented. The other topic of the paper is the perceived value - meaning of the perceived value, the components of perceived value, the determination of perceived value and the increasing of perceived value. In addition, the best company strategies in matrix 'value-cost' are outlined. .

  10. QuickBase

    CERN Document Server

    Conner, Nancy

    2007-01-01

    Ready to put Intuit's QuickBase to work? Our new Missing Manual shows you how to capture, modify, share, and manage data and documents with this web-based data-sharing program quickly and easily. No longer do you have to coordinate your team through a blizzard of emails or play frustrating games of "guess which document is the right one."QuickBase saves your organization time and money, letting you manage and share the information that makes your business tick: sales figures, project timelines, drafts of documents, purchase or work requests--whatever information you need to keep business flowi

  11. Cheboygan Vessel Base

    Data.gov (United States)

    Federal Laboratory Consortium — Cheboygan Vessel Base (CVB), located in Cheboygan, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). CVB was established by congressional...

  12. Hanscom Air Force Base

    Data.gov (United States)

    Federal Laboratory Consortium — MIT Lincoln Laboratory occupies 75 acres (20 acres of which are MIT property) on the eastern perimeter of Hanscom Air Force Base, which is at the nexus of Lexington,...

  13. Network-Based Effectiveness

    National Research Council Canada - National Science Library

    Friman, Henrik

    2006-01-01

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

  14. WormBase

    Data.gov (United States)

    U.S. Department of Health & Human Services — WormBase is an international consortium of biologists and computer scientists dedicated to providing the research community with accurate, current, accessible...

  15. Kelomehele preemia Baseli festivalil

    Index Scriptorium Estoniae

    2000-01-01

    Baselis festivalil "VIPER - International Festival for Film Video and New Media" tunnistati parimaks CD-ROMiks Gustav Deutschi/Anna Schimeki "Odysee today", netiprojektiks itaallaste "01.ORG", äramärkimispreemia - Raivo Kelomehe "Videoweaver"

  16. Risk based modelling

    International Nuclear Information System (INIS)

    Chapman, O.J.V.; Baker, A.E.

    1993-01-01

    Risk based analysis is a tool becoming available to both engineers and managers to aid decision making concerning plant matters such as In-Service Inspection (ISI). In order to develop a risk based method, some form of Structural Reliability Risk Assessment (SRRA) needs to be performed to provide a probability of failure ranking for all sites around the plant. A Probabilistic Risk Assessment (PRA) can then be carried out to combine these possible events with the capability of plant safety systems and procedures, to establish the consequences of failure for the sites. In this way the probability of failures are converted into a risk based ranking which can be used to assist the process of deciding which sites should be included in an ISI programme. This paper reviews the technique and typical results of a risk based ranking assessment carried out for nuclear power plant pipework. (author)

  17. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

  18. Biomimetics: nature based innovation

    National Research Council Canada - National Science Library

    Bar-Cohen, Yoseph

    2012-01-01

    "Based on the concept that nature offers numerous sources of inspiration for inventions related to mechanisms, materials, processes, and algorithms, this book covers the topic of biomimetics and the inspired innovation...

  19. BaseMap

    Data.gov (United States)

    California Natural Resource Agency — The goal of this project is to provide a convenient base map that can be used as a starting point for CA projects. It's simple, but designed to work at a number of...

  20. PHENANTHROLINE TEMPLATED SCHIFF BASE

    African Journals Online (AJOL)

    DNA in intercalative mode and in the development of unique chemotherapeutics where they impact on the ... between base pairs of DNA. .... h, i, j, k belong to fragmentation products of impap. ..... Sm(III) complex and herring sperm DNA. Bull.

  1. Lunar resource base

    Science.gov (United States)

    Pulley, John; Wise, Todd K.; Roy, Claude; Richter, Phil

    A lunar base that exploits local resources to enhance the productivity of a total SEI scenario is discussed. The goals were to emphasize lunar science and to land men on Mars in 2016 using significant amounts of lunar resources. It was assumed that propulsion was chemical and the surface power was non-nuclear. Three phases of the base build-up are outlined, the robotic emplacement of the first elements is detailed and a discussion of future options is included.

  2. Participatory design based research

    DEFF Research Database (Denmark)

    Dau, Susanne; Bach Jensen, Louise; Falk, Lars

    This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus.......This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus....

  3. Maintaining Relationship Based Procurement

    OpenAIRE

    Davis, Peter

    2012-01-01

    Alliance and relationship projects are increasingin number and represent a large pool of work. Tobe successful relationship style contracts dependon soft-dollar factors, particularly the participants'ability to work together within an agreedframework, generally they are not based on lowbid tendering. Participants should be prepared todo business in an open environment based ontrust and mutually agreed governance. Theresearch evaluates relationship maintenance inthe implementation phase of con...

  4. Game-based telerehabilitation.

    Science.gov (United States)

    Lange, B; Flynn, Sheryl M; Rizzo, A A

    2009-03-01

    This article summarizes the recent accomplishments and current challenges facing game-based virtual reality (VR) telerehabilitation. Specifically this article addresses accomplishments relative to realistic practice scenarios, part to whole practice, objective measurement of performance and progress, motivation, low cost, interaction devices and game design. Furthermore, a description of the current challenges facing game based telerehabilitation including the packaging, internet capabilities and access, data management, technical support, privacy protection, seizures, distance trials, scientific scrutiny and support from insurance companies.

  5. REST based mobile applications

    Science.gov (United States)

    Rambow, Mark; Preuss, Thomas; Berdux, Jörg; Conrad, Marc

    2008-02-01

    Simplicity is the major advantage of REST based webservices. Whereas SOAP is widespread in complex, security sensitive business-to-business aplications, REST is widely used for mashups and end-user centric applicatons. In that context we give an overview of REST and compare it to SOAP. Furthermore we apply the GeoDrawing application as an example for REST based mobile applications and emphasize on pros and cons for the use of REST in mobile application scenarios.

  6. Swarm-based medicine.

    Science.gov (United States)

    Putora, Paul Martin; Oldenburg, Jan

    2013-09-19

    Occasionally, medical decisions have to be taken in the absence of evidence-based guidelines. Other sources can be drawn upon to fill in the gaps, including experience and intuition. Authorities or experts, with their knowledge and experience, may provide further input--known as "eminence-based medicine". Due to the Internet and digital media, interactions among physicians now take place at a higher rate than ever before. With the rising number of interconnected individuals and their communication capabilities, the medical community is obtaining the properties of a swarm. The way individual physicians act depends on other physicians; medical societies act based on their members. Swarm behavior might facilitate the generation and distribution of knowledge as an unconscious process. As such, "swarm-based medicine" may add a further source of information to the classical approaches of evidence- and eminence-based medicine. How to integrate swarm-based medicine into practice is left to the individual physician, but even this decision will be influenced by the swarm.

  7. Evidence-Based Toxicology.

    Science.gov (United States)

    Hoffmann, Sebastian; Hartung, Thomas; Stephens, Martin

    Evidence-based toxicology (EBT) was introduced independently by two groups in 2005, in the context of toxicological risk assessment and causation as well as based on parallels between the evaluation of test methods in toxicology and evidence-based assessment of diagnostics tests in medicine. The role model of evidence-based medicine (EBM) motivated both proposals and guided the evolution of EBT, whereas especially systematic reviews and evidence quality assessment attract considerable attention in toxicology.Regarding test assessment, in the search of solutions for various problems related to validation, such as the imperfectness of the reference standard or the challenge to comprehensively evaluate tests, the field of Diagnostic Test Assessment (DTA) was identified as a potential resource. DTA being an EBM discipline, test method assessment/validation therefore became one of the main drivers spurring the development of EBT.In the context of pathway-based toxicology, EBT approaches, given their objectivity, transparency and consistency, have been proposed to be used for carrying out a (retrospective) mechanistic validation.In summary, implementation of more evidence-based approaches may provide the tools necessary to adapt the assessment/validation of toxicological test methods and testing strategies to face the challenges of toxicology in the twenty first century.

  8. LDEF materials data bases

    Science.gov (United States)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

  9. A survey and taxonomy of distributed certificate authorities in mobile ad hoc networks

    Directory of Open Access Journals (Sweden)

    Jabbehdari Sam

    2011-01-01

    Full Text Available Abstract Certificate authorities (CAs are the main components of PKI that enable us for providing basic security services in wired networks and Internet. But, we cannot use centralized CAs, in mobile ad hoc networks (MANETs. So, many efforts have been made to adapt CA to the special characteristics of MANETs and new concepts such as distributed CAs (DCAs have been proposed that distribute the functionality of CA between MANET nodes. In this article, we study various proposed DCA schemes for MANET and then classify these schemes according to their internal structures and techniques. Finally, we propose the characteristics of an ideal DCA system that can be used to verify the completeness of any DCA scheme. This classification and taxonomy identify the weakness and constraints of each scheme, and are very important for designing more secure, scalable, and high performance DCA systems for MANETs and other networks.

  10. Paper based electronics platform

    KAUST Repository

    Nassar, Joanna Mohammad

    2017-07-20

    A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors are provided. A method of producing a paper based sensor can include the steps of: a) providing a conventional paper product to serve as a substrate for the sensor or as an active material for the sensor or both, the paper product not further treated or functionalized; and b) applying a sensing element to the paper substrate, the sensing element selected from the group consisting of a conductive material, the conductive material providing contacts and interconnects, sensitive material film that exhibits sensitivity to pH levels, a compressible and/or porous material disposed between a pair of opposed conductive elements, or a combination of two of more said sensing elements. The method of sensing can further include measuring, using the sensing element, a change in resistance, a change in voltage, a change in current, a change in capacitance, or a combination of any two or more thereof.

  11. Gossip-Based Dissemination

    Science.gov (United States)

    Friedman, Roy; Kermarrec, Anne-Marie; Miranda, Hugo; Rodrigues, Luís

    Gossip-based networking has emerged as a viable approach to disseminate information reliably and efficiently in large-scale systems. Initially introduced for database replication [222], the applicability of the approach extends much further now. For example, it has been applied for data aggregation [415], peer sampling [416] and publish/subscribe systems [845]. Gossip-based protocols rely on a periodic peer-wise exchange of information in wired systems. By changing the way each peer is selected for the gossip communication, and which data are exchanged and processed [451], gossip systems can be used to perform different distributed tasks, such as, among others: overlay maintenance, distributed computation, and information dissemination (a collection of papers on gossip can be found in [451]). In a wired setting, the peer sampling service, allowing for a random or specific peer selection, is often provided as an independent service, able to operate independently from other gossip-based services [416].

  12. Iron-based superconductivity

    CERN Document Server

    Johnson, Peter D; Yin, Wei-Guo

    2015-01-01

    This volume presents an in-depth review of experimental and theoretical studies on the newly discovered Fe-based superconductors.  Following the Introduction, which places iron-based superconductors in the context of other unconventional superconductors, the book is divided into three sections covering sample growth, experimental characterization, and theoretical understanding.  To understand the complex structure-property relationships of these materials, results from a wide range of experimental techniques and theoretical approaches are described that probe the electronic and magnetic proper

  13. Evidence-Based Development

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2004-01-01

    Systems development is replete with projects that represent substantial resource investments but result in systems that fail to meet users’ needs. Evidence-based development is an emerging idea intended to provide means for managing customer-vendor relationships and working systematically toward...... meeting customer needs. We are suggesting that the effects of the use of a system should play a prominent role in the contractual definition of IT projects and that contract fulfilment should be determined on the basis of evidence of these effects. Based on two ongoing studies of home-care management...

  14. Video-based rendering

    CERN Document Server

    Magnor, Marcus A

    2005-01-01

    Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

  15. Process-based costing.

    Science.gov (United States)

    Lee, Robert H; Bott, Marjorie J; Forbes, Sarah; Redford, Linda; Swagerty, Daniel L; Taunton, Roma Lee

    2003-01-01

    Understanding how quality improvement affects costs is important. Unfortunately, low-cost, reliable ways of measuring direct costs are scarce. This article builds on the principles of process improvement to develop a costing strategy that meets both criteria. Process-based costing has 4 steps: developing a flowchart, estimating resource use, valuing resources, and calculating direct costs. To illustrate the technique, this article uses it to cost the care planning process in 3 long-term care facilities. We conclude that process-based costing is easy to implement; generates reliable, valid data; and allows nursing managers to assess the costs of new or modified processes.

  16. Inkjet-based micromanufacturing

    CERN Document Server

    Korvink, Jan G; Shin, Dong-Youn; Brand, Oliver; Fedder, Gary K; Hierold, Christofer; Tabata, Osamu

    2012-01-01

    Inkjet-based Micromanufacturing Inkjet technology goes way beyond putting ink on paper: it enables simpler, faster and more reliable manufacturing processes in the fields of micro- and nanotechnology. Modern inkjet heads are per se precision instruments that deposit droplets of fluids on a variety of surfaces in programmable, repeating patterns, allowing, after suitable modifications and adaptations, the manufacturing of devices such as thin-film transistors, polymer-based displays and photovoltaic elements. Moreover, inkjet technology facilitates the large-scale production of flexible RFID tr

  17. On multivariate Wilson bases

    DEFF Research Database (Denmark)

    Bownik, Marcin; Jakobsen, Mads Sielemann; Lemvig, Jakob

    2017-01-01

    A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. In this paper we give an account of the construction of bimodular Wilson bases in higher dimensions from Gabor frames of redundancy two.......A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. In this paper we give an account of the construction of bimodular Wilson bases in higher dimensions from Gabor frames of redundancy two....

  18. Supramolecular fluorene based materials

    NARCIS (Netherlands)

    Abbel, R.J.

    2008-01-01

    This thesis describes the use of noncovalent interactions in order to manipulate and control the self-assembly and morphology of electroactive fluorene-based materials. The supramolecular arrangement of p-conjugated polymers and oligomers can strongly influence their electronic and photophysical

  19. EPICS based DAQ system

    International Nuclear Information System (INIS)

    Cheng Weixing; Chen Yongzhong; Zhou Weimin; Ye Kairong; Liu Dekang

    2002-01-01

    EPICS is the most popular developing platform to build control system and beam diagnostic system in modern physics experiment facilities. An EPICS based data acquisition system was built in Redhat 6.2 operation system. The system is successfully used in the beam position monitor mapping, it improves the mapping process a lot

  20. Scenario-based strategizing

    DEFF Research Database (Denmark)

    Lehr, Thomas; Lorenz, Ullrich; Willert, Markus

    2017-01-01

    -based efficacy and robustness. To facilitate the colla- borative strategizing in teams, we propose a matrix with robustness and efficacy as the two axes, which we call the Parmenides Matrix. We assess the impact of the novel approach by applying it in two cases, at a govern- mental agency (German Environmental...

  1. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...

  2. Web Based VRML Modelling

    NARCIS (Netherlands)

    Kiss, S.; Sarfraz, M.

    2004-01-01

    Presents a method to connect VRML (Virtual Reality Modeling Language) and Java components in a Web page using EAI (External Authoring Interface), which makes it possible to interactively generate and edit VRML meshes. The meshes used are based on regular grids, to provide an interaction and modeling

  3. Surfel Based Geometry Resonstruction

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Aanæs, Henrik; Bærentzen, Jakob Andreas

    2010-01-01

    We propose a method for retrieving a piecewise smooth surface from noisy data. In data acquired by a scanning process sampled points are almost never on the discontinuities making reconstruction of surfaces with sharp features difficult. Our method is based on a Markov Random Field (MRF) formulat...

  4. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Sporring, Jon; Fogh Olsen, Ole

    2008-01-01

    . To address this problem, we introduce a photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way, we preserve important illumination features, while...

  5. Evidence-based policy

    DEFF Research Database (Denmark)

    Vohnsen, Nina Holm

    2013-01-01

    -makers and the research community (e.g. Boden & Epstein 2006; House of Commons 2006; Cartwright et al 2009; Rod 2010; Vohnsen 2011). This article intends to draw out some general pitfalls in the curious meeting of science and politics by focusing on a particular attempt to make evidence-based legislation in Denmark (for...

  6. Project-Based Science

    Science.gov (United States)

    Krajcik, Joe

    2015-01-01

    Project-based science is an exciting way to teach science that aligns with the "Next Generation Science Standards" ("NGSS"). By focusing on core ideas along with practices and crosscutting concepts, classrooms become learning environments where teachers and students engage in science by designing and carrying out…

  7. Financing Competency Based Programs.

    Science.gov (United States)

    Daniel, Annette

    Literature on the background, causes, and current prevalence of competency based programs is synthesized in this report. According to one analysis of the actual and probable costs of minimum competency testing, estimated costs for test development, test administration, bureaucratic structures, and remedial programs for students who cannot pass the…

  8. Computer Based Expert Systems.

    Science.gov (United States)

    Parry, James D.; Ferrara, Joseph M.

    1985-01-01

    Claims knowledge-based expert computer systems can meet needs of rural schools for affordable expert advice and support and will play an important role in the future of rural education. Describes potential applications in prediction, interpretation, diagnosis, remediation, planning, monitoring, and instruction. (NEC)

  9. Community-Based Care

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Community-Based Care Basic Facts & Information A variety of healthcare options ... day care centers are either in churches or community centers. Adult day care is commonly used to care for people who ...

  10. Polymer based tunneling sensor

    Science.gov (United States)

    Cui, Tianhong (Inventor); Wang, Jing (Inventor); Zhao, Yongjun (Inventor)

    2006-01-01

    A process for fabricating a polymer based circuit by the following steps. A mold of a design is formed through a lithography process. The design is transferred to a polymer substrate through a hot embossing process. A metal layer is then deposited over at least part of said design and at least one electrical lead is connected to said metal layer.

  11. Evidence-based guidelines

    DEFF Research Database (Denmark)

    Rovira, Àlex; Wattjes, Mike P; Tintoré, Mar

    2015-01-01

    diagnosis in patients with MS. The aim of this article is to provide guidelines for the implementation of MRI of the brain and spinal cord in the diagnosis of patients who are suspected of having MS. These guidelines are based on an extensive review of the recent literature, as well as on the personal...

  12. School Based Health Centers

    Science.gov (United States)

    Children's Aid Society, 2012

    2012-01-01

    School Based Health Centers (SBHC) are considered by experts as one of the most effective and efficient ways to provide preventive health care to children. Few programs are as successful in delivering health care to children at no cost to the patient, and where they are: in school. For many underserved children, The Children's Aid Society's…

  13. Internet based benchmarking

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Nielsen, Kurt

    2005-01-01

    We discuss the design of interactive, internet based benchmarking using parametric (statistical) as well as nonparametric (DEA) models. The user receives benchmarks and improvement potentials. The user is also given the possibility to search different efficiency frontiers and hereby to explore...

  14. Problem-based learning

    NARCIS (Netherlands)

    Loyens, Sofie; Kirschner, Paul A.; Paas, Fred

    2010-01-01

    Loyens, S. M. M., Kirschner, P. A., & Paas, F. (2011). Problem-based learning. In S. Graham (Editor-in-Chief), A. Bus, S. Major, & L. Swanson (Associate Editors), APA educational psychology handbook: Vol. 3. Application to learning and teaching (pp. 403-425). Washington, DC: American Psychological

  15. Base tree property

    Czech Academy of Sciences Publication Activity Database

    Balcar, B.; Doucha, Michal; Hrušák, M.

    2015-01-01

    Roč. 32, č. 1 (2015), s. 69-81 ISSN 0167-8094 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : forcing * Boolean algebras * base tree Subject RIV: BA - General Mathematics Impact factor: 0.614, year: 2015 http://link.springer.com/article/10.1007/s11083-013-9316-2

  16. unsymmetrical Schiff base complexes

    Indian Academy of Sciences (India)

    the effect of the substitutional groups of the Schiff base on the oxidation and reduction potentials, we used ... Electrochemistry of these complexes showed that the presence of electron .... a solution of the ligand (1 mmol) in methanol (15 mL).

  17. Home-based care

    African Journals Online (AJOL)

    Mrs. Patience Edoho Samson-Akpan

    study was to ascertain the relationship between home-based care and quality of life of PLWHA in support groups in. Calabar South Local Government Area. A correlational design was utilized and a purposive sample of 74 PLWHA participated in the study. A self developed and well validated questionnaire was used for data ...

  18. Mutually unbiased bases

    Indian Academy of Sciences (India)

    Mutually unbiased bases play an important role in quantum cryptography [2] and in the optimal determination of the density operator of an ensemble [3,4]. A density operator ρ in N-dimensions depends on N2 1 real quantities. With the help of MUB's, any such density operator can be encoded, in an optimal way, in terms of ...

  19. Scenario-based strategizing

    DEFF Research Database (Denmark)

    Lehr, Thomas; Lorenz, Ullrich; Willert, Markus

    2017-01-01

    For over 40 years, scenarios have been promoted as a key technique for forming strategies in uncertain en- vironments. However, many challenges remain. In this article, we discuss a novel approach designed to increase the applicability of scenario-based strategizing in top management teams. Drawi...... Ministry) and a firm affected by disruptive change (Bosch, leading global supplier of technology and solutions)....

  20. 80537 based distance relay

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen

    1999-01-01

    A method for implementing a digital distance relay in the power system is described.Instructions are given on how to program this relay on a 80537 based microcomputer system.The problem is used as a practical case study in the course 53113: Micocomputer applications in the power system.The relay...

  1. Mojave Base Station Implementation

    Science.gov (United States)

    Koscielski, C. G.

    1984-01-01

    A 12.2 meter diameter X-Y mount antenna was reconditioned for use by the crustal dynamic project as a fixed base station. System capabilities and characteristics and key performance parameters for subsystems are presented. The implementation is completed.

  2. Model-based consensus

    NARCIS (Netherlands)

    Boumans, M.; Martini, C.; Boumans, M.

    2014-01-01

    The aim of the rational-consensus method is to produce "rational consensus", that is, "mathematical aggregation", by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  3. Model-based consensus

    NARCIS (Netherlands)

    Boumans, Marcel

    2014-01-01

    The aim of the rational-consensus method is to produce “rational consensus”, that is, “mathematical aggregation”, by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  4. Animation-based Sketching

    DEFF Research Database (Denmark)

    Vistisen, Peter

    This thesis is based on the results of a three-year long PhD-study at the Department of Communication and Psychology at Aalborg University. The thesis consist of five original papers, a book manuscript, as well as a linking text with the thesis’ research questions, research design, and summary...

  5. Refractive index based measurements

    DEFF Research Database (Denmark)

    2014-01-01

    In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature, a chirp in the local spatial frequency of interference fringes of an interference pattern is reduced by mathematical manipulation of the recorded light intensity...

  6. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  7. Schiff base ligand

    Indian Academy of Sciences (India)

    Unknown

    Low-temperature stoichiometric Schiff base reaction in air in 3 : 1 mole ratio between benz- aldehyde and triethylenetetramine (trien) in methanol yields a novel tetraaza µ-bis(bidentate) acyclic ligand L. It was .... electrochemical work was performed as reported in ..... change in ligand shape through change in oxidation.

  8. ISFET based enzyme sensors

    NARCIS (Netherlands)

    van der Schoot, Bart H.; Bergveld, Piet

    1987-01-01

    This paper reviews the results that have been reported on ISFET based enzyme sensors. The most important improvement that results from the application of ISFETs instead of glass membrane electrodes is in the method of fabrication. Problems with regard to the pH dependence of the response and the

  9. Microcontroller base process emulator

    OpenAIRE

    Jovrea Titus Claudiu

    2009-01-01

    This paper describes the design of a microcontroller base emulator for a conventional industrial process. The emulator is made with microcontroller and is used for testing and evaluating the performances of the industrial regulators. The parameters of the emulated process are fully customizable online and downloadable thru a serial communication from a personal computer.

  10. REST based service composition

    DEFF Research Database (Denmark)

    Grönvall, Erik; Ingstrup, Mads; Pløger, Morten

    2011-01-01

    This paper presents an ongoing work developing and testing a Service Composition framework based upon the REST architecture named SECREST. A minimalistic approach have been favored instead of a creating a complete infrastructure. One focus has been on the system's interaction model. Indeed, an aim...

  11. Convolution based profile fitting

    International Nuclear Information System (INIS)

    Kern, A.; Coelho, A.A.; Cheary, R.W.

    2002-01-01

    Full text: In convolution based profile fitting, profiles are generated by convoluting functions together to form the observed profile shape. For a convolution of 'n' functions this process can be written as, Y(2θ)=F 1 (2θ)x F 2 (2θ)x... x F i (2θ)x....xF n (2θ). In powder diffractometry the functions F i (2θ) can be interpreted as the aberration functions of the diffractometer, but in general any combination of appropriate functions for F i (2θ) may be used in this context. Most direct convolution fitting methods are restricted to combinations of F i (2θ) that can be convoluted analytically (e.g. GSAS) such as Lorentzians, Gaussians, the hat (impulse) function and the exponential function. However, software such as TOPAS is now available that can accurately convolute and refine a wide variety of profile shapes numerically, including user defined profiles, without the need to convolute analytically. Some of the most important advantages of modern convolution based profile fitting are: 1) virtually any peak shape and angle dependence can normally be described using minimal profile parameters in laboratory and synchrotron X-ray data as well as in CW and TOF neutron data. This is possible because numerical convolution and numerical differentiation is used within the refinement procedure so that a wide range of functions can easily be incorporated into the convolution equation; 2) it can use physically based diffractometer models by convoluting the instrument aberration functions. This can be done for most laboratory based X-ray powder diffractometer configurations including conventional divergent beam instruments, parallel beam instruments, and diffractometers used for asymmetric diffraction. It can also accommodate various optical elements (e.g. multilayers and monochromators) and detector systems (e.g. point and position sensitive detectors) and has already been applied to neutron powder diffraction systems (e.g. ANSTO) as well as synchrotron based

  12. Integrated Case Based and Rule Based Reasoning for Decision Support

    OpenAIRE

    Eshete, Azeb Bekele

    2009-01-01

    This project is a continuation of my specialization project which was focused on studying theoretical concepts related to case based reasoning method, rule based reasoning method and integration of them. The integration of rule-based and case-based reasoning methods has shown a substantial improvement with regards to performance over the individual methods. Verdande Technology As wants to try integrating the rule based reasoning method with an existing case based system. This project focu...

  13. Rock properties data base

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R.; Gorski, B.; Gyenge, M.

    1991-03-01

    As mining companies proceed deeper and into areas whose stability is threatened by high and complex stress fields, the science of rock mechanics becomes invaluable in designing underground mine strata control programs. CANMET's Mining Research Laboratories division has compiled a summary of pre- and post-failure mechanical properties of rock types which were tested to provide design data. The 'Rock Properties Data Base' presents the results of these tests, and includes many rock types typical of Canadian mine environments. The data base also contains 'm' and 's' values determined using Hoek and Brown's failure criteria for both pre- and post-failure conditions. 7 refs., 3 tabs., 9 figs., 1 append.

  14. Sparse approximation with bases

    CERN Document Server

    2015-01-01

    This book systematically presents recent fundamental results on greedy approximation with respect to bases. Motivated by numerous applications, the last decade has seen great successes in studying nonlinear sparse approximation. Recent findings have established that greedy-type algorithms are suitable methods of nonlinear approximation in both sparse approximation with respect to bases and sparse approximation with respect to redundant systems. These insights, combined with some previous fundamental results, form the basis for constructing the theory of greedy approximation. Taking into account the theoretical and practical demand for this kind of theory, the book systematically elaborates a theoretical framework for greedy approximation and its applications.  The book addresses the needs of researchers working in numerical mathematics, harmonic analysis, and functional analysis. It quickly takes the reader from classical results to the latest frontier, but is written at the level of a graduate course and do...

  15. Problem Based Game Design

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2011-01-01

    At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various ...... projects and how they learn to analyse, design, and develop for innovation by using it. We will present various cases to exemplify the approach and focus on how the method engages students and aspires for innovation in digital entertainment and games.......At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various...

  16. Technology based Education System

    DEFF Research Database (Denmark)

    Kant Hiran, Kamal; Doshi, Ruchi; Henten, Anders

    2016-01-01

    Abstract - Education plays a very important role for the development of the country. Education has multiple dimensions from schooling to higher education and research. In all these domains, there is invariably a need for technology based teaching and learning tools are highly demanded in the acad......Abstract - Education plays a very important role for the development of the country. Education has multiple dimensions from schooling to higher education and research. In all these domains, there is invariably a need for technology based teaching and learning tools are highly demanded...... in the academic institutions. Thus, there is a need of comprehensive technology support system to cater the demands of all educational actors. Cloud Computing is one such comprehensive and user-friendly technology support environment that is the need of an hour. Cloud computing is the emerging technology that has...

  17. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1998-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  18. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A. [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1997-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  19. Conducting Polymer Based Nanobiosensors

    Directory of Open Access Journals (Sweden)

    Chul Soon Park

    2016-06-01

    Full Text Available In recent years, conducting polymer (CP nanomaterials have been used in a variety of fields, such as in energy, environmental, and biomedical applications, owing to their outstanding chemical and physical properties compared to conventional metal materials. In particular, nanobiosensors based on CP nanomaterials exhibit excellent performance sensing target molecules. The performance of CP nanobiosensors varies based on their size, shape, conductivity, and morphology, among other characteristics. Therefore, in this review, we provide an overview of the techniques commonly used to fabricate novel CP nanomaterials and their biosensor applications, including aptasensors, field-effect transistor (FET biosensors, human sense mimicking biosensors, and immunoassays. We also discuss prospects for state-of-the-art nanobiosensors using CP nanomaterials by focusing on strategies to overcome the current limitations.

  20. Fusion safety data base

    International Nuclear Information System (INIS)

    Laats, E.T.; Hardy, H.A.

    1983-01-01

    The purpose of this Fusion Safety Data Base Program is to provide a repository of data for the design and development of safe commercial fusion reactors. The program is sponsored by the United States Department of Energy (DOE), Office of Fusion Energy. The function of the program is to collect, examine, permanently store, and make available the safety data to the entire US magnetic-fusion energy community. The sources of data will include domestic and foreign fusion reactor safety-related research programs. Any participant in the DOE Program may use the Data Base Program from his terminal through user friendly dialog and can view the contents in the form of text, tables, graphs, or system diagrams

  1. Maintaining Relationship Based Procurement

    Directory of Open Access Journals (Sweden)

    Peter Davis

    2012-11-01

    Full Text Available Alliance and relationship projects are increasingin number and represent a large pool of work. Tobe successful relationship style contracts dependon soft-dollar factors, particularly the participants'ability to work together within an agreedframework, generally they are not based on lowbid tendering. Participants should be prepared todo business in an open environment based ontrust and mutually agreed governance. Theresearch evaluates relationship maintenance inthe implementation phase of constructionalliances - a particular derivative of relationshipstyle contracts. To determine the factors thatcontribute to relationship maintenance forty-nineexperienced Australian alliance projectmanagers were interviewed. The main findingswere; the development of relationships early inthe project form building blocks of success fromwhich relationships are maintained and projectvalue added; quality facilitation plays animportant part in relationship maintenance and ahybrid organisation created as a result of alliancedevelopment overcomes destructiveorganisational boundaries. Relationshipmaintenance is integral to alliance project controland failure to formalise it and pay attention toprocess and past outcomes will undermine analliance project's potential for success.

  2. Location-based Scheduling

    DEFF Research Database (Denmark)

    Andersson, Niclas; Christensen, Knud

    on the market. However, CPM is primarily an activity based method that takes the activity as the unit of focus and there is criticism raised, specifically in the case of construction projects, on the method for deficient management of construction work and continuous flow of resources. To seek solutions...... to the identified limitations of the CPM method, an alternative planning and scheduling methodology that includes locations is tested. Location-based Scheduling (LBS) implies a shift in focus, from primarily the activities to the flow of work through the various locations of the project, i.e. the building. LBS uses...... the graphical presentation technique of Line-of-balance, which is adapted for planning and management of work-flows that facilitates resources to perform their work without interruptions caused by other resources working with other activities in the same location. As such, LBS and Lean Construction share...

  3. Trajectory Based Traffic Analysis

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2013-01-01

    We present the INTRA system for interactive path-based traffic analysis. The analyses are developed in collaboration with traffic researchers and provide novel insights into conditions such as congestion, travel-time, choice of route, and traffic-flow. INTRA supports interactive point-and-click a......We present the INTRA system for interactive path-based traffic analysis. The analyses are developed in collaboration with traffic researchers and provide novel insights into conditions such as congestion, travel-time, choice of route, and traffic-flow. INTRA supports interactive point......-and-click analysis, due to a novel and efficient indexing structure. With the web-site daisy.aau.dk/its/spqdemo/we will demonstrate several analyses, using a very large real-world data set consisting of 1.9 billion GPS records (1.5 million trajectories) recorded from more than 13000 vehicles, and touching most...

  4. Carbon Nanotube based Nanotechnolgy

    Science.gov (United States)

    Meyyappan, M.

    2000-10-01

    Carbon nanotube(CNT) was discovered in the early 1990s and is an off-spring of C60(the fullerene or buckyball). CNT, depending on chirality and diameter, can be metallic or semiconductor and thus allows formation of metal-semiconductor and semiconductor-semiconductor junctions. CNT exhibits extraordinary electrical and mechanical properties and offers remarkable potential for revolutionary applications in electronics devices, computing and data storage technology, sensors, composites, storage of hydrogen or lithium for battery development, nanoelectromechanical systems(NEMS), and as tip in scanning probe microscopy(SPM) for imaging and nanolithography. Thus the CNT synthesis, characterization and applications touch upon all disciplines of science and engineering. A common growth method now is based on CVD though surface catalysis is key to synthesis, in contrast to many CVD applications common in microelectronics. A plasma based variation is gaining some attention. This talk will provide an overview of CNT properties, growth methods, applications, and research challenges and opportunities ahead.

  5. Spintronics-based computing

    CERN Document Server

    Prenat, Guillaume

    2015-01-01

    This book provides a comprehensive introduction to spintronics-based computing for the next generation of ultra-low power/highly reliable logic, which is widely considered a promising candidate to replace conventional, pure CMOS-based logic. It will cover aspects from device to system-level, including magnetic memory cells, device modeling, hybrid circuit structure, design methodology, CAD tools, and technological integration methods. This book is accessible to a variety of readers and little or no background in magnetism and spin electronics are required to understand its content.  The multidisciplinary team of expert authors from circuits, devices, computer architecture, CAD and system design reveal to readers the potential of spintronics nanodevices to reduce power consumption, improve reliability and enable new functionality.  .

  6. Knowledge Based Economy Assessment

    OpenAIRE

    Madalina Cristina Tocan

    2012-01-01

    The importance of knowledge-based economy (KBE) in the XXI century is evident. In the article the reflection of knowledge on economy is analyzed. The main point is targeted to the analysis of characteristics of knowledge expression in economy and to the construction of structure of KBE expression. This allows understanding the mechanism of functioning of knowledge economy. The authors highlight the possibility to assess the penetration level of KBE which could manifest itself trough the exist...

  7. Luxury-based Growth

    OpenAIRE

    Shiro Kuwahara

    2006-01-01

    Assuming that there exists a preference for luxury goods and a knowledge spillover from luxury goods production to goods production, this paper constructs an endogenous economic growth model. The model predicts two steady states: one is a steady positive growth state with regard to luxury goods production, and the other is a zero growth state in the absence of luxury goods production. Thus, this study examines the polarization of economies based on luxury goods consumption

  8. Base Stability of Aminocyclopropeniums

    Science.gov (United States)

    2017-11-01

    PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) US Army Research Laboratory Weapons and Materials Research Directorate (ATTN: RDRL-WMM-G) 2800 Powder...Mill Road Adelphi, MD 20783-1138 8. PERFORMING ORGANIZATION REPORT NUMBER ARL-TR-8204 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES...fuel cells to test their utility in anion exchange membranes. While the aminocyclopropeniums showed poor base stability, the cyclopropenium cation

  9. Granular loess classification based

    International Nuclear Information System (INIS)

    Browzin, B.S.

    1985-01-01

    This paper discusses how loess might be identified by two index properties: the granulometric composition and the dry unit weight. These two indices are necessary but not always sufficient for identification of loess. On the basis of analyses of samples from three continents, it was concluded that the 0.01-0.5-mm fraction deserves the name loessial fraction. Based on the loessial fraction concept, a granulometric classification of loess is proposed. A triangular chart is used to classify loess

  10. Educational Process Material Base

    OpenAIRE

    Olga Ozerova; Irina Zabaturina; Vera Kuznetsova; Galina Kovaleva

    2012-01-01

    Based on the data obtained by the Institute for Statistical Studies and the Economics of Knowledge, National Research University - Higher School of Economics Olga Ozerova - Head of the Department for Statistics of Education, Institute for Statistical Studies and the Economics of Knowledge, National Research University - Higher School of Economics, Moscow, Russian Federation. Email: Address: 18 Myasnitskaya St., Moscow, 101000, Russian Federation.Irina Zabaturina - senior resea...

  11. Supramolecular fluorene based materials

    OpenAIRE

    Abbel, R.J.

    2008-01-01

    This thesis describes the use of noncovalent interactions in order to manipulate and control the self-assembly and morphology of electroactive fluorene-based materials. The supramolecular arrangement of p-conjugated polymers and oligomers can strongly influence their electronic and photophysical properties. Therefore, a detailed understanding of such organisation processes is essential for the optimisation of the performance of these materials as applied in optoelectronic devices. In order to...

  12. Graphene-based Nanoelectronics

    Science.gov (United States)

    2013-02-01

    Electrodes were fabricated by drop casting solutions containing the graphene oxide (GO)/CNT/MnAc materials onto titanium (Ti) or stainless steel current...silicon carbide (SiC) substrate can induce a splitting of up to 0.3 eV between the maximum of the valence and minimum of the conduction bands at the...simultaneously hinders the formation of multilayer graphene domains. These results are based on a diffusion-segregation model for carbon precipitation on a Ni

  13. Spiritual-based Leadership

    DEFF Research Database (Denmark)

    Pruzan, Peter

    2015-01-01

    Although far from mainstream, the concept of spiritual-based leadership is emerging as an inclusive and yet highly personal approach to leadership that integrates a leader’s inner perspectives on identity, purpose, responsibility and success with her or his decisions and actions in the outer world...... of business—and therefore it is also emerging as a significant framework for understanding, practicing, communicating and teaching the art and profession of leadership....

  14. Arduino based laser control

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  15. Design bases - Concrete structures

    International Nuclear Information System (INIS)

    Diaz-Llanos Ros, M.

    1993-01-01

    The most suitable title for Section 2 is 'Design Bases', which covers not only calculation but also the following areas: - Structural design concepts. - Project criteria. - Material specifications. These concepts are developed in more detail in the following sections. The numbering in this document is neither complete nor hierarchical since, for easier cross referencing, it corresponds to the paragraphs of Eurocode 2 Part 1 (hereinafter 'EUR-2') which are commented on. (author)

  16. Biosphere data base revision

    International Nuclear Information System (INIS)

    Bergstroem, U.; Andersson, K.; Sundblad, B.

    1985-12-01

    The turnover of long-lived radionuclides in the biosphere has been modelled some time ago and the exposure to man was calculated. The nuclides were long-lived actinides and fission products leaking from a simulated deep rock repository for spent nuclear fuel. The data base for these calculations has been updated in the present work and in addition a number of nuclides that were not included in the earlier work have been treated. (G.B.)

  17. Air Force Smart Bases

    Science.gov (United States)

    2017-10-19

    initiates notification to all personnel on the base, the giant voice announces a lock down, everyone’s smart device shows an alarm requesting...location of the detected sound, they easily find a hunter and send his picture back to the IOC, where the hunter’s identity is verified through facial...computer goes into sleep mode, the thermostat goes back to unoccupied mode and his door locks as he walks through. Meanwhile over in the IOC

  18. Polypeptide based hydrogels

    OpenAIRE

    Hanay, Saltuk

    2018-01-01

    There is a need for biocompatible, biodegradable, 3-D printable and stable hydrogels especially in the areas of tissue engineering, drug delivery, bio-sensing technologies and antimicrobial coatings. The main aim of this Ph.D. work was to fabricate polypeptide based hydrogel which may find a potential application in those fields. Focusing on tyrosine or tryptophan-containing copolypeptides prepared by NCarboxyanhydride (NCA) polymerizations, three different crosslinking strategies have been t...

  19. Knowledge-based utility

    International Nuclear Information System (INIS)

    Chwalowski, M.

    1997-01-01

    This presentation provides industry examples of successful marketing practices by companies facing deregulation and competition. The common thread through the examples is that long term survival of today's utility structure is dependent on the strategic role of knowledge. As opposed to regulated monopolies which usually own huge physical assets and have very little intelligence about their customers, unregulated enterprises tend to be knowledge-based, characterized by higher market value than book value. A knowledge-based enterprise gathers data, creates information and develops knowledge by leveraging it as a competitive weapon. It institutionalizes human knowledge as a corporate asset for use over and over again by the use of databases, computer networks, patents, billing, collection and customer services (BCCS), branded interfaces and management capabilities. Activities to become knowledge-based such as replacing inventory/fixed assets with information about material usage to reduce expenditure and achieve more efficient operations, and by focusing on integration and value-adding delivery capabilities, were reviewed

  20. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  1. As bases do petismo

    Directory of Open Access Journals (Sweden)

    David Samuels

    2004-10-01

    Full Text Available A partir dos dados do ESEB de 2002 o autor realiza um estudo das bases eleitorais do PT e de hipóteses sobre a natureza do petismo. Através de técnicas estatísticas multivariadas, são testadas relações do petismo com variáveis demográficas, socioeconômicas e variáveis relativas a questões políticas específicas. Os resultados apontam que apenas a escolaridade tem uma associação específica com o petismo, com implicações para o seu comportamento sócio-político.Based on the results of the 2002 Brazilian Electoral Study, the author analyses the electoral bases of the Worker´s Party and the factors associated with the "petismo". The relationships between the "petismo"and the socioeconomic, demographic and political variables are tested using multivariate analysis. The results indicate that the only "social category"associated with "petismo"is level of education, and it has clear implications to their social and political behavior.

  2. Value-based genomics.

    Science.gov (United States)

    Gong, Jun; Pan, Kathy; Fakih, Marwan; Pal, Sumanta; Salgia, Ravi

    2018-03-20

    Advancements in next-generation sequencing have greatly enhanced the development of biomarker-driven cancer therapies. The affordability and availability of next-generation sequencers have allowed for the commercialization of next-generation sequencing platforms that have found widespread use for clinical-decision making and research purposes. Despite the greater availability of tumor molecular profiling by next-generation sequencing at our doorsteps, the achievement of value-based care, or improving patient outcomes while reducing overall costs or risks, in the era of precision oncology remains a looming challenge. In this review, we highlight available data through a pre-established and conceptualized framework for evaluating value-based medicine to assess the cost (efficiency), clinical benefit (effectiveness), and toxicity (safety) of genomic profiling in cancer care. We also provide perspectives on future directions of next-generation sequencing from targeted panels to whole-exome or whole-genome sequencing and describe potential strategies needed to attain value-based genomics.

  3. Intrusion detection in Mobile Ad-hoc Networks: Bayesian game formulation

    Directory of Open Access Journals (Sweden)

    Basant Subba

    2016-06-01

    Full Text Available Present Intrusion Detection Systems (IDSs for MANETs require continuous monitoring which leads to rapid depletion of a node's battery life. To address this issue, we propose a new IDS scheme comprising a novel cluster leader election process and a hybrid IDS. The cluster leader election process uses the Vickrey–Clarke–Groves mechanism to elect the cluster leader which provides the intrusion detection service. The hybrid IDS comprises a threshold based lightweight module and a powerful anomaly based heavyweight module. Initially, only the lightweight module is activated. The decision to activate the heavyweight module is taken by modeling the intrusion detection process as an incomplete information non-cooperative game between the elected leader node and the potential malicious node. Simulation results show that the proposed scheme significantly reduces the IDS traffic and overall power consumption in addition to maintaining a high detection rate and accuracy.

  4. Nanoplatform-based molecular imaging

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2011-01-01

    "Nanoplathform-Based Molecular Imaging provides rationale for using nanoparticle-based probes for molecular imaging, then discusses general strategies for this underutilized, yet promising, technology...

  5. Polyolefin-Based Aerogels

    Science.gov (United States)

    Lee, Je Kyun; Gould, George

    2012-01-01

    An organic polybutadiene (PB) rubberbased aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection, exhibiting the flexibility, resiliency, toughness, and durability typical of the parent polymer, yet with the low density and superior insulation properties associated with the aerogels. The rubbery behaviors of the PB rubber-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogel insulation materials. Additionally, with higher content of hydrogen in their structure, the PB rubber aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. Since PB rubber aerogels also exhibit good hydrophobicity due to their hydrocarbon molecular structure, they will provide better performance reliability and durability as well as simpler, more economic, and environmentally friendly production over the conventional silica or other inorganic-based aerogels, which require chemical treatment to make them hydrophobic. Inorganic aerogels such as silica aerogels demonstrate many unusual and useful properties. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven one promising approach, providing a conveniently fielded form factor that is relatively robust toward handling in industrial environments compared to silica aerogel monoliths. However, the flexible silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain applications. Although the cross-linked organic aerogels such as resorcinol-formaldehyde (RF), polyisocyanurate, and cellulose aerogels show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient

  6. Characteristics Data Base

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, E.D.; Moore, R.S. (Automated Sciences Group, Inc., Oak Ridge, TN (USA))

    1990-08-01

    The LWR Serial Numbers Database System (SNDB) contains detailed data about individual, historically discharged LWR spent fuel assemblies. This data includes the reactor where used, the year the assemblies were discharged, the pool where they are currently stored, assembly type, burnup, weight, enrichment, and an estimate of their radiological properties. This information is distributed on floppy disks to users in the nuclear industry to assist in planning for the permanent nuclear waste repository. This document describes the design and development of the SNDB. It provides a complete description of the file structures and an outline of the major code modules. It serves as a reference for a programmer maintaining the system, or for others interested in the technical detail of this database. This is the initial version of the SNDB. It contains historical data through December 31, 1987, obtained from the Energy Information Administration (EIA). EIA obtains the data from the utility companies via the RW-859 Survey Form. It evaluates and standardizes the data and distributes the resulting batch level database as a large file on magnetic tape. The Characteristics Data Base obtains this database for use in the LWR Quantities Data Base. Additionally, the CDB obtains the individual assembly level detail from EIA for use in the SNDB. While the Quantities Data Base retains only the level of detail necessary for its reporting, the SNDB does retain and use the batch level data to assist in the identification of a particular assembly serial number. We expect to update the SNDB on an annual basis, as new historical data becomes available.

  7. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  8. Knowledge based Entrepreneurship

    DEFF Research Database (Denmark)

    Heebøll, John

    This book is dedicated enterprising people with a technical or a scientific background who consider commercializing ideas and inventions within their field of expertise via a new business activity or a new company. It aims at distilling experiences from many successful and not so successful start......-up ventures from the Technical University of Denmark, 1988 – 2008 into practical, portable knowledge that can be used by future knowledge-based entrepreneurs to set up new companies efficiently or to stay away from it; to do what’s needed and avoid the pitfalls....

  9. Polymerization Using Phosphazene Bases

    KAUST Repository

    Zhao, Junpeng

    2015-09-01

    In the recent rise of metal-free polymerization techniques, organic phosphazene superbases have shown their remarkable strength as promoter/catalyst for the anionic polymerization of various types of monomers. Generally, the complexation of phosphazene base with the counterion (proton or lithium cation) significantly improves the nucleophilicity of the initiator/chain end resulting in highly enhanced polymerization rates, as compared with conventional metalbased initiating systems. In this chapter, the general features of phosphazenepromoted/catalyzed polymerizations and the applications in macromolecular engineering (synthesis of functionalized polymers, block copolymers, and macromolecular architectures) are discussed with challenges and perspectives being pointed out.

  10. Web Based Customized Design

    OpenAIRE

    Moi, Morten Benestad

    2013-01-01

    This thesis studies the methods needed to create a web based application to remotely customize a CAD model. This includes customizing a CAD model by using a graphical user interface to be able to remotely control the inputs to- and outputs from the model in NX, and to get the result sent back to the user. Using CAD systems such as NX requires intensive training, is often a slow process and gives a lot of room for errors. An intuitive, simple user interface will eliminate the need for CAD trai...

  11. Location-based games

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    In this dissertation, it is explored which prerequisites are necessary in location-based games (LBGs) to make meaningful the meeting between players and spatiality with an emphasis on physical locations. Throughout the dissertation, it has been shown that LBGs affect players’ perception of and be...... possible. The practical contribution is my creation of the LBG Visions of Sara. People continue to play this game in Odense more than two years after its launch, and DJEEO uses it as a showcase, enabling the company to sell similar LBGs....

  12. LIGHTWEIGHT CONCRETE BASED GRANSHLAK

    Directory of Open Access Journals (Sweden)

    NETESA M. I.

    2016-02-01

    Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

  13. Accelerator-based BNCT.

    Science.gov (United States)

    Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

    2014-06-01

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. © 2013 Elsevier Ltd. All rights reserved.

  14. Cellular based cancer vaccines

    DEFF Research Database (Denmark)

    Hansen, M; Met, Ö; Svane, I M

    2012-01-01

    Cancer vaccines designed to re-calibrate the existing host-tumour interaction, tipping the balance from tumor acceptance towards tumor control holds huge potential to complement traditional cancer therapies. In general, limited success has been achieved with vaccines composed of tumor...... to transiently affect in vitro migration via autocrine receptor-mediated endocytosis of CCR7. In the current review, we discuss optimal design of DC maturation focused on pre-clinical as well as clinical results from standard and polarized dendritic cell based cancer vaccines....

  15. WAP - based telemedicine applications

    International Nuclear Information System (INIS)

    Hung, K.; Zhang, Y.T.

    2001-01-01

    Telemedicine refers to the utilization of telecommunication technology for medical diagnosis, treatment, and patient care. Its aim is to provide expert-based health care to remote sites through telecommunication and information technologies. The significant advances in technologies have enabled the introduction of a broad range of telemedicine applications, which are supported by computer networks, wireless communication, and information superhighway. For example, some hospitals are using tele-radiology for remote consultation. Such a system includes medical imaging devices networked with computers and databases. Another growing area is patient monitoring, in which sensors are used to acquire biomedical signals, such as electrocardiogram (ECG), blood pressure, and body temperature, from a remote patient, who could be in bed or moving freely. The signals are then relayed to remote systems for viewing and analysis. Telemedicine can be divided into two basic modes of operations: real-time mode, in which the patient data can be accessed remotely in real-time, and store-and-forward mode, in which the acquired data does not have to be accessed immediately. In the recent years, many parties have demonstrated various telemedicine applications based on the Internet and cellular phone as these two fields have been developing rapidly. A current, recognizable trend in telecommunication is the convergence of wireless communication and computer network technologies. This has been reflected in recently developed telemedicine systems. For example, in 1998 J. Reponen, et al. have demonstrated transmission and display of computerized tomography (CT) examinations using a remote portable computer wirelessly connected to a computer network through TCP/IP on a GSM cellular phone. Two years later, they carried out the same tests with a GSM-based wireless personal digital assistant (PDA). The WAP (Wireless Application Protocol) Forum was founded in 1997 to create a global protocol

  16. Mars base buildup scenarios

    International Nuclear Information System (INIS)

    Blacic, J.D.

    1985-01-01

    Two surface base build-up scenarios are presented in order to help visualize the mission and to serve as a basis for trade studies. In the first scenario, direct manned landings on the Martian surface occur early in the missions and scientific investigation is the main driver and rationale. In the second scenario, early development of an infrastructure to exploite the volatile resources of the Martian moons for economic purposes is emphasized. Scientific exploration of the surface is delayed at first, but once begun develops rapidly aided by the presence of a permanently manned orbital station

  17. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  18. Refractive index based measurements

    DEFF Research Database (Denmark)

    2014-01-01

    In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature by observing an apparent angular shift in an interference fringe pattern produced by back or forward scattering interferometry, ambiguities in the measurement caused...... by the apparent shift being consistent with one of a number of numerical possibilities for the real shift which differ by 2n are resolved by combining measurements performed on the same sample using light paths therethrough of differing lengths....

  19. Sustainability Base Construction Update

    Science.gov (United States)

    Mewhinney, Michael

    2012-01-01

    Construction of the new Sustainability Base Collaborative support facility, expected to become the highest performing building in the federal government continues at NASA's Ames Research Center, Moffet Field, Calif. The new building is designed to achieve a platinum rating under the leadership in Energy and Environment Design (LEED) new construction standards for environmentally sustainable construction developed by the U. S. Green Building Council, Washington, D. C. When completed by the end of 2011, the $20.6 million building will feature near zero net energy consumption, use 90 percent less potable water than conventionally build buildings of equivalent size, and will result in reduced building maintenance costs.

  20. Chitosan-based nanocomposites

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2012-08-01

    Full Text Available , and hygiene devices. They thus represent a strong and emerging answer for improved and eco-friendly materials. This chapter reviews the recent developments in the area of chitosan-based nanocomposites, with a special emphasis on clay-containing nanocomposites...-sized mineral fillers like silica, talc, and clay are added to reduce the cost and improve chitosan’s performance in some way. However, the mechanical properties such as elongation at break and tensile strength of these composites decrease with the incorporation...

  1. Dynamic social community detection and its applications.

    Directory of Open Access Journals (Sweden)

    Nam P Nguyen

    Full Text Available Community structure is one of the most commonly observed features of Online Social Networks (OSNs in reality. The knowledge of this feature is of great advantage: it not only provides helpful insights into developing more efficient social-aware solutions but also promises a wide range of applications enabled by social and mobile networking, such as routing strategies in Mobile Ad Hoc Networks (MANETs and worm containment in OSNs. Unfortunately, understanding this structure is very challenging, especially in dynamic social networks where social interactions are evolving rapidly. Our work focuses on the following questions: How can we efficiently identify communities in dynamic social networks? How can we adaptively update the network community structure based on its history instead of recomputing from scratch? To this end, we present Quick Community Adaptation (QCA, an adaptive modularity-based framework for not only discovering but also tracing the evolution of network communities in dynamic OSNs. QCA is very fast and efficient in the sense that it adaptively updates and discovers the new community structure based on its history together with the network changes only. This flexible approach makes QCA an ideal framework applicable for analyzing large-scale dynamic social networks due to its lightweight computing-resource requirement. To illustrate the effectiveness of our framework, we extensively test QCA on both synthesized and real-world social networks including Enron, arXiv e-print citation, and Facebook networks. Finally, we demonstrate the applicability of QCA in real applications: (1 A social-aware message forwarding strategy in MANETs, and (2 worm propagation containment in OSNs. Competitive results in comparison with other methods reveal that social-based techniques employing QCA as a community detection core outperform current available methods.

  2. Dynamic social community detection and its applications.

    Science.gov (United States)

    Nguyen, Nam P; Dinh, Thang N; Shen, Yilin; Thai, My T

    2014-01-01

    Community structure is one of the most commonly observed features of Online Social Networks (OSNs) in reality. The knowledge of this feature is of great advantage: it not only provides helpful insights into developing more efficient social-aware solutions but also promises a wide range of applications enabled by social and mobile networking, such as routing strategies in Mobile Ad Hoc Networks (MANETs) and worm containment in OSNs. Unfortunately, understanding this structure is very challenging, especially in dynamic social networks where social interactions are evolving rapidly. Our work focuses on the following questions: How can we efficiently identify communities in dynamic social networks? How can we adaptively update the network community structure based on its history instead of recomputing from scratch? To this end, we present Quick Community Adaptation (QCA), an adaptive modularity-based framework for not only discovering but also tracing the evolution of network communities in dynamic OSNs. QCA is very fast and efficient in the sense that it adaptively updates and discovers the new community structure based on its history together with the network changes only. This flexible approach makes QCA an ideal framework applicable for analyzing large-scale dynamic social networks due to its lightweight computing-resource requirement. To illustrate the effectiveness of our framework, we extensively test QCA on both synthesized and real-world social networks including Enron, arXiv e-print citation, and Facebook networks. Finally, we demonstrate the applicability of QCA in real applications: (1) A social-aware message forwarding strategy in MANETs, and (2) worm propagation containment in OSNs. Competitive results in comparison with other methods reveal that social-based techniques employing QCA as a community detection core outperform current available methods.

  3. Droplet based microfluidics

    International Nuclear Information System (INIS)

    Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan

    2012-01-01

    Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.

  4. DVD Based Electronic Pulser

    International Nuclear Information System (INIS)

    Morris, Scott J.; Pratt, Rick M.; Hughes, Michael A.; Kouzes, Richard T.; Pitts, W K.; Robinson, Eric E.

    2005-01-01

    This paper describes the design, construction, and testing of a DVD based electronic pulser system (DVDEPS). Such a device is used to generate pulse streams for simulation of both gamma and neutron detector systems. The DVDEPS reproduces a random pulse stream of a full HPGe spectrum as well as a digital pulse stream representing the output of a neutron multiplicity detector. The exchangeable DVD media contains over an hour of data for both detector systems and can contain an arbitrary gamma spectrum and neutron pulse stream. The data is written to the DVD using a desktop computer program from either actual or simulated spectra. The targeted use of the DVDEPS is authentication or validation of monitoring equipment for non-proliferation purposes, but it is also of general use whenever a complex data stream is required. The DVD based pulser combines the storage capacity and simplicity of DVD technology with commonly available electronic components to build a relatively inexpensive yet highly capable testing instrument

  5. Evidence-based surgery

    Directory of Open Access Journals (Sweden)

    Miran Rems

    2007-04-01

    Full Text Available Background: Surgery is setting a new ground by the reign of evidence that was brought up by the Evidence Based Medicine (EBM. While experiences and opinion of an expert count the least by the principles of EBM, randomized controlled trials (RCT and other comparative studies have gained their importance. Recommendations that were included in guidelines represent a demanding shift in surgeon’s professional thinking. Their thinking and classical education have not yet been completely based on the results of such studies and are still very very much master-pupil centred. Assessment of someone’s own experiences is threatened by objectivity as negative experiences get recorded in deeper memory. Randomized studies and meta-analyses do appear also in surgery. However, they demand an extra knowledge about critical assessment.Conclusions: Setting a patient to the foreground brings a surgeon’s decision to the field of EBM. The process has already begun and cannot be avoided. Decision hierarchy moves from the experience field to the evidence territory but to a lesser extent when compared to the rest of medicine. There exist objective restrictions with approving a new paradigm. However, these should not stop the process of EBM implementation. Finally, there is an ethic issue to be considered. Too slow activities in research, education and critical assessment can bring the surgeon to the position when a well-informed patient loses his/her trust.

  6. Microlaser-based displays

    Science.gov (United States)

    Bergstedt, Robert; Fink, Charles G.; Flint, Graham W.; Hargis, David E.; Peppler, Philipp W.

    1997-07-01

    Laser Power Corporation has developed a new type of projection display, based upon microlaser technology and a novel scan architecture, which provides the foundation for bright, extremely high resolution images. A review of projection technologies is presented along with the limitations of each and the difficulties they experience in trying to generate high resolution imagery. The design of the microlaser based projector is discussed along with the advantage of this technology. High power red, green, and blue microlasers have been designed and developed specifically for use in projection displays. These sources, in combination with high resolution, high contrast modulator, produce a 24 bit color gamut, capable of supporting the full range of real world colors. The new scan architecture, which reduces the modulation rate and scan speeds required, is described. This scan architecture, along with the inherent brightness of the laser provides the fundamentals necessary to produce a 5120 by 4096 resolution display. The brightness and color uniformity of the display is excellent, allowing for tiling of the displays with far fewer artifacts than those in a traditionally tiled display. Applications for the display include simulators, command and control centers, and electronic cinema.

  7. SPACE BASED INTERCEPTOR SCALING

    Energy Technology Data Exchange (ETDEWEB)

    G. CANAVAN

    2001-02-01

    Space Based Interceptor (SBI) have ranges that are adequate to address rogue ICBMs. They are not overly sensitive to 30-60 s delay times. Current technologies would support boost phase intercept with about 150 interceptors. Higher acceleration and velocity could reduce than number by about a factor of 3 at the cost of heavier and more expensive Kinetic Kill Vehicles (KKVs). 6g SBI would reduce optimal constellation costs by about 35%; 8g SBI would reduce them another 20%. Interceptor ranges fall rapidly with theater missile range. Constellations increase significantly for ranges under 3,000 km, even with advanced interceptor technology. For distributed launches, these estimates recover earlier strategic scalings, which demonstrate the improved absentee ratio for larger or multiple launch areas. Constellations increase with the number of missiles and the number of interceptors launched at each. The economic estimates above suggest that two SBI per missile with a modest midcourse underlay is appropriate. The SBI KKV technology would appear to be common for space- and surface-based boost phase systems, and could have synergisms with improved midcourse intercept and discrimination systems. While advanced technology could be helpful in reducing costs, particularly for short range theater missiles, current technology appears adequate for pressing rogue ICBM, accidental, and unauthorized launches.

  8. Challenge Based Innovation gala

    CERN Multimedia

    CERN. Geneva; Utriainen, Tuuli Maria; Toivonen, Harri; Nordberg, Markus

    2014-01-01

    Challenge Based Innovation gala   There’s a new experiment starting in CERN called IdeaLab where we work together with detector R&D researchers to help them to bridge their knowledge into a more human, societally oriented context. Currently we are located in B153, but will move our activities to a new facility next to the Globe in May 2014. One of our first pilot projects is a 5 month course CBI (Challenge Based Innovation) where two multidisciplinary student teams join forces with Edusafe & TALENT projects at CERN. Their goal is to discover what kind of tools for learning could be created in collaboration with the two groups. After months of user interviews and low resolution prototyping they are ready to share the results with us in the form of an afternoon gala. We warmly welcome you to join us to see the students' results and experience the prototypes they have conceived. The event is in three parts, you are welcome to visit all of them,...

  9. [Competence based medical education].

    Science.gov (United States)

    Bernabó, Jorge G; Buraschi, Jorge; Olcese, Juan; Buraschi, María; Duro, Eduardo

    2007-01-01

    The strategy of curriculum planning in the majority of the Schools of Medicine has shifted, in the past years, from curriculum models based in contents to outcome oriented curricula. Coincidently the interest in defining and evaluating the clinical competences that a graduate must have has grown. In our country, and particularly in the Associated Hospitals belonging to the Unidad Regional de Enseñanza IV of the UBA School of Medicine, evidence has been gathered showing that the acquisition of clinical competences during the grade is in general insufficient. The foundations and characteristics of PREM (Programa de Requisitos Esenciales Mínimos) are described. PREM is a tool to promote the apprenticeship of abilities and necessary skills for the practice of medicine. The objective of the program is to promote the apprenticeship of a well defined list of core competences considered indispensable for a general practitioner. An outcome oriented curriculum with a clear definition of the expected knowledge, skills and attitudes of a graduate of the programme, the promotion of learning experiences centered in the practice and evaluation tools based in direct observation of the student's performance should contribute to close the gap between what the Medicine Schools traditionally teach and evaluate, and what the doctor needs to know and needs to do to perform correctly its profession.

  10. Constraint-based reachability

    Directory of Open Access Journals (Sweden)

    Arnaud Gotlieb

    2013-02-01

    Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

  11. Metasurface-Based Polarimeters

    Directory of Open Access Journals (Sweden)

    Fei Ding

    2018-04-01

    Full Text Available The state of polarization (SOP is an inherent property of light that can be used to gain crucial information about the composition and structure of materials interrogated with light. However, the SOP is difficult to experimentally determine since it involves phase information between orthogonal polarization states, and is uncorrelated with the light intensity and frequency, which can be easily determined with photodetectors and spectrometers. Rapid progress on optical gradient metasurfaces has resulted in the development of conceptually new approaches to the SOP characterization. In this paper, we review the fundamentals of and recent developments within metasurface-based polarimeters. Starting by introducing the concepts of generalized Snell’s law and Stokes parameters, we explain the Pancharatnam–Berry phase (PB-phase which is instrumental for differentiating between orthogonal circular polarizations. Then we review the recent progress in metasurface-based polarimeters, including polarimeters, spectropolarimeters, orbital angular momentum (OAM spectropolarimeters, and photodetector integrated polarimeters. The review is ended with a short conclusion and perspective for future developments.

  12. Risk-based safety indicators

    International Nuclear Information System (INIS)

    Szikszai, T.

    1997-01-01

    The presentation discusses the following issues: The objectives of the risk-based indicator programme. The characteristics of the risk-based indicators. The objectives of risk-based safety indicators - in monitoring safety; in PSA applications. What indicators? How to produce the risk based indicators? PSA requirements

  13. MS Based Metabonomics

    Energy Technology Data Exchange (ETDEWEB)

    Want, Elizabeth J.; Metz, Thomas O.

    2010-03-01

    Metabonomics is the latest and least mature of the systems biology triad, which also includes genomics and proteomics, and has its origins in the early orthomolecular medicine work pioneered by Linus Pauling and Arthur Robinson. It was defined by Nicholson and colleagues in 1999 as the quantitative measurement of perturbations in the metabolite complement of an integrated biological system in response to internal or external stimuli, and is often used today to describe many non-global types of metabolite analyses. Applications of metabonomics are extensive and include toxicology, nutrition, pharmaceutical research and development, physiological monitoring and disease diagnosis. For example, blood samples from millions of neonates are tested routinely by mass spectrometry (MS) as a diagnostic tool for inborn errors of metabolism. The metabonome encompasses a wide range of structurally diverse metabolites; therefore, no single analytical platform will be sufficient. Specialized sample preparation and detection techniques are required, and advances in NMR and MS technologies have led to enhanced metabonome coverage, which in turn demands improved data analysis approaches. The role of MS in metabonomics is still evolving as instrumentation and software becomes more sophisticated and as researchers realize the strengths and limitations of current technology. MS offers a wide dynamic range, high sensitivity, and reproducible, quantitative analysis. These attributes are essential for addressing the challenges of metabonomics, as the range of metabolite concentrations easily exceeds nine orders of magnitude in biofluids, and the diversity of molecular species ranges from simple amino and organic acids to lipids and complex carbohydrates. Additional challenges arise in generating a comprehensive metabolite profile, downstream data processing and analysis, and structural characterization of important metabolites. A typical workflow of MS-based metabonomics is shown in Figure

  14. Skull base tumor model.

    Science.gov (United States)

    Gragnaniello, Cristian; Nader, Remi; van Doormaal, Tristan; Kamel, Mahmoud; Voormolen, Eduard H J; Lasio, Giovanni; Aboud, Emad; Regli, Luca; Tulleken, Cornelius A F; Al-Mefty, Ossama

    2010-11-01

    Resident duty-hours restrictions have now been instituted in many countries worldwide. Shortened training times and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. The development of educational models for brain anatomy is a fascinating innovation allowing neurosurgeons to train without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period. The authors describe the use of Stratathane resin ST-504 polymer (SRSP), which is inserted at different intracranial locations to closely mimic meningiomas and other pathological entities of the skull base, in a cadaveric model, for use in neurosurgical training. Silicone-injected and pressurized cadaveric heads were used for studying the SRSP model. The SRSP presents unique intrinsic metamorphic characteristics: liquid at first, it expands and foams when injected into the desired area of the brain, forming a solid tumorlike structure. The authors injected SRSP via different passages that did not influence routes used for the surgical approach for resection of the simulated lesion. For example, SRSP injection routes included endonasal transsphenoidal or transoral approaches if lesions were to be removed through standard skull base approach, or, alternatively, SRSP was injected via a cranial approach if the removal was planned to be via the transsphenoidal or transoral route. The model was set in place in 3 countries (US, Italy, and The Netherlands), and a pool of 13 physicians from 4 different institutions (all surgeons and surgeons in training) participated in evaluating it and provided feedback. All 13 evaluating physicians had overall positive impressions of the model. The overall score on 9 components evaluated--including comparison between the tumor model and real tumor cases, perioperative requirements, general impression, and applicability--was 88% (100% being the best possible

  15. Plasma based accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  16. Gossip-Based Broadcast

    Science.gov (United States)

    Leitão, João; Pereira, José; Rodrigues, Luís

    Gossip, or epidemic, protocols have emerged as a powerful strategy to implement highly scalable and resilient reliable broadcast primitives on large scale peer-to-peer networks. Epidemic protocols are scalable because they distribute the load among all nodes in the system and resilient because they have an intrinsic level of redundancy that masks node and network failures. This chapter provides an introduction to gossip-based broadcast on large-scale unstructured peer-to-peer overlay networks: it surveys the main results in the field, discusses techniques to build and maintain the overlays that support efficient dissemination strategies, and provides an in-depth discussion and experimental evaluation of two concrete protocols, named HyParView and Plumtree.

  17. Sensory bases of navigation.

    Science.gov (United States)

    Gould, J L

    1998-10-08

    Navigating animals need to know both the bearing of their goal (the 'map' step), and how to determine that direction (the 'compass' step). Compasses are typically arranged in hierarchies, with magnetic backup as a last resort when celestial information is unavailable. Magnetic information is often essential to calibrating celestial cues, though, and repeated recalibration between celestial and magnetic compasses is important in many species. Most magnetic compasses are based on magnetite crystals, but others make use of induction or paramagnetic interactions between short-wavelength light and visual pigments. Though odors may be used in some cases, most if not all long-range maps probably depend on magnetite. Magnetitebased map senses are used to measure only latitude in some species, but provide the distance and direction of the goal in others.

  18. Graphene based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Gürel, Hikmet Hakan, E-mail: hhakan.gurel@kocaeli.edu.tr [Kocaeli University, Kocaeli (Turkey); Salmankurt, Bahadır [Sakarya University, Sakarya (Turkey)

    2016-03-25

    Nanometer-sized graphene as a 2D material has unique chemical and electronic properties. Because of its unique physical, chemical, and electronic properties, its interesting shape and size make it a promising nanomaterial in many biological applications. It is expected that biomaterials incorporating graphene will be developed for the graphene-based drug delivery systems and biomedical devices. The interactions of biomolecules and graphene are long-ranged and very weak. Development of new techniques is very desirable for design of bioelectronics sensors and devices. In this work, we present first-principles calculations within density functional theory to calculate effects of charging on nucleobases on graphene. It is shown that how modify structural and electronic properties of nucleobases on graphene by applied charging.

  19. Integrated data base program

    International Nuclear Information System (INIS)

    Notz, K.J.

    1981-01-01

    The IDB Program provides direct support to the DOE Nuclear Waste Management and Fuel Cycle Programs and their lead sites and support contractors by providing and maintaining a current, integrated data base of spent fuel and radioactive waste inventories and projections. All major waste types (HLW, TRU, and LLW) and sources (government, commerical fuel cycle, and I/I) are included. A major data compilation was issued in September, 1981: Spent Fuel and Radioactive Waste Inventories and Projections as of December 31, 1980, DOE/NE-0017. This report includes chapters on Spent Fuel, HLW, TRU Waste, LLW, Remedial Action Waste, Active Uranium Mill Tailings, and Airborne Waste, plus Appendices with more detailed data in selected areas such as isotopics, radioactivity, thermal power, projections, and land usage. The LLW sections include volumes, radioactivity, thermal power, current inventories, projected inventories and characteristics, source terms, land requirements, and a breakdown in terms of government/commercial and defense/fuel cycle/I and I

  20. Nickel base alloys

    International Nuclear Information System (INIS)

    Gibson, R.C.; Korenko, M.K.

    1980-01-01

    Nickel based alloy, the characteristic of which is that it mainly includes in percentages by weight: 57-63 Ni, 7-18 Cr, 10-20 Fe, 4-6 Mo, 1-2 Nb, 0.2-0.8 Si, 0.01-0.05 Zr, 1.0-2.5 Ti, 1.0-2.5 Al, 0.02-0.06 C and 0.002-0.015 B. The aim is to create new nickel-chromium alloys, hardened in a solid solution and by precipitation, that are stable, exhibit reduced swelling and resistant to plastic deformation inside the reactor. These alloys of the gamma prime type have improved mechanical strengthm swelling resistance, structural stability and welding properties compared with Inconel 625 [fr

  1. Rate based failure detection

    Science.gov (United States)

    Johnson, Brett Emery Trabun; Gamage, Thoshitha Thanushka; Bakken, David Edward

    2018-01-02

    This disclosure describes, in part, a system management component and failure detection component for use in a power grid data network to identify anomalies within the network and systematically adjust the quality of service of data published by publishers and subscribed to by subscribers within the network. In one implementation, subscribers may identify a desired data rate, a minimum acceptable data rate, desired latency, minimum acceptable latency and a priority for each subscription. The failure detection component may identify an anomaly within the network and a source of the anomaly. Based on the identified anomaly, data rates and or data paths may be adjusted in real-time to ensure that the power grid data network does not become overloaded and/or fail.

  2. Behavior based safety

    International Nuclear Information System (INIS)

    Sudhikumaran, T.V.; Mehta, S.C.; Goyal, D.K.

    2009-01-01

    Behaviour Based Safety (popularly known as BBS) is a new methodology for achieving injury free work place and total Safety Culture. BBS is successfully being implemented and is being practiced as a work methodology for achieving a loss and injury free work environment and work practice. Through BBS, it was brought out that the root causes of all Industrial accidents some how originate from the 'at risk' behaviour of some individual or group of individuals at some level. The policy of NPCIL is to excel in the field of Industrial and Fire Safety in comparison to international standards. This article indents to bring out the various parameters helping in installing BBS programme at any plant. (author)

  3. Fuel cycle based safeguards

    International Nuclear Information System (INIS)

    De Montmollin, J.M.; Higinbotham, W.A.; Gupta, D.

    1985-07-01

    In NPT safeguards the same model approach and absolute-quantity inspection goals are applied at present to all similar facilities, irrespective of the State's fuel cycle. There is a continuing interest and activity on the part of the IAEA in new NPT safeguards approaches that more directly address a State's nuclear activities as a whole. This fuel cycle based safeguards system is expected to a) provide a statement of findings for the entire State rather than only for individual facilities; b) allocate inspection efforts so as to reflect more realistically the different categories of nuclear materials in the different parts of the fuel cycle and c) provide more timely and better coordinated information on the inputs, outputs and inventories of nuclear materials in a State. (orig./RF) [de

  4. Bases para proyectiles dirigidos

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1959-03-01

    Full Text Available Aunque actualmente no se ha llegado a una línea general de métodos o sistemas que gobiernen un tipo característico de rampa y servicios auxiliares necesarios para el lanzamiento al espacio de proyectiles dirigidos a grandes alturas y distancias, las experiencias obtenidas en diferentes ensayos, utilizando distintos tipos de proyectiles y trayectorias balísticas, han sentado toda una serie de procedimientos, datos y conclusiones de gran valor balístico que, aun teniendo en cuenta la continua evolución del proyectil, sus formas, combustibles y alcances, se conocen ya, con bastante aproximación, las condiciones mínimas que ha de reunir una base dedicada a este tipo de lanzamientos.

  5. Situation based housing

    DEFF Research Database (Denmark)

    Duelund Mortensen, Peder; Welling, Helen; Wiell Nordberg, Lene

    2007-01-01

    of the average family's lifestyle. These dwellings were ground-breaking when they were built, but today are clearly a product of their time. The reaction to functionalism and the postwar mass production gave rise to flexible dwelling with countless possibilities for room division. The housing of this period has...... characteristics which in the long run have proven to be unfortunate both in terms in terms of durability and architectural quality. Today there is a focus on the development of more open and functionally non-determined housing. A number of new housing schemes in and around Copenhagen reveal a variety...... of approaches to these goals. This working paper reviews not only a selection of new housing types, but also dwellings from the past, which each contain an aspect of changeability. Our study is based on information from users in the selected housing schemes, gathered from questionnaires, information about...

  6. Liaison based assembly design

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted, increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.

  7. Touching base with OPERA

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Three seminars – at CERN, at Gran Sasso and in Japan – and an article calling for the scrutiny of the scientific community: the OPERA Collaboration opened its research publicly. In addition to huge press coverage, this triggered welcome reactions from colleagues around the world, many of whom will attempt to independently interpret and reproduce the measurement. OPERA’s Spokesperson touches base with the Bulletin.   The CERN Main Auditorium was crowded as OPERA Physics co-ordinator Dario Autiero presented the results of their research (23 September 2011). According to the OPERA strategy, the results of the measurements are in the hands of the scientific community and, as for any other scientific result, several months will be needed before other groups will be able to perform an independent measurement. In the meantime, the OPERA Collaboration is dealing with an avalanche of emails from the scientific community, members of the general public, and the press. &...

  8. Pathway-based analyses.

    Science.gov (United States)

    Kent, Jack W

    2016-02-03

    New technologies for acquisition of genomic data, while offering unprecedented opportunities for genetic discovery, also impose severe burdens of interpretation and penalties for multiple testing. The Pathway-based Analyses Group of the Genetic Analysis Workshop 19 (GAW19) sought reduction of multiple-testing burden through various approaches to aggregation of highdimensional data in pathways informed by prior biological knowledge. Experimental methods testedincluded the use of "synthetic pathways" (random sets of genes) to estimate power and false-positive error rate of methods applied to simulated data; data reduction via independent components analysis, single-nucleotide polymorphism (SNP)-SNP interaction, and use of gene sets to estimate genetic similarity; and general assessment of the efficacy of prior biological knowledge to reduce the dimensionality of complex genomic data. The work of this group explored several promising approaches to managing high-dimensional data, with the caveat that these methods are necessarily constrained by the quality of external bioinformatic annotation.

  9. Refractive index based measurements

    DEFF Research Database (Denmark)

    2014-01-01

    A refractive index based measurement of a property of a fluid is measured in an apparatus comprising a variable wavelength coherent light source (16), a sample chamber (12), a wavelength controller (24), a light sensor (20), a data recorder (26) and a computation apparatus (28), by - directing...... coherent light having a wavelength along an input light path, - producing scattering of said light from each of a plurality of interfaces within said apparatus including interfaces between said fluid and a surface bounding said fluid, said scattering producing an interference pattern formed by said...... scattered light, - cyclically varying the wavelength of said light in said input light path over a 1 nm to 20nm wide range of wavelengths a rate of from 10Hz to 50 KHz, - recording variation of intensity of the interfering light with change in wavelength of the light at an angle of observation...

  10. Transaction based approach

    Science.gov (United States)

    Hunka, Frantisek; Matula, Jiri

    2017-07-01

    Transaction based approach is utilized in some methodologies in business process modeling. Essential parts of these transactions are human beings. The notion of agent or actor role is usually used for them. The paper on a particular example describes possibilities of Design Engineering Methodology for Organizations (DEMO) and Resource-Event-Agent (REA) methodology. Whereas the DEMO methodology can be regarded as a generic methodology having its foundation in the theory of Enterprise Ontology the REA methodology is regarded as the domain specific methodology and has its origin in accountancy systems. The results of these approaches is that the DEMO methodology captures everything that happens in the reality with a good empirical evidence whereas the REA methodology captures only changes connected with economic events. Economic events represent either change of the property rights to economic resource or consumption or production of economic resources. This results from the essence of economic events and their connection to economic resources.

  11. Pitch Based Sound Classification

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai; Kjems, U

    2006-01-01

    A sound classification model is presented that can classify signals into music, noise and speech. The model extracts the pitch of the signal using the harmonic product spectrum. Based on the pitch estimate and a pitch error measure, features are created and used in a probabilistic model with soft......-max output function. Both linear and quadratic inputs are used. The model is trained on 2 hours of sound and tested on publicly available data. A test classification error below 0.05 with 1 s classification windows is achieved. Further more it is shown that linear input performs as well as a quadratic......, and that even though classification gets marginally better, not much is achieved by increasing the window size beyond 1 s....

  12. Telephone-Based Coaching.

    Science.gov (United States)

    Boccio, Mindy; Sanna, Rashel S; Adams, Sara R; Goler, Nancy C; Brown, Susan D; Neugebauer, Romain S; Ferrara, Assiamira; Wiley, Deanne M; Bellamy, David J; Schmittdiel, Julie A

    2017-03-01

    Many Americans continue to smoke, increasing their risk of disease and premature death. Both telephone-based counseling and in-person tobacco cessation classes may improve access for smokers seeking convenient support to quit. Little research has assessed whether such programs are effective in real-world clinical populations. Retrospective cohort study comparing wellness coaching participants with two groups of controls. Kaiser Permanente Northern California, a large integrated health care delivery system. Two hundred forty-one patients who participated in telephonic tobacco cessation coaching from January 1, 2011, to March 31, 2012, and two control groups: propensity-score-matched controls, and controls who participated in a tobacco cessation class during the same period. Wellness coaching participants received an average of two motivational interviewing-based coaching sessions that engaged the patient, evoked their reason to consider quitting, and helped them establish a quit plan. Self-reported quitting of tobacco and fills of tobacco cessation medications within 12 months of follow-up. Logistic regressions adjusting for age, gender, race/ethnicity, and primary language. After adjusting for confounders, tobacco quit rates were higher among coaching participants vs. matched controls (31% vs. 23%, p Coaching participants and class attendees filled tobacco-cessation prescriptions at a higher rate (47% for both) than matched controls (6%, p coaching was as effective as in-person classes and was associated with higher rates of quitting compared to no treatment. The telephonic modality may increase convenience and scalability for health care systems looking to reduce tobacco use and improve health.

  13. Model Based Temporal Reasoning

    Science.gov (United States)

    Rabin, Marla J.; Spinrad, Paul R.; Fall, Thomas C.

    1988-03-01

    Systems that assess the real world must cope with evidence that is uncertain, ambiguous, and spread over time. Typically, the most important function of an assessment system is to identify when activities are occurring that are unusual or unanticipated. Model based temporal reasoning addresses both of these requirements. The differences among temporal reasoning schemes lies in the methods used to avoid computational intractability. If we had n pieces of data and we wanted to examine how they were related, the worst case would be where we had to examine every subset of these points to see if that subset satisfied the relations. This would be 2n, which is intractable. Models compress this; if several data points are all compatible with a model, then that model represents all those data points. Data points are then considered related if they lie within the same model or if they lie in models that are related. Models thus address the intractability problem. They also address the problem of determining unusual activities if the data do not agree with models that are indicated by earlier data then something out of the norm is taking place. The models can summarize what we know up to that time, so when they are not predicting correctly, either something unusual is happening or we need to revise our models. The model based reasoner developed at Advanced Decision Systems is thus both intuitive and powerful. It is currently being used on one operational system and several prototype systems. It has enough power to be used in domains spanning the spectrum from manufacturing engineering and project management to low-intensity conflict and strategic assessment.

  14. Mainstreaming gesture based interfaces

    Directory of Open Access Journals (Sweden)

    David Procházka

    2013-01-01

    Full Text Available Gestures are a common way of interaction with mobile devices. They emerged especially with the iPhone production. Gestures in currently used devices are usually based on the original gestures presented by Apple in its iOS (iPhone Operating System. Therefore, there is a wide agreement on the mobile gesture design. In last years, it is possible to see experiments with gesture usage also in the other areas of consumer electronics and computers. The examples can include televisions, large projections etc. These gestures can be marked as spatial or 3D gestures. They are connected with a natural 3D environment rather than with a flat 2D screen. Nevertheless, it is hard to find a comparable design agreement within the spatial gestures. Various projects are based on completely different gesture sets. This situation is confusing for their users and slows down spatial gesture adoption.This paper is focused on the standardization of spatial gestures. The review of projects focused on spatial gesture usage is provided in the first part. The main emphasis is placed on the usability point-of-view. On the basis of our analysis, we argue that the usability is the key issue enabling the wide adoption. The mobile gesture emergence was possible easily because the iPhone gestures were natural. Therefore, it was not necessary to learn them.The design and implementation of our presentation software, which is controlled by gestures, is outlined in the second part of the paper. Furthermore, the usability testing results are provided as well. We have tested our application on a group of users not instructed in the implemented gestures design. These results were compared with the other ones, obtained with our original implementation. The evaluation can be used as the basis for implementation of similar projects.

  15. DNA-based machines.

    Science.gov (United States)

    Wang, Fuan; Willner, Bilha; Willner, Itamar

    2014-01-01

    The base sequence in nucleic acids encodes substantial structural and functional information into the biopolymer. This encoded information provides the basis for the tailoring and assembly of DNA machines. A DNA machine is defined as a molecular device that exhibits the following fundamental features. (1) It performs a fuel-driven mechanical process that mimics macroscopic machines. (2) The mechanical process requires an energy input, "fuel." (3) The mechanical operation is accompanied by an energy consumption process that leads to "waste products." (4) The cyclic operation of the DNA devices, involves the use of "fuel" and "anti-fuel" ingredients. A variety of DNA-based machines are described, including the construction of "tweezers," "walkers," "robots," "cranes," "transporters," "springs," "gears," and interlocked cyclic DNA structures acting as reconfigurable catenanes, rotaxanes, and rotors. Different "fuels", such as nucleic acid strands, pH (H⁺/OH⁻), metal ions, and light, are used to trigger the mechanical functions of the DNA devices. The operation of the devices in solution and on surfaces is described, and a variety of optical, electrical, and photoelectrochemical methods to follow the operations of the DNA machines are presented. We further address the possible applications of DNA machines and the future perspectives of molecular DNA devices. These include the application of DNA machines as functional structures for the construction of logic gates and computing, for the programmed organization of metallic nanoparticle structures and the control of plasmonic properties, and for controlling chemical transformations by DNA machines. We further discuss the future applications of DNA machines for intracellular sensing, controlling intracellular metabolic pathways, and the use of the functional nanostructures for drug delivery and medical applications.

  16. Base Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Everett Sondreal; John Hendrikson

    2009-03-31

    In June 2009, the Energy & Environmental Research Center (EERC) completed 11 years of research under the U.S. Department of Energy (DOE) Base Cooperative Agreement No. DE-FC26-98FT40320 funded through the Office of Fossil Energy (OFE) and administered at the National Energy Technology Laboratory (NETL). A wide range of diverse research activities were performed under annual program plans approved by NETL in seven major task areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, (6) advanced materials, and (7) strategic studies. This report summarizes results of the 67 research subtasks and an additional 50 strategic studies. Selected highlights in the executive summary illustrate the contribution of the research to the energy industry in areas not adequately addressed by the private sector alone. During the period of performance of the agreement, concerns have mounted over the impact of carbon emissions on climate change, and new programs have been initiated by DOE to ensure that fossil fuel resources along with renewable resources can continue to supply the nation's transportation fuel and electric power. The agreement has addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration while expanding the supply and use of domestic energy resources for energy security. It has further contributed to goals for near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources (e.g., wind-, biomass-, and coal-based electrical generation).

  17. The office based CHIVA

    Directory of Open Access Journals (Sweden)

    Passariello F

    2013-09-01

    Full Text Available Fausto Passariello,1 Stefano Ermini,2 Massimo Cappelli,3 Roberto Delfrate,4 Claude Franceschi5 1Centro Diagnostico Aquarius, Napoli, Italy; 2Private Practice, Grassina, Italy; 3Private Practice, Firenze, Italy; 4Casa di Cure Figlie di Maria, Cremona, Italy; 5Hospital St Joseph, Service d'Explorations Vasculaires, Paris, France Abstract: The cure Conservatrice Hémodynamique de l'Insuffisance Veineuse en Ambulatoire (CHIVA can be office based (OB. The OB-CHIVA protocol is aimed at transferring CHIVA procedures to specialists rooms. The protocol will check the feasibility of OB-CHIVA, data pertaining to recurrence, and will offer the opportunity to study saphenous femoral junction (SFJ stump evolution, the role of the washing vessels and the arch recanalization rate, and gather new data about the effect of the length of the treated saphenous vein. A simplified diagnostic procedure will allow an essential ultrasound examination of the venous net while a schematic and easily readable algorithm guides therapeutic choices. The Riobamba draining crossotomy (RDC tactic is composed of a set of OB procedures. While some of these procedures are, at the moment, only proposals, others are already applied. Devices generally used in ablative procedures such as Light Amplification by Stimulated Emission of Radiation (LASER, radio frequency, steam, and mechanical devices are used in this context to serve to conservative interventions for CHIVA. New techniques have also been proposed for devalvulation and tributary disconnection. Detailed follow-up is necessary in order to determine the effects of therapy and possible disease evolution. Finally, information is added about the informed consent and the ethical considerations of OB-CHIVA research. Keywords: CHIVA, office based procedures, LASER, RF, steam

  18. Organic Biochar Based Fertilization

    Science.gov (United States)

    Schmidt, Hans-Peter; Pandit, Bishnu Hari; Cornelissen, Gerard; Kammann, Claudia

    2017-04-01

    Biochar produced in cost-efficient flame curtain kilns (Kon-Tiki) was nutrient enriched either with cow urine or with dissolved mineral (NPK) fertilizer to produce biochar-based fertilizers containing between 60-100 kg N, 5-60 kg P2O5 and 60-100 kg K2O, respectively, per ton of biochar. In 21 field trials nutrient-enriched biochars were applied at rates of 0.5 to 2 t ha-1 into the root zone of 13 different annual and perennial crops. Treatments combining biochar, compost and organic or chemical fertilizer were evaluated; control treatments contained the same amounts of nutrients but without biochar. All nutrient-enriched biochar substrates improved yields compared to their respective no-biochar controls. Biochar enriched with dissolved NPK produced on average 20% ± 5.1% (N=4) higher yields than standard NPK fertilization without biochar. Cow urine-enriched biochar blended with compost resulted on average in 123% ± 76.7% (N=13) higher yields compared to the organic farmer practice with cow urine-blended compost and outcompeted NPK-enriched biochar (same nutrient dose) by 103% ± 12.4% (N=4) on average. 21 field trials robustly revealed that low-dosage root zone application of organic biochar-based fertilizers caused substantial yield increases in rather fertile silt loam soils compared to traditional organic fertilization and to mineral NPK- or NPK-biochar fertilization. This can likely be explained by the nutrient carrier effect of biochar causing a slow nutrient release behavior, more balanced nutrient fluxes and reduced nutrient losses especially when liquid organic nutrients are used for the biochar enrichment. The results promise new pathways for optimizing organic farming and improving on-farm nutrient cycling.

  19. Loyalty-based management.

    Science.gov (United States)

    Reichheld, F F

    1993-01-01

    Despite a flurry of activities aimed at serving customers better, few companies have systematically revamped their operations with customer loyalty in mind. Instead, most have adopted improvement programs ad hoc, and paybacks haven't materialized. Building a highly loyal customer base must be integral to a company's basic business strategy. Loyalty leaders like MBNA credit cards are successful because they have designed their entire business systems around customer loyalty--a self-reinforcing system in which the company delivers superior value consistently and reinvents cash flows to find and keep high-quality customers and employees. The economic benefits of high customer loyalty are measurable. When a company consistently delivers superior value and wins customer loyalty, market share and revenues go up, and the cost of acquiring new customers goes down. The better economics mean the company can pay workers better, which sets off a whole chain of events. Increased pay boosts employee moral and commitment; as employees stay longer, their productivity goes up and training costs fall; employees' overall job satisfaction, combined with their experience, helps them serve customers better; and customers are then more inclined to stay loyal to the company. Finally, as the best customers and employees become part of the loyalty-based system, competitors are left to survive with less desirable customers and less talented employees. To compete on loyalty, a company must understand the relationships between customer retention and the other parts of the business--and be able to quantify the linkages between loyalty and profits. It involves rethinking and aligning four important aspects of the business: customers, product/service offering, employees, and measurement systems.

  20. Routing architecture and security for airborne networks

    Science.gov (United States)

    Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

    2009-05-01

    Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

  1. A microstructural comparison of two nuclear-grade martensitic steels using small-angle neutron scattering

    Science.gov (United States)

    Coppola, R.; Fiori, F.; Little, E. A.; Magnani, M.

    1997-06-01

    Results are presented of a small-angle neutron scattering (SANS) study on two 10-13% Cr martensitic stainless steels of interest for nuclear applications, viz. DIN 1.4914 (MANET specification, for fusion reactors) and AISI 410. The investigation has focussed principally on microstructural effects associated with the differences in chromium content between the two alloys. The size distribution functions determined from nuclear and magnetic SANS components for the two steels given identical heat treatments are in accord with an interpretation based on the presence of ˜ 1 nm size CCr aggregates in the microstructure. Much larger (˜ 10 nm) scattering inhomogeneities with different magnetic contrast are also present and tentatively identified as carbides.

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

    Directory of Open Access Journals (Sweden)

    Nixson Meok

    2009-12-01

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

  3. Privacy-preserving telecardiology sensor networks: toward a low-cost portable wireless hardware/software codesign.

    Science.gov (United States)

    Hu, Fei; Jiang, Meng; Wagner, Mark; Dong, De-Cun

    2007-11-01

    Recently, a remote-sensing platform based on wireless interconnection of tiny ECG sensors called Telecardiology Sensor Networks (TSN) provided a promising approach to perform low-cost real-time cardiac patient monitoring at any time in community areas (such as elder nursing homes or hospitals). The contribution of this research is the design of a practical TSN hardware/software platform for a typical U.S. healthcare community scenario (such as large nursing homes with many elder patients) to perform real-time healthcare data collections. On the other hand, due to the radio broadcasting nature of MANET, a TSN has the risk of losing the privacy of patients' data. Medical privacy has been highly emphasized by U.S. Department of Health and Human Services. This research also designs a medical security scheme with low communication overhead to achieve confidential electrocardiogram data transmission in wireless medium.

  4. AUTHENTICATION ARCHITECTURE USING THRESHOLD CRYPTOGRAPHY IN KERBEROS FOR MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    Hadj Gharib

    2014-06-01

    Full Text Available The use of wireless technologies is gradually increasing and risks related to the use of these technologies are considerable. Due to their dynamically changing topology and open environment without a centralized policy control of a traditional network, a mobile ad hoc network (MANET is vulnerable to the presence of malicious nodes and attacks. The ideal solution to overcome a myriad of security concerns in MANET’s is the use of reliable authentication architecture. In this paper we propose a new key management scheme based on threshold cryptography in kerberos for MANET’s, the proposed scheme uses the elliptic curve cryptography method that consumes fewer resources well adapted to the wireless environment. Our approach shows a strength and effectiveness against attacks.

  5. Minimizing Broadcast Expenses in Clustered Ad-hoc Networks

    Directory of Open Access Journals (Sweden)

    S. Zeeshan Hussain

    2018-01-01

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

  6. Foundry based approach for InP based PIC development

    NARCIS (Netherlands)

    Smit, M.K.

    2014-01-01

    Europe is making significant investments in development of generic photonic foundry platform infrastructures for InP-based and Silicon Photonic ICs. Here we present the present status for the InP-based JePPIX platform.

  7. NMR studies concerning base-base interactions in oligonucleotides

    International Nuclear Information System (INIS)

    Hoogen, Y.T. van den.

    1988-01-01

    Two main subjects are treated in the present thesis. The firsst part principally deals with the base-base interactions in single-stranded oligoribonucleotides. The second part presents NMR and model-building studies of DNA and RNA duplexes containing an unpaired base. (author). 242 refs.; 26 figs.; 24 tabs

  8. Computer-based multi-channel analyzer based on internet

    International Nuclear Information System (INIS)

    Zhou Xinzhi; Ning Jiaoxian

    2001-01-01

    Combined the technology of Internet with computer-based multi-channel analyzer, a new kind of computer-based multi-channel analyzer system which is based on browser is presented. Its framework and principle as well as its implementation are discussed

  9. Base Camp Architecture

    Directory of Open Access Journals (Sweden)

    Warebi Gabriel Brisibe

    2016-03-01

    Full Text Available Longitudinal or time line studies of change in the architecture of a particular culture are common, but an area still open to further research is change across space or place. In particular, there is need for studies on architectural change of cultures stemming from the same ethnic source split between their homeland and other Diasporas. This change may range from minor deviations to drastic shifts away from an architectural norm and the accumulation of these shifts within a time frame constitutes variations. This article focuses on identifying variations in the architecture of the Ijo fishing group that migrates along the coastline of West Africa. It examines the causes of cross-cultural variation between base camp dwellings of Ijo migrant fishermen in the Bakassi Peninsula in Cameroon and Bayelsa State in Nigeria. The study draws on the idea of the inevitability of cultural and social change over time as proposed in the theories of cultural dynamism and evolution. It tests aspects of cultural transmission theory using the principal coordinates analysis to ascertain the possible causes of variation. From the findings, this research argues that migration has enhanced the forces of cultural dynamism, which have resulted in significant variations in the architecture of this fishing group.

  10. Evidence-based management.

    Science.gov (United States)

    Pfeffer, Jeffrey; Sutton, Robert I

    2006-01-01

    For the most part, managers looking to cure their organizational ills rely on obsolete knowledge they picked up in school, long-standing but never proven traditions, patterns gleaned from experience, methods they happen to be skilled in applying, and information from vendors. They could learn a thing or two from practitioners of evidence-based medicine, a movement that has taken the medical establishment by storm over the past decade. A growing number of physicians are eschewing the usual, flawed resources and are instead identifying, disseminating, and applying research that is soundly conducted and clinically relevant. It's time for managers to do the same. The challenge is, quite simply, to ground decisions in the latest and best knowledge of what actually works. In some ways, that's more difficult to do in business than in medicine. The evidence is weaker in business; almost anyone can (and many people do) claim to be a management expert; and a motley crew of sources--Shakespeare, Billy Graham,Jack Welch, Attila the Hunare used to generate management advice. Still, it makes sense that when managers act on better logic and strong evidence, their companies will beat the competition. Like medicine, management is learned through practice and experience. Yet managers (like doctors) can practice their craft more effectively if they relentlessly seek new knowledge and insight, from both inside and outside their companies, so they can keep updating their assumptions, skills, and knowledge.

  11. Skull base tumors

    International Nuclear Information System (INIS)

    Kikinis, R.; Matsumae, M.; Jolesz, F.A.; Black, P.M.; Cline, H.E.; Lorenson, W.E.

    1991-01-01

    This paper reports on an image processing procedure for the planning of surgery of skull base tumors that can extract bone, vessels, tumor, and brain parenchyma and that permits resolution of cranial nerves. Three-dimensional (3D) reconstructions were generated from double-echo long TR interleaved conventional spin-echo and fast-spin-echo MR imaging data. Sixteen cases have been analyzed preoperatively. Image processing consisted of a multistep procedure combining a supervised multivariate analysis with neighborhood operations such as connectivity and erosion/dilation. 3D renderings of anatomic structures of interest were then generated. Cases were evaluated preoperatively and manipulated interactively with the computer-generated images by a team consisting of neuroradiologists, neurosurgeons, and craniofacial surgeons. The preparation of 3D reconstructions required only a few hours and was performed mostly by a research assistant. The preoperative analysis of the 3D reconstructions was found to be a valuable tool, providing information complementing the surgeon's understanding of a case as derived from conventional imaging. The interactive manipulation of data proved to be a powerful way to evaluate alternative surgical approaches

  12. Constraint-based scheduling

    Science.gov (United States)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  13. Refractory metal based superalloys

    International Nuclear Information System (INIS)

    Alonso, Paula R.; Vicente, Eduardo E.; Rubiolo, Gerardo H.

    1999-01-01

    Refractory metals are looked as promising materials for primary circuits in fission reactors and even as fusion reactor components. Indeed, superalloys could be developed which take advantage of their high temperature properties together with the benefits of a two- phase (intermetallic compound-refractory metal matrix) coherent structure. In 1993, researchers of the Office National d'Etudes et de Recherches Aerospatiales of France reported the observation of such a coherent structure in the Ta-Ti-Zr-Al-Nb-Mo system although the exact composition is not reported. The intermetallic compound would be Ti 2 AlMo based. However, the formation of this compound and its possible coexistence with a disordered bcc phase in the ternary system Ti-Al-Mo is a controversial subject in the related literature. In this work we develop a technique to obtain homogeneous alloys samples with 50 Ti-25 Al-25 Mo composition. The resulting specimens were characterized by optical and electronic metallography (SEM), microprobe composition measurements (EPMA) and X-ray diffraction (XRD) analyses. The results show the evidence for a bcc (A2→B2) ordering reaction in the Ti-Al-Mo system in the 50 Ti-25 Al-25 Mo composition. (author)

  14. Fluorescence lifetime based bioassays

    Science.gov (United States)

    Meyer-Almes, Franz-Josef

    2017-12-01

    Fluorescence lifetime (FLT) is a robust intrinsic property and material constant of fluorescent matter. Measuring this important physical indicator has evolved from a laboratory curiosity to a powerful and established technique for a variety of applications in drug discovery, medical diagnostics and basic biological research. This distinct trend was mainly driven by improved and meanwhile affordable laser and detection instrumentation on the one hand, and the development of suitable FLT probes and biological assays on the other. In this process two essential working approaches emerged. The first one is primarily focused on high throughput applications employing biochemical in vitro assays with no requirement for high spatial resolution. The second even more dynamic trend is the significant expansion of assay methods combining highly time and spatially resolved fluorescence data by fluorescence lifetime imaging. The latter approach is currently pursued to enable not only the investigation of immortal tumor cell lines, but also specific tissues or even organs in living animals. This review tries to give an actual overview about the current status of FLT based bioassays and the wide range of application opportunities in biomedical and life science areas. In addition, future trends of FLT technologies will be discussed.

  15. Carbon nanotube based photocathodes

    International Nuclear Information System (INIS)

    Hudanski, Ludovic; Minoux, Eric; Schnell, Jean-Philippe; Xavier, Stephane; Pribat, Didier; Legagneux, Pierre; Gangloff, Laurent; Teo, Kenneth B K; Robertson, John; Milne, William I

    2008-01-01

    This paper describes a novel photocathode which is an array of vertically aligned multi-walled carbon nanotubes (MWCNTs), each MWCNT being associated with one p-i-n photodiode. Unlike conventional photocathodes, the functions of photon-electron conversion and subsequent electron emission are physically separated. Photon-electron conversion is achieved with p-i-n photodiodes and the electron emission occurs from the MWCNTs. The current modulation is highly efficient as it uses an optically controlled reconfiguration of the electric field at the MWCNT locations. Such devices are compatible with high frequency and very large bandwidth operation and could lead to their application in compact, light and efficient microwave amplifiers for satellite telecommunication. To demonstrate this new photocathode concept, we have fabricated the first carbon nanotube based photocathode using silicon p-i-n photodiodes and MWCNT bunches. Using a green laser, this photocathode delivers 0.5 mA with an internal quantum efficiency of 10% and an I ON /I OFF ratio of 30

  16. Based on Channel Characteristics

    Directory of Open Access Journals (Sweden)

    Zhuo Hao

    2013-01-01

    Full Text Available A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

  17. Biosensors based on cantilevers.

    Science.gov (United States)

    Alvarez, Mar; Carrascosa, Laura G; Zinoviev, Kiril; Plaza, Jose A; Lechuga, Laura M

    2009-01-01

    Microcantilevers based-biosensors are a new label-free technique that allows the direct detection of biomolecular interactions in a label-less way and with great accuracy by translating the biointeraction into a nanomechanical motion. Low cost and reliable standard silicon technologies are widely used for the fabrication of cantilevers with well-controlled mechanical properties. Over the last years, the number of applications of these sensors has shown a fast growth in diverse fields, such as genomic or proteomic, because of the biosensor flexibility, the low sample consumption, and the non-pretreated samples required. In this chapter, we report a dedicated design and a fabrication process of highly sensitive microcantilever silicon sensors. We will describe as well an application of the device in the environmental field showing the immunodetection of an organic toxic pesticide as an example. The cantilever biofunctionalization process and the subsequent pesticide determination are detected in real time by monitoring the nanometer-scale bending of the microcantilever due to a differential surface stress generated between both surfaces of the device.

  18. Flow-Based Provenance

    Directory of Open Access Journals (Sweden)

    Sabah Al-Fedaghi

    2017-02-01

    Full Text Available Aim/Purpose: With information almost effortlessly created and spontaneously available, current progress in Information and Communication Technology (ICT has led to the complication that information must be scrutinized for trustworthiness and provenance. Information systems must become provenance-aware to be satisfactory in accountability, reproducibility, and trustworthiness of data. Background:\tMultiple models for abstract representation of provenance have been proposed to describe entities, people, and activities involved in producing a piece of data, including the Open Provenance Model (OPM and the World Wide Web Consortium. These models lack certain concepts necessary for specifying workflows and encoding the provenance of data products used and generated. Methodology: Without loss of generality, the focus of this paper is on OPM depiction of provenance in terms of a directed graph. We have redrawn several case studies in the framework of our proposed model in order to compare and evaluate it against OPM for representing these cases. Contribution: This paper offers an alternative flow-based diagrammatic language that can form a foundation for modeling of provenance. The model described here provides an (abstract machine-like representation of provenance. Findings: The results suggest a viable alternative in the area of diagrammatic representation for provenance applications. Future Research: Future work will seek to achieve more accurate comparisons with current models in the field.

  19. Communication Base Station Log Analysis Based on Hierarchical Clustering

    Directory of Open Access Journals (Sweden)

    Zhang Shao-Hua

    2017-01-01

    Full Text Available Communication base stations generate massive data every day, these base station logs play an important value in mining of the business circles. This paper use data mining technology and hierarchical clustering algorithm to group the scope of business circle for the base station by recording the data of these base stations.Through analyzing the data of different business circle based on feature extraction and comparing different business circle category characteristics, which can choose a suitable area for operators of commercial marketing.

  20. Mindfulness-Based Stress Reduction

    Science.gov (United States)

    ... R S T U V W X Y Z Mindfulness-Based Stress Reduction (MBSR) Information 6 Things You ... Disease and Dementia (12/20/13) Research Spotlights Mindfulness-Based Stress Reduction, Cognitive-Behavioral Therapy Shown To ...

  1. Risk-based configuration control

    International Nuclear Information System (INIS)

    Szikszai, T.

    1997-01-01

    The presentation discusses the following issues: The Configuration Control; The Risk-based Configuration Control (during power operation mode, and during shutdown mode). PSA requirements. Use of Risk-based Configuration Control System. Configuration Management (basic elements, benefits, information requirements)

  2. OLBS: Offline location based services

    OpenAIRE

    Coelho, P; Ana Aguiar; João Correia Lopes

    2011-01-01

    Most existing location-based services rely on ubiquitous connectivity to deliver location-based contents to the users. However, connectivity is not available anywhere at anytime even in urban centres. Underground, indoors, remote areas, and foreign countries are examples situations where users commonly do not have guaranteed connectivity but could profit from location-based contents. In this work, we propose an open platform for publishing, distributing and maintaining location-based contents...

  3. ‘"Education-based Research"

    DEFF Research Database (Denmark)

    Degn Johansson, Troels

    This paper lays out a concept of education-based research-the production of research knowledge within the framework of tertiary design education-as an integration of problem-based learning and research-based education. This leads to a critique of reflective practice as the primary way to facilitate...... learning at this level, a discussion of the nature of design problems in the instrumentalist tradition, and some suggestions as to how design studies curricula may facilitate education-based research....

  4. Health Physics Positions Data Base

    International Nuclear Information System (INIS)

    Kerr, G.D.; Borges, T.; Stafford, R.S.; Lu, P.Y.; Carter, D.

    1992-05-01

    The Health Physics Positions (HPPOS) Data Base of the Nuclear Regulatory Commission (NRC) is a collection of summaries of NRC staff positions on a wide range of topics in radiation protection (health physics). The bases for the data base are 247 original documents in the form of letters, memoranda, and excerpts from technical reports. The HPPOS Data Base was developed by the NRC Headquarters and Regional Offices to help ensure uniformity in inspections, enforcement, and licensing actions

  5. Memory-Based Shallow Parsing

    OpenAIRE

    Sang, Erik F. Tjong Kim

    2002-01-01

    We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving the performance of the memory-based learner. Our approach is evaluated on standard data sets and the results are compared with that of other systems. This reveals that our approach works well for ba...

  6. Lunar Base Heat Pump

    Science.gov (United States)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  7. Performance-Based Funding Brief

    Science.gov (United States)

    Washington Higher Education Coordinating Board, 2011

    2011-01-01

    A number of states have made progress in implementing performance-based funding (PFB) and accountability. This policy brief summarizes main features of performance-based funding systems in three states: Tennessee, Ohio, and Indiana. The brief also identifies key issues that states considering performance-based funding must address, as well as…

  8. Benefit-based tree valuation

    Science.gov (United States)

    E.G. McPherson

    2007-01-01

    Benefit-based tree valuation provides alternative estimates of the fair and reasonable value of trees while illustrating the relative contribution of different benefit types. This study compared estimates of tree value obtained using cost- and benefit-based approaches. The cost-based approach used the Council of Landscape and Tree Appraisers trunk formula method, and...

  9. Different perspectives on economic base.

    Science.gov (United States)

    Lisa K. Crone; Richard W. Haynes; Nicholas E. Reyna

    1999-01-01

    Two general approaches for measuring the economic base are discussed. Each method is used to define the economic base for each of the counties included in the Interior Columbia Basin Ecosystem Management Project area. A more detailed look at four selected counties results in similar findings from different approaches. Limitations of economic base analysis also are...

  10. Memory-Based Shallow Parsing

    NARCIS (Netherlands)

    Tjong Kim Sang, E.F.

    2002-01-01

    We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving

  11. Condition based spare parts supply

    NARCIS (Netherlands)

    Lin, X.; Basten, Robertus Johannes Ida; Kranenburg, A.A.; van Houtum, Geert-Jan

    2012-01-01

    We consider a spare parts stock point that serves an installed base of machines. Each machine contains the same critical component, whose degradation behavior is described by a Markov process. We consider condition based spare parts supply, and show that an optimal, condition based inventory policy

  12. Evidence-based dentistry.

    Science.gov (United States)

    Chambers, David W

    2010-01-01

    Both panegyric and criticism of evidence-based dentistry tend to be clumsy because the concept is poorly defined. This analysis identifies several contributions to the profession that have been made under the EBD banner. Although the concept of clinicians integrating clinical epidemiology, the wisdom of their practices, and patients' values is powerful, its implementation has been distorted by a too heavy emphasis of computerized searches for research findings that meet the standards of academics. Although EBD advocates enjoy sharing anecdotal accounts of mistakes others have made, faulting others is not proof that one's own position is correct. There is no systematic, high-quality evidence that EBD is effective. The metaphor of a three-legged stool (evidence, experience, values, and integration) is used as an organizing principle. "Best evidence" has become a preoccupation among EBD enthusiasts. That overlong but thinly developed leg of the stool is critiqued from the perspectives of the criteria for evidence, the difference between internal and external validity, the relationship between evidence and decision making, the ambiguous meaning of "best," and the role of reasonable doubt. The strongest leg of the stool is clinical experience. Although bias exists in all observations (including searches for evidence), there are simple procedures that can be employed in practice to increase useful and objective evidence there, and there are dangers in delegating policy regarding allowable treatments to external groups. Patient and practitioner values are the shortest leg of the stool. As they are so little recognized, their integration in EBD is problematic and ethical tensions exist where paternalism privileges science over patient's self-determined best interests. Four potential approaches to integration are suggested, recognizing that there is virtually no literature on how the "seat" of the three-legged stool works or should work. It is likely that most dentists

  13. Barrier Data Base user's guide

    International Nuclear Information System (INIS)

    Worrell, R.B.; Gould, D.J.; Wall, D.W.

    1977-06-01

    A special purpose data base for physical security barriers has been developed. In addition to barriers, the entities accommodated by the Barrier Data Base (BDB) include threats and references. A threat is established as a configuration of people and equipment which has been employed to penetrate (or attempt to penetrate) a barrier. References are used to cite publications pertinent to the barriers and threats in the data base. Utilization and maintenance of the Barrier Data Base is achieved with LIST, QUERY, ENTER, DELETE, and CHANGE commands which are used to manipulate the data base entities

  14. From oil-based mud to water-based mud

    International Nuclear Information System (INIS)

    Christiansen, C.

    1991-01-01

    Maersk Olie og Gas AS has used low toxic oil-based muds extensively since 1982 for drilling development wells and later in the development of horizontal well drilling techniques. However, in view of the strong drive towards a reduction in the amount of oil discharged to the North Sea from the oil industry, Maersk Olie og Gas AS initiated trials with new or improved types of water-based mud, first in deviated wells (1989) and then in horizontal wells (1990). The paper reviews Maersk Olie og Gas As experience with oil-based mud since the drilling of the first horizontal well in 1987, specifically with respect to cuttings washing equipment, oil retention on cuttings, and the procedure for monitoring of this parameter. It describes the circumstances leading to the decision to revert to water-based mud systems. Finally, it reviews the experience gained so far with the new improved types of water-based mud systems, mainly glycol and KCl/polymer mud systems. Comparison of operational data, such as rate of penetration, torque and drag, etc., is made between wells drilled with oil-based mud and water-based mud. The trials with the new improved types of water-based mud systems have been positive, i.e. horizontal wells can be drilled successfully with water-based mud. As a result, Maersk Olie og and Gas AS has decided to discontinue the use of low toxic oil-based muds in the Danish sector of the North Sea

  15. Workplace Based Assessment in Psychiatry

    Directory of Open Access Journals (Sweden)

    Ayse Devrim Basterzi

    2009-11-01

    Full Text Available Workplace based assessment refers to the assessment of working practices based on what doctors actually do in the workplace, and is predominantly carried out in the workplace itself. Assessment drives learning and it is therefore essential that workplace-based assessment focuses on important attributes rather than what is easiest to assess. Workplacebased assessment is usually competency based. Workplace based assesments may well facilitate and enhance various aspects of educational supervisions, including its structure, frequency and duration etc. The structure and content of workplace based assesments should be monitored to ensure that its benefits are maximised by remaining tailored to individual trainees' needs. Workplace based assesment should be used for formative and summative assessments. Several formative assessment methods have been developed for use in the workplace such as mini clinical evaluation exercise (mini-cex, evidence based journal club assesment and case based discussion, multi source feedback etc. This review discusses the need of workplace based assesments in psychiatry graduate education and introduces some of the work place based assesment methods.

  16. Case-based reasoning: The marriage of knowledge base and data base

    Science.gov (United States)

    Pulaski, Kirt; Casadaban, Cyprian

    1988-01-01

    The coupling of data and knowledge has a synergistic effect when building an intelligent data base. The goal is to integrate the data and knowledge almost to the point of indistinguishability, permitting them to be used interchangeably. Examples given in this paper suggest that Case-Based Reasoning is a more integrated way to link data and knowledge than pure rule-based reasoning.

  17. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  18. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  19. XML-Based SHINE Knowledge Base Interchange Language

    Science.gov (United States)

    James, Mark; Mackey, Ryan; Tikidjian, Raffi

    2008-01-01

    The SHINE Knowledge Base Interchange Language software has been designed to more efficiently send new knowledge bases to spacecraft that have been embedded with the Spacecraft Health Inference Engine (SHINE) tool. The intention of the behavioral model is to capture most of the information generally associated with a spacecraft functional model, while specifically addressing the needs of execution within SHINE and Livingstone. As such, it has some constructs that are based on one or the other.

  20. Managing the Gap between Curriculum Based and Problem Based Learning

    DEFF Research Database (Denmark)

    Bygholm, Ann; Buus, Lillian

    2009-01-01

    /or but rather both/and. In this paper we describe an approach to design and delivery of online courses in computer science which on the one hand is based on a specified curriculum and on the other hand gives room for different learning strategies, problem based learning being one of them. We discuss......Traditionally there has been a clear distinction between curriculum based and problem based approaches to accomplish learning. Preferred approaches depend of course on conviction, culture, traditions and also on the specific learning situation. We will argue that it is not a question of either...